Block-divided driving apparatus of gradation thermal printhead
US5089831A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1990 |
| Grant date | Feb 18, 1992 |
| Priority date | — |
| Expiry date | May 25, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/355
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A thermal recording apparatus having a thermal head including a plurality of heating element groups each of which consists of a plurality of heating elements driven simultaneously and arranged in a row is so improved that it can record images without forming printing gaps. The apparatus has a driving unit for producing driving signals indicative of tones of the image data of pixels to drive the heating elements. The pixels correspond to the heating elements, respectively. The period of time of driving the heating elements is varied in accordance with the tones. The driving unit comprises a modification circuit for modifying the period of time of driving at least one of the heating elements which is disposed at each of both ends of each of the heating element groups.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.