| 摘要 |
PURPOSE:To make abrasion conditions uniform over an entire range of dot bits which constitute a printing head and enable maintenance of high printing quality for a long time by sequentially selecting printing pins to be used when ordinary characters are printed using only some of printing pin arrays. CONSTITUTION:When a document including only ordinary characters such as alphabet or Kana is printed, a single line of document is printed using nine dot pins of a single array of printing pins among three arrays of printing pins 3a, 3b, 3c of a printing head. Then the printing pin arrays 3a, 3b, 3c are sequentially selected each time a single line is printed. Consequently, the use frequency of each printing pin array 3a, 3b, 3c becomes almost the same. As a result, only specific printing pin arrays 3a, 3b, 3c do not become abraded sooner than the other. Consequently, all the dot pins 2 arranged on the printing head 1 can maintain uniform printing performance, and therefore, the occurrence of printing unevenness when precision characters are printed be prevented. In addition, high printing quality can be retained for a long time. |
