Method and system for utilizing cloak phase in wireless power transfer

Abstract

According to one aspect of the present invention, provided is a wireless power transmission method for transmitting power to a wireless power receiver by using a wireless power transmitter, the method comprising the steps of: starting a cloak phase; and performing at least one of foreign object detection (FOD) and a power mode change in the cloak phase.

Description

Method and system for utilizing clock phase in wireless power transfer

[0001] The present invention relates to a method and system for utilizing a clock phase in wireless power transfer.

[0002] In wireless power transfer systems, communication and power are simultaneously transmitted while maintaining a specific power mode to ensure stable power transfer between a wireless power transmitter and a wireless power receiver. However, power transfer may need to be interrupted to change the power mode or perform foreign object detection (FOD) to determine the presence of external metallic substances. While such interruptions are necessary to protect the transmitter and receiver and ensure the safety of the entire system, interrupting power transfer also results in the loss of the power transfer contract elements. Therefore, to resume power transfer, the negotiation phase between the transmitter and receiver must be re-performed to determine the power transfer contract elements before re-entering the power transfer phase.

[0003] These renegotiations and re-entry into the power transfer phase are time-consuming, which can disrupt power transfer continuity and slow down overall system response. In particular, in environments where power modes frequently change or where external objects frequently interfere with power transfer, requiring frequent detection, the repeated interruptions and subsequent renegotiations can negatively impact device response and charging speed. Therefore, there is a growing need for a method that can perform necessary tasks without completely terminating power transfer.

[0004] In addition, with regard to the change of the power mode described above, conventionally, there was only a method in which the wireless power receiver first requested the wireless power transmitter to change the power mode, thereby changing the power mode. However, there was also a problem in which the wireless power transmitter could not request a change of power mode even though there was a situation in which the presence of a foreign substance was suspected during the wireless power transmission process and the amount of power transmitted by the wireless power transmitter was reduced, or a situation in which the wireless power transmitter could determine the most appropriate amount of power and power mode considering the current situation.

[0005] Accordingly, the inventor(s) of the present invention propose a technology that utilizes a clock phase to temporarily suspend a wireless power transmission phase, but preserves power transmission contract elements before and after the suspension so that there is no need to proceed with a negotiation phase or the like again when resuming power transmission, and a technology that enables a wireless power transmitter to first request a power mode change.

[0006] The purpose of the present invention is to solve all of the problems of the above-mentioned prior art.

[0007] In addition, the present invention has another object of starting a cloak phase and performing at least one of foreign object detection (FOD) and power mode change in the cloak phase.

[0008] In addition, the present invention also aims to prevent time waste and maximize the efficiency of wireless power transfer by performing at least one of external material detection and power mode change in a clock phase that temporarily suspends power transfer during power transfer, thereby omitting the renegotiation phase when resuming power transfer.

[0009] In addition, another object of the present invention is to provide a method by which a wireless power transmitter can request a wireless power receiver to change a power mode or initiate a power mode change.

[0010] A representative configuration of the present invention to achieve the above purpose is as follows.

[0011] According to one aspect of the present invention, a wireless power transfer method is provided, comprising the steps of starting a cloak phase, and performing at least one of foreign object detection (FOD) and power mode change in the cloak phase.

[0012] According to another aspect of the present invention, a wireless power transmitter is provided that starts a cloak phase and performs at least one of foreign object detection (FOD) and power mode change during the cloak phase.

[0013] According to another aspect of the present invention, a wireless power receiver is provided that starts a cloak phase and performs at least one of foreign object detection (FOD) and power mode change during the cloak phase.

[0014] In addition, a non-transitory computer-readable recording medium recording another method for implementing the present invention, another system, and a computer program for executing the method are further provided.

[0015] According to the present invention, a cloak phase can be started, and at least one of foreign object detection (FOD) and power mode change can be performed in the cloak phase.

[0016] In addition, according to the present invention, by performing at least one of external material detection and power mode change in a clock phase that temporarily suspends power transmission during power transmission, the renegotiation phase can be omitted when power transmission is resumed, thereby preventing time waste and maximizing the efficiency of wireless power transmission.

[0017] Additionally, according to the present invention, a method can be provided in which a wireless power transmitter can request a wireless power receiver to change a power mode or initiate a power mode change.

[0018] FIG. 1 is a diagram illustrating an embodiment of a process for performing external material detection in a clock phase according to one embodiment of the present invention.

[0019] FIG. 2 is a diagram exemplarily showing the structure of a first clock phase start packet according to one embodiment of the present invention.

[0020] FIG. 3 is a diagram illustrating one embodiment of a process for performing a power mode change in a clock phase according to one embodiment of the present invention.

[0021] FIG. 4 is a diagram exemplarily showing the structure of a second clock phase start packet according to one embodiment of the present invention.

[0022] FIG. 5 is a diagram exemplarily showing the structure of a mode selection request packet transmitted by a wireless power receiver to a wireless power transmitter according to one embodiment of the present invention.

[0023] FIG. 6 is a diagram exemplarily showing the structure of a response packet to a mode selection request packet according to one embodiment of the present invention.

[0024] FIG. 7 is a diagram exemplarily showing the structure of a mode selection request packet transmitted by a wireless power transmitter to a wireless power receiver according to one embodiment of the present invention.

[0025] FIG. 8 is a diagram illustrating an embodiment of a process in which a wireless power transmitter requests a wireless power receiver to change a power mode according to an embodiment of the present invention.

[0026] <Explanation of symbols>

[0027] 110: Request for detection of foreign matter during power transmission

[0028] 120: Clock phase start and maintenance phase

[0029] 130: Clock phase end stage

[0030] 140: Request for detection of foreign matter during power transmission

[0031] 210: Power mode change request step

[0032] 220: Clock phase start request step

[0033] 230: Clock phase maintenance phase

[0034] 240: Clock phase end stage

[0035] 250: Power transmission resumption phase

[0036] 310: Power mode change request step

[0037] 320: Power mode change start step

[0038] 330: Power mode change progress stage

[0039] The following detailed description of the present invention refers to the accompanying drawings, which illustrate specific embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention, while different from each other, are not necessarily mutually exclusive. For example, specific shapes, structures, and characteristics described herein may be modified and implemented from one embodiment to another without departing from the spirit and scope of the present invention. Furthermore, it should be understood that the positions or arrangements of individual components within each embodiment may also be modified without departing from the spirit and scope of the present invention. Accordingly, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention is to be construed to encompass the scope of the claims and all equivalents thereof. Like reference numerals in the drawings represent the same or similar elements throughout the several aspects.

[0040] Hereinafter, various preferred embodiments of the present invention will be described in detail with reference to the attached drawings so that a person having ordinary skill in the art to which the present invention pertains can easily practice the present invention.

[0041] At least one of a wireless power transmitter (PTx or transmitter) and a wireless power receiver (PRx or receiver) according to one embodiment of the present invention can perform wireless power transmission based on a magnetic power profile (MPP) protocol.

[0042] The MPP protocol according to one embodiment of the present invention may refer to a communication protocol designed to enable more sophisticated and flexible wireless power transfer between a transmitter and a receiver as an extension protocol of the Qi standard. MPP can support advanced functions such as bidirectional communication between the receiver and transmitter, operation in various power modes, power negotiation, advanced foreign material detection, and simultaneous processing of multiple data streams by extending the existing Qi extended power profile (EPP)-based structure. Based on the above-described configuration, the MPP protocol can provide optimal power transfer efficiency and system flexibility tailored to various charging environments and device characteristics.

[0043] A wireless power receiver according to one embodiment of the present invention may refer to a device that receives power generated by magnetic induction from a wireless power transmitter and supplies it to an internal load. The wireless power receiver described above may include a receiving coil, a rectifier circuit, a communication circuit, and the like, and may perform functions such as power negotiation, external material detection, and parameter transmission. Specifically, the wireless power receiver described above may refer to a device that complies with the MPP protocol.

[0044] A wireless power transmitter according to one embodiment of the present invention may refer to a device that generates power and supplies it to a wireless power receiver. The wireless power transmitter may perform frequency regulation, power control, packet-based communication, power mode switching, and external object detection, and may perform efficient and safe power transfer through interaction with the wireless power receiver. Specifically, the wireless power transmitter described above may refer to a device that complies with the MPP protocol.

[0045] Power transfer according to one embodiment of the present invention may mean that a wireless power transmitter wirelessly supplies power to a wireless power receiver. Meanwhile, as described above, the time (or process or stage) during which power is wirelessly supplied may be referred to as a power transfer phase. Specifically, power transfer may mean a phase in which power transfer is actually performed based on a negotiation result (or power transfer contract element) after a negotiation phase is completed. At this time, the wireless power receiver provides feedback through a control packet (e.g., XCE and PLA, etc.), and the wireless power transmitter can adjust power based on the feedback to perform stable transmission.

[0046] The aforementioned power transfer contract elements may refer to negotiated power transfer contract elements. The negotiated power transfer contract elements may refer to power transfer conditions established through data packets exchanged between a wireless power transmitter and a wireless power receiver during the negotiation phase. Subsequently, power transfer may be performed in accordance with the negotiated power transfer contract elements during the power transfer phase.

[0047] The negotiation phase according to one embodiment of the present invention may refer to a stage in which a wireless power receiver and a wireless power transmitter communicate to set the power level, frequency, control method, etc. required prior to power transfer. That is, in order to perform wireless power transfer (i.e., initiate the power transfer phase), a negotiation phase may be required to determine various transfer conditions prior to power transfer. Upon completion of the negotiation phase, the power transfer phase may be initiated based on the negotiated conditions.

[0048] Meanwhile, in order to perform at least one of power mode change and foreign substance detection during power transmission, power transmission may need to be stopped. A method for stopping power transmission during power transmission may include a method of completely stopping power transmission through a power transmission stop (end power transfer) function, or a method of temporarily stopping power transmission using a clock phase to be described later. However, when the above-described power transmission stop function is used, when power transmission is resumed due to loss of power transmission contract elements, the power transmission contract elements must be re-established through the above-described negotiation phase, whereas when the clock phase is used according to an embodiment of the present invention, even if power transmission is stopped, the power transmission contract elements before the transmission stop are maintained as is, so there is no need to go through the negotiation phase again, which can significantly save time and improve power transmission efficiency.

[0049] A power mode change according to one embodiment of the present invention may be initiated or performed upon a request from at least one of a wireless power receiver and a wireless power transmitter. Specifically, the above-described request may be performed by transmitting a packet containing information related to the power mode change request.

[0050] Meanwhile, since only a request packet that a wireless power receiver can transmit to a wireless power transmitter was defined as a packet used for changing a power mode in the past, only the wireless power receiver could request a change in power mode, a wireless power transmitter according to an embodiment of the present invention can request a change in power mode by first transmitting a request packet (or a mode selection request packet) to the wireless power receiver even if there is no request from the wireless power receiver. This solves the problem of the prior art in which the wireless power transmitter could not first request a change in power mode even though it could determine that a change in power mode was necessary based on information that the wireless power transmitter could obtain, thereby improving the efficiency of wireless power transmission.

[0051] Wireless power transmission method according to the present invention

[0052] Below, an example of using a clock phase in relation to power transmission using a wireless power transmitter and a wireless power receiver according to an embodiment of the present invention will be described. Meanwhile, the process described below is only one example of a method for performing wireless power transmission using a wireless power transmitter and a wireless power receiver according to an embodiment of the present invention, and it will be apparent to those skilled in the art that the wireless power transmitter and the wireless power receiver according to an embodiment of the present invention are not limited thereto and can perform wireless power transmission through various processes that are suitable for the purpose of the present invention.

[0053] <Operation of a wireless power transmitter>

[0054] A wireless power transmitter according to one embodiment of the present invention can initiate a cloak phase. Specifically, the initiation of a cloak phase according to one embodiment of the present invention can be performed by a wireless power receiver initiating a cloak phase, or by a wireless power transmitter requesting a wireless power receiver to initiate a cloak phase, and the wireless power receiver in response to the request starting a cloak phase.

[0055] According to one embodiment of the present invention, a cloak phase may refer to a phase in which wireless power transfer is temporarily suspended while maintaining the power transfer contract elements already negotiated between a wireless power receiver and a wireless power transmitter during wireless power transfer. Specifically, in the above-described cloak phase, power transfer can be temporarily suspended without externally indicating the power interruption (e.g., through a user notification). For example, the cloak phase can generally be utilized for various purposes, such as thermal management, power budget adjustment, and communication interference avoidance.

[0056] Continuing, the interruption of power transfer via a clock phase may be a temporary interruption of power transfer, and may not initialize a power transfer contract element, unlike a typical interruption of power transfer (e.g., an interruption of transfer using the power interruption function described above). Specifically, the clock phase may be initiated by a request of the wireless power receiver, or may be initiated by a request of the wireless power transmitter. That is, the clock phase described above may be initiated by the wireless power receiver transmitting an appropriate request packet (e.g., a first clock phase start packet described below) to the wireless power transmitter, or may be initiated by the wireless power transmitter transmitting an appropriate request packet (e.g., a second clock phase start packet described below) to the wireless power receiver.

[0057] A clock phase according to one embodiment of the present invention may be started during a power transfer phase.

[0058] That is, a clock phase according to one embodiment of the present invention can be started at any point during the power transfer phase at the request of a wireless power transmitter or a wireless power receiver.

[0059] A clock phase according to one embodiment of the present invention may be started in response to receiving a clock phase start packet from a wireless power receiver or transmitting a clock phase start packet to a wireless power receiver.

[0060] A packet (or data packet) according to one embodiment of the present invention may refer to a structured information unit or structured data including information fields divided into bytes (B) and bits (b). The wireless power receiver or wireless power transmitter of the present invention may communicate by transmitting packets to each other.

[0061] A clock phase start packet according to one embodiment of the present invention may refer to a data packet transmitted by a wireless power receiver or a wireless power transmitter to initiate a clock phase. The above-described clock phase start packet may refer to one packet, but may also be used as a term that comprehensively refers to two or more packets used to initiate a clock phase. For example, in addition to a clock phase start packet (e.g., a first clock phase start packet or a second clock phase start packet to be described later, etc.), a clock phase start packet may also include a response packet thereto or a packet including information related to a task to be performed in the clock phase (e.g., at least one of power mode conversion and foreign material detection).

[0062] Specifically, the process of a wireless power receiver according to one embodiment of the present invention starting a clock phase may include a process of the wireless power receiver transmitting a first clock phase start packet to a wireless power transmitter. More specifically, the first clock phase start packet may refer to a clock phase start packet that the wireless power receiver transmits to the wireless power transmitter to start a clock phase.

[0063] Specifically, the process of the wireless power transmitter according to one embodiment of the present invention starting (or requesting the start of) a clock phase may include the process of the wireless power transmitter transmitting a second clock phase start packet to the wireless power receiver. More specifically, the second clock phase start packet may refer to a packet that the wireless power transmitter transmits to the wireless power receiver to request the start of a clock phase.

[0064] Specifically, the above-described clock phase may be initiated by responding to receiving a first clock phase start packet from the above-described wireless power receiver, or by the above-described wireless power receiver responding to transmitting a second clock phase start packet to the above-described wireless power receiver.

[0065] The above-described first clock phase start packet may be a data packet having at least one bit (b) and at least one byte (B). Specifically, the above-described first clock phase start packet may include information regarding a reason for starting the clock phase.

[0066] For example, referring to FIG. 2, the first clock phase start packet may include eight bits represented by b0 to b7 and one byte represented by B0. In addition, the areas (fields) defined by b0 to b2 and B0 may include information about the reason for starting the clock phase (e.g., “Reason” in FIG. 2). The information about the reason for starting the above-described clock phase may include information about the reason for starting the clock phase, such as overheating, power shortage, charging completion, and foreign object detection, or a value defined to correspond to each reason. For example, when the clock phase is started for foreign object detection, the information about the reason may be “Cloak: Foreign Object Detection”, and the value defined to correspond thereto may be “7”. Meanwhile, in FIG. 2, “Reserved” in b3 to b7 and B0 may mean that the corresponding area is a reserved field. Here, a preserved field may mean a field that is included within a data field but is currently unused and left blank for future standard extensions or compatibility.

[0067] The above-described second clock phase start packet may be a data packet having at least one bit (b) and at least one byte (B). Specifically, the above-described second clock phase start packet may include information regarding a reason for starting the clock phase.

[0068] For example, referring to FIG. 4, a second clock phase start packet may include eight bits represented by b0 to b7 and one byte represented by B0. In addition, the area defined by b0 to b2 and B0 may include information about a reason for starting a clock phase (e.g., "Reason" in FIG. 4). The information about the reason for starting the above-described clock phase may include information about a reason for starting the clock phase, such as overheating or power shortage, or a value defined to correspond to each reason. For example, when a clock phase is started for a power mode change, the information about the reason may be "Cloak: Power Mode Changes", and the value defined to correspond thereto may be "5". Meanwhile, in FIG. 4, "0 (Selector)" of b3 to b7 and B0 may mean a value (i.e., a selector value) used to distinguish multiple different packets having the same header value (for example, the header value of the second clock phase start packet described above may be "0x1E"). That is, the "0 (Selector)" described above may mean that the selector value of the second clock phase start packet is "0", so that the packet can be distinguished from other packets having the same header value but different selector values.

[0069] More specifically, receiving the above-described first clock phase start packet may include a step of receiving a packet for performing in-power FOD during power transmission from the above-described wireless power receiver, a step of transmitting a rejection packet to the above-described wireless power receiver, and a step of receiving the above-described first clock phase start packet from the above-described wireless power receiver.

[0070] According to one embodiment of the present invention, in-power FOD may refer to a method for detecting the presence of an external object during power transmission by precisely estimating power loss occurring during the power transmission phase. Specifically, this method for detecting an external object during power transmission may refer to a delta ploss method utilizing calibration.

[0071] Specifically, the delta plus method using the above-described calibration may refer to a method for detecting foreign substances during power transmission that can be used when the amount of power being transmitted is high (e.g., 15 W to 25 W, or more than 25 W). Meanwhile, when the amount of power being transmitted is relatively low (e.g., 15 W or less), a method for detecting foreign substances during power transmission based on MPLA (MPP power loss accounting) may be used to detect foreign substances during power transmission. However, the MPLA-based foreign substance detection method is difficult to apply when the amount of power being transmitted is high (e.g., 15 W to 25 W, or more than 25 W), and therefore, when the amount of power being transmitted is high, the delta plus method using calibration can be used to perform foreign substance detection with high accuracy.

[0072] More specifically, the delta-plot method using calibration can be performed in situations where the power mode is changed.

[0073] More specifically, the situation in which the power mode is changed as described above may mean a situation in which the transmitted power is changed from a power mode in which the transmitted power is relatively low to a power mode in which the transmitted power is relatively high.

[0074] For example, a situation can be assumed where a power mode supporting transmission of 8 to 15 W of power is changed to a power mode supporting transmission of 15 to 25 W of power. In this situation, MPLA-based foreign material detection may not be possible due to issues such as reduced accuracy in the power mode supporting transmission of 15 to 25 W of power. Therefore, through the delta plus method using calibration, under the assumption that there is no foreign substance (foreign substance) before the power mode is changed (for example, to a power mode that supports transmission of the power amount of 8 W to 15 W as described above), the relationship (relational expression) between the inverter input power value of the wireless power transmitter and the rectifier power value of the wireless power receiver is calculated in advance through calibration, and in response to the power mode being changed (for example, to a power mode that supports transmission of the power amount of 15 W to 25 W), the calculated value of the rectifier power value of the wireless power receiver is derived from the pre-calculated relationship (relational expression), and the derived calculated value is compared with the actual value of the rectifier power value of the wireless power receiver in the current state, thereby detecting the foreign substance.

[0075] Meanwhile, the detection of a foreign substance during the power transmission described above may be referred to as in-power foreign substance detection (in-power FOD) as a foreign substance detection that may be performed in the process of transmitting power while the wireless power transmitter and wireless power receiver are mated, and thus may be distinguished from the detection of a foreign substance before power transmission (i.e., pre-power FOD) that may be performed before power transmission.

[0076] Meanwhile, in order to use the delta plus method, it may be necessary to be able to perform calibration during power transmission as described above. In order to perform calibration during power transmission, (1) the above-described pre-power external material detection was performed a predetermined time before the point in time at which calibration is to be performed, (2) the result of the pre-power external material detection confirms that there is no external material, (3) the result confirming that there is no external material as described above at the point in time of calibration is valid, and (4) the total calibration time (t cal ) may be required. That is, if pre-power external material detection was performed a predetermined time before the point in time at which calibration is to be performed during power transmission and a valid result was not obtained, then in order to satisfy the above-described condition, it may be necessary to completely stop power transmission and then perform pre-power external material detection. However, when using the wireless power transmission method according to an embodiment of the present invention, since the clock phase can be started and pre-power external material detection can be performed in the clock phase, the time waste caused by completely stopping and then resuming power transmission can be minimized.

[0077] A packet for performing foreign material detection during power transmission (i.e., performing calibration for performing the delta plus method) according to one embodiment of the present invention may refer to a "CAL_ENTER" data packet. "CAL_ENTER" may be transmitted by the wireless power receiver to the wireless power transmitter in response to the wireless power receiver's decision to perform calibration. Meanwhile, the wireless power transmitter, which has received the above-described "CAL_ENTER" packet, may transmit a "CAL_ENTER_RSP" packet to the wireless power receiver in response thereto.

[0078] A rejection packet according to an embodiment of the present invention may be one of the response packets (i.e., the "CAL_ENTER_RSP" packet) to the above-described "CAL_ENTER", and may mean a data packet including content for rejecting the start of calibration. The above-described rejection packet may be transmitted from the wireless power transmitter to the wireless power receiver. Meanwhile, the rejection packet according to an embodiment of the present invention may include information about a reason, and the information about the reason may include the reason for rejecting the start of the above-described calibration. For example, the rejection packet may include "FOD_REFRESH_SEQ" in the information about the reason, which may mean that the start of calibration is rejected because the above-described pre-power foreign material detection needs to be performed in order to start calibration (i.e., at least one of the conditions (1) to (4) described above is not satisfied).

[0079] Meanwhile, in a wireless power transmission method according to an embodiment of the present invention, in response to the wireless power receiver receiving the rejection packet transmitted by the wireless power transmitter to the wireless power receiver as described above, the wireless power receiver transmits a first clock phase start packet to the wireless power transmitter, and in response to the wireless power transmitter receiving the first clock phase start packet, the clock phase can be started by responding (for example, a packet acknowledging the start of the clock phase, such as "ACK") to the wireless power receiver. Continuing, pre-power external material detection can be performed in the clock phase started as described above.

[0080] Meanwhile, the first clock phase start packet described above may include information regarding the reason for starting the clock phase. For example, if the clock phase is to be started to perform pre-power foreign object detection during the clock phase, information regarding the reason for starting the clock phase may be included in the packet in the form of "Cloak: Foreign Object Detection."

[0081] Specifically, transmitting the second clock phase start packet described above may include receiving a mode selection request packet from the wireless power receiver described above or transmitting a mode selection request packet to the wireless power receiver.

[0082] A mode selection request packet according to one embodiment of the present invention may refer to a data packet transmitted by a wireless power transmitter or wireless power receiver to request entry into a specific power mode. Through the above-described mode selection request packet, a desired power mode can be designated and power supply conditions suitable for the designated power mode can be prepared (or a mode change can be rejected).

[0083] According to one embodiment of the present invention, requesting entry into a specific power mode may mean requesting a change to an appropriate power mode based on at least one of the current power transmission status and the predicted future load power status. The aforementioned power mode may mean at least one category divided into a predetermined range based on the amount of power to be transmitted (e.g., the amount of power measured in watts (W)).

[0084] Meanwhile, the fact that transmitting a second clock phase start packet according to one embodiment of the present invention includes a step of receiving a mode selection request packet from the wireless power receiver described above or transmitting a mode selection request packet to the wireless power receiver may mean that transmitting or receiving the above-described mode selection request packet may be performed before or after the time point at which the second clock phase start packet is transmitted.

[0085] Specifically, as described above, receiving a mode selection request packet from a wireless power receiver or transmitting a mode selection request packet to the wireless power receiver may be performed before transmitting the second clock phase start packet described above. That is, the wireless power receiver or the wireless power transmitter may send a mode selection request packet to each other in order to change a power mode, and may perform a mode change by transmitting a corresponding response packet thereto. Meanwhile, in a wireless power transmission method according to an embodiment of the present invention, in order to perform a power mode change in a clock phase, selection of a power mode to be changed may be performed based on a mode selection request packet before transmitting a clock phase start packet.

[0086] A mode selection request packet according to one embodiment of the present invention may include a first mode selection request packet and a second mode selection request packet. Specifically, the first mode selection request packet may refer to a mode selection request packet transmitted from a wireless power receiver to a wireless power transmitter, and the second mode selection request packet may refer to a mode selection request packet transmitted from a wireless power transmitter to a wireless power receiver.

[0087] Specifically, a wireless power receiver according to an embodiment of the present invention can request a mode change by transmitting a first mode selection request packet to a wireless power transmitter. Information about whether the wireless power receiver will send the first mode selection request packet to the wireless power transmitter and which mode to change to can be determined by comparing the amount of power that the current wireless power transmitter can supply (e.g., available power or negotiable power described below) and the amount of power that the wireless power receiver needs to supply. Specifically, a wireless power receiver according to an embodiment of the present invention can determine the amount of power that needs to be supplied according to a predetermined standard and request a change to a power mode that is suitable for supplying the determined amount of power that needs to be supplied.

[0088] A first mode selection request packet transmitted by a wireless power receiver to a wireless power transmitter according to an embodiment of the present invention may have a data packet form including a bit (b) and a byte (B). Specifically, the first mode selection request packet may include eight bits indicated by b0 to b7 and one byte indicated by B0. Specifically, the first mode selection request packet transmitted by the wireless power receiver to the wireless power transmitter may include at least one of information regarding a preference for whether to maintain the contents of a power transfer contract, information regarding a power mode to be changed, and information regarding an auxiliary power mode.

[0089] Specifically, information about a preference for maintaining the above-described power transmission contract may include a value corresponding to no preference information (e.g., “0”), a value corresponding to maintaining the power transmission contract (e.g., “1”), or a value corresponding to not maintaining the power transmission contract (e.g., “2”).

[0090] Continuing, the information about the power mode to be changed described above may include a value corresponding to each power mode to be changed. For example, the value corresponding to the continuous power mode may be "0", the value corresponding to the nominal power mode may be "1", the value corresponding to the low power mode may be "2", and the value corresponding to the high power mode may be "3".

[0091] Continuing, the information about the auxiliary power mode may include information about whether to use the auxiliary power mode. The auxiliary power mode described above may refer to a power operation mode that fixes or limits the system state in order to perform a specific function (e.g., power transfer efficiency measurement). For example, the information about the auxiliary power mode described above may include a value corresponding to not selecting the auxiliary power mode (e.g., "0") or a value corresponding to selecting the auxiliary power mode (e.g., "1"). Continuing, for example, in response to the transmitter receiving a mode selection request packet containing information to execute the auxiliary power mode for gain measurement, which is one of the auxiliary power modes, the transmitter may stop changing the resonant capacitance, etc., and temporarily suspend system adjustments, thereby maintaining a predictable environment for power transfer efficiency measurement.

[0092] Referring to FIG. 5, a first mode selection request packet transmitted by a wireless power receiver to a wireless power transmitter includes information on whether to maintain power transmission contract contents in a part indicated by bits b6 to b7 and byte B0 (i.e., a part indicated as "Preference", which may include one of the values ​​described above), information on a power mode to be changed in a part indicated by bits b3 to b4 and B0 (i.e., a part indicated as "Main Mode", which may include one of the values ​​described above), and information on an auxiliary power mode in a part indicated by bits b0 and B0 (i.e., a part indicated as "Aux", which may include one of the values ​​described above).

[0093] At least one of the information regarding whether a wireless power transmitter according to an embodiment of the present invention will send a second mode selection request packet to a wireless power receiver and which mode to change to be included in the second mode selection request packet described above may be determined by (1) referring to a change in power mode supportability and a current power mode (active power mode), (2) referring to whether the wireless power transmitter is expected to need a change in the current power mode, or (3) comparing the amount of power that the wireless power transmitter can supply (e.g., available power or negotiable power described below) and the amount of power that the wireless power receiver is currently receiving.

[0094] First, the above-mentioned (1) will be explained as follows. Specifically, power mode supportability may refer to information about the changed supportable mode when the supportable mode changes due to changes in the environment related to the wireless power transmitter. More specifically, the wireless power transmitter can support high power mode, normal power mode, and low power mode (in an ideal situation), but the environment related to the wireless power transmitter may change, such as when the power source is limited or the thermal conditions are not suitable, and may not be able to support a specific mode. In this case, it can be said that the supportable mode has changed. Examples of situations in which the supportable mode changes due to changes in the environment related to the wireless power transmitter include situations in which the power source is limited and the high power mode cannot be supported, or situations in which the temperature is high or the high heat generation is excessive and the high power mode cannot be supported.

[0095] Continuing, the information regarding the change in the supportable mode described above may refer to information regarding the changed power mode that may be generated in response to a change in the supported power mode due to a change in the environment related to the wireless power transmitter as described above. For example, in response to the inability to support the high power mode due to power source limitations or high temperatures as described above, the information regarding the change in the supportable mode described above may include information such as "high power mode not supported" or "only normal mode power or low power mode can be supported."

[0096] Continuing, as described above, determining whether the wireless power transmitter will send a second mode selection request packet to the wireless power receiver by referring to a change in power mode supportability (power mode capability) and the current power mode (active power mode) and information regarding which mode to change to be included in the second mode selection request packet may mean that, in response to the wireless power transmitter becoming unable to support the current power mode due to a change in power mode supportability, the wireless power transmitter includes information related to changing to a supportable power mode in the second mode selection request packet and transmits the packet to the wireless power receiver, thereby requesting a change in power mode. For example, in response to a situation where the wireless power transmitter is currently in a high power mode and can no longer maintain the high power mode due to excessive heat generation, the wireless power transmitter may include information related to requesting a change to a normal power mode (or a low power mode) in the second mode selection request packet and transmit the packet to the wireless power receiver.

[0097] Next, the above-mentioned (2) will be explained as follows. Specifically, a situation in which the wireless power transmitter may be expected to need to change the current power mode may mean a situation in which the amount of power transmitted by the wireless power transmitter is adjusted.

[0098] For example, in a situation where power loss exceeds a certain level during a power transmission process (e.g., when a foreign object is present during power transmission), a wireless power transmitter may reduce (throttle) the power level it transmits in response to this, and it may be expected that it will need to change to a power mode that matches the reduced power level. In this situation, the wireless power transmitter may request the wireless power receiver to change to a power mode that supports a lower power amount. More specifically, it may be assumed that the wireless power transmitter detects a foreign object (e.g., the delta plus method described above) during power transmission and lowers the power amount in response to a suspicion that a foreign object has been inserted. This lowering of the power amount in response to the insertion of a foreign object may be referred to as "power throttling." Meanwhile, the wireless power transmitter may first reduce the amount of power transmitted through power throttling, and then request a change to a power mode that corresponds to the reduced amount of power. That is, after performing power throttling, the wireless power transmitter can request the wireless power receiver to change the power mode even if there is no power mode change request from the wireless power receiver. The power mode change request by the wireless power transmitter described above can be performed by the wireless power transmitter transmitting a second mode selection request packet according to an embodiment of the present invention to the wireless power receiver.

[0099] Another example is the charging method of SWC type, where the rectified voltage (V RECT ) can be directly connected to the battery voltage. In this situation, since the change in the amount of power requested by the wireless power receiver to the wireless power transmitter is large, the wireless power transmitter must be able to control the input voltage (V in) may more easily encounter situations where the wireless power transmitter outputs excessive power or the load changes rapidly, and thus it may be expected that it will need to change to an appropriate power mode. In such a situation, the wireless power transmitter may request the wireless power receiver to change to a power mode that supports a higher or lower power amount in response to the fact that the amount of power being transmitted by the wireless power transmitter is close to the minimum or maximum range of the power mode selected by the wireless power receiver (i.e., the amount of power being transmitted by the wireless power transmitter is close to the minimum or maximum range of the current power mode). That is, the wireless power transmitter may request that the power mode be changed to an appropriate power mode that has a range that can encompass the change in the amount of power being transmitted as described above.

[0100] Lastly, the above-described (3) will be described as follows. Specifically, a wireless power transmitter according to an embodiment of the present invention can request a change in power mode by transmitting a second mode selection request packet to the wireless power receiver in response to a difference between the amount of power that the wireless power transmitter can supply and the amount of power that the wireless power receiver is receiving being lower than a predetermined level.

[0101] For example, let's assume that the wireless power transmitter can supply 15W of power (i.e., the maximum power that can be transmitted in the current power mode is 15W), but the wireless power receiver is currently trying to receive power greater than 15W. In response to this situation, the wireless power transmitter can transmit a second mode selection request packet to the wireless power receiver, requesting that the power mode be changed to a mode capable of transmitting power greater than 15W. For example, as described below, the power mode capable of supplying 15W may be a "nominal power mode," and the power mode capable of supplying power exceeding 15W may be a "high power mode." In this case, in the example described above, information related to requesting a change from the current mode, which is the nominal power mode, to the high power mode may be included in the second mode selection request packet described above.

[0102] For another example, let's assume that the wireless power transmitter can supply 25W of power (i.e., the maximum power that can be transmitted in the current power mode is 25W), but the wireless power receiver continues to receive only about 15W of power. In response to this situation, the wireless power transmitter can transmit a second mode selection request packet to the wireless power receiver, requesting that the power mode be changed to a mode suitable for transmitting about 15W of power. For example, as described below, a power mode that can supply 15W may be a "nominal power mode," and a power mode that can supply more than 15W may be a "high power mode." In this case, in the example described above, information related to requesting a change from the current high power mode to the nominal power mode may be included in the second mode selection request packet described above.

[0103] A second mode selection request packet transmitted by a wireless power transmitter to a wireless power receiver according to an embodiment of the present invention may have a data packet form including bits and bytes. Specifically, the second mode selection request packet may include eight bits indicated by b0 to b7 and one byte indicated by B0. Specifically, the second mode selection request packet transmitted by the wireless power transmitter to the wireless power receiver may include at least one of (1) information on a power mode to be changed and (2) information on a preference on whether to maintain the contents of a power transfer contract.

[0104] Specifically, the information about the power mode to be changed described above may include a value corresponding to the power mode to be changed. For example, the value corresponding to the continuous power mode may be "0", the value corresponding to the nominal power mode may be "1", the value corresponding to the low power mode may be "2", and the value corresponding to the high power mode may be "3".

[0105] Continuing, the information regarding the preference for maintaining the above-described power transmission contract content may include a value corresponding to no preference information (e.g., "0"), a value corresponding to maintaining the power transmission contract (e.g., "1"), or a value corresponding to not maintaining the power transmission contract (e.g., "2").

[0106] Referring to FIG. 7, a second mode selection request packet transmitted from a wireless power transmitter to a wireless power receiver may include a portion indicated by bits b5 to b7 and byte B0 and a portion indicated by bits b0 to b2 and byte B0 (i.e., a portion indicated as “Reserved”) that may be preserved, and a portion indicated by bits b3 to b4 and B0 may include information about a power mode to be changed (i.e., a portion indicated as “Main Mode” that may include one of the values ​​described above).

[0107] Meanwhile, as described above, the second mode selection request packet transmitted from the wireless power transmitter to the wireless power receiver may perform a function of causing the wireless power receiver, which receives the second mode selection request packet, to transmit a first mode selection request packet back to the wireless power transmitter. That is, the wireless power receiver may transmit a first mode selection request packet back to the wireless power transmitter in response to receiving the second mode selection request packet from the wireless power transmitter, and the wireless power transmitter may perform a power mode change based on the received first mode selection request packet.

[0108] In summary, selecting or changing the power mode may be performed by (1) the wireless power receiver transmitting a first mode selection request packet to the wireless power transmitter, and the wireless power transmitter responding with a response packet accepting the first mode selection request packet in response to receiving the first mode selection request packet, or (2) the wireless power transmitter transmitting the second mode selection request packet described above to the wireless power receiver, thereby requesting the wireless power receiver to transmit the first mode selection request packet to the wireless power transmitter (i.e., requesting a power mode change).

[0109] Meanwhile, the wireless power receiver that received the above-described second mode selection request packet retransmits the first mode selection request packet generated based on the information included in the second mode selection request packet to the wireless power transmitter, which may mean that the wireless power receiver has accepted the request to change the power mode. On the other hand, the wireless power receiver that received the above-described second mode selection request packet may not accept the power mode change request by transmitting a response packet rejecting the power mode change to the wireless power transmitter or not sending a response at all (ignoring it). Meanwhile, the response packet rejecting the power mode change described above may include information indicating that it has confirmed the receipt of the second mode selection request packet (i.e., the second mode selection request packet was received, but the mode change was rejected). The response packet rejecting the above-described power mode change may be referred to as a DSR / ACK packet.

[0110] Meanwhile, the first mode selection request packet according to one embodiment of the present invention may be referred to as an MSR (mode selection request) packet, and the second mode selection request packet may be referred to as an MSN (mode selection notification) packet.

[0111] More specifically, transmitting the above-described second clock phase start packet may further include a step of transmitting a response packet to the above-described wireless power receiver or receiving a response packet from the above-described wireless power receiver, and a step of transmitting the above-described second clock phase start packet to the above-described wireless power receiver.

[0112] A response packet according to one embodiment of the present invention may include information related to a mode change performed after receiving a mode selection request packet or information regarding a result of performing the mode change.

[0113] Specifically, the above-described response packet may be a packet transmitted by the wireless power transmitter to the wireless power receiver in response to the wireless power transmitter receiving the first mode selection request packet transmitted by the wireless power receiver to the wireless power transmitter. More specifically, the above-described response packet may be referred to as a mode select status (MSS) packet.

[0114] Specifically, the above-described response packet may include eight bits indicated by b0 to b7 and two bytes indicated by B0 to B1. In addition, the above-described response packet may include at least one of information on a mode change result according to a mode change request and information on an error included in the mode change result. Specifically, the information on the mode change result according to the mode change request may be classified into change success (e.g., which may be expressed by a value of "0"), change in progress (e.g., which may be expressed by a value of "1"), change failure (e.g., which may be expressed by a value of "2"), and performing another task (e.g., which may be expressed by a value of "3"). Specifically, information about errors included in the mode change result may be classified as no error (e.g., may be expressed as a value of "0"), the request content is not understood (e.g., may be expressed as a value of "1"), the change was attempted but failed due to an error (e.g., may be expressed as a value of "2"), and the current wireless power transmitter cannot perform power transfer in the requested power mode (e.g., may be expressed as a value of "3").

[0115] Referring to FIG. 6, the response packet may include parts indicated by b2 to b7 and B0 and parts indicated by b2 to b7 and B1 that may be preserved (i.e., parts indicated as “Reserved”), parts indicated by b0 to b1 and B0 may include information about the result of a mode change according to the above-described mode change request (i.e., parts indicated as “Status”), and parts indicated by b0 to b1 and B1 may include information about an error included in the result of the above-described mode change (i.e., parts indicated as “Error Code”).

[0116] In summary, the power mode can be changed in the clock phase starting based on the second clock phase start packet, and before the process of transmitting the second clock phase start packet, the wireless power transmitter or the wireless power receiver can request a change in the power mode. At this time, the wireless power receiver can request a mode change by transmitting a first mode selection request packet to the wireless power transmitter. In addition, the wireless power transmitter can request a mode change by transmitting a second mode selection request packet to the wireless power receiver. Meanwhile, as described above, the second mode selection request packet may request a mode change by itself, or the wireless power receiver may request a mode change by transmitting a first mode selection request packet to the wireless power transmitter.

[0117] In a clock phase according to one embodiment of the present invention, wireless power transfer may be temporarily interrupted.

[0118] Here, the temporary interruption of wireless power transfer during a clock phase can be distinguished from the (complete) interruption of wireless power transfer. Specifically, if wireless power transfer is interrupted, various information determined for the power transfer may be lost. However, if wireless power transfer is temporarily interrupted during a clock phase, various information determined for the power transfer may be maintained. Here, the various information may refer to at least one power transfer contract element.

[0119] In a clock phase according to one embodiment of the present invention, power transfer contract elements before and after wireless power transfer is temporarily suspended may be the same.

[0120] Specifically, to perform wireless power transfer, the power transfer contract elements may need to be finalized through a negotiation phase in advance. At this time, if power transfer is interrupted, the power transfer contract elements may be initialized or lost. To resume power transfer, the power transfer contract elements may need to be re-finalized through a negotiation phase (or renegotiation phase). In contrast, when a clock phase is initiated, wireless transfer may be temporarily interrupted, but the power transfer contract elements may remain intact. When power transfer is resumed, power can be transferred again based on the previously finalized power transfer contract elements without the need for a renegotiation phase.

[0121] The power transfer contract element according to one embodiment of the present invention may refer to various elements that are determined by communication between a wireless power receiver and a wireless power transmitter prior to an actual power transfer phase in order to perform wireless power transfer. The above-described power transfer contract element may necessarily be determined prior to performing wireless power transfer, and even if previously determined, if it is lost due to power transfer interruption or other reasons, it may be necessary to be renegotiated and determined again in order to resume power transfer. For example, the above-described power transfer contract element may include various detailed information related to power transfer, such as frequency, power level, clocking delay, and power control profile, but is not limited thereto.

[0122] That is, according to one embodiment of the present invention, the fact that the power transfer contract elements are the same before and after the temporary suspension of wireless power transfer may mean that the power transfer contract elements remain intact before and after the temporary suspension of wireless power transfer (or before and after the clock phase). Here, since the power transfer contract elements remain intact, wireless power transfer can be resumed immediately before and after the clock phase without a negotiation phase (or a renegotiation phase).

[0123] A wireless power transmitter according to one embodiment of the present invention can perform at least one of foreign object detection (FOD) and power mode change in a clock phase.

[0124] Foreign object detection according to one embodiment of the present invention may mean a method of detecting a foreign object (FO) that may affect transmission efficiency or cause excessive heat generation when performing wireless power transmission.

[0125] According to one embodiment of the present invention, a power mode may refer to at least one mode distinguished by the amount of power transmitted in wireless power transmission. The aforementioned power mode may be distinguished into multiple ranges based on the amount of power transmitted. The aforementioned power mode may also be referred to as a power mode.

[0126] A power mode change according to one embodiment of the present invention may mean changing the current power mode to another power mode. Specifically, a power mode change according to one embodiment of the present invention may mean a power mode change performed during a clock phase.

[0127] In a clock phase according to one embodiment of the present invention, either one of external material detection and power mode change, or both, can be selectively performed.

[0128] Foreign material detection according to one embodiment of the present invention can be performed based on a pre-power FOD method.

[0129] The detection of a foreign substance before power transmission according to one embodiment of the present invention may refer to a method of detecting a foreign substance that can be performed before performing wireless power transmission (or before the power transmission phase). Specifically, the detection of a foreign substance before power transmission may include an open air queue foreign substance detection (Open Air Q FOD) method and a mated queue foreign substance detection (Mated-Q FOD) method. Meanwhile, the detection of a foreign substance before power transmission may be referred to as pre-power FOD.

[0130] Meanwhile, in addition to the aforementioned pre-power transmission foreign substance detection, foreign substance detection can also be performed during power transmission, which may be referred to as "during-power transmission foreign substance detection" or "in-power foreign substance detection (FOD)". For example, the delta-plot method utilizing the aforementioned calibration may be included in the aforementioned during-power transmission foreign substance detection.

[0131] A method for detecting external substances prior to power transmission according to one embodiment of the present invention may include a Mated-Q method.

[0132] The Mated-Q method according to one embodiment of the present invention may refer to one of the methods for detecting foreign substances before power transmission. Specifically, the Mated-Q method may refer to a method for detecting foreign substances performed in a state where a wireless power transmitter and a wireless power receiver are mated (i.e., connected to each other, such as when the wireless power receiver is positioned at the power transmission portion of the wireless power transmitter) but do not yet perform wireless power transmission (i.e., only mated to each other).

[0133] Meanwhile, the above-described open air Q foreign material detection (Open air Q FOD) is one of the foreign material detection methods prior to power transmission, similar to the mated Q method, but unlike the mated Q method, it may refer to a foreign material detection method performed before the wireless power transmitter and wireless power receiver are mated (for example, when the wireless power receiver is not located at the power transmission portion of the wireless power transmitter).

[0134] According to one embodiment of the present invention, foreign substance detection may be performed in response to a predetermined time period exceeding (or elapsed) from the time of the most recent foreign substance detection.

[0135] Specifically, the most recent time point of foreign substance detection according to one embodiment of the present invention may refer to the time point of the most recent foreign substance detection among the foreign substance detections performed in the past from the current time point. Meanwhile, the aforementioned time point of performance may be defined as the elapsed time from the time point of the past foreign substance detection (i.e., the most recent foreign substance detection) to the current time point.

[0136] Specifically, the predetermined period of time according to one embodiment of the present invention is a time interval that can be arbitrarily set or changed, and may generally refer to a predetermined period of time after it has been confirmed that there is no external matter prior to wireless power transmission, during which it is still recognized that there is no external matter when wireless power transmission is performed. In other words, the predetermined period of time described above may be set or changed to an appropriate length as needed.

[0137] For example, when considering the usage environment of a wireless power transmitter and a wireless power receiver, if the environment is one in which there is a lot of change (for example, an environment in which external substances are likely to be located or generated around the wireless power transmitter and the wireless power receiver), the predetermined time can be set short, and conversely, if the environment is one in which there is little change, the predetermined time can be set long.

[0138] Specifically, the most recent foreign material detection described above may have been performed via the Mated-Q method.

[0139] That is, if the absence of a foreign substance (FO) was confirmed most recently (e.g., before the above-described predetermined time elapsed) through the mated-queue method, it is possible to perform foreign substance detection (e.g., the delta plos method using calibration) during the power transfer phase; however, if the presence of a foreign substance (FO) is said to be present, or if the absence of a foreign substance was confirmed through the mated-queue method but a predetermined time has passed since the confirmation, it may not be possible to perform foreign substance detection (e.g., the delta plos method using calibration).

[0140] Meanwhile, the detection of foreign substances through the delta plus described above is a method of detecting foreign substances during power transmission, and may need to be performed during a process in which the power mode is changed to a higher power and the power is increased. At this time, there may be a situation in which the interruption of power transmission is not necessary or is omitted when changing the power mode. In this situation, if the absence of foreign substances is not confirmed through the mated-queue method before power transmission or a predetermined time has passed since the absence of foreign substances was confirmed, a situation may arise in which the calibration execution requirement is not satisfied, calibration cannot be performed, and the mated-queue method cannot be executed again because the power transmission is not interrupted. In this case, since the wireless power transmission method according to an embodiment of the present invention can start a clock phase to temporarily interrupt power transmission and perform the foreign substance detection method (i.e., the foreign substance detection method before power transmission or the mated-queue foreign substance detection method), even at a point in time when wireless power transmission is already being performed, as in the above situation, foreign substance detection before power transmission can be performed while only temporarily stopping power transmission by starting a clock phase.

[0141] According to one embodiment of the present invention, whether to perform a power mode change can be determined by referring to the power being transmitted and the available power in the current mode.

[0142] Specifically, the negotiable load power according to one embodiment of the present invention may mean the maximum amount of power that can be supplied in the current power mode.

[0143] Specifically, determining whether to perform a power mode change by referring to the power being transmitted and the available power in the current mode according to one embodiment of the present invention may mean comparing the power being transmitted and the available power in the current mode and then determining whether to perform a power mode change by using the comparison result.

[0144] The power mode according to one embodiment of the present invention may include a low power mode, a normal power mode, and a high power mode.

[0145] According to one embodiment of the present invention, a power mode can be set to be divided into multiple modes depending on the target amount of power transmission. Specifically, setting a power mode may mean dividing the target power amount into predetermined sections and presetting the system architecture (e.g., series resonant capacitance, inverter voltage, input supply voltage, etc.) for each section. As described above, by dividing the sections based on similar power ranges that can share the same system architecture and setting each section to a different power mode, the power transmission amount can be easily adjusted simply by changing the mode, and power transmission efficiency can be maximized.

[0146] Specifically, the power mode according to one embodiment of the present invention may be divided into three power modes including a low power mode (or light-load power mode), a normal power mode (or nominal power mode) and a high power mode (or high power mode), or may be divided into four power modes including a low power mode, a normal power mode, a high power mode and a continuous power mode (or continuous power mode).

[0147] However, the power modes (or their classifications) according to one embodiment of the present invention are not limited to those listed above, and may be varied within a range that achieves the objectives of the present invention. For example, an extended high power mode may be defined as an additional power mode to correspond to a higher power amount than the aforementioned high power mode.

[0148] Specifically, the low power mode according to one embodiment of the present invention may mean a power mode corresponding to a transmitted power amount of 0 W or more and 5 W or less.

[0149] Specifically, the normal power mode according to one embodiment of the present invention may mean a power mode corresponding to a transmitted power amount of 4.5 W or more and 20 W or less.

[0150] Specifically, a high power mode according to one embodiment of the present invention may mean a power mode corresponding to a transmitted power amount of 12 W or more and 25 W or less.

[0151] Specifically, the extended high power mode according to one embodiment of the present invention may mean a power mode corresponding to a transmitted power amount of 25 W or more (e.g., 50 W).

[0152] Meanwhile, as in the example described above, the ranges of each power mode may overlap to some extent, or may be defined so as not to overlap. Furthermore, in areas where the ranges of each power mode overlap, either power mode may be used.

[0153] The power ranges of the above-described power modes are exemplary, and the power mode according to one embodiment of the present invention is not limited to those listed above, and may be variously changed within a range that can achieve the purpose of the present invention.

[0154] Specifically, the continuous power mode according to one embodiment of the present invention may refer to a power mode that enables continuous and uniform power transmission performance across the entire power operating range, rather than being optimized for a specific power interval. For example, the continuous power mode may be selected in situations where the amount of transmitted power must change frequently.

[0155] A wireless power transmitter according to one embodiment of the present invention can resume wireless power transmission in response to the termination of a clock phase that has been started as described above.

[0156] That is, according to one embodiment of the present invention, the clock phase may be terminated in response to the completion of preparation for resuming wireless power transfer.

[0157] Specifically, according to one embodiment of the present invention, wireless power transfer can be resumed based on the same power transfer contract elements before and after the clock phase.

[0158] Wireless Power Transmitter

[0159] A wireless power transmitter according to one embodiment of the present invention can start a cloak phase and perform at least one of foreign object detection (FOD) and power mode change during the cloak phase.

[0160] <Operation of the wireless power receiver>

[0161] The operation of the wireless power receiver described below is described from the perspective of the wireless power receiver regarding the same operation process as the operation of the wireless power transmitter described above. Even if it is not explicitly stated that it has the same meaning, unless otherwise stated, it is identical in meaning to the description of the wireless power transmitter described above, and the description thereof is omitted to avoid excessive duplication.

[0162] A wireless power receiver according to one embodiment of the present invention can start a cloak phase.

[0163] A clock phase according to one embodiment of the present invention may be started during a power transfer phase.

[0164] A clock phase according to one embodiment of the present invention may be started in response to receiving a clock phase start packet from the wireless power transmitter described above or transmitting a clock phase start packet to the wireless power transmitter described above.

[0165] Specifically, the above-described clock phase may be initiated by the above-described wireless power transmitter responding in response to transmitting a first clock phase start packet to the above-described wireless power transmitter, or by responding in response to receiving a second clock phase start packet from the above-described wireless power transmitter.

[0166] More specifically, transmitting the first clock phase start packet described above may include a step of transmitting a packet for performing in-power FOD during power transmission to the wireless power transmitter described above, a step of receiving a rejection packet from the wireless power transmitter described above, and a step of transmitting the first clock phase start packet to the wireless power transmitter described above.

[0167] More specifically, receiving the above-described second clock phase start packet may include a step of transmitting a mode selection request packet to the above-described wireless power transmitter or receiving a mode selection request packet from the above-described wireless power transmitter.

[0168] More specifically, receiving the above-described second clock phase start packet may include receiving a response packet from the above-described wireless power transmitter or transmitting a response packet to the above-described wireless power transmitter, and receiving the second clock phase start packet from the above-described wireless power transmitter.

[0169] In a clock phase according to one embodiment of the present invention, wireless power transfer may be temporarily interrupted.

[0170] In a clock phase according to one embodiment of the present invention, power transfer contract elements before and after wireless power transfer is temporarily suspended may be the same.

[0171] According to one embodiment of the present invention, at least one of foreign object detection (FOD) and power mode change can be performed in a clock phase.

[0172] Foreign material detection according to one embodiment of the present invention can be performed based on a pre-power FOD method.

[0173] A method for detecting external substances prior to power transmission according to one embodiment of the present invention may include a Mated-Q method.

[0174] According to one embodiment of the present invention, foreign substance detection may be performed in response to a predetermined time elapsed from the time of the most recent foreign substance detection.

[0175] Specifically, the most recent foreign material detection described above may have been performed via the Mated-Q method.

[0176] According to one embodiment of the present invention, whether to perform a power mode change can be determined by referring to the power being transmitted and the available power in the current mode.

[0177] The power mode according to one embodiment of the present invention may include a low power mode, a normal power mode, and a high power mode.

[0178] A wireless power receiver according to one embodiment of the present invention can resume wireless power transmission in response to the termination of a clock phase that has been started as described above.

[0179] Wireless Power Receiver

[0180] A wireless power receiver according to one embodiment of the present invention can start a cloak phase and perform at least one of foreign object detection (FOD) and power mode change in the above-described clock phase.

[0181] Example of detecting foreign substances during wireless power transfer phase

[0182] Hereinafter, with reference to FIG. 1, an embodiment of a process for detecting external substances through a clock phase during a wireless power transmission process will be described.

[0183] First, (1) in the step (110) of requesting detection of a foreign substance during power transmission, the wireless power receiver may refer to a process of transmitting a packet for performing in-power FOD detection to the wireless power transmitter in order to perform in-power FOD detection. Specifically, the in-power FOD detection during power transmission described above may refer to a delta-plot method using calibration, and the packet for performing in-power FOD detection during power transmission may refer to the calibration request packet (111) of FIG. 1. Meanwhile, the wireless power transmitter that receives the packet for performing in-power FOD detection during power transmission described above may transmit a response packet thereto to the wireless power receiver. At this time, if the calibration performance condition is satisfied, the wireless power transmitter may transmit a packet accepting calibration performance as a response packet to the wireless power receiver. On the other hand, if the above-described calibration performance conditions are not satisfied, the wireless power transmitter may transmit a rejection packet (112) containing content rejecting calibration performance as a response packet to the wireless power receiver. At this time, the above-described rejection packet (112) may include information regarding the reason for rejecting the calibration.

[0184] Next, in the (2) clock phase start and maintenance step (120), the clock phase can be started by the wireless power receiver sending a clock phase start request packet (121) to the wireless power transmitter, and the wireless power transmitter transmitting a response packet accepting the clock phase to the wireless power receiver. Specifically, the above-described clock phase start request packet (121) may mean a first clock phase start packet according to an embodiment of the present invention. In response to the start of the clock phase, a foreign substance detection (122) before power transmission can be performed. Specifically, the foreign substance detection (122) before power transmission can be performed by a mated-queue method according to an embodiment of the present invention. That is, by only temporarily stopping the power transmission, the power transmission contract element is not initialized, and the foreign substance detection (122) before power transmission can be performed.

[0185] Next, in the (3) clock phase termination step (130), the clock phase may be terminated in response to the result of performing the foreign substance detection (122) during the power transmission described above (e.g., no foreign substance is detected). At this time, the clock phase may be terminated by the wireless power receiver responding to the wireless power transmitter transmitting a clock phase termination packet.

[0186] Finally, in the (4) calibration re-request step (140), the wireless power receiver retransmits a packet (e.g., calibration request packet (111)) to the wireless power transmitter for performing in-power FOD during power transmission as described above, and the wireless power transmitter accepts the calibration, thereby performing calibration. That is, since the absence of an in-power FOD is confirmed as a result of performing in-power FOD (122) before power transmission in the clock phase start and maintenance step (120), the calibration performance condition is satisfied, thereby enabling calibration to be performed. In conclusion, by temporarily stopping power transmission through the clock phase and performing in-power FOD before power transmission, the power transmission contract elements can be preserved while performing in-power FOD. After the calibration is successfully performed as described above, the delta plus method can be used to detect an in-power FOD during power transmission.

[0187] Example of changing power mode during wireless power transfer phase

[0188] Hereinafter, with reference to FIG. 3, an embodiment of a process of performing a power mode change through a clock phase by a wireless power receiver requesting a power mode change during a wireless power transfer process will be described. Meanwhile, FIG. 3 illustrates a process of performing a power mode change by a wireless power receiver requesting a power mode change in chronological order, with the upper left corner being the earliest point in time and the lower right corner being the later point in time.

[0189] First, in the (1) power mode change request step (210), a power mode change request can be performed by the wireless power receiver transmitting a mode selection request packet (211) to the wireless power transmitter, and the wireless power transmitter transmitting a response packet (212) to the wireless power receiver. Specifically, the mode selection request packet (211) illustrated in FIG. 3 may mean a first mode selection request packet according to an embodiment of the present invention.

[0190] Next, in the (2) clock phase start request step (220), the clock phase start request can be performed by the wireless power transmitter transmitting a clock phase start packet (221) to the wireless power receiver. Specifically, the above-described clock phase start packet (221) can mean a second clock phase start packet according to an embodiment of the present invention.

[0191] Next, in the (3) clock phase maintenance step (230), the clock phase can be started and maintained by the wireless power receiver responding to the clock phase start packet (221). In the clock phase maintenance step (230), a change of the power mode can be performed based on the information included in the above-described mode selection request packet (211). Specifically, the change of the power mode is performed at the clock phase time ("t cloak ")(231) and can be performed within the mode change time (“tmodechange”)(232) that starts simultaneously and ends earlier than the clock phase.

[0192] Next, in the (4) clock phase termination step (240) (“Cloak exit sequence”), the wireless power receiver transmits a clock phase termination packet to the wireless power transmitter, and the wireless power transmitter responds to this, thereby terminating the clock phase. At this time, the clock phase termination may be performed through a procedure in which the wireless power receiver and the wireless power transmitter mutually confirm ID information. To this end, the wireless power receiver may transmit ID information as Report[PRx ID] and request an XID packet of the wireless power transmitter through GET[PTx XID], and in response, the wireless power transmitter may transmit an XID packet to the wireless power receiver. In this way, by mutually confirming the ID (identification) or XID (extended identification) information in the clock phase termination step, a situation in which the wireless power receiver is swapped within the clock phase, if any, may be detected.

[0193] Next, in the (5) power transmission resumption step (250), power transmission can be resumed based on the power mode changed in the aforementioned clock phase. Consequently, since all power transmission contract elements are maintained through the clock phase, power transmission can be resumed immediately without the need for a renegotiation (re-negotiation) of the power transmission contract.

[0194] Hereinafter, with reference to FIG. 8, an embodiment of a process of performing a power mode change through a clock phase by a wireless power transmitter requesting a power mode change during a wireless power transfer process will be described. Meanwhile, FIG. 8 illustrates a process of performing a power mode change by a wireless power transmitter requesting a power mode change in chronological order, with the left side being the earliest time point in time and the right side being the later time point in time.

[0195] First, in the power mode change request step (310), the wireless power transmitter can transmit a mode selection request packet (311) to the wireless power receiver. The difference from the power mode change request process illustrated in FIG. 3 is that FIG. 3 relates to an embodiment in which the power mode change request is initiated by the wireless power receiver initially transmitting a mode selection request packet to the wireless power transmitter, whereas FIG. 8 relates to an embodiment in which the power mode change request is initiated by the wireless power transmitter transmitting a mode selection request packet (311) to the wireless power receiver. Specifically, the mode selection request packet (311) illustrated in FIG. 8 may refer to a second mode selection request packet according to an embodiment of the present invention.

[0196] Next, in the power mode change start step (320), the power mode can be changed by the wireless power receiver transmitting a packet (321) for starting the power mode to the wireless power transmitter. Meanwhile, the above-described power mode start packet (321) may refer to a mode selection request packet (e.g., a first mode selection request packet according to an embodiment of the present invention) transmitted by the wireless power receiver to the wireless power transmitter.

[0197] Next, in the power mode change progress step (330), a process in which the wireless power transmitter responds to a mode selection request packet (e.g., a first mode selection request packet according to an embodiment of the present invention) transmitted by the wireless power receiver to the wireless power transmitter and a subsequent process thereof may be performed. Specifically, in the power mode change progress step (330), from the process in which the wireless power transmitter transmits a response packet (212) to the wireless power receiver among the power mode change request steps (210) illustrated in FIG. 3 to the power transmission resumption step (250) may be performed.

[0198] In summary, when the wireless power transmitter transmits a mode selection request packet (311) (i.e., a mode selection request packet transmitted from the wireless power transmitter to the wireless power receiver, which is distinguished from the mode selection request packet transmitted from the wireless power receiver to the wireless power transmitter) to the wireless power receiver, and accordingly, the wireless power receiver transmits a mode selection request packet (i.e., a mode selection request packet transmitted from the receiver to the transmitter) to the wireless power transmitter and initiates a power mode change, a power mode change progress step (330) may be initiated, and in the power mode change progress step (330), a series of processes including (1) a process of the wireless power transmitter responding to the mode selection request packet transmitted by the wireless power receiver, and (2) a process of changing the power mode in a clock phase may be performed. That is, the part indicated by a dotted line in the power mode change progress step (330) in FIG. 8 may mean that the above-described process may be performed, but that it is omitted from the drawing of FIG. 8.

[0199] Meanwhile, although not shown in FIG. 8, instead of the power mode change start step (320), a power mode change rejection step (not shown) may be performed in which the power mode change is not performed by the wireless power receiver transmitting a response packet (e.g., the above-described DSR / ACK packet) rejecting the power mode change to the wireless power transmitter in response to the wireless power receiver receiving the mode selection request packet (311) transmitted by the wireless power transmitter.

[0200] In summary, although a wireless power receiver may initiate a power mode change by sending a power mode selection request packet to a wireless power transmitter, as described above, when a wireless power transmitter wants to initiate a power mode change, a packet requesting that the wireless power receiver send a power mode selection request packet to the wireless power transmitter may be used (i.e., the mode selection request packet (311) described above or the second mode selection request packet described above).

[0201] Although the present invention has been described above with specific details such as specific components and limited examples and drawings, these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above examples, and those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and changes based on this description.

[0202] Therefore, the idea of ​​the present invention should not be limited to the embodiments described above, and not only the scope of the patent claims described below but also all scopes equivalent to or equivalently modified from the scope of the patent claims are considered to fall within the scope of the idea of ​​the present invention.

Claims

1. A wireless power transmission method for transmitting power to a wireless power receiver using a wireless power transmitter, The step of starting the cloak phase, and A step of performing at least one of foreign object detection (FOD) and power mode change in the above clock phase. Method for wireless power transmission.

2. In paragraph 1, The clock phase starts in response to receiving a clock phase start packet from the wireless power receiver or transmitting a clock phase start packet to the wireless power receiver. Method for wireless power transmission.

3. In paragraph 2, The clock phase is initiated by responding to receiving a first clock phase start packet from the wireless power receiver, or The wireless power receiver starts by responding to the second clock phase start packet transmitted to the wireless power receiver. Method for wireless power transmission.

4. In paragraph 3, Receiving the above first clock phase start packet, A step of receiving a packet for performing in-power FOD during power transmission from the wireless power receiver, a step of transmitting a rejection packet to the wireless power receiver, and A step of receiving the first clock phase start packet from the wireless power receiver. Method for wireless power transmission.

5. In paragraph 3, Transmitting the above second clock phase start packet is: A step of receiving a mode selection request packet from the wireless power receiver or transmitting a mode selection request packet to the wireless power receiver. Method for wireless power transmission.

6. In paragraph 5, Transmitting the above second clock phase start packet is: A step of transmitting a response packet to the wireless power receiver or receiving a response packet from the wireless power receiver, and Further comprising the step of transmitting a second clock phase start packet to the wireless power receiver. Method for wireless power transmission.

7. In paragraph 1, In the above clock phase, wireless power transfer is temporarily suspended, In the above clock phase, the power transfer contract elements before and after the wireless power transfer is temporarily suspended are the same. Method for wireless power transmission.

8. In paragraph 1, The above foreign material detection is performed based on the pre-power FOD method, The above method of detecting foreign substances before power transmission includes the Mated-Q method. Method for wireless power transmission.

9. In paragraph 1, The above foreign substance detection is performed in response to a predetermined time elapsed from the time of the most recent foreign substance detection, The most recent detection of foreign substances was performed using the Mated-Q method. Method for wireless power transmission.

10. As a wireless power transmitter, Starting a cloak phase and performing at least one of foreign object detection (FOD) and power mode change during the cloak phase. Wireless power transmitter.

11. A wireless power transmission method that receives power from a wireless power transmitter using a wireless power receiver, The step of starting the cloak phase, and A step of performing at least one of foreign object detection (FOD) and power mode change in the above clock phase. Method for wireless power transmission.

12. In paragraph 11, The clock phase starts in response to receiving a clock phase start packet from the wireless power transmitter or transmitting a clock phase start packet to the wireless power transmitter. Method for wireless power transmission.

13. In paragraph 12, The clock phase is initiated by the wireless power transmitter responding to the wireless power transmitter transmitting a first clock phase start packet, or Initiated by responding to receiving a second clock phase start packet from the wireless power transmitter. Method for wireless power transmission.

14. In paragraph 13, Transmitting the above first clock phase start packet is: A step of transmitting a packet for performing in-power FOD during power transmission to the wireless power transmitter, A step of receiving a rejection packet from the wireless power transmitter, and A step of transmitting the first clock phase start packet to the wireless power transmitter. Method for wireless power transmission.

15. In paragraph 13, Receiving the above second clock phase start packet, A step of transmitting a mode selection request packet to the wireless power transmitter or receiving a mode selection request packet from the wireless power transmitter. Method for wireless power transmission.

16. In paragraph 15, Receiving the above second clock phase start packet, A step of receiving a response packet from the wireless power transmitter or transmitting a response packet to the wireless power transmitter, and A step of receiving a second clock phase start packet from the wireless power transmitter. Method for wireless power transmission.

17. In paragraph 11, In the above clock phase, wireless power transfer is temporarily suspended, In the above clock phase, the power transfer contract elements before and after the wireless power transfer is temporarily suspended are the same. Method for wireless power transmission.

18. In paragraph 11, The above foreign material detection is performed based on the pre-power FOD method, The above method of detecting foreign substances before power transmission includes the Mated-Q method. Method for wireless power transmission.

19. In paragraph 11, The above foreign substance detection is performed in response to a predetermined time elapsed from the time of the most recent foreign substance detection, The most recent detection of foreign substances was performed using the Mated-Q method. Method for wireless power transmission.

20. As a wireless power receiver, Starting a cloak phase and performing at least one of foreign object detection (FOD) and power mode change during the cloak phase. Wireless power receiver.

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