Abstract: An optical sheet 5 is an optical sheet, at least a first surface of the optical sheet has unevenness. A sparkle contrast of the first surface measured in conformity with JIS C 1006: 2019 is 4% or less. An arithmetic average roughness Ra of the first surface measured in conformity with JIS B 0601: 2001 (with an assessment length set to 290 ?m) may be 0.6 ?m or less. A peak count RPc of the first surface measured in conformity with JIS B 0601: 2001 (with an assessment length set to 290 ?m) may be 16 or more.

Abstract: A display device includes a light-emitting module and a light-diffusing sheet stacked body. The light-emitting module includes at least one light guide plate including an upper surface and a lower surface, and light sources disposed at the lower surface side of the light guide plate. The light-diffusing sheet stacked body includes a first light-diffusing sheet disposed on the light guide plate, a second light-diffusing sheet disposed on the first light-diffusing sheet, and a third light-diffusing sheet disposed on the second light-diffusing sheet. The first light-diffusing sheet includes first protrusions at an upper surface side thereof. The second light-diffusing sheet includes second protrusions at an upper surface side thereof. The third light-diffusing sheet includes third protrusions at an upper surface side thereof. A shape of the third protrusion may be different from a shape of the first protrusions and/or a shape of the second protrusions.

Abstract: A protective film covers the surface of a cover member in an OLED display with a fingerprint recognition system. The protective film includes a base layer with an in-plane retardation value of 25 nm or less. A hard coat layer may be formed on a surface of the base layer. The surface is a surface farther from the cover member.

Abstract: When at least one scope of 0.5 mm square or more of a surface of an optical sheet having the unevenness is measured, height data of each of a plurality of pixels of an image obtained is determined, an approximated surface is calculated, from the height data of each pixel, for a minute region of 100 ?m2 or less, and a calculation is repeatedly performed to obtain an inclination angle between: (i) a flat surface appearing after the unevenness is imaginarily removed and: (ii) the approximated surface, while two-dimensionally shifting the minute region at equal intervals along the flat surface by using at least one of the pixels as a unit to obtain a plurality of minute regions, a total area of some of the minute regions each having the inclination angle of 30° or more, accounts for 30% or more of a total area of all the minute regions.

Abstract: An upper side light diffuser sheet includes a substrate layer, and a light diffusion layer overlaid on a front face side of the substrate layer. The light diffusion layer includes a resin matrix, and resin beads dispersed in the resin matrix. The resin beads include a first resin bead group having an average particle diameter D50 of 1.9 ?m or more and 3.3 ?m or less, and a second resin bead group having an average particle diameter D50 larger than the average particle diameter D50 of the first resin bead group. A mass ratio of the second resin bead group in an entire resin beads is 30% or more and 50% or less. A coating amount of the light diffusion layer is larger than 1.7 g/m2 and smaller than 3.0 g/m2.

Abstract: A display device includes a light-emitting module and a light-diffusing sheet stacked body. The light-emitting module includes at least one light guide plate including an upper surface and a lower surface, and light sources disposed at the lower surface side of the light guide plate. The light-diffusing sheet stacked body includes a first light-diffusing sheet disposed on the light guide plate, a second light-diffusing sheet disposed on the first light-diffusing sheet, and a third light-diffusing sheet disposed on the second light-diffusing sheet. The first light-diffusing sheet includes first protrusions at an upper surface side thereof. The second light-diffusing sheet includes second protrusions at an upper surface side thereof. The third light-diffusing sheet includes third protrusions at an upper surface side thereof. A shape of the third protrusion may be different from a shape of the first protrusions and/or a shape of the second protrusions.

Abstract: When at least one scope of 0.5 mm square or more of a surface of an optical sheet having the unevenness is measured, height data of each of a plurality of pixels of an image obtained is determined, an approximated surface is calculated, from the height data of each pixel, for a minute region of 100 ?m2 or less, and a calculation is repeatedly performed to obtain an inclination angle between: (i) a flat surface appearing after the unevenness is imaginarily removed and: (ii) the approximated surface, while two-dimensionally shifting the minute region at equal intervals along the flat surface by using at least one of the pixels as a unit to obtain a plurality of minute regions, a total area of some of the minute regions each having the inclination angle of 30° or more, accounts for 30% or more of a total area of all the minute regions.

Abstract: A multilayer of light diffusers includes the light diffusers layered one on top of another, and an air layer between adjacent light diffusers. Each of the light diffusers contains a light diffusing agent in a resin matrix. An example of the resin matrix is an aromatic polycarbonate, and an example of the light diffusing agent is a silicone-based diffusing agent.

Abstract: A backlight unit (5) includes a light guide sheet (21) and a light diffusion sheet (23) provided on the surface of the light guide sheet (21). Assuming that the coefficient of static friction between the light guide sheet (21) and the light diffusion sheet (23) measured at a temperature of 23° C. and a humidity of 50% in accordance with JIS K 7125 is Y1, and the difference in coefficient of linear expansion between the light guide sheet (21) and the light diffusion sheet (23) measured in accordance with JIS K 7197 is X, the following relational expression (1) is satisfied. [Math. 1] Y1?1.00×10?4X2?3.43×10?2X+2.35??(1).

Abstract: An upper side light diffuser sheet includes a substrate layer, and a light diffusion layer overlaid on a front face side of the substrate layer. The light diffusion layer includes a resin matrix, and resin beads dispersed in the resin matrix. The resin beads include a first resin bead group having an average particle diameter D50 of 1.9 ?m or more and 3.3 ?m or less, and a second resin bead group having an average particle diameter D50 larger than the average particle diameter D50 of the first resin bead group. A mass ratio of the second resin bead group in an entire resin beads is 30% or more and 50% or less. A coating amount of the light diffusion layer is larger than 1.7 g/m2 and smaller than 3.0 g/m2.

Abstract: An optical sheet includes a plurality of unit prisms disposed in parallel. The unit prism has an interior angle of an apex part within a range of 30° to 80°, inclusive, an inclination angle ?1 of a tip region within at least 10 ?m from the apex part of at least one of two prism surfaces constituting the unit prism that is greater than an inclination angle ?2 of a region other than the tip region, and a height of a ridge that changes in an extending direction of the ridge or differs between unit prisms adjacent to each other. Preferably, a difference (?1??2) between the inclination angle ?1 of the tip region within at least 10 ?m from the apex part and the inclination angle ?2 of the region other than the tip region is within a range of 0.1° to 20°, inclusive.

Abstract: An optical sheet includes a plurality of unit prisms disposed in parallel. The unit prism has an elastic modulus within a range of 0.5 MPa to 10 MPa, inclusive, and a height of a ridge of the unit prism that changes in an extending direction of the ridge or differs between unit prisms adjacent to each other. Preferably, the ridge has a linear shape, a polyline shape, or a curved shape, in a planar view. Preferably, a height of the unit prism of the ridge in the extending direction changes within a range of 0.5 ?m to 15 ?m, inclusive, at an interval within a range of 0.005 mm to 5 mm, inclusive.

Abstract: A laminate sheet includes an intermediate layer, a first matte layer laminated on a front face side of the intermediate layer, and a second matte layer laminated on a back face side of the intermediate layer. A ratio of a gloss at 60° of a back face of the second matte layer to a gloss at 60° of a front face of the first matte layer is no less than 3/2 and no greater than 10. The gloss at 60° of the front face of the first matte layer is preferably no less than 5 and no greater than 20. The gloss at 60° of the back face of the second matte layer is preferably no less than 30 and no greater than 80. An arithmetic average roughness of the front face of the first matte layer is preferably no less than 0.5 ?m and no greater than 1 ?m.

Abstract: A luminance equalization region is formed on one surface of an optical sheet incorporated into a liquid crystal display device to equalize luminance of a visible region of the liquid crystal display device. The luminance equalization region is in at least the visible region in a state in which the optical sheet is incorporated into the liquid crystal display device. The luminance equalization region in the visible region has a colored portion and a light-transmitting portion that surrounds the colored portion. The distance from an end of a display surface of the liquid crystal display device to an end of the visible region is 10 mm or less.

Abstract: Provided is a light diffusion plate that enables uniformization of luminance easily and reliably. The light diffusion plate is to be placed on a side of a light-emitting face of at least one light source, and comprises: a substrate layer that is light-diffusible and has a light-incident face to be opposed to the light-emitting face, and a light-outputting face on an opposite side of the light-incident face; a reflecting dot pattern that is provided on a side of the light-incident face or the light-outputting face of the substrate layer and includes a plurality of reflecting dots; and the light-shielding dot pattern that is provided on a side of the light-incident face or the light-outputting face of the substrate layer and includes a plurality of light-shielding dots, in which the reflecting dot pattern and the light-shielding dot pattern overlap at least partially in a planar view.

Abstract: A light diffusion plate for a direct-lit backlight unit is provided which is capable of inhibiting generation of defects in production, and which is superior in mechanical strength even if being formed to be thin. The light diffusion plate for a direct-lit backlight unit includes a resin matrix, and a diffusion agent dispersed in the resin matrix, in which a principal component of the resin matrix is a polycarbonate resin, a ratio Mw/Mn of a polystyrene equivalent weight average molecular weight Mw to a number average molecular weight Mn of the polycarbonate resin, as determined by gel permeation chromatography is no less than 1.8 and no greater than 3.2, and the weight average molecular weight Mw of the polycarbonate resin is no less than 3.0×104 and no greater than 6.5×104. The light diffusion plate has an average thickness of preferably no less than 0.1 mm and no greater than 1.0 mm.

Abstract: An optical sheet for a backlight unit for guiding toward a front face side rays of light emitted by an LED light source. The optical sheet includes one or more resin layers. Ultrafine grooves oriented in specific directions are provided on a front face side or a back face side of at least one resin layer of the one or more resin layers. An average number of the ultrafine grooves per unit length in a direction perpendicular to an average orientation of the ultrafine grooves is preferably no less than 10/mm and no greater than 10,000/mm. A face of the at least one resin layer provided with the ultrafine grooves preferably has an arithmetic average roughness (Ra) in a direction perpendicular to an orientation of the ultrafine grooves being no less than 0.01 ?m and no greater than 5 ?m. Ultrafine grooves preferably constitute a diffraction grating.

Abstract: A backlight unit satisfies the relationship given by the following expression: S<2(A??3T), where A (mm) represents the length along which the light shielding member covers the light diffusion sheet before shrinkage, T (mm) represents the thickness of the prism sheet, and S (mm) represents the amount of shrinkage of an end on the frame side of the light diffusion sheet in the planar direction of the light diffusion sheet. The backlight unit also satisfies the relationship given by the following expression: E<D, where D (mm) represents the distance between the end on the frame side of the light diffusion sheet before expansion and a frame and E (mm) represents the amount of expansion of the end on the frame side of the light diffusion sheet in the planar direction of the light diffusion sheet.

Abstract: A polarizer protective sheet includes a base material layer and a light diffusing layer formed on a surface of the base material layer. A plurality of protrusions are formed on an opposite surface of the light diffusing layer from the base material layer, and the protrusions have a substantially arc-shaped section. The average radius of the protrusions is 10 ?m or more and 100 ?m or less, and the average height of the protrusions is 10 ?m or less.

Abstract: A buffer sheet is provided capable of sufficiently inhibiting scratches on the prism sheet upon an impact applied by falling, etc. The buffer sheet is for use in a flat panel display including a prism sheet having prisms on a surface thereof and a display element disposed to face the prisms, wherein the buffer sheet is to be disposed between the prism sheet and the display element, and an average microindentation hardness of the buffer sheet is no greater than 250 N/mm2. The buffer sheet preferably has projections on a face on a side to face the prism sheet. The average microindentation hardness is preferably measured at the projections. The buffer sheet preferably includes a buffer layer to face the prism sheet, the buffer layer preferably containing a resin matrix and resin beads dispersed in the resin matrix. A haze value of the buffer sheet is preferably 20%-95%.