(12)
`
`United States Patent
`Coplin et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,310,158 B2
`Nov. 13, 2012
`
`USOO831 O158B2
`
`8/2005 Harrah
`6,936,855 B1
`9, 2005 Kishimura et al.
`6,942,361 B1
`58. E. al
`$33. R
`D531.342 S 10/2006 Kauffman et al.
`7,148,632 B2 12/2006 Berman et al.
`D535,774 S
`1/2007 Weston et al.
`7,347,706 B1
`3/2008 Wu et al.
`(Continued)
`
`FOREIGN PATENT DOCUMENTS
`WO WO 2008135927 A1 * 11, 2008
`inued
`(Continued)
`OTHER PUBLICATIONS
`International Search Report with Written Opinion of the International
`Searching Authority dated Sep. 17, 2010, regarding application PCT/
`US2010/040866, 13 pages.
`(Continued)
`Primary Examiner — Douglas W Owens
`Assistant Examiner — Jianzi Chen
`(74) Attorney, Agent, or Firm — Polsinelli Shughart PC
`
`ABSTRACT
`(57)
`A light emitting diode (LED) light engine is provided for use
`in a light fixture to enable improved and efficient dissipation
`of heat generated in the light fixture. The light engine includes
`a circuit board that includes multiple LEDs for emitting light.
`The light engine includes a chassis that has a plurality of
`upper fins that extend upward from a central flanged portion
`to dissipate heat generated by the LEDs into the lighting
`fixture. The circuit board is mounted to a mounting Surface on
`the chassis that is surrounded by a fin wall that depends from
`the central flanged portion. The chassis also has a plurality of
`lower fins that extend outward from an outer surface of the fin
`wall to dissipate heat out of the fixture and into the ambient air
`environment.
`
`71 Claims, 10 Drawing Sheets
`
`(54) LED LIGHT ENGINE APPARATUS
`(75) Inventors: Barry Cason Coplin, Fairway, KS (US);
`John Robert Householder, Reading,
`MA (US); Clifford Earl Wilson, Holt,
`MO (US)
`
`(73) Assignee: EcoFit Lighting, LLC, Lenexa, KS
`(US)
`
`-
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 380 days.
`(21) Appl. No.: 12/565,584
`1-1.
`(22) Filed:
`(65)
`
`(*) Notice:
`
`Sep. 23, 2009
`Prior Publication Data
`US 2011/0068708 A1
`Mar. 24, 2011
`(51) Int. Cl.
`(2006.01)
`HOL 7/44
`(52) U.S. Cl. ............................................ 315/32: 315/33
`(58) Field of Classification Search .................... 315/32,
`315/33
`See application file for complete search history.
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`D194479 S
`1/1963 Pettengill
`3,183,346 A
`5/1965 Spaulding, et al.
`D278.461 S
`4/1985 Pepall
`5,688,042 A 11/1997 Madadi et al.
`D391,659 S
`3, 1998 Gaskins et al.
`5,892,621 A
`4/1999 McGregor et al.
`6,045,240 A
`4/2000 Hochstein
`D439,695 S
`3/2001 Compton et al.
`6,504,301 B1
`1/2003 Lowery
`6,580,228 B1
`6, 2003 Chen et al.
`6,676.279 B1
`1/2004 Hubbell et al.
`6,705,744 B2
`3, 2004 Hubbell et al.
`
`
`
`t)6- - - - -
`
`Page 1 of 22
`
`SAMSUNG EXHIBIT 1017
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`

`

`US 8,310,158 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`7,350,936 B2
`4/2008 Ducharme et al.
`D568,521 S
`5/2008 Compton
`D570,025 S
`5, 2008 Walker
`D573.288 S
`7/2008 Xu et al.
`D573,290 S
`7/2008 Shuai et al.
`D577,455 S
`9/2008 Zheng et al.
`D578,697 S
`10/2008 Zheng et al.
`7.431489 B2 10, 2008 Y
`1
`I - J.
`eO et al.
`D580,577 S
`1 1/2008 Wang et al.
`D596.777 S
`7/2009 Gordin
`D599,936 S
`9/2009 Wang et al.
`D599.941 S
`9, 2009 W.
`al
`ang et al.
`D599,942 S
`9/2009 Zheng
`3/2010 Holder et al.
`7,674,018 B2
`T.794,119 B2
`9, 2010 Venh
`-
`I
`US
`2002fO163805 A1 11, 2002 Hubbell et al.
`2004/0105.264 A1
`6/2004 Spero
`2005/02O7159 A1
`9, 2005 Maxik
`2006, OOO6821 A1
`1/2006 Singer et al.
`2006/0092639 A1
`5/2006 Livesay et al.
`2007/0076413 A1
`4/2007 Mingozzi
`2007/0076415 A1
`4/2007 Chou et al.
`2007/0O81339 A1
`4/2007 Chung et al.
`2007/0081340 A1
`4/2007 Chung et al.
`2007. O195527 A1
`8, 2007 Russell
`2007/02O1225 A1
`8, 2007 Holder et al.
`2007/0201255 A1
`8/2007 Campbell et al.
`
`2007/0242461 A1 10, 2007 Reisenauer et al.
`2008, 00801.96 A1
`4/2008 Ruud et al.
`2009/0021933 A1
`1/2009 Mayer et al.
`2009 OO73688 A1
`3, 2009 Patrick
`2009, OO73689 A1
`3, 2009 Patrick
`2009/0097.262 A1
`4/2009 Zhang et al.
`2009/O126905 A1
`5, 2009 Dinh
`2009, O168416 A1
`7/2009 Zhang et al.
`2009/O1853.74 A1
`7, 2009 Wu et al.
`2009/0303715 A1 12/2009 Takasago et al.
`2009/0303725 A1 12/2009 Chang
`2010, 0103668 A1
`4/2010 Lueken et al.
`2010, 0118534 A1
`5, 2010 LO
`2010/0134016 A1* 6, 2010 York et al. .................... 315,113
`2010/0134046 A1
`6, 2010 Holder et al.
`2010, 0182786 A1
`7, 2010 Hein
`2010/0202140 A1
`8/2010 Rooymans et al.
`2010/0302790 A1 12/2010 Yen
`
`FOREIGN PATENT DOCUMENTS
`
`WO
`
`T 2009
`2009081382 A1
`OTHER PUBLICATIONS
`
`CAFP Electronical Technology Co., Ltd, led streetlight heat sink.
`http://winszhangen.ecplaza.net/2.asp, Retrieved Sep. 22, 2009, 3
`pageS.
`
`* cited by examiner
`
`Page 2 of 22
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`U.S. Patent
`US. Patent
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`Nov. 13, 2012
`Nov. 13, 2012
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`Sheet 1 of 10
`Sheet 1 of 10
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`US 8,310,158 B2
`US 8,310,158 B2
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`U.S. Patent
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`Nov. 13, 2012
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`Sheet 2 of 10
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`US 8,310,158 B2
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`U.S. Patent
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`US 8,310,158 B2
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`Page 5 of 22
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`U.S. Patent
`US. Patent
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`Nov. 13, 2012
`Nov. 13, 2012
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`Sheet 4 of 10
`Sheet 4 of 10
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`US 8,310,158 B2
`US 8,310,158 B2
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`102 or
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`Page 6 of 22
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`U.S. Patent
`US. Patent
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`Nov. 13, 2012
`Nov. 13, 2012
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`Sheet 5 of 10
`Sheet 5 of 10
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`US 8,310,158 B2
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`Page 7 of 22
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`U.S. Patent
`US. Patent
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`Nov. 13, 2012
`Nov. 13, 2012
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`Sheet 6 of 10
`Sheet 6 of 10
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`US 8,310,158 B2
`US 8,310,158 B2
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`U.S. Patent
`US. Patent
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`Nov. 13, 2012
`Nov. 13, 2012
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`Sheet 7 of 10
`Sheet 7 0f 10
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`US 8,310,158 B2
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`U.S. Patent
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`Nov. 13, 2012
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`Sheet 9 of 10
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`US 8,310,158 B2
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`Page 11 of 22
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`U.S. Patent
`US. Patent
`
`Nov. 13, 2012
`Nov. 13, 2012
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`Sheet 10 of 10
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`US 8,310,158 B2
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`

`

`US 8,310,158 B2
`
`1.
`LED LIGHT ENGINEAPPARATUS
`
`RELATED APPLICATIONS
`
`Not Applicable.
`
`FEDERALLY SPONSORED RESEARCHOR
`DEVELOPMENT
`
`Not Applicable.
`
`COMPACT DISKAPPENDIX
`
`Not Applicable.
`
`BACKGROUND
`
`2
`light engine includes an AC to DC power converter to receive
`the AC power from the terminal block via at least one power
`connector and to convert the AC power to DC power at a DC
`power level. The light engine also includes a circuit board to
`receive the DC power at the DC power level from the AC to
`DC power converter. The circuitboard includes a plurality of
`light emitting diodes to receive the DC power and to emit
`light. The circuit board includes lighting optics to distribute
`the light emitted from the LEDs from the luminaire in a
`desired light pattern. The light engine also includes a chassis
`that mountably fits within the lighting fixture. The chassis has
`a central portion and a first side that includes a plurality of first
`fins that extend vertically upward from the central portion to
`dissipate heatina first direction. The chassis also has a second
`side that includes a mounting Surface for the circuit board and
`a fin wall that depends from the central portion and Surrounds
`the mounting Surface. A plurality of second fins extend hori
`Zontally outward from an outer surface of the fin wall to
`dissipate heat in a second direction.
`According to another aspect, a light engine is provided for
`retrofitting an existing light fixture. The light engine includes
`at least one power connector to connect to a power Source of
`the existing lighting fixture to convey AC power. The light
`engine also includes a current driver to receive the AC power
`via the at least one power connector and to convert the AC
`power to DC power at a DC power level. The light engine also
`includes a circuit board that includes a plurality of light emit
`ting diodes to receive the DC power and to emit light. The
`circuit board also includes a plurality of optical lenses to
`disperse light. Each of the plurality of optical lenses is posi
`tioned overa different one of the LEDs. The circuitboard also
`includes at least one optical reflector positioned over at least
`one of the optical lenses to reflect the light dispersed by the
`lenses to create the desired light pattern. The light engine also
`includes a chassis that has a first side that includes a plurality
`of first fins that extends to dissipate heat in a first direction.
`The light engine also has a second side that includes a mount
`ing Surface for the circuit board and a fin wall Surrounding the
`mounting Surface. A plurality of second fins extends outward
`from an outer surface of the fin wall to dissipate heat in a
`second direction. The chassis includes a central portion that
`has a mounting interface for mounting the chassis to a lid of
`the existing light fixture. The lid includes an opening, a reten
`tion clip, and at least one retention bracket. One end of the
`mounting interface is positioned beneath the retention
`bracket Such that the plurality of second fins passes through
`the opening. An opposite end of the mounting interface is
`secured to the lid by the retention clip.
`According to another aspect, a light engine is provided that
`includes a driver assembly. The driver assembly includes at
`least one power connector to connect to a power source of a
`luminaire to convey AC power. The driver assembly also
`includes an AC to DC power converter to receive the AC
`power via the at least one power connector and to convert the
`AC power to DC power at a DC power level. The driver
`assembly includes a processor to generate a control signal to
`control the AC to DC power converter to convert the AC
`power to the DC power at the DC power level. The light
`engine also includes a circuit board. The circuit board
`includes a plurality of light emitting diodes to receive the DC
`power and to emit light. The circuit board also includes light
`ing optics to distribute the light emitted from the LEDs from
`the luminaire in a desired light pattern. The light engine also
`includes a chassis that has a central portion. The chassis also
`has a first side that includes a plurality of first fins extending
`upward from the central portion to dissipate heat in a first
`direction. The light engine has a second side that includes a
`
`10
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`35
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`40
`
`Conventional lighting products use various lighting tech
`nologies including incandescent, fluorescent, and high inten
`sity discharge (HID) technologies to generate visible light.
`However, more and more lighting products are using Solid
`State Lighting (SSL) technology to meet indoor and outdoor
`lighting requirements for a variety of lighting applications.
`SSL technology uses electronic components, such as inte
`grated circuits, liquid-crystal displays, and light emitting
`diodes (LEDs), to generate visible light. Lighting fixtures that
`use SSL technology typically consume less energy and have
`a longer operating life as compared to lighting fixtures that
`use incandescent, fluorescent, or HID lighting technologies.
`A single LED cannot emit a Sufficient amount of light for
`most outdoor or indoor lighting applications. As a result,
`multiple LEDs are generally required to provide the mini
`mum amount of light or illuminance required to meet project
`specifications for a particular application. For example, mul
`tiple LEDs are typically mounted on a printed circuit board
`(PCB) and configured with separate optics, either refractive
`of reflective, such that the light emitted from each LED can be
`dispersed in a desired direction. Unfortunately, a significant
`amount of heat can be generated when using Such a multiple
`LED configuration. If the heat cannot be quickly removed,
`components within the lighting fixture, including the LEDs,
`can overheat and, thereby, significantly reduce the lighting
`efficiency and service life of the lighting fixture.
`
`SUMMARY
`
`According to one aspect, a light engine is provided that
`includes at least one power connector to connect to a power
`Source of aluminaire. The light engine also includes an alter
`nating current (AC) to direct current (DC) power converter to
`receive the AC power via the at least one power connector and
`to convert the AC power to DC power at a DC power level.
`The light engine also includes a circuit board. The circuit
`board includes a plurality of light emitting diodes to receive
`the DC power and to emit light. The circuit board also
`includes lighting optics to distribute the light emitted from the
`LEDs from the luminaire in a desired light pattern. The light
`engine also includes a chassis that has a first side that includes
`a plurality of first fins that extend upward to dissipate heat in
`a first direction. The chassis has a second side that includes a
`mounting surface for the circuit board and a fin wall that
`Surrounds the mounting Surface. A plurality of second fins
`extends outward from an outer surface of the fin wall to
`dissipate heat in a second direction.
`According to another aspect, a lighting fixture is provided
`that includes a light engine. The lighting fixture includes a
`housing and a terminal block that Supplies AC power. The
`
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`3
`mounting surface for the circuit board and a fin wall that
`depends from the central portion and Surrounds the mounting
`surface. The fin wall includes an inner surface that blocks at
`least a portion of the light from being emitted from the lumi
`naire. A plurality of second fins extends outward from an
`outer surface of the fin wall to dissipate heat in a second
`direction.
`According to another aspect, a light engine for a luminaire
`is provided. The luminaire includes a housing and a terminal
`block for Supplying AC power. The light engine includes a
`driver assembly that includes at least one power connector to
`connect to the terminal block to convey the alternating current
`(AC) power. The driver assembly also includes an AC to
`direct current (DC) power converter to receive the AC power
`via the at least one power connector and to convert the AC
`power to DC power at a DC power level. The driver assembly
`also includes a processor to generate a control signal to con
`trol the AC to DC converter to convert the AC power to the DC
`power at the DC power level. The light engine also includes a
`circuit board comprising a plurality of LEDs to receive the
`DC power and to emit light. The light engine also includes
`lighting optics to distribute the light emitted from the LEDs
`from the luminaire in a desired light pattern. The light engine
`also includes a chassis that has a central portion. The chassis
`also has a first side that includes a plurality of first fins that
`extend vertically upward from the central portion to dissipate
`heat into an interior of the housing. The chassis has a second
`side that includes a mounting Surface for the circuit board and
`a fin wall that depends from the central portion and Surrounds
`the mounting surface. An inner surface of the fin wall blocks
`at least a portion of the light in the desired light pattern from
`being emitted from the luminaire. A plurality of second fins
`extend horizontally outward from an outer surface of the fin
`wall to dissipate heat directly into ambient air outside of the
`housing.
`According to another aspect, a luminaire is provided that
`includes a light engine. The luminaire includes a housing and
`a terminal block that Supplies AC power. The light engine
`includes an AC to DC power converter to receive the AC
`power from the terminal block via at least one power connec
`40
`tor and to convert the AC power to DC power at a DC power
`level. The light engine also includes a circuit board to receive
`the DC power at the DC power level from the AC to DC power
`converter. The circuit board includes a plurality of light emit
`ting diodes to receive the DC power and to emit light. The
`circuit board includes lighting optics to distribute the light
`emitted from the LEDs from the luminaire in a desired light
`pattern. The light engine also includes a chassis that has a
`central portion. The chassis also has a first side that includes
`a plurality of first fins that extends vertically upward from the
`central portion to dissipate heat into an interior of the housing.
`The chassis has a second side that includes a mounting Sur
`face for the circuit board and a fin wall that depends from the
`central portion and Surrounds the mounting Surface. An inner
`surface of the fin wall blocks at least a portion of the light in
`the desired light pattern from being emitted from the lumi
`naire. A plurality of second fins extends horizontally outward
`from an outer surface of the fin wall to dissipate heat directly
`into ambient air outside of the housing.
`
`4
`FIGS. 2A-2D and 2F are isometric diagrams of a chassis,
`lighting circuit, and lighting optics according to aspects of the
`LED light engine.
`FIG. 2E depicts a generated light pattern according to one
`aspect of the LED light engine.
`FIGS. 3A-3D depict various stages of retrofitting an exist
`ing luminaire with the LED light engine.
`FIG. 4 is a block diagram depicting a lighting circuit and a
`driver according to one aspect of the LED light engine.
`FIG. 5A depicts a driver assembly according to one aspect
`of the LED light engine.
`FIG. 5B is a block diagram depicting processing and heat
`sensing components according to one aspect of the LED light
`engine.
`FIGS. 6A-6C depict an adapter plate for connecting the
`LED light engine to an existing luminaire.
`
`DETAILED DESCRIPTION
`
`Aspects of the LED light engine described herein enable
`the efficient dissipation of heat generated in a light fixture that
`uses multiple LEDs to generate light. According to another
`aspect, the LED light engine is configurable to fit a variety of
`existing lighting fixtures with minimal modification.
`Referring to the drawings, an exemplary embodiment of a
`LED light engine is illustrated and generally indicated as 100
`in FIG.1. The LED light engine 100 includes a chassis body
`(“chassis) 102, a lighting circuit ("circuit”) 104, and lighting
`optics (“optics') 106.
`The chassis 102 is configured to fit within an opening of an
`existing or new light fixture. Such as a streetlight luminaire.
`Although the LED light engine 100 is described herein in
`connection with Streetlight luminaires, it is contemplated that
`the LED light engine 100 can be used with a variety of other
`fixtures including, but not limited to, parking lot lights, park
`ing garage lights, exterior building lights, interior overhead
`lights, and/or display signage.
`The circuit 104 is a printed circuit board (PCB) that has
`multiple LEDs 108 and is mounted to the chassis 102.
`According to one aspect, a thermal conducting pad 110 is
`positioned between the circuit 104 and the chassis 102 to
`assist in the transfer of heat generated by the LEDs 108 to the
`chassis 102.
`Optics 106 include multiple optical lens assemblies 112
`and multiple trough shaped reflectors 114. According to one
`aspect, each optical lens assembly 112 includes three optical
`lenses 116. Each optical lens assembly 112 is mounted to the
`lighting circuit 104 such that an optical lens 116 is positioned
`over each LED 108. Each optical lens 116 efficiently captures
`the light exiting a corresponding LED 108 and disperses the
`light.
`A single reflector 114 surrounds a series of the optical lens
`assemblies 112. In the example configuration shown in FIG.
`1, each reflector 114 surrounds six optical lenses 116 or two
`optical lens assemblies 112. The reflector 114 includes a
`reflective surface that substantially reflects the light emitted
`from each optical lens 116 into a desired lighting pattern. The
`combination of optical lens 116 and reflectors 114 create the
`overall desired light pattern for the targeted area of illumina
`tion. For example, if the LED light engine 100 is being used
`in connection with a street light luminaire, the optical lens
`116 and reflectors 114 are configured to create patterns of
`illumination applicable to street light applications according
`to standards set forth by the Illumination Engineering Society
`of North America (IESNA). In addition to the optics 106
`emitting light towards a desired target area, a lower side of the
`chassis 102 includes a finwall that serves as a baffle to prevent
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`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1A is an isometric diagram depicting components of
`an LED light engine according to one aspect of the invention.
`FIG. 1B depicts a light pattern generated by an LED and
`corresponding optics according to one aspect of the LED light
`engine.
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`or block light from being emitted or propagated in unwanted
`directions. For example, as described in more detail below,
`the fin wall controls or prevents light from a street light
`luminaire from being emitted above or below certain angles
`with respect to a horizontal reference plane intersecting the
`bottom of the chassis 102.
`According to another aspect, an acrylic cover 118 mounts
`to the chassis 102 to cover and to protect the circuit 104 and
`optics 106 from environmental conditions. A gasket 120 can
`be positioned between the cover 118 and the chassis body 102
`to provide a seal between the chassis 102 and the cover 118 to
`enhance protection from environmental conditions.
`According to one aspect, the circuit 104, optics 106, cover
`118, and/or gasket 120 may include openings 122 that enable
`mechanical fasteners to pass through for connection to the
`chassis 102. For example, as explained in more detail below,
`a mechanical fastener, Such as a mounting screw, can be used
`to mount the circuit 104, optics 106, and cover 118 to the
`chassis 102.
`The illumination pattern created by the LED light engine
`100 is generally defined by the optics 106. For example, FIG.
`1B depicts a cross section of a trough shaped reflector 114, an
`LED 108, and a lens 116 according to one aspect of the LED
`light engine 100. Light, as indicated by 124, is emitted by the
`LED 108 and dispersed by the lens 116. At least some of the
`dispersed light, as indicated by 126, Strikes a sloped inner
`surface 128 of the reflector 114 and is reflected. The inner
`surface 128 of the trough is, for example, a reflective material
`that may be polished, anodized aluminum (also known as
`“specular aluminum), semi-specular aluminum, or another
`type of reflective material that has the desired reflective and
`other structural properties for a reflector. According to one
`aspect, an aluminum coating is applied to inner Surface of the
`reflector 114, such as a black polycarbonate polished reflec
`tor. The reflected light, as indicated by 130, is distributed
`downward in a light pattern 132 that is consistent with the
`shape of the reflector 114. For example, the angle at which the
`light pattern is distributed downward is consistent with the
`sloped sides of the reflector 114 and, thus, limits horizontal
`spread of illumination. As a result, a greater percentage of the
`illumination created by each LED 108 can be directed
`towards a target area for illumination.
`As the LED light engine 100 includes multiple reflectors
`114, the light pattern from each reflector 114 overlaps with at
`least one adjacent reflector 114 to produce the overall desired
`light pattern for a target illumination area. In one embodi
`ment, the reflector 114 includes individual trough compart
`ments 115 that are associated with each LED 108 and lens
`116. The shape and/or structure of the lens and trough com
`partment 115, including the shape and/or structure and slope
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`of the sides and/or walls of the trough compartment 115 and
`the reflective material on the trough component, define the
`light pattern for that lens and corresponding trough compart
`ment 115, and all LEDs 108 and optics 106 define the light
`pattern for the target illumination area. As discussed above,
`the angle of the generated light pattern can be configured to
`create patterns of illumination applicable to street light appli
`cations according to standards set forth by IESNA, or stan
`dards set forth by any other lighting authority or organization.
`FIG. 2A depicts the chassis 102 according to one aspect of
`the LED light engine 100. The chassis 102 includes a mount
`ing interface that enables the chassis 102 to be attached to a
`luminaire. According to one aspect, the mounting interface
`corresponds to a central portion 202 of the chassis 102. The
`central portion 202 can be secured to the lid of aluminaire via
`retention clips and/or retention brackets located on the lid,
`screws and bolts, or any other fasteners. For example, as
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`explained in more detail below, a retention clip and retention
`brackets previously used to secure a lens cover to the lid of an
`existing luminaire can be used to secure the chassis 102 to the
`lid of an existing luminaire. As a result, the central portion
`202 allows the LED light engine 100 to be connected to an
`existing luminaire that uses incandescent, fluorescent, HID,
`or other lighting components.
`According to one aspect, the chassis 102 is a monolithic
`cast aluminum chassis 102 that serves as a heat sink to trans
`fer heat generated by the LEDs 108 upward into a luminaire
`housing and to transfer heat out of the luminaire into the
`ambient air environment. For example, an upper side 204 of
`the chassis 102 includes a plurality of upper fins 206 that
`extend vertically upward to dissipate heat into an interior of
`the luminaire housing, such as a luminaire housing 304
`shown in FIG.3A. That is, the upper fins 206 are located in the
`interior of the luminaire between the central flanged portion
`202 of the chassis and the luminairehousing. A lower side 208
`of the chassis 102 includes a mounting surface 210 that is
`defined by and surrounded by a fin wall 212 that depends from
`the central flanged portion 202. A plurality of lower fins 214
`extend from an outer surface 216 of the fin wall 212 such that
`the lower fins 214 are along the periphery of the mounting
`surface 210 and extend below the mounting surface 210.
`According to one aspect, the fins extend vertically downward
`from the central flanged portion 202 and extend horizontally
`outward from the fin wall 212. In other aspects, the fins 214
`may extend at angles from the central flanged portion 202
`and/or the fin wall 212. As described below, when the LED
`light engine 100 is installed in a luminaire, the lower fins 214
`extend below the luminaire to dissipate heat into the ambient
`air outside of the luminaire housing. As used herein, ambient
`air refers to the air outside of the luminaire housing. During
`operation of the LEDs 108, the chassis 102 transfers heat
`away from the lighting circuit 104 through radiation and
`convection in both upward and downward directions. In this
`embodiment, the heat dissipated via the upper fins 206 is
`exchanged through air within the interior of the housing and
`then exchanged through the housing into the ambient air.
`However, the heat dissipated by the lower fins 214 is
`exchanged directly with the ambient air and, thus, increases
`the rate at which heat is dissipated from the luminaire.
`The mounting Surface 210 may include multiple receiving
`interfaces 218. Such as holes, openings, or other receiving
`interfaces that enable the lighting circuit 104 and other light
`ing components to be mounted or attached to the mounting
`surface 210. For example, the lighting circuit 104 can be
`attached to the mounting Surface 210 via mounting screws
`220, such as shown in FIG. 2B, which connect to receiving
`interfaces 218 via mating threads. According to one aspect, a
`heat-conducting pad, Such as the thermal pad 110, is posi
`tioned between the lighting circuit 104 and the mounting
`surface 210 to provide optimal thermal contact between the
`lighting circuit 104 and the chassis body 102 to maximize
`heat dissipation.
`The optics 106, including the optical lens assemblies 112
`and the reflectors 114, may be mounted to the mounting
`surface 210 via the mounting screws 220 or other fasteners.
`For example, the optical lens 116 of the optical lens assem
`blies 112 can be mounted over the LEDs 108 via the mounting
`surface 210 as shown in FIG. 2C. Similarly, the reflectors 114
`can be mounted over the optical lens 116 via the mounting
`surface 210 as shown in FIG. 2D.
`In addition to the optics 106 directing light toward a target
`area, the fin wall 212 eliminates the potential of providing
`light in unwanted directions. For example, because the LEDs
`108 are recessed with respect to the fin wall 212, the fin wall
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`US 8,310,158 B2
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`212 serves as a baffle and prevents light from being emitted
`above a horizontal plane that intersects the bottom of the
`chassis 102. In other words, because the fin wall 212 Sur
`rounds the optics 106, the fin wall 212 prevents light from
`being emitted directly into the sky.
`For example, FIG. 2E depicts a horizontal plane 222 that
`intersects the bottom of a chassis 102 of an exemplary lumi
`naire 224. In this example, the bottom of the luminaire 224
`corresponds to the bottom of the fin wall 212. The height of
`the fin wall 212 can be dimensioned to prevent light within a
`desired light pattern, as indicated by 226, from being emitted
`above a target angle, 0, with respect to the horizontal plane
`222. For example, according to one aspect, the target angle, 0.
`is, between 5 to 10 degrees below the horizontal plane 222.
`Thus, the height of the fin wall 212 can be dimensioned to
`prevent light from being emitted above a five-degree angle
`with respect to the horizontal plane 222. Other angles may be
`used. As a result, the fin wall 212 allows the luminaire to meet
`International Dark Sky Association criteria for preventing
`light pollution caused by light being emitted into the sky, and
`to meet the (Draft Jul. 1, 2009) USDOE Energy Star require
`ments for outdoor solid state light sources which limit the
`amount of light emitted above and immediately below the
`horizontal plane intersecting the bottom of the luminaire 302.
`Moreover, as shown in FIG. 2F, the acrylic cover 118 and
`gasket 120 can also be attached to the chassis 102 to provide
`a protective covering for the circuit 104 and the optics 106.
`According to one aspect, as shown in FIG.1, the openings 122
`in the cover 118 are within threaded metal bosses 134 that are
`integrated into the cover 118, for example, during a molding
`process of the cover 118. To mount the cover 118 to the
`chassis 102, mounting screws 220 are inserted downward,
`from the upper side 204 of the chassis 102, through openings
`120 in the chassis 102, circuit 104, and gasket 120 that match
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`the location of the metal bosses 134 on the cover 118. A
`threaded portion of the metal boss 134 receives the threaded
`portion of the mounting screw 220. As a result, after the cover
`118 is secured to the chassis 102, the mounting screw 220 is
`not visible from the lower side 208 of the chassis 102.
`FIGS. 3A-3D depict various stages of a retrofitting process
`for an existing luminaire 302 with the LED light engine 100
`according to one aspect of the invention. In this example, the
`existing luminaire 302 includes a housing 304, a lamp 306, a
`reflector 308, and a lens cover 310 as shown in FIG. 3A. The
`lamp 306 and reflector 308 are removed from the housing 304
`and the lens cover 310 is removed from a lid 312 of the
`luminaire 302, as shown in FIG. 3B. After the reflector is
`removed, an interior 313 of th