Abstract: A highly diffusing plastic sheet having a thickness of from 1 to 5 mm, a haze of 80% or more and a total light transmittance of 80% or more, which includes at least one diffuser layer A, two or more diffuser layers B, and optionally a diffusing agent-free layer C. The diffuser layer A is formed from a first matrix plastic and a first light-diffusing fine particle having an average particle size of from 2 to 6 ?m and a refractive index of from X?0.02 to X+0.02 wherein X is a refractive index of the first matrix plastic. The diffuser layer B is formed from a second matrix plastic and a second light-diffusing fine particle having an average particle size of from 10 to 18 ?m and a refractive index of from Y?0.03 to Y+0.03 wherein Y is a refractive index of the second matrix plastic.

Abstract: A lens sheet for use as a Fresnel lens sheet or a lenticular lens sheet of rear projection screens, which includes a plastic substrate and a lens element disposed on the plastic substrate. The plastic substrate includes at least a first surface layer, an intermediate layer and a second surface layer. Each of the first surface layer and the second surface layer has a saturated water absorptivity higher than that of the intermediate layer.

Abstract: A transmissive screen includes a diffusing plate 7 having two first diffusing layers 13 and 15, to which diffusing particles are added respectively, arranged with a second diffusing layer 14, to which diffusing particles whose particle size is smaller than that of the first diffusing layers 13 and 15 are added, in between. Accordingly, even in the case where a diameter of a projection pupil of a projection lens that projects light onto the transmissive screen is small, an image glaring when displaying a bright image can be controlled, while minimizing deterioration of gain, resolution and uniformity.

Abstract: A Fresnel lens sheet comprising a Fresnel lens substrate and a Fresnel lens, whose surface of the light source side has an average pitch of 200 ?m or smaller and ten point roughness of 3 to 15 ?m, a rear projection screen obtained by assembling the Fresnel lens sheet and a lenticular lens sheet, and a process for producing these. With the use of the Fresnel lens sheet and the rear projection screen in accordance with the present invention, a labyrinth light inside the screen and a surface reflection are diffused effectively and a ghost caused by them is remarkably reduced. Accordingly, the rear projection television employing the Fresnel lens sheet and the rear projection screen of the present invention provides excellent images without ghost light.

Abstract: A highly diffusing plastic sheet having a thickness of from 1 to 5 mm, a haze of 80% or more and a total light transmittance of 80% or more, which includes at least one diffuser layer A, two or more diffuser layers B, and optionally a diffusing agent-free layer C. The diffuser layer A is formed from a first matrix plastic and a first light-diffusing fine particle having an average particle size of from 2 to 6 ?m and a refractive index of from X?0.02 to X+0.02 wherein X is a refractive index of the first matrix plastic. The diffuser layer B is formed from a second matrix plastic and a second light-diffusing fine particle having an average particle size of from 10 to 18 ?m and a refractive index of from Y?0.03 to Y+0.03 wherein Y is a refractive index of the second matrix plastic.

Abstract: A lens sheet for use as a Fresnel lens sheet or a lenticular lens sheet of rear projection screens, which includes a plastic substrate and a lens element disposed on the plastic substrate. The plastic substrate includes at least a first surface layer, an intermediate layer and a second surface layer. Each of the first surface layer and the second surface layer has a saturated water absorptivity higher than that of the intermediate layer.

Abstract: A Fresnel lens sheet comprising a Fresnel lens substrate and a Fresnel lens, whose surface of the light source side has an average pitch of 200 &mgr;m or smaller and ten point roughness of 3 to 15 &mgr;m, a rear projection screen obtained by assembling the Fresnel lens sheet and a lenticular lens sheet, and a process for producing these. With the use of the Fresnel lens sheet and the rear projection screen in accordance with the present invention, a labyrinth light inside the screen and a surface reflection are diffused effectively and a ghost caused by them is remarkably reduced. Accordingly, the rear projection television employing the Fresnel lens sheet and the rear projection screen of the present invention provides excellent images without ghost light.

Abstract: Acrylic resin compositions having excellent antistaticity, good appearance and superior optical properties made by blending (A) 100 parts by weight of an acrylic resin; (B) a phosphonium sulfonate consisted of organic sulfonate anion and organic phosphonium cation; (C) a lithium benzenesulfonate; and (D) 0.05 to 2.0 parts by weight of a fatty acid ester and/or amide, wherein (B)/(C) is 2/8 to 8/2 by weight and (B) plus (C) is 0.2 to 2.5 parts by weight.

Abstract: A methyl methacrylate-styrene copolymer resin composition in the form of an optical sheet which comprises: (A) 100 parts by weight of a methyl methacrylate-styrene copolymer resin having a weight ratio of methyl methacrylate units to styrene units of 75:25 to 50:50, (B) 0.5 to 5 parts by weight of a lithium sulfonate having a C.sub.8 -C.sub.16 alkyl group, and (C) 0.3 to 1.5 parts by weight of glass beads, as a light diffuser. The methyl methacrylate-styrene copolymer resin composition in the form of an optical sheet of the present invention has excellent antistatic properties and appearance properties. By using the lithium sulfonate in the form of a solution, excellent light diffusion properties (without impaired dispersion properties), excellent total light transmittance and desired coloring properties can be obtained, and hence desirable optical properties and desirable physical properties and dimensional stability can be obtained.