The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 22, 1996
Filed:
Jan. 11, 1996
Hiroki Takamori, Osaka, JP;
Masahiro Honjo, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An optical disk apparatus having rewritable optical disk with a spiral groove which is used as an information recording track. The track has two hard address mark areas formed once every rotation of the track around the center of the disk. The hard address mark areas are arranged in a single virtual straight line passing through the center of the disk to avoid crosstalk between recorded data and the hard address mark area. The track also has a periodic radial wobble groove containing frequency information at a specified period. A servo control circuit controls rotation of the disk at a constant linear velocity (CLV) in response to frequency information from the wobble groove. The hard address mark area and the wobble groove are pre-formed when pressing the disk. Sectors of equal length, where picture and sound information is recorded, are formed by recording a soft address mark signal produced in response to the hard address mark. The apparatus minimizes adverse effects due to crosstalk between reproduced data and the hard address mark. Therefore, high packing density recording of information can be achieved.