Hall effect printwheel encoder
US4928089A · kind A · utility
16Cited by
6References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1987 |
| Grant date | May 22, 1990 |
| Priority date | — |
| Expiry date | Dec 21, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07B2017/00548
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An encoder for a wheel comprises a linear Hall-effect sensor and magnet mounted on a non-ferrous metal shaft. A ferrous metal ring having a toothed structure extending inward such that each tooth ends at a point on a spiral curve is molded into the printwheel encircling the shaft. The Hall-effect sensor output provides a determined output when each tooth is positioned over the sensor to enable an absolute position determination while the signal drop off between the teeth as the wheel is moved allows for counting the steps between settings for relative encoding and redundancy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.