KR20190026424A - Wireless Charging Method and Apparatus and System therefor - Google Patents

Abstract

The present invention relates to wireless power transmission technology, and particularly, to a wireless charging method and an apparatus and a system therefor. According to an embodiment of the present invention, the wireless charging method, in a wireless charging method of a wireless power transmitter wirelessly transmitting power to a wireless power receiver, comprises the steps of: receiving a charging state packet from the wireless power transmitter at every first cycle and receiving a receiving power packet at every second cycle; determining whether a charging stage value of the charging state packet is increased; determining whether a receiving power value of the receiving power packet is less than or equal to a predetermined power value; and determining the wireless power receiver to be in a first charging state when the charging state value is not increased and the receiving power value is less than or equal to the predetermined power value.

Description

Technical Field [0001] The present invention relates to a wireless charging method, and a wireless charging method and apparatus and system therefor.

The present invention relates to wireless power transmission techniques and, more particularly, to a wireless charging method and apparatus and system therefor.

Portable terminals, such as mobile phones and laptops, include a battery for storing power and a circuit for charging and discharging the battery. In order for the battery of such a terminal to be charged, power must be supplied from an external charger.

2. Description of the Related Art [0002] Generally, as an example of an electrical connection between a charging device and a battery for charging electric power of a battery, a commercial electric power is supplied to a terminal for converting electric power into voltage and current corresponding to the battery, Supply method. This type of terminal supply is accompanied by the use of physical cables or wires. Therefore, when handling a lot of terminal-supplied equipment, many cables occupy considerable work space, are difficult to organize, and are not well apparent. Also, the terminal supply method may cause problems such as instantaneous discharge due to different potential difference between terminals, burnout due to foreign substances, fire, natural discharge, battery life and deterioration of performance.

In order to solve such a problem, a charging system (hereinafter referred to as a "wireless charging system") and a control method using a method of transmitting power wirelessly are proposed. In addition, since the wireless charging system has not been installed in some portable terminals in the past and the consumer has to purchase a separate wireless charging receiver accessory, the demand for the wireless charging system is low, but the wireless charging user is expected to increase rapidly. Wireless charging function is expected to be equipped basically.

Generally, a wireless charging system comprises a wireless power transmitter for supplying electric energy in a wireless power transmission mode and a wireless power receiver for receiving electric energy supplied from a wireless power transmitter to charge the battery.

Such a wireless charging system may transmit power by at least one wireless power transmission scheme (e.g., electromagnetic induction scheme, electromagnetic resonance scheme, RF wireless power transmission scheme, etc.).

For example, the wireless power transmission scheme may be based on a variety of wireless power transmission standards based on an electromagnetic induction scheme in which a magnetic field is generated in a power transmitter coil and charged using an electromagnetic induction principle in which electricity is induced in a receiver coil under the influence of its magnetic field . Here, the electromagnetic induction type wireless power transmission standard may include an electromagnetic induction wireless charging technique defined by a Wireless Power Consortium (WPC) and an Air Fuel Alliance (formerly PMA, Power Matters Alliance).

In another example, the wireless power transmission scheme may employ an electromagnetic resonance scheme in which the magnetic field generated by the transmission coil of the wireless power transmitter is tuned to a specific resonance frequency to transmit power to a nearby wireless power receiver . Here, the electromagnetic resonance method may include a resonance type wireless charging technique defined in the Air Fuel Alliance (formerly A4WP, Alliance for Wireless Power) standards organization, a wireless charging technology standard organization.

In another example, a wireless power transmission scheme may use an RF wireless power transmission scheme that transmits power to a wireless power receiver located at a remote location by applying low-power energy to the RF signal.

On the other hand, as various devices are equipped with a wireless charging function and the power required for wireless charging is increased, the power of the wireless power receiver is increased by a high intensity input signal. If the temperature increases due to the heat generation, the wireless power receiver may cause a problem such as deterioration of wireless power reception performance or damage to the internal system. The wireless power receiver then requests the wireless power transmitter to control the power transmission according to the state of charge of the wireless power receiver. For example, a wireless power receiver can reduce the power transmission of a wireless power transmitter to protect the battery when the battery temperature is above a certain temperature. However, since the wireless power transmitter can not know the state of charge of the wireless power receiver, the wireless power transmitter operates passively by the wireless power receiver, so that the wireless charging can not be efficiently controlled.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and it is an object of the present invention to provide a wireless charging method and apparatus and system therefor.

It is still another object of the present invention to provide a wireless charging method capable of preventing the heat of a wireless recharging receiver, and an apparatus and system therefor.

It is still another object of the present invention to provide a wireless charging method capable of efficiently cooling a wireless charging receiver, and an apparatus and system therefor.

It is still another object of the present invention to provide a wireless charging method capable of wireless charging efficiently, and an apparatus and system therefor.

It is still another object of the present invention to provide a wireless charging method and apparatus and system therefor that can prevent waste of power consumption due to wireless charging.

It is still another object of the present invention to provide a wireless charging method capable of determining the charging state of a wireless power receiver and a device and system therefor.

It is still another object of the present invention to provide a wireless charging method and apparatus and system therefor, in which a wireless power transmitter can actively control charging according to the charging state of a wireless power receiver.

It is still another object of the present invention to provide a wireless charging method capable of determining whether wireless charging restarts after a wireless charging stop due to charging control of a wireless power transmitter according to a charging state, and an apparatus and system therefor .

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to an aspect of the present invention, there is provided a wireless charging method of a wireless power transmitter for wirelessly transmitting power to a wireless power receiver, the wireless charging method comprising: Receiving a received power packet in a second period; Determining whether the charge state value of the charge state packet increases; Determining whether a received power value of the received power packet is less than or equal to a predetermined power value; And determining that the wireless power receiver is in the first charging state if the charging state value does not increase and the received power value is less than a predetermined power value.

Further, in the wireless charging method according to the embodiment, the first charging state of the wireless power receiver may be a state in which the battery temperature of the wireless power receiver is equal to or higher than a predetermined temperature and the charging rate of the battery of the wireless power receiver does not increase have.

In addition, the wireless charging method according to the embodiment may further include stopping the wireless charging when the wireless power receiver determines that the wireless power receiver is in the first charging state.

According to another aspect of the present invention, there is provided a wireless charging method, wherein the step of determining that the wireless power receiver is in a first charging state includes: if the charging state value does not increase during a first period and the received power value is less than a predetermined power value, It can be determined that the wireless power receiver is in the first charging state.

According to another aspect of the present invention, there is provided a wireless charging method, wherein the timer operates when the charging state value does not increase and the received power value is equal to or less than a predetermined power value. The wireless power transmitter can determine that the wireless power receiver is in the first charging state when the charging state value does not increase during the first period and the received power value is less than the predetermined power value.

In the wireless charging method according to the embodiment, the first period may be longer than the length of the first period.

In addition, in the wireless charging method according to the embodiment, the predetermined power value may be a minimum power intensity required for communication between the wireless power transmitter and the wireless power receiver.

A wireless charging method according to an embodiment is a wireless charging method of a wireless power receiver that wirelessly receives power from a wireless power transmitter, the method comprising: determining whether a battery of the wireless power receiver is at a predetermined temperature or higher in a power transmission step; Operating the wireless power receiver to a first charge state if the battery is at or above a predetermined temperature; Stopping the wireless charging by the wireless power transmitter when the wireless power transmitter determines the first charging state of the wireless power receiver; Receiving a digital ping at the wireless power receiver; Transmitting a first signal strength packet or a second signal strength packet according to the temperature of the battery upon receipt of the digital ping; And maintaining the wireless charge interruption when transmitting the first signal strength packet.

The wireless charging method may further include determining if the battery of the wireless power receiver is above a predetermined temperature when the wireless power receiver receives the digital ping, A first signal strength packet may be transmitted if the temperature is above a predetermined temperature and a second signal strength packet if the temperature of the battery is below a predetermined temperature.

In addition, the wireless charging method according to the embodiment may further include restarting the wireless charging when the second signal strength packet is transmitted.

Also, in the wireless charging method according to the embodiment, the first signal strength packet may have a signal strength value of zero.

Also, in the wireless charging method according to the embodiment, the second signal strength value of the second signal strength packet may be a matching degree value between the transmission coil and the reception coil.

In addition, in the wireless charging method according to the embodiment, the first charging state may be a state in which the battery temperature of the wireless power receiver is higher than a predetermined temperature and the charging rate of the battery of the wireless power receiver is not increased.

In addition, in the wireless charging method according to the embodiment, the step of operating in the first charging state may require the wireless power transmitter to have a minimum power intensity required for communication.

Also, in the wireless charging method according to the embodiment, the wireless power transmitter can request the minimum power intensity by transmitting a control error packet.

Further, in the wireless charging method according to the embodiment, the predetermined temperature may be 41 degrees or more.

Further, a wireless charging method according to an embodiment includes: sensing a battery temperature of the wireless power receiver in a power transmission step; Sensing the battery temperature of the wireless power receiver in the step of sensing the battery temperature.

A wireless charging method according to an embodiment is a wireless charging method of a wireless power transmitter for wirelessly transmitting power to a wireless power receiver, the wireless charging method comprising: in a power transmission step, when the wireless power receiver is determined to be in a first charging state, ; Transmitting a digital ping; Receiving a signal strength packet in response to the digital ping; And determining whether wireless charging is restarted according to the signal strength value of the signal strength packet.

Further, in the wireless charging method according to the embodiment, the first charging state of the wireless power receiver may be a state in which the battery temperature of the wireless power receiver is equal to or higher than a predetermined temperature and the charging rate of the battery of the wireless power receiver does not increase have.

In addition, the wireless charging method according to the embodiment may include: operating a timer when the wireless charging is stopped in the power transmitting step; Determining whether an operation time of the timer is equal to or greater than a second time period; and transmitting the digital ping may transmit the digital work if the operation time of the timer is equal to or longer than a second time period.

The wireless charging method may further include initializing the timer operation time if the signal strength value is equal to or less than a first signal strength value, If the value exceeds the first signal strength value, it can be determined to restart wireless charging.

A wireless charging method according to an embodiment of the present invention is a wireless charging method of a wireless power receiver that wirelessly receives power from a wireless power transmitter, the wireless charging method comprising: sensing a state where charging of the portable device is stopped; Receiving a ping from a wireless power transmitter; Transmitting a signal strength packet including a signal strength value having a value of 0 according to the power reception suspension status to the wireless power transmitter as a response signal to the ping, Wireless power reception from the wireless power transmitter may be interrupted.

A wireless charging method according to an embodiment is a wireless charging method of a wireless power transmitter for wirelessly transmitting power to a wireless power receiver, comprising: transmitting a ping signal to the wireless power receiver; Receiving a signal strength packet signal in response to the ping signal from the wireless power receiver; Determining whether to stop wireless charging according to a signal intensity value included in the signal strength packet, and determining whether to stop the wireless power charging, if the signal strength value includes 0, The power transmission to the wireless power receiver can be stopped.

Effects of the wireless charging method and the apparatus and system for the same according to the present invention will be described as follows.

The present invention can provide a wireless charging method and apparatus and system therefor.

In addition, the present invention can provide a wireless charging method capable of preventing the heat of a wireless charging receiver, and an apparatus and system therefor.

In addition, the present invention can provide a wireless charging method capable of efficiently cooling a wireless charging receiver, and an apparatus and a system therefor.

Further, the present invention can provide a wireless charging method capable of wireless charging efficiently, and an apparatus and system therefor.

In addition, the present invention can provide a wireless charging method capable of preventing waste of power consumption due to wireless charging, and an apparatus and system therefor.

The present invention also provides a wireless charging method and apparatus and system therefor, in which a wireless power transmitter is capable of determining the charging state of a wireless power receiver.

In addition, the present invention can provide a wireless charging method and an apparatus and system therefor, in which a wireless power transmitter can actively control charging according to a charging state of a wireless power receiver.

In addition, the present invention can provide a wireless charging method in which a wireless power receiver can determine whether wireless charging restarts after a wireless charging stop according to charging control of a wireless power transmitter according to a charging state, and an apparatus and system therefor.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. It is to be understood, however, that the technical features of the present invention are not limited to the specific drawings, and the features disclosed in the drawings may be combined with each other to constitute a new embodiment.
1 is a block diagram illustrating a wireless charging system according to an embodiment.
2 is a state transition diagram for explaining a first wireless power transmission procedure defined in the WPC standard;
3 is a state transition diagram for explaining a second wireless power transmission procedure defined in the WPC standard.
4A is a diagram illustrating a wireless power receiver in accordance with an embodiment of the present invention.
FIG. 4B is a detailed embodiment of a portion of the wireless power receiver shown in FIG. 4A.
4C is a detailed embodiment of another portion of the wireless power receiver shown in FIG. 4A.
5 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment.
FIG. 6 is a block diagram illustrating a structure of a wireless power receiver interlocked with the wireless power transmitter of FIG.
FIG. 7 illustrates a method of modulating and demodulating a wireless power signal according to an embodiment of the present invention. Referring to FIG.
8 is a graph showing the temperature change and the charging rate change according to the charging state of the wireless power receiver.
9 is another graph showing the change in temperature and the change in charge rate according to the state of charge of the wireless power receiver.
10 is another graph showing the temperature change and the charge rate change according to the charge state of the wireless power receiver.
11 is a diagram for explaining a wireless charging method on a wireless charging system according to an embodiment.
12 is a diagram for explaining a wireless charging method in a wireless power transmitter in the power transmission step of FIG.
13 is a diagram for explaining a wireless charging method in the wireless power receiver of FIG.
FIG. 14 is a diagram for explaining a wireless charging method in a wireless power transmitter in the step of FIG. 11; FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and various methods to which the embodiments are applied will be described in detail with reference to the drawings. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

The present invention is not necessarily limited to these embodiments, as long as all of the constituent elements of the embodiment are described as being combined or operated together. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. The codes and code segments constituting the computer program may be easily deduced by those skilled in the art. Such a computer program may be stored in a computer-readable storage medium, readable and executed by a computer, thereby realizing embodiments. As the storage medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, or the like may be included.

In the description of the embodiment, in the case of being described as being formed on the "upper or lower", "before" or "after" of each component, (Lower) "and" front or rear "encompass both that the two components are in direct contact with each other or that one or more other components are disposed between the two components.

It is also to be understood that the terms such as " comprises, "" comprising," or "having ", as used herein, mean that a component can be implanted unless specifically stated to the contrary. But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

In the description of the embodiments, an apparatus for transmitting wireless power on a wireless power charging system includes a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a transmitter, a transmitter, a transmitter, , A wireless power transmission device, a wireless power transmitter, a wireless charging device, and the like. For the sake of convenience, a wireless power receiving device, a wireless power receiving device, a wireless power receiving device, a wireless power receiving device, a receiving terminal, a receiving side, a receiving device, a receiver Terminals and the like can be used in combination.

The wireless charging device according to the embodiment may be configured as a pad type, a cradle type, an access point (AP) type, a small base type, a stand type, a ceiling embedded type, a wall type, Power may be transmitted to the device.

As an example, a wireless power transmitter can be used not only on a desk or on a table, but also developed for automobiles and used in a vehicle. A wireless power transmitter installed in a vehicle can be provided in a form of a stand that can be easily and stably fixed and mounted.

A mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a PDA (Personal Digital Assistants), a PMP (Portable Multimedia Player), a navigation device, an MP3 player, (Hereinafter referred to as a " device ") capable of charging a battery by mounting a wireless power receiving means according to an embodiment, but not limited thereto, may be used for a small electronic device such as a toothbrush, an electronic tag, a lighting device, Quot;), and the term terminal or device may be used in combination. A wireless power receiver according to another embodiment may also be mounted on a vehicle, an unmanned aerial vehicle, an air drone or the like.

A wireless power receiver according to an embodiment may include at least one wireless power transmission scheme and may receive wireless power from two or more wireless power transmitters at the same time. Here, the wireless power transmission scheme may include at least one of the electromagnetic induction scheme, the electromagnetic resonance scheme, and the RF wireless power transmission scheme. Particularly, the wireless power receiving means for supporting the electromagnetic induction method includes a wireless power consortium (WPC), which is a wireless charging technology standard organization, and an electromagnetic induction wireless charging technique defined by the Air Fuel Alliance (formerly PMA, Power Matters Alliance) . In addition, the wireless power receiving means supporting the electromagnetic resonance method may include a resonance wireless charging technique defined in the Air Fuel Alliance (formerly Alliance for Wireless Power) standard mechanism, a wireless charging technology standard organization.

Generally, a wireless power transmitter and a wireless power receiver that constitute a wireless power system can exchange control signals or information through in-band communication or Bluetooth low energy (BLE) communication. Here, the in-band communication and the BLE communication can be performed by a pulse width modulation method, a frequency modulation method, a phase modulation method, an amplitude modulation method, an amplitude and phase modulation method, and the like. For example, the wireless power receiver can transmit various control signals and information to the wireless power transmitter by generating a feedback signal by switching on / off the current induced through the reception coil in a predetermined pattern. The information transmitted by the wireless power receiver may include various status information including received power intensity information. At this time, the wireless power transmitter can calculate the charging efficiency or the power transmission efficiency based on the received power intensity information.

1 is a block diagram illustrating a wireless charging system according to an embodiment.

Referring to FIG. 1, the wireless charging system includes a wireless power transmission terminal 10 for wirelessly transmitting power, a wireless power receiving terminal 20 for receiving the transmitted power, and an electronic device 30 Lt; / RTI >

For example, the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 can perform in-band communication in which information is exchanged using the same frequency band as that used for wireless power transmission. In another example, the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 perform out-of-band communication in which information is exchanged using a different frequency band different from the operating frequency used for wireless power transmission .

For example, information exchanged between the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 may include control information as well as status information of each other. Here, the status information and the control information exchanged between the transmitting and receiving end will become more apparent through the description of the embodiments to be described later.

The in-band communication and the out-of-band communication may provide bidirectional communication, but the present invention is not limited thereto. In another embodiment, the in-band communication and the out-of-band communication may be provided.

 For example, the unidirectional communication may be that the wireless power receiving terminal 20 transmits information only to the wireless power transmitting terminal 10, but the present invention is not limited thereto, and the wireless power transmitting terminal 10 may transmit information Lt; / RTI >

In the half duplex communication mode, bidirectional communication is possible between the wireless power receiving terminal 20 and the wireless power transmitting terminal 10, but information can be transmitted only by any one device at any time.

The wireless power receiving terminal 20 according to an exemplary embodiment may acquire various status information of the electronic device 30. [ For example, the status information of the electronic device 30 may include current power usage information, information for identifying a running application, CPU usage information, battery charge status information, battery output voltage / current information, temperature information, But it is not limited to this, and information that can be acquired from the electronic device 30 and available for wireless power control suffices.

2 is a state transition diagram for explaining a first wireless power transmission procedure defined in the WPC standard;

Referring to FIG. 2, power transmission from a transmitter to a receiver according to a first wireless power transmission procedure of the WPC standard is largely divided into a selection phase 210, a ping phase 220, and a configuration phase 230, and a power transfer phase 240.

The selection step 210 may be a phase transition when a specific error or a specific event is detected while initiating a power transmission or maintaining a power transmission. Here, the specific error and the specific event will become clear through the following description. Also, in a selection step 210, the transmitter may monitor whether an object is present on the interface surface. If the transmitter detects that an object is placed on the interface surface, it can transition to the step 220 (S201). In the selection step 210, the transmitter transmits an analog ping signal of a very short pulse and can detect whether an object exists in the active area of the interface surface based on the current change of the transmission coil.

In step 220, the transmitter activates the receiver when an object is detected, and transmits a digital ping to identify whether the receiver is a WPC compliant receiver. If the transmitter does not receive a response signal to the digital ping (e.g., a signal strength indicator) from the receiver in step 220, then the transmitter may transition back to the selection step 210 (step S202). In addition, in the step 220, when the transmitter receives a signal indicating completion of power transmission from the receiver, that is, a charge completion signal, the transmitter may transition to the selection step 210 (S203).

Once the ping step 220 is complete, the transmitter may transition to an identification and configuration step 230 to collect receiver identification and receiver configuration and status information (S204).

In the identifying and configuring step 230, the transmitter determines whether a packet is received or unexpected, a desired packet is not received for a predefined period of time (time out), a packet transmission error (transmission error) (No power transfer contract), the process can be shifted to the selection step 210 (S205).

Once the identification and configuration for the receiver is complete, the transmitter may transition to power transfer step 240, which transmits wireless power (S206).

In a power transfer step 240, the transmitter may receive an unexpected packet, a desired packet is not received for a predefined period of time (time out), a violation of a predetermined power transmission contract occurs transfer contract violation, and if the charging is completed, the selection step 210 can be transited (S207).

Also, in power transfer step 240, if the transmitter needs to reconfigure a power transfer contract based on transmitter state changes, etc., it may transition to identification and configuration step 230 (S208).

The power transmission contract may be set based on the status and characteristic information of the transmitter and the receiver. For example, the transmitter status information may include information on the maximum amount of transmittable power, information on the maximum number of receivable receivers, and the receiver status information may include information on the requested power and the like.

3 is a state transition diagram for explaining a second wireless power transmission procedure defined in the WPC standard.

Referring to FIG. 3, power transmission from a transmitter to a receiver according to a second wireless power transmission procedure of the WPC standard is largely divided into a selection phase 310, a ping phase 320, and Configuration Phase 330, a Negotiation Phase 340, a Calibration Phase 350, a Power Transfer Phase 360, and a Renegotiation Phase 370 .

The selection step 310 includes a step of transitioning, e.g., S302, S304, S308, S310, S312, when a specific error or a specific event is detected while initiating a power transmission or maintaining a power transmission . Here, the specific error and the specific event will become clear through the following description. Also, in a selection step 310, the transmitter may monitor whether an object is present on the interface surface. If the transmitter detects that an object has been placed on the interface surface, it can transition to the zipping step 320. In the selection step 310, the transmitter transmits an analog ping signal of a very short pulse and, based on the current change of the transmission coil or the primary coil, It is possible to detect whether or not there is an error.

If an object is sensed in the selection step 310, the wireless power transmitter may measure the quality factor of the wireless power resonant circuit, e.g., the transmit coil and / or the resonant capacitor for wireless power transmission.

 A wireless power transmitter may measure the inductance of a wireless power resonant circuit (e.g., a power transfer coil and / or a resonant capacitor).

The quality factor and / or inductance may be used in future negotiation step 340 to determine whether a foreign object is present.

In step 320, the transmitter wakes up the receiver and transmits a digital ping to identify whether the object is a wireless power receiver in step S301. If the transmitter does not receive a response signal to the digital ping (e. G., A signal strength packet) from the receiver at step 320, then it may transition back to step 310 again. If the transmitter receives a signal indicating completion of power transmission from the receiver (i.e., a charge completion packet) in the step 320, the flow may proceed to the selection step 310 (S302).

Once the ping step 320 is complete, the transmitter may transition to an identification and configuration step 330 for identifying the receiver and collecting receiver configuration and status information (S303).

In the identifying and configuring step 330, the transmitter determines whether a packet is received or unexpected, a desired packet is received for a predefined period of time (time out), a packet transmission error (transmission error) (No power transfer contract), the process can be shifted to the selection step 310 (S304).

The transmitter may determine whether an entry to the negotiation step 340 is required based on the negotiation field value of the configuration packet received in the identification and configuration step 330. [

If it is determined that negotiation is required, the transmitter may enter the negotiation step 340 (S305). In the negotiation step 340, the transmitter may perform a predetermined FOD detection procedure.

On the other hand, if it is determined that the negotiation is not required, the transmitter may directly enter the power transmission step 360 (S306).

At negotiation step 340, the sender may receive a Foreign Object Detection (FOD) status packet including a reference quality factor value. Or a FOD state packet including a reference inductance value. Or a status packet including a reference quality factor value and a reference inductance value. At this time, the transmitter can determine a quality factor threshold for FO detection based on the reference quality factor value. The transmitter can determine the inductance threshold for FO detection based on the reference inductance value.

The transmitter can detect whether there is an FO in the fill area using the quality factor threshold for the determined FO detection and the currently measured quality factor value, e.g., the quality factor value measured prior to the ping step, Power transmission can be controlled according to the detection result. As an example, if FO is detected, power transmission may be interrupted, but is not limited to this.

The transmitter can detect whether there is an FO in the charging region using the inductance threshold for the determined FO detection and the currently measured inductance value - e.g., the inductance value measured before the ping phase - The power transmission can be controlled. As an example, if FO is detected, power transmission may be interrupted, but is not limited to this.

If FO is detected, the transmitter may return to the selection step 310 (S308). On the other hand, if no FO is detected, the transmitter may enter the power transfer step 360 via the correction step 350 (S307 and S309). In detail, if the FO is not detected, the transmitter determines the strength of the power received at the receiving end in the correcting step 350 and determines the power loss at the receiving end and the transmitting end to determine the strength of the power transmitted at the transmitting end Can be measured. That is, the transmitter can predict the power loss based on the difference between the transmitting power of the transmitting end and the receiving power of the receiving end in the correcting step (350). A transmitter according to one embodiment may compensate the threshold for FOD detection by reflecting the predicted power loss.

In the power transfer phase 360, the transmitter determines whether an unexpected packet is received, a desired packet is received for a predefined period of time (time out), a violation of a predetermined power transmission contract occurs transfer contract violation, and if the charging is completed, the selection step 310 can be performed (S310).

Also, in power transfer step 360, if the transmitter needs to reconfigure the power transfer contract according to transmitter condition changes, it may transition to renegotiation step 370 (S311). At this time, if the renegotiation is normally completed, the transmitter may return to the power transmission step 360 (S313).

The power transmission contract may be set based on the status and characteristic information of the transmitter and the receiver. For example, the transmitter status information may include information on the maximum amount of transmittable power, information on the maximum number of receivable receivers, and the receiver status information may include information on the requested power and the like.

If the renegotiation is not normally completed, the transmitter stops transmitting power to the receiver and may transition to the selection step 310 (S312).

4A is a diagram illustrating a wireless power receiver in accordance with an embodiment of the present invention. FIG. 4B is a detailed embodiment of a portion of the wireless power receiver shown in FIG. 4A. 4C is a detailed embodiment of another portion of the wireless power receiver shown in FIG. 4A.

Referring to FIG. 4A, the wireless power receiver is illustrated in FIG. 4A as a mobile terminal (for example, a mobile phone, a smart phone, a tablet, and the like), but the scope of the present invention is not limited thereto.

The left side of FIG. 4A shows the rear cover 400 of the wireless power receiver, and the rear cover 400 may be equipped with the near field communication coil 401 and the wireless power receiving coil 402. As another example, the short range communication coil 402 and the wireless power receiving coil 401 may be disposed at a certain distance from the rear cover 400. The local communication coil 401 and the wireless power receiving coil 402 may be implemented in size and arrangement to prevent electrical connection with each other and to reduce magnetic interference.

The local communication coil 401 is a coil for transmitting and receiving data to and from other devices capable of short-range communication. The two terminals AC_N1 and AC_N2 for driving the local communication coil 401 are connected to the corresponding local communication module 430 And can be electrically connected to the two terminals AC_N1 and AC_N2.

The wireless power receiving coil 402 is a coil for receiving wireless power transmitted from a wireless power transmitter and each of two terminals AC_W1 and AC_W2 for driving the wireless power receiving coil 402 is connected to a corresponding wireless power receiving module 440, respectively.

The right side of FIG. 4A shows the body 410 of the wireless power receiver and the body 410 includes an application processor 420, a short range communication module 430, a wireless power receiving module 440, a PMIC IC, 450, and a battery 460.

The application processor 420 is a configuration that controls the overall operation of the wireless power receiver including a CPU, a GPU, a modem, an image processor, and various interfaces. The application processor 420 can transmit and receive data to and from the PMIC 450 in an SMPI communication manner using the I2C (Inter Integrated Circuit) communication method between the short distance communication module 430 and the wireless power receiving module 440. [

The short-range communication module 430 may process data for communication with an external short-range communication device through the short-range communication coil 401 under the control of the application processor 420. For example, the short range communication module 430 may operate in accordance with an NFC (Near Field Communication) standard. As described above, the short range communication module 430 may include two terminals AC_N1 and AC_N2 to be electrically connected to the short range communication coil 401. [

The wireless power receiving module 440 processes the data for communication with the external wireless power transmitter through the wireless power receiving coil 402 and performs power conversion to transfer the received wireless power to the battery 460 . For example, the wireless power receiving module 440 may operate according to a Wireless Power Consortium (WPC) or Power Matters Alliance (PMA) standard. As described above, the wireless power receiving module 440 may include two terminals AC_W1 and AC_W2 for being electrically connected to the wireless power receiving coil 402. [ In addition, the wireless power receiving module 440 may include a terminal WLC_I to be electrically connected to the PMIC 450. [ In order to use the power received from the wireless power transmitter as a battery or system drive voltage (internal power source), the wireless power receiving module delivers a predetermined power to the PMIC through the terminal WLC_I.

The PMIC 450 is a configuration for managing the charging and discharging of the battery 460. The PMIC 450 can distribute the power of the battery 460 to each configuration included in the wireless power receiver under the control of the application processor 420 at the time of discharging The charging port (CP, e.g., a USB interface) and the wireless power receiving module 440 during charging. The PMIC 450 may include a terminal WLC_I to be electrically connected to the wireless power receiving module 440. [

Battery 460 is a configuration for supplying power to each configuration included in the wireless power receiver.

The PMIC 450 may include protection means for protecting the battery from overheating. Details will be described with reference to FIG. 4B. The PMIC 450 can notify (notify) the application processor 420 via the SPMI when the battery 460 overheats, for example. The protection means may also include a switch to cut off the path of power applied to the battery. The switch can cut off the power path if it exceeds the limit temperature or reaches a certain percentage of the limit temperature depending on the temperature of the battery.

The application processor 420 may receive a notification from the PMIC 450 indicating that battery overheating has occurred and may thus control the wireless power receiving module 440. [ (Alarm) to the wireless power receiving module 440 that an overheating has occurred.

Upon receiving the overheating notification, the wireless power receiving module 440 may communicate with the wireless power transmitting module to perform an overheating protection operation so that the temperature is no longer increased. Detailed overheat protection operation and communication shall be replaced by detailed descriptions of other drawings.

Referring to FIG. 4B, the structure of the wireless power receiving module 440, the PMIC 450, and the battery 460 shown in FIG. 4A is shown in more detail.

The wireless power receiving module 440 and the PMIC 450 are connected to each other through a terminal WLC_I and the PMIC 450 may include a first switch 452 and a second switch 454. [

One side of the first switch 452 may be connected to the terminal WLC_I and the other side of the first switch 452 may be connected to the internal power supply and the second switch 454. The internal power supply means that the internal power supply is supplied as a power source necessary for operation of a configuration inside the wireless power receiver (for example, application processor 420, main memory, display module, touch module, fingerprint recognition module, etc.) .

One side of the second switch 454 may be connected to the first switch 452 and the other side of the second switch 454 may be connected to the battery 460.

The first switch 452 may transmit or block the DC power of the wireless power receiving module 440 to the internal power supply and the battery 460 according to a predetermined control signal. The first switch 452 may be defined as an overvoltage protection switch. The first switch 452 may be configured to receive a request from the application processor 420 (e.g., if the output voltage of the module is higher than the threshold voltage) or if an abnormality is found in the wireless power receiving module 440 The wireless power receiving module 440 may be a switch for interrupting the connection with the wireless power receiving module 440 in accordance with the wireless power receiving disabled state.

The second switch 454 may connect or disconnect the battery 460 to and from the wireless power receiving module 440 according to a predetermined control signal. The second switch 454 may be defined as an over-temperature protection switch. The second switch 454 is turned on when an anomaly is detected in the battery 460 (e.g., when the temperature sensed from the battery is higher than the threshold temperature) or a request from the application processor 420 May request to use the power of the wireless power receiving module rather than the power of the battery).

The battery 460 may be modeled as a single resistor as shown in FIG. 4A, and the battery 460 may be a lithium-ion battery, but the scope of the present invention is not limited thereto.

FIG. 4C shows an antenna module 470 including the short-range communication coil 401 and the wireless power receiving coil 402 shown in FIG. 4A.

Referring to FIG. 4C, the antenna module 470 includes a printed circuit board 476, a first antenna 471, a second antenna 472, a third antenna 473, a first connection terminal 474, And a connection terminal 475 as shown in FIG.

Here, the first antenna 471 may correspond to the wireless power receiving coil 402, and the second antenna 472 and the third antenna 473 may correspond to the near field communication coil 401. The local communication coil may be omitted. The first connection terminal 474 may correspond to the two terminals AC_W1 and AC_W2 and the second connection terminal 475 may correspond to the two terminals AC_N1 and AC_N2.

In detail, the antenna module 470 according to the embodiment of the present invention includes a printed circuit board 476, a first antenna 471 pattern-printed and disposed in the central area of the printed circuit board 476 for wireless charging, A second antenna 472 pattern-printed and disposed on the outer periphery of the first antenna 471 for short-range wireless communication, a second antenna 472 so as not to overlap with the second antenna 472 for the second short- A first connection terminal 474 and a second antenna 472 for connecting both ends of the first connection pattern corresponding to the first antenna 471, And a second connection terminal 475 for connecting both ends of the second through third connection patterns corresponding to the third antenna 473, respectively.

Here, the first connection terminal 474 and the second connection terminal 475 may be physically separated from the printed circuit board 475. The first connection terminal 474 and the second connection terminal 475 may be physically and electrically connected to the printed circuit board 476 such that the first connection pattern does not overlap the second antenna 472 and the third antenna 473. [ And can be separately arranged.

The connection pattern of each antenna may be formed of a lead wire extending from both ends of the antenna, or may be branched at a specific position of the antenna. Here, the connection patterns of the respective antennas and the positions at which the connection terminals are disposed may be arranged such that the length of the connection pattern is minimized.

For example, the first local area wireless communication may be Magnetic Secure Transmission (MST) and the second local area wireless communication may be Near Field Communication (NFC). Here, the MST operates in the 3.24 MHz band and the NFC operates in the 13.56 MHz band.

As another example, the first short range wireless communication may be Near Field Communication (NFC) and the second short range wireless communication may be Magnetic Secure Transmission (MST).

As another example, the first short range wireless communication and the second short range wireless communication correspond to any one of NFC, RFID communication, Bluetooth communication, UWB (Ultra Wideband) communication, MST communication, Apple Pay communication and Google Pay communication .

The antenna pattern may be disposed on the printed circuit board 476 such that a separation distance between the second antenna 472 and the third antenna 473 is maintained at least 1 millimeter (mm) or more. At this time, the second antenna 472 and the third antenna 473 are mounted on the printed circuit board (not shown) so that the deviation with respect to the separation distance between the second antenna 472 and the third antenna 473 is maintained below a predetermined first reference value 476 < / RTI >

A pattern of the antenna may be disposed on the printed circuit board 476 so that a separation distance between the first antenna 471 and the second antenna 472 is maintained at least 0.5 millimeter (mm) or more. At this time, the first antenna 471 and the second antenna 472 are mounted on the printed circuit board (not shown) so that the deviation from the separation distance between the first antenna 471 and the second antenna 472 is maintained below a predetermined second reference value 476 < / RTI >

For example, the first antenna 471 may be pattern-printed on both sides of the printed circuit board 476, and patterns printed on both sides through through holes (not shown) Can be conducted. Through this, the resistance component of the first antenna can be reduced, and the reception sensitivity of the antenna can be improved accordingly.

The second antenna 472 may be pattern printed on both sides of the printed circuit board 476 and pattern printed on both sides through a through hole (not shown) disposed on the printed circuit board 476 They can be interconnected. Thus, the resistance component of the second antenna can be reduced, and thus the receiving sensitivity of the antenna can be improved.

In another example, the third antenna 473 may be pattern printed on both sides of the printed circuit board 476 and may be pattern printed on both sides through a through hole (not shown) disposed on the printed circuit board 476 Can be interconnected. Thus, the resistance component of the third antenna can be reduced, and the receiving sensitivity of the antenna can be improved accordingly.

In another example, at least one of the first antenna 471, the second antenna 472, and the third antenna 473 may be pattern-printed on both sides of the printed circuit board 476, The corresponding antenna patterns printed on both sides through the through holes (not shown) disposed in the through holes 476 can be conducted to each other. Through this, the resistance component of the antenna can be reduced, and the receiving sensitivity of the antenna can be improved accordingly.

As shown in FIG. 4C, the first antenna 471 may be printed on the printed circuit board 476 in a circular pattern having a predetermined inner diameter, and the first connection terminal may be disposed outside the inner diameter , Which is only one embodiment.

 A temperature sensor may be disposed on the printed circuit board 476. A temperature sensor is disposed to sense the temperature that occurs during wireless power reception. The temperature information may be transmitted to the controller of the wireless power receiving module 440. The wireless power receiving module 440 may perform an overheating protection operation so that the temperature is not further increased through communication with the wireless power transmitting module 440. Detailed overheat protection operation and communication shall be replaced by detailed descriptions of other drawings.

5 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment.

5, the wireless power transmitter 500 mainly includes a power conversion unit 510, a power transmission unit 520, a wireless charging communication unit 530, a control unit 540, a current sensor 550, a temperature sensor 560 A storage unit 570, a fan 580, a timer 590, a short-range communication unit 501, and a wireless communication coil 502. It should be noted that the configuration of the wireless power transmitter 500 described above is not necessarily an essential configuration, and may be configured to include more or less components.

As shown in Fig. 5, the power supply unit 100 may supply power. The power supply unit 100 may correspond to a battery built in the wireless power transmitter 500 and may be an external power supply. The embodiment is not limited to the form of the power supply unit 100.

When power is supplied from the power supply unit 100, the power conversion unit 510 may convert the power to a predetermined intensity.

For this, the power conversion unit 510 may include a DC / DC conversion unit 511 and an amplifier 512.

The DC / DC converting unit 511 may convert DC power supplied from the power supply unit 100 into DC power having a specific intensity according to a control signal of the controller 540. [

The amplifier 512 may adjust the intensity of the DC / DC-converted power according to the control signal of the controller 540. For example, the control unit 540 may receive the power reception status information and / or the power control signal of the wireless power receiver through the wireless charging communication unit 530 and may receive the received power reception status information and / The amplification rate of the amplifier 512 can be dynamically adjusted based on the amplification factor. For example, the power reception status information may include, but is not limited to, the intensity information of the rectifier output voltage, the intensity information of the current applied to the reception coil, and the like. The power control signal may include a signal for requesting power increase, a signal for requesting power reduction, and the like.

The current sensor 550 can measure the input current input to the driving unit 521. [ The current sensor 550 may provide the measured input current value to the controller 540. [ For example, the control unit 540 can adaptively cut off the power supply from the power supply unit 100 or block the supply of power to the amplifier 512 based on the input current value measured by the current sensor 550 have.

The temperature sensor 560 may measure the internal temperature of the wireless power transmitter 500 and provide the measurement result to the control unit 540. [ More specifically, the temperature sensor 560 may include one or more temperature sensors. One or more temperature sensors may be arranged corresponding to the transmission coil 523 of the power transmission unit 520 to measure the temperature of the transmission coil 523. [ For example, the control unit 540 may block the power supply from the power supply unit 100 adaptively based on the temperature value measured by the temperature sensor 560 or block the power supply to the amplifier 512 . To this end, a power cutoff circuit may be further provided at one side of the power conversion unit 510 to cut off the power supplied from the power supply unit 100 or to cut off power supplied to the amplifier 512. In another example, the control unit 540 may adjust the intensity of the power supplied to the power transfer unit 520 based on the temperature value measured by the temperature sensor 560. Thus, the wireless power transmitter according to the embodiment can prevent the internal circuit from being damaged due to overheating.

The power transmitting unit 520 transmits the power signal output from the power converting unit 510 to the wireless power receiver. To this end, the power transmitting unit 520 may include a driving unit 521, a selecting unit 522, and one or more transmitting coils 523. [

The driving unit 521 may generate an AC power signal having an AC component having a specific frequency inserted into the DC power signal output from the power converting unit 510 and transmit the generated AC power signal to the transmitting coil 523. [ At this time, the frequencies of the AC power signals transmitted to the plurality of transmission coils included in the transmission coil 523 may be the same or different from each other.

The selecting unit 522 may receive an AC power signal having a specific frequency from the driving unit 521 and may transmit the AC power signal to the transmitting coil selected from among the plurality of transmitting coils. Here, the coil selector 522 may control the AC power signal to be transmitted to the transmission coil selected by the controller 540 according to a predetermined control signal of the controller 540. More specifically, the selector 522 may include a switch (not shown) for connecting the LC resonant circuit to the plurality of transmission coils 523. The selection unit 522 may be omitted from the power transmission unit 520 when the transmission coil 523 is configured as one transmission coil.

The transmit coil 523 may include at least one transmit coil and may transmit the AC power signal received from the selector 522 to the receiver via a corresponding transmit coil. When there are a plurality of transmission coils, the transmission coil 523 may include first to n-th transmission coils. In order to select the 'corresponding transmission coil' among the plurality of transmission coils, the selection unit 522 may be implemented by a switch (not shown) or by a far-away plexer (not shown). In addition, the transmission coil 523 may include one capacitor (not shown) connected in series with the plurality of transmission coils to implement the LC resonance circuit. One end of the capacitor (not shown) may be connected to the transmission coil 523 and the other end may be connected to the driving unit 521. Here, the 'corresponding transmission coil' may mean a transmission coil having a state capable of being coupled by the electromagnetic field to the reception coil of a wireless power receiver qualified to receive power wirelessly. According to one embodiment, the control unit 540 may select a transmission coil to be used for wireless power transmission among a plurality of transmission coils provided on the basis of a signal strength indicator (signal strength indicator) You can choose dynamically.

The control unit 540 may control the selector 522 or the multiplexer (not shown) so that the detection signals may be sequentially transmitted through the first through n-th transmission coils 523 during the first detection signal transmission procedure have. At this time, the control unit 540 can identify the time at which the sensing signal is transmitted using the timer 590. When the sensing signal transmission time arrives, the controller 540 controls the selecting unit 522 or the multiplexer So that the detection signal can be transmitted through the transmission coil. For example, the timer 590 may transmit a specific event signal to the control unit 540 at predetermined intervals during the ping transmission step. When the event signal is detected, the control unit 540 selects the event signal from the selection unit 522 or the multiplexer So that the digital ping can be transmitted through the corresponding transmission coil.

The modulation unit 531 may modulate the control signal generated by the control unit 540 and transmit the modulated control signal to the driving unit 521. [ Here, the modulation scheme for modulating the control signal includes a frequency shift keying (FSK) modulation scheme, a Manchester coding modulation scheme, a phase shift keying (PSK) modulation scheme, a pulse width modulation scheme, A differential bi-phase modulation method, and the like.

The demodulator 532 can demodulate the detected signal and transmit the demodulated signal to the controller 540 when a signal received through the transmission coil is detected. Here, the demodulated signal may include a signal strength indicator, an error correction (EC) indicator for power control during wireless power transmission, an end of charge indicator (EOC), an overvoltage / overcurrent / overheat indicator, But is not limited to, various status information for identifying the status of the wireless power receiver.

The demodulation unit 532 may identify the signal from which the demodulated signal is received and may provide the control unit 540 with a predetermined transmission coil identifier corresponding to the identified transmission coil.

 In one example, the wireless power transmitter 500 may obtain the signal strength indicator through in-band communication that uses the same frequency used for wireless power transmission to communicate with the wireless power receiver.

In addition, the wireless power transmitter 500 can transmit wireless power using the transmission coil 523, as well as exchange various information with the wireless power receiver through the transmission coil 523. In another example, the wireless power transmitter 500 may further include a separate coil corresponding to each of the transmission coils 523 (i.e., first through n-th transmission coils) It should be noted that it may also perform in-band communication with the receiver.

The storage unit 570 stores the input current value of the wireless power transmitter according to the charging state of the wireless power receiver, the charging power intensity, whether the charging is stopped, the temperature of the wireless power transmitter for charging restart, Operation status, fan RPM, and the like.

The fan 580 may be rotated by the motor to cool the superheated wireless power transmitter 500. The fan 580 can be disposed in correspondence with a configuration in which the degree of overheating is severe. For example, the fan 580 may be disposed corresponding to the power transmission unit 520. [ More specifically, the fan 580 may be disposed corresponding to the transmission coil 523 of the power transmission unit 520. [ The controller 540 may operate the fan 580 according to the state of charge of the wireless power receiver.

The short-range communication unit 501 may perform short-range bidirectional communication through a frequency band different from the frequency band used for wireless power signal transmission. For example, the short-range bidirectional communication may be an NFC (Near Field Communication) method. NFC is one of Radio Frequency IDentification (RFID) technologies and it is a wireless communication technology that transmits various wireless data within a distance of 10cm or less using a frequency of 13.56MHz.

The wireless communication coils 580 may transmit and receive signals for use in short-distance bidirectional communication with a wireless power receiver.

6 is a block diagram illustrating a structure of a wireless power receiver interworking with the wireless power transmitter according to the FIG.

6, the wireless power receiver 600 includes a wireless charging coil module 610, a rectifier 620, a DC / DC converter 630, a load 640, a sensing unit 650, A wireless communication unit 660, a main control unit 670, a local communication unit 680, and a wireless communication coil 690. Here, the wireless charging communication unit 660 may include at least one of a demodulation unit 661 and a modulation unit 662.

In addition, the wireless power receiver 600 may include a short range communication unit 680. The short-range communication unit 680 can perform short-range bidirectional communication through a frequency band different from the frequency band used for wireless power signal transmission. For example, the short-range bidirectional communication may be an NFC (Near Field Communication) method. NFC is one of Radio Frequency IDentification (RFID) technologies and it is a wireless communication technology that transmits various wireless data within a distance of 10cm or less using a frequency of 13.56MHz.

In addition, the wireless power receiver 600 may include a wireless communication coil 690 that transmits and receives signals for use in short-distance bidirectional communication with a wireless power transmitter.

The AC power received through the wireless charging coil module 610 may be delivered to the rectifier 620. The rectifier 620 may convert the AC power to DC power and transmit it to the DC / DC converter 630. The DC / DC converter 630 may convert the intensity of the rectifier output DC power to a specific intensity required by the load 640 and then deliver it to the load 640. In addition, the wireless charging coil module 610 may include a plurality of receiving coils (not shown), that is, first to n-th receiving coils. The frequency of the AC power transmitted to each of the reception coils (not shown) according to an embodiment may be different from each other, and another embodiment may include a predetermined frequency controller having a function of adjusting LC resonance characteristics for different reception coils The resonance frequencies of the respective reception coils can be set differently.

The sensing unit 650 may measure the intensity of the DC power output from the rectifier 620 and may provide it to the main control unit 670. Also, the sensing unit 650 may measure the intensity of the current applied to the reception coil 610 according to the wireless power reception, and may transmit the measurement result to the main control unit 670. For example, the main control unit 670 may compare the measured rectifier output DC power with a predetermined reference value to determine whether an overvoltage is generated. As a result of the determination, when an overvoltage is generated, a predetermined packet indicating that an overvoltage has occurred can be generated and transmitted to the modulating unit 662. Here, the signal modulated by the modulating unit 662 can be transmitted to the wireless power transmitter through the receiving coil 610 or a separate coil (not shown). The main control unit 670 can determine that the detection signal is received when the intensity of the rectifier output DC power is equal to or greater than a predetermined reference value. When receiving the detection signal, the signal intensity indicator corresponding to the detection signal is received by the modulation unit 662 To be transmitted to the wireless power transmitter. The demodulation unit 661 demodulates the AC power signal between the reception coil 610 and the rectifier 620 or the DC power signal output from the rectifier 620 to identify whether or not the detection signal is received, (670). ≪ / RTI > At this time, the main control unit 670 may control the signal intensity indicator corresponding to the detection signal to be transmitted through the modulation unit 662. [ Also, the sensing unit 650 may measure the internal temperature of the wireless power receiver 600 and provide the measured temperature value to the main control unit 670. More specifically, the sensing unit 650 may include one or more temperature sensors. One or more temperature sensors may measure the temperature of the receiving coil of the charging coil module 610. For example, the main control unit 670 can determine whether overheating occurs by comparing the measured internal temperature with a predetermined reference value. As a result of the determination, if overheating has occurred, a predetermined packet indicating that overheating has occurred can be generated and transmitted to the modulating unit 662. [ Here, the signal modulated by the modulating unit 662 can be transmitted to the wireless power transmitter through the receiving coil 610 or a separate coil (not shown).

FIG. 7 illustrates a method of modulating and demodulating a wireless power signal according to an embodiment of the present invention. Referring to FIG.

Hereinafter, a method of encoding a packet to be transmitted will be described in detail with reference to FIGS. 1 to 6. FIG.

Referring to FIG. 1, when the wireless power transmitter 10 or the wireless power receiver 20 does not transmit a specific packet, the wireless power signal is modulated with modulation having a specific frequency, May be an alternating current signal. On the other hand, when the wireless power transmitting terminal 10 or the wireless power receiving terminal 20 transmits a specific packet, the wireless power signal may be an alternating signal modulated by a specific modulation method, as shown in FIG. For example, the modulation scheme may include, but is not limited to, an amplitude modulation scheme, a frequency modulation scheme, a frequency and amplitude modulation scheme, a phase modulation scheme, and the like.

The binary data of the packet generated by the wireless power transmitting terminal 10 or the wireless power receiving terminal 20 may be subjected to differential bi-phase encoding as shown in reference numeral 720. [ Specifically, the differential two-stage encoding has two state transitions to encode data bit one and one state transition to encode data bit zero. That is, the data bit 1 is encoded such that the transition between the HI state and the LO state occurs at the rising edge and the falling edge of the clock signal, and the data bit 0 is at the rising edge of HI State and the LO state may be encoded to occur.

The encoded binary data may be subjected to a byte encoding scheme, as shown in FIG. Referring to reference numeral 730, a byte encoding technique according to an embodiment of the present invention includes a start bit and a stop bit for identifying a start and a type of a bitstream of an 8-bit encoded binary bitstream, , And a parity bit for detecting whether or not an error has occurred in the bitstream (byte).

8 is a graph showing the temperature change and the charging rate change according to the charging state of the wireless power receiver.

Referring to FIG. 8, FIG. 8 shows an example of a change in battery charge rate (a) and battery temperature (b) of a wireless power receiver with respect to time. For example, the battery temperature of the wireless power receiver has reached 41 degrees.

The battery charging rate (a) of the wireless power receiver may rise even when the battery temperature (b) of the wireless power receiver reaches 41 degrees before it reaches 80%. The battery of the wireless power receiver is not charged during the first battery non-charging period T1 when the battery charging rate a of the wireless power receiver reaches 80% and the battery temperature b of the wireless power receiver reaches 41 degrees . In this case, the wireless power receiver may not deliver the wireless power delivered by the wireless power transmitter to the battery. Further, during the first battery non-charging period T1, the wireless power to be transmitted to the wireless power transmitter can be requested only as the minimum power. The strength of the minimum power may be the power strength needed for the wireless power receiver to communicate with the wireless power transmitter. For example, the minimum power may be 3W. Further, during the first battery non-charging period T1, the wireless power receiver still receives heat because it receives wireless power, and the generated heat may be an obstacle to lowering the battery temperature b. That is, the first battery non-charging period T1 may increase. When the battery temperature b of the wireless power receiver is lowered to 41 degrees or less, the first battery non-charging period T1 ends and the battery charging rate a increases again to reach the cushioning state.

Therefore, as the first battery non-charging period T1 increases, the period until the buffering increases and the wasted power consumption increases, so that the wireless charging system needs to reduce the first battery non-charging period T1.

9 is another graph showing the change in temperature and the change in charge rate according to the state of charge of the wireless power receiver.

Referring to FIG. 9, FIG. 8 is another example of a change in battery charge rate (a) and battery temperature (b) of a wireless power receiver with respect to time. For example, the battery temperature of the wireless power receiver is between 41 degrees and 45 degrees.

The battery of the wireless power receiver is not charged during the second battery non-charging period T2 if the battery charging rate a of the wireless power receiver reaches 80% and the battery temperature b is 41 degrees or more and 45 degrees or less Do not. In this case, the wireless power receiver may not deliver the wireless power delivered by the wireless power transmitter to the battery. Further, during the first battery non-charging period T1, the wireless power to be transmitted to the wireless power transmitter can be requested only as the minimum power. The strength of the minimum power may be the power strength needed for the wireless power receiver to communicate with the wireless power transmitter. For example, the minimum power may be 3W. Also, battery temperature b may not be sufficiently cooled due to high ambient temperature of the wireless power receiver or due to heat generation due to driving of the load of the wireless power receiver. In this case, there is a problem that the second battery non-charging period (T2) continues and the battery charging rate (a) does not increase and the battery is not charged even after charging for a long time. As a result, the wireless power system wastes only power consumption.

Therefore, the wireless charging system needs to reduce the second battery non-charging period T2

10 is another graph showing the temperature change and the charge rate change according to the charge state of the wireless power receiver.

Referring to FIG. 10, FIG. 10 is another example of a change in battery charge rate (a), battery temperature (b), and battery charge (c) of a wireless power receiver with respect to time. For example, the battery temperature of the wireless power receiver is above 45 degrees. Table 1 is a table for showing the numerical values in Fig.

[Table 1]

If the battery temperature (b) of the wireless power receiver is greater than or equal to 45 degrees, the wireless power receiver may send a packet to the wireless power transmitter to stop power transmission to stop wireless charging. Thereafter, the wireless power transmitter can restart wireless charging when a predetermined period of time has elapsed. For example, as shown in FIG. 9 and Table 1, since the battery charging amount a is 80% or less, but the battery temperature b is 45 degrees or more, the wireless charging is interrupted during the third battery non-charging period T3, (c) can be stopped. When the third battery non-charging period T3 has elapsed, the wireless charging is restarted. The third battery non-charging period T3 is a preset predetermined period. That is, the wireless power transmitter can restart the wireless charging when a predetermined period of time has elapsed without confirming that the battery temperature (b) of the wireless power receiver has become a temperature suitable for wireless charging. However, the ambient temperature of the wireless power receiver may be high or the battery temperature b may not be sufficiently cooled due to heat generation due to driving of the load of the wireless power receiver. The wireless power receiver can still stop the wireless charging by transmitting a packet to the wireless power transmitter again to stop the power transmission since the battery temperature (b) is still above 45 degrees. Thereafter, the wireless charging is interrupted during the fourth battery non-charging period T4, so that the charging (c) of the battery can be stopped again. This process can repeat the fifth battery non-charging period T5 and the sixth battery non-charging period T6, and the battery non-charging period becomes longer than the battery charging period, Even if the power receiver is connected to the wireless power transmitter, the battery charging rate (a) may be rather reduced.

Thus, the wireless charging system needs to restart the wireless charging after the battery of the wireless power receiver has sufficiently cooled.

11 is a diagram for explaining a wireless charging method on a wireless charging system according to an embodiment.

Referring to FIG. 11, in a power transmission step, the wireless power receiver 1120 may operate in a first charging state (S1101). The first state of charge may be a state where the charge rate of the battery of the wireless power receiver 1120 is maintained or reduced without increasing. More specifically, the first state of charge may be such that the battery temperature of the wireless power receiver 1120 is above a predetermined temperature and the wireless power receiver 1120 does not provide the received wireless power to the battery. Also, in the first state of charge, the wireless power receiver 1120 can only request the wireless power to transmit to the wireless power transmitter 1110 with a minimum power intensity. The strength of the minimum power may be the power strength required for the wireless power receiver 1120 to communicate with the wireless power transmitter 1120. For example, the minimum power may be 3W. For example, the first charging state may be the first battery non-charging period T1 of FIG. 8, or may be the second battery non-charging period T1 of FIG. 9 as another example. Further, the first charging state may be a state in which charging of the portable device is interrupted. The state where the charging of the portable device is stopped may be a state where the power reception is stopped in the non-buffered state of the portable device.

The wireless power receiver 1120 may send a control error packet to the wireless power transmitter 1110 to transmit at a minimum power level (S1102). The control error packet may include a control error value. Here, the control error value may be an integer value ranging from -128 to +127. If the control error value is negative, the transmission power of the radio power transmission apparatus decreases, and if it is positive, the transmission power of the radio power transmission apparatus can be increased. If the control error value is 0, the output power of the wireless power transmitting apparatus may be increased or decreased. In particular, a control error packet (CEP) with a control error value of zero may be referred to as a stable control error packet.

The wireless power receiver 1120 may send a charge state packet to the wireless power transmitter 1110 in a first cycle (S1103). The charge state packet may include a charge state value. The charge state value may indicate the battery charge rate of the wireless power receiver. For example, the charge state value 0 means a completely discharged state, the charge state value 50 may mean a 50% charge state, and the charge state value 100 may mean a full charge state. If the wireless power receiving device does not include a rechargeable battery or can not provide charge state information, the charge state value may be set to OxFF. The first period may be a predetermined period. As an example, the first period may be 5 minutes. As another example, the first period may be 10 minutes.

The wireless power receiver 1120 may transmit the received power packet to the wireless power transmitter 1120 in a second period (S1104). The received power packet may include a received power value. For example, the received power value may correspond to the average rectifier received power value calculated by the wireless power receiver 1120 over a predetermined interval. The second period may be a preset period. In one example, the second period may be the same as the first period. As another example, the second period may be 5 minutes. As another example, the second period may be 10 minutes.

The wireless power transmitter 1110 may determine whether the wireless power receiver 1120 is in the first charging state (S1105). In one example, the wireless power transmitter 1110 may determine whether the wireless power receiver 1120 is in a first state of charge based on the received state of charge packets and received power packets. More specifically, the wireless power transmitter 1110 maintains or decreases the state of charge of a received state of charge packet for a predetermined time period, and if the received power value of the received power packet is less than a predetermined value, the wireless power receiver 1120 It is possible to determine the first state of charge. A detailed description thereof will be given in Fig. The wireless power transmitter 1110 may receive any packet containing battery temperature information from the wireless power receiver 1110 or any packet containing the status information of the wireless power receiver 1110 and transmit it to the wireless power receiver 1120 ) Is in the first charging state. In addition, the determination of the first state of charge of the wireless power receiver 1120 by the wireless power transmitter 1110 may be a determination that the wireless power transmitter 1110 senses the state of charge of the portable device.

The wireless power transmitter 1110 may suspend wireless charging if the wireless power receiver 1120 determines that it is in the first charging state (S1106). For example, the wireless power transmitter 1110 may efficiently perform battery cooling of the wireless power receiver 1120 during the first battery non-charging period T1 of FIG. 8 or the second battery non-charging period T2 of FIG. I will. In other words, it is not necessary to transmit the minimum amount of radio power for communication during the battery uncharged period of FIG. 8 and FIG. 9, so that the radio power receiver 1120 does not generate any more heat, and unnecessary power consumption is prevented .

After the wireless charging termination, the wireless power transmitter 1110 may send a digital ping to the wireless power receiver 1120 to identify if the WPC standard is a compatible wireless power receiver 1120 (S1107).

The wireless power receiver 1120 receiving the digital ping may determine whether wireless charging is restarted (S1108 or S1112). If the wireless power receiver 1120 determines not to perform wireless charging restart, it may transmit a first signal strength packet to maintain the wireless charging suspension (S1109). The wireless power receiver 1120 may transmit a second signal strength packet if it determines to perform wireless charging restart (S1113). The signal strength packet may include a signal strength value having a size of 1 byte. The signal strength packet may be a response signal to the ping. More specifically, the signal strength packet may comprise a first signal strength packet and a second signal strength packet. The first signal packet may comprise a first signal strength value. The first signal strength value may be a randomly set value. For example, the first signal strength value may be less than or equal to one. More specifically, the first signal strength value may be zero. The second signal strength packet may comprise a second signal strength value. The second signal strength value may be a value of degree of coupling between the transmitting coil and the receiving coil. The wireless charging restart determination may determine whether the wireless power receiver 1120 determines that the battery temperature is higher than a predetermined temperature after the wireless charging is interrupted. That is, it can be determined whether the battery temperature of the wireless power receiver 1120 has cooled sufficiently. Accordingly, since the battery temperature of the wireless power receiver 1120 is higher than the predetermined temperature, the wireless power receiver 1120 operates again in the first charging state after the wireless charging restart, and the wireless charging stop by the wireless power transmitter 1110 is stopped again . A detailed description of the wireless charging restart determination will be provided in FIG.

The wireless power transmitter 1110 may determine whether wireless charging is restarted based on the first signal strength packet or the second signal strength packet (S1110 or S1114). More specifically, when the wireless power transmitter 1110 receives the first signal strength packet, it may transmit the digital ping again after a predetermined period of time without restarting wireless charging (S1111). Wireless power transmitter 1110 may restart wireless charging upon receiving a second signal strength packet. The wireless charging restart of the wireless power transmitter 1110 will be described in detail with reference to FIG.

Upon transition to the power transfer phase with a wireless charge restart, the wireless power receiver 1120 may operate in a second charge state (S1115). The second charging state may be a state where the battery charging rate of the wireless power receiver 1120 is increasing. That is, the second charging state may be a state in which the battery temperature of the wireless power receiver 1120 is less than a predetermined temperature and the wireless power receiver 1120 is providing the received wireless power to the battery.

Therefore, the present invention can prevent the heat of the wireless rechargeable receiver. Further, the present invention can efficiently cool the wireless charging receiver. Further, the present invention can efficiently perform wireless charging. In addition, the present invention can prevent waste of power consumption due to wireless charging. The present invention also allows the wireless power transmitter to determine the state of charge of the wireless power receiver. In addition, the present invention enables the wireless power transmitter to actively control charging according to the state of charge of the wireless power receiver. In addition, the present invention can determine whether wireless charging restarts after stopping the wireless charging according to the charging control of the wireless power transmitter according to the charging state of the wireless power receiver.

12 is a diagram for explaining a wireless charging method in a wireless power transmitter in the power transmission step of FIG.

Referring to FIG. 12, a wireless charging method in a wireless power transmitter is performed in a power transmission step. Receiving the packet of the state of charge in the first period, and receiving the received power packet in the second period of time (S1201).

The wireless charging method in the wireless power transmitter may include determining whether the charge state value has increased (S1202). The wireless power transmitter may receive two or more charge state packets. The charge state values of the received two or more charge state packets may be the same and may increase or decrease. For example, the wireless power transmitter may receive the first state of charge packet and the second state of charge packet in order. If the state of charge of the second state of charge packet is greater than the state of charge of the first state of charge packet, it can be determined that the state of charge has increased. If the state of charge of the second state of charge packet is less than or equal to the state of charge of the first state of charge packet, it can be determined that the state of charge is not increased.

The wireless charging method in the wireless power transmitter may include determining whether the received power value is less than or equal to a predetermined power value if the charged state value has not increased (S1203). The predetermined power value may be a value set arbitrarily. In addition, the predetermined power value may be a minimum power intensity for the wireless power receiver to communicate with the wireless power transmitter. For example, the predetermined power value may be 3W. For example, if the charge state value does not increase and the received power value is less than the predetermined power value, it can be determined that the wireless power receiver is in the first charge state. The present invention is not limited thereto. As another example, the wireless power transmitter can determine whether the transmission power is equal to or lower than a certain transmission power value () when the charging state value increases. In another example, the configuration for receiving the received power packet in the second period in step S1201 may not be a mandatory configuration.

The wireless charging method in the wireless power transmitter can operate the timer when the received power value is less than the predetermined power value (S1204).

The wireless charging method in the wireless power transmitter can determine whether the timer operation time is equal to or longer than the first period (S1205). The first period may be an arbitrarily set period. Also, the first period may be the same as or longer than the period of the first period in which the charge state packet is transmitted. That is, the first period allows the wireless power transmitter to accurately determine whether the wireless power receiver is in the first charging state by accurately determining whether the charging state value is increased. More specifically, if the timer operation time is less than the first period, it is possible to repeatedly determine whether the charge state value increases in S1202 and whether the received power value in S1203 is less than or equal to a predetermined power value. If the charge state value does not increase and the received power value is maintained to be equal to or less than the predetermined power value, the timer operation step of S1204 may keep the timer operation and continuously count the timer operation time. When the charge state value increases or the received power value exceeds a predetermined power value, the timer operation time can be initialized (S1206). In this case, the timer operation time of step S1204 may start from zero.

If the timer operation time is equal to or longer than the first period, the wireless power transmitter can determine that the wireless power receiver is in the first charging state (S1207).

The wireless power transmitter may stop the wireless charging if it determines that the wireless power receiver is in the first charging state (S1208).

Thus, the present invention allows the wireless power transmitter to determine the state of charge of the wireless power receiver. In addition, the present invention enables the wireless power transmitter to actively control charging according to the state of charge of the wireless power receiver.

13 is a diagram for explaining a wireless charging method in the wireless power receiver of FIG.

Referring to FIG. 13, in the wireless charging method in the wireless power receiver, the battery temperature can be sensed in the power transmission step (S1301). In one example, the wireless power receiver may sense the battery temperature through the sensing portion. The present invention is not limited thereto, and as another example, the terminal can provide temperature information of the battery to the wireless power receiver.

The wireless charging method in the wireless power receiver may include determining whether the battery temperature of the wireless power receiver is above a predetermined temperature (S1302). The predetermined temperature can be arbitrarily set. Further, the predetermined temperature may be a temperature necessary for protecting the battery of the wireless power receiver. For example, the predetermined temperature may be 41 degrees or more. The wireless charging method in the wireless power receiver can repeat step S1301 if the battery temperature is not equal to or higher than the predetermined temperature.

The wireless charging method in the wireless power receiver may include operating in a first charging state if the battery temperature is above a predetermined temperature (S1303). The first state of charge may be a state where the charge rate of the battery of the wireless power receiver is maintained or reduced without increasing. More specifically, the first state of charge may be a state in which the battery temperature of the wireless power receiver is above a predetermined temperature such that the wireless power receiver does not provide the received wireless power to the battery. Also, in the first charging state, the wireless power receiver can only request the wireless power to transmit to the wireless power transmitter as the minimum power. The strength of the minimum power may be the power strength needed for the wireless power receiver to communicate with the wireless power transmitter. For example, the minimum power may be 3W. For example, the first charging state may be the first battery non-charging period T1 of FIG. 8, or may be the second battery non-charging period T1 of FIG. 9 as another example.

The wireless charging method in the wireless power receiver may include the step of stopping the wireless charging by the wireless power transmitter (S1304).

The wireless charging method in the wireless power receiver may include receiving the digital ping during the wireless charging interruption in S1304 (S1305).

In the wireless charging method in the wireless power receiver, in the step of pinging, the battery temperature can be sensed (S1306). In one example, the wireless power receiver may sense the battery temperature through the sensing portion. The present invention is not limited thereto, and as another example, the terminal can provide temperature information of the battery to the wireless power receiver. From step S1306, the wireless power re-start determination of the wireless power receiver 1120 of FIG. 11 may be included.

The wireless charging method in the wireless power receiver may include determining in step (S1307) whether the battery temperature of the wireless power receiver is above a predetermined temperature. The predetermined temperature can be arbitrarily set. Further, the predetermined temperature may be a temperature necessary for protecting the battery of the wireless power receiver. For example, the predetermined temperature may be 41 degrees or more.

The wireless charging method in the wireless power receiver may include transmitting a first signal strength packet if the battery temperature is above a predetermined temperature (S1308). That is, the wireless power receiver can transmit the first signal strength packet in response to the digital ping. The first signal strength packet may comprise a first signal strength value. In one example, the first signal strength value may be a value arbitrarily set to maintain the wireless charge interruption. That is, the wireless power receiver may intentionally set a value smaller than a signal strength value required for the wireless power transmitter to proceed with wireless charging to a signal strength value. As another example, the first signal strength value may be a predetermined value contracted to maintain a wireless charge break with the wireless power transmitter. More specifically, the first signal strength value may be less than or equal to one. More specifically, the first signal strength value may be zero.

The wireless charging method in the wireless power receiver may include maintaining a wireless charging disruption when transmitting the first signal strength packet (S1309). The wireless power receiver may then repeat the step of receiving the digital ping of S1305.

The wireless charging method in the wireless power receiver may include transmitting a second signal strength packet if the battery temperature is not greater than a predetermined temperature (S1310). That is, the wireless power receiver may transmit the second signal strength packet in response to the digital ping. The second signal strength packet may comprise a second signal strength value. The degree of coupling between the transmitting coil and the receiving coil, and may be a value calculated based on the rectifier output voltage in the digital ping section, the open circuit voltage measured in the output blocking switch, the strength of the received power, . The second signal strength value may range from a minimum of 0 to a maximum of 255, and may have a value of 255 if the actual measured value for a particular variable is equal to the maximum value of the variable (Umax). For example, the second signal strength value may be calculated as U / Umax * 256.

The wireless charging method in the wireless power receiver may include restarting the wireless charging when transmitting the second signal strength packet (S1311).

Accordingly, the present invention can determine whether wireless charging restarts after stopping the wireless charging according to the charging control of the wireless power transmitter according to the charging state of the wireless power receiver.

FIG. 14 is a diagram for explaining a wireless charging method in a wireless power transmitter in the step of FIG. 11; FIG.

Referring to FIG. 14, in the wireless charging method in the wireless power transmitter, the wireless power transmitter determines the first charging state in the power transmission step and stops wireless charging when it is determined that the first charging state (S1401 to S1402).

The wireless charging method in the wireless power transmitter may include a step of operating the timer when the wireless charging is interrupted (S1403).

The wireless charging method in the wireless power transmitter may include determining whether the timer operation time is equal to or greater than a second time period (S1404). The second period may be an arbitrarily set period. For example, the second period may be five minutes.

The wireless charging method in the wireless power transmitter may include transmitting the digital ping if the timer operation time is equal to or longer than the second period (S1405). That is, the wireless power transmitter may transmit a digital ping after a second period of time elapses after the wireless charge ceases. Thus, the wireless power transmitter may cool the battery of the wireless power receiver by preventing the wireless power receiver from generating heat in a sleep mode for a second period of time after the wireless charging ceases.

A wireless charging method at a wireless power transmitter may include receiving a signal strength packet in response to a digital ping transmission (S1406).

The wireless charging method in the wireless power transmitter may include determining whether the signal strength value of the signal strength packet is less than or equal to the first signal strength value (S1407). The first signal strength value may be a value arbitrarily set to maintain the wireless charge interruption. More specifically, the first signal strength value may be less than or equal to one. More specifically, the first signal strength value may be zero.

The wireless charging method in the wireless power transmitter may include initializing the timer operating time if the signal strength value is less than the first signal strength value (S1408). The wireless charging method in the wireless power transmitter can start the timer operation in S1403 again when the timer operation time is initialized. Thus, the wireless power transmitter continues to hold the wireless charge interruption so that the battery of the wireless power receiver can be cooled.

The wireless charging method in the wireless power transmitter may include restarting wireless charging if the signal strength value is not less than the first signal strength value (S1409).

Therefore, according to the present invention, whether or not the wireless charging is restarted after the wireless charging stop according to the charging control of the wireless power transmitter can be proceeded according to the charging state of the wireless power receiver.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

Claims (21)

A wireless charging method of a wireless power transmitter for wirelessly transmitting power to a wireless power receiver,
Receiving a state of charge packet in a first period in the wireless power transmitter and receiving a received power packet in a second period;
Determining whether the charge state value of the charge state packet increases;
Determining whether a received power value of the received power packet is less than or equal to a predetermined power value; And
And determining that the wireless power receiver is in a first charging state when the charging state value does not increase and the received power value is less than a predetermined power value. The method according to claim 1,
Wherein the first charging state of the wireless power receiver is such that the battery temperature of the wireless power receiver is above a predetermined temperature and the charging rate of the battery of the wireless power receiver is not increased. The method according to claim 1,
And stopping wireless charging if the wireless power receiver determines that the wireless power receiver is in the first charging state. The method according to claim 1,
Wherein the step of determining that the wireless power receiver is in the first charging state includes determining that the wireless power receiver is in the first charging state when the charging state value does not increase during the first period and the received power value is below a predetermined power value Wireless charging method. 5. The method of claim 4,
Further comprising: operating the timer if the charge state value does not increase and the received power value is less than or equal to a predetermined power value;
If the timer operation time is equal to or longer than the first period, the wireless power transmitter determines that the wireless power receiver is in the first charging state when the charging state value does not increase during the first period and the reception power value is less than a predetermined power value Wireless charging method. 5. The method of claim 4,
Wherein the first period is longer than the length of the first period. The method according to claim 1,
Wherein the predetermined power value is a minimum power level required for communication between the wireless power transmitter and the wireless power receiver. A wireless charging method of a wireless power receiver for receiving power wirelessly from a wireless power transmitter,
Determining in a power transmission step whether the battery of the wireless power receiver is above a predetermined temperature;
Operating the wireless power receiver to a first charge state if the battery is at or above a predetermined temperature;
Stopping the wireless charging by the wireless power transmitter when the wireless power transmitter determines the first charging state of the wireless power receiver;
Receiving a digital ping at the wireless power receiver;
Transmitting a first signal strength packet or a second signal strength packet according to the temperature of the battery upon receipt of the digital ping;
And maintaining the wireless charge interruption when transmitting the first signal strength packet. 9. The method of claim 8,
And determining if the battery of the wireless power receiver is above a predetermined temperature when the wireless power receiver receives the digital ping,
Wherein the wireless power receiver transmits a first signal strength packet if the temperature of the battery is greater than or equal to a predetermined temperature and transmits a second signal strength packet if the temperature of the battery is less than a predetermined temperature. 9. The method of claim 8,
And re-initiating wireless charging upon transmitting a second signal strength packet. 9. The method of claim 8,
Wherein the first signal strength packet has a signal strength value of zero. 12. The method of claim 11,
Wherein the second signal strength value of the second signal strength packet is a matching value between the transmit coil and the receive coil. 9. The method of claim 8,
Wherein the first charging state is a state in which the battery temperature of the wireless power receiver is higher than a predetermined temperature and the charging rate of the battery of the wireless power receiver is not increased. 9. The method of claim 8,
Wherein operating in the first charging state requires the wireless power transmitter to require a minimum power intensity required for communication. 15. The method of claim 14,
Wherein the wireless power transmitter transmits a control error packet to request the minimum power intensity. 9. The method of claim 8,
Wherein the predetermined temperature is 41 degrees or more. 9. The method of claim 8,
Sensing a battery temperature of the wireless power receiver in a power transmission step;
Sensing a battery temperature of the wireless power receiver in a step of sensing the battery temperature of the wireless power receiver. A wireless charging method of a wireless power transmitter for wirelessly transmitting power to a wireless power receiver,
In the power transmission step, when the wireless power receiver is determined as the first charging state, a wireless charging stop step;
Transmitting a digital ping;
Receiving a signal strength packet in response to the digital ping; And
And determining whether wireless charging is restarted according to the signal strength value of the signal strength packet. 19. The method of claim 18,
Wherein the first charging state of the wireless power receiver is such that the battery temperature of the wireless power receiver is above a predetermined temperature and the charging rate of the battery of the wireless power receiver is not increased. 19. The method of claim 18,
Operating the timer when the wireless charging is stopped in the power transmission step;
And determining whether the operation time of the timer is equal to or longer than a second period,
And transmitting the digital ping when the operation time of the timer is equal to or longer than the second period. 21. The method of claim 20,
And initializing the timer operation time if the signal strength value is less than the first signal strength value,
Wherein the step of determining whether to restart the wireless charging determines to restart wireless charging when the signal strength value exceeds the first signal strength value.

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