JP2000268224A - Method and device for inspecting authenticity of paper money - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a devcie for inspecting the authenticity of paper money by a non-contact system through the use of an inexpensive high sensitivity magnetic impedance-type thin film magnetic sensor whose operation is stable. SOLUTION: A device detecting a magnetic feature that paper money has without a contact and inspecting the authenticity of paper money is provided with a transportation path 71 transporting paper money along a prescribed position, a non-contact-type thin film magnetic sensor 1 which is arranged close to the transportation path in the prescribed position of the transportation path and to which a hyperfiine crystal soft magnetic material whose characteristic is almost equal and which forms a bridge circuit is used, and a comparison decision means which compares and decides a signal outputted from the thin film magnetic sensor with the signal of the reference value of a prescribed denomination, which is previously stored, as paper money is transported along the transportation path and outputs a signal setting paper money to be real when the signal is within the prescribed permission range against the reference value are installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting a change in a residual magnetic flux in a bill printed with magnetic ink in a non-contact manner to check the authenticity of the bill.

[0002]

2. Description of the Related Art In recent years, with the widespread use of vending machines and the like, mischief with vending machines and the like has increased, and devices such as a bill validator provided in the vending machine have been deceived to steal change in the devices. Mischief such as endless.

[0003] In addition, crimes caused by forgery of banknotes are increasing, and foreign banknotes are brought in from various countries along with internationalization, and these foreign banknotes are being used for vending machines intentionally or by mistake. ing.

[0004] Under such circumstances, in consideration of the improvement of banknote printing technology, a banknote recognition device is desired to have improved security and high-accuracy inspection capability.

[0005] A method using magnetic ink is known as one of the banknote printing techniques. For example, in the case of a US dollar bill printed with magnetic ink, about 1 dollar bill is printed from the surface.
The strength of the remanent magnetism detected in a space 1 mm away is about 10-4
Oe (Oersted) or 10-3 Oe (Oersted)
It is. This is equivalent to 1/100 to 1/1000 the intensity of geomagnetism.

As a method of detecting magnetic ink in a conventional apparatus, a method using a magnetic head is generally used. As the conventional magnetic head, a coil type magnetic head in which a coil is wound around a magnetic pole made of a magnetic material, or an MR element type magnetic head using a magnetoresistive (MR) element is used. Among these two magnetic heads, the sensitivity of the MR element type magnetic head having relatively high sensitivity is about 10-2 Oe (Oersted).

In a conventional magnetic head having only this level of sensitivity, the magnetic head is brought into contact with a magnetic ink portion printed on the bill surface in order to increase the sensitivity as much as possible. Furthermore, in order to secure 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 the signal obtained at that time is used to check whether the banknote to be inspected is authentic. Had to be configured.

[0008]

As described above, in the conventional bill validator, the sensitivity of the magnetic head is low. Therefore, in order to detect the magnetism of the magnetic ink portion on the bill surface, the magnetic head must be provided with a magnetic ink. Scanning had to be performed while making contact with the printing section. As a result, traces of scanning the magnetic head portion are left as streaks on the surface of the bill, so that a third party can know which part of the bill is being detected by the device. This is a convenient goal for those who intentionally attempt to mischief the vending machine, and has caused security problems such as deceiving the device.

On the other hand, as described above, since bills are conveyed while being sandwiched between the magnetic head and the rollers, there is a problem that the bills are easily jammed in the conveyance path of the magnetic head portion.
Further, since the bill is transported in contact with the magnetic head portion, mechanical wear of the magnetic head occurs, which shortens the life of the magnetic head and shortens the life of the bill. Further, since scanning is performed by bringing the banknote into contact with the magnetic head and the roller, dust easily adheres to the banknote. In a case where the banknote is extremely significant, a predetermined signal cannot be obtained.

On the other hand, in order to detect the magnetic ink portion printed on the bill surface without contact, a high-sensitivity magnetic sensor having a good S / N ratio is required. As such a magnetic sensor,
A magnetic impedance type magnetic sensor known in JP-A-6-176930 and JP-A-6-283344 can be expected. It is known that this magnetic impedance type magnetic sensor detects a voltage with respect to a temporal change of a circumferential magnetic flux generated by applying a high-frequency current to a magnetic wire as a change due to an externally applied magnetic field.

The sensitivity of the magnetic impedance type magnetic sensor is very high, and FG (flux gate) known for its high sensitivity
It is known that a sensitivity equal to or higher than that of a magnetic sensor can be obtained. The magnetic impedance type magnetic sensor having such a feature is considered to be used as a highly sensitive magnetic sensor operating at room temperature, such as a weak magnetic field measurement.

However, the magnetic impedance type magnetic sensor has a problem. That is, amorphous wires and the like are difficult to handle in manufacturing, and their characteristics deteriorate with time.

In the conventional magnetic impedance type magnetic sensor, a coil for applying a bias magnetic field is formed by winding an electric wire. As a result, the size of the magnetic sensor itself becomes large, and there is a problem that the size of the device cannot be reduced and the device becomes expensive.

The present invention has been made in consideration of the above points, and uses a thin film magnetic sensor of high sensitivity and a stable operation, which can be constructed at a low cost, to check the authenticity of bills in a non-contact manner. An object of the present invention is to provide a method and an apparatus for inspection.

[0015]

In order to achieve the above object, the present invention provides a method for detecting the magnetic characteristics of a bill in a non-contact manner and checking the authenticity of the bill. A non-contact type bridge-type thin film in which a non-contact type thin-film magnetic sensor using an ultrafine crystalline soft magnetic material is bridge-connected to a predetermined position of the conveyance path in the vicinity of the conveyance path. A magnetic sensor is provided, and a signal output from the thin-film magnetic sensor is compared with a signal of a reference value of a predetermined denomination stored in advance as the bill is transported along the transport path, A method for inspecting the authenticity of a bill, characterized by outputting a signal indicating that the bill is genuine when the signal is within a predetermined allowable range with respect to the reference value, and a magnetic method of the bill. Non-contact detection of features In the device for inspecting the authenticity of the bill, a transport path for transporting the bill along a predetermined position, and disposed at a predetermined position of the transport path in close proximity to the transport path, ultra-fine crystalline soft magnetic A non-contact type bridge type thin film magnetic sensor in which a non-contact type thin film magnetic sensor using a material is bridge-connected, and a signal output from the thin film magnetic sensor as the bill is transported along the transport path, A comparison is made by comparing with a signal of a reference value of a predetermined denomination stored in advance, and outputting a signal indicating that the bill is true when the signal is within a predetermined allowable range with respect to the reference value. It is an object to provide an apparatus for inspecting the authenticity of a banknote, comprising: a determination unit;

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1A and 1B are a front view and a side view showing an embodiment of a bridge type thin film magnetic sensor according to the present invention. FIG. 2 is a sectional view taken along the line AA of FIG. 1 according to the present invention. It is an enlarged view. FIG. 3 is an equivalent circuit diagram of the bridge type thin film magnetic sensor according to the present invention, and FIG. 4 is a basic circuit diagram of the bridge type thin film magnetic sensor according to the present invention.

First, the structure of the thin-film magnetic sensor 1 will be described in detail with reference to FIGS. 1 and 2, a thin-film magnetic sensor 1 has a lower insulating layer 6 made of SiO2 on a glass substrate 1a.
b, copper foil 3 and terminals 4a, 4b, 4c, 4d are formed, and magnetic films 2a, 2b, 2c, 2d {for example, Fe73.5%, Si13.5%, B9% (all at %) As a main component and containing additional elements such as Cu and Nb.
The device is made of a high magnetic permeability material. The dimensions of the device are 50 microns in width and 2 mm in length.

The magnetic film 2 is formed such that its end is electrically connected to the end of the copper foil portion 3 and that the magnetic film 2 forms a bridge circuit. Furthermore, Si is placed on the magnetic film 2.
The bridge type thin-film magnetic sensor 1 is formed by forming an upper insulating layer 6a of O2 and forming a magnetized film 5 (eg, a high coercive force material containing Co, Cr, or the like as a main component) on the uppermost portion. .

The magnetic film 2 of the thin-film magnetic sensor 1 is formed by a sputtering method or the like using a target of a high magnetic permeability material having negative magnetostriction characteristics as close to zero magnetostriction as possible.

Next, the basic circuit of the bridge-type thin-film magnetic sensor 1 will be described in detail with reference to FIGS. 3 and 4, the magnetic film 2 of the bridge-type thin-film magnetic sensor 1 is equivalent to a series circuit including an inductance and a resistance.

Now, the equivalent circuit inductance L1 of the magnetic film 2a
And the impedance of the resistor R1 as Z1, the equivalent circuit inductance L2 of the magnetic film 2b and the impedance of the resistor R2 as Z.
2.Equivalent circuit inductance L3 and resistance R3 of magnetic film 2c
If the impedance of the magnetic film 2d is Z3, and the impedance of the equivalent circuit inductance L4 of the magnetic film 2d and the impedance of the resistor R4 are Z4, when the magnetic films 2a to 2d are in an equilibrium state, the following equation is established. Z1 · Z4 = Z2 · Z3 (R1 + jωL1) (R4 + jωL4) = (R2 + jωL2)
(R3 + jωL3) ∴ (R1 + jωL1) (R4 + jωL4) − (R2 + jωL
2) (R3 + jωL3) = 0 As is well known, in order for these formulas to be satisfied, it is required that the characteristics of each element of the magnetic films 2a to 2d of the bridge-type thin-film magnetic sensor 1 be substantially equal.

Since the magnetic films 2a to 2d according to the present invention are formed of thin films as described above, it is possible to obtain elements having substantially the same characteristics.

Next, the configuration and principle for detecting the residual magnetic field of the magnetic printing portion 32 of the banknote 30 to be inspected by the thin-film magnetic sensor 1 will be described in detail with reference to FIGS.
FIG. 5 is a block diagram showing an example of the configuration of a circuit for checking the authenticity of a banknote to be inspected. The configuration and operation will be described after the description with reference to FIGS.

First, the configuration of a certain test bill 30 will be described with reference to FIG. In FIG. 6, a pattern, characters, and the like are printed in a print area 31 on the surface of the test bill 30, and have a magnetic print portion 32 printed with magnetic ink. In the magnetic printing unit 32, there is residual magnetism caused by magnetic powder in the magnetic ink. The magnetic sensor of the present invention is configured as a magnetic impedance type thin film magnetic sensor, and detects the intensity of remanence in a non-contact manner.

FIG. 7 is a diagram showing an example of the configuration of the thin-film magnetic sensor 1 used in the present invention, FIG. 8 is a circuit diagram of a main part showing the principle of the thin-film magnetic sensor 1, and FIG. .

In FIG. 7, the magnetic film of the thin-film magnetic sensor 1 is shown.
2 is separated from the surface of the banknote 30 by a predetermined distance, and
It is arranged so as to face the surface of 0. Leads 41 are connected to the terminals 4a, 4b, 4c, 4d of the magnetic film 2. The thin-film magnetic sensor 1 connected as described above is a magnetic shield
40 is arranged so as to open the surface on the side of the magnetic film 2 and surround the thin-film magnetic sensor 1.

The magnetic shield 40 can block a leakage magnetic flux generated from a power supply of a bill validator (not shown) or a transport motor 53 (FIG. 11) for transporting the test bill 30. Therefore, the S / N ratio of the signal detected from the thin-film magnetic sensor 1 is improved, and the detection accuracy is improved.

In FIG. 8, the magnetic film terminal 4 of the thin film magnetic sensor 1 is connected to the high frequency pulse
Is connected to the output and detection circuit 53. The high-frequency pulse generating means 10 includes a high-frequency oscillation source 50, a capacitor 51, and a resistor.
52. On the other hand, the detection circuit 53 includes a coupling capacitor 54, detection diodes 55 and 56, a smoothing resistor 57, and a capacitor 58.

Here, the thin-film magnetic sensor 1 configured as described above is mounted on the magnetic printing unit 3 printed on the surface of the banknote 30 to be inspected.
The principle of detecting the residual magnetic field of No. 2 will be described in detail.

In FIG. 7, a special magnetic powder contained in the ink is magnetized in the magnetic printing section 32 to generate a residual magnetic field 42. The residual magnetic field 42 appears as an alternating magnetic field corresponding to the magnetization state of the magnetic printing unit 32 with the relative movement of the thin-film magnetic sensor 1.

On the other hand, the magnetic films 2a to 2a of the thin-film magnetic sensor 1
A time-varying high-frequency pulse current is applied to d as shown in FIG. The frequency of this high-frequency pulse current is several MHz to several tens MHz (but is not limited to this)
It is. By applying a high-frequency pulse current to the magnetic film 2, the magnetization vector in the easy magnetization direction (magnetic film width direction) in the magnetic film rotates in the magnetic film length direction in response to the strength of the externally applied magnetic field. It is considered that the impedance of the magnetic film 2 changes when the magnetic permeability μ0 in the magnetic film width direction decreases.

As described above, the thin-film magnetic sensor 1 utilizes the fact that the impedance changes due to an external magnetic field.
The change can be extracted as an output signal proportional to the strength of the external magnetic field.

FIGS. 9 and 10 show characteristics of the magnetic impedance type thin-film magnetic sensor 1. FIG. In FIG. 9, the thin-film magnetic sensor 1 shows bimodal characteristics with respect to an externally applied magnetic field (−Hex to + Hex). Then, as shown in FIG. 9, the characteristics of the thin-film magnetic sensor 1 increase once as the magnetic field increases, and then decrease.

As a magnetic sensor, in order to take out a change with respect to an external magnetic field as a monotonous one, the banknote 3 is magnetized by using a monotonically increasing (or decreasing) region to perform magnetization bias.
The residual magnetic field 42 in the 0 magnetic printing unit 32 can be detected.

The bias magnetic field for the magnetization bias according to the present invention is formed by laminating the magnetic films 5 for each of the magnetic films 2a to 2d to obtain a predetermined bias magnetic field. The magnetic film 5 is formed such that a pole is formed in the longitudinal direction of the magnetic film 2. The magnetization intensity of the magnetic film 5 is several Oe (but is not limited to this).

Next, returning to FIG. 5, the circuit configuration and operation of the bill validator will be described in detail. In FIG.
The high-frequency pulse generating means 10 and the inspection means 11 are connected to the magnetic films 2a, 2b, 2c, 2d of the thin-film magnetic sensor 1. The inspection means 11 includes a signal extraction means 12, a comparison determination means 13, and a reference value signal generation means 14. The magnetic film 2 is connected to the input of the signal extraction means 12, and the output of the signal detection means 12 is input to the comparison determination means 13. The comparison / determination unit 13 compares the signal input from the signal detection unit 12 with the signal input from the reference value signal generation unit 14 and outputs the result to the output terminal 15.

Here, printed with magnetic ink,
For example, a US dollar bill has a residual magnetic strength of about 10-4 Oe (Oersted) to 10-3 Oe (Oersted) in a space about 1 mm away from the surface. For a banknote 30 having such residual magnetism, a thin film magnetic sensor
As shown in FIG. 7, the magnetic film 2 is made so that the surface of the magnetic film 2 is substantially parallel to the surface of the bill 30, and the thin-film magnetic sensor 1 is separated from the bill 30 by a predetermined distance. It is arranged facing the surface.

The thin film magnetic sensor 1 arranged as described above
Scans the magnetic printing unit 32 of the bill 30. At that time, an output signal obtained from the thin-film magnetic sensor 1 is input to the signal extracting means 12. The signal extracting means 12 is such that the thin-film magnetic sensor 1
A signal that changes in response to the magnetic printing unit 32 of 0 is extracted.
From the output of the signal extracting means 12, a signal waveform as shown in FIG. 10 is obtained. The output of the signal extraction means 12 is input to the comparison determination means 13. The comparison / determination means 13 is connected to the reference value signal generation means 14, and the reference value signal generation means 14
Is provided with a memory, and the memory stores a reference value (for example, an upper limit value and a lower limit value) of an acceptable bill of a predetermined denomination.

The reference value stored in the reference value signal generating means 14 is statistical data obtained by measuring in advance a receivable circulation bill of a predetermined given denomination using the magnetic sensor 1. Is the function value obtained from. Comparison judgment means 13
Compares the signal input from the signal extraction means 12 with the signal input from the reference value signal generation means 14 to determine whether the signal input from the signal extraction means 12 is within the reference value. If the input signal is within the reference value,
A signal indicating that 30 is true is output to an external device (not shown).

On the other hand, when this signal deviates from the reference value, a signal indicating that the test bill 30 is false is output to an external device (not shown). Thus, the authenticity of the test bill 30 can be inspected.

Further, in the bridge type thin film magnetic sensor according to the present invention, when a uniform external magnetic field is applied to the elements of the magnetic films 2a to 2d, unnecessary external magnetic fields can be canceled by the balance of the bridge circuit. it can.

Next, the structure and operation of the bill validator according to the present invention will be described in detail with reference to FIGS.
Here, FIG. 11 is a side view showing a schematic configuration of an embodiment of the bill validator according to the present invention, and FIG. 12 is a plan view thereof.

This bill discriminating apparatus is shown in FIGS.
As shown in the figure, the transport passage 71 for guiding the test bill 30 from the insertion slot 70 in the direction of the arrow, the test bill 30 inserted from the insertion slot 70,
Sensors 78-1 and 78-2 for detecting the position of the paper currency, the transport belts 76-1 and 76-2 for transporting the banknote 30 to be inspected inserted through the insertion slot 70 along the transport path 71, and the rollers 77-1 and 77-2 -2,77-3,77-4,77-5,
77-6, 77-7, 77-8, 77-9, 77-10, 77-11, 77-12 to detect the magnetic printing section 32 (FIG. 6) formed on the banknote 30 to be conveyed. Thin-film magnetic sensor 1, worm gears 74-1,74-2 for transmitting power to conveyor belts 76-1,76-2, worm gears 74-1,74-2
Is provided.

Next, the operation of the bill validator will be described.

The banknote 30 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 of the optical sensor. The motor 73 is started by the control means that does not. The output shaft of the motor 73 is connected to the worm gears 74-1 and 74-2, transmitting the power of the motor 73 to the pulleys 75-1 and 75-3, and moving the pulleys 75-1 and 75-3 in a predetermined direction. Rotate.

Further, between a pulley 75-1 rotated by the power of the motor 73 and a pulley 75-2 arranged at a predetermined distance,
And a pulley arranged at a predetermined distance from pulley 75-3
Between 75-4 and 75-4, conveyor belts 76-1 and 76-2 are respectively suspended to drive the conveyor belts 76-1 and 76-2. Then, rollers 77-1, 77-2, 77-3, 77-4, 77-5, 77-6, 77-7, rollers 77-1, 77-2, 77-3, 77-8,
77-9, 77-10, 77-11, and 77-12 are provided, and the roller 77 presses the bill 30 so as to sandwich the bill 30, and conveys the bill 30.

As a result, the banknote 30 inserted from the insertion slot 70 moves in the direction of the arrow, and eventually the thin-film magnetic sensor 1
And move further. At this time, the thin-film magnetic sensor 1 includes a magnetic printing unit 32 formed on the moving banknote 30 to be inspected.
(FIG. 6) is detected in a non-contact manner, and a response signal is output.

[0049]

As described above, according to the present invention, a thin-film magnetic sensor is provided in a bill transporting path of a bill validator, and a predetermined bill is attached to the inserted bill based on the detection output of the thin-film magnetic sensor. Whether or not the magnetic printing portion is formed, because it is configured to detect in a non-contact manner at least one of the magnetic reaction from the non-magnetic printing portion, the miracle of the detection position on the surface of the test bill As a result, security is improved. In addition, since the detection is performed by the non-contact method, there is no mechanical wear of the magnetic head and the life of the device is prolonged. In addition, since the magnetic sensor is configured as a bridge type, an effect is obtained that the magnetic sensor is hardly affected by a disturbance magnetic field.

Further, it is possible to prevent the bill itself from deteriorating due to damage or the like due to non-contact, and it is possible to perform proper processing without damaging the genuine bill and certifying it as a fake bill.

[Brief description of the drawings]

FIG. 1A is a front view showing an embodiment of a bridge type thin film magnetic sensor according to the present invention, and FIG. 1B is a side view thereof.

FIG. 2 is a partially enlarged view along a section AA of FIG. 1;

FIG. 3 is an equivalent circuit diagram of a bridge type thin film magnetic sensor according to the present invention.

FIG. 4 is a basic circuit diagram obtained by rewriting the equivalent circuit of FIG. 3;

FIG. 5 is a block diagram showing one configuration example of an authenticity inspection circuit according to the present invention using the sensor of FIG. 1;

FIG. 6 is a diagram showing an example of a test bill.

FIG. 7 is a diagram showing a configuration example of a bridge-type thin-film magnetic sensor used in the embodiment of FIG. 5;

FIG. 8 is a main part circuit diagram of a bridge type thin film magnetic sensor according to the present invention.

FIG. 9 is a characteristic diagram of the thin-film magnetic sensor.

FIG. 10 is a diagram showing an output waveform of a thin-film magnetic sensor.

FIG. 11 is a side view of a schematic mechanism in one embodiment of the bill validator using the circuit of FIG. 5;

FIG. 12 is a plan view corresponding to FIG. 11;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Bridge type thin film magnetic sensor 2 Magnetic film 3 Copper foil 4 Terminal 5 Magnetized film 6 Insulating layer 10 High frequency pulse generation means 11 Inspection means 12 Signal extraction means 13 Comparison judgment means 14 Reference value signal generation means 15 Output terminal 30 Banknote 31 Printing area 32 Magnetic printing unit 40 Magnetic shield 41 Lead wire (wire for connecting to the terminal of the thin film magnetic sensor) 42 Residual magnetic field 50 High frequency oscillation source 51 Capacitor 52 Resistance 53 Detection circuit 54 Capacitor 55 Diode 56 Diode 57 Resistance 57 Capacitor 60 Bias magnetic field Magnetic field applied to thin-film magnetic sensor at zero-output characteristic 61 Center line of zero bias magnetic field 62 -Center line at the time of applying Hb bias magnetic field 63 + Center line at the time of applying Hb bias magnetic field 70 Insertion port 71 Transport path 72-1 and 72-2 Passage wall 73 motor 74-1, 4-2 worm gear 75-1,75-2,55-3,55-4 pulleys 76-1 and 76-2 conveyor belt 77-1,77-2,77-3,77-4,77-5,
77-6,77-7,77-8,77-9,77-1
0,77-11,77-12 Roller 78-1,78-2 Inlet sensor

Claims (7)

[Claims] 1. A method of detecting the magnetic characteristics of a bill in a non-contact manner and checking the authenticity of the bill, wherein the bill is transported along a predetermined position of a transport path, and the predetermined position of the transport path is determined. A non-contact type thin film magnetic sensor in which a non-contact type thin film magnetic sensor using an ultrafine crystalline soft magnetic material is bridge-connected in proximity to the transport path; The signal output from the thin-film magnetic sensor as it is transported 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. And outputting a signal indicating that the bill is genuine. 2. A device for detecting the magnetic characteristics of a bill in a non-contact manner and inspecting the authenticity of the bill, comprising: a conveying path for conveying the bill along a predetermined position; and a predetermined position on the conveying path. A non-contact type bridge type thin film magnetic sensor in which a non-contact type thin film magnetic sensor using an ultrafine crystalline soft magnetic material is bridge-connected, The 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 falls within a predetermined allowable range with respect to the reference value. An apparatus for inspecting the authenticity of a banknote, comprising: comparison determination means for outputting a signal indicating that the banknote is genuine at one time; 3. The banknote authenticity inspection apparatus according to claim 2, wherein the thin-film magnetic sensor applies a high-frequency current to the magnetic film, and responds to the strength of the externally applied magnetic field. A magnetic impedance type thin film magnetic sensor that detects a signal corresponding to a change in rotation of a magnetization vector in a direction of easy magnetization to be generated as a change due to an externally applied magnetic field, and a signal output from the magnetic impedance type thin film magnetic sensor is a magnetic printed on a banknote. A banknote authenticity inspection apparatus for inspecting the authenticity of a banknote from a signal output in response to the strength of a residual magnetic field of ink. 4. The banknote authenticity inspection apparatus according to claim 3, wherein the magnetic film of the thin-film magnetic sensor is a high magnetic permeability magnetic material having a negative magnetostriction characteristic as close to zero magnetostriction as possible. Authenticity inspection device. 5. The banknote authenticity inspection apparatus according to claim 3, wherein the thin film magnetic sensor includes a magnetic film for applying a bias magnetic field to the magnetic film.
A banknote authenticity inspection device characterized by being laminated on the magnetic film. 6. An authenticity inspection apparatus for a banknote according to claim 3, wherein said thin-film magnetic sensor is arranged so that said banknote surface and said magnetic film surface face each other. apparatus. 7. The apparatus according to claim 2, wherein the thin-film magnetic sensor is disposed corresponding to a position of a predetermined printing unit printed on the surface of the bill with magnetic ink. A banknote authenticity inspection device, wherein a thin-film magnetic sensor scans a predetermined printing portion of the banknote and checks the authenticity of the banknote based on a signal obtained from the thin-film magnetic sensor.