JP2004078611A - Antitheft device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antitheft device which is stable in detection and more accurate in detection. <P>SOLUTION: This is an antitheft device provided with a tag 2 which is provided with conductive patterns 16, 17 and 18 together with an adhesive layer 28 on a flexible insulating film 24, attached to an article 8 detachably by an adhesive layer, and brought into a different state by the removal. In this case, a discontinuous separation layer (a separation ink print layer 26) is provided between the insulating film and the conductive patterns. By this constitution, the breaking of the conductive patterns can be generated at the boundary part between the separation layer and the conductive patterns, and the detection is stabilized and the accuracy in detecting an abnormal state is improved. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anti-theft device that detects a different state due to removal of a tag that is detachably attached to an article that is subject to anti-theft, and issues an alarm according to the change in the state.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a theft prevention device is known in which a tag is detachably attached to an article, a different state due to tag removal is electrically detected, and an alarm is issued according to the state change. For example, in Japanese Patent No. 2799136 “Anti-Theft Device”, a tag that is detachably attached to an article and can take different states upon removal, an alarm means that issues an alarm, a different state connected to the tag is detected, and its state changes Control means for controlling the alarm means according to the tag, the tag has an adhesive layer, a conductive layer formed on the adhesive layer, and a substrate formed on the conductive layer, When the adhesive layer surface is pasted and the resistance value of the conductive layer is detected by the control means and the state becomes different, the alarm means can be driven.
[0003]
[Problems to be solved by the invention]
By the way, in this anti-theft device, when the sheet tag attached to the article is peeled off, the conductive layer on the insulating film is peeled off and torn, and the state change is electrically detected to provide an alarm means. Driven. However, when the sheet tag is peeled off, the conductive layer between the adhesive layer and the insulating film is not torn and is kept attached to one side of the adhesive layer or the insulating film. There is a possibility that the alarm means may not be driven in spite of an abnormal state such as no change in state.
[0004]
Therefore, an object of the present invention is to provide an antitheft device that stabilizes detection and increases detection accuracy.
[0005]
[Means for Solving the Problems]
The configuration of the present invention that solves such a problem is as follows.
[0006]
The anti-theft device of the present invention is provided with conductive patterns 16, 17, and 18 together with an adhesive layer 28 on a flexible insulating film 24, and is removably attached to the article 8 by the adhesive layer. An anti-theft device including a tag 2 to be provided, wherein a discontinuous release layer (release ink printing layer 26) is provided between the insulating film and the conductive pattern.
[0007]
According to such a configuration, when the tag is removed, the peeling layer facilitates peeling between the insulating film and the conductive pattern, and when the tag is peeled off, the conductive pattern peels off at the edge portion of the peeling layer, and the tag is broken. The accuracy of the removal detection can be improved. The inconvenience that the alarm means does not operate at the time of abnormality can be avoided.
[0008]
In the anti-theft device of the present invention, the release layer is formed on at least one end of the insulating film. That is, by providing a release layer on the end side of the insulating film, which is the starting position of peeling, when the tag is peeled off, the conductive pattern is peeled off at the edge of the release layer, and the accuracy of tag removal detection is detected. Can be increased.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an antitheft device according to an embodiment of the present invention. This anti-theft device comprises a sheet-like tag 2 having flexibility, a connector case 4 as a relay member, and a device body 6 as a control means and an alarm means.
[0010]
For example, as shown in FIG. 2, the tag 2 is detachably attached to an article 8 that is a commodity such as a CD that should be prevented from being stolen, and is attached to the connector case 4 by the attaching portion 10 and pulled out from the connector case 4. The cable 12 thus connected is connected to the apparatus main body 6 through the horn plug 14.
[0011]
The tag 2 is provided with conductive patterns 16 and 18 made of a conductor layer formed by printing of silver carbon ink or the like as a detection means for removal from the article 8, that is, a removal detection means that exhibits a different state by peeling. Each conductive pattern 16, 18 is provided with a plurality of bent portions 20. Further, the tag 2 is formed with a mounting portion 10 for connection to the connector case 4, and a restraining projection 22 for preventing separation from the connector case 4 mounted on the mounting portion 10. .
[0012]
For example, as shown in FIG. 3, the tag 2 includes a release ink printing layer 26 made of an insulating material as a plurality of release layers that can be peeled off from the surface of a flexible insulating film 24 formed of an insulating material. Conductive patterns 16 and 18 made of conductors are installed in this embodiment as conductive patterns made of conductors or resistors that are discontinuously installed at arbitrary intervals and straddle the release ink print layer 26. . An adhesive layer 28 is formed so as to cover the surfaces of the conductive patterns 16 and 18. Therefore, the tag 2 is detachably attached to the article 8 with the adhesive layer 28.
[0013]
In this embodiment, the connector case 4 is a casing made of, for example, a synthetic resin, which is installed between the tag 2 and the apparatus main body 6, and a resistor 30 is installed therein, and this The resistor 30 is connected to the horn plug 14 which is a connection means with the apparatus main body 6 through the cable 12 connected to the conductive patterns 16 and 18.
[0014]
The apparatus body 6 is provided with a control device 32 that detects a change in state generated on the tag 2 side and generates an alarm signal. For example, a microcomputer is used for the control device 32 to store the initial state. A storage unit 34 is installed, and an alarm unit 36 including an alarm buzzer and an alarm lamp is connected as an alarm unit that operates according to an alarm signal. In addition, a resistor 40 is installed in the device main body 6 together with a power supply device 38 that generates a constant voltage V. Between the resistor 40 and a ground point (GND), a horn plug 14, a cable 12 and A resistor 30 is connected via the conductive patterns 16 and 18, and a constant voltage V is applied to the series circuit of the resistors 30 and 40 from the power supply device 38. The voltage Vn generated at the voltage dividing point n between the resistors 40 and 30 is applied to the A / D converter input section of the control device 32 and converted into a digital value.
[0015]
In such a configuration, the operation will be described. In a normal state, the state shown in FIG. The voltage applied from the power supply device 38 is V, the resistance values of the resistors 40 and 30 are R, the resistance values r of the cable 12 and the conductive patterns 16 and 18 are r << R, and can be ignored with respect to the resistance value R. If so, the detection voltage Vn applied to the control device 32 through the voltage dividing point n is
Vn = V × (R / 2R) = V / 2 (1)
It becomes. For example, when R = 2.2 [kΩ] and V = 3.3 [volt], Vn = 1.65 [volt].
[0016]
Therefore, in the initial setting, when the tag 2 is connected to the apparatus body 6 via the connector case 4, the detection voltage Vn generated at the voltage dividing point n is captured, and the initial voltage value is converted into a digital value. Each tag 2 is stored in the storage means 34. Then, a voltage range (Vr ± ΔV) obtained by adding an allowable voltage fluctuation range ± ΔV (for example, within ± 0.4 [volt]) that can be regarded as normal to the initial value Vr is set as a normal reference voltage range. The This voltage range (Vr ± ΔV) is stored in the storage means 34 as a digital value. When the detected voltage Vn deviates from this voltage range (Vr ± ΔV), it is determined as abnormal and an alarm signal is issued. In this case, the voltage range (Vr ± ΔV) is a value determined individually for each tag 2 when a plurality of tags 2 are used.
[0017]
When the cable 12 is cut or a part or all of the conductive patterns 16 and 18 are broken (disconnected) by removing the tag 2 at the time of abnormality, the resistor 30 is detached as shown in FIG. 4B, for example. Will do. At this time, the resistance value R between the voltage dividing point n and the ground point (GND) becomes infinite, and the detection voltage Vn applied to the control device 32 through the voltage dividing point n becomes the voltage V of the power supply device 38. That is, when Vn = V and V = 3.3 [volt], Vn = 3.3 [volt].
[0018]
In addition, when the conductive patterns 16 and 18 are short-circuited due to the removal of the tag 2 or an external operation at the time of abnormality, the resistor 30 is short-circuited as shown in FIG. The resistance value R with respect to the ground point (GND) becomes zero, and the detection voltage Vn applied to the control device 32 through the voltage dividing point n becomes zero. That is, Vn = 0.
[0019]
As described above, Vn = V / 2 [volts] in a normal state and Vn = V [volts] or Vn = 0 [volts] in an abnormal state, and therefore, the resistance value R of the resistor 30 between the conductive patterns 16 and 18. And the control device 32 can determine whether the voltage is normal or abnormal based on the value of the detection voltage Vn at the voltage dividing point n representing the state change. In addition to these, when the detection voltage Vn fluctuates outside the voltage range (Vr ± ΔV), which is an added value of the initial value Vr and the allowable voltage fluctuation range ± ΔV, an abnormal state is detected.
[0020]
When these abnormalities occur, an alarm signal is issued from the control device 32, and the alarm device 36 can receive an alarm signal and issue an alarm to notify the abnormal situation.
[0021]
In this case, since the plurality of release ink print layers 26 are discontinuously disposed between the conductive patterns 16 and 18 and the insulating film 24, the conductive patterns 16 and 18 are provided with the release ink print layer 26. When the tag 2 attached to the article 8 is peeled off, the conductive patterns 16 and 18 are easily torn at the cut portion (that is, the interval portion) of the release ink printing layer 26, and FIG. It is possible to increase the accuracy of detecting an abnormal state by generating the state change shown in FIG.
[0022]
In addition, the conductive patterns 16 and 18 formed in a circular shape on the insulating film 24 have a plurality of bent portions 20 and also have a bent portion 20 on the distal end side of the tag 2, so that they receive stress at the time of removal. It is easy to tear and the detection accuracy of an abnormal state is improved.
[0023]
As a method for manufacturing the tag 2, for example, the release ink printing layer 26 is discontinuously formed on the insulating film 24 by printing, and the conductive patterns 16 and 18 are formed thereon by printing. 26 and the conductive patterns 16 and 18 are covered with an adhesive layer 28. According to such a manufacturing method, the uniform tag 2 can be manufactured.
[0024]
Moreover, according to such a tag 2, when the adhesive layer 28 deteriorates, the tag 2 deteriorated from the connector case 4 can be easily replaced by releasing the lock by a lock mechanism (not shown) and removing it. Detection accuracy can be maintained.
[0025]
The conductive patterns 16 and 18 of the tag 2 can be configured by removing the resistor 30 from the connector case 4 if the conductive patterns 16 and 18 of the tag 2 are composed of the conductive pattern 17 and used as a resistor, as shown in FIG. By monitoring the change in the resistance value of the resistor, it is possible to detect an abnormal state such as peeling of the tag 2 by a change in the electrical state.
[0026]
The conductive patterns 16, 17, and 18 are configured to circulate in the longitudinal direction of the tag 2, but may be configured to bend in a zigzag shape in the width direction of the tag 2.
[0027]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
a It is possible to improve the detection accuracy of the abnormal state together with the stabilization of the detection.
b When the tag is peeled off, it can be peeled off at the boundary between the peeling layer and the conductive pattern provided partially or discontinuously and the conductive pattern can be broken. Inconveniences such as malfunction of the means can be prevented, and the reliability of the operation can be improved.
c If the release layer is formed on at least one end of the insulating film, peeling is likely to occur on the end side of the insulating film, so that the tearability of the conductive pattern can be increased correspondingly, and detection accuracy is increased, When an abnormality occurs, it is possible to prevent inconveniences such as failure of alarm means.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing an outline of an antitheft device according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a mounted state and a used state of a connector case and a tag.
FIG. 3 is a cross-sectional view showing the structure of a tag.
4A and 4B are circuit diagrams showing the operation of the anti-theft device, wherein FIG. 4A is a circuit diagram showing normal operation, FIG. 4B is a circuit diagram showing operation at break (disconnection), and FIG. It is a circuit diagram which shows operation | movement.
FIG. 5 is a plan view showing a tag according to another embodiment.
[Explanation of symbols]
2 Tag 8 Article 16, 17, 18 Conductive pattern 24 Insulating film 26 Release ink printing layer (release layer)
28 Adhesive layer

Claims (2)

An antitheft device comprising a tag having a conductive pattern on an insulating film having flexibility together with a conductive pattern and detachably attached to an article by the adhesive layer, and exhibiting different states upon removal,
A theft prevention device, wherein a discontinuous release layer is provided between the insulating film and the conductive pattern. The antitheft device according to claim 1, wherein the release layer is formed on at least one end of the insulating film.

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