| 摘要 |
PURPOSE:To raise the quality of printing by shortening the width of initially applied pulse for the printing operation by a method in which the output signal of a counter circuit for preheating is applied to a thermal head prior to usual printing operations and preheating is made. CONSTITUTION:The width value of applied pulse during the printing time is set in a counter 5a, and also a value corresponding to 10-20% of the set value of the counter 5a, which is enough not to make printing even when heating the thermal head, is also set in a counter 5b. Prior to the printing operation, data of H-level are transferred to the head 3 by a control circuit 2 from a buffer memory 1, PHEN signal of AND gate 6b is changed to H and put in a decoder 4 as PRG signal of applied short pulse for preheating the counter 5b, and a bud 3 is preheated. Printing of the same clearness and density can thus be attained in both initial and final portions without uneven printing and tailing phenomenon. |
