JP2008310572A - Antenna for radio tag communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna for radio tag communication which is excellent in heat dissipation property and does not occur any radio interference. <P>SOLUTION: This antenna for radio tag communication is provided with a heat dissipation case formed of an electromagnetic wave shielding wall including thermal conductive materials and electromagnetic wave absorbing materials on a second face opposite to a first face on which the antenna main body part of a ground contact material is arranged, and composed to store an electronic circuit board. Heat generated in the electronic circuit board is radiated from the thermal conductive materials and the ground member. Meanwhile, an electromagnetic wave generated in the electronic circuit board is absorbed by the electromagnetic wave absorbing member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an RFID tag communication antenna that transmits and receives signals to and from a wireless tag, and more particularly to an RFID tag communication antenna that uses a ground member for heat dissipation.

  In a wireless tag reader / writer that transmits and receives signals to and from a wireless tag, an electronic circuit board built in the wireless tag reader / writer, particularly a power amplifier, generates heat, and it is necessary to dissipate this heat in order to maintain communication quality.

  As shown in FIG. 6, in the conventional RFID tag reader / writer, the RFID tag communication antenna 300 and the heat radiating structure are separately provided as an electronic circuit heat radiating case 202 and a power supply heat radiating case 203. For this reason, there are problems that the number of parts increases and the size of the wireless tag reader / writer 201 must be increased.

  In this regard, a technique has been proposed in which an electronic circuit board is provided on the surface of the ground member that faces the surface on which the antenna body is provided, and heat generated by the electronic circuit board is radiated from the antenna body (for example, Patent Document 1). ).

Further, a technique has been proposed in which an electronic circuit board is provided on the surface of the grounding member that faces the surface on which the antenna body is provided, and heat generated by the electronic circuit board is radiated from the grounding member (for example, Patent Document 2).
JP 2004-215152 A JP 2005-236586 A

  However, depending on the technique described in Patent Document 1, the shape of the antenna must be configured according to the amount of heat to be radiated, and when the amount of heat generation increases, the size of the antenna must be increased beyond a practical range. There was a problem that it would not be.

  In the technique described in Patent Document 2, the shape of the grounding member must be configured according to the amount of heat to be radiated. When the amount of heat generation increases, the size of the grounding member is increased beyond the practical range. There was a problem that it had to be.

  In any of the techniques, there is a problem that radio waves radiated from the electronic circuit board interfere with radio waves radiated from the antenna body.

  The present invention has been made in view of the above problems, and provides an RFID tag communication antenna that can reduce the size of an RFID tag reader / writer, has excellent heat dissipation, and does not cause radio wave interference. The purpose is to do.

  In order to achieve this object, the present invention provides a base substrate formed by laminating a grounding member made of metal and an electromagnetic wave shielding part layer including a heat conductive material and an electromagnetic wave absorbing material; a grounding member or an electromagnetic wave shielding part There is provided a radio tag communication antenna, comprising: a radio tag and an antenna main body that transmits and receives signals, provided on any surface of a heat conductive material of a layer.

  The present invention also provides a grounding member made of metal; an antenna main body that transmits and receives signals to and from the wireless tag provided on the first surface of the grounding member; and a second that faces the first surface of the grounding member. An antenna for wireless tag communication, comprising: a heat radiating case for accommodating an electronic circuit board, on which an electromagnetic wave shielding wall including a heat conductive material and an electromagnetic wave absorbing material is formed.

  According to the present invention, there is an effect that the number of parts can be reduced and the size of the wireless tag reader / writer can be reduced. The heat generated in the electronic circuit board is dissipated from the heat conductive material and the ground member, and the electromagnetic wave generated in the electronic circuit board is absorbed by the electromagnetic wave absorber. For this reason, it has the effect that it is excellent in heat dissipation and does not cause radio wave interference.

  Hereinafter, an embodiment of an antenna for RFID tag communication according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an outline of the configuration of the RFID tag communication antenna of the present embodiment. FIG. 1A is a perspective view of the RFID tag communication antenna 101 of the present embodiment as viewed from the side of the antenna main body 102 that transmits and receives signals to and from the RFID tag, and FIG. 1B is a diagram in FIG. FIG. 1D is a cross-sectional view taken along the line AA, and FIG. 1D is a perspective view of the RFID tag communication antenna 101 as viewed from the side opposite to FIG.

  As shown in FIGS. 1A, 1B, and 1C, the RFID tag communication antenna 101 of the present embodiment includes a grounding member 110A made of metal, a heat conductive material 110Bh, and an electromagnetic wave absorbing material 110Bs. A signal is transmitted to and received from a wireless tag provided on the surface of either the base substrate 110 formed by stacking the electromagnetic wave shielding part layer 110B including the base member 110 and the heat conductive material 110Bh of the grounding member 110A or the electromagnetic wave shielding part layer 110B. An antenna main body 102. Further, the base substrate 110 may be formed of a ground member and an electromagnetic wave absorber 110Bs.

  The electromagnetic wave shielding portion layer 110B is formed by laminating the heat conductive material 110Bs and the electromagnetic wave absorber 110Bs on the ground member 110A of the base substrate 110 in the order of the electromagnetic wave absorber 110Bs and the heat conductive material 110Bh. In the case of the configuration shown in FIG. 1B, the heat conductive material 110Bh may be deleted. Further, the antenna main body 102 may be stacked in the base substrate 110. That is, although not shown, the ground member 110A, the antenna main body 102, the electromagnetic wave absorber 110Bs, and the heat conductive material 110Bh may be configured in this order. Also in this case, the heat conductive material 110Bh may be deleted.

  FIG. 1C shows another embodiment in which the antenna main body 102 is installed on the surface of the heat conductive material 110Bh of the electromagnetic wave shielding layer 110B.

  In addition, as shown in FIG. 1D, the RFID tag communication antenna 101 includes an electromagnetic wave shielding material including a heat conductive material and an electromagnetic wave absorbing material on a surface of the base substrate 110 facing the surface on which the antenna main body 102 is installed. A heat dissipation case 103 for housing an electronic circuit board including a power amplifier and a signal control circuit, on which walls are formed, can also be provided.

  In this case, the electromagnetic wave shielding layer 110B may not be provided. That is, the base substrate 110 may be composed only of the ground member 110A.

  FIG. 2 is an enlarged view of a cross-sectional view taken along line BB in FIG. As shown in FIG. 2 (a), the RFID tag communication antenna 101 of this embodiment transmits and receives signals to and from the wireless tag provided on the first surface of the grounding member 110A and the grounding member 110A. An electronic circuit board 404 having an electromagnetic shielding wall including a heat conductive material 401A and an electromagnetic wave absorbing material 403 formed on a second surface opposite to the first surface of the antenna main body 102 and the grounding member 110A is accommodated. And a heat radiating case 103 to be configured.

    Here, when the electromagnetic shielding layer 110B is provided on the second surface opposite to the first surface of the grounding member 110A on which the antenna main body 102 is installed, the heat radiating case 103 has the electromagnetic shielding layer 110B of the base substrate 110. It is provided on the side surface. That is, the antenna main body 102, the ground member 110 </ b> A, the electromagnetic wave shielding layer 110 </ b> B, and the heat dissipation case 103 are configured in this order.

  Further, the electric circuit board 404 may be installed on the electromagnetic wave shielding layer 110B without using the heat radiating case 103.

  Further, as shown in FIG. 1C, the antenna main body 102 of the RFID tag communication antenna 101 may be installed on the first surface of the heat conductive material 110Bh of the electromagnetic wave shielding portion layer. In this case, the antenna main body 102, the heat conductive material 110Bh of the electromagnetic wave shielding portion layer 110B, the electromagnetic wave absorbing material 110Bs, the grounding member 110A, and the heat dissipation case 103 are configured in this order, and the surface on which the antenna main body 102 is installed and the electronic circuit board An electromagnetic wave absorbing material 403 is provided between the surface on which 404 is installed.

  The RFID tag communication antenna 101 may be installed in the order of the antenna main body 102, the ground member 110A, and the heat dissipation case 103.

  The heat radiating case 103 is large enough to accommodate an electronic circuit board including a power amplifier and a signal control circuit, and can be configured in a rectangular parallelepiped, for example.

  As shown in FIG. 2A, the electromagnetic wave shielding wall of the heat dissipation case 103 of the RFID tag communication antenna 101 of the present embodiment faces the electronic circuit board 404 (hereinafter, illustration of electronic components is omitted). In other words, the electromagnetic wave absorbing material 403 is provided on the inner side, and the heat conductive material 401A is provided on the side opposite to the side facing the electronic circuit board 404, that is, the outer side.

  In the heat dissipation case 103, the first thermal conductive material 110Bh on which the electronic circuit board 404 is placed, the second thermal conductive material 401A having the electromagnetic wave absorbing material 403 inside, and the electronic circuit board 404 are housed inside. And is locked to the grounding member 110 </ b> A by screws 402.

  The heat generated in the electronic circuit board 404 is transmitted through the first heat conductive material 110Bh and is radiated from the second heat conductive material 401A and the ground member 110A. When the thermal conductivity of the first thermal conductive material 110Bh is higher than the thermal conductivity of the grounding member 110A, the first thermal conductive material 110Bh quickly transfers the heat generated in the electronic circuit board 404 to the second thermal conductivity. It plays a role of transmitting to the property material 401A. Therefore, the first thermal conductive material 110Bh may not be provided when the thermal conductivity of the first thermal conductive material 110Bh is not greater than the thermal conductivity of the ground member 110A.

  On the other hand, electromagnetic waves generated in the electronic circuit board 404 are absorbed by the electromagnetic wave absorbers 403 and 110Bs.

  As shown in FIG. 2A, the electromagnetic wave absorbing material 403 may be provided uniformly inside the second thermal conductive material 401A. Further, as shown in FIG. 2B, the electromagnetic wave absorbing material 403 may be provided inside the second heat conductive material 401A in a mold shape, that is, in a hollow shape.

  The electromagnetic wave absorbing material 403 includes, for example, one or more materials selected from polyurethane impregnated with carbon, ferrite, and expanded polystyrene impregnated with carbon, but is not limited thereto.

  The heat conductive materials 110Bh and 401A include a metal or a synthetic resin, but are not limited thereto. The thermal conductive materials 110Bh and 401A only have to have a thermal conductivity higher than that of air, and examples thereof include copper, aluminum, and known thermal conductive resins.

  FIG. 3 is a diagram showing an application example of the RFID tag communication antenna 101 of the present embodiment. As shown in FIG. 3, in the RFID tag communication antenna 101 of this application example, the ground member 110A has the fins 104 for heat dissipation on the second surface.

  FIG. 4 is a diagram showing another application example of the RFID tag communication antenna 101 of the present embodiment. As shown in FIG. 4, the RFID tag communication antenna 101 of this application example has the heat radiation fins 105 on the side opposite to the side where the heat radiation case 103 houses the electronic circuit board 404, that is, outside the heat radiation case 103. . The RFID tag communication antenna 101 of this application example may have a heat radiation fin 104 on a surface of the ground member 110A or the heat conductive material 110Bh that faces the surface on which the antenna main body 102 is installed.

  FIG. 5 is a diagram showing a wireless tag reader / writer 201 using the wireless tag communication antenna 101 of the present embodiment. As described above, the RFID tag reader / writer 201 using the RFID tag communication antenna 101 according to the present embodiment can reduce the number of components and can be reduced in size.

<Effect of this embodiment>
As described above, the RFID tag communication antenna according to the present embodiment includes an electromagnetic wave including a heat conductive material and an electromagnetic wave absorbing material on the second surface facing the first surface on which the antenna main body of the ground member is provided. A shielding layer is provided, and an electronic circuit board is provided on the surface of the electromagnetic shielding layer facing the grounding member. Alternatively, a heat dissipation case for storing an electronic circuit board, in which an electromagnetic wave shielding wall including a heat conductive material and an electromagnetic wave absorbing material is formed on a second surface opposite to the first surface on which the antenna main body portion of the grounding member is provided. Is provided. For this reason, the number of parts can be reduced and the size of the wireless tag reader / writer can be reduced, and there is an effect that heat radiation is excellent and radio wave interference does not occur.

<Possibility in the embodiment of the present invention>
Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

It is the figure which showed the outline | summary of the structure of the antenna for RFID tag communication of this embodiment. It is an enlarged view of the AA line sectional view of Drawing 1 (b). It is the figure which showed the application example of the antenna for radio | wireless tag communication of this embodiment. It is the figure which showed the other application example of the antenna for RFID tag communication of this embodiment. It is the figure which showed the wireless tag reader / writer using the antenna for wireless tag communication of this embodiment. It is the figure which showed the wireless tag reader / writer using the conventional antenna for wireless tag communication.

Explanation of symbols

101: RFID tag communication antenna,
102: Antenna main body,
103: heat dissipation case,
104, 105: heat dissipation fins 401A, 401B: thermally conductive material,
403: Electromagnetic wave absorber.

Claims (10)

A grounding member formed of metal;
An electromagnetic shielding layer including a thermally conductive material and an electromagnetic wave absorbing material;
A base substrate formed by stacking layers;
An antenna body provided on either surface of the grounding member or the heat conductive material of the electromagnetic wave shielding portion layer, for transmitting and receiving signals to and from the wireless tag;
An antenna for wireless tag communication, comprising:   The base substrate on which the antenna main body is installed is laminated in the order of a grounding member, an electromagnetic wave absorbing member, and a heat conductive material, or a grounding member and an electromagnetic wave absorbing material in this order. Antenna for wireless tag communication. On the surface facing the surface on which the antenna main body of the base substrate is installed,
The antenna for RFID tag communication according to claim 1 or 2, further comprising a heat dissipation case for accommodating an electronic circuit board, on which an electromagnetic wave shielding wall including a heat conductive material and an electromagnetic wave absorbing material is formed. . On the surface facing the surface on which the antenna main body of the base substrate is installed,
The electromagnetic wave shielding part layer is formed and laminated in the order of a heat conductive material, an electromagnetic wave absorbing material, a grounding member, or a grounding member, an electromagnetic wave absorbing material, and a heat conductive material from the side where the electronic circuit board is installed, The antenna for RFID tag communication according to claim 3, further comprising an electromagnetic wave absorbing material between a surface on which the antenna main body is installed and a surface on which the electronic circuit board is installed. A grounding member formed of metal;
An antenna main body for transmitting and receiving signals to and from a wireless tag, provided on the first surface of the ground member;
On the second surface facing the first surface of the grounding member,
A heat dissipation case for storing an electronic circuit board, on which an electromagnetic wave shielding wall including a heat conductive material and an electromagnetic wave absorbing material is formed;
An antenna for wireless tag communication, comprising:   The electromagnetic wave shielding wall has the electromagnetic wave absorbing material on a side facing the electronic circuit board, and has a heat conductive material on a side opposite to the side facing the electronic circuit board. The wireless tag communication antenna according to any one of claims 3 to 5.   7. The RFID tag communication antenna according to claim 3, wherein the heat dissipation case has a heat dissipation fin on a side opposite to a side facing the electronic circuit board. .   The radio according to any one of claims 1 to 7, further comprising a heat dissipation fin on a surface of the grounding member or a heat conductive material facing a surface on which the antenna main body is installed. Antenna for tag communication.   9. The electromagnetic wave absorbing material according to claim 1, wherein the electromagnetic wave absorbing material includes one or more materials selected from polyurethane impregnated with carbon, ferrite, and expanded polystyrene impregnated with carbon. RFID tag communication antenna.   The wireless tag communication antenna according to claim 1, wherein the thermal conductive material includes a metal or a synthetic resin.

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