Method and apparatus for switching power mode in wireless power transmission system

Abstract

The present disclosure provides a method and apparatus, which transmit, by a wireless power transmitter, wireless power to a wireless power receiver on the basis of first power in a power transmission phase, receive, by the wireless power transmitter, a specific packet from the wireless power receiver in the power transmission phase, wherein the specific packet is a packet indicating switching from the first power to second power, and transmit, by the wireless power transmitter, the wireless power to the wireless power receiver on the basis of the second power in the power transmission phase.

Description

Method and device for switching power modes in a wireless power transmission system

[0001] This specification relates to wireless power transfer.

[0002] Wireless power transfer technology is a technology that wirelessly transfers power between a power source and an electronic device. For example, wireless power transfer technology allows wireless devices such as smartphones and tablets to charge their batteries simply by placing them on a wireless charging pad. This technology offers greater mobility, convenience, and safety compared to wired charging environments using existing wired charging connectors. Beyond wireless charging of wireless devices, wireless power transfer technology is attracting attention as a potential replacement for existing wired power transfer environments in various fields, including electric vehicles, wearable devices such as Bluetooth earphones and 3D glasses, home appliances, furniture, underground facilities, buildings, medical devices, robots, and leisure activities.

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

[0004] Wireless power transfer technologies vary, including those that transfer power through magnetic coupling, radio frequency (RF), microwaves, and ultrasound. Magnetic coupling-based methods are further categorized into magnetic induction and magnetic resonance. Magnetic induction uses the electromagnetic coupling between the transmitting coil and the receiving coil, resulting in a current induced in the receiving coil by a magnetic field generated by the battery cell of the transmitting coil. Magnetic resonance is similar to magnetic induction in that it utilizes magnetic fields. However, magnetic resonance differs from magnetic induction in that energy is transferred through a phenomenon where resonance occurs when a specific resonant frequency is applied to the transmitting and receiving coils, concentrating the magnetic field at both ends.

[0005] Hereinafter, a method and device for switching power modes in a wireless power transmission system are provided.

[0006] According to one embodiment of the present disclosure, a wireless power transmitter may receive a specific packet from the wireless power receiver during a power transfer phase. The specific packet may be a packet indicating a transition from the first power to the second power.

[0007] According to the present specification, a wireless power transmitter and / or a wireless power receiver can rapidly enter a power transmission mode of 15 W or more. Furthermore, according to the present specification, the wireless power transmitter and / or the wireless power receiver can operate in reverse as needed, quickly switching from a fast-charging mode to a normal-charging mode, thereby enabling efficient operation.

[0008] The effects that can be achieved through specific examples of this specification are not limited to the effects listed above. For example, a person with ordinary skill in the relevant technical field may understand or derive various technical effects 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.

[0009] Figure 1 is a block diagram of a wireless power system (10) according to one embodiment.

[0010] FIG. 2 is a block diagram of a wireless power system (10) according to another embodiment.

[0011] Figure 3 illustrates embodiments of various electronic devices in which a wireless power transmission system is introduced.

[0012] FIG. 4 is a block diagram of a wireless power transmission system according to one embodiment.

[0013] FIG. 5 is a diagram showing an example of a Bluetooth communication architecture to which an embodiment according to the present specification can be applied.

[0014] Fig. 6 is a block diagram illustrating a wireless power transmission system using BLE communication according to an example.

[0015] Fig. 7 is a block diagram illustrating a wireless power transmission system using BLE communication according to another example.

[0016] Figure 8 is a state transition diagram for explaining a wireless power transfer procedure.

[0017] Figure 9 schematically illustrates an example of a protocol of the ping phase (810).

[0018] Figure 10 schematically illustrates an example of a protocol of the configuration phase (820).

[0019] FIG. 11 is a diagram illustrating a message field of a configuration packet (CFG) of a wireless power receiving device according to one embodiment.

[0020] Figure 12 is a flowchart schematically illustrating a protocol of a negotiation step or a renegotiation step according to one embodiment.

[0021] FIG. 13 is a diagram illustrating a message field of a performance packet (CAP) of a wireless power transmission device according to one embodiment.

[0022] Figure 14 schematically illustrates a flowchart of the data flow for the power transfer phase (840) in the baseline protocol.

[0023] Figure 15 schematically illustrates a flowchart of the data flow for the power transfer phase (840) in the extended protocol.

[0024] FIG. 16 illustrates an application-level data stream between a wireless power transmitter (100) and a wireless power receiver (200) according to an example.

[0025] Fig. 17 illustrates a power control method according to one embodiment.

[0026] Figure 18 schematically illustrates the structure of an MPP ID packet.

[0027] Figure 19 schematically illustrates an example of an XID packet in MPP.

[0028] Figure 20 schematically illustrates the protocol in MPP limited mode.

[0029] Figures 21 and 22 schematically illustrate the protocol in MPP full mode.

[0030] Figures 23 and 24 illustrate examples of measurement / calculation of quality factors.

[0031] Figure 25 schematically illustrates a clock data packet transmitted by a wireless power receiver.

[0032] Figure 26 schematically illustrates a clock data packet transmitted by a wireless power transmitter.

[0033] Figure 27 schematically illustrates a clock phase initiated by a wireless power receiver.

[0034] Figure 28 schematically illustrates a clock phase initiated by a wireless power transmitter.

[0035] Figures 29 and 30 schematically illustrate a system model of a wireless power receiver circuit.

[0036] Figure 31 schematically illustrates a power stage block diagram of a wireless power transmitter.

[0037] Figure 32 is a flowchart of a method for switching power according to one embodiment of the present specification.

[0038] Figure 33 schematically illustrates an example of switching to fast charging mode.

[0039] Figure 34 schematically illustrates an example of switching to normal charging mode.

[0040] Figure 35 schematically illustrates an example of switching to fast charging mode.

[0041] Figure 36 schematically illustrates a protocol for transitioning to high power mode.

[0042] Figure 37 schematically illustrates a protocol for transitioning to normal power mode.

[0043] Figure 38 schematically illustrates the protocol when this substance is discovered during a power mode transition.

[0044] Figures 39 and 40 schematically illustrate the configuration of a coil and driver of a wireless power transmitter.

[0045] Figures 41 and 42 schematically illustrate the configuration of a coil and driver of a wireless power transmitter.

[0046] Figure 43 schematically illustrates a clock data packet transmitted by a wireless power receiver.

[0047] Figure 44 schematically illustrates a GET data packet.

[0048] Figure 45 schematically illustrates an FO presence packet.

[0049] FIG. 46 is a flowchart of a mode switching method from the perspective of a wireless power transmitter according to one embodiment of the present specification.

[0050] FIG. 47 is a flowchart of a mode switching method from the perspective of a wireless power receiver according to one embodiment of the present specification.

[0051] In this specification, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, “A or B” in this specification can be interpreted as “A and / or B.” For example, “A, B or C” in this specification can mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.”

[0052] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0053] 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 identically to “at least one of A and B.”

[0054] Additionally, in this specification, “at least one of A, B and C” can 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” can mean “at least one of A, B and C.”

[0055] Additionally, parentheses used herein 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.”

[0056] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously. The term "wireless power" as used hereinafter is used to mean any form of energy related to electric fields, magnetic fields, electromagnetic fields, etc. that is transferred 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. Power conversion in a system for wirelessly charging devices including, for example, mobile phones, cordless phones, iPods, MP3 players, headsets, etc. is described herein. In general, the basic principles of wireless power transfer include, for example, transferring power through magnetic coupling, transferring power through radio frequency (RF), transferring power through microwaves, and transferring power through ultrasound.

[0057] Figure 1 is a block diagram of a wireless power system (10) according to one embodiment.

[0058] Referring to FIG. 1, a wireless power system (10) includes a wireless power transmission device (100) and a wireless power reception device (200).

[0059] A wireless power transmission device (100) receives power from an external power source (S) and generates a magnetic field. A wireless power reception device (200) uses the generated magnetic field to generate current and wirelessly receive power.

[0060] In addition, in the wireless power system (10), the wireless power transmission device (100) and the wireless power reception device (200) can transmit and receive various information required for wireless power transmission. Here, communication between the wireless power transmission device (100) and the wireless power reception 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 referred to as out-of-band communication. Hereinafter, the term out-band communication will be uniformly described. Examples of out-band communication may include NFC, Bluetooth, BLE (Bluetooth Low Energy), etc.

[0061] Here, the wireless power transmission device (100) may be provided in a fixed or mobile form. Examples of fixed forms include those embedded in indoor ceilings, walls, or furniture such as tables, those installed in an implant form in outdoor parking lots, bus stops, or subway stations, and those installed in vehicles or trains. The mobile wireless power transmission device (100) may be implemented as a mobile device with a movable weight or size, or as part of another device, such as the cover of a laptop computer.

[0062] In addition, 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 through a power cable. Representative examples of the wireless power receiving device (200) include portable terminals, cellular phones, smart phones, personal digital assistants (PDAs), portable media players (PMPs), Wibro terminals, tablets, phablets, notebooks, digital cameras, navigation terminals, televisions, electric vehicles (EVs), etc.

[0063] FIG. 2 is a block diagram of a wireless power system (10) according to another embodiment.

[0064] Referring to FIG. 2, in the wireless power system (10), there may be one or more wireless power receiving devices (200). In FIG. 1, the wireless power transmitting device (100) and the wireless power receiving device (200) are expressed as transmitting and receiving power one-to-one, but as shown in FIG. 2, it is also possible for one wireless power transmitting device (100) to transmit power to multiple wireless power receiving devices (200-1, 200-2, ..., 200-M). In particular, when performing wireless power transmission using a magnetic resonance method, one wireless power transmitting device (100) can simultaneously transmit power to multiple wireless power receiving devices (200-1, 200-2, ..., 200-M) by applying a simultaneous transmission method or a time-division transmission method.

[0065] In addition, although FIG. 1 illustrates a wireless power transmission device (100) directly transmitting power to a wireless power reception device (200), a separate wireless power transmission / reception device, such as a relay or repeater, may be provided between the wireless power transmission device (100) and the wireless power reception device (200) to increase the wireless power transmission distance. In this case, power may be transmitted from the wireless power transmission device (100) to the wireless power transmission / reception device, and the wireless power transmission / reception device may then transmit power to the wireless power reception device (200).

[0066] The wireless power receiver, power receiver, and receiver mentioned in this specification below refer to a wireless power receiving device (200). In addition, the wireless power transmitter, power transmitter, and transmitter mentioned in this specification refer to a wireless power receiving / transmitting device (100).

[0067] Figure 3 illustrates embodiments of various electronic devices in which a wireless power transmission system is introduced.

[0068] FIG. 3 illustrates a classification of electronic devices according to the amount of power transmitted and received in a wireless power transmission system. Referring to FIG. 3a, a low-power (about 5 W or less or about 20 W or less) wireless charging method can be applied to wearable devices such as smart watches, smart glasses, head-mounted displays (HMDs), and smart rings, as well as mobile electronic devices (or portable electronic devices) such as earphones, remote controls, smartphones, PDAs, and tablet PCs.

[0069] Medium-power (about 50W or less or about 200W or less) wireless charging can be applied to small and medium-sized home appliances such as laptops, robot vacuums, TVs, audio equipment, vacuum cleaners, and monitors. Kitchen appliances such as blenders, microwave ovens, and electric rice cookers, and personal mobility devices (or electronic devices / transportation means) such as wheelchairs, electric kickboards, electric bicycles, and electric cars can be applied to high-power (about 2kW or less or about 22kW or less) wireless charging.

[0070] 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 may be charged by wirelessly receiving power from a wireless power transmitter.

[0071] Below, a description is given focusing 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 this specification can be applied to various electronic devices described above.

[0072] Standards for wireless power transfer include the Wireless Power Consortium (WPC), Air Fuel Alliance (AFA), and Power Matters Alliance (PMA).

[0073] The WPC consists of the Qi ecosystem, targeting mobile and wearable devices, and the HI ecosystem, targeting kitchen appliances, robots, and light electric vehicles (LEVs). Each ecosystem's standards cover a variety of wireless power transmitters and receivers, each operating at different power levels, and can be categorized into different power classes or categories.

[0074] The Qi standard (belonging 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 power transfer of up to 5 W, while the EPP and MPP relate to wireless power transmitters and receivers that support power transfer in the range of more than 5 W and less than 15 W. In-band (IB) communication is the mandatory communication protocol of the Qi specification, but out-band (OB) communication, which is used as an optional backup channel, can also be used. A wireless power receiver can identify whether it supports OB by setting the OB flag in the configuration packet. A wireless power transmitter that supports OB can enter the OB handover phase by transmitting a bit pattern for OB handover as a response to the configuration packet. The response to the above configuration packet can be NAK, ND, or a newly defined 8-bit pattern. Applications of the Qi spec include smartphones.

[0075] The IND standard (belonging to the HI ecosystem) covers wireless power transmitters and receivers that provide guaranteed power of 30 W to 150 W. IB and OB communication channels can be used for mutual information exchange and power control. Applications for the IND specification include robots and power tools.

[0076] The LEV standard (belonging to the HI ecosystem) concerns wireless power transmitters and receivers that provide guaranteed power of 100 W to 500 W. IB is an essential communication channel for the LEV specification, and can also be used for OB communication. IB can be used for initialization and link establishment with OB. In response to a configuration packet, a wireless power transmitter can enter the OB handover phase using a bit pattern for OB handover.

[0077] The Ki standard (belonging to the HI ecosystem) covers wireless power transmitters and receivers providing guaranteed power of 200 W to 2 kW. It requires the use of on-board communication channels such as NFC or BLE. Its applications include kitchen appliances.

[0078] Wireless power transmission and reception devices can provide a highly convenient user experience and interface (UX / UI). Specifically, a smart wireless charging service can be provided, and this smart wireless charging service can be implemented based on the UX / UI of a smartphone that includes a wireless power transmission device. For these applications, the interface between the smartphone's processor and the wireless power reception device allows for "drop-and-play" bidirectional communication between the wireless power transmission and reception devices.

[0079] For example, a user can experience a smart wireless charging service at a hotel. When a user enters a hotel room and places their smartphone on the wireless charger, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. If the smartphone detects that the smartphone is placed on the wireless charger, detects the reception of wireless power, or receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state where it asks the user to opt-in to additional features. To do this, the smartphone can display a message on the screen, with or without an alarm sound. An example message could include phrases such as "Welcome to ### hotel. Select "Yes" to activate smart charging functions: Yes | No Thanks." The smartphone receives the user's input of "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. The smartphone and the wireless charger then perform the smart charging function together.

[0080] Smart wireless charging services may also include receiving auto-filled WiFi credentials. For example, the wireless charger transmits the WiFi credentials to the smartphone, and the smartphone launches an appropriate app to automatically fill in the WiFi credentials received from the wireless charger.

[0081] Smart wireless charging services may also include running hotel applications offering hotel promotions, remote check-in / check-out, and obtaining contact information.

[0082] As another example, a user can experience a smart wireless charging service in a vehicle. When a user enters the vehicle and places a smartphone on a wireless charger, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. When the smartphone detects that the smartphone is placed on the wireless charger, detects the reception of wireless power, or receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state where it asks the user for identity verification.

[0083] In this state, the smartphone automatically connects to the vehicle via WiFi and / or Bluetooth. The smartphone can display a message on the screen, with or without an alarm sound. An example of the message may include a phrase such as "Welcome to your car. Select "Yes" to synchronize device with in-car controls: Yes | No Thanks." The smartphone receives the user's input of 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. The smartphone and the wireless charger can then run the in-car application / display software to perform smart in-car control functions together. The user can enjoy desired music and check the regular map location. The in-car application / display software may include the ability to provide synchronized access for pedestrians.

[0084] As another example, a user can experience smart wireless charging at home. When a user enters a room and places their smartphone on a wireless charger, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. When the smartphone detects that the smartphone is placed on the wireless charger, detects the reception of wireless power, or receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state asking the user to opt-in to additional features. To do this, the smartphone can display a message on the screen, with or without an alarm sound. An example message could include a phrase such as "Hi xxx, Would you like to activate night mode and secure the building?: Yes | No Thanks." The smartphone receives the user's input of "Yes" or "No Thanks" and performs the next step selected by the user. If "Yes" is selected, the smartphone transmits the information to the wireless charger. Smartphones and wireless chargers can at least recognize your patterns and prompt you to lock doors and windows, turn off lights, or set alarms.

[0085] Below, we redefine "profile" as an indicator / criteria representing / indicating compatibility. In other words, wireless power transmitters and receivers with the same "profile" maintain compatibility, enabling stable power transmission and reception. However, wireless power transmitters and receivers with different "profiles" cannot transmit and receive power. Profiles can be defined based on compatibility and / or application, regardless of (or independently of) the ecosystem.

[0086] The profiles can be broadly divided into four categories: i) mobile, ii) robot, iii) kitchen, and iv) LEV.

[0087] For the 'mobile' profile, the Qi spec, communication protocol / method can be defined as IB and OB, operating frequency can be 87~205kHz, 300~400kHz, and examples of applications can include smartphones, laptops, and wearables.

[0088] For the 'robot' profile, IND spec, communication protocol / method can be IB and OB, and examples of applications can include robots, power tools, etc.

[0089] For the 'Kitchen' profile, the Ki spec, communication protocol / method can be defined as NFC or BLE-based, and the operating frequency can be less than 100 kHz. Examples of applications include kitchen / home appliances.

[0090] For the 'LEV' profile, LEV spec, communication protocol / method are IB and OB, and examples of applications include electric bicycles and electric kickboards.

[0091] NFC or BLE communication can be used as the OB communication channel between the wireless power transmitter and receiver in the profile above. When using NFC, the wireless power transmitter and receiver can mutually confirm that they are NFC devices by exchanging the WPC NDEF (NFC Data Exchange Profile Format).

[0092] FIG. 4 is a block diagram of a wireless power transmission system according to one embodiment.

[0093] Referring to FIG. 4, a wireless power transmission system (10) includes a mobile device (450) that wirelessly receives power and a base station (400) that wirelessly transmits power.

[0094] The base station (400) is a device that provides inductive 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) may transmit inductive power or resonant power and control the transmission. The wireless power transmitter (100) may include a power conversion circuit (power conversion circuit, 110) that converts electrical energy into a power signal by generating a magnetic field through a primary coil (primary coil(s)), and a communications / control circuit (communications & control circuit, 120) that controls communication and power transmission with a wireless power receiver (200) to transmit power at an appropriate level. The system circuit (405) may perform other operation control of the base station (400), such as input power provisioning, control of a plurality of wireless power transmitters, and user interface control.

[0095] The primary coil can generate an electromagnetic field using AC power (or voltage or current). The primary coil receives AC power (or voltage or current) of a specific frequency output from a power conversion circuit (110), and can generate a magnetic field of a specific frequency accordingly. The magnetic field can be generated non-radiatively or radially, and the wireless power receiving device (200) receives it and generates a current. In other words, the primary coil wirelessly transmits power.

[0096] In the magnetic induction method, the primary and secondary coils may have any suitable forms, for example, copper wire wound around a high-permeability formation such as ferrite or an amorphous metal. The primary coil may also be called a transmitting coil, a primary core, a primary winding, a primary loop antenna, etc. Meanwhile, the secondary coil may also be called a receiving coil, a secondary core, a secondary winding, a secondary loop antenna, a pickup antenna, etc.

[0097] When using a self-resonance method, the primary coil and the secondary coil can be provided in the form of a primary resonance antenna and a secondary resonance antenna, respectively. The resonance antenna can have a resonance structure including a coil and a capacitor. At this time, the resonance frequency of the resonance antenna is determined by the inductance of the coil and the capacitance of the capacitor. Here, the coil can be formed in the form of a loop. In addition, a core can be arranged inside the loop. The core can include a physical core such as a ferrite core or an air core.

[0098] Energy transfer between the primary and secondary resonant antennas can be achieved through the resonance phenomenon of magnetic fields. Resonance refers to the phenomenon in which, when a near-field corresponding to the resonant frequency is generated from one resonant antenna and another resonant antenna is located nearby, the two resonant antennas are coupled to each other, resulting in high-efficiency energy transfer between the resonant antennas. When a magnetic field corresponding to the resonant frequency is generated between the primary and secondary resonant antennas, the primary and secondary resonant antennas resonate with each other. Accordingly, the magnetic field generated from the primary resonant antenna is focused toward the secondary resonant antenna with higher efficiency than when it is generally radiated into free space, and thus energy can be transferred from the primary resonant antenna to the secondary resonant 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 alignment between the loops that make up the primary and secondary coils, and the spacing between the loops must be very close.

[0099] Although not illustrated in the drawing, the wireless power transmission device (100) may further include a communication antenna. The communication antenna may transmit and receive communication signals using a communication carrier other than magnetic field communication. For example, the communication antenna may transmit and receive communication signals such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

[0100] The communication / control circuit (120) can transmit and receive information with the wireless power receiving device (200). The communication / control circuit (120) can include at least one of an IB communication module or an OB communication module.

[0101] The IB communication module can transmit and receive information using a magnetic wave with a specific frequency as its center frequency. For example, the communication / control circuit (120) can perform in-band communication by loading communication information on the operating frequency of wireless power transmission and transmitting it through the primary coil, or by receiving the operating frequency containing the information through the primary coil. At this time, the information can be loaded into the magnetic wave or the magnetic wave containing the information can be interpreted using a modulation method such as binary phase shift keying (BPSK), frequency shift keying (FSK), or amplitude shift keying (ASK), and a coding method such as Manchester coding or non-return-to-zero level (NZR-L) coding. 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.

[0102] The OB communication module may also perform out-of-band communication via 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 communication modules such as Wi-Fi 4, Bluetooth, Bluetooth LE, ZigBee, and NFC.

[0103] 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 types of information and control each component of the wireless power transmission device (100).

[0104] The communication / control circuit (120) may be implemented as a computer or 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).

[0105] The communication / control circuit (120) can control the transmission power by controlling the operating point. The controlled operating point 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. In addition, the wireless power transmitter (100) can control the reception power by supplying a constant power and the wireless power receiver (200) can control the resonant frequency.

[0106] Meanwhile, in the WPC Qi system, the wireless power transmitter (100) can be classified, for example, from the viewpoint of the number of primary coils activated for power transmission. At this time, the wireless power transmitter (100) supporting a wireless power transmission amount of up to 5 W (i.e., the wireless power transmitter (100) supporting the BPP protocol) can be classified, for example, into a type A wireless power transmitter (100) and a type B wireless power transmitter (100), and the wireless power transmitter (100) supporting a wireless power transmission amount of 5 W or more (i.e., the wireless power transmitter (100) supporting the MPP or EPP protocol) can be classified, for example, into a type MP A wireless power transmitter (100) and a type MP B wireless power transmitter (100).

[0107] - Type A and Type MP A wireless power transmitters (100)

[0108] Type A and Type MP A wireless power transmitters (100) may have more than one primary coil. 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.

[0109] - Type B and Type MP B wireless power transmitters (100)

[0110] Type B and Type MP B power transmitters may have an array of primary coils. Furthermore, the Type B and Type MP B power transmitters may be positionally independent. To achieve this, the Type B and Type MP B power transmitters may activate one or more primary coils in the array to realize primary cells at different locations on the interface surface.

[0111] Additionally, a wireless power transmitter that utilizes magnets and supports wireless power transmission 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.

[0112] However, for standards after Qi v2.0, BPP can support power of up to 5W for high-power wireless power transmission, EPP can support power of more than 5W but less than 50W, and MPP can support power of more than 5W but less than 50W. In other words, EPP or MPP can be considered to support power of 5 to 50W.

[0113] The mobile device (450) includes a wireless power receiver (power receiver, 200) that receives wireless power through a secondary coil and a load (load, 455) that receives and stores power received from the wireless power receiver (200) and supplies it to the device.

[0114] A wireless power receiver (200) may include a power pick-up circuit (210) and a communications / control circuit (220). The power pick-up circuit (210) may receive wireless power through a secondary coil and convert it into electrical energy. The power pick-up circuit (210) rectifies an AC signal obtained through the secondary coil and converts it into a DC signal. The communications / control circuit (220) may control transmission and reception of wireless power (power transmission and reception).

[0115] 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 a resonant frequency, a magnetic resonance phenomenon occurs between the primary coil and the secondary coil, allowing power to be transmitted more efficiently.

[0116] Meanwhile, although not illustrated in FIG. 4, the communication / control circuit (220) may further include a communication antenna. The communication antenna may transmit and receive communication signals using a communication carrier other than magnetic field communication. For example, the communication antenna may transmit and receive communication signals such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

[0117] The communication / control circuit (220) can transmit and receive information with the wireless power transmission device (100). The communication / control circuit (220) can include at least one of an IB communication module or an OB communication module.

[0118] The IB communication module can transmit and receive information using a magnetic wave having a specific frequency as its center frequency. For example, the communication / control circuit (220) can perform IB communication by loading information onto a magnetic wave and transmitting it through a secondary coil, or by receiving a magnetic wave containing information through the secondary coil. At this time, the information can be loaded onto the magnetic wave or the magnetic wave containing information can be interpreted using a modulation method such as binary phase shift keying (BPSK), frequency shift keying (FSK), or amplitude shift keying (ASK), and a coding method such as Manchester coding or non-return-to-zero level (NZR-L) coding. 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.

[0119] The OB communication module may also perform out-of-band communication via a communication antenna. For example, the communication / control circuit (220) may be provided as a short-range communication module.

[0120] Examples of short-range communication modules include Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

[0121] 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 types of information and control each component of the wireless power receiving device (200).

[0122] The communication / control circuit (220) may be implemented as a computer or 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).

[0123] 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 be implemented and operated with a communication architecture as shown in FIG. 5, respectively.

[0124] FIG. 5 is a diagram showing an example of a Bluetooth communication architecture to which an embodiment according to the present specification can be applied.

[0125] Referring to FIG. 5, (a) of FIG. 5 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).

[0126] Specifically, as illustrated in (a) of FIG. 5, 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 a Host Controller Interface (HCI, 18).

[0127] The above host stack (or host module) (470) refers to a wireless transmission / reception module that receives a 2.4 GHz Bluetooth signal and hardware for transmitting or receiving a Bluetooth packet, and the controller stack (460) is connected to the Bluetooth module to control the Bluetooth module and perform operations.

[0128] 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).

[0129] The above BR / EDR PHY layer (12) is a layer that transmits and receives 2.4 GHz wireless signals, and can transmit data by hopping 79 RF channels when using GFSK (Gaussian Frequency Shift Keying) modulation.

[0130] The above BR / EDR Baseband layer (14) is responsible for transmitting a digital signal, selects a channel sequence that hops 1400 times per second, and transmits a time slot of 625 us in length for each channel.

[0131] The above link manager layer (16) controls the overall operation (link setup, control, security) of the Bluetooth connection by utilizing the Link Manager Protocol (LMP).

[0132] The above link manager layer (16) can perform the following functions.

[0133] - ACL / SCO logical transport, logical link setup and control.

[0134] - Detach: Aborts the connection and informs the other device of the reason for the abort.

[0135] - Power control and role switch.

[0136] - Performs security (authentication, pairing, encryption) functions.

[0137] 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.

[0138] 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).

[0139] The above Logical Link Control and Adaptation Protocol (L2CAP, 21) can provide one bidirectional channel for transmitting data to a specific protocol or profile.

[0140] The above L2CAP (21) can multiplex various protocols, profiles, etc. provided by the upper Bluetooth layer.

[0141] Bluetooth BR / EDR's L2CAP uses dynamic channels, supports protocol service multiplexer, retransmission, streaming mode, and provides segmentation and reassembly, per-channel flow control, and error control.

[0142] The above-mentioned generic attribute profile (GATT, 23) may be operable as a protocol that describes how the attribute protocol (22) is utilized when configuring services. For example, the above-mentioned generic attribute profile (23) may be operable to specify how ATT attributes are grouped together into services, and may be operable to describe features associated with services.

[0143] Accordingly, the general attribute profile (23) and the attribute protocol (ATT, 22) can 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.

[0144] The above attribute protocol (22) and the BR / EDR profile (25) define a service (profile) using Bluetooth BR / EDR and an application protocol for sending and receiving these data, and the Generic Access Profile (GAP, 24) defines device discovery, connection, and security level.

[0145] As illustrated in (b) of FIG. 5, the Bluetooth LE protocol stack includes a controller stack (480) operable to process a timing-critical wireless device interface and a host stack (490) operable to process high level data.

[0146] First, the controller stack (480) may 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.

[0147] The host stack (490) may be implemented as part of an OS running on a processor module, or as an instantiation of a package on top of the OS.

[0148] In some cases, the controller stack and the host stack may operate or execute on the same processing device within a processor module.

[0149] The above controller stack (480) includes a physical layer (Physical Layer, PHY, 32), a link layer (Link Layer, 34), and a host controller interface (Host Controller Interface, 36).

[0150] The above physical layer (PHY, wireless transmission / reception 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.

[0151] The link layer (34), which plays a role in transmitting or receiving Bluetooth packets, performs advertising and scanning functions using three advertising channels, then creates a connection between devices, and provides a function for sending and receiving data packets of up to 257 bytes through 37 data channels.

[0152] The above host stack may include a Generic Access Profile (GAP, 40), a Logical Link Control and Adaptation Protocol (L2CAP, 41), a Security Manager (SM, 42), an Attribute Protocol (ATT, 440), a Generic Attribute Profile (GATT, 44), a Generic Access Profile (Generic Access Profile, 25), and an LT Profile (46). However, the host stack (490) is not limited thereto and may include various protocols and profiles.

[0153] The host stack multiplexes various protocols, profiles, etc. provided above Bluetooth using L2CAP.

[0154] First, L2CAP (Logical Link Control and Adaptation Protocol, 41) can provide a single bidirectional channel for transmitting data to a specific protocol or profile.

[0155] The above L2CAP (41) may be operable to multiplex data between upper layer protocols, segment and reassemble packages, and manage multicast data transmission.

[0156] Bluetooth LE uses three fixed channels by default (one for signaling CH, one for Security Manager, and one for Attribute protocol). Additionally, dynamic channels can be used as needed.

[0157] 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.

[0158] SM (Security Manager, 42) is a protocol for authenticating devices and providing key distribution.

[0159] ATT (Attribute Protocol, 43) defines the rules for accessing data from a client-server device. ATT has six message types: Request, Response, Command, Notification, Indication, and Confirmation.

[0160] ① Request and Response messages: A Request message is a message for requesting and transmitting specific information from a client device to a server device, and a Response message is a response message to a Request message, and is a message that can be used for transmission from a server device to a client device.

[0161] ② Command message: A message sent from a client device to a server device, primarily to instruct a command for a specific action. The server device does not send a response to the Command message to the client device.

[0162] ③ Notification message: A message sent from a server device to a client device for notification of events, etc.; the client device does not send a confirmation message for the Notification message to the server device.

[0163] ④ Indication and Confirm messages: Messages sent from the server device to the client device for notification of events, etc. Unlike the Notification message, the client device sends a confirmation message for the Indication message to the server device.

[0164] This specification transmits a value for data length when requesting long data in a GATT profile using the above-mentioned attribute protocol (ATT, 43), so that the client can clearly know the data length, and can receive a characteristic value from the server using a UUID.

[0165] The Generic 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.

[0166] In addition, the general access profile (45) is mainly used in the device discovery, connection creation and security procedure parts, defines a method for providing information to the user, and defines the type of the attribute as follows.

[0167] ① Service: Defines the basic operation of the device through a combination of data-related behaviors.

[0168] ② Include: Defines the relationship between services

[0169] ③ Characteristics: Data values ​​used in the service

[0170] ④ Behavior: Computer-readable format defined as UUID (Universal Unique Identifier, value type)

[0171] The above LE profile (46) is a profile that is dependent on GATT and is mainly applied to Bluetooth LE devices. LE profiles (46) may include, for example, Battery, Time, FindMe, Proximity, Time, etc., and the specific contents of GATT-based profiles are as follows.

[0172] ① Battery: How to exchange battery information

[0173] ② Time: Method of exchanging time information

[0174] ③ FindMe: Provides distance-based alarm service

[0175] ④ Proximity: How to exchange battery information

[0176] ⑤ Time: Method of exchanging time information

[0177] The above generic attribute profile (GATT, 44) may be operable as a protocol that describes how the attribute protocol (43) is utilized when configuring services. For example, the above generic attribute profile (44) may be operable to specify how ATT attributes are grouped together into services, and may be operable to describe features associated with services.

[0178] Accordingly, the general attribute profile (44) and the attribute protocol (ATT, 43) can 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.

[0179] Below, we will briefly look at the procedures of Bluetooth Low Energy (BLE) technology.

[0180] BLE procedures can be divided into device filtering procedures, advertising procedures, scanning procedures, discovering procedures, and connecting procedures.

[0181] Device Filtering Procedure

[0182] Device filtering procedures are a way to reduce the number of devices that respond to requests, instructions, notifications, etc. in the controller stack.

[0183] When a request is received from any device, since it is unnecessary to respond to it, the controller stack can control the power consumption of the BLE controller stack by reducing the number of requests transmitted.

[0184] An advertising device or scanning device may perform the above device filtering procedure to limit the devices that receive advertising packets, scan requests, or connection requests.

[0185] Here, an advertising device refers to a device that transmits an advertising event, i.e., performs an advertisement, and is also expressed as an advertiser.

[0186] A scanning device is a device that performs scanning and transmits scan requests.

[0187] In BLE, when a scanning device receives some advertising packets from an advertising device, the scanning device must send a scan request to the advertising device.

[0188] However, if a device filtering procedure is used and transmission of scan requests is unnecessary, the scanning device may ignore advertising packets transmitted from the advertising device.

[0189] 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, eliminating the need to send a response to the connection request.

[0190] Advertising Procedure

[0191] An advertising device performs an advertising procedure to perform a non-directional broadcast to devices within the area.

[0192] Here, undirected advertising is advertising directed to all devices rather than broadcasting to a specific device, and all devices can scan the advertising to request additional information or connection.

[0193] In contrast, directed advertising allows only devices designated as receiving devices to scan the advertisement and request additional information or a connection.

[0194] The advertising process is used to establish a Bluetooth connection with a nearby initiating device.

[0195] Alternatively, the advertising procedure may be used to provide periodic broadcasts of user data to scanning devices listening on the advertising channel.

[0196] In the advertising process, all advertisements (or advertising events) are broadcast through the advertising physical channel.

[0197] Advertising devices can receive scan requests from listening devices that are listening to obtain additional user data from the advertising device. The advertising device transmits a response to the scan request to the device that sent the scan request over the same advertising physical channel as the advertising physical channel that received the scan request.

[0198] Broadcast user data sent as part of advertising packets is dynamic data, whereas scan response data is typically static data.

[0199] An advertising device can receive a connection request from an initiating device on an advertising (broadcast) physical channel. If the advertising device uses a connectable advertising event and the initiating device is not filtered by the device filtering procedure, the advertising device stops advertising and enters connected mode. The advertising device can resume advertising after entering connected mode.

[0200] Scanning Procedure

[0201] A device performing scanning, i.e., a scanning device, performs a scanning procedure to listen for non-directional broadcasts of user data from advertising devices using an advertising physical channel.

[0202] The scanning device transmits a scan request to the advertising device via the 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, including the additional data requested from the scanning device via the advertising physical channel.

[0203] The above scanning procedure can be used while connecting with other BLE devices in a BLE piconet.

[0204] If the scanning device receives a broadcasted advertising event and is in initiator mode, which allows it to initiate a connection request, the scanning device can initiate a Bluetooth connection with the advertising device by transmitting a connection request to the advertising device over the advertising physical channel.

[0205] When a scanning device sends a connection request to an advertising device, the scanning device stops initiator mode scanning for further broadcasts and enters connection mode.

[0206] Discovery Procedure

[0207] Devices capable of Bluetooth communication (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.

[0208] The discovery process is performed asymmetrically. A Bluetooth device attempting to locate other devices in its vicinity is called a discovering device and listens for devices advertising scannable advertising events. A Bluetooth device discovered and available to other devices is called a discoverable device and actively broadcasts advertising events over the advertising (broadcast) physical channel to make it scannable.

[0209] Both the discovering device and the discoverable device may already be connected to other Bluetooth devices in the piconet.

[0210] Connecting Procedure

[0211] The connection procedure is asymmetric, requiring one Bluetooth device to perform an advertising procedure while another Bluetooth device performs a scanning procedure.

[0212] That is, the advertising process can be targeted, resulting in only one device responding 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 via the advertising (broadcast) physical channel.

[0213] Next, we will briefly look at the operating states in BLE technology, namely Advertising State, Scanning State, Initiating State, and Connection State.

[0214] Advertising State

[0215] The Link Layer (LL) enters the Advertising state at the direction of the host (stack). When the Link Layer is in the Advertising state, it transmits Advertising Packet Data Circuits (PDUs) in Advertising events.

[0216] Each advertising event consists of at least one advertising PDU, which are transmitted via the advertising channel indices used. An advertising event may terminate when each advertising PDU has been transmitted via the advertising channel indices used, or may terminate earlier if the advertising device needs to free up space for other functions.

[0217] Scanning State

[0218] The link layer enters the scanning state at the direction of the host (stack). In the scanning state, the link layer listens for advertising channel indices.

[0219] There are two types of scanning states: passive scanning and active scanning, and each scanning type is determined by the host.

[0220] No separate time or advertising channel index is defined for performing scanning.

[0221] During the scanning state, the link layer listens for advertising channel indices for the duration of the scanWindow. The scanInterval is defined as the interval between the start points of two consecutive scan windows.

[0222] 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 a different advertising channel index. The link layer uses all available advertising channel indices.

[0223] In passive scanning, the link layer only receives packets and does not transmit any packets.

[0224] When actively scanning, the link layer listens to the advertising device for advertising PDUs and depending on the advertising PDU type, may request additional information about the advertising device.

[0225] Initiating State

[0226] The link layer enters the initiated state at the direction of the host (stack).

[0227] When the link layer is in the initiating state, the link layer listens for advertising channel indices.

[0228] During the initiation state, the link layer listens for advertising channel indices during the scan window period.

[0229] connection state

[0230] The link layer enters a connected state when the device performing the connection request, i.e., the initiating device, sends a CONNECT_REQ PDU to the advertising device, or when the advertising device receives a CONNECT_REQ PDU from the initiating device.

[0231] Once a connection enters the connected state, it is considered established. However, the connection need not be considered established at the time it enters the connected state. The only difference between a newly created connection and an established connection is the link-layer connection supervision timeout value.

[0232] When two devices are connected, they act in different roles.

[0233] The link layer that performs the master role is called the master, and the link layer that performs the slave role is called the slave. The master controls the timing of connection events, and connection events indicate the point in time when the master and slave are synchronized.

[0234] Below, we will briefly examine the packets defined in the Bluetooth interface. BLE devices use the packets defined below.

[0235] Packet Format

[0236] The Link Layer has only one packet format, which is used for both advertising channel packets and data channel packets.

[0237] Each packet consists of four fields: Preamble, Access Address, PDU, and CRC.

[0238] 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.

[0239] Advertising Channel PDU

[0240] An advertising channel PDU (Packet Data Circuit) has a 16-bit header and a payload of various sizes.

[0241] The PDU type field of the advertising channel PDU included in the header indicates the PDU type as defined in Table 1 below.

[0242] PDU TypePacket Name0000ADV_IND0001ADV_DIRECT_IND0010ADV_NONCONN_IND0011SCAN_REQ0100SCAN_RSP0101CONNECT_REQ0110ADV_SCAN_IND0111-1111Reserved

[0243] Advertising PDU

[0244] The advertising channel PDU types below are called advertising PDUs and are used in specific events.

[0245] ADV_IND: Connectable non-directional advertising event

[0246] ADV_DIRECT_IND: Connectable directional advertising event

[0247] ADV_NONCONN_IND: Non-directional ad event that is not reachable

[0248] ADV_SCAN_IND: Scannable non-directional ad event

[0249] The above PDUs are transmitted by the link layer in the advertising state and received by the link layer in the scanning state or initiating state.

[0250] Scanning PDU

[0251] The advertising channel PDU type below is called a scanning PDU and is used in the conditions described below.

[0252] SCAN_REQ: Sent by the link layer in scanning state and received by the link layer in advertising state.

[0253] SCAN_RSP: Sent by the link layer in advertising state and received by the link layer in scanning state.

[0254] Initiating PDU

[0255] The advertising channel PDU type below is called an initiation PDU.

[0256] CONNECT_REQ: Sent by the link layer in the initiating state and received by the link layer in the advertising state.

[0257] Data Channel PDU

[0258] A data channel PDU has a 16-bit header, a payload of variable size, and may include a Message Integrity Check (MIC) field.

[0259] The procedures, states, packet formats, etc. in BLE technology discussed above can be applied to perform the methods proposed in this specification.

[0260] Referring back to FIG. 4, the load (455) may be a battery. The battery can store energy using power output from the power pickup circuit (210). Furthermore, the mobile device (450) does not necessarily need to include a battery. For example, the battery may be provided as a detachable external component. For 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.

[0261] 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 broad 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).

[0262] When 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 reception device (200) including the communication / control circuit (220) can be expressed in a simplified block diagram as in FIG. 6.

[0263] Fig. 6 is a block diagram illustrating a wireless power transmission system using BLE communication according to an example.

[0264] Referring to FIG. 6, a 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).

[0265] Meanwhile, the wireless power receiver (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).

[0266] In one aspect, the BLE communication modules (122, 222) perform the architecture and operation according to FIG. 5. For example, the BLE communication modules (122, 222) may be used to establish a connection between a wireless power transmission device (100) and a wireless power reception device (200) and to exchange control information and packets required for wireless power transmission.

[0267] 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 GATT using BLE transmission.

[0268] Fig. 7 is a block diagram illustrating a wireless power transmission system using BLE communication according to another example.

[0269] 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).

[0270] Hereinafter, a coil or coil portion may also be referred to as a coil assembly, coil cell or cell, including a coil and at least one element proximate to the coil.

[0271] 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 communication protocol can be composed of multiple steps. The communication protocol will be described below.

[0272] Figure 8 is a state transition diagram for explaining a wireless power transfer procedure.

[0273] WPC can define two communication protocols.

[0274] - 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).

[0275] - Extended Protocol (or EPP): Supports bidirectional communication and enhanced foreign object detection (FOD) capabilities, and may also support data transfer stream functionality and authentication options.

[0276] Referring to FIG. 8, the power transfer operation between the wireless power transmitter (100) and the 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.

[0277] - Ping Phase (810)

[0278] In the ping phase (810), the wireless power transmitter (100) may attempt to establish communication with the wireless power receiver (200). Prior to attempting to establish communication, measurements may be performed to determine whether there are any objects, such as bank cards, coins, or other metals, that could be damaged or heated during power transfer. These measurements may be performed without waking up the wireless power receiver (200).

[0279] Here, the wireless power transmitter (100) can obtain design information from the wireless power receiver (200) and then postpone the conclusion on whether the detected metal is a foreign object or a friendly metal to the negotiation phase (830).

[0280] - Configuration phase (820)

[0281] In the configuration phase (820), the wireless power receiver (200) can send basic identification and configuration data to the wireless power transmitter (100). Then, both the wireless power transmitter (100) and the wireless power receiver (200) can use this information to create a baseline power transfer contract.

[0282] 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).

[0283] Here, the wireless power receiver (200) can use features such as enhanced FOD, data transmission stream, and authentication only when implementing an extended protocol.

[0284] - Negotiation phase (830)

[0285] 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 restrictions. Furthermore, the wireless power receiver (200) may provide design information to the wireless power transmitter (100). The design information may then be used to complete the FOD before transitioning to the power transfer phase (840).

[0286] Here, the negotiation phase (830) may correspond to a phase that does not exist in the baseline protocol.

[0287] - Power transmission phase (840)

[0288] The power transfer phase (840) may be a phase in which power is transferred to a load of the wireless power receiver (200).

[0289] In the extended protocol, the wireless power transmitter (100) and wireless power receiver (200) may perform system calibration at the beginning of this phase. This phase may be occasionally interrupted to renegotiate elements of the power transfer agreement. However, power transfer may continue during this renegotiation.

[0290] Hereinafter, the protocols for the ping phase (810), configuration phase (820), negotiation phase (830), and power transfer phase (840) described above will be described in more detail.

[0291] 1. Ping Phase (810)

[0292] 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. Furthermore, the wireless power transmitter (100) cannot recognize the wireless power receiver (200). This is because the system is generally inactive due to a lack of power signals.

[0293] In this 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.

[0294] Figure 9 schematically illustrates an example of a protocol of the ping phase (810).

[0295] 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 exists within its operating volume. For example, the wireless power transmitter can detect whether an object exists within its operating volume based on a change in current in the transmitting coil or primary coil.

[0296] The wireless power transmitter (100) can apply NFC tag protection (S920). Here, NFC tag protection can be performed through the following procedure.

[0297] a) First, it can be determined whether one or more of the detected objects contains an NFC tag.

[0298] b) Afterwards, it can be verified whether the object containing the NFC tag can withstand the power signal without damage.

[0299] c) If the wireless power transmitter (100) determines that the NFC tag cannot withstand the power signal, it does not start the digital ping and maintains the ping phase, and the wireless power transmitter (100) can inform the user of the reason why it cannot continue.

[0300] The wireless power transmitter (100) can perform foreign substance detection (S930). That is, the wireless power transmitter (100) can collect information that helps determine whether there is a foreign substance other than the wireless power receiver (200). To this end, the wireless power transmitter (100) can use various methods, such as the pre-power FOD method.

[0301] Meanwhile, in the three steps described above (S910, S920, S930), the radio power receiver may not operate.

[0302] If the wireless power transmitter (100) performs the above steps and determines that there is a potential 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, such as a signal strength (SIG) data packet or an end power transfer (EPT) data packet, from the wireless power receiver (200).

[0303] Thereafter, 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 coupling, and the SIG data packet may include information about a signal strength value. In addition, the EPT data packet may provide a request to stop power transmission and a reason for the request.

[0304] If the wireless power transmitter (100) does not receive the above response from the wireless power receiver (200), the wireless power transmitter (100) may stay in the ping phase (810) and repeat the above steps.

[0305] 2. Configuration phase (820)

[0306] The configuration phase (820) is part of the following protocol:

[0307] - The wireless power receiver (200) can identify itself to the wireless power transmitter (100).

[0308] - The wireless power receiver (200) and the wireless power transmitter (100) can establish a baseline power transfer contract.

[0309] - The wireless power receiver (200) and the wireless power transmitter (100) can determine a protocol variation to be used for power transmission.

[0310] In the configuration phase (820), the wireless power transmitter (100) and the wireless power receiver (200) may 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) only change when the user moves the wireless power receiver (200) within the operating volume.

[0311] Below, the protocol in the configuration phase (820) will be described in more detail.

[0312] Figure 10 schematically illustrates an example of a protocol of the configuration phase (820).

[0313] 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 the ID data packet and optionally the XID data packet.

[0314] The wireless power transmitter (100) can optionally receive a power control hold-off (PCH) data packet from the wireless power receiver (200) (S1030), and the wireless power transmitter (100) can receive a CFG data packet from the wireless power receiver (200) (S1040). That is, the wireless power receiver (200) can provide data for use in a power transfer contract by using the PCH and / or CFG data packet.

[0315] Finally, the wireless power transmitter (100) can check the extended protocol if possible (S1050).

[0316] If we summarize each data packet explained above, it can be as follows.

[0317] - ID: The ID data packet may be information that identifies the wireless power receiver (200). Here, the ID may include a manufacturer code, a basic device identifier, etc. In addition, the ID may also include information that identifies the presence or absence of an XID data packet in the setup phase.

[0318] - XID: XID data packets may contain additional identification data.

[0319] - PCH: The PCH data packet can configure the delay between the reception of a CE data packet and the wireless power transmitter (100) starting to adjust the coil current.

[0320] - CFG: CFG data packets can provide basic configuration data.

[0321] For example, the CFG data packet can provide all parameters governing power transfer in the baseline protocol. Furthermore, the CFG data packet can provide all FSK communication parameters used in the extended protocol. Furthermore, the CFG data packet can provide additional functionality for the wireless power receiver (200).

[0322] FIG. 11 is a diagram illustrating a message field of a configuration packet (CFG) of a wireless power receiving device according to one embodiment.

[0323] According to FIG. 11, a configuration packet (CFG) according to one embodiment may have a header value of 0x51, and a message field of the configuration packet (CFG) may include a 1-bit authentication (AI) flag and a 1-bit out-of-band (OB) flag.

[0324] The authentication flag (AI) indicates whether the wireless power receiver supports the authentication function. For example, if the value of the authentication flag (AI) is '1', it indicates that the wireless power receiver supports the authentication function or can act as an authentication initiator. If the value of the authentication flag (AI) is '0', it indicates that the wireless power receiver does not support the authentication function or cannot act as an authentication initiator.

[0325] The out-of-band (OB) flag indicates whether the wireless power receiver supports out-of-band communication. For example, if the value of the out-of-band (OB) flag is '1', the wireless power receiver indicates out-of-band communication, and if the value of the out-of-band (OB) flag is '0', the wireless power receiver indicates that out-of-band communication is not supported.

[0326] The provision of the ID and / or XID described above is for identification purposes. Furthermore, the provision of the PCH and / or CFG is for the purpose of establishing a power transmission contract.

[0327] 3. Negotiation Phase (830)

[0328] The negotiation phase (830) is part of an extended protocol that allows the wireless power transmitter (100) and wireless power receiver (200) to change the power transfer agreement. There are two types of this phase.

[0329] - Negotiation Phase (830): The negotiation phase (830) follows the configuration phase (820) and serves to create an initial extended power transfer agreement. Furthermore, the negotiation phase (830) completes the pre-power FOD function. The length of the negotiation phase is not limited.

[0330] - Renegotiation Phase: The renegotiation phase may interrupt the power delivery phase (840) multiple times and typically serves to adjust a single element of the power delivery contract. Additionally, the FOD / qf, FOD / rf, and SRQ / rpr data packets may not be used during the renegotiation phase. The restrictions on CE data packets during the power delivery phase (840) limit the length of the renegotiation phase.

[0331] During the negotiation or renegotiation phase, the Power Transfer Contract relating to the reception / transmission of wireless power between the wireless power receiving device and the wireless power transmitting device may be extended or modified, or the Power Transfer Contract may be renewed to adjust at least some of its elements, or information may be exchanged to establish out-of-band communications.

[0332] Figure 12 is a flowchart schematically illustrating a protocol of a negotiation step or a renegotiation step according to one embodiment.

[0333] Referring to FIG. 12, the wireless power transmitter (100) may receive an FOD status data packet (e.g., FOD) from the wireless power receiver (200) (S1210). Here, the wireless power receiver (200) may use the FOD status data packet to inform the wireless power transmitter (100) of the effect its presence has on selected properties of the reference wireless power transmitter (100). In addition, the wireless power transmitter (100) may use this information to configure the FOD function.

[0334] The wireless power transmitter (100) can transmit ACK / NAK for the above FOD status data packet to the wireless power receiver (200) (S1215).

[0335] 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).

[0336] A general request packet (GRQ) may have a header value of 0x07 and may include a 1-byte message field. The message field of the general request packet (GRQ) may include a header value of a data packet that the wireless power receiver (200) requests from the wireless power transmitter (100) using the GRQ packet.

[0337] 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).

[0338] The wireless power transmitter (100) that receives the GRQ / id can transmit an ID packet to the wireless power receiver (200) (S1225). The ID packet of the wireless power transmitter (100) includes information about the 'Manufacturer Code'. The ID packet including information about the 'Manufacturer Code' allows the manufacturer of the wireless power transmitter (100) to be identified.

[0339] Alternatively, in the negotiation phase 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).

[0340] The wireless power transmitter (100) that receives GRQ / cap can transmit a performance packet (CAP) to the wireless power receiver (200) (S1235).

[0341] Alternatively, in the negotiation phase 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).

[0342] The wireless power transmitter (100) that receives GRQ / xcap can transmit a performance packet (XCAP) to the wireless power receiver (200) (S1245).

[0343] FIG. 13 is a diagram illustrating a message field of a performance packet (CAP) of a wireless power transmission device according to one embodiment.

[0344] A performance packet (CAP) according to one embodiment may have a header value of 0x31 and may include a 3-byte message field, as shown in FIG. 19.

[0345] Referring to FIG. 13, the message field of a performance packet (CAP) may include a 1-bit authentication (AR) flag and a 1-bit out-of-band (OB) flag.

[0346] The authentication flag (AR) indicates whether the wireless power transmitter (100) supports the authentication function. For example, if the value of the authentication flag (AR) is '1', it indicates that the wireless power transmitter (100) supports the authentication function or can operate as an authentication responder. If the value of the authentication flag (AR) is '0', it indicates that the wireless power transmitter (100) does not support the authentication function or cannot operate as an authentication responder.

[0347] The out-of-band (OB) flag indicates whether the wireless power transmitter (100) supports out-of-band communication. For example, if the value of the out-of-band (OB) flag is '1', the wireless power transmitter (100) indicates out-of-band communication, and if the value of the out-of-band (OB) flag is '0', the wireless power transmitter (100) may indicate that it does not support out-of-band communication.

[0348] In the negotiation stage, the wireless power receiver (200) can receive a performance packet (CAP) of the wireless power transmitter (100) to check whether the wireless power transmitter (100) supports the authentication function and whether it supports out-of-band communication.

[0349] Returning to FIG. 12, the wireless power receiver (200) can update elements of a power transfer contract related to power to be provided in the power transfer phase using at least one specific request data packet (SRQ) in the negotiation phase or the renegotiation phase (S1250), and can receive an ACK / NAK for this (S1255).

[0350] Meanwhile, to confirm the extended power transfer contract and end the negotiation phase, the wireless power receiver (200) can transmit SRQ / en to the wireless power transmitter (100) (S1260) and receive ACK from the wireless power transmitter (100) (S1265).

[0351] 4. Power transmission phase (840)

[0352] The power transfer phase (840) is the part of the protocol where actual power is transferred to the load of the wireless power receiver (200). Here, power transfer may proceed according to the terms of the power transfer contract generated in the negotiation phase (830).

[0353] <CE에 기반한 전력 제어>

[0354] The wireless power receiver (200) can control the power level by transmitting control error (CE) data, which measures the deviation between the target and actual operating points 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 0, at which point the system operates at the target power level.

[0355] <In-power transfer FOD method>

[0356] In addition to the 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) can periodically report the amount of power it receives (received power level) to the wireless power transmitter (100), and the wireless power transmitter (100) can notify the wireless power receiver (200) whether it has detected a foreign object. A method that can be used for FOD in the power transfer phase can correspond to, for example, power loss calculation. In this approach, the wireless power transmitter (100) can compare the received power level reported by the wireless power receiver (200) with the amount of transmitted power (transmitted power level) and send a signal to the wireless power receiver (200) (regarding whether it has detected a foreign object) when the difference exceeds a threshold.

[0357] <Renegotiation Phase>

[0358] If necessary, depending on the situation, the wireless power transmitter (100) or wireless power receiver (200) may request renegotiation of the power transfer contract during the power transfer phase. Examples of changed circumstances that may trigger renegotiation of the power transfer contract may include the following.

[0359] - When the wireless power receiver (200) requires (substantially) more power than previously negotiated.

[0360] - When it is detected that the wireless power transmitter (100) is operating at low efficiency.

[0361] - When the wireless power transmitter (100) can no longer maintain its current power level due to increased operating temperature (or vice versa, when the wireless power receiver (200) can operate at a higher power level after it has cooled sufficiently).

[0362] Here, an example of a specific protocol for the renegotiation phase is as described above.

[0363] <Data transmission stream>

[0364] 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 transfer phase (840).

[0365] A key common application here is authentication, whereby both parties can verify the credentials of the other party in a tamper-proof manner. For example, a wireless power receiver (200) may want to verify the credentials of a wireless power transmitter (100) to ensure that the wireless power transmitter (100) can be trusted to operate safely at high power levels. Proper credentials may indicate compliance testing.

[0366] Therefore, the present specification can provide a method to start power delivery at a low power level and control the power to a higher level only after successfully completing the authentication protocol.

[0367] <Protocol in the power transfer phase (840)>

[0368] So far, the operation between the wireless power transmitter (100) and the wireless power receiver (200) in the power transfer phase (840) has been roughly described. Hereinafter, for 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 baseline protocol and the extended protocol.

[0369] Figure 14 schematically illustrates a flowchart of the data flow for the power transfer phase (840) in the baseline protocol.

[0370] 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.

[0371] The wireless power receiver (200) can transmit an RP (received power) data packet (RP8 in the baseline protocol) to the wireless power transmitter (100) typically once every 1.5 seconds (S1420).

[0372] Optionally, the wireless power receiver (200) can transmit a CHS (charge status) data packet to the wireless power transmitter (100) (S1430).

[0373] If we organize and explain the data packets explained above, it can be as follows.

[0374] - 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 that is 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 a positive value, it indicates that the actual operating point is below the target operating point, and the wireless power transmitter (100) may be requested to increase the power signal. If the control error value is a negative value, it indicates that the actual operating point is above the target operating point, and the wireless power transmitter (100) may be requested to decrease the power signal.

[0375] - RP8: RP8 data packets can report the received power level. Here, RP8 data packets can only be included in the baseline protocol.

[0376] - CHS: CHS data packets can provide the charge level of the battery under load.

[0377] Figure 15 schematically illustrates a flowchart of the data flow for the power transfer phase (840) in the extended protocol.

[0378] 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.

[0379] The wireless power receiver (200) can transmit a RP (received power) data packet (RP in the extended protocol) to the wireless power transmitter (100) typically once every 1.5 seconds (S1515).

[0380] In the power transfer phase, control error packets (CE) and received power packets (RP) are data packets that must be repeatedly transmitted / received according to the required timing constraints for controlling wireless power.

[0381] The wireless power transmitter (100) can control the level of wireless power to be transmitted based on the control error packet (CE) and the received power packet (RP) received from the wireless power receiver (200).

[0382] Meanwhile, in the extended protocol, the wireless power transmitter (100) can respond to the received power packet (RP) with a bit pattern such as ACK, NAK, ATN, etc. (S1520).

[0383] For a received power packet (RP / 0) with a mode value of 0, the wireless power transmitter (100) responds with ACK, which means that power transmission can continue at the current level.

[0384] For a received power packet (RP / 0) with a mode value of 0, the wireless power transmitter (100) responds with NAK, which means that the wireless power receiver (200) should reduce power consumption.

[0385] 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 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).

[0386] 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).

[0387] The received power packet (RP / 1) with the mode value of 1 described above may mean the first calibration data point, and the received power packet (RP / 2) with the mode value of 2 may mean an additional calibration data point. Here, the wireless power receiver may transmit multiple additional power calibration values ​​to the wireless power transmitter by transmitting the received power packet (RP / 2) with the mode value of 2 multiple times, and the wireless power transmitter may perform a calibration procedure based on the received RP / 1 and multiple RP / 2s.

[0388] When a wireless power transmitter (100) responds with an attention signal (ATN) to a received power packet (RP), it means that the wireless power transmitter (100) requests permission for communication. That is, the wireless power transmitter (100) can transmit an attention signal (ATN) 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 attention signal (ATN) to the wireless power receiver (200) in response to the RP data packet, thereby requesting permission to transmit a data packet from the wireless power receiver (200).

[0389] Optionally, the wireless power receiver (200) can transmit a CHS (charge status) data packet to the wireless power transmitter (100) (S1525).

[0390] 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 (typically guaranteed load power) in a power transmission contract.

[0391] For example, the wireless power receiver (200) can transmit 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).

[0392] In addition, the wireless power receiver (200) can transmit 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).

[0393] Here, the data packets related to the initiation of the renegotiation phase can be organized as follows.

[0394] - DSR: The DSR data packet can be set to one of the following values:

[0395] i) 0x00-DSR / nak: Indicates that the last received data packet from the wireless power transmitter (100) was rejected.

[0396] ii) 0x33-DSR / poll: Invite the wireless power transmitter (100) to send a data packet.

[0397] iii) 0x55-DSR / nd: Indicates that the last received data packet from the wireless power transmitter (100) was not expected.

[0398] iv) 0xFF-DSR / ack: Confirms that the last received data packet of the wireless power transmitter (100) has been properly processed.

[0399] - CAP: The CAP data packet provides information about the function of the wireless power transmitter (100). The specific details are as described above.

[0400] - NEGO: The NEGO data packet can request the wireless power transmitter (100) to proceed to the renegotiation phase.

[0401] The wireless power transmitter (100) and the wireless power receiver (200) can use auxiliary data control (ADC), auxiliary data transport (ADT), and DSR data packets to exchange application level data.

[0402] That is, from the perspective of transmitting and receiving a data transmission stream for exchanging application level data, the wireless power receiver (200) can transmit ADC / ADT to the wireless power transmitter (100) (S1550), and the wireless power transmitter (100) can transmit ACK / NAK to the wireless power receiver (200) in response thereto (S1555). In addition, the wireless power receiver (200) can transmit DSR to the wireless power transmitter (100) (S1560), and the wireless power transmitter can transmit ADC / ADT to the wireless power receiver (S1565).

[0403] Here, the data transmission stream serves the role of transmitting application-level data from the data stream initiator to the data stream responder. Application-level data can be broadly categorized into: i) authentication applications and ii) proprietary (general-purpose) applications.

[0404] Among the application level data, messages / information related to the authentication application can be organized as follows.

[0405] The message used in the authentication procedure is called an authentication message. Authentication messages are used to convey information related to authentication. There are two types of authentication messages: an authentication request and an authentication response. An authentication request is transmitted by an authentication initiator, and an authentication response is transmitted by an authentication responder. The wireless power transmission device and the wireless power reception device can be either the authentication initiator or the authentication responder. For example, if the wireless power transmission device is the authentication initiator, the wireless power reception device becomes the authentication responder, and if the wireless power reception device is the authentication initiator, the wireless power transmission device becomes the authentication responder.

[0406] The authentication request message includes GET_DIGESTS, GET_CERTIFICATE, and CHALLENGE.

[0407] - GET_DIGESTS: This request can be used to retrieve a certificate chain digest. The wireless power receiver (200) can request as many digests as desired at a time.

[0408] - GET_CERTIFICATE: This request can be used to read a segment of the target certificate chain.

[0409] - CHALLENGE: This request can be used to initiate certification of a power transmitter product device.

[0410] The authentication response message contains DIGESTS, CERTIFICATE, CHALLENGE_AUTH, and ERROR.

[0411] - DIGESTS: The wireless power transmitter (100) can use the DIGESTS response to send a certificate chain summary and report slots containing valid certificate chain summaries.

[0412] - CERTIFICATE: This response can be used by the wireless power transmitter (100) to send the requested segment of the certificate chain.

[0413] - CHALLENGE_AUTH: The wireless power transmitter (100) can respond to a CHALLENGE request using CHALLENGE_AUTH.

[0414] - ERROR: This response can be used to transmit error information from the power transmitter.

[0415] Authentication messages may also be called authentication packets, authentication data, or authentication control information. Additionally, messages like GET_DIGEST and DIGESTS may also be called GET_DIGEST packets, DIGEST packets, and so on.

[0416] Meanwhile, as previously explained, the wireless power receiver (200) and the wireless power transmitter (100) can transmit application-level data via a data transmission stream. The application-level data transmitted via the data transmission stream can be composed of a data packet sequence having the following structure.

[0417] - Initial ADC data packet that opens the stream.

[0418] i) The type of message contained in the stream.

[0419] ii) Number of data bytes in the stream.

[0420] - A series of ADT data packets containing the actual message.

[0421] - Final ADC / end data packet that closes the stream.

[0422] Below, the data transmission stream for an example in which the above ADC, ADT, and ADC / end data packets are used is explained through a drawing.

[0423] FIG. 16 illustrates an application-level data stream between a wireless power transmitter (100) and a wireless power receiver (200) according to an example.

[0424] Referring to FIG. 16, the data stream may include auxiliary data control (ADC) data packets and / or auxiliary data transport (ADT) data packets.

[0425] ADC data packets are used to open a data stream. They can indicate the type of message contained in the stream and the number of data bytes. ADT data packets, on the other hand, are sequences of data containing the actual message. The ADC / end data packet is used to signal the end of a stream. For example, the maximum number of data bytes in a data transport stream can be limited to 2047.

[0426] ACK or NACK (Non-ACK) is used to indicate normal reception of ADC data packets and ADT data packets. Control information required for wireless charging, such as a Control Error Packet (CE) or DSR, may be transmitted between the transmission timing of ADC data packets and ADT data packets.

[0427] Using this data stream structure, authentication-related information or other application-level information can be transmitted and received between a wireless power transmitter and receiver.

[0428] 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 described as follows.

[0429] Fig. 17 illustrates a power control method according to one embodiment.

[0430] 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 simultaneously transmitting and receiving power and communicating. The wireless power transmitter and the wireless power receiver operate at specific control points. The control point represents a combination of voltage and current provided from the output of the wireless power receiver when power transfer is performed.

[0431] More specifically, the wireless power receiver selects a desired control point (e.g., a desired output current / voltage, a temperature at a specific location of the mobile device), and further determines an actual control point (e.g., an actual control point) at which the device is currently operating. Using the desired control point and the actual control point, the wireless power receiver can calculate a control error value and transmit it to the wireless power transmitter as a control error packet.

[0432] And the wireless power transmitter can control power transfer by setting / controlling new operating points - amplitude, frequency and duty cycle - using the received control error packet. Therefore, the control error packet is transmitted / received at regular time intervals in the strategy transmission stage, and as an example, the wireless power receiver can transmit the control error value as a negative number when it wants to reduce the current of the wireless power transmitter, and as a positive number when it wants to increase the current. In this way, in the inductive mode, the wireless power receiver can control power transfer by transmitting the control error packet to the wireless power transmitter.

[0433] In resonant mode, it can operate in a different manner than in inductive mode. In resonant mode, a single wireless power transmitter must be able to serve multiple wireless power receivers simultaneously. However, when controlling power transfer as in the inductive mode described above, since the transferred power is controlled by communication with a single wireless power receiver, it may be difficult to control power transfer to additional wireless power receivers. Therefore, in the resonant mode of this specification, the wireless power transmitter commonly transfers basic power, and the wireless power receiver controls the amount of power it receives by controlling its own resonant frequency, thereby using a method. However, the method described in FIG. 17 is not completely excluded from the operation of this resonant mode, and additional transmission power control can also be performed using the method of FIG. 17.

[0434] <Operation according to power profile>

[0435] Wireless charging methods include magnetic induction, which utilizes the magnetic induction phenomenon between primary and secondary coils, and magnetic resonance, which transmits power by creating magnetic resonance using frequencies ranging from tens of kilohertz to several megahertz. The wireless charging standards for magnetic resonance are led by a consultative body called A4WP, while those for magnetic induction are led by the Wireless Power Consortium (WPC). The WPC is designed to enable the in-band exchange of various status information and commands related to wireless charging systems.

[0436] The Qi standard from WPC defines the baseline power profile (BPP), the extended power profile (EPP), and the magnetic power profile. Below, the BPP, EPP, and MPP are each described.

[0437] A. Baseline power profile (BPP)

[0438] BPP is a power transfer profile between a wireless power transmitter and receiver, supporting power transfer of up to 5W. Furthermore, BPP supports unidirectional communication from the wireless power receiver to the wireless power transmitter. This communication method may correspond to ASK (amplitude shift keying). BPP may include protocol phases for ping, setup, and power transfer.

[0439] B. EPP(extended power profile)

[0440] EPP is a power transfer profile between a wireless power transmitter and receiver that supports power transfer of up to 15W. Furthermore, EPP supports bidirectional communication between a wireless power receiver and a wireless power transmitter. The communication method from the wireless power receiver to the wireless power transmitter may correspond to ASK (amplitude shift keying), and the communication method from the wireless power transmitter to the wireless power receiver may correspond to FSK (frequency shift keying). EPP may have protocol phases of ping, setup, negotiation, and power transfer.

[0441] (a) Compatibility in EPP

[0442] EPP may correspond to a higher profile of BPP.

[0443] For example, when 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.

[0444] For example, when 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.

[0445] That is, EPP can maintain compatibility with BPP.

[0446] (b) EPP instruction method of EPP wireless power receiver

[0447] An EPP wireless power receiver can indicate that it is an EPP wireless power receiver by setting the 'neg' bit to 1 in a configuration packet (i.e., CFG). A specific example of a configuration packet is as described above.

[0448] (c) EPP instruction method of EPP wireless power transmitter

[0449] When the EPP wireless power transmitter receives a configuration packet with the 'neg' bit set to 1 from the wireless power receiver, the EPP wireless power transmitter can respond to the wireless power receiver with an ACK FSK bit pattern.

[0450] For reference, as explained above, BPP wireless power transmitters do not support FSK communication methods, and therefore cannot transmit FSK bit patterns. Therefore, an EPP wireless power receiver that transmits 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 not receiving the ACK response above.

[0451] Meanwhile, Qi v2.0 aims to provide a new power transfer profile for wireless power transfer systems, and among the proposed power transfer profiles is the magnetic power profile (MPP). MPP could be Apple's proprietary extension based on Qi v1.3.0.

[0452] C. MPP(magnetic power profile)

[0453] MPP is a power transfer profile between a wireless power transmitter and receiver that supports power transfer of up to 15 W. Furthermore, MPP supports bidirectional communication between a wireless power receiver and a wireless power transmitter. The communication method from the wireless power receiver to the wireless power transmitter may correspond to Amplitude Shift Keying (ASK), and the communication method from the wireless power transmitter to the wireless power receiver may correspond to Frequency Shift Keying (FSK). Fast FSK (NCYCLE = 128) may be used during the negotiation and power transfer phases.

[0454] In MPP, there may be protocol phases of ping, setup, MPP negotiation, and MPP power transfer.

[0455] (a) Compatibility in MPP

[0456] MPP may correspond to a higher profile of BPP.

[0457] For example, when 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.

[0458] For example, when 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.

[0459] That is, MPP can maintain compatibility with BPP.

[0460] (b) MPP operation of MPP wireless power receiver (MPP instruction method)

[0461] MPP wireless power receivers can utilize specific MPP indicators within extended ID packets.

[0462] In order for an MPP wireless power receiver to indicate whether it supports MPP via XID, the wireless power receiver must inform the wireless power transmitter that the XID is transmitted via an ID packet. The ID packet transmitted by the MPP wireless power receiver may be as follows.

[0463] Figure 18 schematically illustrates the structure of an MPP ID packet.

[0464] According to Fig. 18, in the MPP ID packet, the value of the major version field from b4 to b7 of B0 can be set to 1.

[0465] In the MPP ID packet, the values ​​of the minor version fields b0 - b3 of B0 may be values ​​to be determined later.

[0466] In the MPP ID packet, the values ​​of the manufacturer codes of B1 and B2 can be assigned as PRMC codes.

[0467] In the MPP ID packet, the value of the 'ext' field of b7 of B3 may be set to 1 to indicate that an XID packet is to be additionally transmitted.

[0468] In the MPP ID packet, the values ​​of the random identifier fields b0 to b6 of B3, b3 to b7 of B4, and B5 can be set according to the random device identification policy.

[0469] Figure 19 schematically illustrates an example of an XID packet in MPP.

[0470] According to FIG. 19, an XID packet in MPP may include an 'XID Selector' field, a 'Restricted' field, a 'Freq Mask' field, etc.

[0471] Here, whether MPP is supported or not can be determined based on whether the value of 'XID selector' is 0xFE. That is, if the value of B_0 of XID is 0xFE, the XID at this time can correspond to information indicating that the wireless power receiver supports MPP.

[0472] The 'Restricted' field may correspond to information indicating whether the wireless power receiver operates in MPP restricted mode or MPP full mode. If the wireless power receiver selects 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 selects not to operate in MPP restricted mode), the above field may be set to 0.

[0473] The 'Preferred Frequency' field may indicate the MPP preferred frequency. Here, the wireless power receiver may set this field to 128 kHz if it wishes to retrieve information from the wireless power transmitter before switching frequencies (during the negotiation phase). In other cases, the wireless power receiver may set this field to 360 kHz.

[0474] The 'Freq Mask' field is 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.

[0475] In summary, the wireless power transmitter can determine whether the wireless power receiver supports MPP by determining 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.

[0476] (c) MPP operation of MPP wireless power transmitter (MPP instruction method)

[0477] After detecting the placement of a wireless power receiver on a charging surface, the MPP wireless power transmitter can perform a digital ping and identify the receiver using the information contained in the ID and XID packets.

[0478] Here, the wireless power transmitter may determine that the wireless power receiver supports MPP if all of the following conditions are met.

[0479] - Qi Version: The Qi protocol version of the ID packet is set to (Major=1, Minor=TBD) or higher.

[0480] - MPP support notification: The subheader (byte 0) of the XID packet is set to the MPP selector.

[0481] If the above two conditions are not satisfied, the wireless power transmitter can proceed with the subsequent steps according to the Qi v1.3 specification.

[0482] 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:

[0483] - Activate restricted profile (MPP restricted mode): When the 'restricted' flag is set to 1.

[0484] - Full profile enabled (MPP full mode): when the 'restricted' flag is set to 0.

[0485] Specific examples for the limited profile above and for the full profile are provided below.

[0486] Meanwhile, when the MPP wireless power transmitter receives a configuration packet with the 'neg' bit set to 1 from the wireless power receiver, the MPP wireless power transmitter (in MPP full mode) can respond to the wireless power receiver with an MPP ACK FSK bit pattern.

[0487] For reference, since the wireless power transmitter in MPP limited mode does not support the FSK communication method, the wireless power transmitter in MPP limited mode cannot transmit the FSK bit pattern. However, since the wireless power transmitter in MPP limited mode uses an operating signal of 360 kHz for power transfer, 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.

[0488] (d) MPP mode

[0489] Meanwhile, there can be two modes in MPP. One of them is MPP Restricted mode (also known as MPP Baseline profile) and the other is MPP Full mode (also known as MPP Full profile).

[0490] To briefly explain the difference between the two, in MPP restricted mode, the 'restricted' field in the XID is set to 1, but in MPP full mode, the 'restricted' field in the XID is set to 0.

[0491] Additionally, FSK communication is not supported in MPP limited mode, but FSK communication may be supported in MPP full mode.

[0492] Additionally, MPP limited mode does not support FSK communication, so MPP ACKs for CFGs cannot be transmitted, and therefore MPP negotiation is not supported in MPP limited mode. On the other hand, MPP full mode supports FSK communication, so MPP ACKs for CFGs can be transmitted, and therefore MPP negotiation can be supported in MPP full mode.

[0493] Below, MPP limited mode and MPP full mode will be described in more detail. Here, MPP limited mode can be used interchangeably with the MPP baseline profile, and MPP full mode can be used interchangeably with the MPP full profile.

[0494] Below, to provide a richer understanding of MPP limited mode and MPP full mode, the protocols in each mode will be explained in more detail.

[0495] i) MPP restricted mode

[0496] As previously explained, FSK communication is not supported in MPP limited mode. This means that data packets may not be transmitted from the wireless power transmitter to the wireless power receiver in MPP limited mode. Against this backdrop, the protocol in MPP limited mode is described using drawings.

[0497] Figure 20 schematically illustrates the protocol in MPP limited mode.

[0498] According to FIG. 20, the wireless power receiver can transmit a signal-in-signal (SIG) to the wireless power transmitter at a first operating frequency (e.g., 128 kHz). At this time, the first operating frequency may correspond to an operating frequency at which BPP and / or EPP can be performed. In addition, the first operating frequency at this time corresponds to a frequency at which the wireless power transmitter operates.

[0499] The wireless power receiver can transmit an ID packet to the wireless power transmitter on a first operating frequency. At this time, since the XID must be transmitted in the MPP, the 'ext' bit of the ID can be set to 1 to indicate that the XID is additionally transmitted.

[0500] The wireless power receiver can transmit an XID packet to the wireless power transmitter on a first operating frequency.

[0501] 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 operates in MPP restricted mode.

[0502] Here, if the wireless power transmitter receives the above XID packet indicating MPP limited mode, the wireless power transmitter can remove the power signal and restart the ping phase at the new operating frequency.

[0503] When the ping phase is restarted, the wireless power receiver will resume transmitting SIG, but at a second operating frequency (e.g., 360 kHz).

[0504] Thereafter, the wireless power receiver transmits ID, XID, and CFG packets to the wireless power transmitter at the second operating frequency, respectively. 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.

[0505] ii) MPP full mode

[0506] As previously explained, FSK communication can be supported in MPP full mode. That is, data packets can be transmitted from the wireless power transmitter to the wireless power receiver in MPP full mode. In other words, MPP negotiations can occur between the wireless power transmitter and the wireless power receiver. Against this backdrop, the protocol for MPP full mode is described using drawings.

[0507] Figures 21 and 22 schematically illustrate the protocol in MPP full mode.

[0508] First, according to FIG. 21, the wireless power receiver can transmit a signal-in-signal (SIG) to the wireless power transmitter at a first operating frequency (e.g., 128 kHz). At this time, the first operating frequency may correspond to an operating frequency at which BPP and / or EPP can be performed. In addition, the first operating frequency at this time corresponds to a frequency at which the wireless power transmitter operates.

[0509] The wireless power receiver can transmit an ID packet to the wireless power transmitter on a first operating frequency. At this time, since the XID must be transmitted in the MPP, the 'ext' bit of the ID can be set to 1 to indicate that the XID is additionally transmitted.

[0510] The wireless power receiver can transmit an XID packet to the wireless power transmitter on a first operating frequency.

[0511] 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 so that the above field can indicate that the wireless power receiver operates in MPP full mode.

[0512] Meanwhile, in MPP full mode, unlike MPP limited mode, the wireless power transmitter does not remove the power signal even if it receives an XID packet from the wireless power receiver. At this time, the wireless power receiver still transmits a CFG packet to the wireless power transmitter after the XID packet because the power signal has not been removed.

[0513] And, the wireless power receiver can receive an MPP ACK from the wireless power transmitter as a response to the above CFG packet.

[0514] A wireless power receiver that receives an MPP ACK enters a negotiation phase with a wireless power transmitter, and both the wireless power receiver and the wireless power transmitter can proceed with negotiation.

[0515] After the negotiation process is complete, the wireless power receiver can enter the power transfer phase with the wireless power transmitter.

[0516] 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 the new operating frequency.

[0517] According to FIG. 22, when the ping phase is restarted, the wireless power receiver starts transmitting SIG again. However, the operating frequency at this time may be the second operating frequency (e.g., 360 kHz).

[0518] Thereafter, the wireless power receiver transmits ID, XID, and CFG packets to the wireless power transmitter at the second operating frequency, respectively. Then, the wireless power receiver can receive an MPP ACK from the wireless power transmitter.

[0519] 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.

[0520] After the negotiation process, the wireless power receiver enters a power transfer phase with the wireless power transmitter at a second operating frequency. In addition, the wireless power receiver can receive wireless power based on the MPP full mode from the wireless power transmitter by transmitting an XCE to the wireless power transmitter and receiving a response thereto (e.g., receiving an ACK).

[0521] <Quality Factor Measurement>

[0522] Below, we will explain the measurement of quality factor (Q-factor).

[0523] Figures 23 and 24 illustrate examples of measurement / calculation of quality factors.

[0524] The quality factor, i.e., 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.

[0525] More specifically, the wireless power receiver can remember the value of its reference Q factor in advance and transmit the value of the reference Q factor to the wireless power transmitter via a packet during the negotiation phase. At this time, the value of the reference Q factor can be transmitted from the wireless power receiver to the wireless power transmitter via, for example, FOD / xx (e.g., FOD / rf, FOD / qf) during the negotiation phase.

[0526] A wireless power transmitter can measure the Q-factor by generating a small signal before wireless charging (i.e., before power transfer). The wireless power transmitter can then compare its measured Q-factor value with a value reported by the wireless power receiver (e.g., a reference Q-factor value) to determine whether FOD (i.e., foreign matter detection) is present.

[0527] In-Power FOD Method: Calibrated Power Loss Account

[0528] Wireless charging devices using the WPC Qi standard measure the amount of power loss during charging to determine the presence or absence of foreign matter (FO) during charging.

[0529] This method has a technical limitation that accuracy decreases as the transmission power increases, and a correction function was adopted to overcome this limitation.

[0530] Through compensation, the loss caused by the friendly metal can be set to zero and this can be set as the reference point.

[0531] By measuring the influence of friendly metal components existing in the receiver itself under the current alignment conditions and reflecting it in the foreign substance detection algorithm, the accuracy is improved.

[0532] If compensation is performed in the presence of foreign matter, the current power loss from the foreign matter will be used as a reference point. However, using the power loss from the foreign matter as a reference point can have the counterproductive effect of reducing foreign matter detection performance.

[0533] Therefore, it is necessary to confirm the absence of foreign substances (No FO) by measuring the Q-factor immediately before correction.

[0534] Hereinafter, the present specification will be described in more detail.

[0535] <Cloak>

[0536] A clock is a method for momentarily interrupting power transfer without notifying the user or resetting the negotiated power transfer contract elements. Power transfer can be interrupted for a variety of reasons, including thermal management, power budget changes, and coexistence.

[0537] 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 mode: wireless power receiver, FSK: wireless power transmitter).

[0538] The Clock state begins when the wireless power transmitter terminates power transfer after processing the ASK Clock (CLOAK) data packet.

[0539] The Clock state consists of a power interruption period and a brief power transfer period (cloak ping). This brief power transfer period is called a cloak ping.

[0540] The power receiver (PRx) can maintain the clock state by responding to the clock ping with a clock data packet.

[0541] Alternatively, the Clock state can be terminated by initiating a Clock termination handshake.

[0542] In summary, a clock is a feature that allows the magnetic field to be paused without restarting the protocol.

[0543] It can be initiated by a wireless power transmitter or wireless power receiver, and can stop and / or restore the magnetic field at mutually agreed upon time intervals.

[0544] When the magnetic field is restored, the protocol resumes as a power transfer phase, retaining all information from before the interruption.

[0545] When the wireless power receiver sends a command (CLOAK packet) to start this function to the wireless power transmitter, the wireless power transmitter stops generating a magnetic field.

[0546] This feature allows the wireless power transmitter and wireless power receiver to communicate periodically with each other to cool down or to stop unnecessary magnetic fields when the battery is fully charged, but still maintain the UI that indicates normal charging is in progress.

[0547] Here, the clock data packet transmitted by the wireless power receiver can be described as follows.

[0548] Figure 25 schematically illustrates a clock data packet transmitted by a wireless power receiver.

[0549] 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.

[0550] The reason codes may be as shown in the table below.

[0551] Value Reason 0Cloak: Generic 1Cloak: Forced (unclock request denied) 2Cloak: Thermally constrained 3Cloak: Insufficient Power 4Cloak: Coex Mitigation (wireless power receiver requests clock to perform a task that cannot coexist with wireless power) 5Cloak: End of Charge 6Cloak: PTx initiated 7Reserved

[0552] In response to the above clock data packet, the wireless power transmitter may perform the following response:

[0553] Response Description ACK The wireless power transmitter agrees to start / continue cloaking NAK The pattern is not allowed ND The pattern transmitted when the wireless power receiver uses a reason code that is not supported ATNCloak state: The wireless power transmitter requests to terminate the clock. Other states: The wireless power transmitter prefers to communicate before cloaking.

[0554] Figure 26 schematically illustrates a clock data packet transmitted by a wireless power transmitter.

[0555] According to FIG. 26, a Clock Request data packet may allow a wireless power transmitter to start entering a Clock state. The Clock data packet may include a reason field.

[0556] The reason codes may be as shown in the table below.

[0557] Value Reason 0Cloak: Generic 1Reserved 2Cloak: Thermally constrained 3Cloak: Insufficient Power 4Cloak: Coex Mitigation (Wireless Power Transmitter requests clock to perform a task that cannot coexist with wireless power) 5 - 15Reserved

[0558] Meanwhile, as previously described, a wireless power receiver or wireless power transmitter can initiate a clock. The clock phase initiated by the wireless power receiver and the clock phase initiated by the wireless power transmitter can be described as follows.

[0559] Figure 27 schematically illustrates a clock phase initiated by a wireless power receiver.

[0560] According to FIG. 27, the wireless power receiver starts the clock by transmitting a CLOACK data packet to the wireless power transmitter.

[0561] Here, the wireless power transmitter must respond in one of the following ways after receiving the CLOACK data packet.

[0562] - Remove Power Signal: The wireless power transmitter removes the power signal after receiving the CLOACK data packet, thereby reducing the overall ping duration, which implicitly confirms that it has accepted the cloaking request.

[0563] - FSK - ATN: Indicates that the wireless power transmitter is not ready to enter the Clock state and may request a Clock termination.

[0564] In summary, the wireless power transmitter that receives the clock (CLOAK) packet of the wireless power receiver stops the magnetic field (removal of power signal) for the t_cloak time received in the negotiation phase and then returns (i.e., generates the magnetic field again).

[0565] The wireless power receiver disconnects the load when it detects that the magnetic field has disappeared during the CLOACK input.

[0566] The wireless power transmitter performs a clock ping when returning. This clock ping can be performed in the same manner as when the wireless power transmitter generated the initial digital ping.

[0567] The wireless power transmitter can determine the presence of a wireless power receiver and its willingness to continue the clock phase by confirming that the wireless power receiver sends a clock packet to the digital ping generated at a predetermined period.

[0568] As previously explained, the wireless power transmitter can also initiate a clock phase.

[0569] Figure 28 schematically illustrates a clock phase initiated by a wireless power transmitter.

[0570] 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 (CLOAK) data packet described above.

[0571] After successfully receiving the request, the wireless power receiver may initiate the clock sequence by responding with the wireless power receiver clock (CLOAK) data packet described above within t_ptxcloak.

[0572] If the ASK CLOACK data packet is not received within t_ptxcloaktimeout, the wireless power transmitter may resend the request.

[0573] In a scenario where the wireless power transmitter initiates the clock, the wireless power transmitter must always respond with FSK (ACK or ATN) to the clock data packet before removing the power signal.

[0574] In a scenario where the wireless power transmitter initiates a clock, if the wireless power receiver fails to decode the FSK response, it must retry decoding in the next clock ping. If FSK decoding continues to fail after the retry, the wireless power receiver must transition to the ping phase.

[0575] The wireless power transmitter can determine the presence of a wireless power receiver and its willingness to continue the clock phase by confirming that the wireless power receiver sends a clock packet to the digital ping generated at a predetermined period.

[0576] The wireless power transmitter can request that the clock phase be stopped at will. This is done by sending an FSK response with 'ATN' in the CLOACK packet.

[0577] When a wireless power receiver wants to stop the clock phase on its own, it can express its intention by sending REPORT [wireless power receiver ID] instead of CLOACK, and the wireless power transmitter must unconditionally accept it (FSK ACK).

[0578] Wireless Power Receiver System Model

[0579] Figures 29 and 30 schematically illustrate a system model of a wireless power receiver circuit.

[0580] According to FIGS. 29 and 30, the S1 switch may be open during digital ping and BPP modes.

[0581] After the MPP handshake is completed, the wireless power transmitter can stop transmitting and switch to 360 kHz. When the wireless power receiver detects 360 kHz, it can close S1 to enter MPP power transfer mode.

[0582] A wireless power receiver may consist of the following components:

[0583] - Series impedance tuning network for BPP and MPP

[0584] - Parallel resonant circuit for detection

[0585] - Ideal full bridge rectifier

[0586] Additionally, the system model wireless power receiver can assume a power converter (e.g., a buck converter) at the load. This converter can be used to convert the optimal Vrect (rectified voltage) regulated voltage to a 4V battery voltage.

[0587] Additionally, the wireless charging device of the WPC Qi standard presents a system model that allows the wireless power receiver to induce a desired level of voltage.

[0588] The wireless power receiver is configured as a system that maintains an induced voltage of 12 V or 14 V.

[0589] For example, there's a Buck configuration in the load area. If the voltage in the area indicated by Vrect in the figure above is maintained at around 12 to 14 V, the Buck can step down to 4 V, maintaining a voltage suitable for supplying to the battery.

[0590] Additionally, it can be configured for impedance tuning, such as Crx1 and Crx2, and can be adjusted to settings optimized for BPP (5W) and MPP (15W).

[0591] Wireless Power Transmitter System Model

[0592] Figure 31 schematically illustrates a power stage block diagram of a wireless power transmitter.

[0593] According to Fig. 31, the S1 and S2 switches are closed during BPP mode and 128 kHz digital ping.

[0594] After the MPP handshake, the wireless power transmitter switches to 360 kHz operating mode starting with a 360 kHz digital ping and selects the Ctx capacitor based on coupling estimation.

[0595] The combined estimation threshold and Ctx1 and Ctx2 are set so that the phase delay between the fundamental frequency components of voltage and current is always greater than 20 degrees in the inductive operating mode. It is designed to enable a power transfer of at least 15 W within a 2 mm cylinder.

[0596] The system model wireless power transmitter uses a full-bridge converter that regulates the transmitted power through input voltage control and phase shift control. If possible, the system model wireless power transmitter may prioritize voltage control over phase control.

[0597] The operating frequency is fixed at 360 kHz, and variable frequency mode may not be used.

[0598] The impedance tuning circuit can be composed of Ctx1, Ctx2, Cx3, S1, and S2.

[0599] The wireless power transmitter power stage capacitor switch configuration can be described in a table as follows.

[0600] S1S2 Transmit Frequency Power Transmit Mode Closed Closed 128 kHz Digital Ping 128 kHz and Power Transmit Open Open 360 kHz Digital Ping 360 kHz and Power Transmit (Low Coupling) Closed Open 360 kHz Digital Ping 360 kHz and Power Transmit (High Coupling)

[0601] High coupling and low coupling can be determined at the K estimation stage. This is performed at the digital ping stage, and the 'k' value can distinguish between low and high coupling.

[0602] In summary, the WPC Qi standard wireless charger device presents a system model that allows the wireless power receiver to induce the desired voltage level.

[0603] As shown in the drawing, the wireless power transmitter can adjust Ctx1, Ctx2, and Ctx3 to settings optimized for BPP (5W), MPP-Restricted (5W), and MPP (15W).

[0604] The drawing even mentions fine tuning considering the coupling, which is where you can see the importance of optimized settings.

[0605] Meanwhile, the following points may become issues:

[0606] The Qi power profile has the following requirements regarding hardware configuration:

[0607] The wireless power receiver shall return to / maintain a setting of BPP (5W) when not exposed to a magnetic field.

[0608] The wireless power transmitter must generate a digital ping with a HW setting of BPP (5W).

[0609] Subsequently, different approaches are taken to extend the power profile beyond 5W.

[0610] - EPP 15W

[0611] The wireless power receiver can transmit power by only changing the voltage (Vrect) induced by the initial HW setting (BPP 5W).

[0612] The wireless power transmitter can control the magnetic field according to the requirements of the wireless power receiver with the initial HW setting (BPP 5W).

[0613] In this case, the following problems may arise:

[0614] First, the power transfer efficiency may not be optimized for a configuration that is not optimized for power transfer of 15W or more, which may result in high power loss / heat generation.

[0615] Accordingly, low efficiency and increased heat generation lead to increased temperature in the wireless power receiver. This, in particular, can lead to increased battery temperature, which may require a reduction in transmission power for safety reasons. While the maximum power transmission range is 15W, the amount of power that can be maintained throughout the entire charging cycle is reduced, potentially slowing down charging.

[0616] - MPP 15W

[0617] The wireless power receiver can request a restart from the wireless power transmitter. After the magnetic field disappears, impedance tuning can be performed by changing hardware settings.

[0618] When the wireless power receiver requests a restart, the wireless power transmitter stops generating the magnetic field and then impedance tuning (e.g. changing the resonance cap) can be performed by changing the HW settings.

[0619] In this case, the following problems may arise:

[0620] First, the protocol can be restarted to transition from 5 to 15W. At this point, there is no protocol that reverts from 15 to 5W. In other words, a protocol that reverts only to 15W can be implemented by restarting the entire protocol.

[0621] Accordingly, when the power transfer amount changes from 0 to 15W or more during the charging phase (power transfer phase), it can only be responded to through restarting each time. In addition, although it may be more efficient than the case of EPP 15W because there is a process of changing the HW settings, the action is limited to the first HW change. In addition, since the HW is optimized for 15W power transfer, a separate function is needed to dynamically change the HW settings during charging to the appropriate conditions of low-speed charging / low-power transfer (0 to 5W) or fast charging / high-power transfer (over 15W).

[0622] If we organize the above problems, they can be as follows.

[0623] Wireless chargers using the WPC Qi standard have been able to transmit power at a level of 15W for a long time, so they are optimized for this level of power.

[0624] However, recent technological advancements have led to increased transmission power and faster charging, necessitating the construction of systems optimized for a wider range of power transmission than before.

[0625] For example, for power transmission of 15 W or less, the voltage induced in the receiver (PRx) is sufficient at a maximum level of 14 V, so the voltage gain design of the transmitter (PTx) and the range of voltage applied to the power transmission coil are also optimized to fit this range, but for power transmission of 15 W or more, a voltage of 18 V or more is efficient.

[0626] Additionally, as the size of the transmitted power increases, the absolute value of the size of the energy due to loss increases even at the same efficiency.

[0627] Since most of the loss during the power transmission process appears in the form of heat, it increases the temperature of the power receiver, which poses a risk factor for battery safety.

[0628] Therefore, for the commercialization of high-speed charging technology, the introduction of methods to minimize heat generation is essential. System mode switching based on charging power is one such method. Furthermore, because the amount of transmitted power can change in real time during the battery charging process, flexible system mode switching also requires protocol-level support.

[0629] To address the above issues, this specification provides the following configuration.

[0630] This specification provides packets for switching power between a wireless power transmitter and a wireless power receiver to high power or low power during power transfer.

[0631] Through this, according to the present specification, a cloak function that temporarily suspends the magnetic field during the power transfer phase enables immediate system mode switching optimized for changes in the magnitude of the transmitted power.

[0632] The wireless power transmitter and the wireless power receiver can recognize each other's support information for fast charging (15W or more) mode through mutual communication, and when the wireless power receiver wishes to enter fast charging mode during charging, it can enter a cloak phase for the purpose of mode switching.

[0633] Here, the wireless power transmitter and wireless power receiver can switch their settings to a mode optimized for fast charging and return to the power transfer phase to increase power.

[0634] Conversely, when a wireless power receiver wishes to return to normal charging mode (15W or less) during charging, it can enter a cloak phase for mode switching. At this time, the wireless power transmitter and wireless power receiver can each switch their settings to a mode optimized for normal charging.

[0635] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0636] Figure 32 is a flowchart of a method for switching power according to one embodiment of the present specification.

[0637] According to FIG. 32, the wireless power transmitter can transfer wireless power to the wireless power receiver based on the first power in the power transfer phase (S3210).

[0638] Meanwhile, as previously described, the wireless power transmitter may go through the ping phase, setup phase, and negotiation phase described above before entering the power transfer phase.

[0639] The wireless power transmitter and / or wireless power receiver herein may refer to a wireless power transmitter and / or wireless power receiver that supports MPP, as described above. Specific examples of a wireless power transmitter and / or wireless power receiver that supports MPP are as described above. However, the above description is not intended to exclude the wireless power transmitter and / or wireless power receiver in this specification from supporting EPP as described above. In addition, supporting MPP or EPP may mean basically supporting BPP as described above.

[0640] The wireless power transmitter may receive a specific packet from the wireless power receiver during the power transfer phase (S3220). Here, the specific packet may be a packet indicating a transition from the first power to the second power.

[0641] At this time, the second power may correspond to a different power from the first power. In this case, the second power may be a higher power than the first power, while the second power may be a lower power than the first power.

[0642] Examples of cases where the second power is higher than the first power and examples of cases where the second power is lower than the first power will be described later.

[0643] Meanwhile, the specific packet may be a clock data packet. The clock data packet may include a reason field. In addition, the reason field may indicate a hardware update of the wireless power transmitter for the second power.

[0644] The wireless power transmitter may enter a clock phase based on receiving the clock data packet. The wireless power transmitter may stop transmitting the wireless power during the clock phase.

[0645] The wireless power transmitter can detect this material during the clock phase.

[0646] The wireless power transmitter can receive a GET data packet requesting information on the result of detection of the substance from the wireless power receiver.

[0647] Thereafter, the wireless power transmitter can transmit information on the result of detection of the substance to the wireless power receiver.

[0648] Meanwhile, the wireless power transmitter may 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 may measure a quality factor before transmitting power to determine whether this substance is present or not.

[0649] Even if the absence of this substance is initially determined, the value of the initial quality factor may no longer be valid due to the passage of time since the initial quality factor measurement.

[0650] Accordingly, the present specification also provides an example of the wireless power transmitter detecting this substance during a period in which the wireless power transmission is stopped. In this case, the wireless power transmitter can detect this substance based on the measurement of a quality factor.

[0651] That is, the wireless power transmitter can measure quality factors during power interruption periods to detect this substance. Examples of measuring quality factors have been partially described above, and specific examples of measuring quality factors will be described in the examples below.

[0652] Meanwhile, the wireless power transmitter can transfer the wireless power to the wireless power receiver based on the second power in the power transfer phase (S3230).

[0653] Here, the wireless power transmitter can perform calibration based on the fact that the substance is not detected.

[0654] Prior to performing the calibration, the wireless power transmitter may receive a GET data packet from the wireless power receiver requesting information on the results of detection of the substance.

[0655] In this case, the wireless power transmitter can transmit information regarding the result of detection of the substance to the wireless power receiver. At this time, the information regarding the result of detection of the substance may include the result of measuring a quality factor or the presence or absence of the substance.

[0656] Here, the term "correction" refers to a correction curve based on the previously described RP data packet. Therefore, to avoid repetition, a detailed explanation of the specific example will be omitted.

[0657] Hereinafter, for a more specific understanding of this specification, the contents of Figure 32 described above will be described in more detail.

[0658] 1. Example of mode switching

[0659] Examples of the mode switching described above may include switching to high power mode, switching to normal power mode, and returning to the previous setting when this substance is identified.

[0660] The fast charging mode (high power mode) described below may correspond to a mode in which wireless power is transferred based on relatively high power, and the normal charging mode (normal power mode) may correspond to a mode in which wireless power is transferred based on relatively low power. The fast charging mode may correspond to a mode that supports the transfer of power greater than 15W, for example.

[0661] First, an example of changing HW settings during clocking for the purpose of switching to fast charging mode is explained through a drawing.

[0662] Figure 33 schematically illustrates an example of switching to fast charging mode.

[0663] According to Fig. 33, changes to HW settings optimized for power transfer size in conjunction with the clocking function can be performed through the following steps.

[0664] (1) When the wireless power transmitter receives a cloak entry request from the wireless power receiver and stops power transmission, the wireless power transmitter may receive a cloak request due to a HW transition to a fast charging mode.

[0665] (2) HW switching can be performed during the cloak phase when the magnetic field disappears. At this time, switching from normal mode to high-speed mode can be performed.

[0666] (3) The wireless power transmitter can measure the Q-factor. A specific example of the wireless power transmitter measuring the quality factor will be described later.

[0667] (4) The wireless power transmitter can terminate the cloak phase. The wireless power transmitter can generate a digital ping with the new hardware configuration. The wireless power transmitter can then enter the power transfer phase.

[0668] (5) The wireless power receiver can request Q-factor related information from the wireless power transmitter. This can be done through an FO presence check.

[0669] (6) When No FO is confirmed, the wireless power transmitter can perform power loss calibration based on the new HW settings.

[0670] Below, an example of changing HW settings during clocking for the purpose of switching to normal charging mode is explained through a drawing.

[0671] Figure 34 schematically illustrates an example of switching to normal charging mode.

[0672] According to Fig. 34, changes to HW settings optimized for power transfer size in conjunction with the clocking function can be performed through the following steps.

[0673] (1) When the wireless power transmitter receives a cloak entry request from the wireless power receiver and stops power transmission, the wireless power transmitter may receive a cloak request due to a HW transition to a normal charging mode.

[0674] (2) HW switching can be performed during the cloak phase when the magnetic field disappears. At this time, switching from high-speed mode to normal mode can be performed.

[0675] (3) The wireless power transmitter can measure the Q-factor. A specific example of the wireless power transmitter measuring the quality factor will be described later.

[0676] (4) The wireless power transmitter can terminate the cloak phase. The wireless power transmitter can generate a digital ping with the new hardware configuration. The wireless power transmitter can then enter the power transfer phase.

[0677] (5) The wireless power receiver can request Q-factor related information from the wireless power transmitter. This can be done through an FO presence check.

[0678] (6) When No FO is confirmed, the wireless power transmitter can perform power loss calibration based on the new HW settings.

[0679] Below, an example of reverting to the original settings when confirming this material is described through a drawing. That is, a method of reverting to the original settings when confirming FO during clocking and HW setting changes for the purpose of switching to fast charging mode is described.

[0680] Figure 35 schematically illustrates an example of switching to fast charging mode.

[0681] According to Fig. 35, changes to HW settings optimized for power transfer size in conjunction with the clocking function can be performed through the following steps.

[0682] (1) When the wireless power transmitter receives a cloak entry request from the wireless power receiver and stops power transmission, the wireless power transmitter may receive a cloak request due to a HW transition to a fast charging mode.

[0683] (2) HW switching can be performed during the cloak phase when the magnetic field disappears. At this time, switching from normal mode to high-speed mode can be performed.

[0684] (3) The wireless power transmitter can measure the Q-factor. A specific example of the wireless power transmitter measuring the quality factor will be described later.

[0685] (4) The wireless power transmitter can terminate the cloak phase. The wireless power transmitter can generate a digital ping with the new hardware configuration. The wireless power transmitter can then enter the power transfer phase.

[0686] (5) The wireless power receiver can request Q-factor related information from the wireless power transmitter. This can be done through an FO presence check.

[0687] (6) When FO is confirmed, the wireless power transmitter may receive a cloak entry request from the wireless power receiver. Furthermore, the wireless power transmitter may stop power transmission. At this time, the wireless power transmitter may receive a cloak request due to a hardware transition to a normal charging mode.

[0688] (7) HW switching can be performed during the cloak phase when the magnetic field disappears. At this time, switching from high-speed mode to normal mode can be performed.

[0689] (8) The wireless power transmitter can measure the Q-factor. A specific example of the wireless power transmitter measuring the quality factor will be described later.

[0690] (9) The wireless power transmitter can exit the cloak phase. The wireless power transmitter can generate a digital ping with the new hardware configuration. The wireless power transmitter can enter the power transfer phase.

[0691] 2. Protocol for mode switching

[0692] Meanwhile, the example of this specification described above can be explained from a protocol perspective as follows.

[0693] First, we will explain an example of a protocol for changing HW settings through clocking for general -> fast charging through a drawing.

[0694] Figure 36 schematically illustrates a protocol for transitioning to high power mode.

[0695] According to FIG. 36, the wireless power transmitter can receive a clock data packet from the wireless power receiver. Here, the clock data packet may correspond to a specific packet described above. Furthermore, the clock data packet at this time may correspond to a data packet regarding a transition to a high power mode.

[0696] After receiving the clock data packet, the wireless power transmitter can transmit an ACK response to the wireless power receiver.

[0697] At this time, the wireless power transmitter can update the hardware of the wireless power transmitter from a low power mode to a high power mode.

[0698] The wireless power receiver can update the hardware of the wireless power receiver from a low power mode to a high power mode.

[0699] Wireless power transmitters can measure quality factors in clock phases.

[0700] The wireless power transmitter can receive a REPORT packet related to the ID of the wireless power receiver from the wireless power receiver, and the wireless power transmitter can transmit an ACK to the wireless power receiver in response thereto.

[0701] 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 transmit an ACK to the wireless power receiver in response thereto.

[0702] Meanwhile, the wireless power transmitter may receive a GET packet from the wireless power receiver, requesting a packet indicating the presence of FO (foreign substance). Thereafter, the wireless power transmitter may transmit a packet indicating the presence of FO to the wireless power receiver.

[0703] Thereafter, the wireless power receiver can perform compensation based on the presence or absence of FO.

[0704] Below, an example of a protocol for changing HW settings through clocking for fast -> normal charging is explained through a drawing.

[0705] Figure 37 schematically illustrates a protocol for transitioning to normal power mode.

[0706] According to FIG. 37, the wireless power transmitter can receive a clock data packet from the wireless power receiver. Here, the clock data packet may correspond to a specific packet described above. Furthermore, the clock data packet at this time may correspond to a data packet regarding a transition to a normal power mode.

[0707] After receiving the clock data packet, the wireless power transmitter can transmit an ACK response to the wireless power receiver.

[0708] At this time, the wireless power transmitter can update the hardware of the wireless power transmitter from a high power mode to a low power mode.

[0709] The wireless power receiver can update the hardware of the wireless power receiver from a high power mode to a low power mode.

[0710] Wireless power transmitters can measure quality factors in clock phases.

[0711] The wireless power transmitter can receive a REPORT packet related to the ID of the wireless power receiver from the wireless power receiver, and the wireless power transmitter can transmit an ACK to the wireless power receiver in response thereto.

[0712] 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 transmit an ACK to the wireless power receiver in response thereto.

[0713] Meanwhile, the wireless power transmitter may receive a GET packet from the wireless power receiver, requesting a packet indicating the presence of FO (foreign substance). Thereafter, the wireless power transmitter may transmit a packet indicating the presence of FO to the wireless power receiver.

[0714] Thereafter, the wireless power receiver can perform compensation based on the presence or absence of FO.

[0715] Below, the protocol for discovering FO while changing HW settings through clocking for general -> fast charging is explained through a diagram.

[0716] Figure 38 schematically illustrates the protocol when this substance is discovered during a power mode transition.

[0717] According to FIG. 38, the wireless power transmitter can receive a clock data packet from the wireless power receiver. Here, the clock data packet may correspond to a specific packet described above. Furthermore, the clock data packet at this time may correspond to a data packet regarding a transition to a high power mode.

[0718] After receiving the clock data packet, the wireless power transmitter can transmit an ACK response to the wireless power receiver.

[0719] At this time, the wireless power transmitter can update the hardware of the wireless power transmitter from a low power mode to a high power mode.

[0720] The wireless power receiver can update the hardware of the wireless power receiver from a low power mode to a high power mode.

[0721] Wireless power transmitters can measure quality factors in clock phases.

[0722] The wireless power transmitter can receive a REPORT packet related to the ID of the wireless power receiver from the wireless power receiver, and the wireless power transmitter can transmit an ACK to the wireless power receiver in response thereto.

[0723] 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 transmit an ACK to the wireless power receiver in response thereto.

[0724] Meanwhile, the wireless power transmitter may receive a GET packet from the wireless power receiver, requesting a packet indicating the presence of FO (foreign substance). Thereafter, the wireless power transmitter may transmit a packet indicating the presence of FO to the wireless power receiver.

[0725] In summary, a wireless power receiver that is in the middle of a normal charge can request a change in HW settings (Cloak[HW / high]) to the wireless power transmitter through a clock (cloak) to increase the transmission power and enter fast charging mode.

[0726] Here, it can be determined that the FOD result FO of the wireless power transmitter exists during the cloak phase.

[0727] In this case, the wireless power receiver and wireless power transmitter should give up trying to increase the transmission power and return to their original settings.

[0728] To revert the HW settings for fast charging back to the HW settings for normal charging, the wireless power receiver can request the wireless power transmitter to change the HW settings via a clock (Cloak[HW / low]).

[0729] To this end, the wireless power transmitter may receive a clock data packet from the wireless power receiver. The clock data packet may correspond to a data packet regarding a transition to a normal power mode.

[0730] After receiving the clock data packet, the wireless power transmitter can transmit an ACK response to the wireless power receiver.

[0731] At this time, the wireless power transmitter can update the hardware of the wireless power transmitter from a high power mode to a low power mode.

[0732] The wireless power receiver can update the hardware of the wireless power receiver from a high power mode to a low power mode.

[0733] Wireless power transmitters can measure quality factors in clock phases.

[0734] Since the subsequent protocols are the same as those described above, any explanation of redundant content will be omitted.

[0735] 3. Measurement of quality factors during mode switching

[0736] Meanwhile, measurement of quality factors in clock phases can be performed as follows.

[0737] Figures 39 and 40 schematically illustrate the configuration of a coil and driver of a wireless power transmitter.

[0738] Figure 39 schematically illustrates an attenuation waveform for measuring quality factors.

[0739] According to Fig. 39, when the wireless power transmitter stops driving the coil, the voltage in the coil of the wireless power transmitter is attenuated. At this time, autonomous resonance occurs in the coil of the wireless power transmitter as shown in the drawing, and the quality factor can be estimated from the attenuation ratio of this waveform.

[0740] Here, if we express the voltage of the TX coil within the clock period as a formula, it can be as follows, for example.

[0741] <Formula 1>

[0742]

[0743] The wireless power transmitter can calculate the slot quality factor by measuring the voltage envelope of the resonant capacitor (cap) of the wireless power transmitter during the clock period.

[0744] Here, the envelope can be expressed, for example, as follows.

[0745] <Formula 2>

[0746]

[0747] That is, the wireless power transmitter can estimate the exponential function of the envelope, and the wireless power transmitter can calculate the quality factor (Q factor) as the attenuation ratio of the exponential function.

[0748] According to Fig. 40, when the magnetic field is stopped (removal power signal) at the request of the wireless power receiver, rather than 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.

[0749] Meanwhile, measurement of quality factors in clock phases can also be performed as follows.

[0750] Figures 41 and 42 schematically illustrate the configuration of a coil and driver of a wireless power transmitter.

[0751] Figure 41 schematically illustrates the injection of energy into a coil in the form of pulses. Figure 42 schematically illustrates the coil configuration of a wireless power transmitter.

[0752] In this approach, energy is injected into the coil in pulses and the decay of the ringing response is measured. The Q value is estimated from the envelope of the attenuated signal.

[0753] Each step in FIG. 41 and FIG. 42 can be described as follows.

[0754] - t-startup (startup stage)

[0755] At this stage, the input voltage of the inverter is allowed to reach the nominal voltage required for pinging.

[0756] - t-discharge (discharge stage)

[0757] The purpose of this step is to discharge the resonant capacitor and establish initial conditions for pinging.

[0758] That is, VCtx(0) = 0, iLtx(0) = 0 must be satisfied.

[0759] To do this, the resonant tank must be shorted via the lower switches of the inverting bridge (e.g. Q3 and Q4).

[0760] - t-ping (ping level)

[0761] This step is the step of injecting energy.

[0762] During the t_ping time, DC power is connected to the Tx resonant tank. This can be done by turning off Q3 (Q3 OFF), turning on Q1 (Q1 ON), and keeping Q4 on (Q4 ON).

[0763] - t-response (response stage)

[0764] After energy is injected into the tank during the ping phase, the tank must be short-circuited via a bottom switch to allow free oscillation of the resonant tank. This is done by turning Q1 off and Q3 on. The tank's natural response (e.g., the voltage across the Tx tuning capacitor) is then sampled and processed.

[0765] Meanwhile, to estimate the Q value, the waveform's peaks must be accurately sampled to extract the envelope of the attenuated signal. To eliminate the influence of DC offset, the envelope of the attenuation can be measured as the peak-to-valley difference.

[0766] 4. Packets that can be used in the protocol

[0767] Below, each packet that can be used in the protocol of this specification is described in more detail.

[0768] First, the clock data packet transmitted by the wireless power receiver can be described as follows.

[0769] Figure 43 schematically illustrates a clock data packet transmitted by a wireless power receiver.

[0770] According to FIG. 43, the Clock data packet allows the wireless power receiver to start the Clock. The Clock data packet may include a reason field.

[0771] The reason codes may be as shown in the table below.

[0772] Value Reason 0 Cloak: Generic 1 Cloak: Forced (Unclock request denied) 2 Cloak: Thermally constrained 3 Cloak: Insufficient Power 4 Cloak: Coex Mitigation (Wireless Power Receiver requests clock to perform a task that cannot coexist with wireless power) 5 Cloak: End of Charge 6 Cloak: PTx initiated 7 Reserved New Cloak: Request PTx to update its HW for more power delivery (HW / high) New Cloak: Request PTx to update its HW for less power delivery (HW / low)

[0773] In response to the above clock data packet, the wireless power transmitter may perform the following response:

[0774] Response Description ACK The wireless power transmitter agrees to start / continue cloaking NAK The pattern is not allowed ND The pattern transmitted when the wireless power receiver uses a reason code that is not supported ATNCloak state: The wireless power transmitter requests to terminate the clock. Other states: The wireless power transmitter prefers to communicate before cloaking.

[0775] To summarize, it could be as follows:

[0776] The wireless power receiver can use the reason '(new): HW / high' when requesting a cloak to change the HW settings before starting fast charging by increasing the transmission power during normal charging.

[0777] Here, optionally, the wireless power receiver can perform HW configuration changes for fast charging after entering the cloak phase.

[0778] For example, changes to the HW configuration of a wireless power receiver may include changing the value of the resonant capacitor, or changing a buck to a switch-cap charger.

[0779] The wireless power receiver can use the reason '(new): HW / low' when requesting a cloak to change the HW settings before starting normal charging by lowering the transmission power during fast charging.

[0780] Here, optionally, the wireless power receiver can perform HW configuration changes for normal charging after entering the cloak phase.

[0781] When a wireless power transmitter receives a cloak request and the reason is '(new): HW / high', it can change the hardware settings for fast charging after entering the cloak phase. In addition, the wireless power transmitter can perform Q-factor measurement.

[0782] For example, a change in the HW configuration of a wireless power transmitter may include a change in the value of the resonant capacitor.

[0783] When a wireless power transmitter receives a cloak request and the reason is '(new): HW / low', it can perform hardware configuration changes for normal charging after entering the cloak phase. It can also perform Q-factor measurements.

[0784] The wireless power transmitter can update the FO presence information if it performs Q-factor measurement during the clocking phase.

[0785] Figure 44 schematically illustrates a GET data packet.

[0786] According to FIG. 44, the Get Request - GET (0x28) data packet allows a wireless power receiver (power receiver) to request specific information from a wireless power transmitter (power transmitter).

[0787] A GET data packet may include a parameter field, and the parameter field may include information about parameters requested from a wireless power transmitter.

[0788] The parameter codes can be organized as shown in the table below.

[0789] ValueParameter0 Wireless Power Transmitter Extended Identification2 Wireless Power Transmitter Inverter Voltage3 Wireless Power Transmitter Extended Capabilities4 Wireless Power Transmitter Power Loss Accounting Parameters5 Wireless Power Transmitter Regulation Control Status6 Wireless Power Transmitter Charge Status7 Wireless Power Transmitter Estimated K9 Wireless Power Transmitter Error StatusNew Wireless Power Transmitter FO Presence Information (TBD)

[0790] In response to the above GET data packet, the following FSK response may exist:

[0791] FSK Packet - The wireless power transmitter must respond with the requested packet.

[0792] When a wireless power transmitter receives a GET[FO Presence] request, it can transmit an FO presence packet, which will be described later, to a wireless power receiver.

[0793] Figure 45 schematically illustrates an FO presence packet.

[0794] According to FIG. 45, the wireless power transmitter may include one or more of the following information in the FO presence packet that responds to the GET[FO Presence] request:

[0795] - Presence / absence of FO

[0796] 0: no FO exists

[0797] 1: FO exists

[0798] - Power loss measured (optional)

[0799] Power loss measured (12 bits)

[0800] Measured power loss in mW units.

[0801] (e.g. Power loss value range: 0 to 4095 mW, 0 for negative power loss, 4095 for power loss greater than 4095)

[0802] - Measured Q-factor (quality factor) (optional)

[0803] Measured Q-factor (10 bit)

[0804] The measured Q-factor value. Values ​​can be expressed in increments of 0.1 (e.g., Q-factor value range: 0 to 102.3).

[0805] Below, embodiments of this specification are described again from various subject perspectives.

[0806] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0807] FIG. 46 is a flowchart of a mode switching method from the perspective of a wireless power transmitter according to one embodiment of the present specification.

[0808] According to FIG. 46, the wireless power transmitter can transfer wireless power to the wireless power receiver based on the first power in the power transfer phase (S4610).

[0809] The wireless power transmitter may receive a specific packet from the wireless power receiver during the power transfer phase (S4620). The specific packet may be a packet indicating a transition from the first power to the second power.

[0810] The wireless power transmitter can transfer the wireless power to the wireless power receiver based on the second power in the power transfer phase (S4630).

[0811] Although not shown separately, a wireless power transmitter may be provided. The wireless power transmitter may include a converter related to transferring wireless power to a wireless power receiver and a communication / controller related to controlling the transfer of the wireless power. The wireless power transmitter may transfer the wireless power to the wireless power receiver based on a first power in a power transfer phase. The wireless power transmitter may receive a specific packet from the wireless power receiver in the power transfer phase. The specific packet may be a packet indicating a transition from the first power to a second power. The wireless power transmitter may transfer the wireless power to the wireless power receiver based on the second power in the power transfer phase.

[0812] FIG. 47 is a flowchart of a mode switching method from the perspective of a wireless power receiver according to one embodiment of the present specification.

[0813] According to FIG. 47, the wireless power receiver can receive wireless power from the wireless power transmitter based on the first power in the power transfer phase (S4710).

[0814] The wireless power receiver may transmit a specific packet to the wireless power transmitter during the power transfer phase (S4720). The specific packet may be a packet indicating a transition from the first power to the second power.

[0815] The wireless power receiver can receive the wireless power from the wireless power transmitter based on the second power in the power transfer phase (S4730).

[0816] Although not shown separately, a wireless power receiver may be provided. The wireless power receiver may include a power pickup unit related to receiving wireless power from a wireless power transmitter and a communication / control unit related to controlling the reception of the wireless power. The wireless power receiver may receive the wireless power from the wireless power transmitter based on a first power in a power transfer phase. The wireless power receiver may transmit a specific packet to the wireless power transmitter in the power transfer phase. The specific packet may be a packet indicating a transition from the first power to a second power. The wireless power receiver may receive the wireless power from the wireless power transmitter based on the second power in the power transfer phase.

[0817] Below, the effects of this specification are explained.

[0818] Before explaining the effects of this specification, the problems described above are summarized as follows.

[0819] To commercialize fast-charging technology, the introduction of methods to minimize heat generation is essential. System mode switching based on charging power is one such method. Furthermore, because the amount of transmitted power can change in real time during the battery charging process, flexible system mode switching also requires protocol-level support.

[0820] Here, power switching requires a physical hardware conversion. That is, the wireless power transmitter and / or wireless power receiver must convert their hardware to high or low power to switch power modes.

[0821] At this time, a hardware power conversion section is required for power conversion.

[0822] This specification provides packets for mode switching. Additionally, this specification provides a period for mode switching through clock phases, and this specification also provides a configuration for measuring quality factors for mode switching.

[0823] Through the above configuration, the present specification provides an effect of not having to re-perform a series of processes (e.g., ID, Conf. Negotiation, Authentication, etc.) that are performed in the early stage of the Qi protocol when entering the cloak phase during power transfer (power transfer phase). In other words, even if a wireless power transmitter or wireless power receiver performs a change in the HW settings for fast charging, it can immediately switch to fast charging mode without having to re-perform a series of processes (e.g., ID, Conf. Negotiation, Authentication, etc.) that are performed in the early stage of the Qi protocol. Through this, the wireless power transmitter and / or wireless power receiver can quickly enter power transfer of 15W or more.

[0824] Additionally, according to the present specification, the wireless power transmitter and / or the wireless power receiver can operate in reverse as needed to quickly switch from a fast charging mode to a normal charging mode, thereby enabling efficient operation.

[0825] The effects that can be achieved through specific examples of this specification are not limited to the effects listed above. For example, a person with ordinary skill in the relevant technical field may understand or derive various technical effects 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.

[0826] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

Claims

1. By a wireless power transmitter, wireless power is transferred to a wireless power receiver based on the first power in the power transfer phase; By the wireless power transmitter, a specific packet is received from the wireless power receiver in the power transfer phase, The specific packet is a packet indicating a transition from the first power to the second power; and A method characterized in that the wireless power is transferred to the wireless power receiver based on the second power in the power transfer phase by the wireless power transmitter.

2. A method according to claim 1, characterized in that the second power is higher than the first power.

3. A method according to claim 1, characterized in that the second power is lower than the first power.

4. A method according to claim 1, characterized in that the specific packet is a clock data packet.

5. In paragraph 4, the clock data packet includes a reason field, A method characterized in that the reason field indicates a hardware update of the wireless power transmitter for the second power.

6. In the fourth paragraph, the wireless power transmitter enters a clock phase based on receiving the clock data packet, A method characterized in that the wireless power transmitter stops transmitting the wireless power during the clock phase.

7. A method according to claim 6, wherein the wireless power transmitter detects the material during the clock phase.

8. A method according to claim 7, characterized in that the wireless power transmitter receives a GET data packet requesting information on the result of detection of the substance from the wireless power receiver.

9. A method according to claim 8, characterized in that the wireless power transmitter transmits information on the result of detection of the substance to the wireless power receiver.

10. Wireless power transmitter, A converter associated with transmitting wireless power to a wireless power receiver; and Including a communication / controller related to controlling the transmission of the above wireless power, The above wireless power transmitter: In the power transfer phase, the wireless power is transferred to the wireless power receiver based on the first power; In the above power transfer phase, a specific packet is received from the wireless power receiver, The specific packet is a packet indicating a transition from the first power to the second power; and A wireless power transmitter characterized in that it transfers the wireless power to the wireless power receiver based on the second power in the power transfer phase.

11. By the wireless power receiver, wireless power is received from the wireless power transmitter based on the first power in the power transfer phase; By the wireless power receiver, a specific packet is transmitted to the wireless power transmitter in the power transfer phase, The specific packet is a packet indicating a transition from the first power to the second power; and A method characterized in that the wireless power is received from the wireless power transmitter based on the second power in the power transfer phase by the wireless power receiver.

12. A method according to claim 11, characterized in that the second power is higher than the first power.

13. A method according to claim 11, characterized in that the second power is lower than the first power.

14. A method according to claim 11, characterized in that the specific packet is a clock data packet.

15. In paragraph 14, the clock data packet includes a reason field, A method characterized in that the reason field indicates a hardware update of the wireless power transmitter for the second power.

16. In the 14th paragraph, the wireless power receiver enters a clock phase based on transmitting the clock data packet, A method characterized in that the wireless power receiver stops receiving the wireless power during the clock phase.

17. A method according to claim 16, characterized in that detection of the substance is performed during the clock phase.

18. A method according to claim 17, characterized in that the wireless power receiver transmits a GET data packet requesting information on the result of detection of the substance to the wireless power transmitter.

19. A method according to claim 18, characterized in that the wireless power receiver receives information on the result of detection of the substance from the wireless power transmitter.

20. Wireless power receiver, A power pickup device associated with receiving wireless power from a wireless power transmitter; and Including a communication / controller related to controlling the reception of the above wireless power, The above wireless power receiver: In the power transfer phase, the wireless power is received from the wireless power transmitter based on the first power; In the above power transfer phase, a specific packet is transmitted to the wireless power transmitter, The specific packet is a packet indicating a transition from the first power to the second power; and A wireless power receiver characterized in that it receives the wireless power from the wireless power transmitter based on the second power in the power transfer phase.

Images