Optical disc medium and optical disc device

Patent metadata

Field	Value
Publication number	US-2016111122-A1
Application number	US-201514984179-A
Country	US
Kind code	A1
Filing date	Dec 30, 2015
Priority date	May 31, 2013
Publication date	Apr 21, 2016
Grant date	—

Abstract

An optical disc medium includes a land and a groove at which information can be recorded. A predetermined number of address information units which record address information of the land or groove are provided in a circumferential direction of the optical disc medium. The address information unit of the land includes three or more address recording areas capable of recording address information. The address information is recorded on one area selected from among the three or more address recording areas. The address information unit of the land has address information which is recorded, in the same modulation, on the side of the inner adjacent groove and on the side of the outer adjacent groove. The one area to be selected from among the three or more address recording areas for recording the address information of the land is different among three address information units adjacently arranged in a radial direction.

First claim

What is claimed is:

1 . An optical disc medium comprising a land and a groove at which information can be recorded, wherein
a predetermined number of address information units which record address information of the land or groove are provided in a circumferential direction of the optical disc medium, the address information unit of the land includes three or more address recording areas capable of recording address information, the address information is recorded on one area selected from among the three or more address recording areas, the one area to be selected from among the three or more address recording areas for recording the address information of the land is different among three address information units adjacently arranged in a radial direction, wobbles are formed on the land and the groove, the wobbles include a based wobble and an information wobble indicating a predetermined logical value, the address information is recorded with the logical value of the information wobble, the logical value of the information wobble is represented by a waveform having a phase different from a phase of the base wobble by about −90 degree and a waveform having a phase different from a phase of the base wobble by about +90 degree, the wobble of the groove adjacent to a land on the inner circumference side has the same waveform as the wobble of the groove adjacent to the land on the outer circumference side, and variation of track width of the land or groove is suppressed to a predetermined range.

2 . The optical disc medium according to claim 1 , wherein the predetermined range is 70% of a width of a track having waveform of which phase is different from a phase of the base wobble by 180 degree.

3 . The optical disc medium according to claim 1 , wherein the number of the address information units provided in the circumferential direction and the number of the address recording areas are coprime to each other.

4 . An optical disc device that reproduces information from the optical disc medium according to claim 1 , comprising:
a signal generator configured to generate a signal in accordance with the wobbles formed on the land or groove; a phase-shifted waveform generator configured to generate a signal having a phase difference of 90 degrees with respect to the base wobble, from the signal generated by the signal generator; a phase detector configured to perform phase detection by using the signal generated by the signal generator and the signal generated by the phase-shifted waveform generator to generate an signal; an area determining unit configured to determine one area on which address information is recorded from the three or more address recording areas, according to an absolute value of a signal generated by the phase detector; and an address detector configured to detect an address from the area determined by the area determining unit based on a detection result of the phase detector.

5 . A method of reproducing information from the optical disc medium according to claim 1 , comprising:
generating a signal in accordance with the wobbles formed on the land or groove; generating a signal having a phase difference of 90 degrees with respect to the base wobble, from the signal generated by the signal generator; performing phase detection by using the signal generated by the signal generator and the signal generated by the phase-shifted waveform generator to generate an signal; determining one area on which address information is recorded from the three or more address recording areas, according to an absolute value of a signal generated by the phase detector; and detecting an address from the area determined by the area determining unit based on a detection result of the phase detector.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Minamino Junichi
• Miyashita Harumitsu
• Nakata Kohei

Classifications

• G11B7/00718 Primary

  Groove and land recording, i.e. user data recorded both in the grooves and on the lands · CPC title

• G11B2007/00754

  Track shape, e.g. address or synchronisation information in wobbled track or sidewall · CPC title

• G11B20/1217

  on discs · CPC title

• G11B7/0053

  Reproducing non-user data, e.g. wobbled address, prepits, BCA · CPC title

• G11B7/24085

  Pits · CPC title