JP2018133922A - Charge control device and control method thereof, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a charge time while enhancing safety during non-contact charge of a battery.SOLUTION: A charge control device including a power transmission device and a power reception device includes: radio communication means capable of radio communication with the power reception device; power transmission means capable of transmitting power to the power reception device by radio; and control means for controlling radio communication with the power reception device by the radio communication means and power transmission by the power transmission means. The control means acquires transmission efficiency of transmission power on the basis of power transmitted to the power reception device and power received by the power reception device and performs control to make a power transmission time relatively longer in comparison with the transmission efficiency being less than a threshold value if the transmission efficiency is the prescribed threshold value or more.SELECTED DRAWING: Figure 2

Description

  The present invention relates to battery non-contact charging control.

  In contactless charging, in a state where the power transmission device always emits electromagnetic waves, problems such as heat generation occur in the power receiving device if the power of the electromagnetic waves is excessive. Further, even when a device including a metal that cannot receive power using electromagnetic waves or a foreign material including a metal is disposed in the vicinity of the power transmission device, the problem of heat generation similarly occurs. For this reason, the method of controlling non-contact charge safely between a power transmission apparatus and a power receiving apparatus is desired.

  Patent Document 1 proposes a wireless power transmission system that adjusts the magnitude of transmitted power from a power transmission device based on the power transmission efficiency and the remaining amount of electricity stored in the battery. Patent Document 2 proposes a power feeding system that detects transmission efficiency between a power transmission unit and a power reception unit, and temporarily stops power transmission by the power transmission unit when the transmission efficiency is less than a specified value.

JP 2012-125112 A JP 2010-119246 A

  In non-contact charging, when the power transmission efficiency between the power transmitting device and the power receiving device is high, the positional displacement between the power transmitting device and the power receiving device is small, and the electromagnetic waves emitted from the power transmitting device are absorbed by the power receiving device with high efficiency, Less leaks. However, when the power transmission efficiency is low, the positional deviation between the power transmission device and the power reception device is large, and the leakage of electromagnetic waves emitted from the power transmission device increases.

  For this reason, when the power transmission efficiency is low and the positions of the power transmitting device and the power receiving device are shifted, a device including a metal that cannot receive power with electromagnetic waves in the vicinity of the electromagnetic wave generating portion of the power transmitting device during non-contact charging, If foreign matter including metal is disposed, heat may be generated. In addition, when the power transmission efficiency is low, there is a problem of exposure to electromagnetic waves to the human body because there are many leakages of electromagnetic waves.

  The effect of heat generation and exposure to human body comes from energy that is the product of electromagnetic wave power and time. Therefore, not only the control of electromagnetic wave power but also time control is an important factor to reduce the effect of heat generation and human body exposure. It can be said. Also, if the electromagnetic wave power is reduced to zero when the power transmission efficiency is low, or if the electromagnetic wave power release time is extremely shortened in consideration of heat generation, non-contact charging cannot be performed.

  This invention is made | formed in view of the said subject, The objective is to implement | achieve the technique which can shorten charging time, improving the safety | security at the time of non-contact charge.

  In order to solve the above problems and achieve the object, a charging control device of the present invention includes a wireless communication unit capable of wirelessly communicating with a power receiving device, a power transmitting unit capable of transmitting power wirelessly to the power receiving device, Wireless communication with the power receiving device by the wireless communication means, and control means for controlling power transmission by the power transmission means, the control means, the power transmitted to the power receiving device and the power receiving device Based on the received power, the transmission efficiency of the transmission power is acquired, and when the transmission efficiency is equal to or greater than a predetermined threshold, control is performed to make the power transmission time relatively longer than when the transmission efficiency is less than the predetermined threshold.

  ADVANTAGE OF THE INVENTION According to this invention, charging time can be shortened, improving the safety | security at the time of non-contact charge.

The block diagram which shows the structural example of the power transmission apparatus and power receiving apparatus of this embodiment. 3 is a flowchart illustrating operations of a power transmission device and a power reception device in contactless charging control according to the first embodiment. The figure which shows the example of arrangement | positioning of a power transmission apparatus and a power receiving apparatus. The figure which illustrates the time change of the battery voltage at the time of battery charge of Embodiment 1, and a charging current. The figure which illustrates the table which prescribed | regulated the relationship between the maximum transmission efficiency and a diagram based on the combination of the power transmission apparatus and power receiving apparatus which are used for non-contact charge control of Embodiment 1. The figure which illustrates the diagram which shows the relationship between the transmission efficiency used for the threshold determination of the transmission efficiency in the non-contact charge control of Embodiment 1, and charging power transmission time. The figure which shows notionally control of the charging power transmission time at the time of non-contact charge of Embodiment 1. FIG. 9 is a flowchart illustrating operations of a power transmission device and a power reception device in contactless charging control according to the second embodiment. The figure which illustrates the time change of the battery voltage at the time of battery charge of Embodiment 2, and a charging current. The figure which illustrates the table which prescribed | regulated the relationship between the maximum transmission efficiency, a battery voltage, and a diagram based on the combination of the power transmission apparatus and power receiving apparatus which are used for non-contact charge control of Embodiment 2. The figure which illustrates the diagram which shows the relationship between the transmission efficiency used for the threshold determination of the transmission efficiency in the non-contact charge control of Embodiment 2, and charging power transmission time. The figure which shows notionally control of the charging power transmission time at the time of non-contact charge of Embodiment 2. FIG. FIG. 9 is a block diagram illustrating a configuration example of a power transmission device and a power reception device according to a third embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. The embodiment described below is an example for realizing the present invention, and should be appropriately modified or changed according to the configuration and various conditions of the apparatus to which the present invention is applied. It is not limited to the embodiment. Moreover, you may comprise combining suitably one part of each embodiment mentioned later.

[Embodiment 1]
First, as Embodiment 1, a power transmission device (charge control device) calculates the transmission efficiency of wireless power for charging a battery transmitted and received between the power transmission device and the power reception device, and receives power according to the calculated transmission efficiency. The form which controls the electric power transmission time for charging the secondary battery of an apparatus is demonstrated.

  Hereinafter, a non-contact charging system including the power transmission device and the power reception device of the present embodiment will be described.

  FIG. 1 is a block diagram illustrating a configuration example of a power transmission device and a power reception device according to the present embodiment.

  The contactless charging system of the present embodiment includes a power transmission device 101 and a power reception device 151 that communicates with the power transmission device 101 and receives power supply. When the power receiving device 151 is disposed within a range in which short-range wireless communication and wireless power can be transmitted, the power transmitting device 101 performs communication in a non-contact manner and transmits / receives device status information to / from the power receiving device 151. When the power transmitting apparatus 101 determines that the power receiving apparatus 151 is in a chargeable state, the power transmitting apparatus 101 outputs wireless power via the power transmitting antenna and supplies power to the power receiving apparatus 151. At that time, the power transmitting apparatus 101 can acquire the transmission efficiency of the wireless power received by the power receiving apparatus 151 by receiving the received power information from the power receiving apparatus 151.

  If the power receiving device 151 is a communication device that operates with the power supplied from the secondary battery, a tablet PC, a smartphone, an imaging device such as a digital still camera or a digital video camera, and a playback that plays back audio data and video data. It may be a device. In addition, the power receiving device 151 may be a moving device such as a car that is driven by electric power supplied from the secondary battery. In addition, the power receiving device 151 may be an electronic device that can be operated by electric power supplied from the power transmission device 101 when a secondary battery is not attached.

  In the present embodiment, the power transmitted by the power transmission device 101 wirelessly is referred to as transmitted power, the power received by the power receiving device 151 wirelessly is referred to as received power, and the power transmitted by the power transmission device 101 and the power received by the power receiving device 151. This ratio is referred to as transmission efficiency.

  <Device Configuration> Next, with reference to FIG. 1, the configurations of the power transmitting device and the power receiving device in the non-contact charging system of this embodiment will be described.

  FIG. 1 is a block diagram illustrating a configuration example of a power transmission device and a power reception device according to the present embodiment. In the block diagram used for the description of the present embodiment, power supply connections to blocks that are not necessary for the description of the present embodiment are omitted. Also, detailed descriptions of blocks and operations that are not necessary for the description of the present embodiment are omitted.

  First, the configuration of the power transmission device 101 according to the present embodiment will be described with reference to FIG.

  The power transmission device 101 is a device capable of transmitting wireless power to the power receiving device 151 and performing wireless communication.

  The AC / DC conversion unit 102 is a circuit that converts an AC voltage input from the outside of the power transmission apparatus 101 into a DC voltage. The output voltage converted to DC by the AC / DC conversion unit 102 is converted by the TX constant voltage unit 103 into a voltage that can be supplied to the subsequent circuit block. The TX power supply IC 107 further converts the voltage into a voltage that can be supplied to the subsequent digital low-voltage circuit block.

  The TX control unit 108 includes a CPU that controls the entire apparatus including short-range wireless communication and wireless power transmission of the power transmission apparatus 101, a RAM that is used as a work area, and a ROM that stores a processing procedure described later.

  A non-contact IC reader / writer (R / W) 109 can read data from the non-contact IC and write data to the non-contact IC, and short-range wireless communication with the non-contact IC of the power receiving device 151 and other devices. I do.

  The TX display unit 110 includes, for example, an LCD (Liquid Crystal Display) and an LED (Light Emitting Diode), and displays the status of the power transmission apparatus 101 and the power reception apparatus 151.

  The TX power transmitting unit 104 is a circuit for wirelessly transmitting power to the power receiving device 151, and mainly includes a transistor amplifier circuit, a crystal oscillation circuit, and the like.

  The TX matching unit 105 is a circuit that performs impedance matching among the TX power transmission unit 104, the non-contact IC reader / writer 109, and the TX antenna 106. The TX matching unit 105 is a circuit that can be adjusted by the control of the TX control unit 108, and the circuit setting is variable during short-range wireless communication with the power receiving apparatus 151 and during wireless power transmission. The TX matching unit 105 includes a protection circuit so that an excessive voltage is not generated during wireless power transmission.

  The TX antenna 106 can transmit and receive electromagnetic waves for performing short-range wireless communication with the power receiving apparatus 151 and other apparatuses. Further, the TX antenna 106 can transmit wireless power to the power receiving apparatus 151. The RX antenna 152 is an antenna having a resonance frequency in the vicinity of 13.56 MHz, which is an HF band, for example.

  Next, the configuration and function of the power receiving device 151 of the present embodiment will be described.

  The power receiving device 151 is a device capable of receiving power and communicating wirelessly from the power transmitting device 101.

  The RX antenna 152 can transmit and receive electromagnetic waves for performing short-range wireless communication with the power transmission apparatus 101 and other apparatuses. Further, the RX antenna 152 can receive power from the power transmission apparatus 101 wirelessly. The RX antenna 152 is an antenna having a resonance frequency in the vicinity of 13.56 MHz, which is an HF band, for example.

  The RX matching unit 153 is a circuit for performing impedance matching between the RX antenna 152, the rectifying / smoothing unit 154, and the non-contact IC 158. The RX matching unit 153 is a circuit that can be adjusted by the control of the RX control unit 159, and the circuit setting is variable during short-range wireless communication with the power transmission apparatus 101 and when receiving wireless power. In addition, the RX matching unit 153 includes a protection circuit so that an excessive voltage is not generated when wireless power is received.

  The rectifying / smoothing unit 154 is a circuit that shapes an AC (alternating current) voltage generated by the power received from the power transmission apparatus 101 into a DC (direct current) voltage. The voltage shaped into a DC voltage by the rectifying / smoothing unit 154 is converted to a constant voltage by the RX constant voltage unit 155 and supplied to the subsequent circuit block.

  The charging control unit 156 is a circuit that can charge the battery 157. In addition to the function of charging the battery 157, the charging control unit 156 has a function of outputting the voltage of the battery 157 to another circuit. The battery 157 is, for example, a one-cell lithium ion battery, but is not limited thereto, and may be another rechargeable secondary battery.

  The RX power supply IC 161 converts the voltage input from the charging control unit 156 into voltages of digital low voltage system circuit blocks such as the RX control unit 159 and the main control unit 162 in the subsequent stage.

  The RX control unit 159 includes a CPU that performs control including short-range wireless communication and a non-contact charging sequence of the power receiving apparatus 151, a RAM that is used as a work area, and a ROM that stores a processing procedure described later.

  The power measuring unit 160 is a circuit for measuring received power when receiving wireless power from the power transmitting apparatus 101, and mainly includes a resistive load and a constant current circuit.

  The non-contact IC 158 can operate using only electromagnetic waves during short-range wireless communication with the power transmission apparatus 101 as power. The non-contact IC 158 corresponds to, for example, ISO / IEC21481 that is an international standard for short-range wireless communication.

  The main control unit 162 includes a CPU that controls the entire power receiving apparatus 151. The RAM 163 is a volatile memory used as a work area for the main control unit 162. The ROM 164 stores the processing procedure of the main control unit 162. The ROM 164 is configured by a rewritable nonvolatile memory such as a flash memory.

  The RX display unit 165 is a display unit that can display operation information of the power receiving apparatus 151 and an image captured by the imaging unit 168, and is, for example, a liquid crystal display (LCD).

  The operation input unit 166 is an operation member such as a switch, a button, or a touch panel that receives various operations on the power reception device 151 by a user operation. The operation input unit 166 sends operation information corresponding to the operation of the operation member to the main control unit 162. The recording medium 167 is a memory card or a hard disk, and can write and read image data.

  The imaging unit 168 includes an optical lens, an image sensor such as a CMOS, a lens control unit, an image processing unit, and the like, and performs operations from imaging to recording of moving images and still images.

  The wireless communication unit 169 can wirelessly communicate with other devices using the antenna 170. The wireless communication unit 169 supports a wireless communication standard different from the non-contact IC 158, for example, IEEE 802.11 that is a WLAN standard.

  <Non-Contact Charging Control> Next, with reference to FIG. 2, the operation of the power transmitting apparatus 101 and the power receiving apparatus 151 in the non-contact charging control of this embodiment will be described.

  FIG. 2 is a flowchart showing in parallel the operations of the power transmitting apparatus 101 and the power receiving apparatus 151 in the contactless charging control of the present embodiment. In the processing of FIG. 1, the TX control unit 108 executes control of the power transmission device 101, and the RX control unit 159 executes control of the power reception device 151. Note that the main control unit 162 is not involved in the non-contact charging control of the power receiving device 151, and thus description of the operation of the main control unit 162 and its peripheral functional blocks is omitted.

  In step S <b> 201, the TX control unit 108 of the power transmission apparatus 101 transmits a polling signal using the short-range wireless communication function of the non-contact IC reader / writer 109.

  In S202, the TX control unit 108 of the power transmission apparatus 101 determines whether a response signal from the non-contact IC 158 of the power reception apparatus 151 has been received. The near field communication in S201 captures the non-contact IC 158 using, for example, a request command of JISX6319-4.

  If the TX control unit 108 of the power transmitting apparatus 101 determines in S202 that the response signal has been received from the power receiving apparatus 151, the process proceeds to S203. If it is determined that the response signal has not been received, the process returns to S201. Send polling signal again.

  Here, the operation of the power receiving apparatus 151 will be described.

  In S <b> 251, the non-contact IC 158 of the power receiving apparatus 151 transmits a response signal when receiving a polling signal for short-range wireless communication from the power transmission apparatus 101. In S252, the RX control unit 159 of the power receiving apparatus 151 acquires the state of charge of the battery 157. In S253, the RX control unit 159 of the power receiving apparatus 151 updates the apparatus status information that is a part of the data of the non-contact IC 158. The device status information which is a part of the data of the non-contact IC 158 includes, for example, “device name”, “device ID”, “maximum wireless received power”, “battery presence / absence”, “battery voltage” for the power receiving device 151. "," Chargeability ". In S <b> 253, information on “battery presence / absence”, “battery voltage”, and “chargeability” regarding the state of the battery 157 is updated in the device status information.

  Here, the description returns to the operation of the power transmission apparatus 101.

  In step S <b> 203, the TX control unit 108 of the power transmission apparatus 101 reads apparatus status information that is a part of data of the non-contact IC 158 of the power receiving apparatus 151 using the short-range wireless communication function of the non-contact IC reader / writer 109. Then, the TX control unit 108 of the power transmission device 101 writes the device status information of the power transmission device 101 in the non-contact IC 158.

  When reading the information of the non-contact IC 158 by the short-range wireless communication of S203 and writing the information to the non-contact IC 158, for example, a read command and a write command of JISX6319-4 are used. Hereinafter, a read command of JISX6319-4 is used when reading information of the non-contact IC 158 by short-range wireless communication, and a write command of JISX6319-4 is used when writing information to the non-contact IC 158 by short-range wireless communication.

  Note that when the non-contact IC 158 is read / written by the short-range wireless communication, the non-contact IC 158 outputs an interrupt signal. The RX control unit 159 of the power receiving apparatus 151 detects an interrupt signal, and performs processing for accessing the non-contact IC 158 and controlling charging of the battery 157.

  The device status information of the power transmission device 101 transmitted in S203 includes, for example, “device name”, “device ID”, and “maximum wireless transmitted power”. The device status information of the power receiving device 151 includes, for example, “device name”, “device ID”, “maximum wireless received power”, “battery presence / absence”, “battery voltage”, and “chargeability”.

  Here, the operation of the power receiving apparatus 151 will be described.

  In S254, the RX control unit 159 of the power receiving device 151 reads the device status information of the power receiving device 151 by the short-range wireless communication from the non-contact IC 158, and transmits a response signal to the writing of the device status information of the power transmitting device 101.

  In S255, the RX control unit 159 of the power receiving apparatus 151 determines whether or not it is in a chargeable mode. If it is determined that the mode is chargeable, the process proceeds to S256, and is not in a chargeable mode. If so, the process ends. In S255, for example, when the battery 157 is not attached to the power receiving apparatus 151, or when the battery 157 is fully charged and prohibits recharging to compensate for a voltage drop due to natural discharge, it is not a chargeable mode. It is determined.

  Here, the description returns to the operation of the power transmission apparatus 101.

  In S204, the TX control unit 108 of the power transmitting apparatus 101 determines whether or not the device status information of the power receiving apparatus 151 read in S203 is a chargeable mode. If the TX control unit 108 of the power transmission apparatus 101 determines that the mode is chargeable, the process proceeds to S205, and if it is determined that the mode is not chargeable, the process ends.

  In step S <b> 205, the TX control unit 108 of the power transmission apparatus 101 writes the charging power setting start information to the non-contact IC 158 of the power reception apparatus 151 using the short-range wireless communication function of the non-contact IC reader / writer 109. The charging power setting start information includes “charging power setting transmission power”, “start time”, and “end time”. In the charging power setting start information, “charging power setting transmission power” is 0.2 W.

  In S <b> 206, the TX control unit 108 of the power transmission apparatus 101 controls the TX power transmission unit 104 to transmit charging power setting power. The charging power setting power is set to 0.2 W which is equal to “charging power setting transmission power” which is one of the charging power setting start information written in the non-contact IC 158 in S205. When transmitting power for setting charging power in S206, the TX matching unit 105 is set to a circuit suitable for wireless power transmission from the TX power transmission unit 104.

  In the following, when the TX power transmission unit 104 is controlled to transmit power, the TX matching unit 105 is set to a circuit suitable for wireless power transmission from the TX power transmission unit 104. When the short-range wireless communication function of the non-contact IC reader / writer 109 is used, the TX matching unit 105 is set to a circuit suitable for the short-range wireless communication of the non-contact IC reader / writer 109. A description of control switching is omitted.

  In S207, the power transmission apparatus 101 transmits the power for setting the charging power in S206, and then uses the short-range wireless communication function of the non-contact IC reader / writer 109 to set the charging power transmitted from the non-contact IC 158 of the power receiving apparatus 151. The received power information for the power of is read. The received power information includes “received power” that is power actually received by the power receiving apparatus 151 as a result of the power transmission apparatus 101 transmitting power for setting charging power.

  Here, the operation of the power receiving apparatus 151 will be described.

  In S256, the non-contact IC 158 of the power receiving apparatus 151 transmits a response signal in response to the writing of the charging power setting start information by the short-range wireless communication.

  In S257, the RX control unit 159 of the power receiving apparatus 151 uses, as a trigger, writing of the charging power setting start information to the non-contact IC 158 before reaching the “starting time” which is one of the charging power setting start information. The power measuring unit 160 is connected to the constant voltage unit 155. In S257, the power matching unit 160 is connected, and at the same time, the RX matching unit 153 is set to a circuit suitable for receiving wireless power from the TX power transmission unit 104 of the power transmission apparatus 101.

  In S <b> 258, the RX control unit 159 of the power receiving device 151 receives the power for setting the charging power, measures the power being received by the power measuring unit 160, and writes the result as “received power” in the non-contact IC 158.

  In S259, the RX control unit 159 of the power receiving apparatus 151 releases the connection of the power measurement unit 160 after reaching the “end time” which is one of the charging power setting start information. In S259, at the same time as the connection of the power measurement unit 160 is released, the RX matching unit 153 returns to the circuit setting suitable for the short-range wireless communication of the non-contact IC reader / writer 109 of the power transmission apparatus 101. Hereinafter, when receiving wireless power from the TX power transmitting unit 104 of the power transmitting apparatus 101, the RX matching unit 153 is set to a circuit suitable for receiving wireless power from the TX power transmitting unit 104. When performing short-range wireless communication with the non-contact IC reader / writer 109 of the power transmission apparatus 101, the RX matching unit 153 is set to a circuit suitable for short-range wireless communication with the non-contact IC reader / writer 109. A description of control switching of the matching unit 153 is omitted.

  In S260, the non-contact IC 158 of the power receiving apparatus 151 transmits a response signal in response to reading of the received power information by short-range wireless communication. The received power information includes the “received power”.

  Here, the description returns to the operation of the power transmission apparatus 101.

  After reading the received power information for the charging power setting power in S207, in S208, the TX control unit 108 of the power transmitting apparatus 101 receives the charging power setting power transmitted by the power transmitting apparatus 101 and the power receiving apparatus 151. Calculate transmission efficiency based on power. In S206, since the power transmission device 101 sets the power for setting the charging power to 0.2 W, if the power measurement unit 160 of the power reception device 151 measures, for example, “received power” is 0.1 W, the transmission efficiency Is 50%, and if the “received power” is 0.16 W, the transmission efficiency is 80%.

  FIG. 3 shows an arrangement example of the power transmission device 101 and the power reception device 151. FIG. 3A illustrates a state in which the TX antenna 106 of the power transmission apparatus 101 and the RX antenna 152 of the power reception apparatus 151 are positioned in a directly opposed manner with little deviation. The arrangement state of FIG. 3A has a high transmission efficiency at the time of non-contact charging, and the electromagnetic wave generated by the TX antenna 106 is efficiently absorbed by the RX antenna 152, so that the electromagnetic wave leaking from between the devices is small. It can be said. In the state of FIG. 3A, for example, it is assumed that the transmission efficiency is 80%.

  FIG. 3B illustrates a state in which the TX antenna 106 of the power transmission apparatus 101 and the RX antenna 152 of the power reception apparatus 151 are in positions close to each other with a large shift. The arrangement state of FIG. 3B has a low transmission efficiency during contactless charging, and the electromagnetic wave generated by the TX antenna 106 is not efficiently absorbed by the RX antenna 152. Therefore, it can be said that the arrangement state has a large amount of electromagnetic waves leaking from between the devices. Assume that the transmission efficiency is 50% in the state of FIG.

  In the arrangement state of FIG. 3B, since the power receiving device 151 is not located at the position facing the TX antenna 106 of the power transmission device 101, if there is a foreign object at the position facing the TX antenna 106, the leaked electromagnetic wave Foreign matter easily generates heat. Further, when a part of the human body is close to the position where the TX antenna 106 is directly facing, the leaked electromagnetic wave is exposed to a part of the human body. Therefore, it can be said that the arrangement state of FIG. 3B is an unfavorable arrangement from the viewpoint of efficiency and safety as an arrangement of non-contact charging.

  In S209, the TX control unit 108 of the power transmission apparatus 101 sets the transmission power for charging according to the apparatus status information of the power receiving apparatus 151 acquired in S203 and the transmission efficiency calculated in S208. Since various techniques have already been proposed for setting the transmission power for charging, a detailed description thereof will be omitted.

  Here, the time change of the battery voltage and the charging current of the battery 157 will be described with reference to FIG. FIG. 4A shows the time change of the battery voltage, and FIG. 4B shows the time change of the battery charging current. In FIG. 4A, threshold Vt1 = 3.0 V is a threshold voltage for switching between trickle charge and quick charge control of battery 157. In FIG. 4A, the battery voltage Vc at full charge is set to 4.2V. In FIG. 4B, the charging current during trickle charging is 50 mA, the charging current during fast charging and constant current control section is 500 mA, and the charging end current during fast charging and constant voltage control section is 50 mA.

  When charging of the battery 157 of the power receiving apparatus 151 is in the state of constant current control during the rapid charging and the output of the RX constant voltage unit 155 requires 2.2 W, the power transmitting apparatus 101 has a transmission efficiency of 50%. Sets the transmitted power to 4.4W. If the transmission efficiency is 80%, the power transmitting apparatus 101 sets the transmitted power to 2.75W.

  When charging of the battery 157 of the power receiving apparatus 151 is trickle charging and the power of 0.35 W is required as the output of the RX constant voltage unit 155, the power transmitting apparatus 101 sets the transmitted power to 0.7 W if the transmission efficiency is 50%. Set. If the transmission efficiency is 80%, the power transmitting apparatus 101 sets the transmitted power to 0.44 W.

  Returning to the description of FIG. 2, in S212, the TX control unit 108 of the power transmission apparatus 101 determines whether or not the transmission efficiency calculated in S208 is equal to or greater than a threshold value. The threshold value of the transmission efficiency is determined according to a table that defines the relationship between the maximum transmission efficiency and the diagram based on the combination of the power transmission device and the power reception device shown in FIG. The table shown in FIG. 5 is stored in a ROM built in the TX control unit 108 of the power transmission apparatus 101, for example.

  The TX control unit 108 of the power transmission apparatus 101 determines a diagram to be used for threshold determination of transmission efficiency according to a combination of “apparatus name” which is one of apparatus status information of the power receiving apparatus 151 acquired in S203 and the apparatus. The diagram used for transmission efficiency threshold determination may be changed depending on the combination of devices. For example, according to the table of FIG. 5, in the case of a combination of the power transmitting apparatus 101 and the power receiving apparatus 151, the first diagram (A) is used for threshold determination of transmission efficiency.

  FIG. 6 is an example of a first diagram used for threshold determination of transmission efficiency. In the first diagram (A) of the transmission efficiency and charging power transmission time in FIG. 6 (A), for example, the diagram changes linearly.

  In the first diagram (A) of FIG. 6 (A), if the transmission efficiency is less than 60%, the charging power transmission time in one cycle of the non-contact charging sequence is set to an initial value of 1 second, and linearly increases therefrom. When the transmission efficiency is 95% or more, the charging power transmission time is 8 seconds. In the first diagram (B) of the transmission efficiency and charging power transmission time in FIG. 6 (B), for example, the diagram changes stepwise.

  The first diagram (A) and the first diagram (B) shown in FIGS. 6A and 6B are stored in, for example, a ROM built in the TX control unit 108 of the power transmission apparatus 101. It is assumed that either one can be selected.

  Note that the numerical values in the first diagram (A) and the first diagram (B) shown in FIGS. 6 (A) and 6 (B) are merely examples for explaining the present embodiment. It may be changed appropriately according to the situation.

  When the TX control unit 108 of the power transmission apparatus 101 determines that the transmission efficiency calculated in S208 is less than the threshold, the process proceeds to S213, and the charging power transmission time in one cycle of the non-contact charging sequence is a first diagram. Set to the initial value according to (A).

  When the TX control unit 108 of the power transmission apparatus 101 determines that the transmission efficiency calculated in S208 is equal to or greater than the threshold, the process proceeds to S214, and the charging power transmission time in one cycle of the non-contact charging sequence is set to the first diagram. Set to an extension value according to (A).

  For example, when the arrangement state of the power transmitting apparatus 101 and the power receiving apparatus 151 is the state shown in FIG. 3A, the transmission efficiency is 80%, which exceeds the threshold in the first diagram (A) of FIG. Therefore, the charging power transmission time during one cycle of the non-contact charging sequence is set to an extended value. At a transmission efficiency of 80%, the charging power transmission time during one cycle of the non-contact charging sequence is 5 seconds.

  For example, when the arrangement state of the power transmission apparatus 101 and the power reception apparatus 151 is the state of FIG. 3B, the transmission efficiency is 50%, which is less than the threshold in the first diagram (A) of FIG. Therefore, the charging power transmission time during one cycle of the non-contact charging sequence is set to an initial value. When the transmission efficiency is 50%, the charging power transmission time in one cycle of the non-contact charging sequence is 1 second.

  In step S <b> 218, the TX control unit 108 of the power transmission apparatus 101 writes charging power transmission start information to the non-contact IC 158 of the power reception apparatus 151 using the short-range wireless communication function of the non-contact IC reader / writer 109. The charging power transmission start information includes “charging transmission power”, “charging transmission start time”, and “charging transmission end time”.

  The charging power transmission start information written in S218 is a case where charging of the battery 157 of the power receiving apparatus 151 is in the state of quick charging in FIG. Explained as an example.

  Taking the case where the transmission efficiency is 80% as an example, in the charging power transmission start information written in S218, “charging transmission power” is 2.75 W, and the time difference between “charging power transmission start time” and “charging power transmission end time” Is 5 seconds.

  Note that the process of S218 is not essential in the flow of performing non-contact charging between the power transmitting apparatus 101 and the power receiving apparatus 151. When executing S218, the power transmitting apparatus 101 notifies the power receiving apparatus 151 in advance of wireless power transmission start information during one cycle of the non-contact charging sequence. Then, charging control is performed according to the “charging power transmission start time” and the “charging power transmission end time” in one cycle of the non-contact charging sequence received by the power receiving device 151. When S218 is omitted, the power transmission apparatus 101 transmits wireless power after a predetermined time after performing the process of S207. The power receiving device 151 may detect the state of receiving wireless power, and may determine the charging power transmission period in one cycle of the non-contact charging sequence in the detected state to perform charging control.

  In S219, the TX control unit 108 of the power transmission apparatus 101 controls the TX power transmission unit 104 according to the transmission power set in S209 to transmit wireless power.

  In the present embodiment, when the arrangement state of the power transmission device 101 and the power reception device 151 is FIG. 3A, the transmission efficiency is 80%, the battery 157 is being charged rapidly and is in the constant current control section, power is transmitted in S219. The power is set to the transmitted power 2.75 W set in S209. The charging power transmission time is 5 seconds set in S218.

  When transmitting power for setting charging power in S219, the TX matching unit 105 is set to a circuit suitable for wireless power transmission from the TX power transmission unit 104.

  Thereafter, the power transmission apparatus 101 transmits wireless power in S219, returns the process to S201, transmits a polling signal again, and repeats the non-contact charging control in FIG.

  Here, the operation of the power receiving apparatus 151 will be described.

  In S261, the non-contact IC 158 of the power receiving apparatus 151 transmits a response signal in response to writing of charging power transmission time information by short-range wireless communication.

  In S262, the RX control unit 159 of the power receiving apparatus 151 uses “charging power transmission start time” which is one of charging power transmission start information triggered by the writing of charging power transmission start information to the non-contact IC 158 in S261. The charging control unit 156 is connected to the RX constant voltage unit 155 before reaching. In S262, the RX matching unit 153 is set to a circuit suitable for receiving wireless power from the TX power transmission unit 104 of the power transmission apparatus 101 at the same time as the charging control unit 156 is connected.

  Note that the process of S261 is not essential when performing non-contact charging between the power transmitting apparatus 101 and the power receiving apparatus 151. When executing the process of S261, the wireless power transmission start information in the first cycle of the non-contact charging sequence is received from the power transmission device 101 in advance, and the power receiving device 151 receives the “charging power transmission start time” in the first cycle of the non-contact charging sequence. Charging control is performed according to the “charging power transmission end time”. When S261 is omitted, the power receiving apparatus 151 executes S262 after executing the process of S260 and then executes S262, and then receives wireless power. The power receiving device 151 may detect the state of receiving wireless power, and may determine the charging power receiving period in one cycle of the non-contact charging sequence in the detected state to perform charging control.

  In S263, the RX control unit 159 of the power receiving apparatus 151 receives wireless power from the power transmitting apparatus 101.

  When the reception of wireless power from the power transmission apparatus 101 is completed in S263, the RX control unit 159 of the power reception apparatus 151 acquires the state of the battery 157 in S264. In S264, the power receiving apparatus 151 acquires the voltage, temperature, and charging status of the battery 157, for example.

  In S265, the RX control unit 159 of the power receiving apparatus 151 performs charge control after reaching the “charging power transmission end time” which is one of the charging power transmission start information received in S261, or after the charging power receiving period ends. The connection of the unit 156 is released.

  In S266, the RX control unit 159 of the power receiving apparatus 151 determines whether or not the charging status is fully charged in the state of the battery 157 acquired in S264. If the RX control unit 159 of the power receiving apparatus 151 determines that the charging status of the battery 157 is not fully charged, the process returns to S251 and waits for a polling signal again.

  If the RX control unit 159 of the power receiving apparatus 151 determines that the charging status of the battery 157 is full, the process proceeds to S267, where the apparatus status information that is part of the data of the non-contact IC 158 is updated, and the process is performed. finish. In S267, “battery voltage” related to the state of the battery 157 in the apparatus status information is updated, and “chargeability” is updated from possible to not. In S 267, when “charging is possible” which is one of the device status information which is a part of the data of the non-contact IC 158 is rejected, the battery 157 is frequently recharged and the battery 157 is recharged frequently. It can prevent the cell from being damaged.

  In order to enable “chargeability”, which is one piece of device status information that is a part of the data of the non-contact IC 158, for example, the main control unit 162 of the power receiving device 151 and its peripheral function blocks are operated to operate the battery 157. The apparatus status information may be updated by using the power consumption as a trigger.

  FIG. 7 is a diagram conceptually illustrating control of charging power transmission time during contactless charging according to the present embodiment.

  7A shows the arrangement of the power transmitting apparatus 101 and the power receiving apparatus 151 in FIG. 3A and the transmission efficiency is 80%. FIG. 7B shows the arrangement of the power transmitting apparatus 101 and the power receiving apparatus 151 in FIG. In FIG. 3B, it is assumed that the transmission efficiency is 50%.

  7A and 7B both require charging of the battery 157 of the power receiving device 151 during the rapid charging of FIG. 4 and a constant current control period, and an electric power of 2.2 W as an output of the RX constant voltage unit 155. An example of a state is shown.

  FIG. 7A shows a transmission power of 2.75 W in one cycle of the contactless charging sequence and a charging power transmission time of 5 seconds, whereas FIG. 7B shows a transmission power of 4 in one cycle of the contactless charging sequence. .4W, charging power transmission time is 1 second.

  According to the flow of FIG. 2, the shift between the TX antenna 106 of the power transmission apparatus 101 and the RX antenna 152 of the power reception apparatus 151 is small, and the transmission efficiency at the time of non-contact charging is high, compared to the case of low, FIG. As described above, the charging power transmission time during one cycle of the non-contact charging sequence can be made relatively long. Since the charging power transmission time can be made relatively long, there is little leakage of electromagnetic waves, and charging of the battery 157 can be completed in a faster time.

  When the transmission antenna 101 of the power transmission apparatus 101 and the RX antenna 152 of the power receiving apparatus 151 have a large deviation and the transmission efficiency at the time of non-contact charging is low, the non-contact charging sequence 1 as shown in FIG. It is possible to relatively shorten the charging power transmission time during the cycle. Since the charging power transmission time can be relatively shortened, the battery 157 can be charged while suppressing the leakage of electromagnetic waves and the total amount of heat generation.

  [Embodiment 2] Next, non-contact charge control of Embodiment 2 will be described with reference to FIGS.

  In the second embodiment, a mode in which the charging power transmission time is set by further using the voltage information of the battery 157 of the power receiving device 151 in addition to the first embodiment and the battery 157 of the power receiving device 151 is contactlessly charged will be described.

  FIG. 8 is a flowchart illustrating in parallel the operations of the power transmission device 101 and the power reception device 151 in the contactless charging control according to the second embodiment. In addition, the structure of the power transmission apparatus and power receiving apparatus of this embodiment is the same as that of FIG. 8 are the same as S201 to S209, S218, S219, and S251 to S267 in FIG. 2, and thus description thereof is omitted, and different points are mainly described. .

  In step S810, the TX control unit 108 of the power transmission apparatus 101 determines whether “battery voltage”, which is one of the apparatus status information of the power reception apparatus 151 acquired in step S803, is equal to or higher than the threshold value Vt1. Here, the relationship between the threshold voltages Vt1 and Vt2 of the “battery voltage” will be described with reference to the time change of the charging voltage and charging current of the battery 157 shown in FIG.

  FIG. 9A shows the time change of the battery voltage, and FIG. 9B shows the time change of the battery charging current. In FIG. 9A, the threshold value Vt1 = 3.0V is a threshold voltage for switching between trickle charge control and rapid charge control of the battery 157. In FIG. 9A, the battery voltage Vc at full charge is assumed to be 4.2V. The threshold value Vt2 = 4.15V is a threshold voltage that is close to the charge end state in the constant voltage control section during the rapid charging of the battery 157. In this case, if the charging current of FIG. 9B is a battery voltage that is a little higher than the charging end current of 50 mA, for example, a charging current of about 150 mA that is a predetermined multiple (about 3 times) from 50 mA that is the charging end current. Good.

  If the TX control unit 108 of the power transmitting apparatus 101 determines that the “battery voltage” is less than the threshold value Vt1 in S810, the process proceeds to S815, and the transmission efficiency calculated in S808 is the second diagram (A). It is determined whether or not the threshold value is exceeded.

  The threshold value of transmission efficiency is determined according to the table shown in FIG. 10, for example. The table shown in FIG. 10 is stored in a ROM built in the TX control unit 108 of the power transmission apparatus 101, for example.

  The TX control unit 108 of the power transmitting apparatus 101 determines a diagram to be used for threshold determination of transmission efficiency according to the combination of “apparatus name” which is one of the apparatus status information of the power receiving apparatus 151 acquired in step S803 and the apparatus. Note that the diagram used for threshold determination of transmission efficiency may be changed depending on the combination of devices.

  For example, according to a table that defines the relationship between the maximum transmission efficiency based on the combination of devices in FIG. 10 and the battery voltage and the diagram, in the case of a combination of the power transmitting device 101 and the power receiving device 151, the battery voltage is less than the threshold Vt1 or the threshold If it is Vt2 or more, the second diagram (A) in FIG. 11 (B) is used for threshold determination of transmission efficiency. If the battery voltage is equal to or higher than the threshold value Vt1 and lower than the threshold value Vt2, it is the first diagram (A) in FIG.

  FIG. 11 is an example of a second diagram used for threshold determination of transmission efficiency. The second diagram (A) of the transmission efficiency and charging power transmission time in FIG. 11 (A) changes linearly, for example.

  In the first diagram (A) of FIG. 11 (A), if the transmission efficiency is less than 30%, the charging power transmission time in one cycle of the non-contact charging sequence is set to an initial value of 1 second, and increases linearly therefrom. When the transmission efficiency is 65% or more, the charging power transmission time is 8 seconds.

  The second diagram (B) of the transmission efficiency and charging power transmission time in FIG. 11 (B) changes stepwise, for example. The first diagram is the same as FIG. 6 of the first embodiment.

  The first diagram and the second diagram of the transmission efficiency and the charging power transmission time shown in FIGS. 6 and 11 are stored in, for example, the ROM built in the TX control unit 108 of the power transmission apparatus 101. Can be selected.

  The numerical values in the first diagram and the second diagram of the transmission efficiency and the charging power transmission time shown in FIGS. 6 and 11 are examples for explaining the present embodiment, and are appropriately changed according to the situation. You can do it.

  If the TX control unit 108 of the power transmission apparatus 101 determines in S815 that the transmission efficiency calculated in S808 is less than the threshold value in the second diagram (A), the process proceeds to S816.

  In S816, the TX control unit 108 of the power transmission apparatus 101 sets the charging power transmission time during one cycle of the non-contact charging sequence to an initial value according to the second diagram (A).

  If the TX control unit 108 of the power transmission apparatus 101 determines in S815 that the transmission efficiency calculated in S808 is equal to or greater than the threshold in the second diagram (A), the process proceeds to S817.

  In S817, the TX control unit 108 of the power transmission apparatus 101 sets the charging power transmission time during one cycle of the non-contact charging sequence to an extended value according to the second diagram (A).

  If the TX control unit 108 of the power transmission apparatus 101 determines in S810 that the “battery voltage” is equal to or higher than the threshold value Vt1, the process proceeds to S811.

  In S811, the TX control unit 108 of the power transmission apparatus 101 determines whether or not “battery voltage”, which is one of the apparatus status information of the power receiving apparatus 151 acquired in S803, is equal to or higher than the threshold value Vt2. If the power transmission apparatus 101 determines that the “battery voltage” is equal to or greater than the threshold value Vt2, the process proceeds to step S815. If the power transmission apparatus 101 determines that the “battery voltage” is less than the threshold value Vt2, the process proceeds to step S812.

  In S812, the TX control unit 108 of the power transmission apparatus 101 determines whether or not the transmission efficiency calculated in S808 is equal to or greater than a threshold in the first diagram (A). If the power transmission apparatus 101 determines that the transmission efficiency calculated in S808 is less than the threshold in the first diagram (A), the process proceeds to S813, and if it is determined that the transmission efficiency is greater than or equal to the threshold, the process proceeds to S814.

  In S813, the TX control unit 108 of the power transmission apparatus 101 sets the charging power transmission time during one cycle of the non-contact charging sequence to an initial value according to the first diagram (A).

  In S814, the TX control unit 108 of the power transmission apparatus 101 sets the charging power transmission time during one cycle of the non-contact charging sequence to an extended value according to the first diagram (A).

  For example, when the “battery voltage” of the battery 157 is less than the threshold value Vt1 = 3.0V or the threshold value Vt2 = 4.15V and the arrangement state of the power transmission apparatus 101 and the power reception apparatus 151 is the state shown in FIG. The efficiency is 50%, which exceeds the threshold of the second diagram (A) in FIG. Therefore, the charging power transmission time in one cycle of the non-contact charging sequence is set to an extended value. When the transmission efficiency is 50%, the charging power transmission time in one cycle of the non-contact charging sequence is 5 seconds.

  For example, when the “battery voltage” of the battery 157 is greater than or equal to the threshold value Vt1 = 3.0V and less than the threshold value Vt2 = 4.15V, and the arrangement state of the power transmission apparatus 101 and the power reception apparatus 151 is the state shown in FIG. The efficiency is 50%, which is less than the threshold of the first diagram (A) in FIG. Therefore, the charging power transmission time in one cycle of the non-contact charging sequence is set to an initial value. When the transmission efficiency is 50%, the charging power transmission time in one cycle of the non-contact charging sequence is 1 second.

  FIG. 12 is a diagram conceptually illustrating control of charging power transmission time during contactless charging according to the present embodiment.

  12A shows that the “battery voltage” of the battery 157 of the power receiving apparatus 151 is less than the threshold value Vt1 = 3.0 V or more than the threshold value Vt2 = 4.15 V, and the arrangement of the power transmitting apparatus 101 and the power receiving apparatus 151 is as shown in FIG. (B) Assume that the transmission efficiency is 50%. FIG. 12A shows a state in which charging of the battery 157 of the power receiving apparatus 151 is during trickle charging or rapid charging in FIG. 9 and close to the end of charging in the constant voltage control section, and power is output as the output of the RX constant voltage unit 155. A case where 0.35 W is required will be described as an example.

  12B shows that the “battery voltage” of the battery 157 of the power receiving apparatus 151 is not less than the threshold value Vt1 = 3.0 V and less than the threshold value Vt2 = 4.15 V, and the arrangement of the power transmitting apparatus 101 and the power receiving apparatus 151 is as shown in FIG. (B) Assume that the transmission efficiency is 50%. FIG. 12B illustrates an example in which charging of the battery 157 of the power receiving device 151 is during the rapid charging and the constant current control section of FIG. 9 and the power of 2.2 W is required as the output of the RX constant voltage unit 155. explain.

  FIG. 12A shows a transmission power of 0.7 W during one cycle of the non-contact charging sequence and a charging power transmission time of 5 seconds, while FIG. 12B shows a transmission power of 4 during one cycle of the non-contact charging sequence. .4W, charging power transmission time is 1 second.

  According to the flow of FIG. 8 of the present embodiment, the following effects are obtained in addition to the effects of the first embodiment.

  Even when the antenna difference between the power transmitting apparatus 101 and the power receiving apparatus 151 is large and the transmission efficiency at the time of non-contact charging is low, the charging power transmission during one cycle of the non-contact charging sequence as shown in FIG. The time can be made relatively long.

  When the power supplied for charging is low, the total amount of electromagnetic wave leakage and heat generation is naturally suppressed. Therefore, the discharge state is large by relatively increasing the charging power transmission time in one cycle of the non-contact charging sequence. If the battery is used, the voltage can be restored faster and the battery 157 can be charged in a faster time.

  [Third Embodiment] Next, a non-contact charging system according to a third embodiment will be described with reference to FIG.

  In the first and second embodiments, the power transmission device and the power reception device have been described to share the antenna for short-range wireless communication and the antenna for charging power transmission / reception.

  In the present embodiment, a configuration in which the power transmission device and the power reception device are separately provided with an antenna for short-range wireless communication and an antenna for charging power transmission and reception will be described.

  FIG. 13 is a block diagram illustrating a configuration example of the power transmission device and the power reception device of the present embodiment. In the block diagram used for the description of the present embodiment, power supply connections to blocks that are not necessary for the description of the present embodiment are omitted. Also, detailed descriptions of blocks and operations that are not necessary for the description of the present embodiment are omitted.

  13, functional blocks 1302 to 1310 of the power transmitting apparatus 1301 are the same as the functional blocks 102 to 110 of FIG. 2, and functional blocks 1352 to 1370 of the power receiving apparatus 1351 are functional blocks 152 to 170 of FIG. The description is omitted because it is the same, and the description will focus on the different points.

  The power transmission device 1301 and the power reception device 1351 perform short-range wireless communication between the devices using the TX communication antenna 1322 and the RX communication antenna 1381, and wireless power transmission / reception is performed using the TX antenna 1306 and the RX as in the first and second embodiments. This is done with the antenna 1352.

  A TX communication matching unit 1321 optimized for short-range wireless communication is disposed between the TX communication antenna 1322 and the non-contact IC reader / writer 1309 of the power transmission device 1301. An RX communication matching unit 1382 optimized for short-range wireless communication is disposed between the RX communication antenna 1381 and the non-contact IC 1358 of the power receiving apparatus 1351.

  When the non-contact IC 1358 is compatible with, for example, ISO / IEC21481 which is an international standard for short-range wireless communication, the TX communication antenna 1322 and the X communication antenna 1381 are antennas having a resonance frequency near 13.56 MHz which is the HF band. It is.

  In the present embodiment, since one of the two pairs of antennas is used for short-range wireless communication between the power transmission device and the power reception device, the other antenna can transmit and receive wireless power for charging. Therefore, the TX antenna 1306 and the TX matching unit 1305, and the RX antenna 1352 and the RX matching unit 1353 used for transmitting and receiving the wireless power for charging do not need to be antennas having a resonance frequency near 13.56 MHz which is the HF band. Various frequency band configurations can be applied. For example, an electromagnetic induction coil having a resonance frequency in the LF band of 100 to 400 kHz may be configured as an antenna.

[Other Embodiments]
In Embodiments 1 to 3 described above, the transmission efficiency of charging wireless power transmitted and received between the power transmission device and the power reception device is calculated, and the secondary battery of the power reception device is charged according to the calculated transmission efficiency. The form which controls the power transmission time of the wireless power for the purpose has been described. On the other hand, the procedure for transmitting the power for calculating the transmission efficiency may be omitted, the power during wireless communication may be measured, and the transmission efficiency may be calculated based on the result.

  The setting of the charging power transmission time to which the present invention is applicable may not be a method using transmission efficiency. The present invention can be applied even if the charging power transmission time is set by the coupling coefficient of the antenna due to the magnetic flux during wireless communication or the voltage standing wave ratio of the antenna by the traveling wave and the reflected wave instead of the transmission efficiency. In that case, functional blocks for measuring the coupling coefficient of the antenna and the voltage standing wave ratio of the antenna are added to the block diagrams of FIGS. The transmission efficiency in the diagrams of FIGS. 6 and 11 is replaced with the antenna coupling coefficient and the antenna voltage standing wave ratio, and numerical values for the diagrams are set as appropriate.

  In the second and third embodiments, a mode has been described in which contactless communication is performed between a power transmission device and a power reception device, a battery voltage is acquired, and a diagram for setting a charging power transmission time is selected. On the other hand, the diagram selection for setting the charging power transmission time to which the present invention is applicable may not be a method using the battery voltage. For example, the charging control unit 156 determines the charging mode from the charging current of the battery, the RX control unit 159 of the power receiving apparatus 151 acquires the charging mode, the power transmission apparatus 101 acquires the charging mode, and the acquired charging mode depends on the acquired charging mode. A diagram for setting the charging power transmission time may be selected. Note that the charge mode is a mode such as trickle charge, constant current control section during quick charge, constant voltage control section during quick charge, or during charge termination timer differential in constant voltage control section during quick charge. Also good.

  In that case, since the charging mode cannot be acquired when the first device status information is acquired in one cycle of the non-contact charging sequence in the flow of FIG. 8, the initial values are set instead of the extended values in the diagrams of FIGS. It will be.

  Further, in the first to third embodiments, it has been described that the charging power transmission time is set according to the diagram defining the relationship between the transmission efficiency and the charging power transmission time shown in FIGS. 6 and 11, but the present invention is applied. Possible charging power transmission time settings are not limited to diagrams. For example, the charging power transmission time setting may be changed by referring to a lookup table or calculating using a mathematical expression. In this case, the lookup table and the mathematical formula are stored in the power transmission device.

  In the first to third embodiments, the example in which the non-contact IC is captured and read / written using the JISX6319-4 command as the short-range wireless communication command of the non-contact IC has been described. However, the present invention can be applied. The wireless communication command of such non-contact IC is not limited to this. For example, the present invention can be applied even when a non-contact IC is captured and read / written using an ISO / IEC 14443 command or an ISO / IEC 15693 command.

  In the first to third embodiments, the non-contact IC is described as being compatible with ISO / IEC 21481, which is an international standard for short-range wireless communication. However, the wireless communication standard for a non-contact IC to which the present invention can be applied. Is not limited to ISO / IEC21481. Any standard can be applied as long as it is a non-contact IC that operates using external electromagnetic waves as power. In terms of the frequency of electromagnetic waves, the present invention can be applied even if the frequency is in the frequency band of kHz to GHz of each part of the ISO / IEC18000 standard, even if it is not 13.56 MHz of ISO / IEC21481.

  In the first embodiment, the antenna used for transmitting and receiving the wireless power for charging is described as an antenna having a resonance frequency near 13.56 MHz which is the HF band. In the second embodiment, it has been described that the antenna used for transmitting and receiving the wireless power for charging may be an electromagnetic induction coil having a resonance frequency in the LF band of 100 to 400 kHz, for example. However, the frequency band used for transmission / reception of charging wireless power to which the present invention is applicable is not limited to the HF band or LF band, and any frequency can be used as long as it can transmit and receive wireless power. Even if it exists, this invention is applicable.

  In the first to third embodiments, the non-contact IC is described as an example of the wireless communication unit of the power receiving apparatus. However, the wireless communication unit to which the present invention can be applied is not limited to the non-contact IC. The power receiving apparatus includes a contactless IC reader / writer instead of the contactless IC, and the present invention can be applied even if wireless communication is performed in the card emulation mode or the P2P mode.

  Furthermore, the wireless communication means of the present invention may be IEEE 802.11, which is a WLAN standard, and IEEE 802.15.1, which is a short-range wireless standard. In short, as long as the present invention is a device configuration that performs wireless communication between a power transmission device and a power reception device and transmits and receives wireless power for charging, what is the wireless communication means and the power transmission and reception means for wireless power for charging? It doesn't matter.

  Further, the present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus execute the program. It can also be realized by a process of reading and executing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

101, 1301 ... Power transmission device (charge control device), 106, 1306 ... TX antenna, 108, 1308 ... TX control unit, 151, 1351 ... Power receiving device, 152, 1352 ... RX antenna, 162, 1362 ... RX control unit

Claims (21)

Wireless communication means capable of wireless communication with the power receiving device;
Power transmission means capable of wirelessly transmitting power to the power receiving device;
Wireless communication by the wireless communication means with the power receiving device, and control means for controlling power transmission by the power transmission means,
The control means acquires transmission efficiency of transmitted power based on the power transmitted to the power receiving device and the power received by the power receiving device,
When the transmission efficiency is equal to or higher than a predetermined threshold value, the charging control device controls the power transmission time to be relatively longer than that when the transmission efficiency is lower than the predetermined threshold value.   The control means controls the power transmission time to be increased when the battery voltage of the power receiving apparatus is less than a first threshold value even when the transmission efficiency is less than the predetermined threshold value. The charge control device according to claim 1.   The charge control device according to claim 2, wherein when the battery voltage is less than the first threshold value, trickle charging of the battery of the power receiving device is being performed.   When the battery voltage is less than the first threshold or greater than or equal to a second threshold greater than the first threshold, the control means may The charging control device according to claim 2, wherein control is performed so as to lengthen the power transmission time.   5. The charge control device according to claim 4, wherein the second threshold value is a voltage that is a predetermined multiple of charge current from a charge termination current of a battery of the power receiving device.   The charge control device according to claim 4 or 5, wherein the power transmission time is set according to an initial value when the transmission efficiency is less than the predetermined threshold and a diagram increasing from the initial value. .   The charge control device according to claim 6, wherein the power transmission time varies linearly from the initial value in the diagram.   The charging control device according to claim 6, wherein the power transmission time of the diagram changes stepwise from the initial value.   The charge control device according to claim 6, wherein the diagram is determined from a relationship with a maximum transmission efficiency based on a combination of a power transmission device and a power reception device.   The charge control device according to any one of claims 6 to 8, wherein the diagram is determined from a relationship between a maximum transmission efficiency and a battery voltage based on a combination of a power transmission device and a power reception device.   The diagram includes a first diagram when the battery voltage is greater than or equal to the first threshold and less than the second threshold, and a case where the battery voltage is less than the first threshold or the second 11. The charging control device according to claim 10, further comprising a second diagram when the threshold is equal to or greater than a threshold value, wherein the second diagram has a lower threshold for the transmission efficiency than the first diagram. .   The charge control device according to any one of claims 1 to 11, wherein the power transmission time is one cycle time in contactless charge control.   The charging control apparatus according to claim 1, wherein the control unit calculates transmission efficiency by transmitting predetermined power before transmitting charging power.   The charging control apparatus according to claim 1, wherein the control unit calculates transmission efficiency based on a result of measuring power during wireless communication.   The charging control apparatus according to claim 1, wherein a coupling coefficient of an antenna is used instead of the transmission efficiency.   The charging control apparatus according to claim 1, wherein a standing wave ratio of an antenna is used instead of the transmission efficiency.   The charge control device according to any one of claims 6 to 11, wherein a lookup table or a mathematical expression is used instead of the diagram.   The charging control device according to claim 1, wherein the wireless communication unit and the power transmission unit share an antenna.   The charging control according to any one of claims 1 to 17, wherein the wireless communication unit includes an antenna for wireless communication, and the power transmission unit includes an antenna for transmitting power wirelessly. apparatus. Wireless communication means capable of wireless communication with the power receiving device;
A method of controlling a charging control device comprising: a power transmission means capable of wirelessly transmitting power to the power receiving device;
Controlling wireless communication by the wireless communication means with the power receiving device and power transmission by the power transmission means,
In the controlling step, the transmission efficiency of the transmitted power is acquired based on the power transmitted to the power receiving device and the power received by the power receiving device,
A control method for a charge control device, wherein when the transmission efficiency is equal to or greater than a predetermined threshold, control is performed such that the power transmission time is relatively longer than when the transmission efficiency is less than the predetermined threshold.   The program for functioning a computer as a control means of the charge control apparatus as described in any one of Claim 1 to 19.

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