Fingerprint sensing circuit and fingerprint sensing apparatus
US10803277B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 12, 2018 |
| Grant date | Oct 13, 2020 |
| Priority date | — |
| Expiry date | Dec 17, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/66
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A fingerprint sensing circuit and a fingerprint sensing apparatus are provided. The fingerprint sensing circuit includes a sensing electrode; a first converting circuit connected to the sensing electrode and configured to convert a coupling capacitance sensed by the sensing electrode into a drive voltage, where the drive voltage is equal to a sum of a voltage variation converted from the coupling capacitance and a reference voltage; and a second converting circuit configured to generate a sensing current based on the drive voltage, and send the sensing current to a fingerprint signal processor, where the sensing current is equal to a product of a transconductance gain of the second converting circuit and the voltage variation, and the fingerprint signal processor performs fingerprint sensing based on the sensing current. With the fingerprint sensing circuit and the fingerprint sensing apparatus, the detection accuracy can be improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.