Katten Muchin Zavis Rosenman
High-density optical information recording medium and a substrate and a stamper for the manufacture thereof
An optical information recording medium enables accurate tracking servo throughout the recording area including inner and outer peripheral region by way of reducing the differences between the amplitudes of the push-pull signals from those regions. The medium comprises a light transmitting substrate, a tracking groove formed on a surface of the light transmitting substrate, a recording layer formed on the surface of the substrate having the groove, and a reflective layer, formed on the recording layer, for reflecting recording and reproducing laser beams. The width of the groove at the outer peripheral region is made smaller than that at the inner peripheral region. Specifically, the ratio of the width at the outer peripheral region to that at the inner peripheral region is set to be greater than or equal to 0.8.
Taiyo Yuden Co., Ltd.
G G
G11B G11B
inventional inventional
Emiko Yuji Ryou Toru Toshiaki
Hamada Tomizawa Negishi Fujii Tajima