| 摘要 |
PROBLEM TO BE SOLVED: To increase the gradation value to be expressed per pixel in a multi-value printer and to restrain generation of banding. SOLUTION: In an ink jet printer, an ink is ejected continuously for each pixel during a main scanning operation. The number of the ink ejecting operation for the pixel is set according to the gradation value to be expressed per pixel. The ejected ink has the impact position displaced in the main scanning direction so as to have the formed dots as a flat dot longitudinal in the main scanning direction. The dot pitch in the sub scanning direction is set by an interval sufficiently smaller than the width of the flat dot in the sub scanning direction. The dot pitch in the main scanning direction is set by an interval sufficiently smaller than the width of the flat dot in the main scanning direction without having the number of pixels in the entire image exceed a predetermined value defined according to the printing speed. By forming the dots by the intervals, an image with the excellent gradation expression can be printed at a high speed without generating banding. COPYRIGHT: (C)2004,JPO |
