JP6062013B1 - Magnetic field generator - Google Patents

Abstract

A magnetic field strength of a certain level or more is obtained in most of a closed space, and the boundary of the range can be clarified. A magnetic field generator includes an antenna (first antenna), antennas 12 to 15 (second antenna), and a control device (2) that generates a magnetic field from the first antenna and second antenna (antenna). The second antennas (12 to 15) are arranged along a boundary (for example, a wall) with the outside in the closed space. The second antennas (12 to 15) are arranged so as to sandwich the first antenna (11). [Selection] Figure 1

Description

  The present invention relates to a magnetic field generator that can obtain a magnetic field strength of a certain level or more in a large part of a closed space and can clarify the boundary of the range.

  FIG. 10 shows the range attenuation characteristics of the communication range and the magnetic field strength by the conventional loop antenna.

  A conventional loop antenna is an antenna having a conductive wire in a loop shape, and the distance attenuation characteristic of the magnetic field intensity radiated from the loop antenna is −60 db / dec. For example, communication is performed between a communication device having the loop antenna and a communication device of a partner existing in a range (referred to as a communication range) in which a magnetic field intensity equal to or greater than a certain value TH is obtained.

  When the detection sensitivity of the magnetic field of the counterpart communication device is low, the communication range is narrow, and when it is high, the communication range is widened. In -60db / dec, the fluctuation of this communication range is large. Therefore, even at the same position, it can easily occur that communication can be performed with a communication apparatus of a partner, but communication with another communication apparatus cannot be performed. That is, the communication range becomes unclear.

  On the other hand, the loop antenna described in Patent Document 1 can set the distance attenuation characteristic of the magnetic field strength to -100 db / dec, and can clearly define the boundary of the communication range. However, the boundary position is close to the loop antenna, and the communication range cannot be widened.

  Therefore, with the loop antenna described in Patent Document 1, it is difficult to set most of a closed space such as a room as a communication range.

JP 2013-223117 A

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a magnetic field generator capable of obtaining a magnetic field strength of a certain level or more in a large part of a closed space and clarifying the boundary of the range. To do.

  In order to solve the above-described problems, a magnetic field generator of the present invention includes one or more first antennas that radiate a magnetic field and a distance attenuation of a magnetic field intensity that radiates a magnetic field and is steeper than the distance attenuation characteristic of the magnetic field intensity of the first antenna. A plurality of second antennas having characteristics, wherein the second antenna is disposed along a boundary with the outside in a closed space, and the second antenna is disposed so as to sandwich the first antenna. It is characterized by that.

  For example, the first antenna is a loop-shaped conductor, the second antenna is two loop-shaped conductors, and is opposite to the direction of the current flowing in one loop-shaped conductor of the second antenna. Directional current flows through the other looped conductor of the second antenna.

  For example, the magnetic field radiation device includes a plurality of third antennas that radiate a magnetic field and have a distance attenuation characteristic with a magnetic field strength steeper than a distance attenuation characteristic of the magnetic field strength of the second antenna, and the third antenna includes the first antenna It arrange | positions so that two antennas may be pinched | interposed.

  For example, the first antenna is arranged on a floor surface or a ceiling surface constituting the closed space, and the second antenna is arranged on each wall surface constituting the closed space.

  For example, one first antenna and a plurality of second antennas are arranged on the floor surface constituting the closed space, and another one of the first antennas and another of the plurality of second antennas are closed. It is arranged on the ceiling surface that constitutes the space.

  According to the magnetic field generator of the present invention, a magnetic field strength of a certain level or more can be obtained in most of the closed space, and the boundary of the range can be clarified.

The top view which shows the antenna arrangement | positioning in the magnetic field generator of Example 1, and the distance attenuation | damping characteristic of magnetic field intensity are shown. The structural example of a 2nd antenna is shown. When using a magnetic field generator as a communication apparatus, it is a flowchart of determination when the other communication apparatus starts communication. The top view which shows the antenna arrangement | positioning in the magnetic field generator of Example 2, and the distance attenuation | damping characteristic of magnetic field intensity are shown. The top view which shows the antenna arrangement | positioning in the magnetic field generator of Example 3 is shown. The top view which shows the antenna arrangement | positioning in the magnetic field generator of Example 4, and the distance attenuation | damping characteristic of magnetic field intensity are shown. The top view which shows the antenna arrangement | positioning in the magnetic field generator of Example 5 is shown. The top view which shows the antenna arrangement | positioning in the magnetic field generator of Example 6 is shown. The side view which shows the antenna arrangement | positioning in the magnetic field generator of Example 7, and the distance attenuation | damping characteristic of magnetic field intensity are shown. The range attenuation characteristic of the communication range and magnetic field intensity by the conventional loop antenna is shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Example 1]
FIG. 1 is a top view showing an antenna arrangement in the magnetic field generator of Example 1 and distance attenuation characteristics of magnetic field strength.

  The magnetic field generator includes an antenna 11 (referred to as a first antenna), antennas 12 to 15 (each referred to as a second antenna), and a control device 2 that generates a magnetic field from the first antenna and the second antenna (collectively referred to as an antenna). Including.

  The control device 2 sends a current to the antenna via a signal line (not shown) to generate a magnetic field from the antenna.

  The second antennas (12 to 15) are arranged along a boundary (for example, a wall) with the outside (outside the room) in the closed space (hereinafter, a room is assumed). Further, the second antennas (12 to 15) are arranged so as to sandwich the first antenna (11). For example, the first antenna is arranged near the center of the room, and the second antenna is arranged near the four corners of the room.

  For example, the antenna is arranged on the floor of a room. Thereby, an antenna can be made unnecessary on a ceiling surface or a wall surface.

  The first antenna (11) is a loop-shaped conductor, and the distance attenuation characteristic of the radiated magnetic field strength is, for example, -60 db / dec.

  For example, the room is 3.6 m in the vertical direction and 4.5 m in the horizontal direction in the figure. For example, the diameter of the first antenna is 80 cm, and the diameter of the second antenna is 20 cm.

  FIG. 2 shows a configuration example of the second antenna.

The second antenna is composed of, for example, a plurality of N loop-shaped conductors having the same center arranged in the same plane, and k is an integer of 1 to N, and current flowing through the k-th loop-shaped conductor is determined. when I _k, Mk the number of turns, the radius is r _k, the following condition is satisfied.

FIG. 2 is an example of N = 2. For example, the diameter of each loop-shaped conductor is 1 mm. For example, the outer loop diameter is 20 cm and the inner loop diameter is 13 cm. Since N = 2, the directions of the currents I ₁ and I ₂ are opposite to each other.

  The distance attenuation characteristic of the magnetic field intensity radiated from the second antenna is, for example, -100 db / dec. That is, the second antenna has a distance attenuation characteristic that is steeper than the distance attenuation characteristic of the first antenna.

Returning to FIG. 1, reference numeral B ₁₁ indicates the distance attenuation characteristic of the magnetic field strength of the first antenna (11) along the straight line A. Reference numerals B ₁₂ and B ₁₃ indicate distance attenuation characteristics of the magnetic field strength of the second antenna (12, 13) along the straight line A.

Code _{C 11} is the magnetic field strength of the first antenna (11) indicates the range of greater than or equal to the value TH. The diameter in this range is 3 m, for example. Reference signs C _{12 to} C ₁₅ indicate a range in which the magnetic field strength of the second antenna (12 to 15) is equal to or greater than the value TH. The length of this range in the vertical direction in the figure is, for example, 1 m.

  FIG. 3 is a flowchart of determination when the other communication device starts communication when the magnetic field generator is used as the communication device.

  The communication device converts the magnetic field radiated from the magnetic field generator into a magnetic field strength (S1), and compares the magnetic field strength with a preset threshold TH (S3). If the magnetic field strength is less than the threshold value TH, the process returns to step S1. If the magnetic field strength is greater than or equal to the threshold value TH, communication with the magnetic field generator (communication device) is started (S5), and the determination is completed.

Returning to Figure 1, if, the case without the second antenna (12-15), the range in which the magnetic field strength of the first antenna (11) is equal to or greater than the value TH (communication range of the comparative example), indicated by symbol _{C 11} It is a range. Further, the distance attenuation characteristic of the magnetic field strength that defines the communication range is, for example, -60 db / dec, so the communication range is unclear. ,
Therefore, in the first embodiment, by providing the second antenna (12 to 15), a range of magnetic field strength of the first antenna (11) is equal to or greater than the value TH (the range indicated by reference numeral _{C 11),} a second antenna ( range field strength of 12 to 15) were combined range equal to or larger than the value TH (the range indicated by symbol _C 12 _{-C 15)} (a communication range of example 1) shows the communication range (code _{C 11} of the comparative example Range) becomes wider. That is, a magnetic field strength of a certain level or more can be obtained in most of the room. In other words, the dead space that cannot be communicated in the room can be narrowed.

  Further, for at least a part of the boundary between the communication range and the outside of the first embodiment, the distance attenuation characteristic of the magnetic field strength that defines the boundary portion is based on the second antenna (12 to 15) (for example, -100 db / dec Therefore, the communication range can be clarified.

[Example 2]
FIG. 4 is a top view showing the antenna arrangement in the magnetic field generator of Example 2 and the distance attenuation characteristics of the magnetic field strength.

The difference from the first embodiment is that the number of second antennas is increased. That is, the antennas 12 to 19 are second antennas. Further, symbols C _{12 to} C ₁₉ indicate a range in which the magnetic field strength of the second antenna ( ₁₂ to ₁₉ ) is equal to or higher than the value TH. Reference numerals B ₁₁ , B ₁₅ , and B ₁₆ indicate distance attenuation characteristics of the magnetic field strengths of the antennas ₁₁ , ₁₅ , and ₁₆ along the straight line A.

  According to the second embodiment, the dead space can be narrowed by increasing the number of second antennas.

[Example 3]
FIG. 5 is a top view showing the antenna arrangement in the magnetic field generator of the third embodiment.

  The difference from the first embodiment is that the shape of the room is rectangular and the number of first antennas and second antennas is increased. That is, the antennas 111 and 112 are first antennas, and the antennas 113 to 124 are second antennas.

  According to the third embodiment, by increasing the number of the first antennas in accordance with the shape of the room, a magnetic field strength of a certain level or more can be obtained in most of the room without increasing the number of second antennas.

[Example 4]
FIG. 6 is a top view showing the antenna arrangement in the magnetic field generator of Example 4 and distance attenuation characteristics of the magnetic field strength.

The difference from the second embodiment is that one corner of the room is folded inward and the second antenna at that position is reduced. That is, the antennas 12 to 18 are second antennas. Reference signs C _{12 to} C ₁₈ indicate ranges where the magnetic field strengths of the antennas 12 to 18 are equal to or higher than the value TH. Reference numerals B ₁₂ and B ₁₃ denote distance attenuation characteristics of the magnetic field strength of the antennas 12 and 13 along the straight line A.

  According to the fourth embodiment, by arranging the second antenna in accordance with the shape of the room, a magnetic field strength of a certain level or more can be obtained in most of the room.

[Example 5]
FIG. 7 is a top view showing the antenna arrangement in the magnetic field generator of the fifth embodiment.

  The difference from the first embodiment includes a plurality of third antennas that radiate a magnetic field and have a distance attenuation characteristic with a magnetic field strength that is steeper than a distance attenuation characteristic of the magnetic field strength of the second antenna. It is that it is arrange | positioned so that it may be pinched | interposed.

  The first antenna is the antenna 111, the second antenna is the antennas 112 to 115, and the third antenna is the antennas 116 to 126. The diameter of the third antenna is 1 mm, for example.

  The third antenna has the same configuration as the second antenna shown in FIG. For example, the outer loop diameter is 10 cm and the inner loop diameter is 6.5 cm.

Reference numerals C _{111 to} C ₁₂₆ indicate ranges where the magnetic field strengths of the antennas ₁₁₁ to ₁₂₆ are equal to or higher than the value TH. The diameter of the third antenna (116 to 126) in which the magnetic field strength is greater than or equal to the value TH is, for example, 50 cm.

  According to the fifth embodiment, the dead space can be further narrowed by providing the third antenna.

[Example 6]
FIG. 8 is a top view showing the antenna arrangement in the magnetic field generator of the sixth embodiment.

In Example 6, the first antenna (111) is disposed on the floor surface constituting the room (closed space), and the second antenna (112 to 123) is provided on each wall surface constituting the room (closed space) closed space. It is characterized by being arranged. Reference signs C _{111 to} C ₁₂₃ indicate ranges where the magnetic field strengths of the antennas ₁₁₁ to ₁₂₃ are equal to or higher than the value TH.

  According to the sixth embodiment, by arranging the second antenna on the wall surface, it is possible to prevent the antenna from being concentrated on the floor surface. The first antenna (111) may be arranged on the ceiling surface.

[Example 7]
FIG. 9 shows a side view showing the antenna arrangement in the magnetic field generator of Example 7 and the distance attenuation characteristics of the magnetic field strength.

  In Example 7, one first antenna (11) and a plurality of second antennas (15, 16) are arranged on a floor surface constituting a room (closed space), and another first antenna (12). And a plurality of second antennas (13, 14) arranged on a ceiling surface constituting a room (closed space). Another antenna (17, 18) may be placed on the wall.

Reference numerals C _{11 to} C ₁₈ indicate ranges where the magnetic field strengths of the antennas 11 to ₁₈ are equal to or greater than the value TH. Reference numerals B ₁₁ , B ₁₅ , and B ₁₆ indicate distance attenuation characteristics of the magnetic field strengths of the antennas ₁₁ , ₁₅ , and ₁₆ along the straight line A.

  According to the seventh embodiment, by arranging the first antenna and the second antenna on the floor surface and the ceiling surface, the dead space is prevented from being generated near the floor surface, and the dead space is generated near the ceiling surface. Can be prevented.

  The closed space is not limited to what is called a room, and may be, for example, a space in a warehouse, a space in a gymnasium, a space in a theater, or the like.

11-19, 111-126 Antenna B ₁₁ , B ₁₂ , B ₁₃ , B ₁₅ , B ₁₆ Distance attenuation characteristics of magnetic field strength C ₁₁ -C ₁₉ , C ₁₁₁ -C ₁₂₆ Range in which magnetic field strength is greater than or equal to value TH (communication) range)
2 Control device

Claims (5)

One or more first antennas that radiate a magnetic field and a plurality of second antennas that radiate the magnetic field and have a distance attenuation characteristic with a magnetic field strength steeper than a distance attenuation characteristic of the magnetic field strength of the first antenna;
The second antenna is disposed along a boundary with the outside in a closed space; and
The second antenna is disposed so as to sandwich the first antenna ,
The magnetic field generating apparatus, wherein the first antenna and the second antenna have magnetic field radiation planes arranged on the same plane, and the plurality of second antennas have the same magnetic field strength distance attenuation characteristics . The first antenna is a loop-shaped conductor;
The second antenna is two loop-shaped conductors, and a current in a direction opposite to the direction of the current flowing in one loop-shaped conductor of the second antenna is the other loop-shaped conductor of the second antenna. The magnetic field generator according to claim 1, wherein the magnetic field generator flows through the conductor. A plurality of third antennas that radiate a magnetic field and have a distance attenuation characteristic of a magnetic field intensity steeper than a distance attenuation characteristic of the magnetic field intensity of the second antenna;
The third antenna is disposed so as to sandwich the second antenna ,
3. The magnetic field radiation surfaces of the second antenna and the third antenna are arranged on the same plane, and the distance attenuation characteristics of the magnetic field strengths of the plurality of third antennas are the same. Magnetic field generator. One or more first antennas that radiate a magnetic field and a plurality of second antennas that radiate the magnetic field and have a distance attenuation characteristic with a magnetic field strength steeper than a distance attenuation characteristic of the magnetic field strength of the first antenna;
Emitting surface of the magnetic field of the first antenna is disposed on the floor or ceiling surface constituting the closed space,
The radiation surface of the magnetic field of the second antenna is disposed on each wall surface constituting the closed space ,
Magnetic field generating device you wherein the attenuation characteristics of the magnetic field intensities of a plurality of the second antenna is the same. One of the first antennas and a plurality of the second antennas are disposed on a floor surface that constitutes the closed space,
3. The magnetic field generation device according to claim 1, wherein another one of the first antennas and another plurality of the second antennas are arranged on a ceiling surface forming the closed space.

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