Optical disc

Abstract

An optical disc having a light transmitting layer of a reduced uniform thickness. The optical disc has a transparent film bonded via a pressure-sensitive adhesive sheet or a dry photopolymer sheet on a substrate to serve as a light transmitting layer. The signal recording surface is formed on the substrate and/or the transparent film. The light transmitting layer may be constituted solely by a pressure-sensitive adhesive sheet or a dry photopolymer sheet. In the present optical disc, recording and/or reproduction is performed from the light transmitting layer with respect to the signal recording surface. The pressure-sensitive adhesive sheet or the dry photopolymer sheet is itself in a sheet form and is previously formed into a layer (sheet) of a pre-set thickness, in a manner different from the case in which a UV light curable resin is coated on a substrate. The light transmitting layer of an extremely thin film thickness and devoid of sporadic film thickness variations can easily be formed by using the sheet as an adhesive layer or a light transmitting layer itself.

Dependencies are inferred from the claim text.