ATTORNEY DOCKET GLOLP0108USAL
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`TITLE:
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`LIGHT EMITTING PANEL ASSEMBLIES
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`5
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`CROSS-REFERENCE TO RELATED APPLICATIONS
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`This application is a division of U.S. Patent Application No.1 0/784,527,
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`filed February 23, 2004, which is a division of U.S. Patent Application No.
`09/256,275, filed February 23, 1999, now U.S. Patent No. 6,712,481, dated
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`10 March 30, 2004, which is a continuation-in-part of U.S. Patent Application No.
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`08/778,089, filed January 2, 1997, now U.S. Patent No. 6,079,838, dated June
`27, 2000, which is a division of U.S. Patent Application No. 08/495,176, filed June
`27, 1995, now U.S. Patent No. 5,613,751, dated March 25, 1997.
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`BACKGROUND OF THE INVENTION
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`This invention relates generally, as indicated, to light emitting panel
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`assemblies each including a transparent panel member for efficiently conducting
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`light, and controlling the light conducted by the panel member to be emitted from
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`one or more light output areas along the length thereof.
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`Light emitting panel assemblies are generally known. However, the
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`present invention relates to several different light emitting panel assembly
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`configurations which provide for better control of the light output from the panel
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`assemblies and for more efficient utilization of light, which results in greater light
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`output from the panel assemblies.
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`SUMMARY OF THE INVENTION
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`In accordance with one aspect of the invention, the light emitting panel
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`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
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`light input surface of the panel member.
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`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 andlor 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.
`1
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`LGD_000013
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`LG Display Ex. 1002
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`In accordance with another aspect of the invention, the panel assemblies
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`may include reflective or refractive surfaces for changing the path of a portion of
`the light, emitted from the light source, that would not normally enter the panel
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`members at an acceptable angle that allows the light to remain in the panel
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`5 members for a longer period of time and/or increase the efficiency of the panel
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`members.
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`In accordance with another aspect of the invention, the light emitting panel
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`members include a pattern of light extracting deformities or disruptions which
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`provide a desired light output distribution from the panel members by changing
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`the angle of refraction of a portion of the light from one or more light output areas
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`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.
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`In accordance with yet another aspect of the invention, the panel
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`assemblies include a transition area for mixing the multiple colored lights, prior to
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`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
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`very efficient panel assemblies that may be used to produce increased uniformity
`and higher light output from the panel members with lower power requirements,
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`and allow the panel members to be made thinner and/or longer, and/or of various
`shapes and sizes.
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`To the accomplishment of the foregoing and related ends, the invention
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`then comprises the features hereinafter fully described and particularly pointed
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`out in the claims, the following description and the annexed drawings setting forth
`in detail certain illustrative embodiments of the invention, these being indicative,
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`however, of but several of the various ways in which the principles of the
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`invention may be employed.
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`2
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`LGD_000014
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`In the annexed drawings:
`Figs. 1 through 3 are schematic perspective views of three different forms
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`of light emitting panel assemblies in accordance with this invention;
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`Fig. 4a is an enlarged plan view of a portion of a light output area of a
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`panel assembly showing one form of pattern of light extracting deformities on the
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`light output area;
`Figs. 4b, c and d are enlarged schematic perspective views of a portion of
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`a light output area of a panel assembly showing other forms of light extracting
`deformities formed in or on the light output area;
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`Fig. 5 is an enlarged transverse section through the light emitting panel
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`assembly of Fig. 3 taken generally on the plane of the line 5-5 thereof;
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`Fig. 6 is a schematic perspective view of another form of light emitting
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`panel assembly in accordance with this invention;
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`Fig. 7 is a schematic top plan view of another form of light emitting panel
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`assembly in accordance with this invention;
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`Fig. 8 is a schematic perspective view of another form of light emitting
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`panel assembly in accordance with this invention;
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`Fig. 9 is a schematic top plan view of another form of light emitting panel
`assembly in accordance with this invention;
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`Fig. 10 is a schematic top plan view of still another form of light emitting
`panel assembly in accordance with this invention;
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`Fig. 11 is a side elevation view of the light emitting panel assembly of Fig.
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`10;
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`Fig. 11 a is a fragmentary side elevation view showing a tapered or
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`rounded end on the panel member in place of the prismatic surface shown in
`Figs. 10 and 11;
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`Fig. 12 is a schematic top plan view of another form of light emitting panel
`assembly in accordance with this invention;
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`Fig. 13 is a schematic side elevation view of the light emitting panel
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`assembly of Fig. 12; and
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`Figs. 14 and 15 are schematic perspective views of still other forms of light
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`emitting panel assemblies in accordance with this invention.
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`LGD_000015
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`DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
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`Referring now in detail to the drawings, and initially to Fig. 1, there is
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`schematically shown one form of light emitting panel assembly 1 in accordance
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`with this invention including a transparent light emitting panel 2 and one or more
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`light sources 3 which emit light in a predetermined pattern in a light transition
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`member or area 4 used to make the transition from the light source 3 to the light
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`emitting panel 2, as well known in the art. The light that is transmitted by the light
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`transition area 4 to the transparent light emitting panel 2 may be emitted along
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`the entire length of the panel or from one or more light output areas along the
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`length of the panel as desired to produce a desired light output distribution to fit a
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`particular application.
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`In Fig. 1 the light transition area 4 is shown as an integral extension of one
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`end of the light emitting panel 2 and as being generally rectangular in shape.
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`However, the light transition area may be of other shapes suitable for embedding.
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`potting. bonding or otherwise mounting the light source. Also, reflective or
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`refractive surfaces may be provided to increase efficiency. Moreover, the light
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`transition area 4 may be a separate piece suitably attached to the light input
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`surface 13 of the panel member if desired. Also, the sides of the light transition
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`area may be curved to more efficiently reflect or refract a portion of the light
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`emitted from the light source through the light emitting panel at an acceptable
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`angle.
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`Fig. 2 shows another form of light emitting panel assembly 5 in
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`accordance with this invention including a panel light transition area 6 at one end
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`of the light emitting panel 7 with sides 8, 9 around and behind the light source 3
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`shaped to more efficiently reflect and/or refract and focus the light emitted from
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`the light source 3 that impinges on these surfaces back through the light
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`transition area 6 at an acceptable angle for entering the light input surface 18 at
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`one end of the light emitting panel 7. Also, a suitable reflective material or
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`coating 10 may be provided on the portions of the sides of the light transition
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`areas of the panel assemblies of Figs. 1 and 2 on which a portion of the light
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`impinges for maximizing the amount of light or otherwise changing the light that is
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`reflected back through the light transition areas and into the light emitting panels.
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`4
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`LGD_000016
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`The panel assemblies shown in Figs. 1 and 2 include a single light source
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`3, whereas Fig. 3 shows another light emitting panel assembly 11 in accordance
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`with this invention including two light sources 3. Of course, it will be appreciated
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`that the panel assemblies of the present invention may be provided with any
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`number of light sources as desired, depending on the particular application.
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`The panel assembly 11 of Fig. 3 includes a light transition area 12 at one
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`end of the light emitting panel 14 having reflective and/or refractive surfaces 15
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`around and behind each light source 3. These surfaces 15 may be appropriately
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`shaped including for example curved, straight and/or faceted surfaces, and if
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`desired, suitable reflective materials or coatings may be provided on portions of
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`these surfaces to more efficiently reflect and/or refract and focus a portion of the
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`light emitted for example from an incandescent light source which emits light in a
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`360 0 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
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`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
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`any air gaps or air interface surfaces between the light sources and surrounding
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`light transition areas, thereby reducing light loss and increasing the light output
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`emitted by the light emitting panels. Such mounting of the light sources may be
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`accomplished, for example, by bonding the light sources 3 in the slots, cavities or
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`openings 16 in the light transition areas using a sufficient quantity of a suitable
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`embedding, potting or bonding material 17. The slots, cavities or openings 16
`25 may be on the top, bottom, sides or back of the light transition areas. Bonding
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`can also be accomplished by a variety of methods that do not incorporate extra
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`material, for example, thermal bonding, heat staking, ultrasonic or plastic welding
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`or the like. Other methods of bonding include insert molding and casting around
`the light source(s).
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`A transparent light emitting material of any suitable type, for example
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`acrylic or polycarbonate, may be used for the light emitting panels. Also, the
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`panels may be substantially flat, or curved, may be a single layer or multi-layers,
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`and may have different thicknesses and shapes. Moreover, the panels may be
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`LGD_000017
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`flexible, or rigid, and may be made out of a variety of compounds. Further, the
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`panels may be hollow, filled with liquid, air, or be solid, and may have holes or
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`ridges in the panels.
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`Each light source 3 may also be of any suitable type including, for
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`example, any of the types disclosed in U.S. Patent Nos. 4,897,771 and
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`5,005,108, assigned to the same assignee as the present application, the entire
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`disclosures of which are incorporated herein by reference. In particular, the light
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`sources 3 may be an arc lamp, an incandescent bulb which also may be colored,
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`filtered or painted, a lens end bulb, a line light, a halogen lamp, a light emitting
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`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
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`suitable light source. Additionally, the light sources 3 may be a multiple colored
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`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
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`colored lights such as LEOs of different colors (red, blue, green) or a single LED
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`with multiple colored chips may be employed to create white light or any other
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`colored light output distribution by varying the intensities of each individual
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`colored light.
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`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
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`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
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`disruptions 21 is provided. As used herein, the term deformities or disruptions
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`are used interchangeably to mean any change in the shape or geometry of the
`panel surface and/or coating or surface treatment that causes a portion of the
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`light to be emitted. The pattern of light extracting 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
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`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
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`panel and emitted out the other side.
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`These deformities or disruptions 21 can be produced in a variety of
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`manners, for example, by providing a painted pattern. an etched pattern, a
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`LGD_000018
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`machined pattern, a printed pattern, a hot stamped pattern, or a molded pattern
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`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
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`transfer film process or the like. The deformities may also be printed on a sheet
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`or film which is used to apply the deformities to the panel member. This sheet or
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`film may become a permanent part of the light panel assembly for example by
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`attaching or otherwise positioning the sheet or film against one or both sides of
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`the panel member similar to the sheet or film 27 shown in Figs. 3 and 5 in order
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`to produce a desired effect.
`By varying the density, opaqueness or translucence, shape, depth, color,
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`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
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`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
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`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
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`where greater light output is desired.
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`Varying the percentages and/or size of deformities in different areas of the
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`panel is necessary in order to provide a uniform light output distribution. For
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`20
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`example, the amount of light traveling through the panels will ordinarily be greater
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`in areas closer to the light source than in other areas further removed from the
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`light source. A pattern of light extracting deformities 21 may be used to adjust for
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`the light variances within the panel members, for example, by providing a denser
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`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
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`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.
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`30
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`7
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`LGD_000019
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`

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`Additionally, the pattern of light extracting deformities may be used to
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`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
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`light output areas utilizing a wide spectrum of paints, inks, coatings, epoxies, or
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`5
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`the like, ranging from glossy to opaque or both, and may employ half-tone
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`separation techniques to vary the deformity 21 coverage. Moreover, the pattern
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`of light extracting deformities 21 may be multiple layers or vary in index of
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`refraction.
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`Print patterns of light extracting deformities 21 may vary in shapes such as
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`dots, squares, diamonds, ellipses, stars, random shapes, and the like, and are
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`desirably .006 square inch per deformity/element or less. Also, print patterns that
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`are 60 lines per inch or finer are desirably employed, thus making the deformities
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`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
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`common to light extracting patterns utilizing larger elements. Additionally, the
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`deformities may vary in shape and/or size along the length and/or width of the
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`panel members. Also, a random placement pattern of the deformities may be
`utilized throughout the length and/or width of the panel members. The
`deformities may have shapes or a pattern with no specific angles to reduce moire
`or other interference effects. Examples of methods to create these random
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`patterns are printing a pattern of shapes using stochastic print pattern
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`techniques, frequency modulated half tone patterns, or random dot half tones.
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`Moreover, the deformities may be colored in order to effect color correction in the
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`panel members. The color of the deformities may also vary throughout the panel
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`25 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
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`shown in Fig. 4a, other light extracting deformities including prismatic surfaces,
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`depressions or raised surfaces of various shapes using more complex shapes in
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`a mold pattern may be molded, etched, stamped, thermoformed, hot stamped or
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`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
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`LGD_000020
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`surfaces 25 formed on the exterior of the panel area. The prismatic surfaces,
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`depressions or raised surfaces will cause a portion of the light rays contacted
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`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
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`5
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`directions to produce a desired light output distribution or effect. Moreover, the
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`reflective or refractive surfaces may have shapes or a pattern with no specific
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`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
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`the panel member 14 of Fig. 3 using a suitable adhesive 28 or other method in
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`order to improve light output efficiency of the panel assembly 11 by reflecting the
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`light emitted from that side back through the panel for emission through the
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`opposite side. Additionally, a pattern of light extracting deformities 21, 23, 24
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`and/or 25 may be provided on one or both sides of the panel member in order to
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`change the path of the light so that the internal critical angle is exceeded and a
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`portion of the light is emitted from one or both sides of the panel. Moreover, a
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`transparent film, sheet or plate 27 may be attached or positioned against the side
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`or sides of the panel member from which light is emitted using a suitable
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`adhesive 28 or other method in order to produce a desired effect.
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`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
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`diffuser, or a label or display, a portion of which may be a transparent overlay that
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`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
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`panel, the adhesive is preferably applied only along the side edges of the panel,
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`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
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`the internal critical angle of the light in a less controllable manner than the air
`gaps 30 (see Fig. 5) which are formed between the respective panel surfaces
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`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
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`used. If adhesive were to be used over the entire surface, the pattern of
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`LGD_000021
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`deformities could be adjusted to account for the additional attenuation in the light
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`caused by the adhesive.
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`Referring further to Fig. 2, the panel assembly 5 shown therein also
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`includes molded posts 31 at one or more corners of the panel 7 (four such posts
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`5
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`being shown) which may be used to facilitate mounting of the panel assembly
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`and providing structural support for other parts or components, for example, a
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`display panel such as a liquid crystal display panel as desired.
`Fig. 6 shows another form of light emitting panel assembly 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
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`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 reflector as well as end
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`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
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`refractive surfaces 38 may be provided on the panel member 33 and/or tray 35 to
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`reflect a portion of the light around one or more corners or curves in a non(cid:173)
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`rectangular shaped panel member 33. These secondary reflective/refractive
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`surfaces 38 may be flat, angled, faceted or curved, and may be used to extract a
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`portion of the light away from the panel member in a predetermined pattern. Fig.
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`20
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`6 also shows multiple light output areas 34 on the panel member that emit light
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`from one or more light sources 3.
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`Fig. 7 is a schematic illustration of still another form of light emitting panel
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`assembly 40 in accordance with this invention including a panel member 41
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`having one or more light output areas 42 and one or more light transition areas
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`(mixing areas) 43 containing a plurality of light sources 3 at one or both ends of
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`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 LEOs (red, blue, green) in
`each transition mixing area 43 so that the light from the three LEOs can be mixed
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`to produce a desired light output color that will be emitted from the light output
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`area 42. Alternatively, each light source may be a single LED having multiple
`colored chips bonded to the lead film. Also, two colored LEOs or a single LED
`having two colored chips may be used for a particular application. By varying the
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`LGD_000022
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`intensities of the individual respective LEOs, 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
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`accordance with this invention including a light emitting panel member 46 and a
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`5
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`light source 3 in a light transition area 48 integral with one end of the panel
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`member. In this particular embodiment, the panel member 46 is three(cid:173)
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`dimensionally curved, for example, such that light rays may be emitted in a
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`manner that facilitates aesthetic design of a lighted display.
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`Fig. 9 schematically shows another form of light emitting panel assembly
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`50 in accordance with this invention, including a panel member 51 having
`multiple light output areas 52, and mounting posts and/or mounting tabs 53. This
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`particular panel assembly 50 may serve as a structural member to support other
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`parts or components as by providing holes or cavities 54, 55 in the panel member
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`51 which allow for the insertion of modular components or other parts into the
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`panel member. Moreover, a separate cavity or recess 56 may be provided in the
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`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
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`56 to redirect a portion of the light in a predetermined manner. In this way the
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`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
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`manner. A reflector 58 may be placed on the reflective or refractive surface of
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`the cavity or recess 56 or insert 57. Where the reflector 58 is placed on the
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`reflective or refractive surface of the cavity or recess 56, the cavity or recess may
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`act as a mold permitting transparent material from which the transition area 57 is
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`made to be cast around one or more light sources 3.
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`Figs. 10 and 11 schematically show another form of light emitting panel
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`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(cid:173)
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`axis light transition area 63 is provided that is thicker in cross section than the
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`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
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`11
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`LGD_000023
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`the panel member. Also, a three-dimensional reflective surface 64 (Fig. 11) may
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`be provided on the transition area 63. Moreover, a prism 65 (Fig. 11) or tapered,
`rounded, or otherwise shaped end 66 (Fig. 11 a) may be provided at the end of
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`the panel opposite the light sources 3 to perform the function of an end reflector.
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`5
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`The light sources 3 may be oriented at different angles relative to each other and
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`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.
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`Figs. 12 and 13 schematically show still another form of light emitting
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`panel assembly 70 in accordance with this invention which includes one or more
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`light transition areas 71 at one or both ends of the panel member 72 each
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`containing a Single light source 73. The transition area or areas 71 shown in
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`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
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`15
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`in Figs. 12 and 13 has elliptical and parabolic shape surfaces 74 and 75 in
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`different planes for directing the light rays 76 into the panel member at a desired
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`angle.
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`Providing one or more transition areas at one or both ends of the panel
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`member of any desired dimension to accommodate one or more light sources,
`20 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
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`panel member to be made much longer and thinner than would otherwise be
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`possible. For example the panel members of the present invention may be made
`very thin, i.e., 0.125 inch thick or less.
`Fig. 14 schematically illustrates still another form of light emitting panel
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`25
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`assembly 80 in accordance with this invention including a light emitting panel 81
`and one or more light sources 3 positioned, embedded, potted, bonded or
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`otherwise mounted in a light transition area 82 that is at an angle relative to the
`
`panel member 81 to permit more efficient use of space. An angled or curved
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`30
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`reflective or refractive surface 83 is provided at the junction of the panel member
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`81 with the transition area 82 in order to reflect/refract light from the light source 3
`
`into the body of the panel member 81 for emission of light from one or more light
`
`emitting areas 84 along the length of the panel member.
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`12
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`LGD_000024
`
`

`

`Fig. 15 schematically illustrates still another form of light emitting panel
`assembly 90 in accordance with this invention including a light transition area 91
`at one or both ends of a light emitting panel member 92 containing a slot 93 for
`
`sliding receipt of an LED or other suitable light source 3. Preferably the slot 93
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`5
`
`extends into the transition area 91 from the back edge 94, whereby the light
`
`source 3 may be slid and/or snapped in place in the slot from the back, thus
`
`allowing the transition area to be made shorter and/or thinner. The light source 3
`
`may be provided with wings, tabs or other surfaces 95 for engagement in
`
`correspondingly shaped recesses or grooves 96 or the like in the transition area
`91 for locating and, if desired, securing the light source in place. Also, the light
`
`10
`
`source 3 may be embedded, potted, bonded or otherwise secured within the slot
`93 in the light transition area 91 of the panel member 92. Light from a secondary
`
`light source 97 may be projected through the panel member 92 for indication or
`some other effect.
`
`15
`
`The various light emitting panel assemblies disclosed herein may be used
`
`for a great many different applications including for example LCD back lighting or
`
`lighting in general, decorative and display lighting, automotive lighting, dental
`
`lighting, phototherapy or other medical lighting, membrane switch lighting, and
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`sporting goods and apparel lighting or the like. Also the panel assemblies may
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`20
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`be made such that the panel members and deformities are transparent without a
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`back reflector. This allows the panel assemblies to be used for example to front
`
`light an LCD or other display such that the display is viewed through the
`
`transparent panel members.
`
`Although the invention has been shown and described with respect to
`certain preferred embodiments, it is obvious that equivalent alterations and
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`25
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`modifications will occur to others skilled in the art upon the reading and
`understanding of the specification. The present invention includes all such
`equivalent alterations and modifications, and is limited only by the scope of the
`
`claims.
`
`30
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`13
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`LGD_000025
`
`

`

`WHAT IS CLAIMED IS:
`
`1.
`
`A light emitting panel assembly comprising at least one light source,
`
`an optical panel member having at least one input edge for receiving light from a
`
`light source, the panel member having front and back sides and a greater cross
`sectional width than thickness, both the front and back sides having a pattern of
`
`5
`
`light extracting deformities that are projections or depressions on or in the sides
`
`to cause light to be emitted from the panel member in a predetermined output
`distribution, where the pattern of light extracting deformities on or in at least one
`
`of the sides varies along at least one of the length and width of the panel member
`
`10
`
`and at least some of the light extracting deformities on or in one of the sides are
`
`of a different type or shape than the light extracting deformities on or in the other
`
`side of the panel member.
`
`2.
`
`The assembly of claim 1 wherein the deformities on or in one of the
`
`15
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`sides are prismatic.
`
`3.
`The assembly of claim 1 wherein the deformities on or in one of the
`sides are lenticular.
`
`20
`
`4.
`
`The assembly of