KR200251685Y1 - structure of sensor for article surveillance system - Google Patents

Abstract

Disclosed is an electronic sensor structure of an anti-theft device that enables thinning and stable operation. The electromagnetic sensitive sensor structure of the anti-theft device is wound around the core 90 and the core 90 and the insulating layer 82 and the adhesive layer 83 are sequentially coated on the outer circumference thereof, and the adjacent adhesive layers are wound during winding. Coil 80 to be hot melt bonded, the capacitive 70 is connected to the coil to form a resonant circuit, and the pressure-sensitive adhesive for adhesively fixing the both ends and the capacities 70 of the coil 80 to the core ( 60).

Such a sensor structure can be made thinner by removing the coil bobbin, and the product tag employing the same can be made smaller.

In addition, since the coils wound on the cores are bonded to each other by hot melting, the coils of the coils wound during use and storage are prevented from being loosened, thereby enabling stable operation.

Description

Structure of sensor for article surveillance system

The present invention relates to an electronic sensitive sensor structure of a product anti-theft device, and more particularly, to a product anti-theft device which is adopted in a product anti-theft prevention system installed to prevent the goods from being unfairly removed from a store, etc. It relates to an electromagnetic sensitive sensor structure.

In general, large shops and the like are provided with a product theft prevention system for preventing theft of goods. When the tagged product passes between the gate with the transmitting antenna and the gate with the receiving antenna, the resonant frequency is absorbed by the resonant circuit provided in the tag and received by the receiving antenna. The alarm sound is generated by matching with the set resonant frequency to notify the clerk so as to prevent the unfair carry out of goods.

One example of an electromagnetic sensitive sensor structure employed in such a product antitheft system to form a resonant circuit is shown in FIGS. 1 and 2.

The conventional electromagnetic sensitive sensor structure 50 is provided with a bobbin 20 on the outside of the ferrite core 10, the coil 30 is wound around the bobbin 20, the capacity 40 is connected to the structure have. The electronic sensor is provided on a tag (not shown) attached to the product, in which case the entire volume of the tag due to the coil bobbin 20 is increased and the coil 30 wound around during the movement / storage of the tag occurs. There is a problem.

The present invention has been made to solve the above problems, the object of the present invention is to provide an electronic sensor structure of the anti-theft device is improved in its structure to be thinner.

Another object of the present invention is to provide an electronic sensor structure of the stable anti-theft device by preventing the winding of the coil wound during use and storage.

1 is a perspective view showing a conventional electromagnetic sensor structure;

2 is a cross-sectional view of FIG.

Figure 3 is a perspective view of the present invention electronic sensitive sensor structure,

4 is a front view of FIG. 3;

5 is a cross-sectional view of FIG.

6 is an enlarged cross-sectional view illustrating a coil wound around a core.

<Description of the symbols for the main parts of the drawings>

60 ... Adhesive 70 ... Capacity

80 ... coil 82 ... insulating layer

83 ... adhesive layer 90 ... core

The present invention to achieve the above object is in the electromagnetic sensitive sensor structure of the anti-theft device having a resonance circuit for absorbing radio waves emitted from the gate when passing through the gate,

Core 90,

A coil 80 wound around the core and sequentially covered with an insulating layer and an adhesive layer on its outer circumference, and thermally gluing the adjacent adhesive layers during winding;

A capacity 70 connected to the coil 80 to form a resonance circuit;

Both ends and the capacities 70 of the coil 80 are adhesively fixed to the core 90 by using the adhesive 60.

The core may be formed of an amorphous alloy or ferrite.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 to 5 showing the electronic sensitive sensor of the anti-theft device according to the present invention, the electronic sensitive sensor is installed in, for example, a large shop and is employed in a product theft prevention system for preventing theft of goods.

The electronic sensor is embedded in a tag (not shown) attached to the product, and when the product with the tag passes between the gate with the transmitting antenna and the gate with the receiving antenna provided at the entrance side, Radio waves from the antenna are absorbed by the resonant circuit provided in the tag and the resonant frequency received by the receiving antenna coincides with the set resonant frequency, thereby generating an alarm sound and informing the clerk so as to prevent unfair carry-on of goods.

The electronic sensor of the anti-theft device of the anti-theft device is a coil 80 is wound around the outer periphery of the core 90, the capacities 70 are connected to the coil 80, and at both ends of the coil 80 The adhesive 60 has a structure in which the adhesive 60 is adhered to prevent coil loosening and to fix the capacity 70.

Meanwhile, as illustrated in FIG. 5, the coil 80 is sequentially covered with an insulating layer 82 and an adhesive layer 83 on the outer circumference of the copper wire 81, and hot-melt adhesion between the adjacent adhesive layers 83 during winding is performed. It has a structure.

As such, the electromagnetic sensor constituting the resonant circuit using the coil 80 and the capacitance 70 is provided in a tag attached to the product, absorbs radio waves emitted from the gate when passing through the entrance and sets the set resonance frequency of the receiving antenna. By detecting this, it can be detected to prevent theft of goods.

The core 90 may be formed of a long cylindrical or rod-shaped ferrite, and may be formed of an amorphous alloy core.

The amorphous magnetic material has no crystal magnetic anisotropy, easy magnetization, and small coercive force. In addition, the atomic arrangement is disordered and the electrical resistance is large, so the eddy current loss is small, so the high frequency characteristics are good.

In the high frequency region of several Mhz or more, ferrite core has better magnetic properties than amorphous, and amorphous has good magnetic properties at saturation magnetic flux density.

In addition, when amorphous is used, it is advantageous to miniaturization and weight reduction of the product than when ferrite core is used.

Ferrite cores have a high permeability, resistivity from several kΩ to several MΩ, and magnetostriction is also a material with high characteristics.

When the tag is placed in an alternating magnetic field having a constant frequency band, a resonant circuit such as the resonant frequency of the ferrite core surrounding the tag resonates, thereby causing the ferrite core to undergo mechanical magnetostriction.

In other words, the mechanical magnetostriction of the ferrite core is maximum at the resonant frequency of the material and minimum at the anti-resonant frequency.

Mechanical magnetostriction of ferrite cores in an alternating magnetic field causes a change in the permeability of the material and a change in permeability results in a change in magnetic flux density. Therefore, the variation of the magnetic flux density causes a high induced electromotive force to be applied to the search coil according to Faraday's law of magnetic induction to generate an alarm signal.

The present invention as described above can be thinned by the removal of the coil bobbin employed in the conventional sensor, and further miniaturized the product tag employing the same.

In addition, since the coils wound on the cores are bonded to each other by hot melting, the coils of the coils wound during use and storage are prevented from being loosened, thereby enabling stable operation.

Claims (1)

An electronic sensitive sensor structure of an anti-theft device comprising a resonant circuit that absorbs radio waves emitted from a gate when passing through the gate, Koawa, A coil wound around the core and sequentially covered with an insulating layer and an adhesive layer on an outer circumference thereof, and being hot melt bonded to adjacent adhesive layers during winding; A capacity connected to the coil to form a resonance circuit; Both ends and the capacities of the coil is adhesively fixed to the core by using a pressure-sensitive adhesive electronic sensitive sensor structure of the anti-theft device.