Abstract: A pointer type indicator comprises a dial plate 30 having indexes corresponding to measured values and a pointer 10 for pointing respective indexes of the dial plate 10. Said pointer 10 includes a pointing portion 103 to be illuminated by light emitted from a pointer light source 102, and light guide means 103d, 101d, 101e, 104 for guiding a part of light emitted from the pointer light source 103 to illuminate a limited area of the dial plate 30 behind the pointing portion 103.

Abstract: A backlight apparatus includes a point light source, a linear light guide, a plane light guide, and a light shield unit. Rays of light radiated by the point light source travel through the linear light guide and the plane light guide, and are output to an illuminated object. The light shield unit shuts out a leaking fraction of rays of light that travels directly from the point light source to the plane light guide, thereby assuring uniform brightness of the output light.

Abstract: In one embodiment, the invention is directed toward an apparatus that includes a first layer and a second layer attached with one another via sets of fastening elements formed on the layers. The fastening elements may comprise hook-like elements that engage one another in an interlocking arrangement to attach the layers, or alternatively, the fastening elements may take any form envisioned by a designer. In any case, the apparatus may also form a light guide that can be illuminated with a light source to transmit light by total internal reflection (TIR).

Abstract: There is provided a pointer type instrument which can reduce a light leakage to a side of a display board, and has a pointer 6 which includes an indication member 61 brightened by illumination light introduced from a back side of a rotation center region R and made of a translucent resin material, and a cover member 62 covering its outer periphery except for the back side of the rotation center region R and made of a light shielding resin material, and is driven to be rotated through a driving unit 2; a display board 3 which is disposed behind the pointer 6, is apart from the cover member 62 with a predetermined gap part S intervening, and includes a light passing part 33 corresponding to the rotation center region R; and a light source 5 disposed behind the display board 3, for generating the illumination light, wherein a leakage light prevention part 634 for suppressing a light leakage from the gap part S is provided on the back side (back side of a pedestal part 632) of the rotation center region R except

Abstract: A backlight unit for a display device includes a light guide panel comprising a plate-shaped body, at least one light guide projection for fitting the light guide panel disposed on left side or right side of the plate-shaped body, and a plurality of patterns formed on a lower surface of the plate-shaped body to uniformly project light. Upper and lower surfaces of the light guide projection are disposed remote as much as predetermined intervals, respectively from planes extended from upper and lower surfaces of the plate-shaped body. The light guide projection further includes an inclined surface on a side adjacent to a light source to prevent the light guide projections from cracking. Also, the light guide projection has at least one rounded or chamfered corner in order to efficiently prevent light concentration.

Abstract: A composite lighting device is provided, which is inexpensive and has high uniformity in brightness, in which light emitted from an end face of a backlight having an organic EL device is used to illuminate input buttons and the like. The lighting device includes a transparent substrate having one principal plane on which a transparent electrode film, a luminescent layer, and a reflective electrode film are at least formed. In the lighting device, a liquid crystal display unit is adjacently disposed on the other principal plane, and a light-guide element is adjacent to an end face of the substrate, so that input buttons embedded into the light-guide element are illuminated.

Abstract: A panel light source device includes: a light guide plate 1; a reflecting sheet 5, provided facing a rear face of the light guide plate 1, and an end of which is bent so as to face a side face of the light guide plate 1; a wire 4 disposed at a side face of the light guide plate 1 sandwiching the reflecting sheet 5 therebetween; and a slim case, wherein the slim case is constructed of a rear face case 7 a front face of which is open, the light guide plate 1, the reflecting sheet 5 and the wire 4 being housed therein through the front face thereof; and a front face case 6 engaged with the rear face case 7, the rear face case 7 having an reflecting sheet exposing section 14 formed so that a height of a portion of a side face in the wire side is lower than the other portion to expose the reflecting sheet 5. According to the present invention, there can be provided a panel light source device easy in an assembly work thereof.

Abstract: A low cost light guide is provided for a message waiting light of a telephone. A circuit board is supported inside the telephone housing and a light emitting diode is mounted on the circuit board. A light guide directs light from the light emitting diode to a diffuser located on the outer face of the telephone housing. The light guide is comprised of a flexible reflective material.

Abstract: A display device of the present invention includes a light source 111, a light guide 113 having a light-receiving surface 113a for receiving light from the light source 111 and a light-exiting surface 113c for emitting the light, which has entered the light guide 113 through the light-receiving surface 113a, a reflection type display element 120 provided on one side of the light guide 113 that is closer to the light-exiting surface 113c, and a refractive-index-adjusted layer 131 provided between the light guide 113 and the reflection type display element 120 and having a different refractive index from that of the light guide 113.

Abstract: The invention relates to a display element capable of being mounted on a printed circuit board, having an LED and a device for illuminating a light exit area. It comprises an optical waveguide forming the illuminating device and the light exit area, which optical waveguide has a recess, which has a light coupling-in area for light from the LED and in which the LED is fixed.

Abstract: A display device and a lighting system is provided for providing lighting in exterior and interior lighting applications, such as for center high mount stop lights (CHMSL) and other automotive lighting applications. The display device uses a light guide having light couplers hingedly attached to a light source end for receiving light from at least one light source. The light guide extends from the light source end with a light emitting surface and a light guide surface opposite the light emitting surface. The light emitting surface and the light guide surface extend in a direction substantially parallel to the direction of the light received from the light source. The light guide surface has a plurality of surface sections extending at angles relative to one another. The surface sections may be angled at alternating sections to direct light towards the light emitting surface using total internal reflection.

Abstract: A light pipe includes rectangular upper and lower surfaces, an incidence side surface which is one of side surfaces between the upper and lower surfaces, and light output means formed in one of the upper and lower surfaces so that light incident on the incidence side surface exits from the other one of the upper and lower surfaces through the light output means. A radius of curvature of a corner portion formed at a point of intersection between the incidence side surface and each of side surfaces adjacent to the incidence side surface is not larger than 0.3 mm. A plane light source unit in which a linear light source is disposed on the incidence side surface of the light pipe is provided. A transmission type or reflection type, or reflection-transmission double type liquid-crystal display device which has at least such a plane light source unit and a liquid-crystal cell is provided.

Abstract: A lighting device includes a light source, a light conducting plate having an incident surface receiving light emitted from the light source, a back surface and a light-emitting surface, and a reflection member having a first portion facing the back surface, and a second portion located on a side opposite to a side of the light conducting plate on which the light source is located. The second portion is spaced apart from the light conducting plate so that light emitted from the light conducting plate is oriented toward an emission surface of the lighting device.

Abstract: Disclosed is a light guide panel for a backlight. The light guide panel comprises a plurality of groups of cells regularly or irregularly formed on at least one surface of the light guide panel, with each cell having regularly or irregularly arranged therein a plurality of micro cells.

Abstract: A clear image can be achieved by preventing dusts from collecting in grooves formed in a transparent substrate and by improving contrast as well. A film is provided in such a manner as to cover a light reflection pattern formed in the surface of the transparent substrate. The film is sealingly fixed to the transparent substrate for preventing dusts from entering the light reflection pattern (particularly the grooves) during the process of assembling the spread illuminating apparatus. Also, the surface of the transparent substrate can be protected from scratches thanks to the film fixed. The amount of interface reflection can be reduced by using resin or the like as the film material, and contrast can be improved by setting the thickness of the film to a value smaller than prescribed.

Abstract: A keyboard structure utilizing a plurality of keys which are supported and extend from a surface of a housing. A translucent plate overlies at least a portion of the housing. A partition adjacent the translucent plate forms an envelope which extends around at least the majority of the perimeter of the housing. The envelope is illuminated by a suitable source of light.

Abstract: A backlight unit for a liquid crystal display is disclosed. The unit includes a light guide plate, a reflector, a light source and a frame. The light guide plate further includes a protrusion located on the side surface of the light guide plate, and the frame further includes a first groove, a second groove and a fixing portion. The first groove is connected with the fixing portion, and the second groove is also connected with the fixing portion. The light guide plate is combined with the frame by gliding and inserting the protrusions into the fixing portion through the first and second grooves.

Abstract: A light illumination apparatus comprising a light source on a lateral side of a light-pipe, and a reflector on the backside of the light-pipe, further comprising an air layer or the like between the light-pipe and the reflector, and, in order that light coming from a light source into the light-pipe is emitted from a light emission plane, the apparatus further comprising a light scattering control layer disposed at a portion of the light-pipe and having directivity in a direction substantially normal to the light emission plane, a means for substantially removing light scattering characteristics of a predetermined region of the light scattering control layer so as to satisfy the conditions for totally internal reflection of the incident light from the light source at an interface of the light-pipe, and a means for moving the predetermined region, wherein the time average amount of emitted light is substantially equal in each of all light emission regions, and there is time when the light emissive region subst

Abstract: A sidelight type light source device increases the quantity of light in a corner portion of a light guide plate at low cost while meeting a demand for picture frame narrowing. An incident surface receives light from a stick-shaped light source. The incident surface includes a first incident surface its center a pair or second incident surfaces at the ends of the first incident surface. The second incident surfaces are formed on a corner portion in a width direction of the light guide plate. The second incident surfaces are set back from the first incident surface taken as a reference. Accordingly, a light introducing route is defined between the second incident surface and rubber blocks at the ends of a fluorescent light source. Light from the fluorescent lamp passes along the light introducing route where it is directly incident on the second incident surfaces of the light guide plate.

Abstract: A display device (10) is comprised of a display unit (14) and a high efficiency backlight assembly (28). The backlight assembly (28) is comprised of an inductively coupled electrodless fluorescent lamp (12) for providing light to the display unit (14). The display unit (14) includes a liquid crystal display (LCD) element (16) for displaying an image and a diffuser (22) for using the light generated by the backlight unit (28) to create a relatively uniform level of brightness over the entire area of the LCD element (16). The electrodless lamp (12) is preferably mounted in a reflective lamp housing (24) having a reflective lamp lining (36) designed to provide uniform illumination intensity on the LCD element (16). The electrodless lamp (12) may have a rectangular shape and a center reflector (44) mounted within the rectangular opening to further direct light toward the LCD element (16).

Abstract: A lens mounted to a light emitting diode package internally redirects light within the lens so that a majority of light is emitted from the lens approximately perpendicular to a package axis of the light emitting diode package. In one embodiment, the light emitted by the light emitting diode package is refracted by a sawtooth portion of the lens and reflected by a total internal reflection portion of the lens.

Abstract: A light guiding plate guides light from a light source to illuminate a liquid crystal cell. A reflector reflects light from the light source. A first surface and a second surface selectively transmits or reflects light. A first region is formed on the first surface at a location that is relatively near the light source. The first region includes a first inclined face and a second inclined face. The first inclined face reflects light from the light source to guide light to the reflector. The second inclined face reflects light from the light source to the second surface so that the second surface emits light. A second region is formed on the first surface at a location that is relatively far from the light source. The second region includes a third inclined face and a fourth inclined face. The third inclined face reflects light from the light source to the second surface so that the second surface emits light.

Abstract: An instrument panel includes a base on which indicators are movably mounted and a transparent cover positioned above the base. An illuminating device includes a board interposed between the base and the cover. The board defines a number of recesses in a bottom surface thereof for respectively and movably accommodating the indicators therein. The board defines a number of cavities in an end thereof for receiving illuminators, such as light emitting diodes, of different colors therein. The illuminators are connected to and controlled by a control circuit whereby the illuminators are selectively actuated to light the instrument panel with light of different colors by conducting light through the board. Scales of first unit system are formed by means of etching or other suitable manners on the board. Scales of second unit system are formed on the base. The base is provided with an additional light source.

Abstract: This specification discloses an illuminating apparatus having a light source and an optical unit disposed forwardly on the object side of the light source, the optical unit being provided with an incidence surface on which light from the light source is incident, a light emergence surface provided with a Fresnel lens, and a side reflecting surface for totally reflecting the light incident on the incidence surface toward the Fresnel lens, wherein the light totally reflected by the side reflecting surface is refracted by the Fresnel lens and efficiently irradiates the object.

Abstract: The present invention provides a light guide plate for use in the surface light source equipment of a liquid crystal display or the like, wherein the light guide plate is a molded product of an ionizing-radiation-curable resin, and its maximum thickness on the light-source-fixing part side is 1.0 mm or less.

Abstract: There is provided an FPC for mounting components with an improved workability of fitting into other components. Both a second bend (23) and a third bend (25) are provided with a copper foil(s) (15). The copper foil (15) provided at each bend functions as a core material to be plastically transformed when the respective bends (23, 25) are formed and to prevent an FPC (9) from rebounding due to elastic recovery, thereby enabling the bends to retain their shape as desired. As shown in the figure, in case there are a plurality of bends, the copper foil (15) extends to be disposed at all the bends, thereby avoiding the deterioration in workability of assembly, which is invited due to the FPC (9) rebounding. Further, after assembling the FPC (9), a cover portion (20) does not rebound with time within the other components and does not shift off a predetermined position.

Abstract: A system and method is described for distributing light within a light guide which is used for illuminating the user interface of an electronic device. The light guide is formed as a thin film and impressed with a pattern of input and output diffraction gratings to control the transmission of light into and out of the light guide to efficiently illuminate the user interface.

Abstract: In a pointer instrument, a LED (7) is arranged in such a way that light can pass from it into a free end face (5) of a pointer shaft (2) which is embodied as a light guide. For this purpose, a printed circuit board (4) on which the LED (7) is fitted has an opening (6) which is flush with the end face (5) of the pointer shaft (2) and into which the LED (7) projects, at least partially.

Abstract: A surface lighting device includes a light guiding plate having a light incident surface formed at one end surface and a light exit surface formed on a front surface thereof; an elongated light source facing the light incident surface; a light source reflector which reflects light emitted from the elongated light source toward the light incident surface; a prism sheet, wherein an array of minute parallel prism projections is formed on a surface thereof, the array of minute parallel prism projections facing the light exit surface; a regular reflection type reflector facing a rear surface of the light guiding plate; a light guiding device for guiding light emitted from the elongated light source to two portions of the light incident surface which respectively face opposite ends of the elongated light source; and a diffuser, formed on the light incident surface, which diffuses incident light thereon.

Abstract: A measuring apparatus in which the necessity of a light conductor for illuminating the front panel can be eliminated and cost reduction and slimming is realized, comprising: a circuit board 1; an instrument body 3 disposed on the circuit board 1 and including a drive shaft 2 extending forward; a pointer 4 to be fitted on the tip side of the drive shaft 2; a front panel 5 disposed between the pointer 4 and the circuit board 1 for illuminating at least the display portion 52; a light source 6 disposed in front of the circuit board 1 on the side where the drive shaft 2 resides with respect to the display portion 52; a reflector 7 to be disposed between the front panel 5 and the circuit board 1; and the circuit board 1 including a first reflecting portion 75 facing to the light source 6 for reflecting the illumination from the light source 6 toward the outer periphery, and a second reflecting portion 77 extending outward with an appropriate space interposed between itself and the front panel 5 so as to surround t

Abstract: In the packaging of an LCD module within a small and lightweight case, the case comprising a front case and a rear case, a recess with a predetermined depth, formed at the edge of the bottom side of the LCD module, is combined with a boss formed at the case, and a recess with a predetermined depth, formed at the edge of its surface, is fastened to a fastening means for securing the LCD module, thereby minimizing the difference between the areas of the LCD module and the case and further reducing the number of processes required for combining the LCD module with the case. In addition, the recess formed at the surface edge of the LCD module is combined with a fastening hook formed at the rear case so that the LCD module can be secured to the rear case and to the front case without any separate fastening member such as a stud or insert.

Abstract: An optical system using ambient light. The system includes a screen to be illuminated, an internal light source and an external light collector to collect ambient light to illuminate the screen. A switch may be used to activate the internal light source, providing internal light to be combined with the ambient light to illuminate the screen. A light sensor may also be used to detect the level of light presented to the screen, with or without a controller to automatically control the process of providing illumination to the screen.

Abstract: A method and device for improving lighting of a display having a top surface for viewing.

Abstract: An illuminated frontlit display includes a front light guide having at least one light input face that supplies light to the guide, a viewing face, and a light output face opposite the viewing face, the light output face having a light extraction layer thereon, the extraction layer having a substantially flat light exit face and containing buried reflective facets that extract supplied light from the guide through the light exit face to a reflective light valve and back through the viewing face of the guide to a viewer.

Abstract: The illumination device comprises at least one light source, and a light pipe positioned at the front side of a license plate, and a light diffusing means. A light of the light sources is led, the light pipe emitting a leading light from the surface of the license plate face. The light emitted from the observed face is diffused by the light diffusing means. The light diffusing means is provided with, rugged portions of an observed face opposite to a light emitting face, or, a light diffusing layer composed of two or more kinds of light transmitting materials, refractive indexes of which are different each other, on the observing face, and a light led from a light leading face is reflected and diffused on the light diffusing layer.

Abstract: In a display unit there is provided a front instrument panel (2) for inscription with symbols (9), which have an opaque portion (12) enclosed by a transparent portion (11), a so-called island. This opaque portion (12) is applied to a transparent backing (15) and fitted into an opening (13), made in the front instrument panel (2) to correspond to the contour of the symbol (9), at a distance from an edge region (20) of the opening (13). Use of the backing (15) makes it possible to dispense with connecting cross-pieces between the island and the front instrument panel (2). Furthermore, a process for producing the front instrument panel (2) intended for the display unit is provided, in which process firstly the opening (13) is made by punching and the backing (15) is formed by film-insert molding a transparent plastic behind the front instrument panel (2).

Abstract: A portable computer system includes an illuminated keyboard. The computer system has an enclosure including a base and a cover pivotally attached to the base. The keyboard subassembly is mounted in the base. The keyboard subassembly includes a plurality of key mechanisms mounted on a first side thereof. A light panel having a plurality of openings formed therethrough in a pattern generally corresponding to the plurality of key mechanisms is provided. The light panel is mounted adjacent the first side of the keyboard subassembly with each one of the key mechanisms extending through a respective opening in the light panel. A key cap is mounted on each one of the key mechanisms. In one embodiment, each key cap includes a body formed of a non-opaque material having an opaque character indicia portion formed thereon. Light is transmitted through body such that the character indicia portion may be viewed in low light conditions.

Abstract: A display apparatus comprises a display element, a backlight apparatus provided behind the display element and having a metal case, and a housing accommodating the display element and the backlight apparatus. In the display apparatus, electric wires for providing power to the backlight apparatus extend between the metal case of the backlight apparatus and the housing, and at least one opening is provided in the metal case in a part where the electric wires extend.

Abstract: A light conducting body has a generally conical through bore defined therein. The conical through bore includes a front bore part defined by a sloped surface and a rear bore part defined by a concave surface. A light conducting dial board is installed in the conical through bore with its front face facing forward and positioned in the vicinity of the junction portion between the front and rear bore parts. The dial board has a peripheral edge separated from the inner wall surface of the conical through bore thereby to define therebetween a circumferentially extending space. A light conducting supporting plate is attached to a rear surface of the dial board. The supporting plate is formed with a light transmitting portion which extends rearward and has an rear end intimately received in a recess formed in the rear end of the light conducting body. A plurality of light sources are positioned behind the rear end of the light conducting body.

Abstract: A front-end surface illumination device is provided which is high in visibility when it is illuminated or not, low in power consumption, and compact. When a light beam emitted from an organic electroluminescence element formed on an end face of a light transmission plate reaches projecting portions, the light is emitted from the light transmission plate, and irradiated on an illuminated object. In this constitution, the light transmission plate has the function of projecting the light beam to the illuminated object, and transmitting the light beam reflected by the illuminated object with little diffusion.

Abstract: In the spread illuminating apparatus in which the light emitted from the light emitting diode 4, which is disposed close to the transparent substrate 2, is made to be emitted toward the viewing direction of the transparent substrate 2, the groove 2a is provided on the transparent substrate 2 in such a manner as it crosses orthogonally light emitted in a radial direction from the light emitting diode 4 so that most light beams 5a, 5b, 5c can be emitted toward the viewing direction. Since the light beams 5a, 5b and 5c progress in the viewing direction through the groove 2a, an amount of light turning aside to no purpose can be reduced.

Abstract: The invention provides a device and method for illuminating keypad-type input devices, utilizing a light source, such as an LED, and transmitting the output of the light source to individual input loci via a fiber optic light guide.

Abstract: The present invention relates to lighting unit that comprises at least a trough, a plurality of slots on a light penetration member attached at the bottom of a base, and at least a LED disposed in the trough. Fasteners are attached to the end of the feet of each key to join the key to the slots on the light penetration member. Each key is capable to move up and down freely with respect to the base. The LED connects to a power supply, the LED lights. All relevant keys will have an appropriate luminosity.

Abstract: A guide plate having an emission face for light-output, a back face and an incidence end face for light-input is improved. The emission face is provided with a plurality of projections each of which includes a blunt top portion. The projections have shapes such as like domes or like ridges. Each dome-like projection has a diameter ranging, for example, from 50 &mgr;m to 200 &mgr;m and has a height ranging, for example, from 0.1 &mgr;m to 50 &mgr;m. The dome-like projections distribute with density such that one or more projections are allocated, for example, per box of 0.5 mm×0.5 mm. Ridge-like projections run so as to have a crossing angle, for example, 60 degrees or more with respect to the incidence end face. Ratio of repetition pitch of the ridge-like projections to their height falls within a range, for example, from 5000:1 to 1:1. Height of each ridge-like projection may fall within a range from 1 &mgr;m to 100 &mgr;m.

Abstract: Shaped refractive articles having compound curved surfaces enable a light source to provide substantially uniform illumination of a linear or planar target. The refractive articles can comprise an input edge or face and an output edge or face, the input edge or face having at least one shaped notch or cavity that can at least partially envelop a light source, wherein the notch or cavity has at least two oppositely signed curved portions shaped to provide substantially uniform illumination of a target by the source. The articles can also be optically coupled to and at least partially envelop a light source, and can have an output edge or surface having at least two oppositely signed curved portions shaped to provide substantially uniform illumination of a target region by the source. The shaped articles can be used in, for example, lighting devices, frontlights, backlights and electronic displays.

Abstract: A device for mixing light is disclosed. A mixer body has an aperture that preferably extends entirely therethrough. Light from multiple sources may be introduced on one side of the aperture and removed from the mixer on an opposite side thereof. Multiple reflections of the light between a surface of the body of the mixer that defines the aperture and surfaces of the body that define an exterior of the body promote the mixing of the light. One or more surfaces of the body may be roughened to further promote mixing of the light, for instance all exterior surface of the mixer body except the light entry which is preferably smooth. Another option that may be used alone or in combination with the noted roughening features is the inclusion of a plurality of reflective particles (e.g., metallic) embedded within the mixer body, bubbles embedded within the mixer body, or both. The device is particularly suited for applications where space constraints are an issue.

Abstract: This invention was made to reduce cost and the number of assembly processes and improve productivity by making viewing angle characteristics of light emitted from a light emitting surface even irrespective of a point in a bar-shaped light guide. A bar-shaped light guide of this invention comprises a light incident surface for receiving light emitted from a point light source, a light emitting surface, which is orthogonal to the light incident surface, for emitting light received on the light incident surface in a form of beam light, and a pattern surface made up of a side of the light incident surface and a side of the light emitting surface and having a plurality of grooves formed thereon. The plurality of grooves are regularly arranged on the pattern surface. An angle formed by the groove 106 and the side of the light emitting surface on a side of the point light source is 35-55°.

Abstract: An illuminated control assembly which comprises a light guide having a an outer illumination section and an end illumination section. The assembly also comprises at least one outer light conducting leg and at least one end light conducting leg. Each leg has a light receiving portion proximate to light source and distanced from the illumination sections. Each leg also has a light delivering portion, wherein the light delivering portion of the outer light conducting leg is in light communication with the outer illumination section and the light delivering portion of the end light conducting leg is in light communication with the end illumination section. The assembly also comprises a control member having a light duct. The control member is connected to an input receiver and the control member is in light communication with the end illumination section wherein light from the end illumination section is transmitted through the light duct.

Abstract: There is provided a spread illuminating apparatus to improve a light coupling efficiency between a light conductive member and a transparent substrate. In the spread illuminating apparatus, an FPC mounting section of a frame is set to be lower than a substrate mounting section by the thickness of an FPC, and an extension provided at an FPC main body is let through an opening formed at a stepped part of the frame so as to be disposed on a reverse side of the frame, whereby an upper surface of the light conductive member is adapted to be flush with an upper surface of the transparent substrate while prevention of the deviation in the thickness direction between the light conductive member and the transparent substrate is not obstructed even when the extension is provided, which results in improving the light coupling efficiency.

Abstract: A light-guide plate (1) arranged at a display face (2a) of a liquid crystal (2) and illuminates radiating light from a light source (3) to the display face (2a) is constructed by a light permeability base portion (10) having a first face (8), a second face (9) of the rear face side of the first face (8), and a third face (5) guiding light from the light source (3) from side face, an adhesive layer (11), and light permeability sheet (12) forming plural prism grooves on a light emission face (6) with the predetermined interval and providing on the adhesive layer (11).