| 摘要 |
PURPOSE:To make it possible to obtain a high quality print by a method wherein the width of excitation of each of drive coils is varied every drive timing for printing pins in proportion to the level of a drive voltage so that the torque on each of the printing pins becomes substantially constant. CONSTITUTION:The drive coils L1-Ln are provided for the printing pins within a printing head, respectively, and the common drive voltage Vcc to be impressed on the coils L1-Ln is detected by dividing the voltage into suitable widths. To perform such detection, a number of comparators C1-Cn are connected parallel to a detecting section and the drive voltage Vcc is impressed upon the positive sides of the comparators, respectively. Then the voltage Vcc is compared to detecting volages E1-En and the results of comparison are inputted to CPU so as to detect the level of the drive voltage Vcc. After that, the time of impression of the voltage Vcc is adjusted according to the detected level of the drive voltage so that the torque acting on each of the printing pins becomes substantially constant to thereby equalize the thickness of printing. |
