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:
Dec. 10, 2002
Filed:
Nov. 02, 1999
Atsushi Fukumoto, Kanagawa, JP;
Shinichi Kai, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical disc inclination detecting method for detecting an inclination angle of an optical disc with respect to a light spot, for recording information or reproducing information by irradiating the light spot on the optical disc by an optical pickup. The method includes dividing the light spot into a main spot and both side spots in a specified track and track crossing directions before and after the specified track, detecting signals corresponding to a reflected light from the optical disc by photo detectors corresponding to the main spot and both side spots, and generating a DPP (differential push-pull) signal from signals corresponding to the main spot and both side spots. The method also generates a DPD (differential phase direction) signal by comparing phases from the signals corresponding to the main spot, determining a differential operation value of the DPP and DPD signals, and detecting the inclination angle of the optical disc based on the differential operation value.