Key input circuit, power supply control apparatus, and power supply control method

摘要

A key switch 102 formed by arranging a plurality of key contacts SW11, SW12, SW21, SW22, -at cross points of a key matrix is provided with a power supply control key (SW11), and a key scan circuit 101 for detecting open/close states of the plural key contacts of the key switch 102 is independently arranged from a power supply control key state detecting means for detecting the open/close state of the contact SW11 of the power supply control key. The depression of the power supply control key (SW11) is detected by the power supply control key state detecting means. When the operation is ended, or the power supply is turned OFF, the depression of the power supply control key is detected by the key scan circuit 101, and the supply of the electric power is stopped.