VWGoA - Ex. 1001
`Volkswagen Group of America, Inc., Petitioner
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`1
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`US 6,886,956 132
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`Page 2
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`U.S. PATENT DOCUMENTS
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`3328570 A
`i’fié‘i’gé‘s‘ 2
`7
`7
`3,752,974 A
`3,761,703 A
`3,892,959 A
`3,958,113 A
`4,043,636 A
`4,118,111 A
`4,177,501 A
`4,183,628 A
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`
`*
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`t
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`US 6,886,956 B2
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`1
`LIGHT EMITTING PANEL ASSEMBLIES
`FOR USE IN AUTOMOTIVE APPLICATIONS
`AND THE LIKE
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is a continuation of Application Ser. No.
`10/005,090, filed Dec. 5, 2001 now US. Pat. No. 6,508,563
`B2, which is a continuation of application Ser. No. 09/703,
`088, filed Oct. 31, 2000, now US. Pat. No. 6,367,940, dated
`Apr. 9, 2002, which is a continuation of application Ser. No.
`09/167,949, filed Oct. 7, 1998, now US. Pat. No. 6,158,867,
`dated Dec. 12, 2000, which is a division of application Ser.
`No. 08/585,062, filed Jan. 16, 1996, now US. Pat. No.
`5,895,115, dated Apr. 20, 1999.
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`FIELD OF THE INVENTION
`
`This invention relates generally as indicated to light
`emitting panel assemblies especially for automotive appli-
`cations.
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`BACKGROUND OF THE INVENTION
`
`Light emitting panel assemblies are generally known. The
`present invention relates to certain improvements in light
`emitting panel assemblies especially for automotive appli-
`cations. Also,
`this invention is concerned with passing/
`shining light directly through a light emitting panel member
`or through holes in the panel member for performing speci-
`fied lighting functions, for example, providing brake or turn
`signal lights and/or turning or backup illumination for a
`vehicle.
`
`SUMMARY OF THE INVENTION
`
`In accordance with one aspect of the invention, the light
`emitting panel assemblies of the present
`invention may
`include a light emitting panel member made out of a suitable
`transparent resiliently deformable elastomeric material that
`absorbs impact without breakage. Such panel members are
`especially suitable for use both in interior automotive light-
`ing applications to reduce the possibility of serious injury to
`a driver or passenger of a vehicle when thrown into contact
`with the panel member during a traffic accident, and in
`exterior automotive lighting applications to help eliminate
`damage to the panel member if impacted during a traffic
`accident.
`
`Examples where such a resiliently deformable light emit-
`ting panel member may be effectively used in interior
`automotive lighting applications to reduce injury during
`accidents are steering wheel and dash lighting applications
`for lighting controls, switches, instrument panels, headliner
`lighting, logos and/or accent lighting.
`In steering wheel applications, a resiliently deformable
`light emitting panel member may be mounted in the hub
`portion of the steering wheel outwardly of an air bag for
`lighting controls and/or switches or logos on the steering
`wheel hub and for accent lighting.
`When used on a dash or other flush mount applications
`such as instrument panels and headliner lighting, a resil-
`iently deformable panel member will absorb impact/shock,
`and may be contoured to match the shape of the dash or other
`surface.
`
`Examples where such a resiliently deformable panel
`member may be effectively used in exterior automotive
`lighting applications to reduce or eliminate damage to the
`panel member during accidents are running or accent lights
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`in the bumper or other exterior body portions of a vehicle.
`The light emitting panel member may also be incorporated
`into a trunk lid of a vehicle to provide running lights and/or
`license plate or logo illumination in the trunk lid. In appli-
`cations where the trunk lid is recessed, the panel member
`may be rigid. However, if the trunk lid is substantially flush
`with the body exterior,
`the panel member is desirably
`resiliently deformable to withstand impacts during accidents
`without breakage of the panel member.
`In accordance with another aspect of the invention, one or
`more light sources may be mounted within one or more light
`transition areas or regions adjacent one or more light input
`surfaces of a light emitting panel member.
`In accordance with another aspect of the invention, one or
`more light sources may be positioned adjacent one side of
`the panel member for causing light to shine through the
`panel member or through holes in the panel member for
`performing specified lighting functions, for example, pro-
`viding brake or turn signal lights and/or turning or backup
`illumination for a vehicle.
`
`In accordance with another aspect of the invention, one or
`more light sources may be selectively positioned along an
`edge or side of the panel member for increasing the light
`output from selected light output areas/regions on one or
`both sides of the panel member.
`In accordance with another aspect of the invention, a
`resiliently deformable light emitting panel member may be
`used to backlight a liquid crystal display (LCD) and/or
`multiple control switches or key pads of a radio or other
`electrical device. Such a panel member upon being engaged
`by a control button/key pad will be deformed into electrical
`contact with a switch or other circuitry such as a printed
`circuit
`inwardly of the panel member for performing a
`selected switching function.
`In accordance with another aspect of the invention, a rigid
`light emitting panel member may be used to backlight an
`LCD and/or multiple control buttons/key pads of a radio or
`other electrical device by providing holes or openings
`through the panel member for movement of a portion of the
`control buttons/key pads into and out of electrical contact
`with a printed circuit inwardly of the panel member. Surface
`irregularities such as print patterns or molded in shapes may
`be provided on the panel surfaces around the holes/openings
`to flood the areas around the buttons/key pads with light.
`In accordance with another aspect of the invention, a rigid
`light emitting panel member may be used with dome and
`other such switches for switch area lighting. One or more
`such rigid light emitting panel members each with its own
`separate light source and transition region may support a
`series of push buttons that float on the panel members to
`permit the push buttons to be moved into contact with the
`dome switches.
`
`In accordance with another aspect of the invention, two or
`more stacked light emitting panel members may be used to
`light an instrument panel or the like. One of the panel
`members may be used to provide general backlighting for
`graphic displays on the instrument panel, whereas an other
`panel member may be used to light dial pointers or other
`elements on the instrument panel. Common or separate light
`sources may be used to supply light to input surfaces of two
`or more panel members. Also, separate indicator lights may
`be provided behind the panel members for providing
`through illumination to indicators on the graphic displays of
`the instrument panel.
`In accordance with another aspect of the invention, a rigid
`light emitting panel member may be used as a structural
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`US 6,886,956 B2
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`3
`to provide for
`member for graphic overlays or decals,
`example lighting for designating the gear shift lever posi-
`tions of a vehicle. One or more light sources may be
`inserted/embedded within light transition regions at one or
`more locations along the length of the panel member to
`direct light into input surfaces of the panel member. Indi-
`cator lights may be provided adjacent an edge or side of the
`panel member in line with each indicator position for
`providing increased light output at the selected position.
`Also, a movable color filter may be provided between the
`panel member and label to provide a different colored light
`output at any selected gear shift position. For example, a
`movable red filter may be used to change the color of the
`light output at the selected gear shift lever position from
`white to red.
`
`In accordance with another aspect of the invention, the
`light emitting panel member may have a secondary
`reflective/refractive surface for refiecting/refracting a por-
`tion of the light entering an input surface of the panel
`member around a corner of the panel member.
`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:
`FIG. 1 is a schematic top plan view of a steering wheel of
`a vehicle incorporating one form of light emitting panel
`assembly in accordance with this invention in the hub
`portion of the steering wheel;
`FIG. 2 is a fragmentary transverse section through the
`panel assembly within the hub portion of FIG. 1 taken on the
`plane of the line 2—2 thereof;
`FIG. 2A is an enlarged plan view of a portion of a light
`output surface area of a panel assembly schematically show-
`ing a pattern of light extracting deformities on the light
`output surface area;
`FIG. 3 is a schematic end view of a rear portion of a
`vehicle incorporating other forms of light emitting panel
`assemblies in accordance with this invention;
`FIG. 4 is a fragmentary transverse section through the
`vehicle end portion and panel assemblies of FIG. 3 taken on
`the plane of the line 44 thereof;
`FIG. 5 is a schematic plan view of a radio or other
`electronic device incorporating another form of light emit-
`ting panel assembly in accordance with this invention;
`FIG. 6 is a transverse section through the assembly of
`FIG. 5 taken on the plane of the line 6—6 thereof;
`FIG. 7 is a schematic fragmentary section through a
`portion of a control panel incorporating another form of light
`emitting panel assembly in accordance with this invention;
`FIG. 7A is a fragmentary top plan view of a portion of the
`light emitting panel member of FIG. 7 showing light extract-
`ing deformities on light emitting surfaces of the panel
`member around a hole or opening in the panel member in
`alignment with a control button/key pad;
`FIG. 8 is a schematic fragmentary section through a
`contoured surface such as the dash of a vehicle showing
`other forms of light emitting panel assemblies in accordance
`with this invention interposed between a printed circuit and
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`a series of key pads either molded into the contoured surface
`or extending through openings therein;
`FIG. 9 is a schematic side elevation view of another form
`
`of light emitting panel assembly in accordance with this
`invention used for supporting and illuminating a series of
`floating push buttons above a series of dome switches;
`FIG. 10 is a transverse section through the assembly of
`FIG. 9 taken on the plane of the line 10—10 thereof;
`FIG. 11 is a top plan view of another form of light
`emitting panel assembly in accordance with this invention
`which is also used to support and illuminate a series of
`floating push buttons;
`FIG. 12 is a schematic vertical section through an instru-
`ment panel incorporating other forms of light emitting panel
`assemblies in accordance with this invention;
`FIG. 13 is a top plan view of a graphic overlay for the
`instrument panel of FIG. 12 as seen from the plane of the
`line 13—13 thereof;
`FIG. 14 is a top plan view of one light emitting panel
`assembly in accordance with this invention incorporated in
`the instrument panel of FIG. 12 as seen from the plane of the
`line 14—14 thereof;
`FIG. 15 is a top plan view of another form of light
`emitting panel assembly in accordance with this invention
`incorporated in the instrument panel of FIG. 12 as seen from
`the plane of the line 15—15 thereof;
`FIGS. 16 through 18 are schematic plan views showing
`other forms of light emitting panel assemblies in accordance
`with this invention which provide a structural support for
`graphic overlays/decals used for example to designate the
`various gear shift lever positions of an engine;
`FIG. 19 is a fragmentary transverse section through one
`such light emitting panel member used as a structural
`support; and
`FIGS. 20 through 22 are schematic illustrations showing
`light emitting panel assemblies in accordance with this
`invention used to provide lighting for vanity mirrors and the
`like.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`Referring now in detail to the drawings, and initially to
`FIGS. 1 and 2, there is schematically shown one form of
`light emitting panel assembly 1 in accordance with this
`invention mounted in the hub portion 2 of a steering wheel
`3 of a vehicle outwardly of an air bag 4 to provide back-
`lighting for control switches/buttons 5, the horn, logos, or
`other accent lighting on the steering wheel.
`The light emitting panel assembly 1 includes a transparent
`light emitting panel member 8 having one or more light
`sources 9 mounted within one or more light transition areas
`or regions 10 at one or both ends of the panel member
`mounted within the air bag/steering wheel covering 11
`outwardly of the air bag 4. In FIGS. 1 and 2, two such light
`transition areas or regions 10 and light sources 9 are shown
`at one end of one or two panel members 8 for selectively
`lighting one or two rows of control buttons 5. The light that
`enters the transparent light emitting panel members 8 from
`the light transition region(s) 10 may be emitted along the
`entire length of the panel members or from one or more light
`output surface areas along their length as desired to produce
`a desired light output distribution to fit a particular applica-
`tion.
`
`The light sources 9 may be mechanically held in any
`suitable manner in slots, cavities or openings machined,
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`US 6,886,956 B2
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`5
`molded or otherwise formed in the light transition regions of
`the panel assemblies. However, the light sources may be
`embedded, potted or bonded in the light transition regions in
`order to eliminate any air gaps or air interface surfaces
`between the light sources and surrounding light transition
`regions, thereby reducing light loss and increasing the light
`output emitted by the light emitting panels. Bonding may be
`accomplished using a suitable embedding, potting or bond-
`ing material or by a variety of methods that do not incor-
`porate 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 sources.
`The light sources may be of any suitable type including,
`for example, any of the types disclosed in US. 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 may be non-linear such as an arc lamp, an incan-
`descent bulb which also may be colored, filtered or painted,
`a lens end bulb, a halogen lamp, a light emitting diode
`(LED), a chip from an LED, a neon bulb, a fiber optic light
`pipe transmitting light from a remote light source, a laser or
`laser diode, or linear such as a line light or fluorescent tube,
`or any other suitable light source. Also, the light sources 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
`color or shade light output distribution by varying the
`intensities of each individual colored light. A label/overlay
`with different color light emitting regions can be used in
`conjunction with a panel assembly having a plurality of
`colored light sources for specific indication based on color
`or the frequency of light emitted by the different
`light
`emitting regions.
`Apattern of light extracting deformities or disruptions 12
`(see FIG. 2A) may be provided on one or both sides 13, 14
`of the panel members along the entire length thereof or at
`one or more selected areas of the panel members as desired.
`The terms deformities or disruptions are used interchange-
`ably herein 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. Apattern of light
`extracting deformities may include 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
`members through the side or sides on which the light
`extraction deformities are provided or reflected back through
`the panel members and emitted out the other side.
`Such deformities or disruptions 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 painted pattern, a hot stamped pattern, or a molded
`pattern or the like at selected light output areas on the
`surfaces of the panel members. An ink or adhesive pattern or
`printed pattern may be applied for example by pad printing,
`silk screening, ink jet, photolithography, 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
`sides of the panel members. This sheet or film may become
`a permanent part of the light panel assemblies for example
`by attaching or otherwise positioning the sheet or film
`against one or both sides of the panel members in order to
`produce a desired effect.
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`translucence,
`By varying the density, opaqueness or
`shape, depth, color, area, index of refraction, or type of
`deformities on an area or areas of the panel members, the
`light output of the panel members can be controlled. The
`deformities or disruptions may be used to control the percent
`of light emitted from any surface area of the panel members.
`For example, less and/or smaller size deformities may be
`placed on panel surface areas where less light output is
`wanted. Conversely, a greater percentage of and/or larger
`deformities may be placed on surface areas of the panels
`where greater light output is desired.
`Varying the percentages and/or size of deformities in
`different surface areas of the panels 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 may be used to adjust for the
`light variances within the panel members, for example, by
`providing a denser concentration of light extracting defor-
`mities with increased distance from the light source thereby
`resulting in a more uniform light output distribution from the
`light emitting panels.
`The deformities 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 cause the light rays
`to be emitted 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 may be printed on the light output
`surface areas utilizing a wide spectrum of paints,
`inks,
`coatings, epoxies, adhesives, or the like, ranging from glossy
`to opaque or both, and may employ half-tone separation
`techniques to vary the deformity coverage. If an adhesive is
`used to provide a pattern of light extracting deformities, the
`adhesive may also be used to secure a back reflector to the
`panel member. Moreover,
`the pattern of light extracting
`deformities may be multiple layers or vary in index of
`refraction.
`
`Print patterns of light extracting deformities 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 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 surface
`areas.
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`US 6,886,956 B2
`
`7
`in lieu of these light extracting
`In addition to or
`deformities, 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 surface areas of the panel
`members. The prismatic surfaces, depressions or raised
`surfaces will cause a portion of the light rays contacted
`thereby to be emitted from the panel members. 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.
`
`A back reflector or reflective coating (including trans
`reflectors) 15 (see FIG. 2) may be applied to a bottom side
`of the panel members using a suitable adhesive or other
`method in order to improve light output efficiency of the
`panel assemblies by reflecting the light emitted from that
`side back through the panel members for emission through
`the opposite side. If adhesive is used to adhere the back
`reflector to the panel members, the adhesive is desirably
`applied only along the side edges of the panel members so
`that there is a slight air gap between the back reflector and
`panel members except where there is adhesive, since the
`adhesive changes the internal critical angle of the light in a
`less controllable manner than the air gap between the panel
`surface and back reflector.
`
`Additionally, a pattern of light extracting deformities may
`be provided on one or both sides of the panel members 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 members. Where the
`deformities are created by a print pattern, the back reflector
`can be the same color as the print pattern so that print pattern
`is not visible through the back reflector. Moreover, a trans-
`parent film, sheet or plate may be attached or positioned
`against the side or sides of the panel members from which
`light is emitted using a suitable adhesive or other method in
`order to produce a desired effect.
`The transparent film may be used to further improve the
`uniformity of the light output distribution or change the
`output ray angle distribution. For example, the film 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. Also the film may be
`a prismatic or lenticular lens or other device that changes the
`output ray angle distribution.
`In FIG. 1 the light transition regions or areas 10 are shown
`as an integral extension of one end of the light emitting panel
`members 8 and as having curved edges 16 to more efficiently
`reflect and/or refract and focus the light emitted from the
`light sources that impinges on the curved edges 16 back
`through the light transition regions at an acceptable angle for
`entering the light input surface of the light emitting panel
`members. Also, a suitable reflective material or coating 17
`may be provided on any portions of the edges of the light
`transition regions of the panel members on which any
`portion of the light impinges for maximizing the amount of
`light or otherwise changing the light that is reflected back
`through the light transition regions and into the light emit-
`ting panel members.
`A suitable pattern of light extracting deformities or dis-
`ruptions 12 may be provided on selected areas on one or
`both sides of the panel members 8 corresponding to the
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`8
`location of the control buttons 5 on the air bag covering 11
`above the panel members. In the example shown, the pattern
`of light extracting deformities or depressions is provided on
`the bottom side 14 of the panel member 3 (i.e., the side
`facing away from the control buttons), and a reflective film
`or coating 15 is provided on that side to reflect the light
`emitted from that side back through the panel members.
`Preferably the light emitting panel members 8 are made of
`a transparent resiliently deformable material such as a
`thermoplastic elastomer or silicone rubber which allows
`areas of the panel members in line with the control buttons
`to be flexed into engagement with a printed circuit 19
`located beneath the panel members when the respective
`control buttons are depressed to complete an associated
`control circuit. Also if the air bag 4 should ever be deployed
`or if the driver’s head should be forced into engagement with
`the hub portion 2 of the steering wheel 3 during a traffic
`accident, the resiliently deformable panel members 8 will
`absorb shock, thus greatly reducing the possibility of serious
`injury to the driver because of such contact.
`The printed circuit 19 may be made of a suitable ther-
`moplastic elastomer, silicone rubber or flexible film or
`laminated circuit or membrane or dome switch to absorb
`
`shock, thus further reducing the possibility of serious injury
`to the driver should the driver’s head impact against the hub
`portion of the steering wheel or should the steering wheel air
`bag be deployed and force the panel members and circuit
`outwardly into contact with the driver.
`Light emitting panel assemblies similar to that shown in
`FIGS. 1 and 2 may also be advantageously employed in
`other automotive applications as well such as the dash,
`instrument panel, headliner, and exterior lighting. FIGS. 3
`and 4 show several automotive exterior lighting applications
`including one in which a light emitting panel assembly 21 is
`mounted in a back end or bumper 22 of a vehicle 23 to
`provide running lights in the back end/bumper, another in
`which light emitting panel assemblies 24 are mounted in
`body panels 25 along the rear, front and/or sides of a vehicle
`to provide running lights or accent lights or to light a logo,
`step, running board, or other surface area of a vehicle; and
`still another in which a light emitting panel assembly 26 is
`mounted in a vehicle trunk lid 27 for providing a running
`light or illumination for a logo, accent light or license plate
`mounted on the trunk lid. In each case the respective light
`emitting panel members 28, 29 and 30 are shaped to fit the
`particular application and may be made of a transparent
`resiliently deformable material such as a thermoplastic elas-
`tomer or silicone rubber that will flex upon impact during
`minor traffic accidents without breakage.
`The number and location of light sources 9 and associated
`light transition regions 10 for a given light emitting panel
`member may vary for a given application depending on the
`overall size and shape of each panel member and desired
`amount of light output therefrom. For example, the back
`end/bumper running light application shown in FIGS. 3 and
`4 may only require one light source 9 and associated light
`transition region 10 at each end of the panel member 28,
`whereas the body panel and trunk lid running light applica-
`tions shown in FIGS. 3 and 4 may require a plurality of
`closely spaced light sources 9 and associated light transition
`regions 10 along one or more light input surfaces of the
`panel members. FIGS. 3 and 4 show several such light
`sources and associated light transition regions along the
`back edges of the panel members 29 used to provide running
`taillights for a vehicle and along a top edge of the panel
`member 30 used to provide illumination on a trunk lid.
`
`11
`
`11
`
`

`

`US 6,886,956 B2
`
`9
`Mounting all of the light sources for the tail running lights
`along the back edges of the panel members 29 (i.e., the edges
`closest to the trunk lid) minimizes the risk that the light
`sources themselves will be damaged in the event the tail
`running lights are impacted during minor traffic accidents
`and the like. These panel members may have a relatively
`thin, low profile, for example, less than one quarter inch
`thick, so as not to take up much space. Also, these panel
`members 29 may form the exterior surface of the body panel
`25 as shown at the left hand side of FIG. 4 or a lens or film
`34 may cover the panel members as shown at the right hand
`side of FIG. 4.
`
`In the usual case the light sources are embedded, potted
`or bonded in the