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:
Nov. 25, 2008
Filed:
Jun. 08, 2007
Yung-chih LI, Taipei Hsien, TW;
Hsueh-kun Liao, Hsin-Chu Hsien, TW;
Ching-chuan Hsu, Hsin-Chu Hsien, TW;
Yung-Chih Li, Taipei Hsien, TW;
Hsueh-Kun Liao, Hsin-Chu Hsien, TW;
Ching-Chuan Hsu, Hsin-Chu Hsien, TW;
Mediatek Inc., Hsin-Chu, TW;
Abstract
A laser power control unit used for controlling the laser power of an optical pick-up unit (OPU) is provided. The laser power control unit includes: at least one analog-to-digital converter (ADC) electrically coupled to the OPU for transferring a front photodiode output signal into a digital feedback signal; and at least one digital control circuit electrically coupled to the ADC for generating a power control signal and outputting the power control signal to the OPU in order to control the laser power of the OPU. The digital control circuit has a compensation circuit used for generating a compensation value according to a difference between the digital feedback signal and a digital target feedback signal so as to adjust the power control signal. The front photodiode output signal corresponds to the laser power of the OPU.