Capacitive fingerprint sensor and the panel thereof
US7683638B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 2008 |
| Grant date | Mar 23, 2010 |
| Priority date | — |
| Expiry date | Jul 2, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1306
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A capacitive fingerprint sensor comprises a fingerprint capacitor, an integrator, a first transistor, a second transistor and a multiplexer. The fingerprint capacitor has a capacitance that is either a valley capacitance CFV or a ridge capacitance CFR, wherein CFV is smaller than CFR. The integrator has a reference capacitor Cfb. The first transistor is configured to control the fingerprint capacitor during a scan line period. The second transistor is configured to precharge the fingerprint capacitor and to redistribute the charges between the fingerprint capacitor and the reference capacitor Cfb. The multiplexer is connected to the integrator for providing a first voltage VA and a second voltage VB, wherein the first voltage VA is greater than the second voltage VB.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.