U.S. patent application number 12/235141 was filed with the patent office on 2009-03-26 for optic coupler for light emitting diode fixture.
This patent application is currently assigned to Cooper Technologies Company. Invention is credited to Scott David Wegner.
Application Number | 20090080189 12/235141 |
Document ID | / |
Family ID | 40468427 |
Filed Date | 2009-03-26 |
United States Patent
Application |
20090080189 |
Kind Code |
A1 |
Wegner; Scott David |
March 26, 2009 |
Optic Coupler for Light Emitting Diode Fixture
Abstract
A recessed light fixture includes an LED module, which includes
a single LED package that is configured to generate all light
emitted by the recessed light fixture. For example, the LED package
can include multiple LEDs mounted to a common substrate. The LED
package can be coupled to a heat sink for dissipating heat from the
LEDs. The heat sink can include a core member from which fins
extend. Each fin can include one or more straight and/or curved
portions. A reflector housing may be coupled to the heat sink and
configured to receive a reflector. The reflector can have any
geometry, such as a bell-shaped geometry including two radii of
curvature that join together at an inflection point. An optic
coupler can be coupled to the reflector housing and configured to
cover electrical connections at the substrate and to guide light
emitted by the LED package.
Inventors: |
Wegner; Scott David;
(Peachtree City, GA) |
Correspondence
Address: |
KING & SPALDING LLP
1180 PEACHTREE STREET
ATLANTA
GA
30309-3521
US
|
Assignee: |
Cooper Technologies Company
Houston
TX
|
Family ID: |
40468427 |
Appl. No.: |
12/235141 |
Filed: |
September 22, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60994792 |
Sep 21, 2007 |
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61010549 |
Jan 9, 2008 |
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61065914 |
Feb 15, 2008 |
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61090391 |
Aug 20, 2008 |
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Current U.S.
Class: |
362/235 ;
362/249.02 |
Current CPC
Class: |
F21S 8/026 20130101;
F21V 29/78 20150115; F21V 15/01 20130101; F21V 23/009 20130101;
F21V 29/74 20150115; F21Y 2115/10 20160801; F21V 21/04 20130101;
F21S 8/02 20130101; F21V 7/09 20130101; F21V 29/70 20150115; F21V
29/75 20150115; F21V 21/048 20130101 |
Class at
Publication: |
362/235 ;
362/249.02 |
International
Class: |
F21V 1/02 20060101
F21V001/02; F21V 17/04 20060101 F21V017/04 |
Claims
1. A recessed light fixture, comprising: a light emitting diode
("LED") package comprising at least one LED mounted to a substrate;
at least one electrical connection electrically coupled to the LED
package and configured to provide power thereto; and an optic
coupler covering the at least one electrical connection at the
substrate, the optic coupler comprising: a top end comprising a
first opening; a bottom end comprising a second opening; and at
least one wall member extending between the top end and the bottom
end and defining a channel that connects the first opening and the
second opening, wherein the channel is substantially aligned with
the LEDs so that the LEDs are visible through the channel.
2. The recessed light fixture of claim 1, wherein the LED package
generates substantially all light emitted by the recessed light
fixture.
3. The recessed light fixture of claim 1, wherein the at least one
wall member guides light emitted by the LEDs.
4. The recessed light fixture of claim 1, wherein the at least one
wall member reflects light emitted by the LEDs.
5. The recessed light fixture of claim 1, wherein at least one of
the first opening and the second opening is substantially
circular.
6. The recessed light fixture of claim 1, wherein at least one of
the first opening and the second opening is substantially
rectangular.
7. The recessed light fixture of claim 1, wherein the optic coupler
further comprises: a bottom member defining the second opening; and
a side member extending angularly from the bottom member, wherein
the bottom member and the side member define a region that at least
partially houses the at least one electrical connection at the
substrate.
8. The recessed light fixture of claim 0, wherein the side member
extends substantially away from the bottom end, towards a plane
defined by the first opening.
9. The recessed light fixture of claim 0, wherein a cross-sectional
profile of the bottom member has a substantially frusto-conical
shape.
10. The recessed light fixture of claim 1, further comprising a
reflector, and wherein the optic coupler further comprises an
engaging surface that engages a top end of the reflector.
11. The recessed light fixture of claim 10, wherein the optic
coupler further comprises: a bottom member defining the second
opening; a side member extending angularly from the bottom member;
and an engaging member extending angularly from the side member,
wherein the side member is disposed substantially between the
bottom member and the engaging member, and wherein the engaging
member comprises the engaging surface.
12. The recessed light fixture of claim 11, wherein the engaging
member is substantially parallel to the bottom member.
13. The recessed light fixture of claim 1, wherein the LEDs are
configured in an array having a first shape, and wherein a shape of
the first opening is substantially the same as the first shape.
14. The recessed light fixture of claim 13, wherein the second
opening has a shape that is substantially the same as the shape of
the first opening.
15. A recessed light fixture, comprising: a light emitting diode
("LED") package comprising at least one LED; a reflector housing; a
reflector disposed substantially within the reflector housing,
around at least a portion of the LED package; and an optic coupler
disposed substantially between the LED package and the reflector,
the optic coupler comprising an engaging surface that engages a top
end of the reflector such that the top end of the reflector is
disposed between a side edge of the optic coupler and an inside
surface of the reflector housing.
16. The recessed light fixture of claim 15, wherein the LED package
generates substantially all light emitted by the recessed light
fixture.
17. The recessed light fixture of claim 15, wherein the optic
coupler further comprises: a top member defining a first opening; a
bottom member defining a second opening; and at least one wall
member extending between the top member and the bottom member and
defining a channel that connects the first opening and the second
opening, wherein the channel is substantially aligned with the LEDs
so that the LEDs are visible through the channel.
18. The recessed light fixture of claim 17, wherein the optic
coupler further comprises: a side member extending angularly from
the bottom member; and an engaging member extending angularly from
the side member, wherein the side member is disposed substantially
between the bottom member and the engaging member, and wherein the
engaging member comprises the engaging surface.
19. The recessed light fixture of claim 18, wherein the engaging
member is substantially parallel to the bottom member.
20. The recessed light fixture of claim 18, further comprising at
least one electrical connection electrically coupled to the LED
package and configured to provide power thereto, wherein the bottom
member and the side member define a region that at least partially
houses the at least one electrical connection.
21. The recessed light fixture of claim 20, wherein the at least
one electrical connection are not visible when looking into the
recessed light fixture from an environment illuminated by the
recessed light fixture.
22. A recessed light fixture, comprising: a light emitting diode
("LED") package comprising at least one LED; a reflector disposed
around at least a portion of the LED package; and an optic coupler
disposed substantially between the LED package and the reflector
and covering at least one electrical connection on the LED package,
the optic coupler comprising an aperture through which light
emitted by the LEDs is visible.
23. The recessed light fixture of claim 22, wherein the recessed
light fixture further comprises a housing within which the
reflector is substantially disposed, and wherein the optic coupler
further comprises an engaging surface that engages a top end of the
reflector such that the top end of the reflector is disposed
between a side edge of the optic coupler and an inside surface of
the housing.
24. The recessed light fixture of claim 22, wherein the LED package
generates substantially all light emitted by the recessed light
fixture.
Description
RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn. 119
to U.S. Provisional Patent Application No. 60/994,792, titled
"Light Emitting Diode Downlight Can Fixture," filed Sep. 21, 2007,
U.S. Provisional Patent Application No. 61/010,549, titled
"Diverging Reflector for Light Emitting Diode or Small Light
Source," filed Jan. 9, 2008, U.S. Provisional Patent Application
No. 61/065,914, titled "Dimmable LED Driver," filed Feb. 15, 2008,
and U.S. Provisional Patent Application No. 61/090,391, titled
"Light Emitting Diode Downlight Can Fixture," filed Aug. 20, 2008.
In addition, this application is related to co-pending U.S. patent
application Ser. No. ______, titled "Diverging Reflector," filed
Sep. 22, 2008, U.S. patent application Ser. No. ______, titled
"Thermal Management for Light Emitting Diode Fixture," filed Sep.
22, 2008, U.S. patent application Ser. No. ______, titled "Light
Emitting Diode Recessed Light Fixture," filed Sep. 22, 2008, and
U.S. Design Pat. Application No. 29/305,946, titled "LED Light
Fixture," filed Mar. 31, 2008. The complete disclosure of each of
the foregoing priority and related applications is hereby fully
incorporated herein by reference.
TECHNICAL FIELD
[0002] The invention relates generally to recessed luminaires, and
more particularly, to a light emitting diode downlight can fixture
for a recessed luminaire.
BACKGROUND
[0003] A luminaire is a system for producing, controlling, and/or
distributing light for illumination. For example, a luminaire can
include a system that outputs or distributes light into an
environment, thereby allowing certain items in that environment to
be visible. Luminaires are often referred to as "light
fixtures".
[0004] A recessed light fixture is a light fixture that is
installed in a hollow opening in a ceiling or other surface. A
typical recessed light fixture includes hanger bars fastened to
spaced-apart ceiling supports or joists. A plaster frame extends
between the hanger bars and includes an aperture configured to
receive a lamp housing or "can" fixture.
[0005] Traditional recessed light fixtures include a lamp socket
coupled to the plaster frame and/or the can fixture. The lamp
socket receives an incandescent lamp or compact fluorescent lamp
("CFL") discussed above. As is well known in the art, the
traditional lamp screws into the lamp socket to complete an
electrical connection between a power source and the lamp.
[0006] Increasingly, lighting manufacturers are being driven to
produce energy efficient alternatives to incandescent lamps. One
such alternative was the CFL discussed above. CFLs fit in existing
incandescent lamp sockets and generally use less power to emit the
same amount of visible light as incandescent lamps. However, CFLs
include mercury, which complicates disposal of the CFLs and raises
environmental concerns.
[0007] Another mercury-free alternative to incandescent lamps is
the light emitting diode ("LED"). LEDs are solid state lighting
devices that have higher energy efficiency and longevity than both
incandescent lamps and CFLs. However, LEDs do not fit in existing
incandescent lamp sockets and generally require complex electrical
and thermal management systems. Therefore, traditional recessed
light fixtures have not used LED light sources. Accordingly, a need
currently exists in the art for a recessed light fixture that uses
an LED light source.
SUMMARY
[0008] The invention provides a recessed light fixture with an LED
light source. The light fixture includes a housing or "can" within
which an LED module is mounted. The LED module includes a single
LED package that generates all or substantially all the light
emitted by the recessed light fixture. For example, the LED package
can include one or more LEDs mounted to a common substrate. Each
LED is an LED die or LED element that is configured to be coupled
to the substrate. The LEDs can be arranged in any of a number of
different configurations. For example, the LEDs can be arranged in
a round-shaped area having a diameter of less than two inches or a
rectangular-shaped area having a length of less than two inches and
a width of less than two inches.
[0009] The LED package can be thermally coupled to a heat sink
configured to transfer heat from the LEDs. The heat sink can have
any of a number of different configurations. For example, the heat
sink can include a core member extending away from the LED package
and fins extending from the core member. Each fin can include a
curved, radial portion and/or a straight portion. For example, each
fin can include a radial portion that extends from the core member,
and a straight portion that further extends out from the radial
portion. In this configuration, heat from the LEDs can be
transferred along a path from the LEDs to the core member, from the
core member to the radial portions of the fins, from the radial
portions of the fins to their corresponding straight portions, and
from the corresponding straight portions to a surrounding
environment. Heat also can be transferred by convection directly
from the core member and/or the fins to one or more gaps between
the fins. The LED package can be coupled directly to the core
member or to another member disposed between the LED package and
the core member.
[0010] A reflector housing can be mounted substantially around the
LED package. For example, the reflector housing can be coupled to
the heat sink and/or the can. The reflector housing can be
configured to receive a reflector and to serve as a secondary heat
sink for the LED module. For example, the reflector housing can be
at least partially composed of a conductive material for
transmitting heat away from the LED package. The reflector can be
composed of any material for reflecting, refracting, transmitting,
or diffusing light from the LED package. For example, the reflector
can comprise a specular, semi-specular, semi-diffuse, or diffuse
finish, such as gloss white paint or diffuse white paint. The
reflector can have any of a number of different configurations. For
example, a cross-sectional profile of the reflector can have a
substantially bell-shaped geometry that includes a smooth curve
comprising an inflection point. Top and bottom portions of the
curve are disposed on opposite sides of the inflection point. To
meet a requirement of a top-down flash while also creating a
smooth, blended light pattern, the bottom portion of the curve can
be more diverging than the top portion of the curve.
[0011] An optic coupler can be mounted to the reflector housing,
for covering electrical connections at the substrate of the LED
package and/or for guiding or reflecting light emitted by the LED
package. For example, the optic coupler can include a member with a
central channel that is aligned with one or more of the LEDs of the
LED package such that the channel guides light emitted by the LEDs
while portions of the member around the channel cover the
electrical connections at the substrate of the LED package. The
optic coupler can have any of a number of different geometries that
may or may not correspond to a configuration of the LED package.
For example, depending on the sizes and locations of the electrical
connections at the substrate, the portion of the optic coupler
around the channel can have a substantially square, rectangular,
rounded, conical, or frusto-conical shape.
[0012] The LED module can be used in both new construction and
retrofit applications. The reftrofit applications can include
placing the LED module in an existing LED or non-LED fixture. To
accommodate installation in a non-LED fixture, the LED module can
further include a member comprising a profile that substantially
corresponds to an interior profile of a can of the non-LED fixture
such that the member creates a junction box between the member and
a top of the can when the LED module is mounted in the can. To
install the LED module, a person can electrically couple an Edison
base adapter to both the existing, non-LED fixture and the LED
module. For example, a person can cut at least one wire to remove
an Edison base from the existing fixture, cut at least one other
wire to remove an Edison screw-in plug from the Edison base
adapter, and connect together the cut wires to electrically couple
the Edison base adapter and the existing fixture. Alternatively, a
person can release a socket from the existing fixture and screw the
Edison base adapter into the socket to electrically couple the
Edison base adapter and the existing fixture. The junction box can
house the Edison base adapter and at least a portion of the wires
coupled thereto.
[0013] These and other aspects, features and embodiments of the
invention will become apparent to a person of ordinary skill in the
art upon consideration of the following detailed description of
illustrated embodiments exemplifying the best mode for carrying out
the invention as presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a more complete understanding of the present invention
and the advantages thereof, reference is now made to the following
description, in conjunction with the accompanying figures briefly
described as follows. The patent or application file contains at
least one drawing executed in color. Copies of this patent or
patent application publication with color drawing(s) will be
provided by the Office upon request and payment of the necessary
fee.
[0015] FIG. 1 is an elevational top view of hanger bars, a plaster
frame, a can, and a junction box of a recessed lighting fixture, in
accordance with certain exemplary embodiments.
[0016] FIG. 2 is an elevational cross-sectional side view of the
recessed lighting fixture of FIG. 1, in accordance with certain
exemplary embodiments.
[0017] FIG. 3 is an elevational side view of an LED module of a
recessed lighting fixture, in accordance with certain exemplary
embodiments.
[0018] FIG. 4 is an elevational top view of the LED module of FIG.
3, in accordance with certain exemplary embodiments.
[0019] FIG. 5 is an elevational cross-sectional side view of the
LED module of FIG. 3, in accordance with certain exemplary
embodiments.
[0020] FIG. 6 is a perspective side view of the LED module of FIG.
3, in accordance with certain exemplary embodiments.
[0021] FIG. 7 is an elevational bottom view of the LED module of
FIG. 3, in accordance with certain exemplary embodiments.
[0022] FIG. 8 is a perspective exploded side view of the LED module
of FIG. 3, in accordance with certain exemplary embodiments.
[0023] FIG. 9 is an elevational cross-sectional top view of a heat
sink of the LED module of FIG. 3, in accordance with certain
exemplary embodiments.
[0024] FIG. 10 illustrates a thermal scan of the heat sink of the
LED module of FIG. 3, in accordance with certain exemplary
embodiments.
[0025] FIG. 11 is a perspective side view of a reflector housing of
the LED module of FIG. 3, in accordance with certain exemplary
embodiments.
[0026] FIG. 12 is a perspective side view of a reflector being
inserted in the reflector housing of FIG. 11, in accordance with
certain exemplary embodiments.
[0027] FIG. 13 is a perspective side view of a trim ring aligned
for installation with the reflector housing of FIG. 11, in
accordance with certain exemplary embodiments.
[0028] FIG. 14 is a flow chart diagram illustrating a method for
installing the LED module of FIG. 3 in an existing, non-LED
fixture, in accordance with certain exemplary embodiments.
[0029] FIG. 15 is a perspective side view of the LED module of FIG.
3 connected to a socket of an existing, non-LED fixture via an
Edison base adapter, in accordance with certain exemplary
embodiments.
[0030] FIG. 16 is an elevational side view of the Edison base
adapter of FIG. 15, in accordance with certain exemplary
embodiments.
[0031] FIG. 17 is a perspective top view of an optic coupler of the
LED module of FIG. 3, in accordance with certain exemplary
embodiments.
[0032] FIG. 18 is a perspective bottom view of the optic coupler of
FIG. 17, in accordance with certain exemplary embodiments.
[0033] FIG. 19 is a perspective top view of an optic coupler of the
LED module of FIG. 3, in accordance with certain alternative
exemplary embodiments.
[0034] FIG. 20 is an exaggerated depiction of a profile of the
reflector, in accordance with certain exemplary embodiments.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0035] The following description of exemplary embodiments refers to
the attached drawings, in which like numerals indicate like
elements throughout the several figures. FIG. 1 is an elevational
top view of hanger bars 105, a plaster frame 110, a can-shaped
receptacle for housing a light source (a "can") 115, and a junction
box 120 of a recessed lighting fixture 100, according to certain
exemplary embodiments. FIG. 2 is an elevational cross-sectional
side view of the hanger bars 105, plaster frame 110, can 115, and
junction box 120 of the recessed lighting fixture 100 of FIG. 1, in
accordance with certain exemplary embodiments. With reference to
FIGS. 1 and 2, the hanger bars 105 are configured to be mounted
between spaced supports or joists (not shown) within a ceiling (not
shown). For example, ends of the hanger bars 105 can be fastened to
vertical faces of the supports or joists by nailing or other means.
In certain exemplary embodiments, the hanger bars 105 can include
integral fasteners for attaching the hanger bars 105 to the
supports or joists, substantially as described in co-pending U.S.
patent application Ser. No. 10/090,654, titled "Hanger Bar for
Recessed Luminaires with Integral Nail," and U.S. patent
application Ser. No. 12/122,945, titled "Hanger Bar for Recessed
Luminaires with Integral Nail," the complete disclosures of which
are hereby fully incorporated herein by reference.
[0036] The distance between the supports or joists can vary to a
considerable degree. Therefore, in certain exemplary embodiments,
the hanger bars 105 can have adjustable lengths. Each hanger bar
105 includes two inter-fitting members 105a and 105b that are
configured to slide in a telescoping manner to provide a desired
length of the hanger bar 105. A person of ordinary skill in the art
having the benefit of the present disclosure will recognize that
many other suitable means exist for providing adjustable length
hanger bars 105. For example, in certain alternative exemplary
embodiments, one or more of the hanger bars described in U.S. Pat.
No. 6,105,918, titled "Single Piece Adjustable Hanger Bar for
Lighting Fixtures," the complete disclosure of which is hereby
fully incorporated herein, may be utilized in the lighting fixture
100 of FIG. 1.
[0037] The plaster frame 110 extends between the hanger bars 105
and includes a generally rectangular, flat plate 110a with upturned
edges 110b. For example, the flat plate 110a can rest on a top
surface of the ceiling. The junction box 120 is mounted to a top
surface 110aa of the flat plate 110a. The junction box 120 is a
box-shaped metallic container that typically includes insulated
wiring terminals and knock-outs for connecting external wiring (not
shown) to an LED driver (not shown) disposed within the can 115 of
the light fixture 100 or elsewhere within the light fixture
100.
[0038] In certain exemplary embodiments, the plaster frame 110
includes a generally circular-shaped aperture 110c sized for
receiving at least a portion of the can 115 therethrough. The can
115 typically includes a substantially dome-shaped member
configured to receive an LED module (not shown) that includes at
least one LED light source (not shown). The aperture 110c provides
an illumination pathway for the LED light source. A person of
ordinary skill in the art having the benefit of the present
disclosure will recognize that, in certain alternative exemplary
embodiments, the aperture 110c can have another, non-circular shape
that corresponds to an outer profile of the can 115.
[0039] FIGS. 3-8 illustrate an exemplary LED module 300 of the
recessed lighting fixture 100 of FIG. 1. The exemplary LED module
300 can be configured for installation within the can 115 of the
lighting fixture 100 of FIG. 1. The LED module 300 includes an LED
package 305 mounted to a heat sink 310. The LED package 305 may be
mounted directly to the heat sink 310 or with one or more other
components mounted in-between the LED package 305 and the heat sink
310.
[0040] The LED package 305 includes one or more LEDs mounted to a
common substrate 306. The substrate 306 includes one or more sheets
of ceramic, metal, laminate, circuit board, mylar, or another
material. Each LED includes a chip of semi-conductive material that
is treated to create a positive-negative ("p-n") junction. When the
LED package 305 is electrically coupled to a power source, such as
a driver 315, current flows from the positive side to the negative
side of each junction, causing charge carriers to release energy in
the form of incoherent light.
[0041] The wavelength or color of the emitted light depends on the
materials used to make the LED package 305. For example, a blue or
ultraviolet LED can include gallium nitride ("GaN") or indium
gallium nitride ("InGaN"), a red LED can include aluminum gallium
arsenide ("AlGaAs"), and a green LED can include aluminum gallium
phosphide ("AlGaP"). Each of the LEDs in the LED package 305 can
produce the same or a distinct color of light. For example, the LED
package 305 can include one or more white LED's and one or more
non-white LEDs, such as red, yellow, amber, or blue LEDs, for
adjusting the color temperature output of the light emitted from
the fixture 100. A yellow or multi-chromatic phosphor may coat or
otherwise be used in a blue or ultraviolet LED to create blue and
red-shifted light that essentially matches blackbody radiation. The
emitted light approximates or emulates "white," incandescent light
to a human observer. In certain exemplary embodiments, the emitted
light includes substantially white light that seems slightly blue,
green, red, yellow, orange, or some other color or tint. In certain
exemplary embodiments, the light emitted from the LEDs in the LED
package 305 has a color temperature between 2500 and 5000 degrees
Kelvin.
[0042] In certain exemplary embodiments, an optically transmissive
or clear material (not shown) encapsulates at least a portion of
the LED package 305 and/or each LED therein. This encapsulating
material provides environmental protection while transmitting light
from the LEDs. For example, the encapsulating material can include
a conformal coating, a silicone gel, a cured/curable polymer, an
adhesive, or some other material known to a person of ordinary
skill in the art having the benefit of the present disclosure. In
certain exemplary embodiments, phosphors are coated onto or
dispersed in the encapsulating material for creating white light.
In certain exemplary embodiments, the white light has a color
temperature between 2500 and 5000 degrees Kelvin.
[0043] In certain exemplary embodiments, the LED package 305
includes one or more arrays of LEDs that are collectively
configured to produce a lumen output from 1 lumen to 5000 lumens in
an area having less than two inches in diameter or in an area
having less than two inches in length and less than two inches in
width. In certain exemplary embodiments, the LED package 305 is a
CL-L220 package, CL-L230 package, CL-L240 package, CL-L102 package,
or CL-L190 package manufactured by Citizen Electronics Co., Ltd. By
using a single, relatively compact LED package 305, the LED module
300 has one light source that produces a lumen output that is
equivalent to a variety of lamp types, such as incandescent lamps,
in a source that takes up a smaller volume within the fixture.
Although illustrated in FIGS. 7 and 8 as including LEDs arranged in
a substantially square geometry, a person of ordinary skill in the
art having the benefit of the present disclosure will recognize
that the LEDs can be arranged in any geometry. For example, the
LEDs can be arranged in circular or rectangular geometries in
certain alternative exemplary embodiments.
[0044] The LEDs in the LED package 305 are attached to the
substrate 306 by one or more solder joints, plugs, epoxy or bonding
lines, and/or other means for mounting an electrical/optical device
on a surface. Similarly, the substrate 306 is mounted to a bottom
surface 310a of the heat sink 310 by one or more solder joints,
plugs, epoxy or bonding lines, and/or other means for mounting an
electrical/optical device on a surface. For example, the substrate
306 can be mounted to the heat sink 310 by a two-part arctic silver
epoxy.
[0045] The substrate 306 is electrically connected to support
circuitry (not shown) and/or the driver 315 for supplying
electrical power and control to the LED package 305. For example,
one or more wires (not shown) can couple opposite ends of the
substrate 306 to the driver 315, thereby completing a circuit
between the driver 315, substrate 306, and LEDs. In certain
exemplary embodiments, the driver 315 is configured to separately
control one or more portions of the LEDs to adjust light color or
intensity.
[0046] As a byproduct of converting electricity into light, LEDs
generate a substantial amount of heat that raises the operating
temperature of the LEDs if allowed to accumulate. This can result
in efficiency degradation and premature failure of the LEDs. The
heat sink 310 is configured to manage heat output by the LEDs in
the LED package 305. In particular, the heat sink 310 is configured
to conduct heat away from the LEDs even when the lighting fixture
100 is installed in an insulated ceiling environment. The heat sink
310 is composed of any material configured to conduct and/or
convect heat, such as die cast metal.
[0047] FIG. 9 is an elevational cross-sectional top view of the
exemplary heat sink 310. FIG. 10 illustrates a thermal scan of the
exemplary heat sink 310 in operation. With reference to FIGS. 3-10,
the bottom surface 310a of the heat sink 310 includes a
substantially round member 310b with a protruding center member
310c on which the LED package 305 is mounted. In certain exemplary
embodiments, the center member 310c includes two notches 310d that
provide a pathway for wires (not shown) that extend between the
driver 315 and the ends of the substrate 306. In certain
alternative exemplary embodiments, three or more notches 310d may
be included to provide pathways for wires. In certain alternative
exemplary embodiments, the bottom surface 310a may include only a
single, relatively flat member without any protruding center member
310c.
[0048] Fins 311 extend substantially perpendicular from the bottom
surface 310a, towards a top end 310e of the heat sink 310. The fins
311 are spaced around a substantially central core 905 of the heat
sink 310. The core 905 is a member that is at least partially
composed of a conductive material. The core 905 can have any of a
number of different shapes and configurations. For example, the
core 905 can be a solid or non-solid member having a substantially
cylindrical or other shape. Each fin 311 includes a curved, radial
portion 311a and a substantially straight portion 311b. In certain
exemplary embodiments, the radial portions 311a are substantially
symmetrical to one another and extend directly from the core 905.
In certain alternative exemplary embodiments, the radial portions
311a are not symmetrical to one another. Each straight portion 311b
extends from its corresponding radial portion 311a, towards an
outer edge 310f of the heat sink 310, substantially along a tangent
of the radial portion 311a.
[0049] The radius and length of the radial portion 311a and the
length of the straight portion 311b can vary based on the size of
the heat sink 310, the size of the LED module 300, and the heat
dissipation requirements of the LED module 300. By way of example
only, one exemplary embodiment of the heat sink 310 can include
fins 311 having a radial portion 311a with a radius of 1.25 inches
and a length of 2 inches, and a straight portion 311b with a length
of 1 inch. In certain alternative exemplary embodiments, some or
all of the fins 311 may not include both a radial portion 311a and
a straight portion 311b. For example, the fins 311 may be entirely
straight or entirely radial. In certain additional alternative
exemplary embodiments, the bottom surface 310a of the heat sink 310
may not include the round member 310b. In these embodiments, the
LED package 305 is coupled directly to the core 905, rather than to
the round member 310b.
[0050] As illustrated in FIG. 10, the heat sink 310 is configured
to dissipate heat from the LED package 305 along a heat-transfer
path that extends from the LED package 305, through the bottom
surface 310a of the heat sink, and to the fins 311 via the core
905. The fins 311 receive the conducted heat and transfer the
conducted heat to the surrounding environment (typically air in the
can 115 of the lighting fixture 100) via convection. For example,
heat from the LEDs can be transferred along a path from the LED
package 305 to the core 905, from the core 905 to the radial
portions 311a of the fins 311, from the radial portions 311a of the
fins 311 to their corresponding straight portions 311b, and from
the corresponding straight portions 311b to a surrounding
environment. Heat also can be transferred by convection directly
from the core 905 and/or the fins 311 to one or more gaps between
the fins 311.
[0051] In certain exemplary embodiments, a reflector housing 320 is
coupled to the bottom surface 310a of the heat sink 310. A person
of ordinary skill in the art will recognize that the reflector
housing 320 can be coupled to another portion of the LED module 300
or the lighting fixture 100 in certain alternative exemplary
embodiments. FIG. 11 illustrates the exemplary reflector housing
320. With reference to FIGS. 3-8 and 11, the reflector housing 320
includes a substantially round member 320a having a top end 320b
and a bottom end 320c. Each end 320b and 320c includes an aperture
320ba and 320ca, respectively. A channel 320d extends through the
reflector housing 320 and connects the apertures 320ba and
320ca.
[0052] The top end 320b includes a substantially round top surface
320bb disposed around at least a portion of the channel 320d. The
top surface 320bb includes one or more holes 320bc capable of
receiving fasteners that secure the reflector housing 320 to the
heat sink 310. Each fastener includes a screw, nail, snap, clip,
pin, or other fastening device known to a person of ordinary skill
in the art having the benefit of the present disclosure. In certain
alternative exemplary embodiments, the reflector housing 320 does
not include the holes 320bc. In those embodiments, the reflector
housing 320 is formed integrally with the heat sink 310 or is
secured to the heat sink 310 via means, such as glue or adhesive,
that do not require holes for fastening. In certain exemplary
embodiments, the reflector housing 320 is configured to act as a
secondary heat sink for conducting heat away from the LEDs. For
example, the reflector housing 320 can assist with heat dissipation
by convecting cool air from the bottom of the light fixture 100
towards the LED package 305 via one or more ridges 321.
[0053] The reflector housing 320 is configured to receive a
reflector 1205 (FIG. 12) composed of a material for reflecting,
refracting, transmitting, or diffusing light emitted by the LED
package 305. The term "reflector" is used herein to refer to any
material configured to serve as an optic in a light fixture,
including any material configured to reflect, refract, transmit, or
diffuse light. FIG. 12 is a perspective side view of the exemplary
reflector 1205 being inserted in the channel 320d of the reflector
housing 320, in accordance with certain exemplary embodiments. With
reference to FIGS. 3-8, 11, and 12, when the reflector 1205 is
installed in the reflector housing 320, outer side surfaces 1205a
of the reflector 1205 are disposed along corresponding interior
surfaces 320e of the reflector housing 320. In certain exemplary
embodiments, a top end 1205b of the reflector 1205 abuts an edge
surface 330a of an optic coupler 330, which is mounted to a bottom
edge 310a of the top surface 320bb. The reflector 1205 is described
in more detail below with reference to FIG. 20. The optic coupler
330 includes a member configured to cover the electrical
connections at the substrate 306, to allow a geometric tolerance
between the LED package 305 and the reflector 1205, and to guide
light emitted by the LED package 305. The optic coupler 330 and/or
a material applied to the optic coupler 330 can be optically
refractive, reflective, transmissive, specular, semi-specular, or
diffuse. The optic coupler 330 is described in more detail below
with reference to FIGS. 17-19.
[0054] The bottom end 320c of the reflector housing 320 includes a
bottom surface 320ca that extends away from the channel 320d,
forming a substantially annular ring around the channel 320d. The
surface 320ca includes slots 320cb that are each configured to
receive a corresponding tab 1305a from a trim ring 1305 (FIG. 13).
FIG. 13 illustrates a portion of the trim ring 1305 aligned for
installation with the reflector housing 320. With reference to
FIGS. 3-8 and 11-13, proximate each slot 320cb, the surface 320ca
includes a ramped surface 320cc that enables installation of the
trim ring 1305 on the reflector housing 320 via a twisting
maneuver. Specifically, the trim ring 1305 can be installed on the
reflector housing 320 by aligning each tab 1305a with its
corresponding slot 320cb and twisting the trim ring 1305 relative
to the reflector housing 320 so that each tab 1305a travels up its
corresponding ramped surface 320cc to a higher position along the
bottom surface 320ca. Each ramped surface 320cc has a height that
slowly rises along the perimeter of the housing 320.
[0055] The trim ring 1305 provides an aesthetically pleasing frame
for the lighting fixture 100. The trim ring 1305 may have any of a
number of colors, shapes, textures, and configurations. For
example, the trim ring 1305 may be white, black, metallic, or
another color and may also have a thin profile, a thick profile, or
a medium profile. The trim ring 1305 retains the reflector 1205
within the reflector housing 320. In particular, when the reflector
1205 and trim ring 1305 are installed in the light fixture 100, at
least a portion of a bottom end 1205b of the reflector 1205 rests
on a top surface 1305b of the trim ring 1305.
[0056] Referring now to FIGS. 3-8, a bracket 325 couples torsion
springs 340 to opposite side surfaces 310f of the heat sink 310.
The bracket 325 includes a top member 325a and opposing, elongated
side members 325b that extend substantially perpendicularly from
the top member 325a, towards the bottom end 320c of the reflector
housing 320c. The bracket 325 is coupled to the heat sink 310 via
one or more screws, nails, snaps, clips, pins, and/or other
fastening devices known to a person of ordinary skill in the art
having the benefit of the present disclosure.
[0057] Each side member 325b includes an aperture 325c configured
to receive a rivet 325d or other fastening device for mounting one
of the torsion springs 340 to the heat sink 310. Each torsion
spring 340 includes opposing bracket ends 340a that are inserted
inside corresponding slots (not shown) in the can 115 of the light
fixture 100. To install the LED module 300 in the can 115, the
bracket ends 340a are squeezed together, the LED module 300 is slid
into the can 115, and the bracket ends 340a are aligned with the
slots and then released such that the bracket ends 340a enter the
slots.
[0058] A mounting bracket 335 is coupled to the top member 325a
and/or the top end of heat sink 310 via one or more screws, nails,
snaps, clips, pins, and/or other fastening devices known to a
person of ordinary skill in the art having the benefit of the
present disclosure. The mounting bracket 335 includes a
substantially round top member 335a and protruding side members
335b that extend substantially perpendicular from the top member
335a, towards the bottom end 320c of the reflector housing 320. In
certain exemplary embodiments, the mounting bracket 335 has a
profile that substantially corresponds to an interior profile of
the can 115. This profile allows the mounting bracket 335 to create
a junction box (or "j-box") in the can 115 when the LED module 300
is installed in the light fixture 100. In particular, as described
in more detail below with reference to FIG. 14, electrical
junctions between the light fixture 100 and the electrical system
(not shown) at the installation site may be disposed within the
substantially enclosed space between the mounting bracket 335 and
the top of the can 115 (the junction box), when the LED module 300
is installed.
[0059] In certain exemplary embodiments, the driver 315 and an
Edison base socket bracket 345 are mounted to a top surface 350c of
the top member 350a of the mounting bracket 335. Alternatively, the
driver 315 can be disposed in another location in or remote from
the light fixture 100. As set forth above, the driver 315 supplies
electrical power and control to the LED package 305. As described
in more detail below with reference to FIGS. 14-16, the Edison base
socket bracket 345 is a bracket that is configured to receive an
Edison base socket 1505 (FIGS. 15-16) and an Edison base adapter
1520 (FIGS. 15-16) in a retrofit installation of the LED module 300
in an existing, non-LED fixture. This bracket 345 allows the LED
module 300 to be installed in both new construction and retrofit
applications. In certain alternative exemplary embodiments, the
bracket 345 may be removed for a new construction installation.
[0060] FIG. 14 is a flow chart diagram illustrating a method 1400
for installing the LED module 300 in an existing, non-LED fixture,
in accordance with certain exemplary embodiments. FIGS. 15 and 16
are views of an exemplary Edison base adapter 1520 and of the LED
module being 300 connected to an Edison base socket 1505 of the
existing, non-LED fixture via the Edison base adapter 1520. The
exemplary method 1400 is illustrative and, in alternative
embodiments of the invention, certain steps can be performed in a
different order, in parallel with one another, or omitted entirely,
and/or certain additional steps can be performed without departing
from the scope and spirit of the invention. The method 1400 is
described below with reference to FIGS. 3-8 and 14-16.
[0061] In step 1410, an inquiry is conducted to determine whether
the installation of the LED module 300 in the existing fixture will
be compliant with Title 24 of the California Code of Regulations,
titled "The Energy Efficiency Standards for Residential and
Nonresidential Buildings," dated Oct. 1, 2005. Title 24 compliant
installations require removal of the Edison base socket 1505 in the
existing fixture. An installation that does not need to be Title 24
compliant does not require removal of the Edison base socket
1505.
[0062] If the installation will not be Title 24 compliant, then the
"no" branch is followed to step 1415. In step 1415, the Edison base
socket 1505 from the existing fixture is released. For example, a
person can release the Edison base socket 1505 by removing the
socket 1505 from a plate of the existing fixture. In step 1420, the
person screws the Edison base adapter 1520 into the Edison base
socket 1505. The Edison base adapter 1520 electrically couples the
driver 315 of the LED module 300 to the power source of the
existing fixture via the socket 1505 of the existing fixture and/or
via wires connected to the socket 1505, as described below, with
reference to steps 1455-1460.
[0063] In step 1425, the person plugs wiring 1530 from the LED
module 300 into the Edison base adapter 1520. For example, the
person can plug one or more quick-connect or plug connectors 350
from the driver 315 into the Edison base adapter 1520.
Alternatively, the person may connect wires without connectors from
the driver to the Edison base adapter 1520. In step 1430, the
person mounts the Edison base adapter 1520 and the socket 1505 to
the mounting bracket 335 on the LED module 300. For example, the
person can snap, slide, or twist the Edison base adapter 1520 and
socket 1505 onto the Edison base socket bracket 345 on the mounting
bracket 335, and/or the person can use one or more screws, nails,
snaps, clips, pins, and/or other fastening devices to mount the
Edison base adapter 1520 and socket 1505 to the Edison base socket
bracket 345 and/or mounting bracket 335.
[0064] In step 1435, the person squeezes the torsion springs 340 so
that the bracket ends 340a of each torsion spring 340 move towards
one another. The person slides the LED module 300 into a can 115 of
the existing light fixture, aligns the bracket ends 340a with slots
in the can 115, and releases the bracket ends 340a to install the
bracket ends 340a within the can 115, in step 1440. In step 1445,
the person routes any exposed wires (not shown) into the existing
fixture and pushes the LED module 300 flush to a ceiling
surface.
[0065] Returning to step 1410, if the installation will be Title 24
compliant, then the "yes" branch is followed to step 1450, where
the person cuts wires in the existing fixture to remove the Edison
base, including the Edison base socket 1505, from the existing
fixture. In step 1455, the person cuts wires 1520a on the Edison
base adapter 1520 to remove an Edison screw-in plug 1520b on the
adapter 1520. The person connects the wires 1520a from the Edison
base adapter 1520 to wires (not shown) in the existing fixture, and
plugs wiring 1530 from the LED module 300 into a connector 1520c on
the adapter 1520, in step 1460. These connections complete an
electrical circuit between a power source at the installation site,
the Edison base adapter 1520, and the LED module 300, without using
an Edison base socket 1505. In step 1465, the person mounts the
Edison base adapter 1520 to the mounting bracket 335 on the LED
module 300, substantially as described above in connection with
step 1430.
[0066] As set forth above, the mounting bracket 335 has a profile
that substantially corresponds to an interior profile of the can
115. This profile allows the mounting bracket 335 to create a
junction box (or "j-box") in the can 115 when the LED module 300 is
installed in the light fixture 100 by substantially enclosing the
space between the mounting bracket 335 and the top of the can 115.
In particular, the electrical junctions between the wires 1530, the
driver 315, the Edison base adapter 1520, and, depending on whether
the installation is Title 24 compliant, the socket 1505, may be
disposed within the substantially enclosed space between the
mounting bracket 335 and the top of the can 115 when the LED module
300 is installed.
[0067] FIGS. 17 and 18 are views of the optic coupler 330 of the
LED module 300, in accordance with certain exemplary embodiments.
With reference to FIGS. 17 and 18, the optic coupler 330 includes a
refractive, reflective, transmissive, specular, semi-specular, or
diffuse member that covers the electrical connections at the
substrate 306, to allow a geometric tolerance between the reflector
1205 and the LEDs in the LED package 305, and to guide light
emitted by the LEDs.
[0068] In certain exemplary embodiments, the optic coupler 330
includes a center member 330b having a top surface 330ba and a
bottom surface 330bb. Each surface 330ba and 330bb includes an
aperture 330ca and 330cb, respectively. The apertures 330ca and
330cb are parallel to one another and are substantially centrally
disposed in the center member 330b. A side member 330bc defines a
channel 330d that extends through the center member 330b and
connects the apertures 330ca and 330cb. In certain exemplary
embodiments, the side member 330bc extends out in a substantially
perpendicular direction from the top surface 330ba. Alternatively,
the side member 330bc can be angled in a conical, semi-conical, or
pyramidal fashion.
[0069] When the optic coupler 330 is installed in the LED module
300, the apertures 330ca and 330cb are aligned with the LEDs of the
LED package 305 so that all of the LEDs are visible through the
channel 330d. In certain exemplary embodiments, the geometry of the
side member 330bc and/or one or both of the apertures 330ca and
330cb substantially corresponds to the geometry of the LEDs. For
example, if the LEDs are arranged in a substantially square
geometry, as shown in FIGS. 7 and 8, the side member 330bc and the
apertures 330ca and 330cb can have substantially square geometries,
as shown in FIGS. 17 and 18. Similarly, if the LEDs are arranged in
a substantially round geometry, the side member 330bc and/or one or
both of the apertures 330ca and 330cb can have a substantially
round geometry. In certain exemplary embodiments, the optic coupler
330d is configured to guide light emitted by the LED package 305.
For example, the emitted light can travel through the channel 330d
and be reflected, refracted, diffused, and/or transmitted by the
side member 330bc and/or the bottom surface 330bb of the center
member 330b.
[0070] A side wall member 330e extends substantially
perpendicularly from the top surface 330ba of the optic coupler
330. The side wall member 330e connects the center member 330b and
an edge member 330f that includes the edge surface 330a of the
optic coupler 330. The side wall member 330e has a substantially
round geometry that defines a ring around the center member 330b.
The edge member 330f extends substantially perpendicularly from a
top end 330ea of the side wall member 330e. The edge member 330f is
substantially parallel to the center member 330b.
[0071] The side wall member 330e and center member 330b define an
interior region 330g of the optic coupler 330. The interior region
330g includes a space around the aperture 330ca that is configured
to house the electrical connections at the substrate 306. In
particular, when the optic coupler 330 is installed within the LED
module 300, the optic coupler 330 covers the electrical connections
on the substrate 306 by housing at least a portion of the
connections in the interior region 330g. Thus, the electrical
connections are not visible when the LED module 300 is
installed.
[0072] FIG. 19 is a perspective top view of an optic coupler 1900
of the LED module 300, in accordance with certain alternative
exemplary embodiments. The optic coupler 1900 is substantially
similar to the optic coupler 330, except that the optic coupler
1900 has a wider edge member 1900f and a narrower center member
1900b that has a substantially conical or frusto-conical geometry.
In particular, a bottom surface 1900ba of the center member 1900b
has a larger radius than a top surface 1900bb of the center member
1900b. Each surface 1900ba and 1900bb includes an aperture 1900ca
and 1900cb, respectively, that connects a channel 1900d extending
through the center member 1900b. The bottom surface 1900ba has a
substantially angled profile that bows outward from the channel
1900d, defining the substantially conical or frusto-conical
geometry of the center member 1900b. In certain exemplary
embodiments, the geometry of the center member 1900b can reduce
undesirable shadowing from the optic coupler 1900. In particular,
the center member 1900b does not include sharp angled edges that
could obstruct light from the LED package 305.
[0073] Although FIGS. 17-18 and 19 illustrate center members 330b
and 1900b with square and conical geometries, respectively, a
person of ordinary skill in the art having the benefit of the
present disclosure will recognize that the center members 330b and
1900b can include any geometry. For example, in certain alternative
exemplary embodiments, the optic coupler 300 or 1900 can include a
center member that incorporates a hemispherical or cylindrical
geometry.
[0074] FIG. 20 is an exaggerated depiction of a cross-sectional
profile of the reflector 1205, in accordance with certain exemplary
embodiments. The profile includes a first region 2005 at the top of
the reflector 1205 and a second region 2010 at the bottom of the
reflector 1205. The second region 2010 is more diverging than the
first region 2005. The regions 2005 and 2010 define a curve that
resembles the shape of a side of a bell.
[0075] As is well known to a person of ordinary skill in the art
having the benefit of the present disclosure, reflectors within a
downlight need to create a specific light pattern that is pleasing
to the eye, taking into account human visual perception. Most
visually appealing downlights are designed such that the reflected
image of the source light begins at the top of the reflector and
works its way downward as an observer walks toward the fixture.
This effect is sometimes referred to as "top down flash." It is
generally accepted that people prefer light distributions that are
more or less uniform, with smooth rather than abrupt gradients.
Abrupt gradients are perceived as bright or dark bands in the light
pattern.
[0076] Traditional reflector designs for downlights with large
sources, such as incandescent or compact fluorescent lamps, are
fairly straightforward. A parabolic or nearly parabolic section
created from the edge rays or tangents from the light source will
create a top down flash with the widest distribution possible with
given perception constraints. With respect to the light pattern on
a nearby surface, such as a floor, the light pattern is generally
smooth due to the fact that the large source is reflected into a
large, angular zone.
[0077] Designing a reflector for a small light source, such as an
LED, is not as straightforward. In particular, it has traditionally
been difficult to create a smooth light pattern when using an LED
source. The reflector for a small source downlight, such as an LED
downlight 100, needs to be more diverging than is typical with
downlights having larger sources. The reflected portion of the
light, nearest nadir, or the point directly below the light
fixture, is the most critical area for a small source downlight. If
the transition between the reflector image and the bare source
alone is abrupt in the downlight, a bright or dark ring will be
perceived in the light pattern.
[0078] To compensate, the reflector 1205 of the present invention
becomes radically diverging near this zone to better blend the
transition area. In particular, the bell-shape of the profile of
the reflector 1205 defines at least one smooth curve with a
substantially centrally disposed inflection point. A top portion of
the curve (the first region 2005), reflects light in a more
concentrated manner to achieve desired light at higher angles. For
example, the top portion of the curve can reflect light near the
top of the reflector 1205 starting at about 50 degrees. A bottom
portion of the curve (the second region 2010) is more diverging
than the top portion and reflects light over a large angular zone
(down to zero degrees), blending out what would otherwise be a hard
visible line in the light pattern. This shape has been show to meet
the requirement of a top-down flash while also creating a smooth,
blended light pattern in the LED downlight fixture 100. Although
particularly useful for LED downlights, a person of ordinary skill
in the art having the benefit of the present disclosure will
recognize that the design of the reflector 1205 may be used in any
type of fixture, whether LED-based or not.
[0079] The precise shape of the reflector 1205 can depend on a
variety of factors, including the size and shape of the light
source, the size and shape of the aperture opening, and the desired
photometric distribution. In certain exemplary embodiments, the
shape of the reflector 1205 can be determined by defining a number
of vertices and drawing a spline through the vertices, thereby
creating a smooth, continuous curve that extends through the
vertices. Although it might be possible to approximate this curve
with an equation, the equation would change depending on a given
set of variables. In one exemplary reflector 1205, the vertices of
the spline were determined in a trial and error methodology with
optical analysis software to achieve a desired photometric
distribution. The variables set at the onset of the design were:
the diameter of the aperture (5 inches), the viewing angle an
observer can first see the light source or interior of the optical
coupler through the aperture as measured from nadir, directly below
the fixture (50 degrees), and the cutoff angle of the reflected
light from the reflector as measured from nadir, directly below the
fixture (50 degrees).
[0080] Although specific embodiments of the invention have been
described above in detail, the description is merely for purposes
of illustration. It should be appreciated, therefore, that many
aspects of the invention were described above by way of example
only and are not intended as required or essential elements of the
invention unless explicitly stated otherwise. Various modifications
of, and equivalent steps corresponding to, the disclosed aspects of
the exemplary embodiments, in addition to those described above,
can be made by a person of ordinary skill in the art, having the
benefit of this disclosure, without departing from the spirit and
scope of the invention defined in the following claims, the scope
of which is to be accorded the broadest interpretation so as to
encompass such modifications and equivalent structures.
* * * * *