JP2010119193A - Resonant charging system, power feeding device, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resonant charging system wherein the state of charge of the secondary battery in electronic equipment on the power receiving side can be detected in a power feeding device without providing a communicating means on the power feeding side or the power receiving side. <P>SOLUTION: The resonant charging system is comprised of: the power feeding device 1 having a primary coil L1 connected to a first resonance circuit 10; and the electronic equipment 5 having a secondary coil L2 connected to a second resonance circuit 13. When an alternating-current electric field of a resonance frequency is applied to the primary coil L1, power is induced in the secondary coil L2 by magnetic resonance and the secondary battery 6 of the electronic equipment 5 is thereby charged. In the electronic equipment 5, one resonance frequency can be arbitrarily set from among multiple resonance frequencies. The power feeding device 1 includes a detection unit 11 that detects a resonance frequency set in the electronic equipment 5 and continues power feeding at the detected resonance frequency. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resonance charging system that charges a rechargeable secondary battery included in an electronic device by magnetic resonance, a power supply device that constitutes the resonance charging system, and an electronic device.

  In recent years, the adoption of non-contact power transmission technology for portable electronic devices, industrial devices, and the like has been spreading.

  In particular, this technology is useful for electric appliances and cordless telephones used around water such as electric toothbrushes and electric shavers, and is used in some products.

  As the non-contact charging system, for example, electromagnetic induction between a primary coil provided on the power supply side (power supply device) and a secondary coil provided on the power reception side (electronic device) is used. There is an “electromagnetic induction charging system”. In this system, when charging efficiency is taken into consideration, it is necessary that the coils provided in the power supply side and power reception side devices are arranged opposite to each other and close to each other.

  On the other hand, technologies for supplying power wirelessly to devices several meters away have been developed. It is a “resonant charging system” that uses the electric field or magnetic field resonance between the coil on the power feeding side and the coil on the power receiving side.

  For example, Patent Document 1 discloses a technique for efficiently charging an automobile ignition key using resonance frequencies on a power feeding side and a power receiving side.

In other words, the technique disclosed in Patent Document 1 supplies a plurality of frequency components separated by a certain distance to the power receiving side with respect to the resonance frequency on the power receiving side, which varies depending on environmental conditions such as temperature and humidity. Thus, charging is performed at an optimal resonance frequency.
Japanese Patent Laid-Open No. 11-46157

  However, in the technique proposed in Patent Document 1, waste of power is inevitable because the power supply side continues to supply power even when charging on the power receiving side is completed.

  In addition, the power supply apparatus does not include means for detecting the state of charge of the secondary battery in the electronic device on the power reception side, and it is necessary to separately provide communication means for the devices on the power supply side and the power reception side.

  An object of the present invention is to provide a resonance charging system, a power feeding device, and a power feeding device capable of detecting a charging state of a secondary battery in an electronic device on the power receiving side without providing communication means on the power feeding side and the power receiving side. To provide electronic equipment.

  In order to achieve the above object, a resonance charging system according to claim 1 includes a power supply device including a primary coil connected to a first resonance circuit, and an electronic device including a secondary coil connected to a second resonance circuit; In the resonance charging system in which when an alternating electric field having a resonance frequency is applied to the primary coil, power is induced in the secondary coil by magnetic resonance, and the secondary battery of the electronic device is charged. It is possible to arbitrarily set one resonance frequency from a plurality of resonance frequencies, and the power supply apparatus includes detection means for detecting the resonance frequency set by the electronic device, and the detected frequency is detected. The power supply is continued at the resonance frequency.

  According to a sixth aspect of the present invention, there is provided a resonance charging system according to the first aspect.

  The electronic device according to claim 7 constitutes the resonance charging system according to claim 1.

  According to the resonance charging system of the present invention, it is possible to detect the charging state of the secondary battery in the electronic device on the power receiving side in the power feeding device without providing communication means on the power feeding side and the power receiving side.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram of a resonance charging system according to an embodiment of the present invention.

  In the resonance charging system of the present embodiment, the power supply device 1 charges the rechargeable secondary battery 6 in the electronic device 5 on the power receiving side using magnetic resonance.

  The electronic device 5 is an imaging device, and includes a lens unit 7 and a strobe light emitting unit 8 for photographing on the front surface, and a rechargeable secondary battery 6 (see FIG. 3 described later) inside.

  The power feeding device 1 is provided with a socket 4 for supplying power to the power feeding device 1 from a household outlet. In addition, the power supply device 1 is provided with a charge start / end switch 2 for the user to start or end charging of the electronic device 5, and to the power supply device 1 by the ON / OFF operation of the switch 2. Power is supplied or power supply is cut off.

  The display unit 3 of the power supply device 1 is for notifying the user of the charging state of the secondary battery 6 inside the electronic device 5. For example, the remaining battery level of the secondary battery 6 is a predetermined charge amount. When it is approximately half, “charge 50%” is displayed. When the secondary battery 6 is fully charged, “charge complete” is displayed.

  2 is a block configuration diagram of the power supply apparatus in FIG. 1, and FIG. 3 is a block configuration diagram of the electronic apparatus in FIG.

  As shown in FIG. 2, the power supply apparatus 1 includes a first resonance circuit 10 for performing LC resonance, and a first resonance circuit 10 for uniquely determining the LC characteristics of the first resonance circuit 10. There is one circuit controller 9.

  A primary coil L1 is provided in the first resonance circuit 10. When an alternating electric field having a resonance frequency is applied to the primary coil L1, an oscillating magnetic field is generated around the primary coil L1, and power is transmitted to the secondary coil L2 (FIG. 3) inside the electronic device 5 on the power receiving side by magnetic resonance. The rechargeable secondary battery 6 is charged.

  As shown in FIG. 3, inside the electronic device 5, there is a second resonance circuit 13 including a secondary coil L <b> 2 for resonating with the primary coil L <b> 1 in the power feeding device 1, and the second There is a second circuit control unit 12 for uniquely determining the LC characteristics of the resonance circuit 13.

  Moreover, the power converter 14 which converts the magnetic energy at the time of LC resonance of the primary coil L1 and the secondary coil L2 into electric energy is provided, and the secondary from which the electric power from the power converter 14 can be charged in the electronic device 5 Supply to battery 6.

  FIG. 4 is a configuration diagram of the first resonance circuit in FIG.

  The first resonance circuit 10 in the power supply device 1 is provided with a primary coil L1 in order to function as an LC circuit capable of arbitrarily setting a plurality of different resonance frequencies. Is connected to the first circuit control unit 9.

  Further, in the first resonance circuit 10, a plurality of capacitors having different capacities, here, C11, C12, C13, and C14 respectively have corresponding resistors R11, R12, R13, and R14 and switches SW11, SW12, SW13, and SW14. Are connected in parallel.

  The detection unit 11 in the first resonance circuit 10 reads the value of the current flowing through the primary coil L1 in the first resonance circuit 10 at a constant timing of several ms while power is supplied to the power supply device 1. ing. Then, the detection unit 11 determines whether or not the primary coil L1 of the power feeding device 1 and the secondary coil L2 of the electronic device 5 are in a resonance state.

  That is, the current value flowing through the coil is determined by the LC characteristics of the resonance circuit, but when the primary coil L1 and the secondary coil L2 are in a resonance state, the current value flowing through the primary coil L1 is the minimum value. Further, when the primary coil L1 and the secondary coil L2 are not in a resonance state, the value of the current flowing through the primary coil L1 is a value other than the minimum value.

  The first circuit controller 9 controls whether the switches SW11, SW12, SW13, and SW14 are connected to the circuit, and is connected to the first resonance circuit 10 among the plurality of capacitors C11, C12, C13, and C14. Capacitor is set.

  The LC characteristics of the first resonance circuit 10 are uniquely set by the difference in the capacitors connected to the first resonance circuit 10 among the plurality of capacitors C11, C12, C13, C14. The resonance frequency of the primary coil L1 inside 1 is determined.

  Specifically, the first circuit control unit 9 causes the resonance frequency to be set to A [Hz] by turning on only SW11 in the first resonance circuit 10, and resonant by turning on only SW12. Let the frequency be B [Hz]. Similarly, the resonance frequency is set to C [Hz] by turning on only SW13, and the resonance frequency is set to D [Hz] by turning on only SW14.

  FIG. 5 is a block diagram of the second resonance circuit in FIG.

  As shown in FIG. 5, the second resonance circuit 13 inside the electronic device 5 functions as an LC circuit that can arbitrarily set a plurality of different resonance frequencies, like the first resonance circuit 10. A secondary coil L2 is provided. The second resonance circuit 13 is connected to the second circuit control unit 12.

  Further, in the second resonance circuit 13, a plurality of capacitors having different capacities, here, C21, C22, C23, C24, respectively correspond to resistors R21, R22, R23, R24 and switches SW21, SW22, SW23, SW24. Are connected in parallel.

  Further, as in the case of the power feeding apparatus 1, the second circuit control unit 12 controls whether or not the switches SW21, SW22, SW23, and SW24 are connected to the circuit. The second circuit control unit 12 sets a capacitor to be connected to the second resonance circuit 13 among the plurality of capacitors C21, C22, C23, and C24.

  The LC characteristic of the second resonance circuit 13 is uniquely set by the difference in the capacitors connected to the second resonance circuit 13 among the plurality of capacitors C21, C22, C23, C24. 5, the resonance frequency of the secondary coil L2 inside is determined.

  Specifically, the resonance frequency of the secondary coil L <b> 2 inside the electronic device 5 is uniquely determined by the second circuit control unit 12 according to the remaining amount of the secondary battery 6.

  For example, if the remaining battery level of the secondary battery 6 is 0 to 60% of the fully charged state, the resonance frequency is set to A [Hz] by turning on only the SW 21 in the second resonance circuit 13, 61 If it is ˜80%, the resonance frequency is set to B [Hz] by turning on only SW22.

  Similarly, if 81 to 95%, only the SW23 is turned on to set the resonance frequency to C [Hz], and if 96 to 100%, only the SW24 is turned to ON to set the resonance frequency to D [ Hz].

  The resonance frequencies A to D [Hz] here are the same as the resonance frequencies A to D [Hz] in the above-described power feeding device 1.

  The primary coil L1 and the secondary coil L2 can set different resonance frequencies depending on the connection state of the switches in the respective resonance circuits, but as described above, the resonance frequencies of the primary coil L1 and A plurality of resonance frequencies of the secondary coil L2 are common. Therefore, when the electronic device 5 is charged, charging is performed by using a common resonance frequency in the primary coil L1 and the secondary coil L2.

  The charging method of the present invention by using a plurality of common resonance frequencies will be described.

  FIG. 6 is a flowchart showing a processing procedure centering on the power feeding apparatus side during charging by the resonant charging system of FIG. 1.

  First, when the user turns on the switch 2 of the power supply device 1, power is supplied to the first resonance circuit 10, the first circuit control unit 9, and the detection unit 11, and charging of the electronic device 5 is started. To do.

  On the power supply device 1 side, in order to detect the remaining battery level of the secondary battery 6 inside the electronic device 5 at the start of charging, the first circuit control unit 9 of the power supply device 1 Only SW11 is turned on, and the remaining SW12, SW13, and SW14 are turned off.

  By this switching operation, only the capacitor C11 is connected in the first resonance circuit 9, and after the resonance frequency of the primary coil L1 is set to A [Hz], it is in a resonance state with the secondary coil L2 inside the electronic device 5. The detection unit 11 determines whether or not there is.

  At the start of charging, if the remaining battery level of the secondary battery 6 in the electronic device 5 is 60% or less, that is, if the resonant frequency of the secondary coil L2 is A [Hz], the secondary coil 6 resonates with the primary coil L1 inside the power feeding device 1. The current flowing in the first resonance circuit 10 of the power feeding device 1 is minimized. Thereby, it can discriminate | determine by the detection part 11 by the electric power feeder 1 side that it is a resonance state, and the charge to the electronic device 5 is continued (step S601, S602).

  Further, at the start of charging, when the resonance frequency of the secondary coil L2 inside the electronic device 5 is other than A [Hz], for example, B [Hz], the resonance with the primary coil L1 is not performed. Therefore, the detection unit 11 in the power feeding apparatus 1 determines that there is no change in the current flowing through the first resonance circuit 10 and that the secondary coil L2 is not in a resonance state.

  The same applies to the case where the resonance frequency of the secondary coil L2 in the electronic device 5 is C [Hz] and D [Hz].

  In this case, the first circuit controller 9 of the power supply device 1 uses the first resonance circuit 10 to set the set frequency to B [Hz], which is the frequency next to A [Hz]. The switch SW11 connected to the circuit 10 is switched to the OFF state. Subsequently, an operation of switching only the SW 12 to the ON state is performed.

  Similarly to the above, the detection unit 11 determines whether or not the secondary coil L2 in the electronic device 5 is in a resonance state (steps S603 to S605).

  In addition, when the resonance frequency of the secondary coil L2 inside the electronic device 5 is C [Hz] at the start of charging, the first resonance circuit is set to set the set resonance frequency on the power feeding device 1 side to C [Hz]. SW12 connected to 10 is switched to the OFF state. Subsequently, an operation of switching only the SW 13 to the ON state is performed. Then, the user is notified that charging is almost complete (steps S606 to S608).

  In addition, when the resonance frequency of the secondary coil L2 in the electronic device 5 is D [Hz] at the start of charging, the first resonance circuit is set to set the set resonance frequency on the power feeding device 1 side to D [Hz]. 10 is switched to the OFF state. Subsequently, an operation of switching only the SW 14 to the ON state is performed. Then, the user is notified of the completion of charging (steps S609 to S611).

  In this way, the power supply device 1 specifies the remaining battery level of the secondary battery 6 inside the electronic device 5 at the start of charging in the order of A, B, C, and D [Hz] using the resonance frequency. The resonance frequency to the electronic device 5 at the start of charging is determined.

  FIG. 7 is a flowchart showing a processing procedure centering on the electronic device side during charging by the resonant charging system of FIG. 1.

  The resonance frequency of the electronic device 5 is set to be different depending on the remaining battery level of the secondary battery 6 by the second circuit control unit 12 and the second resonance circuit 13. It shows that the resonance frequency transitions due to an increase in the remaining battery level during charging.

  At the start of charging, when both the power supply device 1 and the electronic device 5 are charged using the resonance frequency of A [Hz], the remaining battery capacity of the secondary battery 6 in the electronic device 5 becomes 61% or more. (Steps S701 to S704), the following processing is performed.

  That is, the second circuit control unit 12 in the electronic device 5 turns off the SW 21 and switches only the SW 22 to the ON state. Thereby, only the capacitor C22 is connected in the second resonance circuit 13, and the resonance frequency of the secondary coil L2 transitions to B [Hz].

  When a change in the resonance frequency of the electronic device 5 occurs, the value of the current flowing through the primary coil L1 of the power supply device 1 changes and the power supply device 1 does not resonate with the electronic device 5, that is, the secondary battery 6 is charged. It turns out that it was not made.

  Therefore, in the first circuit control unit 9 in the power supply apparatus 1, the SW 11 in the first resonance circuit 10 is turned off and only the SW 12 is turned on. Thereby, only the capacitor C12 is connected in the first resonance circuit 9, and the resonance frequency of the primary coil L1 is changed to B [Hz] to continue charging.

  When the remaining battery level of the secondary battery 6 reaches 81% of the fully charged state (steps S705 to S707), the SW 22 in the second resonance circuit 13 is turned off by the second circuit control unit 12. State, and only SW23 is switched to the ON state.

  As a result, only the capacitor C23 is connected in the second resonance circuit 13 and can be shifted to the next resonance frequency C [Hz].

  At this time, as described above, the value of the current flowing through the primary coil L1 of the power feeding device 1 changes due to the change in the resonance frequency of the electronic device 5, and it is found that the power feeding device 1 does not resonate with the electronic device 5.

  Therefore, in the first circuit control unit 9 in the power supply apparatus 1, the SW 12 in the first resonance circuit 10 is turned off and the SW 13 is turned on, so that only the capacitor C 13 is in the first resonance circuit 10. Connected in. And the resonant frequency of the primary coil L1 changes to C [Hz], and the charge to the electronic device 5 is continued.

  Further, when the remaining battery level of the secondary battery 6 reaches 96% of the fully charged state (steps S708 to S710), the SW 23 in the second resonance circuit 13 is turned off by the second circuit control unit 12. State, and only SW24 is switched to the ON state. As a result, only the capacitor C24 is connected in the second resonance circuit 13, and transitions to the next resonance frequency D [Hz].

  At this time, as described above, the detection unit 11 indicates that the value of the current flowing through the primary coil L1 of the power feeding device 1 changes due to the change in the resonance frequency of the electronic device 5 and is not resonating with the electronic device 5 on the power feeding device 1 side. To find out.

  Therefore, in the first circuit control unit 9 in the power supply apparatus 1, the SW 13 in the first resonance circuit 10 is turned off and only the SW 14 is turned on, so that only the capacitor C 14 is in the first resonance circuit. 10 connected. And the resonant frequency of the primary coil L1 changes to D [Hz], and the charge to the electronic device 5 is continued (step S711).

  In this way, the resonance frequency of the electronic device 5 changes to A [Hz], B [Hz], C [Hz], and D [Hz] depending on the remaining battery level of the secondary battery 6. Further, the resonance frequency on the power feeding device 1 side also changes to A [Hz], B [Hz], C [Hz], and D [Hz] so as to follow the change.

  At this time, on the power feeding device 1 side, the remaining amount of the secondary battery 6 inside the electronic device 5 is determined with the resonance frequency by determining at which resonance frequency the resonance is performed. Can be detected and notified to the user.

  When the secondary battery 6 of the electronic device 5 is fully charged, the resonance frequency in that state is recognized by the first circuit control unit 9 of the power supply device 1, and the power supply device 1 supplies power to the electronic device 5. It is also possible to prevent waste of power by stopping the operation.

  In the configuration of the present invention, the resonance frequency is set to A to D [Hz] for convenience, but the number of resonance frequencies is further increased in order to grasp the remaining battery level of the secondary battery in detail on the power feeding device side. May be.

  For example, in the resonance circuit inside the power feeding device 1 and the electronic device 5, the number of capacitors, resistors, and switches to be connected is five, and the remaining amount of the secondary battery 6 is 0 on the electronic device 5 side. If it is ˜60%, the resonance frequency is A [Hz]. Moreover, if it is 61-80%, it will be B [Hz], if it is 81-90%, it will be C [Hz], if it is 91-96%, it will be D [Hz], if it is 97-100%, it will be E [Hz]. To do.

  Further, the power supply device 1 also has a resonance frequency of A to E [Hz] corresponding to the resonance frequency of the electronic device 5, and as described above, as the remaining battery level of the secondary battery 6 increases, The switching (transition) of the resonance frequency is performed finely.

  As a result, the state until the charging of the secondary battery is completed can be detected more accurately on the power feeding device 1 side, and notification to the user improves convenience for the user.

1 is a configuration diagram of a resonance charging system according to an embodiment of the present invention. It is a block block diagram of the electric power feeder in FIG. It is a block block diagram of the electronic device in FIG. FIG. 4 is a configuration diagram of the first resonance circuit in FIG. It is a block diagram of the 2nd resonance circuit in FIG. It is a flowchart which shows the procedure of the process centering on the electric power feeder side at the time of charge by the resonance charge system of FIG. It is a flowchart which shows the procedure of the process centering on the electronic device side at the time of the charge by the 1 resonance charging system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power feeder 2 Switch 3 Display part 4 Socket 5 Electronic device 6 Secondary battery 7 Lens part 8 Strobe light emission part 9 First circuit control part 10 First resonance circuit 11 Detection part 12 Second circuit control part 13 Second Resonance circuit 14 of power converter L1 primary coil L2 secondary coil

Claims (7)

A power supply device including a primary coil connected to the first resonance circuit and an electronic device including a secondary coil connected to the second resonance circuit, and applying an alternating electric field having a resonance frequency to the primary coil, magnetic resonance In the resonance charging system in which power is induced in the secondary coil by the secondary battery of the electronic device is charged,
The electronic device can arbitrarily set one resonance frequency from a plurality of the resonance frequencies,
The power supply apparatus includes a detecting unit that detects the resonance frequency set by the electronic device, and continues power supply at the detected resonance frequency.   The resonance charging system according to claim 1, wherein the electronic device sets the resonance frequency in accordance with a capacity charged in the secondary battery.   The resonance charging system according to claim 2, wherein the power feeding device detects a capacity charged in the secondary battery according to the resonance frequency set by the electronic device.   2. The resonance charging system according to claim 1, wherein the power supply device includes first circuit control means for controlling the first resonance circuit according to a resonance frequency detected by the electronic device.   3. The resonance charging system according to claim 2, wherein the electronic device includes second circuit control means for controlling the second resonance circuit in accordance with a capacity charged in the secondary battery. .   The electric power feeder which comprises the resonance charge system of Claim 1.   The electronic device which comprises the resonance charge system of Claim 1.

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