The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 10, 2009
Filed:
Jun. 07, 2005
Yoshikatsu Ichimura, Tokyo, JP;
Yoshikatsu Ichimura, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
The electric potential measuring instrument comprises an electrode arranged on a semiconductor substrate at a position opposite to the object of measurement and a modulator for modulating the coupling capacitance between the object of measurement and the electrode. The electrode is the gate electrode of a field effect type transistor. The modulated electric current that flows between the source diffusion region and the drain diffusion region of the field effect type transistor is synchronously detected by a detection circuit with the modulation frequency of the modulator. The output signal that appears on the gate electrode of a field effect transistor can be measured with ease by changing the coupling capacitance between the electrode of an electric potential measuring instrument and an object of measurement.