Capacitive distance sensor
US6437583B1 · kind B1 · utility
64Cited by
43References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 11, 2000 |
| Grant date | Aug 20, 2002 |
| Priority date | — |
| Expiry date | Jul 11, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1306
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A distance sensor has a capacitive element in turn having a first capacitor plate which is positioned facing a second capacitor plate whose distance is to be measured. In the case of fingerprinting, the second capacitor plate is defined directly by the skin surface of the finger being printed. The sensor comprises an inverting amplifier, between the input and output of which the capacitive element is connected to form a negative feedback branch. By supplying an electric charge step to the input of the inverting amplifier, a voltage step directly proportional to the distance being measured is obtained at the output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.