Note: Descriptions are shown in the official language in which they were submitted.
LED TUBE LAMP
FIELD OF THE INVENTION
The present disclosure relates to illumination devices, and more
particularly to an LED tube lamp and its components including the light
sources, electronic components, and end caps.
BACKGROUND OF THE INVENTION
LED lighting technology is rapidly developing to replace traditional
incandescent and fluorescent lightings. LED tube lamps are mercury-free in
comparison with fluorescent tube lamps that need to be filled with inert gas
and
mercury.Thus, it is not surprising that LED tube lamps are becoming a highly
desired illumination option among different available lighting systems used in
1
Date Recue/Date Received 2022-03-24
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
homes and workplaces, which used to be dominated by traditional lighting
options such as compact fluorescent light bulbs (CFLs) and fluorescent tube
lamps. Benefits of LED tube lamps include improved durability and longevity
and far less energy consumption; therefore, when taking into account all
factors, they would typically be considered as a cost effective lighting
option.
Typical LED tube lamps have a lamp tube, a circuit board disposed inside
the lamp tube with light sources being mounted on the circuit board, and end
caps accompanying a power supply provided at two ends of the lamp tube with
the electricity from the power supply transmitting to the light sources
through
the circuit board. However, existing LED tube lamps have certain drawbacks.
First, the typical circuit board is rigid and allows the entire lamp tube to
maintain a straight tube configuration when the lamp tube is partially
ruptured
or broken, and this gives the user a false impression that the LED tube lamp
remains usable and is likely to cause the user to be electrically shocked upon
handling or installation of the LED tube lamp.
Second, the rigid circuit board is typically electrically connected with the
end caps by way of wire bonding, in which the wires may be easily damaged
and even broken due to any move during manufacturing, transportation, and
usage of the LED tube lamp and therefore may disable the LED tube lamp.
Third, the lamp tube and the end caps are often secured together by
using hot melt adhesive or silicone adhesive, and it is hard to prevent the
buildup of excess (overflown) adhesive residues.This may cause light
blockage as well as an unpleasant aesthetic appearance.ln addition, a large
amount of manpower is required to clean off the excessive adhesive buildup,
create a further production bottleneck and inefficiency. Also, bad heat
dissipation of the power supply components inside the end caps can cause a
2
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
high temperature and therefore reduces life span of the hot melt adhesive and
simultaneously disables the adhesion between the lamp tube and the end caps,
which may decrease the reliability of the LED tube lamp.
Fourth, the typical lamp tube is a long cylinder sleeved with the end
caps at ends by means of adhesive, in which the end caps each has a larger
diameter than that of the lamp tube. In this way, a packing box for the lamp
tube¨which is also typically in cylinder shape¨will contact only the end caps
such that only the end caps are supported and the connecting part between
the end caps and the lamp tube is apt to break, such as disclosed LED tube
lamp in a published US patent application with publication no. U52014226320
and a published CN patent application with publication no. CN102518972. To
address this issue, a published US patent application with publication no.
U520100103673 discloses an end cap that issealed and inserted into a glass
made lamp tube. However, this kind of lamp tube is subjected to inner stresses
at its ends and may easily break when the ends are subjected to external
forces, which maylead to product defects and quality issues.
Fifth, grainy visual appearances are also often found in the
aforementioned conventional LED tube lamp. The LED chips spatially
arranged on the circuit board inside the lamp tube are considered as spot
light
sources, and the lights emitted from these LED chips generally do not
contribute uniform illuminance for the LED tube lamp without proper optical
manipulation. As a result, the entire tube lamp would exhibit a grainy or
non-uniform illumination effect to a viewer of the LED tube lamp, thereby
negatively affecting the visual comfort and even narrowing the viewing angles
of the lights. As a result, the quality and aesthetics requirements of average
consumers would not be satisfied.To address this issue, the Chinese patent
3
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
application with application no. CN201320748271.6 discloses a diffusion tube
is disposed inside a glass lamp tube to avoid grainy visual effects.
However, the disposition of the diffusion tube incurs an interface on the
light transmission path to increase the likelihood of total reflection and
therefore decrease the light outputting efficiency. In addition, the optical
rotatory absorption of the diffusion tube decreases the light outputting
efficiency.
Accordingly, the prevent disclosureand its embodiments are herein
provided.
SUMMARY OF THE INVENTION
It's specially noted that the present disclosure may actually include one or
more inventions claimed currently or not yet claimed, and for avoiding
confusion due to unnecessarily distinguishing between those possible
inventions at the stage of preparing the specification, the possible plurality
of
inventions herein may be collectively referred to as "the (present) invention"
herein.
Various embodiments are summarized in this section, and are described
with respect to the "present invention," which terminology is used to describe
certain presently disclosed embodiments, whether claimed or not, and is not
necessarily an exhaustive description of all possible embodiments, but rather
is merely a summary of certain embodiments. Certain of the embodiments
described below as various aspects of the "present invention" can be
combined in different manners to form an LED tube lamp or a portion thereof.
The present invention provides a novel LED tube lamp, and aspects
thereof.
4
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
The present invention provides an LED tube lamp including a lamp tube
and a set of end caps secured to the ends of the lamp tube, wherein the end
caps each may have an electrically insulating tube and a thermal conductive
member which is fixedly disposed on an outer circumferential surface of the
electrically insulating tubeand adheredto an outer surface of the lamp tube by
using adhesive.
The present invention also provides an LED tube lamp including a lamp
tube and two differently sized end caps respectively secured to two ends of
the
lamp tube. The size of one end cap may be 30% to 80% of the size of the other
end cap in some embodiments.
The disclosed lamp tube may include a main body region and two rear
end regionsrespectively positioned at two ends of the main body region,
whereineachrear end region has an outer diameter being less than an outer
diameter of the main body region such that the rear end regions
arerespectively sleeved with two end caps having the same outer diameter as
that of the main body region.ln some embodiments, the difference between the
outer diameter of the rear end regions and the outer diameter of the main body
region is about 1 mm to about 10 mm. Most preferably, the difference between
the outer diameter of the rear end regions and the outer diameter of the main
body regionmay be about 2 mm to about 7 mm.
The lamp tube may further include a transition region connecting the main
body region and the rear end region.The transition region may be arc-shaped
at both ends, and an outer surface of the transition region near the main body
region is in tension while an inner surface of the transition region near the
main
body region is in compression, and the outer surface of the transition region
near the rear end region is in compression while the inner surface of the
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
transition region near the rear end region isin tension. The normal vector of
the
arc-shaped surfaceat the end of the transition region near the main body
regionpoints towards outside of the lamp tube, and the normal vector of the
arc-shapedsurface at the end of the transition region near the rear end region
points towards inside of the lamp tube.
The radius of curvature R1 of the arc-shaped surfaceat the end of the
transition region near the main body region may be smaller than the radius of
curvature R2 of the arc-shaped surfaceat the end of the transition region near
the rear end region. For example, the ratio of R1 to R2 may range from about
1:
1.5 to about 1: 10.
Furthermore, in some embodiments, there is no gap between the main
body region of the lamp tube and the end cap.
An arc angle of the arc-shaped surface at the end of the transition region
near the main body region, and an arc angle of the arc-shaped surface at the
end of the transition region near the rear end region may be larger than 90
degrees.The outer surface of the rear end region is in some embodiments a
continuous surface being parallel to an outer surface of the main body region.
In some embodiments, the transition region has a length of about 1 mm to
about 4 mm.
The lamp tube may be made of glass or plastic.
The electrically insulating tube may have a first tubular part and a second
tubular part connected together along an axial direction of the length
direction
of the lamp tube with an outer diameter of the second tubular part being less
than an outer diameter of the first tubular part. In some embodiments, the
outer
diameter difference between the first tubular part and the second tubular part
is between about 0.15 mm to about 0.30 mm.
6
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
The second tubular part may be sleeved with the thermal conductive
member and thereby an outer surface of the thermal conductive member and
an outer circumferential surface of the first tubular part may be
substantially
flush with each other.
The lamp tube may be partially sleeved with the second tubular part and
secured to the thermal conductive member by using an adhesive such as a hot
melt adhesive.
In certain embodiments, theend of the second tubular part that is located
away from the first tubular part is provided with one or a plurality of
notches
that are spatially arranged along a circumferential direction of the second
tubular part.
A ratio of the length of the thermal conductive member along the axial or
length direction of the end cap with respect to the axial length of the
electrically
insulating tubemay be from about 1: 2.5 to about 1: 5.
In some embodiments,the length of the portion of the lamp tube inserted
into the end cap accounts for about one-third to two-thirds of the total
length of
the thermal conductive member in an axial or length direction thereof.
In some embodiments, the thermal conductive member may be a metal
ring.
In some embodiments, the thermal conductive member is tubular.
In some embodiments, the electrically insulating tube is a plastic tube.
The present invention provides a method of adhering an end cap to a tube
to form a tube lamp. The method includes the following steps: applying a hot
melt adhesive to the inner surface of the end cap; sleeving the end cap to an
end of the tube; heating the hot melt adhesive by an external heating
equipment to expand the hot melt adhesive such that the hot melt adhesive
7
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
flow into a space between the inner surface of the end cap and the outer
surface of the end of the tube.
The present invention provides an LED tube lamp including a lamp tube
and a set of end caps secured to the ends of the lamp tube, wherein the end
caps each has an electrically insulating tube and a thermal conductive member
fixedly disposed on an outer circumferential surface of the electrically
insulating tube, and the electrically insulating tube has a first tubular part
and a
second tubular part connected along an axial or length direction of the
electrically insulating tube. In addition, the inner surface of the second
tubular
part, the inner surface of the thermal conductive member, the outer surface of
the rear end region and the outer surface of the transition region may
together
form an accommodation space.
The accommodation space may be disposed with the hot melt adhesive. In
some embodiments, the accommodation space is partially disposed with the
hot melt adhesive. In some embodiments, the space between the inner surface
of the second tubular part and the outer surface of the rear end region is
disposed with part of the hot melt adhesive.
The hot melt adhesive may be filled into the accommodation space at a
location where a first hypothetical plane being perpendicular to the axial
direction of the lamp tube would pass through the thermal conductive member,
the hot melt adhesive, and the outer surface of the lamp tube.
The hot melt adhesive may be filled into the accommodation space at a
location where a second hypothetical plane being perpendicular to the axial
direction of the lamp tube would pass through the thermal conductive member,
the second tubular part, the hot melt adhesive, and the rear end region.
The hot melt adhesive may be filled into the accommodation space at a
8
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
location where a first hypothetical plane being perpendicular to the axial
direction of the lamp tube would pass through the thermal conductive member,
the hot melt adhesive, and the outer surface of the lamp tube. Meanwhile, the
hot melt adhesive also may be filled into the accommodation space at a
location where a second hypothetical plane being perpendicular to the axial
direction of the lamp tube would pass through the thermal conductive member,
the second tubular part, the hot melt adhesive, and the rear end region.
The hot melt adhesive may include one or more of the following substance:
phenolic resin 2127#, shellac, rosin, calcium carbonate powder, zinc oxide,
and ethanol; and the volume of the hot melt adhesive may expand to about 1.3
times the original size when heated from room temperature (e.g., between
about 15 and 30 degrees Celsius)to 200 to 250degreesCelsius.
The present invention provides an LED tube lamp including a lamp tube
and an end cap secured to one end of the lamp tube, wherein the end cap
includes an electrically insulating tube to sleeve the end of the lamp tube,
and
a magnetic metal member is disposed on an inner circumferential surface of
the electrically insulating tube such that at least part of the magnetic metal
member is disposed between the inner circumferential surface of the
electrically insulating tube and the end of the lamp tube. In some
embodiments,
the magnetic metal member has a larger outer diameter than that of the rear
end region of the lamp tube.
The magnetic metal member and the end of the lamp tube may be
adhesively bonded by a material such as a hot melt adhesive.
Alternatively, the magnetic metal member may be entirely disposed inside
the electrically insulating tube and the whole inner surface of the magnetic
member is covered with the hot melt adhesive.
9
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
The electrically insulating tube may be further formed with a supporting
portion on the inner surface of the electrically insulating tube to be
extending
inwardly, and the magnetic metal member may be axially abutted against the
upper edge of the supporting portion. In some embodiments, the thickness of
the supporting portion along the radial direction of the electrically
insulating
tube ranges from 1mm to 2mm.
The electrically insulating tube may be further formed with a protruding
portion on the inner surface of the electrically insulating tube to be
extending
inwardly, and the magnetic metal member may be radially abutted against the
side edge of the protruding portion and the outer surface of the magnetic
metal
member and the inner surface of the electrically insulating tubemay be spaced
apart with a gap. The thickness of the protruding portion along the radial
direction of the electrically insulating tube may be less than the thickness
of the
supporting portion along the radial direction of the electrically insulating
tube.
In some embodiments, the thickness of the protruding portion isabout 0.2 mm
to about 1 mm.
The protruding portion may be arranged along the circumferential
direction of the electrically insulating tube to have a circular
configuration.
Alternatively, the protruding portion may be in the form of a plurality of
bumps
arranged on the inner surface of the electrically insulating tube. The bumps
may be equidistantly arranged along the inner circumferential surface of the
electrically insulating tube. The bumps may be non-equidistantly arranged
along the inner circumferential surface of the electrically insulating tube.
The present invention provides an end cap used for an LED tube lamp,
wherein the end cap includes an electrically insulating tube to sleeve an end
of
a tube of the LED tube lamp, a magnetic metal member secured to the inner
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
surface of the electrically insulating tube, and a hot melt adhesive covering
the
inner surface of the magnetic metal member.
The hot melt adhesive may completely cover the inner surface of the
magnetic metal member.
The magnetic metal member may have a ring shape.
The magnetic metal member may have openings on surface. In some
embodiments, the openings occupy about 10% to about 50% of the surface
area of the magnetic metal member. In some embodiments, the openings are
plural and arranged circumferentially in an equidistantly or un-equidistantly
spaced manner.
The magnetic metal member may have indentation or embossment on
surface facing the electrically insulating tube. For example in one
embodiment,
the embossment is raised from the inner surface of the magnetic metal
member, while the indentation is depressed under the inner surface of the
magnetic metal member.
The magnetic metal member may be tubular and coaxially arranged with
the electrically insulating tube.
The magnetic metal member may have a ring shape or a non-ring shape
such as an ellipse shape.
The hot melt adhesive may include a predetermined proportion of high
permeability powders being uniformly distributed, and the powders will be
charged by receiving electricity from an external heating equipment and
heating the adhesive to be expansive and flowing and finally solidified after
cooling. The goal of securing the end cap and the lamp tube with the hot melt
adhesive is therefore achieved.
Therefore, the present invention provides a hot melt adhesive used for
11
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
LED tube lamp, the hot melt adhesivemay include one or more of the following
substance: phenolic resin 2127#, shellac, rosin, calcium carbonate powder,
zinc oxide, ethanol, and high permeability powders; wherein a volume ratio of
the high permeability powders to the calcite powders is about 1:3-1:1, and the
volume of the hot melt adhesive may expand to about 1.3 times the original
size when heated from room temperature (e.g., between about 15 and 30
degrees Celsius) to 200 to 250 degreesCelsius.
In some embodiments, the permeability of the powders ranges from about
102 to about 106.
In some embodiments, the material of the powders is selected from the
group consisting of iron, nickel, cobalt, and alloy thereof.
In some embodiments, the weight percentage of the powders with respect
to the hot melt adhesive is about 10% to about 50%.
In some embodiments, the powders have mean particle size of 1 to 30
micrometers.
The powders of the hot melt adhesive may form a closed loop when the
hot melt adhesive is in an electromagnetic field.
The powders of the hot melt adhesive may be charged for each particle
whenthe hot melt adhesive is in an electromagnetic field.
The hot melt adhesive may be flowing at a temperature of about 200 to
about 250 degreesCelsius, for example.
The hot melt adhesive may be solidified after cooling from a temperature
of about 200 to about 250 degreesCelsius.
The hot melt adhesive may be solidified immediately when heated to a
temperature of about 200 to about 250 degrees Celsius.
The external heating equipment may be an induction coil connected to a
12
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
power source to create an electromagnetic field when supplied with electrical
power. The magnetic metal member would get current when it enters the
electromagnetic field and therefore be heated to be able to transfer the heat
to
the hot melt adhesive.
The power supply for the external heating equipment may be provided
with a power amplifying unit to increase the alternating current power to
about
1 to 2 times the original.
In some embodiments, the induction coil is made of metal wires having
width of about 5 mm to about 6mm to be a circular coil with a diameter of
about
30mm to about 35mm.
In some embodiments, the material for the induction coil is red copper.
The magnetic metal member may be heated to a temperature generally
between about 250 and about 300 degreesCelsius, and in some
embodimentsbetween about 200 to about 250 degrees Celsius.
The induction coil may be fixed in position to allow the end cap to move or
roll into the induction coil such that the hot melt adhesive is heated to
expand
and flow and then solidify after cooling when the end cap again moves away
from the induction coil. Alternatively, the end cap may be fixed in position
to
allow the induction coil to move to encompass the end cap such that the hot
melt adhesive is heated to expand and flow and then solidify after cooling
when the induction coil again moves away from the end cap.
The induction coil may be fixed in position to allow the end cap to move or
roll into the induction coil such that the hot melt adhesive is heated to
expand
and flow and immediately solidify. Alternatively, the end cap may be fixed in
position to allow the induction coil to move to encompass the end cap such
that the hot melt adhesive is heated to solidify immediately.
13
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
The end cap and the end of the lamp tube could be secured by using the
hot melt adhesive and therefore qualified in a torque test of about 1.5 to
about
newton-meters (Nt-m) and/or in a bending test of about 5 to about 10
newton-meters (Nt-m).
The end cap may formed with openings to dissipate heat. In some
embodiments, the openings are in shape of arc. For example, the openings
may be in the shape of three arcs with different size. In some embodiments,
the openings are in shape of three arcs with gradually varying size.
The lamp tube may include a diffusion film to allow the light emitted from
the light sources of the LED tube lamp to pass through the diffusion film and
the lamp tube surface in sequence.
The diffusion film may be in form of a coating layer covering the inner or
outer surface of the lamp tube. The diffusion film may be in form of a coating
layer covering the surface of the light sources inside the lamp tube. In some
embodiments, the diffusion film has a thickness of about 20pm to about 30pm.
The diffusion film may be in form of a sheet covering the light sources
without
touching the light sources.
In some embodiments, the diffusion film has a light transmittance above
about 85%. In some embodiments, the diffusion film has a light transmittance
of about 92 % to about 94% with a thickness of about 200pm to about 300pm.
The lamp tube may include a reflective film disposed on part of the inner
circumferential surface of the lamp tube. In some embodiments, a ratio of a
length of the reflective film disposed on the inner surface of the lamp tube
extending along the circumferential direction of the lamp tube to a
circumferential length of the lamp tube is about 0.3 to 0.5
The present invention provides an LED tube lamp including a lamp tube,
14
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
an end cap disposed at one end of the lamp tube, a power supply provided
inside the end cap, an LED light strip disposed inside the lamp tube with
light
sources mounted on the LED light strip, wherein the LED light strip has a
bendable circuit sheet to electrically connect the light sources and the power
supply.
The bendable circuit sheet may be a conductive wiring layer, and the light
sources are mounted on the conductive wiring layer to allow electrical
connection between the light sources and the power supply through the
conductive wiring layer.
The bendable circuit sheet may further include a dielectric layer stacked
on the conductive wiring layer. The dielectric layer may be preferably stacked
on a surface of the conductive wiring layer that is opposite to the surface
having the light sources. The dielectric layer may be mounted onto the inner
surface of the lamp tube. In some embodiments, a ratio of the circumferential
length of the bendable circuit sheet to the circumferential length of the
inner
surface of the lamp tube is about 0.2 to 0.5.
The bendable circuit sheet may further include a circuit protection layer.
The bendable circuit sheet and the power supply may be connected by
wire bonding.
The bendable circuit sheet may be disposed on the reflective film.
The bendable circuit sheet may be disposed on one side of the reflective
film.
The bendable circuit sheet may be disposed such that the reflective film is
disposed on two sides of the bendable circuit sheet and extends along the
circumferential direction of the lamp tube.
The lamp tube may have adhesive film on the inner surface or outer
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
surface thereof to isolate inside and outside of the lamp tube that is broken.
The bendable circuit sheet may have its ends pass through the transition
region to reach and electrically connect the power supply.
The bendable circuit sheet may have a set of conductive wiring layers and
a set of dielectric layers that are stacked in a staggered manner and the
light
sources are disposed on the outmost conductive wiring layer through which
the electrical power supplies.
The bendable circuit sheet may be positioned along the axial direction of
the lamp tube and have its ends detached from an inner surface of the lamp
tube. The bendable circuit sheet may have its ends extend beyond two ends of
the lamp tube to respectively form two freely extending end portions with the
freely extending end portions being curled up, coiled or deformed in shape to
be fittingly accommodated inside the lamp tube.
The power supply may be in the form of a single integrated unit (e.g. with
all components of the power supply within a body) disposed in an end cap at
one end of the lamp tube. Alternatively, the power supply may be in form of
two
separate parts (e.g. with the components of the power supply separated into
two pieces) respectively disposed in two end caps.
The end cap may include a socket for connection with a power supply.
The power supply may have a metal pin at one end, while the end cap
may be provided with a hollow conductive pin to accommodate the metal pin of
the power supply.
The bendable circuit sheet may be connected to the power supply via
soldering bonding.
The LED light strip may be connected to the power supply by utilizing a
circuit-board assembly which has a long circuit sheet and a short circuit
board
16
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
that are adhered to each other with the short circuit board being adjacent to
the
side edge of the long circuit sheet. The short circuit board may be provided
with a power supply module to form the power supply. The short circuit board
is
stiffer than the long circuit sheet to be able to support the power supply
module.
The long circuit sheet may be the bendable circuit sheet of the LED light
strip.
The short circuit board may have a length generally of about 15mm to
about 40 mm and may preferably be 19 mm to 36 mm, while the long circuit
sheet may have a length generally of about 800 mm to about 2800mm and
may preferably be about 1200 mm to about 2400 mm. In some embodiments,
a ratio of the length of the short circuit board to the length of the long
circuit
sheet ranges from about 1:20 to about 1:200.
The short circuit board is a hard circuit board to support the power supply
module.
The power supply module and the long circuit sheet may bearranged on
the same side of the short circuit board such that the power supply module is
directly connected to the long circuit sheet. Alternatively, the power supply
module and the long circuit sheet may bearranged on opposite sides of the
short circuit board, respectively, such that the power supply module is
directly
connected to the short circuit board and further connected to the wiring layer
of
the long circuit sheet.
The power supply module may be connected to the end of the short circuit
board in a perpendicularmanner.
The present invention provides an LED tube lamp including a light source
having a lead frame formed with a recess in which a LED chip is disposed. The
lead frame further has first sidewalls and second sidewalls with the height of
the first sidewalls being less than that of the second sidewalls.
17
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
The first sidewallseach may have an inner surface facing toward outside
of the recess being an inclined plane. Furthermore, the inclined plane may be
flat or curved, and/or an included angle between the bottom surface of the
recess and the inner surface may range generally from about 105 degrees to
about 165 degrees and in some embodiments which may be preferable,from
about 120 degrees to about 150 degrees.
Alternatively, the inclined plane may be cambered.
In some embodiments, an LED tube lamp includes an LED light source
and a lamp tube accommodating the LED light source, wherein the LED light
source has a lead frame formed with a recess and a LED chip disposed in the
recess; the lead frame has first sidewalls arranged along the length direction
of
the lamp tube and second sidewalls arranged along the width direction of the
lamp tube, the height of the first sidewalls is less than the height of the
second
sidewalls. Alternatively, an LED tube lamp may include an LED light source
and a lamp tube accommodating the LED light source, wherein the LED light
source has a lead frame formed with a recess and a LED chip disposed in the
recess;the lead frame has first sidewalls extending along the width direction
of
the lamp tube and second sidewalls extending along the length direction of the
lamp tube, the height of the first sidewalls is less than the height of the
second
sidewalls.
The LED light source may be plural, and in some embodiments, the
plurality of LED light sources are arranged in only one row or a number of
rows
with each row of the light sources extending along the length direction of the
lamp tube.
Furthermore, the only one row of the LED light sources may have all the
second sidewalls disposed in same straight line that is in parallel with the
18
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
length direction of the lamp tube. Alternatively, the outermost two rows of
the
LED light sources, which are arranged along the width direction of the lamp
tube, may have all the second sidewalls disposed in two straight lines that
are
in parallel with the length direction of the lamp tube, respectively.
In comparison with the conventional LED lamp tube and the
manufacturing method thereof, the LED lamp tubes provided in the present
disclosure mayhave the following advantages:
The end cap thereof may have a thermal conductive member to
accomplish heating and solidification of the hot melt adhesive used in
connection with the lamp tube, and therefore eases the adhesion and provides
higher efficiency.
The end cap thereof may have a magnetic metal member to accomplish
heating and solidification of the hot melt adhesive used in connection with
the
lamp tube via electromagnetic induction technology, and therefore ease the
adhesion and provides higher efficiency.
The end caps may have different sizes to increase the design and
manufacturing flexibility for product.
The end caps may include sockets for connection with a power supply to
facilitate assembling and increase producing efficiency.
The end caps may be provided with a hollow conductive pin to make
connection with the power supply to increase the design and manufacturing
flexibility for product.
The end caps may have openings on a surface to dissipate heat resulted
from the power supply and to give aesthetic appearance.
The lamp tube may be formed with a rear end region at one end or two
ends with the rear end region having a smaller diameter than that of the main
19
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
body regionsuch that the outer surface of the end cap and the outer surface of
the main body region can be substantially flush with each other. Therefore, a
packing box for the LED tube lamp is able to connect both the lamp tube and
the end cap to uniform the loading of the entire LED tube lamp and prevent the
LED tube lamp from being broken in transportation.
The lamp tube may be formed with a transition region connecting the main
body regionand the rear end region with the end cap being secured to the lamp
tube atthe transition region. The transition region brings a height difference
between the rear end region and the main body region to avoid adhesives
applied on the rear end region being overflowed onto the main body region,
and thereby saves manpower to remove the overflowed adhesive and
increases productivity.
The lamp tube may include a diffusion layer to allow the light emitted from
the light sources to be diffused upon passing through the diffusion layer such
that the light sources function as surface sources and perform an optically
diffusive effect to eventually uniform the brightness of the whole lamp tube.
In
addition, the disposition of the diffusion layer also decreases the visual
effect
perceived by a user to increase visual comfort. The diffusion layer may have
very small thickness to guaranty the light outputting efficiency reaches the
maximum.
The lamp tube may have a reflective film to reflect the light emitted from
the light sources such that observingthe light in other view anglesand
adjustingthe divergence angle of the emitting light to illuminate at elsewhere
without disposition of the reflective film can be achieved. Therefore,the LED
tube lamp can have same illumination under a lower power and energy saving
can be achieved.
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
The illuminating angle may be increased and heat dissipation efficiency
can be improved by having the light sources adhered to the inner surface of
the lamp tube.
The inside and outside of a broken lamp tube may be isolated to assure
safety in manipulating the lamp tube by providing the adhesive film on the
inner or outer surface of the lamp tube.
The lamp tube no longer remains straight when broken and therefore
warns the user not to use the lamp tube such that electrical shock may be
avoided by adopting the bendable circuit sheet as the LED light strip.
The bendable circuit sheet may have parts to be curled up, coiled or
deformed in shape to be fittingly accommodated inside the lamp tube by
forming freely extending portion at ends of the bendable circuit sheet along
the
axial direction of the lamp tube.Therefore, the manufacturing and assembling
process of the LED lamp tube become more convenient.
The connectionbetween the bendable circuit sheet and the power supply
inside the end capmay be firmly secured by directly soldering the bendable
circuit sheet to the output terminal of the power supply.
The connection between the bendable circuit sheet and the printed circuit
board supporting the power supply module of the power supply may be
strengthened and not break easily by utilizing a circuitboard assembly.
The design and manufacturing flexibility of the LED tube lamp is increased
by utilizing different types of power supply modulesfor the power supply.
The light source may be provided with a lead frame formed with a recess
and first sidewalls and second sidewalls encompassing the recess, wherein a
LED chip is disposed in the recess. The first sidewalls are extending along
the
width direction of the lamp tube while the second sidewalls are extending
21
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
along the length direction of the lamp tube. The second sidewalls block a user
from seeingthe LED chips when the user observes the lamp tube laterally and
therefore decrease the grainy effect and improvevisual comfort. Furthermore,
the height of the first sidewalls is less than that of the second sidewalls
toallow
the light emitted from the LED chips pass across the first sidewalls to
illuminateand therefore to increase the light intensity and achieve energy
saving.
The plurality of rows of the LED light sources arranged along the width
direction of the lamp tubemay each have all the second sidewalls disposed in a
same straight line that is in parallel with the length direction of the lamp
tubesuch that the illumination loss along the length direction of the lamp
tube is
reduced and the light is well blocked by the aligned second sidewalls from
entering the user's eye laterally.
The hot melt adhesive may be improved and the heating method of the
hot melt adhesive may be well designed to facilitate secure connection
between the lamp tube and the end capssuch that the reliability of the hot
melt
adhesive could be prevented from decreasing due to high temperature caused
inside the end cap. In addition, the hot melt adhesive may be used to
electrically insulate the lamp tube and the end caps to further prevent from
any
possible electrical shock when the lamp tube is broken.
Brief Description of the Drawings
Fig. 1 is a perspective view schematically illustrating an LED tube lamp
according to one embodiment of the present invention;
Fig. 1A is a perspective view schematically illustrating the different sized
22
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
end caps of an LED tube lamp according to another embodiment of the
present invention to illustrate;
Fig. 2 is an exploded view schematically illustrating the LED tube lamp
shown in Fig. 1;
Fig. 3 is a perspective view schematically illustrating front and top of an
end cap of the LED tube lamp according to one embodiment of the present
invention;
Fig. 4 is a perspective view schematically illustrating bottom of the end
cap as shown in Fig. 3;
Fig. 5 is a plane cross-sectional partial view schematically illustrating a
connecting region of the end cap and the lamp tube of the LED tube lamp
according to one embodiment of the present invention;
Fig. 6 is a perspective cross-sectional view schematically illustrating inner
structure of an all-plastic end cap(having magnetic metal member and hot melt
adhesive inside) according to another embodiment of the present invention;
Fig. 7 is a perspective view schematically illustrating the all-plastic end
cap and the lamp tube being bonded together by utilizing an induction coil
according to the another embodiment of the present invention;
Fig. 8 is a perspective view schematically illustrating a supporting portion
and a protruding portion of the electrically insulating tube of the end cap of
the
LED tube lamp according to the another embodiment of the present invention;
Fig. 9 is a plane cross-sectional view schematically illustrating the inner
structure of the electrically insulating tube and the magnetic metal member of
the end cap of Fig. 8 taken along a line X-X,
Fig. 10 is a plane view schematically illustrating the configuration of the
openings on surface of the magnetic metal member of the end cap of the LED
23
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
tube lamp according to the another embodiment of the present invention;
Fig. 11 is a plane view schematically illustrating the
indentation/embossment on surface of the magnetic metal member of the end
cap of the LED tube lamp according to the another embodiment of the present
invention;
Fig. 12 is a plane cross-sectional view schematically illustrating the
structure of the connection of the end cap of Fig. 8 and the lamp tube along a
radial axis of the lamp tube, where the electrically insulating tube is in
shape of
a circular ring;
Fig. 13 is a plane cross-sectional view schematically illustrating the
structure of the connection of the end cap of Fig. 8 and the lamp tube along a
radial axis of the lamp tube, where the electrically insulating tube is in
shape of
an elliptical or oval ring;
Fig. 14 is a perspective view schematically illustrating still another end cap
of an LED tube lamp according to still another embodiment of the prevent
invention;
Fig. 15 is a plane cross-sectional view schematically illustrating end
structure of a lamp tube of the LED tube lamp according to one embodiment of
the present invention;
Fig. 16 is a plane cross-sectional view schematically illustrating the local
structure of the transition region of the end of the lamp tube of Fig. 15;
Fig. 17 is a plane cross-sectional view schematically illustrating inside
structure of the lamp tube of the LED tube lamp according to one embodiment
of the present invention, wherein two reflective films are respectively
adjacent
to two sides of the LED light strip along the circumferential direction of the
lamp tube;
24
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
Fig. 18 is a plane cross-sectional view schematically illustrating inside
structure of the lamp tube of the LED tube lamp according to another
embodiment of the present invention, wherein only a reflective film is
disposed
on one side of the LED light strip along the circumferential direction of the
lamp
tube;
Fig. 19 is a plane cross-sectional view schematically illustrating inside
structure of the lamp tube of the LED tube lamp according to still another
embodiment of the present invention, wherein the reflective film is under the
LED light strip and extends at both sides along the circumferential direction
of
the lamp tube;
Fig. 20 is a plane cross-sectional view schematically illustrating inside
structure of the lamp tube of the LED tube lamp according to yet another
embodiment of the present invention, wherein the reflective film is under the
LED light strip and extends at only one side along the circumferential
direction
of the lamp tube;
Fig. 21 is a plane cross-sectional view schematically illustrating inside
structure of the lamp tube of the LED tube lamp according to still yet another
embodiment of the present invention, wherein two reflective films are
respectively adjacent to two sides of the LED light strip and extending along
the circumferential direction of the lamp tube;
Fig. 22 is a plane sectional view schematically illustrating the LED light
strip is a bendable circuit sheet with ends thereof passing across the
transition
region of the lamp tube of the LED tube lamp to soldering bonded to the output
terminals of the power supply according to one embodiment of the present
invention;
Fig. 23 is a plane cross-sectional view schematically illustrating a
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
bi-layered structure of the bendable circuit sheet of the LED light strip of
the
LED tube lamp according to an embodiment of the present invention;
Fig. 24 is a perspective view schematically illustrating the soldering pad of
the bendable circuit sheet of the LED light strip for soldering connection
with
the printed circuit board of the power supply of the LED tube lamp according
to
one embodiment of the present invention;
Fig. 25 is a plane view schematically illustrating the arrangement of the
soldering pads of the bendable circuit sheet of the LED light stripof the LED
tube lamp according to one embodiment of the present invention;
Fig. 26 is a plane view schematically illustrating a row of three soldering
pads of the bendable circuit sheet of the LED light strip of the LED tube lamp
according to another embodiment of the present invention;
Fig. 27 is a plane view schematically illustrating two rows of soldering
pads of the bendable circuit sheet of the LED light strip of the LED tube lamp
according to still another embodiment of the present invention;
Fig. 28 is a plane view schematically illustrating a row of four soldering
pads of the bendable circuit sheet of the LED light strip of the LED tube lamp
according to yet another embodiment of the present invention;
Fig. 29 is a plane view schematically illustrating two rows of two soldering
pads of the bendable circuit sheet of the LED light strip of the LED tube lamp
according to yet still another embodiment of the present invention;
Fig. 30 is a plane view schematically illustrating through holes are formed
on the soldering pads of the bendable circuit sheet of the LED light strip of
the
LED tube lamp according to one embodiment of the present invention;
Fig. 31 is a plane cross-sectional view schematically illustrating soldering
bondingprocess utilizingthe soldering pads of the bendable circuit sheet of
the
26
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
LED light strip of Fig. 30 taken from side view and the printed circuit board
of
the power supply according to one embodiment of the present invention;
Fig. 32 is a plane cross-sectional view schematically illustrating soldering
bonding process utilizing the soldering pads of the bendable circuit sheet of
the LED light strip of Fig. 30 taken from side view and the printed circuit
board
of the power supply according to another embodiment of the present invention,
wherein the through hole of the soldering pads is near the edge of the
bendable circuit sheet;
Fig. 33 is a plane view schematically illustrating notches formed on the
soldering pads of the bendable circuit sheet of the LED light strip of the LED
tube lamp according to one embodiment of the present invention;
Fig. 34 is a plane cross-sectional view of Fig. 33 taken along a line A-A,
Fig. 35 is a perspective view schematically illustrating a circuit board
assembly composed of the bendable circuit sheet of the LED light strip and the
printed circuit board of the power supply according to another embodiment of
the present invention;
Fig. 36 is a perspective view schematically illustrating
anotherarrangement of the circuit board assembly of Fig. 35;
Fig. 37 is a perspective view schematically illustrating an LED lead frame
for the LED light sources of the LED tube lamp according to one embodiment
of the present invention;
Fig. 38 is a perspective view schematically illustrating a power supply of
the LED tube lamp according to one embodiment of the present invention;
Fig. 39 is a perspective view schematically illustrating the printed circuit
board of the power supply is perpendicularly adhered to a hard circuit board
made of aluminum via soldering according to another embodiment of the
27
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
present invention;
Fig. 40 is a perspective view illustrating a thermos-compression head
used in soldering the bendable circuit sheet of the LED light strip and the
printed circuit board of the power supply according to one embodiment of the
present invention;
Fig. 41 is a plane view schematically illustrating the thickness difference
between two solders on the pads of the bendable circuit sheet of the LED light
strip or the printed circuit board of the power supply according to one
embodiment of the invention;
Fig. 42 is a perspective view schematically illustrating the soldering
vehicle for soldering the bendable circuit sheet of the LED light strip and
the
printed circuit board of the power supply according to one embodiment of the
invention;
Fig. 43 is a plan view schematically illustrating a rotation status of the
rotary platform of the soldering vehicle in Fig. 41;
Fig. 44 is a plan view schematically illustrating an external equipment for
heating the hot melt adhesive according to another embodiment of the present
invention;
Fig. 45 is a cross-sectional view schematically illustrating the hot melt
adhesive having uniformly distributed high permeability powder particles with
small particle size according to one embodiment of the present invention;
Fig. 46 is a cross-sectional view schematically illustrating the hot melt
adhesive havingnon-uniformly distributed high permeability powder particles
with small particle sizeaccording to another embodiment of the present
invention, wherein the powder particles form a closed electric loop;
Fig. 47 is a cross-sectional view schematically illustrating the hot melt
28
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
adhesive having non-uniformly distributed high permeability powder particles
with large particle size according to yet another embodiment of the present
invention, wherein the powder particles form a closed electric loop;
Fig. 48 is a perspective view schematically illustrating the bendable circuit
sheet of the LED light strip is formed with two conductive wiring layers
according to another embodiment of the present invention.
Detailed Description of preferred Embodiments
The present disclosure provides a novel LED tube lamp based on the
glass made lamp tube to solve the abovementioned problems.The present
disclosurewill now be described in the following embodiments with reference to
the drawings.The following descriptions of variousembodiments of this
invention are presented herein for purpose of illustration and giving examples
only. It is not intended to be exhaustive or to be limited to the precise form
disclosed. These example embodiments are just that ¨ examples ¨ and many
implementations and variations are possible that do not require the details
provided herein. It should also be emphasized that the disclosure provides
details of alternative examples, but such listing of alternatives is not
exhaustive.
Furthermore, any consistency of detail between various examples should not
be interpreted as requiring such detail ¨ it is impracticable to list every
possible
variation for every feature described herein. The language of the claims
should
be referenced in determining the requirements of the invention.
Referring to Figs. 1 and 2, an LED tube lamp of one embodiment of the
present invention includes a lamp tube 1, an LED light strip 2 disposed inside
the lamp tube 1, and two end caps 3 respectively disposed at two ends of the
29
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
lamp tube 1. The lamp tube 1 may be made of plastic or glass. The sizes of the
two end caps 3 may be same or different. Referring to Fig. 1A, the size of one
end cap may in some embodiments beabout 30% to about 80% times the size
of the other end cap.
In one embodiment, the lamp tube 1 is made of glass with strengthened or
tempered structure to avoid being easily broken and incurring electrical shock
occurred to conventional glass made tube lamps, and to avoid the fast aging
process that often occurs inplastic made tube lamps. The glass made lamp
tube 1 may be additionally strengthened or tempered by a chemical tempering
method or a physical tempering method in various embodiments of the present
invention.
An exemplarychemical tempering method is accomplished by exchanging
the Na ions or K ions on the glass surface with other alkali metal ions and
therefore changes composition of the glass surface. The sodium (Na) ions or
potassium (K) ions and other alkali metal ions on the glass surface are
exchanged to form an ion exchange layer on the glass surface. The glass is
then under tension on the inside while under compression on the outside when
cooled to room temperature, so as to achieve the purpose of increased
strength. The chemical tempering method includes but is not limited to the
following glass tempering methods: high temperature type ion exchange
method, the low temperature type ion exchange method, dealkalization,
surface crystallization, and/or sodium silicate strengthening method, further
explained as follows.
The High temperature type ion exchange method includes the following
steps: Inserting glass containing sodium oxide (Na2O) or potassium oxide (K20)
in the temperature range of the softening point and glass transition point
into
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
molten salt of lithium, so that the Na ions in the glass are exchanged for Li
ions
in the molten salt. Later, the glass is then cooled to room temperature, since
the surface layer containing Li ions has a different expansion coefficient
with
respect to the inner layer containing Na ions or K ions, thus the surface
produces residual stress and is reinforced. Meanwhile, the glass containing
A1203, TiO2 and other components, by performing ion exchange, can produce
glass crystals of extremely low coefficient of expansion. The crystallized
glass
surface after cooling produces a significant amount of pressure, up to 700MPa,
which can enhance the strength of glass.
The low-temperature ion exchange method includes the following steps:
First, a monovalent cation (e.g., K ions) undergoes ion exchange with the
alkali
ions (e.g. Na ion) on the surface layer at a temperature range that is lower
than
the strain point temperature, so as to allow the K ions to penetrate the
surface.
For example, for manufacturing a Na2O + CaO + SiO2 system glass, the glass
can be impregnated for ten hours at more than four hundred degrees in the
molten salt. The low temperature ion exchange method can easily obtain glass
of higher strength, and the processing method is simple, does not damage the
transparent nature of the glass surface, and not undergo shape distortion.
Dealkalization includes treating glass using platinum (Pt) catalyst along
with sulfurous acid gas and water in a high temperature atmosphere. The
Na + ions are migrated out and bleed from the glass surface to be reacted with
the Pt catalyst, so that whereby the surface layer becomes a SiO2 enriched
layer, which results in a low expansion glass and produces compressive stress
upon cooling.
The surface crystallization method and the high temperature type ion
exchange method are different, but only the surface layer is treated by heat
31
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
treatment to form low expansion coefficient microcrystals on the glass
surface,
thus reinforcing the glass.
The sodium silicate glass strengthening method is a tempering method
using sodium silicate (water glass) in water solution at 100 degrees Celsius
and several atmospheres of pressure treatment, where a stronger/higher
strength glass surface that is harder to scratch is thereby produced.
The physical tempering method includes but not limited to applying a
coating to or changing structure of an object such as strengthen the easily
broken position. The applied coating can be a ceramic coating, an acrylic
coating, or a glass coating depending on the material used. The coating can be
performed in a liquid phase or gaseous phase.
The above glass tempering methods described including physical
tempering methods and chemical tempering methods can be accomplished
singly or combined together in any fashion.
Referring to Fig. 2 and Fig. 15, a glass made lamp tube of an LED tube
lamp according to one embodiment of the present invention has
structure-strengthened end regionsdescribed as follows. The glass made lamp
tube 1 includes a main body region 102, two rear end regions 101 respectively
formed at two ends of the main body region 102, and end caps 3 that
respectively sleeve the rear end regions 101. The outer diameter of at least
one of the rear end region 101 is less than the outer diameter of the main
body
region 102. In the embodiment of Figs. 2 and 15, the outer diameters of the
two rear end regions 101 are less than the outer diameter of the main body
region 102. The surface of the rear end region 101 is in parallel with the
surface of the main body region 102 in a cross-sectional view.Specifically,
the
glass made lamp tube 1 is strengthened at both ends, such that the rear end
32
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
regions 101 are formed to be strengthened structures. In certain embodiments,
the rear end regions 101 with strengthened structure are respectively sleeved
with the end caps 3, and the outer diameters of the end caps 3 and the main
body region 102 are with little and even no differences. In other words, the
end
caps 3 have same outer diameters as that of the main body region 102 such
that there is no gap between the end caps 3 and the main body region 102. In
this way, a supporting seat in a packing box for transportation of the LED
tube
lamp contacts not only the end caps 3 but also the lamp tube 1 and makes
uniform the loadings on the entire LED tube lamp to avoid situations where
only the end caps 3 are forced and therefore prevent breakage at the
connecting portion between the end caps 3 and the rear end regions 101 due
to stress concentration. The quality and the appearance of the product are
therefore improved.
In one embodiment, the end caps 3 and the main body region 102 have
substantially the same outer diameters. These diameters may have a
tolerance for example within +/- 0.2 millimeter (mm), or in some cases up to
+/-
1.0 millimeter(mm). Depending on the thickness of the end caps 3, the
difference between an outer diameter of the rear end regions 101 and an outer
diameter of the main body region 102 can be about 1 mm to about 10 mm for
typical product applications. In some embodiments, the difference between the
outer diameter of the rear end regions 101 and the outer diameter of the main
body region 102 can be about 2 mm to about 7 mm.
Referring to Fig. 15, the lamp tube 1 is further formed with a transition
region 103 between the main body region 102 and the rear end regions 101. In
one embodiment, the transition region 103 is a curved region formed to have
cambers at two ends to smoothly connect the main body region 102 and the
33
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
rear end regions 101, respectively. For example, the two ends of the
transition
region 103 may be arc-shaped in a cross-section view along the axial direction
of the lamp tube 1. Furthermore, one of the cambers connects the main body
region 102 while the other one of the cambers connects the rear end region
101. The arc angle of the cambers is greater than 90 degrees while the outer
surface of the rear end region 101 is a continuous surface in parallel with
the
outer surface of the main body region 102 when viewed from the cross-section
along the axial direction of the lamp tube. In other embodiments, the
transition
region 103 can be without curve or arc in shape.The length of the transition
region 103 along the axial direction of the lamp tube 1 is between about 1 mm
to about 4 mm. Upon experimentation, it was found that when the length of the
transition region 103 along the axial direction of the lamp tube 1 is less
than 1
mm, the strength of the transition region would be insufficient; when the
length
of the transition region 103 along the axial direction of the lamp tube 1 is
more
than 4 mm, the main body region 102 would be shorter and the desired
illumination surface would be reduced, and the end caps 3 would be longer
and the more materials for the end caps 3 would be needed.
Referring to Fig. 5 and Fig. 16, in certain embodiments, the lamp tube 1 is
made of glass, and has a rear end region 101, a main body region 102, and a
transition region 103. The transition region 103 has two arc-shaped cambers at
both ends to from an S shape; one camber positioned near the main body
region 102 is convex outwardly, while the other camber positioned near the
rear end region 101 is concaved inwardly. Generally speaking, the radius of
curvature, R1, of the camber/arc between the transition region 103 and the
main body region 102 is smaller than the radius of curvature, R2, of the
camber/arc between the transition region 103 and the rear end region 101.
34
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
The ratio R1:R2 may range, for example, from about 1:1.5 to about 1:10, and
in some embodiments is more effective from about 1:2.5 to about 1:5, and in
some embodiments is even more effective from about 1:3 to about 1:4. In this
way, the camber / arc of the transition region 103 positioned near the rear
end
region 101 is in compression at outer surfaces and in tension at inner
surfaces,
and the camber / arc of the transition region 103 positioned near the main
body
region 102 is in tension at outer surfaces and in compression at inner
surfaces.
Therefore, the goal of strengthening the transition region 103 of the lamp
tube
1 is achieved.
Taking the standard specification for T8 lamp as an example, the outer
diameter of the rear end region 101 is configured between 20.9 mm to 23 mm.
An outer diameter of the rear end region 101 being less than 20.9 mm would
be too small to fittingly insert the power supply into the lamp tube 1. The
outer
diameter of the main body region 102 is in some embodiments configured to
be between about 25 mm to about 28 mm. An outer diameter of the main body
region 102 being less than 25mm would be inconvenient to strengthen the
ends of the main body region 102 as far as the current skills are concerned,
while an outer diameter of the main body region 102 being greater than 28 mm
is not compliant to the industrial standard.
Referring to Figs. 3 and 4, in one embodiment of the invention, each end
caps 3 each includes an electrically insulating tube 302, a thermal conductive
member 303 sleeving over the electrically insulating tube 302, and two hollow
conductive pins 301 disposed on the electrically insulating tube 302. The
thermal conductive member 303 can be a metal ring that is tubular in shape.
Referring Fig. 5, in one embodiment, one end of the thermal conductive
member 303 extends away from the electrically insulating tube 302 of the end
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
cap 3 and towards one end of the lamp tube 1, and is bonded and adhered to
the end of the lamp tube 1 using a hot melt adhesive 6. In this way, the end
cap
3 by way of the thermal conductive member 303 to extend to the transition
region 103 of the lamp tube 1. The thermal conductive member 303 and the
transition region 103 are closely connected such that the hot melt adhesive 6
would not overflow out of the end cap 3 and remain on the main body region
102 when using the hot melt adhesive 6 to join the thermal conductive member
303 and the lamp tube1. In addition,the electrically insulating tube 302
facing
toward the lamp tube 1 does not have an end extending to the transition region
103, and that there is a gap between the electrically insulating tube 302 and
the transition region 103. In one embodiment, the electrically insulating tube
302 is not limited to being made of plastic or ceramic, any material that is
not a
good electrical conductor can be used.
The hot melt adhesive 6 is a composite including a so-called commonly
known as"welding mud powder", and in some embodiments includes one or
more of phenolic resin 2127#, shellac, rosin, calcium carbonate powder, zinc
oxide, and ethanol. Rosin is a thickening agent with a feature of being
dissolved in ethanol but not dissolved in water. In one embodiment, a hot melt
adhesive 6 having rosin could be expanded to change its physical status to
become solidified when being heated to high temperature in addition to the
intrinsic viscosity. Therefore, the end cap 3 and the lamp tube1 can be
adhered
closely by using the hot melt adhesive to accomplish automatic manufacture
for the LED tube lamps.ln one embodiment, the hot melt adhesive 6 may be
expansive and flowing and finally solidified after cooling. In this
embodiment,
the volume of the hot melt adhesive 6 expands to 1.3 times the original size
when heated from room temperature to 200 to 250 Degrees Celsius. The hot
36
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
melt adhesive 6 is not limited to the materials recited herein. Alternatively,
a
material for the hot melt adhesive 6 to be solidified immediately when heated
to a predetermined temperature can be used. The hot melt adhesive 6
provided in each embodiments of the present invention is durable with respect
to high temperature inside the end caps 3 due to the heat resulted from the
power supply. Therefore, the lamp tube 1 and the end caps 3 could be secured
to each other without decreasing the reliability of the LED tube lamp.
Furthermore, there is formed an accommodation space between the inner
surface of the thermal conductive member 303 and the outer surface of the
lamp tube 1 to accommodate the hot melt adhesive 6, as indicated by the
dotted line B in Fig. 5. In other words, the hot melt adhesive 6 is filled
into the
accommodation space at a location where a first hypothetical plane (as
indicated by the dotted line B in Fig. 5) being perpendicular to the axial
direction of the lamp tube 1 would pass through the thermal conductive
member, the hot melt adhesive 6, and the outer surface of the lamp tube 1.
The hot melt adhesive 6 may have a thickness of 0.2mm to 0.5mm. The hot
melt adhesive 6 will be expansive to solidify and in connect with the lamp
tube
1 and the end cap 3 to secure both. The transition region 103 brings a height
difference between the rear end region 101 and the main body region 102 to
avoid the hot melt adhesives 6 being overflowed onto the main body region
102, and thereby saves manpower to remove the overflowed adhesive and
increase the LED tube lamp productivity.The hot melt adhesive 6 is heated by
receiving heat from the thermal conductive member 303 to which an electricity
from an external heating equipment is applied, and then expands and finally
solidifies after cooling, such that the end caps 3 are adhered to the lamp
tube
1.
37
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
Referring to Fig. 5, in one embodiment, the electrically insulating tube 302
of the end cap 3 includes a first tubular part 302a and a second tubular part
302b connected along an axial direction of the lamp tube 1. The outer
diameter of the second tubular part 302b is less than the outer diameter of
the
first tubular part 302a. In some embodiments, the outer diameter difference
between the first tubular part 302a and the second tubular part 302b is
between about 0.15 mm andabout 0.30 mm.The thermal conductive member
303 sleeves over the outer circumferential surface of the second tubular part
302b. The outer surface of the thermal conductive member 303 is coplanar or
substantially flush with respect to the outer circumferential surface of the
first
tubular part 302a. In other words, the thermal conductive member 303 and the
first tubular part 302a have substantially uniform exterior diameters from end
to
end. As a result, the entire end cap 3 and thus the entire LED tube lamp are
smooth with respect to the outer appearance and have a substantially uniform
tubular outer surface, such that the loading during transportation on the
entire
LED tube lamp is also uniform. In one embodiment, a ratio of the length of the
thermal conductive member 303 along the axial direction of the end cap 3 to
the axial length of the electrically insulating tube 302 ranges from about 1:
2.5
to about 1: 5.
In one embodiment, for sake of secure adhesion between the end cap 3
and the lamp tube 1, the second tubular part 302b is at least partially
disposed
around the lamp tube 1, and the accommodation space further includes a
space encompassed by the inner surface of the second tubular part 302b and
the outer surface of the rear end region 101 of the lamp tube 1. The hot melt
adhesive 6 is at least partially filled in an overlapped region (shown by a
dotted
line "A" in Fig. 5) between the inner surface of the second tubular part 302b
38
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
and the outer surface of the rear end region 101 of the lamp tube 1. In other
words, the hot melt adhesive 6 is filled into the accommodation space at a
location where a second hypothetical plane (shown by the dotted line A in Fig.
5) being perpendicular to the axial direction of the lamp tube 1 would pass
through the thermal conductive member 303, the second tubular part 302b, the
hot melt adhesive 6, and the rear end region 101.
The hot melt adhesive 6 is not required to completely fill the entire
accommodation space as shown in Fig. 5, especially where a gap is reserved
or formed between the thermal conductive member 303 and the second
tubular part 302b. In other words, the hot melt adhesive 6 can be only
partially
filled into the accommodation space. During manufacturing of the LED tube
lamp, the amount of the hot melt adhesive 6 coated and applied between the
thermal conductive member 303 and the rear end region 101 may be
appropriately increased, such that in the subsequent heating process, the hot
melt adhesive 6 can be caused to expand and flow in between the second
tubular part 302b and the rear end region 101, and thereby solidify after
cooling to join the second tubular part 302b and the rear end region 101.
During fabrication of the LED tube lamp, the rear end region 101 of the
lamp tube 1 is inserted into one of the end caps 3. The axial length of the
inserted portion of the rear end region 101 of the lamp tube 1 accounts for
one-third (1/3) to two-thirds (2/3) of the total axial length of the thermal
conductive member 303. One benefit is that, there will be sufficient creepage
distance between the hollow conductive pins 301 and the thermal conductive
member 303, and thus it is not easy to form a short circuit leading to
dangerous electric shock to individuals. On the other hand, the creepage
distance between the hollow conductive pin 301 and the thermal conductive
39
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
member 303 is increased due to the electrically insulating effect of the
electrically insulating tube 302, and thus a high voltage test is easily to
pass
without causing electrical shocks to people.
Furthermore, the presence of the second tubular part 302b interposed
between the hot melt adhesive 6 and the thermal conductive member 303 may
reduce the heat from the thermal conductive member 303 to the hot melt
adhesive 6. To solve this problem, referring to Fig. 4 in one embodiment, the
end of the second tubular part 302b facing the lamp tube 1 (i.e., away from
the
first tubular part 302a) is circumferentially provided with a plurality of
notches
302c. These notches 302c help to increase the contact areas between the
thermal conductive member 303 and the hot melt adhesive 6 and therefore
provide rapid heat conduction from the thermal conductive member 303 to the
hot melt adhesive 6 so as to accelerate the solidification of the hot melt
adhesive 6. Moreover, the hot melt adhesive 6 electrically insulates the
thermal
conductive member 303 and the lamp tube 1 so that a user would not be
electrically shocked when he touches the thermal conductive member 303
connected to a broken lamp tube 1.
The thermal conductive member 303 can be made of various heat
conducting materials. The thermal conductive member 303 can be a metal
sheet such as an aluminum alloy. The thermal conductive member 303
sleeves the second tubular part 302b and can be tubular or ring-shaped. The
electrically insulating tube 302 may be made of electrically insulating
material,
but in some embodiments have low thermal conductivity so as to prevent the
heat from reaching the power supply module located inside the end cap 3 and
therefore negatively affecting performance of the power supply module. In one
embodiment, the electrically insulating tube 302 is a plastic tube.
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
Alternatively, the thermal conductive member 303 may be formed by a plurality
of metal plates circumferentially arranged on the tubular part 302b with
either
an equidistant space or a non-equidistant space.
The end cap 3 may be designed to have other kind of structures or include
other elements. Referring to Fig. 6, the end cap 3 according to another
embodiment further includes a magnetic metal member 9 within the electrically
insulating tube 302 but exclude the thermal conductive member 3. The
magnetic metal member 9 is fixedly arranged on the inner circumferential
surface of the electrically insulating tube 302 and therefore interposed
between the electrically insulating tube 302 and the lamp tube 1 such that the
magnetic metal member 9 is partially overlapped with the lamp tube 1 in the
radial direction. In this embodiment, the whole magnetic metal member 9 is
inside the electrically insulating tube 302, and the hot melt adhesive 6 is
coated on the inner surface of the magnetic metal member 9 (the surface of
the magnetic metal tube member 9 facing the lamp tube 1) and adhered to the
outer peripheral surface of the lamp tube 1. In some embodiments, the hot
melt adhesive 6 covers the entire inner surface of the magnetic metal member
9 in order to increase the adhesion area and to improve the stability of the
adhesion.
Referring to Fig. 7, when manufacturing the LED tube lamp of this
embodiment, the electrically insulating tube 302 is inserted in an external
heating equipment which is in some embodiments an induction coil 11, so that
the induction coil 11 and the magnetic metal member 9 are disposed opposite
(or adjacent) to one another along the radially extending direction of the
electrically insulating tube 302. The induction coil 11 is energized and forms
an
electromagnetic field, and the electromagnetic field induces the magnetic
41
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
metal member 9 to create an electrical current and become heated. The heat
from the magnetic metal member 9 is transferred to the hot melt adhesive 6 to
make the hot melt adhesive 6 expansive and flowing and then solidified after
cooling, and the bonding for the end cap 3 and the lamp tube 1 can be
accomplished. The induction coil 11 may be made of red copper and
composed of metal wires having width of, for example, about 5 mm to about
6mm to be a circular coil with a diameter of about 30mm to about 35mm, which
is a bit greater than the outer diameter of the end cap 3. Since the end cap 3
and the lamp tube 1 may have the same outer diameters, the outer diameter
may change depending on the outer diameter of the lamp tube 1, and therefore
the diameter of the induction coil 11 used can be changed depending on the
type of the lamp tube 1 used. As examples, the outer diameters of the lamp
tube for T12, T10, T8, T5, T4, and T2 are 38.1mm, 31.8mm, 25.4mm, 16mm,
12.7mm, and 6.4 mm, respectively.
Furthermore, the induction coil 11 may be provided with a power
amplifying unit to increase the alternating current power to about 1 to 2
times
the original. It is better that the induction coil 11 and the electrically
insulating
tube 302 are coaxially aligned to make energy transfer more uniform. In some
embodiments, a deviation value between the axes of the induction coil 11 and
the electrically insulating tube 302 is not greater than about 0.05mm. When
the
bonding process is complete, the end cap 3 and the lamp tube 1 are moved
away from the induction coil. Then, the hot melt adhesive 6 absorbs the energy
to be expansive and flowing and solidified after cooling. In one embodiment,
the magnetic metal member 9 can be heated to a temperatureof about 250 to
300 degreesCelsius; the hot melt adhesive 6 can be heated to a temperature
of 200 to 250 Degrees Celsius. The material of the hot melt adhesive is not
42
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
limited here, and a material of allowing the hot melt adhesive to immediately
solidify when absorb heat energy can also be used.
In one embodiment, the induction coil 11 may be fixed in position to allow
the end cap 3 and the lamp tube 1 to be moved into the induction coil 11 such
that the hot melt adhesive 6 is heated to expand and flow and then solidify
after cooling when the end cap 3 is again moved away from the induction coil
11. Alternatively, the end cap 3 and the lamp tube 1 may be fixed in position
to
allow the induction coil 11 to be moved to encompass the end cap 3 such that
the hot melt adhesive 6 is heated to expand and flow and then solidify after
cooling when the induction coil 11 is again moved away from the end cap 3mn
one embodiment, the external heating equipment for heating the magnetic
metal member 9 is provided with a plurality of devices the same as the
induction coils 11, and the external heating equipment moves relative to the
end cap 3 and the lamp tube 1 during the heating process. In this way, the
external heating equipment moves away from the end cap 3 when the heating
process is completed. However, the length of the lamp tube 1 is far greater
than the length of the end cap 3 and may be up to above about 240 cm in
some special appliances, and this may cause bad connection between the end
cap 3 and the lamp tube 1 during the process that the lamp tube 1 accompany
with the end cap 3 to relatively enter or leave the induction coil 11 in the
back
and for the direction as mentioned above when a position error exists.
Referring to Fig. 44, an external heating equipment 110 having a plurality
sets of upper and lower semicircular fixtures 11a is provided to achieve same
heating effect as that brought by the induction coils 11. In this way, the
above-mentioned damage risk due to the relative movement in back-and-forth
direction can be reduced. The upper and lower semicircular fixtures 11a each
43
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
has a semicircular coil made by winding a metal wire of about 5 mm to about
6mm wide. The combination of the upper and lower semicircular fixtures form
a ring with a diameter of about 30mm to about 35mm, and the inside
semicircular coils form a closed loop to become the induction coil 11 as
mentioned. In this embodiment, the end cap 3 and the lamp tube 1 do not
relatively move in theback-and-forth manner, but roll into the notch of the
lower
semicircular fixture. Specifically, an end cap 3 accompany with a lamp tube 1
initially roll on a production line, and then the end cap 3 rolls into the
notch of a
lower semicircular fixture, and then the upper and the lower semicircular
fixtures are combined to form a closed loop, and the fixtures are detached
when heating is completed. This method reduces the requirement for high
position precision and yield problem in producing.
Referring to Fig. 6, the electrically insulating tube 302 is further divided
into two parts, namely a first tubular part 302d and a second tubular part
302e,
i.e. the remaining part. In order to provide better support of the magnetic
metal
member 9, an inner diameter of the first tubular part 302d for supporting the
magnetic metal member 9 is larger than the inner diameter of the second
tubular part 302e which does not have the magnetic metal member 9, and a
stepped structure is formed at the connection of the first tubular part 302d
and
the second tubular part 302e. In this way, an end of the magnetic metal
member 9 as viewed in an axial direction is abutted against the stepped
structure such that the entire inner surface of the end cap is smooth and
plain.
Additionally, the magnetic metal member 9 may be of various shapes, e.g., a
sheet-like or tubular-like structure being circumferentially arranged or the
like,
where the magnetic metal member 9 is coaxially arranged with the electrically
insulating tube 302.
44
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
Referring to Figs. 8 and 9, the electrically insulating tube may be further
formed with a supporting portion 313 on the inner surface of the electrically
insulating tube 302 to be extending inwardly such that the magnetic metal
member 9 is axially abutted against the upper edge of the supporting portion
313. In some embodiments, the thickness of the supporting portion 313 along
the radial direction of the electrically insulating tube 302 is between lmm to
2mm. The electrically insulating tube 302 may be further formed with a
protruding portion 310 on the inner surface of the electrically insulating
tube
302 to be extending inwardlysuch that the magnetic metal member 9 is radially
abutted against the side edge of the protruding portion 310 and that the outer
surface of the magnetic metal member 9 and the inner surface of the
electrically insulating tube 302 is spaced apart with a gap. The thickness of
the
protruding portion 310 along the radial direction of the electrically
insulating
tube 302 is less than the thickness of the supporting portion 313 along the
radial direction of the electrically insulating tube 302 and be about 0.2 mm
to
about 1 mm in an embodiment.
Referring to Fig. 9, the protruding portion 310 and the supporting portion
are connected along the axial direction, and the magnetic metal member 9 is
axially abutted against the upper edge of the supporting portion 313 while
radially abutted against the side edge of the protruding portion 310 such that
at
least part of the protruding portion 310 intervenes between the magnetic metal
member 9 and the electrically insulating tube 302.The protruding portion 310
may be arranged along the circumferential direction of the electrically
insulating tube 302 to have a circular configuration. Alternatively, the
protruding portion 310 may in form of a plurality of bumps arranged on the
inner surface of the electrically insulating tube 302. The bumps may be
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
equidistantly or non-equidistantly arranged along the inner circumferential
surface of the electrically insulating tube 302 as long as the outer surface
of
the magnetic metal member 9 and the inner surface of the electrically
insulating tube 302 are in a minimum contact and simultaneously hold the hot
melt adhesive 6. In other embodiments, an entirely metal made end cap 3
would need an insulator disposed under the hollow conductive pin to endure
the high voltage.
Referring to Fig. 10, in one embodiment, the magnetic metal member 9
can have at least one or more openings 91 that are circular. However, the
openings 91 may instead be, for example, oval, square, star shaped, etc., as
long as the contact area between the magnetic metal member 9 and the inner
peripheral surface of the electrically insulating tube 302 can be reduced and
the function of the magnetic metal member 9 to heat the hot melt adhesive 6
can be performed. In some embodiments, the openings 91 occupy about 10%
to about 50% of the surface area of the magnetic metal member 9. The
opening 91 can be arranged circumferentially on the magnetic metal member 9
in an equidistantly spaced or non-equidistantly spaced manner.
Referring to Fig. 11, in other embodiments, the magnetic metal member 9
has an indentation/embossment 93 on surface facing the electrically insulating
tube 302. The embossment is raised from the inner surface of the magnetic
metal member 9, while the indentation is depressed under the inner surface of
the magnetic metal member 9. The indentation/embossment reduces the
contact area between the inner peripheral surface of the electrically
insulating
tube 302 and the outer surface of the magnetic metal member 9 while
maintaining the function of melting and curing the hot melt adhesive 6.In sum,
the surface of the magnetic metal member 9 can be configured to have
46
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
openings, indentations, or embossments or any combination thereof to
achieve the goal of reducing the contact area between the inner peripheral
surface of the electrically insulating tube 302 and the outer surface of the
magnetic metal member 9. At the same time, the firm adhesion between the
magnetic metal member 9 and the lamp tube 1 should be secured to
accomplish the heating and solidification of the hot melt adhesive 6.
Referring to Fig. 12, in one embodiment, the magnetic metal member 9 is
a circular ring. Referring to Fig. 13, in another embodiment, the magnetic
metal
member 9 is a non-circular ring such as but not limited to an oval ring. When
the magnetic metal member 9 is an oval ring, the minor axis of the oval ring
is
slightly larger than the outer diameter of the end region of the lamp tube 1
such
that the contact area of the inner peripheral surface of the electrically
insulating
tube 302 and the outer surface of the magnetic metal member 9 is reduced
and the function of melting and curing the hot melt adhesive 6 still performs
properly. For example, the inner surface of the electrically insulating tube
302
may be formed with supporting portion 313 and the magnetic metal member 9
in a non-circular ring shape is seated on the supporting portion 313. Thus,
the
contact area of the outer surface of the magnetic metal member 9 and the
inner surface of the electrically insulating tube 302 could be reduced while
that
the function of solidifying the hot melt adhesive 6 could be performed. In
other
embodiments, the magnetic metal member 9 can be disposed on the outer
surface of the end cap 3 to replace the thermal conductive member 303 as
shown in Fig. 5 and to perform function of heating and solidifying the hot
melt
adhesive 6 via electromagnetic induction.
Referring to Figs. 45 to 47, in other embodiments, the magnetic metal
member 9 may be omitted. Instead, in some embodiments, the hot melt
47
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
adhesive 6 has a predetermined proportion of high permeability powders 65
having relative permeability ranging, for example, from about 102 to about
106.
The powders can be used to replace the calcite powders originally included in
the hot melt adhesive 6, and in certain embodiments, a volume ratio of the
high
permeability powders 65t0 the calcite powders is about 1:1-1:3. In some
embodiments, the material of the high permeability powders 65 is one of iron,
nickel, cobalt, alloy thereof, or any combination thereof; the weight
percentage
of the high permeability powders 65 with respect to the hot melt adhesive is
about 10% to about 50%; and/or the powders may have mean particle size of
about 1 to about 30 micrometers. Such a hot melt adhesive 6 allow the end
cap 3 and the lamp tube 1 to adhere together and be qualified in a destruction
test, a torque test, and a bending test. Generally speaking, the bending test
standard for the end cap of the LED tube lamp is greater than 5 newton-meters
(Nt-m), while the torque test standard is greater than 1.5 newton-meters (Nt-
m).
In one embodiment, upon the ratio of the high permeability powders 65 to the
hot melt adhesive 6 and the magnetic flux applied, the end cap 3 and the end
of the lamp tube 1 secured by using the hot melt adhesive 6 are qualified in a
torque test of 1.5 to 5 newton-meters (Nt-m) and a bending test of 5 to 10
newton-meters (Nt-m).The induction coil 11 is firstly switched on and allow
the
high permeability powders uniformly distributed in the hot melt adhesive 6 to
be charged, and therefore allow the hot melt adhesive 6 to be heated to be
expansive and flowing and then solidified after cooling. Thereby, the goal of
adhering the end cap 3 onto the lamp tube 1 is achieved.
Referring to Figs. 45 to 47, the high permeability powders 65 may have
different distribution manner in the hot melt adhesive 6. As shown in Fig. 45,
the high permeability powders 65 have mean particle size of about 1 to about 5
48
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
micrometers, and are distributed uniformly in the hot melt adhesive 6. When
such a hot melt adhesive 6 is coated on the inner surface of the end cap 3,
though the high permeability powders 65 cannot form a closed loop due to the
uniform distribution, they can still be heated due to magnetic hysteresis in
the
electromagnetic field, so as to heat the hot melt adhesive 6. As shown in Fig.
46, the high permeability powders 65 have mean particle size of about 1 to
about 5 micrometers, and are distributed randomly in the hot melt adhesive 6.
When such a hot melt adhesive 6 is coated on the inner surface of the end cap
3, the high permeability powders 65 form a closed loop due to the random
distribution; they can be heated due to magnetic hysteresis or the closed loop
in the electromagnetic field, so as to heat the hot melt adhesive 6. As shown
in
Fig. 47, the high permeability powders 65 have mean particle size of about 5
to
about 30 micrometers, and are distributed randomly in the hot melt adhesive 6.
When such a hot melt adhesive 6 is coated on the inner surface of the end cap
3, the high permeability powders 65 form a closed loop due to the random
distribution; they can be heated due to magnetic hysteresis or the closed loop
in the electromagnetic field, so as to heat the hot melt adhesive
6.Accordingly,
depending on the adjustment of the particle size, the distribution density and
the distribution manner of the high permeability powders 65, and the
electromagnetic flux applied to the end cap 3, the heating temperature of the
hot melt adhesive 6 can be controlled. In one embodiment, the hot melt
adhesive 6 is flowing and solidified after cooling from a temperature of 200
to
250 Degrees Celsius. In another embodiment, the hot melt adhesive 6 is
immediately solidified at a temperature of about 200 to about 250 Degrees
Celsius.
Referring to Figs. 14 and 39, in one embodiment, an end cap3' has a pillar
49
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
312 at on end, the top end of the pillar 312 is provided with an opening
having
a groove 314 of for example 0.1 1% mm depth at the periphery thereof for
positioning a conductive lead 53 as shown in Fig. 39.The conductive lead 53
passes through the opening on top of the pillar 312 and has its end bent to be
disposed in the groove 314. After that, a conductive metallic cap 311 covers
the pillar 312 such that the conductive lead 53 is fixed between the pillar
312
and the conductive metallic cap 311. In some embodiments, the inner diameter
of the conductive metallic cap 311 is 7.56 5%mm, the outer diameter of the
pillar 312 is 7.23 59mm, and the outer diameter of the conductive lead 53 is
0.5 1%mm. Nevertheless, the mentioned sizes are not limited here once that
the conductive metallic cap 311 closely covers the pillar 312 without using
extra adhesives and therefore completes the electrical connection between the
power supply 5 and the conductive metallic cap 311.
Referring to Figs. 2, 3, 12, and 13, in one embodiment, the end cap 3 may
have openings 304 to dissipate heat generated by the power supply modules
inside the end cap 3 so as to prevent a high temperature condition inside the
end cap 3 that might reduce reliability. In some embodiments, the openings are
in a shape of arc,especially in shape of three arcs with different size.ln one
embodiment, the openings arein a shape of three arcs with gradually varying
size.The openings on the end cap 3 can be in any one of the above-mentioned
shape or any combination thereof.
In other embodiments, the end cap 3 is provided with a socket (not shown)
for installing the power supply module.
Referring to Fig. 17, in one embodiment, the lamp tube 1 further has a
diffusion film 13 coated and bonded to the inner wall thereof so that the
light
outputted or emitted from the LED light sources 202 is diffusedby the
diffusion
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
film 13 and then pass through the lamp tube 1.The diffusion film 13 can be in
form of various types, such as a coating onto the inner wall or outer wall of
the
lamp tube 1, or a diffusion coating layer (not shown) coated at the surface of
each LED light source 202, or a separate membrane covering the LED light
source 202.
Referring again to Fig. 17, when the diffusion film 13 is in form of a sheet,
it covers but not in contact with the LED light sources 202.The diffusion film
13
in form of a sheet is usually called an optical diffusion sheet or board,
usually a
composite made of mixing diffusion particles into polystyrene (PS), polymethyl
methacrylate (PMMA), polyethylene terephthalate (PET), and/or
polycarbonate (PC), and/or any combination thereof. The light passing through
such composite is diffused to expand in a wide range of space such as a light
emitted from a plane source, and therefore makes the brightness of the LED
tube lamp uniform.
In alternative embodiment, the diffusion film 13 is in form of an optical
diffusion coating, which is composed of any one of calcium carbonate, halogen
calcium phosphate and aluminum oxide, or any combination thereof. When the
optical diffusion coating is made from a calcium carbonate with suitable
solution, an excellent light diffusion effect and transmittance to exceed 90%
can be obtained. Furthermore, the diffusion film 13 in form of an optical
diffusion coating may be applied to an outer surface of the rear end region
101
having the hot melt adhesive 6 to produce increased friction resistance
between the end cap 3 and the rear end region 101. Compared with an
example without any optical diffusion coating, the rear end region 101 having
the diffusion film 13 is beneficial for preventing accidental detachment of
the
end cap 3 from the lamp tube 1.
51
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
In the embodiment, the composition of the diffusion film 13 in form of the
optical diffusion coating includes calcium carbonate, strontium phosphate
(e.g.,
CMS-5000, white powder), thickener, and a ceramic activated carbon (e.g.,
ceramic activated carbon SW-C, which is a colorless liquid). Specifically,
such
an optical diffusion coating on the inner circumferential surface of the glass
tube has an average thickness ranging between about 20 to about 30 pm. A
light transmittance of the diffusion film 13 using this optical diffusion
coating is
about 90%. Generally speaking, the light transmittance of the diffusion film
13
ranges from 85% to 96%. In addition, this diffusion film 13 can also provide
electrical isolation for reducing risk of electric shock to a user upon
breakage of
the lamp tube 1. Furthermore, the diffusion film 13 provides an improved
illumination distribution uniformity of the light outputted by the LED light
sources 202 such that the light can illuminate the back of the light sources
202
and the side edges of the bendable circuit sheet so as to avoid the formation
of
dark regions inside the lamp tube 1 and improve the illumination comfort. In
another possible embodiment, the light transmittance of the diffusion film can
be 92% to 94% while the thickness ranges from about 200 to about 300 pm.
In another embodiment, the optical diffusion coating can also be made of
a mixture including calcium carbonate-based substance, some reflective
substances like strontium phosphate or barium sulfate, a thickening agent,
ceramic activated carbon, and deionized water. The mixture is coated on the
inner circumferential surface of the glass tube and has an average thickness
ranging between about 20 to about 30 pm. In view of the diffusion phenomena
in microscopic terms, light is reflected by particles. The particle size of
the
reflective substance such as strontium phosphate or barium sulfate will be
much larger than the particle size of the calcium carbonate. Therefore, adding
52
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
a small amount of reflective substance in the optical diffusion coating can
effectively increase the diffusion effect of light.
In other embodiments, halogen calcium phosphate or aluminum oxide can
also serve as the main material for forming the diffusion film 13. The
particle
size of the calcium carbonate is about 2 to 4 pm, while the particle size of
the
halogen calcium phosphate and aluminum oxide are about 4 to 6 pm and 1 to
2 pm, respectively.VVhen the light transmittance is required to be 85% to 92%,
the required average thickness for the optical diffusion coating mainly having
the calcium carbonate is about 20 to about 30 pm, while the required average
thickness for the optical diffusion coating mainly having the halogen calcium
phosphate may be about 25 to about 35 pm, the required average thickness
for the optical diffusion coating mainly having the aluminum oxide may be
about 10 to about 15 pm. However, when the required light transmittance is up
to 92% and even higher, the optical diffusion coating mainly having the
calcium
carbonate, the halogen calcium phosphate, or the aluminum oxide must be
thinner.
The main material and the corresponding thickness of the optical diffusion
coating can be decided according to the place for which the lamp tube 1 is
used and the light transmittance required.lt is to be noted that the higher
the
light transmittance of the diffusion film is required, the more apparentthe
grainy
visual of the light sources is.
Referring to Fig. 17, the inner circumferential surface of the lamp tube 1
may also be provided or bonded with a reflective film 12. The reflective film
12
is provided around the LED light sources 202, and occupies a portion of an
area of the inner circumferential surface of the lamp tube 1 arranged along
the
circumferential direction thereof. As shown in Fig. 17, the reflective film 12
is
53
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
disposed at two sides of the LED light strip 2 extending along a
circumferential
direction of the lamp tube 1. The LED light strip 2 is basically in a middle
position of the lamp tube 1 and between the two reflective films 12. The
reflective film 12, when viewed by a person looking at the lamp tube from the
side (in the X-direction shown in Fig. 17), serves to block the LED light
sources
202, so that the person does not directly see the LED light sources 202,
thereby reducing the visual graininess effect. On the other hand, that the
lightsemitted from the LED light sources 202 are reflected by the reflective
film
12 facilitates the divergence angle control of the LED tube lamp, so that more
lights illuminates toward directionswithout the reflective film 12, such that
the
LED tube lamp has higher energy efficiency when providing the same level of
illumination performance.
Specifically, the reflection film 12 is provided on the inner peripheral
surface of the lamp tube 1, and has an opening 12a configured to
accommodate the LED light strip 2. The size of the opening 12a is the same
or slightly larger than the size of the LED light strip 2. During assembly,
the
LED light sources 202 are mounted on the LED light strip 2 (a bendable circuit
sheet) provided on the inner surface of the lamp tube 1, and then the
reflective
film 12 is adhered to the inner surface of the lamp tube 1, so that the
opening
12a of the reflective film 12 correspondingly matches the LED light strip 2 in
a
one-to-one relationship, and the LED light strip 2 is exposed to the outside
of
the reflective film 12.
In one embodiment, the reflectance of the reflective film 12 is generally at
least greater than 85%, in some embodimentsgreater than90%, and in some
embodimentsgreater than 95%, to be most effective. In one embodiment, the
reflective film 12 extends circumferentially along the length of the lamp tube
1
54
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
occupying about 30% to 50% of the inner surface area of the lamp tube 1. In
other words, a ratio of a circumferential length of the reflective film 12
along the
inner circumferential surface of the lamp tube 1 to a circumferential length
of
the lamp tube 1 is about 0.3 to 0.5. In the illustrated embodiment of Fig. 17,
the
reflective film 12 is disposed substantially in the middle along a
circumferential
direction of the lamp tube 1, so that the two distinct portions or sections of
the
reflective film 12 disposed on the two sides of the LED light strip 2 are
substantially equal in area. The reflective film 12 may be made of PET with
some reflective materials such as strontium phosphate or barium sulfate or any
combination thereof, with a thickness between about 140pm andabout 350pm
or between about 150pm andabout 220pm for a more preferred effect in some
embodiments. As shown in Fig. 18, in other embodiments, the reflective film 12
may be provided along the circumferential direction of the lamp tube 1 on only
side of the LED light strip 2 occupiing the same percentage of the inner
surface
area of the lamp tube 1(e.g., 15% to 25% for the one side). Alternatively, as
shown in Figs. 19 and 20, the reflective film 12 may be provided without any
opening, and the reflective film 12 is directly adhered or mounted to the
inner
surface of the lamp tube 1 and followed by mounting or fixing the LED light
strip 2 on the reflective film 12 such that the reflective film 12 positioned
on one
side or two sides of the LED light strip 2.
In the above mentioned embodiments, various types of the reflective film
12 and the diffusion film 13 can be adopted to accomplish optical effects
including single reflection, single diffusion, and/or combined reflection-
diffusion.
For example, the lamp tube 1 may be provided with only the reflective film 12,
and no diffusion film 13 is disposed inside the lamp tube 1, such as shown in
Fig. 19, 20, and 21.
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
In other embodiments, the width of the LED light strip 2 (along the
circumferential direction of the lamp tube) can be widened to occupy a
circumference area of the inner circumferential surface of the lamp tube
1.Since the LED light strip 2 has on its surface a circuit protective layer
made
ofan ink which can reflect lights, the widen part of the LED light strip 2
functions like the reflective film 12 as mentioned above. In some embodiments,
a ratio of the length of the LED light strip 2 along the circumferential
direction to
the circumferential length of the lamp tube 1 is about 0.2 to 0.5. The light
emitted from the light sources could be concentrated by the reflection of the
widen part of the LED light strip 2.
In other embodiments, the inner surface of the glass made lamp tube may
be coated totally with the optical diffusion coating, or partially with the
optical
diffusion coating (where the reflective film12 is coated have no optical
diffusion
coating). No matter in what coating manner, it is better that the optical
diffusion
coating be coated on the outer surface of the rear end region of the lamp
tube1
so as to firmly secure the end cap3 with the lamp tube1.
In the present invention, the light emitted from the light sources may be
processed with the abovementioned diffusion film, reflective film, other kind
of
diffusion layer sheet, adhesive film, or any combination thereof.
Referring again to Fig. 2, the LED tube lamp according to the embodiment
of present invention also includes an adhesive sheet 4, an insulation adhesive
sheet 7, and an optical adhesive sheet 8. The LED light strip 2 is fixed by
the
adhesive sheet 4 to an inner circumferential surface of the lamp tube 1. The
adhesive sheet 4 may be but not limited to a silicone adhesive.The adhesive
sheet 4 may be in form of several short pieces or a long piece. Various kinds
of
the adhesive sheet 4, the insulation adhesive sheet 7, and the optical
adhesive
56
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
sheet 8can be combined to constitute various embodiments of the present
invention.
The insulation adhesive sheet 7 is coated on the surface of the LED light
strip 2 that faces the LED light sources 202 so that the LED light strip 2 is
not
exposed and thus electrically insulated from the outside environment. In
application of the insulation adhesive sheet 7, a plurality of through holes
71 on
the insulation adhesive sheet 7 are reserved to correspondingly accommodate
the LED light sources 202 such that the LED light sources 202 are mounted in
the through holes 701. The material composition of the insulation adhesive
sheet 7 includes vinyl silicone, hydrogen polysiloxane and aluminum oxide.
The insulation adhesive sheet 7 has a thickness ranging from about 100 pm to
about 140 pm (micrometers). The insulation adhesive sheet 7 having a
thickness less than 100 pm typically does not produce sufficient insulating
effect, while the insulation adhesive sheet 7 having a thickness more than 140
pm may result in material waste.
The optical adhesive sheet 8, which is a clear or transparent material, is
applied or coated on the surface of the LED light source 202in order to ensure
optimal light transmittance. After being applied to the LED light sources 202,
the optical adhesive sheet 8 may havea granular, strip-like or sheet-like
shape.
The performance of the optical adhesive sheet 8 depends on its refractive
index and thickness. The refractive index of the optical adhesive sheet 8 is
in
some embodiments between 1.22 and 1.6.In some embodiments,it is better for
the optical adhesive sheet 8 to have a refractive index being a square root of
the refractive index of the housing or casing of the LED light source 202,
orthe
square root of the refractive index of the housing or casing of the LED light
source 202 plus or minus 15%, to contribute better light transmittance.The
57
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
housing/casing of the LED light sources 202 is a structure to accommodate
and carry the LED dies (or chips) such as a LED lead frame 202b as shown in
Fig.37. The refractive index of the optical adhesive sheet 8 may range from
1.225 to 1.253. In some embodiments, the thickness of the optical adhesive
sheet 8 may range from 1.1 mm to 1.3 mm. The optical adhesive sheet 8
having a thickness less than 1.1 mm may not be able to cover the LED light
sources 202, while the optical adhesive sheet 8 having a thickness more than
1.3 mmmay reduce light transmittance and increases material cost.
In process of assembling the LED light sources to the LED light strip, the
optical adhesive sheet 8 is firstly applied on the LED light sources 202; then
the insulation adhesive sheet 7 is coated on one side of the LED light strip
2;
then the LED light sources 202 are fixed or mounted on the LED light strip 2;
the other side of the LED light strip2 being opposite to the side of mounting
the
LED light sources 202 is bonded and affixed to the inner surface of the lamp
tube 1 by the adhesive sheet 4; finally, the end cap 3 is fixed to the end
portion
of the lamp tube 1, and the LED light sources 202 and the power supply 5 are
electrically connected by the LED light strip 2. As shown in Fig. 22, the
bendable circuit sheet 2 passes the transition region 103 to be soldered or
traditionally wire-bonded with the power supply 5, and then the end cap 3
having the structure as shown in Fig. 3 or 4 or Fig. 6 is adhered to the
strengthened transition region 103 via methods as shown in Fig. 5 or Fig. 7,
respectively to form a complete LED tube lamp.
In this embodiment, the LED light strip 2 is fixed by the adhesive sheet 4
to an inner circumferential surface of the lamp tube 1, so as to increase the
light illumination angle of the LED tube lamp and broaden the viewing angle to
be greater than 330 degrees. By means of applying the insulation adhesive
58
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
sheet 7 and the optical adhesive sheet 8, electrical insulation of the entire
light
strip 2 is accomplished such that electrical shock would not occur even when
the lamp tube 1 is broken and therefore safety could be improved.
Furthermore, the inner peripheral surface or the outer circumferential
surface of the glass made lamp tube 1 may be covered or coated with an
adhesive film (not shown) to isolate the inside from the outside of the glass
made lamp tube 1 when the glass made lamp tube 1 is broken. In this
embodiment, the adhesive film is coated on the inner peripheral surface of the
lamp tube 1.The material for the coated adhesive film includes methyl vinyl
silicone oil, hydro silicone oil, xylene, and calcium carbonate, wherein
xylene is
used as an auxiliary material.The xylene will be volatilized and removed when
the coated adhesive film on the inner surface of the lamp tube 1 solidifies or
hardens. The xylene is mainly used to adjust the capability of adhesion and
therefore to control the thickness of the coated adhesive film.
In one embodiment, the thickness of the coated adhesive film is in some
embodimentsbetweenabout 100 andabout 140 micrometers (pm). The
adhesive filmhaving a thickness being less than 100 micrometers may not
have sufficient shatterproof capability for the glass tube, and the glass tube
is
thus prone to crack or shatter. The adhesive film having a thickness being
larger than 140 micrometersmay reduce the light transmittance and also
increases material cost. The thickness of the coated adhesive film may be
between about 10 and about 800 micrometers (pm) when the shatterproof
capability and the light transmittance are not strictly demanded.
In this embodiment, the inner peripheral surface or the outer
circumferential surface of the glass made lamp tube 1 is coated with an
adhesive film such that the broken pieces are adhered to the adhesive film
59
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
when the glass made lamp tube is broken. Therefore, the lamp tube 1 would
not be penetrated to form a through hole connecting the inside and outside of
the lamp tube 1 and thus prevents a user from touching any charged object
inside the lamp tube 1 to avoid electrical shock. In addition, the adhesive
film is
able to diffuse light and allows the light to transmit such that the light
uniformity
and the light transmittance of the entire LED tube lamp increases. The
adhesive film can be used in combination with the adhesive sheet 4, the
insulation adhesive sheet 7 and the optical adhesive sheet 8 to constitute
various embodiments of the present invention. As the LED light strip 2 is
configured to be a bendable circuit sheet, no coated adhesive film is thereby
required.
Furthermore, the light strip 2 may be an elongated aluminum plate, FR 4
board, or a bendable circuit sheet. When the lamp tube 1 is made of glass,
adopting a rigid aluminum plate or FR4 board would make a broken lamp tube,
e.g., broken into two parts, remain a straight shapeso that a user may be
under
a false impression that the LED tube lamp is still usable and fully
functional,
and it is easy for him to incur electric shock upon handling or installation
of the
LED tube lamp. Because of added flexibility and bendability of the flexible
substrate for the LED light strip 2, the problem faced by the aluminum plate,
FR4 board, or conventional 3-layered flexible board having inadequate
flexibility and bendability, are thereby addressed. In certain embodiments, a
bendable circuit sheet is adopted as the LED light strip 2 for that such a LED
light strip 2 would not allow a ruptured or broken lamp tube to maintain a
straight shape and therefore instantly inform the user of the disability of
the
LED tube lamp and avoid possibly incurred electrical shock.The following are
further description of the bendable circuit sheet used as the LED light strip
2.
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
Referring to Fig. 23, in one embodiment, the LED light strip 2 includes a
bendable circuit sheet having a conductive wiring layer 2a and a dielectric
layer 2b that are arranged in a stacked manner, wherein the wiring layer 2a
and the dielectric layer 2b have same areas. The LED light source 202 is
disposed on one surface of the wiring layer 2a, the dielectric layer 2b is
disposed on the other surface of the wiring layer 2a that is away from the LED
light sources 202. The wiring layer 2a is electrically connected to the power
supply 5 to carry direct current (DC) signals. Meanwhile, the surface of the
dielectric layer 2b away from the wiring layer 2a is fixed to the inner
circumferential surface of the lamp tube 1 by means of the adhesive sheet
4.The wiring layer 2a can be a metal layer or a power supply layer including
wires such as copper wires.
In another embodiment, the outer surface of the wiring layer 2a or the
dielectric layer 2b may be covered with a circuit protective layer made of an
ink
with function of resisting soldering and increasing reflectivity.
Alternatively, the
dielectric layer can be omitted and the wiring layer can be directly bonded to
the inner circumferential surface of the lamp tube, and the outer surface of
the
wiring layer 2a is coated with the circuit protective layer. Whether the
wiring
layer 2a has a one-layered, or two-layered structure, the circuit protective
layer
can be adopted. The circuit protective layer can be disposed only on one
side/surface of the LED light strip 2, such as the surface having the LED
light
source 202. In some embodiments, the bendable circuit sheet is a one-layered
structure made of just one wiring layer 2a, or a two-layered structure made of
one wiring layer 2a and one dielectric layer 2b, and thus is more bendable or
flexible to curl when compared with the conventional three-layered flexible
substrate (one dielectric layer sandwiched with two wiring layers). As a
result,
61
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
the bendable circuit sheet of the LED light strip 2 can be installed in a lamp
tube with a customized shape or non-tubular shape, and fitly mounted to the
inner surface of the lamp tube. The bendable circuit sheet closely mounted to
the inner surfaceof the lamp tube is preferable in some cases. In addition,
using fewer layers of the bendable circuit sheetim proves the heat dissipation
and lowers the material cost.
Nevertheless, the bendable circuit sheet is not limited to being
one-layered or two-layered; in other embodiments, the bendable circuit sheet
may include multiple layers of the wiring layers 2a and multiple layers of the
dielectric layers 2b, in which the dielectric layers 2b and the wiring layers
2a
are sequentially stacked in a staggered manner, respectively. These staked
layers are away from the surface of the outermost wiring layer 2a which has
the LED light source 202 disposed thereonand is electrically connected to the
power supply 5. Moreover, the length of the bendable circuit sheet is greater
than the length of the lamp tube.
Referring to Fig. 48, in one embodiment, the LED light strip 2 includes a
bendable circuit sheet having in sequence a first wiring layer 2a, a
dielectric
layer 2b, and a second wiring layer 2c. The thickness of thesecond wiring
layer
2c is greater than that of the first wiring layer 2a, and the length of the
LED light
strip2 is greater than that of the lamp tube1. The end region of the light
strip2extending beyond the end portion of the lamp tube 1 without disposition
of the light source 202 is formed with two separate through holes 203 and 204
to respectively electrically communicate the first wiring layer 2a and the
second wiring layer 2c. The through holes 203 and 204 are not communicated
to each other to avoid short.
In this way, the greater thickness of the second wiring layer 2c allow the
62
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
second wiring layer 2c to support the first wiring layer 2a and the dielectric
layer 2b, and meanwhile allow the LED light strip 2 to be mounted onto the
inner circumferential surface without being liable to shift or deform, and
thus
the yield rate of product can be improved. In addition, the first wiring layer
2a
and the second wiring layer 2c are in electrical communication such that the
circuit layout of the first wiring later 2a can be extended downward to the
second wiring layer 2c to reach the circuit layout of the entire LED light
strip2.
Moreover, since the land for the circuit layout becomes two-layered, the area
of each single layer and therefore the width of the LED light strip2 can be
reduced such that more LED light strips 2 can be put on a production line to
increase productivity.
Furthermore, the first wiring layer 2a and the second wiring layer 2c of the
end region of the LED light strip 2 that extends beyond the end portion of the
lamp tube 1 without disposition of the light source 202 can be used to
accomplish the circuit layout of a power supply module so that the power
supply module can be directly disposed on the bendable circuit sheet of the
LED light strip 2.
Referring to Fig. 2, in one embodiment, the LED light strip 2 has a plurality
of LED light sources 202 mounted thereon, and the end cap 3 has a power
supply 5 installed therein. The LED light sources 202 and the power supply 5
are electrically connected by the LED light strip 2. The power supply 5 may be
a single integrated unit (i.e., all of the power supply components are
integrated
into one module unit) installed in one end cap 3. Alternatively, the power
supply 5 may be divided into two separate units (i.e. all of the power supply
components are divided into two parts) installed in two end caps 3,
respectively. When only one end of the lamp tube 1 is strengthened by a glass
63
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
tempering process, it may be preferable that the power supply 5 is a single
integrated unit and installed in the end cap 3 corresponding to the
strengthened end of the lamp tube 1.
The power supply 5 can be fabricated by various ways. For example, the
power supply 5 may be an encapsulation bodyformed by injection molding a
silica gel with high thermal conductivity such as being greater than 0.7w / m
= k.
This kind of power supply has advantages of high electrical insulation, high
heat dissipation, and regular shape to match other components in an assembly.
Alternatively, the power supply 5 in the end caps may be a printed circuit
board
having components that are directly exposed or packaged by a conventional
heat shrink sleeve. The power supply 5 according to some embodiments of the
present invention can be a single printed circuit board provided with a power
supply module as shown in Fig. 23 or a single integrated unit as shown in Fig.
38.
Referring to Figs. 2 and 38, in one embodiment of the present invention,
the power supply 5 is provided with a male plug 51 at one end and a metal pin
52 at the other end, oneend of the LED light strip 2 is correspondingly
provided
with a female plug 201,and the end cap 3 is provided with a hollow conductive
pin 301 to be connected with an outer electrical power source. Specifically,
the
male plug 51 is fittingly inserted into the female plug 201 of the LED light
strip 2,
while the metal pins 52 are fittingly inserted into the hollow conductive pins
301
of the end cap 3. The male plug 51 and the female plug 201 function as a
connector between the power supply 5 and the LED light strip 2. Upon
insertion of the metal pin 502, the hollow conductive pin 301 is punched with
an external punching tool to slightly deform such that the metal pin 502 of
the
power supply 5 is secured and electrically connected to the hollow conductive
64
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
pin 301. Upon turning on the electrical power, the electrical current passes
in
sequence through the hollow conductive pin 301, the metal pin 502, the male
plug 501, and the female plug 201 to reach the LED light strip 2 and go to the
LED light sources 202. However, the power supply 5 of the present invention is
not limited to the modular type as shown in Fig. 38. The power supply 5 may
be a printed circuit board provided with a power supply module and
electrically
connected to the LED light strip 2 via the abovementioned the male plug 51
and female plug 52 combination.
In another embodiment, a traditional wire bonding technique can be used
instead of the male plug 51 and the female plug 52 for connecting any kind of
the power supply 5 and the light strip 2. Furthermore, the wires may be
wrapped with an electrically insulating tube to protect a user from being
electrically shocked. However, the bonded wires tend to be easily broken
during transportation and can therefore cause quality issues.
In still another embodiment, the connection between the power supply 5
and the LED light strip 2 may be accomplished via tin soldering, rivet
bonding,
or welding.Oneway to secure the LED light strip 2 is to provide the adhesive
sheet 4 at one side thereof and adhere the LED light strip 2 to the inner
surface
of the lamp tube 1 via the adhesive sheet 4. Two ends of the LED light strip 2
can be either fixed to or detachedfrom the inner surface of the lamp tube 1.
In case that two ends of the LED light strip 2 are fixed to the inner surface
of the lamp tube 1, it may be preferable that the bendable circuit sheet of
the
LED light strip 2 is provided with the female plug 201 and the power supply is
provided with the male plug 51 to accomplish the connection between the LED
light strip 2 and the power supply 5. In this case, the male plug 51 of the
power
supply 5 is inserted into the female plug 201 to establish electrical
connection.
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
In case that two ends of the LED light strip 2 are detached from the inner
surface of the lamp tube and that the LED light strip 2 is connected to the
power supply 5 via wire-bonding, any movement in subsequent transportation
is likely to cause the bonded wires to break. Therefore, a preferable option
for
the connection between the light strip 2 and the power supply 5 could be
soldering. Specifically, referring to Fig. 22, the ends of the LED light strip
2
including the bendable circuit sheet are arranged to pass over the
strengthened transition region 103 and directly soldering bonded to an output
terminal of the power supply 5 such that the product quality is improved
without
using wires. In this way, the female plug 201 and the male plug 51
respectively
provided for the LED light strip 2 and the power supply 5 are no longer
needed.
Referring to Fig. 24, an output terminal of the printed circuit board of the
power supply 5 may have soldering pads "a" provided with an amount of tin
solder with a thickness sufficient to later form a solder joint.
Correspondingly,
the ends of the LED light strip 2 may have soldering pads "b". The soldering
pads "a" on the output terminal of the printed circuit board of the power
supply
are soldered to the soldering pads "b" on the LED light strip 2 via the tin
solder on the soldering pads "a". The soldering pads "a" and the soldering
pads "b" may be face to face during soldering such that the connection
between the LED light strip 2 and the printed circuit board of the power
supply
5 is the most firm. However, this kind of soldering requires that a
thermo-compression head presses on the rear surface of the LED light strip 2
and heats the tine solder, i.e. the LED light strip 2 intervenes between the
thermo-compression head and the tin solder, and therefor is easily to cause
reliability problems.Referring to Fig. 30, athrough hole may be formed in each
of the soldering pads "b" on the LED light strip 2 to allow the soldering pads
"b"
66
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
overlay the soldering pads "b" without face-to-face and the
thermo-compression head directly presses tin solders on the soldering pads "a"
on surface of the printed circuit board of the power supply 5 when the
soldering
pads "a" and the soldering pads "b" are vertically aligned. This is an easy
way
to accomplish in practice.
Referring again to Fig. 24, two ends of the LED light strip 2 detached from
the
inner surface of the lamp tube 1 are formed as freelyextending portions 21,
while most of the LED light strip 2 is attached and secured to the inner
surface
of the lamp tube 1.0ne of the freely extending portions 21 has the soldering
pads "b" as mentioned above. Upon assembling of the LED tube lamp, the
freely extending end portions 21 along with the soldered connection of the
printed circuit board of the power supply 5 and the LED light strip 2 would be
coiled, curled up or deformed to be fittingly accommodated inside the lamp
tube 1.When the bendable circuit sheet of the LED light strip 2 includes in
sequence the first wiring layer 2a, the dielectric layer 2b, and the second
wiring
layer 2c as shown in Fig. 48, the freely extending end portions 21 can be used
to accomplish the connection between the first wiring layer 2a and the second
wiring layer 2c and arrange the circuit layout of the power supply 5.
In this embodiment, during the connection of the LED light strip 2 and the
power supply 5, the soldering pads "b" and the soldering pads "a"and the LED
light sources 202 are on surfaces facing toward the same direction and the
soldering pads "b" on the LED light strip 2 are each formed with a through
hole
"e"as shown in Fig. 30 such that the soldering pads "b" and the soldering pads
"a" communicate with each other via the through holes "e". When the freely
extending end portions 21 are deformed due to contraction or curling up, the
soldered connection ofthe printed circuit board of the power supply 5 and the
67
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
LED light strip 2 exerts a lateral tension on the power supply 5. Furthermore,
the soldered connection of the printed circuit board of the power supply 5 and
the LED light strip 2 also exerts a downward tension on the power supply
5when compared with the situation where the soldering pads "a" of the power
supply 5 and the soldering pads "b" of the LED light strip 2 are face to face.
This downward tension on the power supply 5 comes from the tin solders
inside the through holes "e" and forms a stronger and more secure electrical
connection between the LED light strip 2 and the power supply 5.
Referring to Fig. 25, in one embodiment, the soldering pads "b" of the LED
light strip 2 are two separate pads to electrically connect the positive and
negativeelectrodes of the bendable circuit sheet of the LED light strip 2,
respectively. The size of the soldering pads "b" may be, for example,about
3.5x2 mm2. The printed circuit board of the power supply 5 is corresponding
provided with soldering pads "a" having reserved tin solders and the height of
the tin solders suitable for subsequent automatic soldering bonding process is
generally, for example, about0.1 to 0.7 mm, in some embodiments 0.3 to 0.5
mm, and in some even more preferable embodimentsabout 0.4mm.
Anelectrically insulating through hole "c" may be formed between the two
soldering pads "b" to isolate and prevent the two soldering pads from
electrically short during soldering. Furthermore, an extrapositioning opening
"d"
may also beprovided behind the electrically insulating through hole "c" to
allow
an automatic soldering machine to quickly recognize the position of the
soldering pads "b".
For the sake of achieving scalability and compatibility, the amount of the
soldering pads "b"on each end of the LED light strip 2 may be more than one
such as two, three, four, or more than four. When there is only one soldering
68
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
pad "b" provided at each end of the LED light strip 2, the two ends of the LED
light strip 2 are electrically connected to the power supply 5 to form a loop,
and
various electrical components can be used. For example, a capacitance may
be replaced by an inductance to perform current regulation. Referring to Fig.
26
to 28, wheneach end of the LED light strip 2 has three soldering pads, the
third
soldering pad can be grounded;when each end of the LED light strip 2 has four
soldering pads, the fourth soldering pad can be used as a signal input
terminal.
Correspondingly, the power supply 5 should has same amount of soldering
pads "a" as that of the soldering pads "b" on the LED light strip 2. As long
as
electrical short between the soldering pads "b" can be prevented, the
soldering
pads "b" should be arranged according to the dimension of the actual area for
disposition,for example, three soldering pads can be arranged in a row or two
rows. In other embodiments, the amount of the soldering pads "b" on the
bendable circuit sheet of the LED light strip 2 may be reduced by
rearrangingthe circuits on the bendable circuit sheet of the LED light strip
2.
The lesser the amount of the soldering pads, the easier the fabrication
process
becomes. On the other hand, a greater number of soldering pads may improve
and secure the electrical connection between the LED light strip 2 and the
output terminal of the power supply 5.
Referring to Fig. 30, in another embodiment, the soldering pads "b" each
is formed with a through hole "e"having a diameter generally of about 1 to 2
mm, in some embodimentsof about 1.2 to 1.8 mm, and in yet some
embodimentsof about 1.5 mm.The through hole "e" communicatesthe
soldering pad "a"with the soldering pad "b" so that the tin solder on the
soldering pads "a" passes throughthe through holes "e" and finally reach the
soldering pads "b". A smaller through holes "e" would make it difficult for
the tin
69
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
solder to pass. The tin solder accumulates around the through holes "e"upon
exiting the through holes "e" and condense to form a solder ball "g" with a
larger diameter than that of the through holes "e" upon condensing. Such a
solder ball "g" functions as a rivet to further increase the stability of the
electrical connection between the soldering pads "a" on the power supply 5
and the soldering pads "b" on the LED light strip 2.
Referring to Figs. 31 to 32, in other embodiments, when a distance from
the through hole "e" to the side edge of the LED light strip 2 is less than 1
mm,
the tin solder maypass throughthe through hole "e" to accumulate on the
periphery of the through hole "e", and extra tin solder may spill over
thesoldering pads "b" to reflow along the side edge of the LED light strip 2
and
join the tin solder on the soldering pads "a" of the power supply 5.The tin
solder
then condenses to form a structure like a rivet to firmly secure the LED light
strip 2 onto the printed circuit board of the power supply 5 such that
reliable
electric connection is achieved. Referring to Fig. 33 and 34, in another
embodiment, the through hole "e" can be replaced by a notch "f" formed at the
side edge of the soldering pads "b" for the tin solder to easily pass through
the
notch "f" and accumulate on the periphery of the notch "f" and to form a
solder
ball with a larger diameter than that of the notch "e" upon condensing. Such a
solder ball may be formedlike a C-shape rivet to enhance the secure capability
of the electrically connecting structure.
The abovementioned through hole "e" or notch "f" might be formed in
advance of soldering or formed by direct punching with a thermo-compression
head, as shown in Fig. 40, during soldering. The portion of the
thermo-compression head for touching the tin solder may be flat, concave, or
convex, or any combination thereof. The portion of the therm 0-compression
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
head for restraining the object to be soldered such as the LED light strip 2
may
be strip-like or grid-like. The portion of the thermo-compression head for
touching the tin solder does not completely cover the through hole "e" or the
notch "f' to make sure that the tin solder is able to pass through the through
hole "e" or the notch "f". The portion of the thermo-compression head being
concave may function as a room to receive the solder ball.
Referring to Fig. 40, athermo-compression head 41 used for bonding the
soldering pads "a" on the power supply 5 and the soldering pads "b" on the
light strip 2 is mainly composed offour sections:a bonding plane 411, a
plurality
ofconcaved guiding tanks 412, a plurality of concaved molding tanks 413, and
a restraining plane 414. The bonding plane 411 is a portionactually touching,
pressing and heating the tin solder to perform soldering bonding. The bonding
plane 411 may be flat, concave, convex or any combination thereof.The
concaved guiding tanks 412 are formed on the bonding plane 411 and opened
near an edge of the bonding plane 411 to guide the heated and melted tin
solder to flow into the through holes or notches formed on the soldering
pads.For example, the guiding tanks 412 may function to guide and stop the
melted tin solders.The concaved molding tanks 413 are positioned beside the
guiding tanks 412 and havea concave portionmore depressed than that of the
guiding tanks 412 such that the concaved molding tanks 413 each form a
housing to receive the solder ball. The restraining plane 414 is a portionnext
to
the bonding plane 411 and formed with the concaved molding tanks 413. The
restraining plane 414 is lower than the bonding plane 411 such that the
restraining plane 414 firmly repress the LED light strip 2 on the printed
circuit
board of the power supply 5 while the bonding plane 411 presses against the
soldering pads "b" during the soldering bonding.The restraining plane 414 may
71
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
be strip-like or grid-like on surface. The difference of height of the bonding
plane 411 and the restraining plane 414 is the thickness of the LED light
strip
2.
Referring to Fig. 41, 25, and 40, soldering pads corresponding to the
soldering pads of the LED light strip are formed on the printed circuit board
of
the power supply 5and tin solder is reservedon the soldering pads on the
printed circuit board of the power supply 5 for subsequent soldering bonding
performed by an automatic soldering bonding machine. The tin solder in some
embodiments has a thickness of about 0.3 to about 0.5 mm such that the LED
light strip 2 can be firmly soldered to the printed circuit board of the power
supply 5. As shown in Fig. 41, in case of having height difference between two
tin solders respectively reserved on two soldering pads on the printed circuit
board of the power supply 5, the higher one will be touched firstly and melted
by the thermo-compression head 41 while the other one will be touched and
start to melt until the higher one is melted to a height the same as the
height of
the other one. This usually incurs unsecured soldering bonding for thereserved
tin solder with smaller height, and therefore affects the electrical
connection
between the LED light strip 2 and the printed circuit board of the power
supply
5. To solve this problem, in one embodiment, the present invention applies the
kinetic equilibrium principal and installs a linkage mechanism on the
thermo-compression head 41 to allow rotation of the thermo-compression
head 41 during a soldering bonding such that the thermo-compression head
41 starts to heat and melt the two reserved tin solders only when the
thermo-compression head 41 detects that the pressure on the two reserved tin
solders are the same.
In the abovementioned embodiment, the thermo-compression head 41 is
72
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
rotatable while the LED light strip 2 and the printed circuit board of the
power
supply 5 remain unmoved. Referring to Fig. 42, in another embodiment, the
thermo-compression head 41 is unmoved while the LED light strip is allowed to
rotate. In this embodiment, the LED light strip 2 and the printed circuit
board of
the power supply 5 are loaded on a soldering vehicle 60 including a rotary
platform 61, a vehicle holder 62, arotating shaft 63, and two elastic members
64.The rotary platform 61 functions to carry the LED light strip 2 and the
printed circuit board of the power supply 5. The rotary platform 61 is movably
mounted to the vehicle holder 62 via the rotating shaft63 so that the rotary
platform 61 is able to rotate with respect to the vehicle holder 62 whilethe
vehicle holder 62 bearsand holds the rotary platform 61. The two elastic
members 64 are disposed on two sides of the rotating shaft 63, respectively,
such that the rotary platform 61 in connection with the rotating 5haft63
always
remains at the horizontal level when the rotary platform61 is not loaded. In
this
embodiment, the elastic members 64 are springs for example, and the ends
thereof are disposed corresponding to two sides of the rotating shaft 63 so as
to function as two pivots on the vehicle holder 62. As shown in Fig. 42, when
two tin solders reserved on the LED light strip 2 pressed by the
thermo-compression head 41 are not at the same height level, the rotary
platform 61 carrying the LED light strip 2 and the printed circuit board of
the
power supply 5 will be driven by the arotating shaft 63 to rotate until the
thermo-compression head 41 detects same pressure on the two reserved tin
solders, and then starts a soldering bond ing.Referring to Fig. 43, when the
rotary platform 61 rotates, the elastic members 64 at two sides of the
rotating
shaft 63 are compressed or pulled; and the driving force of the rotating shaft
63
releases and the rotary platform 61 returns to the original height level by
the
73
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
resilience of the elastic members 64 when the soldering bonding is completed.
In other embodiments, the rotary platform 61 may be designed to have
mechanisms withoutusing the rotating shaft 63 and the elastic members 64.
For example, the rotary platform 61 may be designed to have driving motors
and active rotary mechanisms, and therefore the vehicle holder 62 is saved.
Accordingly, any other embodiments utilizing the kinetic equilibrium principle
to
drive the LED light strip 2 and the printed circuit board of the power supply
5 to
move in order to complete the soldering bonding process are within the spirit
of
the present invention.
Referring to Figs. 35 and 36, in another embodiment, the LED light strip 2
and the power supply 5 may be connected by utilizing a circuit board assembly
25 instead of soldering bonding. The circuit board assembly 25 has a long
circuit sheet 251 and a short circuit board 253 that are adhered to each other
with the short circuit board 253 being adjacent to the side edge of the long
circuit sheet 251. The short circuit board 253 may be provided with power
supply module 250 to form the power supply 5. The short circuit board 253 is
stiffer or more rigid than the long circuit sheet251 to be able to support the
power supply module 250.
The long circuit sheet251 may be the bendable circuit sheet of the LED
light strip including a wiring layer 2a as shown in Fig. 23. The wiring layer
2a of
the long circuit sheet 251 and the power supply module 250 may be electrically
connected in various manners depending on the demand in practice. As
shown in Fig. 35, the power supply module 250 and the long circuit sheet 251
having the wiring layer 2a on surface are on the same side of the short
circuit
board 253 such that the power supply module 250 is directly connected to the
long circuit sheet 251. As shown in Fig. 36, alternatively, the power supply
74
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
module 250 and the long circuit sheet 251 including the wiring layer 2a on
surface are on opposite sides of the short circuit board 253 such that the
power supply module 250 is directly connected to the short circuit board 253
and indirectly connected to the wiring layer 2a of the LED light strip 2 by
way of
the short circuit board 253.
As shown in Fig. 35, in one embodiment, the long circuit sheet 251 and
the short circuit board 253 are adhered together in the first place, and the
power supply module 250 is subsequently mounted on the wiring layer 2a of
the long circuit sheet 251 serving as the LED light strip 2. The long circuit
sheet
251 of the LED light strip 2 herein is not limited to include only one wiring
layer
2a and may further include another wiring layer such as the wiring layer 2c
shown in Fig. 48. The light sources 202 are disposed on the wiring layer 2a of
the LED light strip 2 and electrically connected to the power supply 5 by way
of
the wiring layer 2a.As shown in Fig. 36, in another embodiment, the long
circuit
sheet 251 of the LED light strip 2 may include a wiring layer 2a and a
dielectric
layer 2b.The dielectric layer 2b maybe adhered to the short circuit board 253
in
a first place and the wiring layer 2a is subsequently adhered to the
dielectric
layer 2b and extends to the short circuit board 253.AII these embodiments are
within the scope of applying the circuit board assembly concept of the present
invention.
In the above-mentioned embodiments, the short circuit board 253 may
have a length generally of about 15mm to about 40 mm and in some
embodimentsabout 19 mm to about 36 mm, while the long circuit sheet251
may have a length generally of about 800 mm to about 2800mm and in some
embodiments of about 1200 mm to about 2400 mm. A ratio of the length of the
short circuit board 253 to the length of the long circuit sheet251 ranges
from,
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
for exam ple,about 1:20 to about 1:200.
When the ends of the LED light strip 2 are not fixed on the inner surface of
the lamp tube 1, the connection between the LED light strip 2 and the power
supply 5via soldering bonding could not firmly support the power supply 5, and
it may be necessary to dispose the power supply 5 inside the end cap 3. For
example, a longer end cap to have enough space for receiving the power
supply 5 would be needed.However, this will reduce the length of the lamp
tube under the prerequisite that the total length of the LED tube lamp is
fixed
according to the product standard, and may therefore decrease the effective
illuminating areas.
Referring to Fig. 39, in one embodiment, a hard circuit board 22 made of
aluminum is used instead of the bendable circuit sheet, such that the ends or
terminals of the hard circuit board 22 can be mounted at ends of the lamp tube
1, and the power supply 5 is soldering bonded to one of the ends or terminals
of the hard circuit board 22 in a manner that the printed circuit board of the
power supply 5 is not parallel but may be perpendicular to the hard circuit
board 22 to save space in the longitudinal direction needed for the end cap.
This soldering bonding technique is more convenient to accomplish and the
effective illuminating areas of the LED tube lamp could also be remained.
Moreover, a conductive lead 53 for electrical connection with the end cap 3
could be formed directly on the power supply 5 without soldering other metal
wires between the power supply 5 and the hollow conductive pin 301 as shown
in Fig. 3, and which facilitates the manufacturing of the LED tube lamp.
Referring to Fig. 37, in one embodiment, each of the LED light sources
202 may be provided with a LED lead frame 202b having arecess 202a, and
an LED chip 18 disposed in the recess 202a. The recess 202a may be one or
76
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
more than one in amount. The recess 202a may be filled with phosphor
covering the LED chip 18 to convert emitted light therefrom into a desired
light
color. Compared with a conventional LED chip beinga substantial square, the
LED chip 18 in this embodiment is in some embodimentsrectangular with the
dimension of the length side to the width side at a ratio rangesgenerally from
about 2:1 to about 10:1, in some embodiments from about 2.5:1 to about 5:1,
and in some more desirable embodimentsfrom 3:1 to 4.5:1. Moreover, the LED
chip 18 is in some embodimentsarranged with its length direction extending
along the length direction of the lamp tube 1 to increase the average current
density of the LED chip 18 and improve the overall illumination field shape of
the lamp tube 1. The lamp tube 1 may have a number of LED light sources 202
arranged into one or more rows, and each row of the LED light sources 202 is
arranged along the length direction (Y-direction) of the lamp tube 1.
Referring again to Fig. 37, the recess 202a is enclosed by two parallel first
sidewalls 15 and two parallel second sidewalls 16 with the first sidewalls 15
being lower than the second sidewalls 16. The two first sidewalls 15 are
arranged to be locatedalong a length direction (Y-direction) of the lamp tube
1
and extend along the width direction (X-direction) of the lamp tube 1, and two
second sidewalls 16 are arranged to be locatedalong a width direction
(X-direction) of the lamp tube 1 and extend along the length direction
(Y-direction) of the lamp tube 1.The extending direction of the first
sidewalls 15
is required to be substantially rather than exactly parallel to the width
direction
(X-direction) of the lamp tube 1, and the first sidewalls may have various
outlines such as zigzag, curved, wavy, and the like. Similarly, the extending
direction of the second sidewalls 16 is required to be substantially rather
than
exactly parallel to the length direction (Y-direction) of the lamp tube 1, and
the
77
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
second sidewalls may have various outlines such as zigzag, curved, wavy, and
the like. In one row of the LED light sources 202, the arrangement of the
first
sidewalls 15 and the second sidewalls 16 for each LED light source 202 can
be same or different.
Having the first sidewalls 15 being lower than the second sidewalls 16 and
proper distance arrangement, the LED lead frame 202b allows dispersion of
the light illumination to cross over the LED lead frame 202b without causing
uncomfortable visual feeling to people observing the LED tube lamp along the
Y-direction. The first sidewalls 15 may to be lower than the second sidewalls,
however, and in this case each rows of the LED light sources 202 are more
closely arranged to reduce grainy effects. On the other hand, when a user of
the LED tube lamp observes the lamp tube thereof along the X-direction, the
second sidewalls 16 also can block user's line of sight from seeing the LED
light sources 202, and which reduces unpleasing grainy effects.
Referring again to Fig. 37, the first sidewalls 15 each includes an inner
surface 15a facing toward outside of the recess 202a. The inner surface 15a
maybe designed to be an inclined planesuch that the light illumination easily
crosses over the first sidewalls 15 and spreads out.The inclined plane of the
inner surface 15a may be flat or cambered or combined shape. When the
inclined plane is flat, the slope of the inner surface 15a rangesfrom about 30
degrees to about 60 degrees. Thus, an included angle between the bottom
surface of the recess 202a and the inner surface 15a may range from about
120 toabout 150 degrees. In some embodiments, the slope of the inner
surface 15a ranges from about 15 degrees to about 75 degrees, and the
included angle between the bottom surface of the recess 202a and the inner
surface 15a ranges from about 105 degrees to about 165 degrees.
78
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
There may be one row or several rows of the LED light sources 202
arranged in a length direction (Y-direction) of the lamp tube 1. In case of
one
row, in one embodiment the second sidewalls 16 of the LED lead frames 202b
of all of the LED light sources 202 located in the same row are disposed in
same straight lines to respectively from two walls for blocking user's line of
sight seeing the LED light sources 202.In case of several rows, in one
embodiment only the LED lead frames 202b of the LED light sources 202
disposed in the outermost two rowsare disposed in same straight lines to
respectively form walls for blocking user's line of sight seeing the LED light
sources 202. The LED lead frames 202b of the LED light sources 202
disposed in the other rows can have different arrangements.For example, as
far as the LED light sources 202 located in the middle row (third row) are
concerned, the LED lead frames 202b thereof maybe arranged such that: each
LED lead frame 202b has the first sidewalls 15 arranged along the length
direction (Y-direction) of the lamp tube 1 with the second sidewalls 16
arranged
along in the width direction (X-direction) of the lamp tube 1; each LED lead
frame 202b has the first sidewalls 15 arranged along the width direction
(X-direction) of the lamp tube 1 with the second sidewalls 16 arranged along
the length direction (Y-direction) of the lamp tube 1; or the LED lead frames
202b are arranged in a staggered manner.To reduce grainy effects caused by
the LED light sources 202 when a user of the LED tube lamp observes the
lamp tube thereof along the X-direction, it may be enough to havethe second
sidewalls 16 of the LED lead frames 202b of the LED light sources 202 located
in the outmost rows to block user's line of sight from seeing the LED light
sources 202.Different arrangement may be used for the second sidewalls 16 of
the LED lead frames 202b of one or several of the LED light sources 202
79
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
located in the outmost two rows.
In summary, when a plurality of the LED light sources 202 are arranged in
a row extending along the length direction of the lamp tube 1, the second
sidewalls 16 of the LED lead frames 202b of all of the LED light sources 202
located in the same row may be disposed in same straight lines to respectively
formwalls for blocking user's line of sight seeing the LED light sources 202.
When a plurality of the LED light sources 202 are arranged in a number of
rows being located along the width direction of the lamp tube 1 and extending
along the length direction of the lamp tube 1,the second sidewalls 16 of the
LED lead frames 202b of all of the LED light sources 202 located in the
outmost two rows may be disposed in straight lines to respectively from two
walls for blocking user's line of sight seeing the LED light sources 202. The
one or more than one rows located between the outmost rows may have the
first sidewalls 15 and the second sidewalls 16 arranged in a way the same as
or different from that for the outmost rows.
The LED tube lamps according to various different embodiments of the
present invention are described as above.With respect to an entire LED tube
lamp, the features including "having the structure-strengthened end region",
"adopting the bendable circuit sheet as the LED light strip", "coating the
adhesive film on the inner surface of the lamp tube", "coating the diffusion
film
on the inner surface of the lamp tube", "covering the diffusion film in form
of a
sheet above the LED light sources", "coating the reflective film on the inner
surface of the lamp tube", "the end cap including the thermal conductive
member", "the end cap including the magnetic metal member", "the LED light
source being provided with the lead frame", and "utilizing the circuit board
assembly to connect the LED light strip and the power supply" may be applied
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
in practice singly or integrally such that only one of the features is
practiced or
a number of the features are simultaneously practiced.
Furthermore, any of the features"having the structure-strengthened end
region", "adopting the bendable circuit sheet as the LED light strip",
"coating
the adhesive film on the inner surface of the lamp tube", "coating the
diffusion
film on the inner surface of the lamp tube", "covering the diffusion film in
form
of a sheet above the LED light sources", "coating the reflective film on the
inner
surface of the lamp tube", "the end cap including the thermal conductive
member", "the end cap including the magnetic metal member", "the LED light
source being provided with the lead frame", and "utilizing the circuit board
assembly to connect the LED light strip and the power supply" includes any
related technical points and their variations and any combination thereof as
described in the abovementioned embodiments of the present invention.
As an example, the feature "having the structure-strengthened end region"
may include "the lamp tube includes a main body region, a plurality of rear
end
regions, and a transition region connecting the main body region and the rear
end regions, wherein the two ends of the transition region are arc-shaped in a
cross-section view along the axial direction of the lamp tube; the rear end
regions are respectively sleeved with end caps; the outer diameter of at least
one of the rear end regions is less than the outer diameter of the main body
region; the end caps have same outer diameters as that of the main body
region."
As an example, the feature "adopting the bendable circuit sheet as the
LED light strip" may include "the connection between the bendable circuit
sheet and the power supply is by way of wire bonding or soldering bonding; the
bendable circuit sheet includes a wiring layer and a dielectric layer arranged
in
81
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
a stacked manner; the bendable circuit sheet has a circuit protective layer
made of ink to reflect lights and has widened part along the circumferential
direction of the lamp tube to function as a reflective film."
As an example, the feature"coating the diffusion film on the inner surface of
the
lamp tube" may include "the composition of the diffusion film includes calcium
carbonate, halogen calcium phosphate and aluminum oxide, or any
combination thereof, and may further include thickener and a ceramic
activated carbon; the diffusion film may be a sheet covering the LED light
source."
As an example, the feature"coating the reflective film on the inner surface
of the lamp tube" may include "the LED light sources are disposed above the
reflective film, within an opening in the reflective film or beside the
reflective
film."
As an example, the feature"the end cap including the thermal conductive
member" may include "the end cap includes an electrically insulating tube, the
hot melt adhesive is partially or completely filled in the accommodation space
between the inner surface of the thermal conductive member and the outer
surface of the lamp tube." The feature "the end cap including the magnetic
metal member" includes "the magnetic metal member is circular or non-circular,
has openings or indentation/embossment to reduce the contact area between
the inner peripheral surface of the electrically insulating tube and the outer
surface of the magnetic metal member; has supporting portions and protruding
portions to support the magnetic metal member or reduce the contact area
between the electrically insulating tube and the magnetic metal member."
As an example, the feature "the LED light source being provided with the
lead frame" may include "the lead frame has a recess for receive an LED chip,
82
CA 02961974 2017-03-21
WO 2016/045633
PCT/CN2015/090859
the recess is enclosed by first sidewalls and second sidewalls with the first
sidewalls being lower than the second sidewalls, wherein the first sidewalls
are
arranged to locate along a length direction of the lamp tube while the second
sidewalls are arranged to locate along a width direction of the lamp tube."
As an example, the feature"utilizing the circuit board assembly to connect the
LED light strip and the power supply" may include "the circuit board assembly
has a long circuit sheet and a short circuit board that are adhered to each
other
with the short circuit board being adjacent to the side edge of the long
circuit
sheet; the short circuit board is provided with a power supply module to form
the power supply; the short circuit board is stiffer than the long circuit
sheet."
The above-mentioned features of the present invention can be
accomplished in any combination to improve the LED tube lamp, and the
above embodiments are described by way of example only. The present
invention is not herein limited, and many variations are possible without
departing from the spirit of the present invention and the scope as defined in
the appended claims.
83
