I 1111111111111111 11111 111111111111111 IIIII IIIII 1111111111 111111111111111111
`US007674018B2
`
`c12) United States Patent
`Holder et al.
`
`(IO) Patent No.:
`(45) Date of Patent:
`
`US 7,674,018 B2
`Mar.9,2010
`
`(54) LED DEVICE FOR WIDE BEAM
`GENERATION
`
`(75)
`
`Inventors: Ronald G. Holder, Niguel, CA (US);
`Greg Rhoads, Irvine, CA (US)
`
`(73) Assignee: Illumination Management Solutions
`Inc.
`
`( *) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by O days.
`
`(21) Appl. No.: 11/711,218
`
`(22) Filed:
`
`Feb.26,2007
`
`(65)
`
`Prior Publication Data
`
`US 2007/0201225 Al
`
`Aug. 30, 2007
`
`Related U.S. Application Data
`
`(60) Provisional application No. 60/777,310, filed on Feb.
`27, 2006, provisional application No. 60/838,035,
`filed on Aug. 15, 2006, provisional application No.
`60/861,789, filed on Nov. 29, 2006.
`
`(51)
`
`Int. Cl.
`F21V 3/00
`(2006.01)
`F21V 5104
`(2006.01)
`(52) U.S. Cl. ............................ 362/311.06; 362/311.02;
`362/335
`(58) Field of Classification Search ................. 362/800,
`362/326,335,336,337,338,339,340,235,
`362/236,237,240,244,246,249,311, 612,
`362/227, 317, 97.3; 257/98, 100; 359/718,
`359/720, 741; 313/500, 512,110,112
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`2,908,197 A * 10/1959 Wells et al ............. 340/815.76
`3,596,136 A *
`7/1971 Fischer ....................... 257/794
`4,860,177 A *
`8/1989 Simms ....................... 362/473
`
`4,941,072 A
`5,636,057 A *
`5,924,788 A *
`
`7/1990 Yasumoto
`.................. 359/625
`6/1997 Dick et al.
`7/1999 Parkyn, Jr ................... 362/329
`
`(Continued)
`
`FOREIGN PATENT DOCUMENTS
`
`EP
`
`1431653
`
`6/2004
`
`(Continued)
`
`OTHER PUBLICATIONS
`
`Computer translation of JP 11-154766.*
`
`(Continued)
`
`Primary Examiner-Jong-Suk (James) Lee
`Assistant Examiner-David R Crowe
`(74) Attorney, Agent, or Firm-Daniel L. Dawes
`
`(57)
`
`ABSTRACT
`
`An apparatus and method is characterized by providing an
`optical transfer function between a predetermined illumi(cid:173)
`nated surface pattern, such as a street light pattern, and a
`predetermined energy distribution pattern of a light source,
`such as that from an LED. A lens is formed having a shape
`defined by the optical transfer function. The optical transfer
`function is derived by generating an energy distribution pat(cid:173)
`tern using the predetermined energy distribution pattern of
`the light source. Then the projection of the energy distribution
`pattern onto the illuminated surface is generated. The projec(cid:173)
`tion is then compared to the predetermined illuminated sur(cid:173)
`face pattern to determine if it acceptably matches. The pro(cid:173)
`cess continues reiteratively until an acceptable match is
`achieved. Alternatively, the lens shape is numerically or ana(cid:173)
`lytically determined by a functional relationship between the
`shape and the predetermined illuminated surface pattern and
`predetermined energy distribution pattern of a light source as
`inputs.
`
`98 Claims, 12 Drawing Sheets
`
`Page 1 of 27
`
`SAMSUNG EXHIBIT 1020
`
`

`

`US 7,674,018 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`............... 359/726
`
`6,045,240 A *
`4/2000 Hochstein ................... 362/294
`6,050,707 A *
`4/2000 Kondo et al. ................ 362/346
`5/2001 McDermott
`6,227,685 Bl
`8/2001 Parkyn, Jr.
`6,273,596 Bl
`6,560,038 Bl *
`5/2003 Parkyn et al.
`8/2004 Wang
`6,784,357 Bl
`1/2005 Reill
`6,837,605 B2
`2/2005 Takekuma
`6,850,001 B2
`11/2005 Lei
`6,965,715 B2
`7,104,672 B2 *
`9/2006 Zhang ........................ 362/308
`2/2007 Holder
`7,172,319 B2
`2/2007 Benifez
`7,181,378 B2
`7,322,718 B2 *
`1/2008 Setomoto et al. ............ 362/276
`7,339,200 B2 *
`3/2008 Amano et al .................. 257/98
`7,348,723 B2 *
`3/2008 Yamaguchi et al. ......... 313/501
`5/2003 Reill
`2003/0099115 Al
`2004/0037076 Al*
`2/2004 Katoh et al.
`6/2004 Ducharme
`2004/0105261 Al
`6/2004 Spero
`2004/0105264 Al
`10/2004 Suehiro
`2004/0207999 Al
`2004/0218388 Al* 11/2004 Suzuki ....................... 362/231
`2004/0222947 Al * 11/2004 Newton eta!. ................ 345/39
`11/2004 Squicciarini
`2004/0228127 Al
`2005/0073849 Al
`4/2005 Rhoads et al.
`2006/0034082 Al
`2/2006 Park
`2006/0039143 Al
`2/2006 Katoh
`2006/0081863 Al*
`4/2006 Kim et al. ..................... 257/98
`2006/0138437 Al*
`6/2006 Huang et al. .................. 257/98
`2006/0238884 Al
`10/2006 Jang
`
`................ 362/235
`
`2006/0250803 Al *
`2006/0255353 Al
`2006/0285311 Al *
`2007/0019416 Al
`2007/0063210 Al
`2007 /0066310 Al
`2007/0081340 Al*
`2007/0091615 Al*
`2007/0183736 Al
`2008/0013322 Al*
`2008/0100773 Al
`2008/0174996 Al
`2008/0239722 Al *
`2008/0273327 Al*
`
`11/2006 Chen .......................... 362/373
`11/2006 Taskar
`12/2006 Chang et al. .................. 362/97
`1/2007 Han
`3/2007 Chiu
`3/2007 Haar
`4/2007 Chung et al. ................ 362/294
`4/2007 Hsieh et al. ................. 362/335
`8/2007 Pozdnyakov
`1/2008 Ohkawa ..................... 362/311
`5/2008 Hwang
`7/2008 Lu
`10/2008 Wilcox ....................... 362/268
`11/2008 Wilcox et al. ............... 362/267
`
`FOREIGN PATENT DOCUMENTS
`
`JP
`JP
`WO
`WO
`WO
`WO
`
`11154766
`11154766 A *
`WO-9624802
`WO-03044870
`WO-2005093316
`WO-2007100837
`
`9/1997
`6/1999
`8/1996
`5/2003
`10/2005
`9/2007
`
`OTHER PUBLICATIONS
`
`ISR and Written Opinion of ISA, PCT/US07 /05118.
`Botz, "Optimal Design of a Nonimaging Projection Lens for Use
`with an LED Light Source and a Rectangular Sheet." SPIE, pp.
`130-138, vol. 4092, USA, published 2000.
`
`* cited by examiner
`
`Page 2 of 27
`
`

`

`U.S. Patent
`US. Patent
`
`Mar.9,2010
`Diar.9,2010
`
`Sheet],of12
`Sheet 1 of 12
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`US 7,674,018 B2
`us 7,674,018 32
`
`FIG. 1
`FIG.
`1
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`
`Page 3 of 27
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`8
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`4
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`Page 3 of 27
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`

`

`U.S. Patent
`
`Mar.9,2010
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`Sheet 2 of 12
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`US 7,674,018 B2
`
`Pole, Cendelo Distribution Plo1
`Using Missed Reys
`
`170
`
`180
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`14
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`FIG. 4
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`Page 4 of 27
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`U.S. Patent
`
`Mar.9,2010
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`Sheet 3 of 12
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`US 7,674,018 B2
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`~o
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`FIG. 6
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`28
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`Page 5 of 27
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`

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`U.S. Patent
`
`Mar.9,2010
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`Sheet 4 of 12
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`US 7,674,018 B2
`
`ISO FOOT CANDLE PLOT
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`Page 6 of 27
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`

`

`U.S. Patent
`
`Mar.9,2010
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`Sheet 5 of 12
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`US 7,674,018 B2
`
`FIG. 12
`
`FIG. 13
`
`Page 7 of 27
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`

`

`U.S. Patent
`
`Mar.9,2010
`
`Sheet 6 of 12
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`US 7,674,018 B2
`
`42
`
`FIG. 14
`
`FIG. 15
`
`Page 8 of 27
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`

`

`U.S. Patent
`
`Mar.9,2010
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`Sheet 7 of 12
`
`US 7,674,018 B2
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`50
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`Page 9 of 27
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`U.S. Patent
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`Mar.9,2010
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`Sheet 8 of 12
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`US 7,674,018 B2
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`52
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`Page 10 of 27
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`

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`U.S. Patent
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`Mar.9,2010
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`Sheet 9 of 12
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`US 7,674,018 B2
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`

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`U.S. Patent
`
`Mar.9,2010
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`Sheet 10 of 12
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`US 7,674,018 B2
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`Page 12 of 27
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`

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`U.S. Patent
`
`Mar.9,2010
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`Sheet 11 of 12
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`US 7,674,018 B2
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`Page 13 of 27
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`

`

`U.S. Patent
`
`Mar.9,2010
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`Sheet 12 of 12
`
`US 7,674,018 B2
`
`LED EMISSION PATTERN
`(THREE-DIMENSIONAL)
`
`corv\PLEX/COMPOUND
`LENS SHAPE
`
`------102
`
`THREE-Dllv1ENSIONAL
`C:ANDElLA PATTERN
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`------104
`
`ISO-F<)OT-CANDLE (LUXJ
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`
`FIG 33.
`
`Page 14 of 27
`
`

`

`US 7,674,018 B2
`
`1
`LED DEVICE FOR WIDE BEAM
`GENERATION
`
`RELATED APPLICATIONS
`
`The present application is related to U.S. Provisional
`Patent Application Ser. No. 60/777,310, filed on Feb. 27,
`2006; U.S. Provisional Patent Application Ser. No. 60/838,
`035, filed on Aug. 15, 2006; and U.S. Provisional Patent
`Application Ser. No. 60/861, 789, filed on Nov. 29, 2006, each
`of which are incorporated herein by reference and to which
`priority is claimed pursuant to 35 USC 119.
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`The invention relates to the field of apparatus and methods
`for using light emitting diodes (LEDs) or other light sources
`to generate predetermined wide profile two dimensional illu(cid:173)
`mination patterns using a light source which has been opti- 20
`cally modified to provide a corresponding wide profile beam
`or a flat array of multiple ones of such modified light sources.
`2. Description of the Prior Art
`The initial investment cost of LED illumination is expen(cid:173)
`sive when compared with traditional lighting means using 25
`cost per lumen as the metric. While this may change over
`time, this high cost places a premium on collection and dis(cid:173)
`tribution efficiency of the LED optical system. The more
`efficient the system, the better the cost-benefit comparison
`with traditional illumination means, such as incandescent, 30
`fluorescent and neon.
`A traditional solution for generating broad beams with
`LEDs is to use one or more reflectors and/or lenses to collect
`and then spread the LED energy to a desired beam shape and
`to provide an angled array of such LEDs mounted on a curved 35
`fixture. Street light illumination patterns conventionally are
`defined into five categories, Types I-V. Type 1 is an oblong
`pattern on the street with the light over the center of the
`oblong. Type II is a symmetric four lobed pattern with the
`light over the centerofthe lobed pattern. Type III is a flattened 40
`oblong pattern with the light near the flattened side of the
`oblong. Type IV is parabolic pattern with a flattened base with
`the light near the flattened base. Type V is a circular pattern
`with the light over the center of the circle. Any asymmetric
`aspect of these categorical patterns is obtained by mounting 45
`the light sources in a curved armature or fixture. By curving or
`angling the fixture to point the LEDs or light sources in the
`directions needed to create a broad or spread beam onto a
`surface, such as a street, a portion of the light is necessarily
`directed upward away from the street into the sky. Hence, all 50
`airplane passengers are familiar with the view of a lighted city
`at night on approach. This often dazzling display is largely
`due to street lights and more particularly to street lights that
`have canted fixtures to create spread beams and hence collec(cid:173)
`tively direct a substantial amount of light skyward toward 55
`approaching aircraft. In an efficiently lighted city, the city
`would appear much darker to aircraft, because the street lights
`should be shining only onto the street and not into the sky. The
`dazzling city lights seen from aircraft and hill tops may be
`romantic, but represent huge energy losses, unnecessary fuel 60
`usage, and tons of unnecessary green house gas emissions
`from the electrical plants needed to generate the electricity for
`the wasted light.
`Another technique is to use a collimating lens and/or
`reflector and a sheet optic such as manufactured by Physical
`Devices Corporation to spread the energy into a desired beam.
`A reflector has a predetermined surface loss based on the
`
`2
`metalizing technique utilized. Lenses which are not coated
`with anti-reflective coatings also have surface losses associ(cid:173)
`ated with them. The sheet material from Physical Optics has
`about an 8% loss.
`One example of prior art that comes close to a high effi(cid:173)
`ciency system is the 'Side-emitter' device sold by Lumileds
`as part of their LED packaging offerings. However, the 'side(cid:173)
`emitter' is intended to create a beam with an almost 90 degree
`radial pattern, not a forward beam. It has internal losses of an
`10 estimated 15% as well. Another Lumileds LED, commonly
`called a low dome or bat wing LED, has a lens over the LED
`package to redirect the light, but it is to be noted that it has no
`undercut surface in the lens for redirecting the light from the
`LED which is in the peripheral forward solid angle. Similarly,
`15 it is to be noted that the conventional 5 mm dome lens or
`packaging provided for LEDs lacks any undercut surface in
`the dome at all.
`What is needed is an device that creates a wide angle beam,
`even the possibility of a nonradially symmetric beam, that can
`be created with a design method that allows the al designer to
`achieve a smooth beam profile which is not subject to the
`inherent disadvantages of the prior art.
`
`BRIEF SUMMARY OF THE INVENTION
`
`The illustrated embodiment of the invention includes a
`method of providing a predetermined illuminated surface
`pattern from a predetermined energy distribution pattern of a
`light source comprising the steps of defining an estimated
`optical transfer function of a lens shape; generating an energy
`distribution pattern using the estimated optical transfer func(cid:173)
`tion of a lens shape from the predetermined energy distribu(cid:173)
`tion pattern of the light source; generating a projection of the
`energy distribution pattern onto the illuminated surface; com(cid:173)
`paring the projection of the energy distribution pattern to the
`predetermined illuminated surface pattern; modifying the
`estimated optical transfer function of the lens shape; repeat(cid:173)
`ing the steps of generating the energy distribution pattern
`using the estimated optical transfer function of the lens shape
`from the predetermined energy distribution pattern of the
`light source, generating the projection of the energy distribu(cid:173)
`tion pattern onto the illuminated surface, and comparing the
`projection of the energy distribution pattern to the predeter(cid:173)
`mined illuminated surface pattern until acceptable consis(cid:173)
`tency between the projection of the energy distribution pat(cid:173)
`tern and the predetermined illuminated surface pattern is
`obtained; and manufacturing a lens with the last obtained
`estimated optical transfer function.
`In one embodiment the predetermined illuminated surface
`pattern is a street lighting pattern and the predetermined
`energy distribution pattern of the light source is a LED Lam(cid:173)
`bertian pattern so that what is manufactured is a lens for a
`street light.
`The method further comprises the step of assembling a
`plurality of light sources optically each combined with the
`manufactured lens to form a corresponding plurality of
`devices, each having an identical energy distribution pattern,
`to provide a linearly additive array of devices to produce the
`predetermined illuminated surface pattern.
`In one embodiment each array is manufactured as a modu(cid:173)
`lar unit and the method further comprises the step of scaling
`the intensity of the illumination pattern on the target surface
`without substantial modification of the illumination pattern
`by modular scaling of the arrays into larger or smaller collec-
`65 tions.
`The illustrated embodiment of the invention is also an
`improvement in an apparatus for providing an optical transfer
`
`Page 15 of 27
`
`

`

`US 7,674,018 B2
`
`3
`function between a predetermined illuminated surface pattern
`and a predetermined energy distribution pattern of a light
`source comprising a lens having a shape defined by the optical
`transfer function which is derived by generating an energy
`distribution pattern using the predetermined energy distribu(cid:173)
`tion pattern of the light source and then generating a projec(cid:173)
`tion of the energy distribution pattern onto the illuminated
`surface from the energy distribution pattern, which projection
`acceptably matches the predetermined illuminated surface
`pattern.
`In one embodiment the predetermined illuminated surface
`pattern is a street lighting pattern and the predetermined
`energy distribution pattern of the light source is a LED Lam(cid:173)
`bertian pattern.
`An embodiment of the claimed invention also includes a 15
`light source combined with the lens.
`The illustrated embodiment is also an improvement in a
`lens for use in an apparatus for providing a predetermined
`illuminated surface pattern from a predetermined energy dis(cid:173)
`tribution pattern of a light source comprising an undercut
`surface defined on the lens, the lens having a base adjacent to
`the light source, a lens axis and a surface between the base and
`lens axis, the undercut surface extending from the base of the
`lens at least partially along the surface of the lens toward the
`lens axis to generate an energy distribution pattern using the
`predetermined energy distribution pattern of the light source
`which will then generate a projection of the energy distribu(cid:173)
`tion pattern onto the illuminated surface, which projection
`acceptably matches the predetermined illuminated surface
`pattern.
`The undercut surface comprises portions which refract
`light and which totally internally reflect light from the light
`source into the energy distribution pattern.
`The undercut surface comprises portions which direct light
`from the light source into a broad spread beam.
`The illustrated embodiment is also an improvement in an
`apparatus for providing an optical transfer function between
`a predetermined illuminated surface pattern and a predeter(cid:173)
`mined energy distribution pattern of a light source comprising
`an undercut surface of a lens having a shape defined by the
`optical transfer function which shape is derived by generating
`an energy distribution pattern using the predetermined energy
`distribution pattern of the light source and then generating a
`projection of the energy distribution pattern onto the illumi(cid:173)
`nated surface from the energy distribution pattern, which
`projection acceptably matches the predetermined illuminated
`surface pattern.
`The illustrated embodiment is also an improvement in a
`lens surface for use in an apparatus for providing a predeter(cid:173)
`mined illuminated surface pattern from a predetermined
`energy distribution pattern of a light source, where the lens is
`characterized by an energy distribution pattern with two
`opposing sides, the improvement comprising a complex
`prism defined as part of the lens surface, the complex prism
`being arranged and configured to transfer energy from one
`side of the energy distribution pattern to the opposing side to
`render the energy distribution pattern asymmetric with
`respect to the two opposing sides.
`The illustrated embodiment is also an array for providing a
`predetermined illuminated surface pattern comprising a plu(cid:173)
`rality of light emitting devices for providing the predeter(cid:173)
`mined illuminated surface pattern, each device having an
`identical energy distribution pattern which produces the pre(cid:173)
`determined illuminated surface pattern, a circuit driver
`coupled to each of the devices, and a planar carrier in which
`the plurality oflight emitting devices are arranged to provide
`a spatially organization of the array to collectively produce a
`
`4
`linearly additive illumination pattern matching the predeter(cid:173)
`mined illuminated surface pattern.
`Each array is a modular unit capable of being readily com(cid:173)
`bined with a like array and further comprising a collection of
`5 arrays for scaling the intensity of the illumination pattern on
`the target surface without substantial modification of the illu(cid:173)
`mination pattern by modular scaling of the arrays into a larger
`or smaller collection.
`The array further comprises a plurality of circuit drivers,
`10 one for each device and where the plurality of circuit drivers
`are mounted on or attached to the carrier. The carrier com(cid:173)
`prises a printed circuit board to which the plurality of circuit
`drivers and devices are coupled, a cover for sealing the printed
`circuit board, circuit drivers and devices between the cover
`and carrier. The devices are optionally provided with a flange
`or an indexing flange and where the devices are angularly
`oriented with respect to the cover and carrier by the indexing
`flange. The printed circuit board, circuit drivers and devices
`are optionally sealed between the cover and carrier by means
`20 of a potting compound disposed between the cover and carrier
`in which potting compound the circuit drivers and devices as
`coupled to the printed circuit board are enveloped to render
`the array submersible.
`Another embodiment of the invention is a luminaire for a
`25 street light to provide a predetermined illumination pattern on
`a street surface comprising a lighting fixture, and a plurality
`of arrays of light emitting devices disposed in the lighting
`fixture, each array for providing the predetermined illumina-
`tion pattern on the street surface.
`The array in the luminaire for providing a predetermined
`illuminated surface pattern comprises a plurality of light
`emitting devices for providing the predetermined illuminated
`surface pattern, each device having an identical energy dis(cid:173)
`tribution pattern which produces the predetermined illumi-
`35 nated surface pattern, a circuit driver coupled to each of the
`devices; and a planar carrier in which the plurality of light
`emitting devices are arranged to provide a spatially organiza(cid:173)
`tion of the array to collectively produce a linearly additive
`illumination pattern matching the predetermined illuminated
`40 surface pattern.
`In one embodiment each of the light emitting devices in the
`luminaire comprises a light source and a lens with a lens
`surface, the lens for providing the predetermined illuminated
`surface pattern from a predetermined energy distribution pat-
`45 tern of a light source, where the lens is characterized by an
`energy distribution pattern with two opposing sides, the lens
`surface comprising a complex prism defined as part of the
`lens surface, the complex prism being arranged and config(cid:173)
`ured to transfer energy from one side of the energy distribu-
`50 tion pattern to the opposing side to render the energy distri(cid:173)
`bution pattern asymmetric with respect to the two opposing
`sides.
`In another embodiment each of the light emitting devices in
`the luminaire comprises a light source and a lens with a lens
`55 surface, the lens for providing the predetermined illuminated
`surface pattern from a predetermined energy distribution pat(cid:173)
`tern of a light source, the lens for providing an optical transfer
`function between the predetermined illuminated surface pat(cid:173)
`tern and the predetermined energy distribution pattern of a
`60 light source, the lens having an undercut surface with a shape
`defined by the optical transfer function which shape is derived
`by generating an energy distribution pattern using the prede(cid:173)
`termined energy distribution pattern of the light source and
`then generating a projection of the energy distribution pattern
`65 onto the illuminated surface from the energy distribution
`pattern, which projection acceptably matches the predeter(cid:173)
`mined illuminated surface pattern.
`
`30
`
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`

`

`US 7,674,018 B2
`
`5
`In one embodiment each of the light emitting devices in the
`luminaire comprises a light source and a lens with a lens
`surface, the lens for providing the predetermined illuminated
`surface pattern from a predetermined energy distribution pat(cid:173)
`tern of a light source, the lens having an undercut surface, the 5
`lens having a base adjacent to the light source, a lens axis and
`a surface between the base and lens axis, the undercut surface
`extending from the base of the lens at least partially along the
`surface of the lens toward the lens axis to generate an energy
`distribution pattern using the predetermined energy distribu(cid:173)
`tion pattern of the light source which will then generate a
`projection of the energy distribution pattern onto the illumi(cid:173)
`nated surface, which projection acceptably matches the pre(cid:173)
`determined illuminated surface pattern.
`In another embodiment each of the light emitting devices in
`the luminaire comprises a light source and a lens with a lens
`surface, the lens for providing the predetermined illuminated
`surface pattern from a predetermined energy distribution pat(cid:173)
`tern of a light source, the lens having a shape defined by the
`optical transfer function which is derived by generating an 20
`energy distribution pattern using the predetermined energy
`distribution pattern of the light source and then generating a
`projection of the energy distribution pattern onto the illumi(cid:173)
`nated surface from the energy distribution pattern, which
`projection acceptably matches the predetermined illuminated
`surface pattern.
`Another one of the illustrated embodiments is a luminaire
`for a street light to provide a predetermined illumination
`pattern on a street surface, the predetermined illumination
`pattern having a defined horizon, comprising a lighting fix(cid:173)
`ture, and a plurality of planar arrays oflight emitting devices
`disposed in the lighting fixture, each array for providing the
`predetermined illumination pattern on the street surface with
`substantial reduction of light directed from the luminaire to
`the horizon or above.
`The illustrated embodiment of the invention is comprised
`of a light source, such as a light emitting diode (LED) and a
`lens. It is to be understood that for the purposes of this speci(cid:173)
`fication that a "lens" is to be understood throughout as an
`optical element which is capable of refraction, reflection by
`total internal reflecting surfaces or both. Hence, the more
`general term, "optic" could be used in this specification inter(cid:173)
`changeably with the term, "lens". The lens is characterized by
`directing light from the light source into a smooth, broad
`beam, which when projected onto an illumined surface has a
`50 percent of maximum foot-candle measurement at an angle
`greater than 15 degrees from the centerline of the illumination
`pattern, i.e. a 30 degree full width, half maximum. The lens
`comprises a
`transparent or translucent "blob-like" or
`dimpled-puddle shape, such as plastic or glass, that encom(cid:173)
`passes the light source or LED emitter to generate a high
`angle intensity wide beam without, in the preferred embodi(cid:173)
`ment, adding any additional surface losses, either reflective or
`refractive than the LED would cause itself in this configura(cid:173)
`tion of the invention. Almost all the energy of the LED is 55
`directed into the beam without losses much in excess of those
`generated by the LED without the lens deployed.
`The lens comprises a transparent or translucent "blob-like"
`or dimpled-puddle shape, which produces a high angle inten(cid:173)
`sity wide beam without adding any additional surface losses, 60
`either reflective or refractive than the LED would cause itself
`in this configuration of the invention. Almost all the energy of
`the LED is directed into the beam without losses much in
`excess of those generated by the LED without the lens
`deployed.
`In one embodiment the lens is separate from the LED and
`is glued, affixed or disposed on the light source or original
`
`6
`LED protective dome with an index matching material so as
`to virtually eliminate the seam or any optical discontinuity
`between the two. In another embodiment the lens is manu-
`factured as the protective dome of the LED.
`The lens is characterized by a "blob" zone which is a small
`concentrating zone that is formed along the desired primary
`director of the lens and light source. The blob zone comprises
`a surface portion of the lens which collects the light rays
`emitted by the LED and sends them along a predetermined
`10 direction dependent on the desired beam angle. The nearby
`surrounding surface portion of the lens also collects light
`from the LED emitter and bends it toward the preferential
`direction.
`The blob zone comprises has a central forward cross-sec-
`15 tion which smoothly apportions light from a directed zone to
`the centerline. The portion of the lens which collects the
`peripheral light of the LED emitter either bends the light rays
`toward the preferential direction and/or internally reflects the
`light rays through the forward surface of the lens.
`In one embodiment the lens produces a beam that is a
`function of the azimuthal angle of the beam and thus the lens
`has a cross-section which varies as function of the azimuthal
`angle around the optical axis. In the illustrated embodiment
`the azimuthal light pattern has a multiple lobed distribution of
`25 intensity.
`In one embodiment of this type the lens also directs the
`beam in one or more directions offset from the projected
`centerline of the device. The lens includes additional surface
`shapes or a complexly shaped prism that add further control to
`30 the beam composition. Such additional surface shapes
`include facets, a multiple surface Fresnel type flattening of
`shape or prism, diffusing techniques or other lens surface
`enhancements, modifications or treatments.
`One major advantage of a device of the invention is the
`35 ability to generate the required beam pattern with an array of
`LEDs which are mounted on a flat or planar plate, which most
`likely would be parallel to the street or floor. Thus eliminating
`the need for a complex armature. The illustrated embodiment
`further comprises a plurality of light sources or LEDs and
`40 corresponding lenses as describe above combined into a flat
`array of bars or plates to provide thermal and electrical dis(cid:173)
`tribution required for the LEDs as well as provide means for
`sealing the array from environmental damage. The apparatus
`further comprises circuitry to drive the LEDs included in the
`45 array. It is contemplated that each of the lenses are individu(cid:173)
`ally rotated to create a beam pattern for the flat array that is
`unique from the devices themselves, including all degrees of
`freedom, e.g. separately determined translation, tilt and yaw
`for each lens. The array could comprise similarly colored
`50 LEDs, white or otherwise, or optionally various colored
`LEDs.
`The bars or plates each comprise an extruded or die-cast
`bar of aluminum or other thermally conductive material to
`which the LEDs are bonded directly, and a printed circuit
`board to connect the LEDs to a power source. In one embodi(cid:173)
`ment the circuit board is laminated to the extruded or die-cast
`bar.
`Each LED optionally incorporates a skirt, which is utilized
`to provide a sealed array with a cover, potting compound or
`other covering means.
`The invention further comprises a method of providing a
`light pattern using any one of the devices or arrays described
`above.
`While the apparatus and method has or will be described
`65 for the sake of granimatical fluidity with functional explana(cid:173)
`tions, it is to be expressly understood that the claims, unless
`expressly formulated under 35 USC 112, are not to be con-
`
`Page 17 of 27
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`

`US 7,674,018 B2
`
`7
`strued as necessarily limited in any way by the construction of
`"means" or "steps" limitations, but are to be accorded the full
`scope of the meaning and equivalents of the definition pro(cid:173)
`vided by the claims under the judicial doctrine of equivalents,
`and in the case where the claims are expressly formulated 5
`under 35 USC 112 are to be accorded full statutory equiva(cid:173)
`lents under 35 USC 112. The invention can be better visual(cid:173)
`ized by turning now to the following drawings wherein like
`elements are referenced by like numerals.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`10
`
`8
`asymmetric and is oriented in the figure to show the 'curb'
`side of the streetlight or that side to which less light is
`directed.
`FIG. 22 is a rotated perspective view of the device depicted
`in FIG. 21 showing the 'street' side of the device or that side
`of the device to which more light is directed.
`FIG. 23 is a 'bottom'view