JP6388055B2 - Power supply device - Google Patents

Description

  The present invention relates to a communication device and a power feeding device.

  Conventionally, RFID (Radio Frequency Identification) has been used to transmit and receive information by short-range wireless communication.

  An RFID tag used for RFID (hereinafter, “RFID tag” may be abbreviated as “RF tag”. In addition, in the specification and claims, “RF tag” may be referred to as “wireless device”. ) Has individual identification information in an internal memory, and an RFID reader (hereinafter, referred to as “RFID reader” may be abbreviated as “RF reader”) using radio waves or electromagnetic fields. The “RF reader” is sometimes referred to as a “communication device”).

RFID is used in various fields such as article management and security management. Especially in recent years, it has been made possible to display the URL information of the RF tag and the products and services is stored in the RF tag by which the communication between the tablet device as RF reader, products and services to the tablet terminal. When the tablet terminal acquires the URL information, the WEB page of the URL can be opened by the browser automatically or with the user's consent.

  By the way, in recent years, large-sized tablet terminals are sold, and an antenna for communicating with an RF tag is often arranged in a part of the back side of the tablet terminal. Therefore, when communicating with the RF tag, the back surface of the tablet terminal is brought close to the RF tag. However, it is difficult for the user to grasp the positional relationship between the antenna and the RF tag on the back surface of the tablet terminal, and a positional shift occurs. In particular, if the tablet terminal is enlarged, the positional shift between the antenna and the RF tag tends to increase.

  In Patent Document 1, a charging device that receives electric power from a power transmission device and has a charge is provided with four magnetic sensors, and the magnetic flux generated from the power transmission device is detected by these magnetic force sensors to detect the positions of the power transmission device and the charging device. Identifying relationships is disclosed. By displaying an arrow on the display unit of the charging device based on the specified positional relationship, it is possible to prompt the positional relationship between the power transmission device and the charging device to be a positional relationship suitable for charging.

JP 2010-130729 A

  An antenna included in the RF reader generates a magnetic field when a current flows through itself. This magnetic field is detected by a magnetic sensor provided in the RF reader. That is, since the magnetic sensor detects both the magnetic field generated from the RF tag and the magnetic field generated from the RF reader, it is difficult to specify the position of the RF tag with high accuracy based on the detection result.

  Further, even in a system in which power is transmitted from a power feeding device to a power receiving device in a contactless manner (without requiring a physical electrical connection), a magnetic sensor included in the power feeding device is generated from a power feeding element included in the power feeding device. Both the magnetic field and the magnetic field generated from the power receiving element included in the power receiving device are detected based on the magnetic field generated from the power feeding element. Therefore, it is difficult for the power feeding device to specify the position of the power receiving device with high accuracy.

  In view of the above-described problems, a first object of the present invention is to provide a communication device that can detect the position of a wireless device with high accuracy. A second object is to provide a power feeding device that can detect the position of a power receiving element included in the power receiving device with high accuracy.

  In order to achieve the above object, a communication device of the present invention includes a sensor that detects the strength of a magnetic field, an antenna that communicates with a wireless device that generates a magnetic field during communication, and an output signal of the sensor. A notification means for performing a notification regarding a positional deviation between the wireless device and the antenna, and the sensor at a position where a signal indicating the strength of the magnetic field generated from the antenna is suppressed from being included in the output signal of the sensor. It is characterized by having arranged.

  In the communication device having the above-described configuration, the magnetic field generated from the antenna has a first region and a second region in which directions of magnetic fluxes are opposite to each other, and the sensor has a magnetic field strength of the first region. It is desirable that the second region be disposed at a position where the strength of the magnetic field can be detected.

  In the communication apparatus having the above-described configuration, the sensor indicates the strength of the magnetic field generated from the antenna by adding the detected magnetic field strength of the first region and the detected magnetic field strength of the second region. It is desirable that the signal is suppressed from being included in the output signal of the sensor.

  In the communication apparatus having the above configuration, when the strength of the magnetic field in the first region is different from the strength of the magnetic field in the second region, the strength of the magnetic field is higher than the detection of the strength of the magnetic field in the region where the magnetic field strength is weak. It is desirable to arrange the magnetic sensor at a position where the detection of the magnetic field strength in a strong region is suppressed.

  In the communication device having the above configuration, the sensor is preferably a pickup coil.

  In the communication device having the above-described configuration, the notifying unit may calculate a one-dimensional or two-dimensional displacement direction of the wireless device with respect to the antenna based on an output signal of the sensor, and notify the direction of the wireless device. desirable.

  Further, in the communication device having the above configuration, the notification means indicates that no positional deviation has occurred when the positional deviation between the wireless device and the antenna is equal to or less than a predetermined threshold based on the output signal of the sensor. It is desirable to do.

  In order to achieve the above object, a power feeding device of the present invention includes a sensor for detecting the strength of a magnetic field, a power feeding element for transmitting power in a non-contact manner with a power receiving element of the power receiving device, and an output signal of the sensor. And a notification means for notifying a positional deviation between the power feeding element and the power receiving element, and a signal indicating the strength of the magnetic field generated from the power feeding element is suppressed from being included in the output signal of the sensor. It is characterized in that the sensor is arranged at a certain position.

  In the power supply device having the above-described configuration, the magnetic field generated from the power supply element has a first region and a second region in which the directions of magnetic fluxes are opposite to each other, and the sensor has a strong magnetic field in the first region. And the magnetic field strength of the second region are desirably arranged at positions where they can be detected.

  In the power feeding device having the above-described configuration, the sensor adds the detected magnetic field strength of the first region and the detected magnetic field strength of the second region, thereby obtaining the strength of the magnetic field generated from the power feeding element. It is desirable to suppress the signal to be included in the output signal of the sensor.

  In the power supply apparatus having the above configuration, when the strength of the magnetic field in the first region is different from the strength of the magnetic field in the second region, the strength of the magnetic field is higher than that in the detection of the magnetic field strength in the region where the magnetic field strength is weak. It is desirable to arrange the magnetic sensor at a position where the detection of the magnetic field strength in a strong region is suppressed.

  In the power supply apparatus having the above-described configuration, the sensor is preferably a pickup coil.

  Further, in the power supply apparatus having the above configuration, the notifying unit calculates a one-dimensional or two-dimensional positional shift direction of the power receiving element with respect to the power feeding element based on an output signal of the sensor, and notifies the direction of the power receiving element. Is desirable.

  Further, in the power supply apparatus having the above configuration, the notifying unit indicates that no positional deviation has occurred when the positional deviation between the power receiving element and the power feeding element is equal to or less than a predetermined threshold based on the output signal of the sensor. Notification is desirable.

  According to the present invention, since the sensor is disposed at a position where the output signal of the sensor for detecting the strength of the magnetic field is prevented from including a signal indicating the strength of the magnetic field generated from the antenna, the output signal of the sensor Consists mainly of a signal indicating the strength of a magnetic field generated from a wireless device communicating with the device itself. And the position of a radio | wireless apparatus can be detected with high precision based on the output signal of a sensor, and the notification regarding the position shift of a radio | wireless apparatus and an antenna can be performed.

  Further, since the sensor is arranged at a position where the output signal of the sensor for detecting the strength of the magnetic field is prevented from including a signal indicating the strength of the magnetic field generated from the power feeding element, the output signal of the sensor is mainly It consists of a signal indicating the strength of a magnetic field generated from a power receiving element provided in a power receiving device that transmits power in a non-contact manner. Then, the position of the power receiving element can be detected with high accuracy based on the output signal of the sensor, and notification regarding the positional deviation between the power receiving element and the power feeding element can be performed.

Schematic showing an example of an RFID system The figure which shows an example of a structure of RF tag (wireless apparatus) The figure which shows an example of a structure of RF reader (communication apparatus) The top view which shows the position shift state of RF tag and RF reader The perspective view which shows the position shift state of RF tag and RF reader The top view which shows the 1st example of the internal structure of RF reader | leader Side surface sectional drawing in AA of FIG. The flowchart which shows an example of the process which the control part of RF reader performs The figure which shows the 1st arrangement configuration example of a magnetic sensor The figure which shows the 2nd arrangement configuration example of a magnetic sensor. The figure which shows the 3rd arrangement structural example of a magnetic sensor. The figure which shows the 1st example of a display on a display part. The figure which shows the 2nd example of a display on a display part The figure which shows the 3rd example of a display on a display part. The figure which shows the 4th example of a display on a display part. The top view which shows the 2nd example of internal structure of RF reader Side surface sectional drawing in BB of FIG. The top view which shows the 3rd example of internal structure of RF reader Side surface sectional view in CC of FIG. Explanatory drawing of the modification of RF reader Plan view of first modification of antenna coil Side view of first modification of antenna coil Plan view of second modification of antenna coil Plan view of the third modification of the antenna coil Plan view of a fourth modification of the antenna coil Schematic diagram showing a first example of a non-contact power supply system Diagram showing the configuration of the wireless power supply system The top view which shows the position shift state of a receiving element and a feeding element The perspective view which shows the position shift state of a receiving element and a feed element The top view which shows the 1st example of the internal structure of an electric power feeder. Side surface sectional view in AA of FIG. The flowchart which shows an example of the process which the control part of an electric power feeder performs The figure which shows the 4th example of a structure configuration of a magnetic sensor. The figure which shows the example of 5th arrangement structure of a magnetic sensor. The figure which shows the 6th arrangement configuration example of a magnetic sensor. The figure which shows the 5th example of a display on a display part. The figure which shows the 6th example of a display on a display part. The figure which shows the 7th example of a display on a display part. The figure which shows the 8th example of a display on a display part. The top view which shows the 2nd example of the internal structure of an electric power feeder Side surface sectional view in BB of FIG. The top view which shows the 3rd example of an internal structure of an electric power feeder. Side surface sectional drawing in CC of FIG. Explanatory drawing of the modification of a feeding element Plan view of a fifth modification of the antenna coil Side view of the fifth modification of the antenna coil Plan view of a sixth modification of the antenna coil Plan view of a seventh modification of the antenna coil The top view of the 8th modification of an antenna coil Schematic showing a second example of a non-contact power supply system

<First Embodiment>
The communication device of the present invention will be described below with reference to the drawings. The embodiment described below shows an example of a communication device in order to embody the technical idea of the present invention, and is not intended to identify the present invention as a communication device. It is equally applicable to the apparatus of other embodiments within the scope of the claims.

  FIG. 1 is a schematic diagram illustrating an example of an RFID system. FIG. 2 is a diagram illustrating an example of the configuration of an RF tag (wireless device). FIG. 3 is a diagram illustrating an example of the configuration of an RF reader (communication device).

  The RF tag 1 is attached to, for example, a poster 100 as shown in FIG. The user can acquire information from the RF tag 1 by bringing the antenna coil (details will be described later) of the RF reader 2 close to the RF tag 1. In FIG. 1, the antenna coil is arranged in a section of the RF reader 2 at the center below the back surface. However, where the antenna coil is arranged in the RF reader 2 is not particularly limited.

  The RF tag 1 will be described. The RF tag 1 of this embodiment is a passive tag (passive tag). The passive tag is a tag that operates by non-contact power transmission from the RF reader 2 and does not incorporate a power source such as a battery. The RF tag 1 may be an active tag (active tag). An active tag is a tag with a built-in power source, and emits radio waves with its own power during communication, so the communication distance is longer than that of the passive type.

  The RF tag 1 includes an antenna coil (an example of an antenna) 11, a communication unit 12, a storage unit 13, and a control unit 14. In the RFID system, the antenna coil 21 of the RF reader 2 (to be described later) is brought close to the antenna coil 11 and electromagnetically coupled, so that drive energy and data signals can be transmitted by an electromagnetic induction method. When a current flows through the antenna coil 11, a magnetic field is generated and affects the antenna coil 21 of the RF reader 2. As the frequency of the electromagnetic wave, a generally used 13.56 MHz may be used, or a frequency other than this may be used. The communicable distance between the antenna coil 11 and the antenna coil 21 of the RF reader 2 is set in advance to about several centimeters to several tens of centimeters, for example.

  The communication unit 12 outputs a transmission signal obtained by performing predetermined encoding / modulation processing on data to be transmitted to the RF reader 2 to the antenna coil 11. The antenna coil 11 that has acquired the transmission signal transmits data to the RF reader 2 by electromagnetic induction.

  The storage unit 13 is a storage unit that stores various types of information. For example, an EEPROM is used. The storage unit 13 stores information such as an identification number of the RF tag 1 and information transmitted to the RF reader 2.

  The control unit 14 is a control unit that controls the entire RF tag 1. In response to the read request received from the RF reader 2, the control unit 14 transmits data stored in the storage unit 13 to the RF reader 2 via the communication unit 12 and the antenna coil 11.

  Next, the RF reader 2 will be described. The RF reader 2 includes an antenna coil (an example of an antenna) 21, a communication unit 22, a detection unit 23, a magnetic sensor 24, a display unit 25, and a control unit 26.

  As the antenna coil 21, a loop antenna is used that is wound around a substrate (not shown) in an annular and planar spiral shape. Both ends of the antenna coil 21 are connected to the communication unit 22 of the RF reader 2 via terminals (not shown). When a current is passed through the antenna coil 21, a magnetic field is generated in the antenna coil 21. As described above, the driving energy and the data signal can be transmitted by bringing the antenna coil 21 close to the antenna coil 11 of the RF tag 1 and magnetically coupling with the antenna coil 11 of the RF tag 1.

  The communication unit 22 acquires data input to the antenna coil 21 from the antenna coil 11 of the RF tag 1. The communication unit 22 performs predetermined demodulation / decoding processing on the acquired data and reads the data.

  The detection unit 23 inputs an output signal (detection result) of the magnetic sensor 24 that detects the strength of the magnetic field generated from the antenna coil 11 of the RF tag 1 to the control unit 26. The magnetic sensor 24 detects the strength of the magnetic field in the direction in which the antenna coil 11 and the antenna coil 21 of the RF tag 1 are superposed (see FIG. 4, details will be described later). As the magnetic sensor 24, a pickup coil, a magnetoresistive element (MR element), a Hall element, a magnetic impedance element (MI element), or the like is used. In the present embodiment, the RF reader 2 includes one or more magnetic sensors 24. Details of the arrangement of the magnetic sensor 24 will be described later.

  The display unit 25 displays a predetermined image or video. In the present embodiment, the display unit 25 has a touch panel function and also serves as an operation unit. However, the display unit 25 may have a touch panel function or may be provided with a separate operation unit. As will be described later, information indicating the direction of the RF tag 1 is displayed on the display unit 25.

  The control unit 26 is a control unit that controls the entire RF reader 2. The control unit 26 includes a CPU 261, a ROM 262, and a RAM 263. The ROM 262 stores a program executed by the control unit 26 and parameters and data necessary for executing the program. The CPU 261 executes various programs stored in the ROM 262. The RAM 263 temporarily stores data obtained during various processes and data obtained as a result of various processes. These CPU 261, ROM 262, RAM 263, etc. are connected via a bus. Note that some or all of the CPU 261, ROM 262, and RAM 263 may be integrated on one chip.

  The control unit 26 specifies the position and / or direction of the RF tag 1 based on the output signal of the magnetic sensor 24 input from the detection unit 23, and displays information indicating the position and / or direction of the RF tag 1 on the display unit 25. indicate. Details of the method of specifying the position of the RF tag 1 and the display on the display unit 25 will be described later.

  Next, the arrangement of the magnetic sensor 24 in the RF reader 2 will be described with reference to FIGS. FIG. 4 is a plan view showing a positional deviation state between the RF tag 1 and the RF reader 2. FIG. 5 is a perspective view showing a positional deviation state between the RF tag 1 and the RF reader 2. FIG. 6 is a first plan view showing an example of the internal configuration of the RF reader 2. 7 is a side cross-sectional view taken along the line AA of FIG.

  As described above, the communicable distance between the antenna coil 11 and the antenna coil 21 is set to about several centimeters to several tens of centimeters. In particular, when the communicable distance is set to several centimeters, when the RF reader 2 is brought close to the RF tag 1 and the antenna coil 11 and the antenna coil 21 are largely misaligned, the information of the RF tag 1 is transferred to the RF reader 2 may not be read.

  The positional deviation between the antenna coil 11 and the antenna coil 21 means that when the RF reader 2 is brought close to the RF tag 1, the antenna coil 11 and the antenna coil 21 are overlapped with each other (perpendicular to the paper surface of FIG. 4). This means a state in which the antenna coil 11 does not exist within the area of the antenna coil 21 (in the area shown by hatching in FIG. 4) when projected (see FIG. 4). More specifically, as shown in FIG. 5, the distance between the center of gravity of the magnetic field and the central axis of the antenna coil 11 is a predetermined distance L (the predetermined distance L may be a communicable distance or any distance less than the communicable distance). It may be a distance).

  4 and FIG. 5, a communication failure occurs depending on the communicable distance between the antenna coil 11 and the antenna coil 21. Therefore, in this embodiment, the control unit 26 specifies the position and / or direction of the RF tag 1 based on the output signal of the magnetic sensor 24 input from the detection unit 23, and displays the position and / or direction of the RF tag 1 on the display unit 25. Alternatively, information indicating the direction is displayed.

  As described above, the magnetic sensor 24 detects the strength of the magnetic field generated from the antenna coil 11, but also detects the strength of the magnetic field generated from the antenna coil 21. The strength of the magnetic field generated from the antenna coil 11 is weaker than the strength of the magnetic field generated from the antenna coil 21 particularly when the RF tag 1 is a passive tag, and the magnetic sensor 24 mainly uses the magnetic field generated from the antenna coil 21. It can end up detecting strength.

  Therefore, in this embodiment, the magnetic sensor 24 is disposed at a position where a signal indicating the strength of the magnetic field generated from the antenna coil 21 is suppressed from being included in the output signal of the magnetic sensor 24. In the present embodiment, the magnetic sensor 24 includes two magnetic sensors 24a and 24b, and the magnetic sensors 24a and 24b are magnetoresistive elements.

  The magnetic field generated from the antenna coil 21 has a first region and a second region in which the directions of magnetic fluxes are opposite to each other. The magnetic sensors 24a and 24b are arranged at positions where the magnetic field generated from the antenna coil 21 can detect the strength of a part of the first region, the strength of the magnetic field, and the strength of the magnetic field of the second region. Hereinafter, a specific description will be given with reference to FIGS. 6 and 7. In the following description, the detection of the magnetic field strength of a part of the first region and a part of the second region by the magnetic sensor 24a is simply the strength of the magnetic field of the first region and the second region. It may be described as detecting the thickness.

  As shown in FIG. 6, the magnetic sensors 24 a and 24 b each have a position for detecting the strength of a part of the magnetic field in the first area outside the antenna coil 21, and a position in the second area inside the antenna coil 21. It is arranged at a position where the strength of a part of the magnetic field is detected. The detection unit 23 is an antenna in which the magnetic sensor 24 detects the strength of the magnetic field obtained by adding the strength of the magnetic field of the antenna coil 21 detected by the magnetic sensor 24a and the strength of the magnetic field of the antenna coil 21 detected by the magnetic sensor 24b. This is output to the control unit 26 as the strength of the magnetic field of the coil 21.

  As shown in FIG. 7, when the magnetic sensors 24a and 24b are arranged opposite to the first region and the second region with the antenna coil 21 interposed therebetween, the direction of the magnetic flux detected by the magnetic sensor 24a and the magnetic sensor 24b are arranged. The direction of the magnetic flux detected by is substantially opposite. Therefore, if the absolute values of the magnetic field strengths detected by the magnetic sensors 24a and 24b are substantially the same, the magnetic field strength of the antenna coil 21 detected by the magnetic sensor 24 calculated by adding the output signals of the two is added. Is substantially zero. That is, the output signal of the magnetic sensor 24 is suppressed from including a signal indicating the strength of the magnetic field of the antenna coil 21, and the magnetic sensor 24 is mainly used when the antenna coil 11 and the antenna coil 21 are brought close to each other. It functions as a sensor that detects the strength of the magnetic field of the antenna coil 11.

  Hereinafter, processing executed by the control unit 26 of the RF reader 2 will be described. FIG. 8 is a flowchart illustrating an example of processing executed by the control unit 26 of the RF reader 2 according to the present embodiment.

  The control unit 26 starts processing for displaying the position and / or direction of the RF tag 1 when communication between the antenna coil 11 and the antenna coil 21 is started. In step S <b> 01, the control unit 26 acquires the output signal of the magnetic sensor 24 from the detection unit 23. As described above, since the magnetic sensor 24 is suppressed from including a signal indicating the strength of the magnetic field of the antenna coil 21, the output signal of the magnetic sensor 24 mainly includes a signal indicating the strength of the magnetic field of the antenna coil 11. .

  In step S02, the control unit 26 identifies the positional relationship between the antenna coil 11 and the antenna coil 21. For example, when the RF reader 2 includes one magnetic sensor 24 as shown in FIG. 6, the output signal of the magnetic sensor 24 is compared with a predetermined threshold value, and the proximity or distance of the antenna coil 21 with respect to the antenna coil 11 is compared. Identify

  For example, when the RF reader 2 includes two magnetic sensors 24 (magnetic sensors 241 and 242) as shown in FIG. 9, the output signals of one magnetic sensor 24 and the other magnetic sensor 24 are compared. The one-dimensional direction of the antenna coil 11 is specified by That is, in this embodiment, the antenna coil 21 is disposed in a section at the lower center portion of the RF reader 2 and is not displaced in the vertical direction (Y direction shown in FIG. 4). The position is often displaced in the X direction). Therefore, in FIG. 9, the magnetic sensors 24 are arranged on two sides extending in the vertical direction by the antenna coil 21.

  With this configuration, for example, when the output signal of the magnetic sensor 242 has a stronger magnetic field than the output signal of the magnetic sensor 241, the antenna coil extends in the direction of the magnetic sensor 241 around the center point O of the antenna coil 21. 11 (RF tag 1) is specified. Note that the arrangement of the two magnetic sensors 24 may be changed according to the position of the antenna coil 21 in the RF reader 2. For example, when the antenna coil 21 is disposed in a section on the left central portion of the RF reader 2, it is considered that a vertical displacement often occurs. Therefore, the magnetic sensor 24 may be disposed on each of the two sides extending in the left-right direction of the antenna coil 21.

  For example, as shown in FIG. 10, when the RF reader 2 includes three magnetic sensors 24 (magnetic sensors 243, 244, 245) or three or more magnetic sensors 24, the output signal of each magnetic sensor 24 is output. By comparing, the two-dimensional direction of the direction of the antenna coil 11 is specified.

  In FIG. 10, a total of three magnetic sensors are arranged on two sides (two straight portions) extending in the left-right direction by the antenna coil 21, and one magnetic sensor 24 (magnetic sensor 243) is arranged on one side and the other side. Two magnetic sensors 24 (magnetic sensors 244 and 245) are arranged on the side of the. By comparing the output signal of the magnetic sensor 243 and the output signal of the magnetic sensor 244 and / or 245, the positional deviation in the vertical direction with respect to the RF tag 1 is specified. Further, by comparing the output signals of the magnetic sensor 244 and the magnetic sensor 245, the positional deviation in the left-right direction of the antenna coil 21 with respect to the antenna coil 11 is specified.

  The control unit 26 specifies the positional deviation in the two-dimensional direction based on the specified vertical and horizontal positional deviations. The number of magnetic sensors 24 is not particularly limited, and the position and / or direction of the RF tag 1 can be specified with higher accuracy by arranging more magnetic sensors 24. For example, as shown in FIG. 11, by disposing two magnetic sensors 24 on each side of the antenna coil 21, it is possible to specify a vertical or horizontal positional shift with respect to the RF tag 1 for each side.

  In step S03, the control unit 26 displays the position and / or direction of the antenna coil 11 on the display unit 25 based on the positional relationship between the antenna coil 11 and the antenna coil 21 specified in step S02. For example, when the arrangement of the magnetic sensor 24 is the arrangement shown in FIG. 6, a display indicating the proximity or distance of the antenna coil 21 with respect to the antenna coil 11 is performed as shown in FIG. 12. When the arrangement of the magnetic sensor 24 is the arrangement shown in FIG. 9, the display showing the one-dimensional direction of the antenna coil 11 with reference to the center point O of the antenna coil 21 is performed as shown in FIG. 13. When the arrangement of the magnetic sensor 24 is the arrangement shown in FIGS. 10 and 11, a display showing the two-dimensional direction of the antenna coil 11 with reference to the center point O of the antenna coil 21 is performed as shown in FIG.

  When the difference between the output signal of the magnetic sensor 24 and the predetermined threshold value is equal to or smaller than a predetermined value in the arrangement of the magnetic sensors 24 shown in FIG. 6, each magnetic sensor 24 in the arrangement of the magnetic sensors 24 shown in FIGS. When the difference between the output signals is equal to or less than a predetermined value, the positional deviation between the antenna coil 11 and the antenna coil 21 is a positional deviation that is negligible even if it does not occur. In that case, the control unit 26 may display nothing on the display unit 25 or may display (for example, refer to FIG. 15) indicating that no positional deviation has occurred.

  In step S04, the control unit 26 determines whether the communication between the antenna coil 11 and the antenna coil 21 is completed. If communication has not ended (N in step S04), the process returns to step S01. Thereby, when the RF reader 2 is moved, the display indicating the position and / or direction of the antenna coil 11 is updated. If communication has ended (Y in step S04), the process ends.

  Note that when communication between the antenna coil 11 and the antenna coil 21 is not completed, it is determined whether or not a predetermined time has elapsed since the display indicating the position and / or direction of the antenna coil 11 is performed in step S03. If time has elapsed, the process may return to step S01. With this configuration, the display is updated every predetermined time.

  According to this embodiment, when a current flows through the antenna coil of the RF reader, the signal indicating the strength of the magnetic field generated from the antenna coil of the RF reader is prevented from being included in the output signal of the magnetic sensor. Since the magnetic sensor is arranged, the output signal of the magnetic sensor mainly consists of a signal indicating the strength of the magnetic field generated from the RF tag that communicates with the RF reader. Then, the position and / or direction of the RF tag can be detected with high accuracy based on the output signal of the magnetic sensor, and notification regarding the positional deviation between the antenna coil of the RF tag and the antenna coil of the RF reader can be made.

  The magnetic field generated from the antenna coil has a first region and a second region in which the directions of the magnetic fluxes are opposite to each other, and the magnetic sensor has a magnetic field strength in the first region and a magnetic field in the second region. It is arranged at a position where it can detect the strength. A signal indicating the strength of the magnetic field generated from the antenna coil of the RF reader by adding the detected magnetic field strength of the first region and the magnetic field strength of the second region is included in the output signal of the magnetic sensor. Therefore, the position and / or direction of the RF tag can be detected with high accuracy.

  Also, since the one-dimensional or two-dimensional positional deviation direction of the RF tag antenna coil relative to the antenna coil of the RF reader is calculated and the direction of the RF tag is notified, the user moves the RF reader based on the notification, so that the RF tag It is possible to communicate stably with.

  In addition, if the positional deviation between the antenna coil of the RF tag and the antenna coil of the RF reader is equal to or less than a predetermined threshold, a notification indicating that no positional deviation has occurred is made, so the user maintains the current position of the RF reader. Thus, stable communication with the RF tag is possible.

Second Embodiment
In the first embodiment, a magnetoresistive element is used as the magnetic sensor 24. In the second embodiment, a cheaper pickup coil is used. Examples of the pickup coil include a circular pickup coil (loop coil) and an 8-shaped pickup coil.

  FIG. 16 is a plan view showing a second example of the internal configuration of the RF reader 2. 17 is a side cross-sectional view taken along line BB in FIG. FIG. 18 is a plan view showing a third example of the internal configuration of the RF reader 2. 19 is a side sectional view taken along the line CC of FIG. 16 and 17, the RF reader 2 includes a circular pickup coil as the magnetic sensor 24. 18 and 19, the RF reader 2 includes an 8-shaped pickup coil as the magnetic sensor 24. Hereinafter, the magnetic sensor 24 may be referred to as a pickup coil 24.

  As shown in FIGS. 16 and 17, the magnetic field generated from the antenna coil 21 when viewed in the direction perpendicular to the paper surface of FIG. 16 is outside the antenna coil 21 in which the directions of the magnetic fluxes are opposite to each other (first magnetic field). ) And a magnetic field generated inside the antenna coil 21 (second magnetic field), and the circular pick-up coil 24 detects the strength of a part of the magnetic field in the first region. The sensor unit 246 includes a second sensor unit 247 that detects the strength of a part of the magnetic field in the second region. The detection unit 23 calculates the strength of the magnetic field obtained by adding the strength of the magnetic field of the antenna coil 21 detected by the first sensor unit 246 and the strength of the magnetic field of the antenna coil 21 detected by the second sensor unit 247. Is output to the control unit 26 as the strength of the magnetic field of the antenna coil 21 detected.

  As shown in FIG. 16, the first sensor unit 246 and the second sensor unit 247 are arranged to detect the strength of the magnetic field in a part of the first region and a part of the second region, respectively. The direction of the magnetic flux detected by the sensor unit 246 and the direction of the magnetic flux detected by the second sensor unit 247 are substantially opposite directions. Therefore, if the absolute values of the magnetic field strengths detected by the first sensor unit 246 and the second sensor unit 247 are approximately the same value, the antenna coil detected by the pickup coil 24 calculated by adding the output signals of the two is detected. The strength of the magnetic field 21 is substantially zero. That is, the output signal of the pickup coil 24 is suppressed from including a signal indicating the strength of the magnetic field of the antenna coil 21, and the pickup coil 24 is mainly used when the antenna coil 11 and the antenna coil 21 are brought close to each other. It functions as a sensor that detects the strength of the magnetic field of the antenna coil 11.

  As shown in FIGS. 18 and 19, the 8-shaped pickup coil 24 includes a first coil 248 and a second coil 249. The first coil 248 and the second coil 249 each have a position for detecting the strength of a part of the magnetic field outside the antenna coil 21 (first region), and a part inside the antenna coil 21 (second region). It is arranged at a position for detecting the strength of the magnetic field. The pickup unit 24 detects the intensity of the magnetic field obtained by adding the strength of the magnetic field of the antenna coil 21 detected by the first coil 248 and the strength of the magnetic field of the antenna coil 21 detected by the second coil 249. The strength of the magnetic field of the antenna coil 21 is output to the control unit 26.

  As shown in FIG. 19, the first coil 248 and the second coil 249 are arranged so as to detect the strength of the magnetic field in the first region and the second region, respectively, so that the magnetic flux detected by the first coil 248 is detected. The direction and the direction of the magnetic flux detected by the second coil 249 are substantially opposite to each other. Therefore, if the absolute values of the magnetic field strengths detected by the first coil 248 and the second coil 249 are substantially the same value, the antenna coil 21 detected by the pickup coil 24 calculated by adding the output signals of the two coils is detected. The strength of the magnetic field is substantially zero. That is, the output signal of the pickup coil 24 is suppressed from including a signal indicating the strength of the magnetic field of the antenna coil 21. When the antenna coil 11 and the antenna coil 21 are brought close to each other, the pickup coil 24 is mainly an antenna. It functions as a sensor that detects the strength of the magnetic field of the coil 11.

  According to the present embodiment, the same effects as those of the first embodiment can be obtained. In addition, the cost of the RF reader can be reduced by using an inexpensive pickup coil as the magnetic sensor.

<Supplement>
In each of the above embodiments, the control unit 26 displays the position and / or direction of the antenna coil 11 on the display unit 25 and notifies the user of the position and / or direction of the antenna coil 11. However, the position and / or direction of the antenna coil 11 may be notified to the user by a method other than display. For example, the position and / or direction of the antenna coil 11 may be notified by voice through a speaker. That is, any notification method may be used as long as the position and / or direction of the antenna coil 11 can be recognized.

  In the above embodiments, when the RF reader 2 includes the two magnetic sensors 24, the one-dimensional direction of the antenna coil 11 is specified. However, the RF reader 2 further detects the moving direction of the RF reader 2. The two-dimensional direction may be specified as having an acceleration sensor.

  A specific description will be given with reference to FIG. FIG. 20 is an explanatory diagram of this modification of the RF reader 2. The reader 2 has pickup coils 24c and 24d as the magnetic sensor 24. In this example, the output signal of the pickup coil 24d is stronger than the output signal of the pickup coil 24c. Therefore, it is specified that the antenna coil 11 exists in the direction (left direction) of the pickup coil 24c with the center point O of the antenna coil 21 as a reference. In addition, referring to fluctuations in the strength of the magnetic field detected by the pickup coils 24c and 24d, if the strength of the magnetic field detected by the pickup coils 24c and 24d is weakened when the RF reader 2 is moved in the direction of arrow D1, It can be specified that the RF tag 1 is present in the upward direction. That is, it is specified that the antenna coil 11 exists in the left direction and the upward direction, that is, the upper left direction from the RF reader 2.

  On the other hand, when the RF reader 2 is moved in the direction of the arrow D2, if the strength of the magnetic field detected by the pickup coils 24c and 24d is weakened, it can be specified that the antenna coil 11 exists in the downward direction. That is, it is specified that the RF tag 1 is present leftward and downward from the RF reader 2, that is, in the lower left direction.

  In each of the above embodiments, the output signal of one magnetic sensor 24 is compared with a threshold value, or the output signals of two or more magnetic sensors 24 are compared to indicate the one-dimensional direction or two-dimensional direction of the antenna coil 11. However, the barycentric coordinate P of the magnetic field generated from the antenna coil 11 may be calculated, and the direction of the barycentric coordinate P with reference to the center point O of the antenna coil 21 may be specified as the direction of the antenna coil 11.

When the position coordinates of the i-th magnetic sensor 24 are (X _i , Y _i ) and the output signal of the magnetic sensor 24 is Hi (A / m), the barycentric coordinates P ( X, Y) are X and Y satisfying the following expressions (1) and (2).
Σ (X _i −X) Hi = 0 (1)
Σ (Y _i −Y) Hi = 0 (2)

  In each of the above embodiments, a loop antenna wound in a planar spiral shape is used as the antenna coil 21. However, the present invention is not limited to this. For example, a three-dimensional spiral loop antenna is used as shown in FIG. It is good. FIGS. 21 and 22 are modifications of the antenna coil 21 shown in FIGS. 6 and 7, respectively, but may be applied to the antenna coil 21 of other embodiments.

Here, the strength of the magnetic field of the antenna coil 21 generated in the first region and the strength of the magnetic field of the antenna coil 21 generated in the second region will be described. As shown in the above embodiment, the strength of the magnetic field generated in the second region by the spiral antenna coil 21 is affected by the magnetic field generated from all (four sides) of the antenna coil 21, whereas the first The strength of the magnetic field generated in the region is mainly affected by the magnetic field generated from a part (one side) of the antenna coil 21. Therefore, in general, the magnetic field strength of the second region is larger than the magnetic field strength of the first region.

When the magnetic sensor 24 is a pickup coil in order to make the strength of the magnetic field of the antenna coil 21 detected by the magnetic sensor 24 in such a situation substantially zero, as shown in FIGS. 24, a sensor (first sensor unit 246, first coil 248) for detecting the magnetic field strength of the first region is a sensor (second sensor 247, second coil) for detecting the magnetic field strength of the second region. it may be to be greater than 249).

  When the magnetic sensor 24 is the magnetoresistive element shown in FIGS. 6 and 7, the part of the antenna coil 21 that generates the magnetic field detected by the magnetic sensors 24a and 24b in the first region as shown in FIG. On the other hand, the region where the magnetic sensor 24a detects the magnetic field strength may be set at a position farther than the region where the magnetic sensor 24b detects the magnetic field strength in the second region.

  That is, when the strength of the magnetic field in the first region is different from the strength of the magnetic field in the second region, the magnetic field in the region where the magnetic field strength is stronger than the detection of the magnetic field strength in the region where the magnetic field strength is weak. The magnetic sensor 24 may be disposed at a position where the detection of the intensity of the magnetic field is suppressed.

  Further, by adjusting the gain of the magnetic field output signal in the first region and / or the magnetic field output signal in the second region, the magnetic field strength of the antenna coil 21 detected by the magnetic sensor 24 is made substantially zero. It is good.

<Third Embodiment>
In the first embodiment and the second embodiment, the case where the direction of the RF tag is notified when the RF tag and the RF reader are misaligned with respect to the RFID system has been described. These notifications can also be applied when a positional deviation occurs between the power feeding element included in the power feeding device and the power receiving element included in the power receiving device in the non-contact power feeding system.

  Hereinafter, the non-contact power feeding system will be described with reference to FIGS. 26 and 27. FIG. FIG. 26 is a schematic diagram illustrating a first example of a non-contact power feeding system. FIG. 27 is a diagram illustrating a configuration of a non-contact power feeding system. In the present embodiment and the subsequent embodiments, the power feeding device and the power receiving device included in the non-contact power feeding system are examples of the power feeding device and the power receiving device in order to embody the technical idea of the present invention. The present invention is not intended to specify the power feeding device and the power receiving device, and can equally be applied to the power feeding device and the power receiving device of other embodiments included in the claims.

  The non-contact power feeding system 300 includes a power feeding device 400 and a power receiving device 500. In FIG. 26, the power receiving element 510 is arranged in a section (lower center in FIG. 26) of the back surface of the power receiving device 500 (for example, a smartphone or a tablet terminal). The user can perform non-contact power feeding by bringing the power feeding element 440 included in the power feeding apparatus 400 closer to the power receiving element 510 included in the power receiving apparatus 500.

  When the power receiving device 500 is larger than the power feeding device 400 as shown in FIG. 26, the power receiving device 500 includes the power feeding device 400 (the power feeding element 440 included in the power feeding device 400). It must be moved manually to the 510 position. Therefore, in the present embodiment, the position of the power receiving element 510 is indicated to the user via the display unit 470 included in the power supply apparatus 400.

  The power supply apparatus 400 includes a power supply unit 410, a control unit 420, a power supply drive unit 430, a power supply element 440, a detection unit 450, a magnetic sensor 460, and a display unit 470. The power supply unit 410 is supplied with AC power from a commercial power supply (not shown), and the power supply unit 410 supplies power to the control unit 420 and the power feeding drive unit 430.

  The control unit 420 is a control unit that controls the entire power supply apparatus 400. The power feeding drive unit 430 supplies AC power to the power feeding element 440.

  When AC power is supplied to the feeding element 440, an AC current flows through the feeding element 440, and an alternating magnetic field is generated in a direction perpendicular to the feeding surface 400a. By this alternating magnetic field, an induced current is excited in the power receiving element 510 brought close to the power feeding element 440, and electric power is transmitted.

  In this embodiment and the following embodiments, the material and shape of the power feeding element 440 are not particularly limited. For example, a coil module having a shape that spirals counterclockwise toward the center of the spiral in a top view is used. The

  The detection unit 450 inputs an output signal (detection result) of the magnetic sensor 460 that detects the strength of the magnetic field generated from the power receiving element 510 to the control unit 420. The magnetic sensor 460 detects the strength of the magnetic field in the overlapping direction of the power receiving element 510 and the power feeding element 440 (see FIG. 28, details will be described later). As the magnetic sensor 460, a pickup coil, a magnetoresistive element (MR element), a Hall element, a magnetic impedance element (MI element), or the like is used. In the present embodiment, the power supply apparatus 400 includes one or more magnetic sensors 460. Details of the arrangement of the magnetic sensor 460 will be described later.

  The display unit 470 displays a predetermined image or video. The display unit 470 displays information indicating the direction of the power receiving device 500 (the power receiving element 510 of the power receiving device 500) as described later.

  The power receiving device 500 includes a power receiving element 510, a rectifying unit 520, a power supply unit 530, a control unit 540, a rechargeable battery 550, and a storage unit 560. The power receiving element 510 receives the power transmitted from the power feeding element 440 as described above. The AC power received by the power receiving element 510 is supplied to the rectifying unit 520. The rectifying unit 520 includes, for example, a diode or a capacitor, and converts AC power supplied from the power receiving element 510 into DC power.

  The electric power converted into direct current by the rectifying unit 520 is supplied to the power source unit 530. The control unit 540 is a control unit that controls the entire power receiving apparatus 500, and controls conversion of AC power received by the power receiving element 510 by the rectifying unit 520 into DC power and storage of power in the rechargeable battery 550 by the power source unit 530.

  The storage unit 560 is a storage unit that stores various types of information. For example, an EEPROM is used. The storage unit 560 stores the identification number of the power supply apparatus 400.

  Next, the arrangement of the magnetic sensor 460 in the power supply apparatus 400 will be described with reference to FIGS. FIG. 28 is a plan view showing a positional deviation state between the power receiving element 510 and the power feeding element 440. FIG. 29 is a perspective view showing a positional deviation state between the power receiving element 510 and the power feeding element 440. FIG. 30 is a first plan view illustrating an example of the internal configuration of the power supply apparatus 400. 31 is a side cross-sectional view taken along the line AA of FIG.

  When the power receiving element 510 and the power feeding element 440 are fed in a non-contact manner, it is necessary to bring the power receiving element 510 and the power feeding element 440 close to a relatively short distance (about several centimeters). Therefore, when the power feeding element 440 is brought close to the power receiving element 510, if the positional deviation between the power receiving element 510 and the power feeding element 440 is large, the power receiving element 510 may not be fed.

  The positional deviation between the power receiving element 510 and the power feeding element 440 refers to the overlapping direction of the power receiving element 510 and the power feeding element 440 (perpendicular to the paper surface of FIG. 28) when the power feeding device 400 is brought close to the power receiving element 510. This means a state in which the power receiving element 510 does not exist in the region of the power feeding element 440 when projected (see FIG. 28). More specifically, as shown in FIG. 29, the distance between the center of gravity of the magnetic field and the central axis of the power receiving element 510 is a predetermined distance L (the predetermined distance L may be a power supplyable distance or an arbitrary power supply distance less than or equal to It may be a distance).

  In the case where a positional shift as shown in FIGS. 28 and 29 occurs, a power feeding failure such as a reduction in power feeding efficiency occurs with respect to power feeding from the power feeding element 440 to the power receiving element 510. Therefore, in this embodiment, the control unit 420 specifies the position and / or direction of the power receiving element 510 based on the output signal of the magnetic sensor 460 input from the detection unit 450, and displays the position and / or direction of the power receiving element 510 on the display unit 470. Alternatively, information indicating the direction is displayed.

  As described above, the magnetic sensor 460 detects the strength of the magnetic field generated from the power receiving element 510, but also detects the strength of the magnetic field generated from the power feeding element 440. The strength of the magnetic field generated from the power receiving element 510 is weaker than the strength of the magnetic field generated from the power feeding element 440 particularly when the power receiving element 510 is a passive tag, and the magnetic sensor 460 mainly uses the magnetic field generated from the power feeding element 440. It can end up detecting strength.

  Therefore, in this embodiment, the magnetic sensor 460 is disposed at a position where a signal indicating the strength of the magnetic field generated from the power feeding element 440 is suppressed from being included in the output signal of the magnetic sensor 460. In the present embodiment, the magnetic sensor 460 includes two magnetic sensors 460a and 460b, and the magnetic sensors 460a and 460b are magnetoresistive elements.

  The magnetic field generated from the feed element 440 has a first region and a second region in which the directions of magnetic fluxes are opposite to each other. The magnetic sensors 460a and 460b are arranged at positions where the magnetic field strength generated in the first region, the strength of the magnetic field in the first region, and the strength of the magnetic field in the second region can be detected. Hereinafter, a specific description will be given with reference to FIGS. 30 and 31. In the following description, the detection of the magnetic field strength of a part of the first region and a part of the second region by the magnetic sensor 460a is simply the strength of the magnetic field of the first region and the second region. It may be described as detecting the thickness.

  As shown in FIG. 30, the magnetic sensors 460 a and 460 b each have a position for detecting the strength of a part of the magnetic field in the first region that is outside the power feeding element 440 and a second region that is inside the power feeding element 440. It is arranged at a position where the strength of a part of the magnetic field is detected. The detection unit 450 supplies power detected by the magnetic sensor 460 to the strength of the magnetic field obtained by adding the strength of the magnetic field of the power feeding element 440 detected by the magnetic sensor 460a and the strength of the magnetic field of the power feeding element 440 detected by the magnetic sensor 460b. This is output to the control unit 420 as the strength of the magnetic field of the element 440.

  As shown in FIG. 31, when the magnetic sensors 460a and 460b are arranged opposite to the first region and the second region with the feeding element 440 interposed therebetween, the direction of the magnetic flux detected by the magnetic sensor 460a and the magnetic sensor 460b are arranged. The direction of the magnetic flux detected by is substantially opposite. Therefore, if the absolute values of the magnetic field strengths detected by the magnetic sensors 460a and 460b are substantially the same, the magnetic field strength of the power feeding element 440 detected by the magnetic sensor 460 calculated by adding the output signals of the two sensors. Is substantially zero. That is, the output signal of the magnetic sensor 460 is prevented from including a signal indicating the strength of the magnetic field of the power feeding element 440. When the power receiving element 510 and the power feeding element 440 are brought close to each other, the magnetic sensor 460 is mainly used. It functions as a sensor that detects the strength of the magnetic field of the power receiving element 510.

  Hereinafter, processing executed by the control unit 420 of the power supply apparatus 400 will be described. FIG. 32 is a flowchart illustrating an example of processing executed by the control unit 420 of the power supply apparatus 400 according to the present embodiment.

  The control unit 420 starts a process for displaying the position and / or direction of the power receiving element 510 when the power receiving element 510 and the power feeding element 440 are powered. In step S <b> 11, the control unit 420 acquires the output signal of the magnetic sensor 460 from the detection unit 450. As described above, since the magnetic sensor 460 is suppressed from including a signal indicating the strength of the magnetic field of the power feeding element 440, the output signal of the magnetic sensor 460 mainly includes a signal indicating the strength of the magnetic field of the power receiving element 510. .

  In step S <b> 12, the control unit 420 specifies the positional relationship between the power receiving element 510 and the power feeding element 440. For example, as shown in FIG. 30, when the power supply apparatus 400 includes one magnetic sensor 460, the output signal of the magnetic sensor 460 is compared with a predetermined threshold value, and the proximity or distance of the power supply element 440 to the power receiving element 510 is compared. Identify

  For example, as shown in FIG. 33, when the power supply apparatus 400 includes two magnetic sensors 460 (magnetic sensors 461 and 462), the output signals of one magnetic sensor 460 and the other magnetic sensor 460 are compared. To specify the one-dimensional direction of the power receiving element 510. That is, in the present embodiment, the power feeding element 440 is arranged in a section at the lower central portion of the power feeding device 400, and is less likely to be displaced in the vertical direction (Y direction shown in FIG. 28). The position is often displaced in the X direction). Therefore, in FIG. 33, the magnetic sensor 460 is arranged on each of two sides extending in the vertical direction by the power feeding element 440.

  With this configuration, for example, when the output signal of the magnetic sensor 462 has a stronger magnetic field than the output signal of the magnetic sensor 461, the power receiving element is directed toward the magnetic sensor 461 around the center point O of the power feeding element 440. It is specified that 510 (power receiving element 510) exists. Note that the arrangement of the two magnetic sensors 460 may be changed according to the position of the power feeding element 440 in the power feeding apparatus 400. For example, when the power feeding element 440 is arranged in a section on the left central portion of the power feeding apparatus 400, it is considered that a vertical position shift often occurs. Therefore, the magnetic sensor 460 may be disposed on each of two sides extending in the left-right direction of the power feeding element 440.

  For example, as shown in FIG. 34, when the power supply apparatus 400 includes three magnetic sensors 460 (magnetic sensors 463, 464, 465) or three or more magnetic sensors 460, the output signal of each magnetic sensor 460 is output. The two-dimensional direction of the power receiving element 510 is specified by comparison.

  In FIG. 34, a total of three magnetic sensors are arranged on two sides (two straight portions) extending in the left-right direction by the power feeding element 440, and one magnetic sensor 460 (magnetic sensor 463) is arranged on one side, Two magnetic sensors 460 (magnetic sensors 464 and 465) are arranged on the side of the. By comparing the output signal of the magnetic sensor 463 with the output signal of the magnetic sensor 464 and / or 465, the positional deviation in the vertical direction with respect to the power receiving element 510 is specified. Further, by comparing the output signals of the magnetic sensor 464 and the magnetic sensor 465, the positional deviation in the left-right direction of the power feeding element 440 with respect to the power receiving element 510 is specified.

  The control unit 420 identifies the positional deviation in the two-dimensional direction based on the identified vertical and horizontal positional deviations. The number of the magnetic sensors 460 is not particularly limited. By disposing more magnetic sensors 460, the position and / or direction of the power receiving element 510 can be specified with higher accuracy. For example, as shown in FIG. 35, two magnetic sensors 460 are arranged on each side of the power feeding element 440, so that a vertical or horizontal positional shift with respect to the power receiving element 510 can be specified for each side.

  In step S <b> 13, the control unit 420 displays the position and / or direction of the power receiving element 510 on the display unit 470 based on the positional relationship between the power receiving element 510 and the power feeding element 440 specified in step S <b> 12. For example, when the arrangement of the magnetic sensor 460 is the arrangement shown in FIG. 30, the display indicating the proximity or distance of the power feeding element 440 with respect to the power receiving element 510 is performed as shown in FIG. 36. When the arrangement of the magnetic sensor 460 is the arrangement shown in FIG. 33, the display indicating the one-dimensional direction of the power receiving element 510 with reference to the center point O of the power feeding element 440 is performed as shown in FIG. When the arrangement of the magnetic sensor 460 is the arrangement shown in FIGS. 34 and 35, the display indicating the two-dimensional direction of the power receiving element 510 with reference to the center point O of the power feeding element 440 is performed as shown in FIG.

  When the difference between the output signal of the magnetic sensor 460 and the predetermined threshold is equal to or smaller than a predetermined value in the arrangement of the magnetic sensors 460 shown in FIG. 30, each magnetic sensor 460 in the arrangement of the magnetic sensors 460 shown in FIGS. When the difference between the output signals is equal to or less than a predetermined value, the positional deviation between the power receiving element 510 and the power feeding element 440 is negligible even if it does not occur or has occurred. In that case, the control unit 420 may display nothing on the display unit 470 or may display (for example, refer to FIG. 39) indicating that no positional deviation has occurred.

  In step S <b> 14, control unit 420 determines whether or not power supply to power receiving element 510 has been completed. If the power supply has not been completed (N in step S14), the process returns to step S11. Accordingly, when the power feeding device 400 is moved, the display indicating the position and / or direction of the power receiving element 510 is updated. If the power supply has ended (Y in step S14), the process ends.

  Note that when power supply to the power receiving element 510 is not completed, it is determined whether or not a predetermined time has elapsed since the display indicating the position and / or direction of the power receiving element 510 is performed in step S13. If yes, the process may return to step S11. With this configuration, the display is updated every predetermined time.

  According to this embodiment, since the magnetic sensor is arranged at a position where a signal indicating the strength of the magnetic field generated from the power feeding element when current flows through the power feeding element is suppressed from being included in the output signal of the magnetic sensor. The output signal of the magnetic sensor mainly consists of a signal indicating the strength of the magnetic field generated from the power receiving element that has received power from the power feeding element. Then, the position and / or direction of the power receiving element can be detected with high accuracy based on the output signal of the magnetic sensor, and notification regarding the positional deviation between the power feeding element and the power receiving element can be performed.

  The magnetic field generated from the feeding element has a first region and a second region in which the directions of the magnetic fluxes are opposite to each other, and the magnetic sensor has a magnetic field strength in the first region and a magnetic field in the second region. It is arranged at a position where it can detect the strength. Then, by adding the detected magnetic field strength of the first region and the magnetic field strength of the second region, it is possible to suppress the signal indicating the strength of the magnetic field generated from the feeding element from being included in the output signal of the magnetic sensor. Therefore, the position and / or direction of the power receiving element can be detected with high accuracy.

  Moreover, since the one-dimensional or two-dimensional displacement direction of the power receiving element with respect to the power feeding element is calculated and the direction of the power receiving element is notified, the user efficiently transmits power to the power receiving element by moving the power feeding device based on the notification. can do.

  In addition, if the positional deviation between the power receiving element and the power feeding element is equal to or less than a predetermined threshold value, a notification indicating that no positional deviation has occurred is made. Therefore, the user can improve the efficiency of the power receiving element by maintaining the current position of the power feeding device. Power can be transmitted well.

<Fourth embodiment>
In the third embodiment, a magnetoresistive element is used as the magnetic sensor 460. In the fourth embodiment, a cheaper pickup coil is used. Examples of the pickup coil include a circular pickup coil (loop coil) and an 8-shaped pickup coil.

  FIG. 40 is a plan view showing a second example of the internal configuration of the power feeding apparatus 400. FIG. 41 is a side sectional view taken along line BB in FIG. FIG. 42 is a plan view illustrating a third example of the internal configuration of the power feeding apparatus 400. 43 is a side sectional view taken along the line CC of FIG. 40 and 41, the power supply apparatus 400 includes a circular pickup coil as the magnetic sensor 460. 42 and 43, the power feeding device 400 includes an eight-shaped pickup coil as the magnetic sensor 460. Hereinafter, the magnetic sensor 460 may be referred to as a pickup coil 460.

  As shown in FIGS. 40 and 41, the magnetic field generated from the feed element 440 when viewed in the direction perpendicular to the paper surface of FIG. 40 is outside the first feed field 440 in which the directions of the magnetic fluxes are opposite to each other (first magnetic field). ) And a magnetic field generated inside the feed element 440 (second magnetic field), and the circular pickup coil 460 detects the strength of a part of the magnetic field in the first region. It consists of a sensor unit 466 and a second sensor unit 467 that detects the strength of a part of the magnetic field in the second region. The detection unit 450 determines the magnetic field strength obtained by adding the strength of the magnetic field of the power feeding element 440 detected by the first sensor unit 466 and the strength of the magnetic field of the power feeding element 440 detected by the second sensor unit 467. Is output to the control unit 420 as the strength of the magnetic field of the feed element 440 detected.

  As shown in FIG. 40, the first sensor unit 466 and the second sensor unit 467 are arranged so as to detect the strength of the magnetic field in part of the first region and part of the second region, respectively. The direction of the magnetic flux detected by the sensor unit 466 and the direction of the magnetic flux detected by the second sensor unit 467 are substantially opposite directions. Therefore, if the absolute values of the magnetic field strengths detected by the first sensor unit 466 and the second sensor unit 467 are substantially the same value, the power feeding element detected by the pickup coil 460 calculated by adding both output signals The strength of the magnetic field 440 is substantially zero. That is, the output signal of the pickup coil 460 is suppressed from including a signal indicating the strength of the magnetic field of the power feeding element 440. When the power receiving element 510 and the power feeding element 440 are brought close to each other, the pickup coil 460 is mainly used. It functions as a sensor that detects the strength of the magnetic field of the power receiving element 510.

  As shown in FIGS. 42 and 43, the 8-shaped pickup coil 460 includes a first coil 468 and a second coil 469. The first coil 468 and the second coil 469 are positions for detecting the strength of a part of the magnetic field outside the first feed region 440 and a part inside the second feed region 440 (second region). It is arranged at a position for detecting the strength of the magnetic field. In the detection unit 450, the pickup coil 460 detects the strength of the magnetic field obtained by adding the strength of the magnetic field of the feeding element 440 detected by the first coil 468 and the strength of the magnetic field of the feeding element 440 detected by the second coil 469. Is output to the control unit 420 as the strength of the magnetic field of the feeding element 440.

  As shown in FIG. 43, the first coil 468 and the second coil 469 are arranged to detect the strength of the magnetic field in the first region and the second region, respectively, so that the magnetic flux detected by the first coil 468 is detected. The direction and the direction of the magnetic flux detected by the second coil 469 are substantially opposite to each other. Accordingly, if the absolute values of the magnetic field strengths detected by the first coil 468 and the second coil 469 are substantially the same value, the pickup element 440 detected by the pickup coil 460 calculated by adding both output signals is used. The strength of the magnetic field is substantially zero. That is, the output signal of the pickup coil 460 is prevented from including a signal indicating the strength of the magnetic field of the power feeding element 440, and the pickup coil 460 mainly receives the power when the power receiving element 510 and the power feeding element 440 are brought close to each other. It functions as a sensor that detects the strength of the magnetic field of the element 510.

  According to the present embodiment, the same effects as those of the third embodiment can be obtained. In addition, the cost of the RF reader can be reduced by using an inexpensive pickup coil as the magnetic sensor.

<Supplement>
In the third embodiment and the fourth embodiment, the control unit 420 displays the position and / or direction of the power receiving element 510 on the display unit 470 and notifies the user about the position and / or direction of the power receiving element 510. I decided to do it. However, the position and / or direction of the power receiving element 510 may be notified to the user by a method other than display. For example, the position and / or direction of the power receiving element 510 may be notified by voice through a speaker. That is, any notification method may be used as long as the position and / or direction of the power receiving element 510 can be recognized.

  In the third embodiment and the fourth embodiment, when the power feeding device 400 includes two magnetic sensors 460, the one-dimensional direction of the power receiving element 510 is specified. However, the power feeding device 400 further includes the power feeding device 400. It is good also as specifying a two-dimensional direction as having an acceleration sensor which detects the moving direction of (2).

  A specific description will be given with reference to FIG. FIG. 44 is an explanatory diagram of this modification of the power supply apparatus 400. The reader 2 has pickup coils 460c and 460d as the magnetic sensor 460. In this example, the output signal of the pickup coil 460d is stronger than the output signal of the pickup coil 460c. Therefore, it is specified that the power receiving element 510 exists in the direction of the pickup coil 460c (left direction) with the center point O of the power feeding element 440 as a reference. In addition, referring to fluctuations in the magnetic field intensity detected by the pickup coils 460c and 460d, if the magnetic field intensity detected by the pickup coils 460c and 460d is weakened when the power feeding device 400 is moved in the direction of the arrow D3, It can be specified that the power receiving element 510 exists in the upward direction. That is, the power receiving element 510 is specified to exist in the left direction and the upward direction, that is, the upper left direction from the power supply apparatus 400.

  On the other hand, when the power feeding device 400 is moved in the direction of the arrow D4, it is possible to specify that the power receiving element 510 exists in the downward direction if the strength of the magnetic field detected by the pickup coils 460c and 460d is weakened. That is, the power receiving element 510 is specified to exist in the left direction and the lower direction, that is, the lower left direction from the power supply apparatus 400.

  In the third and fourth embodiments, the output signal of one magnetic sensor 460 is compared with a threshold value, or the output signals of two or more magnetic sensors 460 are compared, and the one-dimensional direction of the power receiving element 510 Alternatively, although the two-dimensional direction is indicated, the barycentric coordinate P of the magnetic field generated from the power receiving element 510 is calculated, and the direction of the barycentric coordinate P with reference to the center point O of the power feeding element 440 is specified as the direction of the power receiving element 510 It is good to do.

When the position coordinate of the j-th magnetic sensor 460 is (X _j , Y _j ) and the output signal of the magnetic sensor 460 is Hj (A / m), the barycentric coordinates P ( X, Y) are X and Y satisfying the following expressions (3) and (4).
Σ (X _j −X) Hj = 0 (3)
Σ (Y _j −Y) Hj = 0 (4)

  In the third embodiment and the fourth embodiment, a loop antenna wound in a planar spiral shape is used as the feed element 440. However, the present invention is not limited to this. For example, as shown in FIG. A loop antenna may be used. 45 and 46 are modifications of the power feeding element 440 shown in FIGS. 30 and 31, respectively, but may be applied to the power feeding element 440 of other embodiments.

Here, the strength of the magnetic field of the feed element 440 generated in the first region and the strength of the magnetic field of the feed element 440 generated in the second region will be described. As shown in the above embodiment, the strength of the magnetic field generated in the second region of the spiral feed element 440 is affected by the magnetic field generated from all (four sides) of the feed element 440, whereas the first The strength of the magnetic field generated in the region is mainly affected by the magnetic field generated from a part (one side) of the feed element 440. Therefore, in general, the magnetic field strength of the second region is larger than the magnetic field strength of the first region.

When the magnetic sensor 460 is a pickup coil in order to make the magnetic field strength of the power feeding element 440 detected by the magnetic sensor 460 in such a situation substantially zero, as shown in FIGS. in 460 a sensor for detecting the intensity of the magnetic field of the first region (first sensor unit 466, first coil 468) sensor that detects the intensity of the magnetic field of the second region (second sensor 467, a second coil it may be to be greater than 469).

  Further, when the magnetic sensor 460 is the magnetoresistive element shown in FIGS. 30 and 31, the portion of the power feeding element 440 that generates the magnetic field detected by the magnetic sensors 460a and 460b in the first region as shown in FIG. On the other hand, the region where the magnetic sensor 460a detects the magnetic field strength may be set to a position farther than the region where the magnetic sensor 460b detects the magnetic field strength in the second region.

  That is, when the strength of the magnetic field in the first region is different from the strength of the magnetic field in the second region, the magnetic field in the region where the magnetic field strength is stronger than the detection of the magnetic field strength in the region where the magnetic field strength is weak. The magnetic sensor 460 may be disposed at a position where the detection of the intensity of the magnetic field is suppressed.

  Further, by adjusting the gain of the magnetic field output signal of the first region and / or the magnetic field output signal of the second region, the magnetic field strength of the power feeding element 440 detected by the magnetic sensor 460 is made substantially zero. It is good.

  In the third embodiment and the fourth embodiment, the case of supplying power to a portable electronic device such as a smartphone or a tablet terminal has been described as an example regarding the non-contact power supply system, but the power supply target is not limited to the portable electronic device. . For example, as shown in FIG. 50, power is supplied to a vehicle including a power receiving element (a passenger car is illustrated in FIG. 50, but it may be a light vehicle such as a motorcycle, a bicycle, or a walking assist vehicle (so-called silver car)). Also good.

  In FIG. 50, the power receiving element 610 is arranged at a substantially central portion of the hood 600 a of the vehicle 600, and feeds power by bringing the power feeding device 400 close to the power receiving element 610. Even in such a case, the position and / or direction of the power receiving element 610 is detected with high accuracy based on the output signal of the magnetic sensor, and a notification regarding the positional deviation between the power feeding element 410 and the power receiving element 610 is given.

DESCRIPTION OF SYMBOLS 1 RF tag 2 RF reader 11 Antenna coil 12 Communication part 13 Memory | storage part 14 Control part 21 Antenna coil 22 Communication part 23 Detection part 24 Magnetic sensor 25 Display part 26 Control part 261 CPU
262 ROM
263 RAM
DESCRIPTION OF SYMBOLS 300 Contactless power supply system 400 Power supply apparatus 410 Power supply part 420 Control part 430 Power supply drive part 440 Power supply element 450 Detection part 460 Magnetic sensor 470 Display part 500 Power reception apparatus 510 Power reception element 520 Rectification part 530 Power supply part 540 Control part 550 Rechargeable battery 560 Storage Part

Claims (9)

A sensor for detecting the strength of the magnetic field;
An antenna that generates a magnetic field and wirelessly transmits power to an external device;
Detecting means for detecting a predetermined position between the external device and the antenna based on an output signal of the sensor;
The sensor is a power feeding device including one circular pickup coil arranged so as to straddle a first region and a second region in which directions of a magnetic field generated from the antenna are opposite to each other.   The power supply device according to claim 1, wherein the sensor is disposed on a plane perpendicular to a winding center axis of the antenna.   The power supply device according to claim 1, wherein a plurality of the sensors are arranged.   The power feeding device according to claim 3, wherein two sensors are arranged, and a center point of the antenna is between the two sensors. The pickup coil has a first sensor unit that detects the strength of a part of the magnetic field in the first region and a second sensor unit that detects the strength of a part of the magnetic field in the second region,
Wherein the first sensor unit feeding apparatus according to any one of the second sensor portion is greater than claims 1-4. The power feeding device according to claim 5 , wherein the magnetic field strength of the second region is larger than the magnetic field strength of the first region. The antenna is a loop antenna wound in a spiral shape,
The first region is outside the loop of the loop antenna;
The power feeding device according to claim 6 , wherein the second region is inside the loop of the loop antenna. The power feeding device according to any one of claims 1 to 7 , wherein a loop shape of the antenna when viewed from a winding central axis direction of the antenna is a rectangular shape. The power feeding device according to claim 8 , wherein the rectangular shape is a rectangular shape including a long side and a short side.