Error correction system for position measuring instruments
US4490914A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 4, 1983 |
| Grant date | Jan 1, 1985 |
| Priority date | — |
| Expiry date | Jan 4, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2448
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An error correction system for correcting machine errors or division errors in a position measuring instrument for precision machines is disclosed. The system is usable, for example, in conjunction with instruments for measuring the relative position of two objects, wherein an incremental grid division formed on a measuring scale is scanned by a scanning unit to generate analog measurement signals. According to this invention, the scale defines additional correction tracks which extend along the scale, parallel to the division, and are scanned by additional scanning elements included in the scanning unit. These additional scanning elements operate to generate analog correction signals from the correction track. These analog correction signals are used to correct the analog measurement signals with respect to errors such as amplitude errors, phase angle errors, and zero crossing errors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.