| 摘要 |
PURPOSE:To provide no excessive load in a printing element driving circuit, improve a reliability of entire device and not to decrease a printing quality by a method wherein a driving frequency is varied in response to a time for driving the printing element and another time for non-driving the printing element. CONSTITUTION:Printing information is fed to a line buffer LB to drive an electro- magnet driving circuit MGD, the MGD drives selectively a wire via electro-magnet MGN. In the counter CNT, one driving number is counted to get the number of non-driving operation, then a value of their difference is calculated. Situation for driving next array is similarly calculated in sequence, a result of each of the calculations is consecutively added within a specified period of time. The counter CNT operates to provide an output to a driving frequency selection circuit DPC whenever the final result exceeds a predetermined value. Space motor speed calculation circuit SMS is operated in response to DPC output to calculate a new rotational speed and to drive the electric motor SM via driving circuit SMD. |
