Title:
【発明の名称】表面電位センサ
Document Type and Number:
Japanese Patent JP3085209
Kind Code:
B2
Abstract:
A surface potential sensor which is less affected by noise superposed on a reference source voltage than prior sensors, and hence can improve measurement accuracy with ease, and which also has higher stability against extraneous noise. The sensor includes an initial-stage input circuit comprising an FET, and a succeeding-stage amplifier circuit mainly comprising an operational amplifier for amplifying a difference between an AC component from the initial-stage input circuit and a reference source voltage. A resistor is connected between a drain of the FET constituting the initial-stage input circuit and a source voltage line to take out a signal from the FET drain. The source voltage supplied to the FET is the reference source voltage.
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Inventors:
Muneharu Yamashita
Application Number:
JP24164396A
Publication Date:
September 04, 2000
Filing Date:
September 12, 1996
Export Citation:
Assignee:
MURATA MANUFACTURING CO.,LTD.
International Classes:
G01R29/12; G01N27/60; G01R19/00; (IPC1-7): G01R29/12
Domestic Patent References:
| JP5915864A | ||||
| JP6290564A | ||||
| JP4307373A |
Attorney, Agent or Firm:
Hisao Komori