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`US 6,712,481 B2
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`US. PATENT DOCUMENTS
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`5,467,417 A
`
`11/1995 Nakamura et al.
`
`1/1996 Qiao et al. .................. .. 362/26
`5,485,291 A *
`1/1997 8'
`5,590,945 A
`4/1997 Klfsllllrilrsna et al.
`5 618 095 A
`9/1997 Redmond etal.
`5,664,862 A *
`9/1997 Taletal‘
`5571994 A *
`............... .. 362/31
`2/1998 Shone et al.
`5,719,649 A
`7/1998 Yoshlkawa et al.
`..
`362/31
`5,775,791 A *
`7/1998 Saito etal.
`........ ..
`362/31
`5,779,337 A *
`7/1998 Ishikawa et al.
`..
`362/31
`5,779,338 A *
`5,961,198 A * 10/1999 Hira etal.
`......... ..
`362/31
`6,011,602 A *
`1/2000 Miyashita et al.
`362/31
`69036329 A *
`3/2000 “"1"” """""""" " 362/31
`6,130,730 A
`10/2000 Jannson et 211.
`
`
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`............. 362/31
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`* cited by examiner
`
`1
`t
`.
`6/1991 S h
`5 027 258 A
`C Omgef 6 a-
`>
`>
`12/1991 Kitazawa et al.
`5,070,431 A
`$333 al"
`gaggiagig i
`8/1992 Schonigeretal.
`5,136,483 A
`5/1993 Murase et al.
`5 207 493 A
`11/1993 Kashima et al
`5’262’928 A
`2/1994 Mumse etal.‘
`5285673 A
`8/1994 Rudisfll et al
`5’339’179 A
`9/1994 Blonderetali
`5349303 A
`12/1994 Tokunaga
`5’375’043 A
`............ .. 362/339
`5377084 A * 12/1994 Kojima etal.
`5,390,085 A
`2/1995 Mari_R0Ca et al.
`5,394,308 A
`2/1995 Watanabe et 211.
`5,467,208 A
`11/1995 Kokawa et al.
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`US 6,712,481 B2
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`1
`LIGHT EMITTING PANEL ASSEMBLIES
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`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is a continuation-in-part of U.S. patent
`application Ser. No. 08/778,089, filed Jan. 2, 1999, now U.S.
`Pat. No. 6,079,838 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.
`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 more efficient utilization of light to suit a particular
`application.
`
`SUMMARY OF THE INVENTION
`
`In accordance with one aspect of the invention, the light
`emitting panel assemblies include a light emitting panel
`member having a pattern of individual
`light extracting
`deformities of well defined shapes on or in one or more
`surface areas of the light emitting panel member.
`In accordance with another aspect of the invention, each
`of the light extracting deformities includes a reflective or
`refractive surface of a predetermined slope for more pre-
`cisely controlling the emission of light by each of said
`deformities.
`
`In accordance with another aspect of the invention, each
`of the light extracting deformities has an end wall that
`produces a relatively small projected surface area on the
`panel surface area to allow the number of deformities on or
`in the panel surface areas to be increased.
`In accordance with another aspect of the invention, the
`light extracting deformities have straight side walls.
`In accordance with another aspect of the invention, the
`light extracting deformities have rounded side walls.
`In accordance with another aspect of the invention, the
`light extracting deformities have planar surfaces in parallel
`spaced relation to the panel surface areas.
`In accordance with another aspect of the invention, the
`panel member is transparent and includes one or more panel
`portions having opposite sides that are free of any reflective
`material, whereby light is free to pass through such opposite
`sides.
`
`In accordance with another aspect of the invention, defor-
`mities on or in one or more of the panel portions are shaped
`to cause more of the light entering the panel member through
`an input edge to be emitted from one of the sides of the panel
`portions than the other side.
`In accordance with another aspect of the invention, the
`one side of the panel portion through which more of the light
`is emitted may be placed in close proximity to a front face
`of a display for front lighting the display.
`In accordance with another aspect of the invention, the
`light emitting deformities have planar surfaces through
`which light from the display passes with minimal optical
`distortion.
`
`In accordance with another aspect of the invention, the
`pattern of light extracting deformities may be uniform or
`variable as desired to obtain a desired light output distribu-
`tion from the panel surface areas.
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`In accordance with another aspect of the invention, the
`size and shape as well as the depth or height and angular
`orientation and location of the light extracting deformities
`may vary along the length and/or width of any given panel
`surface area to obtain a desired light output distribution from
`the panel member.
`In accordance with yet another aspect of the invention, a
`focused light source may be insert molded or cast within a
`light transition area of the light emitting panel member.
`In accordance with still another aspect of the invention,
`molded supports may be provided on the panel member for
`supporting other parts or components in spaced relation
`from the panel member.
`In accordance with another aspect of the invention, an
`array of light sources may be mounted on a printed circuit
`board for directing light through a diffuser or lens mounted
`in spaced relation to the light sources for use in phototherapy
`treatment and the like.
`
`The various light emitting panel assemblies of the present
`invention are relatively 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. 4b, 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;
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`FIG. 11a is a fragmentary side elevation view showing a
`tapered or rounded end on the panel member in place of the
`prismatic surface shown in FIGS. 10 and 11;
`FIG. 12 is a schematic top plan view of another form of
`light emitting panel assembly in accordance with this inven-
`tion;
`FIG. 13 is a schematic side elevation view of the light
`emitting panel assembly of FIG. 12;
`FIGS. 14 and 15 are schematic perspective views of still
`other forms of light emitting panel assemblies in accordance
`with this invention;
`FIGS. 16 and 17 are enlarged schematic fragmentary plan
`views of a surface area of a light panel assembly showing
`still other forms of light extracting deformities in accordance
`with this invention formed on or in a surface of the panel
`member;
`FIGS. 18 and 19 are enlarged longitudinal sections
`through one of the light extracting deformities of FIGS. 16
`and 17, respectively;
`FIGS. 20 and 21 are enlarged schematic longitudinal
`sections through light extracting deformities similar to
`FIGS. 18 and 19, respectively, except that the deformity end
`walls are shown extending substantially perpendicular to the
`panel surface instead of perpendicular to their respective
`reflective/refractive surfaces as shown in FIGS. 18 and 19;
`FIGS. 22 through 30 are enlarged schematic perspective
`views of panel surface areas containing various patterns of
`individual light extracting deformities of other well defined
`shapes in accordance with this invention;
`FIG. 31 is an enlarged schematic longitudinal section
`through another form of light extracting deformity in accor-
`dance with this invention;
`FIGS. 32 and 33 are enlarged schematic top plan views of
`panel surface areas containing light extracting deformities
`similar in shape to those shown in FIGS. 28 and 29 arranged
`in a plurality of straight rows along the length and width of
`the panel surface area;
`FIGS. 34 and 35 are enlarged schematic top plan views of
`panel surface areas containing light extracting deformities
`also similar in shape to those shown in FIGS. 28 and 29
`arranged in staggered rows along the length of the panel
`surface areas;
`FIGS. 36 and 37 are enlarged schematic top plan views of
`panel surface areas containing a random or variable pattern
`of different sized light emitting deformities on the panel
`surface areas;
`FIG. 38 is an enlarged schematic perspective view of a
`panel surface area showing light extracting deformities in
`accordance with this invention increasing in size as the
`distance of the deformities from the light source increases or
`intensity of the light increases along the length of the panel
`surface area;
`FIGS. 39 and 40 are schematic perspective views showing
`different angular orientations of the light extracting defor-
`mities along the length and width of a panel surface area;
`FIGS. 41 and 42 are enlarged perspective views sche-
`matically showing how exemplary light rays emitted from a
`focused light source are reflected or refracted by different
`individual light extracting deformities of well defined shapes
`in accordance with this invention;
`FIG. 43 is a schematic perspective view showing a light
`emitting panel assembly similar to FIG. 42 placed on a front
`face of a display to provide front lighting for the display;
`FIG. 44 is a schematic top plan view of another form of
`light emitting panel assembly in accordance with this inven-
`tion for use in phototherapy treatment and the like; and
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`FIGS. 45 through 47 are schematic side elevation views
`of still other forms of light emitting panel assemblies in
`accordance with this invention for use in phototherapy
`treatment and the like.
`
`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
`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
`embedding, potting, bonding or otherwise mounting the
`light source. Also, reflective or refractive surfaces may be
`provided to increase efficiency. Moreover, the light transi-
`tion 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 refiect 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 refiect 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 refiect 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.
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`5
`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
`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).
`Atransparent 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
`fiat, 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
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`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. 4a includes a
`variable pattern which breaks up the light rays such that the
`internal angle of reflection of a portion of the light rays will
`be great enough to cause the light rays either to be emitted
`out of the 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
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`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
`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 back light, 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
`
`LG E_000489
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`LGE_000489
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`US 6,712,481 B2
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`7
`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. 4a, other light extracting
`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
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`10
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`15
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`20
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`25
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`30
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`35
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`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
`reflector as well as end edge and/or side edge refiectors for
`the panel 33 and side and/or back refiectors 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 refiect 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 fiat, 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
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`LG E_000490
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`LGE_000490
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`US 6,712,481 B2
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`9
`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