JPH0219516B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a shoplifting prevention device, and is intended to prevent theft of displayed products.

B. Conventional technology A variety of devices have been used to prevent theft of products, including those that attach a small transmitter to the product to issue an alarm when the product passes through a detection gate, and those that use a small receiver modulator attached to the product to prevent theft of products. There is a structure in which a gate-side device issues an alarm based on a modulated oscillation obtained by obtaining a radio wave atmosphere, and depending on the radio wave transmission signal.

C. Problems to be solved by the invention However, in the case of the former, the life of the power supply for the small oscillator that must be attached to each product is short, and the maintenance costs associated with replacing batteries etc. are enormous, so this problem is virtually impossible to implement. In the latter case, the alarm is only sent to the gate, making it impossible to identify the culprit among multiple people passing through the gate, which, combined with personnel issues, poses the problem of not being sufficiently effective. Was.

The present invention was made in view of the above problems, and
To provide a shoplifting prevention device capable of detecting shoplifting and giving an alarm, identifying a culprit, limiting battery consumption only when shoplifting occurs, and requiring low maintenance costs.

D. Means for Solving the Problems The shoplifting prevention device of the present invention includes a transmitter that has the appearance of a product advertising sign such as a sign or price tag that is attached to each product, and a transmitter that is installed at required locations in the store to transmit the above-mentioned information. When the device passes, the transmitter is turned on, and
a detection gate equipped with means for detecting and announcing passage;
It is composed of a portable receiver that detects the transmitted signal from the transmitter.

In other words, the oscillator has a built-in power supply such as a battery, and turns on the power supply circuit by receiving weak radio waves of a specific frequency.
It consists of a switching circuit that generates and maintains the signal, an oscillation circuit that oscillates a specific frequency using the power supply circuit, a modulation circuit that converts the oscillation frequency to a specific frequency, and a transmission circuit that wirelessly transmits the modulated signal. The initial drive power for the switching elements in the switching circuit is obtained by a plurality of parallel winding coils.

The above-mentioned multiple parallel winding coil has a special structure in which two or more coiled parts are each wound one or more times using a single conducting wire, and are arranged in parallel in the direction of the winding surface. Both ends of the parallel-wound coil and the switching element were connected via a rectifier.

E. Effect The above-mentioned parallel-wound coil generates a weak electromotive force at both ends of the coil in a radio wave atmosphere of a predetermined frequency like a normal coil, but it alone produces a weak electromotive force at both ends of the coil in a radio wave atmosphere of a predetermined frequency. The necessary voltage can be obtained within a weak radio wave band of 0.5 W or less, and the electromotive force of the parallel wound coil can be used as it is as the initial drive source of the transistor via a rectifier.

Therefore, the oscillator turns on and maintains the power supply circuit depending on the frequency atmosphere emitted by the gate when passing through the gate, and turns on the oscillation circuit, modulation circuit, and transmission depending on the built-in power supplied from the power supply circuit. Through a circuit, a small built-in antenna transmits and maintains radio waves of a specific frequency.

A receiving means for receiving this specific frequency is provided in the detection gate and the portable receiver, and the detection gate receives the received signal and announces a "detection" signal to the gate and an alarm position provided at a desired position. By bringing the mobile receiver close to the person passing through the detection gate at the time of "detection", the radio signal of the transmitter can be received and the location of the transmitter can be confirmed. Becomes able to identify the culprit in the case.

Embodiment Hereinafter, an embodiment of the shoplifting prevention device of the present invention will be explained with reference to the drawings. Fig. 1 is a block diagram showing the principle thereof. The transmitter 1 attached to product a is as shown in Fig. 2. It is housed in a flat shell 10 such as a card or sheet configured in a desired shape such as a triangle or a rectangle, and has an advertisement or display printed on the front and back surfaces to camouflage that it is the transmitter 1, It has a built-in small battery 2 such as a sheet battery or a button battery.

As shown in FIG. 3, the oscillator has a switching circuit 4 which turns on the power supply circuit 3 when receiving a weak radio wave atmosphere of a specific frequency, and receives power from the power supply circuit 3 depending on the ON operation and maintains the ON operation. and,
An oscillation circuit 5 receives power supply from the small battery 2 of the power supply circuit 3 and oscillates at a specific frequency when the switching circuit 4 turns on, and a modulation circuit 6 modulates the oscillation frequency into a radio wave signal of a predetermined frequency.
and a transmitting circuit 7 that wirelessly transmits the modulated signal, and a transmitting antenna 8 of the transmitting circuit 7.
is also accommodated within the flat shell 10.

In addition, the switching circuit 4 can obtain the base current of the transistor T1, which is the switching element, by using the magnetic field current generated in the parallel winding coil 9, through the half-wave rectifier circuit 11 which includes two diodes Di, Di. As shown in FIG. 4, the parallel-wound coil 9 is made up of two coiled parts 12, 12 each of which is made by winding a conductive wire of a predetermined length one or more times. They are arranged in parallel in the direction of the winding surface via connecting portions 13.

The detection gate 15 also includes a known radio wave transmitting means 16 that transmits a weak radio wave (0.5 W or less) in the resonant frequency range of the parallel-wound coil in a limited range, and a known receiver that receives the radio wave transmitted by the pre-oscillation transmitter 1. Means 17
and annunciators 18a and 18b which receive the received signal and make various desired notifications such as warnings or announcements.

Reference numeral 20 denotes a portable receiver incorporating a known receiving means for receiving the radio waves transmitted by the transmitter 1.

The shoplifting prevention device having the above structure is used by installing the detection gate 15 at or near the entrance of the store so as to block the entrance with a radio wave atmosphere, and by attaching the transmitter 1 to each product. , when a normal sale is completed, the person in charge collects the transmitter 1.

When the transmitter 1 passes through the detection gate 15 together with the product a due to a theft incident, etc., the parallel winding coil 9 receives the weak radio waves from the transmitting means 16 of the detection gate 15 and generates a magnetic field current. Transistor T1 is turned on, and radio waves of a predetermined frequency are transmitted from transmitting antenna 8 via oscillation circuit 5, modulation circuit 6, and transmitting circuit 7 using built-in small battery 2.

This radio signal is detected by the receiving means 17 of the gate 15.
receives the signal, and depending on the received signal, the notification devices 18a, 18
By ringing or lighting b, it is announced that the transmitter 1 has passed through the detection gate 15.

Based on the above notification, the staff member can know the shoplifter who has passed through the detection gate 15.

However, when a plurality of customers are passing through the detection gate 15 at the same time, the portable receiver 20 is placed close to the transmitter 1.
It is possible to identify the culprit by receiving a radio wave signal and emitting a "boo" sound.

G. Effects of the Invention As described above, the shoplifting prevention device of the present invention can identify the culprit, so it not only does not cause personnel problems, but also uses the built-in battery only when a theft accident occurs. Because it is a product, it has the characteristic that maintenance costs can be kept low.
The practical effects of the present invention are extremely large.

[Brief explanation of drawings]

The drawings show an embodiment of the shoplifting prevention device of the present invention, and FIG. 1 is an overall block diagram, FIG. 2 is a partially cutaway front view of the transmitter, and FIG. 3 is a circuit diagram of the transmitter. Figure 4a is a front view of the parallel winding coil.
b is a plan view of the same, and c is a right side view of the same. 1 - Transmitter, 2 - Small battery, 3 - Power supply circuit, 4
- switching circuit, 5 - oscillation circuit, 6 - modulation circuit, 7 - transmission circuit, 8 - transmission antenna, 9 - parallel winding coil, 10 - flat shell, 15 - detection gate, 2
0 ~ portable receiver, a ~ product.

Claims (1)

[Claims] 1 Exhibits a flat appearance that is attached to individual products,
A transmitter that includes a built-in small power supply, a switching circuit that turns on and maintains the power supply circuit using the electromotive force of a parallel coil based on external radio waves, and a transmitter circuit that transmits a radio wave signal of a predetermined frequency based on the power supply. and the switching circuit of the above transmitter.
A detection gate that is equipped with a transmitting means that creates a weak radio wave atmosphere of a predetermined frequency that is turned ON and that receives the radio waves transmitted from the transmitter and drives the annunciator, and a mobile phone that receives the radio waves transmitted from the transmitter and makes an announcement. A shoplifting prevention device consisting of a receiver and a receiver.