(12) United States Patent
`Parker
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 7,434,974 B2
`Oct. 14, 2008
`
`US007434974B2
`
`8/1973 Baker et a1.
`3,752,947 A
`9/1973 Addington, Jr.
`3,760,179 A
`3,781,537 A 12/1973 Ramsey
`3,892,959 A
`7/1975 Pulles
`3,958,113 A
`5/1976 Termohlen
`4,043,636 A
`8/1977 Eberhardt et al.
`4,128,332 A 12/1978 Rowe
`4,257,084 A
`3/1981 Reynolds
`4,277,817 A
`7/1981 Hehr
`4,323,951 A
`4/1982 Pasco
`4,373,282 A
`2/1983 Wragg
`4,446,508 A
`5/1984 Kinzie
`4,519,017 A
`5/1985 Daniel
`4,573,766 A
`3/1986 Bournay, Jr. et al.
`
`(Continued)
`Primary ExamineriThomas M Sember
`(74) Attorney, Agent, or FirmiRenner, Otto, Boisselle &
`Sklar, LLP
`
`(57)
`
`ABSTRACT
`
`Light emitting panel assembly includes a light emitting panel
`member received in a cavity or recess in a tray or housing. The
`panel member has a pattern of light extracting deformities on
`or in at least one surface of the panel member to cause light
`received from at least one LED light source positioned near or
`against the light entrance surface of the panel member to be
`emitted from a light emitting surface of the panel member.
`The tray or housing acts as an end edge and/ or side edge
`re?ector for the panel member to re?ect light that Would
`otherwise exit the panel member through the end edge and/or
`side edge back into the panel member for causing additional
`light to be emitted from the panel member.
`
`24 Claims, 4 Drawing Sheets
`
`(54) LIGHT EMITTING PANEL ASSEMBLIES
`
`(75) Inventor: Jeffery R. Parker, Rich?eld, OH (US)
`
`(73) Assignee: Solid State Opto Limited (VG)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 103 days.
`
`(21) Appl.No.: 11/378,080
`
`(22) Filed:
`
`Mar. 17, 2006
`
`(65)
`
`Prior Publication Data
`
`US 2006/0158906 A1
`
`Jul. 20, 2006
`
`Related US. Application Data
`
`(60) Continuation of application No. 10/784,527, ?led on
`Feb. 23, 2004, noW Pat. No. 7,160,015, Which is a
`division of application No. 09/256,275, ?led on Feb.
`23, 1999, noW Pat. No. 6,712,481, Which is a continu
`ation-in-part of application No. 08/778,089, ?led on
`Jan. 2, 1997, noW Pat. No. 6,079,838, Which is a divi
`sion of application No. 08/495,176, ?led on Jun. 27,
`1995, noW Pat. No. 5,613,751.
`
`(51) Int. Cl.
`(2006.01)
`F21V 7/04
`(52) US. Cl. ..................... .. 362/612; 362/619; 362/632;
`362/634
`(58) Field of Classi?cation Search ............... .. 362/231,
`362/800, 27, 619, 613, 612, 620, 608, 609,
`362/621, 600, 632, 634, 26
`See application ?le for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`2,480,178 A
`3,043,947 A
`3,241,256 A
`3,328,570 A
`3,721,815 A
`
`8/1949 Zinberg
`7/1962 Albinger, Jr.
`3/1966 Viret et al.
`6/1967 Balchunas
`3/1973 Wall
`
`53
`
`3‘ /
`
`54
`
`55
`
`53
`
`58
`
`I a I
`56
`52
`
`I‘
`S2
`
`Mercedes-Benz USA, LLC, Petitioner - Ex. 1001
`
`Page 1 of 13
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`

`

`US 7,434,974 B2
`Page2
`
`U.S. PATENT DOCUMENTS
`
`4,630,895 A 12/1986 Abdala, Jr et 91-
`4,648,690 A
`3/1987 0119
`4677531 A
`6/1987 Szeles
`4,714,983 A 12/1987 Lang
`4,729,067 A
`3/1988 0119
`4,729,068 A
`3/1988 0116
`4,729,185 A
`3/1988 Baba
`4,751,615 A
`6/1988 Abrams
`4,761,047 A
`8/1988 Mori
`4763984 A
`8/1988 AWai er 91-
`4,765,701 A
`8/1988 Cheslak
`4,791,540 A 12/1988 Dreyer, Jr. etal.
`4,802,066 A
`V1989 Mori
`4,811,507 A
`3/1989 Blanche/t
`4,825,341 A
`4/1989 AWai
`4,890,201 A 12/1989 Jo?
`4,909,604 A
`3/1990 Kobayashi et a1~
`4,914,553 A
`4/1990 Hamada etal
`4,929,062 A
`5/1990 Guzik 6161.
`4,974,122 A 11/1990 Shaw
`4,975,808 A 12/1990 Bondet a1.
`4,978,952 A 12/1990 Irwin
`4,985,809 A
`1/1991 Matsuietal,
`5,005,108 A
`4/1991 Pristash etal.
`5,027,258 A
`6/1991 Schonigeretal.
`5,050,046 A
`9/1991 Tada ......................... .. 362/26
`5,055,978 A 10/1991 Rogoff
`5,070,431 A 12/1991 Kitazawa et a1.
`
`3/1992 Kashima et a1.
`5,093,765 A
`7/1992 Yokoyama
`5,134,549 A
`8/1992 Pristash et a1.
`5,136,480 A
`8/1992 Schoniger et a1.
`5,136,483 A
`2/1993 Sakumaet a1. ............ .. 362/136
`5,184,888 A *
`3/1993 Milleret a1.
`5,190,370 A
`5/1993 Murase et a1.
`5,207,493 A
`9/1993 Whitehead
`5,243,506 A
`5,262,928 A 11/1993 Kashima et a1.
`5,283,673 A
`2/1994 Murase etal.
`5,339,179 A
`8/1994 Rudisill et a1.
`5,349,503 A
`9/1994 Blonder et a1.
`5,375,043 A 12/1994 Tokunaga
`5,377,084 A 12/1994 Kojimaetal‘
`5,390,085 A
`2/1995 Mari-R003 etal.
`5,390,276 A *
`2/1995 Tai et a1. ................... .. 385/146
`5,390,436 A
`2/1995 AS11311
`5,394,308 A
`2/1995 Watanabe et a1.
`5,434,754 A *
`7/1995 Li et a1. .................... .. 362/511
`5,467,208 A 11/1995 Kokawa et a1.
`5,467,417 A 11/1995 Nakamura 6161.
`5,477,423 A 12/1995 Fredriksz 6161.
`5,479,275 A 12/1995 Abileah
`5,485,291 A
`l/l996 Qiao etal.
`5,485,354 A *
`l/l996 Ciupke etal. ............. .. 362/619
`5600455 A
`2/1997 Ishikawa eta1~
`5,719,649 A
`2/1998 $110110 ‘ital
`5947578 A
`9/1999 Ayres
`5,999,685 A 12/1999 GOtO 6161.
`* cited by examiner
`
`Page 2 of 13
`
`

`

`US. Patent
`
`Oct. 14, 2008
`
`Sheet 1 of4
`
`US 7,434,974 B2
`
`
`
`21‘.23
`
` 24
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`’ i.
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`FlG.4b “6-46
`’28) 45
`f.
`I?
`'2
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`
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`Page 3 of 13
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`Page 3 of 13
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`US. Patent
`US. Patent
`
`Oct.14,2008
`Oct. 14, 2008
`
`Sheet 2 of4
`Sheet 2 0f 4
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`US 7,434,974 B2
`US 7,434,974 B2
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`.4
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`28
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`27
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`3o
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`II
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`/
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`{IIIIIIIIIIII
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`-—___—— -—————‘1
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`US. Patent
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`0a. 14, 2008
`
`Sheet 3 of4
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`US 7,434,974 B2
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`F169
`
`65
`
`3
`
`P16. \0
`
`FIG. H
`r70
`
`FIG. 1 I066
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`/72
`
`FIG. l2
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`Page 5 of 13
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`US. Patent
`US. Patent
`
`Oct. 14, 2008
`Oct. 14, 2008
`
`Sheet 4 of4
`Sheet 4 0f 4
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`US 7,434,974 B2
`US 7,434,974 B2
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`(72 J
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`[70
`FIG. I?)
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`75
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`76
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`73 ‘if
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`Page 6 of 13
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`Page 6 of 13
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`US 7,434,974 B2
`
`1
`LIGHT EMITTING PANEL ASSEMBLIES
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is a continuation of US. patent applica
`tion Ser. No. 10/784,527, ?led Feb. 23, 2004, Which is a
`division of US. patent application Ser. No. 09/256,275, ?led
`Feb. 23, 1999, now US. Pat. No. 6,712,481, dated Mar. 30,
`2004, Which is a continuation-in-part of US. patent applica
`tion Ser. No. 08/778,089, ?led Jan.2,1997,noW US. Pat. No.
`6,079,838, dated Jun. 27, 2000, Which is a division of US.
`patent application Ser. No. 08/495,176, ?led Jun. 27, 1995,
`now US. Pat. No. 5,613,751, dated Mar. 25, 1997.
`
`BACKGROUND OF THE INVENTION
`
`This invention relates generally, as indicated, to light emit
`ting panel assemblies each including a transparent panel
`member for e?iciently conducting light, and controlling the
`light conducted by the panel member to be emitted from one
`or more light output areas along the length thereof.
`Light emitting panel assemblies are generally knoWn.
`HoWever, the present invention relates to several different
`light emitting panel assembly con?gurations Which provide
`for better control of the light output from the panel assemblies
`and for more ef?cient utiliZation of light, Which results in
`greater light output from the panel assemblies.
`
`SUMMARY OF THE INVENTION
`
`In accordance With one aspect of the invention, the light
`emitting panel assemblies include a light emitting panel
`member having a light transition area in Which at least one
`light source is suitably mounted for transmission of light to
`the light input surface of the panel member.
`In accordance With another aspect of the invention, the
`light source is desirably embedded, potted or bonded to the
`light transition area to eliminate any air gaps, decrease surface
`re?ections and/or eliminate any lens effect betWeen the light
`source and light transition area, thereby reducing light loss
`and increasing the light output from the panel assembly.
`In accordance With another aspect of the invention, the
`panel assemblies may include re?ective or refractive surfaces
`for changing the path of a portion of the light, emitted from
`the light source, that Would not normally enter the panel
`members at an acceptable angle that alloWs the light to remain
`in the panel members for a longer period of time and/or
`increase the ef?ciency of the panel members.
`In accordance With another aspect of the invention, the
`light emitting panel members include a pattern of light
`extracting deformities or disruptions Which provide a desired
`light output distribution from the panel members by changing
`the angle of refraction of a portion of the light from one or
`more light output areas of the panel members.
`In accordance With still another aspect of the invention, the
`light source may include multiple colored light sources for
`supplying light to one or more light output areas, and for
`providing a colored or White light output distribution.
`In accordance With yet another aspect of the invention, the
`panel assemblies include a transition area for mixing the
`multiple colored lights, prior to the light entering the panel
`members, in order to effect a desired colored or White light
`output distribution.
`The various light emitting panel assemblies of the present
`invention are very e?icient panel assemblies that may be used
`to produce increased uniformity and higher light output from
`
`2
`the panel members With loWer poWer requirements, and alloW
`the panel members to be made thinner and/ or longer, and/ or of
`various shapes and siZes.
`To the accomplishment of the foregoing and related ends,
`the invention then comprises the features hereinafter fully
`described and particularly pointed out in the claims, the fol
`loWing description and the annexed draWings setting forth in
`detail certain illustrative embodiments of the invention, these
`being indicative, hoWever, of but several of the various Ways
`in Which the principles of the invention may be employed.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`In the annexed draWings:
`FIGS. 1 through 3 are schematic perspective vieWs of three
`different forms of light emitting panel assemblies in accor
`dance With this invention;
`FIG. 4a is an enlarged plan vieW of a portion of a light
`output area of a panel assembly shoWing one form of pattern
`of light extracting deformities on the light output area;
`FIGS. 4b, 0 and d are enlarged schematic perspective vieWs
`of a portion of a light output area of a panel assembly shoWing
`other forms of light extracting deformities formed in or on the
`light output area;
`FIG. 5 is an enlarged transverse section through the light
`emitting panel assembly of FIG. 3 taken generally on the
`plane of the line 5-5 thereof;
`FIG. 6 is a schematic perspective vieW of another form of
`light emitting panel assembly in accordance With this inven
`tion;
`FIG. 7 is a schematic top plan vieW of another form of light
`emitting panel assembly in accordance With this invention;
`FIG. 8 is a schematic perspective vieW of another form of
`light emitting panel assembly in accordance With this inven
`tion;
`FIG. 9 is a schematic top plan vieW of another form of light
`emitting panel assembly in accordance With this invention;
`FIG. 10 is a schematic top plan vieW of still another form of
`light emitting panel assembly in accordance With this inven
`tion;
`FIG. 11 is a side elevation vieW of the light emitting panel
`assembly of FIG. 10;
`FIG. 11a is a fragmentary side elevation vieW shoWing a
`tapered or rounded end on the panel member in place of the
`prismatic surface shoWn in FIGS. 10 and 11;
`FIG. 12 is a schematic top plan vieW of another form of
`light emitting panel assembly in accordance With this inven
`tion;
`FIG. 13 is a schematic side elevation vieW of the light
`emitting panel assembly of FIG. 12; and
`FIGS. 14 and 15 are schematic perspective vieWs of still
`other forms of light emitting panel assemblies in accordance
`With this invention.
`
`20
`
`25
`
`30
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`35
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`40
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`45
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`50
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`55
`
`DETAILED DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`60
`
`65
`
`Referring noW in detail to the draWings, and initially to
`FIG. 1, there is schematically shoWn one form of light emit
`ting panel assembly 1 in accordance With this invention
`including a transparent light emitting panel 2 and one or more
`light sources 3 Which emit light in a predetermined pattern in
`a light transition member or area 4 used to make the transition
`from the light source 3 to the light emitting panel 2, as Well
`knoWn in the art. The light that is transmitted by the light
`transition area 4 to the transparent light emitting panel 2 may
`be emitted along the entire length of the panel or from one or
`
`Page 7 of 13
`
`

`

`US 7,434,974 B2
`
`3
`more light output areas along the length of the panel as
`desired to produce a desired light output distribution to ?t a
`particular application.
`In FIG. 1 the light transition area 4 is shoWn as an integral
`extension of one end of the light emitting panel 2 and as being
`generally rectangular in shape. However, the light transition
`area may be of other shapes suitable for embedding, potting,
`bonding or otherWise mounting the light source. Also, re?ec
`tive or refractive surfaces may be provided to increase e?i
`ciency. Moreover, the light transition area 4 may be a separate
`piece suitably attached to the light input surface 13 of the
`panel member if desired. Also, the sides of the light transition
`area may be curved to more e?iciently re?ect or refract a
`portion of the light emitted from the light source through the
`light emitting panel at an acceptable angle.
`FIG. 2 shoWs another form of light emitting panel assem
`bly 5 in accordance With this invention including a panel light
`transition area 6 at one end of the light emitting panel 7 With
`sides 8, 9 around and behind the light source 3 shaped to more
`e?iciently re?ect and/or refract and focus the light emitted
`from the light source 3 that impinges on these surfaces back
`through the light transition area 6 at an acceptable angle for
`entering the light input surface 18 at one end of the light
`emitting panel 7. Also, a suitable re?ective material or coating
`10 may be provided on the portions of the sides of the light
`transition areas of the panel assemblies of FIGS. 1 and 2 on
`Which a portion of the light impinges for maximizing the
`amount of light or otherWise changing the light that is
`re?ected back through the light transition areas and into the
`light emitting panels.
`The panel assemblies shoWn in FIGS. 1 and 2 include a
`single light source 3, Whereas FIG. 3 shoWs another light
`emitting panel assembly 11 in accordance With this invention
`including tWo light sources 3. Of course, it Will be appreciated
`that the panel assemblies of the present invention may be
`provided With any number of light sources as desired,
`depending on the particular application.
`The panel assembly 11 of FIG. 3 includes a light transition
`area 12 at one end of the light emitting panel 14 having
`re?ective and/or refractive surfaces 15 around and behind
`each light source 3. These surfaces 15 may be appropriately
`shaped including for example curved, straight and/or faceted
`surfaces, and if desired, suitable re?ective materials or coat
`ings may be provided on portions of these surfaces to more
`e?iciently re?ect and/or refract and focus a portion of the
`light emitted for example from an incandescent light source
`Which emits light in a 360° pattern through the light transition
`areas 12 into the light input surface 19 of the light emitting
`panel 14.
`The light sources 3 may be mechanically held in any suit
`able manner in slots, cavities or openings 16 machined,
`molded or otherWise formed in the light transition areas of the
`panel assemblies. HoWever, preferably the light sources 3 are
`embedded, potted or bonded in the light transition areas in
`order to eliminate any air gaps or air interface surfaces
`betWeen the light sources and surrounding light transition
`areas, thereby reducing light loss and increasing the light
`output emitted by the light emitting panels. Such mounting of
`the light sources may be accomplished, for example, by bond
`ing the light sources 3 in the slots, cavities or openings 16 in
`the light transition areas using a suf?cient quantity of a suit
`able embedding, potting or bonding material 17. The slots,
`cavities or openings 16 may be on the top, bottom, sides or
`back of the light transition areas. Bonding can also be accom
`plished by a variety of methods that do not incorporate extra
`material, for example, thermal bonding, heat staking, ultra
`
`30
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`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`sonic orplastic Welding or the like. Other methods of bonding
`include insert molding and casting around the light source(s).
`A transparent light emitting material of any suitable type,
`for example acrylic or polycarbonate, may be used for the
`light emitting panels. Also, the panels may be substantially
`?at, or curved, may be a single layer or multi-layers, and may
`have different thicknesses and shapes. Moreover, the panels
`may be ?exible, or rigid, and may be made out of a variety of
`compounds. Further, the panels may be holloW, ?lled With
`liquid, air, or be solid, and may have holes or ridges in the
`panels.
`Each light source 3 may also be of any suitable type includ
`ing, for example, any of the types disclosed in Us. Pat. Nos.
`4,897,771 and 5,005, 108, assigned to the same assignee as the
`present application, the entire disclosures of Which are incor
`porated herein by reference. In particular, the light sources 3
`may be an arc lamp, an incandescent bulb Which also may be
`colored, ?ltered or painted, a lens end bulb, a line light, a
`halogen lamp, a light emitting diode (LED), a chip from an
`LED, a neon bulb, a ?uorescent tube, a ?ber optic light pipe
`transmitting from a remote source, a laser or laser diode, or
`any other suitable light source. Additionally, the light sources
`3 may be a multiple colored LED, or a combination of mul
`tiple colored radiation sources in order to provide a desired
`colored or White light output distribution. For example, a
`plurality of colored lights such as LEDs of different colors
`(red, blue, green) or a single LED With multiple colored chips
`may be employed to create White light or any other colored
`light output distribution by varying the intensities of each
`individual colored light.
`A pattern of light extracting deformities or disruptions may
`be provided on one or both sides of the panel members or on
`one or more selected areas on one or both sides of the panel
`members, as desired. FIG. 4a schematically shoWs one such
`light surface area 20 on Which a pattern of light extracting
`deformities or disruptions 21 is provided. As used herein, the
`term deformities or disruptions are used interchangeably to
`mean any change in the shape or geometry of the panel
`surface and/ or coating or surface treatment that causes a
`portion of the light to be emitted. The pattern of light extract
`ing deformities 21 shoWn in FIG. 411 includes a variable
`pattern Which breaks up the light rays such that the internal
`angle of re?ection of a portion of the light rays Will be great
`enough to cause the light rays either to be emitted out of the
`panel through the side or sides on Which the light extracting
`deformities 21 are provided or re?ected back through the
`panel and emitted out the other side.
`These deformities or disruptions 21 can be produced in a
`variety of manners, for example, by providing a painted pat
`tern, an etched pattern, a machined pattern, a printed pattern,
`a hot stamped pattern, or a molded pattern or the like on
`selected light output areas of the panel members. An ink or
`printed pattern may be applied for example by pad printing,
`silk screening, ink jet, heat transfer ?lm process or the like.
`The deformities may also be printed on a sheet or ?lm Which
`is used to apply the deformities to the panel member. This
`sheet or ?lm may become a permanent part of the light panel
`assembly for example by attaching or otherWise positioning
`the sheet or ?lm against one or both sides of the panel member
`similar to the sheet or ?lm 27 shoWn in FIGS. 3 and 5 in order
`to produce a desired effect.
`By varying the density, opaqueness or translucence, shape,
`depth, color, area, index of refraction, or type of deformities
`21 on an area or areas of the panels, the light output of the
`panels can be controlled. The deformities or disruptions may
`be used to control the percent of light emitted from any area
`of the panels. For example, less and/ or smaller siZe deformi
`
`Page 8 of 13
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`

`

`US 7,434,974 B2
`
`5
`ties 21 may be placed on panel areas Where less light output is
`Wanted. Conversely, a greater percentage of and/ or larger
`deformities may be placed on areas of the panels Where
`greater light output is desired.
`Varying the percentages and/or siZe of deformities in dif
`ferent areas of the panel is necessary in order to provide a
`uniform light output distribution. For example, the amount of
`light traveling through the panels Will ordinarily be greater in
`areas closer to the light source than in other areas further
`removed from the light source. A pattern of light extracting
`deformities 21 may be used to adjust for the light variances
`Within the panel members, for example, by providing a denser
`concentration of light extracting deformities With increased
`distance from the light source 3 thereby resulting in a more
`uniform light output distribution from the light emitting pan
`els.
`The deformities 21 may also be used to control the output
`ray angle distribution of the emitted light to suit a particular
`application. For example, if the panel assemblies are used to
`provide a liquid crystal display backlight, the light output Will
`be more e?icient if the deformities 21 cause the light rays to
`emit from the panels at predetermined ray angles such that
`they Will pass through the liquid crystal display With loW loss.
`Additionally, the pattern of light extracting deformities
`may be used to adjust for light output variances attributed to
`light extractions of the panel members. The pattern of light
`extracting deformities 21 may be printed on the light output
`areas utiliZing a Wide spectrum of paints, inks, coatings,
`epoxies, or the like, ranging from glossy to opaque or both,
`and may employ half-tone separation techniques to vary the
`deformity 21 coverage. Moreover, the pattern of light extract
`ing deformities 21 may be multiple layers or vary in index of
`refraction.
`Print patterns of light extracting deformities 21 may vary in
`shapes such as dots, squares, diamonds, ellipses, stars, ran
`dom shapes, and the like, and are desirably 0.006 square inch
`per deformity/ element or less. Also, print patterns that are 60
`lines per inch or ?ner are desirably employed, thus making
`the deformities or shapes 21 in the print patterns nearly invis
`ible to the human eye in a particular application thereby
`eliminating the detection of gradient or banding lines that are
`common to light extracting patterns utiliZing larger elements.
`Additionally, the deformities may vary in shape and/or siZe
`along the length and/ or Width of the panel members. Also, a
`random placement pattern of the deformities may be utiliZed
`throughout the length and/ or Width of the panel members. The
`deformities may have shapes or a pattern With no speci?c
`angles to reduce moire or other interference effects.
`Examples of methods to create these random patterns are
`printing a pattern of shapes using stochastic print pattern
`techniques, frequency modulated half tone patterns, or ran
`dom dot half tones. Moreover, the deformities may be colored
`in order to effect color correction in the panel members. The
`color of the deformities may also vary throughout the panel
`members, for example to provide different colors for the same
`or different light output areas.
`In addition to or in lieu of the patterns of light extracting
`deformities 21 shoWn in FIG. 411, other light extracting defor
`mities including prismatic surfaces, depressions or raised
`surfaces of various shapes using more complex shapes in a
`mold pattern may be molded, etched, stamped, thermo
`formed, hot stamped or the like into or on one or more areas
`of the panel member. FIGS. 4b and 40 show panel areas 22 on
`Which prismatic surfaces 23 or depressions 24 are formed in
`the panel areas, Whereas FIG. 4d shoWs prismatic or other
`re?ective or refractive surfaces 25 formed on the exterior of
`the panel area. The prismatic surfaces, depressions or raised
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`surfaces Will cause a portion of the light rays contacted
`thereby to be emitted from the panel member. Also, the angles
`of the prisms, depressions or other surfaces may be varied to
`direct the light in different directions to produce a desired
`light output distribution or effect. Moreover, the re?ective or
`refractive surfaces may have shapes or a pattern With no
`speci?c angles to reduce moiréor other interference effects.
`As best seen in the cross sectional vieW of FIG. 5, a back
`re?ector (including trans re?ectors) 26 may be attached or
`positioned against one side of the panel member 14 of FIG. 3
`using a suitable adhesive 28 or other method in order to
`improve light output ef?ciency of the panel assembly 11 by
`re?ecting the light emitted from that side back through the
`panel for emission through the opposite side. Additionally, a
`pattern of light extracting deformities 21, 23, 24 and/or 25
`may be provided on one or both sides of the panel member in
`order to change the path of the light so that the internal critical
`angle is exceeded and a portion of the light is emitted from
`one or both sides of the panel. Moreover, a transparent ?lm,
`sheet or plate 27 may be attached or positioned against the
`side or sides of the panel member from Which light is emitted
`using a suitable adhesive 28 or other method in order to
`produce a desired effect.
`The member 27 may be used to further improve the uni
`formity of the light output distribution. For example, the
`member 27 may be a colored ?lm, a diffuser, or a label or
`display, a portion of Which may be a transparent overlay that
`may be colored and/or have text or an image thereon.
`If adhesive 28 is used to adhere the back re?ector 26 and/or
`?lm 27 to the panel, the adhesive is preferably applied only
`along the side edges of the panel, and if desired the end edge
`opposite the light transition areas 12, but not over the entire
`surface area or areas of the panel because of the di?iculty in
`consistently applying a uniform coating of adhesive to the
`panel. Also, the adhesive changes the internal critical angle of
`the light in a less controllable manner than the air gaps 30 (see
`FIG. 5) Which are formed betWeen the respective panel sur
`faces and the back re?ector 26 and/or ?lm 27 When only
`adhered along the peripheral edges. Additionally, longer
`panel members are achievable When air gaps 30 are used. If
`adhesive Were to be used over the entire surface, the pattern of
`deformities could be adjusted to account for the additional
`attenuation in the light caused by the adhesive.
`Referring further to FIG. 2, the panel assembly 5 shoWn
`therein also includes molded posts 31 at one or more corners
`of the panel 7 (four such posts being shoWn) Which may be
`used to facilitate mounting of the panel assembly and provid
`ing structural support for other parts or components, for
`example, a display panel such as a liquid crystal display panel
`as desired.
`FIG. 6 shoWs another form of light emitting panel assem
`bly 32 in accordance With this invention including a panel
`member 33, one or more light sources 3, and one or more light
`output areas 34. In addition, the panel assembly 32 includes a
`tray 35 having a cavity or recess 36 in Which the panel assem
`bly 32 is received. The tray 35 may act as a back re?ector as
`Well as end edge and/ or side edge re?ectors for the panel 33
`and side and/or back re?ectors 37 for the light sources 3.
`Additionally, one or more secondary re?ective or refractive
`surfaces 38 may be provided on the panel member 33 and/or
`tray 35 to re?ect a portion of the light around one or more
`corners or curves in a non-rectangular shaped panel member
`33. These secondary re?ective/refractive surfaces 38 may be
`?at, angled, faceted or curved, and may be used to extract a
`portion of the light aWay from the panel member in a prede
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`Page 9 of 13
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`US 7,434,974 B2
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`7
`termined pattern. FIG. 6 also shows multiple light output
`areas 34 on the panel member that emit light from one or more
`light sources 3.
`FIG. 7 is a schematic illustration of still another form of
`light emitting panel assembly 40 in accordance With this
`invention including a panel member 41 having one or more
`light output areas 42 and one or more light transition areas
`(mixing areas) 43 containing a plurality of light sources 3 at
`one or both ends of the panel. Each transition area mixes the
`light from one or more light sources having different colors
`and/ or intensities. In this particular embodiment, each of the
`light sources 3 desirably employs three colored LEDs (red,
`blue, green) in each transition mixing area 43 so that the light
`from the three LEDs can be mixed to produce a desired light
`output color that Will be emitted from the light output area 42.
`Alternatively, each light source may be a single LED having
`multiple colored chips bonded to the lead ?lm. Also, tWo
`colored LEDs or a single LED having tWo colored chips may
`be used for a particular application. By varying the intensities
`of the individual respective LEDs, virtually any colored light
`output or White light distribution can be achieved.
`FIG. 8 shoWs yet another form of light emitting panel
`assembly 45 in accordance With this invention including a
`light emitting panel member 46 and a light source 3 in a light
`transition area 48 integral With one end of the panel member.
`In this particular embodiment, the panel member 46 is three
`dimensionally curved, for example, such that light rays may
`be emitted in a manner that facilitates aesthetic design of a
`lighted display.
`FIG. 9 schematically shoWs another form of light emitting
`panel assembly 50 in accordance With this invention, includ
`ing a panel member 51 having multiple light output areas 52,
`and mounting posts and/ or mounting tabs 53. This particular
`panel assembly 50 may serve as a structural member to sup
`port other parts or components as by providing holes or cavi
`ties 54, 55 in the panel member 51 Which alloW for the
`insertion of modular components or other parts into the panel
`member. Moreover, a separate cavity or recess 56 may be
`provided in the panel member 51 for receipt of a correspond
`ingly shaped light transition area 57 having one or more light
`sources 3 embedded, bonded, cast, insert molded, epoxied, or
`otherWise mounted or positioned therein and a curved re?ec
`tive or refractive surface 58 on the transition area 57 and/or
`Wall of the cavity or recess 56 to redirect a portion of the light
`in a predetermined manner. In this Way the light transition
`area 57 and/ or panel member may be in the form of a separate
`insert Which facilitates the easy placement of the light source
`in a modular manner. A re?ector 58 may be placed on the
`re?ective or refractive surface of the cavity or recess 56 or
`insert 57. Where the re?ector 58 is placed on the re?ective or
`refractive surface of the cavity or recess 56, the cavity or
`recess may act as a mold permitting transparent material from
`Which the transition area 57 is made to be cast around one or
`more light sources 3.
`FIGS. 10 and 11 schematically shoW another form of light
`emitting panel assembly 60 in accordance With this invention
`including a panel member 61 having one or more light output
`areas 62. In this particular embodiment, an off-axis light
`transition area 63 is provided that is thicker in cross section
`than the panel member to permit use of one or more light
`sources 3 embedded or otherWise mounted in the light tran
`sition area that are dimensionally thicker than the panel mem
`ber. Also, a three-dimensional re?ective surface 64 (FIG. 11)
`may be provided on the transition area 63. Moreover, a prism
`65 (FIG. 11) or tapered, rounded, or otherWise shaped end 66
`(FIG. 1111) may be provided at the end of the panel opposite
`the light sources 3 to perform the function of an end re?ector.
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`The light sources 3 may be oriented at different angles relative
`to each other and offset to facilitate better mixing of the light
`rays 67 in the transition area 63 as schematically shoWn in
`FIG. 10 and/ or to permit a shorter length transition area 63 to
`be used.
`FIGS. 12 and 13 schematically shoW still