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. 18, 2007
Filed:
Jan. 06, 2004
Sung-du Kwon, Seoul, KR;
Jun-hyuk Lee, Suwon-si, KR;
Pyong-yong Seong, Seoul, KR;
Hyun-cheal Bang, Suwon-si, KR;
Jong-koog Lee, Seoul, KR;
Yong-jun Cho, Suwon-si, KR;
Sung-du Kwon, Seoul, KR;
Jun-hyuk Lee, Suwon-si, KR;
Pyong-yong Seong, Seoul, KR;
Hyun-cheal Bang, Suwon-si, KR;
Jong-koog Lee, Seoul, KR;
Yong-jun Cho, Suwon-si, KR;
Samsung Electronics Co., Ltd., Suwon-si, KR;
Abstract
In order to improve the frequency characteristic of a laser power monitor device and the precision of laser power control when low-speed recording is performed, there is provided a laser power monitor device for an optical recording and/or reproducing apparatus, the laser power monitor device including a photo diode unit to receive part of a light emitted from a laser diode and output a current proportional to optical power, and a monitor circuit to receive the current output from the photo diode unit, convert the received current into a voltage, and outputs the voltage to an automatic laser power control circuit, and the photo diode unit includes a plurality of photo diodes connected to the monitor circuit to supply current to the monitor circuit. The laser power monitor device further includes a switch unit, wherein the switch unit is located between the photo diode unit and the monitor circuit to receive a signal on a current recording speed and switch so that the number of photo diodes supplying current to the monitor circuit is reduced as the recording speed is increased.