JP4883208B2 - ANTENNA DEVICE AND COMMUNICATION DEVICE HAVING THE SAME - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna device and a communication apparatus equipped with the same which achieves an excellent quality of communication though a communication target such as a noncontact IC card is placed in parallel with a metal body and right above the antenna device or placed perpendicular to the metal body and right beside the antenna device. <P>SOLUTION: The antenna device comprises: an antenna 1 having a coil part 2; and a metal body 6 disposed in proximity to the antenna 1. The coil part 2 of the antenna 1 is disposed on an edge portion of the metal body 6 with an opening perpendicular to the metal body 6 and a longer direction in parallel with the farthest edge of the metal body 6. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an antenna device that performs communication with an RF-ID, that is, a wireless communication medium such as an IC card or an IC tag, and a communication device including the antenna device.

  In recent years, a mobile terminal such as a mobile phone with a built-in RF-ID wireless tag or a non-contact type IC card or a function for reading an IC tag has become widespread. An antenna device in which the coil axis of the antenna is perpendicular to the substrate as in (Patent Document 1) is often used.

Japanese Patent No. 4325621

  However, the structure in which the coil axis is perpendicular to the substrate as in (Patent Document 1) will be described in detail later. For example, a non-contact type IC card is made parallel to the substrate and directly above the antenna device. Information can be read when positioned, but cannot be read when it is perpendicular to the substrate and directly beside the antenna device. That is, when the coil axis is perpendicular to the metal body as the substrate, the magnetic field lines flow in one direction almost directly above the antenna on the loop. As a result, a magnetic field line in one direction acts on the non-contact type IC card, a current is generated in the non-contact type IC card, and the mobile terminal and the non-contact type IC card communicate with each other. However, a magnetic line of force from the antenna side to the outside and a magnetic line of force from the outside to the antenna side are generated almost directly beside the on-loop antenna. Therefore, when a non-contact type IC card is positioned almost perpendicularly to the metal body almost right next to the antenna, magnetic field lines in both directions work against the non-contact type IC card and cancel each other. As a result, no current can be generated in the non-contact type IC card, and the portable terminal and the non-contact type IC card cannot communicate.

  Therefore, in view of the above problems, the present invention includes an antenna device capable of performing good communication even when a communication target such as a non-contact IC card is positioned parallel or perpendicular to a metal body, and the antenna device. An object of the present invention is to provide a communication device.

In order to solve the above-described problems, the present invention is arranged such that an antenna having a core and a coil portion formed by winding a conductor around the core has an outer shape substantially equivalent to the core, and the antenna is in contact with the core. A metal body having an arrangement surface, and the end of the antenna and the end of the metal body are aligned with an opening surface of the coil portion of the antenna being perpendicular to the arrangement surface of the metal body. By disposing the antenna on the inside and outside of the arrangement surface of the metal body within a predetermined distance d from the base point with respect to the position, at least a part of the antenna is on the arrangement surface of the metal body. The antenna device is characterized in that a boundary axis between a magnetic force line in a direction away from the antenna and a magnetic force line in a direction toward the antenna during communication is inclined in a direction away from the metal body.

  According to the present invention, a communication target such as a non-contact type IC card is parallel to the metal body and located almost directly above the antenna device, or perpendicular to the metal body and located almost directly next to the antenna device. Even in this case, it is possible to provide an antenna device that can perform good communication and a communication device including the antenna device.

The conceptual diagram of the antenna in the Example of this invention The conceptual diagram of the antenna apparatus in the Example of this invention The conceptual diagram which shows the magnetic force line which generate | occur | produces from the antenna apparatus shown in FIG. Conceptual diagram of antenna device in conventional example The conceptual diagram of the antenna apparatus in the other Example of this invention. Conceptual diagram showing lines of magnetic force generated from the antenna device shown in FIG. The figure which shows the relationship between the distance D and angle (alpha) of the axis | shaft X of a magnetic field The figure which shows the relationship between the distance d and angle (alpha) of the axis | shaft X of a magnetic field Perspective view when the mobile terminal is disassembled

According to the first aspect of the present invention, there is provided an antenna having a core and a coil part formed by winding a conductor around the core and having an outer shape substantially equivalent to the core, and an arrangement surface on which the antenna is disposed in contact A position where the end of the antenna and the end of the metal body are aligned, with the opening surface of the coil portion of the antenna being perpendicular to the arrangement surface of the metal body. By disposing the antenna inside and outside the arrangement surface of the metal body within a predetermined distance d from the base point as a base point, at least a part of the antenna is an end portion on the arrangement surface of the metal body. An antenna device, wherein the antenna device is disposed in close proximity to and tilts a boundary axis between a magnetic force line in a direction away from the antenna during communication and a magnetic force line in a direction toward the antenna in a direction away from the metal body, and is non-contact Type IC car Even if the object to be communicated is parallel to the metal body and located almost directly above the antenna device, or is perpendicular to the metal body and located almost directly beside the antenna device, it can communicate well. An antenna device that can be provided can be provided.

A second aspect of the present invention is a communication apparatus comprising the antenna according to the first aspect, wherein the metal body is a substrate connected to the antenna, and is a non-contact type IC card or the like. Communication that allows good communication even when the object to be communicated is parallel to the metal body and located almost directly above the antenna device, or perpendicular to the metal body and located almost directly beside the antenna device. An apparatus can be provided. Further, the communication device can be miniaturized by using the substrate as a metal body.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a conceptual diagram of an antenna in an embodiment of the present invention. FIG. 2 is a conceptual diagram of an antenna device according to an embodiment of the present invention.

  The antenna device provides a path through which current flows from the antenna input / output terminal 4 (or 5) to the other antenna input / output terminal 5 (or 4). A surface surrounded by a path including the antenna input / output terminals 4 and 5 is defined as an opening surface of the antenna device. Further, it is defined that the antenna 1 included in the antenna device transmits and receives a signal by a magnetic field generated by a current or a current generated by a magnetic field from the outside. Further, a surface surrounded by the line of the antenna 1 (a cross section of the core 3) is defined as an opening surface of the antenna 1.

  That is, in this embodiment, the antenna device is adjusted so that radio waves of, for example, RFID (13.56 MHz) can be transmitted and received.

  In the present embodiment, the antenna 1 is configured by being inserted together with the core 3 around which the coil portion 2 is wound in the middle of the line constituting the antenna device.

  The coil unit 2 is inserted at a position facing the antenna input / output terminals 4 and 5. Thereby, it can form freely, when connecting the coil part 2 and the antenna input / output terminals 4 and 5, and forming an antenna apparatus. However, the position is not limited to the facing position.

Furthermore, when the coil axis of the coil unit 2 is a, the coil unit 2 is arranged before and after the coil axis a is perpendicular to the opening surface of the antenna device and the coil unit 2 of the line of the antenna 1 is inserted. It is perpendicular to the direction of current flowing in the part (direction C).

In the present embodiment, the coil axis a is perpendicular to the C direction, but may not be parallel.

Moreover, in the present Example, the coil part 2 is arrange | positioned so that it may become perpendicular | vertical to the end surface b of the metal body 6 arrange | positioned at distance D. Although the distance D can be considered from 0 mm to ∞, as will be described later, in any case, the antenna device has good communication performance. In FIG. 2, the distance D is 4 mm.

  In addition, the magnetic material used for the core 3 can be increased because the magnetic flux passing through the coil portion 2 can be increased, and the communication performance is improved when the metal body 6 is in close proximity. It may be composed of In this embodiment, the ferrite core is 8 × 20 × 0.2 mm.

Further, the number of windings of the conductor of the coil portion 2 is about 2.5 turns in this embodiment. The number of conductors wound on the surface of the core 3 facing the metal body (the number of conductors wound on the surface when the conductor is wound around the core 3 on the surface facing the metal body 6 of the core 3). The number of conductors wound around the surface of the core 3 opposite to the surface facing the metal body 6 is smaller.

  By comprising in this way, it can be set as an efficient antenna device with few winding times.

  In FIG. 2, the longitudinal direction of the rectangular parallelepiped core 3 is arranged on the loop of the antenna device, but the short side direction may be arranged, and the coil portion 2 and the coil portion 2 may be arranged in accordance with desired characteristics and mounting space. The shape of the core 3 can be freely selected.

  However, when the short side direction is arranged, it goes without saying that the coil part 2 is wound around the short side direction of the core 3.

  Also, the magnetic field strength increases as the number of turns increases. However, considering the rate of increase, it increases greatly when the number of turns increases from an integer by a half turn.

  However, the number of turns is not limited, and the number of turns may be more or less than about 6.5 turns shown in FIG.

  Note that increasing or decreasing the number of windings by about 0.5 turns from the integral multiple is possible because both ends of the coil unit 2 (connecting portions with the antenna device) can be on both sides with the core 3 interposed therebetween, so that it is inserted into the antenna device. It becomes easy.

  That is, since it can be inserted in such a way as to replace the straight portion of a normal loop antenna, it becomes easier to insert.

  Moreover, about the winding method of the coil part 2, it may be right-handed or left-handed, and can be suitably selected according to the position to arrange | position.

  In addition, the connection between the coil unit 2 and the conductor of the antenna device can be performed by a commonly used connection method such as connection by solder or a connector. Alternatively, the coil unit 2 and the antenna device may be formed of a single connected conductor. The antenna input / output terminals 4 and 5 are connected to the input / output terminals of the matching circuit and IC as is generally known, and the connection method is contact or soldering with pins or springs, connection with a connector, etc. A commonly used connection method can be used.

  Next, the magnetic field generated by the antenna device will be described with reference to FIG. FIG. 3 is a conceptual diagram showing lines of magnetic force generated from the antenna device shown in FIG. FIG. 4 is a conceptual diagram of an antenna device in a conventional example for comparison. FIG. 5 is a conceptual diagram of an antenna device according to another embodiment of the present invention. FIG. 6 is a conceptual diagram showing lines of magnetic force generated from the antenna device shown in FIG. FIG. 7 is a diagram showing the relationship between the distance D and the angle α of the magnetic field axis X, and FIG. 8 is a diagram showing the relationship between the distance d and the angle α of the magnetic field axis X.

  As shown in FIG. 3, the antenna device according to the present embodiment includes an antenna 1 including a coil portion 2 and a metal body 6 disposed close to the antenna 1, and an opening portion of the coil portion 2 of the antenna 1 is It is perpendicular to the metal body 6, and the antenna 1 is arranged at the end of the metal body 6. Note that the end portion of the metal body 6 refers to the case where the end portion of the antenna 1 protrudes from the outermost end portion of the metal body 6 and the end portion of the antenna 1 inside the outermost end portion of the metal body 6. Preferably, the distance d between the end of the antenna 1 described later and the end of the metal body 6 is about -8 mm to +8 mm.

On the other hand, in the conventional antenna device, the opening of the antenna 101 is parallel to the metal plate 6 as shown in FIG. A current flows through the antenna 101 by a signal input to the antenna input / output terminal. In the region A, the magnetic field lines generated from the antenna 101 are one direction away from the antenna. As a result, for example, a non-contact type IC card located in the region A has a unidirectional magnetic force line, a current is generated in the non-contact type IC card, and the portable terminal and the non-contact type IC card communicate with each other. However, in the region B, the magnetic field lines extend in two opposite directions, that is, a direction away from the antenna and a direction toward the antenna, so that they cancel each other. Therefore, when the non-contact type IC card is positioned in the region B, that is, almost right next to the antenna and substantially perpendicular to the metal body 6 , magnetic field lines in both directions act on the non-contact type IC card and cancel each other. As a result, no current can be generated in the non-contact type IC card, and the portable terminal and the non-contact type IC card cannot communicate.

  However, the present application includes the antenna 1 including the coil portion 2 and the metal body 6 disposed in the vicinity of the antenna 1, and the opening of the coil portion 2 of the antenna 1 is perpendicular to the metal body 6. Since the longitudinal direction of the coil portion 2 of the antenna 1 is parallel to the outermost end portion of the metal body 6 and disposed at the end portion, for example, a non-contact type IC card is good not only in the region A but also in the region B. Communication can be performed.

  That is, a current flows through the antenna 1 by a signal input to the antenna input / output terminals 4 and 5. Since the opening of the antenna 1 is perpendicular to the metal body 6, the magnetic field lines generated from the antenna 1 are unidirectional in the direction away from the antenna 1 in the region B. As a result, for example, a non-contact type IC card located in the region B has a magnetic field line in one direction, and a current is generated in the non-contact type IC card. The IC card can communicate with the type IC card.

  Also in the region A, the magnetic field lines are either one of the direction away from the antenna 1 or the direction toward the antenna 1. This is because the magnetic field 8 generated from the antenna 1 attenuates in the vicinity of the metal body 6 so that the axis X of the magnetic field 8 is not perpendicular to the metal body 6 but tilted. The axis X of the magnetic field 8 is a straight line that connects the boundary between the magnetic force lines in the direction away from the antenna 1 and the magnetic force lines in the direction toward the antenna 1. Therefore, for example, when a non-contact type IC card is positioned in the vicinity of the axis X of the magnetic field 8, both the magnetic lines in the direction away from the antenna and the direction toward the antenna as shown in the region B in FIG. . As a result, they cancel each other, and cannot communicate with a portable terminal or the like equipped with the antenna device of the embodiment.

  Next, the reason why the axis X of the magnetic field 8 is inclined with respect to the metal body 6 will be described. That is, an eddy current induced on the surface of the metal body 6 generates a magnetic field in a direction perpendicular to the surface of the metal body 6. Therefore, the magnetic field generated from the antenna 1 and the magnetic field generated from the eddy current induced on the surface of the metal body 6 are combined. As a result, the magnetic field 8 generated from the antenna 1 changes in the vertical direction in the vicinity of the metal body 6. The axis X of the magnetic field 8 is inclined to the side away from the metal body 6.

  Since the antenna 1 is disposed at the end of the metal body 6, the magnetic field on the metal body 6 side (right side in FIG. 3) of the antenna 1 is attenuated, and the side away from the metal body 6 of the antenna 1 (left side in FIG. 3). ) Can be relatively strengthened. As a result, the axis X of the magnetic field 8 can be tilted with respect to the metal body 6. In the configuration of the present embodiment, the angle α of the axis X of the magnetic field 8 is inclined to be about 40 to 85 degrees with respect to the metal body 6. That is, if the antenna 1 is not disposed at the end of the metal body 6, the magnetic field in the direction perpendicular to the surface of the metal body 6 due to the eddy current on the surface of the metal body 6 is small, and the axis X of the magnetic field 8 is It remains almost vertical. In that case, even if communication is possible in region B, communication is not possible in region A.

  Further, as shown in FIG. 7, the distance D between the antenna 1 and the metal body 6 is preferably 0 mm to 8 mm. In FIG. 7, the distance d between the end of the antenna 1 and the end of the metal body 6 is 0 mm. In particular, when the angle is 0 mm to 4 mm, the angle α of the axis X of the magnetic field 8 can be greatly tilted to 55 degrees to 80 degrees. Moreover, even if it is 8 mm-12 mm, it can incline to about 85 degree | times. This is because if the antenna 1 and the metal body 6 are too far apart, the influence of the metal body 6 is reduced, and the force with which the metal body 6 tilts the axis X of the magnetic field 8 is reduced. The communication distance is also affected by the size of the metal body 6, and the longer the metal body 6 is and the longer the side on which the antenna is mounted is, the longer the communication distance is.

3 to 6, the end of the antenna 1 and the end of the metal body 6 are arranged to be aligned, and the distance d between the end of the antenna 1 and the end of the metal body 6 is 0 mm. However, the end of the antenna 1 may protrude beyond the outermost end of the metal body 6 as shown in FIG. In FIG. 8, the distance D between the antenna 1 and the metal body 6 is 4 mm, and the distance d is positive when the end of the antenna 1 protrudes from the outermost end of the metal body 6. By projecting the end of the antenna 1 beyond the end of the metal body 6 , the magnetic field 8 directly above the metal body 6 (region A side) becomes stronger. However, if the end of the antenna 1 protrudes too much than the end of the metal body 6, the force with which the metal body 6 tilts the axis X of the magnetic field 8 is reduced. Therefore, when d = 2 mm, the angle α is the most inclined and is 70 degrees. However, even if it protrudes 8 mm, the angle α can be inclined to 85 degrees.

  Further, the end portion of the antenna 1 may be located inside the outermost end portion of the metal body 6. At this time, the distance d is shown by minus in FIG. If the position of the end portion of the antenna 1 is too much inside the outermost end portion of the metal body 6, the magnetic field 8 on the left side of FIG. 3 (the magnetic field 8 toward the region B) is also attenuated and the entire magnetic field 8 is weakened. Moreover, since the magnetic field is attenuated, the axis X of the magnetic field 8 approaches the metal body 6 perpendicularly. Therefore, when d = 0 mm, the angle α is 78 degrees, and when d = −8 mm, the angle α is 85 degrees.

  From the above, by positioning the antenna 1 at the end of the metal body 6, the current flowing through the metal body 6 can be utilized to the maximum extent. In addition, when the angle α is about 85 degrees, the effect of the present invention can be obtained, and the angle α is preferably 80 degrees or less.

  Next, the results of comparing the communication distances in the directions toward the areas A and B between the antenna device of the present embodiment shown in FIG. 2 and the conventional antenna device shown in FIG. 4 are shown in (Table 1) and (Table 2). I will explain.

In this experiment, in the antenna device of this example shown in FIG. 2, the core 3 is a ferrite core, and the size is 8 × 26 × 0.4 mm. The coil part 2 has 2.5 turns, and the distance D between the metal body 6 and the antenna 1 is 4 mm. In the conventional antenna device shown in FIG. 4, the core 3 is a ferrite core, and the size is 15 × 25 × 0.4 mm. The coil portion 2 has two turns, and the distance D between the metal body 6 and the antenna 1 is 4 mm.

  (Table 1) shows a case where the communication partner of the antenna device shown in FIGS. 2 and 4 is a non-contact type IC card, and (Table 2) shows a case where the communication partner is a reader / writer device.

  As is clear from Table 1 and Table 2, the antenna device of the present embodiment shown in FIG. 2 can perform better communication in the region B than the conventional antenna device shown in FIG. . In addition, it is obvious that good communication can be performed in the area A.

  In FIG. 2, the antenna device and the metal body 6 are arranged with a certain gap. However, when the antenna device and the metal body 6 are arranged in a portable terminal or the like, the gap may not be secured. 6 are arranged close to each other as shown in FIG. FIG. 5 is a conceptual diagram of an antenna device according to another embodiment of the present invention. FIG. 6 is a conceptual diagram showing lines of magnetic force generated from the antenna device shown in FIG. 5 and 6, the distance D between the metal body 6 and the antenna 1 is 0 mm. 2 and 3, the eddy current induced on the surface of the metal body 6 generates a magnetic field opposite to the carrier wave of the antenna 1. Therefore, the magnetic field generated from the antenna 1 and the magnetic field generated from the eddy current induced on the surface of the metal body 6 cancel each other. As a result, the magnetic field 8 generated from the antenna 1 is attenuated in the vicinity of the metal body 6, and the magnetic field 8 on the side relatively away from the metal body 6 (side closer to the region B in FIG. 6) is strengthened. X tilts away from the metal body 6.

  Further, since the antenna 1 is disposed at the end of the metal body 6, the magnetic field on the metal body 6 side (right side in FIG. 6) of the antenna 1 is attenuated, and the side away from the metal body 6 of the antenna 1 (left side in FIG. 6). ) Can be relatively strengthened. As a result, since the axis X of the magnetic field 8 can be tilted with respect to the metal body 6, good communication can be performed regardless of whether the non-contact type IC card is positioned in the area A or the area B, for example.

  The metal body 6 is, for example, a substrate in the portable terminal, but may be another metal body, for example, a battery or a liquid crystal display panel.

  The conductor constituting the antenna device may be formed of a coated copper wire or the like, but may be an electrode pattern formed on the metal body 6 or the like. The coil unit 2 and the magnetic core 3 may also be mounted on the metal body 6. Although not shown, other parts such as a camera module, a speaker, an RF module, and an antenna for other frequencies can be mounted in a vacant space inside the loop of the antenna device.

  Moreover, it can be set as the antenna device which is easy to manufacture because the end surface of the antenna 1 parallel to the opening part of the coil part 2 and the edge part of the metal body 6 are in a straight line.

Further, since the end face of the antenna 1 parallel to the opening of the coil portion 2 protrudes from the end portion of the metal body 6 , the magnetic field 8 directly beside the metal body 6 (region B side) becomes strong.

  Moreover, the angle 1 of the axis X of the magnetic field 8 can be minimized by arranging the antenna 1 and the metal body 6 in contact with each other.

  Moreover, the coil part 2 is arrange | positioned so that it may be located in the edge part of the metal body 6, Thereby, the electric current which flows into the metal body 6 can be utilized to the maximum. Further, since the coil winding direction of the coil portion 2 is parallel to the end portion of the metal body 6, the coil portion 2 can efficiently pick up a large amount of current flowing through the end portion of the metal body 6, and the characteristics of the antenna device Can be improved.

  Next, the case where the antenna device of the present invention is mounted on a portable terminal which is a communication device will be described in detail. FIG. 9 is a perspective view when the portable terminal according to the embodiment of the present invention is disassembled.

  The portable terminal 20 includes a liquid crystal panel 21, operation buttons 22, a casing 25 and a casing 26, a substrate 23 accommodated therein, a battery 24, and the like.

  The metal body 6 described above becomes the substrate 23 in FIG. 9, but metal may be formed on the inner surface of the housing 26 as the metal body (the metal between the housing 26 and the coil portion 2). A film may be provided). In this way, by using the substrate 23 together as the metal body 6, the communication device can be reduced in size.

  The antenna device, the coil part 2, the core 3, and the antenna input / output terminals 4 and 5 of the present invention are formed inside the casing 26. The lines of the antenna device, the antenna input / output terminals 4 and 5 are formed by sheet metal, metal foil tape, printing, or the like, and the coil portion 2 is placed in a predetermined place of the casing 26 by sticking with an adhesive tape or fixing with screws. Install. The connection of the antenna device line and the coil portion 2 is performed by contact connection such as a connector or crimping, or soldering or welding, and the connection between the antenna input / output terminals 4 and 5 and the IC is performed by pin contact or connector connection. For example, soldering of conductive wires can be considered.

  In FIG. 9, the antenna device line is provided on the substrate 23 and the antenna input / output terminals 4 and 5, and the antenna device is formed by being connected to the coil portion 2 provided in the housing 26 by pins. .

  Components such as an RF-ID IC, a matching circuit, an antenna for other frequencies, a camera unit, a speaker, and an RF module are arranged in the space formed between the housing 26 and the substrate 23. These components, the antenna device, and the coil unit are arranged. 2. Good communication is possible regardless of whether the core 3 is in contact with or away from the core 3.

  In addition, since the degree of freedom in forming the antenna device is high as described above, the line of the antenna device formed on the substrate 23 can be arranged avoiding the chips arranged on the substrate 23.

  In this embodiment, it is arranged on a flat part of the casing 26, but it can be arranged along the phase of the casing 26.

  According to the antenna device of the present invention, since the communication characteristics of the antenna can be maintained regardless of the distance between the antenna and the metal body in the casing on which the antenna is mounted, the antenna of various electronic devices such as mobile phones can be maintained. Useful as.

DESCRIPTION OF SYMBOLS 1 Antenna 2 Coil part 3 Core 4, 5 Antenna input / output terminal 6 Metal body 8 Magnetic field 20 Mobile terminal 21 Liquid crystal panel 22 Button 23 Board | substrate 24 Battery 25, 26 Case

Claims (2)

An antenna having an outer shape substantially equivalent to the core having a core and a coil portion formed by winding a conductor around the core;
A metal body having a placement surface on which the antenna is placed in contact ;
The opening surface of the coil portion of the antenna is perpendicular to the arrangement surface of the metal body, and a predetermined distance d from the base point is a position where the end portion of the antenna and the end portion of the metal body are aligned. Within the range, by arranging the antenna inside and outside the arrangement surface of the metal body, at least a part of the antenna is arranged close to an end portion on the arrangement surface of the metal body, and the antenna at the time of communication An antenna device characterized in that a boundary axis between a magnetic force line in a direction away from the magnetic field and a magnetic force line in a direction toward the antenna is inclined in a direction away from the metal body. An antenna according to claim 1,
The communication apparatus, wherein the metal body is a substrate connected to the antenna.

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