Note: Descriptions are shown in the official language in which they were submitted.
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CA 02389631 2001-06-06
TITLE: MODULAR LED CIRCUIT BOARD
FIELD OF THE INVENTION
The invention relates generally to modular LED circuit boards for use in
constructing LED signs
and displays and general illumination.
BACKGROUND OF THE INVENTION
LED displays are finding application in a variety of products. Display signs,
advertising
signs and lighting fixtures are a few examples. A majority of these LED
displays use a plurality
of LEDs mounted on a circuit board. For a majority of applications, each LED
display requires a
custom LED circuit board. As can be appreciated, the costs of manufacturing
custom circuit
boards can be quite high. To overcome the high cost of manufacturing custom
LED boards, one
approach has been to build LED displays from a plurality of modular LED
boards. This
approach does reduce the cost of manufacturing a LED display; however, this
still requires the
step of assembling a plurality of smaller LED boards to form a display. In
some cases, the cost
of assembling a suitable frame to mount the smaller LED boards may be as great
as
manufacturing a custom board. A modular LED board which is more versatile is
therefore
required.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a modular LED
circuit board
consisting of a circuit board being frangible along a first and second set of
intersecting
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CA 02389631 2001-06-06
fragmentation lines, the fragmentation lines dividing the circuit board into a
plurality of sections.
A plurality of LEDs are mounted to the circuit board, at least one LED being
mounted to each
section, each section having a sub-circuit operatively coupled to the LED,
each sub-circuit having
a positive and negative lead.
With the foregoing in view, and other advantages as will become apparent to
those skilled
in the art to which this invention relates as this specification proceeds, the
invention is herein
described by reference to the accompanying drawings forming a part hereof,
which includes a
description of the preferred typical embodiment of the principles of the
present invention.
DESCRIPTION OF THE DRAWINGS
FIGURE 1. is a perspective view of a circuit board made in accordance with the
invention.
FIGURE 2. is a perspective view of the circuit board shown in figure 1 which
has been
fragmented into several fragments in accordance with the invention.
FIGURE 3. is a top view of a circuit board made in accordance with the
invention.
FIGURE 4. is a top view of a fragment of the circuit board shown in figure 3.
FIGURE 5. is a top view of a section of the fragment shown in figure 4 showing
the sub-
circuit.
FIGURE 6. is a side view of the section shown in figure 5.
FIGURE 7. is a schematic view of the circuit of the circuit board shown in
figure 3.
In the drawings like characters of reference indicate corresponding parts in
the different
figures.
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CA 02389631 2001-06-06
DETAILED DESCRIPTION OF THE INVENTION
Refernng firstly to figures l and 2, the present invention is a modular LED
circuit board,
shown generally as item 10 which consists of a circuit board 12 which is
frangible along
intersecting fragmentation lines 14 and 16. Fragmentation lines 14 and 16
divide circuit board
12 into a plurality of modules 18. Each module 18 has LED's 20 mounted
thereto. Preferably,
circuit board 12 comprises a standard pre-printed circuit board. Fragmentation
lines 14 and 16
may be either deep score lines or perforation lines.
Preferably, fragmentation lines 14 and 16 are arranged at right angles to each
other such
that modules 18 are rectangular. By arranging fragmentation lines 14 and 16 in
a grid, board 12
may be broken into smaller fragments of various sizes and shapes. In the
example illustrated in
figure 2, board 12 has been broken into fragments 22, 24, 26, 28, 30, 32, 34
and 36 by breaking
the board along the fragmentation lines. The smallest of these fragments, 26,
is only the size of
one module 18. Each of these fragments will have at least one LED mounted
thereon.
While the particular arrangement of fragmentation lines illustrated in the
drawings results
in rectangular modules, it will be appreciated that any pattern of
intersecting fragmentation lines
may be used depending on the desired shape of the resulting modules. By
selecting an
appropriate pattern of intersecting fragmentation lines, square and even
triangular modules may
be created.
Referring now to figure 3, each module 18 has two LED's 20 mounted thereon.
Any
suitable LED or LED die may be used, however, surface mount LEDs are
particularly useful.
Each module 18 has a sub-circuit (see figure 5) operatively coupled to LED's
20. The sub-circuit
has positive leads 40 and negative leads 42. Supplying a suitable electric
current to leads 40 and
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CA 02389631 2001-06-06
42 will cause LED's 20 to glow. Leads 40 and 42 of adjacent modules 18 are
operatively
coupled to each other such that when a suitable electric current is supplied
to any pair of leads 40
and 42, all of the LED's on board 12 will glow.
Referring now to figure 4, a board fragment 13 is shown having a plurality of
rectangular
module 18. Each section 18 is rectangular and has opposite ends 44 and
opposite sides 46
formed by fragmentation lines 16 and 14, respectively. The corners of sections
18 are formed
from cross shaped apertures 48. Fragmentation lines 14 are basically
perforated lines formed of
apertures 50 and apertures 48. Likewise, fragmentation lines 16 are formed
from apertures 52
and apertures 48. Adjacent sections 18 are connected together along opposite
sides 46 by bridges
54. Likewise, adjacent modules 18 are connected together along opposite ends
44 by bridges 56.
Each module 18 is provided with at least one positive lead 40 positioned at
each end 44 and each
side 46. Likewise, each module 18 is provided with at least one negative lead
42 positioned at
each end 44 and each side 46. Hence, each module 18 will have four positive
and four negative
terminals. Providing four positive and negative terminals on each module
greatly increases the
flexibility of each module, since it can be supplied with electrical power
from any side or end.
Leads 40 and 42 extend across bridges 54 and 56 such that the leads of
adjacent modules
18 are electrically coupled to each other. Hence, suppling any positive and
negative lead on
board fragment 13 with an appropriate current will cause all of the LED's on
the fragment to
light. Board fragment 13 can be broken into still smaller fragments by
breaking the board along
one or more fragmentation lines. When fragment 13 is broken along a
fragmentation line, the
bridges linking adjacent rectangular modules 18 are broken, and the leads
which cross those
bridges are separated. For example, if sections 19, 21 and 23 are to be broken
off to form a
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CA 02389631 2001-06-06
separate fragment, fragment 13 is broken along fragmentation line 16A to break
bridges 56.
Sections 19, 21 and 23 forming the smaller fragment will still be linked
together by bridges 54.
Since bridges 54 will be intact, supplying power to any negative terminal 42
on fragment 23 and
any positive terminal 40 on fragment 19 will cause all the LED in the smaller
fragment to light
up.
Apertures 48 are dimensioned and configured to receive a mounting screw (not
shown) to
permit the fragment to be easily mounted to a suitable housing by attaching
the fragment to the
housing via a plurality of mounting screws. Fragment 13 also has apertures 73
positioned
between adjacent modules 18 and apertures 71 positioned at the center of each
module.
Apertures 73 and 71 are likewise dimensioned to receive a mounting screw.
Apertures 48 are
positioned along fragmentation lines 16 and 16A while apertures 73 are
positioned along
fragmentation lines 14. Hence apertures 48 and 73 act as both a mounting
mechanism and also
as part of the fragmentation lines.
Referring now to figures 5 and 6, each rectangular module 18 will have a sub-
circuit 58
printed onto board material 12. Sub-circuit 58 will generally comprise
conductors 60 and 62
which are part of a layer of conductive material embedded in board material 12
which was etched
with a suitable circuit pattern. Conductor 60 is laid out such that it
electrically couples all of the
positive leads 40 together. Conductor 60 also connects to the positive sides
of both LEDs 20.
Likewise, conductor 62 is laid out such that it electrically couples all of
the negative leads 42
together and the negative sides of both LEDs 20. Preferably, conductors 60 and
62 are made as
thick as possible in order to act as a heat sink for LED's 20. A resistor
element 64 may be
incorporated into circuit 58 in order to limit the current flowing through
LED's 20. A suitable
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CA 02389631 2001-06-06
resistor can be selected depending on the current and voltage rating of the
LEDs 20 and the
desired amount of luminous flux. Each module 18 will be provided with aperture
?1, which is
dimensioned and configure to receive a mounting screw or bolt. Aperture 71
ensures that each
module 18 can be easily mounted to what ever housing is desired.
As mentioned previously, preferably, sections 18 are electrically coupled to
each other in
a parallel circuit such that supplying all the LEDs with current can be
achieved by supplying
current to any pair of positive and negative leads. A suitable circuit diagram
is shown in figure 7.
Each section 18 has a sub-circuit 66. Sub-circuits 66 of adjacent sections 18
are electrically
coupled together in parallel to from a larger circuit 68. Larger circuit 68
may be supplied with
electrical power via terminals ?0. It will be appreciated that figure 7
represents a schematic
representation of the entire circuit of LED's on board 12. Terminal 70
corresponds to terminals
40 and 42 of each module 18 (see figure 6).
Referring back to figures 1 and 2, a user can start with LED circuit board 12
to form
numerous circuit board fragments of useful size and shape. For example, if the
user wishes to
create an "L" shaped LED circuit board in order to manufacture a portion of an
advertising
display sign, the user can simply break board 12 along fragmentation lines 14
and 16 to create
fragment 22 having the desired shape. Various sizes and shapes of circuit
board fragments can
be created simply by breaking the circuit board along the appropriate
fragmentation lines. Each
of the resulting fragments can be easily wired up to a suitable power source
to form a functioning
LED module. The current and voltage will depend on the number of LEDs on the
fragment.
A specific embodiment of the present invention has been disclosed; however,
several
variations of the disclosed embodiment could be envisioned as within the scope
of this invention.
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CA 02389631 2001-06-06
It is to be understood that the present invention is not limited to the
embodiments described
above, but encompasses any and all embodiments within the scope of the
following claims.
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