Fingerprint sensor employing an integrated noise rejection structure
US9779280B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 24, 2014 |
| Grant date | Oct 3, 2017 |
| Priority date | — |
| Expiry date | Dec 24, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1394
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A sensor has drive lines and transverse pickup lines to define an electrode pair where each pickup line crosses a drive line. A reference pickup line is arranged parallel to the pickup lines and a compensation drive line is arranged parallel to the drive lines. A signal source provides a first signal to the drive lines and a second signal that is the inverse of the first signal to the compensation drive line. An amplifier has a first input connected to a pickup line, a second input connected to a reference pickup line, and a output indicative of an object in contact with the electrode pair(s). Each impedance between the compensation drive line and a pickup line, between the reference pickup line and a reference drive line, and between the compensation drive line and the reference pickup line is equal to the impedance at the electrode pair when no object is contact with the electrode pair.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.