Position measuring system
US6018881A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 15, 1997 |
| Grant date | Feb 1, 2000 |
| Priority date | — |
| Expiry date | Dec 15, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/145
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A position measuring system that includes a scale graduation and a scanning element, wherein the scanning element moves relative to the scale graduation along a measurement direction so as to generate position-dependent, intensity-modulated output signals. The scanning element includes a dynamic characteristic, which has saturation areas adjoining both sides of an at least partially approximately linear operating area, in which no significantly changed output signal results any more, even when the input signal changes. The scanning gap (d) between the scale graduation and the scanning element is selected in such a way that as the scanning element moves over its entire measurement range a modulation between maximum input signals, which are located in the saturation areas of the dynamic characteristic, takes place. In order to eliminate the distortions of the output signals which usually occur in this modulation area it is furthermore provided to perform signal filtering in order to remove, in particular, the third harmonic from the output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.