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:
Jun. 24, 2003
Filed:
Jan. 23, 2001
Applicant:
Inventors:
Paul-Werner Von Basse, Wolfratshausen, DE;
Josef Willer, Riemerling, DE;
Assignee:
Micronas GmbH, Freiburg, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R 2/726 ; G06K 9/00 ;
U.S. Cl.
CPC ...
G01R 2/726 ; G06K 9/00 ;
Abstract
A grid of capacitor surfaces is connected to read lines and control lines. The read lines are connected alternately to the output of a feedback operational amplifier and to a collecting capacitor. The capacitances to be measured are charged repeatedly and the charges are collected on the collecting capacitors. Between the charging operations, the potential on the read lines is kept constant through the use of the low-resistance output of the operational amplifier. The use of this method in the case of a fingerprint sensor makes it possible to evaluate all the read lines together.