Method and device for detecting if a finger is present and sensing a fingerprint pattern
US9589171B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 2016 |
| Grant date | Mar 7, 2017 |
| Priority date | — |
| Expiry date | Jun 8, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1306
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a method of sensing a fingerprint pattern of a finger using a fingerprint sensing device comprising an array of sensing elements; an electrically conductive finger detecting structure; and finger detecting circuitry connected to the finger detecting structure for providing a finger detection signal indicative of a capacitive coupling between the finger detecting structure and the finger. The method comprises the steps of: comparing the finger detection signal with a first threshold value indicating a first capacitive coupling, and a second threshold value indicating a second capacitive coupling stronger than the first capacitive coupling; and activating at least a subset of the sensing elements when the finger detection signal changes from a first value indicating a capacitive coupling weaker than the first capacitive coupling to a second value indicating a capacitive coupling stronger than the second capacitive coupling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.