Patent ID: 6938267
Filing Date: 2005-08-30
Classification: G11B

Abstract:
1. An optical disc comprising: a substrate; an information signal portion having a plurality of layers and configured to record and/or reproduce an information signal; and a light transmission layer configured to transmit laser light used to record and/or reproduce the information signal, the information signal portion and the light transmission layer being formed on one main plane of the substrate of the optical disc, wherein the light transmission layer comprises a sheet having light transmissivity and an adhesive layer made of a pressure-sensitive adhering agent for adhering the sheet to the main plane of the substrate, wherein the light transmission layer has a film thickness in the range from 90 μm to 110 μm, and wherein a reaction protection layer having a dielectric of one of silicon nitride and silicon oxide is formed on the information signal portion so that the reaction protection layer faces the adhesive layer.