Monolithic sensor of fingerprints
US5844287A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Oct 10, 1996 |
| Grant date | Dec 1, 1998 |
| Priority date | — |
| Expiry date | Oct 10, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1306
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electronic fingerprint sensor works by the detection of pressure, the ridge lines of the finger exerting a greater pressure than the valleys. The sensor has a matrix of pressure microsensors and electronic control and signal-processing circuits. It is made in an entirely monolithic form, according to techniques for the making of electronic circuits (deposition of thin layers, photo-etching, doping and thermal processing), both for the pressure detection part and for the signal-processing and control part. The matrix-type pressure sensor uses either piezoelectric resistors lying on an insulator layer stretched above a cavity or a variable capacitor or a microcontactor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.