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:
Mar. 28, 2006
Filed:
Jan. 26, 2004
Atsushi Kitaoka, Chiba, JP;
Atsushi Kitaoka, Chiba, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A measurement apparatus which measures a distance between a sensor probe and a target to be measured by using an electrostatic capacitance sensor, comprises first and second sensor probes () which are arranged at respective predetermined gaps to the target (), and first and second sensor amplifiers () which are connected respectively to the first and second sensor probes, wherein when the distance between the target and the first or second sensor probe is measured, said first amplifier supplies a first current with the first sensor probe and said second amplifier supplies a second current which is different phase and/or amplitude from the first current.