Patent Number: 7,085,208

Title: Information recording method

Abstract: A reproducing apparatus for reproducing information recorded on an optical recording medium having a disk-like substrate, a spiral or concentric-shaped groove structure along tracks formed on the substrate, and each of the tracks being divided into a plurality of recording units. Each of the recording units includes a dropout portion of the groove structure which is a non-groove portion along the track in a circumferential direction of the track, and the groove structure is wobbled in a fixed cycle in a radial direction, which continues in the circumferential direction along the track. The apparatus includes an irradiation source for irradiating a light spot on the optical recording medium, an optical detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the detector.

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

Assignee: Hitachi, Ltd.

International Classification: G11B 7/00 (20060101)

Expiration Date: 8/01/02018