Antipatterning printmode for matrix-based scattered-dithered images in incremental printing
US6690484B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1999 |
| Grant date | Feb 10, 2004 |
| Priority date | — |
| Expiry date | Feb 18, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K15/107
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Apparatus defines a dither mask (DM) and printmask (PM) with corresponding dimensions. In one invention form the DM dimension is not an integral factor or multiple of the PM dimension. The two dimensions may be lengths or widths; preferably the apparatus manages both; the corresponding dimensions differ by at least three pixels, and by a multiple of two pixels—more preferably eight or a multiple of eight. Preferably one dimension is an integral multiple of 256 pixels differing by eight pixels from the other. Another invention form has a scanning printhead making multiple passes across a print medium to form swaths of marks, a mechanism to define an offset smaller than at least one of the two dimensions, and a unit to index one mask by that offset between forming of successive swaths. This is valuable if DM and PM are established by preprogrammed circuits (e.g. an ASIC) or algorithms and one dimension is fixed at an integral multiple or factor of the other, with the system being practically incapable of small (or any) changes in the dimensions. Another invention form is a print method that establishes and operates a rendition stage using a DM—and a PM stage using a PM.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.