Method and apparatus for hiding errors in single-pass incremental printing
US6270187A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 1998 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Dec 14, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/2132
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
It is first determined whether any printing element of a printhead has failed. If so, functions of the failed element are reassigned to other elements. Some aspects of the invention do this in such a way as to maintain essentially single-pass operation. Ordinarily the reassigned functions are applied to control operation of the head or heads, to print images on a print medium, and functions of the apparatus and method are effected automatically by program instructions--in nonvolatile memory. One approach to the reassignment includes removing from service all printing elements between the failed element and a nearer end of the head, inclusive--and then preferably operating all remaining in-service elements as a shorter printhead. If the printhead operates in conjunction with a print-medium advance mechanism, then also preferably each operation of that mechanism is shortened to correspond to a height of the shorter head. Another approach, if the failed element is in a black printhead and the printer has three or more subtractive-primary-color heads, includes assigning a corresponding printing element of each of those color heads, in combination, to print in lieu of the failed black-p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.