Abstract: A prism sheet, a back light unit using the same and liquid crystal display device having the back light unit are disclosed, for improvement of light concentration, frontal luminance and viewing angle, in which the prism sheet includes a light-condensing film. The light condensing film has a plurality of prism peaks, each having a triangular cross section inclined surface which is inclined from a top surface of the light-condensing film at an angle of about 20° to about 40°.

Abstract: A diffusively reflective film includes a base film, a light reflection layer and a light diffusion layer. The base film is flexible. The light reflection layer is disposed on the base film. The light reflection film reflects a first light. The light diffusion layer is disposed on the light reflection layer. The light diffusion layer diffuses the first light to form a second light. The diffusively reflective film may be bent to cover the light guide plate without being broken so as to increase the amount of light. Thus, a display quality is enhanced. Further, the diffusively reflective film covers the first side face, the second side face and the first face of light guide plate at once. Thus, productivity is enhanced and its manufacturing cost is reduced.

Abstract: A backlight is provided for illuminating an at least partially transmissive display. The backlight includes a light source. A light guide receives the light from an edge surface and guides the light by total internal reflection. The light extracted from the lightguide has an angular emission profile such that when incident on a prism film, collimated light is produced.

Abstract: Provided is a backlight unit that increases brightness and increases uniformity of the brightness. The backlight unit includes a plurality of point light sources. A light guide panel includes a first surface that receives incident light from the point light sources. A second surface is where the lights from the point light sources cross. Prism patterns are formed on the first surface.

Abstract: One face of a substrate of a diffuser with a light condensing function is disposed with a plurality of prism rods; at least one inclined face of parts of prism rods is disposed with a rough diffusion face; the diffusion face may be positioned on any position of the inclined face of the prism rod; the diffusion face is disposed with a plurality of irregularly arranged raised and indented stripes perpendicular, not perpendicular or parallel to a crest line of the prism rod; chromatid dispersion can be reduced and stripes of the prism rods can be atomized effectively by utilizing the diffusion face to eliminate the occurrence of moiré fringes and elevate the yield factor.

Abstract: There is disclosed a timepiece (40) including optical means for forming a decorative pattern, in the form of a figurative image, in response to an action by the user. The optical means forming a figurative image include an optical guide (1, 51) having two large faces (10, 11) and at least one lateral face (12). Optical extractors (19) each having at least one light reflective surface (20) are arranged in at least one of the large faces (11). A light source (8, 8a, 8b, 8c) is arranged so as to emit light in the direction of the reflective surfaces (20), via the lateral face (12) of the optical guide. Thus, each of the reflective surfaces causes a reflected light beam to form in a well defined direction, the set of light beams forming a figurative image in that direction, which can typically be selected as the normal with respect to the mid-plane of the watch.

Abstract: A light guide plate capable of omitting use of a directional sheet such as a prism sheet as much as possible and ensuring a viewing angle without decreasing brightness in the vertical direction. A light guide plate 1 is used for an edge-light surface illuminant device 10. The light guide plate comprises an emission plane 6, a bottom plane 7 facing the emission plane 6 and an incident end face 8 which enters light emitted from a primary light source 4 provided in a side face between the emission plane 6 and the bottom plane 7. Each of the emission plane 6 and the bottom plane 7 comprises a pattern having convex portions and/or concave portions formed at predetermined pitches. The pattern formed on the emission plane 6 is orthogonal to the incident end face 8 and also the pattern formed on the bottom plane 6 is parallel to the incident end face 8. The emission plane 6 or the bottom plane 7 comprises a trapezoidal convex portion 2 and a trapezoidal concave portion 3 which are alternately arranged.

Abstract: There is disclosed a timepiece (40) including optical means for forming a decorative pattern, in the form of a figurative image, in response to an action by the user. The optical means forming a figurative image include an optical guide (1, 51) having two large faces (10, 11) and at least one lateral face (12). Optical extractors (19) each having at least one light reflective surface (20) are arranged in at least one of the large faces (11). A light source (8, 8a, 8b, 8c) is arranged so as to emit light in the direction of the reflective surfaces (20), via the lateral face (12) of the optical guide. Thus, each of the reflective surfaces causes a reflected light beam to form in a well defined direction, the set of light beams forming a figurative image in that direction, which can typically be selected as the normal with respect to the mid-plane of the watch.

Abstract: Various embodiments disclose an illumination apparatus. The apparatus may comprise a light guide supporting propagation of light and having at least a portion of one of its edges comprising an array of microstructures. These microstructures may be incorporated in the input window of the light guide to control the light intensity distributed within the light guide. In certain embodiments, the directional intensity of the light entering the light guide may be modified to achieve a desired distribution across the light guide.

Abstract: A surface emitting device includes a light emitter, a polarizer having a transmission axis along which light emerging from the light emitter is transmitted, and an optical sheet combination disposed between the light emitter and the polarizer and composed of a plurality of optical sheets. Each of the plurality of optical sheets includes an emergent surface for causing the emergent light to emerge, a spatial structure continuously arrayed on the emergent surface, a first optical axis parallel to an extension direction of the spatial structure and having a first refractive index, and a second optical axis parallel to an array direction of the spatial structure and having a second refractive index different from the first refractive index, wherein the first or second optical axis of a smaller one of the first and second refractive indices extends almost parallel to the transmission axis of the polarizer.

Abstract: A backlight assembly which can reduce manufacturing costs and enhance display quality of a liquid crystal display (“LCD”). The backlight assembly includes: a light source emitting light; and a light guide plate (“LGP”) including an incident surface on which light emitted from the light source is incident, a top surface which adjoins the incident surface, and a bottom surface which adjoins the incident surface, faces the top surface, and includes a plurality of lower prisms separated from one another and flat portions interposed between the lower prisms, wherein each of the lower prisms includes a first surface and a second surface which are adjacent to each other, the first surface including a plurality of oblique planes having different positive slopes, the second surface having a negative slope, and where the slope forms an angle with a line normal to the incident surface.

Abstract: Provided are an integrated optical sheet and an optical device having the same, and more particularly, an integrated optical sheet and an optical device having the same, in which a diffuser film and a prism film are integrated in a thin structure. The optical sheet includes a light collector including a plurality of prism elements extending in a first direction, and an anisotropic diffuser including a plurality of optical elements extending from a surface of the light collector opposite to the surface having the prism elements in a second direction different from the first direction. One part including downward prism elements and scattering elements is formed at one surface and the other part including diffusion elements is formed at the other surface to integrate a conventional diffusion film to a horizontal prism film, providing a thin optical sheet.

Abstract: The subject invention provides a thin and flexible light guide element, which comprises a first optical layer composed of a flexible transparent material; a second optical layer formed on the lower side of the first optical layer and having a light-adjusting structure to change the light path; and a third optical layer formed on the upper side of the first optical layer and having a convex-concave structure to homogenize the light emitted from the first optical layer, wherein the first and second optical layers have different refractive indices.

Abstract: A lighting device includes a housing, a plurality of LEDs arranged on a base of the housing, and a first optical plate positioned above the LEDs. The first optical plate includes a light input surface, a light output surface opposite to the light input surface, and a plurality of V-shaped ridges aligned in at least two different directions formed on the light output surface. The V-shaped ridges aligned in different directions intersect with one another. The lighting device may be used as a backlight module.

Abstract: A light concentrating sheet for a liquid crystal display module includes a first base film having flat inner and outer surfaces; a first light concentrating film on the first base film and having a first thermal expansion coefficient; a second light concentrating film on the first light concentrating film and having a second thermal expansion coefficient; and a second base film on the second light concentrating film and having flat inner and outer surfaces.

Abstract: A light guide plate has a light-receiving surface, a light-emitting surface, and a light-reflecting surface. Multiple first arc-shaped longitudinal structures are arranged on the light-receiving surface with their longitudinal directions being substantially parallel with each other. Multiple second arc-shaped longitudinal structures are arranged on the light-emitting surface with their longitudinal directions being substantially parallel with each other. The light-reflecting surface is shaped to form a plurality of prismatic structures, and a luminance-adjusting structure is formed on part of the light-reflecting surface near the point light source and interlaced with the prismatic structures.

Abstract: An exemplary prism sheet (20) includes a light input surface (201), a light output surface (202) opposite to the light input surface, and a plurality of micro-depressions (205). The plurality of micro-depressions are defined in the light output surface and arranged in a skewed matrix. Each micro-depression has four side surfaces connected to each other, and a transverse width of each side surface decreases along a direction away from the light output surface and close to the light input surface. The present invention also provides a liquid crystal display device (200) using the above-described prism sheet.

Abstract: A light guiding plate, a backlight assembly having the light guiding plate and a display device having the backlight assembly include a light guiding plate body, a polarization transformation layer on a surface of the light guiding plate body to transform a polarization component of light emitted through the light guiding plate, and a polarization extraction layer on the polarization transformation layer.

Abstract: An exemplary prism sheet includes a light input surface, a light output surface opposite to the light input surface, and a plurality of micro-protrusions formed on the light output surface and arranged in a skewed matrix. Each micro-protrusion includes at least three side surfaces connected in turn. A transverse width of each side surface decreases along a direction away from the light output surface. A liquid crystal display device using the prism sheet can efficiently decrease moiré patterns between the prism sheet and the liquid crystal display panel.

Abstract: This invention relates to film layer which is suitable for use in a light guide plate and methods of forming said film layer and light guide plate. The invention also relates to the light guide plate and light guide devices made therefrom. The film and light guide plate are suitable for use in a range of applications, particularly in connection with the backlighting of displays, for example, liquid crystal displays.

Abstract: An exemplary optical plate includes at least one transparent plate unit. The transparent plate unit includes a first surface, a second surface, a plurality of encircling protrusions, a plurality of elongated V-shaped protrusions and a lamp-receiving portion. The second surface is opposite to the first surface. The encircling protrusions are formed at the first surface. The elongated V-shaped protrusions are formed at the second surface. The lamp-receiving portion is defined in one of the first surface and the second surface. A backlight module using the optical plate is also provided.

Abstract: A liquid crystal display (2) includes a liquid crystal panel (29); a backlight module (20) providing light beams to the liquid crystal panel. The backlight module includes a light guide plate (23) having at least one light incident surface (231), and a light emitting surface (232) adjoining the at least one light incident surface; at least one light source (21) disposed adjacent to the at least one light incident surface; a prism sheet (25) disposed at the light emitting surface for converging light beams; and a first diffuser (26) disposed at the prism sheet for scattering the light beams therethrough. A haze ratio of the first diffuser changes according to the brightness differentia over a brightness distribution of the prism sheet for attaining a substantially uniform surface light beams output.

Abstract: An exemplary prism sheet includes a transparent main body. The transparent main body includes a first surface and a second surface. The first surface and the second surface are on opposite sides of the transparent main body. The first surface defines a plurality of micro-depressions. Each micro-depression forms four inner sidewalls connected with each other. A transverse width of each inner sidewall progressively decreases with increasing distance from the first surface. The second surface defines a plurality of parallelogram microstructures. Each parallelogram microstructure defines four adjacent triangular pyramid depressions.

Abstract: A backlight assembly includes a light source, a light-guide plate (LGP), a reflective sheet and at least one optical sheet. The light source emits light. The LGP includes a light-incident surface, a light-reflecting surface and a light-emitting surface. The light-incident surface receives the light from the light source. The light-reflecting surface has a plurality of first prism patterns spaced apart from each other and flat portions formed between the first prism patterns, which are substantially perpendicular to the light-incident surface. The light-emitting surface has a plurality of second prism patterns formed thereon. The reflective sheet is disposed below the LGP. At least one optical sheet is disposed on the LGP.

Abstract: A receiving module for a display device includes a receiving frame and a receiving container. The receiving frame includes a bottom part and a plurality of side parts extending from a peripheral portion of the bottom part creating a receiving space. The receiving container includes a bottom plate and a plurality of sidewalls. The bottom plate is disposed on the bottom part. Each of the sidewalls includes a first side plate extending from an edge portion of the bottom plate and coupled to a corresponding side part to face an outer surface of each of the side parts, and a second side plate bent at an upper end of the first side plate to face an outer surface of the first side plate. Thus, the strength of a display device against an external force, such as a bending stress or a twisting stress, may be improved.

Abstract: A high quality surface light source in which various kinds of unevenness in luminance due to use of small number of spot-like primary light sources for reducing power consumption is eliminated, and a light guide for use therein. The planar light guide (4) guides light emitted from a plurality of spot-like primary light sources (2) and has an incoming end face (41) of lights emitted from the primary light source (2) and an outgoing face (43) of guided light. A high light diffusion region (431) extends substantially along the direction of directivity of light entering the light guide (4) in a plane extending along the outgoing face (43), in the vicinity of the incoming end face of at least one of the outgoing face (43) and its rear surface (44) on the opposite side. The high light diffusion region (431) has a mean inclination angle larger than that of an adjacent region (434).

Abstract: A backlight for a display device, such as a liquid crystal display device, includes a light guiding plate having a front and a rear surface. The front and rear surfaces may be parallel to one another, or may instead be non-parallel. To the extent that such surfaces are non-parallel, one surface may be inclined at a single, or multiple angles with respect to the other surface. The backlight further includes a light source that is coupled to an edge of the light guiding plate by means of an energy conserving coupling section, and which provides light that is conditioned and transmitted through the light guiding plate. Light extractors are disposed on at least one side of the light guiding plate to assist in the transmission and conditioning of the light that is provided to the light guiding plate by the light source.

Abstract: A polarized light emitting light guide plate includes: a transparent substrate of optically isotropic material, in which the light incident through a lateral side thereof travels; an anisotropic liquid crystal polymer layer formed on an upper surface of the substrate and having first and second refractive indices with respect to first and second perpendicular polarization components; and a polarization separation microstructure formed at an interface between the transparent substrate and the liquid crystal polymer layer, which refracts or reflects the first polarization component and transmits the second polarization component. The refractive index of the polarization separation microstructure is substantially equal to the refractive index of the substrate; the first refractive index of the liquid crystal polymer layer is greater than the refractive index of the substrate, and the second refractive index of the liquid crystal polymer layer light is substantially equal to the refractive index of the substrate.

Abstract: Optical assembly includes a light source adjacent a light input edge and generally parallel and planar first and second surfaces each comprising respective patterns of well defined optical elements that are quite small in relation to the length and width of the optical assembly. At least some of the optical elements of each pattern include a respective sloped surface for directing at least some light emitted from the light source. The respective slope angle of the sloped surface of at least some of the optical elements of one of the patterns is different from the respective slope angle of the sloped surface of at least some of the optical elements of the other pattern such that more of the light is emitted from one of the surfaces than is emitted from the other surface.

Abstract: A method for making a prism sheet includes: providing a cutting device comprising a cutter, a table plate, and a control unit, the table plate controlled to move up and down by the control unit, and the cutter having a blade rotatable; providing a mold insert preform on the table plate, the mold insert preform having a flat surface; moving the cutter to etch the flat surface of the mold insert preform along a first direction, and simultaneously driving the table plate to move up and down by the control unit in a first predetermined manner to form first elongated depressions in the flat surface; moving the cutter to etch the flat surface of the mold insert preform along a second direction to form second elongated depressions in the flat surface, thereby forming a mold insert; using the mold insert to form the prism sheet by injection molding method.

Abstract: An exemplary optical plate includes a first transparent layer (21), a second transparent layer (23) and a light diffusion layer (22). The first transparent layer includes an outer surface (210) and a plurality of first conical frustum-shaped depressions (211) defined at the outer surface. The second transparent layer includes an outer surface (230) and a plurality of second conical frustum-shaped depressions (231) defined at the outer surface. The first transparent layer, the light diffusion layer, and the second transparent layer are integrally formed, with the first transparent layer in immediate contact with the light diffusion layer, and the second transparent layer in immediate contact with the light diffusion layer. The light diffusion layer includes a transparent matrix resin (221) and a plurality of diffusion particles (222) dispersed in the transparent matrix resin.

Abstract: A light source device capable of realizing a color display having the high light-use efficiency with a simple configuration is provided. Provided is a light source device including a prism sheet disposed to face a plane to be irradiated, and to bend an incident light to a direction substantially orthogonal to an incident direction; a light source section separately emitting a plurality of color lights having wavelength regions different from each other so that each of the color lights enters into the prism sheet at a small angle with respect to an extending direction of the prism sheet; and a light source drive means for driving the light source section so that each of the color lights periodically scans the plane to be irradiated so as to perform the line-sequential irradiation operation.

Abstract: An illuminating apparatus providing polarized color light and a display apparatus including the illuminating apparatus are provided. The illuminating apparatus includes a light source; a polarization light guide plate (LGP) unit which converts a polarization direction of light emitted from the light source into linearly polarized light, and collimates the linearly polarized light; and a cholesteric liquid crystal color filter which disposed on an upper portion of the polarization LGP unit, and selectively reflects light according to a polarized status and a wavelength of the light.

Abstract: An exemplary optical plate includes a first transparent layer, a second transparent layer and a light diffusion layer. The light diffusion layer is between the first and second transparent layers. The light diffusion layer, the first and second transparent layers are integrally formed. The light diffusion layer includes a transparent matrix resin and a plurality of diffusion particles dispersed in the transparent matrix resin. The first transparent layer includes a plurality of elongated V-shaped protrusions at an outer surface thereof that is distalmost from the second transparent layer. The second transparent layer includes a plurality of micro-recesses at an outer surface thereof that is distalmost from the first transparent layer. Each micro-recess is a frustum of an inverted pyramid in shape. A direct type backlight module using the optical plate is also provided.

Abstract: A backlight module includes a light source module and a diffuser plate. The diffuser plate has a plate body, a plurality of light-scattering areas and a plurality of light-gathering areas. The light-scattering areas and the light-gathering areas are alternately disposed on a light-entrance surface or a light-exit surface of the plate body. The light-scattering area includes a plurality of cambered units while each cambered unit has a convex cambered surface. The light-gathering area includes a plurality of prism lenses. Two side surfaces of the prism lenses intersect at an angle ?.

Abstract: Provided is a wide angle diffuser including a plate-shaped body, a plurality of microlenses, and a plurality of prisms. The plate-shaped body has an incident surface on which light is incident and an exit surface through which light is emitted form the plate-shaped body. The microlenses and the prisms are respectively disposed on one of the incident surface and the exit surface. Also provided is a liquid crystal display including a liquid crystal panel, a backlight unit, provided on a rear surface of the liquid crystal panel, which emits collimated light to the liquid crystal panel, and the wide angle diffuser diffusing light passing through the liquid crystal panel.

Abstract: Disclosed is an organic electroluminescent device comprising a first electrode, a second electrode, at least one organic layer containing a luminescent layer and disposed between the first electrode and the second electrode, a transparent substrate and a prism structure disposed between the first electrode or the second electrode and the transparent substrate, wherein the prism structure is disposed such that the apexes of the prisms face the transparent substrate side and the coefficient of variation in the pitch of the apexes of the prisms is 1% or more.

Abstract: The optical element apparatus for two-dimensional controllable localized partition backlight module is disclosed. The optical element apparatus comprises of a plurality of optical units which include a plurality of point light sources, light guides and collimating sheets. The point light source is located at the center of the light guide. The light guide includes the incident surface, the bottom place connecting with the light incident surface, and the light output surface. There are micro structures on the bottom place of the light guide and the top surface of the collimating sheet.

Abstract: An optical diffusion structure includes an optical diffusion structure comprising a plurality of convex portions and a plurality of concave portions. Each convex portion is adjacent to a plurality of concave portions and each concave portion is adjacent to a plurality of convex portions. The convex portions, the concave portions and each junction of the convex and concave portions have a curvature different from 0. The optical diffusion structure further includes a diffusion plate having a first surface, wherein the optical diffusion structure is formed on the first surface, and the convex portions are arranged in a two dimensional array along a first direction and a second direction, and the concave portions are arranged in a two dimensional array along a third direction and a fourth direction.

Abstract: A surface light source device is disclosed that provides greater light condensation in the frontal direction and higher luminance in comparison to a conventional surface light source device. Disclosed is a surface light source device providing a light source, a light guide having at least one of the side surfaces thereof as an incident surface and an outgoing surface substantially perpendicular to the incident surface, and at least two prism sheets, in which the surfaces formed by the prisms of the prism sheets are arranged so as to face upward, moreover the surfaces of the sides opposing the surfaces formed by the prisms of the prism sheets are arranged substantially parallel to the outgoing surface of the light guide.

Abstract: A light guide plate includes a light-emitting surface, a light-reflecting surface opposed to the light-emitting surface, and a light-incident surface including a protrusion formed continuously along an edge portion of the light-emitting surface. Accordingly, light that has entered the protrusion is transmitted through the protrusion and totally reflected on an inner surface of the light-emitting surface to thus propagate inside the light guide plate. As described above, since incident light components emitted toward an upper portion of the light-incident surface can be effectively blocked by the protrusion, luminance distribution characteristics as well as a light use efficiency can be improved. The light guide plate is produced by a punching press process.

Abstract: A light guide plate has a main-side microprism array sheet (main-side MPA sheet) 3 adhered to the top face 2a thereof, and a sub-side microprism array sheet (sub-side MPA sheet) 4 adhered to the bottom face 2b thereof. A prism formation region of the sub-side MPA sheet 4 is smaller than that of the main-side MPA sheet 3. Prisms in the prism formation region of the main-side MPA sheet 3 are, in an arrangement where the density of prisms arranged increases with distance from a light source 5, so arranged that the density of prisms arranged increases in a region that faces the prism formation region of the sub-side MPA sheet 4.

Abstract: A side type light emitting diode (LED) liquid crystal display (LCD) includes a prism light guide panel in a side type LED backlight to allow scanning and divisional driving to improve motion blur of video or an overall sharpness of an image. The side type LED LCD includes: a lower cover; first and second prism light guide panels disposed in a plurality of layers on the lower cover, ridges of prism mountains formed on the first prism light guide panel being substantially perpendicular to ridges of prism mountains formed on the second prism light guide panel; lamp units being provided on at least one side of each prism light guide panel along the ridges of the prism mountains; and a liquid crystal panel separated from the prism light guide panels that receives light transmitted through the first and second light guide panels emitted from the light units.

Abstract: A plurality of convex strip portions are formed on a front surface (or a back surface) of a light guiding plate, extending in a direction from a light incidence plane to an opposite side surface. A concave portion is formed on a side surface of each convex strip portion. An inner wall of the concave portion is formed from at least two flat planes inclined with respect to three axial directions orthogonal to each other (X, Y and Z axial directions), respectively. Thereby, damage to the surface illuminant equipment such as a light guiding plate due to the interference between a back surface and units disposed on the back surface of the light guiding plate is prevented, while preventing a linear part with relatively low luminance from being viewed from the front surface of the light guiding plate.

Abstract: A solid waveguide comprises opposite TIR surfaces further comprising: a) at least one light input surface for coupling light from a solid state light source; b) at least one mixing section; c) at least one light emitting surface; and d) a desired pattern of light redirecting features located on one TIR surface or between the TIR surfaces.

Abstract: An optical element covering member is provided which can suppress degradation in display performance caused by warping and undulation. The optical element covering member includes at least one optical element, a support medium supporting the optical element; and a covering member covering the optical element and the support medium. In the above optical element covering member, the covering member has a Vicat softening point of more than 85° C., and at least one surface of the covering member, which covers the support medium, has a coefficient of thermal expansion in the range of 85% to 160% of the coefficient of thermal expansion of the support medium.

Abstract: A backlight assembly and a manufacturing method of light guide plate of the backlight assembly is provided. The light guide plate includes an incident surface to which light is incident, an exiting surface from which the light exits, and a reflection surface facing the exiting surface. The light guide plate includes recesses provided on the reflection surface recessed toward the exiting surface to scatter the light. Each of the recesses has a depth-to-width ratio of about 0.2 to about 0.33. Two prism sheets are disposed on the light guide plate. Light exits from the light guide plate at an angle of about 25 degrees to about 30 degrees.

Abstract: A surface light source device has a surface-shaped light source having a light emission surface, a first prism sheet at a side of the light emission surface, and a second prism sheet in an opposite side from the surface-shaped light source with the first prism sheet interposed therebetween. The first prism sheet includes prisms having a greater length in a longitudinal direction and having an apical angle between 72 and 100 degrees which are arranged on a surface facing the surface-shaped light source. The second prism sheet includes prisms having a greater length in a longitudinal direction and having an apical angle between 100 and 125 degrees which are arranged on a surface facing a direction opposite the surface-shaped light source. The first and second prism longitudinal direction form an angle of 15 degrees or less, when the first and second prism sheet are viewed in a perpendicular direction.

Abstract: The invention generally relates to an optical turning film for providing light redirection, comprising: (a) an input surface for accepting incident light comprising a plurality of roof prism structures arranged in a two-dimensional array; and, (b) a substantially planar output surface.

Abstract: The liminance within the viewing angle of an LCD device is increased by using an optical film of transparent material. The film has a first surface having a wave structure including a plurality of isosceles triangle prisms arranged side-by-side, and a second surface having an optically rough structure for performing diffuse transmission. The film may also have a first surface having a structure including a plurality of quadrangular prisms arranged side-by-side, and a second surface having an optically rough structure for performing diffuse transmission.