United States Patent [19]
`Pristash et al.
`
`[11] Patent Number:
`[45] Date of Patent:
`
`5,005,108
`Apr. 2, 1991
`
`[54] THIN PANEL ILLUMINATOR
`Inventors: David J. Pristash, Brecksville;
`[75]
`Jeffery R. Parker, Concord, both of
`Ohio
`[73} Assignee: Lumitex, IDc., Cleveland, Ohio
`[21] Appl. No.: 309,424
`[22] Filed:
`Feb. 10, 1989
`Int. Ct.5 ................................................ F21V 7/04
`[51]
`[52] U.s. Ct •....................•................... 362/31; 362132;
`362/26
`[58] Field of Search ........................ 362/26,27,31,32
`[56]
`References Cited
`U.S. PATENT DOCUMENTS
`2,480,178 8/1949 Zinberg ............................ 350/96.10
`3,043,947 7/1962 Albinger, Jr .......................... 362132
`3,721,815 3/1973 Wall ...................................... 362132
`3,760,179 9/1973 Addington, Jr ...................... 40/546
`3,781,537 1211973 Ramsey ................................. 362132
`4,128,332 12/1978 Rowe .................................... 362/32
`4,257,084 3/1981 Reynolds .............................. 362127
`4,323,951 4/1982 Pasco .................................... 362131
`4,373,282 2/1983 Wragg ................................. 350/126
`
`4,519,017 5/1985 Daniel.
`4,677,531 6/1987 Szeles .................................... 362/32
`4,729,067 3/1988 Ohe ....................................... 362/31
`4,761,047 8/1988 Morl ...................................... 362132
`4,763,984 8/1988 Awai et aI ............................ 362132
`4,765,701 8/1988 Cheslak.
`4,802,066 111989 Morl ...................................... 362131
`4,825,341 4/1989 Awai ..................................... 362/32
`
`Primary Examiner-Stephen F. Husar
`Assistant Examiner-Sue Hagarman
`Attorney, Agent, or Firm-Renner, Otto, Boisselle &
`Sklar
`
`[57]
`ABSTRACT
`Thin panel illuminator includes a solid transparent panel
`member having one or more deformed output regions
`which cause light entering the panel along an input edge
`thereof to be emitted along the length of the panel.
`Light may be transmitted to one or more panel input
`edges from one or more light sources utilizing transition
`devices which convert easily focused light generally to
`the shape of the panel input surfaces.
`
`76 Claims, 6 Drawing Sheets
`
`Sony Corp. Exhibit 1009
`
`SONY_000526
`
`

`

`u.s. Patent
`
`Apr. 2, 1991
`
`Sheet 1 of 6
`
`5,005,108
`
`-
`
`I
`
`i
`
`FIG. I
`
`t
`24",29~ I
`
`SONY_000527
`
`

`

`u.s. Patent
`
`Apr. 2, 1991
`
`Sheet 2 of 6
`
`5,005,108
`
`35
`
`33
`
`FIG.4
`
`34
`
`9
`
`46
`
`47
`48 FIG.6
`
`61
`
`53 FIG.7
`
`SONY_000528
`
`

`

`u.s. Patent
`
`Apr. 2, 1991
`
`Sheet 3 of 6
`
`5,005,108
`
`61
`
`.
`
`\~----'--~~I
`
`-
`
`65
`
`FIG.9
`
`64
`
`63
`
`61
`66 \
`
`65
`
`FIG. 8
`
`73
`
`87.
`
`86
`
`75"
`
`86
`
`77
`
`87
`
`FIG. 10
`
`SONY_000529
`
`

`

`u.s. Patent
`
`Apr. 2, 1991
`
`Sheet 4 of 6
`
`5,005,108
`
`95
`
`93 FI G. II
`
`100
`103
`101
`1CY2~~. ~h" ~ . . _ •• > _ ~_
`
`FI G. 12
`
`105
`
`110
`
`108
`
`FIG. 13
`
`115
`
`FI G. 14
`
`FIG.15 I
`
`SONY_000530
`
`

`

`u.s. Patent
`
`Apr. 2, 1991
`
`Sheet 5 of 6
`
`5,005,108
`
`125
`~ ,/
`
`I
`
`I
`
`126
`
`FIG. 16
`
`FIG. 17
`
`.... ==
`
`FIG. 18
`-==,
`"-
`~ / ~ '"
`-
`:
`
`....
`
`,----137
`
`~,
`
`136
`
`136
`
`141
`
`FIG. 19
`
`SONY_000531
`
`

`

`u.s. Patent
`
`Apr. 2, 1991
`
`Sheet 6 of 6
`
`5,005,108
`
`148
`
`FIG.20
`
`150
`~
`
`FIG.21
`
`155
`
`IIIII
`
`FIG.22
`
`SONY_000532
`
`

`

`1
`
`THIN PANEL ILLUMINATOR
`
`5,005,108
`
`2
`In another form ofthe invention, the transition device
`is made from a solid transparent material, and is pro(cid:173)
`vided with single or multiple input and output ends of a
`desired shape. Also, the input and/or output ends of the
`5 transition device may be lens shaped to spread the light
`evenly across such surfaces, and such surfaces may be
`coated to absorb or reflect certain frequencies of radia(cid:173)
`tion. Moreover, more than one transition device may be
`used to transmit light from more than one light source
`10 to a single panel, and the panel may have one or more
`light output regions of various shapes to produce a
`desired light output distribution.
`To the accomplishment of the foregoing and related
`ends, the invention, then, comprises the features herein-
`15 after fully described and particularly pointed out in the
`claims, the following description and the annexed draw(cid:173)
`ings setting forth in detail certain illustrative embodi(cid:173)
`ments of the invention, these being indicative, however,
`of but several of the various ways in which the princi(cid:173)
`ples of the invention may be employed.
`
`BACKGROUND OF THE INVENTION
`This invention relates generally, as indicated, to a
`thin panel illuminator including a solid transparent
`panel member for conducting light and extractor means
`for causing light conducted by the panel member to be
`emitted along the length thereof.
`Light panel illuminators are generally known. How(cid:173)
`ever, the present invention relates to several different
`panel illuminator configurations which are less expen(cid:173)
`sive to make and/or provide for better control over the
`light output from the panel. Also, the present invention
`provides for more efficient transmission of light from a
`light source to the light emitting panel.
`
`SUMMARY OF THE INVENTION
`In one form of the invention disclosed herein, the 20
`panel illuminator includes a light emitting panel mem(cid:173)
`ber made of a thin light conducting ribbon or film bent,
`cast or formed into a predetermined pattern to cause
`light conducted thereby to be emitted along the length
`thereof. The effective radius of the bends, the number of 25
`bends per unit length, the panel thickness, the index of
`refraction ratio, and the internal ray distribution may be
`controlled to control the panel light output and effi(cid:173)
`ciency.
`In another form of the invention, the panel member 30
`comprises a solid transparent wave guide having a pris(cid:173)
`matic surface on one side to cause the light rays entering
`the wave guide through an input surface (end edge) to
`exceed the internal critical angle and be emitted. The
`size, shape and depth of the surface deformities may be 35
`varied along the length of the panel to produce a de(cid:173)
`sired light output distribution. Also, a back reflector
`may be used to redirect emitted light back through the
`panel. Moreover, a second prismatic film may be placed
`in closely spaced relation to the panel prismatic surface 40
`to redirect the emitted light rays toward a particular
`application.
`In still another form of the invention, the panel mem(cid:173)
`ber comprises a prismatic film having prism ridges run(cid:173)
`ning generally parallel to each other, with deformities 45
`along the tops of the prism ridges to cause light to be
`emitted. Also, diffuser surfaces, which may vary in
`depth and/or width, may be formed along the length of
`the prismatic surfaces.
`In each instance, the panels may be shaped to fit a 50
`particular application. Also, different light sources may
`be used to supply the panels with different types of
`radiation and reduce or eliminate others.
`Further in accordance with the invention, the panel
`input surfaces may be lens shaped or tapered to alter the 55
`input light ray distribution. Also, such panel input sur(cid:173)
`faces may be coated with an antireflective or other
`coating.
`In accordance with another aspect of the invention, a
`transition device is provided for converting easily fo- 60
`cused light received from a light source to the shape of
`the panel input surface. In one form of the invention, the
`transition device includes an optical fiber transition
`member having a round or other shaped connector at
`one end to permit a source of light to be easily focused 65
`thereon, and a rectangular or other shaped connector at
`the other end corresponding in shape to the panel input
`surface.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`In the annexed drawings:
`FIG. 1 is a schematic perspective view of one form of
`thin panel illuminator in accordance with this invention;
`FIG. 2 is a schematic fragmentary perspective view
`of a solid transparent light emitting ribbon panel in
`accordance with this invention;
`FIG. 3 is an enlarged fragmentary side elevation view
`of the ribbon panel of FIG. 2 schematically showing
`how light rays are transmitted through and emitted
`from such panel;
`FIGS. 4-6 are perspective views of various other
`solid transparent light emitting panels in accordance
`with this invention;
`FIG. 7 is a side elevation view of another form of
`solid transparent light emitting panel in accordance
`with this invention schematically showing light rays
`entering opposite ends of the panel and being emitted
`therefrom;
`FIG. 8 is a schematic side elevation view of another
`form of thin panel illuminator in accordance with this
`invention;
`FIG. 9 is a top plan view of the thin panel illuminator
`of FIG. 8;
`FIG. 10 is a top plan view of still another form of thin
`panel illuminator in accordance with this invention;
`FIGS. 11-14 are schematic longitudinal sections of
`several forms of solid transparent light emitting panels
`in accordance with this invention;
`FIG. 15 is a top plan view of one form of transition
`device in accordance with this invention for converting
`an easily focused cross-sectional shape of light to the
`shape of a panel input surface;
`FIGS. 16-19 are schematic perspective views of vari(cid:173)
`ous other forms of transition devices in accordance with
`this invention; and
`FIGS. 20-22 are schematic perspective views of sev(cid:173)
`eral different shapes of panels constructed in accor(cid:173)
`dance with this invention.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`Referring now in detail to the drawings, and initially
`to FIG. 1, there is schematically shown one form of thin
`panel illuminator in accordance with this invention
`including a solid transparent light emitting panel 2 and
`a light source 3 which generates and focuses light, in a
`
`SONY_000533
`
`

`

`5,005,108
`
`3
`predetermined pattern, either directly on a panel input
`edge 4 or on a transition device 5 which is used to make
`the transition from the light source 3 target shape to the
`light emitting panel input edge 4 shape as shown. The
`light that is transmitted from the light source 3 to the 5
`light emitting panel 2 may be emitted along the length
`of the panel as desired to produce a desired light output
`distribution to fit a particular application.
`A light source 3 of any suitable type may be used,
`including, for example, any of the types disclosed in 10
`copending application Ser. No. 125,323, filed Nov. 24,
`1987, now U.S. Pat. No. 4,897,771, granted Jan. 30,
`1990, and assigned to the same assignee as the present
`application, which is incorporated herein by reference.
`Light source 3 includes a radiation source 8 such as an 15
`arc lamp, an incandescent bulb, a lens end bulb, an LED
`or a fluorescent tube or the like, and may have a col1ec(cid:173)
`tor 9 which col1ects the light emitted by the radiation
`source 8 and uniformly focuses the light on the input
`end 10 of the transition device 5 with predetermined ray 20
`angles to fit a particular application. For the thin panel
`illuminator 1 of the present invention to operate effi(cid:173)
`ciently, the light source 3, transition device 5 and light
`emitting panel 2 must be designed to fit each other as 25
`wel1 as the particular application. However, it should be
`understood that the light source 3, transition device 5
`and light emitting panel 2 may also be used separately if
`desired.
`Light emitting panel 2 comprises a solid transparent 30
`or translucent wave guide 15 made of glass, plastic or
`other suitable transparent or translucent material, with
`disruptions 16 on at least one side 17 formed as by cut(cid:173)
`ting, molding, coating, forming or otherwise causing
`mechanical, chemical or other deformations in the exte- 35
`rior surface 18 thereof. When these disruptions 16 are
`struck by the light rays entering the panel input edge 4,
`they cause some of the light rays to exceed the internal
`critical angle and be emitted from the panel. The
`amount of light emitted from the panel will depend on 40
`the type, shape, depth and frequency of the disruptions
`16. For example, if the exterior surface 18 is mechani(cid:173)
`cal1y deformed at decreasingly spaced intervals as the
`distance from the light source 3 increases, there will be
`more uniform emission of light from the surface 18 45
`when viewed from a distance. Also, such disruptions 16
`may vary in depth and shape along the length of the
`panel 2 to produce a desired light output distribution.
`A back reflector 20 may be provided on the side 21 of
`the panel 2 opposite the side 17 with the disruptions 16 50
`therein. In like manner, an end reflector 22 may be
`provided on the end edge 23 opposite the input edge 4
`to minimize the amount of light escaping from these
`surfaces.
`Another light emitting panel 24 in accordance with 55
`this invention is schematical1y shown in FIG. 2 and
`comprises a thin light conducting ribbon or film 25 bent
`into a wave form of predetermined pattern. Although
`the dimensions of the panel 24 may vary, as an example,
`the panel 24 may be approximately 0.020 inch thick and 60
`have an overal1 height of approximately 0.040 inch, and
`be of any desired width or length depending on the
`particular application. Such a panel 24 may be made in
`any suitable manner, for example, by vacuum forming
`or injection molding. During the forming operation, the 65
`ribbon or film 25 is bent in a predetermined pattern,
`with the number of bends 26 per unit length, the effec(cid:173)
`tive bend radius, the panel thickness, the index of refrac-
`
`4
`tion ratio, and the internal ray distribution determining
`the light output and efficiency of the panel.
`When the wave guide 25 is bent, certain light rays
`that were previously internal1y reflected will be emitted
`if the bends are below a critical radius. The critical
`radius is the radius of curvature at which these light
`rays first start to be emitted. By making the bends 26
`more or less pronouced, the percentage of light emitted
`can be control1ed for a given input ray distribution.
`As schematically shown in FIG. 3, as certain light
`rays strike a bend surface 26 of panel 24, they exceed the
`internal critical angle and are emitted. If desired, one
`side of panel 24 may be provided with a back reflector
`27 that reflects the light emitted from that side back
`through the panel towards an application as schemati(cid:173)
`cal1y shown in phantom lines in FIG. 3. Moreover,
`selected light emitting areas 28 of the panel 24 may be
`coated with a transparent coating 29 having a different
`refractive index than the light conducting ribbon or film
`25 to cause changes in the attenuation of light being
`emitted from the panel 24 as further schematically
`shown in phantom lines in FIG. 3.
`FIG. 4 shows another form of light emitting panel 30
`in accordance with this invention including a solid
`transparent wave guide 31 similar to the wave guide 15
`of FIG. 1 but having a prismatic surface 32 on a side 33
`which is covered by a back reflector 34. Accordingly,
`when the prismatic surface 32 is struck by light rays
`entering an input end edge 35 of the wave guide 31,
`causing the light rays to exceed the internal critical
`angle and be emitted, the emitted light rays will be
`reflected back through the panel by the back reflector
`34 and out the other side 36 of the panel as schemati(cid:173)
`cally shown in FIG. 4. The angles and/or depth of these
`prismatic surfaces 32 may be varied along the length of
`the panel 30 to produce uniform or other desired light
`output from the other side 36 of the panel.
`In FIG. 4, the light rays are shown entering the panel
`30 through an end edge 35 generally perpendicular to
`the prism edges 37. Also, an end reflector 38 is shown
`on the end edge 39 of the panel opposite the input end
`edge 35. However, if desired, light rays may be caused
`to enter the panel 30 from both end edges 35, 39, in
`which event the end reflector 38 would be eliminated.
`FIG. 5 shows another form oflight emitting panel 40
`in accordance with this invention comprising a solid
`transparent prismatic film 41 having deformities 42 cut,
`molded or otherwise formed along the top of the prism
`edges 43. Although the deformities 42 are shown as
`being of a generally triangular shape, they may be of
`any desired shape that causes light to be emitted, and
`may vary in depth and shape along the length of the
`prism edges 43 to produce a desired light output distri(cid:173)
`bution. In this embodiment, light rays are caused to
`enter the panel 40 from one or both side edges 44, 45 in
`a direction generally parallel to the prism edges 43.
`Alternatively, diffuser surfaces 46 may be formed
`along the top edges 47 of the prismatic surfaces 48 ·of a
`prismatic film light emitting panel 49 as schematically
`shown in FIG. 6. These diffuser surfaces 46 may vary in
`depth and/or width along the length of the panel 49,
`and may comprise a roughened surface, a lenticular
`surface, or a prismatic surface or the like that consists of
`mUltiple surface deformities. A roughened surface, for
`example, may be produced by grinding, sanding, laser
`cutting or milling. Also, both of the light emitting pan(cid:173)
`els 40 and 49 shown in FIGS. 5 and 6 may have pris(cid:173)
`matic surfaces on both the top and bottom surfaces
`
`SONY_000534
`
`

`

`5,005,108
`
`5
`rather than on just one surface as shown, and one or the
`other of the top or bottom surface may be provided
`with a back reflector similar to the back reflector 34
`shown in FIG. 4 to redirect emitted light back through
`the panel toward a particular application.
`FIG. 7 schematically shows another form of light
`emitting panel 50 in accordance with this invention
`which also comprises a solid transparent prismatic film
`51 having a prismatic surface 52 on one side and a back
`reflector 53 on the other side, similar to the light emit- 10
`ting panel 2 shown in FIG. 1. Light rays may be caused
`to enter the panel 50 perpendicular to the wave guide
`prism edges 54 from one or both end edges 55, 56 of the
`panel, and are internally reflected until they strike a
`deformity (in this case an edge 54 of the panel prismatic 15
`surfaces 52) which causes the light rays to be emitted.
`The size, shape and depth of the wave guide deformities
`52 may be varied along the length of the panel to pro(cid:173)
`duce a desired light output distribution. Also, a back
`reflector 53 may be provided on the bottom side of the 20
`panel 50 to redirect light back through the panel.
`In addition, the panel 50 includes a second prismatic
`film 60 disposed in close proximity to the panel pris(cid:173)
`matic surface 52 to shift the angular emission of light
`toward a particular application. The second prismatic 25
`film 60 may be separated from the first prismatic film or
`wave guide 51 by air or an epoxy filled gap 61. If the
`wave guide 51 and second prismatic film 60 are epoxied
`together, the epoxy 61 must be transparent and have a
`suitable index of refraction. Also, multiple prismatic 30
`films may be used in place of the single prismatic film
`60, or the prismatic film 60 may be replaced by a dif(cid:173)
`fuser or lenticular lens or the like.
`Other examples of thin panel illuminators in accor(cid:173)
`dance with this invention are schematically shown in 35
`FIGS. 8-10. The thin panel illuminator 61 shown in
`FIGS. 8 and 9 includes a light emitting panel 62 and
`transition device 63 for transmitting light from a light
`source 64 focused on its input surface 65 to the panel
`input surface (end edge) 66. In this embodiment, the 40
`light emitting panel 62 comprises a laminated structure
`including a solid transparent wave guide 67 and extrac(cid:173)
`tor 68 joined together as by means of an adhesive layer
`69 or the like. Light that enters the wave guide 67 from
`the transition device 63 is internally reflected until it 45
`strikes the wave guide-extractor interface 70 and is
`emitted from the extractor 68 toward a particular appli(cid:173)
`cation. The index of refraction of the adhesive layer 69
`may be varied relative to the indexes of refraction of the
`wave guide 67 and extractor 68 to produce a desired 50
`light output. If desired, the extractor 68 may be joined
`to the wave guide 67 by methods other than adhesive
`such as clamping, fastening, heat sealing and solvent
`gluing and the like. Also, the extractor 68 may consist of
`one or more coatings applied directly to selected areas 55
`of the top or bottom surfaces of the wave guide 67.
`These coatings may vary in frequency, index of refrac(cid:173)
`tion, color, and/or shape along the length of the panel
`62. Reflectors 71 may also be provided at the end edge
`72 of the wave guide 67 opposite the input edge 66 as 60
`well as at the side edges to reflect light back into the
`wave guide. Also, a back reflector 73 may be provided
`on the bottom surface 74 of the wave guide to reflect
`light back through the wave guide.
`The thin panel illuminator 75 of FIG. 10 also includes 65
`a solid transparent light emitting panel 76, but which
`has multiple light output regions 77, 78, 79 of various
`shapes, and multiple transition devices 80, 81 for trans-
`
`6
`mitting light from multiple light sources 82, 83 to differ(cid:173)
`ent panel input edges 84, 85. In the FIG. 10 embodi(cid:173)
`ment, two such transition devices 80, 81 are shown
`connected to two panel input edges 84, 85 which are
`5 substantially perpendicular to each other. The sides and
`back of the panel 76 may have reflective coatings 86
`thereon.
`Each output region 77-79 contains deformities 87
`produced, for example, by molding, machining, stamp(cid:173)
`ing, etching, abrading, or laser cutting or the like to
`cause light to be emitted therefrom. The light output
`pattern or uniformity of light output from these output
`regions 77-79 may be controlled by varying the shape,
`depth and frequency of the deformities 87 relative to the
`input light ray distribution. For example, the various
`light output regions 77-79 of the panel 76 may be
`etched, roughened or cut into different shapes and lev(cid:173)
`els of deformities using a laser by varying the power,
`position and cutting speed of the laser.
`FIGS. 11-14 schematically illustrate solid transparent
`light emitting panels having differently shaped light
`output regions. FIG. 11 shows a panel 90 with light
`input at one end edge 91 only and typical light ray
`travel. In this embodiment, panel 90 has a back reflector
`92 on the bottom surface 93, an end reflector 94 on the
`end edge 95 opposite the input end edge 91, and a de-
`formed light output region 96 whose depth progres(cid:173)
`sively decreases along the length of the panel from the
`input end edge 91 toward the opposite end edge 95.
`FIG. 12 shows a panel 100 with light input at oppo(cid:173)
`site end edges 101 and 102 and a deformed output re(cid:173)
`gion 103 that progressively decreases in depth from
`both input end edges 101, 102 toward the middle of the
`length of the panel. FIG. 13 shows a panel 104 with
`light input at one end edge 105 only and a deformed
`light output region 106 on the bottom surface 107
`whose depth progressively decreases from the input end
`edge 105 toward the opposite end edge 108. Also, a
`back reflector 109 is shown mounted on the bottom
`surface 107 of the panel 108 to redirect the light that is
`emitted from the light output region 106 back through
`the panel and out the top surface 110. In this embodi(cid:173)
`ment, either an air gap or a transparent fill material 111
`having a suitable index of refraction may separate the
`back reflector 109 from the panel 104.
`Panel 115 shown in FIG. 14 is similar to panel 104 of
`FIG. 13 except that the back reflector 116 of FIG. 14 is
`deposited directly on the deformed light output region
`117 and the depth of the panel is substantially uniform
`throughout its length.
`In each instance, the light input surfaces (end or side
`edges) of the light emitting panels may be lens shaped or
`tapered to alter the input light ray distribution. Also,
`such light input surfaces may be coated with an anti(cid:173)
`reflective coating or a coating that changes the numeri(cid:173)
`cal aperture of the panel. The numerical aperture is the
`sine of the vertex angle of the largest cone of input rays
`that can enter an optical system or element multi pled by
`the refractive index of the medium in which the vertex
`of the cone is located. Moreover, the light input sur(cid:173)
`faces, bottom surface and/or top surface of the panels
`may be coated to reflect or absorb certain frequencies of
`light.
`From the foregoing it will be apparent that the wave
`guide confines and directs light in a direction deter(cid:173)
`mined by its boundaries, whereas the extractor causes
`light to be emitted from the wave guide. Examples of
`wave guides that may be utilized in the thin panel illu-
`
`SONY_000535
`
`

`

`5,005,108
`
`7
`minators of the present invention include glass sheets,
`plastic films, liquid filled transparent enclosures, and
`crystals and the like. Also, examples of extractors that
`may be utilized in the thin panel illuminators include
`prismatic films, diffusers, lenticular lenses, coatings and 5
`other systems or materials that cause the internal critical
`angle to be exceeded which in turn causes light to be
`emitted.
`Referring next to FIGS. 15-19, different forms of
`transition devices for use in transmitting light from a 10
`remote location to the light emitting panels of the pres(cid:173)
`ent invention are shown. As previously indicated, the
`purpose of such transition devices is to transmit light
`focused on its input surface or surfaces to a light emit(cid:173)
`ting panel by converting a relatively easily focused 15
`cross-sectional shape of light to the shape of the panel
`input surface. The transition device 120 shown in FIG.
`15 comprises a plurality of optical fibers 121 having a
`round or other shaped connector 122 at one end on
`which a source oflight is easily focused and a rectangu- 20
`lar or other shaped connector 123 at the other end sub(cid:173)
`stantially corresponding in shape to the panel input
`surface. The optic fibers 121 may be made of glass or a
`suitable transparent plastic material, and may be formed
`into a ribbon-like cable 124 by loosely weaving cross 25
`(fill) threads 125 between the optical fibers 121 which
`act as a harness without causing the optical fibers to
`bend to the degree necessary to emit light from the
`transition device 120. Preferably, the optical fiber
`strands 121 of both of the connectors 122, 123 are 30
`scrambled to produce a higher uniformity in the transi(cid:173)
`tion device output. Moreover, the ends of the connec(cid:173)
`tors 122, 123 are desirably highly polished to minimize
`losses, and may be coated to reflect or absorb certain
`wavelengths of light.
`In lieu of using optical fibers in the transition device,
`the transition device may be made from a solid transpar(cid:173)
`ent material such as glass, plastic or the like having an
`input surface at one end of a cross-sectional shape on
`which a light source is easily focused such as round or 40
`square and having an output surface at the other end in
`the shape of the panel input surface. FIG. 16 shows one
`such solid transparent transition device 125 having a
`substantially square input surface 126 at one end and a
`substantially rectangular output surface 127 at the other 45
`end, whereas FIG. 17 shows another solid transparent
`transition device 130 having a round input surface 131
`at one end and a substantially rectangular output surface
`132 at the other end. Also, FIG. 18 shows a solid trans(cid:173)
`parent transition device 135 including multiple input (or 50
`output) surfaces 136 at one end and a single output (or
`input) surface 137 at the other end. FIG. 19 shows an(cid:173)
`other solid transparent transition device 140 with a lens
`141 at the input surface 142 shaped to spread the light
`evenly across its output surface 143. In like manner, the 55
`output surface of the solid transition devices as well as
`the input surface of the light emitting panels may be lens
`shaped or tapered to alter the input light ray distribu(cid:173)
`tion.
`Although the respective input and output surfaces of 60
`the various transition devices are shown as square,
`round or rectangular, they may be elliptical or any
`other shape necessary to fit a particular application.
`Moreover, multiple light sources may be used with a
`single panel or multiple panels used with a single light 65
`source by providing the transition device with multiple
`input connectors leading to a single output connector or
`a single input connector leading to multiple output con-
`
`8
`nectors as schematically shown in FIG. 18. Further(cid:173)
`more, filters may be placed between the light source
`and panel or transition device to reflect or absorb cer-
`tain wavelengths of light. Also, a moving or rotating
`filter may be used to produce color effects.
`Although the various solid transparent transition
`devices are shown separate from the light emitting pan(cid:173)
`els, it will be appreciated that such transition devices
`may be formed as an integral part of the panels. Also, in
`certain applications the transition devices may be elimi(cid:173)
`nated and the light focused directly on the panel input
`surfaces to cut down on system losses.
`As will be apparent, the various thin panel illumina(cid:173)
`tors disclosed herein may be used for a great many
`different applications, including for example general
`lighting, phototherapy treatment, and radiation curing
`of adhesives and epoxies and the like. Typical general
`lighting applications include back lighting of liquid
`crystal displays or transparencies or the like, task light(cid:173)
`ing, machine vision lighting, safety lighting for both
`commercial and industrial as well as automotive appli-
`cations, explosion-proof lighting, underwater lighting,
`display lighting and infrared heating and the like. Pho-
`totherapy treatment includes such applications as tan(cid:173)
`ning lights, phototherapy of neonatal hyperbilirubine(cid:173)
`mia, photochemotherapy, photosynthesis of plants, and
`so on. Also, radiation curing of adhesives and epoxies
`may be used in a wide variety of applications including
`aerospace, dental, circuit board, electronic component,
`and optical component manufacturing, to name a few.
`To facilitate use of such thin panel illuminators for
`phototherapy, the panels may be formed in the shape of
`a pad, belt, collar, blanket, strap or other suitable shape.
`35 FIG. 20 schematically illustrates a thin panel illumina(cid:173)
`tor 145 in accordance with this invention being used for
`phototherapy treatment of infants including a solid
`transparent light emitting panel 146 in the shape of a
`pad and a light source 147 designed for example to emit
`sufficient radiation in spectral regions that lower plasma
`bilirubin levels. The light source 147 may also be de(cid:173)
`signed to reduce output of infrared and ultraviolet radi(cid:173)
`ation that may be harmful to the infant. In addition,
`such light source may be designed to provide sufficient
`illuminance and color rendering for inspection of an
`infant's skin color. A transition device 148 in accor-
`dance with this invention transmits the light from the
`light source 147 to the light emitting panel 146 in the
`manner previously described.
`Although the light emitting panel 146 is shown in
`FIG. 20 as being flat, it will be appreciated that the
`panel may be curved or otherwise formed to emit light
`in a desired manner or on a particular location. FIG. 21
`schematically shows a light emitting panel 150 bent or
`formed to fit a particular application. Also, FIG. 22
`shows another light emitting panel 151 in accordance
`with this invention in the shape of a channel 152 having
`a bottom wall 153, spaced apart side walls 154 and an
`open top 155, with deformities 156 along the interior
`length of the bottom and side walls 153, 154 to cause
`light to be emitted interiorly. The channel 152 may be
`curved or bent at 157 intermediate its length with the
`radius of curvature around which the light travels being
`sufficiently large that light is not emitted. Also, a reflec(cid:173)
`tive surface 158 may be applied to the exterior surfaces
`of the panel to redirect light interiorly back through the
`panel bottom and side walls 153, 154 toward a particular
`application.
`
`SONY_000536
`
`

`

`5,005,108
`
`10
`9
`transmitting light from said light source to said panel
`Altho