I IIIII
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`1111111111111111111111111111111111111111111111111111111111111
`US007434974B2
`
`c12) United States Patent
`Parker
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,434,974 B2
`Oct. 14, 2008
`
`(54) LIGHT EMITTING PANEL ASSEMBLIES
`
`(75)
`
`Inventor: Jeffery R. Parker, Richfield, 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 AI
`
`Jul. 20, 2006
`
`Related U.S. Application Data
`
`(60) Continuation of application No. 10/784,527, filed on
`Feb. 23, 2004, now Pat. No. 7,160,015, which is a
`division of application No. 09/256,275, filed on Feb.
`23, 1999, now Pat. No. 6,712,481, which is a continu(cid:173)
`ation-in-part of application No. 08/778,089, filed on
`Jan. 2, 1997, now Pat. No. 6,079,838, which is a divi(cid:173)
`sion of application No. 08/495,176, filed on Jun. 27,
`1995, now Pat. No. 5,613,751.
`
`(51)
`
`Int. Cl.
`F21V 7104
`(2006.01)
`(52) U.S. Cl. ....................... 362/612; 362/619; 362/632;
`362/634
`(58) Field of Classification Search ................. 362/231,
`362/800,27,619,613,612,620,608,609,
`362/621,600,632,634,26
`See application file 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 eta!.
`6/1967 Balchunas
`3/1973 Wall
`
`3,752,947 A
`3,760,179 A
`3,781,537 A
`3,892,959 A
`3,958,113 A
`4,043,636 A
`4,128,332 A
`4,257,084 A
`4,277,817 A
`4,323,951 A
`4,373,282 A
`4,446,508 A
`4,519,017 A
`4,573,766 A
`
`8/1973 Baker et al.
`9/1973 Addington, Jr.
`12/1973 Ramsey
`7/1975 Pulles
`5/1976 Termohlen
`8/1977 Eberhardt et a!.
`12/1978 Rowe
`3/1981 Reynolds
`7/1981 Hehr
`4/1982 Pasco
`2/1983 Wragg
`5/1984 Kinzie
`5/1985 Daniel
`3/1986 Bournay, Jr. eta!.
`
`(Continued)
`
`Primary Examiner-Thomas M Sember
`(74) Attorney, Agent, or Firm-Renner, 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 oflight 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
`reflector for the panel member to reflect 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
`
`53
`
`53
`
`52
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`Mercedes-Benz Ex. 1001
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`MBI_000001
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`US 7,434,974 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`12/1986 Abdala, Jr. eta!.
`4,630,895 A
`3/1987 Ohe
`4,648,690 A
`6/1987 Szeles
`4,677,531 A
`12/1987 Lang
`4,714,983 A
`3/1988 Ohe
`4,729,067 A
`3/1988 Ohe
`4,729,068 A
`3/1988 Baba
`4,729,185 A
`6/1988 Abrams
`4,751,615 A
`8/1988 Mori
`4,761,047 A
`8/1988 Awai eta!.
`4,763,984 A
`8/1988 Cheslak
`4,765,701 A
`12/1988 Dreyer, Jr. eta!.
`4,791,540 A
`111989 Mori
`4,802,066 A
`3/1989 Blanchet
`4,811,507 A
`4/1989 Awai
`4,825,341 A
`12/1989 Joft
`4,890,201 A
`3/1990 Kobayashi et a!.
`4,909,604 A
`4/1990 Hamada et al.
`4,914,553 A
`5/1990 Guziket a!.
`4,929,062 A
`1111990 Shaw
`4,974,122 A
`12/1990 Bondet a!.
`4,975,808 A
`12/1990 Irwin
`4,978,952 A
`111991 Matsui eta!.
`4,985,809 A
`4/1991 Pristash et a!.
`5,005,108 A
`6/1991 Schoniger et al.
`5,027,258 A
`5,050,046 A * 9/1991 Tada ........................... 362/26
`5,055,978 A
`10/1991 Rogoff
`5,070,431 A
`12/1991 Kitazawa et al.
`
`3/1992 Kashima et a!.
`5,093,765 A
`7/1992 Yokoyama
`5,134,549 A
`8/1992 Pristash et a!.
`5,136,480 A
`8/1992 Schoniger et a!.
`5,136,483 A
`5,184,888 A * 2/1993 Sakuma eta!. .............. 362/136
`3/1993 Miller eta!.
`5,190,370 A
`5,207,493 A
`5/1993 Murase eta!.
`5,243,506 A
`9/1993 Whitehead
`1111993 Kashima et a!.
`5,262,928 A
`5,283,673 A
`2/1994 Murase eta!.
`5,339,179 A
`8/1994 Rudisill et a!.
`5,349,503 A
`9/1994 Blonder et a!.
`5,375,043 A
`12/1994 Tokunaga
`5,377,084 A
`12/1994 Kojima eta!.
`5,390,085 A
`2/1995 Mari-Roca et al.
`5,390,276 A * 2/1995 Tai eta!. ..................... 385/146
`5,390,436 A
`2/1995 Ashall
`2/1995 Watanabe eta!.
`5,394,308 A
`5,434,754 A * 7/1995 Li eta!. ...................... 362/511
`1111995 Kokawaetal.
`5,467,208 A
`5,467,417 A
`1111995 Nakamura et a!.
`5,477,423 A
`12/1995 Fredriksz eta!.
`5,479,275 A
`12/1995 Abileah
`111996 Qiao eta!.
`5,485,291 A
`5,485,354 A *
`111996 Ciupke eta!. ............... 362/619
`5,600,455 A
`2/1997 Ishikawa et a!.
`5,719,649 A
`2/1998 Shono et al.
`5,947,578 A
`9/1999 Ayres
`12/1999 Goto eta!.
`5,999,685 A
`* cited by examiner
`
`MBI_000002
`
`

`

`U.S. Patent
`
`Oct. 14, 2008
`
`Sheet 1 of 4
`
`US 7,434,974 B2
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`16
`
`FIG. I
`
`FIG. 4a
`
`F\G. 4b
`1s
`
`,~
`I
`
`FIG .4c
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`12
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`14
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`MBI_000003
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`U.S. Patent
`
`Oct. 14, 2008
`
`Sheet 2 of 4
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`US 7,434,974 B2
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`14
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`27
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`/II
`
`FIG. 5 28
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`38
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`34 FIGc 6 34
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`40
`
`(
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`43
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`-42-
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`41
`
`FtG. 7
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`MBI_000004
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`U.S. Patent
`
`Oct. 14, 2008
`
`Sheet 3 of 4
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`US 7,434,974 B2
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`53
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`53
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`52
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`-62-
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`65
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`3
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`~ (60
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`64
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`76
`
`FIG. l I
`110
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`61
`
`62
`
`l {
`
`65
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`J
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`61
`
`)
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`'=-<..
`FIG. lla66
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`__-72
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`FIG. 12
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`MBI_000005
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`U.S. Patent
`
`Oct. 14, 2008
`
`Sheet 4 of 4
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`US 7,434,974 B2
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`71
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`FIG. 13
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`FIG. 14
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`82
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`95
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`lr97
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`FlG. IS
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`MBI_000006
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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 U.S. patent applica(cid:173)
`tion Ser. No. 10/784,527, filed Feb. 23, 2004, which is a
`division ofU.S. patent application Ser. No. 09/256,275, filed
`Feb. 23, 1999, now U.S. Pat. No. 6,712,481, dated Mar. 30,
`2004, which is a continuation-in-part of U.S. patent applica(cid:173)
`tionSer. No. 08/778,089, filed Jan. 2, 1997, now U.S. Pat. No.
`6,079,838, dated Jun. 27, 2000, which is a division of U.S.
`patent application Ser. No. 08/495,176, filed Jun. 27, 1995,
`now U.S. Pat. No. 5,613,751, dated Mar. 25, 1997.
`
`BACKGROUND OF THE INVENTION
`
`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(cid:173)
`lowing description and the armexed drawings setting forth in
`detail certain illustrative embodiments of the invention, these
`being indicative, however, of but several of the various ways
`10 in which the principles of the invention may be employed.
`
`5
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`15
`
`In the annexed drawings:
`FIGS. 1 through 3 are schematic perspective views of three
`different forms of light emitting panel assemblies in accor(cid:173)
`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
`20 oflight extracting deformities on the light output area;
`FIGS. 4b, c and dare enlarged schematic perspective views
`of a portion of a light output area of a panel assembly showing
`other forms oflight 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-
`30 tion;
`FIG. 7 is a schematic top plan view of another form oflight
`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(cid:173)
`tion;
`FIG. 9 is a schematic top plan view of another form oflight
`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(cid:173)
`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(cid:173)
`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 oflight emitting panel assemblies in accordance
`with this invention.
`
`This invention relates generally, as indicated, to light emit(cid:173)
`ting panel assemblies each including a transparent panel
`member for efficiently 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 configurations which provide 25
`for better control of the light output from the panel assemblies
`and for more efficient 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 35
`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
`reflections and/or eliminate any lens effect between the light 40
`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 reflective or refractive surfaces
`for changing the path of a portion of the light, emitted from 45
`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 efficiency of the panel members.
`In accordance with another aspect of the invention, the 50
`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 60
`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 65
`invention are very efficient panel assemblies that may be used
`to produce increased uniformity and higher light output from
`
`55
`
`DETAILED DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`Referring now in detail to the drawings, and initially to
`FIG. 1, there is schematically shown one form oflight emit(cid:173)
`ting panel assembly 1 in accordance with this invention
`including a transparent light emitting panel2 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
`
`MBI_000007
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`

`

`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 fit a
`particular application.
`In FIG. 1 the light transition area 4 is shown as an integral
`extension of one end of the light emitting panel2 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, reflec(cid:173)
`tive or refractive surfaces may be provided to increase effi(cid:173)
`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 efficiently reflect 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 oflight emitting panel assem(cid:173)
`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
`efficiently reflect 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 reflective 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
`reflected 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
`reflective 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 reflective materials or coat(cid:173)
`ings may be provided on portions of these surfaces to more
`efficiently reflect 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
`panel14.
`The light sources 3 may be mechanically held in any suit(cid:173)
`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(cid:173)
`ing the light sources 3 in the slots, cavities or openings 16 in
`the light transition areas using a sufficient quantity of a suit(cid:173)
`able embedding, potting or bonding material17. 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- 65
`plished by a variety of methods that do not incorporate extra
`material, for example, thermal bonding, heat staking, ultra-
`
`4
`sonic or plastic welding or the like. Other methods ofbonding
`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
`flat, or curved, may be a single layer or multi-layers, and may
`have different thicknesses and shapes. Moreover, the panels
`may be flexible, or rigid, and may be made out of a variety of
`compounds. Further, the panels may be hollow, filled with
`10 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(cid:173)
`ing, for example, any of the types disclosed in U.S. Pat. Nos.
`4,897, 771 and 5,005,1 08, assigned to the same assignee as the
`15 present application, the entire disclosures of which are incor(cid:173)
`porated herein by reference. In particular, the light sources 3
`may be an arc lamp, an incandescent bulb which also may be
`colored, filtered or painted, a lens end bulb, a line light, a
`halogen lamp, a light emitting diode (LED), a chip from an
`20 LED, a neon bulb, a fluorescent tube, a fiber 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(cid:173)
`tiple colored radiation sources in order to provide a desired
`25 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
`30 individual colored light.
`A pattern oflight 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
`35 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
`40 portion of the light to be emitted. The pattern oflight extract(cid:173)
`ing deformities 21 shown in FIG. 4a includes a variable
`pattern which breaks up the light rays such that the internal
`angle of reflection of a portion of the light rays will be great
`enough to cause the light rays either to be emitted out of the
`45 panel through the side or sides on which the light extracting
`deformities 21 are provided or reflected 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-
`50 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 film process or the like.
`55 The deformities may also be printed on a sheet or film which
`is used to apply the deformities to the panel member. This
`sheet or film may become a permanent part of the light panel
`assembly for example by attaching or otherwise positioning
`the sheet or film against one or both sides of the panel member
`60 similar to the sheet or film 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 oflight emitted from any area
`of the panels. For example, less and/or smaller size deformi-
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`US 7,434,974 B2
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`10
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`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(cid:173)
`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(cid:173)
`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 efficient 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 25
`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 oflight extract(cid:173)
`ing deformities 21 may be multiple layers or vary in index of
`refraction.
`Print patterns oflight extracting deformities 21 may vary in
`shapes such as dots, squares, diamonds, ellipses, stars, ran(cid:173)
`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 finer are desirably employed, thus making
`the deformities or shapes 21 in the print patterns nearly invis(cid:173)
`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/orwidthofthe panel members. The
`deformities may have shapes or a pattern with no specific
`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(cid:173)
`dom dot halftones. 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(cid:173)
`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(cid:173)
`formed, hot stamped or the like into or on one or more areas
`of the panel member. FIGS. 4b and 4c 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
`reflective or refractive surfaces 25 formed on the exterior of
`the panel area. The prismatic surfaces, depressions or raised
`
`6
`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 reflective or
`refractive surfaces may have shapes or a pattern with no
`specific angles to reduce moireor other interference effects.
`As best seen in the cross sectional view of FIG. 5, a back
`reflector (including trans reflectors) 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 efficiency of the panel assembly 11 by
`reflecting the light emitted from that side back through the
`15 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
`20 one or both sides of the panel. Moreover, a transparent film,
`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(cid:173)
`formity of the light output distribution. For example, the
`member 27 may be a colored film, 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 reflector 26 and/or
`film 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
`35 surface area or areas of the panel because of the difficulty 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 marmerthan the air gaps 30 (see
`FIG. 5) which are formed between the respective panel sur-
`40 faces and the back reflector 26 and/or film 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-
`50 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(cid:173)
`bly 32 in accordance with this invention including a panel
`55 member 33, one or more light sources 3, andoneormorelight
`output areas 34. In addition, the panel assembly 32 includes a
`tray 35 having a cavity or recess 36 in which the panel assem(cid:173)
`bly 32 is received. The tray 35 may act as a back reflector as
`well as end edge and/or side edge reflectors for the panel 33
`60 and side and/or back reflectors 37 for the light sources 3.
`Additionally, one or more secondary reflective or refractive
`surfaces 38 may be provided on the panel member 33 and/or
`tray 35 to reflect a portion of the light around one or more
`corners or curves in a non-rectangular shaped panel member
`65 33. These secondary reflective/refractive surfaces 38 may be
`flat, angled, faceted or curved, and may be used to extract a
`portion of the light away from the panel member in a prede-
`
`30
`
`45
`
`MBI_000009
`
`

`

`US 7,434,974 B2
`
`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 oflight 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 10
`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. 15
`Alternatively, each light source may be a single LED having
`multiple colored chips bonded to the lead film. 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 20
`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. 25
`In this particular embodiment, the panel member 46 is three(cid:173)
`dimensionally curved, for example, such that light rays may
`be emitted in a mam1er that facilitates aesthetic design of a
`lighted display.
`FIG. 9 schematically shows another form oflight emitting 30
`panel assembly 50 in accordance with this invention, includ(cid:173)
`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(cid:173)
`port other parts or components as by providing holes or cavi- 35
`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(cid:173)
`ingly shaped light transition area 57 having one or more light 40
`sources 3 embedded, bonded, cast, insert molded, epoxied, or
`otherwise mounted or positioned therein and a curved reflec(cid:173)
`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 45
`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 reflector 58 may be placed on the
`reflective or refractive surface of the cavity or recess 56 or
`insert 57. Where the reflector 58 is placed on the reflective or 50
`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 oflight 55
`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 60
`sources 3 embedded or otherwise mounted in the light tran(cid:173)
`sition area that are dimensionally thicker than the panel mem(cid:173)
`ber. Also, a three-dimensional reflective 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 65
`(FIG. 11a) may be provided at the end of the panel opposite
`the light sources 3 to perform the function of an end reflector.
`
`8
`The light so