Rotation quantity measuring method and system
US4987299A · kind A · utility
113Cited by
6References
20Claims
0Family size
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Key dates
| Filing date | Aug 23, 1989 |
| Grant date | Jan 22, 1991 |
| Priority date | — |
| Expiry date | Aug 23, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/1861
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A rotation quantity measuring method and system measures a rotation quantity of an object body. The rotation quantity is measured by irradiating a light from a light source on a grating pattern which is formed on a peripheral surface of a cylindrical body which rotates integrally with the object body, and detecting a shadow picture pattern which is generated by a reflected light received from the grating pattern based on a diffraction caused by the grating pattern. Then, the rotation quantity of the object body is measured based on a movement of the shadow picture pattern as the object body rotates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.