| 摘要 |
PROBLEM TO BE SOLVED: To quickly perform key detection. SOLUTION: A key detection device includes voltage holding circuits (RC11 to RC33) for holding a prescribed voltage for a detection line which is charged from an output line for each combination of output lines and detection lines; and a plurality of key switches (S11 to S33) connected to the voltage holding circuits for permitting charging to the voltage holding circuit in such a state that any key switch operation is not performed, and for inhibiting charging to the voltage holding circuit in such a state that any key switch operation is performed. When the voltage holding state of the voltage holding circuit varies due to presence/no presence of the operation of the key switch, a control circuit 10 detects variation of the voltage in the detection line to detect whether the operation of the key switch is performed or not. COPYRIGHT: (C)2010,JPO&INPIT
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