Vernier index position sensor
US5856872A · kind A · utility
7Cited by
2References
23Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 2, 1997 |
| Grant date | Jan 5, 1999 |
| Priority date | — |
| Expiry date | Oct 2, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An index structure and method are disclosed which employ, in addition to a main diffractive grating track of an encoder, a short diffractive grating track (the vernier or index track) having a different frequency than that of the main track. The phase of the index track is used to provide windows for the main track in a manner so that a preselected phase condition of the main track occurs in only one of the windows provided by the index track.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.