| 摘要 |
PURPOSE:To uniform the quality of printing in a dot printer wherein the space between a print head and a print medium is to be maintained at a constant, by obtaining the control information of the head's impact force by causing the head to reverse for a fixed distance after it is once pressed against the medium. CONSTITUTION:Prior to starting print, a pulse motor 9 is caused to rotate normally and by this the end of a print head 1 moves to touch with a print medium 5 and stops, and a displacement indicating bar 17 indicates position P2. Next, when a reverse rotation command is issued, the motoe 9 rotates by a predetermined number of pulse, the print head 1 moves backward by a fixed distance l and stops and the bar 17 indicates position P3. When a position which is moved backward by the distance of l from a platen 6 is assumed as P0, P3- P0 becomes the thickness of the print medium 5. These positions are given to a pulse generator circuit 19 by a detector 16 and they become drive control signals of which standard pulse width is adjusted according to the thickness of the medium 5 and the impact force of the head is controlled so that it becomes constant. |
