Polar co-ordinate digitizer
US4922618A · kind A · utility
Inventors
Key dates
| Filing date | Dec 19, 1988 |
| Grant date | May 8, 1990 |
| Priority date | — |
| Expiry date | Dec 19, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/002
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved polar co-ordinate digitizer where a cord extensible from a base unit moves a cord guide to provide an angle measurement and is wrapped on a drum whose movement reflects a length measurement. Lateral pressure on the cord guide is minimized by a low mass pivot arm whose angle is sensed by optical photodetector techniques. In addition the length of the cord is also sensed by a similar photodetector both mounted for rotation about the origin axis of the polar co-ordinate system and utilizing a fixed reference photodetector all of which sense a continuously rotating disk with an index mark on it. Suitable calibration is provided for the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.