Laser interferometer type length measuring apparatus and positioning method using the same
US5141318A · kind A · utility
19Cited by
3References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 4, 1991 |
| Grant date | Aug 25, 1992 |
| Priority date | — |
| Expiry date | Mar 4, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B9/02049
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a laser interferometer type length measuring apparatus, a measurement laser beam will be influenced by disturbance such as air fluctuation and a change in air pressure distribution due to movement of an object so that a displacement of the object cannot be accurately measured. In order to obviate such an inconvenience, air controlled at a predetermined temperature is uniformly blown at a fixed speed on the entire optical path of the measurement laser beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.