Patent Number: 6,490,233

Title: Optical reproducing method

Abstract: An optical reproducing method for an optical medium including a disk-like substrate having a plurality of tracks associated with a plurality of grooves. A plurality of zones are provided with each zone including at least two tracks. Radially adjacent units of a respective zone are delimited by a pair of radial lines joined to form a central angle at an apex proximate to a center of the disk-like substrate with each unit of a respective zone being delimited by the same central angle and units of different zones being delimited by different central angles. The grooves are wobbled in the radial direction and the length is the same for the different zones. The method includes irradiating an optical spot on the optical medium, detecting a reflected beam from the optical medium, and reproducing information on the optical medium by using a signal obtained by the reflected beam.

Inventors: Miyamoto; Harukazu (Kodaira, JP), Suzuki; Yoshio (Fujisawa, JP), Suzuki; Motoyuki (Yokohama, JP), Sugiyama; Hisataka (Kodaira, JP), Minemura; Hiroyuki (Yokohama, JP), Fushimi; Tetsuya (Chiqasaki, JP), Tokushuku; Nobuhiro (Yokohama, JP)

Assignee: Hitachi, Ltd.

International Classification: G11B 7/007 (20060101); G11B 7/00 (20060101); G11B 27/28 (20060101); G11B 7/09 (20060101); G11B 27/19 (20060101); G11B 19/20 (20060101); G11B 19/247 (20060101); G11B 19/24 (20060101); G11B 19/28 (20060101); G11B 27/30 (20060101); G11B 7/004 (20060101); G11B 7/0037 (20060101); G11B 27/24 (20060101); G11B 007/00 ()

Expiration Date: 12/03/2019