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:
Dec. 03, 2002
Filed:
Oct. 27, 2000
Kenji Koishi, Sanda, JP;
Kohjyu Konno, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A semiconductor laser control circuit of the invention can modulate a light power level among a plurality of set levels including a first level, a second level lower than the first level, and a third level lower than the first level but higher than the second level. The semiconductor laser control circuit includes: a circuit portion for generating a first signal based on a light power level actually detected by a light detector in a first period in which a light power level of laser radiation is to be modulated among the first level, the second level, and the third level; a circuit portion for generating a second signal based on a light power level actually detected by the light detector in a second period in which a light power level of the laser radiation is to be modulated between the first level and the second level; a circuit portion for generating a third signal based on a light power level actually detected by the light detector in a third period in which the light power level of the laser radiation is to be at the third level; and a signal processor for determining a light power level of the first level and a light power level of the second level by operation, based on the first to third signals. The light power level is adjusted based on an output of the signal processor.