Print hammer firing compensation circuit for printer velocity variation
US4527920A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 13, 1983 |
| Grant date | Jul 9, 1985 |
| Priority date | — |
| Expiry date | Jun 13, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J9/50
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Circuit for detecting variations in the nominal velocity of a character band and adjusting the hammer firing times to compensate for the variations. This circuit measures deviations in band velocity that are either faster or slower than a nominal velocity during each character emitter pulse and makes an appropriate correction in the subscan times that gate the hammer firing signals. A bidirectional counter is counted up at a high frequency to a value representing the emitter period including the velocity deviation and then counted down after the error determination at a selected frequency that is a preselected fraction of the high frequency. This technique corrects for each character emitter pulse and incorporates a timing proportionality to assure correct hammer impact.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.