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. 28, 2003
Filed:
Jun. 24, 1999
Toshimasa Miura, Yokohama, JP;
Yoshihisa Miyazaki, Tachikawa, JP;
Yuichi Tsuchimochi, Hino, JP;
Yasuhiro Fujiwara, Hachioji, JP;
Naoyuki Sato, Tokorozawa, JP;
Yoshiyuki Fukuya, Sagamihara, JP;
Olympus Optical, , JP;
Abstract
An amplitude detection circuit detects the peak value of an output signal of a photo-detector amplified by a head amplifier. The peak value detected by the amplitude detection circuit is read into a drive controller, and compared with a target value suitable for coding in a binary format a detected signal. The gain of a variable gain amplifier is adjusted accordingly. Consequently, an analog signal processing circuit can stably codify the detected signal in a binary format. Under the control of the drive controller, a recording power level calculation circuit determines a test writing power level with which test writing is performed on a test track of a magneto-optical disk. The recording power level calculation circuit then calculates an actual record power for each zone of the magneto-optical disk according to the test writing power level.