Capacitive displacement sensor
US6700391B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2002 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | Mar 20, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2412
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A distance measuring system (1) is provided with a capacitive sensor (7a, 7b), designed in the form of a differential capacitor (18), for which the partial capacitors (C1, C2 have capacitances that depend on the position to be determined. The system also includes a processing device (5) for determining the desired distance that contains, for example, a sigma/delta demodulator. The partial capacitors (C1, C2) are triggered periodically with binary signals, wherein the trigger signals from the one partial capacitor (C1) are transmitted with a phase offset to the signals from the other partial capacitor (C2). The processing device (5) determines which trigger signals must be used for the evaluation. Within time windows that are synchronized with the edges of the trigger signals, a switch unit (22) allows the associated receiving signals to pass through to the processing unit (5) and blanks out all other signals. The distance measuring system (1) makes it possible to have a low number of interpolation errors with high resolution and long interpolation periods. The distance measuring system (1) can be expanded by adding two essentially independent, parallel-operating relative measuring …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.