JP2016225795A - Antenna device and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device which can ensure favorable communication performance and be installed even in an electronic device with a limited installation space.SOLUTION: An antenna device 1 that communicates with an external device via an electromagnetic field signal and is incorporated in an electronic device 30 comprises: a metal plate 3 that faces the external device and is provided in a housing interior 32 of the electronic device; and an antenna coil 12 that is inductively coupled to the external device and is provided such that conductive wires 12a facing one another in the widthwise direction across an opening 12b thereof are wound to be close to one another. Furthermore, the antenna coil is provided along a lateral surface 3a of the metal plate.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an antenna device that is incorporated in an electronic device and communicates with an external device such as a transmitter via an electromagnetic field signal, and an electronic device in which the antenna device is incorporated.

  In an electronic device such as a cellular phone, an antenna module for RFID (Radio Frequency Identification) is used in order to mount a short-range non-contact communication function. This antenna module performs communication using an inductive coupling with an antenna coil mounted on a transmitter such as a reader / writer. That is, in this antenna module, when the antenna coil receives the magnetic field from the reader / writer, the antenna coil can convert it into electric power and drive an IC that functions as a communication processing unit.

  The antenna module needs to receive a magnetic flux of a certain value or more from the reader / writer by the antenna coil in order to reliably communicate. Therefore, in the antenna module according to the conventional example, a loop coil is provided in a housing of a mobile phone or the like, and the coil receives a magnetic flux from the reader / writer. Antenna modules built into electronic devices such as mobile phones have the magnetic flux from the reader / writer rebounded due to the eddy current generated when the metal plate inside the device and the metal plate such as the battery pack receive the magnetic field from the reader / writer. It will be. For example, when considering the surface of a mobile phone case, the magnetic field coming from the reader / writer tends to be strong at the outer peripheral portion of the case surface and weak near the center of the case surface.

  For this reason, in order to increase the communication efficiency of the NFC antenna module used in the electronic device, a method of arranging it at the end of a metal plate such as a substrate or a battery pack inside the device has been developed. As a method of arranging the NFC antenna module at the end of the metal plate, for example, Patent Documents 1 and 2 propose a method of bending a part of a magnetic body to the side, and Patent Document 3 includes a metal plate and An elongated antenna device that is mounted between housings has been proposed.

Japanese Patent No. 4013987 Japanese Patent No. 5472153 JP 2012-217133 A

  However, in the type in which a part of the magnetic material is bent on the side surface, there is a concern that the thickness is added and restrictions on mounting occur. In addition, in the type in which a long and narrow antenna device is mounted in the gap between the metal plate and the housing, the antenna device cannot be mounted if there is not enough space to provide the antenna device between the main metal plate and the housing. There was a problem. In particular, as electronic devices become smaller and more sophisticated, there are many restrictions on the mounting space of the antenna device, so there is a demand for mounting in a narrow space while ensuring good communication performance. is there.

  The present invention has been made in view of the above problems, and a new and improved antenna device that can be mounted while securing good communication performance even in an electronic device in which a mounting space is limited, and An object is to provide electronic equipment.

  One embodiment of the present invention is an antenna device that is incorporated in an electronic device and communicates with an external device via an electromagnetic field signal, and is provided inside the casing of the electronic device, and a metal plate that faces the external device; And an antenna coil that is wound around the opening so as to be close to each other in the width direction and inductively coupled to the external device, and the antenna coil is a side surface of the metal plate. It is provided along.

  According to one embodiment of the present invention, by providing the antenna device along the side surface of the metal plate, good communication performance can be ensured even when mounted in a limited narrow space near the side surface of the metal plate.

  At this time, in one aspect of the present invention, the antenna coil is configured to be provided by winding the conductive wire in a substantially strip shape, and the width thereof may be substantially the same as the thickness of the metal plate. .

  In this way, good communication performance can be ensured even when mounted in a limited narrow space near the side surface of the metal plate.

  In the aspect of the invention, the antenna coil may be configured by winding the conductive wire in a substantially strip shape, and the width thereof may be larger than the thickness of the metal plate.

  In this way, good communication performance can be ensured even when mounted in a limited narrow space near the side surface of the metal plate.

  In one embodiment of the present invention, a magnetic sheet formed of a magnetic material and provided through the opening so as to overlap with a part of the antenna coil may be further provided.

  In this way, since the magnetic flux sent from the external device during communication can be guided to the center side of the antenna coil, the antenna can be mounted in a limited narrow space near the side surface of the metal plate while improving the communication characteristics of the antenna.

  In one embodiment of the present invention, the antenna coil includes a side portion in which the conducting wire circulates in one direction and a other side in which the conducting wire circulates in the other direction via a center line that longitudinally cuts the opening in the longitudinal direction. The magnetic sheet is divided into two sides, and the magnetic sheet overlaps the outer side of the one side, overlaps the inner side of the other side, and the one side is formed of the metal plate. The opening may be provided so as to face the side surface.

  In this way, the distribution of the magnetic field generated by the antenna coil can be further widened, so that the antenna can be mounted in a limited narrow space near the side surface of the metal plate while the communication characteristics of the antenna are improved.

  Another embodiment of the present invention is an electronic device in which any of the antenna devices described above is incorporated and can communicate with an external device via an electromagnetic field signal.

  According to another aspect of the present invention, even when the antenna device is mounted in a limited narrow space, good antenna communication characteristics can be ensured. Therefore, the degree of freedom in designing electronic devices that can ensure good antenna communication characteristics is improved. improves.

  As described above, according to the present invention, by providing the antenna device along the side surface of the metal plate, good communication performance can be ensured even when mounted in a limited narrow space near the side surface of the metal plate.

1 is a perspective view illustrating a schematic configuration of a wireless communication system to which an antenna device according to an embodiment of the present invention is applied. (A) is a perspective view which shows an example of the antenna device which concerns on one Embodiment of this invention, (B) is sectional drawing for demonstrating arrangement | positioning of the antenna device which concerns on one Embodiment of this invention. . (A) is a perspective view which shows an example of the antenna device which concerns on other one Embodiment of this invention, (B) is for demonstrating arrangement | positioning of the antenna device which concerns on other one Embodiment of this invention. It is sectional drawing. (A) is a perspective view which shows an example of the antenna device which concerns on other one Embodiment of this invention, (B) is for demonstrating arrangement | positioning of the antenna device which concerns on other one Embodiment of this invention. It is sectional drawing. (A) is a perspective view which shows schematic structure of the normal antenna apparatus used as the comparative example of the antenna apparatus which concerns on one Embodiment of this invention, (B) is a magnetic field of the antenna apparatus shown to FIG. 5 (A). It is a figure which shows intensity | strength. (A) is a perspective view which shows schematic structure of the Example of the antenna apparatus which concerns on one Embodiment of this invention, (B) is a figure which shows the magnetic field intensity of the antenna apparatus shown to FIG. 6 (A). . (A) is a perspective view which shows schematic structure of the comparative example of the antenna apparatus which concerns on other one Embodiment of this invention, (B) is a figure which shows the magnetic field strength of the antenna apparatus shown to FIG. 7 (A). It is. (A) is a perspective view which shows schematic structure of the Example of the antenna apparatus which concerns on other one Embodiment of this invention, (B) is a figure which shows the magnetic field strength of the antenna apparatus shown to FIG. 8 (A). It is. (A) is a perspective view which shows schematic structure of the Example of the antenna apparatus which concerns on other one Embodiment of this invention, (B) is a figure which shows the magnetic field strength of the antenna apparatus shown to FIG. 9 (A). It is. (A) And (B) is a graph which shows the evaluation result in the evaluation test for confirming the effect | action and effect of the antenna apparatus which concerns on one Embodiment of this invention. (A) And (B) is a graph which shows the evaluation result in the evaluation test for confirming the effect | action and effect of the antenna apparatus which concerns on one Embodiment of this invention. (A) And (B) is a graph which shows the evaluation result in the evaluation test for confirming the effect | action and effect of the antenna apparatus which concerns on one Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are essential as means for solving the present invention. Not necessarily.

  First, a configuration of an antenna device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view illustrating a schematic configuration of a wireless communication system to which an antenna device according to an embodiment of the present invention is applied. FIG. 2A is an example of an antenna device according to an embodiment of the present invention. FIG. 2B is a cross-sectional view for explaining the arrangement of the antenna device according to the embodiment of the present invention.

  The antenna device 1 according to the present embodiment is a device that is incorporated in an electronic device 30 and communicates with an external device via an electromagnetic field signal. For example, the antenna device 1 is incorporated in an RFID wireless communication system 100 as shown in FIG. Used.

  As shown in FIG. 1, the wireless communication system 100 includes an antenna device 1 provided in an electronic device 30 and a reader / writer 40 serving as an external device that accesses the antenna device 1. Here, it is assumed that the antenna device 1 and the reader / writer 40 are arranged to face each other on the XY plane of the three-dimensional orthogonal coordinate system XYZ shown in FIG.

  The reader / writer 40 functions as a transmitter that transmits a magnetic field in the Z-axis direction to the antenna devices 1 that face each other in the XY plane, and specifically, an antenna 41 that transmits a magnetic field toward the antenna device 1 And a control board 42 that communicates with the antenna device 1 that is inductively coupled via the antenna 41.

  That is, the reader / writer 40 is provided with a control board 42 that is electrically connected to the antenna 41. A control circuit 43 made of electronic components such as one or a plurality of integrated circuit chips is mounted on the control board 42. The control circuit 43 executes various processes based on the data received from the antenna device 1.

  For example, when transmitting data to the antenna device 1, the control circuit 43 encodes the data, modulates a carrier wave of a predetermined frequency (for example, 13.56 MHz) based on the encoded data, and modulates the data. The modulated signal is amplified, and the antenna 41 is driven by the amplified modulated signal. In addition, when reading data from the antenna device 1, the control circuit 43 amplifies the modulation signal of the data received by the antenna 41, demodulates the modulation signal of the amplified data, and decodes the demodulated data.

  The control circuit 43 uses an encoding method and a modulation method used in a general reader / writer. For example, a Manchester encoding method or an ASK (Amplitude Shift Keying) modulation method is used. In the following description, the antenna device and the like in the non-contact communication system will be described, but the same can be applied to a non-contact charging system such as Qi (Chi).

  The antenna device 1 is incorporated into a housing 32 of an electronic device 30 such as a mobile phone that is disposed so as to face the reader / writer 40 in the XY plane, for example. In this embodiment, the antenna device includes an antenna module 2 having an antenna substrate 11 (see FIG. 2A) on which an antenna coil 12 capable of communicating with an inductively coupled reader / writer 40 is mounted, and an antenna. A communication processing unit 13 that is driven by a current flowing through the coil 12 and performs communication with the reader / writer 40 and the metal plate 3 are provided.

  The antenna module 2 is provided inside the housing 32 (see FIG. 2A) of the electronic device 30 and communicates with the reader / writer 40 that is inductively coupled. In the present embodiment, as shown in FIG. 1, the antenna module 2 includes an antenna substrate 11, a communication processing unit 13, and a connection unit 14.

  For example, an antenna coil 12 formed by patterning or the like of a flexible conductive wire 12 a such as a flexible flat cable is electrically connected to the antenna substrate 11, and the antenna coil 12 and the communication processing unit 13. A terminal portion 14 is mounted.

  When the antenna coil 12 receives a magnetic field transmitted from the reader / writer 40, the antenna coil 12 is magnetically coupled to the reader / writer 40 by inductive coupling, receives the modulated electromagnetic wave, and performs communication processing of the received signal via the terminal unit 14. It has a function of supplying to the unit 13. In this embodiment, as shown in FIG. 2 (A), the antenna coil 12 has a substantially strip shape elongated in the longitudinal direction, and one conductor 12a of the antenna coil 12 is circulated along the outer shape. The center side is the opening 12b. That is, the antenna coil 12 is provided by being wound so that the conductive wires 12a facing each other in the width direction (X direction shown in FIG. 2A) are close to each other through the opening 12b. The antenna coil 12 is arranged so that the main surface around which the conducting wire 12a circulates opposes the reader / writer 40 in the XY plane shown in FIG. 1 during communication.

  The communication processing unit 13 is driven by a current flowing through the antenna coil 12 and communicates with the reader / writer 40. Specifically, the communication processing unit 13 demodulates the received modulation signal, decodes the demodulated data, and writes the decoded data in the internal memory of the communication processing unit 13. The communication processing unit 13 reads the data to be transmitted to the reader / writer 40 from the internal memory, encodes the read data, modulates the carrier wave based on the encoded data, and is magnetically coupled by inductive coupling. The radio wave modulated through the coil 12 is transmitted to the reader / writer 40. Note that the communication processing unit 13 may be driven not by power flowing through the antenna coil 12 but by power supplied from a power supply unit such as a battery pack or an external power source incorporated in the electronic device.

  The metal plate 3 is provided in the housing 32 of the electronic device 30 and serves as a first conductor facing the reader / writer 40 serving as an external device. The metal plate 3 is provided in a housing of an electronic device such as a mobile phone, a smartphone, or a tablet PC, for example, and constitutes a first conductor that faces the reader / writer 40 during communication of the antenna module 2. As the first conductor, for example, a metal cover affixed to the inner surface of the smartphone casing, a metal casing of a battery pack stored in the smartphone, or the back surface of the liquid crystal module of the tablet PC Corresponds to a metal plate or the like.

  Since the metal plate 3 such as a battery pack flows electricity relatively well, when an AC magnetic field is applied from the outside, an eddy current is generated and the magnetic field is rebounded. Examining the magnetic field distribution when an AC magnetic field is applied from the outside, the magnetic field on the outer edge side of the metal plate 3 facing the reader / writer 40 is strong. For this reason, in this embodiment, the antenna coil 12 of the antenna module 2 is provided on the outer edge side of the metal plate 3 such as a battery pack provided in the housing 32 of the mobile phone 30. As described above, by providing the antenna coil 12 on the outer edge side of the metal plate 3, the electronic device 30 can be reduced in size when incorporated in the electronic device 30 such as a cellular phone, and can be favorably connected to the reader / writer 40. Communication characteristics are realized.

  In the present embodiment, the antenna coil 12 is on the XZ plane of a three-dimensional orthogonal coordinate system XYZ as shown in FIG. 2A, for example, and as shown in FIG. It is disposed between the side surface 3 a of the metal plate 3 such as a battery pack provided inside the body 32 and the inner peripheral wall 32 a of the housing 32, and is provided along the side surface 3 a of the metal plate 3. That is, the antenna coil 12 is provided so that the opening 12b faces the side surface 3a, not the side of the metal plate 3 facing the reader / writer 40.

  Further, in the present embodiment, the antenna coil 12 is provided by winding the conducting wire 12a in a substantially strip shape, and the conducting wire 12a is unidirectionally disposed through a center line L1 that vertically cuts the opening 12b in the longitudinal direction. One side portion 12a1 that circulates and the other side portion 12a2 that circulates in the other direction are divided into two. As shown in FIG. 2B, the width of the antenna coil 12 is substantially the same as the thickness of the metal plate 3. That is, the width of the antenna coil 12 is the same as the thickness of the metal plate 3, or one of them is increased by a slight difference.

  As described above, in this embodiment, the opening 12b is formed in the narrow space between the side surface 3a of the metal plate 3 and the inner peripheral wall 32a of the housing 32 of the electronic device 30. It is mounted along the side surface 3a so as to face the side surface 3a. As a result of intensive studies in order to achieve the above-described object of the present invention, the present inventor has made the antenna coil 12 of the metal plate 3 particularly when the shape of the antenna coil 12 is a substantially strip shape elongated in the longitudinal direction. It has been found that even if the opening 12b is provided on the side surface 3a rather than on the side facing the reader / writer 40, a good communication function can be maintained without deteriorating the communication performance of the antenna device 1. For this reason, in this embodiment, since the antenna coil 12 is provided along the side surface 3a of the metal plate 3, good communication performance is ensured even when mounted in a limited narrow space. It is now possible to meet the demand for thinning.

  Note that the antenna device 1 according to an embodiment of the present invention is not limited to the configuration shown in FIGS. That is, as shown in FIGS. 3A and 3B, the antenna device 101 may have a configuration in which the width of the antenna coil 112 is larger than the thickness of the metal plate 103. In the present embodiment, the one side portion 112a1 of the antenna coil 112 faces the side surface 103a of the metal plate 103, and the other side portion 112b is configured to protrude from the side surface 103a.

  Thus, by making the width of the substantially rectangular antenna coil 112 larger than the thickness of the metal plate 103, the area of the antenna coil 112 can be made larger, so that a large induced electromotive force can be generated by the antenna coil 112. Thus, communication performance can be improved. That is, when the depth of the space between the housing 132 of the electronic device 130 and the side surface 103a of the metal plate 103 can be secured to be equal to or greater than the thickness of the metal plate 103, the width of the antenna coil 112 is set to the metal. By making it larger than the thickness of the plate 103, it is possible to improve the communication performance of the antenna even if it is mounted in a limited narrow space near the side surface 103a of the metal plate 103.

  Further, in order to improve the antenna communication performance, as shown in FIGS. 4A and 4B, the opening 212b of the antenna coil 212 is formed so that the magnetic sheet 220 is overlapped with a part of the antenna coil 212. It may be provided so as to penetrate through. The magnetic sheet 220 is formed of a magnetic material such as iron oxide, chromium oxide, cobalt, or ferrite, and the reader / writer 40 (see FIG. 1) during communication of the antenna module 2 in order to improve the communication characteristics of the antenna module 2 (see FIG. 1). 1), the magnetic flux transmitted from the antenna coil 212 is guided toward the center side.

  In this embodiment, as shown in FIG. 4B, the antenna coil 212 has the magnetic sheet 220 superimposed on the outer side with respect to the one side portion 212a1 and superimposed on the inner side with respect to the other side portion 212a2. As shown, the opening 212b is provided through. The one side portion 212 a 1 is opposed to the side surface 203 a of the metal plate 203, and the other side portion 212 a 2 is arranged outside the magnetic sheet 220. Thus, by providing the magnetic sheet 220 so as to penetrate the opening 212b of the antenna coil 212, the distribution of the magnetic field generated in the antenna coil 212 can be further expanded, so that the vicinity of the side surface 203a of the metal plate 203 is limited. When the antenna device 201 is mounted in a narrow space, the communication characteristics of the antenna can be improved.

  Next, an example of examination and evaluation of the antenna device according to the embodiment of the present invention will be described with reference to the drawings. In addition, this invention is not limited to a present Example.

  First, an example showing a verification result of magnetic field strength based on a change in configuration of an antenna coil of an antenna device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 5A is a perspective view showing a schematic configuration of a normal antenna device as a comparative example of the antenna device according to the embodiment of the present invention, and FIG. 5B is an antenna device shown in FIG. It is a figure which shows the magnetic field intensity of. As an antenna device 501 as a comparative example, when an antenna coil 512 having 50 mm × 50 mm and four turns of a conductive wire is provided on the back side of a metal plate 503 provided in a stainless steel casing 532 of 280 mm × 280 mm × 20 mm, The cross section of the antenna coil 512 was observed for the distribution of the magnetic field strength generated in the antenna coil 512 in a state where 600 mW of power was supplied to the terminal of the antenna device 501. As shown in FIG. 5B, it was found that a strong magnetic field distribution appears around the antenna coil 512 provided on the lower side of the metal plate.

  FIG. 6A is a perspective view showing a schematic configuration of an example of an antenna device 201 according to another embodiment of the present invention described above, and FIG. 6B is an antenna shown in FIG. FIG. 6 is a diagram showing the magnetic field strength of the apparatus 201. As an example of the antenna device 201 according to an embodiment of the present invention, an antenna coil 212 having 50 mm × 25 mm and 4 turns of conductive wire is provided on a side surface 203 a of a metal plate 203 provided in a stainless steel housing 232 of 280 mm × 280 mm × 20 mm. In this case, the cross section of the antenna coil 212 was observed for the distribution of the magnetic field strength generated in the antenna coil 212 in a state where 600 mW of power was supplied to the terminal of the antenna device 201.

  As shown in FIG. 6B, it was found that a strong magnetic field distribution appears widely from the side of the metal plate to the top and bottom of the metal plate. In particular, in the present embodiment, as described above, the antenna coil 212 is arranged such that the magnetic sheet 220 is superimposed on the outer side of the one side portion 212a1 and is superimposed on the inner side of the other side portion 212a2. Since the magnetic field generated by the antenna coil 212 spreads around the outside of the magnetic sheet 220 because the opening 212b is provided, the magnetic field of a certain magnitude or more is spread over a wider range. I found out that

  FIG. 7A is a perspective view showing a schematic configuration of a comparative example of the antenna device 201 according to another embodiment of the present invention described above, and FIG. 7B is an antenna shown in FIG. FIG. 4 is a diagram showing the magnetic field strength of the device 301. In the antenna device 301 as a comparative example, the antenna coil 312 has an opening portion so that the magnetic sheet 320 overlaps with the one side portion 312a1 on the inner side and overlaps with the other side portion 312a2 on the outer side. It is provided through 312b. Further, as an example of the antenna device 301 serving as a comparative example, an antenna coil 312 having 50 mm × 25 mm and 4 turns of a conducting wire is provided on a side surface 303 a of a metal plate 303 provided in a stainless steel housing 532 of 280 mm × 280 mm × 20 mm. In the case, the cross section of the antenna coil 312 was observed with respect to the distribution of the magnetic field strength generated in the antenna coil 312 in a state where 600 mW of power was supplied to the terminal of the antenna device 301.

  As shown in FIG. 7B, a strong magnetic field distribution appears widely from the side surface side of the metal plate to the top and bottom of the metal plate, but the spread of the magnetic field distribution is small compared to the embodiment shown in FIG. I understood that. That is, when the magnetic sheet 320 is provided through the opening 312b of the antenna coil 312 and the one side 312a is provided via the magnetic sheet without directly facing the side surface 303a of the metal plate 303, the magnetic field distribution is reduced. It was found that the spread became smaller. Therefore, when the magnetic sheet 220 is provided so as to penetrate the opening 212b of the antenna coil 212, as shown in FIG. 6B, in the form of the antenna device 201 according to another embodiment of the present invention. It has been found that it is preferable to provide the magnetic sheet 220 through the opening 212a of the antenna coil 212.

  FIG. 8A is a perspective view showing a schematic configuration of an example of the antenna device 1 according to the embodiment of the present invention described above, and FIG. 8B is an antenna device 1 shown in FIG. It is a figure which shows the magnetic field intensity of. As an example of the antenna device 1 according to an embodiment of the present invention, the antenna coil 12 having 30 mm × 5 mm and 4 turns of conductor is provided on the side surface 3 a of the metal plate 3 provided in the aluminum housing 32 of 50 mm × 50 mm × 5 mm. In this case, the cross section of the antenna coil 12 was observed for the distribution of the magnetic field strength generated in the antenna coil 12 in a state where 100 mW of power was supplied to the terminal of the antenna device 1. As shown in FIG. 8B, a strong magnetic field distribution appears from the side surface of the metal plate to the periphery thereof, but it has been found that the spread of the magnetic field distribution is narrower than that in the example shown in FIG.

  FIG. 9A is a perspective view showing a schematic configuration of an example of the antenna device 101 according to another embodiment of the present invention described above, and FIG. 9B is an antenna shown in FIG. 4 is a diagram showing the magnetic field strength of the device 101. FIG. As an example of the antenna device 101 according to another embodiment of the present invention, a side surface 103a of a metal plate 103 provided with an antenna casing 12 of 30 mm × 10 mm and 4 turns of a conductive wire in an aluminum casing 132 of 50 mm × 50 mm × 10 mm. The cross section of the antenna coil 112 was observed for the distribution of the magnetic field strength generated in the antenna coil 112 in a state where 100 mW of power was supplied to the terminal of the antenna device 101. As shown in FIG. 9B, a strong magnetic field distribution appears from the side surface of the metal plate to the periphery thereof, and the spread of the magnetic field distribution becomes larger than that in the embodiment shown in FIG. 8A. It was found that the spread of the magnetic field distribution was narrower than in the examples.

  From the verification results of the magnetic field strength described above, it was found that the better communication performance can be secured because the magnetic field distribution of the example of the antenna device 201 according to another embodiment of the present invention described above is the largest. . That is, in order to ensure better antenna communication performance, when the magnetic sheet 220 is provided through the opening 212b of the antenna coil 212, the magnetic sheet 220 is superimposed on the one side 212a1 on the outer side. Then, the opening 212b is penetrated so as to overlap with the other side portion 212a2 inside, the one side portion 212a1 faces the side surface 203a of the metal plate 203, and the other side portion 212a2 is made of the magnetic sheet 220. It turned out that it is preferable to set it as the structure used as an outer side.

  Next, evaluation results in the action / effect evaluation test in the antenna device according to the embodiment of the present invention will be described with reference to the drawings. FIGS. 10A and 10B, FIGS. 11A and 11B, and FIGS. 12A and 12B are diagrams for confirming the operation and effect of the antenna device according to the embodiment of the present invention. It is a graph which shows the evaluation result in an evaluation test.

  In this example, the coupling coefficient when the reader / writer is moved in a predetermined direction to the example of the antenna device 201 according to the embodiment of the present invention described above and the normal antenna device 501 as a comparative example is simulated. I asked for it. Compared to an example according to an embodiment of the present invention in which the antenna coil 212 is provided on the side surface 203a of the metal plate 203 and a comparative antenna apparatus in which the antenna coil 512 is provided on the back side of the metal plate 503, the metal plate FIGS. 10A and 10B show the results of evaluating the coupling coefficient when a reader / writer having a 4-turn coil having an outer shape of 72 mm × 52 mm is brought closer to a distance of 20 mm from the surface side of 203 and 503. 11A and 11B show the results of evaluating the coupling coefficient when the reader / writer is brought closer to a distance of 20 mm from the side surfaces of the metal plates 203 and 503. Further, FIGS. 12A and 12B show the results of evaluating the coupling coefficient by moving the reader / writer closer to a distance of 20 mm from the back side of the metal plates 203 and 503. FIG. 10 (A), 11 (A), and 12 (A) are shown in FIGS. 10 (B) and 11 (B) when the reader / writer is moved in the X direction (see FIGS. 5 and 6). FIG. 12B shows the evaluation results when the reader / writer is moved in the Y direction (see FIGS. 5 and 6).

  As shown in FIGS. 10A and 10B, in the example of the antenna device 201 according to one embodiment of the present invention, even when the antenna size is half that of the conventional technology, on the surface side of the metal plate 203, It has been found that a coupling coefficient twice as large as that of the comparative example as the prior art is obtained, and better communication characteristics are ensured. That is, by setting the antenna device 201 as the side surface 203 of the metal plate 203, even if the antenna size is reduced, better communication characteristics can be ensured. It was found that good communication performance can be secured even if it is mounted in the narrow space.

  Further, as shown in FIGS. 11A and 11B, in the example of the antenna device 201 according to the embodiment of the present invention, the side surface side of the metal plate 203 even when the antenna size is half that of the conventional technology. Thus, it has been found that a coupling coefficient that is more than double the size of the comparative example, which is the prior art, is obtained, and better communication characteristics are ensured. That is, by setting the antenna device 201 as the side surface 203 of the metal plate 203, even if the antenna size is reduced, better communication characteristics can be ensured. It was found that good communication performance can be secured even if it is mounted in the narrow space.

  On the other hand, as shown in FIGS. 12A and 12B, in the example of the antenna device 201 according to the embodiment of the present invention, the back surface side of the metal plate 203 is compared with the comparative example that is the related art. The coupling coefficient is a low value. However, considering the operability of the electronic device 30 to which the antenna device 201 is attached, the surface side or the side surface side of the metal plate 203 is more suitable as a mounting portion of the antenna device 201. It has been found that the example of the antenna device 201 according to one embodiment of the invention ensures better communication characteristics than the comparative example.

  Although the embodiments and examples of the present invention have been described in detail as described above, it will be understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. It will be easy to understand. Therefore, all such modifications are included in the scope of the present invention.

  For example, a term described with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. Further, the configurations and operations of the antenna device and the electronic apparatus are not limited to those described in the embodiments and examples of the present invention, and various modifications can be made.

DESCRIPTION OF SYMBOLS 1 Antenna apparatus, 2 Antenna module 3, 103, 203, 303 Metal plate (1st conductor), 3a, 103a, 203a, 303a (metal plate) side surface, 11, 111, 211 Antenna substrate, 12, 112 , 212, 312 Antenna coil, 12a, 112a, 212a, 312a Conductor, 12a1, 112a1, 212a1, 312a1 One side, 12a2, 112a2, 212a2, 312a2 The other side, 12b, 112b, 212b, 312b Opening, 13 Communication Processing unit, 14 Terminal unit, 220, 320 Magnetic sheet, 30 Electronic device, 32 Housing, 32a (Inner housing) inner wall, 40 Reader / writer (external device), 41 Antenna, 42 Control board, 43 Control circuit, L1 Center line

Claims (6)

An antenna device incorporated in an electronic device and communicating with an external device via an electromagnetic field signal,
A metal plate provided inside the housing of the electronic device and facing the external device;
An antenna coil that is provided by being wound so that the conductors facing in the width direction through the opening are close to each other and inductively coupled to the external device, and
The antenna coil is an antenna device provided along a side surface of the metal plate.   The antenna device according to claim 1, wherein the antenna coil is configured to be provided by winding the conductive wire in a substantially strip shape, and the width thereof is substantially the same as the thickness of the metal plate.   The antenna device according to claim 1, wherein the antenna coil is configured to be provided by winding the conductive wire in a substantially strip shape, and the width thereof is larger than the thickness of the metal plate.   4. The antenna device according to claim 1, further comprising a magnetic sheet that is formed of a magnetic material and is provided to penetrate through the opening so as to overlap with a part of the antenna coil. The antenna coil is bisected into one side part in which the conducting wire circulates in one direction and the other side part in which the conducting wire circulates in the other direction via a center line that vertically cuts the opening in the longitudinal direction,
The magnetic sheet overlaps on the outer side with respect to the one side portion, overlaps on the inner side with respect to the other side portion, and the one side portion faces the side surface of the metal plate. The antenna device according to claim 4, wherein the antenna device is provided so as to penetrate through the opening.   An electronic device in which the antenna device according to any one of claims 1 to 5 is incorporated and can communicate with an external device via an electromagnetic field signal.