Note: Descriptions are shown in the official language in which they were submitted.
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BACK AND EDGE-ILLUMINATED SIGN
BACKGROUND OF THE INVENTION
The present invention relates to back and edge-illuminated sign, particularly
for use as an
advertising sign, an informative sign, a road sign, or the like.
Edge-illuminated signs are known in which a panel of transparent material is
illuminated by light
sources disposed along at least one edge thereof so that light passes through
the panel material in a
direction along the plane of the panel. An image to be displayed is formed on
one of the faces of the
panel whereby the light contrast between the image and the remainder of the
panel increases the visual
impact of the image to a person viewing the sign. A typical known edge-
illuminated sign is disclosed
in the Wragg U.S. Pat. No. 4,373,282 published on February 15, 1983. Wragg
discloses an
illuminator in which light is introduced through one edge of a transparent
substrate having front and
back plane parallel opposed surfaces. The back surface is textured with a
multiplicity of shallow
depressions such as grooves or dimples which have shallow sloped sides such
that light is selectively
directed from the interior of the substrate through a limited angle out of the
substrate towards a
display surface adjacent and coextensive with the back surface of the
substrate and away from a
viewer observing the display surface through the substrate.
Other edge-illuminated signs are also disclosed in the Trusiani U.S. Pat. No.
5,369,553
published on November 29, 1994 and U.S. Pat. No. 5,636,914 published on June
10, 1997. Trusiani
discloses an illuminated panel device comprising a clear or transparent panel
of acrylic material having
a plurality of cut-out lines in a predetermined arrangement to form the
peripheral edges of a pictorial
representation. A lighting unit is secured to the peripheral edge of the panel
and is used to illuminate
the cut-out lines so that the pictorial representation stands out from the
remainder of the panel.
One disadvantage of these known edge-illuminated signs is that it is not
possible to achieve the
illumination of different areas of the pictorial representation with different
colours. Another
disadvantage is that there is nothing provided in order to prevent undesired
loss of light.
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BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel and improved
illuminated sign for
illumination of different portions of the sign with different colours.
Another object of the present invention is to prevent undesired loss of light
in an illuminated
sign.
Still another object is to provide an illuminated sign which can be cheaply
and easily fabricated,
and which can be electrically supplied with a low energy consumption system.
These and other objects and advantages are accomplished in an illuminated sign
in which light is
introduced through one side of a multiplicity of sloped sides grooves provided
on the back surface of
an intermediate transparent substrate. In fact, the light is selectively
directed from the interior of the
substrate through a metallized polyester reflective film towards one side of
the grooves. The
metallized polyester reflective film is translucent on the side facing the
light and reflective on its
opposed side to concentrate the light into the grooves. Another portion of the
sign is illuminated by
backlighting a coloured translucent film provided on a flat portion of the
back surface of the sign. In
this case, the light are directed from the back of the substrate through the
metallized polyester
reflective film towards the coloured translucent film. Again , the metallized
polyester reflective film is
used to allow the light to pass through its translucent side and then
concentrate the light on the
coloured translucent film because of its reflective side. Thus, it is possible
by way of this invention to
illuminate different portions of a pictorial representation with different
colours since the lights are
positioned along the periphery of the grooves and that portions between the
grooves can be
illuminated using backlighting in conjunction with the coloured translucent
film.
The lighting elements may be of any conventional light source, but in order to
provide the
illuminated sign with an energy-saving illumination, the light sources that
can be used are light
emitting diodes (LEDs) or ultraviolet laser diodes (UVLDs) which are connected
in parallel to a low-
voltage electrical feeding system.
The LEDs or UVLDs used can be of all the same colour or of different colours,
so as to
produce various colour effects. Any desired colour could be obtained using
LEDs or UVLDs in
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conjunction with the coloured translucent film or a coloured transparent
liquid (fluorescent gel) which
is solidified within the grooves. For example, different shades of red could
be obtained by providing a
red LED having a given shade and modifying its shade using a red translucent
film of a different
shade.
A multiplicity of coloured LEDs are available on the market. There is the red
LED that oscillate
at 660Nm, the yellow LED that oscillate at 580Nm, the green LED that oscillate
at 568Nm or
525Nm, the blue LED that oscillate at 470Nm, the white or any combination of
those coloured LEDs.
The UVLDs must be used in conjunction with the solidified coloured transparent
liquid or any
other translucent material that will absorb all the energy coming from the
laser beam and will then
provide an incredible luminosity. The UVLDs are oscillating at wavelengths of
between INm and
420Nm, these wavelengths covering the ultraviolet electromagnetic spectrum.
The low-voltage electrical feeding system could be a photovoltaic module which
is set to follow
the suri s trajectory with the aid of a motor which is driven at 12 to 24
volts of direct current (DC).
A rechargeable battery will be used in conjunction with the photovoltaic
module and will be charged
by the latter in order to provide illumination of the sign during the night.
Moreover, a handle will be
used to manually tilt the photovoltaic module in order to perform the seasonal
adjustments due to the
different positions of the sun throughout the seasons.
A second embodiment of the low-voltage electrical feeding system is the use of
an AC/DC
(alternating current to direct current) converter that will directly feed the
illuminated sign. The
converter could also be used to charge a battery that will be used in case of
a power failure.
A third embodiment of the low-voltage electrical feeding system concerns the
use of a simple
low-voltage battery that will be replaced when necessary.
Other electronic elements could also be used in conjunction with the
aforementioned
embodiments of the low-voltage electrical feeding system in order to provide
intermittent illumination
of the sign.
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BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The present invention will be better understood from the following detailed
description of some
preferred embodiments of the invention, taken in conjunction with the
accompanying drawings, in
which like reference numerals refer to like parts, and in which:
FIG. 1 is a cross-sectional view of the illuminated sign of the invention
showing the combination
of back and edge illumination.
FIG. 2 is a rear view of the illuminated sign showing the position of the
light source within the
channels for edge illumination of the grooves.
FIG. 3 is a top view of the illuminated sign showing the front rectangular
panel of opaque
material.
FIG. 4 is a schematic view of the low-voltage electrical feeding system
showing all the
components being part of the three different embodiments of the low-voltage
electrical feeding system
for the illumination of the illuminated sign of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS 1 to 3 of the drawings illustrate an illuminated sign ( I ) according to
a first embodiment of
the invention. The sign ( 1 ) basically comprises an intermediate flat
rectangular panel (2) of light
transmitting material which may be transparent or translucent, such as acrylic
plexiglass, well known
under the trademark LEXANTM, or similar materials. The intermediate panel (2)
is provided with
sloped sides grooves (3) illustrating a pictorial representation such as a
logo accompanied with some
advertising text. The sloped sides grooves (3) may be formed by grinding or
molding the back
surface of the panel (2). The grooves (3) are edge-illuminated along their
contour lines by light
emitting diodes (LEDs) (4) that projects their light through the translucent
side of a metallized
polyester reflective film (5) before impinging upon one side of the grooves
(3).
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The surface areas (~ extending between the grooves (3) are back-illuminated by
LEDs (7) that
projects their light through the translucent side of the metallized polyester
reflective film (5) before
impinging upon a coloured translucent film (8) stuck to the flat back surface
of the intermediate panel
(2). It is noted that coloured translucent film (8) is only covering the
surface areas (6) that needed to
be illuminated.
The LEDs (4) are embedded into channels (9) running along the outer periphery
of the grooves
(3) while the LEDs (7) are embedded into through bores (10) drilled into a
back rectangular panel
( 11 ) of light transmitting material and similar to the intermediate
rectangular panel (2).
In order to prevent any loss of light, a reflective film ( 12) is provided on
the side surface of the
channels (9) facing the back of the LEDs (4) and extends to the bottom of the
channels (9). A similar
reflective film (13) is also provided on the front surface of the back panel
(11). Thus, the LEDs (4)
are surrounded with reflective films ( 12, 13 ) except for the surface of the
channels (9) facing the
LEDs (4) where the rays of the LEDs (4) must pass to illuminate the grooves
(3). In this way, all the
light coming from the LEDs (4) can be concentrate into the grooves (3) to
obtain a maximum of
lumino sity.
The illuminated sign (1) also comprises a front rectangular panel (14) of
opaque material, such
as Gravol PIyTM, having openings (15) corresponding to the grooves (3). The
front panel (14) is
preferably composed of two layers of different colours so that shallow grooves
(16) can be made to
illustrate a logo or any advertising text that will not be illuminated. The
front rectangular panel (14)
is essentially used to hide the LEDs (4) to a viewer of the sign (1). The
three panels (2, 11 and 14)
are brought together as shown in FIG. 1 and are held in that position with the
aid of a frame (17).
FIG. 4 schematically illustrates all the components used in the realization of
the three different
embodiments of a low-voltage electrical system (18) of the illuminated sign
(1). The first
embodiment comprises the use of a photovoltaic module (19) to accumulate the
solar energy into a
rechargeable battery (20) of a suitable dimension for feeding the illuminated
sign (1). Thus, the
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photovoltaic module (19) will be used to feed the battery (20) during the day
in order to illuminate
the sign (1) during the night. The photovoltaic module (19) also comprises a
handle (not shown) to
manually tilt the photovoltaic module (19) in order to perform seasonal
adjustments. Moreover, the
first embodiment of the low-voltage electrical feeding system (18) comprises a
safety diode (21) that
will automatically cut off the current that feeds the battery (20) when the
latter is fully charged.
The second embodiment comprises the use of an AC/DC (alternating current to
direct current)
converter (22) that is connected to a wall plug (not shown) via an electrical
plug (23), and that will
directly feed the illuminated sign (1). The converter could also be used to
charge the battery (20) that
will be used in case of a power failure. Again, the second embodiment could
also comprise a safety
diode (24) that will automatically cut off the current that feeds the battery
(20) when the latter is fully
charged.
The third embodiment of the low-voltage electrical feeding system concerns the
use of a simple
low-voltage battery (20) that will be replaced when necessary.
Other electronic components could also be used in conjunction with the
aforementioned
embodiments of the low-voltage electrical feeding system. For example, a
manual switch (25) could
be used to manually turn on and turn offthe light as needed. A photosensitive
switch (26) could also
be used in order to automatically turn on the light during the night and
automatically turn off the light
during the day.
A miniature surveillance camera (not shown) could be connected to the system (
18) depending
of the type of illuminated sign (1) provided. Finally, a diode (not shown)
could be provided to create
intermittent illumination of the sign ( 1 ).
Although the preferred embodiment of the illuminated sign of this invention
has been described,
it will be understood that various changes may be made in the form, details,
proportion and
arrangement of parts without departing from the teachings of the invention.
The matter set forth in
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the foregoing description and accompanying drawings is offered by way of
illustration only and not as
a limitation. The actual scope of the invention is intended to be defined in
the following claims when
viewed in their proper perspective based on the prior art.
