Abstract: A theft monitoring apparatus does not require any complicated synchronous relationship for the signals received from a plurality of antennas, permits easier installation and maintenance and inspection, and does not adversely affect the appearance of a shop where it is installed. A plurality of antennas (1, 2) send out transmitter signals composed of burst signals (A, B) which continue in predetermined cycles (T1, T2). The transmitter signal from one antenna (antenna 2) except other antenna (antenna 1) is provided with a pause period (D) during which no burst signal (B) is issued. During the pause period (D), the burst signal (A) is issued from the antenna (1).

Abstract: An alarm tag releasing device is provided for a theft monitoring device. The theft monitoring device has a gate installed in a desired position and producing a theft monitoring region of a predetermined range by transmitting radio waves at a predetermined wavelength. A buzzer tag is attached to a protected item by a built-in lock mechanism so as not to be detached, and an alarm circuit operated by a built-in battery to sound an alarm when the radio waves at the predetermined wavelength are received when the buzzer tags enters the monitoring region, said alarm tag releasing device comprising: an insertion part having a shape corresponding to the outer diameter of the buzzer tag and into which the buzzer tag can be inserted, such that the lock mechanism provided in the buzzer tag is unlocked when the buzzer tag is inserted into the insertion part.

Abstract: An E.A.S. capable of surely detecting magnetic fluxes emitted from transmission antennas irrespective of the position of a reception coil within a tag attached to goods. In order to emit magnetic fluxes into an aisle through which customers pass, the system is equipped with at least two transmission antennas 1, 3. These transmission antennas 1, 3 are driven in a time-sharing way so as not to concurrently emit the magnetic fluxes.

Abstract: A portable anti-theft monitor comprises a case; a detection conductive wire led out of said case, having a loop portion; an engaging member provided in said case so as to freely get it in and out, for engaging by catching the loop portion of said detection conductive wire in a state in which it has been pressed in said case; and a locking member for locking said engaging member in the state in which said engaging member has been pressed into said case, and for being attracted by a magnet to be moved in the unlocking direction.

Abstract: A signal transmission apparatus including a main unit having a signal transmission terminal, and one or more sub units (or repeaters) each having first and second signal transmission terminals. A loop connection line is provided between the main unit and a first sub unit, and additional loop connection lines are provided between subsequent pairs of sub units to convey signals from the main unit to each of the sub units, and from each of the sub units to the main unit. The main unit includes a controller, a signal generator for generating and sending a first signal to one of the sub units, and a signal processor for processing a second signal returned from one of the sub units in response to the first signal. Each of the sub units includes a controller, a destination signal determination section, and a signal transfer section for selectively capturing and transferring a signal according to its destination address.

Abstract: An alarm-equipped electronic article surveillance system which is easy to handle, which provides against the triggering of false alarm, and which reliably surveys articles of interest against theft. The system comprises a signal transmitter device located close to the gates of access to an area of interest, and a plurality of tags each attached to an article of merchandise under surveillance. The signal transmitter device includes a signal generator for generating a modulated signal by modulating a carrier frequency signal with a modulation signal, a signal transmitter for transmitting the modulated signal, and a transmitting antenna. The plurality of tags each include a receiving antenna, a signal receiver for selectively receiving the modulated signal, a frequency selector for selecting the modulation signal out of the modulated signal, an alarm generator operable for generating an output indicative of an alarm condition, and an alarm negator for negating the operation of the alarm generator.

Abstract: An electronic surveillance apparatus with an alarm, including a signal transmitter for producing a transmission signal, a tag for generating an alarm when the transmission signal from the signal transmitter is received while the tag is in a warning operation state, and a tag controller, which is selectively coupled to the tag, for controlling the warning operation state of the tag. The tag includes a signal receiving section, a warning generating section, a plurality of external connection terminals, a voltage dividing circuit which is connected to the plurality of external connection terminals, and a warning generation control section which is connected between the voltage dividing circuit and the warning generating section.

Abstract: An E.A.S. system capable of immediately making a decision on a broken condition of a tag 2 itself or its connection cable 8 or a non-connected condition of the connection cable 8 to a repeating device 1 at start-up of the system. The system comprises the repeating device 1 and a tag 2 detachably coupled through the connection cable 8 to the repeating device 1. The repeating device 1 is equipped with a jack 3 having a plug receiver 3a, a fixed contact 3b and a movable contact 3c, a pull-up resistor 4 coupled between the movable contact 3c and a power supply 10, a connection section for connecting the fixed contact 3b and the plug receiver 3a with a ground point, and a tag condition detecting section (5 to 7) coupled to the movable contact 3c. The tag 2 incorporates an internal resistor 2a, and a double pole plug 9 is detachably connected through the connection cable 8 with the jack 3.

Abstract: An antitheft security tag is used in combination with an article surveillance security system. The antitheft security tag comprises a tagging part to be tagged to an article, formed by looping a two-core cable having two insulated copper wires or the like, a connecting part formed out of a cable, to be connected to the article surveillance security system, a joining part for joining the tagging part to the connecting part, and a resistor contained in the joining part and connected in series to the wires of the two-core cable forming the tagging loop. One end of the connecting part to be connected to the article surveillance security system is provided with a connector to be connected to the article surveillance security system. The article surveillance security system monitors the resistance of the antitheft security tag for article surveillance and detects unauthorized tampering with the antitheft security tag through the detection of a change in the resistance of the antitheft security tag.