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:
Jun. 18, 2002
Filed:
Apr. 06, 2000
Toshiya Akagi, Neyagawa, JP;
Yoshiyuki Miyabata, Yawata, JP;
Abstract
A semiconductor laser control method and a semiconductor laser control apparatus allow an outgoing radiation power of a semiconductor laser to be accurately stabilized to a desired value even if a characteristic of the semiconductor laser changes due to temperature variations or deterioration of life. The characteristic of a semiconductor laser is measured by a semiconductor laser characteristic detection unit and a target value is corrected by a target value correction unit based on a threshold current and differential quantum efficiency obtained from the measurement result. A power control unit controls the semiconductor laser by comparing the corrected target value with the output of a power detection unit, making it possible to achieve a desired outgoing radiation power of the semiconductor laser with high accuracy even if the threshold current or differential quantum efficiency of the semiconductor laser changes due to temperature variations or deterioration of life.