Method and apparatus for multiple speed print rate control for dot matrix printer
US3990559A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1975 |
| Grant date | Nov 9, 1976 |
| Priority date | — |
| Expiry date | Oct 20, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J19/202
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for controlling the print rate of a column-sequential dot matrix printer actuated by an input signal comprising a sequence of code words occurring at a given maximum input rate, a print head and a print head drive operating at a speed determined by the frequency of a print rate timing signal, and a multi-stage FIFO input storage register. A multiplicity of constant-frequency print rate timing signals are generated, ranging in frequency from substantially below to substantially above a normal print rate frequency Fn approximately matched to the input rate, and a variable print rate timing signal progressively increasing in frequency from well below Fn to well above Fn is also generated; these signals are applied to the printer in accordance with a predetermined schedule, determined by the number of code words in storage at the beginning of each spacing character cycle, and in accordance with a program affording relatively smooth acceleration and deceleration of the print head. In continuing operation, the number of code words in storage is accumulated to a given level and maintained approximately at that level until the input is interrupted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.