U.S. patent application number 12/976922 was filed with the patent office on 2011-04-21 for multiple positioned light source to achieve uniform or graded illumination.
This patent application is currently assigned to Q TECHNOLOGY, INC.. Invention is credited to Samuel S. Lee, Thomas E. Stack.
Application Number | 20110090675 12/976922 |
Document ID | / |
Family ID | 39283160 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110090675 |
Kind Code |
A1 |
Stack; Thomas E. ; et
al. |
April 21, 2011 |
Multiple Positioned Light Source to Achieve Uniform or Graded
Illumination
Abstract
An integrated and modular lighting system is disclosed. The
lighting system includes a plurality of modules, each module
including at least two echelons of light emitting diodes and a
power supply on a common substrate. The modular lighting system is
used to provide uniform illumination of an enclosed display
stand.
Inventors: |
Stack; Thomas E.; (Oxford,
MI) ; Lee; Samuel S.; (Dublin, CA) |
Assignee: |
Q TECHNOLOGY, INC.
Livermore
CA
|
Family ID: |
39283160 |
Appl. No.: |
12/976922 |
Filed: |
December 22, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11973430 |
Oct 9, 2007 |
7862195 |
|
|
12976922 |
|
|
|
|
60850030 |
Oct 6, 2006 |
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Current U.S.
Class: |
362/125 |
Current CPC
Class: |
H01L 2224/48247
20130101; H01L 2224/48091 20130101; H01L 2224/48091 20130101; F21W
2131/405 20130101; A47F 3/001 20130101; H01L 2924/181 20130101;
F21Y 2105/12 20160801; F21V 19/0045 20130101; F21W 2131/305
20130101; F21Y 2115/10 20160801; F21S 4/20 20160101; F21Y 2105/10
20160801; H01L 2924/00012 20130101; F21Y 2107/50 20160801; H01L
2924/181 20130101; H01L 2924/00014 20130101 |
Class at
Publication: |
362/125 |
International
Class: |
A47F 11/10 20060101
A47F011/10 |
Claims
1-18. (canceled)
19. A display stand comprising: panels defining at least partially
enclosed space, said panels also defining a mullion, a corner, or
both; at least one integrated lighting module running along the
mullion or the corner; said integrated lighting module comprising:
a substrate having a first major surface defining a first plane and
a second major surface defining a second plane; a first echelon of
light emitting diodes mounted on the first major surface, the first
echelon of light emitting diodes mounted at a first angle relative
to the first plane; a second echelon of light emitting diodes
mounted on the first major surface, the second echelon of light
emitting diodes mounted at a second angle relative to the first
plane; and wherein the first angle is different than the second
angle.
20. The lighting system recited in claim 19 wherein said first
echelon of light emitting diodes includes a first number of light
emitting diodes; wherein said second echelon of light emitting
diodes includes a second number of light emitting diodes; and the
first number different than the second number.
21. The lighting system recited in claim 19 further comprising a
third echelon of light emitting diodes mounted on the first major
surface, said third echelon of light emitting diodes mounted at a
third angle relative to the first plane of said substrate, and said
third echelon of light emitting diodes.
22. The lighting system recited in claim 21 wherein said third
echelon of light emitting diodes including a third number of light
emitting diodes.
23. The lighting system recited in claim 19 wherein said first
echelon of light emitting diodes has a first value of a first
characteristic; said second echelon of light emitting diodes has a
second value of the first characteristic; and wherein the first
characteristic is one of the following characteristics: emission
color, emission intensity, angle of emission cone, and focus.
24. The lighting system recited in claim 19 wherein said integrated
lighting module comprising: an input circuit; a power converter
circuit mounted on said substrate, said power converter circuit
connected to the input circuit and connected to the light emitting
diodes; and wherein said power converter circuit is adapted to
convert the input alternating current electrical power to direct
current electrical power for consumption by said plurality of light
emitting diodes.
25. A display stand comprising: panels defining at least partially
enclosed space, said panels also defining a mullion, a corner, or
both; a lighting fixture wherein said lighting fixture including at
least one integrated lighting module; each integrated lighting
module comprising: a substrate having a first major surface
defining a first plane and a second major surface defining a second
plane; a first echelon of light emitting diodes mounted on the
first major surface, the first echelon of light emitting diodes
mounted at a first angle relative to the first plane; a second
echelon of light emitting diodes mounted on the first major
surface, the second echelon of light emitting diodes mounted at a
second angle relative to the first plane; and wherein the first
angle is different than the second angle.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation application of a current
pending U.S. application Ser. No. 11/973,430, filed on Oct. 9,
2007, entitled "Multiple Positioned Light Source to Achieve Uniform
or Graded Illumination," the entirety of which is incorporated by
reference herein and priority of which is claimed herein. The Ser.
No. 11/973,430 application, in turn, claims the benefit of the
filing date of U.S. Provisional Patent Application No. 60/850,030
filed Oct. 6, 2006 entitled "Multiple Positioned Point Sources to
Achieve Uniform or Graded Illumination" under 35 USC sections 119
and 120, and said Provisional Patent Application also being
incorporated herein by reference and priority of which is claimed
herein.
BACKGROUND
[0002] The present invention relates to various aspects of the
lighting systems. In particular, the present invention relates
lighting systems and illumination of partially or fully or enclosed
spaces such as product display cases, grocery canopy, and
under-shelf lighting in various display appliances.
[0003] The use of fluorescent lamps and lighting technology is well
known in the lighting art. However, disadvantages of a fluorescent
lamp and its ballast include the emission of heat as a side effect,
which is counterproductive for use with a cooling apparatus.
Further, unsafe conditions may occur in a fluorescent lighting
system, including the possibility of high voltage arcing, which
could either directly harm the installer, customers, or bystanders,
or indirectly by starting a fire. The use of mercury in a
fluorescent lamp poses a health hazard to store employees,
customers or final consumers due to accidental breakage of a lamp
allowing the mercury to contaminate the cabinet interior or product
surfaces. Finally, fluorescent bulbs have a limited lifetime,
requiring inconvenient replacement.
[0004] Attempts have been made in the art to replace the less
reliable and higher voltage fluorescent bulbs with more reliable
and energy efficient solid state lighting such as light emitting
devices. The use of solid state lighting has various advantages;
however, some of the disadvantages include the need for separate
power supply/power converter units that incur loss of energy and
generation of undesired heat. Further, solid state lighting include
localized lighting devices that do not provide uniform lighting
over a wide area.
[0005] Often theater lighting uses multiple localized light sources
to adjust illumination to highlight individuals or produce other
scenic effects. Differences and size and scale notwithstanding, the
result differs from the needs for uniform display of a product or
uniform lighting of a personnel compartment.
[0006] Accordingly, there remains a need for an improved
illumination system and technology for more uniform or controlled
gradient illumination of substantially enclosed spaces.
SUMMARY
[0007] The need is met by the present invention. In a first
embodiment of the present invention, a display stand includes
panels that define at least partially enclosed space and also
define a mullion, a corner, or both. A lighting fixture runs along
the mullion or the corner. The lighting fixture includes an
integrated lighting system. Each integrated lighting system
integrates a plurality of light emitting diodes and a power supply
on a common substrate. The lighting fixture includes an input
circuit mounted on the substrate, a power converter circuit mounted
on the substrate. The input circuit is adapted to receive
alternating current electrical power from an external source. The
power converter circuit is connected to the input circuit and
connected to the light emitting diodes. The power converter circuit
is adapted to convert the input alternating current electrical
power to direct current electrical power for consumption by the
plurality of light emitting diodes. To the display stand, a motion
detector and a controller can be added to control application of
power to the lighting fixtures of the display stand.
[0008] In a second embodiment of the present invention, a lighting
fixture includes an extrusion frame and a plurality of integrated
lighting modules engaged to the extrusion frame. Each module
includes a substrate, an input circuit mounted on the substrate, a
plurality of light emitting diodes mounted on the substrate, and a
power converter circuit mounted on the substrate. The input circuit
is adapted to receive alternating current electrical power from an
external source. The power converter circuit is connected to the
input circuit and connected to the light emitting diodes. The power
converter is adapted to convert the input alternating current
electrical power to direct current electrical power for consumption
by the plurality of light emitting diodes. An output circuit is
mounted on the substrate, the output circuit connected to the input
circuit and adapted to forward the alternating current electrical
power to an external device. A first integrated lighting module of
the plurality of integrated lighting modules is connected to an
alternating current power source via the input circuit of the first
integrated lighting module. A second integrated lighting module of
the plurality of integrated lighting modules has an input circuit
that is connected to the output circuit of the first integrated
lighting module.
[0009] In the lighting fixture, the first integrated lighting
module includes a first number of light emitting diodes and the
second integrated lighting module includes a second number of light
emitting diodes. The second number of light emitting diodes can be
less than the first number of light emitting diodes. In the
lighting fixture, the first integrated lighting module has a first
length and the second integrated lighting module has a second
length. The second length can be less than the first length. In the
lighting fixture, the extrusion frame defines multiple insertion
slots allowing for engagement of the integrated lighting modules at
varying mounting angles relative to the rest of the extrusion
frame. In the lighting fixture, the extrusion frame defines at
least one groove adapted to engage wire running along the lighting
system.
[0010] In a third embodiment of the present invention, an
integrated lighting system includes a substrate, an input circuit
mounted on the substrate, a plurality of light emitting diodes
mounted on the substrate, a power converter circuit mounted on the
substrate, and an output circuit mounted on the substrate. The
input circuit is adapted to receive alternating current electrical
power from an external source. The power converter circuit is
connected to the input circuit and connected to the light emitting
diodes. The power converter is adapted to convert the input
alternating current electrical power to direct current electrical
power for consumption by the plurality of light emitting diodes.
The output circuit is connected to the input circuit and adapted to
forward the alternating current electrical power to an external
device.
[0011] In the integrated lighting system, the power converter can
include a power factor correction circuit. In the integrated
lighting system, a zener diode can be connected electrically
parallel to each of the light emitting diodes. In the integrated
lighting system, the following additional components can be
connected to the integrated lighting system: a motion sensor and a
power switch connected to the motion sensor and to the power
converter circuit. The power switch operates to apply power to the
converter circuit when motion is detected by the motion sensor.
[0012] In a fourth embodiment of the present invention, an
integrated lighting system includes a substrate, a first echelon of
light emitting diodes; and a second echelon of light emitting
diodes. The substrate has a first major surface defining a first
plane and a second major surface defining a second plane. The first
echelon of light emitting diodes is mounted on the first major
surface, the first echelon of light emitting diodes mounted at a
first angle relative to the first plane of the substrate, and the
first echelon of light emitting diodes including a first number of
light emitting diodes. The second echelon of light emitting diodes
is mounted on the first major surface, the second echelon of light
emitting diodes is mounted at a second angle relative to the first
plane of the substrate, and the second echelon of light emitting
diodes includes a second number of light emitting diodes. The
second number of diodes is different from the first number of
diodes, and the first angle is different from the second angle.
[0013] In the integrated lighting system, a third echelon of light
emitting diodes can be mounted on the first major surface. The
third echelon of light emitting diodes is mounted at a third angle
relative to the first plane of the substrate, and the third echelon
of light emitting diodes includes a third number of light emitting
diodes. The third number of diodes is different from the second
number of diodes, and the third angle is different from the first
angle and the second angle. In the integrated lighting system, the
first echelon of light emitting diodes has a first value of a first
characteristic and the second echelon of light emitting diodes has
a second value of the first characteristic. The first
characteristic is one of the following characteristics: emission
color, emission intensity, angle of emission cone, and focus.
[0014] In a fifth embodiment of the present invention, a lighting
fixture includes an extrusion frame and an integrated lighting
module engaged to the extrusion frame. Each integrated lighting
modules includes a substrate, an input circuit, a plurality of
light emitting diodes, and a power converter. The input circuit is
mounted on the substrate. The input circuit is adapted to receive
alternating current electrical power from an external source. The
plurality of light emitting diodes is mounted on the substrate. The
power converter circuit is mounted on the substrate. The power
converter circuit is connected to the input circuit and connected
to the light emitting diodes. The power converter is adapted to
convert the input alternating current electrical power to direct
current electrical power for consumption by the plurality of light
emitting diodes. The integrated lighting module has a first end
pivotally engaged to the extrusion frame. The integrated lighting
module has a second end movably engaged to the extrusion frame
whereby the integrated lighting module is angularly movable
relative to the extrusion frame.
[0015] In a sixth embodiment of the present invention, a light
emitting diode package includes a light emitting diode and a zener
diode. The light emitting diode is encased within a clear epoxy
packaging material. The light emitting diode connected to two metal
leads coming out of the epoxy packaging. The zener diode is placed
within the epoxy packaging. The zener diode connected electrically
parallel to the light emitting diode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a perspective view of a display stand embodying
one aspect of the present invention;
[0017] FIG. 2 is a cut away cross sectional view of the display
case of the FIG. 1 cut along plane A-A of FIG. 1;
[0018] FIG. 3 is a perspective view of an end jamb fixture
embodying another aspect of the present invention;
[0019] FIG. 4 is a cut away cross sectional view of portions of the
end jamb fixture of FIG. 3 cut along plane B-B;
[0020] FIG. 5 illustrates portions of the end jam fixture at a
different detail;
[0021] FIG. 6 is a more detailed view of an integrated lighting
module component of the end jamb fixture of FIG. 3;
[0022] FIG. 7 is a cut away sectional view of an integrated
lighting module of FIG. 6 along line C-C.
[0023] FIG. 8 illustrates a portion of a prior art display
stand;
[0024] FIGS. 9A, 9B, and 9C illustrate a portion of FIG. 2 in a
greater detail;
[0025] FIG. 10 is a cut away sectional view of an integrated
lighting module of FIG. 6 along line C-C with additional
component;
[0026] FIG. 11 illustrates a graph showing that the degree of
transmissivity;
[0027] FIG. 12 is an electrical schematic representation of an
integrated lighting module;
[0028] FIGS. 13A and 13B illustrate end plates of the end jamb
fixture of FIG. 3 in more detail;
[0029] FIG. 14 illustrates an alternative embodiment of end jamb
fixture of the present invention;
[0030] FIG. 15 is a perspective view of an center mullion fixture
embodying yet another aspect of the present invention;
[0031] FIG. 16 is a perspective view of a portion of the center
mullion fixture of FIG. 15;
[0032] FIG. 17 is a cut away sectional view of the center mullion
fixture of FIG. 15 cut along plane D-D;
[0033] FIGS. 18A and 18B illustrate end plates of the center
mullion fixture of FIG. 15 in more detail;
[0034] FIG. 19 illustrates another aspect of the present invention
in a motion sensitive lighting system;
[0035] FIG. 20 illustrates yet another aspect of the present
invention in a motion sensitive lighting system;
[0036] FIG. 21 is an electrical schematic representation of an
integrated lighting module in accordance with another aspect of the
present invention;
[0037] FIG. 22 illustrates a light emitting diode package in
accordance with yet another aspect of the present invention;
and
[0038] FIG. 23 is an electrical schematic representation of the
light emitting diode package of FIG. 22.
DETAILED DESCRIPTION
[0039] The present invention will now be described with reference
to the FIGS. 1 through 23 which illustrate various aspects,
embodiments, or implementations of the present invention. In the
Figures, some sizes of structures, portions, or elements may be
exaggerated relative to sizes of other structures, portions, or
elements for illustrative purposes and, thus, are provided to aid
in the illustration and the disclosure of the present
invention.
[0040] FIG. 1 illustrates one aspect of the present invention.
According to the illustrated aspect of the present invention, a
display stand 100 includes a number of panels such as side panels
104 and doors or windows 102 either of which may be openable. In
FIG. 1, the display stand 100 is illustrated as a display case
defining is substantially enclosed space. However, the present
invention is applicable to many contexts and appliances such as,
for example, grocery display fixtures in supermarkets; salad
display stations at restaurants.
[0041] The panels 104 and doors or windows 102 meet to define
mullions, corners, or both. In FIG. 1, the display stand 100
includes lighting fixtures 200 and 300 running along a corner and a
mullion of to display stand 100, respectively.
[0042] FIG. 2 illustrates a cut-away sectional view of the display
stand 100 cut along plane A-A looking downward. Referring now to
FIGS. 1 and 2, reference number 110 refers to a shelf within the
display stand 100, the shelf 110 on which the products for sale are
placed. Reference number 112 refers to a leading edge of the shelf
110, the leading edge 112 being proximal to the front of the
display stand 100. Illustrated in FIG. 2 is another lighting
fixture 202 not illustrated in FIG. 1 because it would be hidden
from view by the side panels 104 and doors or windows 102.
[0043] FIG. 3 is a perspective view of the lighting fixture 200 in
FIGS. 1 and 2. Here, the lighting fixture 200 is an end jamb
fixture 200 adaptable for placement at a corner of the display
stand 100 of FIG. 1. The end jamb fixture 200 includes a fixture
frame 210 defining an opening covered by a covering lens 204. Ends
of the frame 210 are covered by end plates 230. FIG. 4 illustrates
a cut away sectional view of the end jamb fixture 200 cut along
plane B-B. To avoid clutter, the covering lens 204 is not
illustrated in FIG. 4. Illustrated in a FIG. 4 but not shown in
FIG. 3 is a cutaway side view of an integrated lighting system 250.
The integrated lighting system 250 is also referred to herein as an
"integrated lighting module" or just "module." Reference number 250
is used to generically or collectively refer to an integrated
lighting module. A particular integrated lighting module is
referred to herein as 250a, 250b, or 250c as illustrated in FIG.
5.
[0044] FIGS. 5 through 7, 10A through 11, 13, 14A, and 14B
illustrate various portions of the end jamb fixture 200 in more
detail. FIG. 5 illustrates the integrated lighting modules 250 of
the end jamb fixture 200 including a more detailed view of the
connections between the modules 250. FIG. 6 is a more detailed view
of the integrated lighting module 250. FIG. 7 illustrates another
cut away sectional view of one of the integrated lighting modules
250 cut along line C-C.
[0045] Referring to FIGS. 3 to 7, the illustrated end jamb fixture
200 includes three integrated lighting systems 250. The number of
integrated lighting modules 250 in a lighting fixture such as the
end jamb fixture 200 can vary from one to many. Two End Plates 230a
and 230b are attached to the ends of the frame 210, one at each
end. For convenience of discussion herein, the End Plates,
generically or collectively, are referred to using reference number
230. The end plate 230 includes a stress relief 232, and defines
several openings such as, for example only, wire access opening
234, end plates screw hole 236, and mounting hole 239. Also, a
ground lug engagement hole 238 allows for electrical grounding of
the electrical components of the integrated lighting modules
250.
[0046] The integrated lighting module 250 includes a plurality of
light emitting diodes (LEDs) and power supply on a common substrate
252. The substrate 252 can be any suitable material such as, for
example, a printed circuit board (PCB), that is substantially flat.
The substrate 252 has a first major surface 251 defining a first
plane and a second major surface 253 defining a second plane.
[0047] The light emitting diodes are mounted on the first major
surface 251 and are arranged in a number of columns or rows
depending on the orientation of the module 250. In this discussion,
word "echelon" will refer to the linear arrangement of light
emitting diodes, not necessarily constrained as to direction, as
the words "row" or "column" might signify. The module 250 includes
at least two echelons of light emitting diodes. In the embodiment
illustrated in the Figures, three echelons are shown.
[0048] A first echelon 260 of light emitting diodes is mounted on
the first major surface 251. The light emitting diodes of the first
echelon 260 are mounted at a first angle 262 relative to the first
plane of the substrate 252. The first angle 262 can be, in the
illustrated sample embodiment, is approximately 90 degrees. In the
Figures, light emitting diode 264 represents a single
representative light emitting diode of the first echelon 260 of
light emitting diodes. Actual number (the first number) of the
light emitting diodes in the first echelon 260 is implementation
dependent and can vary widely from one to thousands or more. In the
illustrated sample embodiment, the first echelon 260 of light
emitting diodes includes about 20 to 30 light emitting diodes per
12 inches, or about two light emitting diodes per inch, the
distance measured along the direction of the echelon.
[0049] A second echelon 270 of light emitting diodes is mounted on
the first major surface 251. The light emitting diodes of the
second echelon 270 are mounted at a second angle 272 relative to
the first plane of the substrate 252. The second angle 272 can be,
in the illustrated sample embodiment, is approximately 63 degrees.
In the Figures, light emitting diode 274 represents a single
representative light emitting diode of the second echelon 270 of
light emitting diodes. Actual number (the second number) of the
light emitting diodes in the second echelon 270 is implementation
dependent and can vary widely from one to thousands or more. In the
illustrated sample embodiment, the second echelon 270 of light
emitting diodes includes about 5 to 15 light emitting diodes per 12
inches, or about two light emitting diodes per inch, the distance
measured along the direction of the echelon.
[0050] Typically, the second number of diodes is different from the
first number of diodes and the second angle is different from the
first angle. This is because, in most implementations, the second
echelon 270 of light emitting diodes and the first echelon 260 of
light emitting diodes are intended to illuminate different areas,
at different intensities, or both. However, in certain
applications, the second number of diodes and the first number of
diodes may be equal. Likewise, in certain applications, the second
angle and the first angle may be equal. These applications are
still within the scope of the present invention.
[0051] A third echelon 280 of light emitting diodes is mounted on
the first major surface 251. The light emitting diodes of the third
echelon 280 are mounted at a third angle 282 relative to the first
plane of the substrate 252. The third angle 282 can be, in the
illustrated sample embodiment, is approximately 35 degrees. In the
Figures, light emitting diode 284 represents a single
representative light emitting diode of the third echelon 280 of
light emitting diodes. Actual number (the third number) of the
light emitting diodes in the third echelon 280 is implementation
dependent and can vary widely from one to thousands or more. In the
illustrated sample embodiment, the third echelon 280 of light
emitting diodes includes about 1 to 9 light emitting diodes per 12
inches, or about two light emitting diodes per inch, the distance
measured along the direction of the echelon.
[0052] Typically, the third number of diodes is different from both
the first number of diodes and the second number of diodes.
Likewise, the third angle is typically different from both the
first angle and the second angle. This is because, in most
implementations, the third echelon 280 of light emitting diodes,
the first echelon 260 of light emitting diodes, and the second
echelon 270 of light emitting diodes are intended to illuminate
different areas, at different intensities, or both. However, in
certain applications, the third number of diodes may be same as the
first number of diodes, the second number of diodes, or both the
first number and the second number of diodes. Likewise, in certain
applications, the third angle may be same as the first angle, the
second angle, or both. These applications are still within the
scope of the present invention.
[0053] The reason for the differences in the number of light
emitting diodes of the three echelons of diodes and the reason for
the differences in the angle in which the light emitting diodes of
the three echelons are mounted can be explained using FIG. 8 which
illustrates a portion of a display stand of a prior art design.
[0054] Light uniformity or desired grading is achieved by
controlling various factors such as the spacing between the light
emitting diodes within each echelon, angle at which the light
emitting diodes are mounted, etc. In the illustrated sample
configuration, light from the light emitting diodes of various
echelons cross each other. This is because of the varying angles in
at which the light emitting diodes are mounted. For this reason,
this arrangement is sometime referred to as cross fire design.
[0055] As discussed above, FIG. 2 illustrates a cut-away sectional
view of the display stand 100 (of FIG. 1) cut along plane A-A
looking downward. A portion 122 of the cut-away sectional view of
the display stand 100 is indicated in FIG. 2. The portion 122 is
illustrated in more detail in FIGS. 9A, 9B, and 9C to aid in the
discussion of the resultant and the desired effects of the
configuration of the integrated lighting module 250.
[0056] FIG. 8 illustrates an analogous portion 122a of a prior art
display stand (not illustrated) that has a similar or same
configuration of the display stand 100 (of FIG. 1) but without the
lighting fixtures 200, 300 of the present invention. Rather, the
prior art display stand includes prior art lighting systems 150 and
152 that provide light of substantially uniform density. Such prior
art lighting systems 150 and 152 can be, for example, fluorescent
lamps 150 and 152. The analogous portion 122a (of the prior art
display stand) is analogous to portion 122 (of the display stand
100 of the present invention). Reference number 112a refers to a
leading edge of a shelf 110a within the prior art display stand.
The leading edge 112a is analogous to the leading edge 112 of the
shelf 110 within the display stand 100 of the present invention
illustrated in FIGS. 1 and 2. The leading edge 112a represents
front of products placed on the self 110a for sale.
[0057] In the prior art display stand, the illumination of the
leading edge 112a is not uniform. For example, a first portion 112b
of the leading edge 112a is more intensely illuminated, that is,
relatively brighter, compared to a second portion 112c of the of
the leading edge 112a which is less intensely illuminated, that is,
relatively darker. This is because, the first portion 112b is
relatively closer to the uniform light source 150 than the second
portion 112 see which is relatively farther from the uniform light
source 150.
[0058] In many applications, a more uniform illumination of the
products placed on the shelf 110a is desired. The present invention
provides for a more uniform illumination of the products on the
shelf. This is illustrated in FIGS. 9A, 9B, and 9C where the
portion 122 of the display stand 100 is illustrated in more detail.
Referring to FIGS. 9A, 9B, and 9C and continuing to refer to FIG.
2, the light emitting diodes of the first echelon 260, as
represented by the representative light emitting diode 264,
illuminates portions of the leading edge 112 that is relatively
farthest from the fixture 200. This can be realized using the
combination of the following factors: (1) predefined emission cone
angles of the light emitting diodes; (2) the angle at which
echelons of diodes are mounted on the substrate to 252; and (3) the
number of light emitting diodes at each echelon.
[0059] The light emitting diodes of the first echelon 260 have
predefined emission cones within which most of the light of the
light emitting diodes is emitted, the emission cone for the light
emitting diode 264 is represented in the Figures by the measurement
angle 265. In the market, light emitting diodes of various
characteristics are available. One of the characteristic is the
angle of the emission cone. In the illustrated sample embodiment of
the present invention, the light emitting diodes have emission cone
angle of approximately 40.degree..
[0060] The light emitting diodes of the second echelon 270, as
represented by the representative light emitting diode 274,
illuminate portions of the leading edge 112 that is relatively
closer to the fixture 200 than the portions illuminated by the
light emitting diodes of the first echelon 260 but that is
relatively father from the fixture 200 then portions illuminated by
the light emitting diodes of the third echelon 280. The light
emitting diodes of the second echelon 270 have predefined emission
cones within which most of the light of the light emitting diodes
is emitted, the emission cone for the light emitting diode 274 is
represented in the Figures by the measurement angle 275. The angle
275 may be same as or different from the angle 265 depending on
application.
[0061] The light emitting diodes of the third echelon 280, as
represented by the representative light emitting diode 284,
illuminate portions of the leading edge 112 that is relatively
closer to the fixture 200 than the portions illuminated by the
light emitting diodes of the first echelon 260 as well as the
portions illuminated by the light emitting diodes of the second
echelon 270. The light emitting diodes of the third echelon 270
have predefined emission cones within which most of the light of
the light emitting diodes is emitted, the emission cone for the
light emitting diode 284 is represented in the Figures by the
measurement angle 285. The angle 285 may be same as or different
from the angle 265, angle 275, or both, depending on
application.
[0062] The portions of the leading edge 112 illuminated by the
three echelons of diodes may overlap depending on the light
emission cone angles 265, 275, and 285, and the mounting angle at
which the diodes of the first echelon 260, the second echelon 270,
and the third echelon 280 at which the diodes are mounted on the
substrate 252.
[0063] If, in the present invention, the light emitting diodes of
the three echelons of diodes in the light having the same
intensity, and the number of diodes in each echelon of diodes is
same, then the illumination of the lead edge 112 would not be
uniform, however, in the present invention, the number of diodes in
the three echelons of diodes are different, as illustrated in the
Figures, the first echelon 250 of diodes include a higher number
(first number) of diodes than the number of diodes (second number)
of the second echelon 270. Likewise, the second number is greater
than the number of diodes (third number) of the third echelon 280.
Accordingly, a more uniform illumination of the leading edge 112 of
the shelf 110 of the display stand 100 is realized.
[0064] In alternate embodiments of the present invention, other
illumination effects can be achieved by using diodes having
different values of various characteristics. For example, the first
echelon 260 of diodes can have a first value of a first
characteristic such as having value red of characteristic color in
the diodes of the second echelon 270 can have value to of
characteristic color. They characteristics of the diodes for which
the values can be selected include, for example only, emission
color, emission intensity, angle of emission cone, and focus.
[0065] FIG. 10 illustrates another aspect of the present invention
relating to the angle of the mounting of the light emitting diodes
on the substrate 252. FIG. 10 illustrates another cut away
sectional view of one of the integrated lighting modules 250 cut
along line C-C of FIG. 6 and covering lens 204 (illustrated in FIG.
3). The covering lens 204 protects interior of the lighting fixture
200 and provides additional support for the lighting fixture 200.
The covering lens 204 is typically made of clear material to allow
light from the light emitting diodes to be transmitted though with
minimal attenuation; however, the covering lens 204 presents some
degree of attenuation to the light. FIG. 11 illustrates a graph
showing that the degree of transmissivity the covering lens 204
presents to the light from the light emitting diodes depends highly
on the angle of incidence of the light on the covering lens 204.
More specifically, the graph shows that the transmissivity declines
drastically for angles of incidence of lower than 45.degree. or
higher than hundred and 35.degree..
[0066] Referring to FIGS. 10 and 11, to minimize loss of light due
to the attenuation presented by the covering lens 204, the light
emitting diodes of the three echelons of light emitting diodes are
mounted on the substrate 252 such that the incidence angles 205 and
207 of the light from the light emitting diodes to not fall below
45.degree. or exceed 135.degree..
[0067] Referring again to FIG. 6, the integrated lighting module
250 is "integrated" in that the module 250 includes, on the common
substrate 252, the aforementioned echelons 260, 270, and 280 of the
light emitting diodes as well as circuit elements (referred herein
as the "power supply" or "power converter") to convert the readily
available alternating current form of electrical power to direct
current form of electrical power needed by the light emitting
diodes as well as the echelons of the light emitting diodes.
[0068] FIG. 12 is an electrical schematic representation of the
integrated lighting module 250. Referring to FIGS. 6 and 12, the
integrated lighting module 250 includes an input circuit 290
mounted on the mounted on the substrate 252. The input circuit 290
includes, for example, connection pads 294a and 294b adapted to
connect to and an external power source and adapted to receive
alternating current electrical power from the external power
source. The input circuit 290 can also include and connection pads
292a and 292b adapted to connect to other integrated lighting
modules 250 to receive electrical power from the other integrated
lighting modules 250.
[0069] The integrated lighting module 250 includes a power
converter circuit (also referred to as the "power supply") mounted
on the substrate 252. The power converter circuit 240 is connected
to the input circuit 290 and connected to the echelons of light
emitting diodes of the integrated lighting module 250. In FIG. 12,
the light emitting diodes of all of the echelons of the integrated
lighting module 250 are represented by the diodes in dashed-box
254. The power converter circuit 240 is adapted to convert the
input alternating current electrical power to direct current
electrical power for consumption by the plurality of light emitting
diodes 254.
[0070] In the power converter circuit 240, a fuse F1 provides
current limiting (to prevent damaging sustained peak current) and a
resistor R1 (to limit inrush current), as well as capacitors C1 and
C2 (to limit steady state current). R1 could also be a negative
temperature coefficient thermistor (NTC) to reduce energy loss
after the initial current surge when the unit is energized. The
power supply circuit 240 drives the light emitting diodes 254 in a
series string configuration. Due to the current limiting
components, the voltage at the supply output, at the connection
points across C3, is reduced to a light emitting diode-safe drive
level under load such as, for example, 132 volts. By use of
capacitors C1 and C2 to limit incoming current, the disadvantages
of heat dissipation in resistors or transistors are avoided. In
case of no-load open circuit, capacitor C3 is rated above the
nominal 340 Vdc produced by a voltage doubler circuit operating
from a 120 Vac line, to avoid the possibility of component
damage.
[0071] In the illustrated sample embodiment, the fuse F1 is a 1-amp
Pico Fuse; the resistor R1 is a 24 ohm resistor rated at 1 watt;
capacitors C1 and C2 have 1 microfarad 250 volt rating; capacitor
C3 has 4.7 microfarad 400 volt rating; diodes D1 and D2 have 1N4004
rating 400 volt, 1 amp.; and the MOV (metal oxide varistor) has 150
volt, 5 mm rating.
[0072] In an effort to provide high efficiency, low noise
production, and low component count, a current limiting power
supply utilizing non dissipative capacitive reactance was selected.
By using a full wave voltage doubler configuration, improved power
factor over a bridge fed capacitor input filter supply can be
realized. Resistor (R1) or NTC (negative temperature coefficient)
thermister provides for surge current limiting at the initial turn
on and charging of C1, C2, and C3. An NTC (negative temperature
coefficient) thermistor can be used since it has a high resistance
at room temperature and turn on, but changes resistance to a lower
value upon passing current and heating up. In that manner,
dissipation losses are minimized after the unit is operating.
[0073] The MOV or metallic oxide varistor in conjunction with a
series current limiting element (R1) provides transient voltage
protection as found in some harsh industrial electrical
environments. Components D1, D2, C1, C2, and C3 comprise a full
wave voltage doubling power supply with the capacitance of C1 and
C2 selected to provide capacitive reactance sufficient to limit the
output current to that of the light emitting diode spec. C3 serves
to reduce the ripple voltage appearing across C1 and C2 and thus
reduces LED 120 Hz blinking Do to the inherent simplicity of this
power supply circuit, reliability is improved, and its low cost can
permit it to be a redundant circuit on each integrated lighting
module.
[0074] Mechanically, to assemble the modules 250 for easier sliding
into the frames 210, some components of the power converter circuit
240 can be mounted on the back (second major surface) of the
substrate 252. The integrated lighting module 250 includes an
output circuit 296 mounted on the substrate 252. The output circuit
296 is connected to the input circuit 290 and is adapted to forward
the alternating current electrical power to an external device such
as another module 250 via its connection pads 298a and 298b.
[0075] As is apparent from the schematic of FIG. 12, integrated
lighting modules 250 can be daisy-chained to each other by
connecting the output pads 298a and 298b of a first integrated
lighting module 250 the input pads 292a in 290b, respectively. To
supply electrical power to the entire chain of the daisy-chained
set of integrated lighting modules, the electrical power need be
connected to only one of the set of the daisy-chained integrated
lighting modules.
[0076] FIG. 5 illustrate portions of the fixture 200 having
multiple integrated lighting modules 250 which are electrically
connected as shown in area 258. As illustrated, a first integrated
lighting module 250a is connected to an alternating current power
source via its input circuit. A second integrated lighting module
250b has its input circuit connected to the output circuit of the
first integrated lighting module 250a.
[0077] Dimensions of the modules 250 are in the order of inches or
tens of inches. There is no requirement in the present invention
that the dimensions of the modules 250 are identical. In fact,
depending on the desired application, modules having various sizes
may be used. For example, the length 251a of the first module 250a
can be greater than the length 251b of the second module 251b.
[0078] By virtue of the cross firing light emitting diodes, lens
slot 218 (of FIG. 4) in the fixture for the lens 204 is kept to
minimum width thereby permitting utilization of thinnest lens
material available while still maintaining mechanical integrity.
This minimizes lens transmission loss. The fixture frame 210 design
also positions and curves the lens to further reduce transmission
attenuation by maintaining a near perpendicular relationship
between the light emitting diodes of each echelon and inside
surface of the lens. The fixture frame design also provides for
abundant external surface area to allow for cooler operation of the
light emitting diode.
[0079] Referring again to FIG. 4, the fixture frame 210 defines a
multiple engagement slots 212a, 212b, and 212c allowing engagement
of the modules 250 within the fixture 200. The engagement slots
212a, 212b, and 212c are generically or collectively referred to
herein as engagement slots 212. In the illustrated example of FIG.
4, the module 250 is engaged to engagement slots 212a and 212b
forming an engagement angle 213 relative to the rest of the fixture
frame 210. It is readily apparent from the Figures that if the
module 250 is engaged to engagement slots 212a and 212c, the
engagement angle would change to some value other than the value of
angle 213. This is one of the techniques in which the angle and the
direction of the light from the light emitting diodes can be
adjusted.
[0080] The fixture frame 210 further defines grooves 214 providing
convenient pocket for engagement with electrical wires that may run
along the fixture 200.
[0081] FIGS. 13A and 13B illustrate end plates 230a and 230b which
are attached to the ends of the frame 210, one at each end as
partially illustrated in FIG. 3.
[0082] FIG. 14 illustrates an alternative embodiment of the present
invention. FIG. 14 illustrates a light fixture 400 that is
similarly configured to the light fixture 200 of FIGS. 3 through
12. However, in the light fixture 400, portions of its extrusion
frame 410 and portions of its end plates 430 are configured
differently. The integrated lighting module 450 is similarly
configured to the integrated lighting module 250 of FIGS. 4 through
7. Here, the integrated lighting module 450 has a first end that is
pivotally engaged to the extrusion frame 410 as illustrated as
pivot point 431. A second end of the integrated lighting module 450
is movably or slide-ably engaged to the end plate 430 in the
direction illustrated by arrows 435. Consequently, the angular
position 433 of the integrated lighting module 450 is angularly
adjustable relative to the extrusion frame 410.
[0083] FIG. 15 is a perspective view of the lighting fixture 300 of
FIG. 1. Here, the lighting fixture 300 is a center mullion fixture
300 adaptable for placement at a mullion of the display stand 100
of FIG. 1. The Center Mullion Fixture 300 includes a fixture frame
310 defining an opening covered by a covering lenses 304a and 304b
(generically or collectively referred to as 304). FIG. 16 is a
perspective view of the fixture frame 310. FIG. 17 illustrates a
cut away sectional view of the center mullion fixture 300 cut along
plane D-D. To avoid clutter, the covering lens 304 is not
illustrated in FIG. 18. Illustrated in FIG. 17 but not shown in
FIG. 15 is a cutaway side view of an integrated lighting system
250. The integrated lighting system 250 of FIG. 17 is the same as
the integrated lighting system 250 illustrated in FIGS. 4 through 7
and discussed above.
[0084] The center mullion fixture 300 has two openings covered by
covering lenses 304a and 304b. This is because the center mullion
fixture 300 is adapted to provide light generally in two directions
as indicated by arrows 301 and 303. For the same reason, the center
mullion fixture 300 includes two sets of integrated lighting
modules 250. The covering lenses 304a and 304b are not shown in
FIG. 17.
[0085] FIGS. 18A and 18B illustrate end plates 330a and 330b which
are attached to the ends of the frame 310, one at each end as
partially illustrated in FIG. 15. For convenience of discussion
herein, the end plates 330a and 330b, generically or collectively,
are referred to using reference number 330. The end plate 330
includes a stress relief 332, and defines several opening such as,
for example only, wire access opening 334, end plates screw hole
336, and mounting hole 339. Also, a ground lug engagement hole 338
allows for electrical grounding of the electrical components of the
integrated lighting modules 350.
[0086] FIG. 19 illustrates another aspect of the present invention.
In FIG. 19, the display stand 100 of FIGS. 1 and 2 connected to a
controller 500 and a motion detector 502. When motion is detected
by the motion detector 502, signal is sent to the controller 500
connected to the motion detector 502. Upon receiving the signal
from the motion detector 502, the controller 500 causes application
of power to the lighting fixtures of the displaced and 100. The
application of power means either that the lighting fixtures of the
displaced and 100 was in unpowered state and that power was applied
to turn on the lighting fixtures of the displaced and 100, or the
lighting fixtures of the displaced and 100 was dimmed at a lower
power and that power was increased to increase the brightness of
the lighting fixtures of the displaced and 100.
[0087] The controller 500 can be programmed to power off or power
down (dim) the lighting fixtures on various conditions such as, for
example, at predetermined time periods when the store is closed;
when no motion is detected by the motion detector 502, or after a
predetermined time period following the detection of motion by the
motion detector 502.
[0088] FIG. 20 illustrates another aspect of the present invention.
In FIG. 20, the integrated lighting module 250 is connected to a
motion sensor 510 including a power switch. The power switch
operates to apply power to the converter circuit (of the integrated
lighting module 250, see FIG. 12) when motion is detected by the
motion sensor 510. Using this embodiment, both the motion sensor
510 and the integrated lighting module 250 can be mounted inside
the display stand 100 of FIG. 1.
[0089] FIG. 21 is an electronic schematic representation of the
integrated lighting module 250 of FIG. 20. The electronic schematic
of FIG. 21 is identical to the electronic schematic of FIG. 12
except that a controller circuit 515 is connected between the
connection pads (294a and 294b) and the power converter circuit
240. The controller circuit 515 is connected to the motions sensor
510 of FIG. 20. The controller circuit 515 includes a relay, sensor
interface, and an adjustable shut off delay circuit. The replay is,
for example, a conventional relay or a solid state relay such as a
zero voltage switching (ZVS) solid state relay (SSR). The sensor
interface is connected to the external sensor. The adjustable shut
off delay circuit is connected to an external time delay adjusting
potentiometer 517.
[0090] FIGS. 22 and 23 illustrate another aspect of the present
invention. In FIG. 22, a light emitting diode package 520 includes
a light emitting diode 522 encased within a clear epoxy packaging
material 528. The light emitting diode 522 is connected to two
metal leads 526 coming out of the epoxy packaging 528 for
electrical connection and for heat spreading. Also encased within
the epoxy packaging material 528 is a zener diode 524 that is also
connected to the two metal leads 526. FIG. 23 is an electrical
schematic of the light emitting diode package 520. As illustrated,
the zener diode 524 is connected electrically parallel to the light
emitting diode 526.
[0091] During normal operations, electrical power passes through
the light emitting diode 526 causing the light emitting diode 526
to emit light. The light emitting diode 526 has a normal operating
voltage range such as from 1.5 volts to 3.8 volts. The zener diode
524 is selected such that its reverse breakdown voltage is slightly
above the upper limit of the normal operating voltage of the light
emitting diode 526. In the present example, the zener diode 524 has
a reverse breakdown voltage of approximately 4 volts. When the
light emitting diode 526 fails causing the circuit to open, the
voltage normally applied to the light emitting diode 526 is now
applied to the zener diode 524. As the electrical current piles up
at the zener diode 524, voltage across the zener diode 524
increases until at the zener diode 524 breaks down and begins to
conduct. Accordingly, a failed light emitting diode does not
prevent the flow of current that is needed in other components such
as other light emitting diodes.
[0092] The placement of the zener diode 524 inside the light
emitting diode package 520 as shown in FIG. 22 is one possible
embodiment of the present invention; however, this is not the only
possible configuration under the present invention. For example,
referring again to FIG. 12 and continuing to refer to FIG. 23, in
the integrated lighting system 250, a zener diode, such as the
diode zener 524, can be connected electrically parallel to one or
more of the light emitting diodes of the echelons of light emitting
diodes represented by the diodes in dashed-box 254. In this
alternate embodiment, the zener diode can be placed outside the
light emitting diodes but mounted on the substrate 510 such as the
printed circuit board (PCB) 510.
[0093] In an alternate embodiment of the present invention, the
light emitting diode package 520 can be used in place of diodes
264, 274, and 284 of echelons 260, 270, and 280 illustrated in
FIGS. 5 through 7. In another alternate embodiment of the present
invention, a zener diode is connected across the each of the light
emitting diodes of the integrated lighting module 250 electrically
parallel to each of the light emitting diodes.
[0094] From the foregoing, it will be appreciated that the present
invention is novel and offers advantages over the current art.
Although a specific embodiment of the invention is described and
illustrated above, the invention is not to be limited to the
specific forms or arrangements of parts so described and
illustrated. For example, differing configurations, sizes, or
materials may be used to practice the present invention. The
invention is limited by the claims that follow.
* * * * *