KR20180012962A - Wireless power transmission control method and apparatus using Near Field Communication - Google Patents

Abstract

The present invention relates to a wireless power transmission control apparatus and method using near field communication (NFC). A wireless power transmitter control method according to an embodiment of the present invention includes the steps of: transmitting a first NFC signal with driving power of a communication unit which a wireless power receiver includes; recognizing the wireless power receiver through a response signal to the first NFC signal; transmitting a second NFC signal for setting an NFC channel as a communication channel for wireless power transmission with the communication unit; and transmitting and receiving a state information signal related to wireless power transmission and reception through the set NFC channel. Accordingly, the present invention can reduce a setting time by using the NFC in comparison with paring.

Description

TECHNICAL FIELD [0001] The present invention relates to a wireless power transmission control method and apparatus using near field communication (NFC)

The present invention relates to wireless power transmission, and more particularly, to an apparatus and method for controlling a wireless power transceiver using near field communication (NFC).

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 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. It is expected to be equipped with charging function.

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 use various wireless power transmission standards based on an electromagnetic induction scheme in which a magnetic field is generated in a power transmission terminal coil and charged using an electromagnetic induction principle in which electricity is induced in a reception terminal coil due to the magnetic field . Here, the electromagnetic induction type wireless power transmission standard may include an electromagnetic induction wireless charging technique defined in a Wireless Power Consortium (WPC) or a Power Matters Alliance (PMA).

In another example, a wireless power transmission scheme may employ an electromagnetic resonance scheme in which a magnetic field generated by a transmission coil of a 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 Alliance for Wireless Power (A4WP) standard mechanism, a wireless charging technology standard mechanism.

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.

Meanwhile, the wireless power transceiver can use an out-of-band communication using a Bluetooth communication to control the wireless power transmission.

In this regard, Korean Patent Application No. 10-2013-7033209 (a receiver for wireless power reception and a wireless power receiving method thereof) has a coil for receiving power energy and a separate field communication (NFC) A receiver for a wireless charging system including a coil has been disclosed.

By using an antenna in which the NFC coil and the wireless power transmitting and receiving coil are integrally formed, it is possible to add or replace a method of detecting a wireless power receiver using NFC communication in addition to a method of detecting a wireless power receiver using Bluetooth communication. Also, NFC communication can be used for power transmission control as well as pairing between wireless power transceivers.

Therefore, there is a need for a method for detecting a wireless power receiver using NFC communication and a specific method for pairing with a detected wireless power receiver.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus and method for controlling a wireless power transmission using near field communication (NFC).

The present invention uses a NFC signal to search for a wireless power transceiver, thereby enabling wireless power transmission using short range communication (NFC communication) capable of transmitting power more quickly when Bluetooth communication is used only by NFC tagging between wireless power transceivers And to provide a control apparatus and method.

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 method of controlling a wireless power transmitter, including: receiving a first Near Field Communication (NFC) signal having a driving power of a communication unit included in a wireless power receiver; Transmitting; Recognizing the wireless power receiver through a response signal to the first short distance communication signal; Transmitting a second short-range communication signal for establishing a short-range communication (NFC) channel as a communication channel for wireless power transmission to the communication unit; And transmitting and receiving a status information signal related to the wireless power transmission / reception through the established short distance communication channel; . ≪ / RTI >

According to an embodiment, the first short-range communication signal may be a signal periodically searching for an NFC tag included in the wireless power receiver.

According to an embodiment, the communication unit includes: an NFC module that performs near field communication (NFC); And a Bluetooth module for performing Bluetooth communication; . ≪ / RTI >

Activating one of an NFC module performing NFC according to the strength of the second short distance communication signal and a Bluetooth module performing Bluetooth communication according to an embodiment; As shown in FIG.

According to an embodiment, the step of transmitting and receiving the status information signal may be performed at regular intervals.

Also, a method of controlling a wireless power receiver according to an embodiment of the present invention includes: transmitting a first Near Field Communication (NFC) signal for searching for a wireless power transmitter; Recognizing the wireless power transmitter through a response signal to the first local area communication signal; Transmitting a second short range communication signal for establishing a short range communication (NFC) channel as a communication channel for wireless power reception from the wireless power transmitter; And transmitting and receiving a status information signal related to the wireless power transmission / reception through the established short distance communication channel; . ≪ / RTI >

According to an embodiment, the first short distance communication signal may be a signal periodically searching for an NFC tag included in the wireless power transmitter.

Activating one of an NFC module performing NFC according to the strength of the second short distance communication signal and a Bluetooth module performing Bluetooth communication according to an embodiment; As shown in FIG.

According to an embodiment, the step of transmitting and receiving the status information signal may be performed at regular intervals.

According to the embodiment, the present invention can provide a computer-readable recording medium on which a program for executing the above-described method is recorded.

According to another aspect of the present invention, there is provided a wireless power transmitter including: a second communication unit for transmitting a first Near Field Communication (NFC) signal having a driving power of a first communication unit included in a wireless power receiver; And a transmitter controller for recognizing the wireless power receiver through a response signal to the first short distance communication signal; Wherein the second communication unit transmits a second short-range communication signal for establishing a short-range communication (NFC) channel as a communication channel for wireless power transmission to the first communication unit, It is possible to transmit and receive status information signals related to transmission and reception.

According to an embodiment, the first short-range communication signal may be a signal periodically searching for an NFC tag included in the wireless power receiver.

According to an embodiment, the second communication unit includes: an NFC module performing near field communication (NFC); And a Bluetooth module for performing Bluetooth communication; . ≪ / RTI >

According to the embodiment, the transmitter control unit may activate either the NFC module performing the NFC according to the strength of the second short distance communication signal or the Bluetooth module performing the Bluetooth communication.

According to the embodiment, the second communication unit can transmit / receive the status information at regular intervals.

According to an embodiment, an antenna in which an NFC coil and a transmission coil are integrally formed; As shown in FIG.

Also, a wireless power receiver according to an embodiment of the present invention includes: a communication unit for transmitting a first Near Field Communication (NFC) signal for searching for a wireless power transmitter; And a receiver controller for recognizing the wireless power transmitter through a response signal to the first short range communication signal; Wherein the communication unit transmits a second short-range communication signal for setting a short-range communication (NFC) channel as a communication channel for wireless power reception from the wireless power transmitter, And can transmit and receive an associated status information signal.

According to an embodiment, the first short distance communication signal may be a signal periodically searching for an NFC tag included in the wireless power transmitter.

According to the embodiment, the receiver control unit may activate either the NFC module performing the short-range communication (NFC) or the Bluetooth module performing the Bluetooth communication according to the strength of the second short distance communication signal.

According to the embodiment, the communication unit can transmit and receive the status information signal at regular intervals.

According to an embodiment, an antenna in which an NFC coil and a transmission coil are integrally formed; As shown in FIG.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And can be understood and understood.

Effects of the Near Field Communication (NFC) wireless power transmission control apparatus and method according to the present invention are as follows.

First, the present invention requires less setup time by using NFC communication than when pairing using Bluetooth communication.

Second, the present invention can detect a wireless power receiver using NFC communication in a harsh environment in which Bluetooth communication is performed.

Third, the present invention can transmit signals and information other than the standard for the wireless power transmission defined by a standard body by using NFC communication.

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 structure of a wireless power transmission system according to an embodiment of the present invention.
2 is an equivalent circuit diagram of a wireless power transmission system of an electromagnetic resonance method according to an embodiment of the present invention.
3 is a state transition diagram for explaining a state transition procedure in a wireless power transmitter of an electromagnetic resonance system according to an embodiment of the present invention.
4 is a state transition diagram of an electromagnetic resonance type wireless power receiver according to an embodiment of the present invention.
5 is a view for explaining an operation region of a wireless power receiver of an electromagnetic resonance type according to a VRECT according to an embodiment of the present invention.
6 is a flowchart illustrating a wireless charging procedure of an electromagnetic resonance method according to an embodiment of the present invention.
7 is a flowchart illustrating an operation of a wireless power transmitter and a wireless power receiver supporting a multimode wireless power transmission scheme according to an embodiment of the present invention.
8 is a diagram for explaining a local area communication (NFC) scheme according to an embodiment of the present invention.
9 is a diagram for explaining a method of searching for and recognizing a wireless power receiver serving as an NFC target when the wireless power transmitter according to an exemplary embodiment of the present invention performs an NFC initiator function.
10 is a diagram for explaining a method of searching for and recognizing a wireless power transmitter serving as an NFC target when the wireless power receiver performs an NFC initiator according to an embodiment of the present invention.
11 is a configuration diagram of a wireless power transmitter including an antenna in which an NFC coil and a wireless charging coil are integrally formed according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and various methods to which embodiments of the present invention 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.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. 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 can be stored in a computer-readable storage medium, readable and executed by a computer, thereby realizing an embodiment of the present invention. 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 present invention 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, Power may be transmitted to the device.

To this end, the wireless power transmitter may provide at least one wireless power transmission scheme, including, for example, an electromagnetic induction scheme, an electromagnetic resonance scheme, and the like.

For example, the wireless power transmission scheme may use various wireless power transmission standards based on an electromagnetic induction scheme in which a magnetic field is generated in a power transmission terminal coil and charged using an electromagnetic induction principle in which electricity is induced in a reception terminal coil due to the magnetic field . Here, the electromagnetic induction type wireless power transmission standard may include an electromagnetic induction wireless charging technique defined in a Wireless Power Consortium (WPC) or a Power Matters Alliance (PMA).

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

As another example, a wireless power transmission scheme may use an RF wireless power transmission scheme that transmits low power energy to an RF signal and transmits power to a remote wireless power receiver located at a remote location.

According to another embodiment of the present invention, the wireless power transmitter according to the present invention may be designed to support at least two or more wireless power transmission schemes among the electromagnetic induction method, the electromagnetic resonance method, and the RF wireless power transmission method.

In this case, the wireless power transmitter may adaptively transmit the wireless power transmission scheme to be used for the wireless power receiver based on the type, state, required power, etc. of the wireless power receiver as well as the wireless power transmission scheme supported by the wireless power transmitter and the wireless power receiver Can be determined.

In addition, the wireless power receiver according to an exemplary embodiment of the present invention may include at least one wireless power transmission scheme, and may simultaneously receive wireless power from two or more wireless power transmitters. Here, the wireless power transmission method may include at least one of the electromagnetic induction method, the electromagnetic resonance method, and the RF wireless power transmission method.

The terminal according to the present invention may be used in 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 the present invention, but not limited thereto, can be used for a small electronic device such as a toothbrush, an electronic tag, Quot;), and the term terminal or device may be used in combination. The wireless power receiver according to another embodiment of the present invention can also be mounted on a vehicle, an unmanned aerial vehicle, an air drone or the like.

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.

In one embodiment of the present invention, wireless communication between a wireless power transmission control device and a terminal (device) comprising a wireless power receiver includes a wireless communication channel for controlling power transmission between the wireless power transmitter and the wireless power receiver, , In-band (BLE) communication channel-can be used. In another example, if the wireless communication channel for controlling power transmission between the wireless power transmitter and the wireless power receiver is an out-of-band communication channel such as Bluetooth low energy (BLE) communication, The communication channel for identifying whether the receiver should activate the power transmitter may be a communication channel different from the out-of-band communication channel.

Hereinafter, the electromagnetic resonance method will be described with reference to FIG. 1 to FIG. 6, and the pairing method of the wireless power transceiver by the Bluetooth communication method (BLE) will be described with reference to FIG. The NFC communication method will be described with reference to FIG. Hereinafter, a method of mutually searching and recognizing wireless power transceivers using the NFC communication method will be described with reference to FIGS.

1 is a block diagram illustrating a structure of a wireless power transmission system according to an embodiment of the present invention.

Referring to FIG. 1, a wireless power transmission system may include a wireless power transmitter 100 and a wireless power receiver 200.

Although the wireless power transmitter 100 is shown in FIG. 1 as transmitting wireless power to one wireless power receiver 200, this is only one embodiment, and the wireless power 100 according to another embodiment of the present invention Transmitter 100 may also transmit wireless power to a plurality of wireless power receivers 200. It should be noted that the wireless power receiver 200 according to yet another embodiment may receive wireless power from a plurality of wireless power transmitters 100 simultaneously.

The wireless power transmitter 100 may generate a magnetic field using a specific power transmission frequency to transmit power to the wireless power receiver 200. [

The wireless power receiver 200 may receive power by tuning to the same frequency as that used by the wireless power transmitter 100. [

As an example, the frequency for power transmission may be, but is not limited to, the 6.78 MHz band.

That is, the power transmitted by the wireless power transmitter 100 may be communicated to the wireless power receiver 200 that is in resonance with the wireless power transmitter 100.

The maximum number of wireless power receivers 200 capable of receiving power from one wireless power transmitter 100 is determined by the maximum transmission power level of the wireless power transmitter 100, the maximum power reception level of the wireless power receiver 200, May be determined based on the physical structure of the power transmitter 100 and the wireless power receiver 200.

The wireless power transmitter 100 and the wireless power receiver 200 can perform bidirectional communication in a frequency band different from the frequency band for the wireless power transmission, i.e., the resonance frequency band. For example, the bi-directional communication may use at least one of half-duplex BLE (Bluetooth Low Energy) communication protocol and Near Field Communication (NFC).

The wireless power transmitter 100 and the wireless power receiver 200 may exchange each other's characteristics and status information, i.e., power negotiation information, via the two-way communication.

In one example, the wireless power receiver 200 may transmit certain power reception state information for controlling the power level received from the wireless power transmitter 100 to the wireless power transmitter 100 via bi-directional communication, 100 can dynamically control the transmission power level based on the received power reception state information. Accordingly, the wireless power transmitter 100 not only can optimize the power transmission efficiency, but also has a function of preventing a load breakage due to an over-voltage, a function of preventing unnecessary power from being wasted due to an under-voltage And the like can be provided.

The wireless power transmitter 100 also performs functions such as authenticating and identifying the wireless power receiver 200 through bidirectional communication, identifying incompatible devices or non-rechargeable objects, identifying a valid load, and the like You may.

Hereinafter, a wireless power transmission process in a resonance mode will be described in more detail with reference to FIG.

The wireless power transmitter 100 includes a power supplier 110, a power conversion unit 120, a matching circuit 130, a transmission resonator 140, a main controller 150, and a communication unit 160, as shown in FIG. The communication unit 160 may include a data transmitter and a data receiver.

The power supply unit 110 may supply a specific supply voltage to the power conversion unit 120 under the control of the main control unit 150. At this time, the supply voltage may be a DC voltage or an AC voltage.

The power conversion unit 210 may convert the voltage received from the power supply unit 110 to a specific voltage under the control of the main control unit 150. [ To this end, the power converter 210 may include at least one of a DC / DC converter, an AC / DC converter, and a power amplifier.

The matching circuit 130 is a circuit that matches impedances between the power conversion unit 210 and the transmission resonator 140 to maximize the power transmission efficiency.

The transmission resonator 140 may transmit power wirelessly using a specific resonance frequency according to the voltage applied from the matching circuit 130. [

The communication unit 160 can perform out-of-band communication with the communication unit 260 of the wireless power receiver as bi-directional half-duplex communication. In one embodiment, the communication unit 160 may include a Bluetooth Low Energy (BLE) module or a Near Field Communication (NFC) module according to a communication method.

The wireless power receiver 200 includes a reception resonator 210, a rectifier 220, a DC-DC converter 230, a load 240, a main controller 250 And a communication unit (260). The communication unit 260 may include a data transmitter and a data receiver.

The reception resonator 210 can receive the power transmitted by the transmission resonator 140 through the resonance phenomenon.

The rectifier 210 may perform a function of converting an AC voltage applied from the reception resonator 210 into a DC voltage.

The DC-DC converter 230 may convert the rectified DC voltage to a specific DC voltage required for the load 240.

The main control unit 250 controls the operation of the rectifier 220 and the DC-DC converter 230 or generates the characteristic and state information of the wireless power receiver 200 and controls the communication unit 260 to control the wireless power transmitter 100, And transmit the characteristics and state information of the wireless power receiver 200 to the wireless terminal. For example, the main control unit 250 may control the operation of the rectifier 220 and the DC-DC converter 230 by monitoring the output voltage and current intensity at the rectifier 220 and the DC-DC converter 230 have.

The monitored output voltage and current intensity information can be transmitted to the wireless power transmitter 100 through the communication unit 260 in real time.

In addition, the main control unit 250 compares the rectified DC voltage with a predetermined reference voltage to determine whether it is an over-voltage state or an under-voltage state, and when a system error state is detected The wireless power transmitter 100 may transmit the detection result to the wireless power transmitter 100 through the communication unit 260.

The main control unit 250 controls the operation of the rectifier 220 and the DC-DC converter 230 to prevent the load from being damaged when a system error condition is detected, or a predetermined overcurrent The power to be applied to the load 240 may be controlled by using a blocking circuit.

The communication unit 260 can perform out-of-band communication with the communication unit 160 of the wireless power transmitter and includes a Bluetooth Low Energy (BLE) module or a Near Field Communication (NFC) module according to a communication method. can do.

1, the main control units 150 and 250 and the communication units 160 and 260 are shown as being composed of different modules, but this is only one embodiment. In another embodiment of the present invention, 150, and 250 and the communication units 160 and 260 may be configured as a single module.

2 is an equivalent circuit diagram of a wireless power transmission system of an electromagnetic resonance method according to an embodiment of the present invention.

In detail, Fig. 2 shows the interface points on the equivalent circuit in which the reference parameters to be described later are measured.

Hereinafter, the meaning of the reference parameters shown in FIG. 2 will be briefly described.

I _TX and I _{TX _COIL} denote the RMS (Root Mean Square) current applied to the matching circuit (or matching network) 201 of the wireless power transmitter and the RMS current applied to the transmitting resonator coil 202 of the wireless power transmitter, respectively do.

Z and Z _{TX TX _IN _IN_COIL} means the input impedance at each of the matching circuit 201. The input impedance of the front end (Input Impedance) and the matching circuit 201 and the rear end transmission resonator coil 202 of the wireless power transmitter front end.

L1 and L2 denote the inductance value of the transmitting resonator coil 202 and the inductance value of the receiving resonator coil 203, respectively.

Z _{RX _IN} means the input impedance of the matching circuit 204 and the rear end filter / rectifier / load 205, the front end of the wireless power receiver.

The resonance frequency used in operation of the wireless power transmission system according to an embodiment of the present invention may be 6.78 MHz ± 15 kHz.

In addition, a wireless power transmission system according to an embodiment may provide simultaneous charging - i.e., multi-charging - for a plurality of wireless power receivers, in which case the remaining wireless power receivers Can be controlled so as not to exceed a predetermined reference value. For example, the received power variation may be +/- 10%, but is not limited thereto.

The condition for maintaining the received power variation should not overlap the existing wireless power receiver when the wireless power receiver is added to or removed from the charging area.

When the matching circuit 204 of the wireless power receiver is connected to a rectifier, the real part of the Z _{TX - - IN} may be inversely related to the load resistance of the rectifier - hereinafter referred to as R _RECT . That is, the increase of the R reduces _RECT Z _{TX _IN} and reduce the R _RECT can increase the Z _{TX _IN.}

The resonator coupling efficiency according to the present invention may be a maximum power reception ratio calculated by dividing the power transmitted from the receiving resonator coil to the load 204 by the power supplied to the resonant frequency band in the transmitting resonator coil 202 have. Resonator matching efficiency between the wireless power transmitter and wireless power receiver can be calculated if the reference port impedance (Z _{TX_IN)} and receiving a reference port impedance (Z _{_IN RX)} of the cavity resonator is a transmission that is perfectly matched.

Table 1 below shows examples of the minimum resonator matching efficiency according to the class of the wireless power transmitter and the class of the wireless power receiver according to an embodiment of the present invention.

If a plurality of wireless power receivers are used, the minimum resonator matching efficiency corresponding to the classes and categories shown in Table 1 may increase.

3 is a state transition diagram for explaining a state transition procedure in a wireless power transmitter of an electromagnetic resonance system according to an embodiment of the present invention.

Referring to FIG. 3, the state of a wireless power transmitter is divided into a configuration state 310, a power save state 320, a low power state 330, a power transfer state 330, , 340, a Local Fault State 350, and a Latching Fault State 360.

When power is applied to the wireless power transmitter, the wireless power transmitter may transition to the configuration state 310. [ The wireless power transmitter may transition to a power saving state 320 when a predetermined reset timer expires in the configuration state 310 or the initialization procedure is completed.

In the power saving state 320, the wireless power transmitter may generate a beacon sequence and transmit it via the resonant frequency band.

Here, the wireless power transmitter may control the beacon sequence to be initiated within a predetermined time after entering the power saving state 320. For example, the wireless power transmitter may control, but is not limited to, initiating the beacon sequence within 50 ms of the power saving state 320 transition.

In the power saving state 320, the wireless power transmitter periodically generates and transmits a first beacon sequence for sensing a wireless power receiver, and detects a change in impedance of the reception resonator, that is, a load variation . Hereinafter, for convenience of explanation, the first beacon and the first beacon sequence will be referred to as Short Beacon and Short Beacon sequences, respectively.

In particular, Short Beacon sequences are generated repeatedly with a short period (t _{SHORT _BEACON)} a predetermined time interval (t _CYCLE) to be a standby power of the wireless transmitter power saving until the wireless power receiver detection may be transmitted. For example, t _{SHORT _BEACON} is less than 30ms, t _CYCLE can be respectively set to 250ms ± 5 ms. Also, the current intensity of the short beacon is not less than a predetermined reference value, and can be gradually increased for a predetermined time period. In one example, the minimum current intensity of the Short Beacon may be set high enough such that the category 2 or higher wireless power receiver of Table 2 can be detected.

The wireless power transmitter according to the present invention may be provided with a sensing means for sensing reactance and resistance change in the reception resonator according to the short beacon.

Also, in the power saving state 320, the wireless power transmitter may periodically generate and transmit a second beacon sequence to provide sufficient power for the booting and response of the wireless power receiver. Hereinafter, for convenience of explanation, the second beacon and the second beacon sequence will be referred to as Long Beacon and Long Beacon sequences, respectively.

That is, the wireless power receiver may broadcast a predetermined response signal over the out-of-band communication channel when booting is completed via the second beacon sequence.

In particular, Long Beacon sequences are generated at a predetermined time interval (t _{LONG _BEACON_PERIOD)} while for a relatively long period (t _{LONG_BEACON)} than the Short Beacon be sent in order to provide sufficient power required by the boot of the wireless power receiver. For example, t _{LONG _BEACON} can be set to 105 ms + 5 ms, and t _{LONG _BEACON_PERIOD} can be set to ₈₅₀ ms, respectively. The current intensity of the long beacon can be relatively strong compared to the current intensity of the short beacon. In addition, the long beacon can maintain the power of a constant intensity during the transmission interval.

Thereafter, the wireless power transmitter may wait for the reception of a predetermined response signal during the long beacon transmission interval after the impedance change of the reception resonator is detected. Hereinafter, for convenience of explanation, the response signal will be referred to as an advertisement signal. Here, the wireless power receiver may broadcast an advertisement signal over an out-of-band communication frequency band that is different from the resonant frequency band.

In one example, the advertisement signal includes message identification information for identifying a message defined in the out-of-band communication standard, a unique service for identifying whether the wireless power receiver is legitimate or compatible with the wireless power transmitter, Information on the output power of the wireless power receiver, information on the rated voltage / current applied to the load, information on the antenna gain of the wireless power receiver, information on identifying the category of the wireless power receiver, wireless power receiver authentication information, Information about whether or not the wireless power receiver is installed, and software version information mounted on the wireless power receiver.

The wireless power transmitter may establish an out-of-band communication link with the wireless power receiver after transitioning from a power saving state 320 to a low power state 330 upon receipt of an advertisement signal. Subsequently, the wireless power transmitter may perform the registration procedure for the wireless power receiver over the established out-of-band communication link. For example, if out-of-band communication is a Bluetooth low-power communication, the wireless power transmitter may perform Bluetooth pairing with the wireless power receiver and exchange at least one of the status information, characteristic information, and control information of each other via the paired Bluetooth link have.

When the wireless power transmitter transmits to the wireless power receiver a predetermined control signal for initiating charging via out-of-band communication in the low power state 330 (i.e., a predetermined control signal requesting the wireless power receiver to transmit power to the load) , The state of the wireless power transmitter may transition from the low power state 330 to the power transfer state 340. [

If the out-of-band communication link establishment procedure or registration procedure in the low power state 330 is not completed normally, the state of the wireless power transmitter may transition from the low power state 330 to the power saving state 320. [

The wireless power transmitter may be driven with a separate Link Expiration Timer for connection to each wireless power receiver and the wireless power receiver may transmit a predetermined message indicating that it is present in the wireless power transmitter at a predetermined time period Should be sent before the link expiration timer expires. The link expiration timer is reset each time the message is received, and the out-of-band communication link established between the wireless power receiver and the wireless power receiver may be maintained if the link expiration timer does not expire.

If all the link expiration timers corresponding to the out-of-band communication link established between the wireless power transmitter and the at least one wireless power receiver have expired in the low power state 330 or the power transfer state 340, The power saving state 320 may be transited.

In addition, the wireless power transmitter in the low power state 330 may drive a predetermined registration timer when a valid advertisement signal is received from the wireless power receiver. At this time, if the registration timer expires, the wireless power transmitter in the low power state 330 may transition to the power saving state 320. At this time, the wireless power transmitter may output a predetermined notification signal notifying the registration failure through a notification display means provided in the wireless power transmitter, for example, an LED lamp, a display screen, a beeper, have.

Further, in the power transfer state 340, the wireless power transmitter may transition to the low power state 330 upon completion of charging all connected wireless power receivers.

In particular, the wireless power receiver may allow registration of a new wireless power receiver in states other than the configuration state 310, the local failure state 350, and the lock failure state 360.

In addition, the wireless power transmitter may dynamically control the transmit power based on state information received from the wireless power receiver in the power transfer state 340. [

At this time, the receiver status information transmitted from the wireless power receiver to the wireless power transmitter may include information on required power information, voltage and / or current information measured at the rear end of the rectifier, charge status information, overcurrent and / or overvoltage and / Information indicating whether or not the means for interrupting or reducing the electric power delivered to the load in accordance with the information, the overcurrent, or the overvoltage is activated. At this time, the receiver status information may be transmitted at a predetermined period or transmitted every time a specific event is generated. In addition, the means for interrupting or reducing the electric power delivered to the load in accordance with the overcurrent or overvoltage may be provided using at least one of an ON / OFF switch and a zener diode.

The receiver status information transmitted from the wireless power receiver to the wireless power transmitter according to another embodiment of the present invention includes information indicating that the external power is connected to the wireless power receiver by wire, information indicating that the out-of-band communication method is changed, And may be changed from NFC (Near Field Communication) to BLE (Bluetooth Low Energy) communication.

In accordance with another embodiment of the present invention, a wireless power transmitter is configured to determine a power intensity to be received by a wireless power receiver based on at least one of the currently available power, the priority of each wireless power receiver, May be adaptively determined. Here, the power intensity for each wireless power receiver can be determined as to how much power should be received at a ratio of the maximum power that can be processed by the rectifier of the corresponding wireless power receiver.

The wireless power transmitter may then send a predetermined power control command to the wireless power receiver that includes information regarding the determined power strength. At this time, the wireless power receiver can determine whether power control is possible with the power intensity determined by the wireless power transmitter, and transmit the determination result to the wireless power transmitter through the predetermined power control response message.

The wireless power receiver according to another embodiment of the present invention may transmit predetermined receiver state information indicating whether wireless power control is possible according to a power control command of the wireless power transmitter before receiving the power control command.

The power transmission state 340 may be in any one of a first state 341, a second state 342 and a third state 343 depending on the power reception state of the connected wireless power receiver.

In one example, the first state 341 may indicate that the power reception state of all wireless power receivers connected to the wireless power transmitter is in a normal voltage state.

The second state 342 may mean that there is no wireless power receiver in which the power reception state of at least one wireless power receiver connected to the wireless power transmitter is in a low voltage state and in a high voltage state.

The third state 343 may mean that the power reception state of at least one wireless power receiver connected to the wireless power transmitter is in a high voltage state.

The wireless power transmitter may transition to the lock fault condition 360 if a system error is detected in the power saving state 320 or the low power state 330 or the power transmission state 340

The wireless power transmitter of the lock fault condition 360 may transition to either a configuration state 310 or a power saving state 320 if all connected wireless power receivers are determined to have been removed from the charging area.

In addition, in the lock fault condition 360, the wireless power transmitter may transition to the local fault condition 350 if a local fault is detected. Here, the wireless power transmitter, which is the local fault condition 350, may transition back to the lock fault condition 360 once the local fault is released.

On the other hand, when transitioning from a state of either configuration state 310, power saving state 320, low power state 330, or power transfer state 340 to local fault state 350, If it is released, it may transition to the configuration state 310.

The wireless power transmitter may shut off the power supplied to the wireless power transmitter if it transitions to the local failure state 350. [ For example, the wireless power transmitter may transition to a local fault condition 350 when a fault such as overvoltage, overcurrent, or overtemperature is detected, but is not limited thereto.

For example, the wireless power transmitter may transmit a predetermined power control command to the connected at least one wireless power receiver to reduce the strength of the power received by the wireless power receiver, if an over-current, over-voltage,

In another example, the wireless power transmitter may send a predetermined control command to the connected at least one wireless power receiver to stop the charging of the wireless power receiver if an overcurrent, overvoltage, overheating, or the like is sensed.

Through the above-described power control procedure, the wireless power transmitter can prevent the device from being damaged due to overvoltage, overcurrent, overheat or the like.

The wireless power transmitter may transition to the lock fault condition 360 if the intensity of the output current of the transmit resonator is above a reference value. At this time, the wireless power transmitter which has transitioned to the lock failure state 360 may attempt to make the intensity of the output current of the transmission resonator less than the reference value for a predetermined time. Here, the attempt may be repeated for a predetermined number of times. If the lock failure state 360 is not released despite repeated execution, the wireless power transmitter transmits a predetermined notification signal to the user indicating that the lock failure state 360 is not released using a predetermined notification means can do. At this time, if all of the wireless power receivers located in the charging area of the wireless power transmitter are removed from the charging area by the user, the locking failure state 360 may be released.

On the other hand, if the intensity of the output current of the transmission resonator falls below the reference value within a predetermined time, or if the intensity of the output current of the transmission resonator falls below the reference value during the predetermined repetition, the lock failure state 360 is automatically canceled Where the state of the wireless power transmitter may automatically transition from the lockout state 360 to the power saving state 320 to perform the detection and identification procedure again for the wireless power receiver.

The wireless power transmitter in the power transfer state 340 can transmit continuous power and adaptively control the transmit power based on the state information of the wireless power receiver and the predefined optimal voltage region setting parameters have.

For example, the Optimal Voltage Region setting parameter may include at least one of a parameter for identifying the low voltage region, a parameter for identifying the optimum voltage region, a parameter for identifying the high voltage region, and a parameter for identifying the overvoltage region .

The wireless power transmitter can increase the transmission power if the power reception state of the wireless power receiver is in the low voltage region, and reduce the transmission power if it is in the high voltage region.

The wireless power transmitter may also control the transmit power to maximize the power transmission efficiency.

The wireless power transmitter may also control the transmit power so that the deviation of the amount of power required by the wireless power receiver is below a reference value.

The wireless power transmitter may also stop transmitting power when the rectifier output voltage of the wireless power receiver reaches a predetermined overvoltage range-that is, when Over Voltage is detected.

4 is a state transition diagram of an electromagnetic resonance type wireless power receiver according to an embodiment of the present invention.

4, the state of the wireless power receiver is largely divided into a disable state 410, a boot state 420, an enable state 430 (or an On state), and a system error state System Error State, 440).

At this time, the state of the wireless power receiver can be determined based on the intensity of the output voltage at the rectifier end of the wireless power receiver - hereinafter referred to as V _RECT for convenience of explanation.

The activation state 430 may be divided into an optimum voltage state 431, a low voltage state 432, and a high voltage state 433 depending on the value of V _RECT .

The wireless power receiver in the deactivation state 410 may transition to the boot state 420 if the measured V _RECT value is greater than or equal to the predefined V _{RECT_BOOT} value.

In the boot state 420, the wireless power receiver establishes an out-of-band communication link with the wireless power transmitter and transmits a V _RECT And wait until the value reaches the required power at the lower end.

The wireless power receiver in the boot state 420 is a V _RECT When it is confirmed that the required power at the lower end has been reached, the charging state can be shifted to the activated state 430 to start charging.

The wireless power receiver in the active state 430 may transition to the boot state 420 if it is confirmed that charging is complete or charging is interrupted.

In addition, the wireless power receiver in the active state 430 may transition to a system error state 440 if a certain system error is detected. Here, system faults may include overvoltage, overcurrent, and overheating, as well as other predefined system fault conditions.

In addition, the wireless power receiver in the active state 430 is a V _RECT If the value falls below the V _{RECT _BOOT} value, it may transition to the inactive state 410.

The wireless power receiver of the boot state 420 or system failure condition 440 may be shifted to, disable state (410) falls below a value V _RECT V _{RECT _BOOT} value.

Hereinafter, the state transition of the wireless power receiver within the active state 430 will be described in detail with reference to FIG. 5, which will be described later.

5 is a view for explaining an operation region of a wireless power receiver of an electromagnetic resonance type according to a VRECT according to an embodiment of the present invention.

Referring to Figure 5, the V _RECT value is smaller than a predetermined V _{RECT _ BOOT,} the wireless power receiver is held in the inactive state (410).

When Thereafter, V _RECT value is increased above V _{RECT _BOOT,} the wireless power receiver and changes to the boot state 420, it is possible to broadcast the advertisement signal within the prescribed time. Thereafter, if the ad signal is detected by the wireless power transmitter, the wireless power transmitter may transmit a predetermined connection request signal for setting the out-of-band communication link to the wireless power receiver.

The wireless power receiver is normally set to communicate the out-of-band link, if a successful registration, V _RECT value of the minimum output voltage of the rectifier for a normal charge-to below, for convenience of explanation V _{RECT _ MIN} as business card is reached You can wait until.

When V _RECT value exceeds V _{RECT _MIN,} status of the wireless power receiver and transitions to the active state 430, the boot state 420 may begin charging the load.

If, when the value V _RECT in active state (430) exceeds the predetermined threshold value of V _{RECT _MAX} for determining an over-voltage, the wireless power receiver is in the active state 430 may transition to a system error condition (440).

5, the activation state 530 is classified into a low voltage state 532, an optimum voltage state 531, and a high voltage state 533 according to the value of V _RECT . .

Low voltage 532 _{V RECT _BOOT <= V RECT <} = V RECT _ means the _MIN state, and the optimum voltage state 531 means a state of V _{RECT _MIN} <V _RECT <= V _{RECT _ HIGH,} a high voltage state 533 may indicate the state _{RECT_HIGH} V <V _RECT <= V _{RECT _ MAX.}

In particular, the wireless power receiver transited to the high voltage state 533 may suspend the operation of shutting off the power supplied to the load for a predetermined time - called a high voltage state holding time for convenience of explanation. At this time, the high-voltage state holding time can be predetermined so as to prevent damage to the wireless power receiver and the load in the high-voltage state (533).

If the wireless power receiver transitions to the system error state 540, it may transmit a predetermined message indicating the occurrence of an overvoltage to the wireless power transmitter over an out-of-band communication link within a predetermined time.

 The wireless power receiver may also control the voltage applied to the load using overvoltage shutdown means provided to prevent damage to the load due to the overvoltage in the system fault state 530. [ Here, an ON / OFF switch and / or a zener diode may be used as the overvoltage shutoff means.

Although a method and means for responding to a system error in a wireless power receiver have been described in the above embodiment when an overvoltage is generated in a wireless power receiver and transition to a system error state 540 is made, Other embodiments may also transition to a system fault state by overheating, overcurrent, and the like in the wireless power receiver.

As an example, if the system transitions to a system fault state due to overheating, the wireless power receiver may send a message to the wireless power transmitter indicating the occurrence of overheating. At this time, the wireless power receiver may drive a cooling fan or the like to reduce internally generated heat.

A wireless power receiver according to another embodiment of the present invention may receive wireless power in cooperation with a plurality of wireless power transmitters. In this case, the wireless power receiver may transition to a system error state 540 if it is determined that the wireless power transmitter that is determined to receive the actual wireless power is different from the wireless power transmitter where the actual out-of-band communication link is established.

Hereinafter, the signaling procedure between the wireless power transmitter and the wireless power receiver according to the present invention will be described in detail with reference to the following drawings.

6 is a flowchart illustrating a wireless charging procedure of an electromagnetic resonance method according to an embodiment of the present invention.

Referring to FIG. 6, the wireless power transmitter can generate a beacon sequence and transmit the beacon sequence through a transmission resonator when the wireless power transmitter is configured according to power application, that is, when booting is completed (S601).

When the beacon sequence is detected, the wireless power receiver may broadcast an advertisement signal including its identification information and characteristic information (S603). It should be noted that the advertisement signal may be repeatedly transmitted at predetermined intervals until a connection request signal, which will be described later, is received from the wireless power transmitter.

When the wireless power transmitter receives the advertisement signal, it may transmit a predetermined connection request signal to the wireless power receiver to establish an out-of-band communication link (S605).

Upon receipt of the connection request signal, the wireless power receiver may establish an out-of-band communication link and transmit its static status information over the established out-of-band communication link (S607).

Here, the static state information of the wireless power receiver includes category information, hardware and software version information, maximum rectifier output power information, initial reference parameter information for power control, information on demand voltage or power, Information about a supportable out-of-band communication method, information about a supportable power control algorithm, and preferred rectifier voltage value information initially set in the wireless power receiver.

The wireless power transmitter may transmit the static state information of the wireless power transmitter to the wireless power receiver via the out-of-band communication link when the static state information of the wireless power receiver is received (S609).

Here, the static state information of the wireless power transmitter includes at least one of transmitter power information, class information, hardware and software version information, information on the maximum number of supportable wireless power receivers, and / or information on the number of currently connected wireless power receivers And may be configured to include one.

Thereafter, the wireless power receiver monitors its own real-time power receiving state and charging state, and may transmit dynamic state information to the wireless power transmitter at a periodic or specific event occurrence (S611).

Here, the dynamic state information of the wireless power receiver includes information on the rectifier output voltage and current, information on the voltage and current applied to the load, information on the internal measured temperature of the wireless power receiver, reference parameter change information A rectified voltage minimum value, a rectified voltage maximum value, and an initially set preferred rectifier terminal voltage change value), charging state information, system error information, and alarm information. The wireless power transmitter may perform power adjustment by changing a set value included in the existing static state information when receiving the reference parameter change information for the power control.

In addition, the wireless power transmitter may send a predetermined control command over the out-of-band communication link to control the wireless power receiver to start charging when sufficient power is available to charge the wireless power receiver (S613).

The wireless power transmitter may then receive dynamic state information from the wireless power receiver and dynamically control the transmit power (S615).

The wireless power receiver may also transmit to the wireless power transmitter data to identify the system error in the dynamic state information and / or data indicating that charging is complete if an internal system error is detected or the charging is completed S617). Here, the system error may include overcurrent, overvoltage, overheating, and the like.

The wireless power transmitter according to another embodiment of the present invention redistributes the power to be transmitted to each wireless power receiver when it can not meet the required power of all the wireless power receivers to which the available power is connected, To the corresponding wireless power receiver.

In addition, if a new wireless power receiver is registered during wireless charging, the wireless power transmitter redistributes the power to be received per connected wireless power receiver based on the current available power and transmits it to the corresponding wireless power receiver through a predetermined control command It is possible.

In addition, the wireless power transmitter may be configured such that when the charging of an existing connected wireless power receiver during wireless charging is completed or the out-of-band communication link is released-for example, when the wireless power receiver is removed from the charging area- It may redistribute the power to be received by the wireless power receiver and transmit it to the corresponding wireless power receiver through a predetermined control command.

In addition, the wireless power transmitter may determine whether the wireless power receiver is equipped with a power control function through a predetermined control procedure. In this case, the wireless power transmitter may perform the power redistribution only for the wireless power receiver equipped with the power control function when the power redistribution condition occurs.

In one example, the power redistribution situation may include receiving a valid advertisement signal from an unconnected wireless power receiver to receive a dynamic parameter indicating a new wireless power receiver's current state or the like of a connected wireless power receiver, This can occur if an event such as no longer exists or an already connected wireless power receiver has been charged, or an alert message is received indicating a system error condition of the connected wireless power receiver have.

Here, the system error state may include an overvoltage state, an overcurrent state, an overheated state, a network connection state, and the like.

In one example, the wireless power transmitter may transmit power redistribution related information to a wireless power receiver via a predetermined control command.

Here, the power redistribution related information includes a wireless power transmitter command for power control,

As an example, the wireless power transmitter can determine whether a new wireless power receiver is registered and can provide the amount of power required by the wireless power receiver based on its available power. As a result of the determination, if the requested amount of power exceeds the amount of available power, the wireless power transmitter can confirm whether or not the power control function is mounted on the corresponding wireless power receiver. As a result, if the power control function is implemented, the wireless power receiver may determine the amount of power that the wireless power receiver will receive within the available power amount and transmit the determined result to the wireless power receiver through a predetermined control command.

Of course, the power redistribution may be performed within a range in which the wireless power transmitter and the wireless power receiver can operate normally and / or within a range in which normal charging is possible.

A wireless power receiver according to another embodiment of the present invention can support a plurality of out-of-band communication methods. If the currently set out-of-band communication link is to be changed in a different manner, the wireless power receiver may send a predetermined control signal to the wireless power transmitter requesting an out-of-band communication change. When the out-of-band communication change request signal is received, the wireless power transmitter can release the currently set out-of-band communication link and establish a new out-of-band communication link in the out-of-band communication mode requested by the wireless power receiver.

For example, the out-of-band communication method applicable to the present invention includes NFC (Near Field Communication) communication, RFID (Radio Frequency Identification) communication, BLE (Bluetooth Low Energy) communication, WCDMA (Wideband Code Division Multiple Access) Term Evolution / LTE-Advance communication, and Wi-Fi communication.

7 is a flowchart illustrating operations of a wireless power transmitter and a wireless power receiver according to an embodiment of the present invention.

Referring to FIG. 7, when power is applied to the wireless power transmitter 700 (S701), the wireless power transmitter 700 can enter a configuration state (S702).

Thereafter, the wireless power transmitter 700 may enter a power save state in a configuration state (S703).

In the power saving state, the wireless power transmitter 700 can apply each type of different power beacons for detection in each cycle. The beacon is a signal using Bluetooth low energy (hereinafter referred to as "BLE ") technology. For example, the wireless power transmitter 700 may apply a power beacon for detection (e.g., a short beacon or a long beacon) (S704, S705) The magnitude of the power value of each of the beacons may be different.

Some or all of the power beacons for detection may have an amount of power capable of driving the communication portion of the wireless power receiver 750. [ For example, the wireless power receiver 750 can communicate with the wireless power transmitter 700 by driving a communication unit by some or all of the power beacons for detection. At this time, the state may be referred to as a null state (S706).

The wireless power transmitter 700 may detect a load change due to the placement of the wireless power receiver 750 and may enter a Low Power state after detecting a load change at step S708.

Meanwhile, the wireless power receiver 750 can drive the communication unit based on the power received from the wireless power transmitter 700 (S709). The wireless power receiver 750 may transmit a wireless power transmitter search (PTU searching) signal to the wireless power transmitter 700 (S710).

The wireless power receiver 750 may transmit a BLE-based Advertisement (AD) signal as a signal to search for a wireless power transmitter. The wireless power receiver 750 may periodically transmit a wireless power transmitter search signal and may receive a response signal from the wireless power transmitter 700 or transmit it until a predetermined time has elapsed.

Also, according to an embodiment of the present invention, the wireless power receiver 750 detects the identification information of the wireless power transmitter 700 included in the beacon signal transmitted from the wireless power transmitter 700, Information may be included in the advertisement signal and transmitted.

When a wireless power transmitter search signal is received from the wireless power receiver 750, the wireless power transmitter 700 may transmit a response signal (PRU Response) signal (S711). Where the response signal may form a connection between the wireless power transmitter 700 and the wireless power receiver 750. [

After the connection between the wireless power transmitter 700 and the wireless power receiver 750 is established, the wireless power receiver 750 may transmit the PRU static signal (S712). Here, the PRU static signal may be a signal indicating the status of the wireless power receiver 750 and may request a subscription to the wireless power network controlled by the wireless power transmitter 400.

The wireless power transmitter 700 may transmit the PTU static signal (S713). The PTU static signal transmitted by the wireless power transmitter 700 may be a signal indicating the capability of the wireless power transmitter 700.

When the wireless power transmitter 700 and the wireless power receiver 750 transmit and receive the PRU static signal and the PTU static signal, the wireless power receiver 750 may periodically transmit the PRU dynamic signal (S714, S715) .

The PRU dynamic signal may include at least one parameter information measured at the wireless power receiver 750. For example, the PRU dynamic signal may include voltage information at the rear end of the rectifying section of the wireless power receiver 750. The state of this wireless power receiver 750 may be referred to as a boot state (S707).

The wireless power transmitter 700 enters a power transfer state at step S716 and the wireless power transmitter 700 transmits a PRU control PRU control, which is a command signal to cause the wireless power receiver 750 to perform charging, The signal can be transmitted (S717). In the power transmission state, the wireless power transmitter 700 can transmit the charging power.

The PRU control signal transmitted by the wireless power transmitter 700 may include information enabling and disabling charging of the wireless power receiver 750 and permission information. The PRU control signal can be transmitted whenever the state of charge is changed. The PRU control signal may be transmitted, for example, every 250 ms, or may be transmitted when there is a parameter change. The PRU control signal may be set to be transmitted within a predetermined threshold time, for example, one second, even if the parameter is not changed.

The wireless power receiver 750 may transmit a wireless power receiver dynamic (PRU Dynamic) signal to change settings according to the PRU control signal and report the status of the wireless power receiver 750 (S718, S719 ).

The PRU dynamic signal transmitted by the wireless power receiver 750 may include at least one of voltage, current, state of the wireless power receiver 750, and temperature information. The state of the wireless power receiver 750 may be referred to as an On state (S720). On the other hand, the PRU dynamic signal can have a data structure as shown in Table 2 below.

Referring to Table 2, the PRU dynamic signal may include at least one field. The voltage information at the rear end of the rectifying section of the radio power receiver 750, the current information at the rear end of the rectifying section of the radio power receiver 750, the voltage at the rear end of the DC / DC converter 750 of the radio power receiver 750, Temperature information, the minimum voltage value information (VRECT_MIN_DYN) at the rear end of the rectifying section of the wireless power receiver 750, the current information of the rear end of the DC / DC converter of the wireless power receiver 750, The maximum voltage value information VRECT_HIGH_DYN at the rear end of the rectifying section of the wireless power receiver 750 and the warning information PRU alert may be set. The PRU dynamic signal may include at least one of the above fields.

For example, at least one voltage set value (e.g., minimum voltage value information (VRECT_MIN_DYN) at the rear end of the rectifying section of the wireless power receiver 750), the optimum value of the rear end of the rectifying section of the wireless power receiver 750 Voltage value information (VRECT_SET_DYN), maximum voltage value information (VRECT_HIGH_DYN) at the rear end of the rectifying section of the wireless power receiver, etc.) in the corresponding field of the PRU dynamic signal. In this manner, the wireless power transmitter 700 receiving the PRU dynamic signal can adjust the wireless charging voltage to be transmitted to each wireless power receiver 750 by referring to the voltage setting values included in the PRU dynamic signal.

Among them, the warning information (PRU Alert) can be formed with a data structure as shown in Table 3 below.

Referring to Table 3, the warning information includes overvoltage, overcurrent, over temperature, wireless power receiver 750 PRU Self Protection, charge complete A Wired Charge Detect, a wireless power receiver 750 PRU Charge Port, and an Adjust Power Response.

Meanwhile, the wireless power receiver 750 may sense an error occurrence. The wireless power receiver 750 may send an alert signal to the wireless power transmitter 700 (S721). The warning signal can be transmitted as a PRU Dynamic (PRU Dynamic) signal or as an alert signal. For example, the wireless power receiver 750 may reflect the error condition in the PRU alert field of Table 5 and transmit it to the wireless power transmitter 700. Or wireless power receiver 750 may send a single alert signal to wireless power transmitter 700 indicating an error condition. When the wireless power transmitter 700 receives the warning signal, it may enter the Latch Fault mode (S722). The wireless power receiver 750 may enter the null state (S723).

8 is a diagram for explaining a local area communication (NFC) scheme according to an embodiment of the present invention.

Referring to FIG. 8, each of the NFC devices performing the Peer to Peer (P2P) mode can serve as an NFC initiator and an NFC target.

NFC communication uses a frequency band of 13.56 MHz and is a kind of RFID technology capable of fast bidirectional communication between NFC devices. In one embodiment, the NFC communication is a short-range wireless communication technology to be. NFC communication can support transmission and reception of data in both directions within a distance of 10cm or less.

In the case of the electromagnetic induction method, it is preferable to use NFC communication for the radio power transmission by the electromagnetic resonance method among the wireless power transmission systems considering the very small point between the wireless power transceivers and the distance between the wireless power transceivers.

With NFC communication, power transmission can be performed only by tagging (identification at close range) between wireless power transceivers.

NFC communication can be classified into a card mode, an RFID reader mode, and a P2P mode according to an operation mode. NFC communication can provide a variety of mobile payment methods such as traffic card and discount coupons with the contactless smart card technology and security in the card mode. In addition, in the RFID reader mode, a web site connection using an RFID tag- And information can be acquired. In the P2P mode, which is a bidirectional communication mode, each of the NFC devices can operate to mutually exchange data and share files.

Each NFC device can perform bidirectional information exchange in P2P mode. In P2P mode, the Logical Link Control Protocol (LLCP) is typically used to build data links and perform activation, deactivation, and management operations.

NFC communication is accomplished by NFC devices with embedded NFC tags. In detail, NFC communication is performed by generating a current due to electromagnetic induction phenomenon while a magnetic field change occurs between the first NFC device including the NFC tag and the NFC coil antenna and the NFC coil antenna included in the second NFC device. That is, a magnetic field change occurs between the NFC coil antennas, and a current is generated by the electromagnetic induction phenomenon, and communication between devices is performed by using this current.

NFC communication can be distinguished into an active mode for reader and reader communication and a passive mode for reader and tag communication.

In the active mode, an NFC initiator 810 serving as a reader and an NFC target 820 serving as a tag can be classified according to roles.

The NFC initiator 810 may provide a carrier field to the NFC target 820 and the NFC target 820 may respond by modulating the current electromagnetic field. The NFC target 820 is also referred to as a radio transponder since it operates by being powered by an electromagnetic field provided by the NFC initiator 810. That is, the NFC initiator 810 can selectively transmit the NFC signal having the driving power of the NFC target 820. [ The NFC initiator 810 and the NFC target 820 serve both as a power supply and selectively generate an electric field for communication. Either the NFC initiator 810 and the NFC target 820 can operate as an NFC target 820 by deactivating the high frequency electromagnetic field when receiving data.

The NFC initiator 810 retrieves the surrounding RF field signal, and transmits the RF field signal if not detected (S830).

The NFC initiator 810 transmits an initial command signal at a specific frequency (S850). The NFC target 820 receiving the initial command signal digitally processes the initial command signal and transmits a response signal at the same frequency (S870).

Since the NFC initiator 810 and the NFC target 820 are classified according to their roles in signal transmission and reception, the wireless power transceiver plays the role of the NFC initiator 810 and the NFC target 820 according to the situation of receiving the initial command signal. .

In other words, depending on the situation, the wireless power transmitter may act as the NFC initiator 810 and the wireless power receiver may serve as the NFC target 820. Conversely, a wireless power receiver may act as an NFC initiator 810, and a wireless power transmitter may serve as an NFC target 820.

9 is a diagram for explaining a method of searching for and recognizing a wireless power receiver serving as an NFC target when the wireless power transmitter according to an exemplary embodiment of the present invention performs an NFC initiator function.

9, the wireless power transmitter may include a controller 910 and an NFC module 920, and the wireless power receiver may also include a controller 930 and an NFC module 940.

The control unit 910 of the wireless power transmitter performs overall control for power transmission to the wireless power receiver and controls the NFC module 920 to search for a wireless power receiver and transmits a control signal .

Although not shown in FIG. 9, the controller 910 of the wireless power transmitter can control a Bluetooth module that performs Bluetooth communication (BLE communication) together with a wireless power receiver, and can control at least either BLE communication or NFC communication It is possible to transmit / receive the control signal using one.

For example, in a situation where the beacon signal intensity according to the BLE communication is less than a predetermined magnitude, the Bluetooth module is deactivated for searching by the NFC communication, the NFC module is activated, and the searching and authentication process of the wireless power receiver by the NFC module is performed .

The controller 910 of the wireless power transmitter may set the connection parameters to the NFC module 920 before starting the search for the wireless power receiver (S901).

The connection parameter may include identification information for identifying the wireless power transmitter and the wireless power receiver is a wireless power transmitter that is qualified to form an NFC communication channel for wireless power transmission through connection parameters received from the wireless power transmitter Can be determined.

In this determination, the NFC module 920 may be based on a Logic Link Control Protocol (LLCP). The LLCP defines a specific method for differently reading or writing data in the NFC module 92.

In one example, the wireless power receiver can determine whether the wireless power transmission standard that the wireless power transmitter can support via the connection parameters of the wireless power transmitter in advance is the A4WP standard, prior to establishing a communication session for wireless power transmission.

The control unit 910 may instruct the NFC module 920 to search the wireless power receiver while setting connection parameters (S902).

The NFC module 920, which has been instructed to search for a wireless power receiver from the controller 910, searches for an RF field signal at a low level (low power level). The wireless power transmitter, as an NFC initiator, may periodically transmit a signal to locate a wireless power receiver as an NFC target (S905).

The NFC module 920 of the wireless power transmitter may selectively transmit a seek signal having power to drive the NFC module 930 of the wireless power receiver to the signal for search.

In the case of the A4WP standard using BLE communication, it transmits the driving power by the beacon signal to cause the wireless power receiver to generate the advertisement signal. In other words, in the case of the A4WP standard, transmission and reception processes of the power transfer signal and the advertisement signal are required. However, when the NFC communication is used, the power for driving the NFC module 930 of the wireless power receiver is transmitted The wireless power receiver can be searched more quickly in the process of identifying.

The NFC module 920 can detect the proximity of the wireless power receiver as an NFC target using as little power as possible. Specifically, the detection of the NFC target can be accomplished by comparing the oscillator frequency with a known reference frequency.

For example, a calibrated low power oscillator (LPO) may be used to monitor the frequency oscillations associated with the NFC antenna and then determine whether the frequency of oscillations from the reference frequency is greater than the frequency deviation threshold .

As another example, if at least one of the current or voltage derived from the NFC antenna exceeds a predetermined value, another NFC device can be detected.

At this time, when the wireless power receiver is positioned within a certain distance (for example, 10 cm) from the wireless power transmitter, a search is made by receiving a response signal for the signal from the wireless power receiver.

Meanwhile, the control unit 940 of the wireless power receiver can set connection configuration parameters in the NFC module 930 (S903).

The connection configuration parameter may include identification information for identifying the wireless power receiver and the wireless power transmitter may determine whether it is a wireless power receiver that is eligible to receive the wireless power transmission through the connection configuration parameters.

The control unit 940 sets the connection configuration parameters and can instruct the NFC module 930 to search for the wireless power transmitter (S904).

When the wireless power transmitter searches for a wireless power receiver, it may generate a connection activation signal including connection parameter information that can identify the wireless power transmitter (S906).

The wireless power transmitter transmits the generated connection activation signal to the NFC module 930 of the wireless power receiver (S907). Upon receiving the connection activation signal, the NFC module 930 transmits the connection configuration parameter information May be generated (S908).

The NFC module 930 transmits a response signal corresponding to the connection activation signal to the NFC module 920 of the wireless power transmitter 920. The NFC module 920 transmits the connection configuration parameters of the detected wireless power receiver to the controller 910 (S930).

The controller 910 of the wireless power transmitter may terminate the process of identifying and recognizing the wireless power receiver by receiving the connection configuration parameters.

The NFC module 930 of the wireless power receiver transmits a response signal to the wireless power transmitter, and then transmits the connection parameter of the wireless power transmitter detected by the controller 940 (S911).

The controller 940 of the wireless power receiver may identify the wireless power transmitter and terminate the search and recognition process through the connection parameters of the wireless power transmitter.

The wireless power transceiver may then periodically transmit and receive each state information using the formed NFC communication channel.

Here, the state information may include, but is not limited to, rectifier output voltage intensity information, and intensity information of a voltage applied to the load. The fault / alarm condition information may include, but is not limited to, overvoltage / overcurrent detection information, overheat information, timer expiration information, and charge completion information.

In one embodiment, each of the wireless power transceivers may receive respective identification information or status information over an NFC communication channel. The identification information of the wireless power transceiver may be standard information related to the standards (e.g., WPC, PMA, A4WP, and Airfuel) of the wireless power transmission that the wireless power transceiver may support.

The wireless power transceiver can transmit and receive the mounting position and type information of the transmitting coil on the wireless power transmitter, and / or the mounting position and type information of the receiving coil on the wireless power receiver, in addition to the signals defined by the standard body using BLE communication. Each of the wireless power transceivers can use this information to identify the alignment state of the transmit coil and the receive coil, and output the information on the identified alignment state on the display screen.

For example, the wireless power transceiver can send / receive a signal instructing to change the position of a transmission / reception coil (antenna) for sorting to increase / decrease the charging efficiency, .

Also, the wireless power transceiver according to an exemplary embodiment of the present invention may calculate the current charging efficiency based on the received power receiving state information, and the information on the calculated charging efficiency may be transmitted through the NFC communication.

10 is a diagram for explaining a method of searching for and recognizing a wireless power transmitter serving as an NFC target when the wireless power receiver performs an NFC initiator according to an embodiment of the present invention.

10, the wireless power receiver may include a controller 1010 and an NFC module 1020, and the wireless power transmitter may include a controller 1030 and an NFC module 1040. [

The controller 1010 of the wireless power receiver may control the NFC module 920 to search for a wireless power receiver and transmit control signals for the detected wireless power receiver and power transmission.

The controller 1010 of the wireless power receiver may set the connection parameters to the NFC module 1020 before starting the search for the wireless power transmitter (S1001).

The connection parameter may include identification information for identifying the wireless power receiver and the wireless power transmitter may be a wireless power receiver that is qualified to form a communication channel for wireless power transmission via connection parameters received from the wireless power receiver Can be determined.

The control unit 1010 can instruct the NFC module 1020 to search for the wireless power transmitter while setting connection parameters (S1002).

The NFC module 1020, which is instructed by the controller 1010 to search for a wireless power transmitter, searches for an RF field signal at a low level (low power level). As opposed to FIG. 9, the wireless power receiver is an NFC initiator and can periodically transmit a signal to look for a wireless power transmitter as an NFC target.

At this time, if the wireless power transmitter is located within a certain distance (for example, 10 cm) from the wireless power receiver, a search is made by receiving a response signal to the wireless power transmitter from the wireless power transmitter (S1005).

Meanwhile, the controller 1040 of the wireless power transmitter can set connection configuration parameters in the NFC module 1030 (S1003). The connection configuration parameters may include identification information for identifying the wireless power transmitter.

The control unit 1040 sets connection configuration parameters and can instruct the NFC module 1030 to search for a wireless power receiver (S1004).

When the wireless power receiver searches for a wireless power transmitter, it may generate a connection activation signal including connection parameter information that can identify the wireless power receiver (S1006).

The wireless power receiver transmits the generated connection activation signal to the NFC module 1030 of the wireless power transmitter (S1007). Upon receiving the connection activation signal, the NFC module 1030 transmits the connection configuration parameter information (S1008). &Lt; / RTI &gt;

The NFC module 1030 transmits a response signal corresponding to the connection activation signal to the NFC module 1020 of the wireless power receiver 1020 and the NFC module 1020 transmits the connection configuration parameters of the detected wireless power transmitter to the controller 1010 (S1030).

The controller 1010 of the wireless power receiver may terminate the process of identifying and recognizing the wireless power transmitter by receiving the connection configuration parameters.

The NFC module 1030 of the wireless power transmitter may transmit the response signal to the wireless power receiver and then forward the connection parameter of the wireless power receiver detected by the controller 1040 (S1011).

The controller 1040 of the wireless power transmitter may identify the wireless power receiver through the connection parameters of the wireless power receiver and terminate the search and recognition process.

The wireless power transceiver can then transmit and receive the respective state information using the formed NFC communication channel.

11 is a configuration diagram of a wireless power transmitter including an antenna in which an NFC coil and a wireless charging coil are integrally formed according to an embodiment of the present invention.

11, the wireless power transmitter includes a communication unit 120 including a controller 1110, an NFC module 1121, and a Bluetooth module 1122, and a wireless charging coil 1131 and an NFC coil 1132 formed integrally with each other And an antenna 1132. The components shown in Fig. 11 are not essential, and a wireless power transmitter having components with more or fewer components may be implemented. A wireless power receiver paired with a wireless power transmitter according to an embodiment of the present invention may have a similar structure.

Hereinafter, the components will be described in detail.

The controller 1110 may control the overall operation of the power transmission of the wireless power transmitter. The standard information to which the wireless power transmitter is applied before the search for the wireless power receiver and authentication and identification information according to the standard information may be transmitted to the communication unit 1120 so as to be controlled to be modulated to a specific frequency.

The communication unit 1120 may include an NFC module 1121 capable of performing NFC communication and a Bluetooth module 1122 capable of performing BLE communication.

The communication unit 1120 can activate one of the NFC module 1121 and the Bluetooth module 1122 and deactivate the other according to the strength of a signal received from the NFC module 1121 and the Bluetooth module 1122. [

The antenna 1132 may have the form of an integral coil including an antenna 1131 for transmitting power energy and an NFC antenna 1132 provided separately at the outer periphery of the antenna. A wireless power transmitter may use an integral coil to control pairing between wireless power transceivers for wireless power transmission.

The wireless power transmitter may include a controller 1110 that controls an antenna 1131 for wireless power transmission and an antenna 1132 that performs NFC communication.

In one embodiment, the controller 1110 may time-share the wireless power signal and the short-range wireless communication signal for wireless power transmission to the wireless power receiver.

An error may occur in the signal due to the magnetic field generated from the antenna 1131 for wireless power transmission and the magnetic field generated from the antenna 1132 performing NFC communication. Therefore, the controller 1110 time- .

The method according to the above-described embodiments may be implemented as a program to be executed by a computer and stored in a computer-readable recording medium. Examples of the computer-readable recording medium include a ROM, a RAM, a CD- , A floppy disk, an optical data storage device, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet).

The computer readable recording medium may be distributed over a networked computer system so that computer readable code can be stored and executed in a distributed manner. And, functional program, code, and code segments for implementing the above-described method can be easily inferred by programmers in the technical field to which the embodiment belongs.

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)

Transmitting a first Near Field Communication (NFC) signal having a driving power of a communication unit included in the wireless power receiver;
Recognizing the wireless power receiver through a response signal to the first short distance communication signal;
Transmitting a second short-range communication signal for establishing a short-range communication (NFC) channel as a communication channel for wireless power transmission to the communication unit; And
Transmitting and receiving a status information signal related to wireless power transmission / reception through the established short-range communication channel;
/ RTI &gt;
A method for controlling a wireless power transmitter. The method according to claim 1,
Wherein the first short-range communication signal is a signal for periodically searching for an NFC tag included in the wireless power receiver,
A method for controlling a wireless power transmitter. The method according to claim 1,
Wherein,
An NFC module performing near field communication (NFC); And
A Bluetooth module for performing Bluetooth communication;
/ RTI &gt;
A method for controlling a wireless power transmitter. The method according to claim 1,
Activating one of an NFC module performing NFC and a Bluetooth module performing Bluetooth communication according to the strength of the second short distance communication signal;
&Lt; / RTI &gt;
A method for controlling a wireless power transmitter. The method according to claim 1,
The transmitting and receiving of the status information signal comprises:
Which is performed every predetermined cycle,
A method for controlling a wireless power transmitter. Transmitting a first Near Field Communication (NFC) signal for searching for a wireless power transmitter;
Recognizing the wireless power transmitter through a response signal to the first local area communication signal;
Transmitting a second short range communication signal for establishing a short range communication (NFC) channel as a communication channel for wireless power reception from the wireless power transmitter; And
Transmitting and receiving a status information signal related to wireless power transmission / reception through the established short-range communication channel;
/ RTI &gt;
A method of controlling a wireless power receiver. The method according to claim 6,
Wherein the first short distance communication signal is a signal for periodically searching for an NFC tag included in the wireless power transmitter,
A method of controlling a wireless power receiver. The method according to claim 6,
Activating one of an NFC module performing NFC and a Bluetooth module performing Bluetooth communication according to the strength of the second short distance communication signal;
&Lt; / RTI &gt;
A method of controlling a wireless power receiver. The method according to claim 6,
The transmitting and receiving of the status information signal comprises:
Which is performed every predetermined cycle,
A method of controlling a wireless power receiver. A computer-readable recording medium storing a program for executing the method according to any one of claims 1 to 9. A second communication unit for transmitting a first near field communication (NFC) signal having a driving power of a first communication unit included in the wireless power receiver; And
A transmitter controller for recognizing the wireless power receiver through a response signal to the first local area communication signal;
/ RTI &gt;
The second communication unit transmits a second short-range communication signal for setting a short-range communication (NFC) channel as a communication channel for wireless power transmission to the first communication unit, and transmits a second short- An information signal transmitting /
Wireless power transmitter. 12. The method of claim 11,
Wherein the first short-range communication signal is a signal for periodically searching for an NFC tag included in the wireless power receiver,
Wireless power transmitter. 12. The method of claim 11,
Wherein the second communication unit comprises:
An NFC module performing near field communication (NFC); And
A Bluetooth module for performing Bluetooth communication;
/ RTI &gt;
Wireless power transmitter. 12. The method of claim 11,
The transmitter control unit,
An NFC module for performing NFC according to the strength of the second short distance communication signal, and a Bluetooth module for performing Bluetooth communication,
Wireless power transmitter. 12. The method of claim 11,
Wherein the second communication unit comprises:
And transmitting and receiving the status information at regular intervals,
Wireless power transmitter. 12. The method of claim 11,
An antenna in which an NFC coil and a transmission coil are integrally formed;
&Lt; / RTI &gt;
Wireless power transmitter. A communication unit for transmitting a first Near Field Communication (NFC) signal for searching for a wireless power transmitter; And
A receiver controller for recognizing the wireless power transmitter through a response signal to the first short distance communication signal;
/ RTI &gt;
The communication unit transmits a second short-range communication signal for setting a short-range communication (NFC) channel as a communication channel for wireless power reception from the wireless power transmitter, and transmits a second short- Lt; / RTI &gt;
Wireless power receiver. 18. The method of claim 17,
Wherein the first short distance communication signal is a signal for periodically searching for an NFC tag included in the wireless power transmitter,
Wireless power receiver. 18. The method of claim 17,
The receiver control unit,
An NFC module for performing NFC according to the strength of the second short distance communication signal, and a Bluetooth module for performing Bluetooth communication,
Wireless power receiver. 18. The method of claim 17,
Wherein,
And transmits and receives the status information signal at regular intervals,
Wireless power receiver. 18. The method of claim 17,
An antenna in which an NFC coil and a transmission coil are integrally formed;
&Lt; / RTI &gt;
Wireless power receiver.

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