Patent ID: 8318056

Claim:
A method for manufacturing an optical sheet having both a light condensing function and a light diffusing function, the optical sheet comprising, on an entire surface thereof, minute convex-concave patterns including micro-dimples at vertices of convex quadrangular pyramids or in edge lines of concave quadrangular pyramids, the method comprising: a liquid application step of consecutively applying a liquid of curable resin onto a web-form transparent support which is being carried to form a resin coat layer; a transfer step of winding the transparent support on which the resin coat layer is formed around a rotating zigzag-faced roller thereby to transfer convex-concave patterns on the surface of the zigzag-faced roller onto the resin coat layer; a curing step of curing, in a state in which the transparent support is wound around the zigzag-faced roller, the resin coat layer to which the convex-concave patterns have been transferred; a peeling step of peeling the transparent support having the resin coat layer off the zigzag-faced roller; and a blow-in step of forming micro-dimples on the surface of the convex-concave patterns on the resin coat layer while being transferred by the transfer step, by blowing gas, immediately before winding the transparent support around the zigzag-faced roller, into a gap between the resin coat layer and the surface of the zigzag-faced roller.