KR20180062653A - Wireless charging method and apparatus using near field communication - Google Patents

Abstract

The present invention relates to wireless power transmitting methods using near-field wireless communication, and an apparatus therefor. According to an embodiment of the present invention, the wireless power transmitting method in a wireless power transmitting apparatus having a near-field wireless communication function, comprises the steps of: transmitting a first signal using a first resonance circuit for near-field wireless communication when power is applied; sensing an object on the basis of a variation of current flowing through the first resonance circuit; and stopping the transmission of the first signal and transmitting a second signal using a second resonance circuit for wireless power transmission, when a response signal corresponding to the first signal is not received for a predetermined time after the object is sensed. Therefore, standby power consumption and EMI generation can be minimized.

Description

TECHNICAL FIELD [0001] The present invention relates to a wireless charging method and apparatus using short-range wireless communication,

The present invention relates to a wireless charging technique, and more particularly, to a wireless power transmission method and apparatus capable of sensing an object through short-range wireless communication and performing wireless charging in a device equipped with a near field wireless communication and a wireless charging function .

The wireless power transmission technology (wireless power transmission or wireless energy transfer) is a technology to transmit electric energy from the transmitter to the receiver wirelessly using the induction principle of the magnetic field. In the 1800s, electric motor or transformer And thereafter, a method of radiating electromagnetic waves such as radio waves, lasers, high frequencies, and microwaves to transfer electrical energy has also been attempted. Our electric toothbrushes and some wireless shavers are actually charged with electromagnetic induction.

Up to the present, energy transmission using radio may be roughly classified into a magnetic induction method, an electromagnetic resonance method, and an RF transmission method using a short wavelength radio frequency.

In the magnetic induction method, when two coils are adjacent to each other and a current is supplied to one coil, a magnetic flux generated at this time causes an electromotive force to the other coils. As a technology, . The magnetic induction method has the disadvantage that it can transmit power of up to several hundred kilowatts (kW) and the efficiency is high, but the maximum transmission distance is 1 centimeter (cm) or less, so it is usually adjacent to the charger or the floor.

The self-resonance method is characterized by using an electric field or a magnetic field instead of using electromagnetic waves or currents. The self-resonance method is advantageous in that it is safe to other electronic devices or human body since it is hardly influenced by the electromagnetic wave problem. On the other hand, it can be used only at a limited distance and space, and has a disadvantage that energy transfer efficiency is somewhat low.

Short wavelength wireless power transmission - simply, RF transmission - takes advantage of the fact that energy can be transmitted and received directly in radio wave form. This technology is a RF power transmission system using a rectenna. Rectena is a combination of an antenna and a rectifier, which means a device that converts RF power directly into direct current power. That is, the RF method is a technique of converting an AC radio wave into DC and using it. Recently, as the efficiency has improved, commercialization has been actively researched.

Wireless power transmission technology can be applied not only to mobile but also to various industries such as car, IT, railway, and household appliance industries.

In a wireless charging system, a wireless power transmitter transmits a specific pattern of wireless power signals at regular intervals to sense an object placed in a charging area.

However, the transmission of the sensing signal causes a large amount of standby power consumption of the wireless power transmitter, and an overheating phenomenon may occur when foreign matter is disposed in the charging region.

It is an object of the present invention to provide a wireless power transmission method using near field wireless communication and an apparatus therefor, in order to minimize standby power consumption.

In addition, the present invention provides a wireless power transmission method and apparatus using NFC tagging capable of minimizing EMI (Electro Magnetic Interference) occurrence.

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.

The present invention can provide wireless power transmission methods using near field wireless communication and an apparatus therefor.

A wireless power transmission method in a wireless power transmission apparatus equipped with a short-range wireless communication function according to an embodiment of the present invention includes transmitting a first signal using a first resonance circuit for short- The method of claim 1, further comprising the steps of: sensing an object based on a change in a current flowing through the first resonant circuit; and detecting, when the response signal corresponding to the first signal is not received for a predetermined time after the object is sensed, And transmitting the second signal using a second resonant circuit for wireless power transmission.

Here, the power consumption during a unit time may be smaller than the second signal.

In addition, the near field communication may be NFC (Near Field Communication).

Also, the first signal may be an NFC command signal.

In addition, the first resonant circuit includes a resistance element, and when the amount of change in the current flowing through the resistance element exceeds a predetermined reference value, it can be determined that the conductive object is sensed.

In addition, the second signal may be a predetermined sensing signal for identifying a wireless power receiver capable of charging.

Here, the sensing signal may be any one of a digital ping and a long beacon.

In addition, when a response signal corresponding to the second signal is received, the sensed object is determined to be a wireless power receiver, and charging to the determined wireless power receiver can be started.

If the response signal corresponding to the second signal is not received, the sensed object is determined not to be a wireless power receiver, and the first signal can be transmitted using the first resonant circuit.

A method of wireless power transmission in a wireless power transmission apparatus equipped with an NFC (Near Field Communication) function according to another embodiment of the present invention includes the steps of entering an NFC mode upon power application and using a first resonance circuit for NFC communication 1 signal, detecting an object on the basis of a change amount of a current flowing in the first resonance circuit, and detecting an object when a predetermined response signal corresponding to the first signal is not received for a predetermined time Stopping transmission of the first signal and switching to a wireless charging mode, and transmitting a second signal using a second resonant circuit for wireless power transmission.

The wireless power transmission apparatus according to another embodiment of the present invention includes a first resonance circuit for short-range wireless communication, a current sensor for measuring a change amount of a current flowing in the first resonance circuit, Wherein the control unit controls the first resonance circuit to transmit the first signal through the first resonance circuit, and when the amount of change of the measured current exceeds a predetermined reference value, A second resonant circuit for wireless power transmission and a control signal for switching to the wireless charging mode are received, the second signal is transmitted through the second resonant circuit And a second control circuit.

Here, the power consumption during a unit time may be smaller than the second signal.

In addition, the near field communication may be NFC (Near Field Communication).

At this time, the first signal may be an NFC command signal.

The first resonance circuit includes a resistance element. When the amount of change of the current flowing through the resistance element exceeds a predetermined reference value, the first control circuit determines that the conductive object is sensed, And can receive the corresponding response signal.

In addition, the second signal may be a predetermined sensing signal for identifying a wireless power receiver capable of charging. Here, the sensing signal may be any one of a digital ping and a long beacon.

Also, when a predetermined response signal corresponding to the second signal is received, the second control circuit determines that the sensed object is a wireless power receiver, and uses the second resonant circuit to determine Can start to charge.

On the other hand, if the response signal corresponding to the second signal is not received, the second control circuit determines that the sensed object is not a wireless power receiver, and the first signal is transmitted through the first resonant circuit So that a predetermined control signal can be transmitted to the first control circuit.

A wireless power transmission apparatus according to another embodiment of the present invention includes a resonant circuit assembly including a first resonant circuit for short-range wireless communication and a second resonant circuit for wireless power transmission, and a processor assembly including at least one processor And at least one memory for storing a program to be loaded and executed by the at least one processor, wherein when the processor assembly is powered on, the first signal is transmitted using the first resonant circuit, If an object disposed in the charging region is sensed based on a change amount of the current flowing through the first resonance circuit and a response signal corresponding to the first signal is not normally received, the transmission of the first signal is stopped, So that the second signal is transmitted through the second antenna.

According to another embodiment of the present invention, a program for realizing the wireless power transmission method and a computer-readable recording medium on which the program is recorded may be provided.

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 method and apparatus according to the present invention will be described as follows.

An advantage of the present invention is to provide a wireless power transmission method using near field wireless communication and an apparatus therefor, which can minimize standby power consumption.

In addition, the present invention has an advantage of providing a wireless power transmission method and apparatus using NFC tagging capable of minimizing EMI (Electro Magnetic Interference) occurrence.

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

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. It is to be understood, however, that the technical features of the present invention are not limited to the specific drawings, and the features disclosed in the drawings may be combined with each other to constitute a new embodiment.
1 is a block diagram illustrating a wireless charging system according to an embodiment of the present invention.
2 is a block diagram illustrating a wireless charging system according to another embodiment of the present invention.
3 is a diagram for explaining a sensing signal transmission procedure in a wireless charging system according to an embodiment of the present invention.
4 is a state transition diagram for explaining a wireless power transmission procedure according to an embodiment of the present invention.
5 is a state transition diagram for explaining a wireless power transmission procedure according to another embodiment of the present invention.
6 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment of the present invention.
7 is a block diagram illustrating a structure of a wireless power receiver interworking with the wireless power transmitter according to the FIG.
8 is a diagram for explaining a modulation and demodulation method of a wireless power signal according to an embodiment of the present invention.
9 is a diagram for explaining a packet structure according to an embodiment of the present invention.
10 is a view for explaining the types of packets transmitted from a wireless power receiver to a wireless power transmitter according to an embodiment of the present invention.
11 is a block diagram for explaining a wireless power transmission apparatus equipped with an NFC function according to an embodiment of the present invention.
12 is a diagram illustrating a structure of an antenna module mounted in a wireless power transmission apparatus according to an embodiment of the present invention.
13 is a diagram for explaining a circuit configuration of a wireless power transmission apparatus using NFC tagging according to an embodiment of the present invention.
FIG. 14 is a flowchart illustrating a wireless power transmission method using NFC tagging according to an embodiment of the present invention. Referring to FIG.
15 is a state transition diagram for explaining a mode switching procedure of a wireless power transmission apparatus according to an embodiment of the present invention.
16 is a block diagram illustrating a configuration of a wireless power transmission apparatus according to another 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.

In the description of the embodiment, in the case where it is described as being formed "above" or "below" each element, the upper or lower (lower) And that at least one further component is formed and arranged between the two components. Also, in the case of "upper (upper) or lower (lower)", it may include not only the upward direction but also the downward direction based on one component.

In the description of the embodiments, an apparatus for transmitting wireless power on a wireless power 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, and the like are used in combination. Also, for the sake of convenience of explanation, it is to be understood that a wireless power receiving apparatus, a wireless power receiving apparatus, a wireless power receiving apparatus, a wireless power receiving apparatus, a receiving terminal, a receiving side, a receiving apparatus, Etc. may be used in combination.

The transmitter according to the present invention may be configured as a pad, a cradle, an access point (AP), a small base station, a stand, a ceiling, a floor, And may transmit wireless power to the power receiving device. To this end, the transmitter may comprise at least one radio power transmission means. Here, the radio power transmission means may be various non-electric power transmission standards based on an electromagnetic induction system in which a magnetic field is generated in a power transmitting terminal coil and charged using an electromagnetic induction principle in which electricity is induced in a receiving terminal coil under the influence of the magnetic field. For example, the wireless power transmission means may include an electromagnetic induction wireless charging technique as defined in a wireless charging technology standards organization such as Wireless Power Consortium (WPC), Power Matters Alliance (PMA), and the like.

Also, a receiver according to an embodiment of the present invention may include at least one wireless power receiving means and may receive wireless power from two or more transmitters at the same time. Here, the wireless power receiving means may include, but is not limited to, an electromagnetic induction wireless charging technique defined by Wireless Power Consortium (WPC), Power Matters Alliance (PMA), which is a wireless charging technology standard mechanism.

A wireless power receiver according to the present invention may be mounted on one side of a transportation device, but is not limited thereto, and may be a device equipped with wireless power receiving means according to the present invention to charge a battery.

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

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

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

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

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

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

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

The wireless power receiving terminal 20 according to an embodiment of the present invention may acquire various status information of the electronic device 30. [ For example, the status information of the electronic device 30 may include current power usage information, information for identifying a running application, CPU usage information, battery charge status information, battery output voltage / current information, And is information obtainable from the electronic device 30 and available for wireless power control.

In particular, the wireless power transmitting terminal 10 according to an embodiment of the present invention can transmit a predetermined packet indicating whether or not to support fast charging to the wireless power receiving terminal 20. The wireless power receiving terminal 20 can inform the electronic device 30 of the connected wireless power transmitting terminal 10 when it is confirmed that it supports the fast charging mode. The electronic device 30 may indicate that fast charging is possible through a predetermined display means, which may be, for example, a liquid crystal display.

Also, the user of the electronic device 30 may select the predetermined fast charge request button displayed on the liquid crystal display means to control the wireless power transmitting terminal 10 to operate in the fast charge mode. In this case, the electronic device 30 can transmit a predetermined fast charge request signal to the wireless power receiving terminal 20 when the quick charge request button is selected by the user. The wireless power receiving terminal 20 may generate a charging mode packet corresponding to the received fast charging request signal and transmit the same to the wireless power transmitting terminal 10 to switch the general low power charging mode to the fast charging mode.

2 is a block diagram illustrating a wireless charging system according to another embodiment of the present invention.

For example, as shown in 200a, the wireless power receiving terminal 20 may include a plurality of wireless power receiving devices, and a plurality of wireless power receiving devices may be connected to one wireless power transmitting terminal 10, Charging may also be performed. At this time, the wireless power transmitting terminal 10 can transmit and distribute power to a plurality of wireless power receiving apparatuses in a time division manner, but is not limited thereto. In another example, the wireless power transmitting terminal 10 may distribute and transmit power to a plurality of wireless power receiving apparatuses using different frequency bands allocated to the wireless power receiving apparatuses.

At this time, the number of wireless power receiving apparatuses connectable to one wireless power transmitting apparatus 10 is set to at least one of the required power amount for each wireless power receiving apparatus, the battery charging state, the power consumption amount of the electronic apparatus, Can be determined adaptively based on

As another example, as shown in 200b, the wireless power transmitting terminal 10 may be composed of a plurality of wireless power transmitting apparatuses. In this case, the wireless power receiving terminal 20 may be connected to a plurality of wireless power transmission apparatuses at the same time, and may simultaneously receive power from connected wireless power transmission apparatuses to perform charging. At this time, the number of wireless power transmission apparatuses connected to the wireless power receiving terminal 20 is adaptively set based on the required power amount of the wireless power receiving terminal 20, the battery charging status, the power consumption amount of the electronic apparatus, Can be determined.

3 is a diagram for explaining a sensing signal transmission procedure in a wireless charging system according to an embodiment of the present invention.

As an example, the wireless power transmitter may be equipped with three transmit coils 111, 112, 113. Each of the transmission coils may be disposed such that a portion of the transmission coils overlaps with the other transmission coils. However, this is merely an example, and the transmission coils may be disposed without overlapping one another or with one transmission coil.

The wireless power transmitter sequentially transmits predetermined sensing signals 117, 127 (e.g., digital ping) for sensing the presence of a wireless power receiver through each transmit coil in a predefined order.

As shown in FIG. 3, the wireless power transmitter sequentially transmits the detection signal 117 when the primary sensing signal transmission procedure shown at 110 is started, and transmits a predetermined response signal - For example, a signal strength indicator 116 or a signal strength packet may be referred to as a signal strength indicator for convenience of explanation. The received transmission coils 111 and 112 can be identified. Subsequently, the wireless power transmitter sequentially transmits the sense signal 127 when the secondary sense signal transmission procedure shown at 120 is started, and when the signal strength indicator 126 indicates that the power of the transmit coils 111 and 112 It is possible to control the transmission efficiency (or charging efficiency) - that is, the alignment state between the transmitting coil and the receiving coil - to identify a good transmitting coil and to allow power to be transmitted through the identified transmitting coil, have.

As shown in FIG. 3, the reason why the wireless power transmitter performs two detection signal transmission procedures is to more accurately identify to which transmission coil the reception coil of the wireless power receiver is well-aligned.

If the signal strength indicators 116 and 126 are received at the first transmission coil 111 and the second transmission coil 112 as shown in the aforementioned numerals 110 and 120 of FIG. 3, Selects a transmission coil having the best alignment based on the received signal strength indicator 126 in each of the first transmission coil 111 and the second transmission coil 112 and performs wireless charging using the selected transmission coil .

4 is a state transition diagram for explaining a wireless power transmission procedure according to an embodiment of the present invention.

Referring to FIG. 4, power transmission from a transmitter to a receiver according to an exemplary embodiment includes a selection phase 410, a ping phase 420, an identification and configuration phase 430, , And a power transfer phase (step 440).

The selection step 410 may be a phase transition when a specific error or a specific event is detected while initiating a power transmission or maintaining a power transmission. Here, the specific error and the specific event will become clear through the following description. Also, in a selection step 410, the transmitter may monitor whether an object is present on the interface surface. If the transmitter detects that an object is placed on the interface surface, it can transition to the step 420 (S401). In a selection step 410, the transmitter transmits an analog ping signal of a very short pulse and can detect whether an object exists in the active area of the interface surface based on the current change in the transmission coil . In another example, the transmitter may detect whether an object exists in the active area of the interface surface based on the change in impedance of the transmission coil or the change in inductance of the transmission coil.

In step 420, the transmitter activates the receiver when it detects an object and transmits a digital ping to identify whether the receiver is a receiver capable of receiving a wireless power receiver from the transmitter. If the transmitter does not receive a response signal for the digital ping (e.g., a signal strength indicator) within a predetermined time from the receiver in step 420, the flow returns to the selection step 410 again in step S402. Also, in step 420, the transmitter may transition to a selection step 410 when receiving a signal indicating completion of power transmission from the receiver, i.e., a charging completion signal (S403).

Once the ping stage 420 is complete, the transmitter may transition to an identification and configuration step 430 to collect receiver identification and receiver configuration and status information (S404).

In the identifying and configuring step 430, the sender may determine whether the packet is unexpected, whether a desired packet is received during a predefined period of time (time out), a packet transmission error (transmission error) (No power transfer contract), the process can be shifted to the selection step 410 (S405).

Once the identification and configuration for the receiver is complete, the transmitter may transition to power transfer step 440, which transmits the wireless power (S406).

In the power transfer step 440, the transmitter determines whether an unexpected packet is received, a desired packet is received for a predefined period of time (time out), a violation of a predetermined power transmission contract occurs transfer contract violation, and if the charging is completed, the selection step 410 can be performed (S407).

In addition, in the power transfer step 440, if the transmitter needs to reconfigure the power transfer contract according to changes in the transmitter state, etc., it may transition to the identification and configuration step 430 (S408).

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

5 is a state transition diagram for explaining a wireless power transmission procedure according to another embodiment of the present invention.

5, power transmission from a transmitter to a receiver is largely divided into a selection phase 510, a ping phase 520, an identification and configuration phase 530, a negotiation phase Phase 540, a calibration phase 550, a power transfer phase 560, and a renegotiation phase 570.

The selection step 510 may be a phase transition when a specific error or a specific event is detected while initiating a power transmission or maintaining a power transmission. Here, the specific error and the specific event will become clear through the following description. Also, in a selection step 510, the transmitter can monitor whether an object is present on the interface surface. If the transmitter detects that an object has been placed on the interface surface, it may transition to a ping step 520. However, analog pings can be replaced by other alternative means. Other alternative means may be a proximity sensor, a Hall sensor for sensing a change in magnetic field, a pressure sensor, or at least one of an abbreviation. In the selection step 510, the transmitter transmits an analog ping signal of a very short pulse and, based on the current change of the transmission coil or the primary coil, It is possible to detect whether or not there is an error.

In step 520, the transmitter activates the receiver when an object is detected, and transmits a digital ping to identify whether the receiver is capable of receiving wireless power from the transmitter. If the transmitter does not receive a response signal for the digital ping (e. G., A signal strength packet) from the receiver within a predetermined time after transmitting the digital ping in step 520, the transmitter may transit to the selection step 510 again. Also, in the step of the ping 520, the transmitter may transition to the selection step 510 upon receiving a signal indicating that the power transmission has been completed from the receiver, that is, the charge completion packet.

Once the ping step 520 is complete, the transmitter may transition to an identification and configuration step 530 for identifying the receiver and collecting receiver configuration and status information.

In the identifying and configuring step 530, the transmitter determines whether a packet is received (unexpected packet), a desired packet is not received during a predefined period of time (time out), a packet transmission error, (No power transfer contract) can be made to the selection step 510.

The transmitter may determine whether an entry to the negotiation step 540 is required based on the negotiation field value of the configuration packet that was made in the identification and configuration step 530. [

If it is determined that negotiation is required, the transmitter may enter a negotiation step 540 to perform a foreign object detection procedure.

On the other hand, if it is determined that negotiation is not required, the transmitter may immediately enter the power transmission step 560.

At negotiation step 540, the transmitter may receive a Foreign Object Detection (FOD) status packet including a reference quality factor value. At this time, the transmitter can determine a threshold value for foreign matter detection based on the reference quality factor value.

For example, the transmitter may determine a value lower than the reference quality factor value by a correction ratio as a threshold for detecting foreign matter, and may measure the current quality factor value prior to entry into the panning step 520 after object detection.

The transmitter compares the determined threshold value with the currently measured quality factor value to determine whether foreign substances are present in the charged area, and can control power transmission according to the foreign matter detection result.

In one example, if a foreign object is detected, the transmitter may return to the selection step 510. On the other hand, if no foreign object is detected, the transmitter may enter the power transfer step 560 via the correction step 550. In detail, if a foreign object is not detected, the transmitter in the correction step 550 determines the strength of the power received at the receiver and determines the strength of the power transmitted at the receiver and at the transmitter Power loss can be measured. That is, the transmitter can estimate the power loss based on the difference between the transmit power of the transmitter and the receive power of the receiver in a correction step 550. [ A transmitter according to an exemplary embodiment may compensate a threshold for detecting a foreign substance by reflecting a predicted power loss. This allows the transmitter to more accurately detect foreign objects.

In the power transfer step 560, the transmitter determines whether an unexpected packet is received, a desired packet is received for a predefined time (time out), a violation of a predetermined power transmission contract occurs transfer contract violation, and if the charging is completed, the selection step 510 can be performed.

Also, in the power transfer step 560, the transmitter may transition to the renegotiation step 570 if it is necessary to reconfigure the power transfer contract according to the transmitter state change or the like. At this time, if the renegotiation is normally completed, the transmitter may return to power transfer step 560. [

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

6 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment of the present invention.

6, the wireless power transmitter 600 may include a power conversion unit 610, a power transmission unit 620, a communication unit 630, a control unit 640, and a sensing unit 650 . It should be noted that the configuration of the wireless power transmitter 600 described above is not necessarily an essential configuration, and may be configured to include more or less components.

6, when the DC power is supplied from the power supply unit 660, the power converting unit 610 may convert the DC power into AC power having a predetermined intensity.

The power converter 610 may include a DC / DC converter 611, an inverter 612, and a frequency generator 613. The inverter 612 may be a half bridge inverter or a full bridge inverter. However, the present invention is not limited thereto, and a circuit configuration capable of converting DC power into AC power having a specific operating frequency is sufficient.

The DC / DC converting unit 611 may convert DC power supplied from the power supply unit 650 into DC power having a specific intensity according to a control signal of the controller 640. [

At this time, the sensing unit 650 may measure the voltage / current of the DC-converted power and provide the measured voltage / current to the controller 640. In addition, the sensing unit 650 may measure the internal temperature of the wireless power transmitter 600 and may provide the measurement result to the controller 640 in order to determine whether overheating occurs. For example, the control unit 640 may adaptively cut off the power supply from the power supply unit 650 or block the supply of power to the amplifier 612 based on the voltage / current value measured by the sensing unit 650 . To this end, a power cutoff circuit may be further provided at one side of the power conversion unit 610 to cut off power supplied from the power supply unit 650 or to cut off power supplied to the amplifier 612.

The inverter 612 can convert the DC / DC converted DC power into AC power based on the reference AC signal generated by the frequency generator 613. At this time, the frequency of the reference AC signal - that is, the operating frequency - can be dynamically changed according to the control signal of the controller 640. The wireless power transmitter 600 according to an exemplary embodiment of the present invention may adjust the operating frequency to adjust the transmission power. For example, the control unit 640 may receive the power reception status information and / or the power control signal of the wireless power receiver through the communication unit 630 and may receive the power control information based on the received power reception status information and / To determine the operating frequency, and to dynamically control the frequency generator 613 to produce the determined operating frequency. For example, the power reception status information may include, but is not limited to, the intensity information of the rectifier output voltage, the intensity information of the current applied to the reception coil, and the like. The power control signal may include a signal for requesting power increase, a signal for requesting power reduction, and the like.

The power transmitting unit 620 may be configured to include a multiplexer 621 (or a multiplexer), a transmitting coil unit 622, and the like. Here, the transmission coil section 622 may be composed of first to n-th transmission coils. In addition, the power transmitting unit 620 may further include a carrier generator (not shown) for generating a specific carrier frequency for power transmission. In this case, the carrier generator may generate a specific carrier frequency for mixing with the output AC power of the inverter 612 transmitted through the multiplexer 621. It should be noted that one embodiment of the present invention may have different frequencies of AC power delivered to each transmit coil. In another embodiment of the present invention, the resonance frequency of each transmission coil may be set differently by using a predetermined frequency controller having a function of controlling LC resonance characteristics for different transmission coils.

The multiplexer 621 may perform a switch function to transmit AC power to the transmission coil selected by the controller 640. [ The controller 640 may select a transmission coil to be used for power transmission to the corresponding wireless power receiver based on the signal strength indicator received for each transmission coil.

The controller 640 according to an exemplary embodiment of the present invention may transmit power through time division multiplexing for each transmission coil when a plurality of wireless power receivers are connected. For example, if the wireless power transmitter 600 has three wireless power receivers-i. E., The first through third wireless power receivers, respectively, identified through three different transmit coils, i. E., First through third transmit coils , The control unit 640 controls the multiplexer 621 to control the AC power to be transmitted only through a specific transmission coil in a specific time slot. At this time, the amount of power transmitted to the corresponding wireless power receiver can be controlled according to the length of the time slot allocated for each transmission coil, but this is only one embodiment. DC power of the DC / DC converter 611 to control the transmission power of each wireless power receiver.

The control unit 640 may control the multiplexer 621 so that the detection signals may be sequentially transmitted through the first through n'th transmission coils 622 during the first differential signal transmission procedure. At this time, the control unit 640 can identify the time at which the detection signal is transmitted using the timer 655. When the time of the transmission of the trashed signal arrives, the control unit 640 controls the multiplexer 621 to output a detection signal To be transmitted. For example, the timer 650 can transmit a specific event signal to the control unit 640 at predetermined intervals during the ping transmission step, and the control unit 640 controls the multiplexer 621 whenever the corresponding event signal is detected, So that the digital ping can be transmitted through the transmission coil.

In addition, the control unit 640 transmits a predetermined transmission coil identifier for identifying a signal strength indicator (Signal Strength Indicator) received through the transmission coil from the demodulation unit 632 during the first detection signal transmission procedure, Lt; / RTI > received signal strength indicator. In the second sensing signal transmission procedure, the controller 640 controls the multiplexer 621 so that the sensing signal can be transmitted only through the transmission coil (s) on which the signal strength indicator is received during the first sensing signal transmission procedure You may. In another example, when there are a plurality of transmit coils in which the signal strength indicator is received during the first differential sense signal transmission procedure, the control unit 640 transmits the received transmit coils to the second differential sense signal transmission It is possible to determine the detection signal as the first transmission coil to be transmitted first, and to control the multiplexer 621 according to the determination result.

The communication unit 630 may include at least one of a modulation unit 631 and a demodulation unit 632.

The modulator 631 may modulate the control signal generated by the controller 640 and transmit the modulated control signal to the multiplexer 621. Here, the modulation scheme for modulating the control signal includes a frequency shift keying (FSK) modulation scheme, a Manchester coding modulation scheme, a phase shift keying (PSK) modulation scheme, a pulse width modulation scheme, A differential bi-phase modulation method, and the like.

The demodulator 632 can demodulate the detected signal and transmit the demodulated signal to the controller 640 when a signal received through the transmission coil is detected. Here, the demodulated signal may include a signal strength indicator, an error correction (EC) indicator for power control during wireless power transmission, an end of charge indicator (EOC), an overvoltage / overcurrent / overheat indicator, But is not limited to, various status information for identifying the status of the wireless power receiver.

Also, the demodulator 632 can identify which of the transmit coils the demodulated signal is received, and provide the control unit 640 with a predetermined transmit coil identifier corresponding to the identified transmit coil.

 The demodulation unit 632 can demodulate the signal received through the transmission coil 623 and transmit the demodulated signal to the control unit 640. In one example, the demodulated signal may include, but is not limited to, a signal strength indicator, and the demodulated signal may include various status information of the wireless power receiver.

In one example, the wireless power transmitter 600 may obtain the signal strength indicator through in-band communication that uses the same frequency used for wireless power transmission to communicate with the wireless power receiver.

In addition, the wireless power transmitter 600 may transmit wireless power using the transmit coil portion 622, as well as exchange various control signals and status information with the wireless power receiver via the transmit coil portion 622. As another example, a separate coil corresponding to each of the first to n-th transmission coils of the transmission coil section 622 may be additionally provided in the wireless power transmitter 600, and wireless power It should be noted that it may also perform in-band communication with the receiver.

Although the wireless power transmitter 600 and the wireless power receiver perform in-band communication in the description of FIG. 6, this is merely an example, and the frequency band used for the wireless power signal transmission Directional communication through different frequency bands. For example, the near-end bi-directional communication may be any one of low-power Bluetooth communication, RFID communication, UWB communication, and Zigbee communication.

6, the power transmission unit 620 of the wireless power transmitter 600 includes a multiplexer 621 and a plurality of transmission coils 622, but this is only one embodiment, It should be noted that the power transmission unit 620 according to the embodiment may be composed of one transmission coil.

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

7, the wireless power receiver 700 includes a receiving coil 710, a rectifying unit 720, a DC / DC converter 730, a load 740, a sensing unit 750, 760, and a main control unit 770. Here, the communication unit 760 may include a demodulation unit 761 and a modulation unit 762.

Although the wireless power receiver 700 shown in the example of FIG. 7 is shown as being capable of exchanging information with the wireless power transmitter 600 through in-band communication, this is only one embodiment, The communication unit 760 according to another embodiment of the present invention may provide short-distance bidirectional communication through a frequency band different from the frequency band used for wireless power signal transmission.

The AC power received via the receiving coil 710 may be delivered to the rectifier 720. The rectifier 720 may convert the AC power to DC power and transmit it to the DC / DC converter 730. [ The DC / DC converter 730 may convert the intensity of the rectifier output DC power to a specific intensity required by the load 740 and then forward it to the load 740.

The sensing unit 750 may measure the intensity of the DC power output from the rectifier 720 and provide it to the main control unit 770. Also, the sensing unit 750 may measure the intensity of the current applied to the reception coil 710 according to the wireless power reception, and may transmit the measurement result to the main control unit 770. The sensing unit 750 may measure the internal temperature of the wireless power receiver 700 and provide the measured temperature value to the main control unit 770.

For example, the main control unit 770 may compare the measured rectifier output DC power with a predetermined reference value to determine whether an overvoltage is generated. As a result of the determination, if an overvoltage is generated, a predetermined packet indicating that the overvoltage has occurred can be generated and transmitted to the modulating unit 762. Here, the signal modulated by the modulating unit 762 may be transmitted to the wireless power transmitter 600 through the receiving coil 710 or a separate coil (not shown). The main control unit 770 may determine that the detection signal is received when the intensity of the rectifier output DC power is equal to or greater than a predetermined reference value and when the signal strength indicator corresponding to the detection signal is received by the modulation unit 762 To be transmitted to the wireless power transmitter 600 via the wireless network. The demodulation unit 761 demodulates the AC power signal between the reception coil 710 and the rectifier 720 or the DC power signal output from the rectifier 720 to identify whether or not the detection signal is received, (770). At this time, the main control unit 770 may control the signal intensity indicator corresponding to the detection signal to be transmitted through the modulation unit 762. [

8 is a diagram for explaining a modulation and demodulation method of a wireless power signal according to an embodiment of the present invention.

8, the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 can encode or decode a packet to be transmitted based on an internal clock signal having the same period.

Hereinafter, a method of encoding a packet to be transmitted will be described in detail with reference to FIGS. 1 to 8. FIG.

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

The binary data of the packet generated by the wireless power transmitting terminal 10 or the wireless power receiving terminal 20 may be subjected to differential bi-phase encoding as shown in 820. [ Specifically, the differential two-stage encoding has two state transitions to encode data bit one and one state transition to encode data bit zero. That is, the data bit 1 is encoded such that the transition between the HI state and the LO state occurs at the rising edge and the falling edge of the clock signal, and the data bit 0 is at the rising edge of HI State and the LO state may be encoded to occur.

The encoded binary data may be subjected to a byte encoding scheme, as shown in FIG. Referring to reference numeral 830, a byte encoding method according to an embodiment of the present invention includes a start bit and a stop bit for identifying a start and a type of a bitstream of an 8-bit encoded binary bitstream, , And a parity bit for detecting whether or not an error has occurred in the bitstream (byte).

9 is a diagram for explaining a packet format according to an embodiment of the present invention.

9, a packet format 900 used for information exchange between the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 includes a function of acquiring synchronization for demodulating the packet and identifying an accurate start bit of the packet A header 920 for identifying a type of a message included in the packet, a message for transmitting the content of the packet (or a payload), a preamble field 910 for transmitting the packet, 930) field and a checksum (940) field for identifying whether an error has occurred in the packet.

As shown in FIG. 9, the packet receiving end may identify the size of the message 930 included in the packet based on the header 920 value.

In addition, the header 920 may be defined for each step of the wireless power transmission procedure, and some values of the header 920 may be defined at different levels. For example, referring to FIG. 9, it should be noted that the header value corresponding to the end power transfer in the ping phase and the power transmission phase in the power transfer phase may be equal to 0x02.

The message 930 includes data to be transmitted at the transmitting end of the packet. For example, the data contained in the message 930 field may be, but is not limited to, a report, request or response to the other party.

The packet 900 according to another embodiment of the present invention may further include at least one of a transmitting end identification information for identifying a transmitting end that transmitted the packet and a receiving end identifying information for identifying a receiving end to receive the packet. Here, the transmitter identification information and the receiver identification information may include IP address information, MAC address information, product identification information, and the like. However, the present invention is not limited thereto.

The packet 900 according to another embodiment of the present invention may further include predetermined group identification information for identifying a corresponding receiving group when the packet is to be received by a plurality of apparatuses.

10 is a view for explaining the types of packets transmitted from a wireless power receiver to a wireless power transmitter according to an embodiment of the present invention.

Referring to FIG. 10, a packet transmitted from a wireless power receiver to a wireless power transmitter includes a signal strength packet for transmitting strength information of a detected ping signal, a power transmission type for requesting a transmitter to stop power transmission, A power control hold-off packet for transmitting time information for waiting until the actual power is adjusted after receiving the control error packet for control control, a configuration for transmitting the configuration information of the receiver, Packet, an identification packet for transmitting the receiver identification information and an extension identification packet, a general request packet for transmitting a general request message, a special request packet for transmitting a special request message, a reference quality parameter value for detecting FO, An FOD state packet, a control error packet for controlling the transmission power of the transmitter, a renegotiation packet for starting renegotiation, A 24-bit receive power packet and an 8-bit receive power packet for transmitting received power intensity information and a charge status packet for transmitting charge status information of the current load.

The packets transmitted from the wireless power receiver to the wireless power transmitter may be transmitted using in-band communication using the same frequency band as that used for wireless power transmission.

11 is a block diagram illustrating a wireless power transmission apparatus equipped with an NFC function according to an embodiment of the present invention.

The wireless power transmission apparatus 1100 according to the present invention may be equipped with a Near Field Communication (NFC) function.

11, the wireless power transmission apparatus 1100 includes a first resonant circuit 1110, a first control circuit 1120, a second resonant circuit 1130, a second control circuit 1140, And a current sensor 1150.

The first resonant circuit 1110 may comprise an LC circuit for transmitting a wireless power signal and the first control circuit 1120 may be configured to process the wireless power signal transmitted via the first resonant circuit 1110 Circuit elements and a processor. The first control circuit 1120 may be a circuit and a processor that demodulates and processes a signal received through a first resonant circuit 1110 or a separately provided receive antenna (not shown).

The first control circuit 1120 includes functions of the power conversion unit 610, the power transfer unit 620, the communication unit 630, the control unit 640, and the sensing unit 650 Can be performed. In another example, the first control circuit 1120 may include at least one microprocessor and memory, various circuit element (s) and sensor (s) controlled by the microprocessor, such as a DC-DC converter, - < / RTI >

The second resonant circuit 1130 may include an LC circuit for short-range wireless communication and the second control circuit 1140 may include a circuit for processing a short-range wireless communication signal transmitted and received through the second resonant circuit 1130 Device, and processor.

The current sensor 1150 can measure the amount of change of the current flowing in the second resonant circuit 1130. [

In one example, the current sensor 1150 may communicate a value for the measured current change amount to the second control circuit 1140. At this time, the second control circuit 1140 may compare the measured current variation with a predetermined reference value to detect that the conductive object is placed (or contacted) with the wireless power transmission apparatus. For example, the second control circuit 1140 may compare the measured current change amount with the first reference value to detect that the conductive object placed in (or contacted with) the wireless power transmission apparatus is a wireless power reception apparatus.

For example, the second control circuit 1140 may compare the measured current variation with a second reference value to detect that the conductive object (or contacted) in the wireless power transmission device is an NFC device.

For example, the second control circuit 1140 may compare the measured current variation with a third reference value to detect that the conductive object placed (or contacted) in the wireless power transmission apparatus is a foreign object.

However, it may be difficult for the second control circuit 1140 to grasp the type of object placed (or contacted) with the wireless power transmission apparatus only by the measured current change amount.

The current sensor 1150 can measure the amount of change of the current flowing at both ends of the resistance provided in the second resonant circuit 1130. At this time, the resistor may be disposed between the inductor and the capacitor connected in parallel on the second resonant circuit 1130, but is not limited thereto.

The wireless power transmission apparatus 1100 according to the present invention may periodically transmit a specific NFC signal through the second resonant circuit 1130 when power is applied. That is, the wireless power transmission apparatus 1100 transmits a sensing signal for sensing an object placed in the charging area in a standby state, for example, an analog ping of the WPC standard or a short beacon of the Airfuel (old, A4WP) standard Instead, it is possible to transmit a predetermined NFC signal with a relatively low power consumption. Here, the NFC signal may be a specific command signal, but is not limited thereto.

The second control circuit 1140 can monitor whether a response signal is received for a predetermined time, if the object is determined to be placed (or contacted).

As a result of the monitoring, if the response signal is not received, the second control circuit 1140 can transmit the predetermined control signal to the first control circuit 1120 indicating that the object is detected.

On the other hand, when the response signal is received as a result of the monitoring, the second control circuit 1140 can exchange information with the NFC device that transmitted the response signal.

The first control circuit 1120 generates a predetermined sensing signal (e.g., digital ping or long beacon) for identifying the wireless power receiver in accordance with the received control signal, and outputs the generated sensing signal to the first resonant circuit 1110 ). ≪ / RTI >

The first control circuit 1120 may initiate charging by transmitting a wireless power signal through the first resonant circuit 1110 when the identification and configuration for the wireless power receiver is normally completed.

Of course, if the wireless power receiver identification fails, the first control circuit 1120 may stop sending the sense signal and then send a predetermined control signal to the second control circuit 1140 requesting the NFC signal transmission.

As described above, the wireless power transmission apparatus according to the present invention not only minimizes standby power consumption, but also minimizes EMI (Electro Magnetic Interference).

Further, the wireless power transmission apparatus according to the present invention is advantageous in that it can prevent the occurrence of overheating due to a foreign matter disposed in a charging region by transmitting a low-power signal in a standby state.

12 is a diagram illustrating a structure of an antenna module mounted in a wireless power transmission apparatus according to an embodiment of the present invention.

12, the antenna module 1200 may be pattern-printed on one printed circuit board 1210. However, the present invention is not limited thereto. For example, the antenna of the lead- Or may be configured to be mounted inside. In another example, the antenna module 1200 may be formed using a nicking coil formed through nicknames of copper plates. In another example, the antenna module 1220 may be pattern printed on a protective film (not shown), and a shielding sheet (not shown) may be disposed on the antenna module 1220. Portions of the shielding sheet (not shown) may include receptacles (not shown) for connection of the antenna module 1220 and the control circuitry.

12, an antenna module 1200 includes a printed circuit board 1210, a first antenna pattern 1220 for wireless power transmission, a second antenna pattern 1230 for short-range wireless communication, And a connection terminal 1240 for connecting the connection terminal 1240. [

For example, the second antenna pattern 1230 may be disposed on the outer periphery of the first antenna pattern 1220 without being overlapped with each other, but this is merely one embodiment, and the arrangement of the antennas is not limited to the design of the person skilled in the art It should be noted that it may be different depending on the application.

The connection terminal 1240 according to an embodiment may be disposed between the first antenna pattern 1220 and the second antenna pattern 1230, but this is merely an example, The connection terminals corresponding to the respective antenna patterns may be separately arranged on the printed circuit board 1210. FIG.

In the embodiment of FIG. 12, two antenna patterns 1220 and 1230 are disposed on the printed circuit board 1210, but this is only an example. It is noted that the antenna pattern may be added to the printed circuit board according to the present invention. For example, the added antenna pattern may include at least one of an antenna pattern for Bluetooth communication, an antenna pattern for mobile financial approval such as Magnetic Secure Transmission, and an antenna pattern for RFID communication.

In the embodiment of FIG. 12, one transmission coil for wireless power transmission is illustrated as an example, but this is only one embodiment. In another embodiment, the antenna includes a plurality of transmission coils It should be noted that the present invention is not limited thereto.

13 is a diagram for explaining a circuit configuration of a wireless power transmission apparatus using NFC tagging according to an embodiment of the present invention.

13, the wireless power transmission apparatus 1300 includes a first control circuit 1310, a first resonant circuit 1320, a second control circuit 1330, a second resonant circuit 1340, a switch 1350, And a power supply 1360.

Here, the power source 1360 may be applied from an external power source terminal through a power plug or an adapter, but this is merely one embodiment, and in another example, it may be a battery of the power source 1360. At this time, the battery may be integrally formed or detachably attached to the wireless power transmission apparatus 1300. Of course, it should be noted that the auxiliary battery may be used as the power supply 1360. [

The first resonant circuit 1320 may be, but is not limited to, an RLC circuit including a resistor, a capacitor, and an inductor. 13, the first resonant circuit 1320 includes first capacitors C1 and 1321, resistors R1 and 1322, first inductors L1 and 1321, and a current sensor 1324, And the like. Here, the first resonant circuit 1320 may be a resonant antenna for NFC communication.

The current sensor 1324 can measure the amount of change of the current flowing across the resistor 1322 according to a predetermined control signal of the first control circuit 1320 and transmit the measurement result to the first control circuit 1310.

For example, the wireless power transmission device 1300 may be configured such that when power is applied, the switch 1350 is powered on by default to the first control circuit 1310. The first control circuit 1310 may generate a predetermined NFC signal when power is applied thereto, and may transmit the generated NFC signal to the first resonance circuit 1320.

The first control circuit 1310 can determine that the conductive object is contacted (or disposed) with the wireless power transmission apparatus 1300 when the amount of change in the current flowing through the resistor 1322 exceeds a predetermined reference value.

The first control circuit 1310 may monitor whether an NFC response signal is received within a predetermined time using an internally provided timer. As a result of the monitoring, when the NFC response signal is received, the first control circuit 1310 can continue to perform NFC communication.

On the other hand, if the NFC response signal is not detected within a predetermined time as a result of the monitoring, the first control circuit 1310 outputs a predetermined control signal indicating that a conductive object is detected in the charging area, Lt; / RTI > to the second control circuit 1330, as shown in FIG. The first control circuit 1320 may also control the switch 1350 to connect the power supply 1360 to the second control circuit 1330. [

The second control circuit 1330 may generate a predetermined sensing signal for identifying the wireless power receiver according to the object detection event signal received from the first control circuit 1310 and may transmit the sensing signal to the second resonant circuit 1340.

The second control circuit 1330 may initiate charging for the wireless power receiver if the wireless power receiver is normally identified according to the sense signal.

If a receiver capable of wireless charging is not identified, the second control circuit 1330 transmits a predetermined control signal for requesting NFC signal transmission, which is called a receiver identification failure event signal, for convenience of explanation, To the circuit 1310. The second control circuit 1330 may also control the switch 1350 to connect the power supply 1360 to the first control circuit 1310. [

The first control circuit 1310 may resume the procedure for transmitting the predetermined NFC signal according to the receiver identification failure event signal.

As described above, the wireless power transmission apparatus according to the present invention operates in the NFC mode until an object is detected in the standby state, thereby minimizing standby power consumption and minimizing EMI (Electro Magnetic Interference) There are advantages to be able to.

11 and FIG. 13, a control circuit for controlling the short-range wireless communication and a control circuit for controlling the wireless power transmission are separately provided. However, this is for convenience of description only, And may be physically configured on one circuit board or on a separate circuit board. In addition, a microprocessor for each control circuit may be provided, but this is merely one embodiment, and the functions of the first control circuit and the second control circuit may be integrally implemented on one microprocessor.

The first control circuit 1310 and the second control circuit 1330 may be provided with a memory. The microprocessor can operate by loading a program stored in memory at boot time of the device.

FIG. 14 is a flowchart illustrating a wireless power transmission method using NFC tagging according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 14, when power is applied, the wireless power transmission apparatus can transmit a first signal through a first antenna in a standby state (S1401). Here, the first signal may be an NFC command signal, but is not limited thereto.

The wireless power transmission apparatus may monitor a change in current flowing to the first antenna using a predetermined current sensor provided during the first signal transmission (S1402).

The wireless power transmission apparatus can compare whether the amount of change in the current flowing through the first antenna exceeds a predetermined reference value (S1403).

The wireless power transmission apparatus can monitor whether a response signal corresponding to the first signal is received within a predetermined time period when the amount of change of the current exceeds the reference value (S1404).

As a result of the monitoring, when the response signal is received, the wireless power transmission apparatus can maintain the NFC mode and perform NFC communication (S1405).

On the other hand, if the response signal is not received within a predetermined time after the monitoring, the wireless power transmission apparatus can switch the NFC mode to the wireless charging mode (S1406).

After switching to the wireless charging mode, the wireless power transmission apparatus transmits a second signal (for example, a predetermined sensing signal) through a second antenna provided for wireless power transmission to identify whether the sensed object is a wireless chargeable receiver (S1407).

As an example, the wireless power transmission device may transmit a digital ping as a sensing signal. In this case, if a signal strength packet is received in response to the digital ping, the wireless power transmission apparatus can determine that the sensed object is a receiver capable of wireless power reception.

In another example, the wireless power transmission device may transmit a long beacon as a sensing signal. In this case, if the advertisement signal is received in response to the long beacon, the wireless power transmission apparatus can determine that the sensed object is a receiver capable of wireless power reception.

According to another embodiment of the present invention, when a response signal corresponding to a detection signal is normally received, the wireless power transmission apparatus can obtain identification and configuration information from the receiver. Here, based on the obtained identification and configuration information, the wireless power transmission apparatus may finally confirm whether wireless charging is possible for the receiver by performing an authentication procedure with the receiver.

If the wireless power transmission apparatus is determined that the sensed object is a wireless chargeable receiver, it can initiate a wireless charge for the receiver (S1408 to S1409).

However, if it is determined in step 1407 that wireless charging is not possible, the wireless power transmission apparatus may switch from the wireless charging mode to the NFC mode and perform step 1401.

14, it should be noted that the intensity of the first signal transmitted through the first antenna in the standby state is smaller than the intensity of the second signal transmitted through the second antenna after switching to the wireless charging mode. More specifically, the power consumed in transmission of the first signal for a unit time may be less than the power consumed in transmission of the second signal.

In the embodiment of FIG. 14 described above, the first antenna is described as being used for NFC communication, but it should be noted that this is only an example and may be used for other short-range wireless communication. For example, the first antenna may be used for short-range wireless communication such as Bluetooth communication, Radio Frequency Identification (RFID) communication, and magnetic security transmission.

As described above, the wireless power transmission method according to the present invention operates in the NFC mode until an object is detected in the standby state, thereby minimizing the standby power consumption in the wireless power transmission apparatus, Interference can be minimized.

15 is a state transition diagram for explaining a mode switching procedure of a wireless power transmission apparatus according to an embodiment of the present invention.

Referring to FIG. 15, the operation mode of the wireless power transmission apparatus may include an NFC mode 1510 and a wireless charging mode 1520.

When the wireless power transmission apparatus is powered on, the wireless power transmission apparatus may enter a first NFC mode (S1510) and transmit a predetermined NFC signal for sensing an object contact.

The wireless power transmission apparatus can monitor whether an NFC response signal is received within a predetermined time when the amount of current change of the NFC antenna during transmission of the NFC signal in the NFC mode 1510 exceeds a predetermined reference value. As a result of the monitoring, if the NFC response signal is received, the NFC mode is maintained, and if the NFC response signal is not received, the NFC mode 1510 to the wireless charge mode 1520 can be performed.

Upon entering the wireless charging mode 1520, the wireless power transmission device may transmit a sensing signal for identifying the wireless power receiver to identify whether the sensed object is a wireless chargeable receiver. As a result of the identification, if the receiver is capable of wireless charging, the wireless power transmission device can initiate charging to the identified receiver. Here, the sensing signal may be a predetermined one or a predetermined beacon signal, but is not limited thereto. In one example, the sense signal may be a digital ping or a long beacon.

In another example, the sense signal may be a digital ping or may include an analog ping or short beacon as well as a long beacon. In this case, when the wireless power transmitter enters the wireless charging mode 1520, it transmits an analog ping (or short beacon) to sense an object, and if an object is detected, ). On the other hand, the wireless power transmission device may switch to the NFC mode 1510 if the receiver fails to identify or the charging is complete.

As described above, the wireless power transmission apparatus according to the present invention not only minimizes standby power consumption, but also minimizes EMI (Electro Magnetic Interference).

16 is a block diagram illustrating a configuration of a wireless power transmission apparatus according to another embodiment of the present invention.

16, the wireless power transmission apparatus 1600 may include a resonant circuit assembly 1610, a processor assembly 1620, a memory 1630, and a power supply assembly 1640.

The power supply assembly 1640 manages the power required for operation of the device, and the resonant circuit assembly 1610 generates a signal of a specific pattern under the control of the processor assembly 1620, It can be transmitted wirelessly.

The resonant circuit assembly 1610 according to the present invention may be configured to include a resonant circuit for short-range wireless communications, e.g., NFC communications, and a resonant circuit for wireless power transmission.

The processor assembly 1620 controls the overall operation of the device and may be configured to include at least one microprocessor. Application software and firmware required for the operation of the processor assembly 1620 can be maintained in the memory 1630. When power is applied to the apparatus, the microprocessor can load and execute the program.

In addition, the wireless power transmission device 1600 may operate based on an operating system (OS) stored in the memory 1630. But are not limited to, for example, Windous Server ™, Mac OS X ™, Unix ™, Linux ™, FreeBSD ™, and the like, stored in memory 1630 of wireless power transmitter 1600.

The memory 1630 may store a series of instructions that are executed by a process assembly 1620, such as an application program. An application program stored in memory 1630 may include one or more modules. At this time, each module may correspond to a series of instruction groups. In addition, the process assembly 1620 may be configured to execute instructions to perform the wireless power transmission methods described above.

For example, when power is applied, the process assembly 1620 controls the first signal to be transmitted using a first resonant circuit for short-range wireless communication, It is possible to detect the placed object.

If the response signal corresponding to the first signal is not received for a predetermined period of time after the object is sensed, the process assembly 1620 stops transmission of the first signal and outputs the signal through the second resonant circuit for wireless power transmission 2 signal can be transmitted. Here, the power consumption during the unit time may be smaller than the second signal.

In another example, the process assembly 1620 may enter an NFC mode upon power up and control the first signal to be transmitted through a first resonant circuit for NFC communications.

The processor assembly 1620 may monitor whether a predetermined response signal corresponding to the first signal is received within a predetermined time, when an object is sensed based on a change amount of a current flowing through the first resonant circuit. As a result of the monitoring, if the response signal is not received, the processor assembly 1620 stops transmission of the first signal and then switches to the wireless charging mode to control the second signal to be transmitted through the second resonant circuit for wireless power transmission .

As described above, the wireless power transmission apparatus according to the present invention not only minimizes standby power consumption, but also minimizes EMI (Electro Magnetic Interference).

The methods according to the above-described embodiments may be implemented as a program for execution in a computer and stored in a computer-readable recording medium. Examples of the computer-readable recording medium include ROM, RAM, CD- , Floppy disks, optical data storage devices, and the like.

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 (20)

A wireless power transmission method in a wireless power transmission apparatus equipped with a short range wireless communication function,
Transmitting a first signal using a first resonant circuit for short-range wireless communication when power is applied;
Sensing an object based on a change amount of a current flowing in the first resonance circuit; And
If the response signal corresponding to the first signal is not received for a predetermined time after the object is detected, the transmission of the first signal is stopped and the second signal is transmitted using the second resonant circuit for wireless power transmission Step
/ RTI > The method according to claim 1,
Wherein power consumption during a unit of time is less than the second signal. 3. The method of claim 2,
Wherein the short-range wireless communication is NFC (Near Field Communication). The method of claim 3,
Wherein the first signal is an NFC command signal. The method according to claim 1,
Wherein the first resonant circuit includes a resistive element and determines that a conductive object is sensed when the amount of change in current flowing through the resistive element exceeds a reference value. The method according to claim 1,
Wherein the second signal is a sensing signal for identifying a wireless power receiver capable of charging. 6. The method of claim 5,
Wherein the sensing signal is one of a digital ping and a long beacon. The method according to claim 1,
And upon receipt of a response signal corresponding to the second signal, determining that the sensed object is a wireless power receiver and initiating charging to the determined wireless power receiver. 9. The method of claim 8,
And determines that the sensed object is not a wireless power receiver if the response signal corresponding to the second signal is not received and transmits the first signal using the first resonant circuit. A wireless power transmission method in a wireless power transmission apparatus equipped with an NFC (Near Field Communication) function,
Transmitting a first signal using a first resonant circuit for NFC communication by entering an NFC mode when power is applied;
Sensing an object based on a change amount of a current flowing in the first resonance circuit;
Stopping transmission of the first signal and switching to a wireless charging mode when a response signal corresponding to the first signal is not received for a predetermined time after the object is sensed; And
Transmitting a second signal using a second resonant circuit for wireless power transmission
/ RTI > A first resonant circuit for short-range wireless communication;
A current sensor for measuring a change amount of a current flowing in the first resonance circuit;
Wherein when the power is applied, the controller enters the NFC mode and controls the first signal to be transmitted through the first resonance circuit, and when the measured amount of change exceeds the reference value, whether or not the response signal corresponding to the first signal is received A first control circuit for controlling the switching to the wireless charging mode based on the first control circuit;
A second resonant circuit for wireless power transmission; And
A second control circuit for controlling the second signal to be transmitted through the second resonant circuit when a control signal for instructing switching to the wireless charging mode is received,
And a second power supply. 12. The method of claim 11,
Wherein the power consumption during a unit time is less than the second signal. 13. The method of claim 12,
Wherein the short range wireless communication is NFC (Near Field Communication). 14. The method of claim 13,
Wherein the first signal is an NFC command signal. 12. The method of claim 11,
Wherein the first resonance circuit includes a resistance element and the first control circuit determines that the conductive object is sensed when the amount of change of the current flowing through the resistance element exceeds a predetermined reference value, And waits to receive a response signal. 12. The method of claim 11,
Wherein the second signal is a predetermined sensing signal for identifying a wireless power receiver capable of charging. 16. The method of claim 15,
Wherein the sensing signal is one of a digital ping and a long beacon. 12. The method of claim 11,
Wherein the second control circuit determines that the sensed object is a wireless power receiver when the response signal corresponding to the second signal is received and the charging to the determined wireless power receiver using the second resonant circuit Wireless power transmission device. 19. The method of claim 18,
If the response signal corresponding to the second signal is not received, the second control circuit determines that the sensed object is not a wireless power receiver, and controls the first signal to be transmitted through the first resonant circuit Signal to the first control circuit. A resonant circuit assembly including a first resonant circuit for short range wireless communication and a second resonant circuit for wireless power transmission;
A processor assembly including at least one processor; And
At least one memory for storing programs to be loaded and executed by the at least one processor,
Lt; / RTI >
The processor assembly
An object disposed in a charging region is sensed based on a change amount of a current flowing in the first resonance circuit and a first signal is transmitted through the first resonance circuit The second signal is transmitted through the second resonant circuit, and the second signal is transmitted through the second resonant circuit when the response signal is not normally received.

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