Power transmission control device, power transmitting device, non-contact power transmitting system, and electronic instrument

[0080] (First embodiment)

[0081] figure 1 (A)~figure 1 (C) shows an outline of a configuration example of a non-contact power transmission system that can switch between the switch mode and the automatic mode. figure 1 The non-contact power transmission system of (A) includes: a power transmission side device (for example, a charger (pallet)) 500; a power receiving side device (for example, a mobile phone terminal) 510, which is mounted on the power transmission side device 500 and passes through Contact power transmission charges the secondary battery (battery). The power transmission device 10 is built in the power transmission side equipment 500. In addition, the power receiving device 40 is built in the power receiving device 510. The power receiving device 40 can be mounted on the power receiving device 510 from the outside using an adapter or the like.

[0082] figure 1 (A) The non-contact power transmission system can switch between switch mode and automatic mode. An operation trigger switch SW1 is provided on the end of the main surface of the power receiving device 510, and an automatic mode switch SW2 is provided on the side surface. The automatic mode switch SW2 functions as an operation mode switching switch for switching the operation mode of the power transmission device 10. As the switches SW1 and SW2, for example, mechanical momentary switches can be used. However, it is not limited to this, and various switches such as a relay switch and a magnetic switch can be used.

[0083] The "switch mode" is a mode in which the user can freely determine the timing of the start/end of power transmission by operating the switch SW1. In the case of the switch mode, if a full charge is detected, the normal power transmission by the power transmission device 10 is automatically stopped, and the initial state (the state waiting for the activation of the operation trigger switch SW1) is automatically stopped. In addition, during normal power transmission, if the user presses the action trigger switch SW1, the normal power transmission by the power transmission device 10 is forcibly suspended and returns to the initial state (a state waiting for the action trigger switch SW1 to be turned on).

[0084] On the other hand, the "automatic mode" is a fully automatic mode as described below. That is, if the user loads the power receiving device 510 on the power transmitting device 500, the power transmitting device 10 automatically detects the setting of the power receiving device 510, A series of actions such as temporary power transmission, ID authentication, normal power transmission, detection of removal or foreign matter, detection of full charge, and stop of normal power transmission are automatically performed. In addition, after the full charge is detected and the normal power transmission is stopped, the determination of whether recharging is necessary or not, the start of recharging, and the removal detection after the full charge can be further automatically performed.

[0085] in figure 1 In the non-contact power transmission system of (A), the user can freely select either the switch mode or the automatic mode. The automatic mode switch SW2 functions as an operation mode switching switch for switching the automatic mode on/off. If the automatic mode is selected by the automatic mode switch SW2, the power transmission control device (power transmission control IC) 20 is in the automatic mode. If the automatic mode is not selected, the switch mode is enabled instead. When the automatic mode is selected, the operation trigger switch SW1 is disabled, and even if the operation trigger switch SW1 is pressed, the operation of the power transmission device 10 will not be affected.

[0086] On the other hand, when the automatic mode is not selected (when the automatic mode is cancelled), the switch mode is automatically selected instead. When the switch mode is selected, the action trigger switch SW1 is activated, and every time the user presses the action trigger switch SW1, the power transmission device 10 repeats the start of power transmission or the end of power transmission.

[0087] In the automatic mode, the user only needs to set the power receiving side device 510 on the power transmission side device 500, and no switching operations are required. Therefore, the user has no burden, and the convenience and ease of use of the system are improved.

[0088] On the other hand, in the switch mode, the user can autonomously determine the timing of power transmission start/stop. Therefore, the user can use the system according to his own ideas. In this regard, a highly convenient system can be realized. In addition, in the case of the switch mode, before the user turns on the action trigger switch SW1, no power transmission is performed. In addition, if a full charge is detected, the normal power transmission is stopped and the initial state is returned. Therefore, no power transmission is performed until the action trigger switch SW1 is pressed again. Therefore, unnecessary power consumption does not occur, and power saving can be achieved.

[0089] in figure 1 In the non-contact power transmission system of (B), the automatic mode switch SW2 is built in the power transmission side device 500. That is, in figure 1 In the system of (B), for example, when the manufacturer ships the power transmission side equipment 500, it is determined whether to select the automatic mode. If the automatic mode is selected, a practitioner of the manufacturer operates the automatic mode switch SW2 to activate the automatic mode. In actual use, the user cannot switch the selection/non-selection of the automatic mode. For example, in the case of unspecified multiple users using the system, it is suitable for use figure 1 (B) The system. That is, when the system is used by unspecified multiple users, if each user selects the automatic mode/switch mode, it may cause confusion instead. Therefore, for example, when the product is shipped, the method of determining the automatic mode or the switch mode on the manufacturer's side will not cause confusion, and it is easy to gain an understanding of the system.

[0090] figure 1 (C) The contactless power transmission system is figure 1 (A) A modification of the system. in figure 1 In the system of (C), two automatic mode switches are prepared. That is, the first automatic mode switch SW2a and the second automatic mode switch SW2b are provided on each of the two side surfaces of the power transmission side device 500. That is, in figure 1 In the system of (C), the type of automatic mode can be selected.

[0091] The automatic mode selected by the first automatic mode switch SW2a is the mode described below, that is, automatic detection, temporary power transmission, ID authentication, normal power transmission, removal or foreign object removal, for example, the setting of the power receiving device 510 is fully automated. A series of actions such as detection, detection of full charge, and stop of normal power transmission. The automatic mode selected by the second automatic mode switch SW2b is a mode that also automatically performs recharging management after full charging. For example, if the second automatic mode is selected through the second automatic mode switch SW2b, the power transmission device 10 automatically performs a series of actions including the following actions, namely, automatic detection of the settings of the power receiving device 510, temporary power transmission, and ID authentication , Detection of normal power transmission, removal or foreign matter, detection of full charge, stop of normal power transmission, determination of the need for recharging after full charge, start of recharging, and removal detection after full charge.

[0092] After being fully charged, the user who is scheduled to use the power receiving device 510 immediately turns on the first automatic mode switch SW2a when using the automatic mode. The user who is scheduled to place the power receiving device 510 for a long time turns on the second automatic mode switch SW2b. In this way, the type of automatic mode can be used according to the user's use form. In addition, the types of automatic modes are not limited to the above examples. You can also set more than three automatic modes, and increase the number of automatic mode switches according to the automatic mode. In addition, it is also possible to set an automatic mode that only performs recharge monitoring after a full charge. That is, the automatic mode corresponding to the second automatic mode switch SW2b can be designated as the automatic mode for recharging management after full charging. For example, a predetermined user who has placed the portable terminal for a long period of time sets the portable terminal on the power transmission side device 500 and turns on the second automatic mode switch SW2b. If the battery of the portable terminal is discharged and needs to be recharged, the portable terminal is automatically recharged. Therefore, the battery of the portable terminal can always be kept in a fully charged state.

[0093] Hereinafter, examples of preferred electronic devices to which the present invention is applied and the principle of contactless power transmission technology will be described.

[0094] (Examples of electronic devices and the principle of non-contact power transmission)

[0095] figure 2 (A)~ figure 2 (C) It is used to explain an example of an electronic device to which a non-contact power transmission method is applied, and the principle of non-contact power transmission using an induction transformer. Such as figure 2 (A), figure 2 As shown in (B), a charger (pallet) 500 as a power transmission side electronic device includes a power transmission device (a power transmission module including a power transmission side control circuit (power transmission side control IC), etc.) 10.

[0096] In addition, the charger (pallet) 500 includes: an action trigger switch SW1, which provides an opportunity (opportunity, trigger) to start and stop power transmission; an automatic mode switch SW2; and a display unit (LED, etc.) 16, which is used when the charger is transmitting power The light is on, and the automatic mode/switch mode can be recognized by changing the luminous color.

[0097] in figure 2 In the charger (pallet) 500 of (A), the action trigger switch SW1 is provided outside the area where the power receiving side electronic device (mobile phone terminal) 510 is mounted. The user who wants to charge the mobile phone terminal 510 presses the action trigger switch SW1 in a state where the automatic mode is not selected. In this way, with this as an opportunity (start), power transmission from the power transmission device 10 (temporary power transmission for position detection and ID authentication) is started. In addition, if the action trigger switch SW1 is pressed during power transmission (including temporary power transmission and normal power transmission), the power transmission is forcibly stopped.

[0098] In addition, in figure 2 In the charger (pallet) 500 of (B), the action trigger switch SW1 is provided in the area where the power receiving device (mobile phone terminal) 510 is mounted. Therefore, if the mobile phone terminal 510 is mounted on the charger (pallet) 500, the action trigger switch SW1 is automatically pressed (turned on) based on the weight of the charger (pallet) 500. Taking this as an opportunity, power transmission from the charger (pallet) 500 (temporary power transmission for position detection or ID authentication) is started. In addition, during power transmission (including temporary power transmission and normal power transmission), if the action trigger switch SW1 is pressed again (for example, after the mobile phone terminal 510 is picked up, the action trigger switch SW1 is pressed by setting the mobile phone terminal again) , The power transmission is forcibly stopped.

[0099] figure 2 (B) The situation shown is also the same as figure 2 As in the case shown in (A), the action trigger switch SW1 has the function of giving an opportunity (start) to the start of power transmission, and is not used to detect the presence of the mobile phone terminal 510 (basically, the mobile phone terminal is judged based on the induced voltage of the primary coil The removal of 510 will be described later). However, this does not exclude that the action trigger switch SW1 also has a function of detecting the presence of the mobile phone terminal 510.

[0100] The mobile phone terminal 510 as a power-receiving device includes a power-receiving device (a power-receiving module including a power-receiving-side control circuit (power-receiving-side control IC), etc.) 40. The mobile phone terminal 510 includes a display unit 512 such as an LCD, an operation unit 514 composed of buttons and the like, a microphone 516 (sound input unit), a speaker 518 (sound output unit), and an antenna 520.

[0101] The charger 500 is supplied with power through the AC adapter 502. This power is transmitted from the power transmission device 10 to the power receiving device 40 by non-contact power transmission. Thereby, it is possible to charge the battery of the mobile phone terminal 510 or to operate the devices in the mobile phone terminal 510.

[0102] Such as figure 2 As shown schematically in (C), the power transmission from the power transmission device 10 to the power receiving device 40 is achieved by electromagnetically coupling the primary coil L1 (transmission coil) and the secondary coil L2 (receiving coil) to form a power transmission transformer Yes, the primary coil L1 is provided on the power transmission device 10 side, and the secondary coil L2 is provided on the power receiving device 40 side. As a result, non-contact power transmission can be realized.

[0103]In addition, the electronic device to which this embodiment is applied is not limited to the mobile phone terminal 510. For example, it can also be applied to various electronic devices such as watches, cordless phones, electric razors, electric toothbrushes, wrist computors, portable terminals, portable information terminals, or electric bicycles.

[0104] As an example of a particularly preferable electronic device, a portable terminal (including a portable telephone terminal, a PDA terminal, and a portable personal computer terminal) or a watch can be cited. The power receiving device of the present invention can be mounted on a portable terminal or the like due to its simple structure and small size. Due to its low loss, for example, the charging time of the secondary battery in electronic equipment can be shortened, and the heat generation is also reduced. Improve the reliability of the safety surface of electronic equipment.

[0105] In particular, portable terminals (including portable phone terminals, PDA terminals, and portable personal computer terminals) have an increased charging current under high load and are also prone to heat generation problems. Therefore, it can be said that it is a device that can fully utilize the low loss and low heat generation characteristics of the present invention.

[0106] (Example of internal structure of power transmission device and power receiving device)

[0107] image 3 It is a circuit diagram showing an example of the specific structure of each part in a non-contact power transmission system including a power transmission device and a power receiving device. As shown in the figure, the power transmission device 10 includes a power transmission control device 20, a power transmission unit 12, a waveform monitoring circuit 14, an action trigger switch SW1, and an automatic mode switch SW2. In addition, the power transmission control device 20 includes a power transmission side control circuit 22, an oscillation circuit 24, a drive control circuit 26, and a waveform detection circuit 28.

[0108] In addition, the power receiving device 40 is provided with a power receiving unit 42, a load modulation unit 46, a power supply control unit 48, and a power receiving control device 50. In addition, the load 90 includes a charging control device 92 and a storage battery (secondary battery) 94. Hereinafter, it will be specifically explained. The electronic equipment on the transmission side such as the charger 500 includes at least image 3 The power transmission device 10 is shown. In addition, the electronic equipment on the power receiving side such as the mobile phone terminal 510 includes at least the power receiving device 40 and the load 90. In addition, according to image 3 The structure shown can realize the following non-contact power transmission (non-contact power transmission) system, that is, the primary coil L1 and the secondary coil L2 are electromagnetically coupled to transmit power from the power transmission device 10 to the power receiving device 40 , A non-contact power transmission system that supplies power (voltage VOUT) from the voltage output node NB6 of the power receiving device 40 to the load 90.

[0109] The power transmission device 10 (power transmission module, primary module) may include a primary coil L1, a power transmission unit 12, a waveform monitoring circuit 14, a display unit 16, and a power transmission control device 20. In addition, the power transmission device 10 or the power transmission control device 20 is not limited to image 3 The structure shown can also be implemented in various modifications such as omitting a part of its structural elements (for example, a display unit, a waveform monitoring circuit), adding other structural elements, or changing the connection relationship. The power transmission unit 12 generates an AC voltage with a predetermined frequency during power transmission, and during data transmission, generates an AC voltage with a different frequency based on the data, and supplies it to the primary coil L1.

[0110] Figure 4 (A) and Figure 4 (B) An example for explaining the principle of information transmission between the power transmission side equipment and the power reception side equipment. Frequency modulation is used in the transmission of information from the primary side to the secondary side. In addition, load modulation is used in the transmission of information from the secondary side to the primary side. Such as Figure 4 As shown in (A), when data "1" is transmitted from the power transmission device 10 to the power receiving device 40, an AC voltage of frequency f1 is generated, and when data "0" is transmitted, an AC voltage of frequency f2 is generated. In addition, such as Figure 4 As shown in (B), the power receiving device 40 can switch between the low load state and the high load state by load modulation, and thereby, "0" and "1" can be transmitted to the primary side (power transmission device 10).

[0111] back to image 3 Continue with the description. image 3 The power transmission unit 12 may include: a first power transmission driver for driving one end of the primary coil L1; a second power transmission driver for driving the other end of the primary coil L1; and at least one of the primary coil L1 together to form a resonance circuit Capacitor. In addition, the first power transmission driver and the second power transmission driver included in the power transmission unit 12 are inverter circuits (or buffer circuits) composed of, for example, power MOS transistors, and are controlled by the drive control circuit 26 of the power transmission control device 20.

[0112] The primary coil L1 (power transmission side coil) and the secondary coil L2 (power reception side coil) are electromagnetically coupled to form a power transmission transformer. For example, when power transmission is required, such as figure 1 As shown, the mobile phone terminal 510 is placed on the charger 500, and the magnetic flux of the primary coil L1 passes through the secondary coil L2. On the other hand, when power transmission is not required, the charger 500 and the mobile phone terminal 510 are physically separated, and the magnetic flux of the primary coil L1 does not pass through the secondary coil L2.

[0113] The waveform monitoring circuit 14 is a circuit for detecting the induced voltage of the primary coil L1, and includes, for example, resistors RA1, RA2, and a diode DA1 between the connection node NA3 and GND (low potential side power supply in a broad sense) of RA1 and RA2. Specifically, the signal PHIN obtained by dividing the induced voltage of the primary coil by the resistors RA1 and RA2 is input to the waveform detection circuit 28 of the power transmission control device 20.

[0114] The display unit 16 displays various states of the contactless power transmission system (power transmission, ID authentication, etc.) using colors, images, etc., for example, by LED (light emitting diode) or LCD (liquid crystal display).

[0115] The power transmission control device 20 is a device for performing various controls of the power transmission device 10, and can be realized by an integrated circuit device (IC) or the like. The power transmission control device 20 includes a power transmission side control circuit 22, an oscillation circuit 24, a drive control circuit 26, and a waveform detection circuit 28.

[0116] In addition, the power transmission side control circuit 22 is used to control the power transmission device 10 or the power transmission control device 20, and is realized by, for example, a gate array or a microcomputer.

[0117] Specifically, the power transmission side control circuit 22 performs various sequence control or judgment processing required for power transmission, load detection, frequency modulation, foreign object detection, or loading and unloading detection. As described above, the power transmission side control circuit 22 uses the opening of the switch (SW) as an opportunity to start temporary power transmission for position detection or ID authentication of the power receiving device 40 (described later).

[0118] The oscillation circuit 24 is composed of, for example, a crystal oscillation circuit, and generates a clock signal on the primary side. The drive control circuit 26 generates a control signal of a desired frequency based on a clock signal generated by the oscillation circuit 24 or a frequency setting signal from the control circuit 22, and outputs the control signal to the power transmission driver (not shown) of the power transmission unit 12 to control The action of the transmission driver.

[0119] The waveform detection circuit 28 monitors the waveform of the signal PHIN corresponding to the induced voltage at one end of the primary coil L1, and performs load detection, foreign object detection, and the like. For example, if the load modulation unit 46 of the power receiving device 40 performs load modulation for transmitting data to the power transmission device 10, the signal waveform of the induced voltage of the primary coil L1 changes accordingly.

[0120] Specifically, such as Figure 4 As shown in (B), if the load modulation section 46 of the power receiving device 40 reduces the load in order to transmit data "0", the amplitude (peak voltage) of the signal waveform becomes smaller, and if the load is increased in order to transmit data "1", Then the amplitude of the signal waveform increases. Therefore, the waveform detection circuit 28 performs peak hold processing of the signal waveform of the induced voltage, etc., to determine whether the peak voltage exceeds the threshold voltage, and can determine whether the data from the power receiving device 40 is "0" or "1". In addition, the method of waveform detection is not limited to the above-mentioned method. For example, physical quantities other than the peak voltage can be used to determine whether the load on the power receiving side has increased or decreased.

[0121] The power receiving device 40 (power receiving module, secondary module) may include a secondary coil L2, a power receiving unit 42, a load modulation unit 46, a power supply control unit 48, and a power receiving control device 50. In addition, the power receiving device 40 or the power receiving control device 50 is not limited to image 3 The structure shown can be implemented in various modifications such as omitting a part of its structural elements, adding its structural elements, or changing the connection relationship.

[0122] The power receiving unit 42 converts the AC induced voltage of the secondary coil L2 into a DC voltage. This conversion is performed by the rectifier circuit 43 included in the power receiving unit 42. The rectifier circuit 43 includes diodes DB1 to DB4. The diode DB1 is arranged between the node NB1 at one end of the secondary coil L2 and the DC voltage VDC generating node NB3, DB2 is arranged between the node NB3 and the node NB2 at the other end of the secondary coil L2, and DB3 is arranged between the nodes NB2 and VSS Between the nodes NB4, DB4 is set between the nodes NB4 and NB1.

[0123] The resistors RB1 and RB2 of the power receiving unit 42 are provided between the nodes NB1 and NB4. In addition, a signal CCMPI is input to the frequency detection circuit 60 of the power reception control device 50, and the signal CCMPI is a signal obtained by dividing the voltage between the nodes NB1 and NB4 by the resistors RB1 and RB2.

[0124] The capacitor CB1 and the resistances RB4 and RB5 of the power receiving unit 42 are provided between the node NB3 of the DC voltage VDC and the node NB4 of the VSS. In addition, the divided voltage VD4 obtained by dividing the voltage between the voltages between the nodes NB3 and NB4 by the resistors RB4 and RB5 is input to the power receiving-side control circuit 52 and the position detection circuit 56 via the signal line LP2. Regarding the position detection circuit 56, the divided voltage VD4 is a signal input (ADIN) for position detection.

[0125] The load modulation unit 46 performs load modulation processing. Specifically, when the desired data is transmitted from the power receiving device 40 to the power transmitting device 10, the load in the load modulation section 46 (secondary side) is variably changed according to the transmission data, so that the induced voltage of the primary coil L1 is reduced The signal waveform changes. Therefore, the load modulation section 46 includes a resistor RB3 and a transistor TB3 (N-type CMOS transistor) which are connected in series between the nodes NB3 and NB4.

[0126] The transistor TB3 is turned on and off by a control signal P3Q which is given from the power receiving side control circuit 52 of the power receiving control device 50 via the signal line LP3. In the authentication stage before the start of normal power transmission, when the load is modulated by the on/off control transistor TB3 and a signal is sent to the power transmission device, the transistor TB2 of the power supply control unit 48 is turned off, and the load 90 is electrically connected to the power receiving device 40 status.

[0127] For example, when the secondary side is set to a low load (large impedance) in order to transmit data "0", the signal P3Q becomes the L level, and the transistor TB3 is turned off. As a result, the load of the load modulation unit 46 becomes almost infinite (no load). On the other hand, when the secondary side has a high load (small impedance) in order to transmit data "1", the signal P3Q becomes the H level, and the transistor TB3 is turned on. Thus, the load of the load modulation unit 46 is the resistance RB3 (high load).

[0128] The power supply control unit 48 controls power supply to the load 90. The voltage regulator (LDO) 49 adjusts the level of the DC voltage VDC obtained by conversion in the rectifier circuit 43 to generate a power supply voltage VD5 (for example, 5V). For example, the power supply voltage VD5 is supplied to the power reception control device 50, and the power reception control device 50 operates.

[0129] In addition, between the input terminal and the output terminal of the regulator (LDO) 49, a switch circuit composed of a PMOS transistor (M1) is provided. By turning on the PMOS transistor (M1) as the switching circuit, a path of a bypass regulator (LDO) 49 is formed. For example, when the load is high (for example, in the early stage of charging a rechargeable battery that consumes a lot, a substantially constant large current needs to flow stably, which is equivalent to high load), the equivalent of the regulator 49 itself Impedance, power loss and heat generation increase, so the regulator bypasses the bypass path to provide current to the load.

[0130] In order to control the on/off of the PMOS transistor (M1) as a switch circuit, an NMOS transistor (M2) and a pull-up resistor R8 functioning as a bypass control circuit are provided.

[0131] When a high-level control signal is applied to the gate of the NMOS transistor (M2) from the power receiving control circuit 52 via the signal line LP4, the NMOS transistor (M2) is turned on. Then, the gate of the PMOS transistor (M1) becomes a low level, the PMOS transistor (M1) is turned on, and a path for bypassing the regulator (LDO) 49 is formed. On the other hand, when the NMOS transistor (M2) is in the off state, the gate of the PMOS transistor (M1) is maintained at a high level by the pull-up resistor R8. Therefore, the PMOS transistor (M1) is off and does not form a bypass path.

[0132] The on/off of the NMOS transistor (M2) is controlled by the power receiving side control circuit 52 included in the power receiving control device 50.

[0133] In addition, the transistor TB2 (P-type CMOS transistor) is provided between the generation node NB5 (the output node of the regulator 49) and the node NB6 (the voltage output node of the power receiving device 40) of the power supply voltage VD5, and is controlled by the power receiving The signal P1Q of the power receiving side control circuit 52 of the device 50 is controlled. Specifically, the transistor TB2 is turned on when the ID authentication is completed (established) and normal power transmission (that is, normal power transmission) is performed.

[0134] In addition, a pull-up resistor RU2 is provided between the power supply voltage generating node NB5 and the node NB8 of the gate of the transistor TB2.

[0135] The power receiving control device 50 is a device for performing various controls of the power receiving device 40, and can be realized by an integrated circuit device (IC) or the like. The power reception control device 50 can be operated by the power supply voltage VD5 generated based on the induced voltage of the secondary coil L2. In addition, the power receiving control device 50 may include a control circuit 52 (power receiving side), a position detection circuit 56, an oscillation circuit 58, a frequency detection circuit 60, a full charge detection circuit 62, and a recharge monitoring circuit 64.

[0136] The power-receiving-side control circuit 52 is used to control the power-receiving device 40 or the power-receiving control device 50, and may be realized by a gate array or a microcomputer, for example. The power-receiving-side control circuit 52 operates with a constant voltage (VD5) at the output terminal of a series regulator (LDO) 49 as a power source. This power supply voltage (VD5) is supplied to the power receiving side control circuit 52 via the power supply line LP1.

[0137] The power-receiving-side control circuit 52 performs various timing control or judgment processing required, specifically, including ID authentication, position detection, frequency detection, full charge detection, judgment of whether recharging is required, and communication load for authentication. Modulation, load modulation for communication that can detect foreign body insertion, etc.

[0138] The position detection circuit 56 monitors the waveform of the signal ADIN corresponding to the waveform of the induced voltage of the secondary coil L2, and determines whether the positional relationship between the primary coil L1 and the secondary coil L2 is appropriate.

[0139] Specifically, the signal ADIN is converted to binary by a comparator to determine whether the positional relationship is appropriate.

[0140] The oscillation circuit 58 is composed of, for example, a CR oscillation circuit, and generates a clock signal on the secondary side. The frequency detection circuit 60 detects the frequency (f1, f2) of the signal CCMPI, and determines whether the transmission data from the power transmission device 10 is "1" or "0".

[0141] The full charge detection circuit 62 (charge detection circuit) is a circuit for detecting whether the storage battery 94 of the load 90 is in a fully charged state (charged state). Specifically, the full charge detection circuit 62 detects the full charge state by, for example, detecting the on/off of the LEDR used for displaying the charge state. That is, when the LEDR is turned off for a predetermined time (for example, 5 seconds), it is determined that the storage battery 94 is in a fully charged state (charge is completed).

[0142] In addition, after the full charge, if the power receiving side device 510 is placed on the pallet 500 for a long time, the battery voltage VBAT decreases due to discharge. The recharging monitoring circuit 64 determines whether or not recharging is necessary based on the battery voltage VBAT. That is, for example, if the battery voltage VBAT is lower than the threshold voltage, the recharge monitoring circuit 64 determines that recharging is necessary.

[0143] In addition, the load 90 includes a charging control device 92 for performing charging control of the storage battery 94 and the like. The charging control device 92 can detect the fully charged state based on the lighting state of the light emitting device (LEDR). The charging control device 92 (charging control IC) can be realized by an integrated circuit device or the like. In addition, like a smart battery, the battery 94 itself can have the function of the charging control device 92. In addition, the load 90 is not limited to the secondary battery. For example, there are cases where the operation is performed by a predetermined circuit, and the circuit becomes a load.

[0144] (About the setting of the action trigger switch and the automatic mode switch)

[0145] Figure 5 ~ Figure 7 The specific setting examples of the action trigger switch and the automatic mode switch are shown. Figure 5 show figure 1 (A) The internal structure of the power transmission device 10 in the system.

[0146] in Figure 5 Here, the power transmission control device (power transmission control IC) 20 includes two terminals, namely, an action trigger input terminal SWONX and an automatic mode terminal AUTO. One end of the action trigger switch SW1 is connected to the action trigger input terminal SWONX. The pull-up action of the pull-up resistor RX triggers one end of the switch SW1. Thus, if the action trigger switch SW1 is in the open state, the action trigger input terminal SWONX is maintained at the H level. The other end of the action trigger switch SW1 is grounded. Therefore, if the action trigger switch SW1 is in the closed state, the action trigger input terminal SWONX changes to the L level. Corresponding to the negative edge (negative edge) NT triggered by each action, the power transmission side control circuit 22 repeatedly performs power transmission/stops power transmission.

[0147] In addition, one end of the automatic mode terminal SW2 is connected to the automatic mode terminal AUTO. Pull up one end of the automatic mode switch SW2 through the pull-up resistor RY1. Thus, if the automatic mode switch SW2 is in the open state, the automatic mode terminal AUTO is maintained at the H level. The other end of the automatic mode switch SW2 is grounded. Therefore, if the automatic mode switch SW2 is in the closed state, the automatic mode terminal AUTO is at the L level. When the automatic mode terminal AUTO is at H level, the power transmission side control circuit 22 is in the automatic mode, and performs automatic setting detection, temporary power transmission, ID authentication, normal power transmission, removal detection, foreign object detection, full charge detection, and normal power transmission in a fully automatic manner. A series of actions such as interruption. When the automatic mode terminal AUTO is at L level, the automatic mode is closed. When the automatic mode is off, the action trigger mode is activated. Therefore, the input of the negative edge NT from the action trigger switch SW1 is valid. As described above, the power transmission side control circuit 22 repeats the power transmission/stops the power transmission every time the negative edge NT is input.

[0148] in Figure 5 Among them, the action trigger switch SW1 and the pull-up resistor RX constitute the action trigger circuit 3. The action trigger circuit 3 plays a role of providing an action trigger for instructing power transmission/stopping the power transmission to the power transmission control device (power transmission control IC) 20 when the automatic mode is inactive. In addition, the automatic mode switch SW2 and the pull-up resistor RY1 constitute the automatic mode circuit 5. The automatic mode circuit 5 functions as an operation mode switching circuit that switches between ON (ON) and OFF (OFF) of the automatic mode. That is, when the output of the automatic mode circuit 5 is H level, the power transmission control device (power transmission control IC) 20 is in the automatic mode, and when the output of the automatic mode circuit 5 is L level, the automatic mode is cancelled and replaced by Validate the switch mode.

[0149] Figure 6 show figure 1 (B) The internal structure of the power transmission device 10 in the system. in Figure 6 Here, the automatic mode circuit 5 (including the automatic mode switch SW2) is provided inside the power transmission device 10. The selection of the automatic mode based on the automatic mode circuit 5 is, for example, performed by an employee of the manufacturer when the product is shipped.

[0150] Figure 7 show figure 1 (C) The internal structure of the power transmission device 10 in the system. in Figure 7 Here, the automatic mode circuit 5 includes a first automatic mode switch SW2a and a second automatic mode switch SW2b. As described above, when the first automatic mode switch SW2a is turned on (ON), the power transmission side control circuit 22 performs a series of actions in a fully automatic manner, such as automatic detection of the settings of the power receiving device 510, and temporary power transmission. , ID authentication, normal power transmission, removal or foreign object detection, full charge detection, and normal power transmission stop. In addition, when the second automatic mode switch SW2b is turned on (ON), the power transmission side control circuit 22 automatically executes a series of actions including the following actions, namely, automatic detection of the setting of the power receiving device 510, temporary power transmission, ID authentication, normal power transmission, removal or foreign object detection, full charge detection, normal power transmission stop, determination of whether recharging is required after full charge, start of recharge, and removal detection after full charge. In addition, Figure 7 Two automatic mode terminals (AUTO1, AUTO2) are provided in the power transmission control device (power transmission control IC) 20.

[0151] (Second embodiment)

[0152] In this embodiment, the operation of the contactless power transmission system when the automatic mode is selected will be described.

[0153] (Outline of operation of power transmission device in automatic mode)

[0154] Figure 8 It is a schematic flowchart showing an example of the operation of the power transmission device in the automatic mode. As described above, the power transmission side control circuit 22 of the power transmission device 10 of the present invention can automatically detect the settings of the power receiving side equipment 510, and can also perform recharge management after a full charge. Therefore, the operation mode in which the power transmission device 10 automatically performs a series of operations is referred to as an automatic mode.

[0155] in Figure 8 As shown in the part enclosed by the thick dashed line, the operation of the power transmission device 10 in the automatic mode is roughly divided into "setting detection and confirmation of the power transmission target (step SA)", "confirmation of the power transmission environment during normal power transmission (step SB)", "Full charge detection (step SC)", "monitoring after full charge (step SD)". Hereinafter, they will be explained in order.

[0156]If the power is turned on (step S0), setting detection and confirmation of the power transmission target are performed (step SA). Step SA includes step S1 to step S4. Through step S1 and step S2, the power transmission device 10 automatically and intermittently drives the primary coil L1 in a predetermined cycle (for example, 0.3 seconds) to perform intermittent temporary power transmission. Next, it is confirmed whether the installation position of the power receiving device 510 is appropriate (step S3), ID authentication of the power receiving device 510 (or the power receiving device 40) is performed, and it is determined whether it is an appropriate power transmission target (step S4).

[0157] When the power receiving device 40 successfully performs position detection (step S3), the ID authentication information is transmitted to the power transmitting device 10 within a predetermined time. The power transmission device 10 performs installation detection of the power receiving device 510 based on whether or not ID authentication information has been sent back from the power receiving device within a predetermined time from the timing of the intermittent temporary power transmission. When the setting of the power receiving device 510 cannot be detected or the ID authentication (step S4) fails (step S5), the temporary power transmission is stopped, and the state (initial state) where temporary power transmission is performed intermittently is returned.

[0158] The above position detection (step S3) is based on image 3 The position detection circuit 56 in the power receiving device 40 rectifies the DC voltage (ADIN) obtained by the induced voltage of the secondary coil (L2). Figure 16 Used to explain the principle of position detection. Such as Figure 16 As shown, according to the positional relationship between the primary coil (L1) and the secondary coil (L2), the level of ADIN changes.

[0159] For example, when the installation position of the power receiving device is inappropriate, the DC voltage (ADIN) of the specified level (V3 level) will not be obtained, and the position is judged to be inappropriate. The position detection result can be obtained from the power receiving device 40 using load modulation, for example. Transfer to the power transmission device 10. In addition, the transmission location may be inappropriate based on the fact that the power receiving device 40 does not transmit the ID authentication information to the power transmission device 10 within a predetermined time after the power reception device 40 receives the start of the temporary power transmission.

[0160] return Figure 8 Continue the description. in Figure 8 If ID authentication is successfully performed (step S4), normal power transmission is started (step S6). In the normal power transmission, metal foreign matter detection (step S7) and detection of an encroachment state based on periodic load change detection (steps S8, S9) are performed in the power transmission device 10. In addition, removal (detachment) detection of the power receiving-side device 510 is also performed (step S10). When any of the metal foreign matter, the encroachment state, and the removal is detected (step S11), the normal power transmission is stopped (step S12), and the process returns to step S1 (step for performing automatic intermittent operation).

[0161] Metallic foreign matter detection (step S7) and removal detection (step S10) can be detected based on the waveform change of the induced voltage signal of the primary coil (L1). The following is a specific explanation.

[0162] Figure 17 (A)~ Figure 17 (F) is used to explain the principle of detecting metal foreign objects (conductive foreign objects). Figure 17 (B)~ Figure 17 (F) shows the relative position of the MET according to the primary coil and the metal foreign body (conductive foreign body) respectively, Figure 17 (A) shows how the induced voltage signal (V(NA2)) of the primary coil L1 changes. As shown in the figure, there is no metal foreign body (MET) at all ( Figure 17 (F)) and the presence of metal foreign matter (MET) ( Figure 17 (B)~ Figure 17 (E)), the waveform (amplitude) of V(NA2) is obviously different. Therefore, the waveform monitoring circuit 14 (refer to image 3 ) Monitor the waveform of the induced voltage signal V(NA2) of the primary coil (L1), and detect metal foreign matter (MET). In addition, the “monitoring waveform” includes monitoring the amplitude of the amplitude, and also includes monitoring the phases of current and voltage.

[0163] Figure 18 (A)~ Figure 18 (D) is used to illustrate the principle of removal detection. Such as Figure 18 As shown in (A), when the power receiving device 510 is installed, the waveform of the induced voltage signal V(NA2) of the primary coil (L1) is as follows Figure 18 (B) shown. On the other hand, such as Figure 18 As shown in (C), when the power receiving side device 510 is removed (when it is detached), the waveform of the induced voltage signal V(NA2) of the primary coil (L1) is as follows Figure 18 As shown in (D), its waveform (amplitude) is obviously Figure 18 The waveform of (B) is distinguished. Therefore, the waveform monitoring circuit 14 (refer to image 3 ) Monitor the waveform of the induced voltage signal V(NA2) of the primary coil (L1), and can detect and remove (detach).

[0164] In addition, the detection of encroachment status ( Figure 8 Step S9) can be detected by whether the intermittent (for example, periodic) load modulation signal on the power receiving side can be detected on the power transmitting side (this point will be described later).

[0165] return Figure 8 Continue the description. in Figure 8 If the power transmission side control circuit 22 of the power transmission device 10 detects the full charge notification sent from the power receiving device 40 indicating that the battery is fully charged (step S13), it stops normal power transmission (step S14) and shifts to full charge The subsequent monitoring step (step SD).

[0166] In addition, the full charge of the battery 94 is caused by image 3 The full charge detection circuit 62 included in the power receiving device 40 performs detection. If a full charge is detected, the power receiving side control circuit 52 included in the power receiving device 40 sends a full charge notification to the power transmission device 10. If the power transmission side control circuit 22 of the power transmission device 10 detects the full charge notification from the power receiving device 40, as described above, it executes the monitoring step after the full charge (step SD).

[0167] The monitoring step after the full charge (step SD) includes the step of performing intermittent power transmission (step S15) for detecting the removal period T1 after the full charge, and the removal detection step (step S16), and whether it is necessary to perform recharging. The step of intermittent power transmission in the detected period T2 (step S17) and the step of detecting the necessity of recharging (step S18). As a result, after the load (battery) 94 of the power receiving device 510 becomes fully charged, it is possible to further monitor the load state and automatically perform recharging again.

[0168] That is, even after being fully charged, in the state where the power receiving device 510 is still installed, the load (battery) 94 may be discharged over time, and recharging may be required. Then, after the full charge is detected, an appropriate period of intermittent power transmission is performed instead of the normal power transmission, and the need for recharging of the load is also automatically determined. If recharging is required, the normal power transmission is performed again (step S6). In this way, recharging of the load (battery) 94 is automatically performed. Therefore, even if the power receiving side device 510 is left for a long time after being fully charged, when the user uses the power receiving side device 510, the load (battery) 94 is always fully charged. Therefore, there is no inconvenience that the charging is finally performed, but due to the subsequent discharge, the inconvenience of an insufficient charging state will result. Therefore, there will be no phenomenon that does not meet the expectations of the user.

[0169] However, in the case of removing the power-receiving device after fully charging, there is no need to perform recharging management. Therefore, unlike the intermittent power transmission for recharge management (step S15), it is preferable to perform intermittent power transmission for removal detection after full charge. For example, if there is no response from the power receiving device 510 that has received the intermittent power transmission for removal detection, it can be determined that the power receiving device 510 has been removed. If removal is detected, the power transmission side control circuit 22 included in the power transmission device 10 returns to the initial state (a state where intermittent temporary power transmission is performed). In addition, the removal of intermittent power transmission for detection and intermittent power transmission for recharging management does not need to be performed frequently, and in order not to increase power consumption unnecessarily, it is preferable to perform the intermittent power transmission at an appropriate cycle. Therefore, the intermittent power transmission for removal detection is performed in the first cycle T10, and the intermittent power transmission for recharging management is performed in the second cycle T20.

[0170] The reason for the difference between the first cycle T10 and the second cycle T20 is that it is desired to optimize the cycle according to the respective purpose. However, the first period T10 and the second period T20 may also be the same. In addition, the above-mentioned "full charge" can also be broadly interpreted as "the state of the load on the power receiving device 40 side is a predetermined state". Therefore, the load is not limited to the battery. For example, it may be a case where a predetermined circuit of the power receiving device 510 becomes a load. That is, for example, "after receiving power from the power transmission device and a predetermined circuit is operating, the predetermined circuit becomes a state where no operation is required" is equivalent to "the load is in a fully charged state", and this also includes Within the technical scope of this method.

[0171] In addition, the period of intermittent temporary power transmission ( Figure 8 The period of the automatic intermittent operation in step S1) can quickly detect the importance of the installation of the power receiving device 510, so it is preferably performed in a short period (for example, 0.5 second period). In this regard, the removal detection after the full charge is longer than the period of temporary power transmission will not cause any problem. If the removal detection is performed frequently, unnecessary power consumption will be increased. Therefore, the first period T10 of the removal detection after the full charge is set to a period larger than the period of temporary power transmission (for example, a period of 5 seconds) to suppress an increase in power consumption. In addition, because the frequency of recharging needs to be detected after a full charge can be further reduced (because it takes a long time for a fully charged battery to discharge until it needs to be recharged. In addition, the need for recharging can be determined even if it is slightly The delay does not cause any problems in practical applications), so the second period T20 for full charge detection is set to be greater than the first period T10 (for example, set to a period of 10 minutes). As a result, intermittent power transmission can be performed at a cycle according to each purpose, and power consumption can be minimized.

[0172] (An example of the configuration of the transmission side control circuit in automatic mode)

[0173] Picture 9 It is a circuit diagram showing an example of the configuration of the power transmission side control circuit in the automatic mode. As shown in the figure, the power transmission side control circuit 22 includes a logic circuit 100. The logic circuit 100 includes a position detection unit 106, an ID authentication unit 108, a removal detection unit 110, a foreign object detection unit 112 (including an invading state detection unit 114), a full charge notification (power transmission stop request) detection unit 116, and a recharge request detection unit 117 A timer 119 for time management, and a power transmission control unit 118 that controls the on/off of power transmission (temporary power transmission and normal power transmission) based on the detection results of each part. The power transmission control unit 118 includes an intermittent power transmission control unit 121 after fully charged.

[0174] (Basic timing example of contactless power transmission system in automatic mode)

[0175] Picture 10 A basic sequence example of a contactless power transmission system in automatic mode is shown. For example, the user installs the power receiving device 510 at a predetermined position of the charger 500. As described above, the power transmission device 10 performs automatic intermittent operation and always performs intermittent temporary power transmission (steps S19, S20). The position detection of the power receiving device 510 that receives the temporary power transmission is performed (step S21), and if the position is not appropriate, the temporary power transmission is stopped (step S22).

[0176]If the installation position of the power receiving device 510 is appropriate, ID authentication is performed (step S23). That is, ID authentication information (manufacturer information, equipment ID number, rating information, etc.) is transmitted from the power receiving device 40 to the power transmitting device 10.

[0177] If the ID authentication is successful, the power transmission device 10 starts normal power transmission to the power reception device 40 (step S26). During the normal power transmission period, as described above, removal detection (step S29), metal foreign object detection (step S30), periodic load authentication on the secondary side (including secondary side load reduction processing as needed: step S31), encroachment State detection (step S32), if any of the situations is detected, the normal power transmission is stopped (step S33). In addition, the load reduction accompanied by the periodic load certification on the secondary side refers to a situation where the primary side cannot receive the modulation signal well even when the load (battery, etc.) is heavy even if the load is modulated. , During load modulation, reducing (or stopping) the power supply to the load, on the surface it seems that the load state of the load is forcibly reduced (in this regard, we will use Figure 23 This will be described later).

[0178] in Picture 10 If the power receiving device 40 detects full charge, it creates a full charge notification (save frame: power transmission stop request frame) and sends it to the power transmission device 10 (step S34). If the power transmission device 10 detects a full charge notification (power transmission stop request frame) (step S35), it cuts off normal power transmission (step S36), and instead performs intermittent power transmission after full charge (step S37). It is determined whether intermittent recharging is necessary or not (step S38), and recharging and normal power transmission are performed again (step S26). In addition, the removal detection of the power receiving device 510 after the full charge is performed (step S39), and if removal is detected, it returns to the initial state.

[0179] Picture 11 Yes means execution Picture 10 The time series of the state transition diagram of the state transition of the contactless power transmission system. As shown in the figure, the state of the system can be roughly divided into the initial state (idle state: ST1), position detection state (ST2), ID authentication state (ST3), power transmission (normal power transmission) state (ST4), periodic load authentication state ( ST5) (and load lightening state ST6), the state of intermittent power transmission after full charge (ST7).

[0180] Through automatic intermittent operation based on the power receiving side equipment installation detection (Q1), from ST1 to ST2, when the position is detected NG, return to ST1 (Q2). If the position detection is OK, go to ST3. If the ID authentication is OK (Q6), it goes to the normal power transmission state (ST4).

[0181] In the normal power transmission state ST4, removal detection (Q12), metal detection (Q10), encroachment state detection (Q17), and full charge detection (Q14) are executed. If any of Q10, Q12, and Q17 is detected, the initial state (Q9, Q11, Q13) is restored. In addition, if a full charge is detected (Q14), it shifts to the intermittent power transmission state ST7 (Q15). In the intermittent power transmission state ST7, recharging necessity detection (Q18) and removal detection (Q16) are executed. If removal is detected, return to the initial state (Q20). In addition, when recharging is required, normal power transmission is performed again (Q19).

[0182] For execution Picture 10 as well as Picture 11 The basic timing non-contact power transmission system can automatically detect the setting of the power receiving side equipment as the power transmission object. Therefore, it is possible to realize a very convenient non-contact power transmission system without requiring the user to operate an action switch or the like. In addition, by using ID authentication as a condition for normal power transmission, improper equipment will not be transmitted to improve reliability and safety. In addition, during normal power transmission, various detection actions (removal detection, metal foreign object detection, encroachment detection based on periodic load authentication on the secondary side, and full charge detection) are performed, and if any of these conditions are detected, they can be quickly The normal power transmission is stopped and returned to the initial state. Therefore, unnecessary power transmission will not occur at all, and comprehensive countermeasures against foreign objects can be implemented, and a system with extremely high reliability (safety) can be realized. Furthermore, if a full charge is detected (the load becomes a predetermined state in a broad sense), intermittent power transmission for monitoring the load state after the full charge is performed (specifically, for example, the intermittent power transmission for detection and the need for recharging are removed. Intermittent power transmission for judging whether or not), so that even after fully charged, the operation for keeping the power-receiving-side device in the most appropriate state is continued. Therefore, user satisfaction is further improved.

[0183] Picture 12 as well as Figure 13 Yes means execution Picture 10 The basic sequence of the flow chart of the operation example of the non-contact power transmission system. in Picture 12 as well as Figure 13 In the middle, the left side shows the operation flow on the power transmission side (primary side), and the right side shows the operation flow on the power receiving side (secondary side).

[0184] Such as Picture 12 As shown, the power transmission side control circuit 22 executes an automatic intermittent operation (step S40). That is, temporary power transmission is started from the power transmission side at predetermined time intervals (for example, the transmission frequency is f1: step S41), and counting by the counter is started (step S42).

[0185] On the power receiving side, if the temporary power transmission is received, the stop state (step S60) is shifted to the on state (step S61), and the position level determination (position detection) is performed. If the position level is NG, the initial state is returned (step S60), and if the position level is OK, an ID authentication frame is generated (step S63), and the ID authentication frame is transmitted (step S64).

[0186] On the power transmission side, ID authentication frame reception processing (step S44) and time-out determination (step S43) are performed, and if the ID authentication frame cannot be received within a predetermined time, the temporary power transmission is stopped (step S51), and the initial state is returned.

[0187] On the other hand, if the ID authentication frame cannot be received within the specified time, the frame authentication process is executed (step S45), and if the authentication is OK, the permission frame is sent to the power receiving side (step S47). In the case of NG authentication Next, the temporary power transmission is stopped (step S51), and the initial state is returned.

[0188] The power receiving device 40 verifies the permission frame from the power transmission device 10 (step S65), and transmits the start frame to the power transmission device 10 (step S66).

[0189] In the power transmission device 10, the start frame is verified (step S48), the detection of periodic load fluctuations (for detecting an invading state) is turned on (step S49), and normal power transmission is started (step S50). In the power receiving device 40, normal power transmission is received, and charging of a load (for example, a storage battery) is started (step S67).

[0190] Then, pass Figure 13 Explain the subsequent process. In the power transmission device 10, the respective detections of removal, metal foreign matter, and encroachment state are continuously performed (step S70), and a full charge notification (power transmission stop request) from the power receiving device 40 is waited for (step S71).

[0191] In the power receiving device 40, the charging of the load is continued, the periodic load modulation for detection of encroachment is performed (step S80), and the full charging of the load is detected (step S81). That is, the full charge detection circuit 62 determines that it is fully charged when the light-off of the light emitting diode LEDR continues for a predetermined time (for example, 5 seconds) or more and is turned off. If full charge is detected, the power receiving device 40 transmits a full charge notification frame (save frame: power transmission stop request) to the power transmission device 10 (step S82).

[0192] When the power transmission device 10 receives a full charge notification frame (save frame: power transmission stop request) from the power receiving device 40, the periodic load change detection is turned off (step S72), and power transmission is stopped (step S73).

[0193] (Regarding the detection of occupation status)

[0194] Next, the detection of the invading state (countermeasures against invading heat) will be specifically explained. The "occupation state" refers to a state in which a foreign object is inserted in a special shape, and it is a state in which the foreign object is mistaken for the power-receiving device and normal power transmission continues. For example, when a thin metal plate is inserted so as to completely block the space between the primary coil and the secondary coil, if viewed from the power transmission side, there is always a considerable load, for example, it becomes difficult to remove the detection.

[0195] (Countermeasures against invading fever)

[0196] First, the "state of encroachment" will be explained in detail. After the authentication of the power receiving device (or the power receiving device) ends and the normal power transmission starts, for example, a large-area foreign object may be inserted between the primary coil L1 and the secondary coil L2. Such as using Figure 17 As explained, the presence of metal foreign objects can be detected by monitoring the induced voltage of the primary coil (L1).

[0197] However, such as Figure 19 As shown in (B), when a metal foreign object (such as a thin metal plate) that interrupts the primary coil L1 and the secondary coil L2 is inserted between the power transmission side equipment and the power reception side equipment, the power transmission energy from the primary side is The metal foreign matter is consumed (that is, the metal foreign matter becomes a load), and therefore, when viewed from the power transmission device 10 side, it is considered that there is always a load (power-receiving-side equipment). Therefore, for example, even if the equipment on the receiving side is removed, it will be impossible to adopt Figure 18 As described above, the removal detection is performed based on the induced voltage of the primary coil L1. In this case, even though there is no power receiving side device, the power transmission from the power transmission device 10 is continued, and the metal foreign matter reaches a high temperature.

[0198] In this way, in this specification, the phenomenon of replacing the original power-receiving-side device 510 with a metal foreign object is referred to as “encroachment. In order to improve the safety and reliability of the contactless power transmission system to a practical level, it is also necessary to take adequate countermeasures against such "encroachment and heat generation". As the case of inserting a foreign object, it is possible to assume a case of accidental insertion of a foreign object and a case of malicious insertion of a foreign object. If a foreign object is inserted into the phenomenon, it will generate heat and cause burns, equipment damage or breakage. Therefore, a contactless power transmission system is required to completely implement safety measures against foreign object insertion. Next, the countermeasures against occupation and heat generation will be explained in detail.

[0199] Figure 19 (A), Figure 19 (B) is a cross-sectional view of an electronic device constituting a non-contact power transmission system for explaining the insertion of a foreign object (occupation state) after the start of normal power transmission.

[0200] in Figure 19 In (A), a mobile phone terminal 510 (electronic equipment including the power receiving device 40) is installed at a predetermined position on the pallet 500 (electronic equipment including the power transmission device 10), and in this state, the primary coil L1 With the secondary coil L2, non-contact power transmission is performed from the pallet (charger) 500 to the mobile phone terminal 510, and the secondary battery (for example, battery pack) 94 built in the mobile phone terminal 510 is charged.

[0201] in Figure 19 In (B), during normal power transmission, a thin-plate-shaped metal foreign object (conductive foreign object) AR is maliciously inserted between the pallet (charger) 500 and the mobile phone terminal 510. If a foreign object AR is inserted, almost all of the power supplied from the primary side device (pallet 500) to the secondary side device (portable phone terminal 510) is consumed by the foreign object (AR) (that is, the invasion of transmission power is generated). AR has an increased risk of fever. So, in becoming Figure 19 In the case of the state shown in (B), it is necessary for the power transmission device 10 included in the equipment (pallet 500) on the primary side to detect the insertion of the foreign object AR and immediately stop normal power transmission.

[0202] However, by using Figure 17 It is difficult to fully grasp the detection method of metal foreign body explained Figure 19 (B) The state of encroachment shown.

[0203] For example, when the load on the power receiving device side is large, the amplitude of the voltage induced by the primary coil L1 increases, and if the load on the power receiving device side is small, the amplitude of the voltage induced by the primary coil L1 decreases. If the secondary battery 94 of the mobile phone terminal 510 is normally charged, the load on the power receiving device 40 side should gradually decrease over time. Here, if the load on the power receiving device 40 side suddenly increases, since the power transmission device 10 monitors the load fluctuation on the power receiving device 40 side, it is possible to detect that the load suddenly increases. However, it cannot be determined whether the load increase is caused by the load (the secondary battery 94 of the mobile phone terminal), the positional deviation between the mobile phone terminal 510 and the pallet 500, or the insertion of a foreign object. Therefore, the power transmission device 10 cannot detect the insertion of a foreign object only by detecting the load fluctuation on the power receiving device 40 side.

[0204] Therefore, in the present invention, during normal power transmission, the power supply to the load (secondary battery, etc.) is continued, and the power receiving device 40 intermittently and consciously changes the load observed from the power transmission device 10 (regular load modulation). Action), and send information to the power transmission device 10.

[0205] If the power transmission device 10 can detect the information based on the intermittent load change at a predetermined timing, the following can be proved.

[0206] (1) The device (mobile phone terminal 510) on the power receiving device 40 side is correctly installed on the device (pallet 500) on the power transmission device 10 side.

[0207] (2) The devices on the power receiving device 40 side (including the secondary battery of the mobile phone terminal 510) operate normally.

[0208] (3) No foreign object AR is inserted.

[0209] On the other hand, if a foreign body AR is inserted during normal power transmission, the information transmitted from the power receiving device 40 will not reach the power transmission device 10 blocked by the foreign body AR. That is, the power transmission device 10 cannot detect intermittent load changes on the power receiving device side (for example, periodic load changes). As the reason why the intermittent load change was not detected after confirming the above (1) to (3), the reason (3) above is most doubtful. That is, it can be determined that the intermittent load change cannot be detected due to the insertion of the foreign object AR.

[0210] Picture 20 (A), Picture 20 (B) is used to describe a specific aspect when the load on the power receiving device side is changed intermittently in order to be able to detect the insertion of a foreign object.

[0211] in Picture 20 In (A), the intermittent change of the load on the power receiving device side is represented by the change of the secondary current (current flowing in the secondary coil L2). As shown in the figure, at times t1, t2, t3, t4, t5..., the load on the power receiving device side changes intermittently.

[0212] Specifically, in Picture 20 In (A), the load changes in period T3. In addition, for example, in the period T2 starting from the time t1, the load is reduced (decrease), and in the subsequent period T1, the load is increased (increase). In the period T3, such a periodic change is repeated.

[0213] Picture 20 (B) shows the change in the primary coil voltage (the induced voltage at one end of the primary coil) with respect to the change in the secondary load current. As described above, in the period T1, the load on the secondary side is large, and in the period T2, the load is small. According to the change in the load on the secondary side, the amplitude (peak value) of the induced voltage (primary coil voltage) at one end of the primary coil (L1) changes. That is, during the period T1 when the load is heavy, the amplitude increases, and during the period T2 when the load is light, the amplitude decreases. Therefore, in the power transmission device 10, the waveform detection circuit 28 (refer to image 3 ), for example, by performing peak detection of the primary coil voltage, the load variation on the power receiving device 40 side can be detected. However, the detection method of load fluctuation is not limited to this method. For example, it is also possible to detect the primary coil voltage or the phase of the primary coil current.

[0214] For example, load modulation can be performed simply by turning on or off the transistor. In addition, the detection of the peak voltage of the primary coil can be accurately performed using analog or digital basic circuits, which places a small burden on the equipment and is relatively easy to implement. In addition, it is also advantageous in terms of controlling the installation area or cost.

[0215] In this way, by adopting the new method described below, it is possible to detect the insertion of foreign objects with high accuracy in a simple method without adding a special configuration. This new method means that the power receiving device 40 performs intermittent-based ( And periodically) load modulation information is transmitted, and the power transmission device 10 detects its load fluctuation.

[0216] (Specific example of foreign body insertion detection)

[0217] Figure 21 It is an extraction indication image 3 A circuit diagram of the main components related to the detection of foreign matter insertion (occupation state) in the non-contact power transmission system shown. in Figure 21 In, and image 3 The common parts are marked with the same reference symbols. In addition, in Figure 21 In the middle, the parts that play an important role in foreign object detection are shown with thick lines.

[0218] in Figure 21 In the power receiving device 40 shown, the circuit configuration that should be noted is to constitute the load modulation section 46 (refer to image 3 ), the load modulation transistor TB3 constitutes the power supply control unit 48 (refer to image 3 The power supply control transistor TB2 of ), the power reception control circuit 52 that controls the on/off of the two transistors (TB2, TB3). In addition, the voltages at the input and output ends of the series regulator (LDO) 49 are input to the power receiving control circuit 52 via the signal lines LP2 and LP1. By monitoring the voltage across the LDO 49, the battery (two) included in the load 90 can be detected. The load state (the size of the load) of the secondary battery 94 is also very important.

[0219] In addition, in the power transmission device 10 (refer to image 3 In ), what should be noted is the configuration of the power transmission control device 20. That is, it is also important to detect the peak value (amplitude) of the induced voltage of the primary coil (L1) by the waveform detection circuit 28, and to detect the load fluctuation on the power receiving device 40 side by the power transmission control circuit 22.

[0220] in Figure 21 , The power receiving device 40 performs load modulation during normal power transmission (continuous power transmission after authentication), and transmits the foreign object detection pattern PT1 to the power transmission device 10, and the power transmission side control circuit 22 of the power transmission device 10 monitors the power receiving device during normal power transmission When the load changes on the side 40 (either continuous monitoring or intermittent monitoring), if the foreign body detection pattern PT1 cannot be received, it is determined that a foreign body AR is inserted, and normal power transmission is stopped.

[0221] (Specific form of foreign object detection pattern PT1)

[0222] Figure 22 (A), Figure 22 (B) Describe a preferable and specific form of load modulation for realizing foreign object detection, Figure 22 (A) shows a timing example of load modulation, Figure 22 (B) specifically shows how the load variation on the power receiving device side detected by the power transmitting device.

[0223] Such as Figure 22 As shown in (A), for example, load modulation for realizing foreign object detection is performed periodically (periodically) in a cycle of 5 seconds (10 sec).

[0224] In addition, time t1 to t6 and time t7 to t12 are periods during which load modulation for realizing foreign object detection is performed. It is 0.5 second (0.5sec) from time t1 to t6 (from time t7 to t12), and the unit of 0.1 second (100msec) obtained by dividing 0.5 second into five equal parts is used to switch the size of the load.

[0225] in Figure 22 In (A), the period indicated by the thick double-headed arrow is a period when the load is heavy. That is, the load increases in each period of time t1 to t2, time t3 to t4, time t5 to t6, time t7 to t8, time t9 to t10, and time t11 to t12. The period during which the load increases is TA.

[0226] On the other hand, in the respective periods of time t2 to t3, time t4 to t5, time t8 to t9, and time t10 to t11, the load decreases. The period of load reduction is TB.

[0227] in Figure 22 In (A), it is obvious that the intermittent change of the load on the power receiving device during normal power transmission is performed periodically (that is, corresponding to each period), and the load changes intermittently at predetermined intervals in one period. Times.

[0228] By performing periodic load changes, it is possible to transmit and receive information based on load changes while the power transmission device 10 and the power receiving device 40 ensure synchronization (that is, the power transmission device 10 can easily know that the power receiving device Timing when the load on the 40 side changes).

[0229] In addition, in Figure 22 In (A), the load is changed intermittently at predetermined intervals only during a partial period (time t1 to t6) within one cycle (for example, time t1 to t7). That is, in the initial period (the first 0.5 sec) of the first half of one cycle (10 sec), load modulation is concentratedly performed. The reason for this type of load modulation will be described below.

[0230] That is, the load change (load modulation) in the normal transmission will affect the load ( Figure 21 Therefore, it is not expected to be performed too frequently. Therefore, for example, one cycle of load modulation is extended to a certain extent (in this way, even if the cycle is slightly extended, there is no problem in detecting foreign objects).

[0231] In addition, the load is intermittently changed multiple times at predetermined intervals only during a part of the one cycle. The limited period is due to consideration of the following reasons. That is, if the interval between load changes is widened, the load condition of the load changes with the passage of time, or the surrounding conditions change. As a result, the The power transmission device detects that the intermittent load change on the power receiving device side causes undesirable effects. That is, for example, a relatively long period (in Figure 22 (A), it is 10sec), and then, in the relatively long one cycle, part of the relatively short period (in Figure 22 In (A), it is 0.5sec) in a concentrated manner multiple times ( Figure 22 In (A), it is five times) intermittent load modulation.

[0232] By performing this form of load modulation, it is possible to minimize the influence on the power supply to the load (94) (for example, the charging of the battery pack), and it is possible to realize high-precision foreign matter (AR) detection on the power transmission device 10 side.

[0233] Figure 22 (B) shows an example of the amplitude change of the induced voltage at one end of the primary coil (L1) of the power transmission device 10 corresponding to the load on the power reception device side viewed from the power transmission device. But when Figure 22 In (B), the load state of the load (battery 94) changes during the load modulation period (t1 to t6) of one cycle in the first half and the load modulation period (t7 to t12) of one cycle in the second half. In the second half of the cycle, the load state of the load (battery 94) increases, and therefore, the peak value of the primary coil voltage increases.

[0234] in Figure 22 At times t1 to t6 in (B), the difference between the primary coil voltage in the period TA when the load is increased and the primary coil voltage in the period TB when the load is decreased is ΔV1. Based on the amplitude difference ΔV1 of the primary coil voltage, the power transmission side control circuit 22 of the power transmission device 10 can detect the load change of the power receiving device 40.

[0235] However, in the second half of the load modulation period (time t7 to t12), the load state of the load (battery 94) increases, and the charging current (Iload) of the load 94 increases. Therefore, the ratio of the charging current (Iload) The ratio of the modulation current (Imod) accompanying the load modulation is reduced, and the difference in the primary coil voltage based on the on/off (ON/OFF) of the modulation current (Imod) is reduced to ΔV2 (ΔV2

[0236] (Measures to forcibly reduce the load)

[0237] In the present invention, during normal power transmission, load modulation is performed without stopping the power transmission to the load 94. Therefore, the transmission of the signal to the power transmission device 10 based on the load modulation is always affected by the power supply to the load 94. The influence of the condition (ie, the load state of the load).

[0238] As described above, when a large charging current is supplied to the load 94 (battery components, etc.), even if a small current is turned on/off for load modulation, the current amount is equal to the charging current (Iload) of the load (battery 94). However, the current amount of the on/off current (Imod) is still small. Therefore, it is undeniable that it is difficult to detect the load change based on the load modulation on the power transmission device 10 side (that is, it is difficult to detect whether it is noise or based on Load modulated signal). On the other hand, when the current supplied to the load 94 is small (the load is small), the relative ratio of the on/off current (Imod) based on the load modulation increases, and it is easy to grasp the load change based on the on/off from the power transmission device 10. .

[0239] Based on the above considerations, in this embodiment, during normal power transmission, when the power receiving device 40 itself monitors the load state of the load 94 and performs load modulation capable of detecting foreign objects, when the load 94 is large (that is, it will be large). When current is supplied to the load 94), measures are taken to forcibly reduce the power supply to the load 94. In addition, reducing the power supply also includes temporarily (or intermittently) stopping the power supply.

[0240] If the power supply to the load 94 is reduced, the load state of the load 94 appears to be reduced, and it is easy to detect the signal based on the load modulation on the power transmission device 10 side. Therefore, even when the load 94 is large, the foreign object detection accuracy is Can be maintained at the desired level. In addition, even when the load 94 is forced to be lowered, the load 94 is always supplied with at least the minimum power required. Therefore, no electronic circuit (charging control device) on the load 94 side is generated. 92) The problem of inability to perform actions.

[0241] In addition, as described above, the load modulation that can detect the insertion of foreign objects is performed intermittently, and the load modulation is performed at appropriate intervals in consideration of the influence on the power supply to the load 94, because it is mandatory. Since the load is reduced, it does not have a particularly bad influence on the power transmission to the load 94. For example, there will never be the disadvantage of extremely increasing the charging time of the battery assembly.

[0242] As a result, when the state of the load 94 is monitored on the power receiving device 40 and the load modulation capable of detecting the insertion of foreign objects is performed, if necessary, the forcible reduction of the load state of the load 94 can be performed at the same time, so that even when the load 94 is large In the case, the detection accuracy of the load change on the power transmission device 10 side may be maintained at a desired level.

[0243] Figure 23 (A)~ Figure 23 (E) is used to explain the load reduction action. Specifically, Figure 23 (A) shows a state where the load is small, Figure 23 (B) shows a state where the load is large, Figure 23 (C) shows Figure 23 (B) The change of the primary coil voltage in the state shown, Figure 23 (D) represents a state where the power supply control transistor is continuously turned on/off, or the power supply control transistor is turned into a semi-conductive state to reduce the load, Figure 23 (E) shows Figure 23 (D) The change of the primary coil voltage in the state shown.

[0244] in Figure 23 In the case shown, since the load (battery) 94 is small (that is, the charging current Iload of the load is small), even if the load reduction action is not performed on the power receiving device 40 side, the power transmission device 10 side can be sufficiently reduced. The ground detects the load change based on the load modulation. Therefore, the power supply control transistor TB2 is always on. The load modulation transistor TB3 is turned on/off intermittently, and thus load modulation is performed.

[0245] in Figure 23 In (B), since the load (battery) 94 is large (that is, the charging current Iload of the load is large), it is difficult to see the current change based on the on/off of the modulation current (Imod). Such as Figure 23 As shown in (C), if the load changes from a small state to a large state, the amount of change in the amplitude of the primary coil voltage is reduced from ΔV1 to ΔV2, making it difficult to detect the load change based on load modulation.

[0246] So, in Figure 23 In (D), when the load is modulated, the load reduction operation is also performed together. That is, in Figure 23 In (D), an operation of continuously turning on/off the power supply control transistor TB2 or putting the power supply control transistor TB2 in a semi-conductive state is performed.

[0247] That is, the digital method of continuously turning on/off the power supply control transistor TB3 existing in the power supply path and intermittently supplying power can forcibly reduce the power transmission to the load 94 (including the case where the power transmission is temporarily stopped). ). Switching transistors continuously is an action usually performed in digital circuits, and it is relatively easy to implement. In addition, by selecting the switching frequency, there is an advantage that it is possible to control with high accuracy how much power consumption to the load is reduced.

[0248] In addition, an analog method is used to provide the gate of the power supply control transistor (PMOS transistor) with a voltage intermediate between the fully-on voltage and the fully-off voltage, so that the PMOS transistor becomes, for example, a so-called semi-conductive state. , Can also reduce the power supplied to the load 94. In addition, it has the advantage that the on-resistance of the power supply control transistor (PMOS transistor) can be finely adjusted by controlling the gate voltage.

[0249] in Figure 23 In (E), the amplitude of the primary coil voltage in a state where the load is large changes from V10 to V20 due to the forced reduction of the load. In the figure, "X" represents the forcible reduction of the load 94. By forcibly lowering the load 94, the amplitude of the primary coil voltage changes from ΔV2 (refer to Figure 23 (C)) Expanding to ΔV3 (ΔV3>ΔV2), in the power transmission device 10, it is easy to detect a load change on the power receiving device 40 side based on load modulation.

[0250] As a result, by performing load reduction operations (including an operation to temporarily stop the load current) simultaneously with load modulation, even when the load is large, it is possible to reliably detect load changes on the power transmission device side.

[0251] (Specific operation of power transmission device)

[0252] Here, for Figure 21 The specific operation of the power transmission control device 20 will be described. As described above, the periodic load variation detection unit 114 of the power transmission side control circuit 22 included in the power transmission control device 20 (refer to Picture 9 ) When the intermittent change in the load on the power receiving device 40 cannot be detected during normal power transmission, it is determined that a foreign object (AR) has been inserted between the primary coil (L1) and the secondary coil (L2), and the power transmission is stopped. As a result, heat generation, burns, or equipment damage or breakage of foreign objects (AR) can be reliably prevented. Therefore, it is possible to implement highly reliable foreign object insertion countermeasures in the non-contact power transmission system.

[0253] In addition, judging whether there is a foreign object inserted or not requires careful comparison. Therefore, it is preferable that the transmission-side control circuit 22 detects the change in load at each of a plurality of cycles, and fails to detect a predetermined number of consecutive cycles. When the load changes, it is determined that a foreign object has been inserted between the primary coil and the secondary coil.

[0254] For example, a change in the load on the power receiving device is detected in each of a plurality of cycles, and when the load change is not detected in a predetermined number of consecutive cycles (for example, three cycles), normal power transmission is stopped. As a result, the detection accuracy of foreign body insertion is improved, and there is no such a situation that, for example, when a load change cannot be detected due to accidental reasons, the normal power transmission is erroneously stopped.

[0255] In addition, it is possible to detect a load change on the power receiving device 40 side seen from the power transmission device 10 side by detecting the waveform of the induced voltage of the primary coil (L1 ), and this waveform detection can be performed by the waveform detection circuit 22.

[0256] As described above, the peak value (amplitude) of the waveform of the induced voltage of the primary coil (L1) increases when the load on the power receiving device 40 side is large, and decreases when the load on the power receiving device 40 side is low. Therefore, it is possible to pass the waveform Peak detection to detect the load change on the power receiving device 40 side. However, it is not limited to this detection method, and other methods such as a method of detecting the phase of the induced voltage or current of the primary coil may be adopted.

[0257] Thus, according to the present embodiment, it is possible to realize a new power transmission device 10 that has a function of detecting foreign body insertion (encroachment) based on periodic load authentication. According to this embodiment, while controlling the number of components, it is possible to detect the insertion of a foreign object between the primary coil and the secondary coil with high accuracy through simple signal processing, and it is possible to achieve high-reliability safety measures in non-contact power transmission. .

[0258] In addition, the power transmission stop function based on periodic load authentication can be used not only for encroachment detection, but also as a final barrier to forcibly stop inappropriate power transmission. For example, even if for some reason the intrusion detection of the power-receiving-side equipment cannot be effectively performed, or when the power-receiving-side equipment is damaged or fails to perform periodic load modulation, etc., it is possible to reliably stop the Power transmission from equipment on the transmission side. Therefore, due to the periodic load authentication function, the safety of the contactless power transmission system is significantly improved. reliability.

[0259] (Regarding whether the recharging needs to be judged after full charge and the removal detection after full charge)

[0260]In the following description, the determination of the need for recharging after full charging and the removal detection after full charging are explained. For example, in figure 1 In the non-contact power transmission system of (C), when the second automatic mode switch SW2a is turned on, not only automatic setting detection to full charge detection, and automatic disconnection of normal power transmission are executed, but also recharging after full charge is always performed Need to judge and remove detection after full charge. In this case, the transmission side control circuit 22 executes Figure 14 as well as Figure 15 The action shown. Hereinafter, they will be explained in order.

[0261] (Recharge after full charge)

[0262] Next, the recharging after fully charged will be described. After being fully charged, for example, if a mobile phone terminal as a power-receiving device is placed on a charging stand (pallet) for a long time, the voltage drops due to the discharge of the battery, and the battery needs to be recharged. Therefore, in this embodiment, it is possible to automatically detect the necessity of recharging the power transmission device after fully charging.

[0263] Figure 14 (A) and Figure 14 (B) is a sequence diagram showing a series of operation steps for recharging management after full charging in the non-contact power transmission system. In addition, Figure 14 (B) steps are in Figure 14 Execute after the step (A).

[0264] If battery 94 (refer to image 3 ) Is the fully charged state, then it will shift to the standby mode after fully charged. In this fully-charged standby mode, the power transmission device 10 intermittently transmits power to the power receiving device 40, and at this time, transmits content indicating the fully-charged standby mode to the power receiving device 40. After receiving the contents of the standby mode after the full charge, the power receiving device 40 confirms the battery voltage VBAT. In addition, when the battery voltage VBAT is less than or equal to the recharging voltage (for example, 3.9V), it is determined that the recharging is necessary, and a recharging instruction is sent to the power transmission device 10. Thus, the power transmission device 10 performs normal power transmission to the power receiving device 40 again. Thus, recharging of the battery 94 is started. At this time, the standby mode after fully charged is released. On the other hand, when the battery voltage VBAT is greater than the recharge voltage, the standby mode after the full charge is continued. Hereinafter, it will be specifically explained.

[0265] image 3 When detecting that the storage battery 94 included in the load is in a fully charged state, the power transmission side control circuit 22 stops normal power transmission to the power receiving device 40 and performs intermittent power transmission. In addition, when the power transmission side control circuit 22 detects that the storage battery 94 has become a state requiring recharging during the intermittent power transmission period, the control circuit 22 performs normal power transmission to the power receiving device 40 again.

[0266] On the other hand, when the battery 94 becomes fully charged and the power transmission device 10 stops normal power transmission and performs intermittent power transmission, image 3 The power receiving-side control circuit 52 of the power-receiving-side control circuit 52 performs control of sending a recharging command to the power transmission device 10 during the intermittent power transmission period, and the recharging command is used to notify information about the recharging state of the storage battery 94. In this case, the full charge detection circuit 62 detects the full charge state of the storage battery 94, and the recharge monitoring circuit 64 monitors the recharge state of the storage battery 94. In addition, the information related to the recharge state refers to information for determining whether the storage battery 94 is in a recharge state, information whether recharging is necessary, and information about the battery voltage VBAT after being fully charged.

[0267] More specifically, such as Figure 14 As shown in A1 of (A), when the storage battery 94 is in a fully charged state, the control circuit 52 on the power receiving side performs the following control, that is, by, for example, load modulation by the load modulation unit 46, to transmit to the power transmission device 10 A full charge command (full charge information) is notified that it has become a fully charged state. In addition, as indicated by A2, the following control is performed to stop the voltage output (power supply) of VOUT to the charging control device 92. For example, if the full-charge detection circuit 62 detects that the LEDR for displaying the charging state continues to turn off for 5 seconds, for example, the control circuit 52 determines that the storage battery 94 is in the fully-charged state (charge is completed). Then, a frame for transmitting a full charge command is shown, the control signal P3Q is subjected to load modulation, and the generated frame is transmitted to the power transmission device 10.

[0268] On the other hand, when a full charge instruction is received during normal power transmission to the power receiving device 40, the control circuit 22 on the power transmission side performs the following control, namely, Figure 14 As shown in A3 of (A), the full charge flag FC is set to 1, and as shown in A4, in the first period T1 (for example, 1 second), the power transmission to the power receiving device 40 is stopped. After that, as shown in A5, power transmission is performed again, and intermittent power transmission is performed. In addition, as shown in A6, during the intermittent power transmission period after the power transmission is re-executed, control is performed so that the power receiving device 40 transmits to the power receiving device 40 a detection indicating the recharging state of the battery 94 (the detection of whether it is a state requiring recharging, or Battery voltage detection after full charge) recharge detection command. That is, the power transmission device 10 passes Figure 4 The method described in (A) generates and transmits a frame of the recharge detection command. In addition, after sending the recharge detection command, as shown in A7, until the timeout waiting period T2 (for example, 30msec. T2

[0269] Such as Figure 14 As indicated by A10 of (A), the power reception control device 50 stops the power transmission from the power transmission device 10 after sending the full charge command and becomes the reset state. That is, since power is not being transmitted from the power transmission device 10, the power supply voltage is 0V, and it is in the reset state. In addition, after the control circuit 52 on the power receiving side releases the reset state based on the intermittent power transmission from the power transmission device 10 as shown in A11, and receives a recharge detection command from the power transmission device 10, it performs the battery operation as shown in A12. Monitoring process of the recharge state of 94. That is, monitor and determine whether the storage battery 94 needs to be recharged. Alternatively, processing for monitoring the battery voltage VBAT and transmitting it to the power transmission device 10 may be performed. The monitoring process of the recharge status is based on image 3 The monitoring results in the recharge monitoring circuit 64 are performed.

[0270] in Figure 14 In B1 of (B), the control circuit 52 on the power receiving side transmits to the power transmission device 10 a recharging command for notifying information about the recharging state of the storage battery 94. For example, when the control circuit 52 on the power receiving side determines that the storage battery 94 is in a rechargeable state based on the monitoring result in the recharge monitoring circuit 64, it sends a recharge instruction to the power transmission device 10. In addition, when the control circuit 22 on the power transmission side receives a recharge command from the power receiving device 40, it resets the full charge flag FC to 0 as shown in B2, and executes the normal operation for the power receiving device 40 again as shown in B3. Power transmission. That is, when it is determined that the storage battery 94 is in a rechargeable state based on the recharge command, the normal power transmission is executed again. As a result, recharging of the battery 94 can be started, and the battery 94 whose voltage has fallen can be recharged.

[0271] If the operation steps of a non-contact power transmission system that automatically perform a series of actions of ID authentication, normal power transmission, full charge detection, and recharge management are summarized, such as Figure 15 Shown. Figure 15 It is a flowchart showing the operation steps of a contactless power transmission system that automatically performs a series of operations of ID authentication, normal power transmission, full charge detection, and recharge management.

[0272] First, the processing on the power transmission side will be described. After completing the ID authentication with the power receiving side (secondary side), the power transmission side (primary side) resets the full charge flag FC to 0 (steps S1 and S2). Then, normal power transmission to the power receiving side is started (step S3). After that, detection of loading and unloading (removal) is performed (step S4), and when loading and unloading (removal) is detected, it shifts to the normal standby mode. That is, in figure 2 (A) (or figure 2 In (B)), when the mobile phone 510 is physically separated from the charger 500 and the magnetic flux of the primary coil L1 does not pass through the secondary coil L2, the attachment and detachment (removal) is detected, and the normal standby mode is transferred mode. In this normal standby mode, the intermittent power transmission such as the full-charge standby mode is not performed, and the power transmission is completely stopped until the mobile phone 510 is placed on the charger 500 again.

[0273] Next, it is judged whether the power transmitting side has received a full charge command from the power receiving side (step S5), and if it has not been received, it returns to step S4. On the other hand, when the full charge instruction is received, the full charge flag FC is set to 1 (step S6). In addition, in the first period (the power transmission stop period) T1, the power transmission from the power transmission side to the power reception side is stopped (step S7). This period T1 is measured by counting processing based on the clock signal on the power transmission side.

[0274] When the first period T1 has elapsed, the power transmission side performs power transmission again and performs intermittent power transmission, and sends a recharge detection command to the power receiving side (step S8). That is, a frame for instructing the detection of the recharge state is generated and transmitted to the power receiving side based on frequency modulation. In addition, after the second period (timeout waiting time) T2 has elapsed, timeout is waited for (step S9). That is, the power receiving side releases the reset state based on the intermittent power transmission, starts operation, and waits for the transmission of a recharge command. In the period until the second period T2 has elapsed, attachment/detachment detection (removal detection) is performed (step S10), and when attachment/detachment (removal) is detected, it shifts to the normal standby mode. In addition, in the period until the second period T2 has elapsed, it is monitored whether a recharge command is received from the power receiving side (step S11), and if the recharge command is not received, the process returns to step S9. In addition, when the second period T2 has elapsed and timed out, the process returns to step S7, and the power transmission from the power transmission side to the power reception side is stopped again. In addition, after the power transmission stop period T1 has elapsed, intermittent power transmission is performed, and a recharge detection command is sent to the power receiving side again (step S8). In this way, the power transmission side repeats the power transmission stop and the intermittent power transmission until the recharge command is received from the power receiving side.

[0275] If the power transmitting side receives a recharge command from the power receiving side in step S11, it returns to step S2 and resets the full charge flag FC to zero. In addition, the normal power transmission for recharging the storage battery 94 is executed again (step S3). As a result, recharging of the battery 94 whose voltage has dropped is started.

[0276] Next, the processing on the power receiving side will be described. After completing the ID authentication with the power transmitting side, the power receiving side starts normal power receiving (steps S21 and S22). After that, it is determined whether the storage battery 94 is in a fully charged state, and when the storage battery 94 is in a fully charged state, a full charging command is sent to the power transmission side (steps S23 and S24). That is, a frame for notifying the full charge is generated and sent to the power transmission side based on load modulation. Thereby, the power transmission side sets the full charge flag FC to 1, and stops power transmission (steps S6 and S7). In addition, the power receiving side stops voltage output to VOUT of the charging control device 92 (step S25). I.e. disconnect image 3 The transistors TB2 and TB1, and interrupt the electrical connection with the load 90. Specifically, the control circuit 52 turns the signal P1Q to H level, thereby turning off the transistor TB2.

[0277] If in Figure 15 In step S7 of the above, if the power transmission side stops power transmission, the power reception side is in a state where no power is being transmitted, and therefore, it becomes a reset state. After that, when the power transmission side starts intermittent power transmission, power is supplied to the power reception side, the power supply voltage on the power reception side rises, and the reset state is released (step S26). Then, it is determined whether the power receiving side has received the recharge detection command (step S27). In addition, if the recharge detection command is not received, the process shifts to the normal ID authentication process. That is, the processing in the normal standby mode is performed.

[0278] When the recharge detection command is received, it is determined whether or not the storage battery 94 needs to be recharged (step S28). Specifically, it is determined whether the battery voltage VBAT is lower than the recharging voltage (for example, 3.9V). In addition, when it is determined that recharging is unnecessary, the power transmission side does not respond. As a result, the timeout is reached in step S9 on the power transmission side, the power transmission from the power transmission side is stopped again, and the power reception side becomes a reset state.

[0279] On the other hand, when it is determined in step S28 that recharging is necessary, the power receiving side transmits a recharging command (step S29). After receiving the recharge command, the power transmission side resets the full charge flag FC to 0, and resumes normal power transmission (steps S2 and S3). Thereby, the power receiving side also performs normal power receiving again (step S22), and exits from the standby mode after fully charged.

[0280] As described above, after detecting that the storage battery 94 is fully charged according to the present embodiment, the power transmission side stops power transmission (step S7). In addition, the power receiving side stops the VOUT output to the charging control device 92 (step S25), and shifts to the fully charged standby mode. In this fully charged standby mode, the power transmission from the power transmission side is stopped. Therefore, the power reception control device 50 enters the reset state, and the VOUT output is stopped, and the charge control device 92 also enters the reset state. Therefore, the standby current flowing in the power receiving control device 50 or the charging control device 92 can be greatly reduced, and power saving can be achieved.

[0281] In addition, according to the present embodiment, after the power receiving side changes to the reset state, the power transmitting side performs intermittent power transmission and sends a recharge detection command (step S8). Thereby, when the reset state is released, the power receiving side performs the monitoring process of the recharge state by the instruction based on the received recharge detection command (steps S27, S28). In addition, when it is determined that recharging is necessary, a recharging command is sent (step S29).

[0282] That is, the power receiving side is in a reset state due to the stop of power transmission, and therefore, it is impossible to maintain information about full charge or recharge. In contrast, the power transmission side can maintain this information. In this embodiment, focusing on this point, during the intermittent power transmission period after the power transmission is stopped, the power transmission side sends a recharge detection command to the power reception side. In this way, even if the power receiving side that is released from the reset state does not maintain full charge or recharge related information, the recharge detection command from the power transmission side can be used as a trigger to start the monitoring process of the recharge state. In addition, when the power receiving side determines that it is in a rechargeable state, it can notify the power transmitting side that it is in a rechargeable state by sending a recharge command. As a result, the fully charged battery 94 can be appropriately recharged.

[0283] On the other hand, if the power transmission side has not received the recharge command within the period T2 and the time has expired, the power transmission is stopped again (steps S9 and S7). That is, until the recharging command is received, power transmission stop and intermittent power transmission are repeated. Therefore, the power receiving side ends only if it does not operate during the intermittent power transmission period. By making the power transmission stop period long enough, the standby current in the standby mode after fully charged can be greatly reduced. Therefore, it is possible to achieve the most appropriate recharging of the storage battery 94 while keeping unnecessary power consumption to a minimum.

[0284] (Removal detection processing after full charge)

[0285] After the full charge, when the power receiving device 510 is removed, there is no need to continue intermittent power transmission. Therefore, in order not to perform unnecessary power transmission, it is necessary to detect that the power receiving device 510 is removed after the full charge. Hereinafter, the removal detection after full charge will be specifically described.

[0286] The removal (loading and unloading) of the power receiving device after the full charge can be detected based on the following conditions, that is, for example, the power transmission device 10 performs intermittent power transmission to the power receiving device 40, and whether it can be received from the power receiving device 40 within a predetermined time To the above ID authentication information. That is, when the battery 94 becomes a fully charged state, the normal power transmission is stopped. As a result, the charging control device 92 (refer to image 3 ) Reset and return to the initial state. After the battery is fully charged, if intermittent power transmission is performed from the power transmission device 10 at predetermined intervals, the power receiving device 40 that receives the intermittent power transmission operates. As described above, the power receiving device 510 (or the power receiving device 40 ) ID authentication information is sent to the power transmission device 10 (refer to Figure 4 的 step S4). Therefore, if the power receiving device 510 is not removed, the ID authentication information should be transmitted from the power receiving device 40 to the power transmitting device 10 within a predetermined time from the time when the intermittent power transmission is started. If the ID authentication information is not transmitted from the power receiving device 40 to the power transmitting device 10 within the predetermined time, it is determined that the power receiving device 510 has been removed. In addition, such as Figure 19 As shown, by observing the AC waveform (ie, the amplitude of the AC voltage) at the coil end of the primary coil L1, the removal of the power receiving-side device 510 can also be detected.

[0287] In this embodiment, unlike the intermittent power transmission for detecting the necessity of recharging, the intermittent power transmission for removing detection is performed. As described above, the first period T10 of the removal detection after the full charge is set to a period (for example, 5 seconds) longer than the period of temporary power transmission (for example, 0.3 seconds), thereby suppressing an increase in power consumption. In addition, the frequency of recharging detection after full charge may be less frequent. Therefore, the second period T20 for full charge detection is set to be longer than the first period T10 (for example, set to 10 minutes). As a result, it is possible to continuously suppress power consumption to the minimum, and to perform each of the installation detection of the secondary side device, the detection of the need for recharging after full charging, and the removal detection after full charging in the most appropriate cycle. Detection. In addition, there is no need to use special hardware, and it is possible to perform removal (detachment) detection of the power-receiving side device after a full charge based on software. Therefore, even if there is no power-receiving-side device, unnecessary power transmission will not occur.

[0288] As explained above, when the automatic mode is selected, a convenient non-contact power transmission system can be realized. That is, according to at least one of the aforementioned embodiments, the following main effects can be obtained. However, it is not limited to simultaneously obtaining the following effects, and the enumeration of the following effects cannot be used as a basis for improperly limiting the technical scope of the present invention.

[0289] (1) In the non-contact power transmission system in which the automatic mode is selected, the setting of the power receiving device is automatically detected and normal power transmission starts. Therefore, the user does not need to perform switch operations, etc., which improves user convenience.

[0290] (2) By performing normal power transmission after ID authentication is performed, normal power transmission will not be performed to equipment that is not suitable for the system, which improves reliability and safety.

[0291] (3) During normal power transmission, various detection actions (removal detection, metal foreign body detection, encroachment detection based on periodic load authentication on the receiving side, and full charge detection) are performed, and if any of them are detected, they are quickly The normal power transmission is stopped and returned to the initial state. Therefore, no unnecessary power transmission is generated, and complete countermeasures against foreign objects can be implemented. Therefore, a system with extremely high reliability (safety) can be realized.

[0292] (4) Not only implement normal foreign matter countermeasures, but also use encroachment heat countermeasures to further improve the safety of the system. In addition, in the power receiving device, when performing intermittent load modulation (periodic load modulation) for encroachment detection, load reduction is performed, so that the power transmission device can reliably detect load changes and improve the accuracy of encroachment detection.

[0293] (5) Moreover, after fully charged, the recharge management (and removal detection) is automatically executed. Therefore, even if the power receiving side device is left on the charger for a long time, the battery is always fully charged. Therefore, users can use the contactless power transmission system with peace of mind, and can obtain sufficient satisfaction.

[0294] (6) The non-contact power transmission system of the present invention has an automatic mode (automatic execution mode) in which all the above-mentioned series of actions are automatically executed. Therefore, it does not cause a burden to the user, and a contactless power transmission system with extremely high convenience and convenient use can be realized.

[0295] (7) Based on the intermittent power transmission from the power transmission device, the installation detection of the power receiving side equipment, the recharge management after the full charge, and the removal detection are performed. Therefore, power consumption can be suppressed and low-power non-contact power can be realized Transmission system. If the periods of intermittent power transmission are optimized according to the above-mentioned purpose, power consumption can be further suppressed.

[0296] (8) The device structure is simplified, and the contactless power transmission system can be miniaturized and lowered in cost.

[0297] (Third embodiment)

[0298] In this embodiment, the operation procedure of the non-contact power transmission system in the switching mode will be described.

[0299] (Outline of operation of power transmission device in switch mode)

[0300] Figure 24 It is a schematic flowchart showing an example of the operation of the power transmission device in the switch mode. As shown in the part enclosed by the thick broken line, the operation of the power transmission device 10 is roughly divided into "confirmation of the power transmission object (step SA)" before power transmission and "confirmation of the power transmission environment during power transmission (including before power transmission) (step SB)" .

[0301] As described above, the power transmission device 10 starts temporary power transmission when the switch (SW1) is turned on (steps S1, S2).

[0302] Next, it is confirmed whether the installation position of the power receiving device 510 is appropriate (step S3), ID authentication of the power receiving device 510 (power receiving device 40) is performed, and it is determined whether it is an appropriate power transmission target (step S4). During ID authentication, since multiple retries are allowed, it is possible to prevent the user from turning on the switch (SW1) again due to an accidental ID authentication error, thereby improving user convenience.

[0303] If the position detection or ID authentication fails (step S5), the temporary power transmission is stopped, and the initial state of waiting for the switch to be turned on (that is, the state of waiting for step S1) is returned.

[0304] In addition, location detection is based on image 3 The position detection circuit 56 in the power receiving device 40 rectifies the DC voltage (ADIN) obtained by the induced voltage of the secondary coil (L2) to make a judgment.

[0305] After ID authentication, normal power transmission (charging power transmission) is started (step S6). During normal power transmission, detection of metal foreign objects (step S7), detection of an invading state based on periodic load fluctuation detection (steps S8, S9), and detection of removal (detachment) of the power receiving device (step S10) are performed, and , The detection of the forced closing of the switch (step S11) and the detection of the full charge notification (request for power transmission) are performed (step S12). After confirming any of the detections (step S13), the normal power transmission is interrupted (step S14), and the initial state is returned (the state of waiting for step S1).

[0306] The detection of metal foreign matter (step S7) and removal detection (step S10) can be performed based on the waveform change of the induced voltage signal of the primary coil (L1).

[0307] (An example of the configuration of the transmission side control circuit in switch mode)

[0308] Figure 25 It is a circuit diagram showing an example of the configuration of the power transmission side control circuit in the switch mode. As shown in the figure, the power transmission side control circuit 22 includes a logic circuit 100.

[0309] The logic circuit 100 includes: a noise removal circuit 102, used to remove the noise generated with the switch SW1 on/off; a flip-flop (F/F) 104, used to store the current state is the power transmission state It is also the initial state; the position detection unit 106; the ID authentication unit 108; the removal detection unit 110; the foreign object detection unit 112 (including the occupation state detection unit 114); the full charge notification (power transmission stop request) detection unit 116; the power transmission control unit 118, based on The detection results of each part control the on/off of power transmission.

[0310] (Basic timing example of non-contact power transmission system)

[0311] Figure 26 A basic sequence example of a contactless power transmission system is shown. As shown in the left part of the figure, a switch SW1 is provided in the power transmission side electronic device (power transmission side device) 500. The user sets the power receiving side electronic device (power receiving side device) 510 at a predetermined position and presses the switch SW1. Using the resulting edge (for example, negative edge NT) as a trigger (trigger), start temporary power transmission from the power transmission device 10 (step S20), perform position detection (step S21), and stop temporary power transmission if the position is inappropriate (Step S22).

[0312] If the installation position of the power receiving device 510 is appropriate, ID authentication is performed (step S23). That is, ID authentication information (manufacturer information, device ID number, quota information, etc.) is sent from the power receiving device to the power transmitting device. Because it is possible that ID authentication may not be permitted occasionally, considering the convenience of the user (in order to save the time of turning on the switch SW1 multiple times), it is preferable to allow a predetermined number of retry attempts (for example, three In the case of failure (in the case of NG), it is determined that the ID authentication has failed (step S24).

[0313] After ID authentication, the power transmission device 10 starts normal power transmission to the power receiving device 40 (step S26). During the normal power transmission period, if it is detected that the switch (SW1) is pressed (forcibly closed) (step S27), the normal power transmission is stopped and the initial state is returned (step S28).

[0314] In addition, as described above, removal detection (step S29), metal foreign object detection (step S30), periodic load authentication on the secondary side (including secondary side load reduction processing: step S31), and encroachment state detection (step S32) are performed, When either of them is detected, the normal power transmission is stopped (step S33). In addition, the load reduction associated with the periodic load certification on the secondary side refers to the following processing: even if the load (battery, etc.) is subjected to load modulation, the primary side cannot receive it well. In the case of modulating signals, when load modulation is performed, the power supply to the load is reduced (or stopped), so that the load state of the original load appears to be forcibly lowered (for this, use Figure 17 Detailed description).

[0315] in Figure 26 In the case where the power receiving device 40 detects full charge, it creates a full charge notification (save frame: power transmission stop request frame) and transmits it to the power transmission side (step S34). When the power transmission device 10 detects the full charge notification (the power transmission stop request frame) (step S35), it cuts off the normal power transmission and returns to the initial state (step S36).

[0316] Figure 27 Yes means execution Figure 26 The time sequence of the state transition diagram of the state transition of the contactless power transmission system. As shown in the figure, the state of the system is roughly divided into the initial state (idle state: ST1), position detection state (ST2), ID authentication state (ST3), power transmission (normal power transmission) state (ST4), periodic load authentication state (ST5) ) (And load reduction state ST6).

[0317] The switch is turned on (Q1), from ST1 to ST2, and when the position is detected NG, it returns to ST1 (Q2). If the location detection is OK, go to ST3 (Q3), monitor whether the ID authentication fails multiple times in succession (Q4), and return to ST1 if it is continuous NG (Q5). If ID authentication is OK (Q6), go to ST4.

[0318] In the normal power transmission state, SW1 close detection (Q7), removal detection (Q12), metal detection (Q10), encroachment detection (Q17), full charge detection (Q14) are executed, and if any of them is detected, recovery To the initial state (Q8, Q9, Q11, Q13, Q15).

[0319] In execution Figure 26 In the basic sequential non-contact power transmission system, power transmission starts with the turning on of the switch, and no power transmission is performed before this opportunity. Therefore, lower power consumption and improved safety can be achieved. In addition, if a full charge notification (a power transmission stop request) is received, the power transmission will be stopped and the initial state (waiting for the switch to turn on) will be stopped. Therefore, there will not be any unnecessary power transmission, which can achieve low power consumption. And the improvement of safety.

[0320] In addition, since ID authentication is used as a condition for normal power transmission, power transmission to inappropriate equipment will not be carried out, and reliability and safety can be improved.

[0321] In addition, during normal power transmission, various detection actions (removal detection, metal foreign object detection, encroachment detection based on periodic load authentication on the secondary side, and full charge detection) are executed, and if any of them are detected, it stops quickly The power is transmitted normally and returns to the initial state. Therefore, no unnecessary power transmission is generated, and complete countermeasures against foreign objects can be implemented. Therefore, a system with extremely high reliability (safety) can be realized.

[0322] Figure 28 as well as Figure 29 Yes means execution Figure 26 The basic sequence of the flow chart of the non-contact power transmission system operation example. in Figure 28 as well as Figure 29 , The operation flow of the primary side is shown on the left, and the operation flow of the secondary side is shown on the right.

[0323] Such as Figure 28 As shown, if the switch SW1 is turned on (step S40), temporary power transmission is started from the power transmission side (for example, the transmission frequency is f1: step S41), and counting by the counter is started (step S42). On the power receiving side, if the temporary power transmission is received, it will transition from the stop state (step S60) to the energized state (step S61), and perform position level judgment (position detection). If the position level is NG, return to the initial state (step S60). ), if the position level is OK, an ID authentication frame is generated (step S63), and the ID authentication frame is transmitted (step S64).

[0324] On the power transmission side, the ID authentication frame reception process (step S44) and time-out determination (step S43) are performed, and if the ID authentication frame cannot be received within a predetermined time, the power transmission is stopped (step S51). On the other hand, when the ID authentication frame cannot be received within the specified time, the frame authentication process is executed (step S45), and if the authentication is OK, the permission frame is sent to the power receiving side (step S47). In the case of NG authentication Next, power transmission is stopped (step S51).

[0325] The power receiving side verifies the permission frame from the power transmitting side (step S65), and transmits the start frame to the power transmitting side (step S66).

[0326] On the power transmission side, the start frame is verified (step S48), the detection of periodic load fluctuations (for detection of an invading state) is turned on (step S49), and charging power transmission (normal power transmission) is started (step S50). On the power receiving side, the charging power transmission (normal power transmission) is received, and the charging of the original load (for example, a storage battery) is started (step S67). Then, pass Figure 29 Explain the subsequent process. On the power transmission side, each detection of removal, metal foreign matter, encroachment state, and switch off is continuously performed (step S70), and a full charge notification (power transmission stop request) is waited for from the power receiving side (step S71).

[0327] On the power receiving side, the charging of the original load is continued, the periodic load modulation for detection of encroachment is performed (step S80), and the original load is fully charged (step S81). If full charge is detected, a full charge notification frame (hold frame: power transmission stop request) is sent to the power transmission side (step S82).

[0328] On the power transmitting side, if a full charge notification frame (save frame: power transmission stop request) is received from the power receiving side, the periodic load change detection is turned off (step S72), and power transmission is stopped (step S73).