Rotary character-carrying member and selector device therefor for a print unit in typewriters
US4778289A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1986 |
| Grant date | Oct 18, 1988 |
| Priority date | — |
| Expiry date | Apr 30, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J1/243
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A print unit for an electronic typewriter comprising a removable character-carrying disc with flexible spokes which is operated by a selector motor which in turn is controlled by a control circuit. The character-carrying disc is provided with a plurality of reflective identification plates and a recognition circuit detects the pattern of the reflective plates present in selected ones of a series of predetermined angular sectors of the disc to identify some characteristics of the disc, e.g. typing pitch and character set. The angular position of the disc is detected by a position transducer which generates a position signal for the control circuit having a period which is double the angular distance between two contiguous character-carrying spokes discriminating the spokes at even positions from those at odd positions. In an initialization phase, a zeroing circuit coarsely positions the character-carrying disc in a zero area defined by a synchronization plate adjacent a plate-free gap and activates the control circuit to stop the character-carrying disc in a zero position in respect of a spoke having a predetermined parity. The print unit is provided with phase regulation elements f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.