Printing method and a printing apparatus
US6491373B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 2000 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | Mar 10, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4051
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Deterioration in image quality is caused by deviation in dot forming positions between rasters in the case of carrying out printing of adjoining two rasters. The rasters are printed by two columns of ejection openings array disposed on an ink-jet head. To suppress image quailty deterioration, the two columns of ejection openings are shifted from each other by a half of a pitch at which the ejection openings are arranged in the column. When allocating input image data quantized into multi-valued levels to 2×2 dot array as pseudo half-tone processing before printing, the mutually different plural dot arrangements are applied concerning each level of the input image data, and the plural dot arrangements are cyclically changed in the main scanning direction according to predetermined rules, and also equalization processing for equalizing the number of said adjoining the two raster dots is properly performed in the one cycle. Thus, differences in a covering ratio of the printing medium with formed dots can be put to 10% or less in a range where the adjoining two rasters are deviated from each other by at least ±2 pixels in the scanning direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.