Scales for position determining apparatus having marks of different amplitudes thereon
US5004982A · kind A · utility
7Cited by
6References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 23, 1990 |
| Grant date | Apr 2, 1991 |
| Priority date | — |
| Expiry date | Jul 23, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B21/042
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A scale is fixed to one part of a position determining apparatus, and a read head is relatively movable on the other part of the apparatus. Incremental scale marks are regularly spaced along the scale and are counted in a counter to give an indication of relative position of the scale and read head. The marks may for example be recorded magnetically. Some scales are distinguishable from the other, e.g., by having different amplitudes. Positioning information can then be encoded in a binary word. This can either be absolute position values, or error correction information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.