JP3294746B2 - Article surveillance signs - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article monitoring sign used in a system for magnetically monitoring articles such as goods.

[0002]

2. Description of the Related Art A magnetic article monitoring system uses a switchable magnetic element on a label or the like of an article.
And a pulse-like output accompanying magnetization reversal generated when an alternating magnetic field is applied to the magneto-sensitive element is detected by a coil or the like. Therefore, in this case, the passage of the article is monitored by providing the inspection gate with an alternating magnetic field generator and a detector for detecting a pulse-like output accompanying the magnetization reversal. As the magnetic sensitive element, an element using an Fe-Co-Si-B-based amorphous alloy, an Fe-Ni-based alloy, or the like is known.

For example, when the above-described magnetic sensitive element is used to monitor a product in a store, a magnetic sensitive element is attached to the product, and when the payment is completed, a process of canceling the magnetization reversal function of the device, That is, it is necessary to perform a process that does not generate a detection signal even when the signal passes through the inspection gate.

In view of such demands, it has been proposed to provide a hard or semi-hard canceling magnetic body near a magnetic element as in the prior art described in, for example, US Pat. No. 3,665,449. Have been. This prior art uses a substrate 2 such as an article monitoring sign 1 shown in FIG.
A plate-shaped or wire-shaped canceling magnetic body 4 is arranged in the vicinity of the magnetic element 3 buried in the substrate. If necessary, the canceling magnetic body 4 is magnetized, and the
By applying a bias magnetic field to the test gate, the magneto-sensitive element 3 is prevented from causing a magnetization reversal even when an alternating magnetic field is applied to the inspection gate.

[0005]

In the sign 1 having the canceling function as in the prior art described above, since the canceling magnetic body 4 is disposed near the magnetic sensitive element 3, the manufacturing cost of the sign 1 is high. Moreover, when the element 3 and the canceling magnetic body 4 overlap in the thickness direction of the marker 1, there is a problem that the thickness of the marker 1 becomes large. Further, since the unevenness of the surface of the sign 1 becomes large, it is difficult to print, for example, a bar code, a commodity price, etc. on the sign 1. Moreover, since the sign 1 itself is not easily bent, it is difficult to attach the sign 1 to a curved surface such as a bottle or a can. Accordingly, an object of the present invention is to provide an article monitoring sign which can be formed thin, has high flexibility, and has a substantially flat surface.

[0006]

According to the present invention, there is provided an article surveillance sign developed to fulfill the above-mentioned object, comprising a base made of a non-magnetic material and a base provided on the base and having a Si concentration of 6 to 6.
Fe formed of 7 wt% Fe-Si alloy and causing a sharp magnetization reversal when an alternating magnetic field exceeding its coercive force is applied
-Si alloy wire, made of a magnetic material that is magnetically hard or semi-hard and can be magnetized, and mixed in the base material in the vicinity of the Fe-Si alloy wire and magnetized in a state of the alloy wire. And a canceling magnetic powder for applying a bias magnetic field for preventing the magnetization reversal to the alloy wire. F above
It is recommended that the e-Si alloy wire has an absolute value of the saturation magnetostriction of 30 × 10 ⁻⁶ or less.

[0007] An example of the above-mentioned base material is a film-like material mainly composed of a flexible material such as paper or synthetic resin. And a canceling magnetic powder.
Further, a protective layer made of a transparent or opaque synthetic resin may be provided on the front side of the film-shaped base material, an adhesive layer may be provided on the back surface side of the base material, and release paper may be provided on the adhesive layer. . Product information such as an optically readable barcode and product price is printed on the surface of the sign as needed.

In the above-mentioned marker, when an alternating magnetic field exceeding the coercive force of the Fe—Si alloy wire is applied, a steep magnetization reversal occurs with almost no magnetostriction due to the large Barkhausen effect (large Barkhausen jump). Therefore, when an alternating magnetic field exceeding the coercive force of the Fe-Si alloy wire is applied to the inspection gate or the like, a sharp magnetization reversal occurs in the Fe-Si alloy wire. By detecting the magnetic field change due to the magnetization reversal by a detector such as a detection coil, a pulse-like output is detected. Then, by comparing the pulse-like output with predetermined reference data or the like, it is determined whether or not the marker is magnetized, that is, whether or not a bias magnetic field is applied to the Fe-Si alloy wire. Can be.

If a bias magnetic field is applied to the Fe—Si alloy wire by magnetizing the canceling magnetic powder as required, the magnetization reversal of the Fe—Si alloy wire can be prevented. In this case, the function of reversing the magnetization of the alloy wire is canceled, and even if an alternating magnetic field is applied to the inspection gate or the like, no pulse-like output is detected.

[0010] Since the Fe-Si alloy wire hardly causes magnetostriction at the time of magnetization reversal, its output is not affected even when buried in a base material. On the other hand, amorphous ferromagnetic wires and Fe-Ni alloy wires used in conventional anti-shoplifting tags and the like have large magnetostriction. No output can be obtained.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. In the example of the article monitoring sign 10 shown in FIGS. 1 and 2, an Fe—Si alloy wire 12 is embedded in a label-like (strip-like) base material 11 made of a nonmagnetic material. Further, a large number of magnetic powders 1 for cancellation are
5 is mixed. The magnetic powder 15 will be described later.

The base 11 is made of a relatively soft material such as paper or synthetic resin, and the thickness of the base 11 is Fe--Si.
If a film-like base material 11 having a diameter substantially equal to the diameter of the alloy wire 12 is employed, the sign 10 can be made highly flexible. As the material of the base material 11, non-conductive materials such as glass and ceramics can be used other than paper or synthetic resin.

The marker 10 is preferably provided with an adhesive layer 13 on the back side of the substrate 11 so that it can be attached to an article. However, in the case of a hanging tag such as a tag, the adhesive layer 13 can be omitted. Further, as shown in a sign 10 shown in FIG. 3, it is provided with a protective layer 20 covering the front side of the base material 11 and a peelable release paper 21 attached to the adhesive layer 13 on the back side of the base material 11. There may be. The marker 10 having the adhesive layer 13 can be attached to a desired position of the product via the adhesive layer 13 by peeling off the release paper 21. Also, like the sign 10 shown in FIG. 4, optically readable product information 27 such as a product identification barcode 25 and a product price 26 is provided on the surface of the sign 10.
May be printed.

The wire-shaped Fe—Si alloy wire 12 is arranged along the longitudinal direction of the base material 11 (the direction in which the marker 10 is magnetically scanned). However, the alloy wire 12 does not necessarily need to be provided at the center in the width direction of the base material 11 and may be arranged at a position closer to one side. The alloy wire 12 is made of an Fe—Si alloy having a Si concentration of 6 to 7 wt% (more preferably, 6.2 to 6.7 wt%). Examples of the size of the Fe—Si alloy wire 12 include a wire diameter of 30 to 150 μm (for example, about 50 μm) and a length of 300 to 1000 times the wire diameter (for example, 40 m).
m) is recommended. The cross-sectional shape of the alloy wire 12 is preferably a circle, but may be a cross-section other than a circle such as an ellipse, a polygon, or a rectangle.

The Fe—Si alloy wire 12 has a strong magnetic anisotropy in the axial direction due to a magnetic effect due to its shape and crystal structure. When an alternating magnetic field having an amplitude larger than 1.0 Oersted is applied, a very steep magnetization reversal occurs due to the large Barkhausen effect.

When this magnetization reversal is detected by, for example, a solenoid coil, a pulse-like output P as shown in FIG.
Is obtained. That is, assuming that the positive coercive force of the Fe—Si alloy wire 12 is Hp and the negative coercive force is −Hp, the Fe—Si alloy wire 12 becomes Fe—Si at the moment that the alternating magnetic field exceeds these coercive forces Hp and −Hp.
A magnetization reversal occurs in the alloy wire 12, and a pulsed output voltage P corresponding to the magnetization reversal is detected. Since the width of this pulse is as very small as 10 to 100 μsec, the output voltage contains many high-frequency components of several KHz or more. The magnetization reversal hardly depends on the frequency of the applied alternating magnetic field,
Even when the frequency is low, the same pulsed output P can be obtained.

The Fe—Si alloy wire 12 has a length of 3 mm in diameter.
If it is 00 times or more, it has about 1.2 to 2.0 times the saturation magnetic flux density as compared with the amorphous alloy wire (amorphous wire), so that it has a higher saturation flux density than the conventional amorphous alloy wire. A large and sufficient output voltage can be obtained. When the wire diameter is 30
In the case of an alloy wire of μm to 150 μm, if the length exceeds 1000 times the wire diameter, the size becomes too large to be practical, so the wire length is 300 to 1000 times the wire diameter. It is desirable that it is set in the range.

Since such an Fe--Si alloy wire 12 is extremely thin and flexible, it can be easily applied not only to an article having a flat surface but also to an article having a curved surface such as a bottle or a can. it can. Further, since the Fe—Si alloy wire 12 is extremely thin, even if it is embedded in the
Since the surface of 0 is almost flat, it is possible to print product information 27 such as a bar code 25 as shown in FIG.

A large number of canceling magnetic powders 15 made of a magnetically hard or semi-hard material are mixed in the base material 11. The material of the magnetic powder 15 has, for example, a coercive force of 10
Γ-Fe ₂ O of about 0 to 5000 Oe (Oe)
₃ and _{Co-γ-Fe 2 O 3} , Fe 3 O 4, Ba ferrite, ferromagnetic materials are suitable, including various ferrites such as Sr ferrite. This magnetic powder 15 is 0.2 μm
Those treated so as to have a particle size of about 1.6 μm are suitable. The volume ratio between the base material 11 and the magnetic powder 15 is preferably in the range of about 1: 2 to 3: 1. In the conventional label for monitoring articles, it is necessary to arrange plate-shaped canceling magnetic materials at regular intervals or to arrange wire-like canceling magnetic materials at a narrow pitch, which complicates the structure of manufacturing equipment and costs. However, the process of mixing the magnetic powder 15 into the base material 11 as in this embodiment can be performed at low cost because the alloy wire 12 is simply embedded in the base material 11.

When the magnetic powder 15 is magnetized, the magnetic powder 15 shown in FIG.
As shown by a two-dot chain line S, a bias magnetic field can be applied to the Fe—Si alloy wire 12. In the case of FIG. 5, the alternating magnetic field acting on the Fe-Si alloy wire 12 is shifted above the coercive force (-Hp) by the bias magnetic field, so that the magnetization reversal does not occur, and the pulsed output P does not occur.

FIG. 6 shows an article (commodity) to which the mark 10 is attached.
An inspection gate 40 for monitoring the passage of M is shown. The gate 40 includes a transmitter 42 as a magnetic field applying unit that generates an alternating magnetic field in an inspection area 41 through which a customer passes, and a receiver 43 as a receiving unit that outputs a change in the magnetic field in the inspection area 41 as an output signal. I have.

The transmitter 42 has a transmitting coil 45 and an AC generator 47 for supplying an alternating current to the transmitting coil 45 via an amplifier 46. The transmitting coil 45 generates an alternating magnetic field according to the alternating current supplied from the alternating current generator 47 via the amplifier 46 and applies the alternating magnetic field to the inspection area 41.

The receiver 43 includes a detection coil 50 functioning as an electromagnetic induction coil, and a detection circuit 51 connected to the detection coil 50. The detection coil 50 is disposed facing the transmitting coil 45 at an interval enough to allow a person to pass through, for example, at an interval of 1 m, and forms the inspection area 41 between the detecting coil 50 and the transmitting coil 45. Then, a current corresponding to the magnetic field in the inspection area 41 is induced in the detection coil 50 constituting the receiving means, and this current is output to the detection circuit 51 as an output signal.

The detection circuit 51 includes a filter 52, an amplifier 53, and a comparator 54 connected to the detection coil 50. The filter 52 extracts a high-frequency component of a pulse-like output signal resulting from the sharp magnetization reversal of the Fe—Si alloy wire 12 from the output signal received by the detection coil 50. Since the pulse output is periodically output each time the polarity of the alternating magnetic field changes, the detection is performed almost instantaneously without moving the article M with the mark 10 relatively to the alternating magnetic field.

The comparator 54 compares the detected pulse-shaped output with reference data prepared in advance, whereby
Whether a pulsed output has occurred (Fe-Si alloy wire 12
Or not, ie, whether or not the canceling magnetic powder 15 is magnetized. Article M
When passing through the gate 40, the canceling magnetic powder 15
If the magnetizing process has not been performed, a pulse-like output is detected by the receiver 43 and the detection circuit 51.

A notification unit 56 is connected to the comparator 54 via a drive unit 55. The drive unit 55 activates the notification unit 56 according to the comparison result of the comparator 54. The notifying means 56 notifies the administrator (a clerk or the like) of the gate 40 of the collation result by a display means such as a warning light or a notification sound.

Next, the operation of the marker 10 having the above configuration will be described. Signs 10 to monitor goods at shops and the like
When using the mark, the marker 10 is attached to the product in advance. In addition, the inspection gate 40 is installed at the exit of the store, for example, at the exit of a checkout station (so-called cash register). The checkout station is provided with a magnetic field generator (not shown) for magnetizing the canceling magnetic powder 15. When the customer pays for the merchandise at the checkout station, the canceling magnetic powder 15 of the marker 10 attached to the merchandise is magnetized by the magnetic field generator.

For this reason, the goods which have been settled are sent to the inspection gate 4
When passing through zero, since the Fe-Si alloy wire 12 does not cause magnetization reversal, this product is allowed to exit from the inspection gate 40. On the other hand, the unpaid products are inspected gate 4
When passing through zero, the Fe-Si alloy wire 12 of the marker 10 attached to the product undergoes magnetization reversal. Therefore, the above-described pulse-shaped output is detected by the coil 50, and the detection circuit 51 operates the notification unit 56 via the drive unit 55.

Note that, as shown in FIG.
The canceling magnetic powder 15 is mixed with a part of the base 11 made of synthetic resin or paper constituting the case itself, a case, a container, and the like, and the Fe-Si alloy wire 12 is mixed in a region where the magnetic powder 15 is mixed. May be buried. In this case, a label 28 on which product information 27 such as an optically readable bar code 25 and a product price 26 is printed is attached to the surface of the base material 11 of the article M.

[0030]

According to the present invention, since the magnetic powder for canceling the magnetization reversal function of the Fe-Si alloy wire is mixed in the base material, the alloy wire is extremely thin and flexible. The flexibility of the sign is not lost, so that the sign can be easily attached not only to an article having a flat surface but also to an article having a curved surface such as a bottle or a can.

Further, the sign can be made thinner than before, and the surface of the sign becomes almost flat, so that it is possible to print bar code and product information such as product price. In addition, since the Fe-Si alloy wire has substantially very small magnetostriction, a desired output can be obtained even when the wire is embedded in the base material. The process of mixing the magnetic powder into the substrate can be performed at low cost. Also, by embedding the alloy wire and the canceling magnetic powder in the article itself or a base material constituting a container or the like, a part of the article can be used as a marker.

[Brief description of the drawings]

FIG. 1 is a perspective view of an article monitoring sign showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a cross-sectional view showing a modification of the sign.

FIG. 4 is a plan view showing a modified example of a sign on which a barcode is printed.

FIG. 5 is a diagram showing a relationship between an excitation magnetic field and an output of the marker shown in FIG. 1;

FIG. 6 is a perspective view showing a configuration of a gate for detecting the sign shown in FIG. 1;

FIG. 7 is a perspective view of an article provided with a sign.

FIG. 8 is a plan view of a conventional marker having a canceling magnetic body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Article monitoring marker 11 ... Base material 12 ... Fe-Si alloy wire 13 ... Adhesive layer 15 ... Canceling magnetic powder 20 ... Protective layer 21 ... Release paper 25 ... Bar code 27 ... Product information

────────────────────────────────────────────────── (5) References JP-A-7-44779 (JP, A) JP-A-7-105454 (JP, A) US Patent 3,665,449 (US, A) (58) Fields studied (Int .Cl. ⁷ , DB name) G08B 13/24

Claims (3)

(57) [Claims] 1. A substrate made of a nonmagnetic material, and a Fe-based material provided on the substrate and having a Si concentration of 6 to 7% by weight.
An Fe-Si alloy wire which is formed of a Si alloy and generates a steep magnetization reversal when an alternating magnetic field exceeding its coercive force is applied; and a magnetic material which is magnetically hard or semi-hard and which can be magnetized. And a canceling magnetic powder that is mixed in the vicinity of the Fe-Si alloy wire and applies a bias magnetic field to the alloy wire to prevent the magnetization reversal of the alloy wire in a magnetized state. Goods monitoring sign. 2. The method according to claim 1, wherein the base material is a film mainly composed of paper or synthetic resin, and a protective layer covering the front surface of the base material, an adhesive layer provided on the back surface of the base material, 2. The article monitoring sign according to claim 1, further comprising a release paper attached to the layer. 3. An article to be monitored or a part of a base material constituting a container for containing the article, wherein the canceling magnetic powder is mixed, and the Fe-Si alloy is mixed in a region where the magnetic powder is mixed. 2. The article monitoring sign according to claim 1, wherein the line is buried.