Capacitive fingerprint sensing device with current readout from sensing elements
US9600705B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 2015 |
| Grant date | Mar 21, 2017 |
| Priority date | — |
| Expiry date | Oct 1, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1306
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a capacitive fingerprint sensing device comprising a plurality of sensing elements. Each sensing element includes a protective dielectric top layer to be touched by a finger; an electrically conductive sensing structure arranged underneath the top layer; a charge amplifier connected to the sensing structure for providing a sensing voltage signal indicative of a change of a charge carried by the sensing structure resulting from a change in a potential difference between the finger and the sensing structure; and a voltage-to-current converter for converting the sensing voltage signal to a sensing current signal indicative of the change of charge carried by the sensing structure. Hereby, accurate sensing as well as faster operation of the sensing elements can be achieved without a corresponding increase in power consumption.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.