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. 26, 2017
Filed:
Mar. 19, 2015
Apple Inc., Cupertino, CA (US);
Pavel Mrazek, Bohemia, CZ;
Giovanni Gozzini, Cupertino, CA (US);
Jean-Marie Bussat, Cupertino, CA (US);
APPLE INC., Cupertino, CA (US);
Abstract
A finger biometric sensing device may include drive circuitry for generating a drive signal and an array of finger biometric sensing pixel electrodes cooperating with the drive circuitry and generating a detected signal based upon placement of a finger adjacent the array. The detected signal may include a drive signal component and a sense signal component superimposed thereon. A gain stage may be coupled to the array and drive signal nulling circuitry may be coupled to the gain stage for reducing the drive signal component from the detected signal. The drive signal nulling circuitry may include a first digital-to-analog converter (DAC) generating an inverted scaled replica of the drive signal for the gain stage. Error compensation circuitry includes a memory storing error compensation data and a second DAC coupled in series with the first DAC compensating an error in the inverted scaled replica based upon the error compensation data.