| 摘要 |
<p>PURPOSE:To confirm and identify the presence/absence of a mobile body in spite of the possession of a response unit without providing an infrared detector, etc., by providing a query electromagnetic transmission means, a proper code signal discrimination means, and a Doppler signal discrimination means. CONSTITUTION:A query microwave transmitted from a transmission means 20 via a transmission/reception antenna 23, etc., is radiated on the path area of the mobile body 2, and when the mobile body 2 exists in an irradiated area, a response microwave is returned from the response unit 3, and supplied to the proper code signal discrimination means 30. Also, when the mobile body 2 in the irradiated area is moving, its moving speed is reflected on the reflected wave of the query microwave as Doppler shift, and it is inputted to the Doppler signal discrimination means 40 via the antenna 23, etc., and when it exceeds a reference value, a mobile body detection signal is supplied to a circuit 50. However, when no mobile body 2 exists in the irradiated area, no response microwave and reflected wave are generated. And it is possible to confirm and identify the mobile body 2 by the output of an identification code from the circuit 50 in spite of the possession of the response unit 3.</p> |
