Charging device, and control method of charging device

Abstract

To provide a charging device capable of efficient cooling, and a control method of the charging device.SOLUTION: A disclosed charging device includes a housing, a second coil, a fan, and a controller. The housing accommodates a chargeable object that has the first coil. The housing has an air intake and an exhaust vent. The second coil is placed in the housing. The second coil can be electromagnetically coupled with the first coil in the object to be charged. The fan is placed in a flow path from the air intake to the exhaust vent. The controller acquires status information about the charging state from the object to be charged. The controller controls the rotation speed of the fan according to the state information.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a charging device and a control method for the charging device. [Background technology]

[0002] In a charging device capable of wireless charging, when an object to be charged is placed near a main surface, power is sent to the object in the form of electromagnetic energy or the like, thereby realizing wireless charging. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-040452 Summary of the Invention [Problem to be solved by the invention]

[0004] Charging devices generate heat during charging, which can limit the charging speed of wireless charging. To speed up wireless charging, efficient cooling is required.

[0005] The present disclosure provides a charging device that can be cooled efficiently and a method for controlling the charging device. [Means for solving the problem]

[0006] The charging device according to the present disclosure includes a housing, a second coil, a fan, and a controller. The housing can accommodate a device to be charged having a first coil. The housing has an air intake port and an air exhaust port. The second coil is disposed within the housing. The second coil can be electromagnetically coupled to the first coil in the device to be charged. The fan is disposed in a flow path extending from the air intake port to the air exhaust port. The controller acquires status information regarding the charging status from the device to be charged. The controller controls the rotation speed of the fan according to the status information. [Effects of the Invention]

[0007] According to the charging device and the control method for the charging device according to the present disclosure, efficient cooling can be achieved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a charging device according to an embodiment; [Figure 2] FIG. 1 is a block diagram showing the configuration of a charging device according to an embodiment. [Figure 3] 4 is a flowchart showing the operation of the charging device according to the embodiment. [Figure 4] FIG. 4 is a waveform diagram showing the operation of the charging device according to the embodiment. [Figure 5] 10 is a flowchart showing the operation of a charging device according to a first modified example of an embodiment. [Figure 6] 10 is a flowchart showing the operation of a charging device according to a second modified example of an embodiment. [Figure 7] 10 is a flowchart showing the operation of a charging device according to a third modified example of an embodiment. [Figure 8] 10 is a flowchart showing the operation of a charging device according to a fourth modified example of an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of a charging device according to the present disclosure will be described with reference to the drawings.

[0010] (Embodiment) The charging device of the embodiment can send power to the object to be charged in the form of electromagnetic energy, etc., when the object to be charged is placed near the main surface, enabling wireless charging, but it is also designed to efficiently cool the object to reduce heat generated during charging.

[0011] The charging device 1 may be configured as shown in Fig. 1. Hereinafter, the direction perpendicular to the main surface 2a of the charging device 1 is defined as the Z direction, the longitudinal direction of the charging device 1 is defined as the X direction, and the direction perpendicular to the X and Z directions is defined as the Y direction. Fig. 1 is a cross-sectional view showing the configuration of the charging device 1, and shows an XZ cross section when the charging device 1 is cut so as to pass through the coil.

[0012] The charging device 1 has a wireless charging function, and an object to be charged 100 can be placed on its main surface 2a via a charging stand 19. The object to be charged 100 is compatible with the wireless charging function. The object to be charged 100 may be an electronic device with a display, such as a smartphone terminal, a tablet terminal, or a smartwatch, or an electronic device without a display, such as a wireless earphone, a wireless speaker, or a wireless mouse. FIG. 1 illustrates a state in which the object to be charged 100 is placed on the main surface 2a via the charging stand 19.

[0013] The charging device 1 includes a housing 2, a circuit board 3, a circuit board 4, a coil 16, a position detection coil 18, a controller 22, a fan 23, and a temperature sensor 24. In the charging device 1, the coil 16 is disposed near the main surface 2a inside the housing 2. The object to be charged 100 has a front surface 100a and a back surface 100b. The object to be charged 100 has a coil 116 near the back surface 100b. The charging device 1 may have a moving-type wireless charging function, and the coil 16 may be configured to be movable in the X and Y directions inside the housing 2. The charging device 1 detects the X and Y positions of the coil 116 using the position detection coil 18. In accordance with the detected X and Y positions, the charging device 1 moves the coil 16 in the X and Y directions so that the X and Y positions of the coil 116 match those of the coil 116, as shown in FIG. 1 . This allows the coil 16 to be electromagnetically coupled to the coil 116, and is also considered to enable high-speed wireless charging.

[0014] The charging device 1 may have a fixed coil type wireless charging function instead of the moving type wireless charging function illustrated in Fig. 1. In this case, the charging device 1 does not have the coil moving mechanism 17 (see Fig. 2) and the position detection coil 18. One or more coils 16 are provided, and when there are multiple coils 16, the coils 16 are arranged in the X and Y directions.

[0015] In the charging device 1, the temperature of the object to be charged 100 may rise during wireless charging, which may limit the charging speed of the wireless charging. For example, according to the Qi standard established by the Wireless Power Consortium (WPC), after charging starts between the charger (power transmitting side) 1 and the object to be charged (power receiving side) 100, communication is performed between the object to be charged 100 and the charging device 1.

[0016] During wireless charging, an induced current flows through each of the coils 16 and 116, and heat may be generated near each of the coils 16 and 116. The object to be charged 100 is heated by heat conduction from a heat source in the charging device 1 (for example, a component near the coil 16) and may also be heated by a heat source in the object to be charged 100 itself (for example, a component near the coil 116).

[0017] If the object to be charged 100 has a temperature protection function for electronic components such as the battery 131, the object to be charged 100 activates the temperature protection function when, for example, the temperature detected by the temperature sensor 121 near the coil 116 rises above a predetermined temperature. In accordance with the temperature protection function, the object to be charged 100 transmits a request to reduce the transmitted power (power transmission rate) to the charging device 1. If the charging device 1 reduces the power transmitted to the object to be charged 100 in response to this, the power received by the object to be charged 100 may decrease, and the speed of wireless charging may decrease.

[0018] In contrast, the charging device 1 is provided with an air-cooling structure for air-cooling the coils 16 and 116.

[0019] 1 is provided with an intake port 2i and an exhaust port 2o. A flow path is provided in the housing 2 from the intake port 2i to the exhaust port 2o so as to pass near the coil 16, and a fan 23 is disposed midway along the flow path. While FIG. 1 illustrates a configuration in which the fan 23 is disposed near the exhaust port 2o, the fan 23 may be disposed at another position midway along the flow path.

[0020] In the air-cooled structure, when the fan 23 is driven, air is drawn in from the outside through the air inlet 2i, passes through the vicinity of the coil 16, reaches the exhaust port 2o, and is discharged to the outside through the exhaust port 2o, as indicated by the dotted arrows. The air that reaches the vicinity of the coil 16 from the air inlet 2i exchanges heat near the coil 16. The air that has gained heat through heat exchange is sent to the exhaust port 2o by the fan 23 and discharged to the outside. This allows the coil 16 to be air-cooled, and the coil 116 can also be indirectly air-cooled via the circuit board 3, the position detection coil 18, the housing 2, and the charging base 19. As a result, when the temperature detected by the temperature sensor 121 drops below a predetermined temperature, the temperature protection function is deactivated, and the object to be charged 100 transmits a request to the charging device 1 to increase the transmission power (power transmission rate). In response, the charging device 1 increases the power transmitted from the object to be charged 1 to the charging device 1, increasing the power received by the object to be charged 100 and restoring the wireless charging rate.

[0021] The cooling capacity of the air-cooled structure depends on the rotation speed of the fan 23. Increasing the rotation speed of the fan 23 can increase the cooling capacity of the air-cooled structure, but this may result in significant periodic pressure fluctuations near the fan 23 due to the rotation of the blades of the fan 23, which may increase the noise of the fan 23 of the charging device 1. In addition, the amount of power supplied to the motor of the fan 23 near the fan 23 may increase, which may increase the power consumption for driving the fan 23 of the charging device 1.

[0022] According to the Qi standard, the charging device 1 cannot receive information related to temperature from the object to be charged 100. Although a temperature sensor 24 is disposed near the coil 16, the temperature detected by the temperature sensor 24 differs from the temperature detected by the temperature sensor 121 near the coil 116. It is difficult for the charging device 1 to directly grasp the temperature near the coil 116. However, according to the Qi standard, the charging device 1 can receive status information related to the received power from the object to be charged 100. It is expected that by using the status information related to the received power, the charging device 1 can indirectly grasp whether the temperature protection function of the object to be charged 100 is activated.

[0023] Therefore, in this embodiment, the charging device 1 receives status information related to the received power from the object to be charged 100, and controls the rotation speed of the fan 23 according to the status information to perform efficient air cooling, thereby achieving both an increase in the speed of wireless charging and a reduction in the noise of the fan 23. Furthermore, it may be possible to further achieve both an increase in the speed of wireless charging and a reduction in the power consumption for driving the fan 23.

[0024] The charging device 1 can be configured as shown in Fig. 2. Fig. 2 is a block diagram showing the configuration of the charging device 1.

[0025] In addition to the housing 2, the circuit board 3, the circuit board 4, the coil 16, the position detection coil 18, the controller 22, the fan 23, and the temperature sensor 24, the charging device 1 further includes a capacitor 5, a DC power supply 11, a DC-DC converter 12, a bridge circuit 13, a voltage detection circuit 14, a current detection circuit 15, a moving mechanism 17, a receiving coil position detection circuit 20, and a temperature acquisition unit 21.

[0026] In the charging device 1, the controller 22 controls each part of the charging device 1 in an integrated manner.

[0027] The controller 22 can also communicate with the object to be charged 100. The controller 22 may receive status information from the object to be charged 100 via the coil 16. The object to be charged 100 detects the power received from the charging device 1, generates status information indicating the received power, modulates the drive amplitude of the coil 116 according to the status information, generates an AC signal including a modulated component, and transmits the AC signal to the charging device 1 via the coil 116. The object to be charged 100 may modulate the drive amplitude using an amplitude modulation method, modulate the drive frequency using a frequency modulation method, or modulate the drive parameters using another modulation method. When the controller 22 receives the AC signal via the coil 16, it extracts the modulated component from the AC signal and restores the status information. The controller 22 may restore the status information using a modulation method corresponding to the object to be charged 100. The controller 22 performs an operation according to the restored status information.

[0028] For example, the controller 22 controls the rotation speed of the fan 23 in accordance with the state information.

[0029] The controller 22 controls the rotation speed of the fan 23 to RN1 during steady state operation. The controller 22 acquires status information related to the received power from the object to be charged 100. The controller 22 can identify the received power of the object to be charged 100 according to the status information. The controller 22 detects a decrease in the received power of the object to be charged 100 when the received power of the object to be charged 100 decreases by a predetermined amount of power ΔP1 or more per unit time. The predetermined amount of power ΔP1 can be determined experimentally in advance as the amount of power decrease that indicates a decrease in the received power. When the controller 22 detects a decrease in the received power of the object to be charged 100, the controller 22 increases the rotation speed of the fan 23 to RN2 (>RN1). As a result, when the temperature of the object to be charged 100 is likely to be higher than the threshold temperature of the temperature protection function, the cooling capacity of the air-cooled structure can be increased by increasing the rotation speed of the fan 23.

[0030] After that, the controller 22 obtains state information regarding the received power from the object to be charged 100. When the received power of the object to be charged 100 increases by a predetermined amount of power ΔP2 or more per unit time according to the state information, the controller 22 detects the increase in the received power. The predetermined amount of power ΔP2 can be experimentally determined in advance as the amount of increase in power indicating the increase in the received power. When the controller 22 detects an increase in the received power, it decreases the rotation speed of the fan 23 to RN1 (<RN2). Thereby, when the temperature of the object to be charged 100 may be lower than the threshold temperature of the temperature protection function, the noise caused by the drive of the fan 23 can be suppressed and the power consumption caused by the drive of the fan 23 can be suppressed by decreasing the rotation speed of the fan 23.

[0031] Alternatively, when the controller 22 does not detect an increase in the received power of the object to be charged 100 according to the state information within the time TM1 after increasing the rotation speed of the fan 23, the controller 22 may decrease the rotation speed of the fan 23. The object to be charged 100 may have a gentle charging function. The gentle charging function is, for example, a function of reducing the required power and charging slowly when the charge amount of the battery 131 becomes equal to or more than the threshold charge amount Cth1. The threshold charge amount Cth1 may be 80%. When the gentle charging function is activated in the object to be charged 100, the object to be charged 100 does not request an increase in the transmitted power. When the received power of the object to be charged 100 does not increase even though the rotation speed of the fan 23 is increased to enhance the cooling capacity of the air-cooled structure, it is expected that the gentle charging function has been activated in the object to be charged 100. The time TM1 can be experimentally determined in advance as the time indicating that the received power of the object to be charged 100 does not increase even though the rotation speed of the fan 23 is increased to enhance the cooling capacity of the air-cooled structure.

[0032] The controller 22 controls the rotation speed of the fan 23 to RN1 during steady state operation. The controller 22 detects a decrease in the received power when the received power of the device to be charged 100 decreases by a predetermined amount of power ΔP1 or more per unit time. When the controller 22 detects a decrease in the received power of the device to be charged 100, the controller 22 increases the rotation speed of the fan 23 to RN2 (>RN1). The controller 22 increases the rotation speed of the fan 23 to RN2 and then starts counting on a timer. If the increase in the received power of the device to be charged 100 per unit time is less than a predetermined amount of power ΔP2 according to the status information until the count time of the timer exceeds time TM1, the controller 22 determines that the device to be charged 100 has activated the battery-friendly charging function and reduces the rotation speed of the fan 23 to RN1. This makes it possible to prevent the rotation speed of the fan 23 from continuing to increase during battery-friendly charging.

[0033] The DC power supply 11 generates a DC power supply voltage Vdc1. The DC power supply 11 may be, for example, a battery, a power supply circuit that receives a DC power supply voltage from an external source, or a power supply circuit that receives an AC power supply voltage from an external source and converts it into a DC power supply voltage. The DC power supply 11 supplies the DC power supply voltage Vdc1 to the DC-DC converter circuit 12.

[0034] The DC-DC converter circuit 12 converts the DC power supply voltage Vdc1 into the DC voltage Vdc2 under the control of the controller 22. The DC-DC converter circuit 12 may step up the DC power supply voltage Vdc1 to convert it into the DC voltage Vdc2, or may step down the DC power supply voltage Vdc1 to convert it into the DC voltage Vdc2, or may convert the DC power supply voltage Vdc1 to the DC voltage Vdc2 while adjusting the waveform while maintaining it at an equal voltage. The DC-DC converter circuit 12 supplies the DC voltage Vdc2 to the bridge circuit 13.

[0035] The bridge circuit 13 converts the DC voltage Vdc2 into a single-phase AC voltage Vac1 under the control of the controller 22. The bridge circuit 13 may include a switching element, and by turning the switching element on and off at a cycle corresponding to the drive frequency, the series voltage Vds2 is converted into the AC voltage Vac1 in a series LC resonant system formed by the capacitor 5 and the coil 16. This enables the bridge circuit 13 to drive the coil 16 via the capacitor 5.

[0036] Capacitor 5 is connected between bridge circuit 13 and coil 16. One end of capacitor 5 is connected to the P-side output node of bridge circuit 13, and the other end is connected to coil 16. Capacitor 5 and coil 16 form a series LC resonant system, and by switching bridge circuit 13 near the resonant frequency, the speed of wireless charging can be improved.

[0037] The coil 16 is connected between the capacitor 5 and the bridge circuit 13. One end of the coil 16 is connected to the capacitor 5, and the other end is connected to the N-side output node of the bridge circuit 13.

[0038] The voltage detection circuit 14 detects the voltage Vin on the input side of the bridge circuit 13. A detection node of the voltage detection circuit 14 is connected to a line connecting the DC-DC converter circuit 12 and the bridge circuit 13. The voltage detection circuit 14 may detect the voltage Vin on the input side of the bridge circuit 13 via the detection node. The voltage detection circuit 14 supplies the detected voltage Vin to the controller 22.

[0039] The current detection circuit 15 detects the current Iac on the output side of the bridge circuit 13. The current detection circuit 15 supplies the detected current Iac to the controller 22. This allows the controller 22 to calculate the transmission power using the voltage Vin and the current Iac.

[0040] The position detection coil 18 is disposed between the coil 16 and the main surface 2a (see FIG. 1). The position detection coil 18 includes a plurality of coils distributed in the X and Y directions.

[0041] The position detection circuit 20 is connected between the position detection coil 18 and the controller 22. The position detection circuit 20 is connected to each of the multiple coils of the position detection coil 18. The position detection circuit 20 is capable of detecting the XY position of the coil 116 under the control of the controller 22.

[0042] The controller 22 may detect the XY position of the coil 116 in the object to be charged 100 using the position detection circuit 20 and the position detection coil 18. The position detection circuit 20 supplies a pulse to each of the multiple coils of the position detection coil 18 in accordance with the control of the controller 22. Each of the multiple coils generates a magnetic flux in accordance with the pulse. When the multiple coils receive the magnetic flux as an echo from the coil 116, they generate an induced current in accordance with the magnetic flux and return it to the position detection circuit 20. The position detection circuit 20 identifies the XY position of the coil 116 in accordance with the induced current in each of the multiple coils. The position detection circuit 20 provides the identified XY position to the controller 22.

[0043] The coil moving mechanism 17 is capable of moving the coil 16 in the X and Y directions under the control of the controller 22 .

[0044] The controller 22 may use the coil moving mechanism 17 to move the coil 16 in the X and Y directions in accordance with the X and Y positions of the coil 116 detected by the position detection circuit 20. The coil moving mechanism 17 moves the coil 16 in the X and Y directions in accordance with the control of the controller 22 so as to approach the X and Y positions of the coil 116. This allows the X and Y positions of the coil 16 to be aligned so as to match the X and Y positions of the coil 116, and the coil 16 can be electromagnetically coupled to the coil 116.

[0045] Next, the operation of the charging device 1 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the operation of the charging device 1.

[0046] The charging device 1 detects the position of the object to be charged in response to the establishment of a predetermined trigger condition (S1). The predetermined trigger condition may be that the charging device 1 is started up, or that the object to be charged 100 is placed near the main surface 2a via the charging stand 19.

[0047] The charging device 1 detects the XY position of the coil 116 using the position detection circuit 20 and the position detection coil 18, and moves the coil 16 to the detected XY position using the coil moving mechanism 17 (S2). The charging device 1 exchanges information about the power level that can be transmitted with the object to be charged 100, and negotiates by confirming the upper limit of the power level, etc. (S3). As a result, the charging device 1 determines a negotiation power according to the upper limit of the power level. The negotiation power may be the maximum value of the effective power that can be transmitted from the charging device 1 to the object to be charged 100.

[0048] When the negotiation is completed, the charging device 1 starts wireless charging (S4). The charging device 1 starts transmitting power to the object to be charged 100 via the coil 16. At the same time, the charging device 1 starts driving the fan 23 at the rotation speed RN1 to start air-cooling the inside of the housing 2 using the air-cooling structure. The charging device 1 continues wireless charging (S5) and receives status information from the object to be charged 100 after a predetermined period has elapsed. The charging device 1 determines whether the received power of the object to be charged 100 has decreased according to the status information (S6). The charging device 1 calculates the amount of decrease in the received power per unit time indicated by the status information, compares the amount of decrease in the received power per unit time with a predetermined power amount ΔP1, and if the amount of decrease in the received power per unit time is less than the predetermined power amount ΔP1, it determines that the received power of the object to be charged 100 has not decreased (No in S6) and continues wireless charging (S5).

[0049] If the amount of decrease in the received power per unit time is equal to or greater than a predetermined power amount ΔP1, the charging device 1 determines that the received power of the object to be charged 100 has decreased (Yes in S6) and judges whether the object to be charged 100 is fully charged (S7). If the charging device 1 receives a notification of charging completion from the object to be charged 100, it determines that the object to be charged 100 is fully charged (Yes in S7), stops wireless charging (S8), and ends the process.

[0050] If the charging device 1 does not receive a notification of charging completion from the object to be charged 100, it determines that the object to be charged 100 is not fully charged (No in S7), increases the rotation speed of the fan 23 from RN1 to RN2 (S9), and starts counting on the timer. The charging device 1 maintains the rotation speed of the fan 23 at RN2 (S10), and after a predetermined period has elapsed, receives status information from the object to be charged 100. The charging device 1 determines whether the received power of the object to be charged 100 has increased according to the status information (S11). The charging device 1 calculates the amount of increase in the received power per unit time indicated by the status information, and compares the amount of increase in the received power per unit time with a predetermined amount of power ΔP2.

[0051] If the increase in the received power per unit time is less than the predetermined power amount ΔP2, the charging device 1 determines that the received power of the device to be charged 100 has not increased (No in S11) and determines whether or not the time TM1 has elapsed since the rotation speed of the fan 23 was increased (S12). The charging device 1 compares the time counted by the timer with the time TM1, and if the time counted by the timer does not exceed the time TM1, it determines that the time TM1 has not elapsed since the rotation speed of the fan 23 was increased (No in S12) and returns the process to S10. If the time counted by the timer exceeds the time TM1, the charging device 1 determines that the time TM1 has elapsed since the rotation speed of the fan 23 was increased (Yes in S12), reduces the rotation speed of the fan 23 from RN2 to RN1 (S13), and returns the process to S5.

[0052] If the increase in the received power per unit time is equal to or greater than a predetermined power amount ΔP2, the charging device 1 determines that the received power of the object to be charged 100 is increasing (Yes in S11), reduces the rotation speed of the fan 23 from RN2 to RN1 (S13), and returns the process to S5.

[0053] The loop process of S5 to S13 is repeated until the answer in S7 is Yes, thereby allowing wireless charging to be performed until the object to be charged 100 is fully charged.

[0054] Next, a use case of the charging device 1 will be described with reference to Fig. 4. Fig. 4 is a waveform diagram showing the operation of the charging device 1. In Fig. 4, the vertical axis indicates power, temperature, or charge amount, and the horizontal axis indicates time. In Fig. 4, the received power of the object to be charged 100 is indicated by a solid line, the temperature detected by the temperature sensor 121 is indicated by a dashed line, and the charge amount of the battery 131 is indicated by a dashed double-dashed line. The slope of the dashed double-dashed line indicates the charge rate of the battery 131, which represents the charge rate of wireless charging by the charging device 1.

[0055] At timing t0, when the charging device 1 is started up, it receives a request for power increase from the object to be charged 100, and in response to the request for power increase, starts supplying power P1a to the object to be charged 100 and starts driving the fan 23 at the rotation speed RN1. The power P1a corresponds to the target power P1 shown in FIG. 4. Charging of the battery 131 starts, and the charge amount starts to increase at a charging speed V1. At the same time, the temperature around the battery 131 starts to rise, and the temperature detected by the temperature sensor 121 starts to rise. The object to be charged 100 starts transmitting status information indicating the received power P1a to the charging device 1. The charging device 1 receives the status information from the object to be charged 100, and determines, based on the status information, that the amount of decrease per unit time of the received power P1a of the object to be charged 100 is less than a predetermined power amount ΔP1, and maintains the rotation speed of the fan 23 at RN1.

[0056] At timing t1, when the detected temperature of the temperature sensor 121 of the object to be charged 100 exceeds the threshold temperature of the temperature protection function and reaches T1, the temperature protection function is activated, and according to the temperature protection function, a request for power reduction is transmitted to the charging device 1. The charging device 1 receives the request for power reduction from the object to be charged 100, and in response to the request for power reduction, reduces the power supplied to the object to be charged 100 from P1a to P2a. The power P2a corresponds to the target power P2 shown in FIG. 4. The object to be charged 100 has the received power reduced from P1a to P2a, and accordingly, the charging speed of the battery 131 decreases from V1 to V2. The object to be charged 100 starts transmitting the state information indicating the received power P2a (<P1a) to the charging device 1. The charging device 1 receives the state information from the object to be charged 100, and determines that the decrease amount of the received power of the object to be charged 100 per unit time in the state information is not less than a predetermined power amount ΔP1, and increases the rotation speed of the fan 23 from RN1 to RN2. Thereby, the cooling capacity of the air cooling structure is improved, and the temperature around the battery 131 starts to decrease.

[0057] At timing t2, when the detected temperature of the temperature sensor 121 of the object to be charged 100 falls below the threshold temperature of the temperature protection function and decreases to T2, the temperature protection function is released, and a request for power increase is transmitted to the charging device 1. The charging device 1 receives the request for power increase from the object to be charged 100, and in response to the request for power increase, increases the power supplied to the object to be charged 100 from P2a to P1a. The object to be charged 100 has the received power increased from P2a to P1a, and accordingly, the charging speed of the battery 131 increases from V2 to V1. The object to be charged 100 starts transmitting the state information indicating the received power P1a to the charging device 1. The charging device 1 receives the state information from the object to be charged 100, and determines that the increase amount of the received power of the object to be charged 100 per unit time in the state information is not less than a predetermined power amount ΔP2, and decreases the rotation speed of the fan 23 from RN2 to RN1. Thereby, the cooling capacity of the air cooling structure decreases, and the temperature around the battery 131 starts to increase.

[0058] At timings t3 to t6, the same operations as those at timings t1 and t2 are repeated.

[0059] At timing t7, when the charge amount of the battery 131 reaches C7a and exceeds the threshold charge amount for full charge, the object to be charged 100 may determine that the battery 131 has reached a fully charged state and transmit a charge completion notification to the charging device 1. When the charging device 1 receives the charge completion notification from the object to be charged 100, it stops power transmission to the object to be charged 100 and stops the fan 23. On the other hand, when the charging device 1 receives a request to reduce power from the object to be charged 100 instead of the charge completion notification, it continues power transmission to the object to be charged 100 at low power (for example, power close to 0 W) and continues driving the fan 23.

[0060] As shown in Fig. 4, the rotation speed of the fan 23 can be temporarily increased during the periods from t1 to t2, from t3 to t4, and from t5 to t6, temporarily improving the cooling capacity of the air-cooling structure and disabling the temperature protection function. This allows high-speed power transmission in accordance with the Qi standard during the periods from t2 to t3, from t4 to t5, and from t6 to t7, thereby improving the charging speed of wireless charging. Furthermore, the rotation speed of the fan 23 can be returned to a normal rotation speed during the periods from t2 to t3, from t4 to t5, and from t6 to t7, thereby reducing noise from the fan 23 of the charging device 1. Furthermore, since the increase in the rotation speed of the fan 23 can be suppressed, the power consumption required to drive the fan 23 can be reduced.

[0061] 4, for comparison, the dotted line indicates the charge amount of battery 131 when the rotation speed of fan 23 is maintained at the steady state RN1 after time t1. In this case, high-speed power transmission according to the Qi standard is not performed after time t1, so the charging rate from time t1 to time t7 remains reduced to V2. Therefore, at time t7, the charge amount is C7, which is less than the threshold charge amount for full charge, and charging device 1 has not yet reached the full charge state.

[0062] As described above, in this embodiment, the charging device 1 receives status information related to the received power from the object to be charged 100, and controls the rotation speed of the fan 23 according to the status information. This allows for efficient air cooling, thereby achieving both high-speed wireless charging and suppression of noise from the fan 23.

[0063] Furthermore, in this embodiment, the charging device 1 controls the rotation speed of the fan 23 in accordance with the state information and can suppress an increase in the rotation speed of the fan 23, thereby achieving both high-speed wireless charging and reduced power consumption.

[0064] The status information regarding the received power may include information indicating the received power, or may include information indicating the required power.

[0065] Alternatively, the charging device 1 may have a fixed-coil wireless charging function instead of the moving-type wireless charging function illustrated in FIG. 1 . In this case, the charging device 1 omits the coil moving mechanism 17 and the position detection coil 18. One or more coils 16 are provided, and if more than one coil 16 is provided, the coils 16 are arranged in the X and Y directions. The position detection circuit 20 energizes the multiple coils 16a and observes the response, thereby determining the coil 16 that is closest to the coil 116 among the multiple coils 16a. The controller 22 can selectively energize the determined coil 16 via the DC-DC converter circuit 12 and the bridge circuit 13.

[0066] Alternatively, the air-cooling structure of the charging device 1 may be a structure different from the structure exemplified in Fig. 1. For example, the air flow may be reversed from that in Fig. 1, and the fan 23 may draw air from the outside and send it into the housing 2. The housing 2 may be provided with an air outlet on the -X side that extends to the Z height of the object to be charged 100 and faces the object to be charged 100, and a flow path may be provided from inside the housing 2 to the air outlet. In this case, air can be sent to the vicinity of the housing of the object to be charged 100, and the object to be charged 100 can be directly air-cooled.

[0067] Alternatively, when increasing the rotation speed of the fan 23, the controller 22 may increase it in stages from RN1 to RN2. The controller 22 may increase the rotation speed of the fan 23 in N stages from RN1 to RN2, where N is an integer equal to or greater than 3. This makes it possible to suppress noise caused by fluctuations in airflow when the rotation speed of the fan 23 increases.

[0068] Alternatively, when reducing the rotation speed of the fan 23, the controller 22 may reduce it in stages from RN2 to RN1. The controller 22 may reduce the rotation speed of the fan 23 in M ​​stages from RN2 to RN1, where M is an integer equal to or greater than 3. This makes it possible to suppress noise caused by fluctuations in airflow when the rotation speed of the fan 23 is reduced.

[0069] Alternatively, when increasing the rotation speed of the fan 23, the controller 22 may increase it in stages from RN1 to RN2, and when decreasing the rotation speed of the fan 23, the controller 22 may decrease it in stages from RN2 to RN1. The controller 22 may increase the rotation speed of the fan 23 in N stages from RN1 to RN2, or may decrease the rotation speed of the fan 23 in M ​​stages from RN2 to RN1. N is an integer greater than or equal to 3, and M is an integer greater than or equal to 3. N and M may be the same or different from each other. This makes it possible to suppress noise caused by fluctuations in airflow when the rotation speed of the fan 23 increases and decreases.

[0070] Alternatively, as a first modified example of the embodiment, the charging device 1 may perform control taking into consideration the negotiated power.

[0071] For example, in the charging device 1, the controller 22 may increase the rotation speed of the fan 23 if it detects, according to the status information at the start of charging, that the received power of the chargeable object 100 is lower than the negotiated power. According to the Qi standard, before starting power transmission to the chargeable object 100, the charging device 1 mutually transmits and receives information regarding the transmittable power level, negotiates, and determines the negotiated power. The negotiated power may be the maximum value of the effective power that can be transmitted from the charging device 1 to the chargeable object 100. If the received power of the chargeable object 100 is lower than the negotiated power at the start of charging, it is expected that the temperature protection function of the chargeable object 100 will be activated immediately after the start of charging.

[0072] The controller 22 controls the rotation speed of the fan 23 to RN1 during steady state operation. The controller 22 acquires status information related to the received power from the object to be charged 100. When the received power specified according to the status information is lower than the negotiated power at the start of charging, the controller 22 increases the rotation speed of the fan 23 to RN2 (>RN1). As a result, when there is a possibility that the temperature of the object to be charged 100 is higher than the threshold temperature of the temperature protection function from the start of charging, the rotation speed of the fan 23 is increased, thereby making it possible to increase the cooling capacity of the air-cooling structure.

[0073] In this case, the charging device 1 may perform operations that differ from those of the embodiment in the following respects, as shown in Fig. 5. Fig. 5 is a flowchart showing the operation of the charging device 1 according to a first modified example of the embodiment.

[0074] After steps S1 to S4 are performed in the same manner as in the embodiment, when a predetermined period has elapsed, the charging device 1 receives status information from the object to be charged 100. According to the status information, the charging device 1 determines whether or not there is a difference between the received power of the object to be charged 100 and the negotiated power (S21).

[0075] The charging device 1 calculates the difference between the received power and the negotiated power indicated in the status information, and if the difference is smaller than the threshold difference Dth, it determines that the received power of the object to be charged 100 is no different from the negotiated power (No in S21) and has not detected that the received power of the object to be charged 100 is lower than the negotiated power, and proceeds to S5.

[0076] The charging device 1 calculates the difference between the received power indicated by the status information and the negotiated power, and if the difference is equal to or greater than the threshold difference Dth, it determines that there is a difference between the received power of the object to be charged 100 and the negotiated power (Yes in S21) and that the received power of the object to be charged 100 is lower than the negotiated power, and proceeds to S7. As a result, if the object to be charged 100 is not fully charged (No in S7), the charging device 1 increases the rotation speed of the fan 23 (S9). Thereafter, S10 to S13 are performed in the same manner as in the embodiment.

[0077] As described above, in the first modified example of the embodiment, when the charging device 1 detects that the received power of the object to be charged 100 is lower than the negotiated power according to the status information at the start of charging, the controller 22 increases the rotation speed of the fan 23. As a result, when there is a possibility that the temperature of the object to be charged 100 is higher than the threshold temperature of the temperature protection function from the start of charging, the rotation speed of the fan 23 is increased, thereby making it possible to increase the cooling capacity of the air-cooling structure.

[0078] Alternatively, as a second modification of the embodiment, the charging device 1 may perform control taking into consideration the temperature detected by the temperature sensor 24.

[0079] For example, in the charging device 1, the controller 22 may detect a decrease in the received power of the object to be charged 100 according to the status information and maintain the rotation speed of the fan 23 when the temperature detected by the temperature sensor 24 is lower than the threshold temperature Tth1. The object to be charged 100 may have a battery-assisted charging function. The battery-assisted charging function is activated even when the temperature of the object to be charged 100 is lower than the threshold temperature of the temperature protection function. When the temperature detected by the temperature sensor 24 is lower than the threshold temperature Tth1, it is expected that the temperature of the object to be charged 100 is lower than the threshold temperature of the temperature protection function. The threshold temperature Tth1 can be experimentally determined in advance as a temperature indicating that the temperature of the object to be charged 100 is lower than the threshold temperature of the temperature protection function.

[0080] The controller 22 controls the rotation speed of the fan 23 to RN1 during normal operation. The controller 22 acquires status information related to the received power from the object to be charged 100. When the controller 22 detects a decrease in the received power of the object to be charged 100 according to the status information and the temperature detected by the temperature sensor 24 is lower than the threshold temperature Tth1, the controller 22 assumes that the temperature of the object to be charged 100 is lower than the threshold temperature of the temperature protection function, determines that the carious charging function has been activated in the object to be charged 100, and maintains the rotation speed of the fan 23 at RN1. This makes it possible to prevent the rotation speed of the fan 23 from increasing during carious charging.

[0081] Furthermore, after increasing the rotation speed of the fan 23, if the controller 22 detects an increase in the received power of the object to be charged 100 according to the state information and the temperature detected by the temperature sensor 24 is equal to or higher than the threshold temperature Tth1, the controller 22 may maintain the rotation speed of the fan 23. Even if an increase in the received power of the object to be charged 100 is detected, if the temperature detected by the temperature sensor 24 is equal to or higher than the threshold temperature Tth1, it is expected that the temperature of the object to be charged 100 has not dropped sufficiently.

[0082] The controller 22 controls the rotation speed of the fan 23 to RN1 during steady state operation. The controller 22 detects a decrease in the received power when the amount of decrease in the received power of the device to be charged 100 per unit time becomes equal to or greater than a predetermined power amount ΔP1. When the controller 22 detects a decrease in the received power of the device to be charged 100, the controller 22 increases the rotation speed of the fan 23 to RN2 (>RN1). The controller 22 starts counting the timer after increasing the rotation speed of the fan 23 to RN2. The controller 22 detects an increase in the received power when the amount of increase in the received power of the device to be charged 100 per unit time according to the status information becomes equal to or greater than a predetermined power amount ΔP2. The controller 22 maintains the rotation speed of the fan 23 at RN2 until the count time of the timer exceeds time TM1, provided that the controller 22 detects an increase in the received power of the device to be charged 100 according to the status information and the temperature detected by the temperature sensor 24 is equal to or greater than a threshold temperature Tth1. This allows the rotation speed of the fan 23 to continue to increase, and the cooling capacity of the air-cooled structure to continue to increase, when the temperature of the object to be charged 100 is temporarily lower than the threshold temperature of the temperature protection function but there is a possibility that it will soon rise above that threshold temperature.

[0083] In this case, the charging device 1 may perform operations that differ from those of the embodiment in the following respects, as shown in Fig. 6. Fig. 6 is a flowchart showing the operation of the charging device 1 according to a second modification of the embodiment.

[0084] After steps S1 to S6 are performed in the same manner as in the embodiment, if the object to be charged 100 is not in a fully charged state (No in S7), the charging device 1 determines whether the temperature detected by the temperature sensor 24 is equal to or higher than the threshold temperature Tth1 (S31).

[0085] If the temperature detected by the temperature sensor 24 is not equal to or higher than the threshold temperature Tth1 (No in S31), the charging device 1 determines that the battery-friendly charging function is activated, and returns the process to S5 while maintaining the rotation speed of the fan 23.

[0086] If the temperature detected by the temperature sensor 24 is equal to or higher than the threshold temperature Tth1 (Yes in S31), the charging device 1 determines that the battery-friendly charging function is not activated, increases the rotation speed of the fan 23 (S9), and then performs S10 to S12 in the same manner as in the embodiment.

[0087] If the increase in the received power per unit time is equal to or greater than a predetermined amount of power ΔP2, the charging device 1 determines that the received power of the object to be charged 100 is increasing (Yes in S11) and determines whether the temperature detected by the temperature sensor 24 is equal to or greater than the threshold temperature Tth1 (S32).

[0088] If the temperature detected by the temperature sensor 24 is equal to or higher than the threshold temperature Tth1 (Yes in S32), the charging device 1 determines that the temperature of the object to be charged 100 has not dropped sufficiently, maintains the rotation speed of the fan 23 at RN2 (S10), and makes the judgment of S11 again.

[0089] If the temperature detected by the temperature sensor 24 is lower than the threshold temperature Tth1 (No in S32), the charging device 1 determines that the temperature of the object to be charged 100 has dropped sufficiently, reduces the rotation speed of the fan 23 from RN2 to RN1 (S13), and returns the process to S5.

[0090] As described above, in the second modified example of the embodiment, the charging device 1 detects a decrease in the received power of the object to be charged 100 according to the state information, and when the temperature detected by the temperature sensor 24 is lower than the threshold temperature Tth1, the charging device 1 maintains the rotation speed of the fan 23. This makes it possible to prevent the rotation speed of the fan 23 from increasing in the case of battery-friendly charging.

[0091] In addition, in the second modified example of the embodiment, the charging device 1 detects an increase in the received power of the object to be charged 100 according to the state information after increasing the rotation speed of the fan 23, and if the temperature detected by the temperature sensor 24 is equal to or higher than the threshold temperature Tth1, the charging device 1 maintains the rotation speed of the fan 23. As a result, when the temperature of the object to be charged 100 is temporarily lower than the threshold temperature of the temperature protection function but may soon rise above the threshold temperature, the rotation speed of the fan 23 can be continuously increased, and the cooling capacity of the air-cooling structure can be continuously improved.

[0092] Alternatively, as a third modified example of the embodiment, the charging device 1 may perform a control that combines the control of the first modified example of the embodiment and the control of the second modified example of the embodiment.

[0093] In this case, the charging device 1 may perform operations that differ from those of the embodiment in the following respects, as shown in Fig. 7. Fig. 7 is a flowchart showing the operation of the charging device 1 according to a third modification of the embodiment.

[0094] After steps S1 to S4 are performed in the same manner as in the embodiment, when a predetermined period has elapsed, the charging device 1 receives status information from the object to be charged 100. According to the status information, the charging device 1 determines whether or not there is a difference between the received power of the object to be charged 100 and the negotiated power (S21).

[0095] The charging device 1 calculates the difference between the received power and the negotiated power indicated in the status information, and if the difference is smaller than the threshold difference Dth, it determines that the received power of the object to be charged 100 is no different from the negotiated power (No in S21) and has not detected that the received power of the object to be charged 100 is lower than the negotiated power, and proceeds to S5.

[0096] The charging device 1 calculates the difference between the received power indicated by the status information and the negotiated power, and if the difference is equal to or greater than the threshold difference Dth, it determines that there is a difference between the received power of the object to be charged 100 and the negotiated power (Yes in S21) and that the received power of the object to be charged 100 is lower than the negotiated power, and proceeds to S7. If the object to be charged 100 is not fully charged (No in S7), the charging device 1 determines whether the temperature detected by the temperature sensor 24 is equal to or greater than the threshold temperature Tth1 (S31).

[0097] If the temperature detected by the temperature sensor 24 is not equal to or higher than the threshold temperature Tth1 (No in S31), the charging device 1 determines that the battery-friendly charging function is activated, and returns the process to S5 while maintaining the rotation speed of the fan 23.

[0098] If the temperature detected by the temperature sensor 24 is equal to or higher than the threshold temperature Tth1 (Yes in S31), the charging device 1 determines that the battery-friendly charging function is not activated, increases the rotation speed of the fan 23 (S9), and then performs S10 to S12 in the same manner as in the embodiment.

[0099] If the increase in the received power per unit time is equal to or greater than a predetermined amount of power ΔP2, the charging device 1 determines that the received power of the object to be charged 100 is increasing (Yes in S11) and determines whether the temperature detected by the temperature sensor 24 is equal to or greater than the threshold temperature Tth1 (S32).

[0100] If the temperature detected by the temperature sensor 24 is equal to or higher than the threshold temperature Tth1 (Yes in S32), the charging device 1 determines that the temperature of the object to be charged 100 has not dropped sufficiently, maintains the rotation speed of the fan 23 at RN2 (S10), and makes the judgment of S11 again.

[0101] If the temperature detected by the temperature sensor 24 is lower than the threshold temperature Tth1 (No in S32), the charging device 1 determines that the temperature of the object to be charged 100 has dropped sufficiently, reduces the rotation speed of the fan 23 from RN2 to RN1 (S13), and returns the process to S5.

[0102] As described above, in the third modified example of the embodiment, when the charging device 1 detects that the received power of the object to be charged 100 is lower than the negotiated power according to the status information at the start of charging, it increases the rotation speed of the fan 23. As a result, when there is a possibility that the temperature of the object to be charged 100 is higher than the threshold temperature of the temperature protection function from the start of charging, the rotation speed of the fan 23 is increased, thereby making it possible to increase the cooling capacity of the air-cooling structure.

[0103] In a third modified example of the embodiment, the charging device 1 detects a decrease in the received power of the object to be charged 100 according to the state information, and when the temperature detected by the temperature sensor 24 is lower than the threshold temperature Tth1, the charging device 1 maintains the rotation speed of the fan 23. This makes it possible not to increase the rotation speed of the fan 23 in the case of battery-friendly charging.

[0104] Furthermore, in a third modified example of the embodiment, the charging device 1 detects an increase in the received power of the object to be charged 100 according to the state information after increasing the rotation speed of the fan 23, and if the temperature detected by the temperature sensor 24 is equal to or higher than the threshold temperature Tth1, the charging device 1 maintains the rotation speed of the fan 23. As a result, when the temperature of the object to be charged 100 is temporarily lower than the threshold temperature of the temperature protection function but may soon rise above the threshold temperature, the rotation speed of the fan 23 can be continuously increased, and the cooling capacity of the air-cooling structure can be continuously improved.

[0105] Alternatively, as a fourth modified example of the embodiment, the charging device 1 may perform control taking into consideration charging efficiency. The charging efficiency is the ratio of the power received by the object to be charged 100 to the power transmitted from the coil 16.

[0106] For example, in the charging device 1, the controller 22 may increase the rotation speed of the fan 23 when it detects that the charging efficiency is lower than the threshold efficiency according to the status information. If the charging efficiency decreases due to misalignment between the coils 116, 16, etc., the object to be charged 100 transmits a request to the charging device 1 to increase power in order to maintain the received power. In response, the charging device 1 increases the transmitted power, which may increase the temperature of the charging device 1, which may also affect the temperature of the object to be charged 100. If the charging efficiency is lower than the threshold efficiency, it is expected that the temperature of the object to be charged 100 will exceed the threshold temperature of the temperature protection function, activating the temperature protection function.

[0107] Furthermore, after increasing the rotation speed of the fan 23, if the controller 22 detects that the charging efficiency is higher than the threshold efficiency according to the state information, the controller 22 may decrease the rotation speed of the fan 23. If the charging efficiency is higher than the threshold efficiency, it is expected that the state in which the temperature of the object to be charged 100 is no longer prone to increase is present.

[0108] The controller 22 controls the rotation speed of the fan 23 to RN1 during steady state operation. The controller 22 acquires status information related to the received power from the device to be charged 100. The controller 22 calculates the transmitted power using the voltage detected by the voltage detection circuit 14 and the current detected by the current detection circuit 15. The controller 22 identifies the received power according to the status information. The controller 22 calculates the charging efficiency as the ratio of the received power to the transmitted power. The controller 22 compares the charging efficiency with a threshold efficiency. If the charging efficiency is lower than the threshold efficiency, the controller 22 increases the rotation speed of the fan 23 to RN2 (>RN1). As a result, when the charging efficiency has deteriorated and the device to be charged 100 is likely to be in a state where its temperature is likely to rise, the cooling performance of the air-cooled structure can be improved by increasing the rotation speed of the fan 23. In addition, increasing the rotation speed of the fan 23 can alert the user to the decrease in charging efficiency.

[0109] After that, the controller 22 obtains state information regarding the received power from the object to be charged 100. The controller 22 calculates the transmitted power using the detected voltage and the detected current, identifies the received power according to the state information, and obtains the charging efficiency using the transmitted power and the received power. When the charging efficiency is higher than the threshold efficiency, the controller 22 reduces the rotation speed of the fan 23 to RN1 (<RN2). As a result, when there is a possibility that the charging efficiency has increased and the temperature of the object to be charged 100 is not likely to rise, by reducing the rotation speed of the fan 23, the noise caused by the driving of the fan 23 can be suppressed, and the power consumption caused by the driving of the fan 23 can be suppressed.

[0110] Further, when the controller 22 does not detect that the charging efficiency is higher than the threshold efficiency according to the state information within the time TM1 after increasing the rotation speed of the fan 23, the controller 22 may reduce the rotation speed of the fan 23. The object to be charged 100 may not be properly arranged on the main surface 2a of the charging device 1 via the charging base 19. For example, although there is a convex portion (see FIG. 1) on the back surface 100b of the object to be charged 100, if this convex portion rides on the step of the charging base 19 and is arranged, the distance between the coil 116 and the coil 16 in the Z direction becomes longer. In this case, it is expected that it is difficult for the charging efficiency to rise to the threshold efficiency.

[0111] During normal operation, the controller 22 controls the rotation speed of the fan 23 to RN1. When the charging efficiency becomes lower than the threshold efficiency according to the state information, the controller 22 increases the rotation speed of the fan 23 to RN2 (>RN1). The controller 22 starts counting the timer after increasing the rotation speed of the fan 23 to RN2. If the charging efficiency does not exceed the threshold efficiency according to the state information until the count time of the timer exceeds the time TM1, assuming that the object to be charged 100 is not properly arranged, the controller 22 reduces the rotation speed of the fan 23 to RN1. As a result, when the object to be charged 100 is not properly arranged, it is possible to prevent the rotation speed of the fan 23 from continuing to increase.

[0112] In this case, the charging device 1 may perform operations that differ from those of the embodiment in the following respects, as shown in Fig. 8. Fig. 8 is a flowchart showing the operation of the charging device 1 according to a fourth modification of the embodiment.

[0113] After steps S1 to S5 are performed in the same manner as in the embodiment, if the object to be charged 100 is not fully charged (No in S7), the charging device 1 calculates the charging efficiency according to the status information and determines whether the charging efficiency has decreased (S41).

[0114] If the charging efficiency is not below the threshold efficiency (No in S41), the charging device 1 determines that the charging efficiency has not decreased and the temperature of the object to be charged 100 is not likely to rise, and returns the process to S5 while maintaining the rotation speed of the fan 23.

[0115] If the charging efficiency is equal to or lower than the threshold efficiency, the charging device 1 determines that the charging efficiency has decreased (Yes in S41) and that the temperature of the object to be charged 100 is likely to rise, so it increases the rotation speed of the fan 23 (S9) and starts counting the timer. The charging device 1 maintains the rotation speed of the fan 23 at RN2 (S10), and after a predetermined period has elapsed, receives status information from the object to be charged 100. The charging device 1 calculates the charging efficiency according to the status information and determines whether the charging efficiency has increased (S42).

[0116] If the charging efficiency is equal to or less than the threshold efficiency, the charging device 1 determines that the charging efficiency has not increased (No in S42) and determines whether or not time TM1 has elapsed since the rotation speed of the fan 23 was increased (S12). The charging device 1 compares the time counted by the timer with time TM1, and if the time counted by the timer does not exceed time TM1, it determines that time TM1 has not elapsed since the rotation speed of the fan 23 was increased (No in S12) and returns the process to S10. If the time counted by the timer exceeds time TM1, the charging device 1 determines that time TM1 has elapsed since the rotation speed of the fan 23 was increased (Yes in S12) and the object to be charged 100 is not properly positioned, so it reduces the rotation speed of the fan 23 from RN2 to RN1 (S13) and returns the process to S5.

[0117] If the charging efficiency is greater than the threshold efficiency, the charging device 1 determines that the charging efficiency has increased (Yes in S42) and that the condition is not such that the temperature of the object to be charged 100 is likely to increase, and reduces the rotation speed of the fan 23 from RN2 to RN1 (S13), and returns the process to S5.

[0118] As described above, in the fourth modified example of the embodiment, when the controller 22 detects that the charging efficiency is lower than the threshold efficiency according to the state information, the controller 22 increases the rotation speed of the fan 23. As a result, when the charging efficiency is reduced and there is a possibility that the temperature of the object to be charged 100 is likely to rise, the cooling performance of the air-cooled structure can be improved by increasing the rotation speed of the fan 23. In addition, by increasing the rotation speed of the fan 23, the user can be made aware of the decrease in charging efficiency.

[0119] Furthermore, in a fourth modified example of the embodiment, if the controller 22 detects that the charging efficiency is higher than the threshold efficiency according to the state information within a time TM1 after increasing the rotation speed of the fan 23, the controller 22 reduces the rotation speed of the fan 23. As a result, when the charging efficiency is high and it is possible that the state in which the temperature of the object to be charged 100 is no longer prone to rise is reached, the rotation speed of the fan 23 is reduced, thereby making it possible to suppress noise caused by driving the fan 23 and power consumption caused by driving the fan 23.

[0120] Furthermore, in a fourth modified example of the embodiment, if the controller 22 does not detect that the charging efficiency is higher than the threshold efficiency according to the state information within a time TM1 after increasing the rotation speed of the fan 23, the controller 22 reduces the rotation speed of the fan 23. This makes it possible to prevent the rotation speed of the fan 23 from continuing to increase if the object to be charged 100 is not appropriately positioned.

[0121] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0122] 1 Charging device 2. Case 16,116 coils 22 Controller 23 Fans 24 Temperature Sensor

Claims

1. a housing in which an object to be charged having a first coil can be placed and which has an air intake port and an air exhaust port; a second coil disposed in the housing and capable of being electromagnetically coupled to the first coil in the object to be charged; a fan disposed in a flow path from the intake port to the exhaust port; a controller that acquires status information related to received power from the object to be charged and controls the rotation speed of the fan in accordance with the status information; A charging device comprising:

2. The controller increases the rotation speed of the fan when detecting a decrease in the power received by the device to be charged according to the state information. The charging device according to claim 1 .

3. a temperature sensor disposed in the housing and configured to detect a temperature; The controller detects a decrease in the power received by the object to be charged according to the state information and maintains the rotation speed of the fan when the temperature detected by the temperature sensor is lower than a threshold value. The charging device according to claim 1 .

4. The controller reduces the rotation speed of the fan when an increase in the received power of the device to be charged is not detected according to the status information within a first time period after increasing the rotation speed of the fan. The charging device according to claim 2 .

5. When the controller detects an increase in the power received by the device to be charged according to the state information after increasing the rotation speed of the fan, the controller reduces the rotation speed of the fan. The charging device according to claim 2 .

6. a temperature sensor disposed in the housing and configured to detect a temperature; The controller detects an increase in the power received by the device to be charged according to the state information after increasing the rotation speed of the fan, and maintains the rotation speed of the fan when the temperature detected by the temperature sensor is higher than a threshold value. The charging device according to claim 2 .

7. When the controller detects that the power received by the device to be charged is lower than the negotiated power according to the status information at the start of charging, the controller increases the rotation speed of the fan. The charging device according to claim 1 .

8. When the controller detects that charging efficiency, which is a ratio of power received by the device to power transmitted from the second coil, is lower than a threshold value according to the state information, the controller increases the rotation speed of the fan. The charging device according to claim 1 .

9. The controller decreases the rotation speed of the fan when detecting that the charging efficiency is higher than a threshold according to the status information after increasing the rotation speed of the fan. The charging device according to claim 8.

10. The controller reduces the rotation speed of the fan if it does not detect that the charging efficiency is higher than a threshold according to the status information within a first time period after increasing the rotation speed of the fan. The charging device according to claim 8.

11. A charging device includes a housing having an air intake port and an air exhaust port in which a charged object having a first coil can be placed, a second coil arranged in the housing and capable of being electromagnetically coupled to the first coil in the charged object, and a fan arranged in a flow path from the air intake port to the air exhaust port, and acquires status information relating to a charging status from the charged object arranged in the housing; controlling the rotation speed of the fan in accordance with the state information; A method for controlling a charging device, comprising:

12. A charging device includes a housing having an air intake port and an air exhaust port in which a charged object having a first coil can be placed, a second coil arranged in the housing and capable of being electromagnetically coupled to the first coil in the charged object, and a fan arranged in a flow path from the air intake port to the air exhaust port, and acquires power information related to charging power from the charged object arranged in the housing; When detecting that a ratio of the power received by the device to the power transmitted from the second coil is lower than a threshold value according to the power information, increasing the rotation speed of the fan; A method for controlling a charging device, comprising:

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