Abstract: A color conversion filter substrate includes a transparent support substrate, one or more types of color conversion layers with a thickness more than 5 ?m formed on the support substrate in a desired pattern, and a protective layer formed of a transparent material for covering the support substrate and the color conversion layers and having a flat surface. After a display is produced, the color conversion pattern layers contain unsaturated functional groups at a concentration equal to or less than 1.4×10?3 mol/g.

Abstract: An illumination system according to the principles of the invention may include a first LED and a carrier material. The carrier material may be comprised of plastic, synthetic material, polymer, latex, rubber or other material. The carrier material may also contain a phosphor, fluorescent material, organic fluorescent material, inorganic fluorescent material, impregnated phosphor, phosphor particles, phosphor material, YAG:Ce phosphor, or other material for converting electromagnetic radiation into illumination or visible light.

Abstract: An ultraviolet type white color light emitting device (Q) including a 340 nm–400 nm ultraviolet InGaN-LED, a first fluorescence plate of ZnS doped with more than 1×1017cm?3 Al, In, Ga, Cl, Br or I for absorbing ultraviolet rays and producing blue light (fluorescence), a second fluorescence plate of ZnSSe or ZnSe doped with more than 1×1017 cm?3 Al, In, Ga, Cl, Br or I for absorbing the blue light, producing yellow light (fluorescence) and synthesizing white color light by mixing the yellow light with the blue light. A blue light type white color light emitting device (R) including a 410 nm–470 nm blue light InGaN-LED, a fluorescence plate of ZnSxSe1-x (untreated 0.2?x?0.6; heat-treated 0.3?x?0.67) doped with more than 1×1017 cm?3 Al, In, Ga, Cl, Br or I for absorbing the blue light, producing 568 nm–580 nm yellow light (fluorescence) and synthesizing white color light by mixing the yellow light with the blue LED light.

Abstract: To adjust for differences in service life among light emissive materials used for respective colors by determining the length of a pixel region in the row direction according to the service lives of the light emissive materials. To allow for material change after completion of the laying out process, a light emitting region is formed such that a margin is ensured in the row or column direction within each pixel region.

Abstract: A light emittng device according to one aspect of the present invention includes a first light emitting component including a light-emitting semiconductor layer that emits light in a blue region, a second light emitting component including a light-emitting semiconductor layer that emits light in a red region, and a phosphor capable of absorbing a part of light emitted by the first light emitting component and emitting light in a yellow region.

Abstract: A display panel is provided that is capable of enhancing visibility outdoors and which can be easily manufactured. In a display panel in which at least one side thereof serves as a display surface, the display panel includes a first reflectance layer, which may be made of titanium, titanium nitride, or an alloy of titanium and tungsten and a second reflectance layer, which may be made of indium tin oxide, indium zinc oxide, or gallium zinc oxide, the first and second low reflection layer being deposited at positions corresponding to pixels on a substrate.

Abstract: A phosphor for light sources, the emission from which lies in the short-wave optical spectral region, as a garnet structure A3B5O12. It is activated with Ce, the second component B representing at least one of the elements Al and Ga, and the first component A is terbium or terbium together with at least one of the elements Y, Gd, La and/or Lu. In a preferred embodiment, a phosphor having a garnet of structure (Tb1?x?yRExCEy)3(Al,Ga)5O12, where RE=Y, Gd, La and/or Lu; 0?x?0.5?y; 0<y<0.1 is used.

Abstract: A phosphor having the formula Na2(Ln1-y-zCeyTbz)2B2O7, wherein Ln is selected from the group consisting of La, Y, Gd, Lu, Sc and combinations thereof and wherein y=0.01-0.3 and z=0.0-0.3. The phosphor is suitable for use in a white-light emitting device including a UV/blue semiconductor light source having a peak emission from about 250 to about 550 nm and a phosphor blend including a blue emitting phosphor, a red emitting phosphor and a green emitting phosphor having the above described formula.

Abstract: The invention provides light emitting devices having a phosphor layer that are useful as sources of white light, and other applications. The invention provides a light emitting device having a LED and a phosphor composition positioned to receive light from the LED. The LED is adapted to emit cyan light, and the phosphor composition is adapted to absorb cyan light from the LED and emit red light.

Abstract: A light emitting diode is provided which includes a circuit substrate, a semi-spherical concave surface part formed in the circuit substrate, and a transparent stage disposed in the semi-spherical concave surface part in the circuit substrate. An LED chip is mounted on the horizontal upper surface of the transparent stage, a reflective member forms a truncated cone-shaped concave surface part disposed to be joined to an end of the semi-spherical concave surface part and attached on the substrate. A sealing body is disposed in the joined concave surface parts to cover the LED chip. The transparent stage includes a lower surface having a convex surface corresponding to a concave surface of the semi-spherical concave surface part and an upper surface formed in a horizontal surface. The LED chip is mounted on the horizontal upper surface of the transparent stage.

Abstract: A device is provided. The device includes a substrate, a first electrode disposed over the substrate, a small molecule organic emissive layer disposed over the first electrode, and a second electrode disposed over the organic emissive layer. The substrate has a first index of refraction, and the organic emissive layer has a second index of refraction. The first index of refraction is higher than the second index of refraction. The device may have an external electroluminescent efficiency of at least about 56%. Bulky substituents or dopants may be used to decrease the index of refraction and/or the density of the organic emissive layer.

Abstract: A light-emitting diode with no fluctuations in optical properties and good sealing properties, and a simple production method for producing this light-emitting diode. The light-emitting diode has a base comprising a cup part on which the light-emitting diode is placed, a resin material introduced into cup part, and a lens member placed on top of a cup for focusing light emitted by a light-emitting diode chip. A layer of fluorescent material, which converts the wavelength of at least some of the light from the light-emitting diode chip, is applied to the inner convex face of the lens member. When the lens member is attached to the base, the inner convex face deforms the resin material and air and excess resin material can be pushed to the outside.

Abstract: A light source device including at least one first substrate, at least one second substrate, first light emitting elements, which emit red color light, and second light emitting elements, which emit infrared rays. The first light emitting elements are disposed at the first substrate, and the second light emitting elements are disposed at the second substrate. The light source device further has a light damping member, which dampens the infrared rays, and a transmitting member through which the infrared rays pass. The light damping member is disposed to correspond to the first substrate, and the transmitting member is disposed to correspond to the second substrate.

Abstract: A self light emitting display device having high level of the external coupling efficiency and high grade image presentation as no optical cross-talk or blur can be obtained by a new light-emitting element. The device is constructed as follows. A plurality of picture elements, each of which picture elements has an organic layer composing light emitting areas, a transparent electrode and a reflective electrodes, are formed on a substrate. Between the picture elements, a bank which has a tilted reflective surface is formed so that the light emitting area is surrounded by the bank wherein the transparent optical waveguide layer is formed as optically isolated for each of the picture elements.

Abstract: A light emitting device including a UV semiconductor light source and a phosphor blend including a blue emitting phosphor, a green emitting phosphor and a deep red emitting phosphor comprising (Ba,Sr,Ca)3MgxSi2O8:Eu2+, Mn2+, wherein 1?x?2. Also disclosed is a phosphor blend comprising a blue emitting phosphor, a phosphor, a green emitting phosphor and a red emitting phosphor comprising (Ba,Sr,Ca)3MgxSi2O8:Eu2, Mn2+.

Abstract: A light-emitting package includes a substantially transparent substrate having a first surface and a second surface including a lens. The package also includes a light-emitting diode (LED) adapted to emit light having a predetermined wavelength, the LED being secured over the first surface of the substantially transparent substrate. The second surface of the substrate defines a principal light emitting surface of the package. The lens at the second surface has a grating pattern that matches the predetermined wavelength of the light emitted from the LED for controlling the emission geometry of the light emitted by the package. The grating pattern has a radial configuration including a series of circles that are concentric.

Abstract: The invention provides a display unit which can improve emission efficiency of lights for image display, and assure luminance of display images. The display unit comprises micro prisms which are arranged in the positions corresponding to organic EL devices, and which have a high refraction index to refract a light, and auxiliary prisms with a low refraction index which are embedded in voids between each micro prism. A light volume of the light viewed as an image in the direction facing an organic EL display (facing direction) is a total of a light volume of a light essentially emitted from the organic EL device in the facing direction, and lights which are directed in the facing direction by utilizing refraction phenomenon based on differences of refraction index between the micro prism and the auxiliary prism. Compared to the case wherein the micro prisms and the auxiliary prisms are not provided, an emission volume of the light in the facing direction is increased by the light volumes of the lights.

Abstract: A light source which may be used as part of a dental curing lamp is comprised of at least one, and preferably a plurality, of LEDs. To increase the efficiency of the light output the LEDs are encapsulated in a beam converger including an extractor portion and a collimator portion. Light rays leaving the collimator portion have an angle which matches the entrance angle input requirements of an associated light guide. In another aspect, cooling of LEDs is accomplished by reservoirs located in a hand piece and in a base station. In another aspect of the invention, cooling is achieved by use of a heat pipe and a cooling jacket. The cooling jacket may contain a material having a high latent heat of fusion at a phase change temperature suitable for cooling the LEDs.

Abstract: An OLED device, having a pixel includes a plurality of individually addressable first white light emitting elements; a corresponding plurality of color filters located over the first white light emitting elements to filter the light emitted by the first white light emitting elements; and a second separately addressable white light emitting element located over the color filters for passing the filtered white light and emitting white light.

Abstract: As a red light emitting phosphor capable of efficiently emitting red light at a high luminance in response to exciting light having a wavelength of 350-420 nm, and practically used in a light emitting device for red display or a light emitting device for white or intermediate color display in combination with green and blue light emitting phosphors, the invention provides a red light emitting phosphor capable of emitting red light upon excitation with light having a wavelength of 350-420 nm and having compositional formula (1): AEuxLn(1-x)M2O8??(1) wherein A is at least one element selected from among Li, Na, K, Rb and Cs, Ln is at least one element selected from among Y and rare earth elements exclusive of Eu, M is at least one element selected from among W and Mo, and x is a positive number satisfying 0<x?1; and a red light emitting phosphor having compositional formula (2): D0.

Abstract: An electroluminescent device in which the intensity of the light emission is enhanced by photopumping with radiation from a radiation source of a suitable photon energy. The photopumping radiation from the radiation source interacts with the wide band-gap semiconductor forming the electroluminescent device so as to, when the device is electrically biased to provide light emission, generate additional carriers that enhance the intensity of the light emission from a light-emitting element present in the wide band-gap semiconductor. A waveguide structure may be integrated into a substrate carrying the electroluminescent device for transferring the radiation from the radiation source to the electroluminescent device. Multiple electroluminescent devices may be arranged in pixels for forming a flat panel display in which certain of the devices are photopumped with radiation.

Abstract: The amount of usefully captured light in an optical system may be increased by concentrating light in a region where it can be collected by the optical system. A light emitting device may include a substrate and a plurality of semiconductor layers. In some embodiments, a reflective material overlies a portion of the substrate and has an opening through which light exits the device. In some embodiments, reflective material overlies a portion of a surface of the semiconductor layers and has an opening through which light exits the device. In some embodiments, a light emitting device includes a transparent member with a first surface and an exit surface. At least one light emitting diode is disposed on the first surface. The transparent member is shaped such that light emitted from the light emitting diode is directed toward the exit surface.

Abstract: The invention provides a display of a type of getting light out of a second electrode side, capable of increasing contrast by suppressing external light reflection, simplifying a manufacturing process, and reducing cost, and a method of manufacturing the same. A substrate for driving is provided with organic electroluminescence (EL) devices for getting light out of a cathode side. A red filter, a green filter, and a blue filter are formed on a substrate for sealing by printing so as to face the organic EL devices. By overlapping at least two filters out of the red, green, and blue filters by printing, a black matrix is formed so as to face the boundary region of the organic EL devices, so that external light reflection by a wiring electrode between the devices is suppressed.

Abstract: When the density of excitons in an organic single crystal (including the linear acenes, polyacenes, and thiophenes) approaches the density of molecular sites, an electron-hole plasma may form in the material altering the overall excitonic character of the system. The formation of the electron-hole plasma arises as a result of the screening of Coulomb interactions within individual excitons by injected free carriers. The large exciton densities required to accomplish this screening process can only be realized when excitons collect near dislocations, defects, traps, or are confined in heterostructures. Such confinement and subsequently large exciton densities allows for the observation of physical phenomena not generally accessible in an organic material. Specifically, the formation of an electron-hole plasma in an organic single crystal can allow for the observation of field-effect transistor action and electrically-pumped lasing.

Abstract: An active matrix organic electroluminescent display device includes a first substrate and a second substrate facing and spaced apart from each other, a thin film transistor on an inner surface of the first substrate, a first electrode connected to the thin film transistor, an organic electroluminescent layer on the first electrode, a second electrode on the organic electroluminescent layer, a passivation layer on the second electrode, a black matrix on an inner surface of the second substrate, the black matrix includes a plurality of open portions, a color filter layer at the plurality of open portions, a color changing layer on the color filter layer, an overcoat layer on the color changing layer, and an adhesive film between the passivation layer and the overcoat layer.

Abstract: Pixels for organic light emitting full color display panels are made by simultaneously depositing red, green, and blue dopants such that the blue dopant is dispersed in at least one non-blue subpixel. Another aspect of the method relates to using a shadow mask comprising ribs which, in an angled evaporation method, can correct for parallax.

Abstract: An organic EL display device having comprises a supporting substrate; and an organic EL element including an organic luminescent medium sandwiched between a lower electrode and an upper electrode thereon. A color changing medium and/or a transparent resin layer are arranged between the supporting substrate and the lower electrode. EL emission is taken out from the lower electrode. Various relationships are indicated among the refractive indices of the various elements of the organic EL display device. In such arrangement, a large quantity of EL emission can be taken to the outside.

Abstract: A color conversion filter substrate includes a transparent support substrate, at least one color conversion filter layer formed of a resin film containing a fluorescence colorant with a thickness of at least 5 ?m and arranged on the support substrate in a desired pattern, and a transparent gas-barrier layer formed in a flat film for covering the color conversion layer. The gas-barrier layer has a water-vapor permeability of 1.0 g/m2·24 hr or less, and a portion covering the color conversion filter layer with a thickness tPL expressed by the following equation, 0<tPL<0.1 W wherein W is a minimum width of a pixel.

Abstract: A structure includes semiconductor light emitting device and a wavelength converting layer. The wavelength converting layer converts a portion of the light emitted from the semiconductor light emitting device. The dominant wavelength of the combined light from the semiconductor light emitting device and the wavelength converting layer is essentially the same as the wavelength of light emitted from the device. The wavelength converting layer may emit light having a spectral luminous efficacy greater than the spectral luminous efficacy of the light emitted from the device. Thus, the structure has a higher luminous efficiency than a device without a wavelength converting layer.

Abstract: In a light emitting apparatus comprising a light emitting device, a fluorescent substance capable of absorbing at least a portion of light emitted by the light emitting device and emitting light having a different wavelength, and a color converting member which contains the fluorescent substance and directly coat the light emitting device, the color converting member contains at least an epoxy resin derived from triazine and a mixing ratio of the epoxy resin derived from triazine to the acid anhydride curing agent in the color converting member is from 100:80 to 100:240.

Abstract: A lens and encapsulant made of an amorphous fluoropolymer for a light-emitting diode (LED) or diode laser, such as an ultraviolet (UV) LED (UVLED). A semiconductor diode die (114) is formed by growing a diode (110) on a substrate layer (115) such as sapphire. The diode die (114) is flipped so that it emits light (160, 365) through the face (150) of the layer (115). An amorphous fluoropolymer encapsulant encapsulates the emitting face of the diode die (114), and may be shaped as a lens to form an integral encapsulant/lens. Or, a lens (230, 340) of amorphous fluoropolymer may be joined to the encapsulant (220). Additional joined or separate lenses (350) may also be used. The encapsulant/lens is transmissive to UV light as well as infrared light. Encapsulating methods are also provided.

Abstract: An electronic device comprising a population of quantum dots embedded in a host matrix and a primary light source which causes the dots to emit secondary light of a selected color, and a method of making such a device. The size distribution of the quantum dots is chosen to allow light of a particular color to be emitted therefrom. The light emitted from the device may be of either a pure (monochromatic) color, or a mixed (polychromatic) color, and may consist solely of light emitted from the dots themselves, or of a mixture of light emitted from the dots and light emitted from the primary source. The dots desirably are composed of an undoped semiconductor such as CdSe, and may optionally be overcoated to increase photoluminescence.

Abstract: An OLED display device for displaying a color image, the display device being viewed from a front side includes a plurality of OLED elements including first color elements that emit a first color of light and second color elements that emit a second color of light different from the first color; a reflector located behind the OLED elements; and a corresponding plurality of filter elements aligned with the OLED elements, including first and second color filters for passing the first or second color of light emitted by the corresponding OLED element, and blocking other colors of light.

Abstract: A method and apparatus for achieving multicolor displays using an integrated color chip is provided. The integrated color chip contains one or more multicolor generation sites on a single substrate. Each multicolor generation site is comprised of two or more light emitting regions in close proximity to one another, the number of light emitting regions per site dependent upon the number of required colors. The active light generation system for each light emitting region, e.g., an LED, is preferably identical in device structure although size and shape may vary. In order to achieve the desired colors, one or more light conversion layers are applied to individual light emitting regions. Each light emitting region may also include index matching layers, preferably interposed between the outermost surface of the light emitter and the light conversion layer, and protective layers.

Abstract: A double-faced LED device includes a substrate having opposed faces, a central recess formed in each of the opposed faces, a pair of electrode layers formed on each of the opposed faces, the electrode layer having a surface within the central recess formed into a reflector surface, and an LED securely mounted on the electrode layer within the central recess of each of the opposed faces, to which electric current may be applied to emit light from both of the opposed faces.

Abstract: The invention relates to flat panel display terminals based on cold emission cathodes. The aim of said invention is to develop a full color processing display terminal using a cold emission cathode having high emission characteristics. The inventive cold emission film cathode comprises an insulated substrate which can be made of glass and a nanocrystalline carbon film emitter placed on it, said emitter is embodied in the form of a mono layer of grains of powder of a high temperature resistive material having a grain size ranging from 10?9 to 10?4 m, said grains being covered with a nanocrystalline carbon film. The inventive flat display terminal comprises flat glass plates on one of which a system of cold emission cathodes is arranged, said cathodes are embodied in a form of busbars coated with the mono layer of grains of powder of high temperature resistive material having a grain size ranging from 10?9 to 10?4 m which are covered with a nanocrystalline carbon film.

Abstract: An electroluminescence system includes two electrodes, a dielectric layer with a pigment, another dielectric and, optional pigment layers, which are serially connected; a device for the production of an electroluminescence system including a dispensing roll and an applier roll carrying slots sized to the one of the strips forming the layers.

Abstract: Light-emitting devices are disclosed that comprise a light source emitting first light, a first material substantially transparent to and located to receive at least a portion of the first light, and particles of a second material dispersed in the first material. The second material has an index of refraction greater than an index of refraction of the first material at a wavelength of the first light. The particles of the second material have diameters less than about this wavelength. Particles of a third material may also be dispersed in the first material.

Abstract: A solid state lamp includes a mounting area adapted to contain a light emitting diode (LED) chip and a suspension media which physically isolates the diode from the mounting area. The suspension media, while substantially optically transparent, includes suspended phosphor particles for down conversion and scattering of LED emissions. Additionally, the suspension media includes thermal conductivity additives to improve device thermal conductivity in higher power operations.

Abstract: The luminance of different colors of light emitted from EL elements in a pixel portion of a light emitting device is equalized and the luminance of light emitted from the EL elements is raised. The pixel portion of the light emitting device has EL elements whose EL layers contain triplet compounds and EL elements whose EL layers contain singlet compounds in combination. The luminance of light emitted from the plural EL elements is thus equalized. Furthermore, a hole transporting layer has a laminate structure to thereby cause the EL elements to emit light of higher luminance.

Abstract: A display includes a front panel and a back panel with a light control material in between. One of the panels includes a rigid substrate, for example made of glass or rigid plastic. The other of the panels includes a flexible substrate, for example made of a flexible plastic film. The panel with the flexible substrate may be made by a roll-to-roll process, with various fabrication operations formed while the flexible substrate is still part of a web of material. The panel with the rigid substrate may be separately fabricated, then combined with the other panel on the web through a pick and place operation that accurately locates the front panel relative to the back panel. The display may be any of a variety of displays, such as liquid crystal displays (LCDs), and electroluminescent displays, such as polymer light emitting devices (PLEDs) and organic light emitting devices (OLEDs).

Abstract: An electroluminescence display device comprising a thin film transistor and an electroluminescence element wherein the electroluminescence element's anode and a portion of the thin film transistor's source/drain electrode are deposited on to a same surface and the electroluminescence element's anode and the portion of the thin film transistor's source/drain electrode overlap and make an electrical contact with improved contact resistance.

Abstract: A light-emitting diode with no fluctuations in optical properties and good sealing properties, and a simple production method for producing this light-emitting diode. The light-emitting diode has a base comprising a cup part on which the light-emitting diode is placed, a resin material introduced into cup part, and a lens member placed on top of a cup for focusing light emitted by a light-emitting diode chip. A layer of fluorescent material, which converts the wavelength of at least some of the light from the light-emitting diode chip, is applied to the inner convex face of the lens member. When the lens member is attached to the base, the inner convex face deforms the resin material and air and excess resin material can be pushed to the outside.

Abstract: A device for the generation of specific colored light including white light by luminescent down conversion and additive color mixing based on a light-emitting diode (LED) comprising a semiconductor light-emitting layer emitting near UV light about 370-420 nm or blue light about 420-480 nm and phosphors which absorb completely or partly the light emitted by the light-emitting component and emit light of wavelengths longer than that of the absorbed primary light, wherein the light emitting layer of the light emitting component is preferably a Ga(In)N-based semiconductor; and at least one of the phosphors contains a metal sulfide fluorescent material activated with europium containing at least one element selected from the group consisting of Ba, Sr, Ca, Mg and Zn; and/or at least another phosphor which contains a complex thiometalate fluorescent material activated with either europium, cerium or both europium and cerium containing 1) at least one element selected from the group consisting of Ba, Sr, Ca, Mg and

Abstract: An organic EL element (100) emits light containing blue, green and red components. A blue color filter (420) transmits only the blue component. A green-converting member (340) converts the blue component to the green component, and a green color filter (440) transmits only the green component. A red-converting member (360) converts the blue component and the green component to the red component, and a red color filter (460) transmits only the red component. Since the respective color filters (420, 440 and 460) block unnecessary color components, the reproducibility of the respective color is improved. Since the luminescence of the organic EL element (100) contains the green component and the red component besides the blue component, white balance becomes good. It is therefore possible to provide a color luminous device from which improved light rays in the three primary colors can be emitted.

Abstract: A white light source is obtained by converting short wavelength color light emitted from a light emitting diode (LED). The conversion is achieved by covering the LED chip with a fluorescent glue. The LED chip is mounted on a split substrate, and the outer ends of the substrate serve as terminals for the LED. A wall may be erected around the LED chip to contain the fluorescent glue, and another transparent glue may be used to cover the fluorescent glue for protection.

Abstract: A light emitting device having an anode and a cathode provided on a substrate, and an organic light emitting layer between the anode and the cathode, where the organic light emitting layer includes a light emitting material and a dopant for improving the dispersibility thereof. As the dopant, there are employed a light emitting compound and a non-light emitting compound or a current enhancing material. In case of employing the light emitting compound, the composition corresponds to a case of utilizing plural light emitting materials, and, in such case, the light emission wavelengths are preferably mutually closer. Also, evaporation of the light emitting material and the dopant in the same evaporation boat makes it possible to reduce evaporation temperature, thereby improving the dispersability of the light emitting material.

Abstract: The light emitting device includes a light emitting portion having a larger refraction index than air, and a medium which is provided on a light extraction surface extracting light from the light emitting portion and which has different haze ratios depending on a light incident angle, wherein a haze ratio is defined as follows: the haze ratio=(scattered light transmission factor/total light transmission factor)×100 (%), or =(scattered light transmission factor/(scattered light transmission factor+parallel light transmission factor))×100 (%). The light emitting device improves the light extraction efficiency from the light emitting device.

Abstract: A light-emitting device is disclosed with improved luminance even with increased arrangement density of a reflector regardless of a light-emitting region. The disclosed device includes a reflector between an electrode for extracting light from a layer including a luminescent material, which serves as a light-emitting region of a light-emitting element, and an exterior space (air). In addition, a light-extraction efficiency can be improved by setting an angle made by a surface of the reflector, which faces the light-emitting element, and a side surface of the reflector (hereinafter, referred to as a slope angle of the reflector) in a predetermined range as for a shape of the reflector.

Abstract: A light extracting sheet is provided on a light extracting surface of an organic EL device. A prism sheet is provided on the light extracting sheet. The light extracting sheet has a first incident surface contacting the light extracting surface and a light exit surface located at an opposite side from the first incident surface. The light exit surface defines a plurality of first projections. Each of the first projections is pyramid. The prism sheet has a second incident surface that is substantially parallel to the light extracting surface and a light exit surface located at an opposite side from the second incident surface. The light exit surface defines a plurality of second projections. Each of the second projections is pyramid.