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:
Jan. 20, 2009
Filed:
Apr. 16, 2004
Akira Yoshikawa, Nara, JP;
Shin-ichi Yamada, Katano, JP;
Akira Yoshikawa, Nara, JP;
Shin-ichi Yamada, Katano, JP;
Panasonic Corporation, Osaka, JP;
Abstract
The present invention provides an optical disk control device that can perform focus pulling in a short time for a target information surface of an optical disk having a plurality of information surfaces. An objective lens () is moved toward an optical disk () having a plurality of information surfaces (A,B) by the output signal of a driving signal generating circuit (B), passage of an initial focused focal position is detected by a focal point passage detecting circuit (), and when the objective lens moves past that position only a predetermined amount closer to the optical disk, an n-rotation delay circuit () outputs a reversal instruction f. After changing directions and moving the objective lens away from the optical disk, a focus pulling-in circuit (B) switches a signal 'a' that is output to an actuator driving circuit () from the output signal of the driving signal generating circuit to the output signal of the control circuit, activates a control circuit and performs focus pulling-in.