PRINTER

PURPOSE:To prevent a printing sheet from being put out of its correct position when a power source is switched off by providing a driver circuit which generates drive signals only when the power source is switched on. CONSTITUTION:When a third printing data 103c are sent from an upper unit, an interface CPU circuit 3 outputs a signal to a power source control circuit 7, instructing the power source to be switched on. The circuit 7, with the aforementioned instruction signal inputted, makes its output signal 104 zero, and the power source 15 takes the aforementioned output in, and makes a secondary output 101 from its DC 'on'. Thereby a spring-equipped solenoid 16 works again as a drive signal 105 is made 'on' with a power source of a driver circuit 12 switched on, and thereby a printing sheet being held with the spring of the solenoid in the middle of the printing work is set free. By virtue of the aforementioned operation, the printing sheet is not be put out of its correct position even at the time when the power source for the driver circuit 12 is switched off.