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:
Apr. 27, 2004
Filed:
Oct. 24, 2001
Kenji Koishi, Hyogo, JP;
Yoshiyuki Miyabata, Kyoto, JP;
Makoto Usui, Osaka, JP;
Kohjyu Konno, Osaka, JP;
Yasuhiro Ueki, Kanagawa, JP;
Tomonori Ueno, Kanagawa, JP;
Yutaka Osada, Kanagawa, JP;
Toru Fujimoto, Kanagawa, JP;
Other;
Abstract
Playback signal amplitude drops and continuity of the signal track amplitude is lost at the beginning the data recording area when data is incrementally written to optical discs such as DVD-R or DVD-RW media. Feed-forward control quickly settles semiconductor laser recording power to the target power level immediately after an incremental recording starts. While recording continues, feedback control maintains laser power at a desired recording power level even when the required current supply varies due to the temperature characteristics of the semiconductor laser when recording lasts for an extended period of time. A semiconductor laser control method and semiconductor laser control device thereby maintain laser power at a stable target recording power level quickly and for as long as recording continues.