To provide a locking/unlocking sensor for a crescent lock capable of preventing an intruder from unlocking the crescent lock by detecting an approach of an unauthorized magnet and reporting it.
A locking/unlocking sensor for a crescent lock includes: a normal magnet 1 provided in a crescent type rotary member 2; a magnetism detection part 6 composed of radio transmitters 5 mounted to a structure outside a double sliding structure and detecting a state of a magnetic flux by the normal magnet 1; and an unauthorized magnet detector 4 reacting to a magnetic field of an unauthorized magnet 30 other than the normal magnet 1 and detecting an approach of the unauthorized magnet 30. The unauthorized magnet detector 4 includes: a movable magnetic material attracted to the unauthorized magnet 30 side by the approach of the unauthorized magnet 30; and a displacement detection sensor detecting the displacement of the movable magnetic material.
SHIBATA KIWAMU
OKADA KENJI
OTA TOMOHIRO
| JP2003281636A | 2003-10-03 | |||
| JP2000311567A | 2000-11-07 |
Katsumi Taguchi
Shinichi Mizuta
Itaya Masayuki
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