JPS63159481U - - Google Patents

Description

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, Fig. 2 is a block circuit diagram of a specific example of the same, Figs. 3 to 5 are explanatory diagrams of the same operation, and Fig. 6 is a conventional example. FIG. 1 is a transmitter, 2 is a receiver, 3 and 4 are detection means,
5 is a mode switching means, and 6 is an abnormality determining means.

Claims (1)

[Scope of claim for utility model registration] (1) Ultrasonic waves of a predetermined frequency are transmitted from a transmitter to a warning area, and the Doppler component contained in the reflected waves received by a receiver is detected to detect the warning area. A detection means in a movement detection mode that detects moving objects within the warning area, and a pulsed ultrasonic wave is sent to the warning area, and based on the reflected waves received by the receiver, it is detected whether the object exists in the warning area. a detection means in a presence detection mode for detecting an object that moves, a mode switching means for switching the detection mode from a movement detection mode to a presence detection mode at a constant or irregular cycle by appropriately switching the operation of both detection means; An ultrasonic crime prevention device comprising an abnormality determining means for determining the presence or absence of an abnormality depending on whether or not an object detection state at the time is a previously predicted state. (2) An abnormality display signal will be output when the reflected wave from an object at the predicted position cannot be received, or when the reflected wave from an object near the transducer is obtained. The ultrasonic security alarm device according to claim 1 of the registered utility model claim, characterized in that an abnormality determining means is formed.