U.S. patent application number 13/473929 was filed with the patent office on 2012-12-20 for flat panel lighting device and driving circuitry.
This patent application is currently assigned to PIXI LIGHTING LLC. Invention is credited to John Araki, J. Richard Myers, Arthur N. Wong.
Application Number | 20120320627 13/473929 |
Document ID | / |
Family ID | 46246190 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120320627 |
Kind Code |
A1 |
Araki; John ; et
al. |
December 20, 2012 |
FLAT PANEL LIGHTING DEVICE AND DRIVING CIRCUITRY
Abstract
The present application is directed to a lighting fixture having
a light emitting diode (LED) panel. The light fixture is configured
to include a pair of LED configurations that are driven alternately
by driving circuitry. The light fixture can include driving
circuitry that is configured to be housed within a frame of the LED
panel.
Inventors: |
Araki; John; (Tustin,
CA) ; Myers; J. Richard; (Pasadena, CA) ;
Wong; Arthur N.; (Redondo Beach, CA) |
Assignee: |
PIXI LIGHTING LLC
Orange
CA
|
Family ID: |
46246190 |
Appl. No.: |
13/473929 |
Filed: |
May 17, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61579472 |
Dec 22, 2011 |
|
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61487253 |
May 17, 2011 |
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Current U.S.
Class: |
362/608 ;
362/249.02; 362/382; 362/612 |
Current CPC
Class: |
F21S 8/04 20130101; F21V
23/02 20130101; F21V 23/06 20130101; G02B 6/0088 20130101; H05B
47/11 20200101; F21V 21/02 20130101; G02F 1/133608 20130101; F21K
9/20 20160801; G02B 6/0055 20130101; F21Y 2115/10 20160801; F21V
29/89 20150115; G02B 6/009 20130101; F21K 9/61 20160801; G02B
6/0091 20130101; G02B 6/0073 20130101; F21V 23/001 20130101; G02B
6/0083 20130101; Y02B 20/30 20130101; H05B 45/20 20200101; F21Y
2103/20 20160801; F21Y 2105/10 20160801; G02F 1/133603 20130101;
F21K 9/64 20160801; F21V 21/005 20130101; F21V 23/009 20130101;
F21Y 2101/00 20130101; G02B 6/0068 20130101; G02F 1/133615
20130101; F21V 15/01 20130101; F21V 23/002 20130101; H05B 45/10
20200101; H05B 47/105 20200101; H05K 999/99 20130101; F21K 9/275
20160801; F21V 23/023 20130101; G02B 6/0051 20130101; F21V 23/003
20130101; G02B 6/0085 20130101; F21K 9/278 20160801; F21K 9/235
20160801; F21Y 2103/10 20160801 |
Class at
Publication: |
362/608 ;
362/382; 362/249.02; 362/612 |
International
Class: |
F21V 21/00 20060101
F21V021/00; F21V 13/02 20060101 F21V013/02; F21V 8/00 20060101
F21V008/00 |
Claims
1. A light fixture comprising: a frame; a light emitting diode
(LED) panel disposed within the frame; and power circuitry disposed
within the frame, the power circuitry being configured to
electrically couple the substantially flat LED panel to an external
power supply.
2. The light fixture of claim 1, wherein power circuitry is sized
to be positioned within a channel defined by the frame.
3. The light fixture of claim 1, wherein the power circuitry
includes driving circuitry configured to convert an AC input into a
DC output suitable for powering the LED panel.
4. The light fixture of claim 1, wherein the power circuitry has a
length and a width, wherein the length-to-width ratio is at least 5
to 1.
5. The light fixture of claim 1, wherein the power circuitry has a
length and a width, wherein the length-to-width ratio is at least
10 to 1.
6. The light fixture of claim 1, wherein at least a portion of the
frame defines a first channel configured to support the power
circuitry.
7. The light fixture of claim 6, wherein at least a portion of the
frame is configured to support an array of LEDs disposed adjacent
an edge of the frame.
8. The light fixture of claim 7, wherein the first channel is
configured to support the array of LEDs.
9. The light fixture of claim 7, wherein at least a portion of the
frame defines a second channel configured to support the array of
LEDs.
10. The light fixture of claim 7, wherein at least a portion the
frame is configured to support electrical connectors between the
power circuitry and the array of LEDs.
11. The light fixture of claim 10, wherein the power circuitry
includes an array of circuit modules supported by the first
channel.
12. The light fixture of claim 6, wherein the first channel has a
height of no more than about 0.5 inches.
13. The light fixture of claim 9, wherein the first channel has a
width of no more than about 1.0 inches.
14. The light fixture of claim 6, wherein at least a portion of the
frame defines a second channel configured to support the power
circuitry
15. The light fixture of claim 14, wherein at least a portion of
the frame defines a third channel configured to support an array of
LEDs disposed adjacent to an edge of the frame.
16. The light fixture of claim 1, wherein the LED panel is edge
lit.
17. The light fixture of claim 1, wherein the LED panel includes a
plurality of LEDs disposed adjacent at least one edge of the
frame.
18. The light fixture of claim 1, wherein the frame is rectangular
and the LED panel includes an array of LEDs incorporated into at
least two sides of the frame.
19. The light fixture of claim 1, wherein the LED panel includes:
an optically-transmissive panel; and an array of LEDs disposed
adjacent at least one edge of the frame and disposed adjacent the
optically transmissive panel.
20. The light fixture of claim 1, wherein the LED panel includes:
an optically-transmissive panel; and an array of LEDs disposed
across a first surface of the optically-transmissive panel.
21. The light fixture of claim 20, wherein the array of LEDs is
disposed across substantially the entire first surface of the
optically-transmissive panel.
22. The light fixture of claim 1, wherein the frame of the light
fixture has a thickness of no more than about 0.5 inches.
23. The light fixture of claim 1, wherein the frame of the light
fixture has a thickness of no more than about 1.0 inches.
24. The light fixture of claim 1, wherein the frame is rectangular
and the LED panel includes: a light guide plate; a first array of
LEDs incorporated into a first side of the frame adjacent a first
side of the light guide plate, the first array of LEDs emitting
light focused along a first direction; a second array of LEDs
incorporated into a second side of the frame adjacent a second side
of the light guide plate, the second array of LEDs emitting light
focused along a second direction that is opposite the first
direction; a first brightness enhancement film (BEF) positioned
adjacent the light guide plate and configured to collimate light
emitted by the first array of LEDs; and a second BEF positioned
adjacent the first BEF and configured to collimate light emitted by
the second array of LEDs.
25. The light fixture of claim 1, wherein the power circuitry
includes a controller configured to control the intensity of the
light emitted by the LED panel.
26. The light fixture of claim 1, wherein the LED panel includes: a
first configuration of LEDs; and a second configuration of
LEDs.
27. The light fixture of claim 26, wherein the power circuitry is
configured to power the first configuration of LEDs for a first
time period and to power the second configuration of LEDs for a
second time period equal to the first time period.
28. The light fixture of claim 26, wherein the LED panel includes a
third configuration of LEDs; and wherein the power circuitry is
configured to power the first configuration of LEDs for a first
time period, to power the second configuration of LEDs for a second
time period equal to the first time period, and to power the third
configuration of LEDs for a third time period equal to the first
time period.
29. The light fixture of claim 26, wherein the power circuitry is
configured to alternatively power the first configuration of LEDs
and the second configuration of LEDs over a cyclical time period
including the first time period and the second time period.
30. The light fixture of claim 26, wherein the first configuration
of LEDs and the second configuration of LEDs are arranged in a
single row in an alternating arrangement.
31. The light fixture of claim 26, wherein the first configuration
of LEDs is arranged in a first row and the second configuration of
LEDs is arranged in a second row adjacent the first row.
32. The light fixture of claim 26, wherein the first configuration
of LEDs and the second configuration of LEDs are arranged in a pair
of rows, wherein each row of the pair of rows includes the first
configuration of LEDs and the second configuration of LEDs arranged
in an alternating arrangement
33. The light fixture of claim 26, wherein first configuration of
LEDs includes a first array on a first side of the frame and a
second array on a second side of the frame opposite the first side
of the light frame.
34. The light fixture of claim 33, wherein the second configuration
of LEDs includes a third array on a third side of the frame and a
fourth array on a fourth side of the frame opposite the third side
of the light frame.
35. The light fixture of claim 26, wherein the first configuration
of LEDs includes a first array on a first side of the frame and a
second array on a second side of the frame adjacent the first side
of the light frame.
36. The light fixture of claim 35, wherein the second configuration
of LEDs includes a third array of LEDs on a third side of the frame
opposite the first side of the frame and a fourth array of LEDs on
a fourth side of the frame opposite the second side of the
frame.
37. The light fixture of claim 26, wherein the power circuitry
comprises a first LED driver operatively coupled to the first
configuration of LEDs and a second LED driver operatively coupled
to the second configuration of LEDs.
38. The light fixture of claim 37, wherein the first LED driver is
configured to selectively power the first configuration of LEDs and
the second LED driver is configured to selectively power the second
configuration of LEDs
39. The light fixture of claim 37, wherein the power circuitry
includes a controller operatively coupled to the first LED driver
and the second LED driver, wherein the controller is configured to
control the first LED driver and the second LED driver to power the
first configuration of LEDs for a first time period and to power
the second configuration of LEDs for a second time period equal to
the first time period.
40. The light fixture of claim 37, wherein the power circuitry
includes a controller operatively coupled to the first LED driver
and the second LED driver, wherein the controller is configured to
monitor failure of the first LED driver and the second LED
driver.
41. The light fixture of claim 26, wherein the power circuitry
comprises a first LED driver operatively coupled to the first
configuration of LEDs and the second configuration of LEDs, and a
second LED driver operatively coupled to the first configuration of
LEDs and the second configuration of LEDs.
42. The light fixture of claim 41, wherein the first LED driver is
configured to selectively power the first configuration of LEDs and
the second configuration of LEDs, and the second LED driver is
configured to selectively power the first configuration of LEDs and
the second configuration of LEDs.
43. The light fixture of claim 41, wherein the power circuitry
includes a controller operatively coupled to the first LED driver
and the second LED driver, wherein the controller is configured to
control the first LED driver and the second LED driver to power the
first configuration of LEDs for a first time period and to power
the second configuration of LEDs for a second time period equal to
the first time period.
44. The light fixture of claim 41, wherein the power circuitry
includes a controller operatively coupled to the first LED driver
and the second LED driver, wherein the controller is configured to
monitor failure of the first LED driver and the second LED
driver.
45. The light fixture of claim 44, wherein the controller is
configured to selectively activate the second LED driver to power
the first configuration of LEDs and the second configuration of
LEDs upon detection of failure or malfunction by the first LED
driver.
46. A light fixture comprising: a first set of light emitting
diodes (LEDs); a second set of light emitting diodes (LEDs); an
optically transmissive panel, each of the first set of LEDs and the
second set of LEDs being disposed adjacent to an edge of the
optically transmissive panel; and driving circuitry operatively
coupled to the first set of LEDs and the second set of LEDs and an
associated power supply, wherein the driving circuitry is
configured to selectively power the first set of LEDs and the
second set of LEDs in an alternating manner.
47. The light fixture of claim 46, wherein the driving circuitry is
configured to power the first set of LEDs for a first time period
and to power the second set of LEDs for a second time period equal
to the first time period.
48. The light fixture of claim 46, further comprising a third set
of light emitting diodes (LEDs), wherein the driving circuitry is
configured to power the first set of LEDs for a first time period,
to power the second set of LEDs for a second time period equal to
the first time period, and to power the third set of LEDs for a
third time period equal to the first time period.
49. The light fixture of claim 46, wherein the first set of LEDs
and the second set of LEDs are arranged in a single row in an
alternating arrangement.
50. The light fixture of claim 46, wherein the first set of LEDs is
arranged in a first row and the second set of LEDs is arranged in a
second row adjacent the first row.
51. The light fixture of claim 46, wherein the first set of LEDs
and the second set of LEDs are arranged in a pair of rows, wherein
each row of the pair of rows includes the first set of LEDs and the
second set of LEDs arranged in an alternating arrangement
52. The light fixture of claim 46, wherein the first set of LEDs is
arranged in a row on a first side of the optically transmissive
panel and the second set of LEDs is arranged in a row on a second
side of the optically transmissive panel opposite the first side of
the optically transmissive panel.
53. The light fixture of claim 46, wherein the driving circuitry
comprises a first LED driver operatively coupled to the first set
of LEDs and a second LED driver operatively coupled to the second
set of LEDs.
54. The light fixture of claim 53, wherein the driving circuitry
includes a controller operatively coupled to the first LED driver
and the second LED driver, wherein the controller is configured to
control the first LED driver and the second LED driver to power the
first set of LEDs for a first time period and to power the second
set of LEDs for a second time period equal to the first time
period.
55. The light fixture of claim 53, wherein the driving circuitry
includes a controller operatively coupled to the first LED driver
and the second LED driver, wherein the controller is configured to
monitor failure of the first LED driver and the second LED
driver.
56. The light fixture of claim 55, wherein the controller is
configured to activate the second LED driver to power the first set
of LEDs and the second set of LEDs upon detection of failure of the
first LED driver.
57. The light fixture of claim 46, wherein the driving circuitry
comprises a first LED driver operatively coupled to the first set
of LEDs and the second set of LEDs, and a second LED driver
operatively coupled to the first set of LEDs and the second set of
LEDs.
58. The light fixture of claim 57, wherein the first LED driver is
configured to selectively power the first set of LEDs and the
second set of LEDs, and the second LED driver is configured to
selectively power the first set of LEDs and the second set of
LEDs.
59. The light fixture of claim 57, wherein the driving circuitry
includes a controller operatively coupled to the first LED driver
and the second LED driver, wherein the controller is configured to
control the first LED driver and the second LED driver to power the
first set of LEDs for a first time period and to power the second
set of LEDs for a second time period equal to the first time
period.
60. The light fixture of claim 57, wherein the driving circuitry
includes a controller operatively coupled to the first LED driver
and the second LED driver, wherein the controller is configured to
monitor failure of the first LED driver and the second LED
driver.
61. The light fixture of claim 60, wherein the controller is
configured to selectively activate the second LED driver to power
the first set of LEDs and the second set of LEDs upon detection of
failure or malfunction by the first LED driver.
62. A light fixture comprising: an array of light emitting diodes
(LEDs); and driving circuitry operatively coupled to the array of
LEDs, wherein the driving circuitry includes: a first LED driver
selectively operatively coupled to the array of LEDs and a second
LED driver selectively operatively coupled to the array of LEDs;
and a controller operatively coupled to the first LED driver and
the second LED driver, wherein the controller is configured to
selectively activate the second LED driver to power the array of
LEDs upon detection of failure or malfunction by the first LED
driver.
63. The light fixture of claim 62, wherein the controller is
configured to selectively activate the first LED driver to power
the array of LEDs upon detection of failure of malfunction by the
second LED driver.
64. A light fixture comprising: a frame; a light emitting diode
(LED) panel disposed within the frame, wherein the LED panel
includes: a first configuration of light emitting diodes (LEDs);
and a second configuration of light emitting diodes (LEDs); and
driving circuitry operatively coupled to the first configuration of
LEDs and the second configuration of LEDs, wherein the driving
circuitry is configured to selectively power the first
configuration of LEDs and the second configuration of LEDs in an
alternating manner.
65. A method for extending rated life of a light emitting diode
(LED) light fixture, the LED light fixture having at least one
array of LEDs, the method comprising: providing a first LED driver
selectively operatively coupled to the at least one array of LEDs;
providing a second LED driver selectively operatively coupled to
the at least one array of LEDs; electrically coupling the first LED
driver to the at least one array of LEDs and; monitoring the first
LED driver for failure, malfunction or reduced performance; if
failure, malfunction or reduced performance is detected for the
first LED driver, electrically coupling the second LED driver to
the at least one array of LEDs and electrically decoupling the
first LED driver from the at least one array of LEDs.
66. A method of extending rated life of a light emitting diode
(LED) light fixture, the method comprising: providing a first
configuration of LEDs; providing a second configuration of LEDs;
and selectively powering the first configuration of LEDs and the
second configuration of LEDs in an alternating manner.
Description
RELATED APPLICATION DATA
[0001] The present application claims benefit of U.S. Provisional
App. No. 61/487,253, filed May 17, 2011, which is incorporated by
reference in its entirety. The present application also claims
benefit of U.S. Provisional App. No. 61/579,472, filed Dec. 22,
2011, which is incorporated by reference in its entirety.
FIELD OF INVENTION
[0002] The present invention relates generally to lighting
assemblies, and more particularly to a versatile, substantially
flat panel light emitting diode lighting assembly and associated
driving circuitry.
BACKGROUND
[0003] For years, lighting systems, such as ceiling mounted
lighting fixtures or luminaires, have made use of fluorescent lamps
and/or incandescent lamps. In addition to the lamps, lighting
systems typically include an assembly of components, such as
ballasts and reflectors. Luminaires that incorporate fluorescent
lamps are the most commonly used commercial light sources due to
their relatively high efficiency, diffuse light distribution
characteristics, and long operating life. Luminaires that
incorporate light emitting diodes are emerging as an attractive
alternative to fluorescent lamp luminaires, providing marked
improvements in efficiency and operating life.
[0004] Over the lifetime of a lighting system, for example, a
commercial lighting system, the expenditures associated with
operating and maintaining the system can be significant. As
lighting fixtures age and deteriorate, the light-emitting ability
degrades and the light output per unit of consumed electrical
energy is significantly reduced. Modern ballasts, lamps and
reflectors are available that can significantly enhance the
light-emitting ability of the lighting system and also
significantly enhance the energy efficiency by reducing the power
consumption. As a result, the light output could be increased,
while simultaneously reducing the associated energy costs. In many
applications, long operating life, which reduces the burden of
maintaining or replacing light fixtures, is seen as an important
characteristic.
SUMMARY OF INVENTION
[0005] The present application is directed to a light fixture
including a light emitting diode panel and associated driving
circuitry. In accordance with one aspect of the disclosed
technology, the light fixture includes power circuitry sized and
configured to be housed within the frame of the light fixture. In
accordance with one aspect, the light fixture can include multiple
configurations of light emitting diode (LED) arrays that can be
operated alternately. In accordance with another aspect, the light
fixture can include multiple drivers operatively coupled to a LED
array, where the drivers can be selectively operated to drive the
LED array.
[0006] One aspect of the disclosed technology relates to a light
fixture that includes a frame; a light emitting diode (LED) panel
disposed within the frame; and power circuitry disposed within the
frame, the power circuitry being configured to electrically couple
the substantially flat LED panel to an external power supply.
[0007] According to one feature, the power circuitry is sized to be
positioned within a channel defined by the frame.
[0008] According to one feature, the power circuitry includes
driving circuitry configured to convert an AC input into a DC
output suitable for powering the LED panel.
[0009] According to one feature, the power circuitry has a length
and a width, wherein the length-to-width ratio is at least 5 to
1.
[0010] According to one feature, the power circuitry has a length
and a width, wherein the length-to-width ratio is at least 10 to
1.
[0011] According to one feature, at least a portion of the frame
defines a first channel configured to support the power
circuitry.
[0012] According to one feature, at least a portion of the frame is
configured to support an array of LEDs disposed adjacent to an edge
of the frame. According to one feature, the first channel is
configured to support the array of LEDs.
[0013] According to one feature, at least a portion of the frame
defines a second channel configured to support the array of
LEDs.
[0014] According to one feature, at least a portion the frame is
configured to support electrical connectors between the power
circuitry and the array of LEDs.
[0015] According to one feature, at least a portion the frame is
configured to support electrical connectors between the power
circuitry and the array of LEDs.
[0016] According to one feature, the power circuitry includes an
array of circuit modules supported by the first channel.
[0017] According to one feature, the first channel has a height of
no more than about 0.5 inches.
[0018] According to one feature, the first channel has a width of
no more than about 1.0 inches.
[0019] According to one feature, at least a portion of the frame
defines a second channel configured to support the power
circuitry.
[0020] According to one feature, the power circuitry within the
second channel has a length of about 12 inches.
[0021] According to one feature, at least a portion of the frame
defines a third channel configured to support an array of LEDs
disposed adjacent at least one side of the frame.
[0022] According to one feature, the power circuitry includes a LED
driver having a length, a width and a height, wherein the length is
about 12 inches, the width is about 1.0 inches and the height is
about 0.5 inches.
[0023] According to one feature, the LED panel is edge lit.
[0024] According to one feature, the LED panel includes a plurality
of LEDs disposed adjacent at least one edge of the frame.
[0025] According to one feature, the frame is rectangular and the
LED panel includes an array of LEDs incorporated into at least two
sides of the frame.
[0026] According to one feature, the LED panel includes: an
optically-transmissive panel; and an array of LEDs disposed
adjacent at least one edge of the frame and disposed adjacent the
optically transmissive panel.
[0027] According to one feature, the LED panel includes an
optically-transmissive panel; and an array of LEDs disposed across
a first surface of the optically-transmissive panel.
[0028] According to one feature, the array of LEDs is disposed
across substantially the entire first surface of the
optically-transmissive panel.
[0029] According to one feature, the frame of the light fixture has
a thickness of no more than about 0.5 inches.
[0030] According to one feature, the frame of the light fixture has
a thickness of no more than about 1.0 inches.
[0031] According to one feature, the frame is rectangular and the
LED panel includes: a light guide plate; a first array of LEDs
incorporated into a first side of the frame adjacent a first side
of the light guide plate, the first array of LEDs emitting light
focused along a first direction; a second array of LEDs
incorporated into a second side of the frame adjacent a second side
of the light guide plate, the second array of LEDs emitting light
focused along a second direction that is opposite the first
direction; a first brightness enhancement film (BEF) positioned
adjacent the light guide plate and configured to collimate light
emitted by the first array of LEDs; and a second BEF positioned
adjacent the first BEF and configured to collimate light emitted by
the second array of LEDs.
[0032] According to one feature, the power circuitry includes a
controller configured to control the intensity of the light emitted
by the LED panel.
[0033] According to one feature, the LED panel includes: a first
configuration of LEDs; and a second configuration of LEDs.
[0034] According to one feature, the power circuitry is configured
to power the first configuration of LEDs for a first time period
and to power the second configuration of LEDs for a second time
period equal to the first time period.
[0035] According to one feature, the LED panel includes a third
configuration of LEDS, wherein the power circuitry is configured to
power the first configuration of LEDs for a first time period, to
power the second configuration of LEDs for a second time period
equal to the first time period, and to power the third
configuration of LEDs for a third time period equal to the first
time period.
[0036] According to one feature, the power circuitry is configured
to alternatively power the first configuration of LEDs and the
second configuration of LEDs over a cyclical time period including
the first time period and the second time period.
[0037] According to one feature, the first configuration of LEDs
and the second configuration of LEDs are arranged in an alternating
arrangement.
[0038] According to one feature, the first configuration of LEDs is
arranged in a first row and the second configuration of LEDs is
arranged in a second row adjacent the first row.
[0039] According to one feature, the first configuration of LEDs
and the second configuration of LEDs are arranged in a first row
and a second row below the first row.
[0040] According to one feature, the first configuration of LEDs
and the second configuration of LEDs are arranged in a pair of
rows, wherein each row of the pair of rows includes the first
configuration of LEDs and the second configuration of LEDs arranged
in an alternating arrangement
[0041] According to one feature, the first configuration of LEDs
and the second configuration of LEDs are arranged in a pair of rows
in an alternating arrangement.
[0042] According to one feature, the first configuration of LEDs is
arranged in a first row on a first side of the frame and the second
configuration of LEDs is arranged in a second row on a second side
of the frame opposite the first side of the frame.
[0043] According to one feature, first configuration of LEDs
includes a first array on a first side of the frame and a second
array on a second side of the frame opposite the first side of the
light frame.
[0044] According to one feature, the second configuration of LEDs
includes a third array on a third side of the frame and a fourth
array on a fourth side of the frame opposite the third side of the
light frame.
[0045] According to one feature, the first configuration of LEDs
includes a first array on a first side of the frame and a second
array on a second side of the frame adjacent the first side of the
light frame.
[0046] According to one feature, the second configuration of LEDs
includes a third array of LEDs on a third side of the frame
opposite the first side of the frame and a fourth array of LEDs on
a fourth side of the frame opposite the second side of the
frame.
[0047] According to one feature, the first configuration of LEDs
and the second configuration of LEDs are arranged in a pair of
arrays on opposite sides of the frame, wherein the first
configuration of LEDs and the second configuration of LEDs are
arranged in an alternating arrangement in the pair of arrays on
opposite sides of the light fixture.
[0048] According to one feature, the power circuitry comprises a
first LED driver operatively coupled to the first configuration of
LEDs and a second LED driver operatively coupled to the second
configuration of LEDs.
[0049] According to one feature, the first LED driver is configured
to selectively power the first configuration of LEDs and the second
LED driver is configured to selectively power the second
configuration of LEDs
[0050] According to one feature, the power circuitry includes a
controller operatively coupled to the first LED driver and the
second LED driver, wherein the controller is configured to control
the first LED driver and the second LED driver to power the first
configuration of LEDs for a first time period and to power the
second configuration of LEDs for a second time period equal to the
first time period.
[0051] According to one feature, the power circuitry includes a
controller operatively coupled to the first LED driver and the
second LED driver, wherein the controller is configured to monitor
failure of the first LED driver and the second LED driver.
[0052] According to one feature, the power circuitry comprises a
first LED driver operatively coupled to the first configuration of
LEDs and the second configuration of LEDs, and a second LED driver
operatively coupled to the first configuration of LEDs and the
second configuration of LEDs.
[0053] According to one feature, the first LED driver is configured
to selectively power the first configuration of LEDs and the second
configuration of LEDs, and the second LED driver is configured to
selectively power the first configuration of LEDs and the second
configuration of LEDs.
[0054] According to one feature, the power circuitry includes a
controller operatively coupled to the first LED driver and the
second LED driver, wherein the controller is configured to control
the first LED driver and the second LED driver to power the first
configuration of LEDs for a first time period and to power the
second configuration of LEDs for a second time period equal to the
first time period.
[0055] According to one feature, the power circuitry includes a
controller operatively coupled to the first LED driver and the
second LED driver, wherein the controller is configured to monitor
failure of the first LED driver and the second LED driver.
[0056] According to one feature, the controller is configured to
selectively activate the second LED driver to power the first
configuration of LEDs and the second configuration of LEDs upon
detection of failure or malfunction by the first LED driver.
[0057] Another aspect of the disclosed technology relates to a
light fixture that includes a first set of light emitting diodes
(LEDs); a second set of light emitting diodes (LEDs); an optically
transmissive panel, each of the first set of LEDs and the second
set of LEDs being disposed adjacent to an edge of the optically
transmissive panel; and driving circuitry operatively coupled to
the first set of LEDs and the second set of LEDs and an associated
power supply, wherein the driving circuitry is configured to
selectively power the first set of LEDs and the second set of LEDs
in an alternating manner.
[0058] According to one feature, the driving circuitry is
configured to power the first set of LEDs for a first time period
and to power the second set of LEDs for a second time period equal
to the first time period.
[0059] According to one feature, the light fixture includes a third
set of light emitting diodes (LEDs), and the driving circuitry is
configured to power the first set of LEDs for a first time period,
to power the second set of LEDs for a second time period equal to
the first time period, and to power the third set of LEDs for a
third time period equal to the first time period.
[0060] According to one feature, the first set of LEDs and the
second set of LEDs are arranged in a single row in an alternating
arrangement.
[0061] According to one feature, the first set of LEDs is arranged
in a first row and the second set of LEDs is arranged in a second
row adjacent the first row.
[0062] According to one feature, the first set of LEDs and the
second set of LEDs are arranged in a first row and a second row
below the first row.
[0063] According to one feature, the first set of LEDs and the
second set of LEDs are arranged in a pair of rows, wherein each row
of the pair of rows includes the first set of LEDs and the second
set of LEDs arranged in an alternating arrangement
[0064] According to one feature, the first set of LEDs and the
second set of LEDs are arranged in a pair of rows in an alternating
arrangement.
[0065] According to one feature, the first set of LEDs is arranged
in a row on a first side of the optically transmissive panel and
the second set of LEDs is arranged in a row on a second side of the
optically transmissive panel opposite the first side of the
optically transmissive panel.
[0066] According to one feature, the first set of LEDs includes a
first array on a first side of the light fixture and a second array
on a second side of the light fixture opposite the first side of
the light fixture.
[0067] According to one feature, the second set of LEDs includes a
third array on a third side of the light fixture and a fourth array
on a fourth side of the light fixture opposite the third side of
the light fixture.
[0068] According to one feature, the first set of LEDs includes a
first array on a first side of the light fixture and a second array
on a second side of the light fixture adjacent the first side of
the light fixture.
[0069] According to one feature, the second set of LEDs includes a
third array of LEDs on a third side of the light fixture opposite
the first side of the light fixture and a fourth array of LEDs on a
fourth side of the light fixture opposite the second side of the
light fixture.
[0070] According to one feature, the first set of LEDs and the
second set of LEDs are arranged in a pair of arrays on opposite
sides of the light fixture, wherein the first set of LEDs and the
second set of LEDs are arranged in an alternating arrangement in
the pair of arrays on opposite sides of the light fixture.
[0071] According to one feature, the driving circuitry comprises a
first LED driver operatively coupled to the first set of LEDs and a
second LED driver operatively coupled to the second set of
LEDs.
[0072] According to one feature, the first LED driver is configured
to selectively power the first set of LEDs and the second LED
driver is configured to selectively power the second set of
LEDs.
[0073] According to one feature, the driving circuitry includes a
controller operatively coupled to the first LED driver and the
second LED driver, wherein the controller is configured to control
the first LED driver and the second LED driver to power the first
set of LEDs for a first time period and to power the second set of
LEDs for a second time period equal to the first time period.
[0074] According to one feature, the driving circuitry includes a
controller operatively coupled to the first LED driver and the
second LED driver, wherein the controller is configured to monitor
failure of the first LED driver and the second LED driver.
[0075] According to one feature, the driving circuitry comprises a
first LED driver operatively coupled to the first set of LEDs and
the second set of LEDs, and a second LED driver operatively coupled
to the first set of LEDs and the second set of LEDs.
[0076] According to one feature, the first LED driver is configured
to selectively power the first set of LEDs and the second set of
LEDs, and the second LED driver is configured to selectively power
the first set of LEDs and the second set of LEDs.
[0077] According to one feature, the driving circuitry includes a
controller operatively coupled to the first LED driver and the
second LED driver, wherein the controller is configured to control
the first LED driver and the second LED driver to power the first
set of LEDs for a first time period and to power the second set of
LEDs for a second time period equal to the first time period.
[0078] According to one feature, the driving circuitry includes a
controller operatively coupled to the first LED driver and the
second LED driver, wherein the controller is configured to monitor
failure of the first LED driver and the second LED driver.
[0079] According to one feature, the controller is configured to
activate the second LED driver to power the first set of LEDs and
the second set of LEDs upon detection of failure of the first LED
driver.
[0080] According to one feature, the controller is configured to
selectively activate the second LED driver to power the first set
of LEDs and the second set of LEDs upon detection of failure or
malfunction by the first LED driver.
[0081] According to another aspect of the disclosed technology, a
light fixture includes an array of light emitting diodes (LEDs);
and driving circuitry operatively coupled to the array of LEDs,
wherein the driving circuitry includes: a first LED driver
selectively operatively coupled to the array of LEDs and a second
LED driver selectively operatively coupled to the array of LEDs;
and a controller operatively coupled to the first LED driver and
the second LED driver, wherein the controller is configured to
selectively activate the second LED driver to power the array of
LEDs upon detection of failure or malfunction by the first LED
driver.
[0082] According to one feature, the controller is configured to
selectively activate the first LED driver to power the array of
LEDs upon detection of failure of malfunction by the second LED
driver.
[0083] Another aspect of the disclosed technology relates to a
light fixture that includes a frame; a light emitting diode (LED)
panel disposed within the frame, wherein the LED panel includes: a
first configuration of light emitting diodes (LEDs); and a second
configuration of light emitting diodes (LEDs); and driving
circuitry operatively coupled to the first configuration of LEDs
and the second configuration of LEDs, wherein the driving circuitry
is configured to selectively power the first configuration of LEDs
and the second configuration of LEDs in an alternating manner.
[0084] Another aspect of the disclosed technology relates to a
method for extending rated life of a light emitting diode (LED)
light fixture, where the LED light fixture having at least one
array of LEDs. The method includes providing a first LED driver
selectively operatively coupled to the at least one array of LEDs;
providing a second LED driver selectively operatively coupled to
the at least one array of LEDs; electrically coupling the first LED
driver to the at least one array of LEDs and; monitoring the first
LED driver for failure, malfunction or reduced performance; if
failure, malfunction or reduced performance is detected for the
first LED driver, electrically coupling the second LED driver to
the at least one array of LEDs and electrically decoupling the
first LED driver from the at least one array of LEDs.
[0085] Another aspect of the disclosed technology relates to a
method of extending rated life of a light emitting diode (LED)
light fixture. The method includes providing a first configuration
of LEDs; providing a second configuration of LEDs; and selectively
powering the first configuration of LEDs and the second
configuration of LEDs in an alternating manner.
[0086] These and further features of the present invention will be
apparent with reference to the following description and attached
drawings. In the description and drawings, particular embodiments
of the invention have been disclosed in detail as being indicative
of some of the ways in which the principles of the invention may be
employed, but it is understood that the invention is not limited
correspondingly in scope. Rather, the invention includes all
changes, modifications and equivalents coming within the spirit and
terms of the claims appended thereto.
[0087] Features that are described and/or illustrated with respect
to one embodiment may be used in the same way or in a similar way
in one or more other embodiments and/or in combination with or
instead of the features of the other embodiments.
[0088] It should be emphasized that the term "comprises/comprising"
when used in this specification is taken to specify the presence of
stated features, integers, steps or components but does not
preclude the presence or addition of one or more other features,
integers, steps, components or groups thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0089] Many aspects of the invention can be better understood with
reference to the following drawings. The components in the drawings
are not necessarily to scale, emphasis instead being placed upon
clearly illustrating the principles of the present invention.
Likewise, elements and features depicted in one drawing may be
combined with elements and features depicted in additional
drawings. Moreover, in the drawings, like reference numerals
designate corresponding parts throughout the several views.
[0090] FIG. 1 is a diagrammatic illustration of a LED panel light
fixture in accordance with one aspect of the disclosed
technology;
[0091] FIG. 2 is a diagrammatic illustration of a LED panel light
fixture in accordance with one aspect of the disclosed
technology;
[0092] FIG. 3 is a diagrammatic illustration of a LED panel light
fixture in accordance with one aspect of the disclosed
technology;
[0093] FIG. 4 is a perspective view of a LED panel light fixture in
accordance with one aspect of the disclosed technology;
[0094] FIG. 5 is a rear view of a LED panel in accordance with one
aspect of the disclosed technology;
[0095] FIG. 6 is a rear perspective view of a LED panel in
accordance with one aspect of the disclosed technology;
[0096] FIG. 7 is a diagrammatic illustration of a substantially
flat LED panel in accordance with one aspect of the disclosed
technology;
[0097] FIG. 8 is a diagrammatic illustration of a substantially
flat LED panel in accordance with one aspect of the disclosed
technology;
[0098] FIG. 9 is a diagrammatic illustration of a substantially
flat LED panel in accordance with one aspect of the disclosed
technology;
[0099] FIG. 9A is a diagrammatic illustration of a substantially
flat LED panel in accordance with one aspect of the disclosed
technology;
[0100] FIG. 9B is a diagrammatic illustration of a substantially
flat LED panel in accordance with one aspect of the disclosed
technology;
[0101] FIG. 10 is shows an exploded view of an optical stack of a
LED panel in accordance with one aspect of the disclosed
technology;
[0102] FIG. 11 is shows an exploded view of an optical stack of a
LED panel in accordance with one aspect of the disclosed
technology;
[0103] FIG. 12 is a rear perspective view of a LED panel in
accordance with one aspect of the disclosed technology;
[0104] FIG. 13 is a rear view of a portion of a LED panel in
accordance with one aspect of the disclosed technology;
[0105] FIG. 14 is a diagrammatic illustration of a portion of a
frame housing power circuitry in accordance with one aspect of the
disclosed technology;
[0106] FIG. 14A is a diagrammatic illustration of a portion of a
frame housing power circuitry in accordance with one aspect of the
disclosed technology;
[0107] FIG. 15 is a rear view of a portion of a LED panel in
accordance with one aspect of the disclosed technology;
[0108] FIG. 16 is a diagrammatic illustration of a portion of a
frame in accordance with one aspect of the disclosed
technology;
[0109] FIG. 17 is a perspective view of a portion of a LED panel in
accordance with one aspect of the disclosed technology;
[0110] FIG. 18 is a perspective view of a portion of a LED panel in
accordance with one aspect of the disclosed technology;
[0111] FIG. 19 is a perspective view of a portion of a LED panel in
accordance with one aspect of the disclosed technology;
[0112] FIG. 20 is a perspective view of a portion of a frame in
accordance with one aspect of the disclosed technology;
[0113] FIG. 21 is a perspective view of a portion of a frame in
accordance with one aspect of the disclosed technology;
[0114] FIG. 22 is a perspective view of a portion of a LED panel in
accordance with one aspect of the disclosed technology;
[0115] FIG. 23 is a perspective view of a portion of a LED panel in
accordance with one aspect of the disclosed technology;
[0116] FIG. 24 is a diagrammatic illustration of the light fixture
in accordance with one aspect of the disclosed technology;
[0117] FIG. 25 is a diagrammatic illustration of the light fixture
in accordance with one aspect of the disclosed technology;
[0118] FIG. 26 is a diagrammatic illustration of the light fixture
in accordance with one aspect of the disclosed technology;
[0119] FIG. 27 is a diagrammatic illustration of the light fixture
in accordance with one aspect of the disclosed technology;
[0120] FIG. 28 is a diagrammatic illustration of the light fixture
in accordance with one aspect of the disclosed technology;
[0121] FIG. 29 is a diagrammatic illustration of a LED assembly in
accordance with one aspect of the disclosed technology;
[0122] FIG. 30 is a diagrammatic illustration of a LED assembly in
accordance with one aspect of the disclosed technology;
[0123] FIG. 31 is a diagrammatic illustration of a LED assembly in
accordance with one aspect of the disclosed technology;
[0124] FIG. 32 is a diagrammatic illustration of the light fixture
in accordance with one aspect of the disclosed technology;
[0125] FIG. 33 is a diagrammatic illustration of the light fixture
in accordance with one aspect of the disclosed technology;
[0126] FIG. 34 is a diagrammatic illustration of the light fixture
in accordance with one aspect of the disclosed technology;
[0127] FIG. 35 is a diagrammatic illustration of the light fixture
in accordance with one aspect of the disclosed technology.
DETAILED DESCRIPTION
[0128] To illustrate aspects of the disclosed technology in a clear
and concise manner, the drawings may not necessarily be to scale
and certain features may be shown in somewhat schematic form.
[0129] A growing sophistication about the economics of lighting has
emerged, and with it, recognition that luminous efficacy, or lumens
per watt, is not the only important variable in designing and
maintaining cost-effective, quality lighting. Lamp life is another
important consideration. Service life is increasingly a driver in
the development of new lamps and lighting systems. More lamp
manufacturers are using life to distinguish their own products from
those of their competitors.
[0130] Lamp packaging typically states the manufacturer's
determination of lamp life, called rated life, usually in hours.
The most straightforward interpretation of these ratings is
arguably that they tell us how long the lamp will operate before it
fails ("burns out"). But the definition of life is different for
different lamp types.
[0131] Incandescent lamp life is measured by operating a sample of
lamps continuously in a specified position and at a specified
voltage. The number of burning hours at which half the lamps have
failed is considered the rated life of the lamps. Fluorescent lamps
can be tested while operating at a specified temperature (e.g.,
25.degree. C./77.degree. F.) on a continuous 3-hour-on,
20-minute-off cycle, with a standard ballast circuit that controls
the current. As with incandescent lamps, rated life is the elapsed
number of operating hours at which half of the lamps in a sample
have burned out.
[0132] Light Emitting Diode (LED) light sources typically do not
fail in the sense that other sources do. Over time, however, their
light output can decrease until they are no longer useful for a
given purpose. LEDs often last hundreds of times longer than
incandescent bulbs and fluorescent tubes--up to 100,000 hours.
[0133] Because LEDs require much smaller voltages of direct
current, another factor that reduces the apparent long life of LEDs
is the need for auxiliary electronics and equipment to house and
operate these sources. Because electrical power commercially
available in the United States is in the form of alternating
current, LEDs require direct current converters. Such devices may
have rated lives significantly shorter than the LEDs with which
they are used. Higher voltage and high temperatures can also
increase lumen depreciation in LEDs.
[0134] In addition, while some substantially flat LED panel
lighting fixtures have been employed, these lighting fixtures make
use of an AC-to-DC power converter module external to the fixture
(e.g., extending outward from the back surface of the fixture). A
power converter module external to the lighting fixture limits
design flexibility in integrating LED flat panel fixtures or
luminaires into a range of applications, and adds complexity to
installation. For example, in installations in which a lighting
fixture would be surface mounted in a visible location, there would
be no out-of-view place for ancillary equipment such as a power
converter.
[0135] The present disclosure recognizes shortcomings associated
with conventional fluorescent lamp and incandescent lamp lighting
systems. In addition, the present disclosure recognizes potential
shortcomings with LED-based lighting assemblies and associated
power circuitry, and provides an improved lighting fixture and
associated power circuitry.
[0136] The present disclosure recognizes that the operating life on
an entire lighting product or system must be considered, rather
than just the potentially-promising long-rated life of LEDs within
the lighting product or system. Besides improving the effects of
lumen depreciation of LEDs, the present disclosure reduces the
likelihood of catastrophic failure of other parts of the lighting
product or system, including in particular a power supply or driver
for the LEDs. As is described more fully below, the present
application is directed to a light fixture including a light
emitting diode panel and associated driving circuitry. In
accordance with one aspect of the disclosed technology, the light
fixture includes power circuitry configured to be housed within the
frame of the light fixture. In accordance with one aspect, the
light fixture can include multiple configurations of light emitting
diode (LED) arrays that can be operated alternately. In accordance
with another aspect, the light fixture can include multiple drivers
operatively coupled to a LED array, where the drivers can be
selectively operated to drive the LED array. In accordance with
another aspect, the output of LED arrays can be adjusted to
maintain lumen brightness and uniformity.
[0137] Referring now to FIGS. 1-9B, an exemplary embodiment of a
light fixture 10 having a light emitting diode (LED) panel 12 is
provided. In one embodiment, the LED panel 12 is a substantially
flat LED panel (also referred to simply as a LED panel). The term
"substantially flat LED panel" as used in connection with the
description of the various embodiments, is meant to include LED
panels having a thickness that is substantially less than the
length and width of the panel. The term "LED panel fixture," as
used in connection with the description of the various embodiments,
denotes a light fixture 10 that incorporates a substantially flat
LED panel. LED panel fixtures may be of slightly non-uniform
thickness due to the configuration of the LED panel or of another
part of the light fixture 10. For example, an LED panel fixture can
include a frame (designated generally as 14) having a thickness
that is greater than the thickness of the LED panel 12.
[0138] As shown in the various figures, the light fixture 10
includes a frame 14 that surrounds the LED panel 12. The frame 14
provides structural support, contains components of the LED panel
fixture such as arrays, strips, or bars of LEDs 20 and the power
circuitry (also referred to as driving circuitry, and as LED power
circuitry or LED driving circuitry) (designated generally as 16),
and provides heat dissipation. As is described more fully below,
the frame can be configured to house or otherwise support LED power
circuitry as well as associated wiring and electrical connections
between the power circuitry and the LED arrays.
[0139] The light fixture 10, including the LED panel 12 may take on
a variety of dimensions and form factors, including, but not
limited to, rectangular, other polygonal (e.g., octagonal),
circular and elliptical form factors. For example, the light
fixture can be square (see FIG. 1) with a size of approximately
nine inches by nine inches, approximately twelve inches by twelve
inches, or approximately twenty-four inches by twenty-four inches.
By way of example, the light fixture 10 also can be rectangular
with a size of approximately one foot by four feet (1 foot.times.4
feet) (see FIG. 2) or a size of approximately two feet by four feet
(2 feet.times.4 feet) (see FIG. 3), corresponding to exemplary
lower dimensions of standard fluorescent ceiling troffers. In
another embodiment, the light fixture 10 can be sized to standard
lengths for under counter or under cabinet lighting applications
(e.g., twelve inches, eighteen inches, twenty-four inches,
thirty-six inches, etc.). The LED panel can take on any lateral
size, while maintaining a relatively small thickness, without
departing from the scope of the disclosed technology. This
versatility in sizing provides enhanced flexibility in use in
connection with a variety of applications.
[0140] As noted above, in accordance with one exemplary embodiment,
the light fixture 10 can include a frame 14, a substantially flat
LED panel 12 disposed within the frame 14 and power circuitry 16
disposed or otherwise housed within the frame 14. The power
circuitry 16 is configured to electrically couple the LED panel 12
to an external power supply (not shown), for example, via a
suitable electrical connector such as a plug or socket connector
18. It will be appreciated that the LED panel fixture can be
configured to provide bright, uniform light in a relatively thin
package. For example, in accordance with one embodiment, the
substantially flat LED panel 12 can have a thickness of less than
about 1.0 inches. In accordance with another embodiment, the
substantially flat LED panel 12 can have a thickness of less than
about 0.5 inches. In accordance with one exemplary embodiment, the
frame 14 can be made up of four segments having mitred joints.
Alternatively, the frame 14 can be formed from two pieces (e.g., a
top piece and a bottom piece) snapped or otherwise joined together.
The frame can define or otherwise include stand-offs on the back of
the frame (e.g., for providing ventilation when the frame is
surface mounted to a support surface).
[0141] Referring now to FIGS. 10-11, and with continued reference
to FIGS. 1-9, exemplary embodiments, in which the LED panel
includes a plurality of layers along with edge lighting disposed
adjacent to at least one edge of the frame, are provided. In the
illustrated exemplary embodiments, the LED panel includes an
optically-transmissive panel 22, e.g., a light guide plate or other
polycarbonate or acrylic plate configured to produce even
distribution of light received at edges of the
optically-transmissive panel 22. An array of LEDs (designated
generally as 20) can be disposed adjacent at least one edge of the
frame 14 and the optically transmissive panel 22. For example, a
strip of LEDs 20 may be supported adjacent to one edge of the frame
14 (e.g., disposed within a channel in the frame) and adjacent to
one edge of the optically-transmissive panel 22. Alternatively, the
LED panel 12 can include strips, arrays or configurations of LEDs
20 incorporated into or at least partially supported by two edges
of the frame 14. (References in this disclosure to LEDs 20 being
supported by, incorporated into or adjacent an edge of the frame
includes the LEDs being supported by a wall of a channel located at
the edge of the frame, wherein the channel wall is offset from the
edge of the frame by the width of the channel).
[0142] The strips, arrays or configurations of LEDs can be mounted
to the frame using one of a number of suitable methods. For
example, the LED strips or arrays 20 can be secured to a portion of
the frame (e.g., within a channel in the frame) using a suitable
adhesive or suitable fasteners. It will be appreciated that the LED
strips or arrays 20 can be mounted to the frame in a way that
controls the dissipation of heat from the LED strips or arrays to
the frame. For example, it can be desirable to use the frame to
dissipate some heat from LED arrays 20, while limiting the amount
of heat passing to the frame to prevent the frame from becoming too
warm. In accordance with one exemplary embodiment, a suitable
adhesive can be used to allow a limited amount of heat transfer
from the LED arrays 20 to the frame 14. Alternatively, metal
fasteners (or direct contact with the frame) can be used to
facilitate a greater degree of heat transfer from the LED arrays to
the frame.
[0143] In yet another exemplary embodiment in which the light
fixture 10 has a rectangular form factor, the LED panel 12) can
include strips, arrays or configurations of LEDs 20 incorporated
into or at least partially supported by all four edges of the frame
14. The LEDs can be sized and positioned such that the "emission
dimension" of the LED elements has the same thickness or slightly
less thickness than the thickness of the light input edge of the
optically-transmissive panel, thereby allowing for an extremely
thin profile. Not shown in the drawings, the LEDs may include
optical coupling structures such as lenses or reflectors that
direct light emitted by the LEDs into an edge of
optically-transmissive panel 22.
[0144] The LED panel 12 can include a diffuser film 24 disposed on
a first side of the optically-transmissive panel 22, e.g., below
the optically transmissive panel 22 when the fixture is mounted
horizontally for a ceiling lighting application. The outer diffuser
film 24 is configured to provide uniform light output, and can be
made of any suitable material. For example, for outdoor
applications, the outer diffuser film 24 can be a weatherable film.
The outer diffuser film 24 can be configured as a soft film or as a
hard, abrasion-resistant film depending upon the particular
application. The outer diffuser film 24 can be made waterproof or
moisture proof depending upon the desired application.
[0145] The LED panel 12 can include a brightness enhancement film
(BEF) 26 disposed on a second side of the optically-transmissive
panel 22, e.g., above the optically-transmissive panel 22 when the
fixture is mounted horizontally for a ceiling lighting application.
The brightness enhancement film 26 can be configured to collimate
light along a vertical axis to improve the overall light output
from the LED panel 12. In accordance with one embodiment, the LED
panel can be configured to include multiple BEFs optimized for the
particular arrangement of LEDs along one or more edges of the LED
panel. In this exemplary embodiment, the LED panel can include an
optically-transmissive panel in the form of a light guide plate
with a first array of LEDs incorporated into a first side of the
frame adjacent a first side of the light guide plate, the first
array of LEDs emitting light focused along a first direction, and a
second array of LEDs incorporated into a second side of the frame
adjacent a second side of the light guide plate, the second array
of LEDs emitting light focused along a second direction that is
opposite the first direction. The substantially flat LED panel can
include a first brightness enhancement film (BEF) positioned
adjacent the light guide plate and configured to collimate light
emitted by the first array of LEDs, and a second BEF positioned
adjacent the first BEF and configured to collimate light emitted by
the second array of LEDs.
[0146] The LED panel 12 can include a reflector 28 positioned on
the other side of the BEF 26 (e.g., above the BEF 26) when the
fixture is mounted horizontally (e.g., for a ceiling lighting
application). The reflector 28 is configured and position to return
a portion of the light emitted by the optically-transmissive panel
22 in a direction opposite the intended output direction, thereby
providing enhanced total light output. In the illustrated exemplary
embodiments, the substantially flat LED panel 12 includes a backing
30, e.g., a sheet metal backing disposed adjacent the other side of
the reflector 28. A sheet metal backing 30 in combination with a
metallic (e.g. aluminum) frame 14 can provide excellent dissipation
of heat generated by the LEDs.
[0147] While aspects of the disclosed technology have been
described with respect to LED strips or arrays disposed adjacent to
edges of the frame and the optically-transmissive panel, it will be
appreciated that other configurations may be employed without
departing from the scope of the present invention. For example,
FIG. 9B shows an embodiment in which an array of LEDs (e.g., a full
array of LEDs) is disposed across most or substantially all of the
area of an optically-transmissive panel, while receiving power from
edge-mounted power circuitry within the frame of the flat panel
lighting fixture. For example, the panel can incorporate rows of
LEDs at one face of the optically-transmissive panel, wherein the
LEDs in each row are electrically coupled by a power line to a
driver located at the edge of the LED fixture.
[0148] With continued reference to FIGS. 1-9B, and turning now to
FIGS. 12-23, in accordance with one exemplary embodiment, the light
fixture 10 includes power circuitry 16 disposed or otherwise housed
within the frame 14, where the power circuitry 16 is configured to
electrically couple the LED panel 12 to an external power source
(e.g., via a suitable electrical connector 18). It will be
appreciated that this embodiment serves to provide an LED panel
fixture with an extremely thin form factor that can be easily
mounted to a flat surface, such as a wall, an underside of a
cabinet or the like. As shown in FIGS. 7-9, the light fixture 10
can be configured to include first and second LED strips, bars,
arrays or configurations (designated generally as 20) disposed on
opposite sides of the frame 14, along with power circuitry in the
form of a pair of LED drivers 16 positioned in one or both of the
remaining sides of the rectangular frame. The illustrated
embodiment shows a first LED driver 16 electrically coupled to and
configured to control a first LED array (e.g., an LED strip 20),
along with a second LED driver 16 coupled to and configured to
control the second LED array (e.g., an LED strip).
[0149] As noted above, the light fixture includes power circuitry
16 disposed within or otherwise housed by the frame, where the
power circuitry 16 is configured to electrically couple the LED
panel 12 to an external power source. It will be appreciated that
the power circuitry will be configured to have a relatively long
and narrow form factor, allowing it to be housed within a portion
of a frame. FIGS. 14-18 show exemplary embodiments of the power
circuitry 16, or portions of the power circuitry disposed or
otherwise housed within a portion the frame 14. For example, in
accordance with one exemplary embodiment, the power circuitry (or
component boards of the power circuitry) can have a length and a
width, where the length-to-width ratio is at least 5-to-1. In
accordance with another exemplary embodiment, the power circuitry
can have a length-to-width ratio of at least 10-to-1.
[0150] The frame 14 can be configured to define or otherwise
provide one or more channels to support aspects of the power
circuitry, the associated wiring as well as LED arrays or bars. For
example, a portion of the frame may be configured to define a
channel 40 (e.g., a channel designated as a first channel or a
second channel) sized to house a portion of the power circuitry 16.
For example, in accordance with one embodiment, the first channel
40 within a portion of the frame can be configured to house power
circuitry (e.g., LED driver circuitry) having dimensions of
approximately twelve inches in length, approximately one inch of
width and approximately one half inch in height. It will be
appreciated that the disclosed technology is not limited to these
exemplary dimensions. The first channel 40 can take on other
dimensions without departing from the scope of the disclosed
technology.
[0151] Such compact power and control circuitry can be obtained by
employing miniaturized power and/or control boards. For example, a
programmable logic controller (PLC) motherboard can serve as a
real-time clock with timing control logic to regulate operation of
the LED arrays. As is discussed more fully below, multiple arrays,
sets or configurations of LEDs can be operated in an alternating
manner according to a predetermined timing sequence. This
motherboard may operate in coordination with one or more
daughterboards, which are disposed or otherwise housed within the
frame (e.g., within a first or second channel defined by a portion
of the frame) to provide additional functionality. For example, a
sensor module can process signals from one or more sensors within
the light fixture (e.g., a sensor to determine the intensity and/or
color temperature of light being emitted by the light fixture)
(see, for example, FIGS. 22-23). Output from these sensors can be
used, for example, to control the output intensity of the lighting
fixture in the case of lumen depreciation for some or all of the
LEDs within the lighting fixture.
[0152] It will be appreciated that various sensors can be employed
without departing from the scope of the disclosed technology. For
example, infrared sensors may be used for remote control dimming.
Also, ambient light sensors may be employed to provide automatic
adjustment to dimming. It also will be appreciated that the light
fixture can be configured to receive external inputs to control
operation, such as signals from an associated security camera or
motion sensor system
[0153] Multiple control modules may be distributed within the frame
for efficient use of space. For example, two primary drivers may be
disposed or otherwise housed at opposite edges of the frame and one
or more input/output modules can be housed at a transverse edge of
the frame. As shown in FIG. 14A, the use of miniaturized circuit
elements permits multiple power supply or control modules to be
arrayed within a given channel 40 of the frame 14. Three power
supply modules 16A, 16B, and 16C are arrayed within the channel. As
shown these are separate circuit elements, but multiple power
supply or control modules also can be integrated on a single
circuit board. Respective power supply circuits can be electrically
coupled to different sets of LEDs within an array of LEDs (not
shown in FIG. 14A). This arrangement permits the DC voltage and
current output specifications of each power supply circuit to be
matched to input requirements of a subset of the LEDs within the
LED array, while making efficient use of limited space within frame
14. Further, this arrangement can facilitate under-driving an array
of LEDs to allow for increased driving in the case of lumen
depreciation.
[0154] In accordance with one exemplary embodiment, the frame or a
portion of the frame 14 can be configured to define another channel
42 (e.g., a channel designated as a first channel or a secondary
channel) for housing wiring or other electrical connectors
associated with the light fixture. For example, as shown in FIGS.
16-17, portions of the frame can include a channel 42 to support a
number of wires connecting the LED arrays to the driving circuitry.
It will be appreciated that given the potentially limited
cross-sectional dimensions of the channel in certain portions of
the frame or all of the frame, it might be undesirable to route
wiring or cables alongside circuit boards associated with the power
circuitry. In this situation, a channel can be defined to house
embedded conductive traces to conserve space within the frame. In
this exemplary embodiment, cables or other conventional wiring can
be used at other locations around the frame, such as
interconnecting an LED bar and driving circuitry at a corner of the
frame or at another area in the frame where power circuitry or
driver circuitry is not present.
[0155] It will be appreciated that the driving circuitry can be
tailored or otherwise customized to support the relatively long,
but narrow, geometry of the driving circuitry. For example,
space-sensitive components, such as capacitors and the like, can be
oriented along the long direction of the power circuitry footprint.
In addition, printed circuit boards associated with the power
circuitry can be configured to include multi-layers in which
conductive layers and/or conductive traces are stacked between
insulating material. In addition as noted above, multiple circuit
modules can be arrayed at a given channel or edge area of frame
14.
[0156] In accordance with one exemplary embodiment, the frame or a
portion of the frame can be configured to yet another channel 44
(e.g., a channel designated as a third channel) for housing a
supporting arrays or strips of LEDs 20.
[0157] It will be appreciated that housing the power circuitry
within the frame can provide an LED panel fixture with an extremely
thin form factor that can be easily mounted to a flat surface, such
as a wall, an underside of a cabinet or the like. As discussed
above, the light fixture 10 can be configured to include first and
second LED strips or bars 20 disposed on opposite sides of the
frame 14, along with power circuitry in the form of a pair of LED
drivers positioned in one or both of the remaining sides of the
rectangular frame. The illustrated exemplary embodiments shows a
first LED driver electrically coupled to and configured to control
a first LED array along with a second LED driver coupled to and
configured to control the second LED array.
[0158] FIG. 9 shows an alternative light fixture 10 with the first
and second LED arrays disposed on opposite sides of the frame 14
(e.g., on a top side of the frame and a bottom side of the frame in
the orientation provided in the figure), and with a pair of LED
drivers positioned on both remaining sides of the frame.
[0159] In FIG. 8 and FIG. 9, LED strips or bars 20 are located at
different sides of the frame 14 than LED drivers 16. As seen in
FIG. 9A, it is also possible to locate the LED drivers 16 on the
same sides of the frame as the LED strips 20. This arrangement
makes less efficient use of the space at the edges of frame 14, but
may simplify electrical connection of drivers 16 to LED strips
20.
[0160] Turning now to FIGS. 24-35, another aspect of the disclosed
technology will be described in greater detail. In accordance with
one exemplary embodiment, the light fixture can include multiple
sets or configurations of LEDs. For example, the light fixture can
be configured to include a first set or configuration of LEDs 20a
and a second set or configuration of LEDs 20b along with power
circuitry (also referred to as driving circuitry) 16 operatively
coupled to the first set of LEDs 20a and the second set of LEDs 20b
and an associated power supply (designated generally as 50), for
example, a standard AC power supply found in a home or office
setting, wherein the driving circuitry 16 is configured to
selectively power the first set of LEDs 20a and the second set of
LEDs 20b in an alternating manner.
[0161] In accordance with one embodiment (see FIGS. 25-26, and also
FIG. 34), the power circuitry 16 can include a first driver 52
operatively coupled to the first LED configuration 20a and a second
driver 54 operatively coupled to the second LED configuration 20b.
The power circuitry 16 can include a controller 56 operatively
coupled to the first driver 52 and the second driver 54, and
configured to selectively operate the first driver 52 and the
second driver 54 to control the first configuration of LEDs 20a and
the second configuration of LEDs 20b in a desired manner. FIG. 27
shows another exemplary embodiment in which switching circuitry 58
is operatively coupled to the first driver 52 and the second driver
54, and configured to selectively activate the first configuration
of LEDs 20a and the second configuration of LEDs 20b. FIG. 28 shows
yet another exemplary embodiment in which the controller 56 is
operatively coupled to the first driver 52 and the second driver 54
to selectively control operation of the first driver 52 and the
second driver 54, as well as monitor the first driver 52 and the
second driver 54 to ensure that the respective drivers are
functioning properly. This embodiment will be discussed in greater
detail below.
[0162] In accordance with one embodiment, the first set or
configuration of LEDs 20a and the second set or configuration of
LEDs 20b are driven alternately. For example, while the first
configuration of LEDs 20a is active, the second configuration of
LEDs 20b can be set to inactive and vice versa. In a preferred
embodiment, the first and second configurations of LEDs can be
driven cyclically, for example, repeated over periods of time where
the "on" cycle time for the first set of LEDs is identical or
substantially identical to the "on" cycle time for the second set
of LEDs. It will be appreciated that permitting the LEDs adequate
time to cool can extend the operating life of the LEDs, thereby
potentially extending the operating life of the light fixture. It
also will be appreciated that various timing cycles can be
implemented within the scope of the disclosed technology. For
example, in accordance with one exemplary embodiment, the first set
of LEDs 20a can be on for a twenty-four hour period and off for the
next twenty-four hour period, where the second set of LEDs 20b is
on.
[0163] It will be appreciated that the first and second
configurations of LEDs can be implemented in a number of ways
without departing from the scope of the disclosed technology. For
example, as shown in FIG. 29, the first configuration of LEDs 20a
and the second configuration of LEDs 20b can be arranged in a
single strip or bar in which a single row of LED elements are
arrayed in an alternating arrangement (e.g., A B A B arrangement,
where A corresponds to an LED within the first LED configuration
20a and B corresponds to an LED within the second LED configuration
20b).
[0164] Alternatively, as shown in FIG. 30, the LEDs may be disposed
in or otherwise arranged in a two-strip bar in which the first
configuration of LEDs 20a is included along the top row and the
second configuration of LEDs 20b is included along the bottom row.
In yet another embodiment, as shown in FIG. 31, the LEDs can be
arranged in a two-strip or two-row formation such that the first
strip includes alternating arrangements of LEDs from the first
configuration of LEDs 20a and the second configuration of LEDs 20b,
and the second row of LEDs includes alternating arrangements from
the first configuration of LEDs 20a and the second configuration of
LEDs 20b. It will be appreciated that in these two-row
arrangements, the traditional two-wire power supply for a single
row of LEDs operated together would be replaced by at least a
four-wire power supply.
[0165] In yet another exemplary embodiment, as shown in FIG. 32,
the light fixture can be configured to have a first row of LEDs
disposed on one side of the frame and a second set of LEDs disposed
on an opposite side of the frame where the first set of LEDs and
the second set of LEDs are driven alternately according to a
predetermined time cycle. In yet another alternative embodiment,
the first set of LEDs 20a can include a row or array of LEDs on one
side of the frame and another row or array of LEDs on the opposite
side of the frame. In this embodiment, the second set of LEDs can
be configured to include a first row of LEDs on one side of the
frame disposed between the two sides used for the first set. In yet
another exemplary embodiment, the light fixture can include a first
array of LEDs having alternating LEDs from the first set and the
second set, with a mirror image configuration on the opposite side
of the frame.
[0166] In accordance with yet another aspect of the disclosed
technology, the light fixture can be configured to include multiple
drivers per LED configuration. For example, as shown in FIG. 33, in
a simple case of a single LED configuration 20, a first driver 52
and a second driver 54 can be selectively operatively coupled to
the LED configuration 20 together with appropriate switching or
controlling circuitry 56. In this exemplary embodiment, a first
driver 52 would be selected to electrically couple the LED
configuration to the power supply 50. Fault detection circuitry
(e.g., incorporated into the controller 56) can be employed to
determine whether the first driver 52 is operating properly. If a
fault condition occurs with the first driver 52, the controller or
switching circuitry 56 can then switch over to the second driver 54
such that the second driver 54 electrically couples the LED
configuration 20 to the associated power supply 50.
[0167] In accordance with another aspect of the disclosed
technology, the light fixture can incorporate more than two
configurations of LEDs, with a respective driver for each
configuration of LEDs. For example in FIG. 35, the power circuitry
16 can include a first driver 52 operatively coupled to the first
LED configuration 20a, a second driver 54 operatively coupled to
the second LED configuration 20b, and a third driver 60 operatively
coupled to the third LED configuration 20c. The power circuitry 16
can include a controller 56 operatively coupled to the first driver
52, the second driver 54 and the third driver 60, and configured to
selectively operate the first driver 52, the second driver 54 and
the third driver 56, thereby to control the first, second and third
configurations of LEDs 20a, 20b, 20c in a desired manner. In a
preferred embodiment, the first, second and third configurations of
LEDs can be driven cyclically, for example, repeated over periods
of time where the "on" cycle time for the first set of LEDs is
identical or substantially identical to the "on" cycle time for the
second set of LEDs and the "on" cycle time for the third set of
LEDs. For example, while the first configuration of LEDs 20a is
active, the second configuration of LEDs 20b and third
configuration of LEDs can be set to inactive. Alternatively, two
configurations of LEDs can be set to active during a given time
period, while the third can be set to inactive. In the case of more
than two configurations of LEDs, it will be appreciated that the
configurations can be arranged in a manner consistent with the
descriptions of two configurations above. For example, the first,
second and third configurations of LEDs can be arranged in an
alternating manner and/or in alternating strips or arrays.
[0168] In the case of the light fixture having multiple LED
configurations, for example, a first LED configuration 20a and a
second LED configuration 20b, the first driver can be selectively
operatively coupled to both the first LED configuration and the
second LED configuration. Similarly, the second driver can be
selectively operatively coupled to the second LED configuration as
well as the first LED configuration. The associated control and/or
switching circuitry can be configured to monitor any fault
conditions with one of the drivers and effectively switch the
second driver over to control operation of the first and/or second
LED configuration in the case of a malfunction in the first driver.
For example, FIG. 28 shows an embodiment implementing this concept
except that the embodiment of FIG. 28 shows a first LED
configuration 20a and a second LED configuration 20b, where the
first LED configuration and the second LED configuration are
selectively operatively coupled to both the first driver 52 and the
second driver 54. In this embodiment, the controller 56 provides
similar functionality as that described above with respect to FIG.
33.
[0169] It will be appreciated that the provision of multiple
driving circuitry along with appropriate control and fault
detection circuitry can serve to prolong the rated life of the
light fixture. This is due in part to the fact that in the case of
LED-based light fixtures, the associated driving or control
circuitry is more likely to fail than the LED arrays within the
light fixture.
[0170] While aspects of the disclosed technology have been
described in connection with a light fixture having a substantially
flat LED panel, it will be appreciated that other LED-based
configurations may be employed. For example, arrays of LEDs may be
employed in connection with other focusing and/or
brightness-enhancement optical elements besides those described
above with respect to the various figures.
[0171] In addition, the LED panel can include a plurality of LEDs
having outputs of various colors and/or color temperatures. For
example, the substantially flat LED panel can include white LEDs
having output of a predetermined color temperature. In accordance
with another embodiment, the substantially flat LED panel can
include multiple arrays of white LEDs having outputs of different
color temperatures. These multiple arrays can be selectively
energized to provide a "white light" of a variable color
temperature. Alternatively, the multiple arrays can be selectively
energized to maintain a desired overall lumen output to address or
otherwise compensate for lumen degradation.
[0172] In accordance with another embodiment, the substantially
flat LED panel can include a plurality of colored LEDs (e.g., LEDs
having red output, green output and blue output), where the colored
LEDs are configured to cooperate to produce white light when
energized. In the case of a plurality of colored LEDs, the light
fixture can include control circuitry that is configured to
selectively energize the colored LEDs to provide light output of
variable color temperature. The control circuitry also can be
configured to control the intensity of the light emitted by the
substantially flat LED panel, thereby providing a dimming
function.
[0173] As described above, the preferred scheme for driving first
and second configurations of LEDs is for these configurations to be
activated alternatively. However, in special circumstances in which
it is desirable to provide additional brightness, both
configurations can be activated at the same time. For example, if
an ambient light sensor of light fixture 10 detects brightness
below a desired threshold value, light fixture 10 can activate two
(or more, if available) configurations of LEDs at the same time.
Alternatively, a stepping function can be applied to selectively
energize multiple configurations of LEDs.
[0174] In accordance with one alternative embodiment, the LED panel
can include one or more strips of LEDs disposed adjacent and least
one edge of the frame, where each strip of LEDs is removably
coupled to the power circuitry via a suitable electrical connector.
It will be appreciated that this configuration allows for the easy
replacement of one or more strips of LEDs within the substantially
flat LED panel. For example, in the case of LED failure or burnout,
the strip of LEDs could be easily replaced without replacing the
entire fixture. In addition, the color output of the light fixture
could be altered by swapping out one or more of the LED strips. For
example, a holiday effect could be achieved by removing a strip of
white LEDs and replacing the strip of white LEDs with colored
LEDs.
[0175] To facilitate replacement of one or more LED strips within
the flat LED panel, the frame can be provided with one or more
sections that can be detached or otherwise separated from the
remainder of the frame. For example, a cover section of the frame
containing an LED strip may include a hinged connection to the
remainder of the frame, and a pull tab. The user would pull open
the cover section of the frame in order to uncover the LED strip
for replacement.
[0176] In accordance with one embodiment, the light fixture
includes at least one mounting member configured to mount (e.g.,
removably or permanently mount) the frame to a support surface. It
will be appreciated that the mounting member may take on numerous
forms depending on the desired application. For example, the
mounting member can be configured to mount the frame to a
substantially vertical support surface, such as a wall. In this
case, the mounting member may include suitable clips, brackets or
the like configured to anchor the light fixture to a wall in a
home, a wall in a hotel, a wall in a parking garage or the like. In
another exemplary embodiment, the mounting member can be configured
to mount the frame to a substantially horizontal support surface,
such as a ceiling, the underside of a cabinet or the like. Examples
of other applications include, but are not limited to, stairwell
lighting, emergency lighting (optionally including a battery
backup), task lighting for cubicles, under counter lighting (e.g.,
kitchen work areas and within china cabinets), home or commercial
garage lighting, lighting for retail shelving, aquarium lighting,
and the like. As is described more fully below, the light fixture
can be employed in a retrofit kit to retrofit an existing
fluorescent lighting unit.
[0177] It will be appreciated that the light fixture can be
arranged and/or installed together with a plurality of light
fixtures where a primary light fixture is electrically coupled to
an external power supply and other light fixtures can be coupled to
the external power supply by way of the primary light fixture (so
called "daisy chaining").
[0178] Examples of applications include, but are not limited to,
stairwell lighting, emergency lighting (optionally including a
battery backup), task lighting for cubicles, under counter lighting
(e.g., kitchen work areas and within china cabinets), home or
commercial garage lighting, lighting for retail shelving, aquarium
lighting, and the like. The provision of a substantially flat LED
panel fixture having edge lighting allows for thin panels of
flexible length and width providing uniform light output.
[0179] Although the invention has been shown and described with
respect to a certain embodiment or embodiments, it is obvious that
equivalent alterations and modifications will occur to others
skilled in the art upon the reading and understanding of this
specification and the annexed drawings. In particular regard to the
various functions performed by the above described elements
(components, assemblies, devices, compositions, etc.), the terms
(including a reference to a "means") used to describe such elements
are intended to correspond, unless otherwise indicated, to any
element which performs the specified function of the described
element (i.e., that is functionally equivalent), even though not
structurally equivalent to the disclosed structure which performs
the function in the herein illustrated exemplary embodiment or
embodiments of the invention. In addition, while a particular
feature of the invention may have been described above with respect
to only one or more of several illustrated embodiments, such
feature may be combined with one or more other features of the
other embodiments, as may be desired and advantageous for any given
or particular application.
* * * * *