Matsushita Electric Works, Ltd.

Hiroshi Ohashi

Hiromitsu Inoue

Susumu Katayama

Yuji Takada

Mikio Kondo

An intrusion warning system for indicating the presence of an intruder to a given area includes an antenna provided around the area and which is insulated from the ground. An oscillator is provided for feeding an alternating current signal to the antenna, and a coupling impedance is connected between an output of the oscillator and the antenna. The coupling impedance includes an arrangement to vary the impedance to an appropriate value such that the voltage fed to the antenna is approximately 50% of the voltage fed from the oscillator to the coupling impedance. By this arrangement the detection sensitivity is always kept at an optimum. The system also includes a signal processing apparatus for producing an output signal responsive to a change in the voltage of the alternating current on the antenna exceeding a predetermined level.

Intrusion warning system

An intrusion warning system for indicating the presence of an intruder to a given area comprises a single antenna line encircling the area insulated from the ground, a high frequency oscillator (e.g. of 1 kHz to 10 kHz) for feeding a high frequency signal to the antenna, a coupling impedance, for example, a capacitor, connected between the output terminal of the oscillator and the antenna, and a signal processing part which produces an alarm when detecting a voltage change over a predetermined level of the antenna induced by a proximation of the intruder.

Capacitively coupled electromagnetic intrusion warning system

Means for mounting a member functioning with a directivity to a mounting station of an associated device or the like. A housing for the member with its functional end surface exposed to the exterior is tapered at the periphery toward the other end to be, for example, hemispherical and rotatably born at diametrally opposed positions adjacent the functional end surface by both ends of a semiarcuate bearing means, the mounting station has a hole including peripherally opposing grooves of a size and shape capable of slidably engaging with the tapered periphery of the housing and receiving semiarcuate body of the bearing means, the housing is inserted in the hole on said the other end side, and the semiarcuate body of the bearing means in the inserted position of the member engages slidably with a resilient means acting to resiliently urge the tapered periphery of the housing against peripheral edge of the hole. In this mounted state, the functional surface of the member is allowed to be manually freely inclined in all 360.degree. directions with respect to the plane of the mounting station to set the directivity and normally stably retained in set inclined position.

Variable directivity mounting means

A moving object detecting device employing a pair of Doppler signals as a pair of vector signals of respective received-wave signals representing momentary reflected waves from a moving object. These vector signals are processed to obtain signals denoting in which ones of predetermined zones for the vector rotation depending on the movements of the object the vector is momentarily present, and shifting states of such zone signals through the zones are traced to sequentially determine the direction and period of the vector rotation and to actuate an alarm or the like when the rotation is in a fixed direction.

Moving object detecting device

An echo-type switch using ultrasonic wave for detecting any object present in a predetermined area with reliable operation irrespective of environmental variations or foreign waves. After the wave is once radiated, the detection is suspended for a fixed time period T.sub.1 and presence or absence of reflected wave received is confirmed during another period T.sub.2. If reflected wave is received in the period T.sub.2, this period is again set for further confirming if the received wave continues and, until absence of the received wave is confirmed after several times of the waves received during the period T.sub.2, next ultrasonic wave is not radiated. Only in case the reflected wave received continues for more than two of the periods, the presence of the object to be detected in the area is indicated.

Ultrasonic wave echo-type switch

This invention provides an ultrasonic wave watching device for detecting a moving object wherein an ultrasonic wave signal generated by an oscillator is transmitted from a transmitter, reflected signals from a stationary object and moving object are received by a receiver and the variation with time of the phase difference between these received signals and the transmitted signal is detected to determine the presence and moving direction of the moving object.

Ultrasonic wave watching device of moving object detecting type

An ultrasonic wave horn adaptable to any desired radiation pattern varying in length-to-breadth ratio of intended detecting area. The horn comprises at least a horn body having gradually expanding caliber from a constricted throat to an expanded opening which is of a flat shape with an unequal length-to-breadth ratio, and an ultrasonic wave generating source of which wave emitting side is disposed adjacent the constricted throat of the horn body, wherein the constricted throat of the horn body is also of a flat shape having an unequal length-to-breadth ratio and the respective major axes of the flat-shaped constricted throat and expanded opening of the horn body are in a relation of intersecting each other at right angles.

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Hirakata, Japan

Hiroshi Ohashi