JP6860040B2 - Controls, electronic devices and wireless power transfer systems - Google Patents

Description

The present invention relates to control devices, electronic devices, non-contact power transmission systems, 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, households Charging of electronic devices such as personal devices and mobile terminals has been proposed.

Various charge control methods in contactless power transfer are also disclosed. For example, Patent Document 1 discloses a method of maintaining an operating state of a charge control unit on a power receiving device side by performing power save power transmission when fully charged. In Patent Document 1, wasteful power consumption is suppressed because it is possible to easily realize a smooth return to normal power transmission and stop power transmission when the power receiving device is removed during power save power transmission.

Further, Patent Document 2 discloses a method in which a switch is provided on the power transmission device side and provisional power transmission for authentication is performed based on the operation of the switch.

Further, Patent Document 3 discloses a charge control method called smart charging.

Japanese Unexamined Patent Publication No. 2008-202632 JP-A-2009-11129 U.S. Patent Application Publication No. 2014/0320089

When the power receiving device has a battery (secondary battery), it is preferable to store the state information of the battery and perform control according to the state information. For example, if some error information is stored as state information, it is possible to suppress the occurrence of serious problems such as equipment failure or damage by performing control according to the error. Alternatively, if the information on the number of times the battery is charged is stored, it is possible to evaluate the degree of deterioration of the battery. Alternatively, if the past charging voltage is stored, charging control such as smart charging disclosed in Patent Document 3 is also possible. However, in the conventional method, the power receiving device side of the non-contact power transmission system does not disclose the one including the non-volatile memory for storing the state information, and the control based on the information stored in the non-volatile memory is not disclosed. There is no disclosure.

According to some aspects of the present invention, it is possible to provide a control device, an electronic device, a non-contact power transmission system, etc. that perform appropriate control based on the state information stored in the non-volatile memory.

One aspect of the present invention is a control device on the power receiving side in a non-contact power transmission system having a power transmitting device and a power receiving device, and a battery is based on the power received by the power receiving unit that receives power from the power transmitting device. The non-volatile memory includes a charging unit for charging, a control unit for performing charge control, and a non-volatile memory, the non-volatile memory stores the state information of the battery, and the control unit is stored in the non-volatile memory. It relates to a control device that performs the charge control based on the state information.

In one aspect of the present invention, the non-volatile memory provided on the power receiving device side of the non-contact power transmission system stores the state information of the battery, and the control unit of the control device on the power receiving side is stored in the non-volatile memory. Charge control is performed based on the information. In this way, the battery status information can be appropriately stored on the power receiving device side, and appropriate charging control can be performed according to the battery status.

Further, in one aspect of the present invention, the non-volatile memory may store temperature abnormality detection information as the state information.

As a result, the temperature abnormality detection information can be stored in the non-volatile memory, and charging control can be performed based on the temperature abnormality detection information.

Further, in one aspect of the present invention, the load modulation unit includes a load modulation unit that transmits communication data to the power transmission device by load modulation, and the load modulation unit is described by the load modulation when a temperature abnormality is detected. The temperature abnormality detection information may be transmitted to the power transmission device.

This makes it possible to transmit the temperature abnormality detection information to the power transmission device side by load modulation.

Further, in one aspect of the present invention, the non-volatile memory may store charge count information indicating the charge count of the battery as the state information.

This makes it possible to store the number of times the battery has been charged as status information.

Further, in one aspect of the present invention, when the temperature abnormality detection information is stored in the non-volatile memory, the control unit does not update the charge count information of the non-volatile memory, and the non-volatile memory. If the temperature abnormality detection information is not stored in the non-volatile memory, the charging frequency information of the non-volatile memory may be updated.

This makes it possible to appropriately determine whether to update or not update the number of times of charging according to the temperature abnormality detection information.

Further, in one aspect of the present invention, the non-volatile memory may store the battery voltage when a temperature abnormality is detected as the state information.

This makes it possible to store the battery voltage at the time of detecting an abnormal temperature as the state information.

Further, in one aspect of the present invention, the control unit stores the battery voltage in the non-volatile memory even when the temperature abnormality detection information is stored in the non-volatile memory. When the voltage is lower than the battery voltage, the charge number information of the non-volatile memory may be updated.

As a result, when the temperature abnormality detection information is stored, it is possible to appropriately determine whether to update or not update the number of times of charging by referring to the change in the battery voltage.

Further, in one aspect of the present invention, when the control unit stores the state information in the non-volatile memory, the state information is written to the first address, and after a given time elapses, the state information is described. May be written to a second address different from the first address.

This makes it possible to increase the possibility of writing information appropriately.

Further, in one aspect of the present invention, the non-volatile memory may operate at a power supply voltage based on the output voltage of the power receiving unit.

This makes it possible to operate the non-volatile memory with a voltage based on the output voltage of the power receiving unit.

Further, in one aspect of the present invention, the non-volatile memory may store the charge control information of the battery.

As a result, the non-volatile memory can store not only the state information but also the charge control information.

Another aspect of the present invention is a control device on the power transmission side in a non-contact power transmission system having a power transmission device and a power reception device, and is a driver that controls a power transmission driver of a power transmission unit that transmits power to the power reception device. The control unit includes a control circuit, a control unit that controls the driver control circuit, and a communication unit that performs communication processing between the power receiving device that transmits communication data by load modulation, and the control unit includes the power receiving device. The present invention relates to a control device that causes the power transmission unit to perform intermittent power transmission when communication data including temperature abnormality detection information is received from the power transmission unit.

In another aspect of the present invention, when the control device on the power transmission side of the non-contact power transmission system receives communication data including temperature abnormality detection information from the power receiving device that performs load modulation, the power transmission unit is made to perform intermittent power transmission. .. In this way, when a temperature abnormality occurs on the power receiving device side, it is possible to perform appropriate power transmission control and the like.

Further, another aspect of the present invention relates to an electronic device including the above-mentioned control device.

Another aspect of the present invention is a non-contact power transmission system including a power transmission device and a power reception device, wherein the power transmission device transmits power to the power reception device and also transmits communication data by load modulation. The power receiving device performs communication processing with the power receiving device, and the power receiving device has a non-volatile memory for storing battery status information, and the power received from the power transmission device and the power stored in the non-volatile memory. The battery is charged based on the state information, and communication data is transmitted to the power transmission device by the load modulation, and the power receiving device transmits the temperature abnormality detection information when a temperature abnormality is detected. The state information is stored in the non-volatile memory, and the temperature abnormality detection information is transmitted to the power transmission device by the load modulation, and the power transmission device transmits the communication including the temperature abnormality detection information from the power receiving device. It relates to a non-contact power transmission system that transmits power to the power receiving device by intermittent power transmission when data is received.

In another aspect of the present invention, when the power receiving device detects a temperature abnormality, the power receiving device stores the temperature abnormality detection information in the non-volatile memory and transmits the temperature abnormality detection information to the power transmission device, and when the power transmission device receives the temperature abnormality detection information. Perform intermittent power transmission. In this way, by using the temperature abnormality detection information, it becomes possible to execute appropriate control for the temperature abnormality in both the power receiving device and the power transmission device.

1 (A) and 1 (B) are explanatory views of the non-contact power transmission system of the present embodiment. Configuration example of the power transmission device, the power reception device, the power transmission side, and the control device on the power reception side of the present embodiment. Explanatory drawing of the outline of the operation sequence of the non-contact power transmission system of this embodiment. The signal waveform diagram explaining the operation sequence of this embodiment. The signal waveform diagram explaining the operation sequence of this embodiment. The signal waveform diagram explaining the operation sequence of this embodiment. The signal waveform diagram explaining the operation sequence of this embodiment. Configuration example of non-volatile memory. An example of information stored in non-volatile memory. The figure explaining the operation sequence of this embodiment. 11 (A) and 11 (B) are flowcharts for explaining the flow of control regarding the temperature abnormality. A flowchart explaining the flow of smart charging. Explanatory drawing of communication method by load modulation. Configuration example of the communication unit. Explanatory drawing of communication configuration of power receiving side. An explanatory diagram of problems caused by noise during communication. The explanatory view of the communication method of this embodiment. The explanatory view of the communication method of this embodiment. 19 (A) and 19 (B) are examples of communication data formats. A flowchart illustrating a detailed example of communication processing. Detailed configuration example of the power receiving unit and charging unit.

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 the configurations described in the present embodiment are indispensable as a means for solving the present invention. Not necessarily.

1. 1. Electronic Equipment Fig. 1 (A) shows an example of the non-contact power transmission system of this 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. Further, the electronic device 510 has a switch unit 514 for operation and a battery 90. Although the battery 90 is schematically shown in FIG. 1A, the battery 90 is actually built in the electronic device 510. The non-contact power transmission system of the present embodiment is configured by the power transmission device 10 and the power reception device 40 of FIG. 1A.

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). Further, various devices can be assumed as the electronic device 510 to which this embodiment is applied. For example, various types of hearing aids, watches, biometric information measuring devices (wearable devices), personal digital assistants (smartphones, mobile phones, etc.), cordless telephones, shavers, electric toothbrushes, wrist computers, handy terminals, electric vehicles, or electric bicycles. You can imagine an electronic device.

As schematically shown in FIG. 1 (B), power transmission from the power transmission device 10 to the power reception device 40 is performed by a primary coil L1 (power transmission coil) provided on the power transmission side and a secondary coil provided on the power reception side. This is achieved by electromagnetically coupling the coils L2 (power receiving coils) to form a power transmission transformer. This enables non-contact power transmission.

2. Power transmission device, power receiving device, power transmitting side, power receiving side control device FIG. 2 shows a configuration example of the power transmission device 10, the power receiving device 40, the power transmitting side control device 20, and the power receiving side control device 50 of the present embodiment. The power transmission side electronic device such as the charger 500 of FIG. 1 (A) includes at least the power transmission device 10 of FIG. Further, the electronic device 510 on the power receiving side can include at least a power receiving device 40, a battery 90, and a power supply target 100. The power supply target 100 is various devices such as a processing unit (DSP or the like). Then, according to the configuration of FIG. 2, non-contact power transmission (contactless power transmission) 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 to charge the battery 90 or the like. A non-contact power transmission) system is realized.

The power transmission device 10 (power transmission module, primary module) includes a primary coil L1, a power transmission unit 12, a display unit 16, and a control device 20. The power transmission device 10 is not limited to the configuration shown in FIG. 2, and various modifications such as omitting a part of its components (for example, a display unit), adding other components, and changing the connection relationship. It is possible to carry out.

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. Further, the power transmission unit 12 can include at least one capacitor (capacitor) forming a resonance circuit together with the primary coil L1.

Each of the power transmission drivers DR1 and DR2 of the power transmission unit 12 is realized by, for example, an inverter circuit (buffer circuit) composed of power MOS transistors. These power transmission drivers DR1 and DR2 are controlled (driven) by the driver control circuit 22 of the control device 20.

The power supply voltage control unit 14 of the power transmission unit 12 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 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.

The primary coil L1 (transmission side coil) is electromagnetically coupled with the secondary coil L2 (power receiving side coil) to form a power transmission transformer. For example, when power transmission is required, as shown in FIGS. 1A and 1B, 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. Make it in a good state. 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 display unit 16 displays various states of the non-contact power transmission system (during power transmission, ID authentication, etc.) using colors, images, and the like, and can be realized by, for example, an LED or an LCD.

The control device 20 performs various controls on the power transmission side, and can be realized by an integrated circuit device (IC) or the like. The control device 20 includes a driver control circuit 22, a control unit 24, and a communication unit 30. Further, the control device 20 can include a clock generation circuit 37 and an oscillation circuit 38. The control device 20 is not limited to the configuration shown in FIG. 2, and some of its components (for example, clock generation circuit, oscillation circuit, etc.) may be omitted, other components may be added, or the connection relationship may be changed. It is possible to carry out various modifications of. For example, it is possible to carry out a modification in which the power transmission unit 12 or the like is built in the control device 20.

The driver control circuit 22 controls the power transmission drivers DR1 and DR2 of the power transmission unit 12 that transmits power to the power receiving device 40. 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 control unit 24 executes various control processes of the control device 20 on the power transmission side. For example, the control unit 24 controls the driver control circuit 22. Specifically, the control unit 24 performs various sequence control and determination processing necessary for power transmission, communication processing, and the like. This control unit 24 can be realized by, for example, a logic circuit generated by an automatic placement and routing method such as a gate array, or various processors such as a microcomputer.

The communication unit 30 performs communication processing of communication data with the power receiving device 40. For example, the communication unit 30 performs communication processing with the power receiving device 40 (control device 50) that transmits communication data by load modulation. Specifically, the communication unit 30 performs a process for detecting and receiving communication data from the power receiving device 40.

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 drive frequency. Then, the driver control circuit 22 generates a control signal of a given frequency (drive frequency) based on the drive clock signal, the control signal from the control unit 24, and the like, and causes the power transmission drivers DR1 and DR2 of the power transmission unit 12 to generate a control signal. Output and control.

The power receiving device 40 (power receiving module, secondary module) includes a secondary coil L2 and a control device 50. The power receiving device 40 is not limited to the configuration shown in FIG. 2, and various modifications such as omitting a part of the components, adding other components, and changing the connection relationship can be performed.

The control device 50 performs various controls on the power receiving side, and can be realized by an integrated circuit device (IC) or the like. The control device 50 includes a power receiving unit 52, a control unit 54, a load modulation unit 56, a charging unit 58, and a discharging unit 60. Further, the non-volatile memory 62 and the detection unit 64 can be included. The control device 50 is not limited to the configuration shown in FIG. 2, and various modifications such as omitting a part of the components, adding other components, and changing the connection relationship can be performed. For example, it is possible to carry out deformation such as providing a power receiving unit 52 or the like outside the control device 50.

The power receiving unit 52 receives the electric power from the power transmission device 10. Specifically, the power receiving unit 52 converts the AC induced voltage of the secondary coil L2 into a DC rectified voltage VCS and outputs it. This conversion is performed by the rectifier circuit 53 included in the power receiving unit 52. The rectifier circuit 53 can be realized by, for example, a plurality of transistors and diodes.

The control unit 54 executes various control processes of the control device 50 on the power receiving side. For example, the control unit 54 controls the load modulation unit 56, the charging unit 58, and the discharging unit 60. It is also possible to control the power receiving unit 52, the non-volatile memory 62, the detection unit 64, and the like. This control unit 54 can be realized by, for example, a logic circuit generated by an automatic placement and routing method such as a gate array, or various processors such as a microcomputer.

The load modulation unit 56 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 voltage). 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, so that the load modulation is performed. 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 charging unit 58 charges the battery 90 (charge control). For example, the charging unit 58 charges the battery 90 based on the electric power received by the power receiving unit 52 that receives the electric power from the power transmitting device 10. 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 CC charging circuit 59. The CC charging circuit 59 is a circuit for CC (Constant-Current) charging of the battery 90.

The discharge unit 60 discharges the battery 90. For example, the discharge unit 60 (power supply unit) discharges the battery 90 and supplies the power from the battery 90 to the power supply target 100. For example, the discharge unit 60 is supplied with the battery voltage VBAT of 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 battery 90 is, for example, a rechargeable secondary battery, such as a lithium battery (lithium ion secondary battery, lithium ion polymer secondary battery, etc.), a nickel battery (nickel / hydrogen storage battery, nickel / cadmium storage battery, etc.) and the like. The power supply target 100 is, for example, a device (integrated circuit device) such as a processing unit (DSP, microcomputer), which is provided in an electronic device 510 (FIG. 1 (A)) having a power receiving device 40 built-in, and power of a battery 90. It is a device to be supplied.

The non-volatile memory 62 is a non-volatile memory device that stores various types of information. The non-volatile memory 62 stores various information such as the state information of the battery 90, which will be described later, and the status information of the power receiving device 40 (control device 50). 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. For example, overvoltage protection, high temperature protection, and low temperature protection can be realized by detecting overvoltage and temperature abnormality by the detection unit 64 during charging. Further, the detection unit 64 detects over-discharge and over-current at the time of discharge, so that over-discharge protection and over-current protection can be realized.

3. 3. Operation sequence of the non-contact power transmission system Next, an example of the operation sequence of the non-contact power transmission system of the present embodiment will be described. FIG. 3 is a diagram illustrating an outline of an operation sequence.

In A1 of FIG. 3, 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 side is in the waiting state, and the power reception side is in the discharge operation on state.

Specifically, in the standby state, the power transmission unit 12 of the power transmission device 10 performs intermittent power transmission for landing detection. That is, the power transmission unit 12 is in a state of detecting the landing of the electronic device 510 by performing intermittent power transmission that intermittently transmits power every given period without performing continuous power transmission as in normal power transmission. 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. That is, the discharge unit 60 of the power receiving device 40 performs an operation of discharging the power from the battery 90 to the power supply target 100. 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. 3, 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 side normally transmits power, and the power receiving side turns on the charging operation and turns off the discharging operation. In addition, the power receiving side transmits communication data by load modulation.

Specifically, in the communication check & charging 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. In addition, control based on the state of charge of the battery 90 is also performed. The state of power transmission is, for example, a state determined by the positional relationship (distance between coils, etc.) of the primary coil L1 and the secondary coil L2, and is based on information such as the rectified voltage VCS which is the output voltage of the power receiving unit 52. I can judge. 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 information such as power transmission status information (VCC, etc.), charge status information (VBAT, various status flags, etc.), and temperature is transmitted from the power receiving side by constant load modulation during the normal transmission period. Sent to the side. For example, the power control by the power supply voltage control unit 14 of the power transmission unit 12 is performed based on the power transmission state information included in the communication data.

As shown in A3 of FIG. 3, when the fully charged battery 90 is detected, the fully charged standby state is set. In the fully charged standby state, the power transmission side is in the waiting state, and the power receiving side is in the state in which the discharge operation remains off.

Specifically, the power transmission unit 12 performs intermittent power transmission for, for example, removal detection. That is, the power transmission unit 12 is in a state of detecting the removal of the electronic device 510 by performing intermittent power transmission that intermittently transmits power every given period without performing continuous power transmission as in normal power transmission. 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. 3, 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 A2 of FIG. 3, 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. 3, when the full charge of the battery 90 is detected, the normal power transmission is stopped, and the intermittent power transmission for the 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 of the power receiving unit 52 (for example, the rectified voltage VCS).

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, it is suitable for the type of electronic device 510 (for example, an electronic device worn by a user such as a hearing aid) in which the electronic device 510 does not operate during the charging period when the electronic device 510 is placed on the charger 500. An operation sequence of non-contact power transmission can be realized. That is, in such a type of electronic device 510, power saving can be realized by turning off the discharge operation of the power from the battery 90 during the charging period (normal power transmission period). Then, when the removal is detected, the discharge operation is automatically turned on, so that the power from the battery 90 is supplied to various devices that are the power supply target 100 of the electronic device 510, and the devices are supplied with power. It becomes possible to operate, and it becomes possible to automatically shift to the normal operation mode of the electronic device 510.

4, 5 and 6 are signal waveform diagrams for explaining the operation sequence of the non-contact power transmission system of the present embodiment.

B1 in FIG. 4 is the standby state of A1 in FIG. 3, and intermittent power transmission for landing detection is performed. That is, power transmission is performed at intervals of period TL2 at intervals of period TL1. The interval of TL1 is, for example, 3 seconds, and the interval of TL2 is, for example, 50 milliseconds. In B2 and B3 of FIG. 4, since the rectified voltage VCS, which is the output voltage of the power receiving unit 52, is 6.0 V or less, communication by load modulation is not performed.

On the other hand, in B4, since the rectified voltage VCS exceeds the threshold voltage of 6.0 V for landing detection, the load modulation unit 56 starts load modulation as shown in B5. That is, in B2 and B3, the coils of L1 and L2 are not sufficiently in the electromagnetically coupled state, but in B4, the coils of L1 and L2 are in the proper electromagnetically coupled state as shown in FIG. 1 (B). ing. Therefore, the rectified voltage VCS rises and exceeds 6.0 V, and load modulation starts. Then, when this load modulation (empty communication data) is detected by the power transmission side, normal power transmission by the power transmission unit 12 starts as shown in B6. The normal power transmission of B6 is a continuous power transmission different from the intermittent power transmission of B1, and the charging unit 58 starts charging the battery 90 by the power generated by this normal power transmission. At this time, the discharge operation of the discharge unit 60 is turned off. Further, by the load modulation shown in B5, communication data including various information such as a rectified voltage, a battery voltage, and a status flag is transmitted from the power receiving side to the power transmission side, and power transmission control is executed. The load modulation of B5 is started when the rectified voltage VCS rises due to the intermittent power transmission for landing detection shown in B7.

In C1 of FIG. 5, the electronic device 510 is removed during the normal power transmission period in which the battery 90 is charged. As shown in C2 and C3, the removal of C1 is the removal of the battery 90 before it is fully charged. That is, the removal is performed in a state where the full charge flag is at the L level, which is the inactive level.

When the electronic device 510 is removed in this way, the power on the power transmitting side is not transmitted to the power receiving side, and the rectified voltage VCS, which is the output voltage of the power receiving unit 52, decreases. Then, as shown in C4, for example, when VCS <3.1V, the load modulation by the load modulation unit 56 is stopped as shown in C5. When the load modulation is stopped, the normal power transmission by the power transmission unit 12 is stopped as shown in C6.

Further, when the rectified voltage VCS (output voltage) decreases and falls below, for example, 3.1 V, which is a determination voltage, discharge of the start capacitor on the power receiving side (not shown) starts. This start capacitor is a capacitor for starting the discharge operation on the power receiving side (for measuring the starting period), and is provided as an external component of the control device 50 on the power receiving side, for example. Then, when the start-up period TST elapses after the rectified voltage VCS falls below the determination voltage (3.1 V), the discharge operation of the discharge unit 60 switches from off to on as shown in C8, and the power from the battery 90 becomes electric power. It will be supplied to the supply target 100. Specifically, when the voltage of the start capacitor (charging voltage) falls below the threshold voltage for turning on the discharge operation, it is determined that the start-up period TST has elapsed, the discharge operation of the discharge unit 60 is turned on, and the battery 90 Is discharged to the power supply target 100. As a result, as shown in A5 of FIG. 3, the electronic device 510 becomes usable. Further, after the normal power transmission is stopped, the power transmission unit 12 starts intermittent power transmission for landing detection as shown in C9.

In D1 of FIG. 6, the full charge flag is set to the H level, which is the active level, and the full charge of the battery 90 is detected. When full charge is detected in this way, the state shifts to the full charge standby state as shown in A3 of FIG. 3, and intermittent power transmission for removal detection after full charge is performed as shown in D2. That is, power transmission is performed at intervals of period TR2 at intervals of period TR1. The interval of TR1 is, for example, 1.5 seconds, and the interval of TR2 is, for example, 50 milliseconds. The interval of the intermittent power transmission period TR1 for removal detection is shorter than the interval of the intermittent power transmission period TL1 for landing detection.

Due to this intermittent power transmission for detection of removal, the rectified voltage of the power receiving unit 52 becomes VCS> 6.0 as shown in D3 and D4 of FIG. 6, and load modulation is performed as shown in D5 and D6. By detecting this load modulation (empty communication data, etc.), the power transmission side can detect that the electronic device 510 has not been removed yet.

Then, the interval of the intermittent power transmission period TR1 for removal detection (for example, 1.5 seconds) is shorter than the interval of the start-up period TST shown in D7 (for example, 3 seconds) set by the start capacitor described above. Therefore, in the state where the electronic device 510 is not removed, the voltage (charging voltage) of the start capacitor does not fall below the threshold voltage VT for turning on the discharge operation, and as shown in D8, the discharge operation is changed from off to on. There is no switching.

On the other hand, in D9, the electronic device 510 has been removed. Then, after the end of the intermittent power transmission period TR2 for the removal detection shown in D4, as shown in D10, the rectified voltage VCS of the power receiving unit 52 is lower than the determination voltage of 3.1 V, so that the start-up period TST shown in D7 Measurement starts. Then, in D11, the voltage of the start capacitor is lower than the threshold voltage VT for turning on the discharge operation, and the passage of the start-up period TST is detected. As a result, the discharge operation of the discharge unit 60 is switched from off to on, and the power from the battery 90 is supplied to the power supply target 100. Further, as shown in D12, intermittent power transmission for landing detection of the electronic device 510 will be performed.

FIG. 7 is a signal waveform diagram for explaining an operation sequence in the overall wait state due to a temperature abnormality (temperature error).

In E1 of FIG. 7, for example, a temperature abnormality (high temperature abnormality) in which the battery temperature reaches 50 degrees is detected, and the temperature error flag is set to the H level, which is the active level. In this case, in the present embodiment, the overall wait period TOW is set as shown in E2. During this wait period TOW, normal power transmission is stopped, and for example, intermittent power transmission for removal detection is performed. That is, intermittent power transmission similar to the fully charged standby state described with reference to FIG. 6 is performed. For example, communication data including a temperature error flag is transmitted from the power receiving side to the power transmission side by load modulation, whereby the normal power transmission of the power transmission unit 12 is stopped and intermittent power transmission is started.

The interval of the wait period TOW is, for example, 5 minutes. In the wait period TOW, the normal power transmission, which is continuous power transmission, is not performed, and the battery 90 is not charged. Therefore, the battery 90 dissipates heat, and the battery temperature drops as shown in E3 of FIG. Then, when the wait period TOW elapses, normal power transmission resumes as shown in E4, and charging of the battery 90 resumes. At this time, in the present embodiment, as shown in E5, the update process of the number of cycles representing the number of charges is not performed. That is, since the repetition of battery charging due to the temperature abnormality should not be included in the number of charges, the update process for increasing the number of cycles (cycle time) by +1 is not performed.

In E6 of FIG. 7, the battery temperature reaches 50 degrees again, and the temperature error flag is set to H level. As a result, the wait period TOW shown in E7 is set, normal power transmission is stopped, and intermittent power transmission is performed.

Then, in E8 of FIG. 7, when the electronic device 510 is removed and the voltage of the start capacitor described in FIG. 6 falls below the threshold voltage VT, the discharge operation of the discharge unit 60 changes from off to on as shown in E9. Switch. Then, as shown in E10, intermittent power transmission for landing detection is performed by the power transmission unit 12.

As described above, in the present embodiment, on the condition that the power receiving device 40 has started the load modulation as shown in B5 of FIG. 4, the normal power transmission by the power transmission unit 12 is started as shown in B6. Then, while the load modulation of B5 is continued, the normal power transmission shown in B6 is continued. Specifically, when the load modulation is not detected as shown in C5 of FIG. 5, the normal power transmission by the power transmission unit 12 is stopped as shown in C6. Then, as shown in C9, intermittent power transmission for landing detection is performed by the power transmission unit 12.

As described above, in the present embodiment, the normal power transmission is started on the condition that the load modulation is started, the normal power transmission is continued while the load modulation is continued, and the normal power transmission is stopped when the load modulation is not detected. The sequence is adopted. In this way, complicated authentication processing and the like can be eliminated, and wireless power transmission and communication by load modulation can be realized with a simple and simple operation sequence. In addition, efficient non-contact power transmission according to the state of power transmission can be realized by performing communication by constant load modulation during the normal power transmission period.

Further, in the present embodiment, as shown in D1 of FIG. 6, when a fully charged battery 90 of the power receiving device 40 is detected based on the communication data from the power receiving side, as shown in D2, the power transmission unit 12 Normal power transmission will be stopped, and intermittent power transmission for removal detection will be performed. Then, as shown in D9, the electronic device 510 is removed, and when the removal is detected, intermittent power transmission for landing detection is performed by the power transmission unit 12 as shown in D12.

In this way, when a full charge is detected, the normal power transmission, which is continuous power transmission, is stopped, and the power transmission is intermittently shifted to intermittent power transmission. As a result, it is possible to suppress unnecessary power consumption during the removal period and the like, and it becomes possible to achieve power saving and the like.

Further, in the present embodiment, even when an abnormality on the power receiving side is detected based on the communication data, the normal power transmission by the power transmission unit 12 is stopped, and the intermittent power transmission for removal detection is performed. The abnormality on the power receiving side is, for example, a battery charging error such as a battery failure in which the voltage of the battery 90 falls below 1.0V, or a timer end error in which the charging time exceeds a predetermined period (for example, 6 to 8 hours). is there. In this way, when an abnormality on the power receiving side is detected, normal power transmission, which is continuous power transmission, is automatically stopped and shifts to intermittent power transmission, so safety, reliability, etc. can be ensured. ..

Further, even when a temperature abnormality occurs as an abnormality on the power receiving side, the normal power transmission by the power transmission unit 12 is stopped, and intermittent power transmission for removal detection is performed. However, in the case of a temperature abnormality, a special operation sequence as shown in FIG. 7 is executed. Specifically, as shown in E1 of FIG. 7, when a temperature abnormality (high temperature error) of the battery 90 of the power receiving device 40 is detected based on communication data (temperature error flag), normal power transmission is stopped and E2 As shown in the above, intermittent power transmission is performed by the power transmission unit 12 during the wait period TOW. Then, after the wait period TOW elapses, normal power transmission by the power transmission unit 12 is resumed as shown in E4.

In this way, in the case of a temperature abnormality, a wait period TOW is set, and during the wait period TOW, normal power transmission, which is continuous power transmission, is not performed, and the battery 90 is not charged. This makes it possible to dissipate heat from the battery 90 by using the wait period TOW. Further, after the wait period TOW has elapsed, charging of the battery 90 by normal power transmission can be resumed. Therefore, for example, it becomes possible to realize appropriate charge control of the battery 90 in a high temperature environment or the like.

Further, in the present embodiment, as described with reference to FIGS. 5 and 6, the power receiving device 40 has the battery 90 after the rectifying voltage VCS, which is the output voltage of the power receiving unit 52, has decreased and the start-up period TST of the discharge operation has elapsed. Is discharged to the power supply target 100. Specifically, the discharge operation starts after the start-up period TST elapses after the rectified voltage VCS falls below the determination voltage (3.1 V). That is, as shown in C8 of FIG. 5 and D11 of FIG. 6, the discharge operation of the discharge unit 60 is turned on, and the power from the battery 90 is supplied to the power supply target 100. Then, in the present embodiment, as shown in D2 and D7 of FIG. 6, intermittent power transmission for removal detection is performed at intervals of TR1 (for example, 1.5 seconds) shorter than the activation period TST (for example, 3 seconds). ..

In this way, since the start-up period TST does not elapse during the length of the removal detection period TR1, the discharge operation of the discharge unit 60 is not turned on during the period of intermittent power transmission for removal detection. Then, as shown in D9 of FIG. 6, when the electronic device 510 is removed, the rectified voltage VCS does not rise periodically as in the period of intermittent power transmission for detection of removal, and the start-up period TST shown in D7 elapses. By doing so, the discharge operation of the discharge unit 60 is turned on as shown in D11. Therefore, when the removal of the electronic device 510 is detected, the discharge operation of the discharge unit 60 is automatically turned on, and the electric power from the battery 90 can be supplied to the power supply target 100.

4. State information stored in the non-volatile memory and control based on the state information Next, the details of the non-volatile memory 62 included in the control device 50 of the power receiving device 40, and the power transmission device 10 and the power receiving device performed based on the information. The control of 40 will be described.

4.1 Non-volatile memory The non-volatile memory 62 in this embodiment operates at a power supply voltage based on the output voltage VCS of the power receiving unit 52. Specifically, it operates based on VD5, which is the output voltage of the regulator 57, which will be described later with reference to FIG. The regulator 57 is a regulator that regulates the output voltage VCS of the power receiving unit 52 and outputs VD5. More specifically, the non-volatile memory 62 internally boosts the VD5 and operates based on the voltage after the boost.

FIG. 8 is a configuration example of the non-volatile memory 62. As shown in FIG. 8, the non-volatile memory 62 includes a verify sequencer 65, a control circuit 66, a memory cell array 67, and a charge pump circuit (boost circuit) 68. However, the non-volatile memory 62 is not limited to the configuration shown in FIG. 8, and various modifications can be performed.

The verify sequencer 65 performs writing, reading, and data confirmation (verification). Hereinafter, an example of control in each operation will be described, but various modifications can be implemented in the specific method. At the time of writing, the verify sequencer 65 acquires 16-bit write data from the control unit 54, generates 16-bit ECC (Error Correcting Code) based on the acquired write data, and outputs the write data and ECC. The combined 32-bit data is written to the memory cell array 67 (in a narrow sense, a given memory cell included in the memory cell array 67).

At the time of reading, 32-bit data including ECC is read from the memory cell array 67, it is determined whether or not the data is damaged based on ECC, and 16-bit data excluding ECC is output to the control unit 54. To do. When data is corrupted, error correction processing may be performed based on ECC, and the 16-bit data after the error correction processing may be output to the control unit 54. However, the error correction here is limited to, for example, a 1-bit error.

Further, in the verify sequencer 65, after writing the data, it is confirmed whether the signal level of the memory cell included in the memory cell array 67 is appropriate.

Specific write and read operations are performed by the control circuit 66, the memory cell array 67, and the charge pump circuit 68. A voltage based on the output voltage VCS of the power receiving unit 52 (for example, VD5 as described above) is supplied to the charge pump circuit 68, and by boosting the voltage, a relatively high voltage VPP for erasing and writing is output. .. Then, the control circuit 66 reads and writes by supplying an appropriate voltage such as VPP to the word line, source line, and bit line provided in the memory cell array 67 based on the signal from the verify sequencer 65. , Erase. As described above, the non-volatile memory 62 may use, for example, a MONOS type structure, and the structure of each memory cell is widely known. Therefore, further detailed description thereof will be omitted.

The control unit 54 according to the present embodiment may include a charge system control unit and a discharge system control unit. The control unit of the charging system operates at a voltage based on the output voltage VCS of the power receiving unit 52, and controls each unit of the charging system. Specifically, the control unit of the charging system operates based on VD5 described later with reference to FIG. 19, and controls the load modulation unit 56, the charging unit 58, the non-volatile memory 62, and the like. Further, the discharge system control unit operates at a voltage based on the battery voltage VBAT, and controls each part of the discharge system. Specifically, the control unit of the discharge system operates based on the battery voltage VBAT, and controls the discharge unit 60 and the like.

The control unit of the discharge system controls to start the discharge with the removal as a trigger. Specifically, the control device 50 may include a circuit that outputs a signal that becomes a low level when the VCS is 3.1 V or more and becomes a high level when the VCS falls below 3.1 V. If the reset is performed at the low level and the reset is released at the high level, the signal can be used as a power-on reset signal of the control unit of the charging system, and the above circuit is a power-on reset circuit. I can think. Further, the signal may be output to the control unit of the discharge system, and the control unit of the discharge system may control charging and discharging of the start capacitor based on the signal. As an example, the control unit of the discharge system supplies a voltage based on VBAT to the start capacitor when the input signal is high level to charge the start capacitor, and charges the start capacitor when the input signal is low level (for example, a given resistance). It may have a circuit that connects to the ground (via) to discharge. Further, the control unit of the discharge system may also control the on / off of the discharge unit 60 (charge pump circuit 61) by the above signal.

FIG. 9 shows an example of information stored in the non-volatile memory 62. As shown in FIG. 9, the non-volatile memory 62 stores charging current information, temperature correction information, charging frequency information, battery voltage, and temperature abnormality detection information. The state information of the battery 90 in the present embodiment is information including at least one of the charging frequency information, the battery voltage, and the temperature abnormality detection information.

The charging current information is, for example, a constant current value used for CC charging. More specifically, when the current value in normal charging performed when the battery voltage during charging is high to some extent (for example, 2.5V or more) and when the battery voltage during charging is low to some extent (for example, less than 2.5V). It may be the current value in the pre-charging performed in. The pre-charging here represents the charging performed at the time of returning from the over-discharged state.

Further, the temperature correction information is information used for correcting the temperature information detected by the detection unit 64 based on the temperature detection voltage or the like from the temperature detection unit. Since the temperature information in this embodiment is information used for battery control, it is desirable that the temperature information represents the temperature of the battery 90 itself. However, in reality, there is a slight difference between the position where the temperature detection unit is provided and the battery position. Therefore, the temperature detection unit detects, for example, the temperature of the substrate on which the temperature detection unit is provided, and the temperature of the battery 90. There is a temperature difference with. The temperature correction information is, for example, information for correcting this temperature difference.

The charging current information and temperature correction information include how the power receiving device 40 is mounted, for example, what kind of battery is used as the battery 90, how the battery 90 and the temperature detection unit are arranged, and the like. The appropriate value changes according to. Therefore, it is assumed that these pieces of information are programmed (written in the non-volatile memory 62) when the power receiving device 40 is mounted. The charging current information here and the charging voltage information (CV) described later are information used for charging control of the battery 90. That is, the non-volatile memory 62 may store the charge control information of the battery 90.

The charge count information is information indicating the number of times the battery 90 has been charged. The charging number information (hereinafter, also referred to as the cycle number) is incremented in principle at the timing when charging is started, as will be described later with reference to S3 and S5 of FIG. It is known that the performance of a secondary battery deteriorates as it is repeatedly charged (for example, the battery capacity when fully charged decreases), and by storing the charge count information, it is possible to monitor the degree of deterioration. Become.

The battery voltage is information representing the battery voltage at a given timing. For example, the detection unit 64 stores the battery voltage when a battery temperature abnormality (the temperature is higher than the upper limit of the normal range or lower than the lower limit of the normal range) is detected. As described above, the temperature detected by the temperature detection unit is not the temperature of the battery 90 itself, but the temperature corresponding to the temperature of the battery 90 is obtained by performing the correction process. Therefore, in this specification, terms such as "battery 90 temperature" or "battery 90 temperature abnormality" may be used, but this is based on the detection result of the temperature detection unit provided at a position different from that of the battery 90. It may represent a temperature or an abnormality detection result based on the temperature.

The temperature abnormality detection information is information indicating whether or not a temperature abnormality has been detected. The temperature abnormality detection information may be, for example, 1-bit flag information, and corresponds to the temperature error flag in FIG. 7. As can be seen from this, each piece of information in FIG. 9 does not have to have the same number of bits. For example, as the charging current information, 16-bit information including the constant current value in 8-bit normal charging and the constant current value in 8-bit pre-charging may be stored, or the 16-bit information may be stored. On the other hand, 16-bit ECC may be added. In addition, charge count information, battery voltage, etc. are expressed in 12 bits, and 4-bit data (some flag information or data fixed to 0 or 1) is added to the 12-bit data to obtain 16-bit data. It may be treated as data.

As described above, the non-volatile memory 62 operates at a power supply voltage based on the output voltage VCS of the power receiving unit 52. Therefore, as shown in A2 of FIG. 3, the electronic device 510 having the power receiving device 40 operates in a state of being placed on the charger 500 having the power transmitting device 10, and the power receiving device 40 takes it like A1 and A5. It does not work when left. Since the non-contact power transmission system is assumed in this embodiment, the power receiving device 40 can be easily removed. For example, since it is not necessary to attach it to a cradle or the like, the user may easily remove it, or when some object collides with the power transmission device 10 or the power receiving device 40 (or the table on which they are placed). It may be removed unintentionally.

Therefore, in the non-volatile memory 62 of the present embodiment, there is a tendency that the power supply for operation is stopped during writing of the non-volatile memory 62 as compared with other general systems. In that case, a write error occurs, and the information being written becomes unreliable.

Therefore, in the present embodiment, when writing to the non-volatile memory 62, data may be written to different addresses with a time lag. Specifically, when storing the state information in the non-volatile memory 62, the control unit 54 writes the state information to the first address, and after a lapse of a given time, the state information is different from the first address. Write to the second address.

In this way, when writing the given state information, the write timing and the write destination address can be changed and multiplexed, so that the state information can be appropriately written to the non-volatile memory 62. It becomes possible to increase. For example, even if the power receiving device 40 is removed while writing to one address and a write error occurs, the writing to the other address is performed at different timings, so that the operation can be performed normally. Can be considered. Of course, the possibility that both writes will result in an error is not 0, but the possibility of writing normally is improved as compared with the case where such a method is not adopted.

For example, as data including the charge count information, 32 bits including 12-bit charge count information, 4-bit additional information (for example, FULL data, the temperature error flag described above, etc.), and 16-bit ECC. When writing the data of, 64 bits are reserved as a data writing area including the charge count information. Then, the address representing 32 bits of the 64 bits (for example, the start address) may be the first address, and the address representing the next 32 bits may be the second address.

Further, the non-volatile memory 62 may store information other than the above, and the information stored in the non-volatile memory 62 can be modified in various ways. Further, the process of writing data to different addresses with a time difference is not limited to that performed when writing the state information, but is performed when writing other information (charge control information, etc.) to the non-volatile memory 62. May be good.

4.2 Control at abnormal temperature If the temperature of the battery 90 is excessively high or too low, the battery 90 itself may be damaged or the desired output may not be obtained. Therefore, when a temperature abnormality is detected, it is necessary to control the temperature to return to the normal range (at least to promote or not continue the abnormal state). For example, when the battery 90 becomes hot, in the conventional method, the power receiving device 40 stops charging, and the power transmission device 10 also stops power transmission. When charging is stopped, it is expected that the battery 90 will not become hot and the temperature will return to the normal range over time.

However, in the conventional method, charging is stopped at a high temperature, so that charging may be insufficient. Therefore, in the present embodiment, as described above with reference to FIG. 7, when a temperature abnormality is detected (E1), the power transmission side is intermittently operated for a given wait period TOW (E2), and then normal power transmission is performed. Return to charge the battery 90 (E4). In this way, charging can be continued even when a temperature abnormality is detected, so that it is possible to prevent insufficient charging.

However, when such control is performed, counting the number of cycles becomes a problem as shown in E5 of FIG. In the wait period TOW of FIG. 7, since the power transmission device 10 operates intermittently at an appropriate interval TR1, the start capacitor voltage does not fall below the VT, and the operation of the discharge unit 60 of the power receiving device 40 is not started. That is, even if a temperature abnormality is detected and the charging of the battery 90 is temporarily stopped, the period (wait period) is short and the discharge unit 60 is not discharged. Therefore, the performance of the battery 90 is deteriorated. The impact is small.

That is, considering that the charge count information (cycle count) is the state information of the battery 90, that is, the information indicating the deteriorated state of the battery 90 in a narrow sense, the battery 90 can be charged by sandwiching the wait period TOW. Even if it is divided into multiple times, it is appropriate to treat them as a series of (single) charges rather than as separate charges.

However, as will be described later with reference to FIG. 20, in principle, the number of cycles is incremented at the start of charging. According to this principle, the number of cycles is incremented even at the return timing from the wait period shown in E5 of FIG. Therefore, in the present embodiment, the temperature abnormality detection information is stored in the non-volatile memory 62 as described above. By using this temperature abnormality detection information, it is possible to appropriately count the number of cycles.

When a temperature abnormality is detected, the load modulation unit 56 transmits the temperature abnormality detection information to the power transmission device 10 by load modulation. As a result, the fact that a temperature abnormality has occurred on the power receiving side is also transmitted to the power transmission side, so that the power transmission device 10 can perform appropriate power transmission control (intermittent operation).

In the control unit 54, when the temperature abnormality detection information is stored in the non-volatile memory 62, the charge count information of the non-volatile memory 62 is not updated, and the temperature abnormality detection information is not stored in the non-volatile memory 62. May update the charge count information of the non-volatile memory 62. In this way, it is possible to appropriately distinguish the return from the wait period due to the temperature abnormality detection, that is, the start of charging corresponding to E5 in FIG. 7 and the start of charging other than that. When the temperature abnormality detection information is stored (temperature error flag = H), the start of charging at that time is the recovery from the temperature abnormality and is not included in the count of the number of cycles. On the other hand, when the temperature abnormality detection information is not stored (temperature error flag = L), the charging start at that time is set in the power transmission device 10 after normal charging, for example, the power receiving device 40 is used by the user. Since it can be determined that the state has been reached, the number of cycles may be incremented as a general rule.

However, even with the above control, the number of cycles may not be updated properly. Specifically, it is a case where the power receiving device 40 is removed within the wait period. A specific example is shown in FIG.

The horizontal axis direction of FIG. 10 represents time, and is a diagram showing an example of an operation sequence of the power transmitting device 10 and the power receiving device 40. First, when the temperature abnormality is not detected, the power transmission device 10 normally transmits power as in G1, and the power receiving device 40 charges the battery 90. On the other hand, when a temperature abnormality is detected as in G2, the temperature abnormality detection information is written in the non-volatile memory 62 in the power receiving device 40 (temperature error flag = H), and charging is stopped as in G3. Enter the wait period. On the other hand, the temperature abnormality detection information is also transmitted to the power transmission device 10, and the power transmission device 10 starts intermittent power transmission for temperature abnormality like G4. The intermittent power transmission for temperature abnormality may be the same as the intermittent power transmission at the time of removal detection as described above.

Here, it is assumed that the power receiving device 40 is removed as in the G5 before the waiting period is completed (for example, before the elapse of 5 minutes). In this case, in the power receiving device 40, as in FIG. 5, the discharge unit 60 is discharged after the start-up period (TST) has elapsed after the output voltage VCS of the power receiving unit 52 falls below the determination threshold value (3.1 V). Start operation. Further, like the G6, the power transmission device 10 starts intermittent power transmission for landing detection.

The problem of updating or not updating the number of cycles is when the removal is performed before the end of the wait period as in G5, and then the landing detection is performed as in G7. In this case, the non-volatile memory 62 of the power receiving device 40 like the G8 holds the temperature abnormality detection information written in the G2 (the state of the temperature error flag = H is maintained). Therefore, if the above control is performed, the number of cycles is not incremented in the determination of G8.

After being removed within the wait period, until the electronic device 510 having the power receiving device 40 is placed on the charger 500 having the power transmitting device 10 again (the period between G5 and G8 in FIG. 10). If the consumption of the battery 90 is small, the deterioration of the battery 90 during the period is not so large. That is, in the same way that the battery charging before and after the wait period TOW described above is regarded as a series of charging, the charging in this case (charging at G9) is also the charging before removal (charging at G1) and the series of charging. Can be understood as. Therefore, there is no problem even if the number of cycles is not updated in the determination in G8.

However, if the battery 90 is fully used after being removed within the wait period, that is, if it is discharged in the same manner as in normal operation, the deterioration of the battery 90 due to the discharge should be considered. If charging is started after that, it is necessary to consider the charging separately from the charging before removal. That is, in the determination in G8, since the number of cycles needs to be incremented, it is inappropriate to set the number of cycles to non-update even if the temperature abnormality detection information is written in the non-volatile memory 62.

Therefore, in the present embodiment, as described above, the battery voltage when the temperature abnormality is detected is stored in the non-volatile memory 62. Then, the battery voltage VBAT at the start of charging and the battery voltage stored in the non-volatile memory 62 are compared to determine how much the battery 90 is consumed after the removal. Specifically, the control unit 54 sets the battery voltage VBAT to a predetermined voltage higher than the battery voltage stored in the non-volatile memory 62 even when the temperature abnormality detection information is stored in the non-volatile memory 62. If it is lowered, the charge count information of the non-volatile memory 62 is updated. The predetermined voltage here can be set in various ways, and is, for example, a value of 0.15 V.

In this way, the number of cycles can be appropriately counted even when the removal is performed within the wait period. The battery voltage stored in the non-volatile memory 62 is the battery voltage at the time of detecting a temperature abnormality, and may be considered to be equivalent to the battery voltage at the time of removal. That is, the case where the battery voltage VBAT at the start of charging is lower than the battery voltage stored in the non-volatile memory 62 by a predetermined voltage corresponds to the case where the battery 90 is discharged to some extent after the removal. That is, by performing the above control, it is possible to count the number of cycles according to the usage status of the battery 90 after removal.

11 (A) and 11 (B) are flowcharts for explaining the above control. FIG. 11A shows a temperature abnormality detection operation that is constantly performed, and the control unit 54 determines whether or not the temperature abnormality occurs at a given interval, and in the example of FIG. 11A, whether or not the temperature exceeds 50 ° C. (S11). If No in S11, the temperature abnormality is not detected, so the process returns to S11 without any particular processing. On the other hand, in the case of Yes in S11, since the temperature abnormality was detected, the temperature abnormality detection information is written in the non-volatile memory 62 (temperature error flag = H), and the battery voltage at that time is written (S12).

Further, FIG. 11B is a flowchart illustrating count control of the number of cycles at the start of charging. In FIG. 20, which will be described later, in order to simplify the explanation, the number of cycles is always incremented in S5, but in reality, the step in S5 in FIG. 20 may be replaced with FIG. 11 (B).

In the control of the number of cycles, it is first determined whether or not the increment of the number of cycles is necessary. First, when the temperature abnormality detection information is not stored in the non-volatile memory 62, it can be determined that the increment is necessary because the processing may be performed according to the principle. Even if the temperature abnormality detection information is stored, if the battery voltage drops, it needs to be incremented. That is, it may be determined whether or not the above-mentioned condition satisfies OR (VBAT0 <VBATT-0.15) (where the temperature abnormality detection information is not stored) (S21). Here, VBAT0 is the battery voltage at the start of charging, and VBATT is the battery voltage at the time of temperature abnormality detection written in S12 of FIG. 11 (A).

If Yes in S21, the number of cycles is incremented (S22). On the other hand, if No in S21, the number of cycles is not updated. Further, in any case, the temperature error flag is reset to prepare for the next and subsequent processing (S23).

As described above, the detection unit 64 performs temperature detection (temperature abnormality detection) based on the signal from the temperature detection unit. The temperature detection unit of the present embodiment can be realized by various forms. For example, an external temperature detection unit (thermistor TH) of the control device 50 may be used as described later with reference to FIG. 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.

Further, although not shown in FIG. 9, the non-volatile memory 62 of the present embodiment stores setting information for setting whether to use an external thermistor TH or a BGR circuit as a temperature detection unit. You may. Further, as the temperature correction information, both the correction information for the thermistor TH and the correction information for the BGR circuit may be stored.

4.3 Smart charging Further, the control based on the information stored in the non-volatile memory 62 is not limited to the above-mentioned example of temperature abnormality. For example, when performing smart charging disclosed in Patent Document 3, the information stored in the non-volatile memory 62 may be referred to.

Like FIG1 (Prior Art) of Patent Document 3, the relationship between the charging voltage, the battery voltage at the time of full charge (charging power), and the number of cycles has been known from before Patent Document 3. As can be seen from FIG1, if the charging voltage is increased, the charging power is increased and the battery capacity can be effectively utilized, but the number of cycles is reduced. The number of cycles here is information indicating the number of times of charging in which the chargeable capacity is reduced to a predetermined ratio (for example, 90%) with respect to the original capacity of the battery.

Patent Document 3 proposes an algorithm for efficiently using a battery (lithium ion battery) on the premise of the relationship of FIG1. The specific method is shown in FIG. When the battery voltage at the start of charging is 3.22V to 3.5V, the charging voltage at the time of the previous charging is kept. On the other hand, when it is 3.5V or more, the charging voltage is lowered as compared with the previous time, and when it is 3.22V or less, the charging voltage is raised as compared with the previous time.

If the battery voltage is 3.22V or less during charging, it is assumed that the target device is often used. That is, since it is assumed that the battery 90 is consumed heavily, the charging voltage is increased and the charging power with respect to the battery capacity is increased so as not to be insufficiently charged.

On the other hand, if the battery voltage is 3.5V or higher during charging, it is assumed that the target device is not used much. That is, since it is assumed that the battery 90 is not consumed violently, the deterioration of the battery is suppressed by suppressing the charging voltage.

That is, as shown in FIG. 1, there is a trade-off relationship between the charging power with respect to the battery capacity and the degree of deterioration of the battery. It can be said that it is a method of setting an appropriate charging voltage value.

Although not shown in FIG. 9, the non-volatile memory 62 of the present embodiment stores the charging voltage in the charging control, and the control unit 54 may perform the charging control based on the stored charging voltage.

FIG. 12 shows a flowchart for explaining a specific processing flow. When this process is started, first, the battery voltage VBAT0 at the start of charging is acquired (S31). Then, it is determined whether VBAT0 is 3.22V or less (S32). In the case of Yes in S32, it is considered that the target battery 90 is used a lot, so the charging voltage is increased so that the battery capacity can be fully utilized (so that the charged power becomes large). Specifically, the previous charging voltage CV is read from the non-volatile memory 62, and an update process is performed in which the voltage is increased by a given voltage (0.05V) (S33). Then, the updated voltage value CV is stored in the non-volatile memory 62. The stored updated CV will be used at the start of charging from the next time onward. In the process of S33, it is preferable to set an upper limit on the updated charging voltage so that the charging voltage does not become excessively high. For example, the maximum value of CV is set to 4.20V.

On the other hand, when No in S32, it is determined whether VBAT0 is 3.5 V or more (S34). In the case of Yes in S34, it is considered that the target battery 90 is not used much, so the charging voltage is lowered. Specifically, the previous charging voltage CV is read from the non-volatile memory 62, and an update process is performed to lower the charging voltage CV by a given voltage (0.05V) (S35). Also in this case, the updated voltage value CV is stored in the non-volatile memory 62. In the process of S35, it is preferable to set a lower limit for the updated charging voltage so that the charging voltage does not become excessively low. For example, the minimum value of CV is set to 4.00V (or 4.05V).

Further, in the case of No in S34, the use of the battery 90 is in an intermediate state, and it is determined that there is no problem if the same charging as the previous time is performed. Therefore, the CV update process is not performed and the process is terminated. After the processing of FIG. 12, the battery 90 may be charged using the set charging voltage CV. The threshold values for determining the usage status of the battery 90, such as 3.22V and 3.50V, and the CV limit values of 4.20V and 4.00V are not limited to these, and various modifications are made. It is possible to carry out.

As described above, the method of the present embodiment can be applied to the control device 50 on the power receiving side in the non-contact power transmission system having the power transmission device 10 and the power reception device 40, and the control device 50 is from the power transmission device 10. It includes a charging unit 58 that charges the battery 90 based on the electric power received by the power receiving unit 52 that receives electric power, a control unit 54 that controls charging, and a non-volatile memory 62. Then, the non-volatile memory 62 stores the state information of the battery, and the control unit 54 performs charging control based on the state information stored in the non-volatile memory 62.

In this way, it is possible to realize appropriate charge control according to the state of the battery 90, for example, the control at the time of detecting an abnormal temperature described above.

Further, the method of the present embodiment can be applied to a control device 20 on the power transmission side in a non-contact power transmission system having a power transmission device 10 and a power reception device 40, and the control device 20 is a power transmission unit that transmits power to the power reception device 40. Communication processing is performed between the driver control circuit 22 that controls the power transmission drivers (DR1 and DR2) of 12, the control unit 24 that controls the driver control circuit 22, and the power receiving device 40 that transmits communication data by load modulation. The communication unit 30 is included. Then, when the control unit 24 receives the communication data including the temperature abnormality detection information from the power receiving device 40, the control unit 24 causes the power transmission unit 12 to perform intermittent power transmission. Specifically, the control unit 24 may cause the driver control circuit 22 to execute control for performing intermittent power transmission.

In this way, since the transmitting side is notified that the temperature abnormality has been detected on the receiving side, it is possible to appropriately execute the power transmission control (control for performing intermittent power transmission) necessary for detecting the temperature abnormality. ..

Further, the method of the present embodiment can be applied to a control device 50 or an electronic device including the control device 20. As described above, the electronic device 510 including the control device 50 may have various forms such as a hearing aid. The electronic device including the control device 20 is, for example, the charger 500 described above.

Further, the method of the present embodiment can be applied to a non-contact power transmission system including the above-mentioned power transmission device 10 and power receiving device 40. The power transmitting device 10 transmits power to the power receiving device 40 and performs communication processing with the power receiving device 40 that transmits communication data by load modulation, and the power receiving device 40 is a non-volatile device that stores the state information of the battery 90. The battery 90 is charged based on the electric power received from the power transmission device 10 and the state information stored in the non-volatile memory 62, and communication data is transmitted to the power transmission device 10 by load modulation. To send. Further, when a temperature abnormality is detected, the power receiving device 40 stores the temperature abnormality detection information as state information in the non-volatile memory 62, and transmits the temperature abnormality detection information to the power transmission device 10 by load modulation. When the power transmission device 10 receives communication data including temperature abnormality detection information from the power reception device 40, the power transmission device 10 transmits power to the power reception device 40 by intermittent power transmission.

5. Communication Method FIG. 13 is a diagram illustrating a communication method by load modulation. As shown in FIG. 13, on the power transmission side (primary side), the power transmission drivers DR1 and DR2 of the power transmission unit 12 drive the primary coil L1. Specifically, 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 of FIG. 1A) 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.

FIG. 14 shows an example of a specific configuration of the communication unit 30. As shown in FIG. 14, the communication unit 30 includes a current detection circuit 32, a comparison circuit 34, and a demodulation unit 36. Further, an amplifier AP for signal amplification and a filter unit 35 can be included. The communication unit 30 is not limited to the configuration shown in FIG. 14, and various components such as omitting some of the components, adding other components (for example, a bandpass filter unit), changing the connection relationship, and the like are used. Deformation can be carried out.

The current detection circuit 32 detects the current ID 1 flowing from the power supply (power supply device) to the power transmission unit 12. Specifically, the current ID 1 flowing from the power source to the power transmission unit 12 via the power supply voltage control unit 14 is detected. The current ID 1 may include, for example, a current flowing through a driver control circuit 22 or the like.

In FIG. 14, the current detection circuit 32 is configured by an IV conversion amplifier IVC. The non-inverting input terminal (+) of the IV conversion amplifier IVC is connected to one end of the sense resistor RCS, and the inverting input terminal (−) is connected to the other end of the sense resistor RCS. Then, the IV conversion amplifier IVC amplifies the minute voltage VC1-VC2 generated by the flow of the minute current ID1 through the sense resistor RCS, and outputs it as the detection voltage VDT. This detected voltage VDT is further amplified by the amplifier AP and output to the comparison circuit 34 as the detected voltage VDTA. Specifically, the amplifier AP inputs the detection voltage VDT to its non-inverting input terminal, inputs the reference voltage VRF to its inverting input terminal, and outputs a signal of the detection voltage VDTA amplified with reference to the reference voltage VRF. ..

The comparison circuit 34 performs a comparison determination between the detection voltage VDTA by the current detection circuit 32 and the determination voltage VCP = VRF + VOFF. Then, the comparison determination result CQ is output. For example, a comparative determination is made as to whether the detected voltage VDTA is above or below the determination voltage VCP. The comparison circuit 34 can be configured by, for example, a comparator CP. In this case, for example, the voltage VOFF of the determination voltage VCP = VRF + VOFF may be realized by the offset voltage of the comparator CP or the like.

The demodulation unit 36 determines the load modulation pattern based on the comparison determination result CQ (comparison determination result FQ after filtering) of the comparison circuit 34. That is, by performing the demodulation processing of the load modulation pattern, the communication data is detected and output as the detection data DAT. The control unit 24 on the power transmission side performs various processes based on the detection data DAT.

In FIG. 14, a filter unit 35 is provided between the comparison circuit 34 and the demodulation unit 36. Then, the demodulation unit 36 determines the load modulation pattern based on the comparison determination result FQ after the filter processing by the filter unit 35. As the filter unit 35, for example, a digital filter or the like can be used, but a passive filter may be used as the filter unit 35. By providing the filter unit 35, for example, the adverse effect of noise at F1 and F2 in FIG. 16 described later can be reduced.

The filter unit 35 and the demodulation unit 36 operate by supplying, for example, a drive clock signal FCK. The drive clock signal FCK is a signal that defines the power transmission frequency, and the driver control circuit 22 is supplied with the drive clock signal FCK to drive the power transmission drivers DR1 and DR2 of the power transmission unit 12. Then, the primary coil L1 is driven at a frequency (transmission frequency) defined by this drive clock signal FCK.

The communication unit 30 may be provided with a bandpass filter unit that passes signals in the load modulation frequency band and performs bandpass filter processing that attenuates signals in bands other than the load modulation frequency band. In this case, the communication unit 30 detects the communication data from the power receiving device 40 based on the output of the bandpass filter unit. Specifically, the bandpass filter unit performs bandpass filter processing on the detection voltage VDT by the current detection circuit 32. Then, the comparison circuit 34 performs a comparison determination between the detection voltage VDTA after the bandpass filter processing by the bandpass filter unit and the determination voltage VCP. This bandpass filter unit can be provided, for example, between the IV conversion amplifier IVC and the amplifier AP.

FIG. 15 is a diagram illustrating a communication configuration on the power receiving side. The power receiving unit 52 extracts a clock signal having a frequency corresponding to the drive clock signal FCK and supplies it to the communication data generation unit 55. The communication data generation unit 55 is provided in the control unit 54 of FIG. 2, and performs communication data generation processing based on the supplied clock signal. Then, the communication data generation unit 55 outputs a control signal CSW for transmitting the generated communication data to the load modulation unit 56, and the control signal CSW controls, for example, on / off of the switch element SW to perform communication data. The load modulation unit 56 is made to perform the load modulation corresponding to the above.

The load modulation unit 56 performs load modulation by changing the load state (load due to load modulation) on the power receiving side, such as 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. That is, even if the load is modulated on the power receiving side, the current ID1 flowing through the sense resistor RCS on the power transmission side becomes a very small current due to this load modulation. Therefore, when noise is superimposed, a data detection error occurs, and a communication error caused by noise or the like occurs.

For example, FIG. 16 is a diagram schematically showing the signal waveforms of the detection voltage VDTA, the determination voltage VCP of the comparison circuit 34, and the comparison determination result CQ. As shown in FIG. 16, the detection voltage VDTA is a voltage signal that changes with reference to the reference voltage VRF, and the determination voltage VCP is a voltage obtained by adding the offset voltage VOFF of the comparator CP to this reference voltage VRF. It is a signal.

Then, as shown in FIG. 16, for example, when noise is superimposed on the signal of the detection voltage VDTA, the position of the edge of the signal of the comparison judgment result CQ changes as shown in F1 and F2, and the width (interval) of the period TM1 becomes long. It fluctuates, such as becoming shorter or shorter. For example, assuming that the period TM1 is a period corresponding to the logic level "1", if the width of the period TM1 fluctuates, a communication data sampling error occurs, and a communication data detection error occurs. In particular, when communication is performed by constantly performing load modulation during the normal power transmission period, noise superimposed on the communication data may increase, and the probability that a detection error of the communication data will occur increases.

Therefore, in the present embodiment, the logic level "1" (data 1) and the logic level "0" (data 0) of each bit of the communication data are transmitted from the power receiving side using the load modulation pattern and detected on the power transmission side. The method of doing is adopted.

Specifically, as shown in FIG. 17, the load modulation unit 56 on the power receiving side 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. Load modulation is performed. On the other hand, 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 is 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 FIG. 17, the period TM1 of the first load state is a period in 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 FIG. 17, the second load state period TM2 is a period during which the switch element SW of the load modulation unit 56 is turned off, and the L level (bit =) of the first and second patterns PT1 and PT2. This is the period corresponding to 0).

Then, in FIG. 17, the first pattern PT1 is 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. 17, the first pattern PT1 is a pattern corresponding to, for example, the bit pattern (1110). 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 logic level of the bit of the communication data is “0”.

Here, when the drive frequency of the power transmission unit 12 is FCK and the drive cycle is T = 1 / FCK, the lengths of the first and second patterns PT1 and PT2 can be expressed as, for example, 512 × T. it can. 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. 18 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. That is, it is an interval corresponding to the lengths of the first and second patterns PT1 and PT2, which are load modulation patterns. For example, in FIG. 17, 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. 18, the load modulation patterns in the periods TS1, TS2, TS3, TS4, TS5, and TS6 are PT1, PT2, PT1, PT2, PT2, and PT2, respectively. Here, the periods TS1, TS2, TS3, TS4, TS5, and TS6 are periods corresponding to the sampling points SP1, SP2, SP3, SP4, SP5, and SP6. Therefore, in the case of FIG. 18, 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, the communication unit 30 detects a pulse whose signal level is H level, and performs bit synchronization when the pulse width is within the first range width (for example, 220 × T to 511 × T). Do. Then, in the case of bit synchronization, the first sampling point SP1 is set at the center point of the pulse width, and signals are taken from the first sampling point SP1 at each sampling interval SI (for example, 512 × T). If the level of the captured signal is H level, it is determined to be logic level "1" (first pattern PT1), and if it is L level, it is determined to be logic level "0" (second pattern PT2). Judge that. By doing so, the communication data (101000) is taken in in FIG. Actually, after bit synchronization (after fetching 1 bit of data in SP1), by fetching 15 bits of data, 16 bits of communication data are fetched as a whole. In this 16-bit communication data, the first 1 bit (bit synchronized bit) is always "1".

As described above, in the present embodiment, when the width of the period TM1 in the first load state is within the first range width (220 × T to 511 × T), as shown in FIG. 18, the first The first sampling point SP1 is set in the load state 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. 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.

That is, as described with reference to FIG. 16, the width of the period TM1 fluctuates due to noise or the like. 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 as shown in FIG. 16, appropriate bit synchronization can be performed and an appropriate first sampling point SP1 can be set.

Then, after setting the first sampling point SP1 in this way, sampling is performed at each sampling interval SI, and based on the signal level at each sampling point, either the first or second pattern PT1 or PT2. To judge. That is, when the load state is the first load state (when the signal level is the H level) at the second sampling point SP2 following the first sampling point SP1, the communication unit 30 is the second. It is determined that the load modulation pattern at the sampling point SP2 is the first pattern PT1. That is, it is determined that the logical level of the bit of the communication data is "1".

On the other hand, when the load state is the second load state (when the signal level is the L level) at the second sampling point SP2, the load modulation pattern at the second sampling point SP2 is the second pattern. It is judged to be PT2. That is, it is determined that the logical level of the bit of the communication data is "0". The same applies to the subsequent sampling points.

For example, in FIG. 18, since the load state at the sampling point SP2 is the second load state (L level), it is determined to be the second pattern PT2, and the logic level is determined to be “0”. Since the load state at the sampling point SP3 is the first load state (H level), it is determined that it is the first pattern PT1 and the logic level is determined to be “1”. Since the load state at the sampling points SP4, SP5, and SP6 is the second load state (L level), it is determined to be the second pattern PT2, and the logic level is determined to be "0".

At each of the sampling points SP2 to SP6 in FIG. 18, it may be confirmed whether or not the width of the load state period including the sampling point is within a predetermined width range.

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. For example, conventionally, the first load state in which the switch element SW of the load modulation unit 56 is turned on is determined to be the logic level "1", and the second load state in which the switch element SW is turned off is set to the logic level "0". We have adopted a method of judgment. However, in this conventional method, as described with reference to FIG. 16, there is a possibility that a communication data detection error may occur due to noise or the like.

On the other hand, in the present embodiment, the logic level of each bit of the communication data is determined by determining whether the load modulation pattern is, for example, the first or second pattern PT1 or PT2 as shown in FIG. Is being detected. Therefore, even in a situation where there is a lot of noise as shown in FIG. 16, it is possible to properly detect communication data. That is, in the first and second patterns PT1 and PT2 of FIG. 17, for example, the width of the period TM1 in the first load state (H level) is significantly different, and in the present embodiment, the width of the period TM1 is different. By discriminating, the pattern is discriminated and the logic level of each bit of the communication data is detected. For example, in the first bit synchronization of FIG. 18, when the width of the period TM1 is within the first range width (220 × T to 511 × T), the sampling point SP1 is set at the center point of the period TM1, and then the sampling point SP1 is set. The signals are captured at the sampling points SP2, SP3, SP4 ... 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.

The communication method of the present embodiment is not limited to the methods described with reference to FIGS. 17 and 18, and various modifications can be made. For example, in FIG. 17, 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 in FIG. 17 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 FIG. 17, the first and second patterns PT1 and PT2 are set to the same length, but may be set to different lengths. Further, in FIG. 17, 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 second patterns of the bit patterns different from these are used. PT1 and PT2 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), and are different from those in FIG. Pattern can be adopted.

19 (A) and 19 (B) show an example of the communication data format used in this embodiment.

In FIG. 19A, the communication data is composed of 64 bits, and one packet is composed of the 64 bits. The first 16 bits are 00h. 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), until the current detection circuit 32 of the communication unit 30 operates and communication data can be properly detected. In addition, some time is required. Therefore, 00h, which is dummy (empty) data, is set in the first 16 bits. In the first 16-bit 00h communication period, the power transmission side performs various processes necessary for, for example, bit synchronization.

The data code and rectified voltage (VCC) information are set in the next second 16 bits. As shown in FIG. 19B, the data code is a code for specifying the data to be communicated by the next third 16 bits. The rectified voltage (VCC) is used as transmission power setting information of the transmission device 10. Specifically, the power supply voltage control unit 14 variably controls the power supply voltage VDCV supplied to the power transmission drivers DR1 and DR2 based on the information of the rectified voltage (VCC), thereby transmitting power of the power transmission unit 12. Is variably controlled.

Information such as temperature, battery voltage, charging current, status flag, number of cycles, or IC number 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 charging current are the voltage of the battery 90 (VBAT or the like) and the charging current, and are information indicating the charging state. 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 times of charging. The IC number is a number for identifying the IC of the control device. CRC information is set in the fourth 16 bits. The CRC is information for checking the error of the CRC.

When the landing of the electronic device 510 is detected in FIG. 4 and the VCS> 6.0V, in the load modulation of B5, for example, one packet (64 bits) of empty data (dummy data) is first used. Communication data is transmitted. Then, the power transmission side detects the communication data of this empty data and starts normal power transmission.

FIG. 20 is a flowchart illustrating a detailed example of the communication process of the present embodiment. First, the power receiving side (control unit 54) determines whether or not the rectified voltage is VCS> 6.0V (step S1). For example, when the power transmitting side transmits power, the rectified voltage VCS rises due to the power received by the power receiving side, and the rectified voltage VCS becomes VCS> 6.0V. For example, the control device 50 on the power receiving side operates with a power source generated by the transmitted power on the power transmitting side. Therefore, during the period when power is not transmitted from the power transmission side, the control device 50 (excluding the discharge system circuit) is not supplied with power and is in a reset state, for example.

When the rectified voltage becomes VCS> 6.0, the power receiving side first transmits the IC number to the power transmitting side by the load variable (step S2). For example, in FIGS. 19A and 19B, communication of an IC number is specified by a data code, and communication data including the information of the IC number is transmitted.

Then, for example, in the case of pre-charging (charging the over-discharged battery) when the battery voltage is VBAT <2.5V, or in the case of a battery error when VBAT <1.0V, normal charging cannot be started ( In step S3: NO), the power receiving side transmits communication data including information such as rectified voltage, charging voltage, charging current, temperature, and status flag by load modulation (step S4).

On the other hand, when normal charging can be started (step S3: YES), the number of charging cycles is incremented by 1 (step S5), and the number of cycles after the increment is transmitted by load modulation (step S6). Then, during the normal charging period, the transmission of communication data including information such as the rectified voltage, the charging voltage, the charging current, the temperature, and the status flag is repeated (step S7). The power transmitting side can determine the charging state of the power receiving side based on this information.

Although an example of the communication method of the present embodiment has been shown above, the communication method of the present embodiment is not limited to this, and various modifications can be made. For example, the communication method of the present embodiment is not limited to the method of associating the load modulation pattern with the logic level as shown in FIGS. 17 and 18, for example, the first load state is associated with the logic level "1", and the first A method of associating the load state of 2 with the logic level "0" may be adopted. Further, the format of the communication data and the communication process are not limited to the methods shown in FIGS. 18 and 19, and various modifications can be performed.

6. Power receiving unit and charging unit FIG. 21 shows a detailed configuration example of the power receiving unit 52, the charging unit 58, and the like. As shown in FIG. 21, 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.

The transistor TA1 is provided between the node NB1 at one end of the secondary coil L2 and the node of the GND (low potential side power supply voltage). The transistor TA2 is provided between the node NB1 and the node NVC having a rectified voltage VCS. The transistor TA3 is provided between the node NB2 at the other end of the secondary coil L2 and the node of the GND. The transistor TA4 is provided between the node NB2 and the node NVC. A body diode is provided between the drain and source of each of these 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 of FIG. This makes it possible to monitor the rectified voltage VCS and realize power control based on the information of the rectified voltage VCS.

The regulator 57 adjusts (regulates) the rectified voltage VCS 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 (for example, 4.25V). 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. The transistor TC2 is controlled based on the output signal of the operational amplifier OPC. The non-inverting input terminal of the operational amplifier OPC is connected to one end of the resistor RC1. The other end of the resistor RC1 is connected to one end of the sense resistor RS provided as an external component of the control device 50. The other end of the sense resistor RS is connected to the inverting input terminal of the operational amplifier OPC. The current source ISC is provided between the non-inverting input terminal of the operational amplifier OPC and the node of the GND. The current flowing through the current source ISC is controlled based on the signal ICDA.

Transistor TC2 controls 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 VCS2 (voltage at the inverting input terminal) by virtual grounding of the operational amplifier OPC. Will be done. 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 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) 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.

At the time of charging, the signal CHON becomes active. As a result, the transistors TC3 and TC4 are turned on, and the battery 90 is charged. Further, backflow from the battery 90 is also prevented by the resistor RC2 or the like provided between the gate of the transistor TC3 and the node NBAT of the battery voltage VBAT. Further, resistors RC3 and RC4 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 RC3 and RC4 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.

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 the different term anywhere in the specification or drawing. 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 receiving 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, IVC IV conversion amplifier, AP amplifier, CP comparator, TA1-TA4, TC1-TC4 transistor , RCS, RS sense resistance, RB1, RB2, RC1-RC3 resistance, OPC operational amplifier, TH thermister (temperature detector), 10 power transmission device, 12 power transmission unit, 14 power supply voltage control unit, 16 display unit, 20 control unit , 22 Driver control circuit, 24 Control unit, 30 Communication unit, 32 Current detection circuit, 34 Comparison circuit, 35 Filter unit, 36 Demodition unit, 37 Clock generation circuit, 38 Oscillation circuit, 40 Power receiving device, 50 Control device, 51 Rectifier Control unit, 52 Power receiving unit, 53 Rectifier circuit, 54 Control unit, 55 Communication data generation unit, 56 Load modulation unit, 57 Regulator, 58 Charging unit, 59 CC charging circuit, 60 Discharging unit, 61 Charge pump circuit, 62 Non-volatile Memory, 64 detector, 65 verify sequencer, 66 control circuit, 67 memory cell array, 68 charge pump circuit, 90 battery, 100 power supply target, 500 charger, 502 power adapter, 510 electronic device, 514 switch section

Claims (7)

A control device on the power receiving side in a non-contact power transmission system having a power transmitting device and a power receiving device.
A charging unit that charges the battery based on the power received by the power receiving unit that receives power from the power transmission device, and a charging unit that charges the battery.
A control unit that controls charging and
With non-volatile memory
Including
The non-volatile memory is
As the state information of the battery, the temperature abnormality detection information, the charge number information indicating the charge number of the battery, and the battery voltage when the temperature abnormality is detected are stored.
The control unit is said to be non-volatile when the battery voltage is lower than the battery voltage stored in the non-volatile memory even if the temperature abnormality detection information is stored in the non-volatile memory. A control device characterized by updating the charge count information of the battery stored in the volatile memory. In claim 1 ,
A load modulation unit that transmits communication data to the power transmission device by load modulation is included.
The load modulator
A control device characterized in that when a temperature abnormality is detected, the temperature abnormality detection information is transmitted to the power transmission device by the load modulation. In claim 1 or 2 ,
The control unit
When storing the state information in the non-volatile memory, the state information is written to the first address, and after a given time elapses, the state information is written to a second address different from the first address. A control device characterized by. In any of claims 1 to 3 ,
The non-volatile memory is
A control device characterized in that it operates at a power supply voltage based on the output voltage of the power receiving unit. In any of claims 1 to 4 ,
The non-volatile memory is
A control device characterized by storing charge control information of the battery. An electronic device comprising the control device according to any one of claims 1 to 5. A non-contact power transmission system that includes a power transmission device and a power reception device.
The power transmission device
While transmitting power to the power receiving device, communication processing is performed with the power receiving device that transmits communication data by load modulation.
The power receiving device is
It has a non-volatile memory that stores the state information of the battery, charges the battery based on the power received from the power transmission device and the state information stored in the non-volatile memory, and by the load modulation. , Send communication data to the power transmission device,
The power receiving device is
When a temperature abnormality is detected, the temperature abnormality detection information is stored in the non-volatile memory as the state information, and the temperature abnormality detection information is transmitted to the power transmission device by the load modulation.
The power transmission device
When the communication data including the temperature abnormality detection information is received from the power receiving device, power is transmitted to the power receiving device by intermittent power transmission.
The non-volatile memory of the power receiving device is
As the state information of the battery, the temperature abnormality detection information, the charge number information indicating the charge number of the battery, and the battery voltage when the temperature abnormality is detected are stored.
The power receiving device is
Even when the temperature abnormality detection information is stored in the non-volatile memory, if the battery voltage is lower than the battery voltage stored in the non-volatile memory, the non-volatile memory is used. A non-contact power transmission system characterized by performing charge control for updating the charge count information of the battery stored in the sex memory.

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