| 摘要 |
PURPOSE:To enhance printing quality and a printing speed and to shorten a drive time, by providing a displacement sensor in a wire dot head to measure the displacement of a printing wire and controlling the drive time based on the measured data. CONSTITUTION:An electrostatic capacity sensor 24 constituted of an armature 9 and a fixed electrode 31 is provided to a wire dot head 23 to measure the displacement of a printing wire 10. The signal of the sensor 24 is taken out as the signal showing the displacement of the printing wire 10 by a sensor circuit 25 and a control circuit 28 extracts the moving start time of the printing wire 10 and the collision timing thereof with a printing medium from a timing extraction circuit 26, and cuts off the drive voltage and regenerative current supplied to a coil 12 from a drive circuit 27 based on said timings to control the drive time of the printing wire 10. By this method, the enhancement of printing quality and an increase in a printing speed are achieved and the drive time is optimized to make it possible not only to shorten a time but also to conserve power consumption. |
