Zero reference generating method and apparatus for optical encoders
US4602155A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 25, 1983 |
| Grant date | Jul 22, 1986 |
| Priority date | — |
| Expiry date | Jul 25, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/366
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved apparatus for generating an index signal in incremental encoders, wherein an index sequence of code elements is provided on the code disc, and the degree of registration between the index sequence and a mask sequence is detected, and further wherein the mask sequence and index sequence are configured so that there is maximum registration of the elements between the index sequence and mask sequence for the index position of the code disc and the degree of registration for all other angular positions of the code disc is at or below a predetermined background registration level, and so that the degree of registration for angular positions adjacent to the index or zero reference position is greater than zero and preferably no greater than the background registration level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.