Patent ID: 7923090
Filing Date: 2011-04-12
Classification: G11B,Y10T

Abstract:
1. An optical information recording medium comprising: a transparent protective layer; a signal recording layer; and a supporting substrate, wherein the respective layers are formed in this order from the light incident side for recording and reproducing, and the thickness of the transparent protective layer is 10 μm to 200 μm, wherein the transparent protective layer is formed of at least a resin film and an adhesive layer for making the resin film stick to the signal recording layer, layered in this order, from the light incident side for recording and reproducing, and the transparent protective layer has a boundary layer between the resin film and the adhesive layer, wherein the resin film has unevenness A on the surface contacting the boundary layer, and accordingly, the boundary layer has unevenness B on the surface contacting the adhesive layer where the unevenness A is existing, wherein the height or depth of the unevenness B is smaller than the height or depth of the unevenness A, wherein the unevenness A has a height or depth ranging from 0.3 μm to 3 μm, and when nf, na and ni represent index of refraction of the resin film, index of refraction of the adhesive layer and index of refraction of the boundary layer, respectively, the indices nf, na and ni satisfy the following equation: and further satisfy the following equations: