| 摘要 |
PURPOSE:To attain the saving of electric power for an image display device of an information processing unit without failing in cost reduction and miniaturization by using the switch of a stylus pen belonging to a coordinate input device to turn on an image display device once turned off. CONSTITUTION:When a pen tip switch 121 of stylus pen 12 is turned on in a state the supply to a LCD 6 and a backlight 7 is shut off, a stylus pen control section 13 outputs a low level signal to a power supply control section 9. The polarity of this low level signal is then inverter 91, and inputted to an AND gate 92. On the other hand, a peripheral control logic circuit 4, when it judges that the switch 121 of pen 2 is turned on outside the input display area, outputs a high level signal to the AND gate 92, and the gate 902 outputs a high signal to an OR gate 93. At this timer, since the circuit 4 already outputs a high level signal to the gate 93, the output from gate 93 is et at high level and inputted to a power supply section 8. Thus, the power supply section 8 supplies the power to the backlight 7 and LCD 6. |
