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:
Dec. 02, 2008
Filed:
Jul. 19, 2005
Richard A. Erhart, Tempe, AZ (US);
Darioush Keyvani, Scottsdale, AZ (US);
Fred G. Benkley, Iii, Andover, MA (US);
Jaswinder Jandu, Chandler, AZ (US);
Richard A. Erhart, Tempe, AZ (US);
Darioush Keyvani, Scottsdale, AZ (US);
Fred G. Benkley, III, Andover, MA (US);
Jaswinder Jandu, Chandler, AZ (US);
Validity Sensors, Inc., San Jose, CA (US);
Abstract
Image sensing apparatus includes an image pickup plate disposed generally orthogonally with respect to an expected direction of movement of an object, such as a finger, multiple image drive plates in spaced relation to the image pickup plate to define sensor gaps between respective image drive plates and the image pickup plate, and a reference plate disposed substantially parallel to the image pickup plate. The reference plate is spaced from the image pickup plate to permit common mode noise and coupling to be cancelled and is spaced from the image drive plates to permit a differential image signal to develop between the image pickup plate and the reference plate. A differential amplifier coupled to the image pickup plate and the reference plate provides noise cancellation. The apparatus may further include a comb plate spaced from the reference plate and coupled to a reference potential, such as ground.