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.

Date of Patent:
Feb. 28, 2012

Filed:

Sep. 16, 2009
Applicants:

Kazuki Kajikawa, Osaka, JP;

Toshiaki Fukui, Osaka, JP;

Inventors:

Kazuki Kajikawa, Osaka, JP;

Toshiaki Fukui, Osaka, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

This optical disk device includes a pickup, an offset means, a focus servo means, and a layer jump means. The offset means generates a focus error signal on the basis of the output of the pickup, and applies an offset voltage to that focus error signal. And the layer jump means performs layer jump operation, including kick start operation, kick end operation taking a second threshold value as a reference, brake start operation taking a third threshold value as a reference, and brake end operation. Moreover, before executing this layer jump operation, the layer jump means changes this second threshold value or this third threshold value, according to the value of the offset voltage.


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