JPS55119064A - Surface electrometer - Google Patents

Surface electrometer

Info

Publication number
JPS55119064A
JPS55119064A JP2732879A JP2732879A JPS55119064A JP S55119064 A JPS55119064 A JP S55119064A JP 2732879 A JP2732879 A JP 2732879A JP 2732879 A JP2732879 A JP 2732879A JP S55119064 A JPS55119064 A JP S55119064A
Authority
JP
Japan
Prior art keywords
voltage
potential
measuring electrode
fet110
erased
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
JP2732879A
Other languages
Japanese (ja)
Inventor
Yoshikazu Yokomizo
Koji Suzuki
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.)
Canon Inc
Original Assignee
Canon Inc
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 Canon Inc filed Critical Canon Inc
Priority to JP2732879A priority Critical patent/JPS55119064A/en
Publication of JPS55119064A publication Critical patent/JPS55119064A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: To enable to accurately measure the surface potential of a material by applying a DC voltage to a measuring electrode through an element having a high resistance, whereby an offset voltage remaining in the measuring electrode can be erased.
CONSTITUTION: When a chopper vane 103 is roated to open and close a potential detection bore 107, an electric field between a material 106 to be measured and a measuring electrode 104 is varied to generate an extremely small amount of AC voltage in the electrode. The amplitude of this AC voltage is proportional to the potential of the material 106. This AC voltage is converted into a low-impedance signal by a FET110, amplified to a desired value by an AC amplifier 112 and subjected to rectifying integration in a recticfier integrating circuit 113. As a result, an output of a DC voltage in proportion to the potential of the material 106 are obtained. In the FET110, a gate voltage is kept positive by DC bias power source 118. Accordingly, an offset potential Eo remaining in the measuring electrode 104 can be erased so that the surface potential of the material 106 can be accurately measured.
COPYRIGHT: (C)1980,JPO&Japio
JP2732879A 1979-03-09 1979-03-09 Surface electrometer Pending JPS55119064A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2732879A JPS55119064A (en) 1979-03-09 1979-03-09 Surface electrometer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2732879A JPS55119064A (en) 1979-03-09 1979-03-09 Surface electrometer

Publications (1)

Publication Number Publication Date
JPS55119064A true JPS55119064A (en) 1980-09-12

Family

ID=12217998

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2732879A Pending JPS55119064A (en) 1979-03-09 1979-03-09 Surface electrometer

Country Status (1)

Country Link
JP (1) JPS55119064A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59119278A (en) * 1982-12-13 1984-07-10 ザ・シムコ・カンパニ−・インコ−ポレイテツド Panoramic electrostatic field sensor
US5187442A (en) * 1988-09-29 1993-02-16 Friedemann Freund Method and apparatus for charge distribution analysis

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59119278A (en) * 1982-12-13 1984-07-10 ザ・シムコ・カンパニ−・インコ−ポレイテツド Panoramic electrostatic field sensor
US5187442A (en) * 1988-09-29 1993-02-16 Friedemann Freund Method and apparatus for charge distribution analysis

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