(12) United States Patent
`Parker et a].
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 7,434,973 B2
`*Oct. 14, 2008
`
`US007434973B2
`
`LIGHT EMITTING PANEL ASSEMBLIES
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`7/1962 Albinger, Jr.
`3,043,947 A
`1/1963 Miller
`3,070,913 A
`6/1967 Balchunas
`3,328,570 A
`3,543,014 A 11/1970 Bustad
`3,571,585 A
`3/1971 Schermerhorn
`3,752,974 A
`8/1973 Baker et a1.
`3,761,703 A
`9/1973 Mund et a1.
`3,892,959 A
`7/1975 Pulles
`3,958,113 A
`5/1976 Termohlen
`4,043,636 A
`8/1977 Eberhardt et a1.
`4,118,111 A 10/1978 Laesser
`4,177,501 A 12/1979 Karlin
`4,183,628 A
`1/1980 Laesser
`4,257,084 A
`3/1981 Reynolds
`
`(Continued)
`Primary ExamineriSandra O’Shea
`Assistant ExamineriBao Q Truong
`(74) Attorney, Agent, or FirmiRenner, Otto, Boisselle &
`Sklar, LLP
`
`(57)
`
`ABSTRACT
`
`Light emitting panel assemblies include a light emitting panel
`member having at least one light source optically coupled to
`a portion of an input edge of the panel member. A plurality of
`individual light extracting deformities on or in at least one
`panel surface of the panel member are of Well de?ned shape
`and have a length and Width substantially smaller than the
`length and Width of the panel surface. At least some of the
`deformities have at least one surface that is angled at different
`orientations relative to the input edge depending on the loca
`tion of the deformities on the panel surface to face a portion of
`the input edge to Which a light source is optically coupled.
`
`14 Claims, 14 Drawing Sheets
`
`(54)
`
`(75)
`
`Inventors: Jeffery R. Parker, Strongsville, OH
`(US); Gregory A. Coghlan, Olmsted
`Falls, OH (US); Robert M. Ezell,
`Copley, OH (U S)
`
`(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 0 days.
`
`This patent is subject to a terminal dis
`claimer.
`
`(21)
`
`(22)
`
`(65)
`
`(60)
`
`(51)
`
`(52)
`
`(58)
`
`Appl. No.: 11/673,302
`
`Filed:
`
`Feb. 9, 2007
`
`Prior Publication Data
`
`Jun. 28, 2007
`US 2007/0147087 A1
`Related U.S. Application Data
`
`Continuation of application No. 10/ 619,815, ?led on
`Jul. 15, 2003, noW Pat. No. 7,195,389, Which is a
`continuation of application No. 09/256,275, ?led on
`Feb. 23, 1999, noW Pat. No. 6,712,481, Which is a
`continuation-in-part of application No. 08/778,089,
`?led on Jan. 2, 1997, noW Pat. No. 6,079,838, Which is
`a division of application No. 08/495,176, ?led on Jun.
`27, 1995, noW Pat. No. 5,613,751.
`Int. Cl.
`(2006.01)
`F21V 7/00
`U.S. Cl. ..................... .. 362/606; 362/613; 362/618;
`362/619
`Field of Classi?cation Search ............... .. 362/ 800,
`362/606i6l0, 6124613, 6174620, 615, 6234629;
`349/65, 63, 62
`See application ?le for complete search history.
`
`LGD_000001
`
`LG Display Ex. 1001
`
`

`

`US 7,434,973 B2
`Page 2
`
`US. PATENT DOCUMENTS
`
`8/1981 Kringel @191
`4,282,560 A
`9/1981 Thompson et al.
`4,290,093 A
`5/1984 Kinzie
`4,446,508 A
`7/1984 M011 ........................ .. 362/558
`4,460,940 A
`9/1985 Whitehead
`4,542,449 A
`3/1986 Bournay, Jr. et al.
`4,573,766 A
`4,630,895 A 12/1986 Abdala, Jr 91 91-
`4,714,983 A 12/1987 Lang
`4,729,185 A
`3/1988 Baba
`4751615 A
`6/1988 Abrams
`4,763,984 A
`8/1988 AWaI @191
`4,765,701 A
`8/1988 cheslak
`4,906,070 A
`3/1990 C9bb,Jr~
`4,974,122 A 11/1990 Shaw
`4,975,808 A 12/1990 Bondet 91
`4,978,952 A 12/1990 IYWIII
`5,005,108 A
`4/1991 Pristash et a1.
`5,027,258 A
`6/1991 Schoniger @131
`5,056,892 A 10/1991 C9bb,Jr~
`5,070,431 A 12/1991 Kitazawaet 31.
`5,093,765 A
`3/1992 Kashimaet a1.
`5,134,549 A
`7/1992 Yokoyama
`5,136,483 A
`8/1992 Schonigeretal
`5,178,447 A
`V1993 Murase @191-
`5207493 A
`5/1993 Murase @191-
`5,262,928 A 11/1993 Kashima @191
`5283673 A
`2/1994 Murase @191-
`5,303,322 A
`4/1994 Winston etal.
`5,307,244 A
`4/1994 GauFlétte
`2,323,232 2
`$133: E1931“ 6‘ all'
`
`on ereta'
`’
`’
`5,375,043 A 12/1994 Tokunaga ................. .. 362/601
`..
`5,377,084 A 12/1994 Kojlmaetal.
`5,390,085 A
`2/1995 Mari-Roca et a1.
`5,394,308 A
`M995 Watanabe et a1‘
`
`5,467,208 A 11/1995 Kokawa et a1.
`5,467,417 A 11/1995 Nakamura et a1.
`5,485,291 A
`1/1996 Qiao etal.
`5506929 A
`4/1996 T31‘ etal‘
`5,521,342 A
`5/1996 Barley et a1.
`5,576,078 A 11/1996 Schatz
`5,579,134 A 11/1996 Lengyel
`5590945 A
`V1997 Simms
`5,598,281 A
`1/1997 Zimmerman et a1.
`5,600,462 A
`2/1997 Suzuki et a1.
`5,618,095 A
`4/1997 Kashima et a1.
`5,649,754 A
`7/1997 Matsumoto
`5,664,862 A
`9/1997 Redmond et a1.
`5,671,994 A
`9/1997 Tai etal.
`5,711,592 A
`1/1998 Hotta
`5,719,649 A *
`2/1998 Shono etal. ................ .. 349/65
`5,771,328 A
`6/1998 WoItman etal.
`5,775,791 A
`7/1998 Yoshikawaet a1.
`5,779,337 A
`7/199g Saito et a1‘
`5,779,338 A
`7/1998 Ishikawa et a1.
`5,808,784 A
`9/1998 Ando et a1.
`5,844,720 A 12/199g Ohara et a1‘
`5,890,791 A
`4/1999 Saito
`5,917,664 A
`6/1999 O’Neill et a1.
`5,919,551 A
`7/1999 Cobb, Jr. et a1.
`5,931,555 A
`8/1999 Akahane et a1.
`5,961,198 A 10/1999 Hiraetal.
`5,971,559 A 10/1999 Ishikawa et a1.
`6,011,602 A
`1/2000 Miyashita etal.
`6,036,329 A
`3/2000 Iimura
`6,091,547 A
`7/2000 Gardiner et a1.
`6,120,280 A
`9/2000 Mimum et a1.
`
`6,130,730 A 10/2000 Jannson et a1.
`.
`6,151,169 A 11/2000 K1m
`t 1
`V2001 K .k
`6172809 Bl
`’
`’
`*
`0‘ ee 3'
`7,195,389 B2
`3/2007 Parkeretal. .............. .. 362/606
`
`5,396,350 A
`5,442,523 A
`
`3/1995 Beeson etal. ............... .. 349/62
`8/ 1995 Kashima et a1.
`
`* cited by examiner
`
`LGD_000002
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`US. Patent
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`0a. 14, 2008
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`Sheet 1 0f 14
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`US 7,434,973 B2
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`LGD_000003
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`US. Patent
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`0a. 14, 2008
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`Sheet 2 0f 14
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`US 7,434,973 B2
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`I4
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`27
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`LGD_000004
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`

`US. Patent
`
`0a. 14, 2008
`
`Sheet 3 0f 14
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`US 7,434,973 B2
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`53
`
`SI
`3Q / 577/
`
`54
`
`55
`
`53
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`
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`LGD_000005
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`US. Patent
`
`Oct. 14, 2008
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`Sheet 4 of 14
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`US 7,434,973 B2
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`73
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`
`FIG. I?)
`
`72
`
`77
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`LGD_000006
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`US. Patent
`
`0a. 14, 2008
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`Sheet 5 0f 14
`
`US 7,434,973 B2
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`9O 22
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`US. Patent
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`0a. 14, 2008
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`Sheet 6 0f 14
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`US 7,434,973 B2
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`LGD_000008
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`

`US. Patent
`
`0a. 14, 2008
`
`Sheet 7 0f 14
`
`US 7,434,973 B2
`
`.26
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`
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`
`

`

`US. Patent
`
`0a. 14, 2008
`
`Sheet 8 0f 14
`
`US 7,434,973 B2
`
`FIG. 3C)
`
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`

`

`U.S. Patent
`
`Oct. 14, 2008
`
`Sheet 9 0f 14
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`US 7,434,973 B2
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`

`US. Patent
`
`Oct. 14, 2008
`
`Sheet 10 0f14
`
`US 7,434,973 B2
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`US. Patent
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`0a. 14, 2008
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`Sheet 11 0f 14
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`US 7,434,973 B2
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`LGD_000013
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`US. Patent
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`0a. 14, 2008
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`Sheet 12 0f 14
`
`US 7,434,973 B2
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`US. Patent
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`0a. 14, 2008
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`Sheet 13 0f 14
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`US 7,434,973 B2
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`LGD_000015
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`US. Patent
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`Oct. 14, 2008
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`Sheet 14 of 14
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`US 7,434,973 B2
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`
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`LGD_000016
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`LGD_000016
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`

`

`US 7,434,973 B2
`
`1
`LIGHT EMITTING PANEL ASSEMBLIES
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is a continuation of US. patent applica
`tion Ser. No. 10/619,815, ?led Jul. 15, 2003 now US. Pat.No.
`7,195,389, Which is a continuation 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 ofU.S. patent application 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.
`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 more ef?cient utiliZation of light to suit a particular
`application.
`
`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 pattern of individual light extracting defor
`mities of Well de?ned shapes on or in one or more surface
`areas of the light emitting panel member.
`In accordance With another aspect of the invention, each of
`the light extracting deformities includes a re?ective or refrac
`tive surface of a predetermined slope for more precisely con
`trolling the emission of light by each of said deformities.
`In accordance With another aspect of the invention, each of
`the light extracting deformities has an end Wall that produces
`a relatively small projected surface area on the panel surface
`area to alloW the number of deformities on or in the panel
`surface areas to be increased.
`In accordance With another aspect of the invention, the
`light extracting deformities have straight side Walls.
`In accordance With another aspect of the invention, the
`light extracting deformities have rounded side Walls.
`In accordance With another aspect of the invention, the
`light extracting deformities have planar surfaces in parallel
`spaced relation to the panel surface areas.
`In accordance With another aspect of the invention, the
`panel member is transparent and includes one or more panel
`portions having opposite sides that are free of any re?ective
`material, Whereby light is free to pass through such opposite
`sides.
`In accordance With another aspect of the invention, defor
`mities on or in one or more of the panel portions are shaped to
`cause more of the light entering the panel member through an
`input edge to be emitted from one of the sides of the panel
`portions than the other side.
`In accordance With another aspect of the invention, the one
`side of the panel portion through Which more of the light is
`emitted may be placed in close proximity to a front face of a
`display for front lighting the display.
`In accordance With another aspect of the invention, the
`light emitting deformities have planar surfaces through Which
`light from the display passes With minimal optical distortion.
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`In accordance With another aspect of the invention, the
`pattern of light extracting deformities may be uniform or
`variable as desired to obtain a desired light output distribution
`form the panel surface areas.
`In accordance With another aspect of the invention, the siZe
`and shape as Well as the depth or height and angular orienta
`tion and location of the light extracting deformities may vary
`along the length and/or Width of any given panel surface area
`to obtain a desired light output distribution from the panel
`member.
`In accordance With yet another aspect of the invention, a
`focused light source may be insert molded or cast Within a
`light transition area of the light emitting panel member.
`In accordance With still another aspect of the invention,
`molded supports may be provided on the panel member for
`supporting other parts or components in spaced relation from
`the panel member.
`In accordance With another aspect of the invention, an array
`of light sources may be mounted on a printed circuit board for
`directing light through a diffuser or lens mounted in spaced
`relation to the light sources for use in phototherapy treatment
`and the like.
`The various light emitting panel assemblies of the present
`invention are relatively ef?cient panel assemblies that may be
`used to produce increased uniformity and higher light output
`from 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;
`
`LGD_000017
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`

`US 7,434,973 B2
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`3
`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;
`FIGS. 14 and 15 are schematic perspective vieWs of still
`other forms of light emitting panel assemblies in accordance
`With this invention;
`FIGS. 16 and 17 are enlarged schematic fragmentary plan
`vieWs of a surface area of a light panel assembly shoWing still
`other forms of light extracting deformities in accordance With
`this invention formed on or in a surface of the panel member;
`FIGS. 18 and 19 are enlarged longitudinal sections through
`one of the light extracting deformities of FIGS. 16 and 17,
`respectively;
`FIGS. 20 and 21 are enlarged schematic longitudinal sec
`tions through light extracting deformities similar to FIGS. 18
`and 19, respectively, except that the deformity end Walls are
`shoWn extending substantially perpendicular to the panel sur
`face instead of perpendicular to their respective re?ective/
`refractive surfaces as shoWn in FIGS. 18 and 19;
`FIGS. 22 through 30 are enlarged schematic perspective
`vieWs of panel surface areas containing various patterns of
`individual light extracting deformities of other Well de?ned
`shapes in accordance With this invention;
`FIG. 31 is an enlarged schematic longitudinal section
`through another form of light extracting deformity in accor
`dance With this invention;
`FIGS. 32 and 33 are enlarged schematic top plan vieWs of
`panel surface areas containing light extracting deformities
`similar in shape to those shoWn in FIGS. 28 and 29 arranged
`in a plurality of straight roWs along the length and Width of the
`panel surface area;
`FIGS. 34 and 35 are enlarged schematic top plan vieWs of
`panel surface areas containing light extracting deformities
`also similar in shape to those shoWn in FIGS. 28 and 29
`arranged in staggered roWs along the length of the panel
`surface areas;
`FIGS. 36 and 37 are enlarged schematic top plan vieWs of
`panel surface areas containing a random or variable pattern of
`different siZed light emitting deformities on the panel surface
`areas;
`FIG. 38 is an enlarged schematic perspective vieW of a
`panel surface area shoWing light extracting deformities in
`accordance With this invention increasing in siZe as the dis
`tance of the deformities from the light source increases or
`intensity of the light increases along the length of the panel
`surface area;
`FIGS. 39 and 40 are schematic perspective vieWs shoWing
`different angular orientations of the light extracting deformi
`ties along the length and Width of a panel surface area;
`FIG. 39A is an enlarged schematic top plan vieW of the
`panel surface area of FIG. 39 shoWing the re?ective or refrac
`tive surfaces of the light extracting deformities oriented to
`face the portion of the Width of the input edge to Which the
`light source is optically coupled across the Width of the panel
`surface and the deformities in close proximity to the input
`edge increasing in density, siZe and depth or height as the
`distance of the deformities from the light source increases
`across the Width of the panel surface.
`FIG. 39B is an enlarged fragmentary top plan vieW similar
`to FIG. 39A but shoWing a plurality of light sources optically
`coupled to different portions of the Width of the input edge of
`the panel surface With the re?ective or refractive light extract
`
`4
`ing surfaces of the deformities at different locations across the
`Width of the panel surface oriented to face the different por
`tions of the Width of the input edge to Which the different light
`sources are optically coupled and the deformities in close
`proximity to the input edge increasing in density, siZe and
`depth or height as the distance of the deformities from the
`respective light sources increases across the Width of the
`panel surface.
`FIGS. 41 and 42 are enlarged perspective vieWs schemati
`cally shoWing hoW exemplary light rays emitted from a
`focused light source are re?ected or refracted by different
`individual light extracting deformities of Well de?ned shapes
`in accordance With this invention;
`FIG. 43 is a schematic perspective vieW shoWing a light
`emitting panel assembly similar to FIG. 42 placed on a front
`face of a display to provide front lighting for the display;
`FIG. 44 is a schematic top plan vieW of another form of
`light emitting panel assembly in accordance With this inven
`tion for use in phototherapy treatment and the like; and
`FIGS. 45 through 47 are schematic side elevation vieWs of
`still other forms of light emitting panel assemblies in accor
`dance With this invention for use in phototherapy treatment
`and the like.
`
`20
`
`25
`
`DETAILED DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`30
`
`35
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`40
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`45
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`60
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`65
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`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
`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.
`
`LGD_000018
`
`

`

`US 7,434,973 B2
`
`5
`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
`sonic or plastic 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.
`
`20
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`25
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`30
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`35
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`40
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`6
`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
`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 back light, 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
`
`LGD_000019
`
`

`

`US 7,434,973 B2
`
`7
`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. 4a, 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
`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 moire or 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