| 摘要 |
PROBLEM TO BE SOLVED: To secure a stable print quality by alternately arranging upper and lower printing hammers and mounting the printing hammers with a shift from a predetermined pitch to change a drive order of the printing hammers so that most adjacent printing hammers are not driven with an equal timing. SOLUTION: Hammer mechanism parts are arranged in an upper and a lower two stages in the printing apparatus. The hammer mechanism part includes a plurality of dot-printing hammers arranged with a predetermined pitch along a plurality of dot lines of printing lines. A hammer bank is constituted of hammer groups of 24 stages, 12 upper stages and 12 lower stages via 1/180 inch in a longitudinal direction. Longitudinal 12 dot lines are arranged via a distance of 0.105 inch in a lateral direction to each of the upper and lower hammer banks and to a position with a shift of 12 dots for each pin. 12 modules each comprising 12 pins, that is, 144 printing pins 6 in total are mounted. Since the printing pins 6 driving at the same time in the upper and lower banks are thus spaced, a degree of influences of magnetic interference is reduced and a stable print quality is obtained.
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