COMPOSITION FOR SUBSTRATE OF ASPHERICAL PROJECTION LENS, SUBSTRATE OF ASPHERICAL PROJECTION LENS USING THE COMPOSITION AND ASPHERICAL PROJECTION LENS

摘要

PROBLEM TO BE SOLVED: To provide a large-sized projection lens, which has high shape precision in spite of its being light-weight and low price and can project an image of high precision, having no distortion and no deformation by being incorporated into a projection device for projecting to a screen in particular, not in the vertical direction but in an inclined direction, especially from below in the inclined direction, and to provide a substrate thereof and a composition for the substrate.;SOLUTION: In a resin composition for constituting the projection lens by providing a reflection layer on the surface of an optical function forming plane of an aspherical molding having ≥150 cm2 plane area, with ≥10 cm minimum width for the plane, ≥3 mm molding thickness, the composition for the substrate of the aspherical lens is constituted by containing an amorphous thermoplastic resin, in which OH group content is ≤250 ppm and glass transition point is ≥70°C, and a mold releasing agent consisting of a fatty acid ester of an alcohol by 100 to 2,000 ppm with respect to the resin.;COPYRIGHT: (C)2002,JPO