| 摘要 |
PURPOSE:To enable to control density in a printer and that in a display device by a single controlling means, by varying the resistances of variable resistors by operating a single knob, in a printer for a portable electronic calculator or the like. CONSTITUTION:In response to a signal from a CPU, a printer driver PD and a display device driver DD generates respective driving voltages to thereby drive the printer P and the display device D. The density in the printer P and that in the display device D are controlled respectively by variable resistors RP, RD for controlling power sources, which control is effected through a single knob A7. By moving the knob A7 leftward or rightward, slidable pieces A5, A6 are moved on a resistor A1 on the VPP side, a resistor A4 on the VDi side and copper foil patterns A2, A3 on the positive side of a battery B, and voltages supplied to the printer P and the display device D are simultaneously controlled. Accordingly, both the density in the printer P and that in the display device D can be controlled by the single controlling means. |
