Hitachi Computer Peripherals Co., Ltd.

Hitachi, Ltd.

Kazuhiro Soga

Motoyasu Terao

Takeshi Shimano

Yasushi Miyauchi

Toshimasa Kamisada

Shinichi Nakatsuka

Eiji Sahota

Shin Matsumoto

Hitoshi Ishii

Yoshiaki Ogino

To achieve stable, high capacity, high speed recording. Of two light beams emitted from a light irradiation means, one or two beams are made pass through an optical path changeable member whereof at least one of the thickness and refractive index changes continuously or in two or more steps immediately after emission from the light irradiation means, so that a difference is introduced into the optical path length of the two beams, and the focusing point of one beam is made to vary to coincide with a position in the recording layer used for playback or recording. Another light beam is used for servo. Converging of light during recording or read of a multilayer recording medium is performed with higher precision than in the prior art, so higher density, higher capacity recording/playback can be performed.

Information recording apparatus, information recording medium and information recording medium

Initial crystallization method of recording media and device thereof

Growing community of inventors

Odawara, Japan

Kazuhiro Soga