JP2001056906A - Magnetic detector and magnetic material discriminating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetic detector capable of reliably discriminating the coercive force of the magnetic material such as a magnetic stripe and to obtain a magnetic material discriminating device using the detector. SOLUTION: The device is provided with a magnetic sensor part 2 arranged so that exciting coils 8 and detecting coils 9 are wound around two magnetic poles 5, 6 formed so as to have a gap part 4 and the magnetic flux passing one magnetic pole 5 out of the magnetic poles 5, 6 is changed with respect to another magnetic pole 6 to discriminate the magnetic material 10 provided on a body 30 to be detected in the manner of detecting the change of the magnetic flux on one magnetic pole 5 by the detecting coil 9. Further, a magnetic head part 3 is furnished for reading out a magnetic signal recorded on the magnetic material 10 of the body 30 to be detected, and the magnetic sensor part 2 and the magnetic head part 3 are integrated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic detection device for detecting an object based on a change in magnetic flux according to the magnetic permeability of the object, and further uses the magnetic detection device. The present invention also relates to a magnetic material identification device for identifying a magnetic material provided on the detection object.

[0002]

2. Description of the Related Art As a magnetic material identification device, for example, there is a card reader. In recent years, there has been a tendency to increase the coercive force of the magnetic stripe of the card in order to improve the recording data reliability of the card, and high coercive force cards called Hico cards and low coercive force cards called Lowco cards are on the market. They are used together. Therefore, a card reader is required to have a function of recording data with an appropriate current value according to cards having various coercive forces.

[0003] The applicant of the present invention pays attention to the correlation between the coercive force and the magnetic permeability of a magnetic material, and identifies the coercive force of the card by detecting a change in magnetic flux depending on the magnetic permeability of the magnetic stripe of the card. Filed earlier for a differential magnetic sensor.

[0004]

However, the invention according to the prior application has room for further improvement. As described above, in the invention according to the prior application, the coercive force of the card is identified by detecting a change in magnetic flux depending on the magnetic permeability of the magnetic stripe. Since the magnetic flux changes depending on the distance (clearance) between the magnetic stripe and the magnetic sensor, if the distance between the magnetic stripe and the magnetic sensor is not kept constant, it is necessary to accurately identify the coercive force of the card. May not be possible. For example, if a warped card is inserted into a card reader or if dust is attached to the magnetic stripe of the card,
Since the distance between the magnetic stripe and the magnetic sensor is larger than usual, the change in the magnetic flux is different from that in the normal case, and as a result, the coercive force of the card may be erroneously identified.

FIG. 6 shows the relationship between the output of the magnetic sensor and the distance between the magnetic stripe of the card and the magnetic sensor, and the symbol a indicates the clearance characteristic of a card (medium) having a coercive force of 300 (Oe). The coercive force is 65
0 (Oe) indicates the clearance characteristic of the card, and symbol C indicates the clearance characteristic of the card having a coercive force of 2750 (Oe). For example, if the coercive force is 300 (O
e) When reading the card, if the distance between the magnetic stripe and the magnetic sensor is 0.1 mm, the output value of the magnetic sensor when this card is identified indicates that the magnetic stripe and the magnetic sensor are in complete contact. Since the output value of the magnetic sensor of the 650 (Oe) card is substantially the same,
The (Oe) card is erroneously identified as the 650 (Oe) card. The coercive force is 300 (O
If the distance between the magnetic stripe and the magnetic sensor is about 0.37 mm or more when reading the card in e), 3
In some cases, the 00 (Oe) card is mistakenly identified as the 2750 (Oe) card.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has been made in view of the above. A magnetic detecting apparatus and a magnetic detecting apparatus using the magnetic detecting apparatus capable of reliably identifying the coercive force of a magnetic material such as a magnetic stripe. It is an object to provide a material identification device.

[0007]

According to the first aspect of the present invention,
The present invention relates to a magnetic detection device, wherein an excitation coil and a detection coil are wound around two magnetic poles formed to have a gap so that a magnetic flux passing through one of the magnetic poles changes with respect to the other magnetic pole. And a magnetic sensor unit that detects a change in magnetic flux at the one magnetic pole by the detection coil to identify a magnetic material provided on the detection target, and is recorded on the magnetic material of the detection target. A magnetic head unit for reading a magnetic signal, wherein the magnetic sensor unit and the magnetic head unit are integrated.

According to a second aspect of the present invention, in the first aspect of the invention, the magnetic sensor section and the magnetic head section are housed in a single case, and constitute a continuous contact surface with the object to be detected. It is characterized by doing.

According to a third aspect of the present invention, in the first aspect of the present invention, the magnetic head has a reading gap for reading a magnetic signal recorded on the object to be detected. The width of the gap portion of the sensor portion and the width of the reading gap of the magnetic head portion are different from each other.

According to a fourth aspect of the present invention, in the first aspect of the present invention, at least a part of the magnetic core part forming the two magnetic poles of the magnetic sensor part and the magnetic core part forming the magnetic head part are formed. It is characterized by being shared.

According to a fifth aspect of the present invention, there is provided a magnetic material discriminating apparatus, wherein an exciting coil and a detecting coil are wound around two magnetic poles formed so as to have a gap, and one of the magnetic poles is connected to the magnetic pole. A magnetic sensor unit is provided so that a magnetic flux passing therethrough is changed with respect to the other magnetic pole, and a change in magnetic flux at the one magnetic pole is detected by the detection coil to identify a magnetic material provided on the object to be detected. ,
A magnetic head unit for reading a magnetic signal recorded on the magnetic material of the object to be detected; and a magnetic detection device in which the magnetic sensor unit and the magnetic head unit are integrated. .

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the object to be detected is a card, and a magnetic material of a magnetic stripe provided on the card is identified. According to a seventh aspect of the present invention, in the fifth aspect of the invention, the magnetic sensor unit and the magnetic head unit are housed in one case, and constitute a continuous contact surface with the card. The presence or absence of clearance between the card and the contact surface is detected based on the magnitude of a magnetic signal from a magnetic head unit.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a magnetic detecting apparatus according to the present invention. FIG. 1 (A),
(B) shows a magnetic detection device 1 according to the present invention. The magnetic detection device 1 is configured by integrating a magnetic sensor unit 2 and a magnetic head unit 3.

The magnetic sensor section 2 has two substantially U-shaped magnetic poles 5 and 6. The two magnetic poles 5 and 6 are connected by a connecting portion 7 on the side of the magnetic head 3 and are arranged so as to have a substantially π shape. The magnetic poles 5 and 6 are located between the gaps 4 and 4 respectively.
Each of the gaps 4, 4 is open at both ends in the length direction of the magnetic sensor 2. Magnetic poles 5, 6
Has a winding portion 1 formed by the gap portions 4 and 4.
Excitation coil 8 and detection coil 9 are wound around 1 and 12, respectively, and magnetic sensor unit 2 is formed symmetrically. In this embodiment, the width of each gap portion 4 is formed to be approximately 0.5 mm. Further, the magnetic poles 5, 6 and the connecting portion 7 are integrally formed of a high magnetic permeability magnetic material such as ferrite or sendust.

The magnetic sensor unit 2 is located at a magnetic detection position of a card of a card reader (magnetic recording device) as a magnetic material identification device. When a card 30 as an object to be detected passes through the transport path, the magnetic material 10 forming the magnetic stripe passes through one of the magnetic poles 5 and 6 of the magnetic sensor unit 2 so as to be close to the magnetic pole. 5 is provided so as to change with respect to the other magnetic pole 6.
Therefore, a change in the magnetic flux of the magnetic pole 5 with respect to the magnetic pole 6 is detected by the detection coil 9, and the detected output level identifies the magnetic material 10 of the magnetic stripe of the card 30, that is, whether the card is a high coercive force card or a low coercive force. It is configured so that it can be identified as a card.

As described above, the exciting coil 8 is wound around the winding portion 11 of the magnetic pole 5 and the winding portion 12 of the magnetic pole 6 in opposite directions. The detection coil 9 is
Similarly, the winding part 11 of the magnetic pole 5 and the winding part 12 of the magnetic pole 6
And the magnetic fluxes passing through the magnetic poles 5 and 6 are opposite to each other, so that a closed-loop magnetic flux φ1 is generated as a whole (FIG. 1A).
(B)). That is, the detection coil 9 is wound so as to be a differential coil. On the contrary, the exciting coil 8
May be wound so as to form a differential coil. In the above example, the exciting coil 8 is wound around the winding portion 11 of the magnetic pole 5 and the winding portion 12 of the magnetic pole 6, respectively.
As shown in FIG. 1, the winding part 11 of the magnetic pole 5 and the winding part 12 of the magnetic pole 6 may be wound so as to be included. In addition, the detection coil 9 is wound around the winding part 11 of the magnetic pole 5 and the winding part 12 of the magnetic pole 6 as shown in FIGS.

A circuit shown in FIG. 3 is connected to the magnetic sensor unit 2. In the case of the embodiment of FIGS. 1A and 1B, the two exciting coils 8 are connected in series to the AC power supply 15 and pass through the two magnetic poles 5 and 6 to generate a magnetic flux φ1 that forms a closed loop. generate. The two detection coils 9, 9 magnetically coupled to the excitation coil 8 and wound around the magnetic poles 5, 6, respectively, are connected in a bridge, and the differential outputs of this bridge are connected to the + input terminal and the-input terminal of the operational amplifier 16, respectively. ing. A detection circuit 17 is connected to an output terminal of the operational amplifier 16, and an output of the detection circuit 17 is converted into a digital signal by an analog / digital conversion circuit 18.
The input is made to U19.

When the magnetic material 10 of the magnetic stripe of the card 30 does not exist around the magnetic sensor unit 2 and the magnetic fluxes passing through the magnetic poles 5 and 6 are equal, the magnetic fluxes passing through the magnetic poles 5 and 6 are balanced. The output of the detection coil 9 does not change. In this state, when the magnetic material 10 of the magnetic stripe of the card 30 approaches the magnetic sensor unit 2 (see FIGS. 1A and 1B), a magnetic flux φ2 leaking from one magnetic pole 5 toward the magnetic material 10 is generated. . As a result, the balance of the magnetic flux passing through each of the magnetic poles 5 and 6 is lost. The degree of leakage of the magnetic flux φ2 varies depending on the magnetic permeability of the magnetic material 10 of the magnetic stripe, and is output from the bridge-connected detection coils 9 and 9 as a differential signal between the two detection coils. This differential output is amplified by an operational amplifier 16 and rectified by a detection circuit 17 as shown in FIG. Thereafter, the signal is converted from an analog signal to a digital signal by an analog / digital conversion circuit 18, and the magnetic material 10 of the magnetic stripe is converted to a digital signal.
Is input to the CPU 19 as an output signal having a magnitude corresponding to the magnetic permeability of. Since there is a certain relationship between the magnetic permeability of the magnetic material 10 of the magnetic stripe and the coercive force of the card 30, the output value of the detection coil 9 corresponding to the magnitude of the coercive force is confirmed in advance by the CPU 19. Thereby, the coercive force of the magnetic material 10 of the magnetic stripe of the card 30 can be identified based on the output of the detection coil 9.

That is, in the magnetic sensor section 2, the winding section 1
1, 12 and the connecting portion 7 are arranged so as to have a substantially π shape. Exciting coils 8 and 8 are wound around each of the winding portions 11 and 12, and a magnetic flux φ1 generated by energizing the exciting coils 8 and 8 is applied to the winding portion 11, the coupling portion 7, and the winding portion 1.
2 to form a closed loop. On the other hand, the detection coils 9 and 9 are wound so as to be of a differential type. When the magnetic material 10 of the magnetic stripe of the card 30 approaches the magnetic sensor unit 2, a part of the magnetic flux φ1 leaks into a loop composed of the magnetic pole 5 and the magnetic material 10, and the magnetic flux φ2 is generated in this loop. The magnetic flux φ2 is a magnetic flux depending on the magnetic permeability of the magnetic material 10 of the magnetic stripe of the card 30,
The magnetic sensor unit 2 can operate even on the data recording area of the magnetic material 10 without a large magnetic flux acting so as to impair the data recorded on the magnetic material 10.

On the other hand, the magnetic head unit 3 is shown in FIG.
As shown in (A) and (B), it is configured by inductive head cores 20A and 20B as magnetic core portions and a magnetic signal reproducing coil 21 wound around the lower end of the inductive head core 20A. A reading gap 22 for reading a magnetic signal recorded on the magnetic material 10 of the magnetic stripe of the card 30 is formed at the upper end of the inductive head core 20. The formation of the reading gap 22 will be described later. Magnetic head 3
Is to read a magnetic signal recorded on the magnetic material 10 by detecting a magnetic flux of the magnetic material 10 by the magnetic signal reproducing coil 21.

The magnetic head unit 3 is integrated with the magnetic sensor unit 2. For example, there is a structure in which the magnetic head unit 3 and the magnetic sensor unit 2 are housed in one case 31. In addition, there is a configuration in which at least a part of the magnetic core unit forming the two magnetic poles 5 and 6 of the magnetic sensor unit 2 and the inductive head cores 20A and 20B forming the magnetic head unit 3 are shared. Specifically, FIG. 1 (A),
As shown in FIG. 4B and the embodiment shown in FIG. 4, the magnetic core part constituting the two magnetic poles 5 and 6 of the magnetic sensor part 2 and the inductive head core 20B are configured to be shared. More specifically, both ends of the connecting portion 7 are extended to form one magnetic pole of each of the magnetic poles 5 and 6, and
The connecting portion 7 and both extended end portions thereof constitute a part of the inductive head core 20B, and the read gap 2 between the inductive head cores 20A and 20B.
2 are formed. It is not necessary to share and integrate the cores in this way. That is, as shown in FIG. 8B, the magnetic sensor unit 2 and the magnetic head unit 3 which are separately configured are integrated by being supported by a common leaf spring (not shown). And this is shown in FIG.
It may be integrated as shown in FIG.

The reading gap 22 shown in FIGS. 1A and 1B and FIG.
A is formed by a gap between the upper end portion of the magnetic core portion A and the magnetic core portions constituting the two magnetic poles 5 and 6 of the magnetic sensor portion 2, and as shown in FIG. It is a right angle. The gap width of the reading gap 22 is approximately 30 μm, which is largely different from the width (approximately 0.5 mm) of the gap portion 4 of the magnetic sensor unit 2. The gap width of the reading gap 22 and the magnetic sensor unit 2
The width of the gap portion 4 may be the same when the reading accuracy does not have to be strict.

As shown in FIGS. 1A, 1B, and 4, the magnetic sensor 2 and the magnetic head 3 are housed in a single case 31, and the magnetic poles of the magnetic sensor 2 are The upper surface of the magnetic head 5 and the upper end surface of the inductive head core 20A of the magnetic head 3 constitute a continuous contact surface with the magnetic material 10 of the magnetic stripe of the card 30.

As shown in FIG. 7, the output of the magnetic sensor unit 2 and the output of the magnetic head unit 3 change depending on the clearance between the magnetic stripe of the card 30 and the contact surface. Therefore, as shown in FIGS. 1A and 1B, if the magnetic sensor unit 2 and the magnetic head unit 3 are integrated, or the magnetic sensor unit 2 and the magnetic head unit 3 are supported by a common spring. If the magnetic head unit 3 moves substantially integrally, for example, the magnetic stripe of the card 30 in the magnetic sensor unit 2 and the contact surface depend on the magnitude of the magnetic signal output from the magnetic head unit 3. The presence or absence of clearance can be detected. Hereinafter, this will be described in detail.

As shown in FIG. 7, as the clearance between the magnetic stripe of the card 30 and the contact surface increases, the output of the magnetic sensor unit 2 gradually decreases, but the output of the magnetic head unit 3 decreases. Are sharply reduced. In the case of a card having a coercive force of 300 (Oe), the output value of the magnetic sensor unit 2 is always larger than the output value of the magnetic head unit 3.

Therefore, if the output value of the magnetic head 3 with respect to the clearance is equal to or larger than a certain value (hereinafter referred to as "threshold"), the magnetic sensor 2
Can be confirmed to be a value obtained in a state of being equal to or less than the clearance value at that time. For example,
When the threshold value of the output of the magnetic head unit 3 is set to the output value when the clearance value is 0.02 mm, if the output value of the magnetic sensor unit 2 is equal to or larger than the threshold value, It can be confirmed that the output value of the magnetic sensor unit 2 is a value obtained when the clearance value is 0.02 mm or less.

As described in the section of the problem to be solved by the invention, if the clearance is large, the coercive force of the magnetic material may be erroneously identified. By integrating the sensor 2 and detecting the output of the magnetic head unit 3,
If the output value of the magnetic sensor unit 2 can be confirmed to be a value obtained when the clearance value is equal to or less than a certain value (normal clearance), the coercive force of the magnetic material can be obtained. Can be reliably identified, and the coercive force of the magnetic material can be reliably identified. Therefore, the threshold value may be set in a range where the coercive force of the magnetic material is not erroneously identified. For example, when the clearance is 0.1 mm as shown in FIG. 6, a 300 (Oe) card may be erroneously identified as a 650 (Oe) card. Is a value higher than the output value of the magnetic head unit 3 when the clearance value is 0.1 mm, preferably the clearance value is 0.0
The value may be set so as to be higher than the output value of the magnetic head unit 3 at 2 mm.

Next, the operation of the above embodiment will be described. The magnetic detection device 1 of the present case is provided before the shutter of the card reader insertion slot. At this time, as shown in FIGS. 4 and 5, when the user inserts the card 30 into the card insertion slot (not shown), at this time, the magnetic head unit 3 only needs to detect the presence or absence of the magnetic output. Therefore, the threshold value is set to a low value, and the magnetic head unit 3 detects only the presence or absence of the output signal of the card 30 (1).
Times). That is, the output of the magnetic head unit 3 is monitored.
When the output signal of the card 30 is not detected by the magnetic head unit 3, the shutter is not opened, and the card 30 is not taken in from the card insertion slot.

On the other hand, when a magnetic output signal is detected by the magnetic head unit 3, the shutter is opened, and the card 30 is driven by a drive motor (not shown) for transporting the card, so that the card 30 is moved by an appropriate position detecting means. While the position is detected, the sheet is transported to the magnetic detection position. Then, the presence or absence of the output signal of the card 30 is detected by the magnetic head unit 3 for identification of the coercive force (second time).

Here, the first detection of the output signal by the magnetic head unit 3 simply detects the presence or absence of the output signal, but the second detection of the output signal by the magnetic head unit 3
It is detected whether the output value of the magnetic head unit 3 is equal to or greater than the above-described threshold value for determination. If the output value of the magnetic head unit 3 is smaller than the above threshold value, it means that an unexpected clearance has occurred between the magnetic head unit and the card. 30 can be returned to the card slot or read data
Only perform operations other than writing.

On the other hand, if the output value of the magnetic head unit 3 is equal to or larger than the threshold value, the power of the magnetic head unit 3 is turned off,
The power of the magnetic sensor unit 2 (card identification sensor) is turned on. As a result, a current flows through the exciting coil 8 of the magnetic sensor unit 2 and the magnetic material 10 of the magnetic stripe of the card 30 is formed.
As a result, the magnetic flux passing through one of the magnetic poles 5 and 6 changes with respect to the magnetic flux passing through the other magnetic pole 6, and the change in the magnetic flux at the magnetic pole 5 is detected by the detection coil 9. The CPU 1 outputs an output signal having a magnitude corresponding to the magnetic permeability of the magnetic material 10 of the magnetic stripe of FIG.
9 (see FIG. 3). In the present embodiment, the power supply of the magnetic head unit 3 is turned off before the power supply of the magnetic sensor unit 2 is turned on. However, the present invention is not limited to this. That is, the power of the magnetic head unit 3 may be kept on, and the power of the magnetic sensor unit 2 may be turned on. In this case, the output from the magnetic sensor unit 2 and the magnetic head unit 3 is mixed from the detection coil 9, but using a filter circuit that passes only a predetermined frequency band,
An output signal from the magnetic sensor unit 2 may be extracted.

Then, the position of the card 30 is detected by appropriate position detecting means, and the card 30 is moved to the magnetic detecting device 1.
When the position exceeds the magnetic detection position, the magnetic sensor unit 2 reads a value when there is no card as a correction value.
Based on the correction value, the coercive force of the magnetic material 10 is identified from the output signal having a magnitude corresponding to the magnetic permeability of the magnetic material 10 taken into the CPU 19. After that, data is written on the magnetic stripe of the card 30 by a data recording / reproducing magnetic head provided inside the card reader.
In addition, the magnetic head unit 3 is used not only for reading, but also for reading.
It can also be used for data writing.

In the above embodiment, at least a part of the magnetic core part of the magnetic sensor part 2 and the magnetic core part constituting the magnetic head part 3 are shared. However, as shown in FIG. The magnetic sensor unit 2 and the magnetic head unit 3 may be integrated with the case where the magnetic head unit 3 and the magnetic head unit 3 are provided independently of each other. The one shown in FIG.
The magnetic material 10 of the 0 magnetic stripe is formed in three rows, the track 51 and the track 52 are formed so as to pass over the magnetic head section 3, and the track 53 is formed so as to pass over the magnetic sensor section 2. This is an example.

Further, in the embodiment described above, the inductive head cores 20A and 20B are used for the magnetic head section 3. However, as in the embodiment shown in FIG. 2, a magnetic head comprising an MR element (magnetoresistive element) is used. The unit 40 can also be used. The magnetic head unit 40 includes a glass substrate 41 attached to a core of the magnetic sensor unit 2 and a glass substrate 41.
And a MR element provided between the glass substrate 41 and the glass substrate 42. FIG. 10 shows a case where the magnetic head unit 40 and the magnetic sensor unit 2 are integrated and housed in one case 31. The MR element may be provided between the core of the magnetic sensor unit 2 and the glass substrate 41. In this case, the glass substrate 42 becomes unnecessary.

[0035]

According to the present invention, an exciting coil and a detecting coil are wound around two magnetic poles formed so as to have a gap, and a magnetic flux passing through one of the magnetic poles with respect to the other magnetic pole. And a magnetic sensor unit for detecting a change in magnetic flux at the one magnetic pole by the detection coil to identify a magnetic material provided on the detection target, and a magnetic sensor of the detection target. A magnetic head unit for reading a magnetic signal recorded on the material is provided, and the magnetic sensor unit and the magnetic head unit are configured as an integrated magnetic detection device. It can be confirmed that the output value of the sensor unit is a value obtained in a normal clearance state,
The coercive force of the magnetic material can be reliably identified. Further, since the magnetic sensor unit and the magnetic head unit are integrated, the number of times of contact between the detection target and the magnetic head unit can be reduced, and deterioration of jitter and the like can be prevented.

Further, according to the present invention, since the magnetic sensor section and the magnetic head section are housed in one case and form a continuous contact surface with the object to be detected, And the number of times of contact with the magnetic head can be reduced,
Deterioration of jitter and the like can be prevented.

Further, according to the present invention, the magnetic head has a reading gap for reading a magnetic signal recorded on the object to be detected. Since the widths of the read gaps of the magnetic head section are different from each other, a gap width suitable for the purpose can be formed, and appropriate detection suitable for the purpose can be performed.

Further, according to the present invention, at least a part of the magnetic core part forming the two magnetic poles of the magnetic sensor part and the magnetic core part forming the magnetic head part are shared. Therefore, cost can be reduced.

According to the present invention, an exciting coil and a detecting coil are wound around two magnetic poles formed so as to have a gap portion, and a magnetic flux passing through one of the magnetic poles with respect to the other magnetic pole. A magnetic sensor unit for detecting a change in magnetic flux at the one magnetic pole by the detection coil to identify a magnetic material of a magnetic stripe provided on the card, and the magnetic material of the card. The magnetic sensor unit and the magnetic head unit are configured as a magnetic detection device in which the magnetic sensor unit and the magnetic head unit are integrated with each other. It can be confirmed that the output value of the sensor unit is a value obtained in a normal clearance state, and the coercive force of the magnetic material can be reliably identified. Further, since the magnetic sensor unit and the magnetic head unit are integrated, the number of contacts of the card with the magnetic head unit and the like can be reduced, and deterioration of jitter and the like can be prevented.

According to the present invention, the magnetic sensor section and the magnetic head section are housed in a single case and constitute a continuous contact surface with the card. Since the presence or absence of the clearance between the card and the contact surface is detected based on the magnitude of the signal, the output value of the magnetic sensor unit based on the output of the magnetic head unit is a value obtained in a normal clearance state. Can be obtained, and the coercive force of the magnetic material of the card can be reliably identified.

[Brief description of the drawings]

FIGS. 1A and 1B are side views showing an embodiment of a magnetic detection device and a magnetic material identification device using the same according to the present invention.

FIG. 2 is a side view showing another embodiment.

FIG. 3 is a circuit diagram showing an example of a detection circuit connected to a magnetic sensor unit applicable to the present invention.

FIG. 4 is a perspective view showing an example of a head unit and an example of a card of the card identification device according to the present invention.

FIG. 5 is a flowchart showing the operation of the embodiment.

FIG. 6 is a graph showing the relationship between the output of the magnetic sensor and the distance between the magnetic stripe of the card and the magnetic sensor.

FIG. 7 is a graph showing a relationship between each output of a magnetic sensor unit and a magnetic head unit and a distance between a magnetic stripe of a card and a magnetic sensor.

FIG. 8 is a side view showing another embodiment.

FIG. 9 is a perspective view showing an example of a magnetic head unit and an example of a card of a card reader as a magnetic material identification device according to the present invention.

FIG. 10 is a perspective view showing an example of a head unit and an example of a card of the magnetic material identification device according to the present invention.

FIG. 11 is a side view showing still another embodiment of the present invention.

[Description of Signs] 1 Magnetic detection device 2 Magnetic sensor unit 3 Magnetic head unit 4 Air gap 5 Magnetic pole 6 Magnetic pole 7 Connecting part 8 Exciting coil 9 Detection coil 10 Magnetic material 16 Amplifier circuit 17 Detection circuit 18 A / D means 19 CPU 20 Inductive head core 21 magnetic signal reproducing coil 22 reading gap 30 magnetic card 31 case

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 5/187 G11B 5/187 J

Claims (7)

[Claims] 1. A method of manufacturing a semiconductor device, comprising:
An excitation coil and a detection coil are wound around three magnetic poles, and a magnetic flux passing through one of the magnetic poles is provided so as to change with respect to the other magnetic pole, and a change in magnetic flux at the one magnetic pole is detected by the detection coil. A magnetic sensor unit for identifying a magnetic material provided on the detected object, and a magnetic head unit for reading a magnetic signal recorded on the magnetic material of the detected object, the magnetic sensor unit And a magnetic head unit. 2. The magnetic detection device according to claim 1, wherein the magnetic sensor unit and the magnetic head unit are housed in one case and form a continuous contact surface with the object to be detected. 3. The magnetic head section has a reading gap for reading a magnetic signal recorded on the object to be detected, and the width of the gap section of the magnetic sensor section and the reading of the magnetic head section. 2. The magnetic detecting device according to claim 1, wherein the widths of the use gaps are different from each other. 4. The magnetic device according to claim 1, wherein at least a part of a magnetic core part forming two magnetic poles of the magnetic sensor part and a magnetic core part forming the magnetic head part are shared. Detection device. 5. A semiconductor device according to claim 1, wherein said second portion has a gap.
An excitation coil and a detection coil are wound around three magnetic poles, and a magnetic flux passing through one of the magnetic poles is provided so as to change with respect to the other magnetic pole, and a change in magnetic flux at the one magnetic pole is detected by the detection coil. A magnetic sensor unit for identifying a magnetic material provided on the detected object, and a magnetic head unit for reading a magnetic signal recorded on the magnetic material of the detected object, the magnetic sensor unit A magnetic material identification device comprising a magnetic detection device in which a magnetic head unit and a magnetic head unit are integrated. 6. The magnetic material identification apparatus according to claim 5, wherein the object to be detected is a card, and the magnetic material of the magnetic stripe provided on the card is identified. 7. The magnetic sensor unit and the magnetic head unit are housed in one case, and constitute a continuous contact surface with the card. The magnetic sensor unit and the magnetic head unit depend on the magnitude of a magnetic signal from the magnetic head unit. 6. The magnetic material identification device according to claim 5, wherein the presence or absence of a clearance between the card and the contact surface is detected.