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:
Mar. 18, 2014
Filed:
Jul. 26, 2012
Fumio Isshiki, Yokohama, JP;
Fumio Isshiki, Yokohama, JP;
Hitachi Media Electronics Co., Ltd., Iwate, JP;
Abstract
The amplitude deviation of a tracking error signal in an optical disk apparatus is reliably corrected by processing signals at low costs. A servo signal generator generates a tracking error signal and a lens error signal from a photodetected signal. A lens error deviation signal memory circuit stores the lens error signal generated at the servo signal generator, and reproduces the one-turn deviation of the lens error signal. A tracking error signal corrector learns an amplitude correcting value for the tracking error signal from the tracking error signal detected in reproducing the one-turn deviation of the lens error signal, and stores the amplitude correcting value in a correcting signal generator.