JPH11213327A - Magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic head which can detect two different kinds of quantities of magnetism with one head. SOLUTION: C-shaped cores 12 and 13 are arranged so as to face each other interposing a first bar-shaped core 11 between them, and a first gap 14 is provided between one end of the first core 11 and that of the second core 12 on the medium side where a processing medium is placed, and a second gap different in size from the first gap 14 is provided between one end of the first core 11 and that of the third code 13. On the counter medium side, the other end of the first core 11 and the other ends of second and third cores 12 and 13 are joined respectively, and a first detection coil 18 is wound on the first gap 14 side of the second core 12, and a first exciting coil 19 is wound on the junction side to the first core 11, and a second detection coil 20 is wound on the second gap 15 side of the third core 13, and a second exciting coil 21 is wound on the junction side to the first core 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used for processing various kinds of magnetic information, for example, for identifying bills and processing magnetic cards.

[0002]

2. Description of the Related Art For example, in magnetic recording, information is written by magnetizing a recording medium, or information is read out by detecting the magnetization state of the recording medium.
It is applied to various fields such as banknote identification.

The magnetic head used for such magnetic recording generally has a structure in which one magnetic head has one gap. For this reason, the conventional magnetic head has a problem that the number of magnetic heads used is significantly increased. Therefore, a magnetic head having a structure having two gaps for one magnetic head has recently been developed (for example, see Japanese Patent Application Laid-Open No. 7-210811).

[0004]

However, the conventional magnetic head having two gaps can detect only one kind of magnetic quantity since both gaps have the same size, which limits the application. There was a problem that was. Accordingly, an object of the present invention is to provide a magnetic head that can detect two different types of magnetic quantities with one head.

[0005]

According to the present invention, there is provided a magnetic head comprising:
It is characterized by having two different types of gaps on the same head. Further, in the magnetic head of the present invention, the C-shaped second and third cores are arranged with the rod-shaped first core interposed therebetween so that their respective openings are opposed to each other, and the magnetic head is used for processing. On the side of the medium where the medium to be
A first gap is provided between one end of the first core and one end of the second core, and the first gap is provided between one end of the first core and one end of the third core. A second gap having a size different from that of the first core is provided, and the other end of the first core and the other ends of the second and third cores are joined on the opposite side to the medium. Then, a first detection coil is wound around the first gap side of the second core, and a first excitation coil is wound around the joint side with the first core. A second detection coil is wound around the second gap side, and a second excitation coil is wound around the joint side with the first core.

Further, the magnetic head of the present invention has a rod-shaped first
C-shaped second and third cores are disposed with their respective openings facing each other, and the first side is disposed on the medium side where the medium to be processed by the magnetic head is located. A predetermined first gap is provided between one end of the core and one end of the second core, and the first gap is provided between one end of the first core and one end of the third core. A second gap having a different size is provided, and the other end of the first core and the other end of each of the second and third cores are joined on the opposite side of the medium from the medium. , The second
A first detection coil is wound around the core, a second detection coil is wound around the third core, and the first detection coil is wound around the third core.
Characterized in that an exciting coil is wound around the core.

Further, in the magnetic head of the present invention, the C-shaped second and third cores are arranged with the rod-shaped first core interposed therebetween such that their respective openings face each other. A predetermined first gap is provided between one end of the first core and one end of the second core on the medium side where the medium to be processed by the head is located, and one end of the first core is A second gap having a size different from the first gap is provided between one end of the third core and the other end of the first core and the other end on the opposite side to the medium. The other ends of the second and third cores are joined to each other,
A first detection coil is wound around a first gap side of the first core, and a first excitation coil is wound around a joint side with the first core, and a second gap side of the third core is wound. , A second excitation coil is wound on the joint side with the first core, and the first excitation coil and the second excitation coil are connected in series, A bias voltage is supplied from a single bias power supply to a series circuit of the first excitation coil and the second excitation coil.

According to the present invention, by providing two types of gaps on the same head, the difference in the reaching distance of the magnetic flux causes a difference in the magnetic amount of only the front and back of the medium to be processed. Two magnetic quantities can be detected by one magnetic head.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment will be described. FIG. 1 schematically shows a configuration of the magnetic head according to the first embodiment. In FIG. 1, the first and second cores 12 and 13 each formed in a C-shape are respectively opposed to each other with the first core 11 formed in the shape of a square bar therebetween. It is arranged in.
Here, the first, second, and third cores 11, 12, and 13 are:
For example, it is formed of a high-density ferrite material or the like.

Then, on the side of the medium where the medium (a bill or a magnetic recording medium) to be processed by the magnetic head is located, one end 11a of the first core 11 and one end 12a of the second core 12 are arranged.
a first gap 14 is formed between the first core 11 and the first gap 14 between the one end 11a of the first core 11 and the one end 13a of the third core 13. Two gaps 15 are formed. On the other hand, on the opposite side to the medium, the other end 11b of the first core 11 and the other ends 12b,
13b.

The distance L1 between the first gaps 14 is set smaller than the distance L2 between the second gaps 15. The first and second gaps 14 and 15 have gap members 16 made of a non-magnetic material such as glass, respectively.
17 are filled.

A first detection coil 18 is wound around the first gap 14 of the second core 12, and a first excitation coil 19 is wound around the joint with the first core 11. A second detection coil 20 is wound around the third core 13 on the side of the second gap 15, and a second excitation coil 21 is wound on the joint side with the first core 11. Is equipped. Then, the first and second excitation coils 19, 21
Are connected to different AC bias power supplies 22 and 23, respectively.

In such a configuration, by applying a bias voltage to the first and second excitation coils 19 and 21 by separate AC bias power supplies 22 and 23, respectively, the first and second excitation coils 19 and 21 are actuated by electromagnetic induction. 2 detection coils 1
N * dφ / dt, N ′ * dφ ′ / dt for 8, 20
(N, N 'is the number of turns of the detection coil, and φ, φ' are magnetic fluxes flowing through the detection coil). At this time,
The first core 11 serves as a common core for each magnetic path.

In this state, when a medium having magnetic information passes over the first and second gaps 14 and 15, the magnetic flux leaked by the respective gaps 14 and 15 changes due to the magnetic component of the medium. An induced voltage corresponding to the change in the magnetic flux is generated in the first and second detection coils 18 and 20.

FIG. 2 is an example showing the arrival position of a magnetic flux passing through a bill when this magnetic head is mounted on a bill discriminating apparatus. As shown in FIG. 2, in the first gap 14, the interval L1 is set to be sufficiently small with respect to the thickness of the banknote P, so that the magnetic flux φ1 from the first gap 14 becomes smaller. On the front surface, in the other second gap 15, the distance L2 is set to a width approximately equal to the distance to the back surface of the banknote P, so that the magnetic flux φ2 from the second gap 15 reaches the back surface of the banknote P. I do.

Therefore, when the magnetic ink applied portion of the banknote P comes over the magnetic head, the first and second gaps 1
The magnetic fluxes φ1 and φ2 leaked from the paper moneys P4 and P15 change with the magnetic component on the front surface of the banknote P, and the magnetic flux φ1 and φ2 change with both the magnetic component on the back surface of the banknote P. The induced power according to the change is the first and second detection coils 1
Occurs at 8,20.

With such an operation, the magnetic information on the front and back sides of the banknote P can be easily detected by one magnetic head. In addition, the first and second gaps 14,
15 are on the same head, the absolute position of the magnetic information on the front surface and the magnetic information on the back surface of the banknote P can be known, and it is possible to cope with misalignment of printing on the front and back of the banknote P. improves.

Next, a second embodiment will be described. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted. FIG. 3 schematically shows the configuration of the magnetic head according to the second embodiment. In FIG. 3, the first and second cores 12 and 13 are interposed with the first core 11 therebetween.
Are arranged such that their openings face each other. Then, on the medium side, a predetermined first gap 14 is formed between one end 11 a of the first core 11 and one end 12 a of the second core 12, and the first core 11
Between the one end 11a of the third core 13 and the one end 13a of the third core 13, the second gap 1 having a different size from the first gap 14.
5 are formed. On the other hand, on the side opposite to the medium, the other end 11b of the first core 11 and the other ends 12b, 13b of the second and third cores 12, 13 are respectively joined.

The second core 12 has a first detection coil 18
Is wound, and the third core 13 is wound with the second detection coil 20. The first core 11 is common to the first and second detection coils 18 and 20. The exciting coil 24 is wound. Then, the exciting coil 24
Are connected to an AC bias power supply 25.

In such a configuration, the exciting coil 24
In response to this, by applying a bias voltage from the AC bias power supply 25, the first and second
N * dφ / dt, N ′
An induced voltage of * dφ '/ dt is generated. At this time, the first core 11 becomes a common core of each magnetic path.

In this state, when a medium having magnetic information passes over the first and second gaps 14 and 15, the magnetic flux leaked by the respective gaps 14 and 15 changes due to the magnetic component of the medium. An induced voltage corresponding to the change in the magnetic flux is generated in the first and second detection coils 18 and 20.

Next, a third embodiment will be described. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted. FIG. 4 schematically shows the configuration of the magnetic head according to the third embodiment. In FIG. 4, the first and second cores 11 and 12 are interposed with the first and second cores 11 and 12 therebetween.
Are arranged such that their openings face each other. Then, on the medium side, a predetermined first gap 14 is formed between one end 11 a of the first core 11 and one end 12 a of the second core 12, and the first core 11
Between the one end 11a of the third core 13 and the one end 13a of the third core 13, the second gap 1 having a different size from the first gap 14.
5 are formed. On the other hand, on the side opposite to the medium, the other end 11b of the first core 11 and the other ends 12b, 13b of the second and third cores 12, 13 are respectively joined.

A first detecting coil 18 is wound around the first gap 14 of the second core 12, and a first exciting coil 19 is wound around the joining side with the first core 11. A second detection coil 20 is wound around the third core 13 on the side of the second gap 15, and a second excitation coil 21 is wound on the joint side with the first core 11. Is equipped. The first and second excitation coils 19 and 21 are connected in series and connected to a common single AC bias power supply 26.

In such a configuration, an AC bias power supply 25 applies a bias voltage to the first and second excitation coils 19 and 21, thereby causing the first and second detection coils 18 and 21 to be driven by electromagnetic induction. , 20 and N
* Dφ / dt and N ′ * dφ ′ / dt induced voltages are generated. At this time, the first core 11 becomes a common core of each magnetic path.

In this state, when a medium having magnetic information passes over the first and second gaps 14 and 15, the magnetic flux leaked by the respective gaps 14 and 15 changes due to the magnetic component of the medium. An induced voltage corresponding to the change in the magnetic flux is generated in the first and second detection coils 18 and 20.

According to the magnetic head described above,
By providing two different types of gaps on the same head, two types of magnetic information can be detected by one magnetic head. For example, in a bill validator, the accuracy of identification can be improved. In addition, by using a common excitation coil, a magnetic head that is structurally and electrically efficient can be configured.

In the above embodiment, the case where an AC bias power supply is used as the bias power supply has been described. However, the present invention is not limited to this, and a DC bias power supply may be used.

[0028]

As described above in detail, according to the present invention, 1
It is possible to provide a magnetic head that can detect two different types of magnetic quantities with one head.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a configuration of a magnetic head according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a reaching position of a magnetic flux penetrating a bill when the magnetic head is mounted on the bill validator.

FIG. 3 is a configuration diagram schematically showing a configuration of a magnetic head according to a second embodiment of the invention.

FIG. 4 is a configuration diagram schematically showing a configuration of a magnetic head according to a third embodiment of the invention.

[Explanation of symbols]

11 first core, 12 second core, 13 third core, 14 first gap, 15 second gap, 16, 17 gap member, 18 ... first detection coil, 19 ... first excitation coil, 20 ... second
Detection coil, 21... Second excitation coil, 22, 23
... AC bias power supply, 24 ... Excitation coil, 25, 2
6 AC bias power supply.

Claims (5)

[Claims] 1. A magnetic head having two different types of gaps on the same head. 2. A C-shaped second and third cores are disposed so that their respective openings face each other with a rod-shaped first core interposed therebetween. A predetermined first gap is provided between one end of the first core and one end of the second core on one side of the medium, and one end of the first core and one end of the third core are provided. A second gap having a size different from the first gap is provided between the other end of the first core and the second and third cores on the opposite side to the medium from the medium. Respectively, and a first detection coil is wound around the first gap side of the second core, and a first excitation coil is wound around the joining side with the first core. A second detection coil wound around the second gap side of the third core; Magnetic head is characterized in that formed by winding the second exciting coil to the bonding side. 3. A C-shaped second and third cores are arranged with a rod-shaped first core in between so that their respective openings are opposed to each other, and a medium to be processed by the magnetic head is located at the position. A predetermined first gap is provided between one end of the first core and one end of the second core on one side of the medium, and one end of the first core and one end of the third core are provided. A second gap having a size different from the first gap is provided between the other end of the first core and the second and third cores on the opposite side to the medium from the medium. And the other ends of the first core and the second core are wound around a first detection coil, and the third core is wound around a second detection coil, and the first core is wound around the third core. A magnetic head comprising an exciting coil wound around the magnetic head. 4. A C-shaped second and third cores are disposed so that their respective openings face each other with a rod-shaped first core interposed therebetween, and a medium to be processed by the magnetic head is located at the position. A predetermined first gap is provided between one end of the first core and one end of the second core on one side of the medium, and one end of the first core and one end of the third core are provided. A second gap having a size different from the first gap is provided between the other end of the first core and the second and third cores on the opposite side to the medium from the medium. Respectively, and a first detection coil is wound around the first gap side of the second core, and a first excitation coil is wound around the joining side with the first core. A second detection coil wound around the second gap side of the third core; A second exciting coil is wound around the joining side, the first exciting coil and the second exciting coil are connected in series, and a single circuit is connected to a series circuit of the first exciting coil and the second exciting coil. A magnetic head, wherein a bias voltage is supplied from one bias power supply. 5. The method according to claim 2, wherein the interval between the first gaps is smaller than the interval between the second gaps.
5. The magnetic head according to any one of 4.