Capacitive distance sensor
US6320394A · kind A · utility
136Cited by
44References
23Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 5, 1998 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Feb 5, 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 armature which is positioned facing a second armature whose distance is to be measured. In the case of fingerprinting, the second armature 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.