Wireless power transmitter

A wireless power transmitter includes a body having a coil module therein, and configured to transmit power in a wireless manner, a blowing module configured to cool the coil module by moving a fluid by convection and a guide module extending from the blowing module to outside of the body such that the fluid from the blowing module is discharged to outside of the body after cooling the coil module. The coil module has a shape corresponding to an outer circumference of the coil module partially or wholly.

CROSS-REFERENCE TO RELATED APPLICATION

Pursuant to 35 U.S.C. §119(a), this application claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2013-0002232, filed on Jan. 8, 2013 the contents of which is incorporated by reference herein in its entirety.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to a wireless power transmitter, and particularly, to a wireless power transmitter capable of charging an electronic device in a wireless manner.

2. Description of Related Art

As functions of a mobile terminal become more diversified, the mobile terminal can support more complicated functions such as capturing images or video, reproducing music or video files, playing games, receiving broadcast signals, and the like. By comprehensively and collectively implementing such functions, the mobile terminal may be embodied in the form of a multimedia player or a device.

Terminals can be divided into mobile/portable terminals and stationary terminals according to their mobility. The mobile terminal is a portable device that can be carried anywhere and have one or more of a function of performing voice and video calls, a function of inputting/outputting information, a function of storing data, etc.

In order to support and enhance such functions of the terminal, it can be considered to improve configuration and/or software of the terminal.

In recent years, a mobile terminal which can be wirelessly charged, without an adapter configured to connect an external power to the mobile terminal for charging of a battery, is being developed.

A wireless power transmitter, configured to wirelessly charge the mobile terminal, is also being developed. In order to effectively reduce heat emission from inside of the wireless power transmitter, a new structure of the wireless power transmitter may be considered.

SUMMARY OF THE DISCLOSURE

Therefore, an aspect of the detailed description is to provide a wireless power transmitter having an enhanced structure, and capable of cooling inside of a body in a more efficient manner.

To achieve these and other advantages and in accordance with the purpose of this specification, as embodied and broadly described herein, there is provided a wireless power transmitter, comprising: a body having a coil module therein, and configured to transmit power in a wireless manner; a blowing module configured to cool the coil module by moving a fluid by convection; and a guide module extending from the blowing module to outside of the body such that the fluid from the blowing module is discharged to outside of the body after cooling the coil module, and having a shape corresponding to an outer circumference of the coil module partially or wholly.

In an embodiment of the present invention, the wireless power transmitter may further comprise a front case and a rear case which form appearance of the body, and the guide module may be formed on an inner surface of the front case.

In an embodiment of the present invention, the coil module may comprise: a fixing plate fixed to the rear case; and a coil disposed on the fixing plate.

In an embodiment of the present invention, the front case may comprise protrusions configured to make an electronic device for receiving wireless power spaced from an outer surface of the front case when the electronic device is mounted on the outer surface of the front case.

In an embodiment of the present invention, the front case may further comprise an outer guide configured to guide the fluid discharged from the blowing module to be discharged to a space between the electronic device and the outer surface of the front case through an opening of the front case.

In an embodiment of the present invention, the wireless power transmitter may further comprise a circuit board having devices for supplying wireless power signals to the coil module.

In an embodiment of the present invention, the guide module may comprise: a coil cooling portion configured to cool the coil module; and a circuit board cooling portion configured to cool the circuit board.

In an embodiment of the present invention, the coil cooling portion may be formed in a ring shape to enclose an outer circumference of the coil of the coil module. One side of the coil cooling portion may be communicated with the blowing module, and another side thereof may be communicated with the circuit board cooling portion.

In an embodiment of the present invention, the circuit board cooling portion may comprise a pair of ribs protruding from an inner surface of the body.

In an embodiment of the present invention, the wireless power transmitter may further comprise a pad disposed between the circuit board and the circuit board cooling portion such that heat generated from the circuit board is transferred to the circuit board cooling portion.

In an embodiment of the present invention, at least part of the pad may be disposed between the ribs.

In an embodiment of the present invention, the blowing module may comprise: a housing; and a diaphragm configured to move up and down in the housing when supplied with a voltage.

In an embodiment of the present invention, the blowing module may be formed to be rotatable at a prescribed angle with respect to the guide module, so as to blow the fluid.

According to another aspect of the present invention, there is provided a wireless power transmitter, comprising: a coil module mounted in a body, and configured to wirelessly charge an electronic device disposed close thereto; a case which forms appearance of the body; a guide module formed to enclose the coil module, and having an opening penetratingly-formed at the case; and a blowing module communicated with the guide module such that heat generated from the coil module is discharged to outside of the body through the opening.

In an embodiment of the present invention, part of the guide module enclosing the coil module may have a ring shape.

In an embodiment of the present invention, the wireless power transmitter may further comprise a circuit board having devices for supplying wireless power signals to the coil module.

In an embodiment of the present invention, the guide module may comprise: a coil cooling portion configured to cool the coil module; and a circuit board cooling portion configured to cool the circuit board.

In an embodiment of the present invention, one side of the coil cooling portion may be communicated with the blowing module, and another side thereof may be communicated with the circuit board cooling portion.

In an embodiment of the present invention, the circuit board cooling portion may comprise a pair of ribs protruding from an inner surface of the body.

In an embodiment of the present invention, the wireless power transmitter may further comprise a pad disposed between the circuit board and the circuit board cooling portion such that heat generated from the circuit board is transferred to the circuit board cooling portion.

In an embodiment of the present invention, part of the coil cooling portion contacting the coil module may have higher thermal conductivity than other parts.

In an embodiment of the present invention, the guide module and the case may be integrally formed with each other.

According to the present invention, when an electronic device is charged, heat generated from the body of the wireless power transmitter can be controlled more effectively, under a novel structure of the blowing module mounted in the body, and the guide module for cooling the circuit board.

DETAILED DESCRIPTION OF THE DISCLOSURE

The technologies disclosed herein may be applicable to wireless power transfer (contactless power transfer). However, the technologies disclosed herein are not limited to this, and may be also applicable to all kinds of power transmission systems and methods, wireless charging circuits and methods to which the technological spirit of the technology can be applicable, in addition to the methods and apparatuses using power transmitted in a wireless manner.

It should be noted that technological terms used herein are merely used to describe a specific embodiment, but not to limit the present invention. Also, unless particularly defined otherwise, technological terms used herein should be construed as a meaning that is generally understood by those having ordinary skill in the art to which the invention pertains, and should not be construed too broadly or too narrowly. Furthermore, if technological terms used herein are wrong terms unable to correctly express the spirit of the invention, then they should be replaced by technological terms that are properly understood by those skilled in the art. In addition, general terms used in this invention should be construed based on the definition of dictionary, or the context, and should not be construed too broadly or too narrowly.

Incidentally, unless clearly used otherwise, expressions in the singular number include a plural meaning. In this application, the terms “comprising” and “including” should not be construed to necessarily include all of the elements or steps disclosed herein, and should be construed not to include some of the elements or steps thereof, or should be construed to further include additional elements or steps.

In addition, a suffix “module” or “unit” used for constituent elements disclosed in the following description is merely intended for easy description of the specification, and the suffix itself does not give any special meaning or function.

Furthermore, the terms including an ordinal number such as first, second, etc. can be used to describe various elements, but the elements should not be limited by those terms. The terms are used merely for the purpose to distinguish an element from the other element. For example, a first element may be named to a second element, and similarly, a second element may be named to a first element without departing from the scope of right of the invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar elements are designated with the same numeral references regardless of the numerals in the drawings and their redundant description will be omitted.

In describing the present invention, moreover, the detailed description will be omitted when a specific description for publicly known technologies to which the invention pertains is judged to obscure the gist of the present invention. Also, it should be noted that the accompanying drawings are merely illustrated to easily explain the spirit of the invention, and therefore, they should not be construed to limit the spirit of the invention by the accompanying drawings.

FIG. 1is an exemplary view conceptually illustrating a wireless power transmitter and an electronic device according to the embodiments of the present invention. Referring toFIG. 1, the wireless power transmitter100may be a power transfer apparatus configured to transfer power required for the electronic device (or wireless power receiver)200in a wireless manner.

Furthermore, the wireless power transmitter100may be a wireless charging apparatus configured to charge a battery of the electronic device (or wireless power receiver)200by transferring power in a wireless manner. A case where the wireless power transmitter100is a wireless charging apparatus will be described later with reference toFIG. 9.

Additionally, the wireless power transmitter100may be implemented with various forms of apparatuses transferring power to the electronic device (or wireless power receiver)200requiring power in a contactless state.

The electronic device (or wireless power receiver)200is a device that is operable by receiving power from the wireless power transmitter100in a wireless manner. Furthermore, the electronic device (or wireless power receiver)200may charge a battery using the received wireless power.

On the other hand, an electronic device for receiving power in a wireless manner as described herein should be construed broadly to include a portable phone, a cellular phone, a smart phone, a personal digital assistant (PDA), a portable multimedia player (PMP), a tablet, a multimedia device, or the like, in addition to an input/output device such as a keyboard, a mouse, an audio-visual auxiliary device, and the like.

The electronic device (or wireless power receiver)200, as described later, may be a mobile communication terminal, (for example, a portable phone, a cellular phone, and a tablet or multimedia device). In case where the electronic device is a mobile terminal, it will be described later with reference toFIG. 10.

On the other hand, the wireless power transmitter100may transfer power in a wireless manner without mutual contact to the electronic device (or wireless power receiver)200using one or more wireless power transfer methods. In other words, the wireless power transmitter100may transfer power using at least one of an inductive coupling method based on magnetic induction phenomenon by the wireless power signal and a magnetic resonance coupling method based on electromagnetic resonance phenomenon by a wireless power signal at a specific frequency.

Wireless power transfer in the inductive coupling method is a technology transferring power in a wireless manner using a primary coil and a secondary coil, and refers to the transmission of power by inducing a current from a coil to another coil through a changing magnetic field by a magnetic induction phenomenon.

Wireless power transfer in the resonance coupling method refers to a technology in which the electronic device (or wireless power receiver)200generates resonance by a wireless power signal transmitted from the wireless power transmitter100to transfer power from the wireless power transmitter100to the wireless power receiver200by the resonance phenomenon.

Hereinafter, the wireless power transmitter100and electronic device (or wireless power receiver)200according to the embodiments disclosed herein will be described in detail. In assigning reference numerals to the constituent elements in each of the following drawings, the same reference numerals will be used for the same constituent elements even though they are shown in a different drawing.

FIGS. 2A and 2Bare exemplary block diagrams illustrating the configuration of a wireless power transmitter100and an electronic device (or wireless power receiver)200that can be employed in the embodiments disclosed herein. Referring toFIG. 2A, the wireless power transmitter100may include a power transmission unit110. The power transmission unit110may include a power conversion unit111and a power transmission control unit112.

The power conversion unit111transfers power supplied from a transmission side power supply unit190to the electronic device (or wireless power receiver)200by converting it into a wireless power signal. The wireless power signal transferred by the power conversion unit111is generated in the form of a magnetic field or electro-magnetic field having an oscillation characteristic. For this purpose, the power conversion unit111may be configured to include a coil for generating the wireless power signal.

The power conversion unit111may include a constituent element for generating a different type of wireless power signal according to each power transfer method.

In accordance with exemplary embodiments, the power conversion unit111may include a primary coil for forming a changing magnetic field to induce a current to a secondary coil of the electronic device (or wireless power receiver)200. Furthermore, the power conversion unit111may include a coil (or antenna) for forming a magnetic field having a specific resonant frequency to generate a resonant frequency in the electronic device (or wireless power receiver)200according to the resonance coupling method.

Furthermore, the power conversion unit111may transfer power using at least one of the foregoing inductive coupling method and the resonance coupling method.

Among the constituent elements included in the power conversion unit111, those for the inductive coupling method will be described later with reference toFIGS. 4A, 4B and 5, and those for the resonance coupling method will be described with reference toFIGS. 7A, 7B and 8.

On the other hand, the power conversion unit111may further include a circuit for controlling the characteristics of a used frequency, an applied voltage, an applied current or the like to form the wireless power signal.

The power transmission control unit112controls each of the constituent elements included in the power transmission unit110. The power transmission control unit112may be implemented to be integrated into another control unit (not shown) for controlling the wireless power transmitter100.

On the other hand, a region to which the wireless power signal can be approached may be divided into two types. First, an active area denotes a region through which a wireless power signal transferring power to the electronic device (or wireless power receiver)200is passed. Next, a semi-active area denotes an interest region in which the wireless power transmitter100can detect the existence of the electronic device (or wireless power receiver)200. Here, the power transmission control unit112may detect whether the electronic device (or wireless power receiver)200is placed in the active area or detection area or removed from the area. Specifically, the power transmission control unit112may detect whether or not the electronic device (or wireless power receiver)200is placed in the active area or detection area using a wireless power signal formed from the power conversion unit111or a sensor separately provided therein. For instance, the power transmission control unit112may detect the presence of the electronic device (or wireless power receiver)200by monitoring whether or not the characteristic of power for forming the wireless power signal is changed by the wireless power signal, which is affected by the electronic device (or wireless power receiver)200existing in the detection area. However, the active area and detection area may vary according to the wireless power transfer method such as an inductive coupling method, a resonance coupling method, and the like.

The power transmission control unit112may perform the process of identifying the electronic device (or wireless power receiver)200or determine whether to start wireless power transfer according to a result of detecting the existence of the electronic device (or wireless power receiver)200.

Furthermore, the power transmission control unit112may determine at least one characteristic of a frequency, a voltage, and a current of the power conversion unit111for forming the wireless power signal. The determination of the characteristic may be carried out by a condition at the side of the wireless power transmitter100or a condition at the side of the electronic device (or wireless power receiver)200. In exemplary embodiments, the power transmission control unit112may decide the characteristic based on device identification information. In another exemplary embodiment, the power transmission control unit112may decide the characteristic based on required power information of the electronic device (or wireless power receiver)200or profile information related to the required power. The power transmission control unit112may receive a power control message from the electronic device (or wireless power receiver)200. The power transmission control unit112may determine at least one characteristic of a frequency, a voltage and a current of the power conversion unit111based on the received power control message, and additionally perform other control operations based on the power control message.

For example, the power transmission control unit112may determine at least one characteristic of a frequency, a voltage and a current used to form the wireless power signal according to the power control message including at least one of rectified power amount information, charging state information and identification information in the electronic device (or wireless power receiver)200.

Furthermore, as another control operation using the power control message, the wireless power transmitter100may perform a typical control operation associated with wireless power transfer based on the power control message. For example, the wireless power transmitter100may receive information associated with the electronic device (or wireless power receiver)200to be auditorily or visually outputted through the power control message, or receive information required for authentication between devices.

In exemplary embodiments, the power transmission control unit112may receive the power control message through the wireless power signal. In other exemplary embodiment, the power transmission control unit112may receive the power control message through a method for receiving user data.

In order to receive the foregoing power control message, the wireless power transmitter100may further include a modulation/demodulation unit113electrically connected to the power conversion unit111. The modulation/demodulation unit113may modulate a wireless power signal that has been modulated by the electronic device (or wireless power receiver)200and use it to receive the power control message.

In addition, the power transmission control unit112may acquire a power control message by receiving user data including a power control message by a communication means (not shown) included in the wireless power transmitter100.

In accordance with one exemplary embodiment, the wireless power transmitter100may supply power to a plurality of electronic devices. Here, collision may occur between wireless power signals which have been modulated by the plurality of electronic devices. Hence, the constituent elements included in the wireless power transmitter100may perform various operations to avoid such collision between the modulated wireless power signals.

In one exemplary embodiment, the power conversion unit111may convert power supplied from the transmission side power supply unit190into a wireless power signal and transfer it to the plurality of electronic devices. For example, the plurality of electronic devices may be two electronic devices, namely, a first electronic device and a second electronic device.

The power conversion unit111may generate a wireless power signal for power transmission and receive a first response signal and a second response signal corresponding to the wireless power signal.

The power transmission control unit112may determine whether or not the first and second response signals collide with each other. When the first and second response signals collide with each other according to the determination result, the power transmission control unit112may reset the power transmission.

The first and second response signals may be generated by modulating the wireless power signal through the first and second electronic devices.

Through the resetting of the power transmission, the power transmission control unit112may control the power conversion unit111to sequentially receive the first and second response signals, which are generated to avoid collision with each other.

The sequential reception indicates that the first response signal is received after a first time interval and the second response signal is received after a second time interval within a predetermined response period. The first and second time intervals may be decided based on a value obtained by generating a random number.

The predetermined response period (Tping interval) may be decided to be long enough to include both the first response signal and the second response signal. Also, it may be decided after resetting the power transmission.

In accordance with one exemplary embodiment, occurrence or non-occurrence of the collision may be determined according to whether or not the first and second response signals are decoded using a present format. The present format may include a preamble, a header and a message. Whether or not the first and second response signals collide with each other may be determined based on whether or not the first and second response signals are not recoverable due to an error generation in at least one of the preamble, the header and the message caused by the collision.

In accordance with one exemplary embodiment, the power conversion unit111may periodically receive a response signal of the first device, which does not collide with a response signal of the second device within a first response period (Tping interval_1). The power transmission control unit may decode the first response signal and the second response signal using a present format, and determine whether or not the first and second response signals have collided with each other based on whether or not the decoding is performed. Here, the first response signal and the second response signal may be periodically received within a second response period (Tping interval_2). The second response period (Tping interval_2) may be decided long enough to include both the first and second response signals, and be decided after resetting the power transmission.

Referring toFIG. 2B, the electronic device (or wireless power receiver)200may include a power supply unit290. The power supply unit290supplies power required for the operation of the electronic device (or wireless power receiver)200. The power supply unit290may include a power receiving unit291and a power reception control unit (or power receiving control unit)292.

The power receiving unit291receives power transferred from the wireless power transmitter100in a wireless manner.

The power receiving unit291may include constituent elements required to receive the wireless power signal according to a wireless power transfer method. Furthermore, the power receiving unit291may receive power according to at least one wireless power transfer method, and in this case, the power receiving unit291may include constituent elements required for each method.

First, the power receiving unit291may include a coil for receiving a wireless power signal transferred in the form of a magnetic field or electromagnetic field having a vibration characteristic.

For instance, as a constituent element according to the inductive coupling method, the power receiving unit291may include a secondary coil to which a current is induced by a changing magnetic field. In exemplary embodiments, the power receiving unit291, as a constituent element according to the resonance coupling method, may include a coil and a resonant circuit in which resonance phenomenon is generated by a magnetic field having a specific resonant frequency.

In another exemplary embodiments, when the power receiving unit291receives power according to at least one wireless power transfer method, the power receiving unit291may be implemented to receive power by using a coil, or implemented to receive power by using a coil formed differently according to each power transfer method.

Among the constituent elements included in the power receiving unit291, those for the inductive coupling method will be described later with reference toFIGS. 4A and 4B, and those for the resonance coupling method with reference toFIGS. 7A and 7B.

On the other hand, the power receiving unit291may further include a rectifier and a regulator to convert the wireless power signal into a direct current. Furthermore, the power receiving unit291may further include a circuit for protecting an overvoltage or overcurrent from being generated by the received power signal.

The power reception control unit (or power receiving control unit)292may control each constituent element included in the power supply unit290.

Specifically, the power reception control unit (or power receiving control unit)292may transfer a power control message to the wireless power transmitter100. The power control message may instruct the wireless power transmitter100to initiate or terminate a transfer of the wireless power signal. Furthermore, the power control message may instruct the wireless power transmitter100to control a characteristic of the wireless power signal.

In exemplary embodiments, the power reception control unit (or power receiving control unit)292may transmit the power control message through the wireless power signal. In another exemplary embodiment, the power reception control unit (or power receiving control unit)292may transmit the power control message through a method for transmitting user data.

In order to transmit the foregoing power control message, the electronic device (or wireless power receiver)200may further include a modulation/demodulation unit293electrically connected to the power receiving unit291. The modulation/demodulation unit293, similarly to the case of the wireless power transmitter100, may be used to transmit the power control message through the wireless power signal. The power communications modulation/demodulation unit293may be used as a means for controlling a current and/or voltage flowing through the power conversion unit111of the wireless power transmitter100. Hereinafter, a method for allowing the power communications modulation/demodulation unit113or293at the side of the wireless power transmitter100and at the side of the electronic device (or wireless power receiver)200, respectively, to be used to transmit and receive a power control message through a wireless power signal will be described.

A wireless power signal formed by the power conversion unit111is received by the power receiving unit291. At this time, the power reception control unit (or power receiving control unit)292controls the power communications modulation/demodulation unit293at the side of the electronic device (or wireless power receiver)200to modulate the wireless power signal. For instance, the power reception control unit (or power receiving control unit)292may perform a modulation process such that a power amount received from the wireless power signal is varied by changing a reactance of the power communications modulation/demodulation unit293connected to the power receiving unit291. The change of a power amount received from the wireless power signal results in the change of a current and/or voltage of the power conversion unit111for forming the wireless power signal. At this time, the modulation/demodulation unit113at the side of the wireless power transmitter100may detect a change of the current and/or voltage to perform a demodulation process.

In other words, the power reception control unit (or power receiving control unit)292may generate a packet including a power control message intended to be transferred to the wireless power transmitter100and modulate the wireless power signal to allow the packet to be included therein, and the power transmission control unit112may decode the packet based on a result of performing the demodulation process of the power communications modulation/demodulation unit113to acquire the power control message included in the packet.

In addition, the power reception control unit (or power receiving control unit)292may transmit a power control message to the wireless power transmitter100by transmitting user data including the power control message by a communication means (not shown) included in the electronic device (or wireless power receiver)200.

In addition, the power supply unit290may further include a charger (or charging unit)298and a battery299.

The electronic device (or wireless power receiver)200receiving power for operation from the power supply unit290may be operated by power transferred from the wireless power transmitter100, or operated by charging the battery299using the transferred power and then receiving the charged power. At this time, the power reception control unit (or power receiving control unit)292may control the charger (or charging unit)298to perform charging using the transferred power.

In one exemplary embodiment, the plurality of electronic devices may receive power from the wireless power transmitter100. Here, collision may occur between wireless power signals which have been modulated by the plurality of electronic devices. Hence, the constituent elements included in the wireless power transmitter100may perform various operations to avoid such collision between the modulated wireless power signals.

In one exemplary embodiment, the power receiving unit291may receive the wireless power signal for the power transmission from the wireless power transmitter.

Here, the power reception control unit (or power receiving control unit)292may control the power receiving unit291to transmit a third response signal corresponding to the wireless power signal after a time interval set to a first time within the first response period (Tping interval_1).

In one exemplary embodiment, the power reception control unit (or power receiving control unit)292may determine whether or not the power transmission of the wireless power transmitter100has been reset due to collision between the modulated wireless power signal, and set the time interval to a second time when the power transmission has been reset according to the determination result.

In one exemplary embodiment, the power reception control unit (or power receiving control unit)292may control the power receiving unit291to transmit a fourth response signal corresponding to the wireless power signal after the time interval set to the second time within the second response period (Tping interval_2). The second time may be decided by a value obtained by generating a random number.

Hereinafter, a wireless power transmitter and an electronic device applicable to the embodiments disclosed herein will be described.

First, a method of allowing the wireless power transmitter to transfer power to the electronic device according to the inductive coupling method will be described with reference toFIGS. 3 through 5.

FIG. 3is a view illustrating a concept in which power is transferred from a wireless power transmitter to an electronic device in a wireless manner according to an inductive coupling method.

When the power of the wireless power transmitter100is transferred in an inductive coupling method, if the strength of a current flowing through a primary coil within the power transmission unit110is changed, then a magnetic field passing through the primary coil will be changed by the current. The changed magnetic field generates an induced electromotive force at a secondary coil in the electronic device (or wireless power receiver)200.

According to the foregoing method, the power conversion unit111of the wireless power transmitter100may include a transmitting (Tx) coil1111abeing operated as a primary coil in magnetic induction. Furthermore, the power receiving unit291of the electronic device (or wireless power receiver)200may include a receiving (Rx) coil2911abeing operated as a secondary coil in magnetic induction.

First, the wireless power transmitter100and electronic device (or wireless power receiver)200are disposed in such a manner that the transmitting (Tx) coil1111aat the side of the wireless power transmitter100and the receiving coil at the side of the electronic device (or wireless power receiver)200are located adjacent to each other. Then, if the power transmission control unit112controls a current of the transmitting (Tx) coil1111ato be changed, then the power receiving unit291controls power to be supplied to the electronic device (or wireless power receiver)200using an electromotive force induced to the receiving (Rx) coil2911a.

The efficiency of wireless power transfer by the inductive coupling method may be little affected by a frequency characteristic, but affected by an alignment and distance between the wireless power transmitter100and the electronic device (or wireless power receiver)200including each coil.

On the other hand, in order to perform wireless power transfer in the inductive coupling method, the wireless power transmitter100may be configured to include an interface surface (not shown) in the form of a flat surface. One or more electronic devices may be placed at an upper portion of the interface surface, and the transmitting (Tx) coil1111amay be mounted at a lower portion of the interface surface. In this case, a vertical spacing is formed in a small-scale between the transmitting (Tx) coil1111amounted at a lower portion of the interface surface and the receiving (Rx) coil2911aof the electronic device (or wireless power receiver)200placed at an upper portion of the interface surface, and thus a distance between the coils becomes sufficiently small to efficiently implement contactless power transfer by the inductive coupling method.

Furthermore, an alignment indicator (not shown) indicating a location where the electronic device (or wireless power receiver)200is to be placed at an upper portion of the interface surface. The alignment indicator indicates a location of the electronic device (or wireless power receiver)200where an alignment between the transmitting (Tx) coil1111amounted at a lower portion of the interface surface and the receiving (Rx) coil2911acan be suitably implemented. The alignment indicator may alternatively be simple marks, or may be formed in the form of a protrusion structure for guiding the location of the electronic device (or wireless power receiver)200. Otherwise, the alignment indicator may be formed in the form of a magnetic body such as a magnet mounted at a lower portion of the interface surface, thereby guiding the coils to be suitably arranged by mutual magnetism to a magnetic body having an opposite polarity mounted within the electronic device (or wireless power receiver)200.

On the other hand, the wireless power transmitter100may be formed to include one or more transmitting coils. The wireless power transmitter100may selectively use some of coils suitably arranged with the receiving (Rx) coil2911aof the electronic device (or wireless power receiver)200among the one or more transmitting coils to enhance the power transmission efficiency. The wireless power transmitter100including the one or more transmitting coils will be described later with reference toFIG. 5.

Hereinafter, a configuration of the wireless power transmitter and electronic device using an inductive coupling method applicable to the embodiments disclosed herein will be described in detail.

FIGS. 4A and 4Bare a block diagram illustrating part of the wireless power transmitter100and electronic device (or wireless power receiver)200in a magnetic induction method that can be employed in the embodiments disclosed herein. A configuration of the power transmission unit110included in the wireless power transmitter100will be described with reference toFIG. 4A, and a configuration of the power supply unit290included in the electronic device (or wireless power receiver)200will be described with reference toFIG. 4B.

Referring toFIG. 4A, the power conversion unit111of the wireless power transmitter100may include a transmitting (Tx) coil1111aand an inverter1112.

The transmitting (Tx) coil1111amay form a magnetic field corresponding to the wireless power signal according to a change of current as described above. The transmitting (Tx) coil1111amay alternatively be implemented with a planar spiral type or cylindrical solenoid type.

The inverter1112transforms a DC input obtained from the power supply unit190into an AC waveform. The AC current transformed by the inverter1112drives a resonant circuit including the transmitting (Tx) coil1111aand a capacitor (not shown) to form a magnetic field in the transmitting (Tx) coil1111a.

In addition, the power conversion unit111may further include a positioning unit1114.

The positioning unit1114may move or rotate the transmitting (Tx) coil1111ato enhance the effectiveness of contactless power transfer using the inductive coupling method. As described above, it is because an alignment and distance between the wireless power transmitter100and the electronic device (or wireless power receiver)200including a primary coil and a secondary coil may affect power transfer using the inductive coupling method. In particular, the positioning unit1114may be used when the electronic device (or wireless power receiver)200does not exist within an active area of the wireless power transmitter100.

Accordingly, the positioning unit1114may include a drive unit (not shown) for moving the transmitting (Tx) coil1111asuch that a center-to-center distance of the transmitting (Tx) coil1111aof the wireless power transmitter100and the receiving (Rx) coil2911aof the electronic device (or wireless power receiver)200is within a predetermined range, or rotating the transmitting (Tx) coil1111asuch that the centers of the transmitting (Tx) coil1111aand the receiving (Rx) coil2911aare overlapped with each other.

For this purpose, the wireless power transmitter100may further include a detection unit (not shown) made of a sensor for detecting the location of the electronic device (or wireless power receiver)200, and the power transmission control unit112may control the positioning unit1114based on the location information of the electronic device (or wireless power receiver)200received from the location detection sensor.

Furthermore, to this end, the power transmission control unit112may receive control information on an alignment or distance to the electronic device (or wireless power receiver)200through the power communications modulation/demodulation unit113, and control the positioning unit1114based on the received control information on the alignment or distance.

If the power conversion unit111is configured to include a plurality of transmitting coils, then the positioning unit1114may determine which one of the plurality of transmitting coils is to be used for power transmission. The configuration of the wireless power transmitter100including the plurality of transmitting coils will be described later with reference toFIG. 5.

On the other hand, the power conversion unit111may further include a power sensing unit1115. The power sensing unit1115at the side of the wireless power transmitter100monitors a current or voltage flowing into the transmitting (Tx) coil1111a. The power sensing unit1115is provided to check whether or not the wireless power transmitter100is normally operated, and thus the power sensing unit1115may detect a voltage or current of the power supplied from the outside, and check whether the detected voltage or current exceeds a threshold value. The power sensing unit1115, although not shown, may include a resistor for detecting a voltage or current of the power supplied from the outside and a comparator for comparing a voltage value or current value of the detected power with a threshold value to output the comparison result. Based on the check result of the power sensing unit1115, the power transmission control unit112may control a switching unit (not shown) to cut off power applied to the transmitting (Tx) coil1111a.

Referring toFIG. 4B, the power supply unit290of the electronic device (or wireless power receiver)200may include a receiving (Rx) coil2911aand a rectifier (or rectifying) circuit2913.

A current is induced into the receiving (Rx) coil2911aby a change of the magnetic field formed in the transmitting (Tx) coil1111a. The implementation type of the receiving (Rx) coil2911amay be a planar spiral type or cylindrical solenoid type similarly to the transmitting (Tx) coil1111a.

Furthermore, series and parallel capacitors may be configured to be connected to the receiving (Rx) coil2911ato enhance the effectiveness of wireless power reception or perform resonant detection.

The receiving (Rx) coil2911amay be in the form of a single coil or a plurality of coils.

The rectifier (or rectifying) circuit2913performs a full-wave rectification to a current to convert alternating current into direct current. The rectifier (or rectifying) circuit2913, for instance, may be implemented with a full-bridge rectifier generation circuit made of four diodes or a circuit using active components.

In addition, the rectifier (or rectifying) circuit2913may further include a regulator circuit for converting a rectified current into a more flat and stable direct current. Furthermore, the output power of the rectifier (or rectifying) circuit2913is supplied to each constituent element of the power supply unit290. Furthermore, the rectifier (or rectifying) circuit2913may further include a DC-DC converter for converting output DC power into a suitable voltage to adjust it to the power required for each constituent element (for instance, a circuit such as a charger (or charging unit)298).

The power communications modulation/demodulation unit293may be connected to the power receiving unit291, and may be configured with a resistive element in which resistance varies with respect to direct current, and may be configured with a capacitive element in which reactance varies with respect to alternating current. The Power reception control unit (or power receiving control unit)292may change the resistance or reactance of the power communications modulation/demodulation unit293to modulate a wireless power signal received to the power receiving unit291.

On the other hand, the power supply unit290may further include a power sensing unit2914. The power sensing unit2914at the side of the electronic device (or wireless power receiver)200monitors a voltage and/or current of the power rectified by the rectifier (or rectifying) circuit2913, and if the voltage and/or current of the rectified power exceeds a threshold value as a result of monitoring, then the power reception control unit (or power receiving control unit)292transmits a power control message to the wireless power transmitter100to transfer suitable power.

FIG. 5is a block diagram illustrating a wireless power transmitter configured to have one or more transmitting coils receiving power according to an inductive coupling method that can be employed in the embodiments disclosed herein. Referring toFIG. 5, the power conversion unit111of the wireless power transmitter100according to the embodiments disclosed herein may include one or more transmitting coils1111a-1to1111a-n. The one or more transmitting coils1111a-1to1111a-nmay be an array of partly overlapping primary coils. An active area may be determined by some of the one or more transmitting coils.

The one or more transmitting coils1111a-1to1111a-nmay be mounted at a lower portion of the interface surface. Furthermore, the power conversion unit111may further include a multiplexer1113for establishing and releasing the connection of some of the one or more transmitting coils1111a-1to1111a-n.

Upon detecting the location of the electronic device (or wireless power receiver)200placed at an upper portion of the interface surface, the power transmission control unit112may take the detected location of the electronic device (or wireless power receiver)200into consideration to control the multiplexer1113, thereby allowing coils that can be placed in an inductive coupling relation to the receiving (Rx) coil2911aof the electronic device (or wireless power receiver)200among the one or more transmitting coils1111a-1to1111a-nto be connected to one another.

For this purpose, the power transmission control unit112may acquire the location information of the electronic device (or wireless power receiver)200. For example, the power transmission control unit112may acquire the location of the electronic device (or wireless power receiver)200on the interface surface by the location detection unit (not shown) provided in the wireless power transmitter100. For another example, the power transmission control unit112may alternatively receive a power control message indicating a strength of the wireless power signal from an object on the interface surface or a power control message indicating the identification information of the object using the one or more transmitting coils1111a-1to1111a-n, respectively, and determines whether it is located adjacent to which one of the one or more transmitting coils based on the received result, thereby acquiring the location information of the electronic device (or wireless power receiver)200.

On the other hand, the active area as part of the interface surface may denote a portion through which a magnetic field with a high efficiency can pass when the wireless power transmitter100transfers power to the electronic device (or wireless power receiver)200in a wireless manner. At this time, a single transmitting coil or one or a combination of more transmitting coils forming a magnetic field passing through the active area may be designated as a primary cell. Accordingly, the power transmission control unit112may determine an active area based on the detected location of the electronic device (or wireless power receiver)200, and establish the connection of a primary cell corresponding to the active area to control the multiplexer1113, thereby allowing the receiving (Rx) coil2911aof the electronic device (or wireless power receiver)200and the coils belonging to the primary cell to be placed in an inductive coupling relation.

In the meantime, upon disposing one or more electronic devices200on an interface surface of the wireless power transmitter100, which includes the one or more transmitting coils1111a-1to1111a-n, the power transmission control unit112may control the multiplexer1113to allow the coils belonging to the primary cell corresponding to the position of each electronic device to be placed in the inductive coupling relation. Accordingly, the wireless power transmitter100may generate the wireless power signal using different coils, thereby transferring it to the one or more electronic devices in a wireless manner.

Also, the power transmission control unit112may set power having a different characteristic to be supplied to each of the coils corresponding to the electronic devices. Here, the wireless power transmitter100may transfer power by differently setting a power transfer scheme, efficiency, characteristic and the like for each electronic device. The power transmission for one or more electronic devices will be described later.

Furthermore, the power conversion unit111may further include an impedance matching unit (not shown) for controlling an impedance to form a resonant circuit with the coils connected thereto.

Hereinafter, a method for allowing a wireless power transmitter to transfer power according to a resonance coupling method will be disclosed with reference toFIGS. 6 through 8.

FIG. 6is a view illustrating a concept in which power is transferred to an electronic device from a wireless power transmitter in a wireless manner according to an resonance coupling method.

First, resonance will be described in brief as follows. Resonance refers to a phenomenon in which an amplitude of vibration is remarkably increased when periodically receiving an external force having the same frequency as the natural frequency of a vibration system. Resonance is a phenomenon occurring at all kinds of vibrations such as mechanical vibration, electric vibration, and the like. Generally, when exerting a vibratory force to a vibration system from the outside, if the natural frequency thereof is the same as a frequency of the externally applied force, then the vibration becomes strong, thus increasing the width.

With the same principle, when a plurality of vibrating bodies separated from one another within a predetermined distance vibrate at the same frequency, the plurality of vibrating bodies resonate with one another, and in this case, resulting in a reduced resistance between the plurality of vibrating bodies. In an electrical circuit, a resonant circuit can be made by using an inductor and a capacitor.

When the wireless power transmitter100transfers power according to the inductive coupling method, a magnetic field having a specific vibration frequency is formed by alternating current power in the power transmission unit110. If a resonance phenomenon occurs in the electronic device (or wireless power receiver)200by the formed magnetic field, then power is generated by the resonance phenomenon in the electronic device (or wireless power receiver)200.

However, if the plurality of vibrating bodies resonates with each other in an electromagnetic manner as aforementioned, extremely high power transmission efficiency may be exhibited due to non affection by adjacent objects except for the vibrating bodies. An energy tunnel may be generated between the plurality of vibrating bodies which resonate with each other in the electromagnetic manner. This may be referred to as energy coupling or energy tail.

The resonance coupling disclosed herein may use an electromagnetic wave having a low frequency. When power is transferred using the electromagnetic wave having the low frequency, only a magnetic field may affect an area located within a single wavelength of the electromagnetic wave. The magnetic resonance may be generated when the wireless power transmitter100and the electronic device (or wireless power receiver)200are located within the single wavelength of the electromagnetic wave having the low frequency.

Here, in general, human bodies are sensitive to an electric field but tolerant to a magnetic field. Hence, when power is transferred using a magnetic resonance, the human bodies may be badly affected due to being exposed to the electromagnetic wave. Also, as the energy tail is generated in response to the resonance phenomenon, the form of power transmission may exhibit a non-radiative property. Consequently, upon transferring power using such electromagnetic wave, a radiative problem which occurs frequently may be solved.

The resonance coupling method may be a method for transferring power using the electromagnetic wave with the low frequency, as aforementioned. Thus, the transmitting (Tx) coil1111bof the wireless power transmitter100may form a magnetic field or electromagnetic wave for transferring power in principle. However, the resonance coupling method will be described hereinafter from the perspective of a magnetic resonance, namely, a power transmission by a magnetic field.

The resonant frequency may be determined by the following formula in Equation 1.

Here, the resonant frequency (f) is determined by an inductance (L) and a capacitance (c) in a circuit. In a circuit forming a magnetic field using a coil, the inductance can be determined by a number of turns of the coil, and the like, and the capacitance can be determined by a gap between the coils, an area, and the like. In addition to the coil, a capacitive resonant circuit may be configured to be connected thereto to determine the resonant frequency.

Referring toFIG. 6, when power is transmitted in a wireless manner according to the resonance coupling method, the power conversion unit111of the wireless power transmitter100may include a transmitting (Tx) coil1111bin which a magnetic field is formed and a resonant circuit (or resonant generation circuit)1116connected to the transmitting (Tx) coil1111bto determine a specific vibration frequency. The resonant circuit (or resonant generation circuit)1116may be implemented by using a capacitive circuit (capacitors), and the specific vibration frequency may be determined based on an inductance of the transmitting (Tx) coil1111band a capacitance of the resonant circuit (or resonant generation circuit)1116.

The configuration of a circuit element of the resonant circuit (or resonant generation circuit)1116may be implemented in various forms such that the power conversion unit111forms a magnetic field, and is not limited to a form of being connected in parallel to the transmitting (Tx) coil1111bas illustrated inFIG. 6.

Furthermore, the power receiving unit291of the electronic device (or wireless power receiver)200may include a resonant circuit (or resonant generation circuit)2912and a receiving (Rx) coil2911bto generate a resonance phenomenon by a magnetic field formed in the wireless power transmitter100. In other words, the resonant circuit (or resonant generation circuit)2912may be also implemented by using a capacitive circuit, and the resonant circuit (or resonant generation circuit)2912is configured such that a resonant frequency determined based on an inductance of the receiving coil2911band a capacitance of the resonant circuit (or resonant generation circuit)2912has the same frequency as a resonant frequency of the formed magnetic field.

The configuration of a circuit element of the resonant circuit (or resonant generation circuit)2912may be implemented in various forms such that the power receiving unit291generates resonance by a magnetic field, and is not limited to a form of being connected in series to the receiving coil2911bas illustrated inFIG. 6.

The specific vibration frequency in the wireless power transmitter100may have LTX, CTX, and may be acquired by using the Equation 1. Here, the electronic device (or wireless power receiver)200generates resonance when a result of substituting the LRX and CRX of the electronic device (or wireless power receiver)200to the Equation 1 is same as the specific vibration frequency.

According to a contactless power transfer method by resonance coupling, when the wireless power transmitter100and electronic device (or wireless power receiver)200resonate at the same frequency, respectively, an electromagnetic wave is propagated through a short-range magnetic field, and thus there exists no energy transfer between the devices if they have different frequencies.

As a result, an efficiency of contactless power transfer by the resonance coupling method is greatly affected by a frequency characteristic, whereas the effect of an alignment and distance between the wireless power transmitter100and the electronic device (or wireless power receiver)200including each coil is relatively smaller than the inductive coupling method.

Hereinafter, the configuration of a wireless power transmitter and an electronic device in the resonance coupling method applicable to the embodiments disclosed herein will be described in detail.

FIGS. 7A and 7Bis a block diagram illustrating part of the wireless power transmitter100and electronic device (or wireless power receiver)200in a resonance method that can be employed in the embodiments disclosed herein.

A configuration of the power transmission unit110included in the wireless power transmitter100will be described with reference toFIG. 7A.

The power conversion unit111of the wireless power transmitter100may include a transmitting (Tx) coil1111b, an inverter1112, and a resonant circuit (or resonant generation circuit)1116. The inverter1112may be configured to be connected to the transmitting (Tx) coil1111band the resonant circuit (or resonant generation circuit)1116.

The transmitting (Tx) coil1111bmay be mounted separately from the transmitting (Tx) coil1111afor transferring power according to the inductive coupling method, but may transfer power in the inductive coupling method and resonance coupling method using one single coil.

The transmitting (Tx) coil1111b, as described above, forms a magnetic field for transferring power. The transmitting (Tx) coil1111band the resonant circuit (or resonant generation circuit)1116generate resonance when alternating current power is applied thereto, and at this time, a vibration frequency may be determined based on an inductance of the transmitting (Tx) coil1111band a capacitance of the resonant circuit (or resonant generation circuit)1116.

For this purpose, the inverter1112transforms a DC input obtained from the power supply unit190into an AC waveform, and the transformed AC current is applied to the transmitting (Tx) coil1111band the resonant circuit (or resonant generation circuit)1116.

In addition, the power conversion unit111may further include a frequency adjustment unit1117for changing a resonant frequency of the power conversion unit111. The resonant frequency of the power conversion unit111is determined based on an inductance and/or capacitance within a circuit constituting the power conversion unit111by Equation 1, and thus the power transmission control unit112may determine the resonant frequency of the power conversion unit111by controlling the frequency adjustment unit1117to change the inductance and/or capacitance.

The frequency adjustment unit1117, for example, may be configured to include a motor for adjusting a distance between capacitors included in the resonant circuit (or resonant generation circuit)1116to change a capacitance, or include a motor for adjusting a number of turns or diameter of the transmitting (Tx) coil1111bto change an inductance, or include active elements for determining the capacitance and/or inductance

On the other hand, the power conversion unit111may further include a power sensing unit1115. The operation of the power sensing unit1115is the same as the foregoing description.

Referring toFIG. 7B, a configuration of the power supply unit290included in the electronic device (or wireless power receiver)200will be described. The power supply unit290, as described above, may include the receiving (Rx) coil2911band resonant circuit (or resonant generation circuit)2912.

In addition, the power receiving unit291of the power supply unit290may further include a rectifier (or rectifying) circuit2913for converting an AC current generated by resonance phenomenon into DC. The rectifier (or rectifying) circuit2913may be configured similarly to the foregoing description.

Furthermore, the power receiving unit291may further include a power sensing unit2914for monitoring a voltage and/or current of the rectified power. The power sensing unit2914may be configured similarly to the foregoing description.

FIG. 8is a block diagram illustrating a wireless power transmitter configured to have one or more transmitting coils receiving power according to a resonance coupling method that can be employed in the embodiments disclosed herein. Referring toFIG. 8, the power conversion unit111of the wireless power transmitter100according to the embodiments disclosed herein may include one or more transmitting coils1111b-1to1111b-nand resonant (or resonant generation) circuits (1116-1to1116-n) connected to each transmitting coils. Furthermore, the power conversion unit111may further include a multiplexer1113for establishing and releasing the connection of some of the one or more transmitting coils1111b-1to1111b-n.

The one or more transmitting coils1111b-1to1111b-nmay be configured to have the same vibration frequency, or some of them may be configured to have different vibration frequencies. It is determined by an inductance and/or capacitance of the resonant (or resonant generation) circuits (1116-1to1116-n) connected to the one or more transmitting coils1111b-1to1111b-n, respectively.

In the meantime, when one or more electronic devices200are disposed in an active area or a detection area of the wireless power transmitter100including the one or more transmitting coils1111b-1to1111b-n, the power transmission control unit112may control the multiplexer1113to allow the electronic devices to be placed in different resonance coupling relations. Accordingly, the wireless power transmitter100may wirelessly transfer power to the one or more electronic devices by generating the wireless power signal using different coils.

In addition, the power transmission control unit112may set power with a different characteristic to be supplied to each of the coils corresponding to the electronic devices. Here, the wireless power transmitter100may transfer power by differently setting a power transmission scheme, a resonant frequency, efficiency, a characteristic and the like for each electronic device. The power transmission for one or more electronic devices will be described later with reference to FIG.28. For this purpose, the frequency adjustment unit1117may be configured to change an inductance and/or capacitance of the resonant circuits (1116-1to1116-n) connected to the one or more transmitting coils1111b-1to1111b-n, respectively.

On the other hand, hereinafter, an example of the wireless power transmitter implemented in the form of a wireless charger will be described.

FIG. 9is a block diagram illustrating a wireless power transmitter further including an additional element in addition to the configuration illustrated inFIG. 2A. Referring toFIG. 9, the wireless power transmitter100may further include a sensor unit120, a communication unit130, an output unit140, a memory150, and a control unit (or Controller)180in addition to the power transmission unit110and power supply unit190for supporting at least one of the foregoing inductive coupling method and resonance coupling method.

The control unit (or Controller)180controls the power transmission unit110, the sensor unit120, the communication unit130, the output unit140, the memory150, and the power supply unit190.

The control unit (or Controller)180may be implemented by a module separated from the power transmission control unit112in the power transmission unit110described with reference toFIG. 2or may be implemented by a single module.

The sensor unit120may include a sensor for detecting the location of the electronic device (or wireless power receiver)200. The location information detected by the sensor unit120may be used for allowing the power transmission unit110to transfer power in an efficient manner.

For instance, in case of wireless power transfer according to the inductive coupling method, the sensor unit120may be operated as a detection unit, and the location information detected by the sensor unit120may be used to move or rotate the transmitting (Tx) coil1111ain the power transmission unit110.

Furthermore, for example, the wireless power transmitter100configured to include the foregoing one or more transmitting coils may determine coils that can be placed in an inductive coupling relation or resonance coupling relation to the receiving coil of the electronic device (or wireless power receiver)200among the one or more transmitting coils based on the location information of the electronic device (or wireless power receiver)200.

On the other hand, the sensor unit120may be configured to monitor whether or not the electronic device (or wireless power receiver)200approaches a chargeable region. The approach or non-approach detection function of the sensor unit120may be carried out separately from the function of allowing the power transmission control unit112in the power transmission unit110to detect the approach or non-approach of the electronic device (or wireless power receiver)200.

The communication unit130performs wired or wireless data communication with the electronic device (or wireless power receiver)200. The communication unit130may include an electronic component for at least any one of Bluetooth™, Zigbee, Ultra Wide Band (UWB), Wireless USB, Near Field Communication (NFC), and Wireless LAN.

The output unit140may include at least one of a display unit141and an audio output unit (or sound output unit)142. The display unit141may include at least one of a liquid crystal display (LCD), a thin film transistor-liquid crystal display (TFT-LCD), an organic light-emitting diode (OLED), a flexible display, and a three-dimensional (3D) display. The display unit141may display a charging state under the control of the control unit (or Controller)180.

The memory150may include at least one storage medium of a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., SD or XD memory), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, and the like. The wireless power transmitter100may operate in association with a web storage performing the storage function of the memory150on the Internet. A program or commands performing the foregoing functions of the wireless power transmitter100may be stored in the memory150. The control unit (or Controller)180may perform the program or commands stored in the memory150to transmit power in a wireless manner. A memory controller (not shown) may be used to allow other constituent elements (e.g., control unit (or Controller)180) included in the wireless power transmitter100to access the memory150.

However, it would be easily understood by those skilled in the art that the configuration of a wireless power transmitter according to the embodiment disclosed herein may be applicable to an apparatus, such as a docking station, a terminal cradle device, and an electronic device, and the like, excluding a case where it is applicable to only a wireless charger.

FIG. 10is view illustrating a configuration in case where an electronic device (or wireless power receiver)200according to the embodiments disclosed herein is implemented in the form of a mobile terminal.

Furthermore, the terminal200may further include a wireless communication unit210, an Audio/Video (A/V) input unit220, a user input unit230, a sensing unit240, an output unit250, a memory260, an interface unit270, and a controller280.FIG. 10illustrates the terminal100having various components, but it is understood that implementing all of the illustrated components is not a requirement. Greater or fewer components may alternatively be implemented.

Hereinafter, each component is described in sequence.

The wireless communication unit210may typically include one or more modules which permit wireless communications between the terminal200and a wireless communication system or between the terminal200and a network within which the terminal200is located. For example, the wireless communication unit210may include a broadcast receiving module211, a mobile communication module212, a wireless internet module213, a short-range communication module214, a position information module215and the like.

The broadcast receiving module211receives a broadcast signal and/or broadcast associated information from an external broadcast managing entity via a broadcast channel.

The broadcast channel may include a satellite channel and a terrestrial channel. The broadcast center may indicate a server which generates and transmits a broadcast signal and/or broadcast associated information or a server which receives a pre-generated broadcast signal and/or broadcast associated information and sends them to the portable terminal. The broadcast signal may be implemented as a TV broadcast signal, a radio broadcast signal, and a data broadcast signal, among others. The broadcast signal may further include a data broadcast signal combined with a TV or radio broadcast signal.

Examples of broadcast associated information may denote information associated with a broadcast channel, a broadcast program, a broadcast service provider, and the like. The broadcast associated information may be provided via a mobile communication network. In this case, it may be received by the mobile communication module212.

The broadcast associated information may be implemented in various formats. For instance, broadcast associated information may include Electronic Program Guide (EPG) of Digital Multimedia Broadcasting (DMB), Electronic Service Guide (ESG) of Digital Video Broadcast-Handheld (DVB-H), and the like.

The broadcast receiving module211may be configured to receive digital broadcast signals transmitted from various types of broadcast systems. Such broadcast systems may include Digital Multimedia Broadcasting-Terrestrial (DMB-T), Digital Multimedia Broadcasting-Satellite (DMB-S), Media Forward Link Only (MediaFLO), Digital Video Broadcast-Handheld (DVB-H), Integrated Services Digital Broadcast-Terrestrial (ISDB-T) and the like. The broadcast receiving module211may be configured to be suitable for every broadcast system transmitting broadcast signals as well as the digital broadcasting systems.

Broadcast signals and/or broadcast associated information received via the broadcast receiving module211may be stored in a suitable device, such as a memory260.

The mobile communication module212transmits/receives wireless signals to/from at least any one of a base station, an external portable terminal, and a server on a mobile communication network. The wireless signal may include audio call signal, video (telephony) call signal, or various formats of data according to transmission/reception of text/multimedia messages.

The wireless internet module213supports wireless Internet access for the mobile terminal200. This module may be internally or externally coupled to the terminal100. Examples of such wireless Internet access may include Wireless LAN (WLAN) (Wi-Fi), Wireless Broadband (Wibro), Worldwide Interoperability for Microwave Access (Wimax), High Speed Downlink Packet Access (HSDPA) and the like.

The short-range communication module214denotes a module for short-range communications. Suitable technologies for implementing this module may include Bluetooth, Radio Frequency IDentification (RFID), Infrared Data Association (IrDA), Ultra-WideBand (UWB), ZigBee, and the like. On the other hand, Universal Serial Bus (USB), IEEE 1394, Thunderbolt of Intel technology, and the like, may be used for wired short-range communication.

The wireless internet module213or the short-range communication module214may establish data communication connection to the wireless power transmitter100.

Through the established data communication, when there is an audio signal to be outputted while transferring power in a wireless manner, the wireless internet module213or the short-range communication module214may transmit the audio signal to the wireless power transmitter100through the short-range communication module. Furthermore, through the established data communication, when there is information to be displayed, the wireless internet module213or the short-range communication module214may transmit the information to the wireless power transmitter100. Otherwise, the wireless internet module213or the short-range communication module214may transmit an audio signal received through a microphone integrated in the wireless power transmitter100. Furthermore, the wireless internet module213or the short-range communication module214may transmit the identification information (e.g., phone number or device name in case of a portable phone) of the mobile terminal200to the wireless power transmitter100through the established data communication.

The position information module215is a module for acquiring a position of the terminal. An example of the position information module215may include a Global Position System (GPS) module.

Referring toFIG. 10, the A/V input unit220is configured to provide audio or video signal input to the portable terminal. The A/V input unit220may include a camera221and a microphone222. The camera221processes image frames of still or moving images obtained by an image sensor in a video call mode or a capture more. The processed image frames may be displayed on the display unit251.

The image frames processed by the camera221may be stored in the memory260or transmitted to the exterior via the wireless communication unit210. Two or more cameras221may be provided therein according to the use environment.

The microphone222may receive an external audio signal by a microphone in a phone call mode, a recording mode, a voice recognition mode, or the like to process it into electrical audio data. The processed audio data is converted and outputted into a format transmittable to a mobile communication base station via the mobile communication module212in case of the phone call mode. The microphone222may include various noise removal algorithms to remove noises generated while receiving the external audio signal.

The user input unit230may generate input data to allow the user to control the operation of the terminal. The user input unit230may include a keypad, a dome switch, a touchpad (e.g., static pressure/capacitance), a jog wheel, a jog switch and the like.

The sensing unit240may include a proximity sensor241, a pressure sensor242, a motion sensor243, and the like. The proximity sensor241detects an object approaching the mobile terminal200, or the presence or absence of an object existing adjacent to the mobile terminal200, and the like without any mechanical contact. The proximity sensor241may detect a proximity object using a change of the AC magnetic field or static magnetic field, a change rate of the electrostatic capacity, or the like. Two or more proximity sensors241may be provided according to the aspect of configuration.

The pressure sensor242may detect whether or not a pressure is applied to the mobile terminal200, a size of the pressure, and the like. The pressure sensor242may be provided at a portion where the detection of a pressure is required in the mobile terminal200according to the use environment. When the pressure sensor242is provided in the display unit251, it may be possible to identify a touch input through the display unit251and a pressure touch input by which a pressure larger than the touch input is applied according to a signal outputted from the pressure sensor242. Furthermore, it may be possible to know a size of the pressure applied to the display unit251during the input of a pressure touch.

The motion sensor243detects the location or movement of the mobile terminal200using an acceleration sensor, a gyro sensor, and the like. The acceleration sensor used in the motion sensor243is an element for converting an acceleration change in any one direction into an electrical signal. Two or three axes are typically integrated into a package to constitute an acceleration sensor, and only one Z-axis may be required according to the use environment. Accordingly, when an acceleration sensor in the direction of X-axis or Y-axis should be used instead of the direction of Z-axis due to any reason, the acceleration sensor may be erected and mounted on a main substrate using a separate piece substrate. Furthermore, the gyro sensor is a sensor for measuring an angular speed of the mobile terminal200in a rotational movement to detect a rotated angle with respect to each reference direction. For instance, the gyro sensor may detect each rotational angle, i.e., azimuth, pitch and roll, with reference to three directional axes.

The output unit250is provided to output visual, auditory, or tactile information. The output unit250may include a display unit251, an audio output module252, an alarm unit253, a haptic module254, and the like.

The display unit251may display (output) information processed in the terminal200. For example, when the terminal is in a phone call mode, the display unit251will provide a User Interface (UI) or Graphic User Interface (GUI) associated with the call. When the terminal is in a video call mode or a capture mode, the display unit251may display images captured and/or received, UI, or GUI.

Some of those displays may be configured as a transparent type or a light transmission type through which the outside is visible, which is referred to as a transparent display. A representative example of the transparent display may include a Transparent OLED (TOLED), or the like. The rear surface of the display unit151may also be implemented to be optically transparent. Under this configuration, the user can view an object positioned at a rear side of the terminal body through a region occupied by the display unit251of the terminal body.

The display unit251may be implemented in two or more in number according to a configured aspect of the terminal200. For instance, a plurality of the display units251may be arranged on one surface to be spaced apart from or integrated with each other, or may be arranged on different surfaces.

Here, if the display unit251and a touch sensitive sensor (referred to as a touch sensor) have a layered structure therebetween, the display unit251may be used as an input device rather than an output device. The touch sensor may be implemented as a touch film, a touch sheet, a touch pad, and the like.

The touch sensor may be configured to convert changes of a pressure applied to a specific part of the display unit251, or a capacitance occurring from a specific part of the display unit251, into electric input signals. Also, the touch sensor may be configured to sense not only a touched position and a touched area, but also a touch pressure.

When touch inputs are sensed by the touch sensors, corresponding signals are sent to a touch controller. The touch controller processes the received signals, and then transmits corresponding data to the controller280. Accordingly, the controller280may sense which region of the display unit151has been touched.

The proximity sensor241may be arranged at an inner region of the terminal covered by the touch screen, or near the touch screen. The proximity sensor refers to a sensor to sense the presence or absence of an object approaching a surface to be sensed, or an object disposed near a surface to be sensed, using an electromagnetic field or infrared rays without a mechanical contact. The proximity sensor has a longer lifespan and a more enhanced utility than a contact sensor.

The proximity sensor may include a transmissive type photoelectric sensor, a direct reflective type photoelectric sensor, a mirror reflective type photoelectric sensor, a high-frequency oscillation proximity sensor, a capacitance type proximity sensor, a magnetic type proximity sensor, an infrared rays proximity sensor, and so on. When the touch screen is implemented as a capacitance type, proximity of a pointer to the touch screen is sensed by changes of an electromagnetic field. In this case, the touch screen (touch sensor) may be categorized into a proximity sensor.

Hereinafter, for the sake of brief explanation, a status that the pointer is positioned to be proximate onto the touch screen without contact will be referred to as a “proximity touch”, whereas a status that the pointer substantially comes in contact with the touch screen will be referred to as a “contact touch”. For the position corresponding to the proximity touch of the pointer on the touch screen, such position corresponds to a position where the pointer faces perpendicular to the touch screen upon the proximity touch of the pointer.

The proximity sensor senses proximity touch, and proximity touch patterns (e.g., distance, direction, speed, time, position, moving status, etc.). Information relating to the sensed proximity touch and the sensed proximity touch patterns may be output onto the touch screen.

The audio output module252may output audio data received from the wireless communication unit210or stored in the memory260, in a call-receiving mode, a call-placing mode, a recording mode, a voice recognition mode, a broadcast reception mode, and so on. The audio output module252may output audio signals relating to functions performed in the terminal200, e.g., sound alarming a call received or a message received, and so on. The audio output module252may include a receiver, a speaker, a buzzer, and so on.

The alarm253outputs signals notifying the occurrence of an event from the terminal200. The event occurring from the terminal100may include call received, message received, key signal input, touch input, and so on. The alarm253may output not only video or audio signals, but also other types of signals such as signals notifying occurrence of events in a vibration manner. Since the video or audio signals can be output through the display unit251or the audio output unit252, the display unit251and the audio output module252may be categorized into part of the alarm253.

The haptic module254generates various tactile effects which a user can feel. A representative example of the tactile effects generated by the haptic module254includes vibration. Vibration generated by the haptic module254may have a controllable intensity, a controllable pattern, and so on. For instance, different vibration may be output in a synthesized manner or in a sequential manner.

The haptic module254may generate various tactile effects, including not only vibration, but also arrangement of pins vertically moving with respect to a skin being contacted, air injection force or air suction force through an injection hole or a suction hole, touch by a skin surface, presence or absence of contact with an electrode, effects by stimulus such as an electrostatic force, reproduction of cold or hot feeling using a heat absorbing device or a heat emitting device, and the like.

The haptic module254may be configured to transmit tactile effects through the user's direct contact, or the user's muscular sense using a finger or a hand. The haptic module254may be implemented in two or more in number according to the configuration of the terminal200.

The memory260may store a program for the processing and control of the controller280. Alternatively, the memory260may temporarily store input/output data (e.g., phonebook data, messages, still images, video and the like). Also, the memory260may store data related to various patterns of vibrations and audio output upon the touch input on the touch screen.

In some embodiments, software components including an operating system (not shown), a module performing a wireless communication unit210function, a module operating together with the user input unit230, a module operating together with the A/V input unit220, a module operating together with the output unit250may be stored in the memory260. The operating system (e.g., LINUX, UNIX, OS X, WINDOWS, Chrome, Symbian, iOS, Android, VxWorks, or other embedded operating systems) may include various software components and/or drivers to control system tasks such as memory management, power management, and the like.

In addition, the memory260may store a setup program associated with contactless power transfer or wireless charging. The setup program may be implemented by the controller280.

Furthermore, the memory260may store an application associated with contactless power transfer (or wireless charging) downloaded from an application providing server (for example, an app store). The wireless charging related application is a program for controlling wireless charging transmission, and thus the electronic device (or wireless power receiver)200may receive power from the wireless power transmitter100in a wireless manner or establish connection for data communication with the wireless power transmitter100through the relevant program.

The memory260may be implemented using any type of suitable storage medium including a flash memory type, a hard disk type, a multimedia card micro type, a memory card type (e.g., SD or xD memory), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, and the like. Also, the terminal200may be operated in association with a web storage performing the storage function of the memory150on the Internet.

The interface unit270may generally be implemented to interface the portable terminal with all external devices. The interface unit270may allow a data reception from an external device, a power delivery to each component in the terminal200, or a data transmission from the terminal200to an external device. The interface unit270may include, for example, wired/wireless headset ports, external charger ports, wired/wireless data ports, memory card ports, ports for coupling devices having an identification module, audio input/output (I/O) ports, video input/output (I/O) ports, earphone ports, and the like.

The identification module may be configured as a chip for storing various information required to authenticate an authority to use the terminal200, which may include a User Identity Module (UIM), a Subscriber Identity Module (SIM), and the like. Also, the device having the identification module (hereinafter, referred to as “identification device”) may be implemented in a type of smart card. Hence, the identification device can be coupled to the terminal200via a port.

Also, the interface unit may serve as a path for power to be supplied from an external cradle to the terminal200when the terminal100is connected to the external cradle or as a path for transferring various command signals inputted from the cradle by a user to the terminal200. Such various command signals or power inputted from the cradle may operate as signals for recognizing that the terminal200has accurately been mounted to the cradle.

The controller280typically controls the overall operations of the terminal200. For example, the controller280performs the control and processing associated with telephony calls, data communications, video calls, and the like. The controller280may include a multimedia module281for multimedia playback. The multimedia module281may be implemented within the controller280, or implemented separately from the controller280.

The controller280can perform a pattern recognition processing so as to recognize a writing input or image drawing input carried out on the touch screen as a text or image.

The controller280performs wired or wireless charging according to the user input or internal input. Here, the internal input represents a signal for notifying that an induced current generated from a secondary coil within the terminal has been detected.

When the foregoing wireless charging is carried out, an operation of allowing the controller280to control each constituent element will be described in detail below with reference to the operation phase inFIG. 14. As described above, the power reception control unit (or power receiving control unit)292within the power supply unit290may be implemented to be included in the controller280, and in the present disclosure, it should be understood that the controller280performs the operation by the power reception control unit (or power receiving control unit)292.

The power supply unit290receives internal and external power under the control of the controller280to supply power required for the operation of each constituent element.

The power supply unit290is provided with a battery299for supplying power to each constituent element of the terminal200, and the battery299may include a charger (or charging unit)298for performing wired or wireless charging.

The present disclosure discloses a mobile terminal as an example of the apparatus for receiving power in a wireless manner, but it would be easily understood by those skilled in the art that the configuration according to the embodiment disclosed herein may be applicable to a stationary terminal, such as a digital TV, a desktop computer, and the like, excluding a case where it is applicable to only the mobile terminal.

FIG. 11is a front perspective view of a wireless power transmitter300according to an embodiment of the present invention.

A body303of the wireless power transmitter300comprises a case (casing, housing, cover, etc.) which forms the appearance of the wireless power transmitter. In this embodiment, the case may include a front case301and a rear case302. A space formed by the front case301and the rear case302may accommodate various components therein. At least one intermediate case may be additionally disposed between the front case301and the rear case302.

Such cases may be formed by injection-molded synthetic resin, or may be formed using a metallic material such as stainless steel (STS) or titanium (Ti).

On the body303, may be disposed an output unit such as a display unit341or an audio output unit342, a user input unit360, a socket389for supplying power to the body303, an interface (not shown) to which an external device is coupled, etc.

The display unit341may be formed on an upper surface of the front case301. The user input unit360, the socket389, etc. may be disposed on side surfaces of the front case301and the rear case302.

The user input unit360is manipulated to receive a command for controlling the operation of the mobile terminal100, and may include a plurality of manipulating units361and362. The manipulating units361and362may be referred to as ‘manipulating portions’, and may include any type of ones that can be manipulated in a user's tactile manner.

Contents input by the first manipulating unit361or the second manipulating unit362may be set in various manners. For instance, the first manipulating unit361may be configured to input commands such as starting and ending a wireless charging operation. And the second manipulating unit362may be configured to input commands such as controlling the size of a sound output from the audio output unit342, or controlling brightness of the display unit341.

A mounting surface301a, which is configured to mount thereon an electronic device200to be charged, is formed on an upper surface of the body303. Once the electronic device200is disposed on the mounting surface301a, a sensor of the body303may sense the mounted state of the electronic device200. Then, the electronic device200may be wirelessly charged.

FIG. 12is an exploded perspective view ofFIG. 11. Referring toFIG. 12, a coil module370, a circuit board355and a blowing module325(refer toFIGS. 13A and 13B) may be disposed at a space formed between the front case301and the rear case302.

As aforementioned, once the electronic device200is disposed on the mounting surface301a, the coil module370transmits power to the electronic device200in a wireless manner.

The coil module370may include a fixing plate372and a coil371. The coil module370may be fixed to the rear case302by the fixing plate372. The fixing plate372may be formed of a material having high thermal conductivity, so that heat generated from the coil371can be emitted to outside of the rear case302. Part of the rear case302, which is covered by the fixing plate372, may include one or more openings so as to facilitate radiation of heat from the fixing plate372.

The coil371may be formed as at least one conductive line is wound on a cylindrical body. A magnet373may be disposed on an inner circumferential surface of a cylindrical coil according to a wireless charging type.

The circuit board355is disposed near the coil module370. The circuit board355includes various types of devices, and generates a wireless power signal if power is supplied thereto. Then, the circuit board355provides the generated wireless power signal to the coil module370. For generation of a wireless power signal, the circuit board355may include one or more devices which constitute a power converter, a power transmission controller or a modulation/demodulation unit.

The blowing module325is configured to discharge a fluid toward a guide module380. For instance, the blowing module325may discharge a fluid under a structure where a fan is installed in a housing and the fan is rotated by a motor. However, in this case, noise may occur. Further, the motor and the fan should be formed to have a size more than a prescribed value, for cooling efficiency. This may cause a limitation in designing the motor and the fan.

The blowing module325, configured to discharge a fluid by transforming a diaphragm325bin a curved manner by a piezoelectric device (refer toFIG. 14), may be applied to the wireless power transmitter300according to the present invention. The blowing module325is configured to discharge a fluid when supplied with an external voltage, by up-down moving part of the diaphragm325bdisposed in the housing, using an actuator including a piezoelectric device. As the diaphragm325b, a metallic plate having a high Young's modulus may be used.

The fluid may be air or cooling water.

FIGS. 13A and 13Bare perspective views of the front case301ofFIG. 11.

As shown inFIGS. 13A and 13B, the guide module380may be integrally formed with the case301to thus form a passage of a fluid, so that heat generated from the coil module370can be discharged to outside of the body303. The guide module380may be extended up to outside of the body303through the blowing module325and the coil module370, sequentially. One or more openings383may be penetratingly formed at the front case301and the rear case302which constitute the body303. The guide module380may be configured to discharge heat generated from inside of the body303to outside through the opening383. That is, the guide module380is formed so that a fluid from the blowing module325can be discharged to outside of the body303after cooling the coil module370.

The guide module380may be integrally formed with one of the front case301and the rear case302which implement the appearance of the body303.

The guide module380may comprise a coil cooling portion381and a circuit board cooling portion382.

The coil cooling portion381has a shape corresponding to an outer circumference of the coil371. In this case, the coil cooling portion381may be formed to enclose the outer circumference of the coil371. For instance, as shown inFIG. 13A, the coil cooling portion381may have a shape as partition walls381aand381bthereof are protruding from the front case301, and the coil371may be disposed at a space formed between the partition walls381aand381b. In this case, an inner wall381aof the coil cooling portion381may be formed of a material having high thermal conductivity. Under such configuration, heat generated from the coil371can be transferred to the coil cooling portion381.

As shown inFIG. 13B, a region on one surface of the front case301may be recessed in correspondence to the coil371, thereby forming a space. The coil371may be disposed at the space.

As shown inFIG. 13A, the coil cooling portion381may be provided with an inner wall381aand an outer wall381b. Alternatively, as shown inFIG. 13B, the coil cooling portion381′ may be provided with only an outer wall.

Still alternatively, the coil cooling portion381may be configured as an annular pipe, and part of the coil cooling portion381contacting the coil371may be formed of material having high thermal conductivity. Under such configuration, heat generated from the coil371may be transferred to the coil cooling portion381.

One side of the coil cooling portion381may be communicated with the blowing module325, and another side thereof may be communicated with the circuit board cooling portion382. Under such configuration, a fluid generated from the blowing module325may be introduced to one side of the coil cooling portion381. Then, the fluid may be discharged to another side of the coil cooling portion381to be connected to the circuit board cooling portion382, while moving with enclosing the coil371. Therefore, a fluid introduced to one side of the coil cooling portion381from the blowing module325may move along the coil cooling portion381to thus be discharged to another side of the coil cooling portion381. That is, the coil cooling portion381may be a passage along which a fluid discharged from the blowing module325moves to the circuit board cooling portion382.

One side of the circuit board cooling portion382may be connected to the coil cooling portion381, and another side thereof may be connected to the opening383of the case. The circuit board cooling portion382may be a passage along which a fluid from the coil cooling portion381is discharged to outside of the body303through the opening383.

The circuit board cooling portion382may be configured as a pipe. Alternatively, the circuit board cooling portion382may be configured as a pair of ribs382aand382bprotruding from one surface of the case. Here, a space formed by the case301, the ribs382aand382b, and the circuit board355may define a passage through which a fluid moves.

In order to increase a moving speed of a fluid inside the guide module, a sectional surface of the coil cooling portion may be variable according to a position. Generally, the larger a sectional area is, the slower a fluid moves. However, as a sectional area is increased, a contact area is increased to enhance cooling efficiency. For instance, if part of the coil cooling portion adjacent to the blowing module has a first sectional area, part of the coil cooling portion contacting the circuit board cooling portion may have a second sectional area larger than the first sectional area. The reason is in order to enhance cooling efficiency even if a moving speed of a fluid is slow. The circuit board cooling portion contacting the coil cooling portion having the second sectional area may be configured so that its sectional area can be increased or decreased toward one side. That is, for control of a moving speed of a fluid, the circuit board cooling portion may have its sectional area gradually increased or decreased toward a direction far from the coil cooling portion.

Referring toFIG. 14, once the blowing module325operates, a fluid is discharged from the blowing module325to thus be discharged to outside of the body303through the guide module380.

The fluid discharged from the blowing module325primarily cools the coil module370while passing through the coil cooling portion381. Then, the fluid secondarily cools the circuit board cooling portion382while passing through the circuit board cooling portion382connected to the coil cooling portion381.

In a case where the coil cooling portion381is formed to have a ring shape and a partition wall is formed between the coil cooling portion381and the coil371, the fluid discharged to the guide module380may cool heat transferred to the partition wall.

On the other hand, in a case where no partition wall is formed between the coil cooling portion381and the coil371as the coil cooling portion381is concaved from one surface of the front case301, the fluid discharged to the guide module380may cool the coil371with directly contacting the coil371.

FIG. 15is a conceptual view illustrating a coupled state of a pad385to the front case ofFIG. 13.

The guide module380is integrally formed with the front case301, and the circuit board cooling portion382is disposed to cover at least part of the circuit board355.

The pad385may be disposed between the circuit board355and the circuit board cooling portion382, so that heat generated from the circuit board355can be smoothly discharged to outside of the body303. The pad385may be formed of a material having high thermal conductivity for enhanced heat transfer from the circuit board355to the circuit board cooling portion382.

One surface of the pad385may be disposed to cover part of the circuit board355, and another surface thereof may contact the circuit board cooling portion382. In this case, at least part of the pad385may be disposed between the circuit board cooling portion382and the circuit board355. That is, if the circuit board cooling portion382is configured in the form of a groove, the pad385is disposed to cover the groove. In this case, the pad385may be disposed so that a fluid can pass through a space between the pad385and the front case301.

Cooling efficiency of the wireless power transmitter300according to the preferred embodiment where both of the blowing module325and the guide module380are provided, was compared with that of a wireless power transmitter according to a comparative embodiment where only the blowing module325is provided. As experimental results, temperature of the coil module370was increased up to about 62° C. in the comparative embodiment when the electronic device200is charged, while temperature of the coil module370was increased up to about 47° C. in the preferred embodiment. Further, temperature of the circuit board355was increased up to about 40° C. in the comparative embodiment when the electronic device200is charged, while temperature of the circuit board355was increased up to about 29° C. in the preferred embodiment.

FIG. 16is a modification embodiment of a wireless power transmitter, which illustrates an example of the blowing module325configured to be rotatable. As shown inFIG. 16, a blowing module325′ may be coupled to a supporting plate326fixed to one of the front case301and the rear case302. More specifically, a shaft327is protruding toward two sides of a housing of the blowing module325′, and the shaft327is coupled to the supporting plate326. Under such configuration, the blowing module325can rotate around the shaft327.

Although not shown, a diaphragm325bmay be rotatably coupled to the supporting plate326.

As the blowing module325is configured to be rotatable, a discharge amount of a fluid to the guide module380per unitary hour can be increased.

FIG. 17is still another modification embodiment of a wireless power transmitter, which illustrates an example where an outer guide is formed at the front case.

If temperature of the wireless power transmitter300is increased, temperature of the electronic device200attached to the wireless power transmitter300may be also increased.

This embodiment is configured to prevent the temperature increase of the electronic device200due to the wireless power transmitter300.

Referring toFIG. 17, protrusion301care formed on a mounting surface301aof the front case301, the mounting surface301aon which the electronic device200is positioned. Due to the protrusions301c, the electronic device200can be spaced from the front case301. This can reduce heat transfer from the wireless power transmitter300to the electronic device200resulting from direct contact therebetween.

Further, due to the protrusions301c, a contact area between the wireless power transmitter300and the electronic device200can be reduced.

The front case301may further comprise an outer guide301bso that part of a fluid discharged from the blowing module325can be discharged to a space between the electronic device200and the front case301.

The outer guide may guide air discharged from the blowing module325to be discharged to a space between the protrusions301c. Under such configuration, the amount of heat transferred to the electronic device200from the wireless power transmitter300can be significantly reduced.

Various embodiments described herein may be implemented in a computer-readable medium using, for example, software, hardware, or some combination thereof.

For software implementation, the embodiments such as procedures and functions may be implemented together with separate software modules each of which performs at least one of functions and operations. The software codes can be implemented with a software application written in any suitable programming language. Also, the software codes may be stored in the memory150of the wireless power transmitter100, and executed by the controller180or the power transmission control unit112.

It is obvious that the configuration of the wireless power transmitter according to the present invention may be also applicable to a docking station, a terminal cradle device, and other electronic device, except for a case where the configuration of the wireless power transmitter is applicable only to a wireless charger.