Sharp Kabushiki Kaisha Corporation

Memory-Tech Holdings Inc.

Memory-Tech Corporation

Tdk Corporation

Masahito Konishi

Hideharu Tajima

Masaki Yamamoto

Hirohisa Yamada

Takayuki Naka

Go Mori

Yoshihisa Adachi

Yasuhiro Harada

Isamu Kuribayashi

Atsushi Etoh

Hiroaki Ashiwa

Ryo Kojima

An optical disk () of the present invention includes (i) a medium information region () (a) in which type identification information is recorded by recesses and/or protrusions which are formed by a given modulation method and whose lengths are longer than a length of an optical system resolution limit of a playback device and (b) in which first address information is recorded in a first address data format and (ii) a data region () (a) in which content data is recorded by recesses and/or protrusions which are formed by the given modulation method and which include a recess and/or a protrusion whose length is shorter than the length of the optical system resolution limit and (b) in which second address information is recorded in a second address data format.

Method for playing back information recording medium

Information recording medium and reproduction device

A reproducing device () includes (i) an optical pickup () for irradiating, with reproduction light, an optical disk () which is a super-resolution medium, (ii) an RF signal processing circuit () for converting, into a reproduction signal, light which reflected off optical disk (), (iii) an i-MLSE detecting section () for evaluating quality of the reproduction signal, and (iv) a spherical aberration correcting section () for correcting a spherical aberration by using a result of evaluation of the quality of the reproduction signal.

Reproducing device

In a case where (i) a reflectance calculated from a reflected light amount obtained from a longest pit (Pmax) or a longest space (Smax) in a first pit row is defined as a first reflectance and (ii) a reflectance calculated from a reflected light amount obtained from a longest pit (Pmax) or a longest space (Smax) in the second pit row is defined as a second reflectance, the first pit row is formed such that the first reflectance becomes substantially identical with the second reflectance.

Optical information recording medium having first and second pit row of identical reflectance

Optical information recording medium having first and second pit rows of identical reflectance

Optical information recording medium and reproduction method

Growing community of inventors

Chikusei, Japan

Masahito Konishi