Optical recording medium

Application Number: 00108349
Application Date: 2000.05.12
Publication Number: 1274151
Publication Date: 2000.11.22
Priority Information: 1999/5/13 JP 133361/1999
International: G11B7/24
Applicant(s) Name: Sony Corp.
Inventor(s) Name: Koki Motoyu;Yukimoto Tomomi;Yamazaki Katashi
Patent Agency Code: 11038
Patent Agent: ma gao
Abstract An optical recording medium prohibiting the grazing or deformation from being produced on its light transmitting layer to assure optimum recording and/or reproduction. The optical recording medium includes a substrate, 0.3 mm to 1.2 mm in thickness, and a light transmitting layer, 3 mum to 177 mum in thickness, bonded on the recording layer. The information may be record and/or reproduce by irradiating the light from the side of the light transmitting layer. The surface of the light transmitting layer is surface-processed with a view to increasing the hardness, reducing the frictional coefficient and to prevention of electrification. The surfaceprocessed light transmitting layer has a hardness not less than 3 HMV in terms of Vickers hardness. Alternatively, the surface-processed light transmitting layer has a hardness not less than 0.5 GPa and a Young's modulus not less than 4 GPa as measured by the nano-indentation method.