Title:
【発明の名称】自動利得制御回路
Document Type and Number:
Japanese Patent JP2542607
Kind Code:
B2
Abstract:
PURPOSE:To obtain an output independent of the brightness background light in case of amplification of the detection output of a photodetector by automatically changing the conversion rate of a current-voltage converting means in accordance with the brightness of background light. CONSTITUTION:The output current outputted from a photodetector 2 is converted to a voltage signal by a current-voltage converting means consisting of an operational amplifier 1, resistance 3 and 4, and a variable resistance circuit 5 and is outputted to an output terminal 10. The resistance value of an optical resistance element 6 in the feedback loop of the operational amplifier 1 is determined by the light irradiated from a light emitting element 7. The light emitting element 7 emits light based on the output corresponding to the brightness of background light. Consequently, the conversion rate of the current- voltage converting circuit is automatically changed in accordance with the brightness of background light.
Inventors:
KOSEKI KEIJIRO
Application Number:
JP3315887A
Publication Date:
October 09, 1996
Filing Date:
February 18, 1987
Export Citation:
Assignee:
TOKYO SHIBAURA ELECTRIC CO
International Classes:
H03G3/30; G01S7/48; (IPC1-7): G01S7/48; H03G3/30
Domestic Patent References:
| JP57166579A | ||||
| JP5547466A | ||||
| JP61110004A | ||||
| JP62200903A | ||||
| JP6129778A | ||||
| JP57166578A | ||||
| JP6060576A | ||||
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| JP58103218A | ||||
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| JP58134783U | ||||
| JP433164B2 | ||||
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Attorney, Agent or Firm:
Noriyuki Noriyuki (1 person outside)