JP3725361B2 - 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 using magnetic ink is known as one of the banknote printing techniques. For example, in US dollar bills printed with magnetic ink, the 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 Application 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 the sensitivity is equivalent to or higher than that of the FG (flux gate) type magnetic sensor known for high sensitivity. 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 amorphous is difficult to handle in production, and the 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 consideration of the above points, and uses a non-contact method to check the authenticity of a banknote using a highly sensitive magneto-impedance thin film magnetic sensor that is stable in operation and can be configured at low cost. And providing an apparatus.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention,
In a method of 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 of a transport path, and the transport path is placed at a predetermined position of the transport path. A non-contact type bridge type thin film magnetic sensor in which a non-contact type thin film magnetic sensor using an ultrafine crystal soft magnetic material is bridge-connected is disposed so that the bill is conveyed along the conveyance path. Therefore, the signal output from the thin film magnetic sensor is compared 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, the bill is In a method for inspecting the authenticity of a banknote characterized by outputting a signal indicating that the banknote is authentic, and a device for detecting the magnetic characteristics of the banknote in a non-contact manner and inspecting the authenticity of the banknote, Along the specified position. A non-contact type bridge in which a non-contact type thin film magnetic sensor using an ultrafine crystal soft magnetic material is bridge-connected to a predetermined position of the transfer path and close to the transfer path A type thin film magnetic sensor, 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 comparing and judging means for outputting a signal indicating that the bill is true when the signal is within a predetermined allowable range with respect to the reference value. apparatus,
Is to provide.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0017]
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, and FIG. 2 is a partially enlarged view of the AA section of FIG. 1 according to the present invention. is there. 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.
[0018]
First, the configuration 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 is formed by forming a lower insulating layer 6b of SiO2 on a glass substrate 1a, a copper foil portion 3 and terminals 4a, 4b, 4c, 4d, and magnetic films 2a, 2b, 2c, 2d {For example, an element made of a high permeability material containing Fe73.5%, Si13.5%, B9% (all at%) as the main component and containing additive elements such as Cu, Nb, etc. Forms a width of 50 microns and a length of 2 mm}.
[0019]
The magnetic film 2 is formed so that the end thereof is electrically connected to the end of the copper foil portion 3 and the magnetic film 2 forms a bridge circuit. Further, an upper insulating layer 6a made of SiO2 is formed on the magnetic film 2, and a magnetized film 5 {for example, a high coercivity material mainly composed of Co, Cr, etc.} is formed on the uppermost portion, and this bridge type is formed. A thin film magnetic sensor 1 is configured.
[0020]
The magnetic film 2 of the thin film magnetic sensor 1 is formed by sputtering or the like using a target of high permeability material having negative magnetostriction characteristics as close to zero magnetostriction as possible.
[0021]
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 with inductance and resistance.
[0022]
Now, the impedance of the equivalent circuit inductance L1 and resistance R1 of the magnetic film 2a is Z1, the equivalent circuit inductance L2 and resistance R2 of the magnetic film 2b is Z2, the equivalent circuit inductance L3 and resistance R3 of the magnetic film 2c is Z3, and Assuming that the equivalent circuit inductance L4 of the magnetic film 2d and the impedance of the resistor R4 are Z4, the following formula is established when the magnetic films 2a to 2d are in an equilibrium state.
Z1 ・ Z4 = Z2 ・ Z3
(R1 + jωL1) (R4 + jωL4) = (R2 + jωL2) (R3 + jωL3)
∴ (R1 + jωL1) (R4 + jωL4) − (R2 + jωL2) (R3 + jωL3) = 0
As is well known, in order for these mathematical expressions to be established, the characteristics of the elements of the magnetic films 2a to 2d of the bridge-type thin film magnetic sensor 1 are approximately equal.
[0023]
Since the magnetic films 2a to 2d according to the present invention are formed of thin films as described above, elements having substantially the same characteristics can be obtained.
[0024]
Next, the configuration and principle for detecting the residual magnetic field of the magnetic printing unit 32 of the banknote 30 to be examined 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 the authenticity inspection circuit for a banknote to be examined. The configuration and operation will be described after the description with reference to FIGS.
[0025]
First, the configuration of a certain test banknote 30 will be described with reference to FIG. In FIG. 6, 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 as a magneto-impedance thin film magnetic sensor, and detects the strength of residual magnetism in a non-contact manner.
[0026]
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 principal part showing the principle of the thin film magnetic sensor 1, and FIG. 9 is a characteristic diagram of the thin film magnetic sensor 1.
[0027]
In FIG. 7, 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. A lead wire 41 is connected to the terminals 4a, 4b, 4c, 4d of the magnetic film 2. The thin film magnetic sensor 1 connected as described above 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.
[0028]
The magnetic shield 40 can block leakage magnetic flux generated from a power source of a banknote identification device (not shown) or a transport motor 53 (FIG. 11) that transports the banknote 30 to be examined. Therefore, the S / N ratio of the signal detected from the thin film magnetic sensor 1 is improved, and the detection accuracy is improved.
[0029]
In FIG. 8, 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. 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.
[0030]
Here, the principle for detecting the residual magnetic field of the magnetic printing unit 32 printed on the surface of the banknote 30 to be tested by the thin film magnetic sensor 1 configured as described above will be described in detail.
[0031]
In FIG. 7, in the magnetic printing unit 32, a special magnetic powder contained in the ink is magnetized to generate a residual magnetic field. 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.
[0032]
On the other hand, a high-frequency pulse current that changes with time is applied to the magnetic films 2a to 2d of the thin film magnetic sensor 1 as 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). By applying a high-frequency pulse current to 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 as the magnetic permeability μ0 in the width direction of the magnetic film decreases.
[0033]
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.
[0034]
FIG. 9 and FIG. 10 show the characteristics of the magnetic impedance type thin film magnetic sensor 1. In FIG. 9, the thin film magnetic sensor 1 exhibits a bimodal characteristic with respect to an externally applied magnetic field (-Hex to + Hex). As shown in FIG. 9, the characteristics of the thin film magnetic sensor 1 once increase with an increase in the magnetic field and then decrease.
[0035]
As a magnetic sensor, in order to take out changes to the external magnetic field as monotonous, the residual magnetic field 42 in the magnetic printing unit 32 of the banknote 30 is detected by magnetizing bias using a monotonically increasing (or decreasing) region. Can do.
[0036]
The bias magnetic field for the magnetization bias according to the present invention is formed by laminating the magnetized film 5 for each of the magnetic films 2a to 2d to obtain a predetermined bias magnetic field. The magnetized film 5 is formed so as to have a pole in the longitudinal direction of the magnetic film 2. The magnetization intensity of the magnetic film 5 is a few Oe (however, it is not limited to this).
[0037]
Next, returning to FIG. 5, the configuration and operation of the circuit of the bill validator will be described in detail. In FIG. 5, high-frequency pulse generating means 10 and inspection means 11 are connected to magnetic films 2a, 2b, 2c and 2d of the thin film magnetic sensor 1. The inspection unit 11 includes a signal extraction unit 12, a comparison / determination unit 13, and a reference value signal generation unit 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.
[0038]
Here, for example, US dollar bills printed with magnetic ink have 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 bill 30 having such residual magnetism, the magnetic film 2 of the thin film magnetic sensor 1 is formed so that the surface of the magnetic film 2 is substantially parallel to the surface of the bill 30 as shown in FIG. The magnetic sensor 1 is disposed opposite to the bill surface at a predetermined distance from the surface of the bill 30.
[0039]
The thin film magnetic sensor 1 arranged as described above scans the magnetic printing unit 32 of the banknote 30. At that time, an output signal obtained from the thin film magnetic sensor 1 is input to the signal extraction means 12. The signal extraction unit 12 extracts a signal that changes in response to the magnetic printing unit 32 of the banknote 30 by the thin film magnetic sensor 1. A signal waveform as shown in FIG. 10 is obtained from the output of the signal extraction means 12. The output of the signal extraction unit 12 is input to the comparison determination unit 13. Further, the comparison / determination means 13 is connected to the reference value signal generating means 14, and the reference value signal generating means 14 is provided with a memory, and a predetermined denomination can be received in this memory. Reference values (for example, an upper limit value and a lower limit value) in banknotes are stored.
[0040]
The reference value stored in the reference value signal generating means 14 is obtained from statistical data obtained by measuring in advance using the magnetic sensor 1 a banknote that can be received in a given denomination. Function value. The comparison determination unit 13 compares the signal input from the signal extraction unit 12 with the signal input from the reference value signal generation unit 14, and determines whether the signal input from the signal extraction unit 12 is within the reference value. If the input signal is within the reference value, a signal indicating that the banknote 30 to be tested is true is output to an external device (not shown).
[0041]
On the other hand, when this signal is out of the reference value, a signal indicating that the banknote 30 to be examined 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.
[0042]
The bridge-type thin film magnetic sensor according to the present invention can cancel an unnecessary external magnetic field by the balance of the bridge circuit when a uniform external magnetic field is applied to the elements of the magnetic films 2a to 2d.
[0043]
Next, the configuration and operation of the banknote recognition apparatus 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 banknote recognition apparatus according to the present invention, and FIG. 12 is a plan view thereof.
[0044]
As shown in FIGS. 11 and 12, the banknote identification device includes a conveyance path 71 that guides the test banknote 30 in the direction of the arrow from the insertion port 70, and an inlet sensor that detects the test banknote 30 inserted from the insertion port 70. 78-1, 78-2, conveying belts 76-1, 76-2 for conveying the banknote 30 to be examined inserted from the insertion port 70 along the conveying path 71, and rollers 77-1, 77-2, 77- 3,77-4,77-5,77-6,77-7,77-8,77-9,77-10,77-11,77-12 Thin film magnetic sensor 1 for detecting the printing unit 32 (FIG. 6), worm gears 74-1 and 74-2 for transmitting power to the conveyor belts 76-1 and 76-2, and a motor for driving the worm gears 74-1 and 74-2 73.
[0045]
Next, operation | movement of this banknote identification device is demonstrated.
[0046]
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 of the optical sensor. Based on the signal output from the entrance sensor 78, control means (not shown) Thus, the motor 73 is started. 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.
[0047]
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. Are respectively wound around conveyor belts 76-1 and 76-2 and drives the conveyor belts 76-1 and 76-2. In addition, rollers 77-1, 77-2, 77-3, 77-4, 77-5, 77-6, 77-7, which are arranged at predetermined intervals are disposed on the conveyor belts 76-1, 76-2. 77-8, 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.
[0048]
As a result, 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. At this time, the thin film magnetic sensor 1 detects the magnetic printing part 32 (FIG. 6) formed on the moving bill 30 to be contacted and outputs a response signal.
[0049]
【The invention's effect】
As described above, according to the present invention, the thin film magnetic sensor is disposed in the banknote conveyance path of the banknote identification device, and a predetermined magnetic printing unit is provided on the inserted banknote based on the detection output of the thin film magnetic sensor. Since at least one of whether it is formed or whether there is a magnetic reaction from the non-magnetic printing part is configured to be detected in a non-contact manner, there is no miracle of the detection position on the surface of the banknote to be inspected. Improvement is achieved. In addition, since the detection is performed by a non-contact method, there is no mechanical wear of the magnetic head and the life of the apparatus is prolonged. And since the magnetic sensor was comprised in the bridge type, there exists an effect that it is hard to receive the influence of a disturbance magnetic field.
[0050]
Furthermore, deterioration due to damage or the like of the bill itself can be prevented by non-contact, and proper processing can be performed without certifying the genuine bill 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 of the same.
FIG. 2 is a partially enlarged view along the AA section of FIG.
FIG. 3 is an equivalent circuit diagram of a bridge-type thin film magnetic sensor according to the present invention.
4 is a basic circuit diagram in which the equivalent circuit of FIG. 3 is rewritten.
5 is a block diagram showing a configuration example of an authenticity inspection circuit according to the present invention using the sensor of FIG.
FIG. 6 is a diagram showing an example of a banknote to be examined.
7 is a diagram showing a configuration example of a bridge-type thin film magnetic sensor used in the embodiment of FIG.
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 a thin film magnetic sensor.
FIG. 10 is a view showing an output waveform of the thin film magnetic sensor.
FIG. 11 is a side view of a schematic mechanism in an embodiment of a banknote recognition apparatus using the circuit of FIG.
12 is a plan view corresponding to FIG. 11. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bridge type thin film magnetic sensor 2 Magnetic film 3 Copper foil 4 Terminal 5 Magnetization film 6 Insulating layer 10 High frequency pulse generation means 11 Inspection means 12 Signal extraction means 13 Comparison determination means 14 Reference value signal generation means 15 Output terminal 30 Bill 31 Printing area 32 Magnetic printing part 40 Magnetic shield 41 Lead wire (electric wire for connecting to the terminal of a thin film magnetic sensor)
42 Residual magnetic field 50 High frequency oscillation source 51 Capacitor 52 Resistor 53 Detection circuit 54 Capacitor 55 Diode 56 Diode 57 Resistor 58 Capacitor 60 Magnetic field applied to thin film magnetic sensor at zero bias magnetic field-output characteristic 61 Center line 62 of zero bias magnetic field -Hb bias magnetic field Center line 63 at the time of application + Center line 70 at the time of applying a Hb bias magnetic field Insertion slot 71 Transport passages 72-1, 72-2 Passage wall 73 Motors 74-1, 74-2 Worm gears 75-1, 75-2, 55-3 , 55-4 Pulleys 76-1, 76-2 Conveying belts 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 (7)

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 bridge type thin film magnetic sensor in which a non-contact type thin film magnetic sensor using an ultrafine crystal soft magnetic material is bridge-connected to a predetermined position of the transfer path is disposed,
A signal output from the thin film magnetic sensor as the bill is transported along the transport path is compared with a reference value signal of a predetermined denomination stored in advance, and the signal becomes the reference value. A method for inspecting the authenticity of a banknote, characterized in that a signal indicating that the banknote is true is output when the banknote is within a predetermined allowable range. 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 bridge type thin film magnetic sensor, which is disposed in a predetermined position of the transport path in the vicinity of the transport path, and a non-contact type thin film magnetic sensor using an ultrafine crystal soft magnetic material is bridge-connected;
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 magnetic film for applying a bias magnetic field to the magnetic film is laminated on the magnetic film. 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.

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