(12) United States Patent
`Parker
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 7,384,177 B2
`Jun. 10, 2008
`
`US0073 84177B2
`
`(54) LIGHT EMITTING PANEL ASSEMBLIES
`
`(75)
`
`Inventor:
`
`Jeflery 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. 15403) by 232 days.
`
`(21) App1.N0.: 11/244,544
`
`(22)
`
`Filed;
`
`Oct 6, 2005
`
`(65)
`
`Prior Publication Data
`
`US 2006/0028817 A1
`
`Feb. 9, 2006
`_
`_
`Related U-S- APP11¢at10I1 Data
`(60) Division of application No. 10/784,527, filed on Feb.
`23, 2004, now Pat. No. 7,160,015, which is a division
`ofapplicationNo.09/256,275,filed on Feb.23, 1999,
`now Pat. No. 6,712,481, which is a continuation-in-
`part of application No. 08/778,089, filed on Jan. 2,
`1997, now Pat. No. 6,079,838, which is a division of
`application No. 08/495,176, filed on Jun. 27, 1995,
`new Pat‘ No‘ 5’613’75 1'
`Int. CL
`F21V 7/04
`
`(51)
`
`(2006.01)
`
`(52) U.S. Cl.
`
`.................... .. 362/601; 362/612; 362/613;
`362/623; 362/609; 362/231
`h .............. .. 362/601
`'
`'fi
`'
`S
`(58) Fleld of (33:25/s6l02cag:)03n 6ggrg07 612 613 618 619’
`’
`’
`/
`’
`’
`’7 23’1 26’ 609’
`.
`.
`362 620’ 623,62 ’
`.
`’
`’
`See apphcauon file for Complete Search hlstory‘
`'
`References Cited
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`Eh‘:
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`
`.
`(comlnued)
`Primary Examiner—Thomas M. Sember
`A
`A
`F ' —R
`Eiigfey,
`gent, or
`zrm
`enner,
`
`’
`
`(57)
`
`ABSTRACT
`
`O
`
`tto,
`
`B '
`11 &
`oisse e
`
`~
`~
`~
`~
`~
`~
`Light emitting assemblies include a tray that forms a cavity
`or recess containing one or more light sources. A sheet, film
`or substrate is positioned over the cavity or recess for
`controlling the light emitted from the assembly. The tray acts
`as a back side or ed e reflector and has one or more
`d
`,
`fl
`.
`g f
`.
`s f
`secon ary re ective or re ractive sur aces.
`
`2,480,178 A
`
`8/1949 Zinberg
`
`27 Claims, 4 Drawing Sheets
`
`34
`
`38
`
`33
`
`
`
`37
`
`Page 1 of 11
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`TOYOTA EXHIBIT 1001
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`Page 1 of 11
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`TOYOTA EXHIBIT 1001
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`

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`US 7,384,177 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`
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`4,751,615 A
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`’
`’
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`
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`8/1988 Cheslak
`12/1988 Dreyer, Jr, et 31,
`1/1989 M011
`3/1989 Blanchet
`4/1989 Awai
`7/1989 Murata ...................... .. 345/83
`12/1989 1011
`3/1990 Kobayashi et 81,
`4/1990 Hamada 61111
`5/1990 GuZi1<eta1~
`11/1990 Shaw
`12/1990 BOIIC1 61 al.
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`.8
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`
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`’
`’
`
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`12/1999 Goto et 211.
`
`* cited by examiner
`
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`US 7,384,177 B2
`
`1
`LIGHT EMITTING PANEL ASSEMBLIES
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is a division of U.S. patent application
`Ser. No. 10/784,527, filed Feb. 23, 2004 now U.S. Pat. No.
`7,160,015, 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 ofU.S. patent application Ser. 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
`
`to light
`This invention relates generally, as indicated,
`emitting 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
`for better control of the light output from the panel assem-
`blies 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
`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 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 sur-
`faces for changing the path of a portion of the light, emitted
`from the light source, that would not normally enter the
`panel members at an acceptable angle that allows the light
`to remain in the panel members for a longer period of time
`and/or increase the efficiency of the panel members.
`In accordance with another aspect of the invention, the
`light emitting panel members include a pattern of light
`extracting deformities or disruptions which provide a
`desired light output distribution from the panel members by
`changing the angle of refraction of a portion of the light from
`one or more light output areas of the panel members.
`In accordance with still another aspect of the invention,
`the light source may include multiple colored light sources
`for supplying light to one or more light output areas, and for
`providing a colored or white light output distribution.
`In accordance with yet another aspect of the invention, the
`panel assemblies include a transition area for mixing the
`multiple colored lights, prior to the light entering the panel
`members, in order to effect a desired colored or white light
`output distribution.
`
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`The various light emitting panel assemblies of the present
`invention are very efficient 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
`following 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
`accordance 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. 419, c 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 inven-
`tion;
`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 inven-
`tion;
`FIG. 10 is a schematic top plan view of still another form
`of light emitting panel assembly in accordance with this
`invention;
`FIG. 11 is a side elevation view of the light emitting panel
`assembly of FIG. 10;
`FIG. 11 a is a fragmentary side elevation view showing a
`tapered or rounded end on the panel member in place of the
`prismatic surface shown in FIGS. 10 and 11;
`FIG. 12 is a schematic top plan view of another form of
`light emitting panel assembly in accordance with this inven-
`tion;
`FIG. 13 is a schematic side elevation view of the light
`emitting panel assembly of FIG. 12; and
`FIGS. 14 and 15 are schematic perspective views of still
`other forms of light emitting panel assemblies in accordance
`with this invention.
`
`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 light
`emitting panel assembly 1 in accordance with this invention
`including a transparent light emitting panel 2 and one or
`
`Page 7 of 11
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`US 7,384,177 B2
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`3
`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 distribu-
`tion 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 panel 2 and as
`being generally rectangular in shape. However, the light
`transition area may be of other shapes suitable for embed-
`ding, potting, bonding or otherwise mounting the light
`source. Also, reflective or refractive surfaces may be pro-
`vided to increase efficiency. 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 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 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 inven-
`tion including two light sources 3. Of course,
`it will be
`appreciated that the panel assemblies of the present inven-
`tion 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
`coatings 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 panel 14.
`The light sources 3 may be mechanically held in any
`suitable 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 bonding the light sources 3 in the slots, cavities
`
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`or openings 16 in the light transition areas using a sufficient
`quantity of a suitable embedding, potting or bonding mate-
`rial 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 accomplished by a variety of methods that do not
`incorporate extra material, for example, thermal bonding,
`heat staking, ultrasonic 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
`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 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
`including, for example, any of the types disclosed in U.S.
`Pat. Nos. 4,897,771 and 5,005,108, assigned to the same
`assignee as the present application, the entire disclosures of
`which are incorporated 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 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 multiple colored radiation sources
`in order to provide a desired colored or white light output
`distribution. For example, a plurality of colored lights such
`as LEDs of different colors (red, blue, green) or a single
`LED with multiple colored chips may be employed to create
`white light or any other colored light output distribution by
`varying the intensities of each individual colored light.
`A pattern of light extracting deformities or disruptions
`may be provided on one or both sides of the panel members
`or on one or more selected areas on one or both sides of the
`
`panel members, as desired. FIG. 4a schematically shows one
`such light surface area 20 on which a pattern of light
`extracting deformities or disruptions 21 is provided. As used
`herein, the term deformities or disruptions are used inter-
`changeably 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 extracting deformities 21 shown in FIG. 411 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 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
`pattern, 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. 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 other-
`wise positioning the sheet or film against one or both sides
`
`Page 8 of 11
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`Page 8 of 11
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`US 7,384,177 B2
`
`5
`of the panel member 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 of light
`emitted from any area of the panels. For example, less and/or
`smaller size deformities 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
`different 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 pro-
`viding 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 panels.
`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
`light extractions of the panel members. The pattern of light
`extracting deformities 21 may be printed on the light output
`areas utilizing a wide spectrum of paints,
`inks, coatings,
`epoxies, or the like, ranging from glossy to opaque or both,
`and may employ half-tone separation techniques to vary the
`deformity 21 coverage. Moreover,
`the pattern of light
`extracting 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,
`random 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 invisible 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 defor-
`mities may be utilized throughout the length and/or width of
`the 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 random dot half tones. Moreover, the
`deformities may be colored in order to effect color correction
`in the panel members. The color of the deformities may also
`vary throughout the panel members, for example to provide
`different colors for the same or different light output areas.
`In addition to or in lieu of the patterns of light extracting
`deformities 21 shown in FIG. 411, other light extracting
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`deformities including prismatic surfaces, depressions or
`raised surfaces of various shapes using more complex
`shapes in a mold pattern may be molded, etched, stamped,
`thermoformed, 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 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
`moire or 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
`panel for emission through the opposite side. Additionally, a
`pattern of light extracting deformities 21, 23, 24 and/or 25
`may be provided on one or both sides of the panel member
`in order to change the path of the light so that the internal
`critical angle is exceeded and a portion of the light is emitted
`from one or both sides of the panel. Moreover, a transparent
`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
`uniformity 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
`
`the adhesive is preferably
`and/or film 27 to the panel,
`applied only along the side edges of the panel, and if desired
`the end edge opposite the light transition areas 12, but not
`over the entire surface area or areas of the panel because of
`the difficulty in consistently applying a uniform coating of
`adhesive to the panel. Also, the adhesive changes the inter-
`nal critical angle of the light in a less controllable manner
`than the air gaps 30 (see FIG. 5) which are formed between
`the respective panel surfaces 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
`providing structural support for other parts or components,
`for example, a display panel such as a liquid crystal display
`panel as desired.
`FIG. 6 shows another form of light emitting panel assem-
`bly 32 in accordance with this invention including a panel
`member 33, one or more light sources 3, and one or more
`light output areas 34. In addition, the panel assembly 32
`includes a tray 35 having a cavity or recess 36 in which the
`panel assembly 32 is received. The tray 35 may act as a back
`
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`US 7,384,177 B2
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`7
`reflector as well as end edge and/or side edge reflectors for
`the panel 33 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 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 predetermined pattern. FIG. 6 also shows multiple light
`output areas 34 on the panel member that emit light from one
`or more light sources 3.
`FIG. 7 is a schematic illustration of still another form of
`
`light emitting panel assembly 40 in accordance with this
`invention including a panel member 41 having one or more
`light output areas 42 and one or more light transition areas
`(mixing areas) 43 containing a plurality of light sources 3 at
`one or both ends of the panel. Each transition area mixes the
`light from one or more light sources having different colors
`and/or intensities. In this particular embodiment, each of the
`light sources 3 desirably employs three colored LEDs (red,
`blue, green) in each transition mixing area 43 so that the
`light from the three LEDs can be mixed to produce a desired
`light output color that will be emitted from the light output
`area 42. Alternatively, each light source may be a single
`LED having multiple colored chips bonded to the lead 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 output or white light distribution can be
`achieved.
`
`FIG. 8 shows yet another form of light emitting panel
`assembly 45 in accordance with this invention including a
`light emitting panel member 46 and a light source 3 in a light
`transition area 48 integral with one end of the panel member.
`In this particular embodiment,
`the panel member 46 is
`three-dimensionally curved, for example, such that light rays
`may be emitted in a manner that facilitates aesthetic design
`of a lighted display.
`FIG. 9 schematically shows another form of light emitting
`panel assembly 50 in accordance with this invention, includ-
`ing a panel member 51 having multiple light output areas 52,
`and mounting posts and/or mounting tabs 53. This particular
`panel assembly 50 may serve as a structural member to
`support other parts or components as by providing holes or
`cavities 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
`correspondingly shaped light transition area 57 having one
`or more light sources 3 embedded, bonded, cast,
`insert
`molded, epoxied, or otherwise mounted or positioned
`therein and a curved reflective or refractive surface 58 on the
`
`transition area 57 and/or wall of the cavity or recess 56 to
`redirect a portion of the light in a predetermined manner. In
`this way the light transition area 57 and/or panel member
`may be in the form of a separate insert which facilitates the
`easy placement of the light source in a modular manner. A
`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 refractive surface
`of the cavity or recess 56, the cavity or recess may act as a
`mold permitting transparent material from which the tran-
`sition area 57 is made to be cast around one or more light
`sources 3.
`
`FIGS. 10 and 11 schematically show another form of light
`emitting panel assembly 60 in accordance with this inven-
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`tion including a panel member 61 having one or more light
`output areas 62. In this particular embodiment, an off-axis
`light transition area 63 is provided that is thicker in cross
`section than the panel member to permit use of one or more
`light sources 3 embedded or otherwise mounted in the light
`transition area that are dimensionally thicker than the panel
`member. Also, a three-dimensional reflective surface 64
`(FIG. 11) may be provided on the transition area 63. More-
`over, a prism 65 (FIG. 11) or tapered, rounded, or otherwise
`shaped end 66 (FIG. 11a) may be provided at the end of the
`panel opposite the light sources 3 to perform the function of
`an end reflector. The light sources 3 may be oriented at
`different angles relative to each other and offset to facilitate
`better mixing of the light rays 67 in the transition area 63 as
`schematically shown in FIG. 10 and/or to permit a shorter
`length transition area 63 to be used.
`FIGS. 12 and 13 schematically show still another form of
`light emitting panel assembly 70 in accordance with this
`invention which includes one or more light transition areas
`71 at one or both ends of the panel member 72 each
`containing a single light source 73. The transition area or
`areas 71 shown in FIGS. 12 and 13 collect
`light with
`multiple or three-dimensional surfaces and/or collect light in
`more than one plane. For example each transition area 71
`shown in FIGS. 12 and 13 has elliptical and parabolic shape
`surfaces 74 and 75 in different planes for directing the light
`rays 76 into the panel member at a desired angle.
`Providing one or more transition areas at one or both ends
`of the panel member of any desired dimension to accom-
`modate one or more light sources, with reflective and/or
`refractive surfaces on the transition areas for redirecting the
`light rays into the panel member at relatively low angles
`allows the light emitting panel member to be made much
`longer