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:
Sep. 14, 2010
Filed:
Nov. 29, 2007
Shinya Shimizu, Osaka, JP;
Shinya Shimizu, Osaka, JP;
Funai Electric Co., Ltd., Osaka, JP;
Abstract
The whole reflection signal and a tracking error signal are detected while an objective lens is being moved in the radial direction of an optical disk, and the temporal difference between a time at which the value of the whole reflection signal becomes a maximum and a time at which the value of the tracking error signal becomes zero is detected in a predetermined time period. In addition, a value which is obtained by dividing the temporal difference by the time period of one cycle of the tracking error signal is acquired as a tilt appearance magnitude. Relational information in which a tilt appearance magnitude and a tilt correction magnitude corresponding to the tilt appearance magnitude are associated is read out, and the relational information read out and the current tilt appearance magnitude detected by a tilt-appearance-magnitude detection circuit are compared, thereby to determine the tilt correction magnitude necessary for a tilt correction. The tilt correction magnitude is notified to a tilt correction circuit, and is used in making the tilt correction.