JP3725358B2 - Method and apparatus for inspecting authenticity of banknotes - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method and apparatus for detecting a change in residual magnetic flux in a banknote printed with magnetic ink in a non-contact manner and inspecting the authenticity of the banknote.
[0002]
[Prior art]
In recent years, as vending machines and the like have become widespread, mischief against vending machines has increased, and there have been traces of mischief such as tricking devices such as bill validators installed in vending machines to take change in the devices. There is no end.
[0003]
In addition, crimes due to counterfeiting of banknotes are increasing, and with the internationalization, foreign banknotes are brought in from various countries, and cases where these foreign banknotes are used in vending machines intentionally or mistakenly are increasing.
[0004]
From such a situation, in consideration of the improvement of banknote printing technology, the banknote recognition apparatus is required to have improved security and highly accurate inspection capability.
[0005]
A method of using magnetic ink is known as one of the banknote printing techniques. For example, in US dollar bills printed with magnetic ink, residual magnetism detected in a space about 1 mm away from the surface is known. The strength is about 10 ⁻⁴ Oe (Oersted) to 10 ⁻³ Oe (Oersted). This is equivalent to 1 / 100th to 1 / 1000th the strength of geomagnetism.
[0006]
As a method for detecting magnetic ink in a conventional apparatus, a method using a magnetic head is generally used. As a conventional magnetic head, a coil type magnetic head in which a coil is wound around a magnetic pole made of a magnetic material, an MR element type magnetic head using a magnetoresistive (MR) element, or the like is used. Among these two magnetic heads, the sensitivity of the MR element type magnetic head having a relatively high sensitivity is about 10 ⁻² Oe (Oersted).
[0007]
In a conventional magnetic head having only this level of sensitivity, the magnetic head is brought into contact with the magnetic ink portion printed on the surface of the banknote in order to increase the sensitivity as much as possible. Furthermore, in order to ensure the contact between the banknote and the magnetic head, the banknote is attached and scanned so as to be sandwiched between the magnetic head and the roller, and whether or not the banknote to be tested is authentic is inspected from the signal obtained at that time. Was configured to do.
[0008]
[Problems to be solved by the invention]
Thus, since the sensitivity of the magnetic head is low in the conventional banknote discriminator, in order to detect the magnetism of the magnetic ink part on the banknote surface, scanning is performed while the magnetic head is in contact with the magnetic ink printing part. Had to be done. As a result, traces of scanning the magnetic head portion remain as streaks on the surface of the banknote, so that a third party knows which part of the banknote the apparatus detects. This is a convenient target for those who deliberately try to mischief vending machines, causing security problems such as tricking the device.
[0009]
On the other hand, as described above, since the banknote is sandwiched and transported between the magnetic head and the roller, there is a problem that the banknote is easily jammed in the transport path of the magnetic head unit. Further, since the bill is conveyed while being brought into contact with the magnetic head portion, mechanical wear of the magnetic head occurs, and the life of the magnetic head is shortened and the bill is shortened. In addition, since the bill is scanned with the magnetic head and the roller in contact with each other, dust is likely to adhere to the banknote, and if it is remarkable, a predetermined signal cannot be obtained.
[0010]
On the other hand, in order to detect the magnetic ink part printed on the banknote surface in a non-contact manner, a highly sensitive magnetic sensor with a good S / N ratio is required. As such a magnetic sensor, a magnetic impedance type magnetic sensor known in Japanese Patent Laid-Open Nos. 6-176930 and 6-283344 can be expected. This magneto-impedance type magnetic sensor is known to detect a voltage with respect to a temporal change in circumferential magnetic flux generated by applying a high-frequency current to a magnetic wire as a change caused by an externally applied magnetic field.
[0011]
The sensitivity of the magneto-impedance type magnetic sensor is very high, and it is known that a sensitivity equivalent to or higher than that of an FG (flux gate) type magnetic sensor known for high sensitivity can be obtained. The magnetic impedance type magnetic sensor having such a feature is considered to be used for weak magnetic field measurement as a highly sensitive magnetic sensor operating at room temperature.
[0012]
However, the magnetic impedance type magnetic sensor has a problem. That is, a wire such as an amorphous wire is difficult to handle in production, and its characteristics deteriorate with time.
[0013]
Further, in the conventional magnetic impedance type magnetic sensor, a coil for applying a bias magnetic field is formed by winding by wire winding. As a result, the magnetic sensor itself becomes large, and there is a problem that the apparatus cannot be downsized and is expensive.
[0014]
The present invention has been made in view of the above points, and an object of the present invention is to provide a method and apparatus for accurately and reliably inspecting the authenticity of a banknote using a non-contact magnetic detection method.
[0015]
[Means for Solving the Problems]
In order to achieve the above-described object, according to the present invention, in a method for detecting magnetic characteristics of a banknote in a non-contact manner and inspecting the authenticity of the banknote, the banknote is transported along a predetermined position on a transport path. A non-contact type thin film magnetic sensor using an ultrafine crystal soft magnetic material is disposed at a predetermined position of the transport path in the vicinity of the transport path, and the bill is transported along the transport path. And comparing the signal output from the thin film magnetic sensor with a reference value signal of a predetermined denomination stored in advance, and when the signal is within a predetermined allowable range with respect to the reference value, In a method for inspecting the authenticity of a banknote characterized by outputting a signal that is true, and a device for detecting the magnetic characteristics of the banknote in a non-contact manner and inspecting the authenticity of the banknote, Transport bills along a predetermined position A non-contact thin film magnetic sensor using an ultrafine crystalline soft magnetic material disposed in the vicinity of the conveyance path at a predetermined position of the conveyance path, and the banknotes along the conveyance path A signal output from the thin film magnetic sensor as it is conveyed is compared with a signal of a reference value of a predetermined denomination stored in advance, and the signal is within a predetermined allowable range with respect to the reference value. A device for inspecting the authenticity of the banknote, characterized in that it comprises a comparison judgment means for outputting a signal that the banknote is true.
Is to provide.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0017]
FIG. 1 is a view showing one embodiment of a thin film magnetic sensor according to the present invention, FIG. 1 (a) is a front view, FIG. 1 (b) is a partially enlarged view of AA section in FIG. 1 (a), and FIG. 1 (c) is a partially enlarged view of the BB cross section in FIG. 1 (a). FIG. 2 is a block diagram showing an embodiment of the authenticity inspection circuit for banknotes to be examined according to the present invention. Furthermore, FIG. 3 shows an example which imitates the test banknote 30 used in this embodiment.
[0018]
First, the structure of the banknote 30 to be used used in this embodiment will be described with reference to FIG. In FIG. 3, a pattern, characters, and the like are printed on a printing area 31 on the surface of the banknote 30 to be examined, and has a magnetic printing unit 32 printed with magnetic ink. In the magnetic printing unit 32, there is residual magnetism caused by the magnetic powder in the magnetic ink. The magnetic sensor of the present invention is configured to detect the strength of residual magnetism in a non-contact manner using a magnetic impedance type thin film magnetic sensor.
[0019]
Here, the configuration of the thin film magnetic sensor 1 will be described in detail with reference to FIG. The thin film magnetic sensor 1 has a lower thin film coil layer 3b, a magnetic film terminal 4 (4a, 4b) and a thin film coil terminal 5 (5a, 5b) formed on a glass substrate 1a, and a lower insulating layer of SiO ₂ thereon. 6b is formed. Further, on the lower insulating layer 6b, a magnetic film 2 (for example, a high permeability material containing Fe _73.5 , Si _13.5 , B ₉ (at%) as a main component and containing additional elements such as Cu and Nb) is formed. Then, the upper insulating layer 6a made of SiO ₂ is formed. The material of the magnetic film 2 is known as an ultrafine crystalline soft magnetic material (for example, “Finemet FT-3” series manufactured by Hitachi Metals, Ltd.) as a high permeability material having negative magnetostriction characteristics as close to zero magnetostriction as possible. Is used).
[0020]
An upper thin film coil layer 3a is formed on the uppermost part, and the thin film coil 3 is formed by connecting the lower thin film coil layer 3b and the upper thin film coil layer 3a with a joint 7. The magnetic film 2 and the thin film coil 3 are connected to a magnetic film terminal 4 and a thin film coil terminal 5, respectively, to constitute the thin film magnetic sensor 1. The magnetic film 2 of the thin film magnetic sensor 1 is formed by sputtering using a high permeability material target having negative magnetostriction characteristics as close to zero magnetostriction as possible.
[0021]
Next, with reference to FIG. 4 to FIG. 6, the configuration and principle of essential parts for the thin film magnetic sensor 1 to detect the residual magnetic field of the magnetic printing unit 32 of the banknote 30 to be examined will be described in detail.
[0022]
4 is a diagram showing a state of the thin film magnetic sensor 1 used in the present invention at the time of bill side detection, FIG. 5 is a main circuit diagram showing the principle of the thin film magnetic sensor 1, and FIG. 6 is a characteristic diagram of the thin film magnetic sensor 1. It is. First, in FIG. 4, the magnetic film 2 of the thin film magnetic sensor 1 is arranged so as to be separated from the surface of the banknote 30 to be examined by a predetermined distance and to face the surface of the banknote 30 to be examined. Lead wires 41 (41a, 41b) are connected to the magnetic film terminals 4 of the magnetic film 2.
[0023]
On the other hand, the lead wire 42 (42a, 42b) is connected to the thin film coil terminal 5 of the thin film coil 3. The thin film magnetic sensor 1 connected in this way is disposed so as to surround the thin film magnetic sensor 1 so that the magnetic shield 40 opens the surface on the magnetic film 2 side. Since the magnetic shield 40 can block the leakage magnetic flux generated from the power source of the banknote identification device (not shown) or the transport motor 73 (FIG. 8) that transports the banknote 30 to be examined, the signal detected from the thin film magnetic sensor 1 This improves the S / N ratio and improves detection accuracy.
[0024]
Next, in FIG. 5, the magnetic film terminal 4 of the thin film magnetic sensor 1 is connected to the output of the high frequency pulse generating means 10 and the detection circuit 53 by a lead wire 41. The high frequency pulse generating means 10 is composed of a high frequency oscillation source 50, a capacitor 51, and a resistor 52, as shown in FIG.
[0025]
On the other hand, the detection circuit 53 includes a coupling capacitor 54, a detection diode 55, a smoothing resistor 56, and a capacitor 57. On the other hand, the thin-film coil terminal 5 of the thin-film coil 3 shown in FIG. 1 is connected to a DC power source 12 and a variable resistor 13 by a lead wire 42 as shown in FIG. ing.
[0026]
Here, the principle for the thin film magnetic sensor 1 configured as described above to detect the residual magnetic field of the magnetic printing unit 32 printed on the surface of the banknote 30 to be examined will be described in detail with reference to FIG.
[0027]
As shown in FIG. 4, a special magnetic powder contained in the ink is magnetized in the magnetic printing unit 32 to generate a residual magnetic field 43. This residual magnetic field 43 appears as an alternating magnetic field with the relative movement of the thin film magnetic sensor 1 corresponding to the magnetization state of the magnetic printing unit 32.
[0028]
On the other hand, a high-frequency pulse current that changes with time is applied to the magnetic film 2 of the thin-film magnetic sensor 1 by a high-frequency oscillation source 50 shown in FIG. The frequency of the high-frequency pulse current is several MHz to several tens of MHz (however, it is not limited thereto). In this magnetic film 2, when a high-frequency pulse current is applied, the magnetization vector in the easy magnetization direction (magnetic film width direction) in the magnetic film changes in the length direction of the magnetic film in response to the strength of the externally applied magnetic field. And the magnetic permeability μ 0 in the magnetic film width direction decreases. This is considered to change the impedance of the magnetic film 2. Thus, the thin film magnetic sensor 1 can take out the change as an output signal proportional to the strength of the external magnetic field by utilizing the fact that the impedance is changed by the external magnetic field.
[0029]
Here, the characteristics of the magnetic impedance type thin film magnetic sensor 1 will be described in detail with reference to FIGS. In FIG. 6, the thin film magnetic sensor 1 exhibits a bimodal characteristic with respect to an externally applied magnetic field (−Hex to + Hex). From FIG. 6, the characteristic of the thin film magnetic sensor 1 shows a characteristic that once increases with an increase in the magnetic field and then decreases.
[0030]
It is desirable that the output of the magnetic sensor changes monotonously. And in order to take out the change with respect to an external magnetic field as a monotonous thing, according to the intensity | strength of the residual magnetic field which should be detected using the area | region (for example, area | region Hex0-HexP of FIG. 6) of a monotone increase (or decrease). By applying the magnetization bias, the residual magnetic field 43 in the magnetic printing unit 32 of the banknote 30 to be examined can be detected.
[0031]
The bias magnetic field generating circuit for magnetization bias according to the present invention forms a thin film coil 3 so as to surround the magnetic film 2 and applies a direct current to the thin film coil 3 to obtain a predetermined bias magnetic field.
[0032]
FIG. 7 shows the signal waveform of the output of the signal extraction means 15. This signal waveform corresponds to the detection output of the thin film magnetic sensor 1 and is drawn in accordance with the scanning of the banknote surface. The horizontal axis indicates the banknote scanning direction, and the vertical axis indicates the strength of the magnetic field due to the residual magnetic flux. Each is represented.
[0033]
Next, the configuration and operation of the main circuit of the banknote recognition apparatus will be described in detail with reference to FIG. In FIG. 2, the output of the high-frequency pulse generation means 10 and the inspection means 14 are connected to the magnetic film 2 of the thin film magnetic sensor 1. The inspection unit 14 includes a signal extraction unit 15, a comparison determination unit 16, and a reference value signal generation unit 17. The magnetic film 2 is connected to the input of the signal extraction means 15, and the output of the signal extraction means 15 is input to the comparison determination means 16. The comparison determination unit 16 compares the signal input from the signal extraction unit 15 with the signal input from the reference value signal generation unit 17 and outputs the result to the output terminal 18.
[0034]
On the other hand, the bias magnetic field generating means 11 is configured by connecting a DC power source 12 and a variable resistor 13 to the thin film coil 3 to constitute the bias magnetic field generating means 11. Here, for example, a US dollar bill printed by magnetic ink has a remanence of about 10 ⁻⁴ Oe (Oersted) to 10 ⁻³ Oe (Oersted) in a space about 1 mm away from the surface. ). For the banknote 30 to be examined having such residual magnetism, the magnetic film 2 of the thin film magnetic sensor 1 is arranged so that the surface of the magnetic film 2 is substantially parallel to the surface of the banknote 30 to be examined as shown in FIG. In addition, the thin film magnetic sensor 1 is disposed so as to be opposed to the surface of the banknote 30 to be separated by a predetermined distance.
[0035]
The thin film magnetic sensor 1 arranged in this way scans the magnetic printing unit 32 of the banknote 30 to be examined. At that time, an output signal obtained from the thin film magnetic sensor 1 is input to the signal extraction means 15. The signal extraction means 15 extracts a signal that the thin film magnetic sensor 1 changes in response to the magnetic printing unit 32 of the banknote 30 to be examined.
[0036]
The output of the signal extraction unit 15 is input to the comparison determination unit 16. Further, the comparison determination means 16 is connected to a reference value signal generation means 17, and in this reference value signal generation means 17, a reference value (for example, an upper limit value, etc.) in a banknote that can be received in a predetermined denomination is given. Lower limit value) is stored in the memory.
[0037]
The reference value stored in the reference value signal generating means 17 is a function obtained from statistical data obtained by measuring in advance a circulation of accepted banknotes in a given denomination using the magnetic sensor 1. Value. The comparison determination unit 16 compares the signal input from the signal extraction unit 15 with the signal input from the reference value signal generation unit 17, and determines whether the signal input from the signal extraction unit 15 is within the reference value. If it is within the reference value, a signal indicating that the banknote to be examined 30 is true is output to an external device (not shown). However, when this signal is out of the reference value, a signal indicating that the banknote to be examined 30 is false is output to an external device (not shown). In this way, the authenticity of the banknote 30 to be examined can be inspected.
[0038]
Next, the mechanism and operation of the bill validator according to the present invention will be described in detail with reference to FIGS. FIG. 8 is a side view showing a schematic mechanism of an embodiment of the banknote recognition apparatus according to the present invention, and FIG. 9 is a plan view thereof.
[0039]
In this embodiment, as shown in FIGS. 8 and 9, a conveyance path 71 that guides the banknote 30 to be tested in the direction of the arrow from the insertion slot 70, and an inlet sensor 78 that detects the banknote 30 that has been inserted from the insertion slot 70. -1,78-2, conveying belts 76-1,76-2, rollers 77-1,77-2,77-3, which convey the bill 30 to be examined inserted from the insertion port 70 along the conveying path 71 77-4, 77-5, 77-6, 77-7, 77-8, 77-9, 77-10, 77-11, 77-12 Magnetic printing section formed on the banknote 30 to be examined A thin film magnetic sensor 1 for detecting 32 (FIG. 3), worm gears 74-1 and 74-2 for transmitting power to the conveyor belts 76-1 and 76-2, and a motor 73 for driving the worm gears 74-1 and 74-2. The banknote identification device 100 is configured.
[0040]
Next, the mechanism operation of the banknote recognition apparatus 100 will be described.
[0041]
The banknote 30 to be examined inserted from the insertion slot 70 moves in the direction of the arrow, and is detected by the entrance sensors 78-1 and 78-2 that optically detect the object, and based on the signal output from the entrance sensor 78. The motor 73 is started by control means (not shown). The output shaft of the motor 73 is connected to the worm gears 74-1 and 74-2, and the power of the motor 73 is transmitted to the pulleys 75-1 and 75-3, and the pulleys 75-1 and 75-3 are moved in a predetermined direction. Rotate.
[0042]
Further, between the pulley 75-1 rotated by the power of the motor 73 and the pulley 75-2 arranged at a predetermined distance, and between the pulley 75-3 and the pulley 75-4 arranged at a predetermined distance. In the meantime, conveying belts 76-1 and 76-2 are respectively hung and drive the conveying belts 76-1 and 76-2.
[0043]
Further, rollers 77-1, 77-2, 77-3, 77-4, 77-5, 77-6, 77-7, 77 arranged at predetermined intervals are provided on the conveyor belts 76-1, 76-2. -8, 77-9, 77-10, 77-11, 77-12 are provided, and the roller 77 presses the test banknote 30 so as to sandwich the test banknote 30, and conveys the test banknote 30. The banknote 30 to be examined inserted from the insertion port 70 moves in the direction of the arrow, and eventually reaches the thin film magnetic sensor 1 and further moves. The thin film magnetic sensor 1 detects the magnetic printing part 32 (FIG. 3) formed on the moving banknote 30 to be moved in a non-contact manner, and outputs a response signal.
[0044]
FIG. 10 shows an authenticity inspection circuit in which the magnetic printing part 32 and the non-magnetic printing part of the banknote 30 to be detected are switched and identified from the detection output of the thin film magnetic sensor 1 as an alternative to the circuit of FIG. It is a block diagram to show.
[0045]
In FIG. 10, the magnetic sensor 1-1 and the magnetic sensor 1-2 are both magnetic impedance type thin film magnetic sensors. The means for inspecting the banknote 30 to be inspected from the signal obtained from the thin film magnetic sensor 1 is the same as the circuit shown in FIG. In FIG. 10, parts having the same functions as those in the embodiment shown in FIG. 2 are denoted by the same reference numerals as those used in FIG. 2, and detailed description thereof is omitted.
[0046]
Here, the thin film magnetic sensor 1-1 inspects the magnetic printing part 32 of the banknote 30 to be examined, and the thin film magnetic sensor 1-2 inspects the nonmagnetic printing part of the banknote 30 to be examined. The changeover switch 20 operates based on the output signal of the changeover circuit 21, and the changeover switch 20 selects one of the output signal of the magnetic sensor 1-1 or the output signal of the thin film magnetic sensor 1-2, An output signal is input to the signal extraction means 15. The changeover switch 20 is operated by inputting a changeover signal 22 from an external device (not shown).
[0047]
The output signal of either the thin film magnetic sensor 1-1 or the thin film magnetic sensor 1-2 selected by the changeover switch 20 is inspected by the inspection means 14. The signal extraction means 15 of the inspection means 14 is a signal that changes in response to an output signal of either the thin film magnetic sensor 1-1 or the thin film magnetic sensor 1-2 in response to the magnetic printing unit 32 of the banknote 30 to be inspected and nonmagnetic printing. At least one of the signals that react to the part is extracted. The signal extracted by the signal extraction means 15 is compared with the reference value generated by the reference value signal generation means 17 in the comparison determination means 16.
[0048]
If this signal is within the reference value, the comparison / determination means 16 confirms that the banknote 30 to be tested is true, assuming that the banknote 30 to be tested matches a banknote of a predetermined denomination. The signal shown is output to an external device (not shown). However, when this signal is out of the reference value, a signal indicating that the banknote to be examined 30 is false is output to an external device (not shown). In this way, by inspecting the portion where the banknote 30 to be tested has the magnetic printing part 32 and the portion that is not, for example, there is no magnetic reaction at a predetermined portion of the banknote to be tested, or there is a magnetic reaction. It is possible to inspect fraudulent banknotes with high accuracy, for example, there is a magnetic reaction at a place where they must not be.
Here, the reference value signal generating means 17 changes the generated reference value with respect to the operation of the changeover switch 20 (the output signal of the changeover circuit 21). This is because the reference value for determining the signal detected by the thin film magnetic sensor 1-1 for the magnetic printing unit 32 and the signal for detecting the non-magnetic printing unit by the thin film magnetic sensor 1-2 are different.
[0049]
【The invention's effect】
In the present invention, as described above, a thin film magnetic sensor is disposed in the banknote conveyance path of the banknote identification device, and a predetermined magnetic printing unit is formed on the inserted banknote based on the detection output of the thin film magnetic sensor. Since at least one of whether or not there is a magnetic reaction from the non-magnetic printing unit is detected in a non-contact manner, it is possible to provide a banknote identification device that is excellent in both security and life. That is, since no trace of the detection position remains on the surface of the banknote to be examined, security can be improved, and since there is no contact, there is no mechanical wear and the life of the apparatus is prolonged. Moreover, since it is non-contact, the deterioration by the damage of the test banknote which arises with a contact system can be prevented, and there exists an effect that the appropriate process of a banknote can always be performed.
[Brief description of the drawings]
FIG. 1 (a) is a front view showing an embodiment of a thin film magnetic sensor according to the present invention, FIG. 1 (b) is a partially enlarged view of the AA section in FIG. 1 (a), and FIG. ) Is a partially enlarged view of the BB cross section in FIG.
FIG. 2 is a block diagram showing an embodiment of a bill authenticity inspection circuit using the thin film magnetic sensor of FIG. 1;
FIG. 3 is a diagram showing an example of a banknote to be examined.
4 is a diagram showing a state when a banknote surface of a thin film magnetic sensor used in combination with the circuit of FIG. 2 is detected.
FIG. 5 is a principal circuit diagram showing the principle of a thin film magnetic sensor.
6 is a characteristic diagram of the thin film magnetic sensor shown in FIG.
7 is a waveform showing an output example of the thin film magnetic sensor shown in FIG.
FIG. 8 is a side view showing a schematic mechanism in the embodiment of FIG. 2;
FIG. 9 is a plan view corresponding to FIG. 8;
10 is a block diagram showing a configuration example of an authenticity inspection circuit that can replace the circuit of FIG. 2;
[Explanation of symbols]
1 Thin film magnetic sensor
2 Magnetic film
3 Thin film coil
4 Magnetic film terminal
5 Thin film coil terminals
6 Insulation layer
7 Joint
10 High-frequency pulse generation means
11 Bias magnetic field generation means
12 DC power supply
13 Variable resistor
14 Inspection methods
15 Signal extraction means
16 Comparison judgment means
17 Reference value signal generation means
18 Output terminal
20 selector switch
21 switching circuit
22 Switching signal input terminal
30 banknotes
31 Print area
32 Magnetic printing section
40 Magnetic shield
41a, 41b Lead wire (wire to connect to thin film magnetic sensor)
42a, 42b Lead wire (wire to connect to thin film coil)
43 Residual magnetic field
50 High frequency oscillation source
51 capacitors
52 resistance
53 Detection circuit
54 capacitors
55 Diode
56 Resistance
57 capacitors
60 Magnetic field applied to thin film magnetic sensor at zero bias magnetic field vs. output characteristics
61 Center line with zero bias field
62 Center line when bias magnetic field is applied
63 Applied magnetic field vs. output characteristics of thin film magnetic sensor when bias magnetic field is applied
70 insertion slot
71 Transfer path
72-1,72-2 Aisle wall
73 motor
74-1,74-2 Worm gear
75-1,75-2,55-3,55-4 pulley
76-1,76-2 Conveyor belt
77-1,77-2,77-3,77-4,77-5,77-6,77-7,77-8,77-9,77-10,77-11,77-12 Roller
78-1,78-2 Inlet sensor

Claims (8)

In a method for detecting the magnetic characteristics of a bill in a non-contact manner and inspecting the authenticity of the bill,
A banknote is transported along a predetermined position on the transport path,
A non-contact type thin film magnetic sensor using an ultrafine crystalline soft magnetic material is disposed in a predetermined position of the transport path in the vicinity of the transport path,
Comparing a signal output from the thin film magnetic sensor as the bill is transported along the transport path and a reference value signal of a predetermined denomination stored in advance,
A method for inspecting the authenticity of a bill, comprising outputting a signal indicating that the bill is true when the signal is within a predetermined allowable range with respect to the reference value. In a device for detecting the magnetic characteristics of a bill in a non-contact manner and inspecting the authenticity of the bill,
A transport path for transporting bills along a predetermined position;
A non-contact type thin film magnetic sensor using an ultrafine crystalline soft magnetic material disposed in the vicinity of the transport path at a predetermined position of the transport path;
A comparison is made between a signal output from the thin film magnetic sensor as the bill is transported along the transport path and a reference value signal of a predetermined denomination stored in advance, and the signal is the reference value. Comparing and determining means for outputting a signal indicating that the banknote is true when it is within a predetermined allowable range,
A device for inspecting the authenticity of banknotes, characterized by having In the authenticity inspection apparatus of the banknote of Claim 2,
The thin film magnetic sensor is
Magnetic impedance that detects a signal for the rotation change of the magnetization vector in the easy magnetization direction generated in the magnetic film in response to the strength of the externally applied magnetic field as a change due to the externally applied magnetic field by applying a high-frequency current to the magnetic film Type thin film magnetic sensor,
A signal output from the magneto-impedance thin film magnetic sensor is used to inspect the authenticity of the banknote from a signal output in response to the strength of the residual magnetic field of the magnetic ink printed on the banknote. Authenticity testing device. In the authenticity inspection apparatus of the banknote of Claim 3,
A bill authenticity inspection apparatus, wherein the magnetic film of the thin film magnetic sensor is a high permeability magnetic material having negative magnetostriction characteristics as close to zero magnetostriction as possible. In the authenticity inspection apparatus of the banknote of Claim 3,
The thin film magnetic sensor is
A bill authenticity inspection apparatus, wherein a thin film coil for applying a bias magnetic field to the magnetic film is wound around the magnetic film as a magnetic core. In the authenticity inspection apparatus of the banknote of Claim 3,
The thin film magnetic sensor is
A bill authenticity inspection device, wherein the bill surface and the magnetic film surface are arranged to face each other. In the authenticity inspection apparatus of the banknote of Claim 2,
The thin film magnetic sensor is
A signal obtained from the thin film magnetic sensor is arranged corresponding to the arrangement position of the predetermined printing portion printed on the bill surface by magnetic ink, and the thin film magnetic sensor scans the predetermined printing portion of the bill. An authenticity inspection apparatus for banknotes, which inspects the authenticity of the banknotes. In the authenticity inspection apparatus of the banknote of Claim 2,
The thin film magnetic sensor is
A first thin film magnetic sensor arranged corresponding to the arrangement position of a predetermined printing portion printed on the banknote surface with magnetic ink;
A second thin film magnetic sensor disposed on the banknote surface corresponding to the disposed position of the predetermined printing portion printed with non-magnetic ink,
The first thin film magnetic sensor outputs a signal obtained by scanning a predetermined magnetic ink printing part of the banknote, and the second thin film magnetic sensor scans a predetermined nonmagnetic ink printing part of the banknote. A bill authenticity inspection apparatus that outputs a signal obtained and inspects the authenticity of the bill based on signals from the first and second thin film magnetic sensors.

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