Method and apparatus for determining existence of foreign material on surface of fingerprint sensor of terminal
US10628653B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 2018 |
| Grant date | Apr 21, 2020 |
| Priority date | — |
| Expiry date | May 21, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1329
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and an apparatus for determining existence of a foreign material on a surface of a fingerprint sensor of a terminal are provided. The method includes the following. A current capacitance value of the fingerprint sensor of the terminal is obtained. A first difference between the current capacitance value and a preset capacitance reference value is calculated. Determine that the foreign material is present on the surface of the fingerprint sensor when the first difference is within a preset foreign-material threshold range. The preset capacitance reference value is a capacitance value tested with no foreign material on the surface of the fingerprint sensor before leaving the factory and is stored in a system in advance. The preset foreign-material threshold range is set in advance according to experimental data of capacitance-change tests performed on the fingerprint sensor when different conductive foreign materials are on the surface of the fingerprint sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.