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:
Nov. 20, 2001
Filed:
Jul. 12, 1999
Takashi Inoue, Osaka, JP;
Keiichi Kameda, Uji, JP;
Tatsuya Suzuki, Katano, JP;
Hideaki Hatanaka, Katano, JP;
Masaaki Takata, Hirakata, JP;
Abstract
An object of this invention is to provide a method for processing signals for an optical disc device and an optical disc device for immediately determining the on-track state of a main beam light impinging on an optical disc including land areas on which information is recorded, said optical disc being track-formatted to have a double spiral structure. In recording or reproducing information on or from the land areas while track-controlling a first reflected light (MB) based on a second reflect light (SB,) and a third reflect light (SB,), the phases of a sum signal (SUM) and a difference signal (DIFF) between a first push-pull signal (PP,) obtained from an output from a first split photo conductor (,) and a second push-pull signal (PP,) obtained from an output from a second split photo conductor (,) are compared to determine from the mutual phase relationship which land area is providing the first reflected light (MB).