| 摘要 |
<p>PURPOSE:To suppress occurrence of surge by limiting a drive switching time of a driver IC element. CONSTITUTION:Driver IC elements 3 are connected with individual drive signal lines 4, common drive signal lines 6 and, in addition, control signal lines 7, too; and through the control signal lines 7 image signals are put in. The drive switching of of output transistors Tr1, Tr2... of the driver IC elements 3 is controlled by the above image signals, and heat generating resistors 2 selectively generate heat. And with this heat, color development is caused to occur on a heat sensitive recording paper which moves in contact with a thermal head, and printing is carried out. A surge occurrence has an inseparable relationship with switching time of the driver IC elements, and the longer the switching time gets, the less the occurrence of surge takes place, and even if a surge is generated the voltage becomes lower. In view of this, if a switching time of the drive IC elements is limited within a scope of 100-300n sec, generation of surge voltage is wiped out, and even if it should occur, the voltage may be much reduced.</p> |
