| 摘要 |
<p>The usability of a portable terminal device having a key operation lock function is increased. If there is not a key operation over a predetermined period of time, a lock control unit (23) receives a timeout signal input from a timer (22). If the housings are closed, the lock control unit (23) receives a detection result indicating that the housings are closed from an open/close detecting unit (6). If the timeout signal is input, or if the detection result supplied from the open/close detecting unit (6) indicates that the housings are closed, the lock control unit (23) determines that a lock instruction has been issued, and determines whether the state of the portable telephone device satisfies a predetermined condition. If the predetermined condition is satisfied, the lock control unit (23) outputs a key operation lock activation signal to a control unit (25). If the predetermined condition is not satisfied, the lock control unit (23) waits for the predetermined condition to be satisfied before outputting a key operation lock activation signal.</p> |
