U.S. patent application number 13/921028 was filed with the patent office on 2014-01-02 for multi-facet light engine.
The applicant listed for this patent is Flextronics AP, LLC. Invention is credited to Jordon Musser, Chris Stratas.
Application Number | 20140003053 13/921028 |
Document ID | / |
Family ID | 49777182 |
Filed Date | 2014-01-02 |
United States Patent
Application |
20140003053 |
Kind Code |
A1 |
Musser; Jordon ; et
al. |
January 2, 2014 |
MULTI-FACET LIGHT ENGINE
Abstract
A lighting assembly includes a plurality of LEDs configured as a
multi-facet light engine. A first group of LEDs are arrayed as a
main light source and the remaining LEDs are angled relative to the
first group of LEDs to generate an intended lighting pattern. The
first group of LEDs are arrayed on a first planar surface of a
first substrate, and the remaining LEDs are arrayed on second
planar surfaces of additional substrates positioned around the
first substrate. The planar surfaces of the additional substrates
are angled relative to the planar surface of the first substrate.
The angles of the second planar surfaces to the first planar
surface can be application specific and can be acute or obtuse.
Inventors: |
Musser; Jordon; (Coppell,
TX) ; Stratas; Chris; (Burlingame, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Flextronics AP, LLC |
Broomfield |
CO |
US |
|
|
Family ID: |
49777182 |
Appl. No.: |
13/921028 |
Filed: |
June 18, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61665179 |
Jun 27, 2012 |
|
|
|
61673660 |
Jul 19, 2012 |
|
|
|
Current U.S.
Class: |
362/249.03 ;
362/249.06 |
Current CPC
Class: |
F21S 8/04 20130101; F21V
29/89 20150115; F21K 9/20 20160801; F21Y 2115/10 20160801; H01L
33/64 20130101; F21V 29/70 20150115; F21V 17/12 20130101; F21V
29/71 20150115 |
Class at
Publication: |
362/249.03 ;
362/249.06 |
International
Class: |
F21K 99/00 20100101
F21K099/00 |
Claims
1. A lighting assembly comprising: a. a first substrate having a
first planar surface and a first plurality of light emitting diodes
coupled to the first planar surface; and b. a plurality of second
substrates each second substrate having a second planar surface and
a second plurality of light emitting diodes coupled to the second
planar surface, wherein each second substrate is positioned at an
angle to the first substrate such that each of the second planar
surfaces are angled relative to the first planar surface, further
wherein the first planar surface and the plurality of second planar
surfaces are aligned to provide illumination from the first and
second plurality of light emitting diodes directly onto an external
illumination surface.
2. The lighting assembly of claim 1 wherein the first planar
surface and the plurality of second planar surfaces form a concave
shape.
3. The lighting assembly of claim 1 wherein the first planar
surface and the plurality of second planar surfaces form a convex
shape.
4. The lighting assembly of claim 1 wherein directional light is
output from the first and second plurality of light emitting diodes
at converging angles.
5. The lighting assembly of claim 1 wherein directional light is
output from the first and second plurality of light emitting diodes
at diverging angles.
6. The lighting assembly of claim 1 wherein each second planar
surface forms an acute angle with the first planar surface.
7. The lighting assembly of claim 1 wherein each second planar
surface forms an obtuse angle with the first planar surface.
8. The lighting assembly of claim 1 wherein the first planar
surface is parallel to the external illumination surface.
9. The lighting assembly of claim 1 wherein the first planar
surface and the plurality of second planar surfaces are angled to
provide a determined lighting pattern on the external illumination
surface.
10. The lighting assembly of claim 1 wherein each second substrate
is rotatably coupled to the first substrate so as to enable change
of the angle at which the second substrate is coupled to the first
substrate.
11. The lighting assembly of claim 1 wherein the angle that each
second substrate is positioned relative to the first substrate is
the same.
12. The lighting assembly of claim 1 wherein the angle that one or
more of the second substrates is positioned relative to the first
substrate is different.
13. The lighting assembly of claim 1 wherein the first substrate
comprises a plurality of first outer edges and each second
substrate comprises at least a second outer edge, further wherein
the second outer edge of each second substrate is coupled to a
corresponding one first outer edge of the first substrate.
14. The lighting assembly of claim 13 wherein a number of first
outer edges equals a number of second substrates.
15. The lighting assembly of claim 13 wherein a number of first
outer edges is not equal to a number of second substrates.
Description
RELATED APPLICATIONS
[0001] This Patent Application claims priority under 35 U.S.C. 119
(e) of the co-pending U.S. provisional application, Ser. No.
61/665,179, filed Jun. 27, 2012, and entitled "LED LIGHTING" and
U.S. provisional application, Ser. No. 61/673,660, filed Jul. 19,
2012, and entitled "HIGH BAY LED LIGHTING AND HEAT DISSIPATION",
both by these same inventors. This application incorporates U.S.
provisional application, Ser. No. 61/665,179 and U.S. provisional
application, Ser. No. 61/673,660 in their entireties by
reference.
FIELD OF THE INVENTION
[0002] The present invention is generally directed to the field of
light emitting diode (LED) lighting. More specifically, the present
invention is directed to a LED device configured as a multi-facet
light engine.
BACKGROUND OF THE INVENTION
[0003] A light-emitting diode (LED) is a semiconductor light
source. LEDs are increasingly being used in a wide variety of
lighting applications. LEDs continue growing in popularity due in
part to their efficiency and extended lifetimes. However, due to
the directional nature of the output light, LED lighting produces
shadowing effects when the LED lighting is used to directly
illuminate an intended area. The shadowing effects increase as the
LED lighting is increasingly separated from an intended
illumination area. High bay lighting applications are those light
structures designed for use in buildings with high ceilings, or
"high bays" such as warehouses, manufacturing facilities, or the
like where the ceilings can be 30-40 feet high. High bay facilities
typically mount lighting devices at or near the ceiling. When used
as a direct lighting source, LED lighting used in high bay
facilities results in greater shadowing effects than used in
standard offices or homes that have 8-10 feet ceilings.
[0004] To offset the shadowing effect, lighting assemblies that use
LED lighting also include secondary optical elements, such as
reflectors and/or lenses, to disperse the light output from the LED
lighting. In this manner, the light output from the LED lighting is
indirectly provided to the intended illumination source via the
secondary optical elements. Although useful to reduce shadowing
effects, the additional optical elements reduce efficiency and add
cost and complexity to the lighting assembly.
SUMMARY OF THE INVENTION
[0005] A lighting assembly includes a plurality of LEDs configured
as a multi-facet light engine. A first group of LEDs are arrayed as
a main light source and the remaining LEDs are angled relative to
the first group of LEDs to generate an intended lighting pattern.
In some embodiments, the first group of LEDs are arrayed on a first
planar surface of a first substrate, and the remaining LEDs are
arrayed on second planar surfaces of additional substrates
positioned around the first substrate. The planar surfaces of the
additional substrates are angled relative to the planar surface of
the first substrate. The angles of the second planar surfaces to
the first planar surface can be application specific and can be
acute or obtuse. In some embodiments, the substrates are printed
circuit boards.
[0006] In an aspect, a lighting assembly includes a first substrate
having a first planar surface and a first plurality of light
emitting diodes coupled to the first planar surface, and a
plurality of second substrates each second substrate having a
second planar surface and a second plurality of light emitting
diodes coupled to the second planar surface. Each second substrate
is positioned at an angle to the first substrate such that each of
the second planar surfaces are angled relative to the first planar
surface. The first planar surface and the plurality of second
planar surfaces are aligned to provide illumination from the first
and second plurality of light emitting diodes directly onto an
external illumination surface.
[0007] In some embodiments, the first planar surface and the
plurality of second planar surfaces form a concave shape. In other
embodiments, the first planar surface and the plurality of second
planar surfaces form a convex shape. In some embodiments,
directional light is output from the first and second plurality of
light emitting diodes at converging angles. In other embodiments,
directional light is output from the first and second plurality of
light emitting diodes at diverging angles. In some embodiments,
each second planar surface forms an acute angle with the first
planar surface. In other embodiments, each second planar surface
forms an obtuse angle with the first planar surface.
[0008] In some embodiments, the first planar surface is parallel to
the external illumination surface. In some embodiments, the first
planar surface and the plurality of second planar surfaces are
angled to provide a determined lighting pattern on the external
illumination surface. In some embodiments, each second substrate is
rotatably coupled to the first substrate so as to enable change of
the angle at which the second substrate is coupled to the first
substrate. In some embodiments, the angle that each second
substrate is positioned relative to the first substrate is the
same. In other embodiments, the angle that one or more of the
second substrates is positioned relative to the first substrate is
different. In some embodiments, the first substrate includes a
plurality of first outer edges and each second substrate includes
at least a second outer edge, further wherein the second outer edge
of each second substrate is coupled to a corresponding one first
outer edge of the first substrate. In some embodiments, a number of
first outer edges equals a number of second substrates. In other
embodiments, a number of first outer edges is not equal to a number
of second substrates.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Several example embodiments are described with reference to
the drawings, wherein like components are provided with like
reference numerals. The example embodiments are intended to
illustrate, but not to limit, the invention. The drawings include
the following figures:
[0010] FIG. 1 illustrates a perspective view of a lighting assembly
according to an embodiment.
[0011] FIG. 2 illustrates a side view of the lighting assembly of
FIG. 1.
[0012] FIG. 3 illustrates a bottom perspective exploded view of the
evaporator disassembled from an exemplary light source according to
an embodiment.
[0013] FIG. 4 illustrates a top down perspective view of an
exemplary evaporator having a hemispherical configuration according
to an embodiment.
[0014] FIG. 5 illustrates a cut out side view of the evaporator of
FIG. 4.
[0015] FIG. 6 illustrates a cut-out side view of a multi-facet LED
light source according to an embodiment.
[0016] FIG. 7 illustrates the substrates configured such that the
planar surfaces are aligned having obtuse angles to form a convex
shape.
[0017] FIG. 8 illustrates a top down perspective view of an
exemplary multi-facet LED light source having four side substrates
coupled to a main substrate.
[0018] FIG. 9 illustrates a top down view of the multi-facet LED
light source of FIG. 8.
[0019] FIG. 10 illustrates a perspective view of a lighting
assembly according to another embodiment.
[0020] FIG. 11 illustrates a side view of the lighting assembly of
FIG. 10.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] Embodiments of the present application are directed to a
lighting assembly. Those of ordinary skill in the art will realize
that the following detailed description of the lighting assembly is
illustrative only and is not intended to be in any way limiting.
Other embodiments of the lighting assembly will readily suggest
themselves to such skilled persons having the benefit of this
disclosure.
[0022] Reference will now be made in detail to implementations of
the lighting assembly as illustrated in the accompanying drawings.
The same reference indicators will be used throughout the drawings
and the following detailed description to refer to the same or like
parts. In the interest of clarity, not all of the routine features
of the implementations described herein are shown and described. It
will, of course, be appreciated that in the development of any such
actual implementation, numerous implementation-specific decisions
must be made in order to achieve the developer's specific goals,
such as compliance with application and business related
constraints, and that these specific goals will vary from one
implementation to another and from one developer to another.
Moreover, it will be appreciated that such a development effort
might be complex and time-consuming, but would nevertheless be a
routine undertaking of engineering for those of ordinary skill in
the art having the benefit of this disclosure.
[0023] FIG. 1 illustrates a perspective view of a lighting assembly
according to an embodiment. The lighting assembly includes a light
source, a cooling system, one or more power supply units, device
electronics, and a mounting structure. The cooling system includes
one or more cooling loops, each cooling loop including an
evaporator, a vertically ascending pipe, a radiator and a return
pipe. The exemplary cooling system shown in FIG. 1 includes two
cooling loops, each cooling loop shares a common evaporator 14.
FIG. 2 illustrates a side view of the lighting assembly 2 of FIG.
1. A first cooling loop includes the evaporator 14, a vertically
ascending pipe 16, a radiator 18, and a return pipe 20. A second
cooling loop includes the evaporator 14, a vertically ascending
pipe 26, a radiator 28 and a return pipe 30. FIGS. 1 and 2 also
show an optional reflector 12. The light source is positioned
within the reflector 12. The first cooling loop and the second
cooling loop are each closed loop. Although two closed loop cooling
systems are shown in the lighting assembly of FIGS. 1 and 2, it is
understood that a lighting assembly can be configured to include a
single closed loop cooling system or three or more closed loop
cooling systems. The lighting assembly includes a mounting
structure 10 coupled to the evaporator 14 and to device electronics
8. In this exemplary configuration, the lighting assembly includes
two power supplies 6. The power supplies 6 can be mounted to the
mounting structure 10, a housing of the device electronics 8, the
evaporator 14, the pipes 16 and 26 or some combination thereof. An
external mounting base 7 is coupled to the housing of the device
electronics 8. The external mounting base 7 is used to mount the
lighting assembly. In some embodiments, the external mounting base
7 is configured to receive a conduit, which in turn is mounted to
an external support, such as a ceiling.
[0024] The cooling system is configured to enable the dissipation
of a large amount of energy in the form of heat without heating
surrounding components, such as the one or more power supply units
and device electronics. In some embodiments, the cooling loop is
configured as a thermal siphon that uses a boiling fluid to
transport heat between the evaporator and the radiators. In some
embodiments, the evaporator also functions as a device chassis,
which reduces the overall part count. In some embodiments, the
light source is a plurality of LEDs. LEDs have a well defined
thermal performance and therefore operate properly within a defined
temperature range. The cooling system is designed to maintain the
LED temperatures within the defined temperature range. The one or
more power supply units are arranged such that heat generated by
the one or more power supply units does not negatively impact the
thermal performance of the LED light source.
[0025] The evaporator 14 is a fluid-based heat exchanger that
conceptually functions as a boiling unit. In some embodiments, the
evaporator 14 includes a fluid reservoir that is filled, or
partially filled, with a fluid or fluid mixture, herein referred to
collectively as a fluid. The evaporator 14 is thermally coupled to
the light source such that heat generated by the light source is
transferred to the fluid within the evaporator 14. The heat causes
fluid in the evaporator 14 to evaporate. The resulting vapor rises
through the vertically ascending pipes 16, 26 to the radiators 18,
28. In some embodiments, each pipe 16, 26 includes a first portion
that extends straight up from the evaporator 14 and a second
portion that bends at an angle from completely vertical, but not
horizontal, which is coupled to the radiator 18, 28. In some
embodiments, the angle of the second portion is 45 degrees relative
to vertical. The portion of pipes 16, 26 shown in FIG. 2 is the
second, angled portion. It is understood that the pipes 16, 26 can
be alternatively shaped so as to provide an upward path from the
evaporator 14 to the radiator 18, 28. In some embodiments, the
pipes 16, 20 are configured with fins, and the pipe with fins is
made of thermally conductive materials. Heat from the rising vapor
can be shed during transport through the pipes 16, 26. In some
embodiments, the pipes 16, 26 are configured having an oval
cross-section to accommodate the internal pressure.
[0026] The radiator 18 is aligned at a decline, or downward angle
relative to horizontal, such that one end is higher than the other
end. The pipe 16 is coupled to a top portion of the radiator 18 and
the return pipe 20 is coupled to a bottom portion of the radiator
18. In some embodiments, the pipe 16 is coupled to an end of the
top portion of the radiator 18. In some embodiments, the return
pipe 20 is coupled to an end of the bottom portion of the radiator
18. Vapor entering the radiator 18 from the pipe 16 condenses and
the liquid flows downward through the radiator 18 to the return
pipe 20. Due to the declining orientation of the radiator 18,
liquid within the radiator is gravity fed toward the bottom end and
to the return pipe 20. The return pipe 20 is aligned at a decline
such that one end is higher than the other end such that liquid
received from the radiator 18 is gravity fed to the evaporator
14.
[0027] The second cooling loop is configured similarly as the first
cooling loop. The radiator 28 is aligned at a decline, or downward
angle relative to horizontal, such that one end is higher than the
other end. The pipe 26 is coupled to a top portion of the radiator
28 and the return pipe 30 is coupled to a bottom portion of the
radiator 28. In some embodiments, the pipe 26 is coupled to an end
of the top portion of the radiator 28. In some embodiments, the
return pipe 30 is coupled to an end of the bottom portion of the
radiator 28. Vapor entering the radiator 28 from the pipe 16
condenses and the liquid flows downward through the radiator 28 to
the return pipe 30. Due to the declining orientation of the
radiator 28, liquid within the radiator is gravity fed toward the
bottom end and to the return pipe 30. The return pipe 30 is aligned
at a decline such that one end is higher than the other end such
that liquid received from the radiator 28 is gravity fed to the
evaporator 14.
[0028] The cooling loops are described above has having separate
pipes 16 and 26 that couple the evaporator to the radiators 18 and
28, respectively. Alternatively, the pipes 16 and 26 can include a
common portion that splits for coupling to the radiators 18 and 28.
For example, a single vertically ascending pipe can be coupled to
the evaporator 14, and at a top portion of the pipe, the pipe
branches, such as into two branches, each branch bends at an angle
from completely vertical, but not horizontal. One or more branches
are coupled to the radiator 18 and one or more branches are coupled
to the radiator 28. Still alternatively, multiple separate pipes
can be coupled between the evaporator 14 and a single radiator. For
example, two or more pipes, each pipe similar to the pipe 16, can
be coupled between the evaporator 14 and the radiator 18.
[0029] As shown in FIG. 1, each radiator 18 and 28 includes an
input header coupled to the pipe 16 and 26, respectively. The input
header laterally distributes the vapor received from the pipe. The
radiator can also include one or more fluid conduits coupled to the
input header and fins coupled to the fluid conduits. The fluid
conduits can be arranged laterally and/or layered to form a
vertical stack of fluid conduits, each layer separated by fins. The
radiator can also include an output header coupled to the one or
more fluid conduits. The output header is coupled to the return
pipe. In general, the radiators are designed to dissipate the heat
to the atmosphere using convection cooling without the need for
fans blowing over the radiators.
[0030] In some embodiments, the fluid is a fluid mixture consisting
of at least two different types of fluids that each evaporate at a
different temperature. The thermal characteristics of the cooling
system and fluid mixture are configured such that the heat supplied
to the fluid within the evaporator is sufficient to evaporate one
of the fluids, but insufficient to evaporate the second fluid. The
evaporated fluid forms vapor bubbles within the remaining
non-evaporated fluid mixture. In this manner, heat transferred to
the fluid mixture results in a boiling fluid, a portion of which is
a vapor and another portion of which is a liquid. The configuration
of the fluid mixture and the vertically ascending pipes enables a
pumping means whereby the boiling fluid, including the vapor and
liquid forms of fluid mixture, rises from the evaporator 14,
through the pipes 16 and 26, to the radiators 18 and 28. The vapor
bubbles within the boiling fluid are used to siphon non-evaporated
fluid up the pipes 16 and 26 and into the radiators 18 and 28. In
this manner, a pumping means is integral to the cooling loop
without including a discrete pumping component such as a powered
pump. An example of such a pumping means is a bubble pump found in
U.S. Patent Application Publication No. 2007/0273024, which is
hereby incorporated in its entirety be reference. Although the
boiling fluid includes a non-evaporated liquid component, this
liquid component has been heated and as such the circulating liquid
provides additional thermal transport from the evaporator to the
radiator. In the case where the pipes 16 and 26 are finned pipes,
heat from the rising boiling fluid can be shed during transport
through the pipes 16 and 26.
[0031] Alternative configurations of the lighting assembly are also
contemplated. FIG. 10 illustrates a perspective view of a lighting
assembly according to another embodiment. The lighting assembly
includes a light source, a cooling system, one or more power supply
units, and a mounting structure. The cooling system includes one or
more cooling loops, each cooling loop including an evaporator, a
vertically ascending pipe, a radiator and a return pipe. The
lighting assembly of FIG. 10 functions similarly as the lighting
assembly of FIG. 1 to provide cooling for the light source. The
exemplary cooling system shown in FIG. 10 includes two cooling
loops, each cooling loop shares a common evaporator 114. FIG. 11
illustrates a side view of the lighting assembly 102 of FIG. 10. A
first cooling loop includes the evaporator 114, a vertically
ascending pipe 116, a radiator 118, and a return pipe 120. A second
cooling loop includes the evaporator 114, a vertically ascending
pipe 126, a radiator 128 and another return pipe (not shown). FIGS.
10 and 11 also show an optional reflector 112. The light source is
positioned within the reflector 112. The first cooling loop and the
second cooling loop are each closed loop. Although two closed loop
cooling systems are shown in the lighting assembly of FIGS. 10 and
11, it is understood that a lighting assembly can be configured to
include a single closed loop cooling system or three or more closed
loop cooling systems.
[0032] As shown in FIG. 10, the radiator 118 and the radiator 128
are each coupled to an input header 119 and to an output header
121. In this manner, a single condensing unit is formed having two
separate radiator portions coupled via common input and output
headers. In the exemplary configuration shown in FIG. 10,
separation of the radiators 118 and 128 forms a pathway
therebetween within which accessory elements can be positioned. The
vertically ascending pipes 116 and 126 are each coupled at one end
to the evaporator 114 and at the other end to the input header 119.
The return pipe 120 and the other return pipe (not shown) are each
coupled at one end to the output header 121 and at the other end to
the evaporator 114. The input header 119 laterally distributes the
vapor received from the vertically ascending pipes 116 and 126. The
radiators 118 and 128 can also include one or more fluid conduits
coupled to the input header 119 and to the output header 121, and
fins coupled to the fluid conduits. The fluid conduits can be
arranged laterally and/or layered to form a vertical stack of fluid
conduits, each layer separated by fins. The output header 121
collects the condensed liquid from the radiators 118 and 128.
[0033] The lighting assembly includes a mounting structure 110
coupled to the evaporator 114 and positioned in the pathway between
the radiators 118 and 128. The mounting structure 110 includes
handles 111 for carrying the lighting assembly. In this exemplary
configuration, the lighting assembly includes four power supplies
106. The power supplies 106 can be mounted to the mounting
structure 110, as shown, the evaporator 114, the vertically
ascending pipes 116 and 126 or some combination thereof. An
external mounting base 107 is coupled to the mounting structure 110
and/or to the evaporator 114. Bracing elements 113 provide
additional support and couple the radiators 118 and 128 to the
mounting structure 110, the external mounting base 107, the
evaporator 114 or some combination thereof. The external mounting
base 107 is used to mount the lighting assembly. In some
embodiments, the external mounting base 107 is configured to
receive a conduit, which in turn is mounted to an external support,
such as a ceiling.
[0034] In the configuration shown in FIGS. 10 and 11, a separate
device electronics and housing, such as device electronics 8 in
FIGS. 1 and 2, is not included. In the configuration shown in FIGS.
10 and 11, device electronics are included as part of a light
source assembly, such as the light source 36 shown in FIG. 3 and
described below. It is understood that device electronics and
housing such as the device electronics 8 in FIGS. 1 and 2 can be
added to the lighting assembly 102, such as mounted to the mounting
structure 110 and/or to the external mounting base 107.
[0035] As described above, the evaporator is configured to transfer
heat from a light source coupled to the evaporator to fluid within
the evaporator. FIG. 3 illustrates a bottom perspective exploded
view of the evaporator 14 disassembled from an exemplary light
source 36 according to an embodiment. The evaporator 14 includes a
thermal exchange surface 32. As shown in FIG. 3, the thermal
exchange surface 32 is a rectangular, planar surface.
Alternatively, the surface can be shaped other than a rectangle.
Preferably, the shape of the thermal exchange surface matches that
of a corresponding thermal exchange surface of the light source.
The thermal exchange surface 32 is made of a thermally conductive
material, which can be the same or different than the material used
to make the remainder of the evaporator. The light source 36 is
thermally coupled to the thermal exchange surface 32 via a thermal
interface material 34. In some embodiments, the light source 36 is
a plurality of LEDs mounted to a printed circuit board. In some
embodiments, the printed circuit board is modified for enhanced
rigidity. Such a modification is found in the co-pending U.S.
patent application Ser. No. (Attorney Docket Number FLEX-12303),
filed ______, and entitled "Relampable LED structure", which is
hereby incorporated in its entirety be reference. The light source
36 is mounted to the evaporator 14 using any conventional mounting
means including, but not limited to, screws, clamps, and/or
brackets.
[0036] As shown in FIGS. 1-3, the evaporator 14 has planar surfaces
as in a rectangle or other trapezoidal configuration.
Alternatively, the evaporator is configured as a hemispherical
evaporator. A hemispherical design mimics the geometry of a
pressure vessel with its spherical based shape. Such an evaporator
configuration provides significantly improved hoop strength. In
some embodiments, the bottom side of the evaporator remains planar
in order to interface with a planar light source. In other
embodiments, the bottom side is contoured to match some or all of a
non-planar thermal exchange surface of the light source. Regardless
of the bottom side configuration, at least an upper portion of the
evaporator can have a hemispherical configuration. FIG. 4
illustrates a top down perspective view of an exemplary evaporator
40 having a hemispherical configuration according to an embodiment.
FIG. 5 illustrates a cut out side view of the evaporator 40 of FIG.
4. The evaporator 40 includes an upper spherical casing 42 coupled
to a lower base 44. The upper spherical casing 42 includes one or
more openings. In the exemplary configuration shown in FIG. 4 there
are two openings 48 and 50. Each opening is coupled to a vertically
ascending pipe. For example, the opening 48 is coupled to the
vertically ascending pipe 26 (FIG. 2) and the opening 50 is coupled
to the vertically ascending pipe 16 (FIG. 2). The lower base 44
includes a support portion 52 configured to receive the upper
spherical casing 42. The lower base 44 also includes a thermal
interface plate 54. The thermal interface plate 54 includes an
outer surface 56 and an inner surface 58. The outer surface 56 is
thermally coupled to the light source. In some embodiments, the
outer surface 56 is planer, as shown in FIG. 5. In other
embodiments, the outer surface is non-planar and is configured to
match some or all of a surface contour of the light source. In some
embodiments, the lower base 44 has a circular configuration, as
shown in FIG. 4. The lower base 44 can also include additional
threaded attachments for the light source, such as an external ring
when the lower base has a circular shape. In other embodiments, the
lower base is alternatively shaped. The inner surface 58 is
configured to promote nucleate boiling of the fluid. In some
embodiments, the inner surface 58 has an arrangement of fins and/or
divots. In some embodiments, the inner surface 58 includes a
specialized surface finish that promotes nucleate boiling.
[0037] In some embodiments, the upper spherical casing 42 and the
lower base 44 are designed with an interface that allows them to be
made with different processes to optimize costs. The separation of
the upper spherical casing and the lower base allows the upper
portion to be cast, for example, while the lower base is machined,
for example, to achieve higher precise and more optimal heat
transfer.
[0038] In some embodiments, the thermal exchanging surface of the
evaporator is a non-planar surface. In this alternative
configuration, a contour of the thermal exchanging surface is
configured to match that of the corresponding thermal exchange
surface of the light source. In some embodiments, the light source
is configured with a plurality of planar surfaces angled relative
to each other. In an exemplary configuration, the light source is a
multi-facet LED light source where each facet is a planar surface
having a plurality of LEDs. The facets are angled so as to provide
a desired lighting pattern and backfilling. Configuring the light
source as a multi-facet LED light source reduces shadowing and
provides light directly to an external illumination surface without
having to use additional secondary optical elements such as a
reflector and/or lenses.
[0039] In contrast to the planar light source 36 in FIG. 3, FIG. 6
illustrates a cut-out side view of a multi-facet LED light source
60 according to an embodiment. The multi-facet LED light source 60
has a main, or first, substrate 62 including a first planar surface
68. One or more LEDs (not shown) are coupled to the first planar
surface 68. In some embodiments, an array of LEDs is coupled to the
first planar surface 68. A second substrate 64 and a third
substrate 66 are each coupled to the first substrate 62. The second
substrate 64 includes a second planar surface 70 and the third
substrate 66 includes a third planar surface 72. One or more LEDs
(not shown) are coupled to the second planar surface 70 and one or
more LEDs (not shown) are coupled to the third planar surface 72.
In some embodiments, an array of LEDs is coupled to the second
planar surface 70 and an array of LEDs is coupled to the third
planar surface 72. In some embodiments, each of the substrates 62,
64 and 66 are printed circuit boards to which the LEDs are
mechanically and electrically coupled. In some embodiments, each
substrate 62, 64 and 66 is a discrete element, such as a discrete
printed circuit board. In other embodiments, each substrate 62, 64
and 66 is part of a single substrate, such as an aluminum core
printed circuit board that can be folded to form the substrates 62,
64 and 66.
[0040] In some embodiments, the second substrate 64 is rotatably
coupled to the first substrate 62 so as to be able to change an
angle between the first planar surface 68 and the second planar
surface 70, and the third substrate 66 is rotatably coupled to the
first substrate 62 so as to as to be able to change an angle
between the first planar surface 68 and the third planar surface
72. These angles are set or changed to achieve a desired lighting
pattern generated by the light source 60. In the exemplary
configuration shown in FIG. 6, the angles are acute and the first
planar surface 68, the second planar surface 70 and the third
planar surface 72 form a concave shape. FIG. 7 illustrates the
substrates configured such that the planar surfaces are aligned
having obtuse angles to form a convex shape. As also shown in FIGS.
6 and 7, the angle between the first planar surface 68 and the
second planar surface 70 is the same as the angle between the first
planar surface 68 and the third planar surface 72. Alternatively,
the angles can be different. As LEDs output substantially
directional light, the LEDs on each planar surface outputs a
corresponding directional light. In the case of a concave
configuration, such as that shown in FIG. 6, the directional light
output from each planar surface converges and overlaps. In the case
of a convex configuration, such as that shown in FIG. 7, the
directional light output from each planar surface diverges. In
general, the overall non-planar configuration of the light emitting
surfaces 68, 70, and 72 provides different illumination angles
relative to the intended illumination surface. These different
illumination angles essentially reproduce the effect of a reflector
or other secondary optical elements without additional components
and associated losses. Light output from the
[0041] LEDs is provided directly from the LEDs on the planar
surfaces to the illumination area, without the light being
redirected through any secondary optical elements. The angles at
which the light emitting surfaces are positioned relative to each
other are determined according to the desired lighting pattern. In
the case where the side substrates are rotatably coupled to the
main substrate, a given multi-facet LED light source can be
adjusted to change the angles of the light emitting surfaces and
therefore change the lighting pattern according to a specific
application. Configuring the LED light source with LEDs providing
illumination from multiple different angels enables backfilling of
light and reduction of shadowing.
[0042] As shown in FIG. 3, the light source is thermally coupled to
the evaporator to provide heat transfer. In the case of the
multi-facet LED light source, one or more of the substrates is
thermally coupled to the evaporator. In some embodiments, the
thermal exchange surface of the evaporator is configured to match a
contour of the coupled light source substrates. For example, where
the substrates form a concave shape as in FIG. 6, the thermal
exchange surface of the evaporator can be configured to match the
concave shape of the light source substrates, which would result in
a convex shaped thermal exchange surface. In other embodiments, the
thermal exchange surface and the light source substrates can be
configured such that the light source substrates are thermally
coupled to each other, and the thermal exchange surface is
mechanically coupled to only the main light source substrate.
[0043] FIGS. 6 and 7 show two-dimensional representations of the
multi-facet LED light source, which in these cases include two side
substrates 64 and 66 positioned on opposing sides of the main
substrate 62. It is understood that the concept can be expanded to
three dimensions such that, for example, an additional side
substrate extending out of the page of FIG. 6 is coupled to the
main substrate and an additional side substrate extending into the
page of FIG. 6 is coupled to the opposing side of the main
substrate. FIG. 8 illustrates a top down perspective view of an
exemplary multi-facet LED light source having four side substrates
coupled to a main substrate. FIG. 9 illustrates a top down view of
the multi-facet LED light source of FIG. 8. In this exemplary
configuration, the multi-facet LED light source 80 includes a main
substrate 82 having four side substrates 84, 86, 88, 90. Each side
substrate has a planar surface and one or more LEDs coupled to the
planar surface. The multi-facet LED light source 80 is configured
symmetrically having side substrates 84 and 88 on opposing sides of
the main substrate 82, and side substrates 86 and 90 on opposing
sides. Asymmetrical configurations are also contemplated as well as
configurations that have odd numbers of side substrates.
[0044] As shown in FIGS. 8 and 9, each of the side substrates is
configured as a rectangle and none of the side substrates or their
corresponding planar surfaces contact each other. Alternatively,
the side substrates can be alternatively shaped, such as
trapezoids, and can also be configured to contact adjacent side
substrates at a common edge. In general, the multi-facet LED engine
can be configured to include one or more side substrates, each
having a planar surface with one or more LEDs included thereon,
coupled to the main substrate, aligned symmetrically or
asymmetrically around the main substrate to achieve a desired
lighting pattern. The angle between the main substrate planar
surface and the planar surface of a any given side substrate can be
concave or convex.
[0045] The LEDs can be positioned on a planar surface in any
desired pattern. The spacing between LEDs is application specific,
which when combined with the angles of the light emitting surfaces,
is designed to achieve a specific light intensity per unit area.
The size of the LEDs impacts this determination as smaller LEDs
typically generate less illumination than larger LEDs.
[0046] In an exemplary application, the lighting assembly is
designed for high bay lighting, such as 40-50 feet high ceilings.
In such an application, the lighting assembly generates 100-400 kW.
In some applications, the lighting assembly generates more than
400kW. In general, the lighting assembly is useful for those
applications requiring lighting solutions with higher wattages than
those found in typical office environments having 8-10 feet high
ceilings.
[0047] The present application has been described in terms of
specific embodiments incorporating details to facilitate the
understanding of the principles of construction and operation of
the multi-facet LED device. Many of the components shown and
described in the various figures can be interchanged to achieve the
results necessary, and this description should be read to encompass
such interchange as well. As such, references herein to specific
embodiments and details thereof are not intended to limit the scope
of the claims appended hereto. It will be apparent to those skilled
in the art that modifications can be made to the embodiments chosen
for illustration without departing from the spirit and scope of the
application.
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