OPTICAL INFORMATION RECORDING MEDIUM

摘要

PURPOSE:To eliminate a difference in recording sensitivity in the diametral direction within an optical disk and to improve and stabilize the sensitivity of the disk by forming the recording layer of the disk to the light absorption efficiency higher on the outer periphery than on the inner periphery. CONSTITUTION:A reflection layer 2 is formed in order to enhance the absorption efficiency of the incident rays in the recording layer 4 and to expand the design range of an optical information recording medium in association with the refractive indices, attenuation coeffts. and film thicknesses of the other layers. The light absorption efficiency in the recording layer 4 is higher as the light reflectivity in the reflection layer 2 is increased. The reflection layer 2 is formed to have the reflectivity higher on the outer periphery than on the inner periphery by utilizing such fact. The optical disk which is not deteriorated in the recording sensitivity even on the outer periphery where the line speed is high as compared to the inner periphery is thereby obtd.