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:
May. 14, 2002
Filed:
Jun. 09, 1999
Norio Tanaka, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A signal generation method capable of generating a cross track signal having a predetermined phase difference from a tracking error signal even in a land and groove recording method in which a land width and a groove width are made equal, wherein a main spot is detected at a split photodetector, a first side spot is detected at a split photodetector, and a second side spot is detected at a split photodetector; a first error is calculated as an error of the optical disk in a radial direction from four detection signals detected at the photodetector, a second error is calculated as the error of two detection signals of the photodetector, a third error is calculated as the error of two detection signals of the third photodetector, and the sum of the second and third errors is subtracted from the first error to calculate a tracking error signal; and a difference between the second error and the third error is found to calculate a cross track signal having a phase shifted by 90° from the tracking error signal TE.