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:
Sep. 27, 2005
Filed:
Jul. 28, 1999
Atsushi Miyazaki, Kyoto, JP;
Hiroyuki Yamaguchi, Hyogo, JP;
Chikashi Inokuchi, Osaka, JP;
Toshiya Akagi, Osaka, JP;
Atsushi Miyazaki, Kyoto, JP;
Hiroyuki Yamaguchi, Hyogo, JP;
Chikashi Inokuchi, Osaka, JP;
Toshiya Akagi, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
A laser power control method according to the present invention is a method for controlling an output power of a laserwhich is used for recording information on a recording medium. The method comprises steps of: detecting emitted light of the laser by a first detection section; obtaining a first driving current of the laser by a first control sectionbased on an output of the first detection section; detecting reflected light or transmitted light from the recording medium by a second detection section; and obtaining a second driving current of the laser by a second control sectionbased on an output of the second detection section. The laser is driven based on the first driving current or the second driving current while the first control section and the second control section are operated alternately such that the second control section does not operate when the first control section is operating, and the first control section does not operate when the second control section is operating. With such a structure, even when a plurality of laser powers which are switched at a high speed are required for recording of information, each laser power can be controlled so as to be an appropriate power for recording of information.