| 摘要 |
PURPOSE:To prevent the malfunctioning of systems of printer, etc. by the thermal head, by installing a delay circuit, delaying drive circuits, performing the switching operation, and making the current flowing once in the heat element source line to make the counter electromotive force small by parasite inductance of a heating element source line. CONSTITUTION:A delay circuits 14 are installed in a signal line 15 between a control signal input terminal 10 and a gate circuit 3. For a gate circuit 3 and a drive circuit 4, when both a printing data D and a control signal EN are at H level (see D1-D3, EN as illustrated), the output of the drive circuit 4 becomes L level, and the output of the drive circuit 4 in the input inditions other than it is in the state of high impedance. The control signal EN is delayed successively by the delay circuit 14 in serted into the control signal line 15, transmitted (see EN1-EN3 as illustrated), every drive circuits 4 perform the switching operation delaying successively (see OUT1-OUT3 are illustrated), for that reason the current flowing in the heat element source line comes to change successively. In such a way, the current flowing once in the heat element source line is made small by performing the switching operation delaying successively every drive circuit. |
