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. 21, 2010
Filed:
May. 07, 2008
Shinsuke Onoe, Fujisawa, JP;
Shinsuke Onoe, Fujisawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An optical disk as disclosed herein includes, among other things, a summing module that sums a compensation signal to a predetermined signal in a servo loop. The compensation signal compensates for a periodical disturbance input into a servo system of the optical disk device in units of a rotation angle of the disk rotating module. A phase lead imparting module imparts a predetermined amount of phase lead to an output signal from an optical detector module and outputs the predetermined amount of phase lead as the compensation signal. The predetermined amount of phase lead is determined in accordance with the rotation period information. The optical disk device performs an accurate iterative learning control to provide stable servo performance. The iterative learning control is performed such that the signal having imparted an optimal amount of phase lead in accordance with the rotation period information is added to the servo loop.