PURPOSE: To prevent a forcible entry by an alarm sounding when an alarm inhibition code known only in person is not input within a specific time after unlocking.
CONSTITUTION: Detection objective of a monitoring mode in an alarm device is unlocking or not of a lock. When a person as user returns to his home and unlocks a key for a door, this unlocking is detected by an unlocking detection portion 10. A first timer T1 is thus set, so that counting of one minute is started. During the time, the person opens the door and inputs an alarm inhibition code placed indoors to an alarm inhibition code inputting portion 30. Counting by the first timer T1 is then stopped and the device returns to the monitoring mode. In the case when an unlawful intruder enters and unlocks the key unlawfully, this unlocking is detected by a door release-opening detection portion 40. When an alarm inhibition code is not inputted, when the one minute counting by the first timer T1 finishes, a signal is outputted to a driving portion 24 from CPU 21. A buzzer B is thus operated so that an alarm is sounded.
ITO MASATO
UMEZAWA MASAMICHI
