OPTICAL INFORMATION RECORDING MEDIUM AND MANUFACTURING METHOD THEREOF

摘要

There is provided an optical information recording medium assuring a preferable signal quality even in a high-density recording using a translucent information layer. The optical information recording medium includes at least one layer of the information layer including a recording layer for recording/reproducing an information signal by laser beam irradiation. The first information layer of the information layer at the side of irradiation side has a guide groove formed in a spiral or coaxial shape on the surface. The inclined surfaces of the inner circumferential side and the outer circumferential side of the guide groove are formed on a protection substrate or an isolation layer having inclination angles alpha and beta, respectively, with respect to the bottom of the guide groove. The guide groove has, in the radial direction, one or more asymmetric regions where the inclination angles alpha and beta are different. The information layer has a film thickness which is substantially identical at the inclined surfaces of the inner circumferential side and the outer circumferential side of the asymmetric region.