| 摘要 |
PURPOSE:To decrease the cost of a printer by using only one signal wire between a printing head unit and a control part. CONSTITUTION:The output terminal of a head driver 4 and the input terminal of a microcomputer 7 are connected through a signal wire 9 and a temp. sensor 5 is connected across the output terminal of the head driver 4 and a reference potential point 10. The microcomputer 7 controls the printing operation of a printing head on the basis of the voltage level of the signal wire 9 and compares the voltage level of the signal wire 9 with a preset reference voltage level to judge whether an overload signal is outputted from the head driver 4 and outputs an alarm signal to an alarm circuit 8 when the overload signal is judged to be outputted. |
