JP6672735B2 - Antenna device and communication device - Google Patents

Description

  The present invention relates to an antenna device and a communication device.

  A magnetic coupling type communication method represented by NFC (Near Field Communication) is also adopted for a portable information terminal such as a smartphone or a wearable terminal, and is equipped with an antenna for realizing the function. With such portable information terminals becoming lighter, thinner, smaller and more multifunctional, there is an increasing demand for smaller and thinner antennas to be mounted.

  For example, there is an antenna in which a conductive wire is wound around a magnetic material. If such an antenna is thinned and processed into a curved shape and then mounted on a wristband of an information processing terminal, stress will be applied to the conductor where the coil contacts the corner of the magnetic body, and the coil will be damaged. May be disconnected.

  Therefore, in order to prevent the disconnection of the conductor in the coil, there has been disclosed a magnetic rotation sensor which is covered with a conductive resin while being connected to the lead wire at the start and end of the winding of the conductor and the lead tang (for example, see Patent Reference 1).

  However, in the magnetic rotation sensor as disclosed in Patent Literature 1, disconnection of the coil in the middle of the conductor cannot be prevented.

  The present invention has been made in view of the above, and it is an object of the present invention to provide an antenna device and a communication device that, when a flexible magnetic material is bent, reduce stress applied to a conductive wire due to contact with the magnetic material. Aim.

In order to solve the above-described problems and achieve the object, an antenna device according to the present invention includes a flexible plate-shaped magnetic body, a coil having a conductive wire wound around the magnetic body, and a member having elastic force. And a cushioning member provided between the magnetic body and the coil, and a fixing member that sandwiches the magnetic body, wherein the cushioning member is provided between the fixing member and the magnetic body. The coil is characterized in that the conducting wire is wound around the magnetic body sandwiched between the fixing member and the cushioning material .

  ADVANTAGE OF THE INVENTION According to this invention, when a flexible magnetic body is bent, there exists an effect that the stress applied to a conducting wire by contact with a magnetic body can be eased.

FIG. 1 is a diagram illustrating a structure of an antenna device using a plate-shaped magnetic body. FIG. 2 is an explanatory diagram of a state in which the antenna device using the plate-shaped magnetic body is bent. FIG. 3 is a diagram illustrating the antenna device according to the first embodiment. FIG. 4 is a diagram illustrating the antenna device according to the second embodiment. FIG. 5 is a diagram illustrating an antenna device according to the third embodiment. FIG. 6 is a diagram illustrating the antenna device according to the fourth embodiment. FIG. 7 is a diagram illustrating an antenna device according to a fifth embodiment. FIG. 8 is a diagram illustrating the antenna device according to the sixth embodiment. FIG. 9 is a diagram illustrating an antenna device according to a seventh embodiment.

  Hereinafter, embodiments of an antenna device and a communication device will be described in detail with reference to the accompanying drawings.

(First embodiment)
For example, a type of an antenna device mounted on a portable device or the like includes a loop antenna and a spiral antenna. Among them, the spiral antenna is considered to increase the communication distance.

  In order to form such a thin antenna device using a spiral antenna, it is necessary to make the magnetic material of the core around which the coil is wound thin. However, when the core is made of a ferrite material having ordinary rigidity as a magnetic material, cracks may occur at the time of manufacture or at the time of assembling into a product, and practical use is difficult.

  Therefore, there is known a technique in which a ferrite obtained by dividing ferrite into small pieces each having several mm is sandwiched by a PET resin or the like to use a bar-shaped or plate-shaped magnetic material. In the following embodiments, an antenna device in which a conductive wire is wound around such a magnetic body will be described.

  FIG. 1 is a diagram illustrating a structure of an antenna device using a plate-shaped magnetic body. FIG. 1 shows the antenna device in a three-view drawing, and defines an XYZ coordinate system which is a rectangular coordinate system. FIG. 2 is an explanatory diagram of a state in which the antenna device using the plate-shaped magnetic body is bent.

  The antenna device 100 shown in FIG. 1 is a magnetic coupling type antenna device, and includes a magnetic body 10, an adhesive layer 20, an organic tape 30, and a coil 40 as shown in FIG.

  The magnetic coupling type antenna device 100 is different from a resonance type antenna device which transmits or receives a radio wave by causing resonance with a radio wave of a specific frequency. The communication is performed by coupling to. For this reason, while the communication distance of the resonance type antenna device is several meters to several kilometers or more, the communication distance of the magnetic coupling type antenna device 100 is, for example, about 1 meter or less.

  In other words, the magnetic coupling type antenna device 100 is an antenna device for short-range communication or short-range communication. The antenna device 100 illustrated in FIG. 1 transmits or receives a signal with a frequency of 13.56 MHz, for example.

  The magnetic body 10 is, for example, a plate-shaped sintered ferrite having flexibility. Here, the magnetic body 10 has a plate shape. However, the magnetic body 10 may be arbitrarily determined as a shape according to the size and shape of the space in which the antenna device is mounted and a communication range necessary for the characteristics of the antenna device. it can. The magnetic material 10 is not limited to sintered ferrite, and may be iron, nickel, manganese, zinc, or an alloy thereof as long as it is a so-called ferromagnetic material.

  The coil 40 is formed by winding a conductive wire around the magnetic body 10 along the lateral direction (Y-axis direction) of the magnetic body 10. Both sides of the coil 40 are connected to a communication unit of a device that performs communication using the antenna device 100. Then, the communication unit communicates with the external device.

  As the conductive wire of the coil 40, for example, a copper wire can be used. The number of turns of the conductor of the coil 40 is, for example, about 14 times. The surface of the conductor used as the coil 40 is coated with an enamel.

  Note that the number of turns and the manner of winding of the conductive wire of the coil 40 are merely examples, and may be appropriately set according to the use of the antenna device 100 and the like. In the antenna device 100, a description will be given of a mode in which the conductor of the coil 40 is wound in the short direction of the magnetic body 10. This is because better characteristics are obtained when the coil 40 is wound in the short direction of the magnetic body 10 than when the coil 40 is wound in the long direction of the magnetic body 10.

  That is, a demagnetizing field is generated at both ends (an end on the X-axis positive direction side and an end on the X-axis negative direction side) of the magnetic body 10 by the conductive wire wound in a loop shape in the short direction of the magnetic body 10. . The effect of the demagnetizing field is reduced as the distance between the portion around which the conductor is wound and both ends of the magnetic body 10 is increased. In addition, when the conductor is wound in the longitudinal direction of the magnetic body 10, the cross-sectional area increases as compared with the case where the conductor is wound in the transverse direction, so that the magnetic resistance decreases.

  For this reason, in the antenna device 100, it is preferable that the conductive wire of the coil 40 be wound along the lateral direction of the magnetic body 10, and that the magnetic body 10 be rectangular in plan view.

  The organic tape 30 is a sheet-like fixing member that sandwiches the magnetic body 10 and is adhered to the magnetic body 10 by the adhesive layer 20. The organic tape 30 may be, for example, PET (polyethylene terephthalate) or a resin having heat resistance such as polyimide. The adhesive layer 20 is a layer of an adhesive substance such as an adhesive portion of a cellophane tape. That is, the coil 40 has a conductive wire wound around the magnetic body 10 sandwiched between the organic tapes 30.

  The antenna device 100 configured as described above uses the ferrite having rigidity as the magnetic body 10 as described above. Therefore, as shown in FIG. 2, when a force in the direction of arrow A in FIG. 2 is applied to the antenna device 100, the antenna device bends as shown in the lower diagram of FIG. At this time, in the antenna device 100, the outer peripheral portion of the magnetic body 10 becomes longer than before bending due to the difference between the inner periphery and the outer periphery, and the coil 40 wound therearound is entirely pulled. Then, the pulled coil 40 comes into contact with the corner of the magnetic body 10 and stress is applied to the conductor. An antenna device for avoiding this will be described below.

  FIG. 3 is a diagram illustrating the antenna device according to the first embodiment. As shown in FIG. 3, the antenna device 200 of the present embodiment includes a magnetic body 10, an adhesive layer 20, an organic tape 30, a coil 40, and a cushioning material 50. Here, the magnetic body 10, the adhesive layer 20, the organic tape 30, and the coil 40 are the same as in the antenna device 100 (see FIG. 1).

  The cushioning member 50 is a sheet-like member having an elastic force, and is provided between the magnetic body 10 and the coil 40. In the first embodiment, the cushioning material 50 is provided inside the organic tape 30, that is, between the organic tape 30 and the magnetic body 10. Therefore, the coil 40 has a conductive wire wound around the magnetic body 10 sandwiched between the organic tape 30 and the cushioning material 50.

  As described above, in the first embodiment, since the cushioning member 50 is provided between the organic tape 30 and the magnetic body 10, the pressure generated when the flexible magnetic body 10 is bent is reduced. And the stress applied to the conductor of the coil 40 due to the contact between the coil 40 and the magnetic body 10 can be reduced.

(Second embodiment)
In the antenna device of the first embodiment, the buffer is provided inside the organic tape, but in the present embodiment, the buffer is provided outside the organic tape.

  FIG. 4 is a diagram illustrating the antenna device according to the second embodiment. As shown in FIG. 4, the antenna device 300 of the present embodiment includes a magnetic body 10, an adhesive layer 20, an organic tape 30, a coil 40, and a cushioning material 51. Here, the magnetic body 10, the adhesive layer 20, the organic tape 30, and the coil 40 are the same as in the antenna device 100 (see FIG. 1).

  The cushioning member 51 is a sheet-like member having an elastic force, and is provided between the magnetic body 10 and the coil 40. In the second embodiment, the cushioning material 51 is provided outside the organic tape 30, that is, between the organic tape 30 and the coil 40. Therefore, the coil 40 has a conductive wire wound around the magnetic body 10 sandwiched between the cushioning material 51 and the organic tape 30.

  As described above, in the second embodiment, by providing the cushioning material 51 between the organic tape 30 and the coil 40, the cushioning material 51 can reduce the pressure generated when the flexible magnetic body 10 is bent. The stress applied to the conductor of the coil 40 due to the absorption and the contact between the coil 40 and the magnetic body 10 can be reduced.

(Third embodiment)
In the antenna device of the first embodiment, the cushioning material is provided inside the organic tape. However, in the present embodiment, the cushioning material is formed on the side of the magnetic body 10 (in the X-axis direction and the Z-axis direction). Surface).

  FIG. 5 is a diagram illustrating an antenna device according to the third embodiment. As shown in FIG. 5, the antenna device 400 of the present embodiment includes a magnetic body 10, an adhesive layer 20, an organic tape 30, a coil 40, and a cushioning material 52. Here, the magnetic body 10, the adhesive layer 20, the organic tape 30, and the coil 40 are the same as in the antenna device 100 (see FIG. 1).

  The cushioning member 52 is a sheet-like member having an elastic force, and is provided between the magnetic body 10 and the coil 40. In the third embodiment, the cushioning material 52 is provided on the side surface of the magnetic body 10 that intersects with the surface in contact with the organic tape 30 and that is generated by the X-axis direction and the Z-axis direction. Therefore, the coil 40 has a conductive wire sandwiched between the organic tapes 30 and wound around the magnetic body 10 provided with the cushioning material 52 on the side surface.

  As described above, in the third embodiment, since the cushioning member 52 is provided on the side surface of the magnetic body 10, the cushioning member 52 absorbs the pressure generated when the flexible magnetic body 10 is bent, and The stress applied to the conductive wire of the coil 40 due to the contact between the magnetic material 10 and the magnetic material 10 can be reduced.

(Fourth embodiment)
In the antenna device of the first embodiment, the buffer is provided separately from the organic tape, but in the present embodiment, the organic tape is used as the buffer and is longer than the magnetic material.

  FIG. 6 is a diagram illustrating the antenna device according to the fourth embodiment. As shown in FIG. 6, the antenna device 500 of the present embodiment includes a magnetic body 10, an adhesive layer 20, an organic tape 31, and a coil 40. Here, the magnetic body 10 and the coil 40 are the same as those of the antenna device 100 (see FIG. 1).

  The organic tape 31 is a sheet-like fixing member having elasticity and sandwiching the magnetic body 10, and is adhered to the magnetic body 10 by the adhesive layer 20. The organic tape 31 may be, for example, PET or a resin having heat resistance such as polyimide. That is, the coil 40 is wound around the magnetic body 10 in which the conductive wire is sandwiched by the organic tape 31.

  As shown in FIG. 6, the length of the organic tape 31 in the direction in which the conductor of the coil 40 is wound (Y-axis direction) is longer than the length of the magnetic body 10 in the short direction (Y-axis direction). I have. As a result, two adjacent surfaces of the magnetic body 10, that is, a corner 10 a formed by contact between a surface formed by the Z-axis direction and the X-axis direction and a surface formed by the X-axis direction and the Y-axis direction Is provided so as to cover the organic tape 31.

  As described above, in the fourth embodiment, when the length of the organic tape 31 is longer than that of the magnetic body 10 and the corners 10a of the magnetic body 10 are covered, when the flexible magnetic body 10 is bent, The generated pressure is absorbed by the organic tape 31 serving as a buffer, and the stress applied to the conductor of the coil 40 due to the contact between the coil 40 and the magnetic body 10 can be reduced. Further, the sharp corners 10a of the magnetic body 10 can be protected by an organic tape 31 such as PET.

(Fifth embodiment)
In the antenna device according to the fourth embodiment, the organic tape serving as the buffer is configured to be longer than the magnetic material. However, in the present embodiment, the organic tape is used as the buffer and wraps around the magnetic material.

  FIG. 7 is a diagram illustrating an antenna device according to a fifth embodiment. As shown in FIG. 7, the antenna device 600 of the present embodiment includes the magnetic body 10, the adhesive layer 22, the organic tape 32, and the coil 40. Here, the magnetic body 10 and the coil 40 are the same as those of the antenna device 100 (see FIG. 1).

  The organic tape 32 is a sheet-like fixing member having elasticity and surrounding the magnetic body 10, and is adhered to the magnetic body 10 by the adhesive layer 22. The organic tape 32 may be, for example, PET or a resin having heat resistance such as polyimide. That is, the coil 40 has the conductive wire wound around the magnetic body 10 sandwiched between the organic tapes 32.

  Specifically, as shown in FIG. 7, the organic tape 32 wraps the magnetic body 10 in a direction in which the conductive wire of the coil 40 is wound. As a result, two adjacent surfaces of the magnetic body 10, that is, a corner 10 a formed by contact between a surface formed by the Z-axis direction and the X-axis direction and a surface formed by the X-axis direction and the Y-axis direction To be covered by the organic tape 32.

  As described above, in the fifth embodiment, by covering the magnetic material 10 with the organic tape 32 and covering the corners 10a of the magnetic material 10, the pressure generated when the flexible magnetic material 10 is bent is buffered. The organic tape 32 as a material is absorbed, and the stress applied to the conductive wire of the coil 40 due to the contact between the coil 40 and the magnetic body 10 can be reduced. In addition, the sharp corner 10a of the magnetic body 10 can be protected by covering it with an organic tape 32 such as PET.

(Sixth embodiment)
In the antenna device of the first embodiment, the cushioning material is provided, but in the present embodiment, a gap is provided between the magnetic body and the coil.

  FIG. 8 is a diagram illustrating the antenna device according to the sixth embodiment. As shown in FIG. 8, the antenna device 700 of the present embodiment includes a magnetic body 10, an adhesive layer 20, an organic tape 30, and a coil 41. Here, the magnetic body 10, the adhesive layer 20, and the organic tape 30 are the same as those of the antenna device 100 (see FIG. 1).

  The coil 41 is formed by winding a conducting wire along the short direction (Y-axis direction) of the magnetic body 10 in the longitudinal direction (X-axis direction) of the magnetic body 10. Both sides of the coil 41 are connected to a communication unit of a device that performs communication using the antenna device 700. Then, the communication unit communicates with the external device. The material, the number of windings, the winding method, and the like of the coil 41 are the same as those in the first embodiment.

  Further, the coil 41 of the present embodiment is loosely wound around the magnetic body 10. That is, the air layer 60 is formed by winding the coil 41 around the magnetic body 10 while maintaining a predetermined interval (the interval B in FIG. 8) between the coil 41 and the magnetic body 10.

  As described above, in the sixth embodiment, since the air layer 60 is formed between the magnetic body 10 and the coil 41, the pressure generated when the flexible magnetic body 10 is bent is reduced up to the coil 41. It is difficult to be transmitted. For this reason, it becomes difficult for the coil 41 to contact the magnetic body 10, and the stress applied to the conductor of the coil 41 due to the contact between the coil 41 and the magnetic body 10 can be reduced.

(Seventh embodiment)
In the antenna device according to the sixth embodiment, a gap is provided between the magnetic body and the coil. However, in the present embodiment, the magnetic body is further provided with a groove into which the conductor of the coil enters.

  FIG. 9 is a diagram illustrating an antenna device according to a seventh embodiment. As shown in FIG. 9, the antenna device 800 according to the present embodiment includes a magnetic body 11, an adhesive layer 20, an organic tape 30, and a coil 41. Here, the adhesive layer 20 and the organic tape 30 are the same as those of the antenna device 100 (see FIG. 1). The coil 41 is the same as in the sixth embodiment (see FIG. 8).

  The magnetic body 11 is, for example, a plate-shaped sintered ferrite having flexibility. Here, the magnetic body 11 is plate-shaped, but can be arbitrarily determined as a shape according to the size and shape of the space in which the antenna device is mounted, and according to the communication range necessary for the characteristics of the antenna device. The magnetic material 11 is not limited to sintered ferrite, and may be iron, nickel, manganese, zinc, or an alloy thereof as long as it is a so-called ferromagnetic material.

  Further, the magnetic body 11 is provided with a groove 11a at a position where the conductive wire of the coil 41 is wound on the side surface, the groove portion 11a being deep enough to receive the conductive wire. As a result, the conductor of the coil 41 is inserted into the groove 11a, and the conductor is wound around the magnetic body 11, whereby the position of the conductor relative to the magnetic body 11 is fixed. That is, the intervals between the conductive wires are determined, and the magnetic wires 11 are fixed so that the conductive wires do not shift with respect to the longitudinal direction.

  As described above, in the seventh embodiment, since the air layer 60 is formed between the magnetic body 11 and the coil 41, the pressure generated when the flexible magnetic body 11 is bent is reduced up to the coil 41. It is difficult to be transmitted. For this reason, the coil 41 and the magnetic body 11 are hardly in contact with each other, and the stress applied to the conductive wire of the coil 41 due to the contact between the coil 41 and the magnetic body 11 can be reduced. In addition, since the conducting wire enters the groove 11a provided on the side surface of the magnetic body 11, the tension on the conducting wire can be reduced.

10, 11 Magnetic body 10a Corner 11a Groove 20,22 Adhesive layer 30,31,32 Organic tape 40,41 Coil 50,51,52 Buffer material 60 Air layer 100,200,300,400,500,600,700, 800 Antenna device

JP-A-5-231811

Claims (7)

A plate-shaped magnetic material having flexibility,
A coil having a conductive wire wound around the magnetic body,
A member having elasticity, a cushioning material provided between the magnetic body and the coil,
A fixing member sandwiching the magnetic body,
The cushioning material is provided between the fixing member and the magnetic body,
In the coil, the conductor is wound around the magnetic body sandwiched between the fixing member and the cushioning material.
An antenna device characterized by the above-mentioned . Further comprising a fixing member sandwiching the magnetic body,
The cushioning material is provided between the fixing member and the coil,
The antenna device according to claim 1, wherein the coil is wound around the magnetic body sandwiched between the cushioning material and the fixing member. Further comprising a fixing member sandwiching the magnetic body,
The cushioning material is provided on a side surface of the magnetic body that intersects a surface that contacts the fixing member,
2. The antenna device according to claim 1, wherein the coil has the conductive wire sandwiched by the fixing member and wound around the magnetic body provided with the cushioning material on the side surface. 3.   The cushioning material sandwiches the magnetic body, has a length in a direction in which the conductive wire is wound longer than a length of the magnetic body, and covers a corner formed by contacting two adjacent surfaces of the magnetic body. The antenna device according to claim 1, wherein the antenna device is a fixing member provided on the antenna.   The said buffer material is a fixing member which wraps the said magnetic body in the direction in which the said conductive wire was wound, and was provided so that the two adjacent surfaces of the said magnetic body may contact and may form the corner formed. 2. The antenna device according to 1. A plate-shaped magnetic material having flexibility,
A coil having a conductive wire wound around the magnetic body,
Maintaining a predetermined distance between the magnetic body and the coil ,
The magnetic body has a groove at a position where the conductive wire is wound.
An antenna device characterized by the above-mentioned . An antenna device according to any one of claims 1 to 6 ,
A communication unit connected to the antenna device and communicating with the outside;
A communication device comprising:

Images