JP2001085926A - Antenna coil and wireless information processing unit using this antenna coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antenna coil where concentration of a magnetic flux is suppressed and flow of an overcurrent to the antenna coil of a wireless information storage medium can be prevented while keeping a communication distance between the wireless information storage medium and a wireless information processing unit constant and to provide the wireless information processing unit using this antenna coil. SOLUTION: The wireless information processing unit 1 has a communication area 1a with a wireless IC card 20 on its upper face. A transmission antenna and a reception antenna are provided inside this communication area 1a. The transmission antenna 7 and the reception antenna 8 can communicate with the wireless IC card 20 when the wireless IC card 20 approaches the communication area 1a. Furthermore, the transmission antenna 70 consisting of the loop shaped antenna coils is formed in a rectangle, and corners 70a on which magnetic flux is concentrated are folded in a direction opposite to an approaching direction of the wireless IC card 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless information processing apparatus capable of reading information from and writing information to a wireless information storage medium wirelessly and in a non-contact manner, and an antenna coil used therefor.

[0002]

2. Description of the Related Art At present, wireless IC cards capable of wirelessly communicating in a non-contact manner from a contact IC card have been actively introduced. Along with this, it is necessary to satisfy many demands such as reliability on wireless IC cards, necessity of high-level printing, necessity of embossing, use in combination with a magnetic stripe, and the like. For this reason, a wide variety of wireless IC cards have been produced by respective systems and manufacturers.

A wireless IC card obtains power and a clock signal necessary for its own operation by a power supply wave transmitted from a reader / writer which is a wireless information processing device. In data communication from the reader / writer to the wireless IC card, data is often superimposed on such a power supply wave, and the receiving circuit of the wireless IC card receives and demodulates this large-level radio wave. Therefore, the antenna of the wireless IC card is generally constituted by a simple loop-shaped antenna coil.

On the other hand, a reader / writer that communicates with a wireless card transmits a power supply wave and demodulates data from a wireless IC card that operates with the power of the power transmission wave. Therefore, the transmission antenna of the reader / writer is also generally constituted by a loop-shaped antenna coil. As such a wireless information processing apparatus, Japanese Patent Application Laid-Open No. 8-139516 discloses a reader / writer having a rectangular transmitting / receiving antenna coil.

[0005]

In the conventional device as described above, since a strong power supply wave is supplied to reliably operate the wireless IC card, when the wireless IC card is brought close to a location where the magnetic flux is strong. In addition, an overcurrent flows through the antenna coil of the wireless IC card, and there is a risk that the wireless IC card may be deformed by heating or the diode may be destroyed. Also, by reducing the current flowing through the transmission antenna of the reader / writer, the influence on the wireless IC card can be avoided, but in this case, the problem that the communication distance is shortened occurs.

The present invention has been made in view of the above points, and an antenna coil capable of suppressing the concentration of magnetic flux and preventing an overcurrent from flowing to an antenna coil of a wireless information storage medium while maintaining a communication distance. It is an object to provide a wireless information processing device using an antenna coil.

[0007]

In order to achieve the above object, an antenna coil according to the present invention is an antenna coil used in a wireless information processing apparatus for writing or reading information to or from a wireless information storage medium wirelessly. The corner portion is formed in a ring shape having at least one corner portion, and the corner portion is formed such that a distance between the corner portion and the wireless information storage medium is larger than a distance between the corner portion and the wireless information storage medium. It is characterized by being formed by deformation.

According to another aspect of the present invention, there is provided a wireless information processing apparatus for writing or reading information to or from a wireless information storage medium wirelessly. A ring formed by deforming the corner portion in a direction in which the distance from the wireless information storage medium at the corner portion is greater than the distance from the wireless information storage medium at the portion other than the corner portion. It has a trust antenna coil.

According to the above-described configuration, the present invention is configured such that the corner portion of the antenna coil formed into a shape having at least one corner portion is deformed in a direction in which the distance from the wireless information storage medium is increased. I have. This has the effect of suppressing concentration of magnetic flux and preventing overcurrent from flowing through the antenna coil of the wireless information storage medium while maintaining the communication distance.

According to another aspect of the present invention, there is provided a wireless information processing apparatus for writing or reading information to or from a wireless information storage medium wirelessly. A transmitting antenna coil formed in a ring shape having: and a wireless information storage medium in a side of the corner portion of the transmitting antenna coil that approaches the wireless information storage medium, and cancels at least a part of a magnetic flux generated in the corner portion. And a canceling member.

With the above-described structure, the present invention provides a canceling member for canceling at least a part of a magnetic flux generated in the above-mentioned corner at a corner of the transmitting antenna coil formed in a shape having at least one corner. Is provided. This has the effect of suppressing concentration of magnetic flux and preventing overcurrent from flowing through the antenna coil of the wireless information storage medium while maintaining the communication distance.

According to another aspect of the present invention, there is provided a wireless information processing apparatus for writing or reading information to or from a wireless information storage medium wirelessly. A distance from the wireless information storage medium in a close portion where a part of the transmit antenna coil is close to a predetermined distance or more, and the wireless information storage medium other than the close portion. The proximity portion is deformed so as to be larger than the distance between

According to the above-described structure, the present invention is formed by deforming a portion of the transmission antenna coil formed in an annular shape in a direction away from the wireless information storage medium so that a portion of the transmission antenna coil which is closer than a predetermined distance is separated. ing. This has the effect of suppressing concentration of magnetic flux generated by coupling between antennas approaching by a predetermined distance or more, and preventing overcurrent from flowing through the antenna coil of the wireless information storage medium while maintaining the communication distance.

According to another aspect of the present invention, there is provided a wireless information processing apparatus for writing or reading information to or from a wireless information storage medium wirelessly. A transmitting antenna coil, and a portion of the transmitting antenna coil is provided on a side where the wireless information storage medium approaches in a proximity portion that is closer than a predetermined distance, and at least a magnetic flux generated in the proximity portion. And a canceling member for canceling a part.

According to the above-described configuration, the present invention provides at least a part of the magnetic flux generated in the proximity portion to a proximity portion where a part of the transmission antenna coil formed in an annular shape is closer than a predetermined distance. A cancel member for canceling is provided. This has the effect of suppressing concentration of magnetic flux generated by coupling between antennas approaching by a predetermined distance or more, and preventing overcurrent from flowing through the antenna coil of the wireless information storage medium while maintaining the communication distance.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 shows a wireless information processing system A using the wireless information processing apparatus 1 according to the present invention.
FIG. As shown in FIG. 2, the wireless information processing system A communicates with the wireless information processing device 1, a host computer 10 connected to the wireless information processing device 1 as a host device, and the wireless information processing device 1. Wireless information storage medium (hereinafter referred to as wireless IC card)
20.

The wireless information processing apparatus 1 has a wireless I
It has a communication area 1a with the C card 20. A transmission antenna 7 and a reception antenna 8 described later are provided inside the communication area 1a. The transmitting antenna 7 and the receiving antenna 8 are provided with the wireless IC card 20 in the communication area 1a.
Is able to communicate with the wireless IC card 20 when the user approaches.

FIGS. 3 and 4 are diagrams for explaining a schematic structure of the wireless IC card 20 used in the wireless information processing system A shown in FIG. As shown in FIGS. 3 and 4, the wireless IC card 20 is mounted on a coil-shaped transmitting / receiving antenna 25 (25 a, 25 b) inside a rectangular card member 26, similarly to a contact IC card, and on the surface of the substrate. And an electronic component 27 connected to the transmitting / receiving antenna 25 (25a, 25b).

FIG. 5 is a diagram for schematically explaining the antenna structure of the wireless information processing apparatus 1. As shown in FIG. As shown in FIG. 5, the wireless information processing apparatus 1 includes a transmission antenna 7 formed in a coil shape, and a transmission antenna 7 inside the transmission antenna 7.
And a receiving antenna 8 formed in a smaller coil shape. The ends of the transmitting antenna 7 and the receiving antenna 8 are connected via a cable 28 to a control circuit 107 described later.

FIG. 6 is a control block diagram of the wireless information processing apparatus 1 and the wireless IC card 20. As shown in FIG.
The wireless information processing apparatus 1 includes an antenna input circuit 101 that receives a modulated wave transmitted from the wireless IC card 20 by the receiving antenna 8 and removes an unnecessary component from the received modulated wave, and an amplification circuit 102 that amplifies received data. A demodulation circuit 103 for demodulating the amplified received data, a modulation circuit 104 for modulating a command or data for transmission to the outside,
An output circuit 105 for amplifying the output for transmitting the modulated data by the transmission antenna 7, a transmission antenna 7 for emitting a modulated wave to an external space, an interface circuit 106 connected to the host computer 10, and these circuits. And a control circuit 107 including a CPU (Central Processing Unit) for controlling.

The wireless IC card 20 includes a transmitting / receiving antenna 25 for receiving a modulated wave transmitted from the wireless information processing apparatus 1 and for emitting a modulated wave to the outside, and for supplying the received modulated wave to an internal circuit. A power generation circuit 201 for generating power, a demodulation circuit 202 for demodulating a modulated wave received by the transmission / reception antenna 25, a modulation circuit 203 for modulating data to be transmitted to the outside, and storing a control program, information to be transmitted / received, and the like. And a control circuit 205 including a CPU (Central Processing Unit) for controlling these circuits.

FIG. 7 is a diagram for explaining the relationship between the conventional transmitting antenna 7 of the wireless information processing apparatus 1 and the wireless IC card 20. As shown in FIG. 7, in the rectangular transmitting antenna 7 composed of the loop-shaped antenna coil, the magnetic flux concentrates particularly at the corners. If you place the wireless IC card close to a strong magnetic flux such as this corner,
An overcurrent flows through the antenna coil of the wireless IC card, and the wireless IC card may be deformed by heating or the diode may be destroyed.

Therefore, in the transmitting antenna 7 of the wireless information processing apparatus 1, a radio IC
FIG. 1 shows a structure of a transmission antenna of the wireless information processing apparatus 1 according to the first embodiment in order to avoid an excessive influence on the card 20. As shown in FIG. 1, the transmitting antenna 70
A loop-shaped (ring-shaped) antenna coil having at least one corner portion, which is formed by bending a corner portion 70a where magnetic flux concentrates in a direction opposite to a direction in which the wireless IC card 20 is approached.

Thus, the corner portion 70a where the magnetic flux is concentrated
Is bent in a direction opposite to the direction in which the wireless IC card 20 is approached, so that when the wireless IC card 20 approaches, the distance between the antenna 70a at the corner and the wireless IC card 20 is changed to another antenna other than the corner. The distance between the portion 70b and the wireless IC card 20 can be increased (the distance can be increased). Therefore, since the distance between the antenna part where the magnetic flux is concentrated and the wireless IC card 20 is long, the wireless IC card 2 due to the concentration of the magnetic flux is
It is possible to reduce the influence on zero.

FIG. 8 is a diagram showing the structure of the transmitting antenna of the wireless information processing apparatus 1 according to the second embodiment. As shown in FIG. 8, the transmitting antenna 71 is a loop-shaped (ring-shaped) rectangular antenna coil having at least one corner portion, and the wireless IC card 20 at the corner portion 71a where the magnetic flux is concentrated.
On the side, a metal shielding plate 81 is provided.

FIG. 9 is a view for explaining a shielding member in the transmitting antenna 71 according to the second embodiment shown in FIG. As shown in FIG. 9, an eddy current is generated in the metal shielding plate 81 provided on the corner portion 71a.
Since extra current is consumed by the eddy current generated in the shielding plate 81, no overcurrent is supplied to the antenna coil of the wireless IC card, and no deformation due to heating occurs.

Thus, the corner portion 71a where the magnetic flux is concentrated
By providing a metal shielding member to the, extra current can be consumed. Therefore, when the wireless IC card 20 approaches the antenna portion where the magnetic flux concentrates, the magnetic flux of the antenna portion is weakened by the shielding member, so that the magnetic flux concentration affects the wireless IC card 20 (the occurrence of overcurrent, Deformation due to heating, etc.) can be reduced.

FIG. 10 is a diagram showing the structure of the transmitting antenna of the wireless information processing apparatus 1 according to the third embodiment. FIG.
As shown in (1), the transmission antenna 72 is a loop-shaped (ring-shaped) rectangular antenna coil having at least one corner portion, and is provided on the wireless IC card 20 side of the corner portion 72a where the magnetic flux concentrates to cancel the magnetic flux. This is provided with a cancel antenna 82 as a member. As described above, by providing the cancel antenna 82 that generates a magnetic flux opposite to the magnetic flux generated at the corner 72a, the magnetic flux at the corner 72a can be weakened, and the concentration of the magnetic flux can be reduced.

As described above, the corner portion 72a where the magnetic flux is concentrated
By providing a cancel antenna that generates a magnetic flux in a direction opposite to the magnetic flux of the transmitting antenna 72, the intensity of the concentrated magnetic flux can be canceled and the magnetic flux can be weakened. Therefore, the wireless IC card 20 is located at the antenna portion where the magnetic flux is concentrated.
Since the magnetic flux in the antenna portion is weakened by the cancel antenna when the vehicle approaches, it is possible to reduce the influence on the wireless IC card 20 due to the concentration of the magnetic flux.

FIG. 11 is a diagram showing the structure of another embodiment of the transmitting antenna of the wireless information processing apparatus 1. FIG.
As shown in (a), the transmission antenna 73 according to the fourth embodiment is formed in a rectangular shape with a loop-shaped antenna coil, and a corner 73a where magnetic flux concentrates is formed by a wireless IC.
The card 20 is bent at 90 degrees in a direction opposite to the direction in which the card 20 approaches. Further, as shown in FIG. 11B, a transmitting antenna 74 according to the fifth embodiment has
The corner portion 74a, which is formed in a rectangular shape by a loop-shaped antenna coil and where magnetic flux is concentrated,
Bend 180 degrees in the direction opposite to the direction in which
The corner portion 74a has a folded configuration.

Thus, the corner portion 73a where the magnetic flux is concentrated
Is bent by 90 degrees to 180 degrees in a direction opposite to the direction in which the wireless IC card 20 is approached, so that when the wireless IC card 20 approaches, the distance between the corner antenna 70a and the wireless IC card 20 is increased. Antenna part 7
0b and the wireless IC card 20. Therefore, the antenna portion where the magnetic flux is concentrated and the wireless IC
Since the distance from the card 20 is long, the influence of the concentration of the magnetic flux on the wireless IC card 20 can be reduced.

As described above, it is possible to suppress the magnetic flux from being concentrated, particularly at the corners of the transmitting antenna of the wireless information processing apparatus, and to prevent the overcurrent from flowing to the antenna coil of the wireless information storage medium such as a wireless IC card. It is possible to reduce the influence on the wireless information storage medium, that is, the destruction of the wireless information storage medium and the deformation due to heating. As a result, the current flowing through the transmitting antenna of the wireless information processing apparatus remains unchanged (that is, the current flowing through the transmitting antenna is not reduced), and the communication is performed without adversely affecting the wireless information storage medium while maintaining the communication distance. This has the effect of being possible.

In this embodiment, a rectangular antenna coil is used as a ring having at least one corner portion, but the present invention is not limited to this. In addition, a rectangular corner portion may be used as a portion where the coils of the transmitting antenna coil are close to each other by a predetermined distance or more and the coil is coupled to each other to affect the approaching wireless IC card. But I am not limited to this. Further, in the present embodiment, the receiving antenna is provided inside the transmitting antenna. However, the present invention is not limited to this.

[0034]

As described above, according to the present invention,
It is possible to suppress the concentration of the magnetic flux and prevent an overcurrent from flowing to the antenna coil of the wireless information storage medium while maintaining the communication distance.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a (transmission) antenna coil of a wireless information processing apparatus 1 according to a first embodiment of the present invention.

FIG. 2 is a diagram schematically illustrating a wireless information processing system A using the wireless information processing apparatus 1;

FIG. 3 is a wireless IC used in a wireless information processing system A;
FIG. 3 is a diagram for explaining a schematic structure of the card 20.

FIG. 4 is a wireless IC used in the wireless information processing system A;
FIG. 3 is a diagram for explaining a schematic structure of the card 20.

FIG. 5 is a diagram schematically illustrating an antenna structure of the wireless information processing apparatus 1;

FIG. 6 is a diagram showing a control block configuration of the wireless information processing apparatus 1 and the wireless IC card 20.

FIG. 7 shows a conventional transmitting antenna 7 of the wireless information processing apparatus 1.
For explaining the relationship between the wireless IC card 20 and the wireless IC card 20. FIG.

FIG. 8 is a diagram showing a structure of a (transmission) antenna used in the wireless information processing apparatus 1 according to a second embodiment;

FIG. 9 is a view for explaining cancellation of magnetic flux by a shielding member in a transmission antenna 71 according to the second embodiment.

FIG. 10 is a diagram showing a structure of an antenna coil (for transmission) used in a wireless information processing apparatus 1 according to a third embodiment;

FIG. 11 is a diagram showing the structure of another embodiment of an antenna coil (for transmission) used in the wireless information processing apparatus 1.

[Explanation of symbols]

 A wireless information processing system 1 wireless information processing device 7, 70, 71, 72, 73, 74 transmitting antenna 8 receiving antenna 10 host computer 20 wireless IC card 25, 25a, 25b transmitting / receiving antenna 26 card member 27 electronic component 28 cable 70a, 71a, 72a, 73a, 74a Corner portion 81 Shielding plate 82 Canceling antenna

Claims (14)

[Claims] An antenna coil for use in a wireless information processing device that wirelessly writes or reads information to or from a wireless information storage medium, wherein the antenna coil is formed in a ring shape having at least one corner portion. An antenna coil formed by deforming the corner so that the distance to the wireless information storage medium is larger than the distance to the wireless information storage medium other than the corner. 2. An antenna coil for use in a wireless information processing device for writing or reading information to or from a wireless information storage medium wirelessly, wherein said antenna coil is formed in a ring shape having at least one corner portion, An antenna coil characterized in that the corner portion is bent in a direction opposite to a direction in which the antenna coil approaches. 3. A wireless information processing apparatus for writing or reading information wirelessly to or from a wireless information storage medium, wherein the wireless information storage medium is formed in a ring shape having at least one corner portion. A wireless information processing apparatus having a transmitting antenna coil formed by deforming the corner so that the distance to the wireless information storage medium other than the corner is larger than the distance to the wireless information storage medium. 4. A wireless information processing apparatus for writing or reading information to or from a wireless information storage medium wirelessly, wherein the wireless information storage medium is formed in a ring shape having at least one corner, and the direction in which the wireless information storage medium approaches. A transmitting antenna coil formed by bending the corner portion in a direction opposite to the direction described above. 5. A corner portion of the transmitting antenna coil,
5. The wireless information processing device according to claim 4, wherein the wireless information processing device is formed to be bent substantially 90 degrees. 6. A wireless information processing apparatus for wirelessly writing or reading information to or from a wireless information storage medium, comprising: a transmitting antenna coil formed in a ring shape having at least one corner portion; A wireless information processing device, comprising: a canceling member provided on the side of the corner portion of the antenna coil at which the wireless information storage medium approaches, for canceling at least a part of magnetic flux generated at the corner portion. . 7. The canceling member according to claim 6, wherein the canceling member comprises a canceling antenna provided to generate a magnetic flux in a direction opposite to a magnetic flux generated in the corner portion of the transmitting antenna coil. Wireless information processing device. 8. The wireless information processing apparatus according to claim 6, wherein said canceling member is made of a metal plate. 9. A wireless information processing apparatus for wirelessly writing or reading information to or from a wireless information storage medium, comprising: a transmission antenna coil formed in a ring shape; The proximity portion is deformed so that the distance to the wireless information storage medium in a proximity portion where the devices are closer to each other by a predetermined distance or more is larger than the distance to the wireless information storage medium in a portion other than the proximity portion. A wireless information processing device. 10. A wireless information processing device for writing or reading information to or from a wireless information storage medium wirelessly, comprising: a transmitting antenna coil formed in a ring shape; A wireless information processing apparatus, wherein a close portion where two or more approach each other by a predetermined distance or more is formed in a direction opposite to a direction in which the wireless information storage medium approaches. 11. The wireless information processing apparatus according to claim 10, wherein a close portion where a part of the transmitting antenna coil is closer than a predetermined distance is formed by bending substantially 90 degrees. . 12. A wireless information processing device for writing or reading information to or from a wireless information storage medium wirelessly, wherein a transmission antenna coil formed in a ring shape and a part of the transmission antenna coil are connected to each other. And a canceling member provided on a side of the proximity portion approaching by a predetermined distance or more, where the wireless information storage medium approaches, and canceling at least a part of magnetic flux generated in the proximity portion. Wireless information processing device. 13. The canceling member according to claim 12, wherein the canceling member comprises a canceling antenna provided so as to generate a magnetic flux in a direction opposite to a magnetic flux generated in the adjacent portion of the transmitting antenna coil. Wireless information processing device. 14. The wireless information processing apparatus according to claim 12, wherein said canceling member is made of a metal plate member.