JP6784129B2 - Control devices, power receiving devices, electronic devices and non-contact power transmission systems - Google Patents

Description

The present invention relates to a control device, a power receiving device, an electronic device, a non-contact power transmission system, and the like.

In recent years, non-contact power transmission (non-contact power transmission) that uses electromagnetic induction to enable power transmission without contacts in metal parts has been in the limelight. As an application example of this non-contact power transmission, charging of electronic devices such as household devices and mobile terminals has been proposed.

The performance of a battery deteriorates as it is repeatedly charged and discharged. The deterioration of the performance here means that, for example, the battery voltage at the time of full charge becomes lower than the battery capacity at the time of the first full charge. Therefore, a method of managing the degree of deterioration of the battery by counting the number of times the battery is charged is known.

For example, Patent Document 1 discloses a method of counting the number of times of charging when a charging current of a predetermined time or more flows for a predetermined time or more.

Japanese Unexamined Patent Publication No. 07-099069

In the power transmission (non-contact power transmission) between the wireless power transmission device and the wireless power receiving device assumed in the present embodiment, there is a possibility that charging may be unintentionally stopped and restarted as compared with the power transmission having metal contacts. high. For example, the relative positions of the power transmitting device and the power receiving device may shift due to factors such as vibration, and there may be a period during which charging cannot be continued. When charging of a battery that is almost fully charged is temporarily stopped due to vibration, etc., and then charging is resumed, the charging after the restart is a substantial charging that deteriorates the battery performance. It can not be said. Therefore, it is not preferable to count up the charge after resumption as one charge, and it is important to count the number of charges according to the actual charge state.

However, in Patent Document 1, the time integral value of the charging current is simply used for counting the number of charging times.

According to some aspects of the present invention, in non-contact power transmission using a power transmission device and a power receiving device, a control device, a power receiving device, an electronic device, a non-contact power transmission system, etc. that appropriately manage the number of times the battery is charged are provided. Can be provided.

One aspect of the present invention is a control device for a power receiving device that receives power supplied by non-contact power transmission from a power transmitting device, and uses a battery based on the power received by the power receiving unit in the power receiving device. A charging unit for charging and a control unit for controlling the charging unit are included, and the control unit controls switching between constant current charging and constant voltage charging, and switches from the constant current charging to the constant voltage charging. The present invention relates to a control device that controls to update the charge number information indicating the charge number of the battery on the condition that the above is performed.

In one aspect of the present invention, on the condition that the control device for the power receiving device that receives the power supplied by the non-contact power transmission from the power transmitting device is switched from the constant current charging to the constant voltage charging. Update the charge count information. When switching from constant current charging to constant voltage charging, parameters related to charging such as battery voltage are used. That is, by using the information related to the switching of the charge control, it becomes possible to manage the charge number information appropriately and easily.

Further, in one aspect of the present invention, the control unit may perform control to gradually increase the charging current from a given reference value from the start of charging the battery.

By doing so, it is possible to properly distinguish between the case where the constant current charging is switched to the constant voltage charging and the case where it is not, and the decrease of the rectified voltage at the start of charging is suppressed, so that the control circuit can be used. It is possible to stabilize the operation.

Further, in one aspect of the present invention, the control unit switches to the constant current charging when the charging current reaches the constant current value of the constant current charging before the battery voltage reaches a given threshold voltage. May be done.

In this way, when a predetermined condition is satisfied, it is possible to appropriately switch to constant current charging.

Further, in one aspect of the present invention, the control unit switches to the constant voltage charging when the battery voltage reaches the given threshold voltage after switching to the constant current charging, and the charging is performed. Control may be performed to update the number-of-times information.

In this way, it is possible to appropriately switch the charging mode and appropriately manage the charging number information based on the switching result.

Further, in one aspect of the present invention, the control unit determines the constant voltage when the battery voltage reaches the given threshold voltage before the charging current reaches the constant current value of the constant current charging. You may switch to charging and control so that the charging number information is not updated.

In this way, it is possible to appropriately switch the charging mode and appropriately manage the charging number information based on the switching result.

Further, in one aspect of the present invention, the control unit may control to update the charge number information based on the update amount weighted according to the set value of the given threshold voltage.

In this way, it is possible to manage information on the number of times of charging appropriately according to the degree of deterioration of the battery.

Further, in one aspect of the present invention, the control unit may control to update the charge number information based on the update amount weighted according to the temperature information during charging.

In this way, it is possible to manage information on the number of times of charging appropriately according to the degree of deterioration of the battery.

Further, in one aspect of the present invention, the control unit may control to transmit the charge number information to the power transmission device.

In this way, it becomes possible to manage the charge number information on the power transmission device side.

Further, another aspect of the present invention relates to a power receiving device including the control device according to any one of the above.

Further, another aspect of the present invention relates to an electronic device including the control device according to any one of the above.

Another aspect of the present invention is a non-contact power transmission system including a power transmission device and a power receiving device, wherein the power transmission device transmits power to the power receiving device, and the power receiving device is in the power receiving device. The battery is charged based on the electric power received by the power receiving unit, and the power receiving device controls switching between constant current charging and constant voltage charging, and switches from the constant current charging to the constant voltage charging. In this case, it relates to a non-contact power transmission system that controls to update the charge number information indicating the charge number of the battery.

Configuration example of the control device. Detailed configuration example of control device, power transmission device, and power receiving device. Explanatory drawing of the relationship between a primary coil and a secondary coil. Configuration example of an electronic device including a control device. Explanatory drawing of a non-contact power transmission system. Detailed configuration example of the power receiving unit and charging unit. Example of time change of charging current and battery voltage. Other examples of time variation of charging current and battery voltage. A flowchart illustrating charge control. Explanatory drawing of an example of the operation sequence of the non-contact power transmission system. Explanatory drawing of communication method by load modulation. Explanatory drawing of the communication method of this embodiment. Explanatory drawing of the communication method of this embodiment. Explanatory drawing of the communication method of this embodiment. An example of a communication data format. An example of a communication data format.

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

1. 1. Method of this Embodiment First, the method of this embodiment will be described. When charging is performed by the non-contact power transmission system described later using FIG. 2 or the like, charging may be interrupted or restarted accidentally. In a power transmission system having contacts, it is necessary to mechanically lock the power transmission device 10 (charger) and the power receiving device 40 (electronic device) when charging, but in a non-contact power transmission system, the power receiving device This is because it is sufficient to bring 40 closer to the power transmission device 10 to some extent.

Specifically, in the example of FIG. 5 described later, it is conceivable that the user tries to remove the electronic device 510 including the power receiving device 40 from the device (charger 500) including the power transmitting device 10 and fails to remove it. The term “not missed by the user” means an operation in which the user temporarily grasps the electronic device 510 by hand, but the electronic device 510 falls out of the hand and returns to the original position. Therefore, if a failure occurs, the battery cannot be charged due to a temporary gripping operation by the user. Immediately after that, the battery is recharged by dropping from the hand and returning the power receiving device 40 to its original position. Move to a possible state. In this case, the power receiving device 40 will start charging the battery again.

Further, although an example of the user's failure is shown here, the same applies when the relative positions of the power transmitting device 10 and the power receiving device 40 change due to vibration or the like. The device (charger) including the power transmission device 10 has a configuration for adjusting the position with the power receiving device 40 (electronic device 510) so as to return to the rechargeable positional relationship even if the position shift occurs due to vibration or the like. There are also things. In this case as well, the battery temporarily shifts to a non-rechargeable state and then returns to a rechargeable state.

The problem here is the case where charging is resumed for a battery that is already nearly fully charged. In this case, the charging of the battery is almost completed, and the battery is not discharged significantly. That is, even if the battery is charged again, the charging has a small effect on the deterioration of the battery and cannot be said to be a substantial charging.

As an index for managing the battery, a method using charge count information (hereinafter, also referred to as cycle count and cycle time) is widely known. Since it is known that a battery deteriorates due to repeated charging and discharging, it is possible to manage the deterioration of the battery by counting the number of times of charging.

The charge count information may be a value according to the charge count, for example, it may be counted up at the start of charging or when charging is completed (full charge flag = 1). However, it cannot be said that it is appropriate to count up the number of times of charging in the above-mentioned charging which has a small influence on the deterioration of the battery. In the above example, although the degree of deterioration of the battery is actually small, the number of times of charging is counted many times due to the influence of failure or vibration, and there is a possibility that it is erroneously determined that the degree of deterioration is large.

Therefore, it is preferable to control the count-up of the charge count information depending on whether or not the charge to the battery is substantial, that is, whether or not the influence on the deterioration is large. At that time, it is useful to use the information regarding the charge control of the battery.

In battery charging, a method using two charging modes, constant current charging and constant voltage charging, is known. Hereinafter, in the present specification, constant current charging is also referred to as CC (Constant-Current) charging, and constant voltage charging is also referred to as CV (Constant-Voltage) charging. CC charging is charging using a given constant current value iCC as the charging current iBAT. CV charging is charging that controls the charging current iBAT so that the battery voltage VBAT becomes a given constant voltage value CV (so as not to exceed CV).

As will be described later with reference to FIG. 7 and the like, the battery voltage VBAT can be greatly increased in a short time by using CC charging. Further, by using CV charging, the charging current iBAT gradually decreases, so that it is possible to suppress a sudden fluctuation of the charging current iBAT and stabilize the current value and the voltage value. By performing charge control that shifts from CC charging to CV charging, the charging current iBAT and the battery voltage VBAT can be accurately controlled, so that stable charging becomes possible.

As shown in FIG. 1, the control device 50 of the present embodiment is a control device for a power receiving device 40 that receives power supplied by non-contact power transmission from the power transmitting device 10, and is a power receiving unit in the power receiving device 40. It includes a charging unit 58 that charges the battery 90 based on the electric power received by the 52, and a control unit 54 that controls the charging unit 58. Then, the control unit 54 controls to switch between constant current charging and constant voltage charging, and on condition that the constant current charging is switched to constant voltage charging, the charge number information indicating the number of times the battery 90 is charged is input. Control to update.

In this way, it becomes possible to control the charging number information based on the switching from CC charging to CV charging. As described above, in CC charging and CV charging constant, the charging current iBAT and the battery voltage VBAT are finely controlled, so that the switching of the charging mode is the information indicating what kind of charging is performed to the battery 90. Become. That is, by using the information regarding the switching from CC charging to CV charging, it is possible to appropriately count the charging count information, that is, to appropriately manage the deterioration of the battery.

Further, in the switching control from CC charging to CV charging, information on both the charging current iBAT and the battery voltage VBAT is used. That is, since both the current and the voltage are used for the count-up determination of the charge count information, an appropriate count-up is possible as compared with Patent Document 1 which uses the capacitance value (time integration of the current). In a narrow sense, the battery 90 according to this embodiment may be a lithium ion battery. The lithium ion battery is considered to have a large influence of the battery voltage VBAT on the deterioration of the battery 90 as compared with the nickel hydrogen battery which is the subject of Patent Document 1. Therefore, by using the method of the present embodiment, it is possible to count information on the number of times of charging more appropriately than the method of Patent Document 1.

Further, the control of performing CC charging, the control of performing CV charging, and the control of switching between CC charging and CV charging are widely performed as the charging control of the battery 90. Therefore, in the method of the present embodiment, it is less necessary to perform a process peculiar to the update process of the charge number information as in the method of Patent Document 1 (time integration of current). For example, it is possible to control the charge number information by a simple process, such as the management of the flag information (iCCflag) described later with reference to FIG. 9.

Hereinafter, configuration examples of the control device, the power receiving device, the electronic device, and the non-contact power transmission system according to the present embodiment will be described with reference to FIGS. 2 to 5. Further, the configuration of the charging unit, charging control by the control unit, and update control of charging number information will be described later with reference to FIGS. 6 to 9. After that, an example of the operation sequence of the non-contact power transmission system and an example of the communication method from the power receiving device to the power transmission device will be described.

2. Detailed configuration example of the power transmission device, the power receiving device, and the control device FIG. 2 shows a detailed configuration example of the control device 50 of the present embodiment and the power receiving device 40 including the control device 50. Further, FIG. 2 also shows a configuration example of the power transmission device 10 including the control device 20.

An electronic device on the power transmission side, such as the charger 500 of FIG. 5, which will be described later, includes a power transmission device 10. Further, the electronic device 510 on the power receiving side includes a power receiving device 40 and a load 80. Then, with the configuration of FIG. 2, a non-contact power transmission (non-contact power transmission) system is realized in which the primary coil L1 and the secondary coil L2 are electromagnetically coupled to transmit power from the power transmission device 10 to the power receiving device 40. Will be done.

The power transmission device 10 includes a primary coil L1, a power transmission unit 12, a notification unit 16, and a control device 20. The power transmission unit 12 generates an AC voltage having a predetermined frequency during power transmission and supplies the AC voltage to the primary coil L1. The power transmission unit 12 includes a first power transmission driver DR1 that drives one end of the primary coil L1, a second power transmission driver DR2 that drives the other end of the primary coil L1, and a power supply voltage control unit 14. Each of the power transmission drivers DR1 and DR2 is realized by, for example, an inverter circuit (buffer circuit) composed of a power MOS transistor. These power transmission drivers DR1 and DR2 are controlled (driven) by the driver control circuit 22 of the control device 20. That is, the control unit 24 controls the power transmission unit 12 via the driver control circuit 22.

The power supply voltage control unit 14 controls the power supply voltage VDCV of the power transmission drivers DR1 and DR2. For example, the control unit 24 controls the power supply voltage control unit 14 based on the communication data (transmission power setting information) received from the power receiving side. As a result, the power supply voltage VDCV supplied to the power transmission drivers DR1 and DR2 is controlled, and for example, variable control of the power transmission power is realized. The power supply voltage control unit 14 can be realized by, for example, a DCDC converter or the like. For example, the power supply voltage control unit 14 boosts the power supply voltage (for example, 5V) from the power supply to generate a power supply voltage VDCV (for example, 6V to 15V) for the power transmission driver and supplies it to the power transmission drivers DR1 and DR2. .. Specifically, when the power transmitted from the power transmitting device 10 to the power receiving device 40 is increased, the power supply voltage control unit 14 increases the power supply voltage VDCV supplied to the transmission drivers DR1 and DR2 and lowers the transmitted power. In that case, the power supply voltage VDCV is lowered.

As schematically shown in FIG. 3, power transmission from the power transmission device 10 to the power reception device 40 is performed by a primary coil L1 (transmission coil) provided on the power transmission side and a secondary coil L2 (transmission coil) provided on the power reception side. It is realized by forming a power transmission transformer by electromagnetically coupling a power receiving coil). This enables non-contact power transmission. As the non-contact power transmission method, various methods such as an electromagnetic induction method and a magnetic field resonance method can be adopted.

When power transmission is required, for example, as shown in FIG. 5 described later, an electronic device 510 is placed on the charger 500 so that the magnetic flux of the primary coil L1 passes through the secondary coil L2. On the other hand, when power transmission is not required, the charger 500 and the electronic device 510 are physically separated so that the magnetic flux of the primary coil L1 does not pass through the secondary coil L2.

The notification unit 16 (display unit) notifies (displays) various states (during power transmission, ID authentication, etc.) of the non-contact power transmission system using light, sound, an image, or the like. For example, an LED or a buzzer. It can be realized by or LCD.

The control device 20 on the power transmission side includes a driver control circuit 22, a control unit 24, a communication unit 30, a clock generation circuit 37, and an oscillation circuit 38. The driver control circuit 22 (pre-driver) controls the power transmission drivers DR1 and DR2. For example, the driver control circuit 22 outputs a control signal (drive signal) to the gates of the transistors constituting the power transmission drivers DR1 and DR2, and drives the primary coil L1 by the power transmission drivers DR1 and DR2. The oscillation circuit 38 is composed of, for example, a crystal oscillation circuit or the like, and generates a clock signal on the primary side. The clock generation circuit 37 generates a drive clock signal or the like that defines a transmission frequency (drive frequency). Then, the driver control circuit 22 generates a control signal of a given frequency (transmission frequency) based on the drive clock signal, the control signal from the control unit 24, and the like, and outputs the control signal to the transmission drivers DR1 and DR2 of the transmission unit 12. And control.

The power receiving device 40 includes a secondary coil L2 and a control device 50. The control device 50 on the power receiving side includes a power receiving unit 52, a control unit 54, a load modulation unit 56, a power supply unit 57, a non-volatile memory 62, and a detection unit 64.

The power receiving unit 52 includes a rectifier circuit 53 composed of a plurality of transistors, diodes, and the like. The rectifier circuit 53 converts the AC induced voltage of the secondary coil L2 into a DC rectified voltage VCS and outputs it.

The load modulation unit 56 (communication unit in a broad sense) performs load modulation. For example, the load modulation unit 56 has a current source IS, and load modulation is performed using this current source IS. Specifically, the load modulation unit 56 has a current source IS (constant current source) and a switch element SW. The current source IS and the switch element SW are provided in series between, for example, the node NVC of the rectified voltage VCS and the node of GND (in a broad sense, the low potential side power supply). Then, for example, the switch element SW is turned on or off based on the control signal from the control unit 54, and the current (constant current) of the current source IS flowing from the node NVC to the GND is turned on or off to perform load modulation. It will be realized.

One end of the capacitor CM is connected to the node NVC. This capacitor CM is provided, for example, as an external component of the control device 50. Further, the switch element SW can be realized by a MOS transistor or the like. The switch element SW may be provided as a transistor constituting the circuit of the current source IS. Further, the load modulation unit 56 is not limited to the configuration shown in FIG. 2, and various modifications such as using a resistor instead of the current source IS can be performed.

The power supply unit 57 includes a charging unit 58 and a discharging unit 60. The charging unit 58 charges the battery 90 (charge control). For example, the charging unit 58 is supplied with a voltage based on the rectified voltage VCS (DC voltage in a broad sense) from the power receiving unit 52 to charge the battery 90. The charging unit 58 can include a power supply switch 42 and a CC charging circuit 59. The CC charging circuit 59 is a circuit for CC charging the battery 90.

The discharge unit 60 discharges the battery 90. For example, the discharge unit 60 discharges the battery 90 and supplies the electric power from the battery 90 to the power supply target 100. For example, the discharge unit 60 is supplied with the battery voltage VBAT from the battery 90, and supplies the output voltage VOUT to the power supply target 100. The discharge unit 60 can include a charge pump circuit 61. The charge pump circuit 61 steps down the battery voltage VBAT (for example, 1/3 step down) and supplies the output voltage VOUT (VBAT / 3) to the power supply target 100. The discharge unit 60 (charge pump circuit) operates using, for example, the battery voltage VBAT as the power supply voltage.

The non-volatile memory 62 (in a broad sense, a storage unit) is a non-volatile memory device that stores various types of information. The non-volatile memory 62 stores various information such as status information of the power receiving device 40, for example. The status information may include charge count information (cycle count) according to the present embodiment. As the non-volatile memory 62, for example, EEPROM or the like can be used. As the EEPROM, for example, a MONOS (Metal-Oxide-Nitride-Oxide-Silicon) type memory can be used. For example, a flash memory using a MONOS type memory can be used. Alternatively, another type of memory such as a floating gate type may be used as the EEPROM.

The detection unit 64 performs various detection processes. For example, the detection unit 64 monitors the rectified voltage VCS, the battery voltage VBAT, and the like, and executes various detection processes. Specifically, the detection unit 64 has an A / D conversion circuit 65, and a voltage based on the rectified voltage VCS and the battery voltage VBAT, a temperature detection voltage from a temperature detection unit (not shown), and the like can be obtained from the A / D conversion circuit 65. A / D conversion is performed, and the detection process is executed using the obtained digital A / D conversion value. As the detection process performed by the detection unit 64, detection processing of over-discharge, over-voltage, over-current, or temperature abnormality (high temperature, low temperature) can be assumed.

Then, in FIG. 2, when the landing of the power receiving device 40 is detected, the control unit 54 (discharge system control unit) turns off the discharge operation of the discharge unit 60 and stops the discharge operation. That is, when the landing of the power receiving device 40 (electronic device on the power receiving side) is detected in FIG. 5, the discharging operation (supply of VOUT) of the discharging unit 60 is stopped, and the power of the battery 90 is discharged to the power supply target 100. Prevent it from being done. Then, during the normal power transmission period in which the power transmission device 10 normally transmits power, the discharge operation of the discharge unit 60 is turned off. For example, during the charging period of the battery 90, the discharging operation of the discharging unit 60 is left off.

Then, the control unit 54 turns on the discharge operation of the discharge unit 60 when the removal of the power receiving device 40 is detected. Then, during the removal period (the period during which the power receiving device is removed), the discharge unit 60 is made to perform a discharge operation. By this discharge operation, the electric power from the battery 90 is supplied to the electric power supply target 100 via the discharge unit 60.

Further, the load modulation unit 56 starts load modulation when the landing of the power receiving device 40 (electronic device on the power receiving side) is detected. The power transmission device 10 (control unit 24) starts normal power transmission by the power transmission unit 12, for example, on condition that the power reception device 40 (load modulation unit 56) has started load modulation. Then, when the removal of the power receiving device 40 is detected, the load modulation unit 56 stops the load modulation. The power transmission device 10 (control unit 24) continues the normal power transmission by the power transmission unit 12 while the load modulation is continued. That is, when the load modulation is not detected, the normal power transmission is stopped, and for example, the power transmission unit 12 is made to perform intermittent power transmission for landing detection. In this case, the control unit 54 on the power receiving side can perform landing detection and removal detection based on the output voltage VCS of the power receiving unit 52.

Further, the control unit 54 (discharge system control unit) turns on the discharge operation of the discharge unit 60 after the output voltage (VCC, VD5) of the power receiving unit 52 drops and the discharge operation start-up period (TST) elapses. Start the discharge operation. Specifically, the control unit 54 starts the discharge operation of the discharge unit 60 after the start-up period elapses after the output voltage of the power receiving unit 52 falls below the determination voltage. The start-up period (TST) is, for example, a period from the start timing of the start-up operation of the discharge operation to the timing of actually starting the discharge operation, and corresponds to a wait period until the start timing of the discharge operation.

Further, the power transmission device 10 performs intermittent power transmission for removal detection. For example, when a fully charged battery 90 is detected or an abnormality on the power receiving side is detected, the power transmission device 10 normally stops power transmission and performs intermittent power transmission for removal detection. The activation period of the discharge operation of the discharge unit 60 is longer than the interval of the intermittent power transmission period for the removal detection.

The method of this embodiment can be applied to a power receiving device 40 including the above-mentioned control device 50. That is, the method of this embodiment can be applied to the power receiving device 40 of FIG. 1 and the power receiving device 40 of FIG.

Further, the method of the present embodiment can be applied to the electronic device 510 including the control device 50 described above. The electronic device 510 according to the present embodiment includes a power receiving device 40 having the control device 50 of FIG. Various devices can be assumed as the electronic device 510 to which this embodiment is applied. For example, as shown in FIG. 4, the electronic device 510 of the present embodiment may be a hearing aid having a power receiving device 40, a switch unit 514 for operation (operation unit in a broad sense), and a battery 90 (not shown).

However, the electronic device 510 is not limited to a hearing aid, and is a watch, a biological information measuring device (a wearable device that measures pulse waves, etc.), a personal digital assistant (smartphone, a mobile phone, etc.), a cordless telephone device, a shaver, an electric toothbrush, and a list. Various electronic devices such as computers, handy terminals, in-vehicle devices, hybrid vehicles, electric vehicles, electric bikes, and electric bicycles can be assumed. For example, the control device (power receiving device, etc.) of the present embodiment can be incorporated into various moving bodies such as a car, an airplane, a motorcycle, a bicycle, or a ship. The moving body is, for example, a device / device provided with a drive mechanism such as a motor or an engine, a steering mechanism such as a steering wheel or a rudder, and various electronic devices (vehicle-mounted devices), and moves on the ground, in the air, or on the sea.

Further, the method of this embodiment can be applied to the non-contact power transmission system 600. That is, the non-contact power transmission system 600 according to the present embodiment is a non-contact power transmission system including a power transmission device 10 and a power receiving device 40, and the power transmission device 10 transmits power to the power receiving device 40 and the power receiving device 40 Charges the battery 90 based on the power received by the power receiving unit 52 in the power receiving device 40. Then, the power receiving device 40 controls to switch between constant current charging and constant voltage charging, and on condition that switching from constant current charging to constant voltage charging is performed, charge number information indicating the number of times the battery 90 is charged is provided. Control to update.

FIG. 5 shows an example of the non-contact power transmission system 600 of the present embodiment. The charger 500 (one of the electronic devices) has a power transmission device 10. The electronic device 510 has a power receiving device 40. The electronic device 510 assumes a hearing aid as in FIG. 4, but as described above, various modifications can be performed. The non-contact power transmission system 600 of the present embodiment is configured by the power transmission device 10 and the power reception device 40 of FIG.

Electric power is supplied to the charger 500 via the power adapter 502, and this electric power is transmitted from the power transmitting device 10 to the power receiving device 40 by non-contact power transmission. As a result, the battery 90 of the electronic device 510 can be charged, and the device in the electronic device 510 can be operated. The power supply of the charger 500 may be a power supply by USB (USB cable).

3. 3. Configuration of Charging Unit and Example of Charge Control Next, a detailed configuration example of the charging unit 58 and a control example of the control unit 54 will be described. In addition, some modifications will be described.

3.1 Detailed configuration example FIG. 6 shows a detailed configuration example of the power receiving unit 52, the charging unit 58, and the like. As shown in FIG. 6, the rectifier circuit 53 of the power receiving unit 52 includes transistors TA1, TA2, TA3, and TA4 for rectification, and a rectifier control unit 51 that controls these transistors TA1 to TA4. A body diode is provided between the drain and source of the transistors TA1 to TA4. The rectification control unit 51 outputs a control signal to the gates of the transistors TA1 to TA4 and performs rectification control for generating the rectified voltage VCS.

Resistors RB1 and RB2 are provided in series between the node NVC of the rectified voltage VCS and the node of the GND. The voltage ACH1 obtained by dividing the rectified voltage VCS by the resistors RB1 and RB2 is input to, for example, the A / D conversion circuit 65. This makes it possible to monitor the rectified voltage VCS, and realize power control based on the VCS and control of communication start and charging start based on the VCS.

The regulator 67 adjusts the voltage of the rectified voltage VCS (regulates) and outputs the voltage VD5. This voltage VD5 is supplied to the CC charging circuit 59 of the charging unit 58 via the transistor TC1. The transistor TC1 is turned off based on the control signal GC1, for example, when the battery voltage VBAT detects an overvoltage exceeding a given voltage. Each circuit of the control device 50 (circuit excluding the discharge system circuit such as the discharge unit 60) operates using a voltage based on this voltage VD5 (such as a voltage regulated by VD5) as a power supply voltage.

The CC charging circuit 59 includes a transistor TC2, an operational amplifier OPC, a resistor RC1, and a current source ISC. Due to the virtual grounding of the operational amplifier OPC, the voltage at one end of the resistor RC1 (voltage at the non-inverting input terminal) and the voltage at the other end of the sense resistor RS, which is an external component (voltage at the inverting input terminal), are made equal. In addition, the transistor TC2 is controlled. The current flowing through the current source ISC under the control of the signal ICDA is defined as IDA, and the current flowing through the sense resistor RS is defined as IRS. Then, it is controlled so that IRS × RS = IDA × RC1. That is, in this CC charging circuit 59, the current IRS (charging current iBAT) flowing through the sense resistor RS is controlled to be a constant current value set by the signal ICDA. This enables CC (Constant-Current) charging.

The transistor TC3 is provided between the output node of the CC charging circuit 59 and the supply node NBAT of the battery voltage VBAT. The drain of the N-type transistor TC4 is connected to the gate of the P-type transistor TC3, and the charge control signal CHON from the control unit 54 is input to the gate of the transistor TC4. Further, a pull-up resistor RC2 is provided between the gate of the transistor TC3 and the node NBAT, and a pull-down resistor RC3 is provided between the gate of the transistor TC4 and the node of the GND (low potential side power supply). Has been done. The power supply switch 42 of FIG. 2 is realized by the transistor TC3 (TC4).

At the time of charging, the control unit 54 sets the control signal CHON to H level (active). As a result, the N-type transistor TC4 is turned on, and the gate voltage of the P-type transistor TC3 becomes L level. As a result, the transistor TC3 is turned on and the battery 90 is charged.

On the other hand, when the control unit 54 sets the control signal CHON to the L level (inactive), the N-type transistor TC4 is turned off. Then, the gate voltage of the P-type transistor TC3 is pulled up to the battery voltage VBAT by the resistor RC2, so that the transistor TC3 is turned off and the charging of the battery 90 is stopped.

When the power supply voltage of the charging system becomes lower than the operating lower limit voltage of the circuit, the gate voltage of the transistor TC4 is pulled down to GND by the resistor RC3, so that the transistor TC4 is turned off. Then, the gate voltage of the transistor TC3 is pulled up to the battery voltage VBAT by the resistor RC2, so that the transistor TC3 is turned off. In this way, for example, when the power receiving side is removed and the power supply voltage becomes lower than the operating lower limit voltage, the transistor TC3 is turned off, so that the output node of the CC charging circuit 59 and the node NBAT of the battery 90 become The path between them is electrically cut off. As a result, backflow from the battery 90 when the power supply voltage becomes equal to or lower than the operating lower limit voltage can be prevented.

Further, resistors RC4 and RC5 are provided in series between the node NBAT and the node of GND, and the voltage ACH2 obtained by dividing the battery voltage VBAT by the resistors RC4 and RC5 is input to the A / D conversion circuit 65. To. This makes it possible to monitor the battery voltage VBAT and realize various controls according to the state of charge of the battery 90. A thermistor TH (in a broad sense, a temperature detection unit) is provided near the battery 90. The voltage RCT at one end of the thermistor TH is input to the control device 50, which enables the measurement of the battery temperature.

3.2 Example of charge control Next, charge control and charge count information control in the control unit 54 will be described. As described above, the control unit 54 controls to switch between CC charging and CV charging. Specifically, the battery voltage VBAT is monitored, and the control unit 54 controls to switch to CV charging (shift to CV charging) when VBAT ≥ CV (CV is a given threshold voltage). ..

However, when the control for executing CC charging is performed from the start of charging, the switching control from CC charging to CV charging is executed regardless of the state of the battery 90. Specifically, even when charging the battery 90 which is almost fully charged, or when charging the battery 90 whose consumption is high and the battery voltage is relatively low, CC charging to CV Switching control to charging is executed. That is, when the control to execute CC charging is performed from the start of charging, the information on how the charging mode is switched cannot be said to be useful for counting the charging number information.

Therefore, the control unit 54 controls to gradually increase the charging current iBAT from a given reference value from the start of charging the battery 90. The control that gradually increases here may be a control that continuously changes the charging current iBAT, or a control that changes it discretely (stepwise). Hereinafter, in FIGS. 7 and 8, an example of linearly increasing the charging current iBAT will be described. Further, various modifications can be made to a given reference value which is an initial value of the charging current iBAT, and various current values smaller than the constant current value iCC for CC charging can be applied. In the example described later in FIGS. 7 and 8, a given reference value will be described as 0 (A). Further, in the present specification, the charging control (charging mode) that gradually increases the charging current iBAT is referred to as SC (Step-Current) charging.

In SC charging, the charging current iBAT is increased from the above given reference value toward the constant current value iCC of CC charging. Therefore, when the charging current iBAT reaches the iCC, the control unit 54 does not need to increase the charging current iBAT any more, and may switch from SC charging to CC charging. However, what should be realized by the charge control of the control unit 54 is to make the battery voltage VBAT reach a desired voltage value, that is, a constant voltage value CV for CV charging. That is, when VBAT ≥ CV is satisfied, switching to CV charging is performed regardless of whether the current charging mode is SC charging or CC charging.

Therefore, when performing SC charging, two patterns can be considered for switching (transition, transition) of the charging mode until charging is completed. FIG. 7 is a diagram showing time-series changes in the charging current iBAT and the battery voltage VBAT when the charging mode is switched in the first pattern. FIG. 8 is a diagram showing time-series changes in the charging current iBAT and the battery voltage VBAT when the charging mode is switched in the second pattern. The horizontal axis of FIGS. 7 and 8 represents time, where t = 0 is the start of charging. The start of charging is, for example, the timing of transition from A1 to A2 in FIG. 10, which will be described later.

In the example shown in FIG. 7, SC charging is started from t = 0, and the charging current iBAT gradually increases from 0. As a result, the battery voltage VBAT gradually increases from the voltage VBAT0 at the start of charging. In FIG. 7, the charging current iBAT reaches iCC at t = t1. Since the battery voltage VBAT at t = t1 has not reached CV, the control unit 54 switches from SC charging to CC charging at the timing of t = t1.

In CC charging, the battery voltage VBAT increases with time by continuing charging at the constant current value iCC, and VBAT reaches CV at t = t2. Therefore, the control unit 54 switches from CC charging to CV charging at the timing of t = t2. After switching to CV charging, the control unit 54 controls the charging current iBAT so that the battery voltage VBAT does not exceed CV. Specifically, as shown in FIG. 7, the control unit 54 controls to gradually reduce the charging current iBAT.

Then, when the charging end condition is satisfied while CV charging is being performed, the control unit 54 ends charging of the battery 90. Various charging end conditions can be considered, and for example, a predetermined time may elapse after the charging current iBAT becomes equal to or less than a given threshold current.

Also in the example shown in FIG. 8, SC charging is started from t = 0, and the charging current iBAT gradually increases from 0. However, in the example of FIG. 8, unlike the case of FIG. 7, the VBAT reaches the CV before the charging current iBAT reaches the iCC (t = t3). In this case, switching from SC charging to CV charging is performed without going through CC charging. It is the same as in FIG. 7 in that the charging current iBAT is gradually reduced so that the battery voltage VBAT does not exceed CV after switching to CV charging.

As can be seen by comparing FIGS. 7 and 8, whether to shift from SC charging to CC charging to CV charging (FIG. 7) or directly from SC charging to CV charging (FIG. 8) is determined at the start of charging. It depends on the magnitude of the battery voltage VBAT0. This is because SC charging ends when the charging current iBAT reaches iCC (switched to CC charging), so there is an upper limit to the amount of increase in battery voltage VBAT due to SC charging. When VBAT0 is significantly less than the upper limit with respect to CV, the battery voltage VBAT cannot reach CV only by SC charging as shown in FIG. 7, and CC charging needs to be executed. On the other hand, if VBAT0 is almost fully charged, the battery voltage VBAT can reach CV only by SC charging.

That is, when switching from CC charging to CV charging is performed as shown in FIG. 7, it can be determined that the battery 90 in a sufficiently exhausted state has been charged, and SC as shown in FIG. When switching from charging to CV charging is performed, it can be determined that the battery 90 in a state close to full charge has been charged. Therefore, in the example of FIG. 7, the control unit 54 counts up the charge count information assuming that the deterioration of the battery-90 progresses, and in the example of FIG. 8, the charge count information is calculated as not being substantially charged. Do not count up.

In this way, it is possible to appropriately count the charge count information based on whether or not the switch from CC charging to CV charging has been performed. The SC charging of the present embodiment has an advantage that the case of FIG. 7 and the case of FIG. 8 can be distinguished, but other effects by using the SC charging can be considered.

Specifically, by using SC charging, it is possible to reduce the current value flowing through the power receiving device 40 at the start of charging. If the charging current iBAT corresponding to the iCC is suddenly applied at the start of charging, the rectified voltage is greatly reduced due to the charging current iBAT. On the other hand, in SC charging, the current value at the start of charging is smaller than that of iCC, so that the decrease in rectified voltage can be suppressed to a small extent. As the charging current iBAT increases with the passage of time, the amount of decrease in the rectified voltage also increases. However, in SC charging, the charging current iBAT is gradually increased, so that the voltage drop per unit time can be suppressed. Therefore, it is easy to perform control for compensating for the decrease in the rectified voltage, and it is easy to keep the voltage level of the rectified voltage at a desired value.

FIG. 9 is a flowchart illustrating charge control by the control unit 54 and control of charge count information (cycle count). When this control is started, the control unit 54 first sets the charging current iBAT to a predetermined reference value (step S101). In the example of FIG. 9, the predetermined reference value is set to 0A as shown in FIGS. 7 and 8. As described above with reference to FIG. 6, the charging current iBAT is set by the signal ICDA. Therefore, in step S101, the control unit 54 sets a value (ICDA = 0 in the example of FIG. 9) that realizes the charging current iBAT = 0 (A) as the value of the signal ICDA.

The control unit 54 determines whether or not the battery voltage VBAT is less than the target value CV (step S102). In the case of Yes in S102, the control unit 54 determines whether or not the charging current iBAT has reached the constant current value iCC (step S103). If No in step S103, SC charging is continued, so control is performed to increase the charging current iBAT (step S104). Here, since an example is shown in which the charging current iBAT increases as the signal ICDA increases, the control unit 54 controls to increase the ICDA in step S104. Although an example of incrementing ICDA is shown in step S104, various modifications can be made to increase the ICDA (incremented width of iCC). Further, if the setting is such that the charging current iBAT increases as the ICDA value decreases, the control unit 54 controls to decrease the ICDA in step S104. The reduction range in this case can be variously modified, and the control unit 54 may decrement the ICDA or reduce it by another reduction range. After step S104, the process returns to step S102. In SC charging, the loop of S102 to S104 is continued until it is determined to be Yes in step S102 or step S103.

If YES in step S103, that is, when the charging current iBAT reaches the constant current value iCC, the flag iCC flag indicating switching to CC charging is set to 1 (step S105). In this case, since CC charging is performed, it is not necessary to increase the charging current iBAT any more, and the process returns to step S102 as it is. In CC charging, the loop of S102, S103, and S105 is continued until it is determined to be Yes in step S102. If the flag is already set, the processes of S103 and S105 can be omitted.

If No is determined in step S102 during the SC charging loop or the CC charging loop, the process proceeds to CV charging. In this case, the control unit 54 determines whether or not iCCflag = 1 (step S106). In the case of Yes in step S106, the control unit 54 controls to increase the charge number information (cycle number) (step S107). In step S107, the control unit 54 may perform control to increase the charge number information by 1, for example.

As described above, in the control unit 54, the charging current iBAT reaches the constant current value iCC of the constant current charging before the battery voltage VBAT reaches the given threshold voltage CV (step S102 becomes No) (step). If Yes in S103), control is performed to switch to constant current charging. In this way, in SC charging, when the battery voltage VBAT does not reach CV, it is possible to appropriately switch to CC charging.

Then, the control unit 54 switches to constant voltage charging when the battery voltage VBAT reaches a given threshold voltage CV after switching the constant current charging, and controls to update the charging number information. In this way, the charging number information can be updated on condition that the CC charging is switched to the CV charging. That is, as shown in FIG. 7, when VBAT0 is small to some extent and substantial charging is performed, it is possible to increase the charging number information.

On the other hand, the case of No in step S106 corresponds to the case where the battery voltage VBAT reaches a given threshold voltage CV before the charging current iBAT reaches the constant current value iCC of constant current charging, and in this case, control. The unit 54 controls the transition to constant voltage charging without going through constant current charging. Then, as shown in FIG. 9, the control unit 54 skips the process of step S107 and controls the charging number information to be non-updated. By doing so, as shown in FIG. 8, when VBAT0 is large to some extent (close to full charge, close to CV) and substantial charging is not performed, it is possible not to increase the charge count information. become.

After the processing in step S107, or if No in step S106, the control unit 54 determines whether or not to end the CV charging (step S108). Although various specific procedures can be considered, for example, the control unit 54 repeats a loop for reducing the charging current iBAT (signal ICDA), and in each loop, whether or not the charging current iBAT is equal to or less than a given threshold current. And the duration after the current becomes less than the threshold current. Then, the control unit 54 ends the process of FIG. 9 when a predetermined time elapses after the charging current iBAT becomes equal to or less than a given threshold current and becomes equal to or less than the threshold current.

3.3 Modification example In step S107 of FIG. 9, for example, an example of increasing the charge number information by 1 has been described. However, considering that the charge count information is an evaluation index of the deterioration degree of the battery 90, it is preferable to weight the increase amount of the charge count information according to the deterioration degree.

For example, in a lithium ion battery, it is known that the degree of deterioration of the battery 90 varies greatly depending on the target voltage for charging, that is, the magnitude of the constant voltage value CV in the CV charging described above. For example, when CV = 4.2V, the deterioration of the battery 90 progresses after charging about 500 times, whereas when CV = 4.1V, the battery 90 can be charged about 1000 times before it deteriorates to the same extent. Is. As described above, simply changing the CV by 0.1 V greatly changes the influence on the deterioration of the battery 90, and generally, the larger the CV, the larger the degree of deterioration. That is, when the control device 50 in which the CV can be set variably is used, if the charging at CV = 4.2 and the charging at CV = 4.1V are counted as the same one time, the actual battery 90 is used. There is a risk that the discrepancy between the degree of deterioration and the charge count information will increase.

Therefore, the control unit 54 may control to update the charge number information based on the update amount weighted according to the set value of the given threshold voltage (CV). For example, assuming that charging at CV = 4.2V is performed once, CV = 4.1V is counted 0.9 times, CV = 4.05V is counted 0.8 times, and so on. Alternatively, CV = 4.05V may be set to 1 time, CV = 4.1V may be set to 1.1 times, and CV = 4.2V may be set to 1.2 times, and various modifications can be performed for specific numerical values. is there.

By doing so, it is possible to suppress the discrepancy between the value of the charge count information and the actual deterioration degree of the battery 90, and it is possible to appropriately manage the deterioration degree of the battery 90 by using the charge count information. become.

It is also known that the higher the temperature of the battery 90, the greater the degree of deterioration. Therefore, the control unit 54 may control to update the charge number information based on the update amount weighted according to the temperature information during charging. Specifically, when the temperature is high, the control unit 54 increases the update amount of the charge number information as compared with the case where the temperature is low. In this case as well, it is possible to suppress the discrepancy between the value of the charge count information and the actual deterioration degree of the battery 90, and it is possible to appropriately manage the deterioration degree of the battery 90 by using the charge count information. ..

The temperature information here is information acquired based on a signal from the temperature detection unit. The temperature detection unit can be realized by various forms. For example, as described above with reference to FIG. 6, an external temperature detection unit (thermistor TH) of the control device 50 may be used. Specifically, the detection unit 64 supplies a given constant current IREF to the thermistor TH, and A / D converts the voltage value generated by the constant current IREF by the A / D conversion circuit 65 to obtain the temperature. Detection may be performed. The value of IREF does not have to be one, and for example, the value of IREF may be different between the high temperature region and the low temperature region. Alternatively, the control device 50 may include a BGR circuit (Band Gap Reference circuit) and perform temperature detection based on the BGR circuit. Since the temperature detection unit using the band gap has a widely known configuration, detailed description thereof will be omitted.

It is also possible to make the magnitude of the constant current value iCC in CC charging and the increase range of the charging current iBAT in SC charging variable. In this case, the upper limit of the amount of increase in the battery voltage VBAT in SC charging can be made variable. In other words, VBAT0, which is the boundary between the pattern of switching to CV charging via CC charging (FIG. 7) and the pattern of switching from SC charging to CV charging (FIG. 8), can be made variable. Depending on the user, there are cases where the charge count information is to be counted up only when VBAT0 is significantly reduced with respect to the CV, and cases where the charge count information is to be counted up even if the decrease in VBAT0 with respect to the CV is small. There is also. In that respect, it is possible to flexibly meet these demands by making the size of iCC and the increase width of the charging current iBAT in SC charging variable.

Further, in the above, when the charging current iBAT reaches the constant current value iCC, the charging number information is counted up. However, not only the charging current iBAT reaches the constant current value iCC but also maintaining the state for a predetermined period may be a condition for counting up the charging number information. In other words, when the transition from SC charging to CC charging is performed, CC charging is continued for a predetermined period, and then CC charging is shifted to CV charging, the charging count information is counted up. Then, when the charging current iBAT reaches the constant current value iCC for a very short time (CC charging is performed for a very short time) and shifts to CV charging, the charging number information is not counted up. By doing so, when the deterioration of the battery 90 is larger than that in the above-described example, the charge count information is counted up, so that the charge count information can be flexibly controlled.

Further, in the above, when the SC charging is directly switched to the CV charging, the count-up of the charging number information is always omitted, but the present invention is not limited to this. For example, the control unit 54 sets a given current threshold value, and when the charging current iBAT in SC charging exceeds the threshold value, charging is performed even when the SC charging is directly switched to the CV charging. Control to execute the count-up of the number-of-times information may be executed. Also in this case, since the charge number information is counted up even if the decrease width of VBAT0 with respect to CV is small, the charge number information can be flexibly controlled.

Further, in the above, three charging controls (charging modes), SC charging, CC charging, and CV charging, have been described. When the charging by these is set to the normal charging mode, the control device 50 (control unit 54) of the present embodiment may perform charging in a quick charging mode different from the normal charging mode. The quick charge mode is executed, for example, when the battery voltage VBAT0 at the start of charging is significantly lower than that in the fully charged state, and is executed, for example, when VBAT0 <3.75 V. However, the specific voltage value is not limited to 3.75 V, and various modifications can be performed.

The quick charge mode is a charge for enabling operation for a certain long time (for example, 7 to 8 hours) by charging for a short time (for example, 30 minutes) when the battery 90 is heavily consumed. In the quick charge mode, the control unit 54 gradually increases the charging current iBAT from a given reference value (for example, 0A) toward a given constant current value iFAST, and when the charging current iBAT reaches iFAST. Maintain that state. Here, the iFAST value may be modified in various ways, but may be larger than the constant current value iCC in the normal charging mode (CC charging) from the viewpoint of performing sufficient charging in a short time.

Current control in the fast charge mode is similar to SC charge and CC charge because it gradually increases the charge current iBAT from a given reference value towards a given constant current value. However, the count-up of the charge count information in the present embodiment is determined only by whether or not the CC charge has shifted to the CV charge. That is, the condition for counting up is that the charging current iBAT reaches the constant current value iCC for CC charging, and even if the charging current iBAT reaches the constant current value iFAST in the quick charge mode, it counts up the charge count information. Does not contribute to.

In the first place, the quick charging mode is intended to charge a certain amount of time in a short time as described above, and it is not assumed that the battery voltage VBAT is increased to the constant voltage value CV in CV charging. For example, it is assumed that the quick charge mode ends when a predetermined time elapses or when the battery voltage VBAT reaches a predetermined voltage. The predetermined voltage here is, for example, 3.75 V described above, which is smaller than the CV. That is, it is unlikely that the rapid charging mode is directly shifted to CV charging, and for example, the transition from quick charging mode to CC charging to CV charging is performed. Considering the above points, the control unit 54 determines that the charging current iBAT has reached the constant current value iCC in the normal charging mode regardless of whether the charging current iBAT has reached the constant current value iFAST in the quick charging mode. The charge count information may be controlled based on whether or not the charge is performed.

Further, in the control device 50 (control unit 54), charging in which the charging current iBAT shown in FIG. 7 reaches iCC and then shifts to CV charging (from CC charging) and the charging current iBAT shown in FIG. 8 are converted to iCC. The output (notification) to the user or another device may be switched depending on whether the charging shifts to CV charging without reaching (without shifting to CC charging) or the charging is performed.

For example, when the charging of FIG. 7 is performed a certain number of times, the battery 90 is significantly deteriorated, so that the control unit 54 may notify the user to that effect. The notification here may be, for example, light emission from an LED or the like, or may generate sound or vibration. Alternatively, if the deterioration of the battery 90 is large, further charging is not preferable, so the control unit 54 may transmit information to the power transmission device 10 to instruct the power transmission to be stopped. On the other hand, in the case of charging in FIG. 8, the degree of deterioration of the battery 90 is relatively small. Therefore, the control unit 54 controls such that the user is not notified or the power transmission stop instruction is not given to the power transmission device.

In summary, the method of the present embodiment is a control device 50 for a power receiving device 40 that receives power supplied by non-contact power transmission from the power transmitting device 10, and the power receiving unit 52 in the power receiving device 40 receives power. It includes a charging unit 58 that charges the battery 90 based on electric power, and a control unit 54 that controls the charging unit 58. Then, the control unit 54 controls to switch between constant current charging and constant voltage charging, and when charging for switching from constant current charging to constant voltage charging is performed a predetermined number of times, the user is notified and power is transmitted to the power transmission device 10. Give at least one of the stop instructions. Here, charging that switches from constant current charging to constant voltage charging refers to charging in which switching to constant voltage charging is performed after the charging current iBAT reaches a given threshold current (constant current value iCC for CC charging). Correspond. Further, when the charging current iBAT does not reach a given threshold current (constant current value iCC) and the charging for switching to the constant voltage charging is performed a predetermined number of times, the control unit 54 notifies the user. And do not give an instruction to stop power transmission to the power transmission device 10. The predetermined number of times here is the number of times the battery 90 is charged so that it may be significantly deteriorated (to the extent that continuous use is not preferable), for example, about 1000 times. However, various modifications can be performed for a predetermined number of times.

In this way, even when charging is performed the same number of times, it is possible to appropriately control the notification to the user, the instruction to stop power transmission to the power transmission device 10, and the like according to the actual charging status. It will be possible.

4. Operation Sequence of Non-contact Power Transmission System Next, an example of the operation sequence of the non-contact power transmission system 600 of the present embodiment will be described. FIG. 10 is a diagram illustrating an outline of an operation sequence. Although the battery 90 is schematically shown in FIG. 10, the battery 90 is actually built in the electronic device 510.

In A1 of FIG. 10, the electronic device 510 having the power receiving device 40 is not placed on the charger 500 having the power transmitting device 10, and is in a removed state. In this case, it is in the standby state. In this standby state, the power transmission unit 12 of the power transmission device 10 performs intermittent power transmission for landing detection, and is in a state of detecting the landing of the electronic device 510. Further, in the standby mode, in the power receiving device 40, the discharge operation to the power supply target 100 is turned on, and the power supply to the power supply target 100 is enabled. As a result, the power supply target 100 such as the processing unit can operate by being supplied with the power from the battery 90.

As shown in A2 of FIG. 10, when the electronic device 510 is placed on the charger 500 and the landing is detected, the communication check & charging state is set. In this communication check & charge state, the power transmission unit 12 of the power transmission device 10 performs normal power transmission, which is continuous power transmission. At this time, normal power transmission is performed while performing power control in which the power changes variably according to the state of power transmission. Control based on the state of charge of the battery 90 is also performed. The state of power transmission is determined by, for example, the positional relationship (distance between coils, etc.) of the primary coil L1 and the secondary coil L2, and can be determined based on information such as the rectified voltage VCS of the power receiving unit 52. The state of charge of the battery 90 can be determined based on information such as the battery voltage VBAT.

Further, in the communication check & charging state, the charging operation of the charging unit 58 of the power receiving device 40 is turned on, and the battery 90 is charged based on the power received by the power receiving unit 52. Further, the discharge operation of the discharge unit 60 is turned off, and the power from the battery 90 is not supplied to the power supply target 100. Further, in the communication check & charge state, the communication data is transmitted to the power transmission side by the load modulation of the load modulation unit 56. For example, communication data including power transmission status information (VCC, etc.), charge status information (VBAT, various status flags, etc.), and temperature information is transmitted from the power receiving side by constant load modulation during the normal transmission period. Sent to the side.

As shown in A3 of FIG. 10, when the fully charged battery 90 is detected, the fully charged standby state is set. In this fully charged standby state, the power transmission unit 12 is in a state of detecting the removal of the electronic device 510 by performing intermittent power transmission for detecting the removal, for example. Further, the discharge operation of the discharge unit 60 remains off, and the power supply to the power supply target 100 also remains disabled.

When the removal of the electronic device 510 is detected as shown in A4 of FIG. 10, the electronic device 510 is put into use as shown in A5, and the discharge operation on the power receiving side is turned on. Specifically, the discharge operation of the discharge unit 60 is switched from off to on, and the electric power from the battery 90 is supplied to the power supply target 100 via the discharge unit 60. As a result, the electric power from the battery 90 is supplied, the electric power supply target 100 such as the processing unit operates, and the user can normally use the electronic device 510.

As described above, in the present embodiment, as shown in A1 of FIG. 10, when the landing of the electronic device 510 is detected, normal power transmission is performed, and constant load modulation is performed during this normal power transmission period. When the landing is detected, the discharge operation of the discharge unit 60 is stopped. Then, in this constant load modulation, communication data including information for power control on the power transmission side and information indicating the status of the power reception side is transmitted from the power reception side to the power transmission side. For example, by communicating information for power control (power transmission state information), it is possible to realize optimum power control according to, for example, the positional relationship between the primary coil L1 and the secondary coil L2. In addition, an optimal and safe charging environment can be realized by communicating information indicating the status of the power receiving side. Then, in the present embodiment, while the load modulation is continued, the normal power transmission is also continued, and the discharge operation of the discharge unit 60 remains off.

Further, in the present embodiment, as shown in A3 of FIG. 10, when a fully charged battery 90 is detected, normal power transmission is stopped, and intermittent power transmission for removal detection is performed. Then, as shown in A4 and A5, when the removal is detected and the removal period is reached, the discharge operation of the discharge unit 60 is performed. As a result, the electric power from the battery 90 is supplied to the electric power supply target 100, and the normal operation of the electronic device 510 becomes possible. The landing detection and the removal detection are performed based on the output voltage VCS of the power receiving unit 52.

As described above, in the present embodiment, since the discharge operation to the power supply target 100 is turned off during the charging period (normal power transmission period) of the battery 90 of the electronic device 510, the power supply target 100 wastes power during the charging period. Can be suppressed from being consumed.

Then, when the removal of the electronic device 510 is detected, the normal power transmission is switched to the intermittent power transmission, and the discharge operation to the power supply target 100 is turned on. By turning on the discharge operation in this way, the power from the battery 90 is supplied to the power supply target 100, and the normal operation of the power supply target 100 such as the processing unit (DSP) becomes possible. By doing so, for example, in an electronic device 510 of a type that does not operate during the charging period in which the electronic device 510 is placed on the charger 500 (for example, an electronic device worn by a user such as a hearing aid or a wearable device). , A suitable non-contact power transmission operation sequence can be realized.

5. Communication Method FIG. 11 is a diagram illustrating a communication method by load modulation. As shown in FIG. 11, on the power transmission side, the power transmission drivers DR1 and DR2 operate based on the power supply voltage VDCV supplied from the power supply voltage control unit 14 to drive the primary coil L1.

On the other hand, on the power receiving side (secondary side), the rectifier circuit 53 of the power receiving unit 52 rectifies the coil end voltage of the secondary coil L2, and the rectified voltage VCS is output to the node NVC. The primary coil L1 and the capacitor CA1 form a resonance circuit on the power transmission side, and the secondary coil L2 and the capacitor CA2 form a resonance circuit on the power reception side.

On the power receiving side, by turning on / off the switch element SW of the load modulation unit 56, the current ID 2 of the current source IS is intermittently flowed from the node NVC to the GND side, and the load state on the power receiving side (potential on the power receiving side). To fluctuate.

On the power transmission side, the current ID1 flowing through the sense resistor RCS provided in the power supply line fluctuates due to the fluctuation of the load state on the power reception side due to the load modulation. For example, a sense resistor RCS for detecting the current flowing through the power source is provided between the power source on the power transmission side (for example, a power source device such as the power adapter 502 in FIG. 5) and the power supply voltage control unit 14. The power supply voltage control unit 14 is supplied with a power supply voltage from the power supply via the sense resistor RCS. Then, the current ID1 flowing from the power supply to the sense resistor RCS fluctuates due to the fluctuation of the load state on the power receiving side due to the load modulation, and the communication unit 30 detects this current fluctuation. Then, the communication unit 30 performs detection processing of communication data transmitted by load modulation based on the detection result. The communication unit 30 is based on a comparison determination result between a current detection circuit that detects the current ID 1 flowing from the power supply to the transmission unit 12, a comparison circuit that performs a comparison determination between the detection voltage and the determination voltage by the current detection circuit, and a comparison circuit. A demodulator that determines the load modulation pattern based on the load modulation pattern can be included.

The control unit 54 (charging system control unit) of FIG. 2 measures the power transmission frequency of the power transmission signal of the power transmission device 10, generates a control signal for transmitting communication data, and outputs the control signal to the load modulation unit 56. Then, on / off control of the switch element SW of FIG. 11 is performed by this control signal, and the load modulation unit 56 is made to perform the load modulation corresponding to the communication data.

The load modulation unit 56 performs load modulation by changing the load state (load due to load modulation) on the power receiving side, for example, a first load state and a second load state. The first load state is, for example, a state in which the switch element SW is turned on, and a state in which the load state on the power receiving side (load of load modulation) becomes a high load (small impedance). The second load state is, for example, a state in which the switch element SW is turned off, and a state in which the load state on the power receiving side (load of load modulation) becomes a low load (large impedance).

Then, in the conventional load modulation method, for example, the first load state is made to correspond to the logical level "1" (first logical level) of the communication data, and the second load state is made to correspond to the logical level "1" of the communication data. Communication data was transmitted from the power receiving side to the power transmitting side in correspondence with "0" (second logical level). That is, when the logical level of the communication data bit is "1", the switch element SW is turned on, and when the logical level of the communication data bit is "0", the switch element SW is turned off. As a result, communication data of a predetermined number of bits was transmitted.

However, for example, in applications where the degree of coupling between the coils is low, the coils are small, and the transmitted power is also low, it is difficult to realize proper communication by such a conventional load modulation method. That is, even if the load state on the power receiving side is changed to the first load state and the second load state by load modulation, the logic levels of the communication data are "1" and "0" due to noise and the like. A data detection error occurs.

Therefore, in the present embodiment, as shown in FIG. 12, the load modulation unit 56 has a load modulation pattern of the first pattern PT1 for the first logic level “1” of the communication data transmitted to the power transmission device 10. Perform load modulation. On the other hand, as shown in FIG. 13, for the second logic level “0” of the communication data, load modulation is performed so that the load modulation pattern is a second pattern PT2 different from the first pattern PT1.

Then, the communication unit 30 (demodulation unit) on the power transmission side determines that the communication data has the first logic level "1" when the load modulation pattern is the first pattern PT1. On the other hand, when the load modulation pattern is the second pattern PT2 different from the first pattern PT1, it is determined that the communication data has the second logic level “0”.

Here, the load modulation pattern is a pattern composed of a first load state and a second load state. The first load state is a state in which the load on the power receiving side by the load modulation unit 56 becomes, for example, a high load. Specifically, in FIGS. 12 and 13, the period TM1 of the first load state is the period during which the switch element SW of the load modulation unit 56 is turned on and the current of the current source IS flows from the node NVC to the GND side. This is the period corresponding to the H level (bit = 1) of the first and second patterns PT1 and PT2. On the other hand, the second load state is a state in which the load on the power receiving side by the load modulation unit 56 becomes, for example, a low load. Specifically, in FIGS. 12 and 13, the period TM2 of the second load state is the period during which the switch element SW of the load modulation unit 56 is turned off, and the L level of the first and second patterns PT1 and PT2. It is a period corresponding to (bit = 0).

Then, in FIGS. 12 and 13, the first pattern PT1 has a pattern in which the width of the period TM1 in the first load state is longer than that of the second pattern PT2. As described above, the logic level "1" is determined for the first pattern PT1 in which the width of the period TM1 of the first load state is longer than that of the second pattern PT2. On the other hand, the logic level "0" is determined for the second pattern PT2 in which the width of the period TM1 in the first load state is shorter than that of the first pattern PT1.

As shown in FIG. 12, the first pattern PT1 is a pattern corresponding to, for example, the bit pattern (1110). As shown in FIG. 13, the second pattern PT2 is a pattern corresponding to, for example, the bit pattern (1010). In these bit patterns, bit = 1 corresponds to a state in which the switch element SW of the load modulation unit 56 is turned on, and bit = 0 corresponds to a state in which the switch element SW of the load modulation unit 56 is turned off.

For example, when the bit of the communication data to be transmitted is the logic level "1", the power receiving side turns on the switch element SW of the load modulation unit 56 with the bit pattern (1110) corresponding to the first pattern PT1. Turn off. Specifically, switch control is performed to turn on, on, on, and off the switch element SW in order. Then, when the load modulation pattern is the first pattern PT1 corresponding to the bit pattern of (1110), the power transmission side determines that the logical level of the bit of the communication data is "1".

On the other hand, when the bit of the communication data to be transmitted is the logic level "0", the power receiving side turns on the switch element SW of the load modulation unit 56 with the bit pattern (1010) corresponding to the second pattern PT2. Or turn it off. Specifically, switch control is performed to turn on, off, on, and off the switch element SW in order. Then, when the load modulation pattern is the second pattern PT2 corresponding to the bit pattern of (1010), the power transmission side determines that the logical level of the bit of the communication data is “0”.

Here, when the power transmission frequency (frequency of the drive clock signal FCK) of the power transmission unit 12 is fck and the power transmission cycle is T = 1 / fck, the lengths of the first and second patterns PT1 and PT2 are For example, it can be expressed as 512 × T. In this case, the length of one bit interval is expressed as (512 × T) / 4 = 128 × T. Therefore, on the power receiving side, when the bit of the communication data is the logic level "1", the load modulation unit 56 has a bit pattern (1110) corresponding to the first pattern PT1 at intervals of, for example, 128 × T. Switch element SW is turned on or off. On the power receiving side, when the bit of the communication data is the logic level "0", the load modulation unit 56 has a bit pattern (1010) corresponding to the second pattern PT2 at intervals of, for example, 128 × T. Switch element SW is turned on or off.

On the other hand, the power transmission side performs the communication data detection process and the capture process by, for example, the method shown in FIG. For example, the communication unit 30 (demodulation unit) samples the load modulation pattern at a given sampling interval SI from the first sampling point SP1 set in the period TM1 of the first load state in the first pattern PT1. And fetch communication data of a given number of bits.

For example, the sampling points SP1, SP2, SP3, SP4, SP5, and SP6 in FIG. 14 are sampling points set for each sampling interval SI. This sampling interval SI is an interval corresponding to the length of the load modulation pattern. For example, in FIGS. 12 and 13, since the lengths of the first and second patterns PT1 and PT2 are 512 × T (= 512 / fck), the length of the sampling interval SI is also 512 × T.

And in FIG. 14, the load modulation patterns in the periods TS1, TS2, TS3, TS4, TS5, and TS6 are PT1, PT2, PT1, PT2, PT2, and PT2, respectively. Therefore, in the case of FIG. 14, by sampling the load modulation pattern at the sampling interval SI from the first sampling point SP1, for example, communication data (101000) having the number of bits = 6 is taken in.

Specifically, when the width of the period TM1 of the first load state is within the first range width (220 × T to 511 × T), as shown in FIG. 14, the width of the first load state The first sampling point SP1 is set in the period TM1. That is, when the width of the period TM1 at which the signal level becomes the H level is within the first range width, bit synchronization is performed, and the first sampling point SP1 is set at, for example, the center point in the period TM1. .. Then, sampling is performed at each sampling interval SI from the set first sampling point SP1. If the level of the captured signal is H level (first load state), it is determined that it is logic level "1" (first pattern PT1), and it may be L level (second load state). For example, it is determined that the logic level is “0” (second pattern PT2).

Here, the first range width (220 × T to 511 × T) is a range width set corresponding to the period TM1 (384 × T) of the first load state in the first pattern PT1. For example, the width of the period TM1 fluctuates due to noise superimposed on the signal. The typical value of the width of the period TM1 in the first pattern PT1 is 128 × 3 × T = 384 × T, which is the width corresponding to 3 bits (111). Therefore, the first range width 220 × T to 511 × T is set so as to include the 384 × T. Then, for the H level period within the first range width 220 × T to 511 × T, it is determined that the period TM1 of the first pattern PT1 is set, and a bit for setting the first sampling point SP1. Synchronize. By doing so, even when noise is superimposed on the signal, appropriate bit synchronization can be performed and an appropriate first sampling point SP1 can be set.

At each sampling point SP2 to SP6 in FIG. 14, it may be confirmed whether or not the width of the load state period including the sampling point is within a predetermined range width.

For example, in the second sampling point SP2, the load state is the first load state (H level), and the width of the period TM1 of the first load state including the second sampling point SP2 is in the first range. When it is within the width (220 × T to 511 × T), it is determined that the load modulation pattern at the second sampling point SP2 is the first pattern PT1 (logical level “1”).

On the other hand, at the second sampling point SP2, the load state is the second load state (L level), and the width of the period TM2 of the second load state including the second sampling point SP2 is the second. When it is within the range width (for example, 80 × T to 150 × T), it is determined that the load modulation pattern at the second sampling point SP2 is the second pattern PT2 (logical level “0”).

Here, the second range width (80 × T to 150 × T) is a range width set corresponding to the period TM2 (128 × T) of the second load state in the second pattern PT2. Since the typical value of the period TM2 is 128 × T, which is a width corresponding to one bit, a second range width of 80 × T to 150 × T including this 128 × T is set.

As described above, in the present embodiment, the load modulation pattern is discriminated to determine the logical level of the communication data. Therefore, even in a situation where there is a lot of noise, it is possible to properly detect the communication data. That is, in the first and second patterns PT1 and PT2 of FIGS. 12 and 13, for example, the width of the period TM1 in the first load state (H level) is significantly different, and in the present embodiment, the period TM1 By discriminating the difference in width, the pattern is discriminated and the logic level of each bit of the communication data is detected. Therefore, even when the width of the period TM1 at the sampling point SP1 fluctuates due to noise, for example, proper detection of communication data becomes possible. Further, since the subsequent sampling points SP2, SP3, SP4 ... Can be set by simple processing based on the sampling interval SI, there is an advantage that the processing load of the communication data detection processing can be reduced.

15 and 16 show an example of the communication data format used in this embodiment.

In FIG. 15, the communication data is composed of 64 bits, and one packet is composed of the 64 bits. The first 16 bits are 0000h. For example, when the load modulation on the power receiving side is detected and the power transmission side starts normal power transmission (or intermittent power transmission), the current detection circuit of the communication unit 30 or the like operates until communication data can be detected appropriately. , It takes some time. Therefore, 0000h, which is dummy (empty) data, is set in the first 16 bits. The power transmission side will perform various processes necessary for, for example, bit synchronization during the first 16-bit 0000h communication period.

The data code and rectified voltage (VCC) information are set in the next second 16 bits. As shown in FIG. 16, the data code is a code for specifying the data communicated by the next third 16 bits. The rectified voltage (VCC) is used as transmission power setting information of the transmission device 10.

Information such as temperature, battery voltage, battery current, status flag, number of cycles, IC number / charge execution / off-start, or ID is set in the third 16 bits according to the setting in the data code. The temperature is, for example, the battery temperature. The battery voltage and the battery current are information indicating the state of charge of the battery 90. The status flag is information indicating the status of the power receiving side such as temperature error (high temperature abnormality, low temperature abnormality), battery error (battery voltage of 1.0 V or less), overvoltage error, timer error, full charge (normal end), and the like. .. The number of cycles (cycle time) is information indicating the number of charges. The IC number is a number for identifying the IC of the control device. The charge execution flag (CGO) is a flag indicating that the authenticated power transmission side is appropriate and that charging is performed based on the power transmitted from the power transmission side. The off-start flag (OFST) is a flag that notifies that the discharge operation is set to off when the removal is detected. CRC information is set in the fourth 16 bits.

As shown in FIGS. 15 and 16, the control unit 54 controls to transmit the charge number information (cycle number) to the power transmission device 10. In this way, it is possible to manage the degree of deterioration of the battery 90 on the power transmission device 10 side as well.

The communication method of the present embodiment is not limited to the methods described with reference to FIGS. 12 to 16, and various modifications can be performed. For example, in FIGS. 12 and 13, the first pattern PT1 is associated with the logic level “1” and the second pattern PT2 is associated with the logic level “0”, but this association may be reversed. .. Further, the first and second patterns PT1 and PT2 of FIGS. 12 and 13 are examples of load modulation patterns, and the load modulation pattern of the present embodiment is not limited to this, and various modifications can be performed. For example, in FIGS. 12 and 13, the first and second patterns PT1 and PT2 are set to have the same length, but may be set to different lengths. Further, in FIGS. 12 and 13, the first pattern PT1 of the bit pattern (1110) and the second pattern PT2 of the bit pattern (1010) are used, but the first and first bit patterns different from these are used. The patterns PT1 and PT2 of 2 may be adopted. For example, the first and second patterns PT1 and PT2 may be patterns having at least different lengths of the first load state period TM1 (or the second load state period TM2), as shown in FIGS. 12 and 13. Can employ a variety of different patterns. Further, the format of the communication data and the communication processing are not limited to the method described in this embodiment, and various modifications can be performed.

Although the present embodiment has been described in detail as described above, those skilled in the art will easily understand that many modifications that do not substantially deviate from the novel matters and effects of the present invention are possible. Therefore, all such modifications are included in the scope of the present invention. For example, a term described at least once in a specification or drawing with a different term in a broader or synonymous manner may be replaced by that different term anywhere in the specification or drawing. Further, all combinations of the present embodiment and modifications are also included in the scope of the present invention. Further, the configuration / operation of the power transmission side, the control device on the power reception side, the power transmission device, the power reception device, and the like are not limited to those described in the present embodiment, and various modifications can be made.

L1 ... primary coil, L2 ... secondary coil, DR1, DR2 ... power transmission driver,
IS, ISC ... current source, SW ... switch element, CM ... capacitor,
TA1-TA4, TC1-TC4 ... Transistor,
RCS, RS ... sense resistance, RB1, RB2, RC1-RC5 ... resistance,
OPC ... operational amplifier, TH ... thermistor (temperature detector),
10 ... power transmission device, 12 ... power transmission unit, 14 ... power supply voltage control unit, 16 ... notification unit,
20 ... control device, 22 ... driver control circuit, 24 ... control unit,
30 ... Communication unit, 37 ... Clock generation circuit, 38 ... Oscillation circuit,
40 ... Power receiving device, 42 ... Power supply switch,
50 ... control device, 51 ... rectifier control unit, 52 ... power receiving unit, 53 ... rectifier circuit, 54 ... control unit,
56 ... load modulation section, 57 ... power supply section, 58 ... charging section, 59 ... CC charging circuit,
60 ... Discharge unit, 61 ... Charge pump circuit, 62 ... Non-volatile memory,
64 ... Detection unit, 65 ... A / D conversion unit, 67 ... Regulator,
80 ... load, 90 ... battery, 100 ... power supply target,
500 ... Charger, 502 ... Power adapter, 510 ... Electronic equipment, 514 ... Switch

Claims (9)

It is a control device for a power receiving device that receives power supplied by non-contact power transmission from a power transmitting device.
A charging unit that charges the battery based on the power received by the power receiving unit in the power receiving device.
A control unit that controls the charging unit and
Including
The control unit
Control to switch between constant current charging and constant voltage charging, and to update charge count information indicating the number of times the battery has been charged, provided that the constant current charging has been switched to the constant voltage charging. There line,
The control unit
From the start of charging the battery, control is performed to gradually increase the charging current from a given reference value.
The control unit
A control device comprising switching to the constant current charging when the charging current reaches the constant current value of the constant current charging before the battery voltage reaches a given threshold voltage . In claim 1 ,
The control unit
After switching to the constant current charging, when the battery voltage reaches the given threshold voltage, the switching to the constant voltage charging is performed, and control is performed to update the charging number information. Control device. In claim 1 or 2 ,
The control unit
If the battery voltage reaches the given threshold voltage before the charging current reaches the constant current value of the constant current charging, the switching to the constant voltage charging is performed and the charging number information is not obtained. A control device characterized by performing control to be updated. In any one of claims 1 to 3 ,
The control unit
A control device characterized by performing control to update the charge number information based on an update amount weighted according to a set value of the given threshold voltage. In any of claims 1 to 4 ,
The control unit
A control device characterized by performing control to update the charge number of times information based on an update amount weighted according to temperature information during charging. In any of claims 1 to 5 ,
The control unit
A control device characterized in that it controls transmission of the charge number information to the power transmission device. A power receiving device including the control device according to any one of claims 1 to 6 . An electronic device comprising the control device according to any one of claims 1 to 6 . A non-contact power transmission system that includes a power transmission device and a power reception device.
The power transmission device
Power is transmitted to the power receiving device,
The power receiving device is
The battery is charged based on the power received by the power receiving unit in the power receiving device.
The power receiving device is
Performs control of switching the constant-current charging and constant voltage charging, when said switching of said to the constant voltage charging from the constant current charging is performed, the row physician control of updating the charging count information indicating the number of times of charging the battery ,
The power receiving device is
From the start of charging the battery, control is performed to gradually increase the charging current from a given reference value.
The power receiving device is
A non-contact power transmission system comprising switching to the constant current charging when the charging current reaches the constant current value of the constant current charging before the battery voltage reaches a given threshold voltage .

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