Absolute position transducer having a non-binary code-track-type scale
US6271661A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1999 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Mar 16, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2495
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An absolute position transducer system has two members movable relative to each other and includes a code track transducer and at least one fine wavelength transducer. The code track is arranged to form a sequential pattern of base-N code words, where N is greater than two (i.e., non-binary). Each sequential non-binary code word identifies an absolute position of one member with respect to the other at a first resolution. Alternatively, the code track is arranged to form a pseudo-random non-binary code word pattern. In this case, the transducer system compares a non-binary code word with a look-up table to determine an absolute position of one member with respect to the other at a first resolution. In order to generate a non-binary code word pattern, code track transducer employs different-sized flux disrupters, different-sized flux enhancers, or a combination of flux disrupters and enhancers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.