Capacitance-type measuring device for absolute measurement of positions
US5023559A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1989 |
| Grant date | Jun 11, 1991 |
| Priority date | — |
| Expiry date | Jun 29, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2415
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Capacitive-type measuring apparatus for making absolute measurements comprises first and second support members which are relatively displaceable with respect to a measurement axis; an array of first electrodes disposed on the first support member; an array of second electrodes disposed on the second support member such that differing portions of the second electrode array are capacitively coupled with the first electrode array in dependence on the relative positions of the support members; an array of third electrodes disposed on the second support member so as to be electrically connected to corresponding second electrodes and spatially offset therefrom by an amount which varies according to the position of the third electrodes from a reference position; and a fourth electrode arrangement disposed on the first support member for providing in combination with the other arrays a plurality of discrete signal transmission paths each having a capacitive transfer function with two components, one of which varies according to a predetermined function over a first wavelength, and the other of which varies according to a predetermined function over a second wavelength shorter than the fir…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.