JPS55149855A - Noise reducing circuit in noncontact type electrometer - Google Patents

Noise reducing circuit in noncontact type electrometer

Info

Publication number
JPS55149855A
JPS55149855A JP4535979A JP4535979A JPS55149855A JP S55149855 A JPS55149855 A JP S55149855A JP 4535979 A JP4535979 A JP 4535979A JP 4535979 A JP4535979 A JP 4535979A JP S55149855 A JPS55149855 A JP S55149855A
Authority
JP
Japan
Prior art keywords
electric field
differential amplifier
voltage
output
detecting electrode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP4535979A
Other languages
Japanese (ja)
Inventor
Minoru Aoki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP4535979A priority Critical patent/JPS55149855A/en
Publication of JPS55149855A publication Critical patent/JPS55149855A/en
Pending legal-status Critical Current

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  • Measurement Of Current Or Voltage (AREA)

Abstract

PURPOSE: To prevent disturbance noise from occurring, by applying to an electric field modulator an output from a current-voltage converter, which is generated in accordance with an electric potential of an object to be measured, and an output voltage from a differential amplifier into which a predetermined D/C voltage is inputted.
CONSTITUTION: An electric field generated on the surface of an object 1 to be measured is applied to a detecting electrode 4 as a passing area for the electric field is periodically changed by an electric field modulator 5. An output from the detecting electrode 4 is applied to one of input terminals of a differential amplifier 8 through an operational amplifier 7, and a predetermined DC voltage to the other terminal of the differential amplifier 8. An output voltage from the differential amplifier 8 is applied to the electric field modulator 5 through a shield plate 2 so as to offset an undue potential difference occurring between the electric field modulator 5 and the detecting electrode 4.
COPYRIGHT: (C)1980,JPO&Japio
JP4535979A 1979-04-16 1979-04-16 Noise reducing circuit in noncontact type electrometer Pending JPS55149855A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4535979A JPS55149855A (en) 1979-04-16 1979-04-16 Noise reducing circuit in noncontact type electrometer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4535979A JPS55149855A (en) 1979-04-16 1979-04-16 Noise reducing circuit in noncontact type electrometer

Publications (1)

Publication Number Publication Date
JPS55149855A true JPS55149855A (en) 1980-11-21

Family

ID=12717079

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4535979A Pending JPS55149855A (en) 1979-04-16 1979-04-16 Noise reducing circuit in noncontact type electrometer

Country Status (1)

Country Link
JP (1) JPS55149855A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS564062A (en) * 1979-06-25 1981-01-16 Canon Inc Surface electrometer
JPS56126767A (en) * 1980-02-18 1981-10-05 Williams Bruce T Static voltmeter

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS564062A (en) * 1979-06-25 1981-01-16 Canon Inc Surface electrometer
JPH036467B2 (en) * 1979-06-25 1991-01-30 Canon Kk
JPS56126767A (en) * 1980-02-18 1981-10-05 Williams Bruce T Static voltmeter
JPH0128348B2 (en) * 1980-02-18 1989-06-02 Williams Bruce T

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