JP5529697B2 - Non-contact charging device and non-contact charging system - Google Patents

Description

  The present invention relates to a contactless charging apparatus that performs charging and information communication in a contactless manner with respect to a device to be charged that incorporates a secondary battery.

  As a charging means for electronic devices (charged devices) such as mobile phones, digital cameras, PDAs, media players, and small television receivers with a built-in secondary battery, it can be connected to a fixed power source such as a commercial power source or a large-capacity battery. There is a non-contact charging device that is mounted and charges a device to be charged in a non-contact manner using, for example, electromagnetic induction or magnetic field resonance. Such a non-contact charging device does not cause poor contact with the device to be charged, and both the case of the device to be charged and the non-contact charging device are waterproof because there are no exposed contacts on the surface. It has the advantage of being able to have a sex.

  In such a non-contact charging device, information such as the remaining battery level and identification information indicating that the device to be charged is a regular charging target rather than a foreign object or other device can be charged using, for example, electromagnetic wave conveyance. A function of communicating information with a device in a contactless manner has also been proposed.

  A non-contact charging apparatus that performs charging and information communication in a non-contact manner is disclosed in, for example, Patent Document 1. The non-contact charging system disclosed in Patent Document 1 includes a device to be charged with a built-in secondary battery and a non-contact charging device that performs charging and information communication in a non-contact manner with respect to the device to be charged. The non-contact charging device communicates information with a to-be-charged device, a power transmission unit that outputs power for charging, a power transmission coil that is connected to the power transmission unit, and transmits power for charging using electromagnetic induction or magnetic resonance. And a communication antenna that is connected to the communication unit and transmits / receives an information signal to be communicated using an electromagnetic wave carrier. The device to be charged includes a power receiving unit to which charging power is input, a power receiving coil that is connected to the power receiving unit and receives power for charging using electromagnetic induction or magnetic resonance, and power input to the power receiving unit. A charging unit that charges a secondary battery using a communication unit, a communication unit as a communication unit that communicates information with a non-contact charging device, and an information signal to be communicated using an electromagnetic wave carrier And a communication antenna. In this example, the communication unit of the device to be charged is configured by a non-contact IC card unit, and the communication unit of the non-contact charging device is configured by an IC card reader. The non-contact charging device of Patent Literature 1 operates to acquire and determine identification information from the non-contact IC card unit of the device to be charged, and to charge only the regular device to be charged.

  By the way, since the to-be-charged device has a built-in battery, it is usually a portable electronic device, and a reduction in size, thickness and weight are desired. In response to such a demand, in a device to be charged, the power receiving coil and the communication antenna are often arranged close to each other in a small and thin casing. Accordingly, also in the non-contact charging device, the power transmission coil and the communication antenna are arranged close to each other. In this case, the magnetic field for power delivery sent from the power transmission coil causes electromagnetic induction on the communication antenna, adversely affects the operation of the communication unit, and information communication is hindered. As a workaround, a non-contact charging device configured to stop the output of the power transmission unit (operation of the power transmission unit) when communicating information with the device to be charged has been proposed.

Patent Gazette of Japanese Patent No. 4155408

  However, even in a non-contact charging device configured to stop the operation of the power transmission unit during information communication, the electronic circuit of the power transmission unit that has stopped operating includes impedance elements such as resistors, inductors, and capacitors. Such an electronic circuit and a power transmission coil form an impedance circuit that can be operated passively.

  For this reason, electromagnetic waves that carry information signals that are transmitted and received through the respective communication antennas between the contactless charging device and the device to be charged during information communication are transmitted to the power transmission coils that are arranged close to these communication antennas. Cause electromagnetic induction. This electromagnetic induction is more likely to occur as the distance between the communication antenna and the power transmission antenna is smaller.

  And by this electromagnetic induction, an electric current flows into the above-mentioned impedance circuit, and electric power is consumed by the impedance element contained in an impedance circuit. As a result, a part of the information signal that should be originally transmitted and received between the non-contact charging device and the device to be charged is deprived, so that a sufficient level of information signal is not transmitted and received and information communication is hindered. It will be.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is a non-contact charging apparatus for charging information to be charged using electromagnetic induction or magnetic field resonance and performing information communication using electromagnetic wave conveyance. It is providing the non-contact charging device which can perform favorable information communication between.

  The other subject of this invention is providing the non-contact charging system which has such a non-contact charging device and a to-be-charged apparatus.

According to the present invention, a non-contact charging apparatus that performs charging using electromagnetic induction or magnetic resonance and performs information communication using electromagnetic wave conveyance in a non-contact manner with respect to a charging target device incorporating a secondary battery. A non-contact power transmission coil for transmitting charging power and a communication antenna for transmitting and receiving information communication signals, and configured to stop charging power transmission during information communication The charging device includes a switch inserted in parallel with the power transmission coil, and the switch is configured to be turned on during information communication, and the power transmission coil and the communication antenna overlap each other at a distance. Thus , a non-contact charging device can be obtained.

  The switch may be configured using a semiconductor element.

  The switch may have an internal resistance of 5Ω or less.

According to the present invention, the non-contact charging device, the non-contact charging system, characterized by having a target charging device is obtained.

  The non-contact charging apparatus according to the present invention can perform good information communication with a device to be charged.

  In addition, the non-contact charging device according to the present invention can arrange the communication antenna and the power transmission coil closer to each other without hindering information communication, and can reduce the size, thickness, and weight of the device. Useful for.

It is a block diagram which shows the structure of the non-contact charge system by Example 1 of this invention. It is a block diagram which shows the structure of the non-contact charging system by Example 2 of this invention. It is a block diagram which shows the structure of the non-contact charge system by Example 3 of this invention. It is a perspective view which shows notionally the power transmission coil and communication antenna in the non-contact charging device by Example 3 of this invention. It is a figure which shows the relationship between the internal resistance of the switch in the non-contact charging device as an experimental result of Example 4 of this invention, and the magnetic field intensity which a communication antenna emits toward a communicating party.

  The non-contact charging apparatus according to the present invention includes a power transmission coil that transmits charging power and a communication antenna that transmits and receives information communication signals. During information communication, transmission of charging power is stopped.

  In particular, the non-contact charging apparatus has a switch inserted in parallel with the power transmission coil. This switch is configured to be turned on (connected) during information communication.

  With the above-described configuration, during information communication, the power transmission coil is in a state that can be regarded as a simple conductor loop that includes almost no impedance component, independent of a circuit (power transmission unit) that outputs charging power. For this reason, the electric current induced in the power transmission coil by the electromagnetic waves emitted from the respective communication antennas in the non-contact charging device and the device to be charged hardly flows into the electronic circuit of the power transmission unit having many impedance elements. As a result, there is little energy loss of electromagnetic waves that carry information signals to be transmitted / received between the non-contact charging device and the device to be charged via each communication antenna, information signals of sufficient level can be transmitted / received, and good information Communication can be performed.

  Further, the non-contact charging device according to the present invention arranges the power transmission coil and the communication antenna closer to each other without hindering information communication, for example, by placing the power transmission coil and the communication antenna at a slight distance. Can be arranged in an overlapping manner, which is useful for reducing the size, thickness and weight of the apparatus.

  In addition, this non-contact charging apparatus is made to comply with the NFCIP-1 (Near Field Communication Interface and Protocol-1) standard, which is an international standard for short-range wireless communication, for example, as a communication method using the communication unit and the communication antenna. Is possible.

  Hereinafter, with reference to the drawings, more specific embodiments of the contactless charging apparatus and the contactless charging system according to the present invention will be described in detail.

  Referring to FIG. 1, a contactless charging system according to a first embodiment of the present invention includes a charged device 600 such as a mobile phone with a built-in secondary battery, and non-contact electromagnetic induction or magnetic field resonance with respect to the charged device 600. And a non-contact charging apparatus 100 that performs information communication using electromagnetic wave conveyance.

  The non-contact charging device 100 is connected to a commercial power source, and an AC adapter unit (not shown) that supplies power to the device, a power transmission unit 110 that outputs charging power, and the charging power to electromagnetic induction or magnetic field. A power transmission coil 120 that transmits using resonance, a communication unit 130 that communicates information with the device 600 to be charged, and a communication antenna 140 that is connected to the communication unit 130 and transmits and receives information signals to be communicated using electromagnetic wave conveyance. And a table (not shown) having a device mounting surface on which the device to be charged of the non-contact charging apparatus 100 is mounted.

  The power transmission coil 120 and the communication antenna 140 are arranged side by side, and the separation distance d1 is about several mm.

  In addition, the power transmission unit 110 is configured to stop the transmission of power for charging during information communication by the communication unit 130 and the communication antenna 140.

  A device to be charged 600 includes a secondary battery 640 that supplies power to the device, a power receiving coil 610 that receives power for charging sent from the non-contact charging device 100 using electromagnetic induction or magnetic resonance, and a device for charging A power receiving unit 620 to which power is input, a charging unit 630 that charges the secondary battery 640 using the power input to the power receiving unit 620, a communication unit 650 that communicates information with the non-contact charging device 100, A communication antenna 660 is connected to the communication unit and transmits / receives an information signal to be communicated using an electromagnetic wave carrier.

  In particular, the contactless charging apparatus 100 includes a switch 150 inserted in parallel with the power transmission coil 120 and a switch control unit 160. The switch 150 is a mechanical switch.

  The switch control unit 160 is connected to the communication unit 130 and the power transmission unit 110, acquires a signal indicating whether information communication is in progress from the communication unit 130 or the power transmission unit 110, and based on this, the switch 150 is turned on during information communication ( Control is performed so that it is turned off (disconnected).

  Therefore, during information communication, in addition to the operation of the power transmission unit 110 being stopped, the power transmission coil 120 is in a state that can be regarded as a simple wire loop that is independent of the power transmission unit 110 and includes almost no impedance component. For this reason, the electric current induced in the power transmission coil 120 by the electromagnetic waves emitted from the communication antennas 140 and 660 in the non-contact charging apparatus 100 and the to-be-charged device 600 almost flows into the electronic circuit of the power transmission unit 110 having many impedance elements. There is no. As a result, there is little energy loss of electromagnetic waves that carry information signals to be transmitted and received between the contactless charging apparatus 100 and the to-be-charged device 600 via the communication antennas 140 and 660, and an information signal with a sufficient level is transmitted and received. And good information communication can be performed.

  The second embodiment of the present invention is different from the first embodiment in that the switch inserted in parallel with the power transmission coil is configured using a semiconductor element. For this reason, detailed description of the same or similar parts as in the first embodiment will be omitted.

  Referring to FIG. 2, the non-contact charging system according to the second embodiment of the present invention includes a charged device 600 such as a mobile phone with a built-in secondary battery, and non-contact electromagnetic induction or magnetic field resonance with respect to the charged device 600. And a non-contact charging device 200 that performs information communication using electromagnetic wave conveyance.

  The non-contact charging device 200 includes an AC adapter unit (not shown), a power transmission unit 110, a power transmission coil 120, a communication unit 130, a communication antenna 140, and a table (not shown) provided with a device mounting surface. And have. The power transmission coil 120 and the communication antenna 140 are arranged side by side, and the separation distance d1 is about several mm. The power transmission unit 110 is configured to stop the transmission of power for charging during information communication by the communication unit 130 and the communication antenna 140.

  Charged device 600 includes secondary battery 640, power receiving coil 610, power receiving unit 620, charging unit 630, communication unit 650, and communication antenna 660.

  The non-contact charging device 200 includes a switch 250 inserted in parallel with the power transmission coil 120 and a switch control unit 260.

  The switch 250 is configured using a semiconductor element such as an FET (Field-Effect Transistor).

  The switch control unit 260 is connected to the communication unit 130 and the power transmission unit 110, acquires a signal indicating whether information communication is in progress from the communication unit 130 or the power transmission unit 110, and based on this, the switch 250 is turned on during information communication ( Control is performed so that it is turned off (disconnected).

  Therefore, during information communication, in addition to the operation of the power transmission unit 110 being stopped, the power transmission coil 120 is in a state that can be regarded as a simple wire loop that is independent of the power transmission unit 110 and includes almost no impedance component. For this reason, the electric current induced in the power transmission coil 120 by the electromagnetic waves emitted from the communication antennas 140 and 660 in the non-contact charging device 200 and the to-be-charged device 600 almost flows into the electronic circuit of the power transmission unit 110 having many impedance elements. There is no. As a result, there is little energy loss of electromagnetic waves that carry information signals to be transmitted / received between the non-contact charging device 200 and the to-be-charged device 600 via the communication antennas 140 and 660, and an information signal with a sufficient level is transmitted / received. And good information communication can be performed.

  The third embodiment of the present invention is different from the second embodiment in that the power transmission coil and the communication antenna are superimposed. For this reason, detailed description of the same or similar parts as those in the second embodiment will be omitted.

  Referring to FIG. 3, a non-contact charging system according to a third embodiment of the present invention includes a charged device 800 such as a mobile phone incorporating a secondary battery, and electromagnetic induction or magnetic field resonance in a non-contact manner with respect to the charged device 800. And a non-contact charging device 300 that performs information communication using electromagnetic wave conveyance.

  The non-contact charging apparatus 300 includes an AC adapter unit (not shown), a power transmission unit 110, a power transmission coil 320, which will be described later, a communication unit 130, a communication antenna 340, which will be described later, and a table (equipment mounting surface). (Not shown). The power transmission unit 110 is configured to stop the transmission of power for charging during information communication by the communication unit 130 and the communication antenna 340.

  Charged device 800 includes secondary battery 640, power receiving coil 810 described later, power receiving unit 620, charging unit 630, communication unit 650, and communication antenna 860 described later.

  The non-contact charging apparatus 300 includes a switch 250 inserted in parallel with the power transmission coil 320 and a switch control unit 260. The switch 250 is configured using a semiconductor element such as an FET.

  Referring also to FIG. 4, both the power transmission coil 320 and the communication antenna 340 have a coil shape (loop shape). The outer sizes of power transmission coil 320 and communication antenna 340 are substantially the same. For example, the outer sizes of the power transmission coil 320 and the communication antenna 340 are both 100 mm × 180 mm.

  The power transmission coil 320 and the communication antenna 340 are overlapped with each other so that the centers of the respective loops are substantially coincided with each other inside the table provided with the device mounting surface. The power transmission coil 320 and the communication antenna 340 are disposed at a relatively small distance d3. For example, the distance d3 is 5 mm.

  In this example, the communication antenna 340 is disposed closer to the device placement surface than the power transmission coil 320. Conversely, the power transmission coil 320 may be disposed closer to the device placement surface than the communication antenna 340. Good.

  As described above, since the outer sizes of the power transmission coil 320 and the communication antenna 340 are substantially the same, and the centers of the respective loops are approximately the same, charging the charged device 800 on the device mounting surface of the table. The range and the information communication range are approximately the same range in the XY direction.

  Regarding the charging range in the Z direction perpendicular to the XY direction and the information communication range, both ranges can be made approximately the same range by adjusting the output of the power transmission unit 110 and the output and sensitivity of the communication unit 130. it can.

  As described above, since the charging range and the information communication range are the same range, the power receiving coil 810 and the communication antenna 860 are overlapped and arranged at a relatively small distance in the casing of the device 800 to be charged. be able to. That is, in the present invention, not only the non-contact charging device but also the charged device can be reduced in size and thickness.

  The switch control unit 260 is connected to the communication unit 130 and the power transmission unit 110, acquires a signal indicating whether information communication is in progress from the communication unit 130 or the power transmission unit 110, and based on this, the switch 250 is performing information communication. Control is performed so that it is turned on (connected) while it is turned off (disconnected) at other times.

  Therefore, during the information communication, in addition to the operation of the power transmission unit 110 being stopped, the power transmission coil 320 is in a state that can be regarded as a simple conductor loop that is independent of the power transmission unit 110 and includes almost no impedance component. For this reason, the current induced in the power transmission coil 320 by the electromagnetic waves emitted from the communication antennas 340 and 860 in the non-contact charging apparatus 300 and the charged device 800 almost flows into the electronic circuit of the power transmission unit 110 having a large number of impedance elements. There is no. As a result, there is little energy loss of electromagnetic waves that carry information signals to be transmitted and received between the contactless charging apparatus 300 and the charged device 800 via the communication antennas 340 and 860, and an information signal with a sufficient level is transmitted and received. And good information communication can be performed.

  In the present invention, it is desirable that the loop constituted by the power transmission coil and the switch during information communication does not include an impedance component. For this reason, it is desirable that the internal resistance (ON resistance) of the switch 150 which is the mechanical switch of the first embodiment and the switch 250 configured using the semiconductor elements of the second and third embodiments are low. However, semiconductor switches generally have an internal resistance of the order of several ohms, compared to an internal resistance of approximately 0 ohms except for mechanical switches.

  Therefore, an experiment was conducted to determine how much the internal resistance of the switch inserted in parallel with the power transmission coil is allowed in practice in the present invention.

  In the non-contact charging system of the third embodiment shown in FIG. 3, a variable resistor is attached in place of the switch 250 to stop the operation of the power transmission unit 110 and from the communication antenna 340 to the communication antenna 860 of the device 800 to be charged. An experiment was conducted in which the electromagnetic field intensity was transmitted between the communication antenna 340 and the communication antenna 860 while changing the resistance value of the variable resistor. The outer dimensions of the power transmission coil 320, the communication antenna 340, the power reception coil 810, and the communication antenna 860 are 100 mm × 180 mm, the separation distance d3 between the power transmission coil 320 and the communication antenna 340 is 5 mm, and the separation between the power reception coil 810 and the communication antenna 860. The distance was 5 mm, and the signal output from the communication unit 130 was 1.0 W. The result is shown in FIG.

  As a comparative example, an experiment was conducted in which the power transmission coil 320 and the switch 250 were removed from the non-contact charging apparatus 300 shown in FIG. 3 and the other parameters were the same as those described above. The magnetic field strength in this case was 7.5 A / m (ampere per meter).

  As is apparent from FIG. 5, the magnetic field strength between the communication antenna of the non-contact charging device and the communication antenna of the device to be charged decreases as the resistance value increases. Here, considering that the magnetic field strength is 7.5 A / m when information communication can be performed at a sufficient level without the presence of the power transmission coil 320, in the present invention, for example, 80 when the power transmission coil is not present. The resistance value when a magnetic field strength of at least% was obtained was 5Ω or less. Therefore, it is presumed that good information communication can be performed by adopting a semiconductor switch or mechanical switch having a resistance value of 5Ω or less as an internal resistance.

  In addition, it is desirable that the impedance component of the conductive loop constituted by the power transmission coil and the switch at the time of information communication is small not only for the R component but also for the L component and the C component as described above.

  Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the technical scope described in the claims.

  For example, a switch may be inserted in parallel to the power receiving coil of the device to be charged so that the switch is turned on (connected) during information communication.

100, 200, 300 non-contact charging apparatus 110 power transmitting section 120 or 320 transmitting coil 130 communication unit 140, 340 communication antenna 150, 250 switch 160 switch controller 600, 800 to be charged devices 610,810 receiving coil 620 receiving unit 630 charging unit 640 Secondary battery 650 Communication unit 660, 860 Communication antenna

Claims (4)

A non-contact charging device that performs charging using electromagnetic induction or magnetic resonance and non-contact charging with a built-in secondary battery, and performs information communication using electromagnetic wave conveyance. In a non-contact charging device configured to have a power transmission coil for transmitting power and a communication antenna for transmitting and receiving signals for information communication, and configured to stop the transmission of power for charging during information communication,
A switch inserted in parallel with the power transmission coil;
The switch is configured to be turned on during information communication ,
The non-contact charging device, wherein the power transmission coil and the communication antenna are overlapped with a distance .   The contactless charging apparatus according to claim 1, wherein the switch is configured using a semiconductor element.   The non-contact charging device according to claim 1, wherein the switch has an internal resistance of 5Ω or less. Non-contact charging system, characterized in that it comprises a non-contact charging apparatus according to any one of claims 1 to 3, and the object to be charged device.

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