Kabushiki Kaisha Toshiba

Nec Corporation

Masaaki Matsumaru

Chosaku Noda

Kozo Taira

Kazuo Watabe

Toshiyuki Nakano

Hideo Ando

Akihito Ogawa

Yutaka Kashihara

Yutaka Yamanaka

Toyoki Taguchi

Toshiaki Iwanaga

Tatsunori Ide

Isao Hoshino

Masahiko Tanaka

Yasuo Motegi

In order to stably carry out reproduction of information in an optical disc medium () using a PRML (partial-response maximum-likelihood) method for reproducing the signal, the optical disc medium () has not only a data recording area () where data is recorded at high density but also a system information recording area () where information is recorded at low density and binary equalizing/reproducing can be easily made. Information required to circuit setting is recorded in the system information recording area.

Optical disc medium having a system information recording area of low recording density

Header regions are formed by dividing a groove or grooves. Each of the header regions is provided with two ID sections G-ID, G-IDstoring address information and a track center detection mark section, arranged between the two ID sections, so as to be used for detecting the track center.

Disk, disk device and track center detection method

An information recording medium has a recording track, a plurality of address areas which are formed on the recording track and record address information, and mark areas, the number of which is larger than the number of address areas, and which are formed at predetermined intervals and include mark information. Each address area records address information by means of pits, and each mark area records mark information by means of wobbles as a part of a track boundary.

Information recording medium, information recording apparatus, and information reproduction apparatus

An optical disk comprises a mark train, which has at least one shortest mark and at least one other mark, recording readable information by applying a light beam, wherein the shortest mark of the mark train have a width larger than that of the other mark.

Optical disk and method of manufacturing the same

An optical disk including a substrate and a recording film formed on the surface of the substrate, wherein the recording film includes an information recording domain. A servo information for a tracking control and a format condition information for formatting the information recording domain are provided on the substrate, and the information recording domain is formatted in accordance with the format condition information.

Optical disk having a format condition information drive

An optical disk has first and second substrates, at least one of which is provided with optically readable pits corresponding to record data, and a reflection film coated on the pits. In the optical disk, the first and second substrates are laminated on each other such that the surface on which the pits are formed, is located inside. Label information, indicative of the record data, is formed on at least one of the surfaces of the first and second substrates, which contact each other.

Optical disk and optical information reproducing apparatus

A primary optical disk recording apparatus comprises a first light source for recording a signal on a primary optical disk, an objective lens for converging a light beam from the first light source on the primary optical disk, a second light source for detecting a focus error between the objective lens and the primary optical disk, and a controller for detecting a reflection light beam from the first light source, which is reflected from the primary optical disk, while the signal is being recorded on the primary optical disk, and for subjecting a signal of the reflection beam to an arithmetic operation process, thereby detecting a first focus error signal and controlling the focus error on the basis of the first focus error signal.

Growing community of inventors

Funabashi, Japan

Masaaki Matsumaru