Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
Optical disk having clamp portion higher than substrate
A magneto-optical disc is prepared having substrates made from polycarbonate, on which recording layers are formed to serve as signal recording medium sections facing each other via a spacer. The magneto-optical disc is also provided with a clamp portion formed in such a way that when the magneto-optical disc is mounted on an optical disc recording and/or reproduction apparatus having an objective lens with a focal distance L0 the recording layer is positioned at a distance L1 which is equal to a focal distance of the objective lens obtained in the substrate via refraction.
Sony Corporation
G G G
G11B G11B G11B
inventional inventional inventional
Kenji
Yamazaki