Invention Grant
- Patent Title: Multi-beam laser light-intensity control circuit and optical scanning apparatus including the same
- Patent Title (中): 多光束激光光强度控制电路和包括其的光学扫描装置
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Application No.: US12838918Application Date: 2010-07-19
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Publication No.: US08238393B2Publication Date: 2012-08-07
- Inventor: Mitsutaka Iwasaki
- Applicant: Mitsutaka Iwasaki
- Applicant Address: JP Tokyo
- Assignee: Ricoh Company, Ltd.
- Current Assignee: Ricoh Company, Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Cooper & Dunham LLP
- Priority: JP2009-180472 20090803
- Main IPC: H01S3/00
- IPC: H01S3/00

Abstract:
A multi-beam laser light-intensity control circuit includes laser diodes; a light-receiving element for receiving a laser beam emitted from each laser diode and outputting a current corresponding to the light intensity of the received laser beam; and an automatic power control circuit for automatically controlling output power of each laser diode based on the current output from the light-receiving element. The automatic power control circuit includes a current/voltage conversion unit for converting the current output from the light-receiving element into a voltage; an error amplifying circuit for amplifying a difference voltage between the voltage output from the current/voltage conversion unit and a predetermined reference voltage; storing circuits each configured to store the difference voltage output from the error amplifying circuit in association with the corresponding laser diode; and drive current generating units each configured to generate a drive current for the corresponding laser diode based on the difference voltage.
Public/Granted literature
- US20110026552A1 MULTI-BEAM LASER LIGHT-INTENSITY CONTROL CIRCUIT AND OPTICAL SCANNING APPARATUS INCLUDING THE SAME Public/Granted day:2011-02-03
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