Method and device for supporting foreign substance detection function in a wireless power transmission temporary interruption section in a wireless power transmission system

Abstract

The present disclosure provides a method and apparatus for transmitting wireless power to a wireless power receiver based on a first power by means of a wireless power transmitter, pausing the transmission of the wireless power by means of the wireless power transmitter, detecting a foreign substance by means of the wireless power transmitter during the period in which the transmission of the wireless power is paused by means of the wireless power transmitter, performing calibration by means of the wireless power transmitter based on the fact that the foreign substance is not detected by means of the wireless power transmitter, and transmitting the wireless power to the wireless power receiver based on a second power after performing the calibration by means of the wireless power transmitter.

Description

Technology Field

[0001] This specification relates to wireless power transmission. Background Technology

[0002] Wireless power transmission technology is a technology that transmits power wirelessly between a power source and an electronic device. For example, wireless power transmission technology enables the battery of a wireless terminal, such as a smartphone or tablet, to be charged simply by placing it on a wireless charging pad, thereby providing superior mobility, convenience, and safety compared to the existing wired charging environment using wired charging connectors. In addition to wireless charging of wireless terminals, wireless power transmission technology is attracting attention as a potential replacement for the existing wired power transmission environment in various fields, including electric vehicles, various wearable devices such as Bluetooth earphones and 3D glasses, home appliances, furniture, underground facilities, buildings, medical devices, robots, and leisure.

[0003] Wireless power transmission methods are also referred to as contactless power transmission methods, no point of contact power transmission methods, or wireless charging methods. A wireless power transmission system may be composed of a wireless power transmission device that supplies electrical energy via a wireless power transmission method, and a wireless power receiving device that receives electrical energy supplied wirelessly from the wireless power transmission device and supplies power to a receiving device such as a battery cell.

[0004] Wireless power transmission technologies are diverse, including methods that transmit power via magnetic coupling, radio frequency (RF), microwaves, and ultrasound. Methods based on magnetic coupling are further classified into magnetic induction and magnetic resonance. Magnetic induction is a method of transmitting energy by utilizing the current induced in the receiving coil due to the magnetic field generated by the battery cell of the transmitting coil, resulting from the electromagnetic coupling between the transmitting coil and the receiving coil. Magnetic resonance is similar to magnetic induction in that it utilizes a magnetic field. However, magnetic resonance differs from magnetic induction in that energy is transmitted through the phenomenon where a magnetic field is concentrated at both ends of the transmitting and receiving coils when resonance occurs when a specific resonant frequency is applied to the transmitting and receiving coils.

[0005] Hereinafter, a method and device for supporting a foreign substance detection function in a temporary interruption section of wireless power transmission are provided. means of solving the problem

[0006] According to one embodiment of the present specification, a wireless power transmitter can transmit wireless power to a wireless power receiver based on a first power. The wireless power transmitter can pause the transmission of the wireless power. The wireless power transmitter can detect a substance during the period in which the transmission of the wireless power is paused. The wireless power transmitter can perform calibration based on the fact that the substance is not detected. After performing the calibration, the wireless power transmitter can transmit the wireless power to the wireless power receiver based on a second power.

[0007] According to the present specification, the charger and receiver have the advantage of being able to improve FOD performance by measuring the Q-factor (quality factor) at the time calibration is required to secure a highly reliable calibration curve.

[0008] The effects obtainable through the specific examples of this specification are not limited to those listed above. For example, there may be various technical effects that a person having ordinary skill in the related art can understand or derive from this specification. Accordingly, the specific effects of this specification are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of this specification. Brief explanation of the drawing

[0009] FIG. 1 is a block diagram of a wireless power system (10) according to one embodiment. FIG. 2 is a block diagram of a wireless power system (10) according to another embodiment. Figure 3 shows examples of various electronic devices in which a wireless power transmission system is introduced. FIG. 4 is a block diagram of a wireless power transmission system according to one embodiment. FIG. 5 is a figure showing an example of a Bluetooth communication architecture to which an embodiment according to the present specification can be applied. FIG. 6 is a block diagram illustrating a wireless power transmission system using BLE communication according to an example. FIG. 7 is a block diagram illustrating a wireless power transmission system using BLE communication according to another example. Figure 8 is a state transition diagram to explain the wireless power transmission procedure. FIG. 9 schematically illustrates an example of a protocol for a ping phase (810). FIG. 10 schematically illustrates an example of a protocol for a configuration phase (820). FIG. 11 is a diagram illustrating the message field of a configuration packet (CFG) of a wireless power receiving device according to one embodiment. FIG. 12 is a flowchart schematically illustrating a protocol for a negotiation phase or a renegotiation phase according to one embodiment. FIG. 13 is a diagram illustrating the message field of a performance packet (CAP) of a wireless power transmission device according to one embodiment. FIG. 14 schematically illustrates a flowchart of the data flow for the power transfer phase (840) in the baseline protocol. FIG. 15 schematically illustrates a flowchart of the data flow for the power transfer phase (840) in the extended protocol. FIG. 16 illustrates an application-level data stream between a wireless power transmitter (100) and a wireless power receiver (200) according to an example. FIG. 17 illustrates a power control method according to one embodiment. Figure 18 schematically illustrates the structure of an MPP ID packet. Figure 19 schematically illustrates an example of an XID packet in MPP. Figure 20 schematically illustrates the protocol in MPP limited mode. Figures 21 and 22 schematically illustrate the protocol in MPP full mode. Figures 23 and 24 illustrate examples of the measurement / calculation of quality factors. FIG. 25 schematically illustrates a clock data packet transmitted by a wireless power receiver. FIG. 26 schematically illustrates a clock data packet transmitted by a wireless power transmitter. FIG. 27 schematically illustrates the clock phase initiated by the wireless power receiver. FIG. 28 schematically illustrates the clock phase initiated by the wireless power transmitter. Figure 29 schematically illustrates an example of a sensing ping. FIG. 30 schematically illustrates an example showing that improvements to FOD during charging are necessary during high-speed charging. FIG. 31 is a flowchart of a method for detecting foreign substances in a temporary interruption section of wireless power transmission according to one embodiment of the present specification. FIG. 32 schematically illustrates the power loss calibration operation using the FOD function during cloaking. Figure 33 schematically illustrates an example of a method for measuring Q-factor (quality factor) values ​​in conjunction with a cloaking function. FIGS. 34 and 35 schematically illustrate the configuration of the coil and driver of a wireless power transmitter. Figures 36 and 37 schematically illustrate the configuration of the coil and driver of a wireless power transmitter. FIG. 38 is a flowchart schematically illustrating an example of a correction protocol utilizing the FOD function during cloaking. FIG. 39 schematically illustrates a clock data packet transmitted by a wireless power receiver. Figure 40 schematically illustrates a GET data packet. Figure 41 schematically illustrates an FO presence packet. Figure 42 schematically illustrates an example of an additional method for an unadjusted charging architecture. Figure 43 schematically illustrates examples of high-power and low-power circuits. Figure 44 schematically illustrates an example of a transition from low power charging to high power charging. FIG. 45 is a flowchart of a method for detecting foreign substances in a temporary interruption period of wireless power transmission in the view of a wireless power transmitter, according to one embodiment of the present specification. FIG. 46 is a flowchart of a method for detecting foreign substances in a temporary interruption period of wireless power transmission from the perspective of a wireless power receiver, according to one embodiment of the present specification. Specific details for implementing the invention

[0010] In this specification, “A or B” may mean “only A,” “only B,” or “both A and B.” Alternatively, in this specification, “A or B” may be interpreted as “A and / or B.” For example, in this specification, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0011] As used herein, a slash ( / ) or a comma may mean “and / or.” For example, “A / B” may mean “A and / or B.” Accordingly, “A / B” may mean “only A,” “only B,” or “both A and B.” For example, “A, B, C” may mean “A, B or C.”

[0012] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as synonymous with “at least one of A and B.”

[0013] Additionally, in this specification, “at least one of A, B and C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” may mean “at least one of A, B and C.”

[0014] Additionally, parentheses used in this specification may mean “for example.” Specifically, when indicated as “Control Information (PDCCH),” “PDCCH” may be proposed as an example of “Control Information.” In other words, “Control Information” in this specification is not limited to “PDCCH,” and “PDCCH” may be proposed as an example of “Control Information.” Furthermore, even when indicated as “Control Information (i.e., PDCCH),” “PDCCH” may be proposed as an example of “Control Information.”

[0015] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously. The term "wireless power" as used below refers to any form of energy related to an electric field, magnetic field, electromagnetic field, etc., transmitted from a wireless power transmitter to a wireless power receiver without the use of physical electromagnetic conductors. Wireless power may also be referred to as a wireless power signal and may mean an oscillating magnetic flux enclosed by a primary coil and a secondary coil. For example, power conversion in a system for wirelessly charging devices including mobile phones, cordless phones, iPods, MP3 players, headsets, etc., is described herein. Generally, the basic principles of wireless power transmission include, for example, methods of transmitting power via magnetic coupling, methods of transmitting power via radio frequency (RF), methods of transmitting power via microwave, and methods of transmitting power via ultrasound.

[0016] FIG. 1 is a block diagram of a wireless power system (10) according to one embodiment.

[0017] Referring to FIG. 1, the wireless power system (10) includes a wireless power transmission device (100) and a wireless power receiving device (200).

[0018] A wireless power transmission device (100) generates a magnetic field by receiving power from an external power source (S). A wireless power receiving device (200) generates an electric current using the generated magnetic field and receives power wirelessly.

[0019] In addition, in the wireless power system (10), the wireless power transmission device (100) and the wireless power receiving device (200) can transmit and receive various information necessary for wireless power transmission. Here, communication between the wireless power transmission device (100) and the wireless power receiving device (200) can be performed according to either in-band communication using a magnetic field used for wireless power transmission or out-band communication using a separate communication carrier. Out-band communication may also be called out-of-band communication. Hereinafter, the term out-band communication will be used consistently. Examples of out-band communication may include NFC, Bluetooth, BLE (Bluetooth Low Energy), etc.

[0020] Here, the wireless power transmission device (100) may be provided as a fixed or mobile type. Examples of the fixed type include being embedded in a ceiling or wall or furniture such as a table indoors, being installed as an implant in an outdoor parking lot, bus stop or subway station, or being installed in a means of transportation such as a vehicle or train. The mobile wireless power transmission device (100) may be implemented as part of another device, such as a portable device of a movable weight or size, or a laptop computer cover.

[0021] Also, the wireless power receiving device (200) should be interpreted as a comprehensive concept that includes various electronic devices equipped with batteries and various home appliances that are powered wirelessly instead of using power cables. Representative examples of the wireless power receiving device (200) include portable terminals, cellular phones, smartphones, personal digital assistants (PDA), portable media players (PMP), Wibro terminals, tablets, phablets, notebooks, digital cameras, navigation terminals, televisions, and electric vehicles (EVs).

[0022] FIG. 2 is a block diagram of a wireless power system (10) according to another embodiment.

[0023] Referring to FIG. 2, in the wireless power system (10), there may be one or multiple wireless power receiving devices (200). In FIG. 1, the wireless power transmission device (100) and the wireless power receiving device (200) are depicted as exchanging power one-to-one, but as in FIG. 2, it is also possible for a single wireless power transmission device (100) to transmit power to multiple wireless power receiving devices (200-1, 200-2, ..., 200-M). In particular, when wireless power transmission is performed using a magnetic resonance method, a single wireless power transmission device (100) can transmit power to multiple wireless power receiving devices (200-1, 200-2, ..., 200-M) simultaneously by applying a simultaneous transmission method or a time-division transmission method.

[0024] Additionally, although FIG. 1 illustrates a wireless power transmission device (100) directly transmitting power to a wireless power receiving device (200), a separate wireless power transmission and reception device, such as a relay or repeater, may be provided between the wireless power transmission device (100) and the wireless power receiving device (200) to increase the wireless power transmission distance. In this case, power is transmitted from the wireless power transmission device (100) to the wireless power transmission and reception device, and the wireless power transmission and reception device can then transmit power to the wireless power receiving device (200).

[0025] In the following specification, the wireless power receiver, power receiver, and receiver refer to a wireless power receiving device (200). Additionally, the wireless power transmitter, power transmitter, and transmitter refer to a wireless power receiving transmission device (100).

[0026] Figure 3 shows examples of various electronic devices in which a wireless power transmission system is introduced.

[0027] Figure 3 illustrates electronic devices classified according to the amount of power transmitted and received in a wireless power transmission system. Referring to Figure 3a, a low-power (approximately 5W or less or approximately 20W or less) wireless charging method can be applied to wearable devices such as smart watches, smart glasses, HMDs (Head Mounted Displays), and smart rings, as well as mobile electronic devices (or portable electronic devices) such as earphones, remote controls, smartphones, PDAs, and tablet PCs.

[0028] Medium-to-small power wireless charging methods (approx. 50W or less or approximately 200W or less) may be applied to small and medium-sized home appliances such as laptops, robot vacuums, TVs, audio equipment, vacuum cleaners, and monitors. High-power wireless charging methods (approx. 2kW or less or 22kW or less) may be applied to kitchen appliances such as blenders, microwave ovens, and electric rice cookers, as well as personal mobility devices (or electronic devices / means of transportation) such as wheelchairs, electric scooters, electric bicycles, and electric vehicles.

[0029] The electronic devices / mobile means described above (or illustrated in FIG. 1) may each include a wireless power receiver described below. Accordingly, the electronic devices / mobile means described above can be charged by receiving power wirelessly from a wireless power transmitter.

[0030] The following description focuses on mobile devices to which a power wireless charging method is applied, but this is merely an example, and the wireless charging method according to the present specification can be applied to various electronic devices described above.

[0031] Standards regarding wireless power transmission include the Wireless Power Consortium (WPC), the Air Fuel Alliance (AFA), and the Power Matters Alliance (PMA).

[0032] The WPC consists of the Qi ecosystem, which targets mobile and wearable devices, and the HI ecosystem, which targets kitchen appliances, robots, LEVs (light electric vehicles), etc. Various wireless power transmission and reception devices using different power levels are covered by standards within each ecosystem and can be classified into different power classes or categories.

[0033] The Qi standard (belong to the Qi ecosystem) defines the baseline power profile (BPP), the extended power profile (EPP), and the magnetic power profile. The BPP relates to wireless power transmitters and receivers that support 5W power transmission, while the EPP and MPP relate to wireless power transmitters and receivers that support power transmission in a range greater than 5W and less than 15W. In-band (IB) communication is the mandatory communication protocol of the Qi spec, but out-band (OB) communication, which is used as an optional backup channel, may also be used. A wireless power receiver can identify whether it supports OB by setting an OB flag within a configuration packet. A wireless power transmitter that supports OB can enter the OB handover phase by transmitting a bit pattern for OB handover in response to the configuration packet. The response to the above configuration packet may be NAK, ND, or a newly defined 8-bit pattern. Applications of the Qi spec include smartphones.

[0034] The IND standard (belong to the HI ecosystem) relates to wireless power transmission and reception devices that provide guaranteed power of 30W to 150W. IB and OB communication channels may be used for mutual information exchange and power control. Applications of the IND spec include robots and power tools.

[0035] The LEV standard (belong to HI ecosystem) relates to wireless power transmission and reception devices that provide guaranteed power of 100W to 500W. IB is an essential communication channel for the LEV spec, and OB communication may also be used. IB can be used for initialization and link establishment to OB. The wireless power transmission device may enter the OB handover phase using a bit pattern for OB handover in response to a configuration packet.

[0036] The Ki standard (belong to the HI ecosystem) relates to wireless power transmission and reception devices that provide guaranteed power of 200W to 2kW, and necessarily uses OB communication channels such as NFC or BLE. Its applications include kitchen appliances.

[0037] Wireless power transmission and reception devices can provide a very convenient user experience and interface (UX / UI). That is, a smart wireless charging service can be provided. The smart wireless charging service can be implemented based on the UX / UI of a smartphone that includes a wireless power transmission device. For such an application, the interface between the smartphone's processor and the wireless charging receiver allows "drop and play" bidirectional communication between the wireless power transmission device and the receiver.

[0038] For example, a user can experience a smart wireless charging service at a hotel. When a user enters a hotel room and places a smartphone on a wireless charger in the room, the charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger transmits information regarding the smart wireless charging service to the smartphone. When the smartphone detects that it is positioned on the wireless charger, detects the reception of wireless power, or receives information regarding the smart wireless charging service from the charger, the smartphone enters a state to ask the user for consent (opt-in) to additional features. To this end, the smartphone may display a message on the screen, with or without an alarm sound. An example of a message could include phrases such as "Welcome to ### hotel. Select 'Yes' to activate smart charging functions : Yes | No Thanks." The smartphone receives input from the user selecting "Yes" or "No Thanks" and performs the next step selected by the user. If "Yes" is selected, the smartphone transmits the corresponding information to the wireless charger. Then, the smartphone and the wireless charger perform the smart charging function together.

[0039] Smart wireless charging services may also include receiving auto-filled WiFi credentials. For example, the wireless charger transmits WiFi credentials to a smartphone, and the smartphone runs an appropriate app to automatically fill in the WiFi credentials received from the wireless charger.

[0040] The smart wireless charging service may also include running a hotel application that offers hotel promotions, or obtaining remote check-in / check-out and contact information.

[0041] As another example, a user can experience a smart wireless charging service inside a vehicle. When a user enters the vehicle and places a smartphone on the wireless charger, the charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger transmits information regarding the smart wireless charging service to the smartphone. When the smartphone detects that it is positioned on the wireless charger, detects the reception of wireless power, or receives information regarding the smart wireless charging service from the charger, the smartphone enters a state where it requests identity verification from the user.

[0042] In this state, the smartphone automatically connects to the car via WiFi and / or Bluetooth. The smartphone can display a message on the screen, with or without an alarm sound. An example of a message might include phrases such as, "Welcome to your car. Select 'Yes' to sync device with in-car controls: Yes | No Thanks." The smartphone receives input from the user selecting Yes or No Thanks and performs the subsequent steps selected by the user. If Yes is selected, the smartphone transmits the corresponding information to the wireless charger. The smartphone and the wireless charger can then jointly perform smart in-car control functions by running in-car application / display software. The user can enjoy desired music and check their regular map location. The in-car application / display software may include the capability to provide synchronized access for pedestrians.

[0043] As another example, a user can experience smart wireless charging within their home. When a user enters a room and places a smartphone on a wireless charger, the charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger transmits information regarding the smart wireless charging service to the smartphone. When the smartphone detects that it is positioned on the wireless charger, detects the reception of wireless power, or receives information regarding the smart wireless charging service from the charger, the smartphone enters a state to ask the user for consent (opt-in) to additional features. To this end, the smartphone can display a message on the screen, with or without an alarm sound. An example of a message might include phrases such as, "Hi xxx, Would you like to activate night mode and secure the building?: Yes | No Thanks." The smartphone receives input from the user selecting Yes or No Thanks and performs the next step based on the user's selection. If Yes is selected, the smartphone transmits the corresponding information to the wireless charger. Smartphones and wireless chargers can at least recognize the user's patterns and suggest that the user lock doors and windows, turn off lights, or set alarms.

[0044] In the following, 'profile' is newly defined as an indicator or criterion representing / indicating compatibility. That is, it can be interpreted that compatibility is maintained and stable power transmission is possible between wireless power transceivers having the same 'profile,' while power transmission is impossible between wireless power transceivers having different 'profiles.' Profiles may be defined based on compatibility and / or applications, regardless of (or independently of) the ecosystem.

[0045] Profiles can be broadly classified into four categories: i) mobile, ii) robot, iii) kitchen, and iv) LEV.

[0046] For the 'mobile' profile, the Qi spec, communication protocol / method can be defined as IB and OB, and operating frequency can be defined as 87~205kHz and 300~400kHz, and examples of applications may include smartphones, laptops, wearables, etc.

[0047] For the 'Robot' profile, the IND spec, communication protocols / methods may be IB and OB, and examples of applications may include robots, power tools, etc.

[0048] For the 'Kitchen' profile, the Ki spec, communication protocol / method may be defined as NFC or BLE-based, and the operating frequency may be less than 100 kHz, and examples of applications may include kitchen / home appliances.

[0049] For the 'LEV' profile, the LEV spec, communication protocol / method is IB and OB, and examples of applications may include electric bicycles, electric scooters, etc.

[0050] NFC or BLE communication can be used as an OB communication channel between the wireless power transmission device and the receiving device of the above profile. When NFC is used, the wireless power transmission device and the receiving device can confirm to each other that they are NFC devices by exchanging WPC NDEF (NFC Data Exchange Profile Format).

[0051] FIG. 4 is a block diagram of a wireless power transmission system according to one embodiment.

[0052] Referring to FIG. 4, the wireless power transmission system (10) includes a mobile device (450) that receives power wirelessly and a base station (400) that transmits power wirelessly.

[0053] A base station (400) is a device that provides induced power or resonant power and may include at least one wireless power transmitter (power transmitter, 100) and a system circuit (405). The wireless power transmitter (100) can transmit induced power or resonant power and control the transmission. The wireless power transmitter (100) may include a power conversion circuit (110) that converts electrical energy into a power signal by generating a magnetic field through a primary coil(s), and a communications and control circuit (120) that controls communication with a wireless power receiver (200) and power transmission to transmit power at an appropriate level. The system circuit (405) can perform other operational controls of the base station (400), such as input power provisioning, control of multiple wireless power transmitters, and user interface control.

[0054] The primary coil can generate an electromagnetic field using alternating current power (or voltage or current). The primary coil receives alternating current power (or voltage or current) of a specific frequency output from the power conversion circuit (110) and, accordingly, can generate a magnetic field of a specific frequency. The magnetic field can be generated in a non-radiative or radiative manner, and the wireless power receiving device (200) receives it to generate current. In other words, the primary coil transmits power wirelessly.

[0055] In the magnetic induction method, the primary coil and the secondary coil can have any suitable form, and for example, they may be copper wire wound around a high-permeability material such as ferrite or amorphous metal. The primary coil may be called a transmitting coil, primary core, primary winding, primary loop antenna, etc. Meanwhile, the secondary coil may be called a receiving coil, secondary core, secondary winding, secondary loop antenna, pickup antenna, etc.

[0056] When using a magnetic resonance method, the primary coil and the secondary coil can be provided in the form of a primary resonant antenna and a secondary resonant antenna, respectively. The resonant antenna may have a resonant structure including a coil and a capacitor. In this case, the resonant frequency of the resonant antenna is determined by the inductance of the coil and the capacitance of the capacitor. Here, the coil may be formed in the form of a loop. Additionally, a core may be placed inside the loop. The core may include a physical core, such as a ferrite core, or an air core.

[0057] Energy transfer between the primary and secondary resonant antennas can be achieved through magnetic field resonance. Resonance refers to a phenomenon where, when a near-field corresponding to the resonant frequency is generated by one resonant antenna and another resonant antenna is located nearby, the two resonant antennas become coupled, resulting in high-efficiency energy transfer between them. When a magnetic field corresponding to the resonant frequency is generated between the primary and secondary resonant antennas, the two antennas resonate with each other. Consequently, compared to the general case where the magnetic field generated by the primary antenna is radiated into free space, the magnetic field is focused toward the secondary resonant antenna with higher efficiency; thus, energy can be transferred from the primary antenna to the secondary antenna with high efficiency. The magnetic induction method can be implemented similarly to the magnetic resonance method, but in this case, the frequency of the magnetic field does not need to be the resonant frequency. Instead, the magnetic induction method requires matching between the loops constituting the primary and secondary coils, and the spacing between the loops must be very close.

[0058] Although not shown in the drawing, the wireless power transmission device (100) may further include a communication antenna. The communication antenna can transmit and receive communication signals using a communication carrier other than magnetic field communication. For example, the communication antenna can transmit and receive communication signals such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

[0059] The communication / control circuit (120) can transmit and receive information with the wireless power receiving device (200). The communication / control circuit (120) may include at least one of an IB communication module or an OB communication module.

[0060] The IB communication module can transmit and receive information using a magnetic wave with a specific frequency as the center frequency. For example, the communication / control circuit (120) can perform in-band communication by transmitting communication information through a primary coil by carrying it on the operating frequency of wireless power transmission, or by receiving the operating frequency containing the information through the primary coil. At this time, information can be embedded in the magnetic wave or the magnetic wave containing the information can be interpreted using modulation methods such as binary phase shift keying (BPSK), frequency shift keying (FSK), or amplitude shift keying (ASK), and coding methods such as Manchester coding or non-return-to-zero level (NZR-L) coding. By using such IB communication, the communication / control circuit (120) can transmit and receive information over a distance of several meters at a data transmission rate of several kbps.

[0061] The OB communication module may also perform out-band communication through a communication antenna. For example, the communication / control circuit (120) may be provided as a short-range communication module. Examples of short-range communication modules include Wi-Fi 4, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0062] The communication / control circuit (120) can control the overall operation of the wireless power transmission device (100). The communication / control circuit (120) can perform calculations and processing of various information and control each component of the wireless power transmission device (100).

[0063] The communication / control circuit (120) may be implemented as a computer or a similar device using hardware, software, or a combination thereof. In terms of hardware, the communication / control circuit (120) may be provided in the form of an electronic circuit that processes electrical signals to perform control functions, and in terms of software, it may be provided in the form of a program that drives the hardware communication / control circuit (120).

[0064] The communication / control circuit (120) can control the transmission power by controlling the operating point. The operating point to be controlled may correspond to a combination of frequency (or phase), duty cycle, duty ratio, and voltage amplitude. The communication / control circuit (120) can control the transmission power by adjusting at least one of the frequency (or phase), duty cycle, duty ratio, and voltage amplitude. Additionally, the wireless power transmission device (100) may supply constant power, and the wireless power receiving device (200) may control the reception power by controlling the resonant frequency.

[0065] Meanwhile, in the WPC Qi system, wireless power transmitters (100) can be classified, for example, in terms of the number of primary coils that are activated for power transmission. At this time, wireless power transmitters (100) that support a maximum wireless power transmission amount of 5W (i.e., wireless power transmitters (100) that support the BPP protocol) can be classified, for example, into type A wireless power transmitters (100) and type B wireless power transmitters (100), and wireless power transmitters (100) that support a wireless power transmission amount of 5W or more (i.e., wireless power transmitters (100) that support the MPP or EPP protocol) can be classified, for example, into type MP-A wireless power transmitters (100) and type MP-B wireless power transmitters (100).

[0066] - Type A and Type MP A wireless power transmitters (100)

[0067] Type A and Type MP A wireless power transmitters (100) may have one or more primary coils. Since Type A and Type MP A wireless power transmitters (100) activate a single primary coil at a time, a single primary cell matching the activated primary coil may be used.

[0068] - Type B and Type MP B wireless power transmitters (100)

[0069] Type B and Type MP B power transmitters may have a primary coil array. Additionally, Type B and Type MP B power transmitters can enable free positioning. To this end, Type B and Type MP B power transmitters can realize primary cells at different locations on the interface surface by activating one or more primary coils in the array.

[0070] Additionally, a wireless power transmitter that utilizes magnets and supports a wireless power transmission amount of 5W or more (i.e., a wireless power transmitter that supports the MPP protocol) can be proposed, and the MPP protocol will be described later.

[0071] However, for standards after Qi v2.0, for high-power wireless power transmission, BPP supports a maximum power of 5W, EPP supports power exceeding 5W and up to 50W, and MPP supports power exceeding 5W and up to 50W. In other words, EPP or MPP can be seen as supporting power between 5 and 50W.

[0072] The mobile device (450) includes a wireless power receiver (200) that receives wireless power through a secondary coil and a load (455) that receives and stores the power received from the wireless power receiver (200) and supplies it to the device.

[0073] A wireless power receiving device (200) may include a power pick-up circuit (210) and a communications and control circuit (220). The power pick-up circuit (210) can receive wireless power through a secondary coil and convert it into electrical energy. The power pick-up circuit (210) rectifies the alternating current signal obtained through the secondary coil and converts it into a direct current signal. The communications and control circuit (220) can control the transmission and reception (power transfer and reception) of wireless power.

[0074] The secondary coil can receive wireless power transmitted from the wireless power transmission device (100). The secondary coil can receive power using the magnetic field generated from the primary coil. Here, when a specific frequency is the resonance frequency, a magnetic resonance phenomenon occurs between the primary coil and the secondary coil, allowing power to be received more efficiently.

[0075] Meanwhile, although not shown in FIG. 4, the communication / control circuit (220) may further include a communication antenna. The communication antenna can transmit and receive communication signals using a communication carrier other than magnetic field communication. For example, the communication antenna can transmit and receive communication signals such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

[0076] The communication / control circuit (220) can transmit and receive information with the wireless power transmission device (100). The communication / control circuit (220) may include at least one of an IB communication module or an OB communication module.

[0077] The IB communication module can transmit and receive information using a magnetic wave with a specific frequency as the center frequency. For example, the communication / control circuit (220) can perform IB communication by transmitting information carried on a magnetic wave through a secondary coil or by receiving a magnetic wave containing information through a secondary coil. At this time, information can be carried on a magnetic wave or a magnetic wave containing information can be interpreted using modulation methods such as binary phase shift keying (BPSK), frequency shift keying (FSK), or amplitude shift keying (ASK), and coding methods such as Manchester coding or non-return-to-zero level (NZR-L) coding. By using such IB communication, the communication / control circuit (220) can transmit and receive information over a distance of several meters at a data transmission rate of several kbps.

[0078] The OB communication module may also perform out-band communication through a communication antenna. For example, the communication / control circuit (220) may be provided as a short-range communication module.

[0079] Examples of short-range communication modules include Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

[0080] The communication / control circuit (220) can control the overall operation of the wireless power receiving device (200). The communication / control circuit (220) can perform calculations and processing of various information and control each component of the wireless power receiving device (200).

[0081] The communication / control circuit (220) may be implemented as a computer or a similar device using hardware, software, or a combination thereof. In terms of hardware, the communication / control circuit (220) may be provided in the form of an electronic circuit that processes electrical signals to perform control functions, and in terms of software, it may be provided in the form of a program that drives the hardware communication / control circuit (220).

[0082] When the communication / control circuit (120) and the communication / control circuit (220) are Bluetooth or Bluetooth LE as OB communication modules or short-range communication modules, the communication / control circuit (120) and the communication / control circuit (220) can each be implemented and operated with a communication architecture as shown in FIG. 5.

[0083] FIG. 5 is a figure showing an example of a Bluetooth communication architecture to which an embodiment according to the present specification can be applied.

[0084] Referring to FIG. 5, FIG. 5 (a) shows an example of a protocol stack of Bluetooth BR (Basic Rate) / EDR (Enhanced Data Rate) supporting GATT, and (b) shows an example of a protocol stack of Bluetooth LE (Low Energy).

[0085] Specifically, as illustrated in FIG. 5(a), the Bluetooth BR / EDR protocol stack may include an upper controller stack (Controller stack, 460) and a lower host stack (Host Stack, 470) based on the host controller interface (Host Controller Interface, HCI, 18).

[0086] The above host stack (or host module) (470) refers to a wireless transceiver module that receives a 2.4 GHz Bluetooth signal and hardware for transmitting or receiving Bluetooth packets, and the above controller stack (460) is connected to the Bluetooth module to control the Bluetooth module and perform operations.

[0087] The above host stack (470) may include a BR / EDR PHY layer (12), a BR / EDR Baseband layer (14), and a Link Manager layer (Link Manager, 16).

[0088] The above BR / EDR PHY layer (12) is a layer that transmits and receives 2.4 GHz wireless signals, and when using GFSK (Gaussian Frequency Shift Keying) modulation, it can transmit data by hopping 79 RF channels.

[0089] The above BR / EDR Baseband layer (14) is responsible for transmitting digital signals, selecting a channel sequence that hops 1400 times per second, and transmitting a time slot of 625 µs length for each channel.

[0090] The above link manager layer (16) controls the overall operation (link setup, control, security) of the Bluetooth connection using the Link Manager Protocol (LMP).

[0091] The above link manager layer (16) can perform the following functions.

[0092] - Performs ACL / SCO logical transport, logical link setup, and control.

[0093] - Detach: Terminates the connection and informs the other device of the reason for the termination.

[0094] - Perform power control and role switching.

[0095] - Performs security (authentication, pairing, encryption) functions.

[0096] The above host controller interface layer (18) provides an interface between the host module and the controller module, allowing the host to provide commands and data to the controller, and allowing the controller to provide events and data to the host.

[0097] The above host stack (or host module, 20) includes a logical link control and adaptation protocol (L2CAP, 21), an attribute protocol (Protocol, 22), a generic attribute profile (GATT, 23), a generic access profile (GAP, 24), and a BR / EDR profile (25).

[0098] The above logical link control and adaptation protocol (L2CAP, 21) can provide a single bidirectional channel for transmitting data to a specific protocol or profile.

[0099] The above L2CAP (21) can multiplex various protocols, profiles, etc. provided by Bluetooth.

[0100] Bluetooth BR / EDR's L2CAP uses dynamic channels, supports protocol service multiplexer, retransmission, and streaming modes, and provides segmentation and reassembly, per-channel flow control, and error control.

[0101] The above general attribute profile (GATT, 23) may operate as a protocol that explains how the attribute protocol (22) is used when configuring services. For example, the above general attribute profile (23) may operate to define how ATT attributes are grouped together into services and may operate to explain the features associated with the services.

[0102] Accordingly, the general attribute profile (23) and the attribute protocol (ATT, 22) may use features to describe the state and services of the device, and to describe how the features relate to each other and how they are used.

[0103] The above attribute protocol (22) and the above BR / EDR profile (25) define the definition of a service (profile) using Bluetooth BR / EDR and the application protocol for exchanging these data, and the above Generic Access Profile (GAP, 24) defines device discovery, connection, and security levels.

[0104] As illustrated in FIG. 5(b), the Bluetooth LE protocol stack includes a controller stack (480) operable to handle a timing-sensitive wireless device interface and a host stack (490) operable to handle high-level data.

[0105] First, the controller stack (480) can be implemented using a communication module that may include a Bluetooth wireless device, for example, a processor module that may include a processing device such as a microprocessor.

[0106] The host stack (490) can be implemented as part of an OS running on a processor module, or as an instance of a package on top of the OS.

[0107] In some cases, the controller stack and the host stack may operate or run on the same processing device within the processor module.

[0108] The above controller stack (480) includes a physical layer (PHY, 32), a link layer (34), and a host controller interface (36).

[0109] The above physical layer (PHY, wireless transceiver module, 32) is a layer that transmits and receives 2.4 GHz wireless signals and uses GFSK (Gaussian Frequency Shift Keying) modulation and a frequency hopping technique consisting of 40 RF channels.

[0110] The link layer (34), which is responsible for transmitting or receiving Bluetooth packets, performs Advertising and Scanning functions using 3 Advertising channels, creates a connection between devices, and provides the function of exchanging data packets of up to 257 bytes through 37 Data channels.

[0111] The above host stack may include GAP (Generic Access Profile, 40), Logical Link Control and Adaptation Protocol (L2CAP, 41), Security Manager (SM, 42), Attribute Protocol (ATT, 440), Generic Attribute Profile (GATT, 44), Generic Access Profile (25), and LT Profile (46). However, the above host stack (490) is not limited to these and may include various protocols and profiles.

[0112] The host stack uses L2CAP to multiplex various protocols, profiles, etc. provided by Bluetooth overlay.

[0113] First, L2CAP (Logical Link Control and Adaptation Protocol, 41) can provide a single bidirectional channel for transmitting data to a specific protocol or profile.

[0114] The above L2CAP (41) may be capable of multiplexing data between upper layer protocols, segmenting and reassembling packages, and managing multicast data transmission.

[0115] Bluetooth LE uses three fixed channels by default (one for the signaling CH, one for the Security Manager, and one for the Attribute protocol). Additionally, dynamic channels can be used as needed.

[0116] On the other hand, BR / EDR (Basic Rate / Enhanced Data Rate) uses dynamic channels by default and supports protocol service multiplexer, retransmission, streaming mode, etc.

[0117] SM (Security Manager, 42) is a protocol for authenticating devices and providing key distribution.

[0118] ATT (Attribute Protocol, 43) defines rules for accessing data from a counterpart device in a server-client structure. ATT includes the following six message types (Request, Response, Command, Notification, Indication, Confirmation).

[0119] ① Request and Response Messages: A Request message is a message used to request and transmit specific information from a client device to a server device, while a Response message is a response to a Request message and refers to a message that can be used to send from a server device to a client device.

[0120] ② Command Message: A message transmitted from a client device to a server device, primarily to instruct a specific action; the server device does not send a response to the Command message back to the client device.

[0121] ③ Notification Message: A message sent from a server device to a client device for notification, such as events; the client device does not send an acknowledgment message for the notification message to the server device.

[0122] ④ Indication and Confirm messages: Messages sent from a server device to a client device for notification, such as events. Unlike notification messages, the client device sends a confirmation message (Confirm message) for the indication message to the server device.

[0123] The present specification describes a GATT profile using the attribute protocol (ATT, 43) that transmits a value for the data length when a long data request is made, so that the client can clearly know the data length, and can receive a characteristic value from the server using a UUID.

[0124] The above General Access Profile (GAP, 45) is a newly implemented layer for Bluetooth LE technology and is used to control role selection for communication between Bluetooth LE devices and how multi-profile operation occurs.

[0125] In addition, the above general access profile (45) is primarily used for device discovery, connection creation, and security procedures, defines a method for providing information to the user, and defines the type of attribute as follows.

[0126] ① Service: Defines the basic operation of a device as a combination of data-related behaviors

[0127] ② Include: Defines the relationships between services

[0128] ③ Characteristics: Data values ​​used in the service

[0129] ④ Behavior: A computer-readable format defined by a UUID (Universal Unique Identifier, value type).

[0130] The above LE profile (46) is a profile that depends on GATT and is mainly applied to Bluetooth LE devices. The LE profile (46) may include, for example, Battery, Time, FindMe, Proximity, Time, etc., and the specific details of the GATT-based profiles are as follows.

[0131] ① Battery: Battery Information Exchange Method

[0132] ② Time: Method of exchanging time information

[0133] ③ FindMe: Provides alarm service based on distance

[0134] ④ Proximity: Battery Information Exchange Method

[0135] ⑤ Time: Method of exchanging time information

[0136] The above general attribute profile (GATT, 44) may operate as a protocol that explains how the attribute protocol (43) is used when configuring services. For example, the above general attribute profile (44) may operate to define how ATT attributes are grouped together into services and may operate to explain the features associated with the services.

[0137] Accordingly, the general attribute profile (44) and the attribute protocol (ATT, 43) may use features to describe the state and services of the device, and to describe how the features relate to each other and how they are used.

[0138] Below, we will briefly examine the procedures of Bluetooth Low Energy (BLE) technology.

[0139] BLE procedures can be divided into device filtering procedures, advertising procedures, scanning procedures, discovering procedures, and connecting procedures.

[0140] Device Filtering Procedure

[0141] The device filtering procedure is a method to reduce the number of devices performing responses to requests, instructions, notifications, etc., in the controller stack.

[0142] Since it is unnecessary to respond to requests received from all devices, the controller stack can reduce the number of requests sent, thereby controlling the BLE controller stack to reduce power consumption.

[0143] An advertising device or a scanning device may perform the device filtering procedure to restrict the device receiving the advertising packet, scan request, or connection request.

[0144] Here, an advertising device refers to a device that transmits advertising events, that is, performs advertising, and is also referred to as an advertiser.

[0145] A scanning device refers to a device that performs scanning or transmits a scan request.

[0146] In BLE, when a scanning device receives some advertisement packets from an advertisement device, the scanning device must send a scan request to the advertisement device.

[0147] However, if a device filtering procedure is used and the transmission of a scan request is unnecessary, the scanning device may ignore advertising packets transmitted from the advertising device.

[0148] Device filtering procedures may also be used during the connection request process. If device filtering is used during the connection request process, the connection request is ignored, thereby eliminating the need to transmit a response to the connection request.

[0149] Advertising Procedure

[0150] The advertising device performs an advertising procedure to carry out non-directional broadcasts to devices within the area.

[0151] Here, undirected advertising is advertising directed at all devices rather than a specific device, and all devices can scan the advertisement to request additional information or a connection.

[0152] In contrast, with directed advertising, only devices designated as receiving devices can scan the advertisement and request additional information or a connection.

[0153] The advertising process is used to establish a Bluetooth connection with a nearby initiation device.

[0154] Alternatively, the advertising process may be used to provide periodic broadcasts of user data to scanning devices that are listening on the advertising channel.

[0155] In the advertising process, all advertisements (or advertising events) are broadcast through physical advertising channels.

[0156] Ad devices may receive scan requests from listening devices that are listening to obtain additional user data from the ad devices. The ad device sends a response to the scan request to the device that sent the scan request through the same ad physical channel that received the scan request.

[0157] Broadcast user data sent as part of ad packets is dynamic data, whereas scan response data is generally static data.

[0158] An ad device can receive a connection request from a starter device on an ad (broadcast) physical channel. If the ad device has used a connectable ad event and the starter device has not been filtered by the device filtering procedure, the ad device stops the ad and enters connected mode. The ad device can start the ad again after entering connected mode.

[0159] Scanning Procedure

[0160] A device performing scanning, that is, a scanning device, performs a scanning procedure to listen for non-directional broadcasts of user data from advertising devices using advertising physical channels.

[0161] The scanning device transmits a scan request to the advertising device via an advertising physical channel to request additional data from the advertising device. The advertising device transmits a scan response, which is a response to the scan request, via the advertising physical channel, including the additional data requested by the scanning device.

[0162] The above scanning procedure can be used while connecting with other BLE devices in a BLE piconet.

[0163] If the scanning device receives a broadcasted advertisement event and is in an initiator mode capable of initiating a connection request, the scanning device can initiate a Bluetooth connection with the advertisement device by transmitting a connection request to the advertisement device through the advertisement physical channel.

[0164] When the scanning device sends a connection request to the advertising device, the scanning device stops initiator mode scanning for additional broadcasts and enters connection mode.

[0165] Discovery Procedure

[0166] Bluetooth-enabled devices (hereinafter referred to as "Bluetooth devices") perform advertising and scanning procedures to discover nearby devices or to be discovered by other devices within a given area.

[0167] The discovery process is performed asymmetrically. A Bluetooth device that seeks to find other nearby devices is called a discovering device, and it listens to find devices that advertise scannable ad events. A Bluetooth device that is discovered and available by other devices is called a discoverable device, and it actively broadcasts ad events through an advertising (broadcast) physical channel so that other devices can scan them.

[0168] Both the discovering device and the discoverable device may already be connected to other Bluetooth devices in the piconet.

[0169] Connecting Procedure

[0170] The connection procedure is asymmetric, and it requires that while a specific Bluetooth device performs the advertising procedure, another Bluetooth device performs the scanning procedure.

[0171] In other words, the advertising process can be the objective, and as a result, only one device will respond to the advertisement. After receiving an accessible advertising event from the advertising device, a connection can be initiated by sending a connection request to the advertising device through the advertising (broadcast) physical channel.

[0172] Next, we will briefly examine the operational states in BLE technology, namely the Advertising State, Scanning State, Initiating State, and Connection State.

[0173] Advertising State

[0174] The Link Layer (LL) enters the advertisement state upon the direction of the host (stack). When the Link Layer is in the advertisement state, it transmits advertisement PDUs (Packet Data Circuits) in advertisement events.

[0175] Each ad event consists of at least one ad PDU, and the ad PDUs are transmitted through the ad channel indices used. The ad event may be terminated earlier if the ad event ends when the ad PDUs are transmitted through the ad channel indices used, or if the ad device needs to free up space to perform other functions.

[0176] Scanning State

[0177] The link layer enters the scanning state at the direction of the host (stack). In the scanning state, the link layer listens for ad channel indices.

[0178] There are two types of scanning states: passive scanning and active scanning, and each scanning type is determined by the host.

[0179] No separate time or ad channel index is defined for performing scanning.

[0180] During the scanning state, the link layer listens for ad channel indices for a scan window duration. The scan interval is defined as the interval between the start points of two consecutive scan windows.

[0181] The link layer must listen for the completion of all scan intervals in the scan window as directed by the host, provided there are no scheduling conflicts. In each scan window, the link layer must scan different ad channel indexes. The link layer uses all available ad channel indexes.

[0182] In passive scanning, the link layer only receives packets and cannot transmit any packets.

[0183] When active scanning, the link layer performs listening to rely on ad PDU types that can request ad PDUs and additional information related to the ad device from the ad device.

[0184] Initiating State

[0185] The link layer enters the initiation state at the direction of the host (stack).

[0186] When the link layer is in the initiation state, the link layer performs listening for ad channel indices.

[0187] During the initiation state, the link layer listens for the ad channel index during the scan window period.

[0188] connection state

[0189] The link layer enters a connection state when the device performing the connection request—that is, the initiator device—transmits a CONNECT_REQ PDU to the advertiser device, or when the advertiser device receives a CONNECT_REQ PDU from the initiator device.

[0190] A connection is considered to be created after entering the connected state. However, it is not necessary to consider the connection established at the moment it enters the connected state. The only difference between a newly created connection and an established connection is the link layer supervision timeout value.

[0191] When two devices are connected, they act in different roles.

[0192] The link layer performing the master role is called the master, and the link layer performing the slave role is called the slave. The master controls the timing of connection events, and a connection event refers to the point in time when the master and the slave are synchronized.

[0193] Below, we will briefly examine the packets defined in the Bluetooth interface. BLE devices use the packets defined below.

[0194] Packet Format

[0195] The Link Layer has only one packet format used for both ad channel packets and data channel packets.

[0196] Each packet consists of four fields: Preamble, Access Address, PDU, and CRC.

[0197] When a packet is transmitted on an advertising channel, the PDU will be an advertising channel PDU, and when a packet is transmitted on a data channel, the PDU will be a data channel PDU.

[0198] Advertising Channel PDU

[0199] An ad channel PDU (Packet Data Circuit) has a 16-bit header and payloads of various sizes.

[0200] The PDU type field of the ad channel PDU included in the header represents the PDU type as defined in Table 1 below.

[0201] PDU Type Packet Name 0000 ADV_IND 0001 ADV_DIRECT_IND 0010 ADV_NONCONN_IND 0011 SCAN_REQ 0100 SCAN_RSP 0101 CONNECT_REQ 0110 ADV_SCAN_IND 0111-1111 Reserved

[0202] Advertising PDU (Advertising PDU)

[0203] The following ad channel PDU types are referred to as ad PDUs and are used in specific events.

[0204] ADV_IND: Connectable non-directional ad event

[0205] ADV_DIRECT_IND: Connectable directional ad events

[0206] ADV_NONCONN_IND: Non-connectable non-directional ad event

[0207] ADV_SCAN_IND: Scannable non-directional ad event

[0208] The above PDUs are transmitted at the Link Layer in the advertising state and received by the Link Layer in the scanning state or initiating state.

[0209] Scanning PDU

[0210] The advertising channel PDU type below is called a scanning PDU and is used in the conditions described below.

[0211] SCAN_REQ: Transmitted by the link layer in the scanning state and received by the link layer in the advertising state.

[0212] SCAN_RSP: Transmitted by the link layer in the ad state and received by the link layer in the scanning state.

[0213] Initiating PDU

[0214] The advertising channel PDU type below is called a launch PDU.

[0215] CONNECT_REQ: Transmitted by the link layer in the initiation state and received by the link layer in the advertisement state.

[0216] Data Channel PDU

[0217] A data channel PDU has a 16-bit header, payloads of various sizes, and may include a Message Integrity Check (MIC) field.

[0218] The procedures, states, packet formats, etc. in BLE technology discussed above can be applied to perform the methods proposed in this specification.

[0219] Referring again to FIG. 4, the load (455) may be a battery. The battery may store energy using power output from the power pickup circuit (210). Meanwhile, the mobile device (450) does not necessarily have to include a battery. For example, the battery may be provided as an external component that is detachable. As another example, the wireless power receiving device (200) may include a driving means for driving various operations of the electronic device instead of a battery.

[0220] The mobile device (450) is illustrated as including a wireless power receiving device (200) and the base station (400) is illustrated as including a wireless power transmitting device (100), but in a broader sense, the wireless power receiving device (200) may be identified with the mobile device (450) and the wireless power transmitting device (100) may be identified with the base station (400).

[0221] In cases where the communication / control circuit (120) and the communication / control circuit (220) include Bluetooth or Bluetooth LE as an OB communication module or a short-range communication module in addition to the IB communication module, the wireless power transmission device (100) including the communication / control circuit (120) and the wireless power receiving device (200) including the communication / control circuit (220) can be represented by a simplified block diagram as in FIG. 6.

[0222] FIG. 6 is a block diagram illustrating a wireless power transmission system using BLE communication according to an example.

[0223] Referring to FIG. 6, the wireless power transmission device (100) includes a power conversion circuit (110) and a communication / control circuit (120). The communication / control circuit (120) includes an in-band communication module (121) and a BLE communication module (122).

[0224] Meanwhile, the wireless power receiving device (200) includes a power pickup circuit (210) and a communication / control circuit (220). The communication / control circuit (220) includes an in-band communication module (221) and a BLE communication module (222).

[0225] In one aspect, BLE communication modules (122, 222) perform the architecture and operation according to FIG. 5. For example, BLE communication modules (122, 222) may be used to establish a connection between a wireless power transmission device (100) and a wireless power receiving device (200) and to exchange control information and packets necessary for wireless power transmission.

[0226] In another aspect, the communication / control circuit (120) may be configured to operate a profile for wireless charging. Here, the profile for wireless charging may be a GATT using BLE transmission.

[0227] FIG. 7 is a block diagram illustrating a wireless power transmission system using BLE communication according to another example.

[0228] Referring to FIG. 7, the communication / control circuits (120, 220) each include only in-band communication modules (121, 221), and the BLE communication modules (122, 222) may be provided separately from the communication / control circuits (120, 220).

[0229] In the following description, the coil or coil part may be referred to as a coil assembly, coil cell, or cell, including the coil and at least one element adjacent to the coil.

[0230] Meanwhile, when a user places a wireless power receiver (200) within the operating volume of a wireless power transmitter (100), the wireless power transmitter (100) and the wireless power receiver (200) begin communicating for the purpose of configuring and controlling power transmission. At this time, the power signal can provide a carrier for all communications, and the protocol for communication can be composed of multiple stages. The communication protocol will be described below.

[0231] Figure 8 is a state transition diagram to explain the wireless power transmission procedure.

[0232] WPC can define two communication protocols.

[0233] - Baseline Protocol (or BPP): This may refer to an original protocol that supports only one-way communication from a wireless power receiver (200) to a wireless power transmitter (100).

[0234] - Extended Protocol (or EPP): Supports bidirectional communication and enhanced FOD (foreign object detection) capabilities, and can also support data transmission stream functions and authentication options.

[0235] Referring to FIG. 8, the power transfer operation between a wireless power transmitter (100) and a wireless power receiver (200) according to one embodiment of the present specification can be broadly divided into a ping phase (810), a configuration phase (820), a negotiation phase (830), and a power transfer phase.

[0236] - Ping Phase (810)

[0237] In the ping phase (810), the wireless power transmitter (100) may attempt to establish communication with the wireless power receiver (200). Before attempting to establish communication, a measurement may be performed to determine whether there are any objects, such as bank cards, coins, or other metals, that may be damaged or heated during power transmission. Here, this measurement may be performed without waking up the wireless power receiver (200).

[0238] Here, the wireless power transmitter (100) can delay the conclusion regarding whether the detected metal is a foreign object or a friendly metal to a negotiation phase (830) after obtaining design information from the wireless power receiver (200).

[0239] - Configuration Phase (820)

[0240] In the configuration phase (820), the wireless power receiver (200) can send basic identification and configuration data to the wireless power receiver (200). Then, both the wireless power transmitter (100) and the wireless power receiver (200) can use this information to create a baseline power transfer contract.

[0241] Additionally, the wireless power transmitter (100) and the wireless power receiver (200) can determine whether to continue the Baseline Protocol or the Extended Protocol in the configuration phase (820).

[0242] Here, the wireless power receiver (200) can use features such as enhanced FOD, data transmission stream, and authentication only when implementing an extended protocol.

[0243] - Negotiation Phase (830)

[0244] In the negotiation phase (830), the wireless power transmitter (100) and the wireless power receiver (200) may establish an extended power transfer contract that includes additional settings and limits. Additionally, the wireless power receiver (200) may provide design information to the wireless power transmitter (100). Later, the design information may be used to complete the FOD before transitioning to the power transfer phase (840).

[0245] Here, the negotiation phase (830) may correspond to a phase that does not exist in the baseline protocol.

[0246] - Power transfer phase (840)

[0247] The power transfer phase (840) may be a phase in which power is transferred to the load of the wireless power receiver (200).

[0248] In the extension protocol, the wireless power transmitter (100) and the wireless power receiver (200) can perform system calibration when this step begins. This step may occasionally be paused to renegotiate elements of the power delivery contract. However, power delivery may continue even during such renegotiation.

[0249] Below, the protocols for the Ping Phase (810), Configuration Phase (820), Negotiation Phase (830), and Power Transfer Phase (840), which were previously described, will be explained in more detail.

[0250] 1. Ping Phase (810)

[0251] When the ping phase (810) begins, the wireless power transmitter (100) does not yet know whether the wireless power receiver (200) is within the operating volume. Additionally, the wireless power transmitter (100) cannot recognize the wireless power receiver (200). For this reason, the system is generally disabled due to a lack of power signal.

[0252] In such a situation, before the wireless power transmitter (100) initiates a digital ping to request a response from the wireless power receiver (200), the wireless power transmitter (100) may go through the following steps.

[0253] FIG. 9 schematically illustrates an example of a protocol for a ping phase (810).

[0254] According to FIG. 9, the wireless power transmitter (100) can perform an analog ping (S910). That is, the wireless power transmitter (100) can transmit an analog ping to determine whether an object is present in the operating volume. For example, the wireless power transmitter can detect whether an object is present in the operating volume based on a change in current of the transmitting coil or the primary coil.

[0255] The wireless power transmitter (100) can apply NFC tag protection (S920). Here, NFC tag protection can be performed through the following procedure.

[0256] a) First, it can be determined whether one or more of the detected objects include an NFC tag.

[0257] b) Afterwards, it can be verified whether the object containing the NFC tag can withstand the power signal without damage.

[0258] c) If the wireless power transmitter (100) determines that the NFC tag cannot withstand the power signal, it does not start a digital ping and maintains the ping phase, and the wireless power transmitter (100) can inform the user of the reason why it cannot continue.

[0259] The wireless power transmitter (100) can perform foreign object detection (S930). That is, the wireless power transmitter (100) can collect information that helps determine whether there is foreign object other than the wireless power receiver (200). To this end, the wireless power transmitter (100) can use various methods such as the free-power FOD method.

[0260] Meanwhile, in the three steps (S910, S920, S930) described above, the radio power receiver may not operate.

[0261] When the wireless power transmitter (100) performs the above steps and determines that there is a wireless power receiver (200) in the operating volume, the wireless power transmitter (100) may initiate a digital ping (S940). Here, the digital ping may request a response from the wireless power receiver (200), such as a signal strength (SIG) data packet or an End Power Transfer (EPT) data packet.

[0262] Subsequently, the wireless power transmitter (100) may receive a SIG or EPT from the wireless power receiver (200) (S950). Here, the SIG data packet may provide a measurement of the coupling, and the SIG data packet may include information regarding the signal strength value. Additionally, the EPT data packet may provide a request to stop power transmission and the reason for the request.

[0263] If the wireless power transmitter (100) does not receive such a response from the wireless power receiver (200), the wireless power transmitter (100) may remain in the ping phase (810) and repeat the steps above.

[0264] 2. Configuration Phase (820)

[0265] The configuration phase (820) is part of the following protocol.

[0266] - The wireless power receiver (200) can identify itself to the wireless power transmitter (100).

[0267] - The wireless power receiver (200) and the wireless power transmitter (100) can establish a baseline power transmission contract.

[0268] - The wireless power receiver (200) and the wireless power transmitter (100) can determine the protocol variant to be used for power transmission.

[0269] In the configuration phase (820), the wireless power transmitter (100) and the wireless power receiver (200) can continue to operate using digital ping parameters. This may mean that the power and current levels of both the wireless power transmitter (100) and the wireless power receiver (200) change only when the user moves the wireless power receiver (200) within the operating volume.

[0270] Below, the protocol in the configuration phase (820) will be described in more detail.

[0271] FIG. 10 schematically illustrates an example of a protocol for a configuration phase (820).

[0272] According to FIG. 10, the wireless power transmitter (100) can receive an ID (identification) from the wireless power receiver (200) (S1010). Alternatively, the wireless power transmitter (100) can also receive an XID (extended identification) from the wireless power receiver (200) (S1020). That is, the wireless power receiver (200) can identify itself using an ID data packet and optionally an XID data packet.

[0273] The wireless power transmitter (100) may optionally receive a power control hold-off (PCH) data packet from the wireless power receiver (200) (S1030), and the wireless power transmitter (100) may receive a CFG data packet from the wireless power receiver (200) (S1040). That is, the wireless power receiver (200) may provide data for use in a power delivery contract using the PCH and / or CFG data packets.

[0274] Finally, the wireless power transmitter (100) can check an extended protocol if possible (S1050).

[0275] The data packets explained earlier can be summarized as follows.

[0276] - ID: The ID data packet may be information identifying the wireless power receiver (200). Here, the ID may include a manufacturer code, a basic device identifier, etc. Additionally, the ID may also include information identifying the presence or absence of an XID data packet in the configuration phase.

[0277] - XID: The XID data packet may contain additional identification data.

[0278] - PCH: The PCH data packet can constitute the delay between the reception of the CE data packet and the wireless power transmitter (100) starting coil current adjustment.

[0279] - CFG: CFG data packets can provide basic configuration data.

[0280] For example, the CFG data packet can provide all parameters governing power transmission in the baseline protocol. In addition, the CFG data packet can provide all FSK communication parameters used in the extension protocol. Furthermore, the CFG data packet can provide additional functions of the wireless power receiver (200).

[0281] FIG. 11 is a diagram illustrating the message field of a configuration packet (CFG) of a wireless power receiving device according to one embodiment.

[0282] According to FIG. 11, a configuration packet (CFG) according to one embodiment may have a header value of 0x51, and the message field of the configuration packet (CFG) may include a 1-bit authentication (AI) flag and a 1-bit outband (OB) flag.

[0283] The Authentication Flag (AI) indicates whether the wireless power receiver supports authentication functions. For example, if the value of the Authentication Flag (AI) is '1', it indicates that the wireless power receiver supports authentication functions or can act as an Authentication Initiator, and if the value of the Authentication Flag (AI) is '0', it indicates that the wireless power receiver does not support authentication functions or cannot act as an Authentication Initiator.

[0284] The Outband (OB) flag indicates whether the wireless power receiver supports outband communication. For example, if the value of the Outband (OB) flag is '1', the wireless power receiver indicates outband communication, and if the value of the Outband (OB) flag is '0', it indicates that the wireless power receiver does not support outband communication.

[0285] The provision of the ID and / or XID explained earlier is for identification purposes. And, the provision of the PCH and / or CFG is for building a power delivery contract.

[0286] 3. Negotiation Phase (830)

[0287] The negotiation phase (830) is part of an extension protocol that allows the wireless power transmitter (100) and the wireless power receiver (200) to change the power transmission contract. There are two types of this phase.

[0288] - Negotiation Phase (830): The negotiation phase (830) follows directly after the configuration phase (820) and serves to create an initial extended power transmission contract. Additionally, the negotiation phase (830) also serves to complete the pre-power FOD function. Here, the length of the negotiation phase is not limited.

[0289] - Renegotiation Phase: The renegotiation phase may interrupt the power delivery phase (840) multiple times and generally serves to adjust a single element of the power delivery contract. Additionally, FOD / qf, FOD / rf, and SRQ / rpr data packets may not be used during the renegotiation phase. Restrictions on CE data packets in the power delivery phase (840) limit the length of the renegotiation phase.

[0290] During the negotiation or renegotiation phase, a Power Transfer Contract related to the reception / transmission of wireless power between a wireless power receiving device and a wireless power transmitting device may be extended or modified, a Power Transfer Contract may be renewed by adjusting at least some of the elements of the Power Transfer Contract, or information may be exchanged to establish outband communication.

[0291] FIG. 12 is a flowchart schematically illustrating a protocol for a negotiation phase or a renegotiation phase according to one embodiment.

[0292] Referring to FIG. 12, a wireless power transmitter (100) can receive an FOD status data packet (e.g., FOD) from a wireless power receiver (200) (S1210). Here, the wireless power receiver (200) can use the FOD status data packet to inform the wireless power transmitter (100) of the effect that its presence has on selected attributes of the reference wireless power transmitter (100). Then, the wireless power transmitter (100) can use this information to configure the FOD function.

[0293] The wireless power transmitter (100) can transmit an ACK / NAK for the above FOD status data packet to the wireless power receiver (200) (S1215).

[0294] Meanwhile, the wireless power receiver (200) can receive the ID (Identification data packet), CAP (Capabilities data packet), and XCAP (extended CAP) of the wireless power transmitter (100) using GRQ (General Request data packet).

[0295] A general request packet (GRQ) may have a header value of 0x07 and may include a message field of 1 byte. The message field of the general request packet (GRQ) may include the header value of a data packet that the wireless power receiver (200) requests from the wireless power transmitter (100) using the GRQ packet.

[0296] For example, in the negotiation phase or renegotiation phase, the wireless power receiver (200) can transmit a GRQ packet (GRQ / id) requesting an ID packet of the wireless power transmitter (100) to the wireless power transmitter (100) (S1220).

[0297] A wireless power transmitter (100) that has received a GRQ / id can transmit an ID packet to a wireless power receiver (200) (S1225). The ID packet of the wireless power transmitter (100) includes information about a 'Manufacturer Code'. The ID packet containing information about a 'Manufacturer Code' enables the identification of the manufacturer of the wireless power transmitter (100).

[0298] Alternatively, during the negotiation or renegotiation phase, the wireless power receiver (200) may transmit a GRQ packet (GRQ / cap) requesting a performance packet (CAP) of the wireless power transmitter (100) to the wireless power transmitter (100) (S1230). The message field of the GRQ / cap may include the header value (0x31) of the performance packet (CAP).

[0299] A wireless power transmitter (100) that receives GRQ / cap can transmit a performance packet (CAP) to a wireless power receiver (200) (S1235).

[0300] Alternatively, during the negotiation or renegotiation phase, the wireless power receiver (200) may transmit a GRQ packet (GRQ / xcap) requesting a performance packet (CAP) of the wireless power transmitter (100) to the wireless power transmitter (100) (S1240). The message field of the GRQ / xcap may include the header value (0x32) of the performance packet (XCAP).

[0301] A wireless power transmitter (100) that receives GRQ / xcap can transmit a performance packet (XCAP) to a wireless power receiver (200) (S1245).

[0302] FIG. 13 is a diagram illustrating the message field of a performance packet (CAP) of a wireless power transmission device according to one embodiment.

[0303] A performance packet (CAP) according to one embodiment may have a header value of 0x31, and, referring to FIG. 19, may include a message field of 3 bytes.

[0304] Referring to FIG. 13, the message field of the performance packet (CAP) may include a 1-bit authentication (AR) flag and a 1-bit outband (OB) flag.

[0305] The authentication flag (AR) indicates whether the wireless power transmitter (100) supports an authentication function. For example, if the value of the authentication flag (AR) is '1', it indicates that the wireless power transmitter (100) supports an authentication function or can operate as an authentication responder, and if the value of the authentication flag (AR) is '0', it indicates that the wireless power transmitter (100) does not support an authentication function or cannot operate as an authentication responder.

[0306] The outband (OB) flag indicates whether the wireless power transmitter (100) supports outband communication. For example, if the value of the outband (OB) flag is '1', the wireless power transmitter (100) indicates outband communication, and if the value of the outband (OB) flag is '0', the wireless power transmitter (100) indicates that it does not support outband communication.

[0307] During the negotiation phase, the wireless power receiver (200) receives a performance packet (CAP) of the wireless power transmitter (100) to check whether the wireless power transmitter (100) supports authentication functions and outband communication.

[0308] Returning to Fig. 12, the wireless power receiver (200) can update elements of a Power Transfer Contract related to the power to be provided in the Power Transfer Phase using at least one Specific Request Data Packet (SRQ) during the negotiation phase or renegotiation phase (S1250), and can receive an ACK / NAK for this (S1255).

[0309] Meanwhile, to confirm the extended power delivery contract and terminate the negotiation phase, the wireless power receiver (200) transmits an SRQ / en to the wireless power transmitter (100) (S1260) and can receive an ACK from the wireless power transmitter (100) (S1265).

[0310] 4. Power transfer phase (840)

[0311] The power transfer phase (840) is part of the protocol in which actual power is transferred to the load of the wireless power receiver (200). Here, the power transfer can proceed according to the terms of the power transfer agreement created in the negotiation phase (830).

[0312] <CE에 기반한 전력 제어>

[0313] The wireless power receiver (200) can control the power level by transmitting control error (CE) data, which measures the deviation between the target and the actual operating point of the wireless power receiver (200), to the wireless power transmitter (100). The wireless power transmitter (100) and the wireless power receiver (200) aim to make the control error data zero, at which point the system operates at the target power level.

[0314] In-power transfer FOD method

[0315] In addition to control error data, the wireless power transmitter (100) and the wireless power receiver (200) can exchange information to facilitate FOD. The wireless power receiver (200) periodically reports the amount of power received (received power level) to the wireless power transmitter (100), and the wireless power transmitter (100) can notify the wireless power receiver (200) whether foreign matter has been detected. A method that can be used for FOD in the power delivery phase may, for example, correspond to power loss calculation. In this approach, the wireless power transmitter (100) compares the received power level reported by the wireless power receiver (200) with the amount of transmitted power (transmitted power level) and can send a signal to the wireless power receiver (200) (regarding whether foreign matter has been monitored) when the difference exceeds a threshold value.

[0316] <Renegotiation Phase>

[0317] If necessary depending on the situation, the wireless power transmitter (100) or the wireless power receiver (200) may request renegotiation of the power transmission contract during the power transmission phase. Examples of changed situations in which renegotiation of the power transmission contract may take place may be as follows.

[0318] - When the wireless power receiver (200) requires more power than previously negotiated (substantially).

[0319] - When it is detected that the wireless power transmitter (100) is operating at low efficiency.

[0320] - When the wireless power transmitter (100) can no longer maintain the current power level due to the increased operating temperature (or vice versa, i.e., when the wireless power receiver (200) can operate at a higher power level after it has cooled sufficiently).

[0321] Here, an example of a specific protocol for the renegotiation phase is as described above.

[0322] <Data transmission stream>

[0323] The wireless power transmitter (100) and the wireless power receiver (200) can initiate a data transmission stream to exchange application-level data throughout the power delivery phase (840).

[0324] Here, an important common application is authentication, where both parties can verify each other's credentials in a tamper-proof manner. For example, the wireless power receiver (200) may want to verify the credentials of the wireless power transmitter (100) to ensure that the wireless power transmitter (100) is trusted to operate safely at high power levels. If appropriate credentials exist, it may mean that the compliance test has been passed.

[0325] Accordingly, the present specification may provide a method of initiating power delivery at a low power level and controlling power to a higher level only after the authentication protocol has been successfully completed.

[0326] <Protocol in power transfer phase (840)>

[0327] Up to this point, the operation between the wireless power transmitter (100) and the wireless power receiver (200) in the power transfer phase (840) has been described in a general manner. Below, to facilitate a smooth understanding of the operation in the power transfer phase (840), the protocol in the power transfer phase (840) will be described separately for the case of a baseline protocol and the case of an extended protocol.

[0328] FIG. 14 schematically illustrates a flowchart of the data flow for the power transfer phase (840) in the baseline protocol.

[0329] According to FIG. 14, the wireless power receiver (200) can transmit CE to the wireless power transmitter (100) (S1410). Here, the wireless power receiver (200) can generally transmit CE data packets several times per second.

[0330] The wireless power receiver (200) can transmit a received power (RP) data packet (RP8 in the baseline protocol) to the wireless power transmitter (100) generally once every 1.5 seconds (S1420).

[0331] Optionally, the wireless power receiver (200) can transmit a charge status (CHS) data packet to the wireless power transmitter (100) (S1430).

[0332] The data packet explained earlier can be summarized as follows.

[0333] - CE: The CE data packet may provide feedback on the desired power level. The CE data packet may include a control error value, which may be a signed integer value representing a relative measurement of the deviation between the actual operating point and the target operating point of the wireless power receiver (200). If the control error value is positive, it indicates that the actual operating point is below the target operating point and may request the wireless power transmitter (100) to increase the power signal. If the control error value is negative, it indicates that the actual operating point is above the target operating point and may request the wireless power transmitter (100) to decrease the power signal.

[0334] - RP8: The RP8 data packet can report the received power level. Here, the RP8 data packet can be included only in the baseline protocol.

[0335] - CHS: CHS data packets can provide the battery charge level under load.

[0336] FIG. 15 schematically illustrates a flowchart of the data flow for the power transfer phase (840) in the extended protocol.

[0337] According to FIG. 15, the wireless power receiver (200) can transmit CE to the wireless power transmitter (100) (S1510). Here, the wireless power receiver (200) can generally transmit CE data packets several times per second.

[0338] The wireless power receiver (200) can transmit a received power (RP) data packet (RP in the extended protocol) to the wireless power transmitter (100) generally once every 1.5 seconds (S1515).

[0339] In the power transfer phase, the control error packet (CE) and the received power packet (RP) are data packets that must be repeatedly transmitted and received in accordance with the timing constraints required for wireless power control.

[0340] The wireless power transmitter (100) can control the level of wireless power being transmitted based on the control error packet (CE) and the received power packet (RP) received from the wireless power receiver (200).

[0341] Meanwhile, in an extended protocol, the wireless power transmitter (100) can respond to a received power packet (RP) with a bit pattern such as ACK, NAK, ATN (S1520).

[0342] For a received power packet (RP / 0) with a mode value of 0, the wireless power transmitter (100) responding with an ACK means that power transmission can continue at the current level.

[0343] For a received power packet (RP / 0) with a mode value of 0, the wireless power transmitter (100) responding with NAK means that the wireless power receiver (200) must reduce power consumption.

[0344] For a received power packet (RP / 1 or RP / 2) with a mode value of 1 or 2, the wireless power transmitter (100) responding with an ACK means that the wireless power receiver (200) has accepted the power correction value included in the received power packet (RP / 1 or RP / 2).

[0345] For a received power packet (RP / 1 or RP / 2) with a mode value of 1 or 2, the wireless power transmitter (100) responding with NAK means that the wireless power receiver (200) did not accept the power correction value included in the received power packet (RP / 1 or RP / 2).

[0346] The previously described received power packet (RP / 1) with a mode value of 1 may represent the first calibration data point, and the received power packet (RP / 2) with a mode value of 2 may represent an additional calibration data point. Here, the wireless power receiver may transmit multiple additional power calibration values ​​by transmitting the received power packet (RP / 2) with a mode value of 2 multiple times to the wireless power transmitter, and the wireless power transmitter may proceed with the calibration procedure based on the received RP / 1 and multiple RP / 2s.

[0347] When the wireless power transmitter (100) responds to a received power packet (RP) with an ATN, it means that the wireless power transmitter (100) requests permission for communication. That is, the wireless power transmitter (100) can transmit an ATN (attention) response pattern to request permission to transmit a data packet in response to the RP data packet. In other words, the wireless power transmitter (100) can transmit an ATN to the wireless power receiver (200) in response to the RP data packet to request permission to transmit a data packet from the wireless power receiver (200).

[0348] Optionally, the wireless power receiver (200) can transmit a CHS (charge status) data packet to the wireless power transmitter (100) (S1525).

[0349] Meanwhile, the wireless power transmitter (100) and the wireless power receiver (200) can exchange DSR (data stream response) data packets, CAP data packets, and NEGO data packets to initiate renegotiation of elements (generally guaranteed load power) in the power transmission contract.

[0350] For example, the wireless power receiver (200) transmits a DSR data packet to the wireless power transmitter (100) (S1530), and the wireless power transmitter (100) can transmit a CAP to the wireless power receiver (200) (S1535).

[0351] In addition, the wireless power receiver (200) transmits a NEGO data packet to the wireless power transmitter (100) (S1540), and the wireless power transmitter (100) can transmit an ACK to the wireless power receiver (200) in response to the NEGO data packet (S1545).

[0352] Here, the data packets related to the initiation of the renegotiation phase can be organized as follows.

[0353] - DSR: Any one of the following values ​​can be set in the DSR data packet.

[0354] i) 0x00-DSR / nak: Indicates that the last received data packet from the wireless power transmitter (100) was rejected.

[0355] ii) 0x33-DSR / poll: Invite the wireless power transmitter (100) to send a data packet.

[0356] iii) 0x55-DSR / nd: Indicates that the last received data packet of the wireless power transmitter (100) was not expected.

[0357] iv) 0xFF-DSR / ack: Confirms that the last received data packet of the wireless power transmitter (100) has been properly processed.

[0358] - CAP: The CAP data packet provides information about the function of the wireless power transmitter (100). The specific details are as described above.

[0359] - NEGO: The NEGO data packet can request the wireless power transmitter (100) to proceed to the renegotiation stage.

[0360] The wireless power transmitter (100) and the wireless power receiver (200) can use ADC (auxiliary data control), ADT (auxiliary data transport), and DSR data packets for the exchange of application-level data.

[0361] That is, in terms of transmitting and receiving data transmission streams for the exchange of application-level data, the wireless power receiver (200) can transmit an ADC / ADT to the wireless power transmitter (100) (S1550), and the wireless power transmitter (100) can transmit an ACK / NAK to the wireless power receiver (200) in response to this (S1555). In addition, the wireless power receiver (200) can transmit a DSR to the wireless power transmitter (100) (S1560), and the wireless power transmitter can transmit an ADC / ADT to the wireless power receiver (S1565).

[0362] Here, the data transmission stream serves to transfer application-level data from the data stream initiator to the data stream responder. Application-level data can be broadly classified into i) authentication applications and ii) proprietary (general-purpose) applications.

[0363] Among application-level data, messages / information related to authentication applications can be organized as follows.

[0364] Messages used in an authentication procedure are called authentication messages. Authentication messages are used to carry information related to authentication. There are two types of authentication messages: one is an authentication request, and the other is an authentication response. An authentication request is transmitted by an authentication initiator, and an authentication response is transmitted by an authentication responder. Wireless power transmission devices and receivers can act as authentication initiators or authentication responders. For example, if a wireless power transmission device is an authentication initiator, a wireless power receiver becomes an authentication responder, and if a wireless power receiver is an authentication initiator, a wireless power transmission device becomes an authentication responder.

[0365] The authentication request message includes GET_DIGESTS, GET_CERTIFICATE, and CHALLENGE.

[0366] - GET_DIGESTS: This request can be used to retrieve certificate chain digests. The wireless power receiver (200) can request any number of digests at a time.

[0367] - GET_CERTIFICATE: This request can be used to read a segment of the target certificate chain.

[0368] - CHALLENGE: This request can be used to initiate certification of power transmitter product devices.

[0369] The authentication response message includes DIGESTS, CERTIFICATE, CHALLENGE_AUTH, and ERROR.

[0370] - DIGESTS: The wireless power transmitter (100) can use the DIGESTS response to send a certificate chain summary and report a slot containing a valid certificate chain summary.

[0371] - CERTIFICATE: This response can be used by the wireless power transmitter (100) to send the requested segment of the certificate chain.

[0372] - CHALLENGE_AUTH: The wireless power transmitter (100) can respond to a CHALLENGE request using CHALLENGE_AUTH.

[0373] - ERROR: This response can be used to transmit error information from the power transmitter.

[0374] Authentication messages may be called authentication packets, authentication data, or authentication control information. Additionally, messages such as GET_DIGEST and DIGESTS may be called GET_DIGEST packets, DIGEST packets, etc.

[0375] Meanwhile, as previously explained, the wireless power receiver (200) and the wireless power transmitter (100) can transmit application-level data through a data transmission stream. The application-level data transmitted through the data transmission stream may consist of a sequence of data packets with the following structure.

[0376] - Initial ADC data packet to open the stream.

[0377] i) Message types included in the stream.

[0378] ii) Number of data bytes in the stream.

[0379] - A series of ADT data packets containing the actual message.

[0380] - Final ADC / end data packet closing the stream.

[0381] Below, a data transmission stream for an example in which the above-mentioned ADC, ADT, and ADC / end data packets are used will be explained through a diagram.

[0382] FIG. 16 illustrates an application-level data stream between a wireless power transmitter (100) and a wireless power receiver (200) according to an example.

[0383] Referring to FIG. 16, the data stream may include auxiliary data control (ADC) data packets and / or auxiliary data transport (ADT) data packets.

[0384] ADC data packets are used to open a data stream. ADC data packets can indicate the type of message included in the stream and the number of data bytes. On the other hand, ADT data packets are sequences of data containing the actual message. ADC / end data packets are used to signal the end of a stream. For example, the maximum number of data bytes in a data transmission stream can be limited to 2047.

[0385] To indicate whether the ADC data packet and the ADT data packet have been received normally, an ACK or NAC (NACK) is used. Between the transmission timing of the ADC data packet and the ADT data packet, control information necessary for wireless charging, such as a control error packet (CE) or DSR, may be transmitted.

[0386] Using this data stream structure, authentication-related information or other application-level information can be transmitted and received between a wireless power transmission device and a receiving device.

[0387] An example for understanding the operation between the wireless power transmitter (100) and the wireless power receiver (200) in the power transfer phase (840) described above may be as follows.

[0388] FIG. 17 illustrates a power control method according to one embodiment.

[0389] In the power transfer phase of FIG. 17, the wireless power transmitter (100) and the wireless power receiver (200) can control the amount of power transferred by communicating in parallel with power transmission and reception. The wireless power transmitter and the wireless power receiver operate at a specific control point. The control point represents a combination of voltage and current provided at the output of the wireless power receiver when power transfer is performed.

[0390] To explain in more detail, the wireless power receiver selects a desired control point—such as a desired output current / voltage or the temperature of a specific location on a mobile device—and additionally determines the actual control point currently in operation. Using the desired control point and the actual control point, the wireless power receiver calculates a control error value and can transmit it to the wireless power transmitter as a control error packet.

[0391] Furthermore, the wireless power transmission device can control power transfer by using the received control error packet to set / control new operating points—amplitude, frequency, and duty cycle. Accordingly, the control error packet is transmitted / received at regular time intervals during the strategy transmission phase, and as an example, the wireless power receiving device can transmit the control error value by setting it to a negative value when intending to reduce the current of the wireless power transmission device, and to a positive value when intending to increase the current. In this way, in induction mode, the wireless power receiving device can control power transfer by transmitting the control error packet to the wireless power transmission device.

[0392] In resonant mode, operation can be performed in a manner different from that in inductive mode. In resonant mode, a single wireless power transmission device must be able to serve multiple wireless power reception devices simultaneously. However, when power transmission is controlled as in the aforementioned inductive mode, power transmission to additional wireless power reception devices may be difficult to control because the transmitted power is controlled by communication with a single wireless power reception device. Therefore, in the resonant mode of this specification, the wireless power transmission device transmits basic power in common, and the wireless power reception device controls the amount of power received by controlling its own resonant frequency. However, even in the operation of this resonant mode, the method described in FIG. 17 is not completely excluded, and additional control of transmitted power may be performed using the method of FIG. 17.

[0393] Operation based on power profile

[0394] Wireless charging methods include magnetic induction, which utilizes the phenomenon of magnetic induction between a primary coil and a secondary coil, and magnetic resonance, which transmits power by achieving magnetic resonance using frequencies in the range of tens of kHz to several MHz. Here, wireless charging standards for the magnetic resonance method are led by a council called A4WP, while standards for the magnetic induction method are led by the Wireless Power Consortium (WPC). In this case, the WPC is designed to allow the in-band exchange of various status information and commands related to the wireless charging system.

[0395] The Qi standard in WPC defines the Baseline Power Profile (BPP), Extended Power Profile (EPP), and Magnetic Power Profile. Below, BPP, EPP, and MPP will be explained individually.

[0396] A. Baseline power profile (BPP)

[0397] BPP relates to a power transfer profile between a wireless power transfer device and a receiver that supports power transfer up to 5W. In addition, unidirectional communication from a wireless power receiver to a wireless power transfer device is supported in BPP. The communication method in this case may correspond to ASK (amplitude shift keying). In BPP, protocol phases for ping, setup, and power transfer may exist.

[0398] B. EPP(extended power profile)

[0399] EPP relates to a power transfer profile between a wireless power transfer device and a receiver that supports power transfer up to 15W. In addition, EPP supports bidirectional communication between a wireless power receiver and a wireless power transfer device. The communication method from the wireless power receiver to the wireless power transfer device may correspond to ASK (amplitude shift keying), and the communication method from the wireless power transfer device to the wireless power receiver may correspond to FSK (frequency shift keying). In EPP, protocol phases such as ping, setup, negotiation, and power transfer may exist.

[0400] (a) Compatibility in EPP

[0401] EPP can correspond to the upper profile of BPP.

[0402] For example, if a BPP wireless power receiver is placed on an EPP wireless power transmitter, the EPP wireless power transmitter can operate as a BPP wireless power transmitter.

[0403] For example, if an EPP wireless power receiver is placed on a BPP wireless power transmitter, the EPP wireless power receiver can operate as a BPP wireless power receiver.

[0404] In other words, EPP can maintain compatibility with BPP.

[0405] (b) EPP indication method of EPP wireless power receiver

[0406] An EPP wireless power receiver can indicate that it is an EPP wireless power receiver by setting the 'neg' bit in the configuration packet (i.e., CFG) to 1. A specific example of a configuration packet is as described above.

[0407] (c) EPP indication method of EPP wireless power transmitter

[0408] When the EPP wireless power transmitter receives a configuration packet from the wireless power receiver in which the 'neg' bit is set to 1, the EPP wireless power transmitter can respond to the wireless power receiver with an ACK FSK bit pattern.

[0409] For reference, as explained above, BPP wireless power transmitters do not support the FSK communication method, so BPP wireless power transmitters cannot transmit FSK bit patterns. Accordingly, an EPP wireless power receiver that sends a configuration packet to a BPP wireless power transmitter with the 'neg' bit set to 1 can identify that the other wireless power transmitter is a BPP wireless power transmitter by failing to receive the above ACK response.

[0410] Meanwhile, starting with Qi v2.0, there is an intention to provide new power transfer profiles for wireless power transfer systems, and among the proposed power transfer profiles is the magnetic power profile (MPP). The MPP may correspond to a proprietary extension from Apple based on Qi v1.3.0.

[0411] C. MPP(magnetic power profile)

[0412] MPP relates to a power transfer profile between a wireless power transfer device and a receiver that supports power transfer up to 15W. In MPP, bidirectional communication between a wireless power receiver and a wireless power transfer device is supported. The communication method from the wireless power receiver to the wireless power transfer device may correspond to ASK (amplitude shift keying), and the communication method from the wireless power transfer device to the wireless power receiver may correspond to FSK (frequency shift keying). In this case, fast FSK (NCYCLE = 128) may be used during the negotiation and power transfer phases.

[0413] In MPP, there may be protocol phases of ping, setup, MPP negotiation, and MPP power transfer.

[0414] (a) Compatibility in MPP

[0415] MPP can correspond to the upper profile of BPP.

[0416] For example, if a BPP wireless power receiver is placed on an MPP wireless power transmitter, the MPP wireless power transmitter can operate as a BPP wireless power transmitter.

[0417] For example, if an MPP wireless power receiver is placed on a BPP wireless power transmitter, the MPP wireless power receiver can operate as a BPP wireless power receiver.

[0418] In other words, MPP can maintain compatibility with BPP.

[0419] (b) MPP operation of MPP wireless power receiver (MPP indication method)

[0420] MPP wireless power receivers can use specific MPP indicators within extended ID packets.

[0421] In order for an MPP wireless power receiver to indicate whether it supports MPP via an XID, the wireless power receiver must notify the wireless power transmitter that the XID is being transmitted via an ID packet. The ID packet transmitted by the MPP wireless power receiver may be as follows.

[0422] Figure 18 schematically illustrates the structure of an MPP ID packet.

[0423] According to Fig. 18, in the MPP ID packet, the values ​​of the major version fields from b4 to b7 of B0 can be set to 1.

[0424] In the MPP ID packet, the values ​​of the minor version fields from b0 to b3 of B0 may be values ​​determined later.

[0425] In the MPP ID packet, the values ​​of the manufacturer codes of B1 and B2 can be assigned as PRMC codes.

[0426] In the MPP ID packet, the value of the 'ext' field of b7 in B3 can be set to 1 to indicate that an additional XID packet is transmitted.

[0427] In the MPP ID packet, the values ​​of the random identifier fields b0 to b6 of B3, and b3 to b7 of B4 and B5 can be set according to the random device identification policy.

[0428] Figure 19 schematically illustrates an example of an XID packet in MPP.

[0429] According to Fig. 19, the XID packet in MPP may include an 'XID Selector' field, a 'Restricted' field, a 'Freq Mask' field, etc.

[0430] Here, whether MPP is supported can be determined based on whether the value of the 'XID selector' is 0xFE. That is, if the value of B_0 of the XID is 0xFE, the XID in this case may correspond to information indicating that the wireless power receiver supports MPP.

[0431] The 'Restricted' field may contain information indicating whether the wireless power receiver is operating in MPP restricted mode or MPP full mode. If the wireless power receiver is selected to operate in MPP restricted mode, the above field may be set to 1. On the other hand, in other cases (e.g., if the wireless power receiver is selected not to operate in MPP restricted mode), the above field may be set to 0.

[0432] The 'Preferred Frequency' field may represent the MPP preferred frequency. Here, if the wireless power receiver intends to retrieve information from the wireless power transmitter before frequency switching (in the negotiation phase), this field may be set to 128 kHz. Otherwise, the wireless power receiver may be set to 360 kHz.

[0433] The 'Freq Mask' field is a field used to determine whether an operating frequency of 360 kHz is supported. That is, if the 'Freq Mask' field is set to 0, 360 kHz is supported.

[0434] In summary, the wireless power transmitter determines whether the 'Ext' bit of the ID received from the wireless power receiver is set to 1 and whether B_0 of the XID is set to 0xFE, thereby determining whether the wireless power transmitter supports the MPP of the wireless power receiver.

[0435] (c) MPP operation of MPP wireless power transmitter (MPP indication method)

[0436] After detecting the placement of a wireless power receiver on a charging surface, the MPP wireless power transmitter can perform a digital ping using information contained in ID and XID packets and identify the receiver.

[0437] Here, the wireless power transmitter can determine that the wireless power receiver supports MPP if all of the following conditions are met.

[0438] - Qi Version: The Qi protocol version of the ID packet is set to (Major=1, Minor=TBD) or higher.

[0439] - MPP Support Notification: The subheader (byte 0) of the XID packet is set to the MPP selector.

[0440] If the above two conditions are not satisfied, the wireless power transmitter can proceed with subsequent procedures in accordance with the Qi v1.3 specification.

[0441] Meanwhile, depending on the MPP operating mode requested by the MPP wireless power receiver in the XID packet, the wireless power transmitter performs the following:

[0442] - Enable restricted profile (MPP restricted mode): When the 'restricted' flag is set to 1.

[0443] - Full profile enabled (MPP full mode): When the 'restricted' flag is set to 0.

[0444] Specific examples of the above limited profile and the full profile will be described later.

[0445] Meanwhile, when the MPP wireless power transmitter receives a configuration packet from the wireless power receiver in which the 'neg' bit is set to 1, the MPP wireless power transmitter (in MPP full mode) can respond to this with an MPP ACK FSK bit pattern to the wireless power receiver.

[0446] For reference, since wireless power transmitters in MPP limited mode do not support FSK communication methods, wireless power transmitters in MPP limited mode cannot transmit FSK bit patterns. However, since wireless power transmitters in MPP limited mode use a 360 kHz operating signal for power transmission, an MPP wireless power receiver that transmits a configuration packet to a wireless power transmitter operating in MPP limited mode by setting the 'neg' bit to 1 can identify that the other wireless power transmitter is a wireless power transmitter in MPP limited mode through the operating frequency.

[0447] (d) MPP mode

[0448] Meanwhile, there can be two modes in MPP. One is MPP Restricted mode (also known as MPP Baseline Profile), and the other is MPP Full mode (also known as MPP Full Profile).

[0449] To briefly explain the difference between the two, in MPP restricted mode, the 'restricted' field in XID is set to 1, whereas in MPP full mode, the 'restricted' field in XID is set to 0.

[0450] In addition, FSK communication is not supported in MPP limited mode, but it can be supported in MPP full mode.

[0451] Additionally, in MPP limited mode, FSK communication is not supported, so MPP ACKs for CFGs cannot be transmitted, and consequently, MPP negotiation is not supported in MPP limited mode. On the other hand, in MPP full mode, FSK communication is supported, so MPP ACKs for CFGs can be transmitted, and consequently, MPP negotiation can be supported in MPP full mode.

[0452] Below, MPP Limited Mode and MPP Full Mode will be explained in more detail. Here, MPP Limited Mode can be used in combination with the MPP Baseline Profile, and MPP Full Mode can be used in combination with the MPP Full Profile.

[0453] Below, to provide a comprehensive understanding of MPP limited mode and MPP full mode, the protocols in each mode will be explained in more detail.

[0454] i) MPP restricted mode

[0455] As previously explained, FSK communication is not supported in MPP-restricted mode. In other words, in MPP-restricted mode, there may be no data packets transmitted from the wireless power transmitter to the wireless power receiver. Against this backdrop, the protocol in MPP-restricted mode will be explained through the drawings.

[0456] Figure 20 schematically illustrates the protocol in MPP limited mode.

[0457] According to FIG. 20, the wireless power receiver can transmit a SIG to the wireless power transmitter on a first operating frequency (e.g., 128 kHz). In this case, the first operating frequency may correspond to an operating frequency at which BPP and / or EPP can be performed. And, the first operating frequency corresponds to the frequency at which the wireless power transmitter operates.

[0458] A wireless power receiver can transmit an ID packet to a wireless power transmitter on a first operating frequency. At this time, since an XID must be transmitted in the MPP, the 'ext' bit of the ID can be set to 1 to indicate that an additional XID is transmitted.

[0459] The wireless power receiver can transmit an XID packet to the wireless power transmitter on the first operating frequency.

[0460] The value of B0 in the XID at this time may be 0xFE, and if the value of B0 in the XID is set to 0xFE, this may correspond to information indicating that the wireless power receiver supports MPP. In addition, the 'Restricted' field in the XID at this time may be set to 1 to indicate that the wireless power receiver is operating in MPP restricted mode.

[0461] Here, if the wireless power transmitter receives the above XID packet indicating the MPP limiting mode, the wireless power transmitter can remove the power signal and restart the ping phase at a new operating frequency.

[0462] When the ping phase restarts, the wireless power receiver restarts from the transmission of the SIG. However, the operating frequency at this time may be the second operating frequency (e.g., 360 kHz).

[0463] Subsequently, the wireless power receiver transmits ID, XID, and CFG packets to the wireless power transmitter, respectively, at the second operating frequency. In addition, the wireless power receiver can receive wireless power based on the MPP baseline from the wireless power transmitter by transmitting the CEP to the wireless power transmitter.

[0464] ii) MPP full mode

[0465] As previously explained, FSK communication can be supported in MPP full mode. That is, in MPP full mode, data packets can be transmitted from the wireless power transmitter to the wireless power receiver. In other words, MPP negotiations can take place between the wireless power transmitter and the wireless power receiver. Against this backdrop, the protocol in MPP full mode will be explained using diagrams.

[0466] Figures 21 and 22 schematically illustrate the protocol in MPP full mode.

[0467] First, according to FIG. 21, the wireless power receiver can transmit a SIG to the wireless power transmitter on a first operating frequency (e.g., 128 kHz). At this time, the first operating frequency may correspond to an operating frequency in which BPP and / or EPP can be performed. And, the first operating frequency at this time corresponds to the frequency in which the wireless power transmitter operates.

[0468] A wireless power receiver can transmit an ID packet to a wireless power transmitter on a first operating frequency. At this time, since an XID must be transmitted in the MPP, the 'ext' bit of the ID can be set to 1 to indicate that an additional XID is transmitted.

[0469] The wireless power receiver can transmit an XID packet to the wireless power transmitter on the first operating frequency.

[0470] The value of B0 in the XID at this time may be 0xFE, and if the value of B0 in the XID is set to 0xFE, this may correspond to information indicating that the wireless power receiver supports MPP. In addition, the 'Restricted' field in the XID at this time may be set to 0 to indicate that the wireless power receiver is operating in full MPP mode.

[0471] Meanwhile, in MPP full mode, unlike MPP limited mode, the wireless power transmitter does not remove the power signal even when it receives an XID packet from the wireless power receiver. At this time, since the power signal is still not removed, the wireless power receiver transmits a CFG packet after the XID packet to the wireless power transmitter.

[0472] And, the wireless power receiver can receive an MPP ACK from the wireless power transmitter in response to the above CFG packet.

[0473] Upon receiving the MPP ACK, the wireless power receiver enters the negotiation phase with the wireless power transmitter, and both the wireless power receiver and the wireless power transmitter can proceed with the negotiation.

[0474] After the negotiation proceeds, the wireless power receiver can enter the power transfer phase with the wireless power transmitter.

[0475] Meanwhile, the wireless power receiver transmits an EPT packet to the wireless power transmitter. Upon receiving the EPT packet, the wireless power transmitter removes the power signal and can then restart the ping phase at a new operating frequency.

[0476] According to FIG. 22, when the ping phase is restarted, the wireless power receiver restarts from the transmission of the SIG. However, the operating frequency at this time may be the second operating frequency (e.g., 360 kHz).

[0477] Subsequently, the wireless power receiver transmits ID, XID, and CFG packets to the wireless power transmitter, respectively, at the second operating frequency. Then, the wireless power receiver can receive an MPP ACK from the wireless power transmitter.

[0478] The wireless power receiver that receives the MPP ACK enters a negotiation phase with the wireless power transmitter at the second operating frequency, and both the wireless power receiver and the wireless power transmitter can proceed with negotiation.

[0479] After the negotiation proceeds, the wireless power receiver enters the power transfer phase with the wireless power transmitter at the second operating frequency. In addition, the wireless power receiver can receive wireless power based on MPP full mode from the wireless power transmitter by transmitting XCE to the wireless power transmitter and receiving a response (e.g., an ACK) to it.

[0480] Quality Factor Measurement

[0481] Below, we will explain the measurement of the quality factor (Q-factor).

[0482] Figures 23 and 24 illustrate examples of the measurement / calculation of quality factors.

[0483] The quality factor, i.e., the Q-factor, in FIGS. 23 and 24 is wL / R, which corresponds to a physical property used to find the resistance (R) component under given inductance (L) and frequency (w) conditions. In addition, the above quality factor may be a value used for foreign object detection (FOD) between a wireless power transmitter and a wireless power receiver.

[0484] More specifically, the wireless power receiver can store its reference Q-factor value in advance and transmit the reference Q-factor value to the wireless power transmitter via a packet during the negotiation phase. In this case, the reference Q-factor value can be transmitted from the wireless power receiver to the wireless power transmitter, for example, via FOD / xx (e.g., FOD / rf, FOD / qf) during the negotiation phase.

[0485] A wireless power transmitter can measure the Q-factor by generating a small signal before wireless charging (i.e., before power transfer). Then, the wireless power transmitter can determine whether FOD (i.e., foreign substance detection) is present by comparing the Q-factor value it measured with the value reported by the wireless power receiver (e.g., the reference Q-factor value).

[0486] <In-Power FOD Method: Calibrated Power Loss Account>

[0487] Wireless charging devices using the WPC Qi standard measure power loss during charging to determine the presence or absence of foreign substances (FO) during charging.

[0488] This method has a technical limitation in that precision decreases as transmission power increases, so a correction function was adopted to overcome this.

[0489] Through calibration, the loss caused by the friendly metal can be set to zero, and this can be set as a reference point.

[0490] By measuring the influence of the friendly metal component present in the receiver itself under current alignment conditions and reflecting it in the foreign substance detection algorithm, there is an effect of improving accuracy.

[0491] If calibration is performed in the presence of foreign substances, the amount of power loss currently occurring from the foreign substances is used as the reference point. However, using the power loss from foreign substances as the reference point in this way results in a counterproductive effect where the foreign substance detection performance actually deteriorates.

[0492] Therefore, it is necessary to verify that there are no foreign substances (No FO) by measuring the Q-factor immediately before calibration.

[0493] The present specification will be described in more detail below.

[0494] <Cloak>

[0495] A clock is a method of momentarily suspending power transmission without notifying the user or resetting negotiated power transmission contract elements. Power transmission can be suspended for various reasons, including thermal management, power budget changes, and coexistence.

[0496] The clock state can be initiated by the wireless power receiver or requested by the wireless power transmitter using an MPP clock (CLOAK) data packet (ASK method: wireless power receiver, FSK: wireless power transmitter).

[0497] The clock state begins when the wireless power transmitter terminates power delivery after processing the ASK clock data packet.

[0498] The clock state consists of a power interruption period and a short power transmission period (cloak ping). This short power transmission period is called a cloak ping.

[0499] The power receiver (PRx) can maintain the clock state by responding to a clock ping with a clock data packet, and

[0500] Alternatively, you can end the clock state by starting a clock termination handshake.

[0501] In summary, a clock is a function that allows the magnetic field to be temporarily suspended without restarting the protocol.

[0502] It can be initiated by a wireless power transmitter or a wireless power receiver, and the magnetic field can be stopped and / or restored at mutually agreed time intervals.

[0503] Upon restoration of the magnetic field, the protocol resumes as a power transfer phase while retaining all information from before the interruption.

[0504] When the wireless power receiver sends a command (CLOAK packet) to the wireless power transmitter to start this function, the wireless power transmitter stops generating the magnetic field.

[0505] This function enables the wireless power transmitter and wireless power receiver to communicate periodically with each other so that the wireless power transmitter or wireless power receiver can lower the temperature or stop unnecessary magnetic fields when battery charging is complete, while maintaining a UI for the user indicating that charging is in progress.

[0506] Here, the clock data packet transmitted by the wireless power receiver can be described as follows.

[0507] FIG. 25 schematically illustrates a clock data packet transmitted by a wireless power receiver.

[0508] According to FIG. 25, the clock data packet allows the wireless power receiver to start the clock. The clock data packet may include a reason field.

[0509] The reason codes may be as shown in the table below.

[0510] Value Reason 0 Cloak: General (Generic) 1 Cloak: Forced (Unclock request denied) 2 Cloak: Thermally constrained 3 Cloak: Insufficient Power 4 Cloak: Coex Mitigation (A wireless power receiver requests a clock to perform a task that cannot coexist with wireless power) 5 Cloak: End of Charge 6 Cloak: Initiated by wireless power transmitter (PTx initiated) 7 Reserved

[0511] In response to the above clock data packet, the wireless power transmitter can perform the following response.

[0512] Response Description ACK Agree to the wireless power transmitter start / continue cloaking NAK The pattern is not allowed ND Pattern transmitted when using the code for the reason why wireless power receivers are not supported ATN Cloak state: The wireless power transmitter requests clock shutdown. Other state: The wireless power transmitter prefers to communicate before cloaking.

[0513] FIG. 26 schematically illustrates a clock data packet transmitted by a wireless power transmitter.

[0514] According to FIG. 26, a clock request data packet can allow the wireless power transmitter to begin entering a clock state. The clock data packet may include a reason field.

[0515] The reason codes may be as shown in the table below.

[0516] Value Reason 0 Cloak: General (Generic) 1 Reserved 2 Cloak: Thermally constrained 3 Cloak: Insufficient Power 4 Cloak: Coex Mitigation (Wireless power transmitter requests a clock to perform tasks that cannot coexist with wireless power) 5 - 15 Reserved

[0517] Meanwhile, as previously explained, a wireless power receiver or a wireless power transmitter may initiate the clock. In this case, the clock phase initiated by the wireless power receiver and the clock phase initiated by the wireless power transmitter may be described as follows.

[0518] FIG. 27 schematically illustrates the clock phase initiated by the wireless power receiver.

[0519] According to Fig. 27, the wireless power receiver starts the clock by transmitting a clock data packet to the wireless power transmitter.

[0520] Here, the wireless power transmitter must respond in one of the following ways after receiving a clock data packet.

[0521] - Remove Power Signal: The wireless power transmitter removes the power signal after receiving the clock data packet to reduce the total ping duration, which can implicitly confirm that the cloaking request has been accepted.

[0522] - FSK - ATN: Indicates that the wireless power transmitter is not ready to enter the clock state and may request clock termination.

[0523] In summary, the wireless power transmitter that receives the clock packet from the wireless power receiver removes the magnetic field (removal of power signal) for the t_cloak time received during the negotiation phase and then returns (i.e., generates the magnetic field again).

[0524] The wireless power receiver disconnects the load when it detects that the magnetic field has disappeared upon entering the clock.

[0525] The wireless power transmitter performs a clock ping when returning. This clock ping can be performed in the same way as when the wireless power transmitter generated the initial digital ping.

[0526] The wireless power transmitter can determine the presence of the wireless power receiver and its intention to sustain the clock phase by confirming that the wireless power receiver sends a clock packet to the digital ping generated at a promised period.

[0527] As explained above, the wireless power transmitter can also initiate the clock phase.

[0528] FIG. 28 schematically illustrates the clock phase initiated by the wireless power transmitter.

[0529] According to Fig. 28, the wireless power transmitter can start the clock by transmitting a clock request to the wireless power receiver using the wireless power transmitter clock data packet described above.

[0530] After successfully receiving the request, the wireless power receiver can start the clock sequence by responding with the wireless power receiver clock (CLOAK) data packet described above within t_ptxcloak.

[0531] If the ASK clock (CLOAK) data packet is not received within t_ptxcloaktimeout, the wireless power transmitter may resend the request.

[0532] In a scenario where a wireless power transmitter starts the clock, the wireless power transmitter must always respond with an FSK (ACK or ATN) to the clock data packet before removing the power signal.

[0533] In a scenario where the wireless power transmitter starts the clock, if the wireless power receiver fails to decode the FSK response, it must attempt to decode it again on the next clock ping (retry). If FSK decoding continues to fail even after the retry, the wireless power receiver must switch to the ping phase.

[0534] The wireless power transmitter can determine the presence of the wireless power receiver and its intention to sustain the clock phase by confirming that the wireless power receiver sends a clock packet to the digital ping generated at a promised period.

[0535] The wireless power transmitter can request to stop maintaining the clock phase at its own discretion. This is possible by sending an FSK response with 'ATN' in the clock packet.

[0536] When a wireless power receiver wishes to interrupt the clock phase on its own, it may express its intention by sending a REPORT [wireless power receiver ID] instead of a CLOAK, and the wireless power transmitter must unconditionally accept (FSK ACK).

[0537] <detect ping>

[0538] Below is an explanation of generating a detection ping in the clock phase.

[0539] Power receivers can select an option to increase the clock period. This is used to reduce the thermal footprint caused by the clock ping. However, since increasing the clock period also increases the device removal detection latency, some devices may need to enable the device presence detection ping during the clock to reduce the detection latency.

[0540] Figure 29 schematically illustrates an example of a sensing ping.

[0541] According to FIG. 29, the power receiver (PRx) can negotiate a device presence detection mechanism and can use an SRQ / detect request for this purpose. This allows both the power transmitter (PTx) and the power receiver (PRx) to detect whether the device is removed or present during a long clock period.

[0542] If Detect Ping is enabled (negotiated at the power receiver), the power transmitter (PTx) can apply detection mechanisms such as Object Detection and Low Power Ping during the t_cloakdetect timing. Additionally, Short Power Ping can be applied during the t_dactive time.

[0543] Through this short power ping, the power receiver (PRx) can detect the presence of the power transmitter (PTx).

[0544] In summary, the wireless power receiver can have a long cloak period, and receive information on the presence or absence of the wireless power transmitter and wireless power receiver at a desired frequency with low energy ping.

[0545] This is implemented by using a sense ping instead of a digital ping during the cloaking period.

[0546] The detection ping creates an event that the wireless power receiver can recognize with minimal energy consumption by keeping t_dactive short to the level of 2 to 5 ms.

[0547] Meanwhile, the following points could become issues.

[0548] FIG. 30 schematically illustrates an example showing that improvements to FOD during charging are necessary during high-speed charging.

[0549] According to Figure 30, for Qi2 MPP, accuracy in power loss estimation is sought through parameter refinement via loss split modeling.

[0550] Here, up to the existing 15W power transmission (low power), the FOD performance degradation caused by power loss estimation errors is at a level that is acceptable in terms of safety.

[0551] However, power transmission exceeding 15W (high power) results in a larger error in power loss estimation, lower FOD performance, and increased safety risks due to FO. Therefore, power loss calibration must be introduced to ensure FOD performance during high-power charging.

[0552] To create a reliable calibration curve, the presence of no FO at the current time must be verified.

[0553] The problem is that if the presence of FO is confirmed using the MPLA (power loss FOD) results in the 15W range for power loss calibration, there is a concern that FOD performance will degrade due to the accumulation of errors.

[0554] For this reason, in order to safely perform calibration, it is necessary to determine the presence or absence of current foreign substances by remeasuring the current Q-factor (quality factor) (refreshing outdated q-factor).

[0555] However, the power being transmitted must be interrupted to measure the Q-factor (quality factor). Here, the current Qi protocol does not have a way to perform the above operation.

[0556] The issues explained earlier can be summarized as follows.

[0557] Wireless chargers using the WPC Qi standard measure power loss during charging to determine the presence or absence of foreign substances.

[0558] Technology is advancing toward high-speed charging by increasing transmission power, and it is generally the case that the accuracy of power loss-based FOD methods decreases as transmission power increases. Therefore, considering that safety risks caused by FO increase with higher transmission power, there is a need for an FOD method that maintains accuracy.

[0559] One method to improve power loss-based FOD accuracy is run-time power loss calibration in the current Extended Power Profile (EPP). However, there is a fundamental risk of misjudgment because the Q-factor (quality factor) measured prior to digital ping generation is used as proof of no FO presence at the time of calibration.

[0560] Slotted-Q FOD is being discussed as a technology to solve this problem, but there are concerns about overvoltage and shutdown on the wireless power receiver side.

[0561] Since the MPP (Magnetic Power Profile) does not have a calibration function, it is difficult to secure FOD performance without introducing calibration when extending to transmission power exceeding 15W.

[0562] To resolve the above issues, the present specification provides the following configuration.

[0563] By introducing a power loss calibration function to the MPP to improve foreign object detection performance during charging, the charging power can be safely expanded.

[0564] To confirm the presence of no FO, the wireless power transmitter stops power transmission at an agreed time / situation via the MPP cloaking function immediately before calibration and measures the Q-factor (quality factor).

[0565] Based on the Q-factor (quality factor) measured when power transmission is interrupted, the wireless power transmitter determines the presence of no FO.

[0566] After confirming No FO from the wireless power transmitter, the wireless power receiver changes the load of the wireless power receiver from a light load to a full load, and at this time, the wireless power transmitter records the relevant parameters and creates a calibration curve.

[0567] Subsequently, the presence or absence of foreign matter (FOD) is determined based on the difference between the calibration curve during charging and the current power loss.

[0568] The following drawings are prepared to illustrate a specific example of the present specification. The names of specific devices or specific signals / messages / fields described in the drawings are presented as examples, and therefore the technical features of the present specification are not limited to the specific names used in the following drawings.

[0569] FIG. 31 is a flowchart of a method for detecting foreign substances in a temporary interruption section of wireless power transmission according to one embodiment of the present specification.

[0570] According to FIG. 31, the wireless power transmitter transmits wireless power to the wireless power receiver based on the first power (S3110). Here, the wireless power transmitter can transmit wireless power to the wireless power receiver based on the first power in the power transmission phase. And, the first power at this time may mean, for example, a power of up to 15W.

[0571] Meanwhile, as explained earlier, the wireless power transmitter may go through the ping phase, setup phase, and negotiation phase described earlier before entering the power transfer phase.

[0572] The wireless power transmitter and / or wireless power receiver referred to herein may mean a wireless power transmitter and / or wireless power receiver that supports MPP, as previously described. Specific examples of wireless power transmitters and / or wireless power receivers that support MPP are as previously described. However, the prior description is not intended to exclude the wireless power transmitter and / or wireless power receiver in this specification from supporting the previously described EPP. Furthermore, supporting MPP or EPP may mean fundamentally supporting the previously described BPP.

[0573] The wireless power transmitter can pause the transmission of the wireless power (S3120). Here, although it is expressed that the wireless power transmitter pauses the wireless power, this can also be expressed in another way as the wireless power transmitter interrupting the wireless power.

[0574] Here, the wireless power transmitter can receive a clock data packet. The wireless power transmitter can enter a clock phase based on receiving the clock data packet. Here, the wireless power transmitter can stop the transmission of the wireless power during the clock phase.

[0575] The above clock data packet may include a reason field. Here, the reason field may indicate that the wireless power transmitter performs detection of the foreign substance.

[0576] Meanwhile, the wireless power transmitter can measure a quality factor before transmitting the wireless power to the wireless power receiver based on the first power. For example, the wireless power transmitter can determine whether or not there is a substance by measuring the quality factor before proceeding with power transmission.

[0577] Even though it was initially determined that this substance was not present, the validity period of the initial quality factor may expire as time has passed since the initial quality factor was measured. In this case, based on the passage of a specific time since the quality factor was measured, the wireless power transmitter may receive the clock data packet from the wireless power receiver.

[0578] The reasons why a wireless power transmitter stops wireless power and specific examples of stopping wireless power will be described later.

[0579] The wireless power transmitter can detect this substance during the period when the transmission of the wireless power is stopped (S3130). At this time, the wireless power transmitter can detect the substance based on the measurement of a quality factor.

[0580] In other words, the wireless power transmitter can measure quality factors during power interruption periods to detect this material. Some examples of measuring quality factors have been explained earlier, and specific examples of measuring quality factors will also be explained in the examples to be described below.

[0581] The above wireless power transmitter can perform calibration based on the fact that the above material is not detected (S3140).

[0582] Here, prior to performing correction, the wireless power transmitter may receive a GET data packet from the wireless power receiver requesting information on the result of the detection of the substance.

[0583] In this case, the wireless power transmitter may transmit information regarding the result of the detection of the substance to the wireless power receiver. At this time, the information regarding the result of the detection of the substance may include the measurement result of a quality factor or whether the substance is present.

[0584] Here, the term "correction" was explained in the example of forming a correction curve based on the RP data packet described earlier. Therefore, to avoid repetition, the explanation of a specific example will be omitted.

[0585] The wireless power transmitter can transmit the wireless power to the wireless power receiver based on the second power after performing the correction (S3150). Here, the wireless power transmitter can transmit the wireless power to the wireless power receiver based on the second power in the power transmission phase. And, at this time, the second power may mean, for example, a power greater than 15W.

[0586] In summary, the second power may be higher than the first power.

[0587] Hereinafter, for a more specific understanding of the present specification, the contents of FIG. 31 described above will be explained in more detail.

[0588] 1. Power loss calibration operation using FOD function during cloaking

[0589] FIG. 32 schematically illustrates the power loss calibration operation using the FOD function during cloaking.

[0590] According to Fig. 32, the protocol can be carried out in the following order for safe calibration.

[0591] 1) To transmit power of 15W or more, the wireless power transmitter may need to ensure there is no FO to secure a calibration curve (preparing calibration).

[0592] 2) Before starting calibration, the wireless power receiver may request a clock from the wireless power transmitter.

[0593] 3) The wireless power transmitter can enter the cloak phase. The wireless power transmitter can confirm the presence of FO by measuring the Q-factor (quality factor) before the end of the cloak phase.

[0594] 4) When the designated cloaking phase ends, the wireless power receiver may request the wireless power transmitter to measure the Q-factor (quality factor) or determine whether there is an FO.

[0595] 5) The wireless power transmitter provides the wireless power receiver with the most recently updated FO presence / determination information, which may include Q-factor (quality factor) values.

[0596] 6) After confirming that there is no FO, the wireless power receiver can continuously supply received power to the wireless power transmitter by increasing the load from a low level to a high level.

[0597] 7) The wireless power transmitter can generate a power loss calibration curve by collecting data during the calibration process.

[0598] 8) Afterwards, during charging, the level of power loss can be determined by comparing the calibration curve of the wireless power transmitter with the received power value provided by the wireless power receiver, and the presence or absence of FO can be determined.

[0599] 2. FOD method during cloaking

[0600] It was previously explained that the value of the quality factor is measured to detect this material during cloaking (in the clock phase).

[0601] Here, the Q-factor value can be measured in the following three ways in conjunction with the cloaking function. The wireless power transmitter can measure the Q-factor value using one or more of these three methods.

[0602] Figure 33 schematically illustrates an example of a method for measuring Q-factor (quality factor) values ​​in conjunction with a cloaking function.

[0603] According to Fig. 33, the quality factor can be measured at the following points.

[0604] (1) When the wireless power receiver receives a clock entry request and stops power transmission

[0605] As a method to stop coil driving, the lower part of the coil driver can be formed into a closed loop. The Q-factor (quality factor) value can be calculated from the decay waveform generated in this case.

[0606] (2) The point at which the sense ping is generated and then stopped (the sense ping may be an optional configuration in the MPP specification. Applicable when used at the request of the wireless power receiver)

[0607] As a method to stop coil driving, the lower part of the coil driver can be formed into a closed loop. The Q-factor (quality factor) value can be calculated from the decay waveform generated in this case.

[0608] The measurement method of the quality factor used in (1) and (2) above can be described as follows. The configuration diagram of the coil and driver of the wireless power transmitter can be simplified as shown in the figure below.

[0609] FIGS. 34 and 35 schematically illustrate the configuration of the coil and driver of a wireless power transmitter.

[0610] Figure 34 schematically illustrates a damping waveform for measuring a quality factor.

[0611] According to FIG. 34, when the wireless power transmitter stops driving the coil, the voltage in the coil of the wireless power transmitter attenuates. At this time, as shown in the figure, autonomous resonance occurs in the coil of the wireless power transmitter, and a quality factor can be estimated from the attenuation ratio of this waveform.

[0612] Here, if we express the voltage of the TX coil within the clock interval as a formula, it can be, for example, as follows.

[0613] <Formula 1>

[0614]

[0615] The wireless power transmitter can calculate the slot quality factor by measuring the voltage envelope of the wireless power transmitter's resonant capacitor (cap) during the clock interval.

[0616] Here, the envelope can be expressed, for example, as in the following formula.

[0617] <Equation 2>

[0618]

[0619] In other words, the wireless power transmitter can estimate the exponential function of the envelope, and the wireless power transmitter can calculate the quality factor (Q factor) using the attenuation ratio of the exponential function.

[0620] According to Fig. 35, when removing the magnetic field at the request of the wireless power receiver, instead of simply stopping the PWM signal for driving, a decay response can be generated by opening switches Q1 and Q2 and closing switches Q3 and Q4.

[0621] The value of the Q-factor can be calculated as shown in Fig. 35 (a) by measuring the envelope of this waveform.

[0622] ③ The wireless power transmitter can generate a decay response by injecting a pulse of energy into the coil during a ping-free period. Through this, the wireless power transmitter can measure the Q-factor (quality factor).

[0623] Figures 36 and 37 schematically illustrate the configuration of the coil and driver of a wireless power transmitter.

[0624] FIG. 36 schematically illustrates the injection of energy into a coil in the form of pulses. FIG. 37 schematically illustrates the coil configuration of a wireless power transmitter.

[0625] In this approach, energy is injected into the coil in the form of pulses, and the decay of the ringing response is measured. The Q value is estimated from the envelope of the decayed signal.

[0626] Each step in FIGS. 36 and FIGS. 37 can be described as follows.

[0627] - t-startup (startup phase)

[0628] At this stage, the input voltage of the inverter is allowed to reach the nominal voltage required for ping.

[0629] - t-discharge (discharge stage)

[0630] The purpose of this step is to discharge the resonant capacitor and set the initial conditions for ping.

[0631] That is, VCtx(0) = 0 and iLtx(0) = 0 must be satisfied.

[0632] To do this, the resonant tank must be shorted through the bottom switches (e.g., Q3 and Q4) of the inverting bridge.

[0633] - t-ping (ping step)

[0634] This step is the energy injection step.

[0635] During the t_ping time, the DC power is connected to the Tx resonant tank. To do this, Q3 can be turned off, Q1 can be turned on, and Q4 can be kept on.

[0636] - t-response (response stage)

[0637] After energy is injected into the tank during the ping phase, the tank must be short-circuited via the bottom switch to allow free oscillation of the resonant tank. To do this, Q1 is turned off and Q3 is turned on. Subsequently, the natural response of the tank (e.g., voltage of the Tx tuning capacitor) is sampled and processed.

[0638] Meanwhile, to estimate the Q value, the waveform peaks must be accurately sampled to extract the envelope of the attenuated signal. To eliminate the effect of the DC offset, the attenuation envelope can be measured as the peak-to-valley difference.

[0639] 3. Calibration protocol utilizing FOD function during cloaking

[0640] FIG. 38 is a flowchart schematically illustrating an example of a correction protocol utilizing the FOD function during cloaking.

[0641] According to FIG. 38, the wireless power transmitter can receive a clock data packet (CLOCK[FOD]) from the wireless power receiver. Here, the clock data packet may indicate that the above clock data packet is for the execution of FOD.

[0642] Afterwards, the wireless power transmitter can transmit an ACK to the wireless power receiver in response to the above clock data packet.

[0643] A wireless power transmitter that receives a clock data packet can measure the quality factor in the clock phase.

[0644] A wireless power transmitter can receive a REPORT packet related to the ID of the wireless power receiver from a wireless power receiver, and the wireless power transmitter can send an ACK to the wireless power receiver in response.

[0645] The wireless power transmitter can receive a GET packet related to the wireless power transmitter XID from the wireless power receiver, and the wireless power transmitter can send an ACK to the wireless power receiver in response.

[0646] Meanwhile, the wireless power transmitter can receive a GET packet from the wireless power receiver requesting a packet indicating the presence of FO (foreign substance). Subsequently, the wireless power transmitter can transmit a packet indicating the presence of FO to the wireless power receiver.

[0647] Afterwards, the wireless power receiver can perform correction based on the presence or absence of FO.

[0648] A more detailed explanation of each packet that can be used in the above protocol is as follows.

[0649] Here, the clock data packet transmitted by the wireless power receiver can be described as follows.

[0650] FIG. 39 schematically illustrates a clock data packet transmitted by a wireless power receiver.

[0651] According to FIG. 39, the clock data packet allows the wireless power receiver to start the clock. The clock data packet may include a reason field.

[0652] The reason codes may be as shown in the table below.

[0653] Value Reason 0 Cloak: General (Generic) 1 Cloak: Forced (Unclock request denied) 2 Cloak: Thermally constrained 3 Cloak: Insufficient Power 4 Cloak: Coex Mitigation (A wireless power receiver requests a clock to perform a task that cannot coexist with wireless power) 5 Cloak: End of Charge 6 Cloak: Initiated by wireless power transmitter (PTx initiated) 7 Reserved new Cloak: Requesting the wireless power transmitter to perform Q factor foreign material detection

[0654] In response to the above clock data packet, the wireless power transmitter can perform the following response.

[0655] Response Description ACK Agree to the wireless power transmitter start / continue cloaking NAK The pattern is not allowed ND Pattern transmitted when using the code for the reason why wireless power receivers are not supported ATN Cloak state: The wireless power transmitter requests clock shutdown. Other state: The wireless power transmitter prefers to communicate before cloaking.

[0656] In summary, a wireless power receiver may use the following reasons when requesting a clock to verify no FO before starting calibration.

[0657] 0: Generic; or

[0658] (New): Request to perform detection of this substance

[0659] A wireless power transmitter can perform Q-factor (quality factor) measurements when it receives a cloak request and the reason is '0: Generic or (New): Request to perform detection of this material'.

[0660] The wireless power transmitter can update the FO presence information when performing Q-factor (quality factor) measurements during the cloaking phase.

[0661] Figure 40 schematically illustrates a GET data packet.

[0662] According to Fig. 40, the Get Request - GET (0x28) data packet enables a wireless power receiver (power receiver) to request specific information from a wireless power transmitter (power transmitter).

[0663] A GET data packet may include a parameter field, and the parameter field may include information about parameters requested from the wireless power transmitter.

[0664] The parameter codes can be organized as shown in the table below.

[0665] Value Parameter 0 Wireless Power Transmitter Extended Identification 2 Wireless Power Transmitter Inverter Voltage 3 Wireless Power Transmitter Extended Capabilities 4 Wireless Power Transmitter Power Loss Accounting Parameters 5 Wireless Power Transmitter Regulation Control Status 6 Wireless Power Transmitter Charge Status 7 Wireless power transmitter estimate K (Estimated K) 9 Wireless Power Transmitter Error Status new Wireless Power Transmitter FO Presence Information (TBD)

[0666] In response to the above GET data packet, the following FSK response may exist.

[0667] FSK Packet - The wireless power transmitter must respond with the requested packet.

[0668] In summary, the wireless power receiver can obtain information on the presence or absence of an FO by using GET[FO Presence] when returning from a cloaking phase that has entered one or more times with a cloak request to confirm the absence of an FO before starting calibration.

[0669] The wireless power receiver can switch the operating mode to a fast charging (15W or higher) mode before the clock phase ends.

[0670] In this case, the following examples may exist.

[0671] (15W or less mode) Wireless power receiver coil -> Rectifier -> Buck converter -> Battery (load)

[0672] (15W or higher mode) Wireless power receiver coil -> Rectifier -> Switching capacitor DC-DC converter -> Battery (Load)

[0673] When a wireless power transmitter receives a GET[FO Presence] request, it can transmit the FO presence packet described below to a wireless power receiver.

[0674] Figure 41 schematically illustrates an FO presence packet.

[0675] According to FIG. 41, the FO presence packet that responds to a GET[FO Presence] request from a wireless power transmitter may include one or more of the following information.

[0676] - Presence / Absence of FO

[0677] 0: No FO exists

[0678] 1: FO exists

[0679] - Power loss measured (optional)

[0680] Power loss measured (12 bits)

[0681] Measured power loss in mW units.

[0682] (e.g. Power loss value range: 0 ~ 4095 mW, 0 for negative power loss, 4095 for power loss is greater than 4095)

[0683] - Measured Q-Factor (Quality Factor) (optional)

[0684] Measured Q-Factor (Quality Factor) (10 bit)

[0685] Measured Q-Factor value. Values ​​can be expressed in units of 0.1. (e.g., Q-Factor value range: 0 ~ 102.3)

[0686] 4. Example of switching to fast charging mode

[0687] Meanwhile, a high VRECTV_{RECT}VRECT value can significantly improve efficiency at higher power.

[0688] At this time, a method to increase the variable VRECTV_{RECT}VRECT value up to 18V may be considered. In this case, efficiency is improved, and higher peak power and thermally sustainable power can be provided. The details regarding this are explained below with reference to the drawings.

[0689] Figure 42 schematically illustrates an example of an additional method for a non-adjustable charging architecture.

[0690] According to FIG. 42 (a), a structure of wireless power receiver IC -> buck charger -> battery pack may exist. According to FIG. 42 (b), the structure of FIG. 42 (a) can be extended to include a non-regulated charging architecture (4:1 SWC).

[0691] Figure 43 schematically illustrates examples of high-power and low-power circuits.

[0692] According to Fig. 43, for steady-state power transmission control, no special control packets other than XCE and PLA are required.

[0693] Meanwhile, existing MPP / EPP protocols can be utilized for switching between low-power and high-power profiles. Additionally, a proposal to add a Vrect_target packet may be included.

[0694] Here, the power paths (High Power Path & Low Power Path) can be as follows.

[0695] - High Power Path

[0696] Wireless Power Receiver IC -> 4:1 SWC -> Buck -> Battery Pack

[0697] Voltage and current variables: V_RECT, I_RECT, I_CHG, V_Bat

[0698] - Low Power Path

[0699] Wireless Power Receiver IC -> Battery Pack

[0700] Figure 44 schematically illustrates an example of a transition from low power charging to high power charging.

[0701] According to Fig. 44, Buck <-> SWC replacement can be performed through a zero charging current section (no load) while the magnetic field is maintained.

[0702] Here, the above Buck <-> SWC switching operation can be performed during the clock interval in this specification.

[0703] Hereinafter, embodiments of the present specification will be described again from the perspective of various subjects.

[0704] The following drawings are prepared to illustrate a specific example of the present specification. The names of specific devices or specific signals / messages / fields described in the drawings are presented as examples, and therefore the technical features of the present specification are not limited to the specific names used in the following drawings.

[0705] FIG. 45 is a flowchart of a method for detecting foreign substances in a temporary interruption period of wireless power transmission in the view of a wireless power transmitter, according to one embodiment of the present specification.

[0706] According to FIG. 45, the wireless power transmitter can transmit wireless power to the wireless power receiver based on the first power (S4510).

[0707] The above wireless power transmitter can pause the transmission of the wireless power (S4520).

[0708] The above wireless power transmitter can detect this substance during the period when the transmission of the wireless power is stopped (S4530).

[0709] The above wireless power transmitter can perform calibration based on the fact that the above material is not detected (S4540).

[0710] After performing the correction, the wireless power transmitter can transmit the wireless power to the wireless power receiver based on the second power (S4550).

[0711] Here, the wireless power transmitter can detect the aforementioned substance based on the measurement of a quality factor.

[0712] The wireless power transmitter can receive a clock data packet. The wireless power transmitter can enter a clock phase based on receiving the clock data packet. The wireless power transmitter can stop the transmission of the wireless power during the clock phase.

[0713] The above clock data packet may include a reason field. The reason field may indicate that the wireless power transmitter performs detection of the foreign substance.

[0714] The wireless power transmitter can measure a quality factor before transmitting the wireless power to the wireless power receiver based on the first power. Based on the elapsed time after measuring the quality factor, the wireless power transmitter can receive the clock data packet from the wireless power receiver.

[0715] The wireless power transmitter can receive a GET data packet from the wireless power receiver requesting information on the result of the detection of the substance.

[0716] The above wireless power transmitter can transmit information of the result of the detection of the above material to the above wireless power receiver.

[0717] The information regarding the result of the detection of the above-mentioned substance may include the measurement result of a quality factor or whether the above-mentioned substance is present.

[0718] The above second power may be a higher power than the above first power.

[0719] Although not otherwise described, a wireless power transmitter may be provided. The wireless power transmitter may include a converter related to transmitting wireless power to a wireless power receiver and a communication / controller related to controlling the transmission of said wireless power. The wireless power transmitter may transmit said wireless power to the wireless power receiver based on a first power. The wireless power transmitter may pause the transmission of said wireless power. The wireless power transmitter may detect a foreign substance during the period in which the transmission of said wireless power is paused. The wireless power transmitter may perform calibration based on the fact that said foreign substance is not detected. After performing said calibration, the wireless power transmitter may transmit said wireless power to the wireless power receiver based on a second power.

[0720] FIG. 46 is a flowchart of a method for detecting foreign substances in a temporary interruption period of wireless power transmission from the perspective of a wireless power receiver, according to one embodiment of the present specification.

[0721] According to FIG. 46, the wireless power receiver can receive wireless power from the wireless power transmitter based on the first power (S4610).

[0722] The above wireless power receiver can pause the reception of the wireless power (S4620).

[0723] The above wireless power receiver can perform calibration based on the fact that the above substance is not detected during the period when the reception of the above wireless power is stopped (S4630).

[0724] After performing the correction, the wireless power receiver can receive the wireless power from the wireless power transmitter based on the second power (S4640).

[0725] Although not separately described, a wireless power receiver may be provided. The wireless power receiver may include a power pickup related to receiving wireless power from a wireless power transmitter and a communication / controller related to controlling the reception of said wireless power. The wireless power receiver may receive said wireless power from said wireless power transmitter based on a first power. The wireless power receiver may pause the reception of said wireless power. The wireless power receiver may perform calibration based on the fact that said foreign substance is not detected during the period in which the reception of said wireless power is paused. After performing said calibration, the wireless power receiver may receive said wireless power from said wireless power transmitter based on a second power.

[0726] The effects of the present specification are described below.

[0727] Before explaining the effects of this specification, the problems described above are summarized as follows.

[0728] As explained earlier, since the Magnetic Power Profile (MPP) lacks a calibration function, it is difficult to secure FOD performance without the introduction of calibration when extending transmission power to more than 15W.

[0729] To address this, the present specification introduces a power loss calibration function into the MPP to improve the foreign substance detection performance during charging, thereby safely implementing the expansion of charging power.

[0730] To confirm the presence of no FO, the wireless power transmitter stops power transmission at an agreed time / situation via the MPP cloaking function immediately before calibration and measures the Q-factor (quality factor).

[0731] Through this method, the charger and receiver can improve FOD performance by measuring the Q-factor (quality factor) at the time calibration is required to secure a highly reliable calibration curve.

[0732] This has the advantage of allowing the calibration curve to be updated by repeating the same process, even when re-calibration is required.

[0733] In addition, it has the effect of enhancing judgment by entering a cloaking phase and measuring the Q-factor (quality factor) as needed to perform FOD independent of transmission power.

[0734] By providing a clock period, the wireless power receiver can safely switch operating modes, such as changing PMIC settings for fast charging (15W or more), if necessary.

[0735] The effects obtainable through the specific examples of this specification are not limited to those listed above. For example, there may be various technical effects that a person having ordinary skill in the related art can understand or derive from this specification. Accordingly, the specific effects of this specification are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of this specification.

[0736] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims in this specification may be combined to be implemented as a device, and the technical features of the device claims in this specification may be combined to be implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a device, and the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a method.

Claims

Claim 1 A method characterized by transmitting wireless power to a wireless power receiver based on a first power by means of a wireless power transmitter; pausing the transmission of the wireless power by means of the wireless power transmitter; detecting a foreign substance by means of the wireless power transmitter during the period in which the transmission of the wireless power is paused by means of the wireless power transmitter; performing calibration by means of the wireless power transmitter based on the fact that the foreign substance is not detected by means of the wireless power transmitter; and transmitting the wireless power to the wireless power receiver based on a second power after performing the calibration by means of the wireless power transmitter. Claim 2 A method according to claim 1, characterized in that the wireless power transmitter detects the foreign substance based on the measurement of a quality factor. Claim 3 A method according to claim 1, wherein the wireless power transmitter receives a clock data packet, the wireless power transmitter enters a clock phase based on receiving the clock data packet, and the wireless power transmitter stops the transmission of the wireless power in the clock phase. Claim 4 A method according to paragraph 3, wherein the clock data packet includes a reason field, and the reason field indicates that the wireless power transmitter performs detection of the foreign substance. Claim 5 A method according to claim 3, wherein the wireless power transmitter measures a quality factor before transmitting the wireless power to the wireless power receiver based on the first power, and, based on a specific time elapsed after measuring the quality factor, the wireless power transmitter receives the clock data packet from the wireless power receiver. Claim 6 A method according to claim 1, wherein the wireless power transmitter receives a GET data packet from the wireless power receiver requesting information on the result of the detection of the substance. Claim 7 A method according to claim 1, wherein the wireless power transmitter transmits information of the result of the detection of the substance to the wireless power receiver. Claim 8 A method according to claim 7, characterized in that the information of the result of the detection of the above substance includes the measurement result of a quality factor or the presence of the above substance. Claim 9 A method according to claim 1, characterized in that the second power is a higher power than the first power. Claim 10 A wireless power transmitter comprises: a converter related to transmitting wireless power to a wireless power receiver; and a communication / controller related to controlling the transmission of the wireless power, wherein the wireless power transmitter comprises: transmitting the wireless power to the wireless power receiver based on a first power; pausing the transmission of the wireless power; detecting a substance during the period in which the transmission of the wireless power is paused; performing a calibration based on the fact that the substance is not detected; and transmitting the wireless power to the wireless power receiver based on a second power after performing the calibration. Claim 11 A method characterized by receiving wireless power from a wireless power transmitter based on a first power by means of a wireless power receiver; pausing the reception of the wireless power by means of the wireless power receiver; performing calibration by means of the wireless power receiver based on the fact that the foreign substance is not detected during the period in which the reception of the wireless power is paused; and receiving the wireless power from the wireless power transmitter based on a second power after performing the calibration by means of the wireless power receiver. Claim 12 A method according to claim 11, characterized in that the above substance is detected based on the measurement of quality factors. Claim 13 A method according to claim 11, wherein the wireless power receiver transmits a clock data packet, the wireless power receiver enters a clock phase based on the transmission of the clock data packet, and the wireless power receiver stops receiving the wireless power during the clock phase. Claim 14 A method according to claim 13, wherein the clock data packet includes a reason field, and the reason field indicates that the wireless power transmitter performs detection of the foreign substance. Claim 15 A method according to claim 13, characterized in that, based on the elapsed time after a quality factor is acquired, the wireless power receiver transmits the clock data packet to the wireless power transmitter. Claim 16 A method according to claim 11, characterized in that the wireless power receiver transmits a GET data packet requesting information on the result of the detection of the substance to the wireless power transmitter. Claim 17 A method according to claim 11, wherein the wireless power receiver receives information of the result of the detection of the substance from the wireless power transmitter. Claim 18 A method according to claim 17, characterized in that the information of the result of the detection of the above substance includes the measurement result of a quality factor or the presence of the above substance. Claim 19 A method according to claim 11, characterized in that the second power is a higher power than the first power. Claim 20 A wireless power receiver comprises: a power pickup related to receiving wireless power from a wireless power transmitter; and a communication / controller related to controlling the reception of the wireless power, wherein the wireless power receiver: receives the wireless power from the wireless power transmitter based on a first power; pauses the reception of the wireless power; performs a calibration based on the fact that the foreign substance is not detected during the period in which the reception of the wireless power is paused; and receives the wireless power from the wireless power transmitter based on a second power after performing the calibration.

Images