Dot matrix printhead driver
US4242004A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 21, 1979 |
| Grant date | Dec 30, 1980 |
| Priority date | — |
| Expiry date | Mar 21, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/275
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A driver mechanism for a dot matrix printhead, including an electromagnet, an armature, and a print impact element connected to the armature by a cantilever spring, energization of the electromagnet and consequent movement of the armature to closed position driving the impact element to impact a record sheet supported on a platen; a concentrated mass load is mounted on the spring, sufficient to maintain the impact element essentially in its rest position during a substantial portion of the armature movement so that the force/travel characteristic of the spring governs movement of the impact element, with maximum force at the outset and near zero or zero force at impact. Energization of the electromagnet is interrupted when the armature closes, and a shunt circuit holds the armature closed until just before impact.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.