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:
Oct. 05, 1993
Filed:
Apr. 12, 1990
Kyosuke Yoshimoto, Amagasaki, JP;
Osamu Ito, Amagasaki, JP;
Kimiyuki Koyanagi, Amagasaki, JP;
Yoshiki Nakajima, Amagasaki, JP;
Shuitsu Takeda, Amagasaki, JP;
Kyoji Shimoda, Amagasaki, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical disk drive for recording and reproducing information on an optical disk medium includes a servo circuit for controlling tracking of a light beam on a predetermined track and a servo circuit for controlling focus of the light beam on the disk surface. The disk surface is divided into a plurality of regions, and calibration values for adjusting the servo circuits are determined in each region. The calibration values are stored in a memory and are used to adjust the servo circuits during tracking on a predetermined track. The calibration values include tracking offset values, focus offset values, servo deviation threshold values and sensor gain values. A number of techniques are disclosed for automatically determining the calibration values.