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. 21, 2017
Filed:
Jun. 29, 2016
Fingerprint Cards Ab, Göteborg, SE;
Fredrik Ramberg, Göteborg, SE;
Hans Thörnblom, Kungsbacka, SE;
David Carling, Mölndal, SE;
Frank Robert Riedijk, Delft, NL;
FINGERPRINT CARDS AB, Göteborg, SE;
Abstract
There is provided a capacitive fingerprint sensing device comprising a plurality of sensing elements, sensing circuitry for providing an analog sensing signal, drive signal circuitry providing a drive signal comprising a drive pulse having a maximum level and a minimum level, providing a change in potential difference between the finger and the sensing structure, analog sampling circuitry comprising at least three analog sample and hold circuits arranged to sample the sensing signal, and a sampling control unit for individually controlling the sample and hold circuits to capture a sample at a specified time, wherein the samples comprises one sample captured when the drive signal is at a first voltage level Vand one sample captured when the drive signal is at a second voltage level V, different from V; and an analog-to-digital converter, ADC, configured to convert a combination of the samples into a digital signal, wherein the three samples are captured times such that a noise component is suppressed from the sensing signal when the combination is formed.