| 摘要 |
PURPOSE:To prevent a power source in a printer driver from being left ON after use, by controlling the ON/OFF state of the power source in the printer device by a switching means through utilizing a power-ON information signal indicating the ON/OFF state of a power source for a printer. CONSTITUTION:A power-ON information signal (+5V signal) is divided by resistors R3, R2, and the resultant voltage is supplied to the base of a transistor TR2 to turn ON the transistor TR2. A transistor TR1 is turned ON when the transistor TR2 has been turned ON, whereby a loop for a battery E (transistor TR1 - resistor R1 - transistor TR2) is formed, and the voltage of +5V taken out at that time is supplied to each of functional blocks 12-14 in a control part 11. With a power source for a printer 2 turned OFF, the power-ON information signal is turned OFF, and a switching part 30 in a printer driver 1 breaks the loop for the battery E, thereby stopping the supply of the voltage of +5V to the control part 11. |
