CAPACITIVE SENSOR - TOKYO ELECTRON LTD

Title:

CAPACITIVE SENSOR

Document Type and Number:

WIPO Patent Application WO/2005/078404

Kind Code:

A1

Abstract:

A capacitive sensor (10) in which a parasitic capacitance does not function as a capacitor and its effect on the detected capacitance can be eliminated apparently because a guard electrode (4) is arranged between a first electrode (1) and a second electrode (2), potentials of the first electrode (1) and the guard electrode (4) are equalized by bringing the AC potential difference thereof substantially to zero through a capacitive sensor detecting circuit (64), and a variation in impedance is detected between the first electrode (1) and the second electrode (2), so that the potential difference across a parasitic capacitance between first electrode (1) and the guard electrode (4) is decreased apparently or brought substantially to zero. Thus, only a capacitance variation of the capacitive sensor (10) can be detected by means of the capacitive sensor detecting circuit (64).

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JPS60153180	SEMICONDUCTOR PRESSURE SENSOR

Inventors:

HOSHINO TOMOHISA (JP)

Application Number:

PCT/JP2005/002165

Publication Date:

August 25, 2005

Filing Date:

February 14, 2005

Export Citation:

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Assignee:

TOKYO ELECTRON LTD (JP)
HOSHINO TOMOHISA (JP)

International Classes:

G01L9/00; G01D5/24; G01F1/28; G01L9/12; G01N27/22; (IPC1-7): G01L9/12

Foreign References:

JP2000028462A	2000-01-28
JP3447062B2	2003-09-16
JP2000028462A	2000-01-28
EP0973012A1	2000-01-19
EP0982576A1	2000-03-01

Other References: