JPS582994A - Detector for existing in sheet paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to paper JIl such as checks or banknotes.
This invention relates to a device for detecting gold pieces present in paper ms, which detects elongated metal pieces inserted in advance for counterfeit prevention into paper ms.

In recent years, in order to prevent counterfeiting of checks and banknotes, for example, many countries have taken measures against counterfeiting by inserting long thin metal pieces into the paper during the manufacturing process.

Therefore, recently, a method has been considered for detecting the presence or absence of the above-mentioned friend metal piece by utilizing eddy current loss in a discrimination device that automatically discriminates the authenticity of banknotes and the like.

However, with this method.

However, it is highly sensitive to non-magnetic metal pieces such as aluminum, and it is possible to reliably detect their presence or absence.

In particular, the sensitivity is refreshingly low to magnetic metal pieces.

For this reason, there was a problem of false detection or failure to detect.

The present invention was developed in view of the above-mentioned circumstances, and its purpose is to be able to reliably detect the presence or absence of metal pieces present in paper slips, even if they are magnetic.

An object of the present invention is to provide a device for detecting metal pieces present in paper sheets, which is effective for determining the authenticity of paper products.

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1(a) and 1(b) show an example of a banknote P containing metal pieces according to the present invention 4, where 1 is a sheet of paper and 2 is a metal piece present in this paper 1. This metal piece 2 is, for example, a sulfuric material, and its thickness is approximately 20 μm @ length and width are approximately 0
The length is 1 to 1 mm@degree, the same as the 10th dimension of the paper, and it is inserted in the direction perpendicular to the longitudinal direction of the paper l (which is the conveyance direction of the banknote P).

1st! Figures (M) and (b) show the detection head of the detection device according to the present invention and its installation state, and the above-mentioned banknotes P are conveyed in the direction of the arrow by the conveyance belt 3 . In this case, the two banknotes P are conveyed while being held at a plurality of locations in the transverse direction by the conveyor belts 3, respectively. Consequently, the metal pieces 2 within the two banknotes P are present in a direction intersecting the conveyance direction 1 thereof. Note that 21 indicates the position 0 of the metal piece t during normal conveyance, and 22 indicates the position of the metal piece when the banknote P is conveyed to the reverse direction. Pairs of detection heads 41+G are arranged facing each other on both sides (upper and lower) of the intermediate portion of the conveyor belt 3, corresponding to the positions of the metal pieces 21+21. 7
, one of the detection heads 41 is composed of an elongated μ permanent magnet 51 provided on one side of the banknote, and an elongated i magnetoresistive element 61 facing this permanent magnet 51 with the banknote P in between. Similarly, permanent magnet 5 and magnetoresistive element 6
! It consists of. However.

The banknote P is conveyed between the permanent magnet 51*5g and the magnetic resistance elements 61+61 in a non-contact manner. In addition, the above permanent magnet 51+5! and magnetoresistive element 61+6
The length of each piece of snow is, for example, slightly longer than the radius of the metal piece 2 in consideration of the skew of the banknote P being conveyed and the displacement of the conveyance position. Furthermore, the above permanent magnet 51e5! As shown in FIG. 2(b) K, the magnetic field 71e7m is generated perpendicularly to the surface of the banknote P to be transported, and its shape The shape is elongated in the direction orthogonal to the conveying direction 1.

FIG. 3 shows the electric circuit of the detection device according to the present embodiment, in which one end of each of the magnetoresistive elements 61 and 61 is grounded, and the other end is connected to the DC power source V through resistors 111 and tt2, respectively. It is connected to the.

This is K, magnetoresistive element 61 + 61 and resistor 111 t
A voltage signal corresponding to a change in the resistance value of the magnetoresistive element can be obtained at the connection point M1 or MIX with the magnetoresistive element. The connection point M1 (Ax) above is the capacitor 121
(12) is connected to the input terminal of the amplifier circuit 131 (13!), and the output of this amplifier circuit 1st (132) is supplied to the comparator 151 (15m) K. This comparator 151 (ts) is an amplification 1113t (13z
) is converted into a binary signal by comparing the output signal with a predetermined reference level signal. 19.
(19,) is a length detection circuit that detects the width of the ratio IIk @ 151 (15*) 0 output ff ; b binary signal 1011115, which measures the length of the metal piece 2s (2g). . Reference numeral 20 denotes an OR circuit, which outputs an OR signal when an output signal is generated from either the length detection path 191 or 19, which is finally used as a metal piece detection signal.

Next, the operation in such a configuration will be explained.

- Air resistance element 81 @t) The operation will be explained. The operation on the magnetoresistive element 62 side is exactly the same as that on the 61 side. The magnetic resistance element 61 has a certain resistance value in response to the magnetic field 71 (7, the magnetic field generated by 5z) generated by the permanent magnet 51 when the banknote P is not conveyed.

In this state, when the banknote P containing the metal piece 21 is conveyed and passes between the permanent magnet 51 of the detection head 41 and the magnetoresistive element 61, the metal piece 21 will pass through the magnetic field 71. y) The distribution of the magnetic field 71 changes, and thereby the resistance value of the magnetoresistive element 61 also changes. This appears as a voltage change at the connection point between the resistor 111 and the magnetoresistive element 61, and this voltage signal is transmitted to the amplifier 11 circuit 13. The signal B is amplified by the signal B shown in FIG. 4(a). Reference numeral 171 in this signal B is a signal portion when the metal piece 21 passes. Incidentally, although FIG. 5 shows the same signal waveform as FIG. 4, it is for the case where the metal piece 21 is cut in the middle.

18 of signal B is that part. This signal B is the comparator 1
51, where it is compared with a reference level signal and converted into a binary signal C as shown in FIG. 4(b). This signal C is added to a length detection path 191 composed of a counter, etc., and the one-hour width is checked, and if the length exceeds a certain standard, the output signal C is
This is generated as a detection signal. This signal is sent to the banknote discriminating device via the OR circuit 20 and is used for determining the authenticity of the banknote P.

Lol! FIG. 6 shows a detection head and its installed state in another embodiment of the present invention. In addition.

The same parts as in the second WJ (b) are given the same reference numerals.

This embodiment includes permanent magnets 51+51 and magnetoresistive elements 61.・One side of the banknote P being conveyed (for example,
) in close proximity to each other.

A suppression mechanism is provided to press the banknotes P being conveyed against the magnetoresistive element '1s61. That is, the magnetoresistive elements 61+ 62 are the sensing heads 41 T 4! Permanent magnets 51, 5. are positioned below the magnetoresistive elements 61 and 63, respectively. In addition, suppressing mechanisms 211 and 212 are provided above the detection head 41+G to press against the upper surface of the bill Pt-detection head 41*G being conveyed. This pressing mechanism 21. , 21. For example, the detection heads 41.4 . A plate-shaped elastic body 22 that is pressed against the upper surface of the 22. ,
222, and supports 231 and 23 that support and fix the rear ends of the elastic bodies 221 and 223! It is composed of. In this case, the elastic bodies 221, 22. The pressing force is the banknote P
The value of S[ is set to a weak value that does not affect the conveyance of the material.

Even in this case, it is of course possible to achieve the same purpose as in the embodiment described above, and even more reliable detection operation becomes possible.

In the above embodiment, the metal pieces contained in one type of banknote were explained, but if there are multiple types of falls of nine banknotes and the positions of the metal pieces are different, the metal pieces are Detection head 41141' according to the position of the piece.
14114! ' should be placed respectively. Moreover, the metal pieces 21 and 2 filtration represent a situation in which two banknotes are transported in the forward direction and the opposite direction at the position of the metal piece of one banknote. 2 l/
and 28' are for metal pieces of other types of banknotes.

Furthermore, if the metal piece is located in the center, only one detection head is needed. Furthermore, in the above embodiment, 2
Although the description will be given of the case of detecting metal pieces present in banknotes, it goes without saying that the present invention can also be applied to detecting metal pieces present in, for example, checks or other securities.

As detailed above, according to the present invention, a permanent magnet is provided on the side of a predetermined location in a direction perpendicular to the conveying direction of nine paper sheets, and a magnetic resistance element is provided in the magnetic flux path of this permanent magnet. By configuring the structure to detect a change in the resistance value of the magnetoresistive element caused by a change in the magnetic field when a metal piece present on the paper sheet passes through the magnetic flux path, Even if the metal piece is a magnetic material, it is possible to provide a detection device for a metal piece in the presence of paper MflAK, which is effective for determining the authenticity of paper slips by accurately detecting the presence or absence of 7.

[Brief explanation of the drawing]

Figure 1 t13. (b) to 5 show an embodiment of the present invention, in which 1st m (M), (b) is a plan view and a cross-sectional view showing an example of a banknote containing metal pieces, and 2nd fig.
E(a). (b) is a plan view and a side view showing the detection head and its installation state, FIG. 3 is a configuration diagram of an electric circuit, FIG. 1=4 and FIG. 5 are main part signal waveform diagrams for explaining the operation, FIG. 61 is a side view showing a detection head and its installation state in another embodiment of the present invention, and FIG. 7 is a plan view showing the installation state of the detection head in still another embodiment. P...Banknotes (paper slips), e 21+ 21...Metal pieces, 3.33 helmet transport help) l 41* 4=...
・Detection spatula F'+ 51. s=...Permanent magnet m6l
-62... Magnetoresistive element, 131.132...
Amplifier circuit + 151* 152...Ratio IR1! , 2
11.21! ...Press mechanism, 191.19fi...
・Length detection circuit. Agent Patent attorney Kensuke Chika (and 1 other person) Figure 1 Figure 2 <(1) Figure 3 ■ Figure 4 (n) Figure 5

Claims (1)

[Claims] (1) A permanent magnet installed on the side of a predetermined location in a direction orthogonal to the direction of conveyance of two types of paper in a device that detects metal pieces present in paper products being conveyed. A magnetic resistance element is provided in the magnetic flux path of this permanent magnet, and a metal piece present in the paper ms passes through the magnetic flux path.The change in resistance value of the magnetic resistance element caused by the change in the magnetic field is detected. 1. A device for detecting metal pieces present in paper industry products, characterized in that: (27II) In a device that detects metal pieces present in paper sheets being fed, a permanent magnet is installed on the side of a predetermined location in a direction perpendicular to the conveying direction of 9 paper types, and the magnetic flux path of this permanent magnet is A magnetic resistance element provided, a suppression mechanism that presses the transported paper Jl@ against the magnetic resistance element, and a change in the magnetic field when a metal piece present in the paper sheet passes through the magnetic flux path. A device for detecting metal fragments present in paper sheets, characterized in that it is equipped with means for detecting changes in the resistance value of the magnetoresistive element caused by Claim 1, characterized in that at least one pair of magnetoresistive elements is arranged opposite to each other, with a permanent magnet on one side and a magnetoresistive element on the other side.
Item 9 is a device for detecting metal pieces present in paper type M described in item 2. (4) A metal piece present in the paper sheet according to claim 2, characterized in that at least one pair of a permanent magnet and a magnetoresistive element are arranged close to each other on one side of the paper sheet to be conveyed. detection device. (5) The metal piece is a magnetic material.Claims 1 and 9 are a detection device for a metal piece present in a paper industry as set forth in claim 2. (6) The metal piece has an elongated shape and is present in a direction parallel to the conveying direction of the paper sheet. Claims 1 and 9 exist in the paper class jlI described in claim 2. Metal fragment detection device. (7) The permanent magnet and the magnetoresistive element are provided in plural pairs in a direction orthogonal to the conveyance direction of paper products, respectively. A device to detect metal fragments present in paper sheets. (8) The length of each of the permanent magnet and the magnetic resistance element is equal to or longer than the length of the metal piece in the width direction, as set forth in claim 6 or 7. A device to detect metal fragments present in paper sheets. (9) What is the means for detecting the change in resistance value of the magnetoresistive element? A patent claim comprising a circuit that converts a change in resistance value into a voltage change, a comparator that converts the output of this circuit into a duplex signal KR, and a length detection circuit that flatters the length of this duplex signal. Range 1. ! 31 The first is a device for detecting metal pieces present in paper type IIA described in item 112.