Optical displacement sensor using color variations to monitor displacement of two gratings.
US4814601A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 15, 1988 |
| Grant date | Mar 21, 1989 |
| Priority date | — |
| Expiry date | Mar 15, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A moire fringe displacement sensor includes first and second gratings (3) (4), a polychromatic light source (1) illuminating the gratings, and a detector (8). The gratings are disposed such that a relative displacement of the first and second gratings causes a variation in the color of the light reaching the detector. The detector (8) comprises first and second photo-responsive elements (11) (12), the responsivity with respect to wavelength of the first element (11) being different from that of the second (12). Signals from the photo-responsive elements are fed to a micro-processor (15) which calculates the color of the light incident on the detector as represented by two or more parameters on the Chromaticity (CIE) Diagram, and interprets the color in terms of the displacement of the first and second gratings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.