System and method for measuring the angular position of a rotatably positionable object
US6031613A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 26, 1998 |
| Grant date | Feb 29, 2000 |
| Priority date | — |
| Expiry date | Oct 26, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/345
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method for measuring the angular position of a rotatably positionable object are disclosed. The system includes a rotating polarizing filter coupled to the rotatably positionable object so that the rotating polarizing filter co-rotates with the rotatably positionable object. Light generated by a light source is directed along a path through the rotating polarizing filter and through a stationary polarizing filter. In this configuration, the intensity of the light passed through the rotating and stationary polarizing filters varies according to the angular position of the rotatably positionable object. A light sensor senses the intensity of the light passed through the rotating and stationary polarizing filters. Based on the intensity of the light, as sensed by the light sensor, a processor determines the angular position of the rotatably positionable object. In one embodiment, first and second stationary polarizing filters are provided having angularly offset orientations. The intensity of the light passing through the first and second stationary polarizing filters produces first and second responses that differ in phase to permit measurement of rotatable object having…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.