Capacitive distance sensor
US6114862A · kind A · utility
104Cited by
31References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 9, 1998 |
| Grant date | Sep 5, 2000 |
| Priority date | — |
| Expiry date | Mar 9, 2018 |
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.