Abstract: Disclosed are a base plate for use for a lens sheet that can realize the unlikeliness to be cracked while the self-sustenance of the lens sheet is being maintained, the lens sheet, and a projection screen comprising that lens sheet. In a base plate, the base plate constructing a lens sheet as a base sheet for a UV-curable resin layer by being bonded to the UV-curable resin layer and being made of ductile materials, the breaking flexure by bending of the ductile material is 0.08 or more; and the Izod impact value thereof is 5 KJ/m2 or more. Also, in a base plate consisting of fragile material, there is used a material that has respective physical properties wherein when it is assumed that F (MPa) represents the shearing force of the UV-curable resin; h (m) represents the thickness of the base plate; E (MPa) represents the bending modulus of elasticity of the fragile material; and &ohgr; (dimensionless quantity) represents the breaking flexure by bending, the relationship of F/hE&ohgr;<1.5 holds true.

Abstract: A lenticular lens sheet having an entrance surface and an exit surface comprises a base part, an entrance lens part forming the entrance surface and having an array of a plurality of convex lens elements capable of gathering light rays. A tinted layer is formed at least in a portion of the entrance lens part near the entrance surface. A light absorbing layer is formed in light-nongathering regions in the exit surface in which light rays refracted by the convex lens elements do not gather.

Abstract: Disclosed are a lens sheet wherein when molding a resin no damage is caused to a mold to there by enable the optical function of light diffusion agent particles to be enhanced, a projection screen, and a method of manufacturing the lens sheet.

Abstract: An apparatus for manufacturing a lens sheet comprises an application device, a substrate supply device, a pressing device and an irradiation device. The application device applies ionizing radiation curing type resin in the form of liquid on the upper surface of a forming die for a lens sheet to form an uncured resin body on the upper surface of the forming die. The substrate supply device places a substrate on the uncured resin body. The pressing device presses the substrate against the uncured resin body to flatten the uncured resin body, so as to form a uncured resin layer, while spreading the uncured resin body to an outside periphery of the forming die. The irradiation device irradiates ionizing radiation on the uncured resin layer through the substrate to cure the uncured resin layer.

Abstract: A lenticular lens sheet having an entrance surface and an exit surface comprises a base part, an entrance lens part forming the entrance surface and having an array of a plurality of convex lens elements capable of gathering light rays. A tinted layer is formed at least in a portion of the entrance lens part near the entrance surface. A light absorbing layer is formed in light-nongathering regions in the exit surface in which light rays refracted by the convex lens elements do not gather.

Abstract: A rear projection screen 10 comprises a Fresnel lens sheet 11 arranged on the projection side, and a lenticular lens sheet 12 arranged on the observation side. The Fresnel lens sheet 11 has a lenticular lens 11a for vertical diffusion on its light-entering side. The lenticular lens 11a for vertical diffusion contains a plurality of convex lenses which extend horizontally, and these plural convex lenses are arranged with a constant pitch. Further, the diffusion angle of the lenticular lens 11a for vertical diffusion continuously increases, and, at the same time, the direction of diffusion is gradually inclined to the central part side as the distance from the central part toward the edge side on the screen surface increases. The diffusion properties (the angle and direction of diffusion) of the lenticular lens 11a thus continuously vary between the central part and edge of the screen surface.

Abstract: A lenticular lens sheet for use as a rear projection screen, comprises a base lenticular lens sheet having a surface provided with a plurality of lenticular elements, and a surface diffusing part having minute diffusing elements. The surface diffusing part is combined with the base lenticular lens sheet by laminating a plastic film having one surface provided with the minute diffusing elements to the base lenticular lens sheet so that the minute diffusing elements lie on the surfaces of the lenticular elements or by embossing the minute diffusing elements in the surfaces of the lenticular elements of the base lenticular lens sheet with an embossing plastic film having a surface of a shape complementary to the minute diffusing elements.

Abstract: A rear projection screen including a Fresnel lens sheet arranged on the projection side, and a lenticular lens sheet arranged on the observation side. The Fresnel lens sheet has a lenticular lens for vertical diffusion on its light-entering side. The lenticular lens for vertical diffusion containing a plurality of convex lenses that extend horizontally, and these plural convex lenses are arranged with a constant pitch. Further, the diffusion angle of the lenticular lens for vertical diffusion continuously increases, and, at the same time, the direction of diffusion is gradually inclined to the central part as the distance from the central part toward each of the edges on the screen surface increases. The diffusion properties (the angle and direction of diffusion) of the lenticular lens thus continuously vary between the central part and the edges of the screen surface.

Abstract: A lenticular lens sheet 10A comprises, on the light-entering surface thereof, a light-entering lens part in which a plurality of light-entering lenses 11 are formed, and, on the light-emerging surface, a light-emerging lens part in which a plurality of light-emerging lenses 12 are formed. The light-emerging lenses 12 are so arranged that they respectively correspond to the condensing positions of the light-entering lenses 11. Further, a protruded portion 13A having a substantially rectangular cross section is formed on the light-emerging surface, at a position corresponding to the non-condensing position of each one of the light-entering lenses 11, and a black stripe 14 is formed on the top face 13a of this protruded portion 13A by the application of a light-absorbing agent. The light-entering lens 11 is in the shape of a convex lens projecting toward the light-entering side, and so designed that its condensing point will be inside the lenticular lens sheet 10A.

Abstract: A lenticular lens sheet for use as a rear-projection screen, comprises a body sheet; back lenses having a substantially elliptic cross section and formed in a back surface of the body sheet; front lenses formed in a front surface of the body sheet at the focal points of the back lenses or in the vicinity thereof; and a light absorbing layer formed on sections of the front surface at the non-focal points of the back lenses. Pitches p of the back and the front lenses, and thickness t of the lenticular lens sheet equal to distance between a plane in contact with the back lenses and a plane in contact with the front lenses meet an inequality: 1.1.ltoreq.t/p.ltoreq.1.4, and conic coefficient k of a conic section defining the cross section of the back lenses is in the range of -0.5 to -0.4.

Abstract: A lenticular lens sheet for use as a rear projection screen, includes a base lenticular lens sheet having a surface provided with a plurality of lenticular elements, and a surface diffusing part having minute diffusing elements. The surface diffusing part is combined with the base lenticular lens sheet by laminating a plastic film having one surface provided with the minute diffusing elements to the base lenticular lens sheet so that the minute diffusing elements lie on the surfaces of the lenticular elements or by embossing the minute diffusing elements in the surfaces of the lenticular elements of the base lenticular lens sheet with an embossing plastic film having a surface of a shape complementary to the minute diffusing elements.

Abstract: A lenticular lens sheet for a rear projection television, which exhibits smooth color change and has a wide viewing angle even in a television set having a large convergence angle. A group of vertical straight-line shaped entrance-side lens surfaces are provided on an entrance side I of the lenticular lens sheet. Each entrance-side lens surface has a cross-section defined approximately by a part of an ellipse, and satisfies the condition of 2.5.ltoreq.bp/a.sup.2 .ltoreq.3.0, where b is the major axis of the ellipse; a is the minor axis of the ellipse; and p is the width of each entrance-side lens surface. A group of vertical straight-line shaped exit-side lens surfaces are provided on an exit side O of the lenticular lens sheet. Each exit-side lens surface has a cross-section defined approximately by a part of an ellipse, and satisfies the condition of 0.55.ltoreq.b/(a.sup.2 .phi.).ltoreq.0.75, where .phi. is a convergence angle formed by two adjacent projection tubes.

Abstract: A film stretching structure holds a non-self-supporting film, sheet or the like taut so that the film, sheet or the like may not crease or slacken. The film stretching structure comprises a frame structure having, as principal components, a quadrangular outer frame having two opposite side members for supporting a film, a sheet or the like thereon, and an inner frame having side members substantially parallel to those of the outer frame, respectively, and disposed inside the outer frame so as to form gaps between the side members of the outer frame and the corresponding side frames of the inner frame, respectively, and bar-shaped stretching members. A film, a sheet or the like is supported on the two opposite side members of the outer frame, and the stretching members are pushed together with portions of the film, the sheet or the like into the gaps contiguous with the opposite side members of the outer frame supporting the film, the sheet or the like to stretch the same.

Abstract: The method and apparatus can manufacture a plastic sheet of uniform thickness and reduced distortion, by use of metallic molds and in accordance with cast molding polymerization (casting) technique. The plastic sheet manufacturing apparatus for manufacturing a plastic sheet by injecting a raw material into a polymerization cell (101) and by polymerizing the injected raw material by heat, includes a pair of first and second molds (104A, 104B) for forming the polymerization cell (101); and first and second heat conductors (102, 103) attached to both outside surfaces of the first and second molds, respectively, so as to be opposed to each other and to sandwich the first and second molds therebetween. Here, in particular, each of the first and second heat conductors is formed with a fluid passage (210) therein to circulate a heated fluid whose temperature is controlled.

Abstract: In a projection screen for a rear projection type television set, three lens sheets are arranged in the order of a lenticular lens sheet, a linear Fresnel lens sheet, and a circular Fresnel lens sheet when seen from a viewer's side toward a projector tube. As compared with the arrangement in which the linear and circular Fresnel lens sheets are exchanged with each other, it is possible to obtain a higher brightness and a more uniform brightness, and color uniformity in the picture plane. Further, when the light incident surface of the linear Fresnel lens sheet is matted, it is possible to eliminate white bands (seen from the viewer's side) effectively.

Abstract: A projection screen comprises a horizontal refracting linear Fresnel lens sheet, a vertical refracting linear Fresnel lens sheet and a light diffusing lenticular lens sheet, which are arranged from the beam-projection side starting with the horizontal refracting linear Fresnel lens sheet followed by the vertical refracting linear Fresnel lens sheet and ending with the light diffusing lenticular lens sheet.