Abstract:
A non-contact power transmission apparatus accurately determines the kind of object that is placed on the charging deck of the non-contact power transmission apparatus, and, only when a non-contact power receiving apparatus is placed on the power transmission apparatus, allows power transmission and data communication to take place, thereby accurately determining the state of the receiver side and efficiently controlling the transmission of power. In the power transmission apparatus, the power supplied to the non-contact power receiving apparatus is measured, and the output power of the wireless power signal output from two different cores is controlled, thereby allowing the charging operation to be stably conducted even if the non-contact power receiving apparatus is moved anywhere on the power transmission apparatus. The power transmission apparatus improves both the reliability of operation of the non-contact charging system, and the competitiveness of related products, such as portable terminals, battery packs and the like.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 14/798,440 filed Jul. 13, 2015 in the U.S. Patent and Trademark Office, which is a continuation of U.S. application Ser. No. 13/857,858, filed Apr. 5, 2013 in the U.S. Patent and Trademark Office, now issued to U.S. Pat. No. 9,269,490 on May 22, 2014 in the U.S. Patent and Trademark Office, which is a continuation of U.S. application Ser. No. 13/162,861, filed Jun. 17, 2011, now issued to U.S. Pat. No. 8,436,492 on May 7, 2013 in the U.S. Patent and Trademark Office, which is a continuation of U.S. application Ser. No. 12/741,534, filed May 5, 2010, now issued to U.S. Pat. No. 8,552,593 on Oct. 8, 2013 in the U.S. Patent and Trademark Office, which is a 371 National Stage of PCT Application No. PCT/KR2009/007430, filed Dec. 11, 2009 with the World Intellectual Property Organization. PCT/KR2009/007430 claims priority to Korean Application No. 10-2008-0126271, filed Dec. 12, 2008, Korean Application No. 10-2009-0058139, filed Jun. 29, 2009, and Korean Application No. 10-2009-0082773, filed Sep. 3, 2009, all in the Korean Intellectual Property Office. The disclosures of all of these applications are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a noncontact power transmission apparatus, and more particularly to a non-contact power transmission apparatus for transmitting electric energy in a wireless power transmission manner, which detects an object placed on the charging deck thereof and enables power transmission and data communication only when a non-contact power receiving apparatus is present, thereby accurately perceiving the state of the receiver side and efficiently controlling the power. 
         [0004]    2. Description of the Related Art 
         [0005]    The Generally, a battery pack is a kind of power supply that is charged with power (electric energy) received from an external charger and supplies the power so that portable electronic devices, such as cellular phones, personal digital assistants (PDAs) and the like can be operated, and consists of a battery cell which is charged with electric energy and circuits for charging and discharging the battery cell (supplying electric energy to portable terminals). 
         [0006]    The electrical connection between the battery pack, which is used in the portable terminals, and the charger for charging electric energy to the battery pack may be achieved using a connector supply system, which receives the power from a regular power source and converts the voltage and current thereof to correspond to those of the battery pack, and supplies the electric power to the battery pack via a connector of the corresponding battery pack. 
         [0007]    However, such a connector supply system has drawbacks, including instant discharge owing to the difference in potential between the charger connector and the battery connector, the risk of fire and concomitant damage due to fire caused by the presence of foreign substances, reduction in the life and performance of the battery pack, and the like. 
         [0008]    To solve the above-mentioned problems, a noncontact charging system and control method thereof using a wireless power transmission system were recently proposed. 
         [0009]    This non-contact charging system includes a non-contact power transmission apparatus for wirelessly supplying electric power, a non-contact power receiving apparatus receiving the electric power from the non-contact power transmission apparatus and charging the battery cell with it, and the like. 
         [0010]    Meanwhile, due to its non-contact nature, the non-contact charging system conducts a charging operation while the non-contact power receiving apparatus is placed in the non-contact power transmission apparatus. 
         [0011]    Here, if foreign substances, such as a metal, are placed in the non-contact power receiving apparatus, the foreign substances cause problems such as abnormal power transmission, product damage due to fire caused by overload or the like. 
         [0012]    The information disclosed in this Background of the Invention section is only for the enhancement of understanding of the background of the invention and should not be taken as an acknowledgment or any form of suggestion that this information forms the prior art that would already be known to a person skilled in the art. 
       SUMMARY OF THE INVENTION 
       [0013]    To solve the above-mentioned problems, the present invention is directed to a non-contact power transmission apparatus formed to send out an asking signal via a power transmission coil to identify an object placed thereon, measure the standby time taken up to the time when a response signal is received, and compare the measured standby time with a set reference standby time to rapidly determine whether the object is a foreign substance or a non-contact power receiving apparatus of a battery pack or the like. 
         [0014]    Meanwhile, since it is difficult to implement communication using an amplitude shift keying (ASK) method, which determines whether the object placed thereon is a foreign substance such as a metal or a non-contact power receiving apparatus, if the amplitude of a signal is narrow under DC load modulation conditions, it cannot perceive the state of the receiver side and fails to transmit power or control the transmission of power, thereby causing the problem of reduced power transmission efficiency. 
         [0015]    To solve this problem, the present invention is directed to a non-contact power transmission apparatus for wirelessly supplying electric power, which, upon ASK data communication with a non-contact power receiving apparatus, which receives the supplied power and charges a battery cell with it, uses Pulse Width Modulation (PWM) for smooth data communication. 
         [0016]    Further, the present invention is directed to a non-contact power transmission apparatus using an ASK charging control module, which, even under DC load modulation conditions, accurately perceives the state of the receiver side and efficiently controls the power even when a non-contact power receiving apparatus is moved on the charging deck thereof. 
         [0017]    According to an aspect of the present invention, the non-contact power transmission apparatus may include a primary core, which wirelessly sends out a wireless power signal to a non-contact power receiving apparatus having a secondary core, which is operated such that, when a change in the load of the primary core is detected, measures the delay time from the output time of an asking signal, asking what the object on the non-contact power transmission apparatus is, to the time of receipt of a response signal corresponding to the asking signal, the signals being transmitted via the primary core, compares the measured time with a reference standby time, and, if the measured time is shorter than the reference standby time, determines that the object is a foreign substance, and if the measured time is longer than the reference standby time, determines that the object is the normal non-contact power receiving apparatus, signal, and sends out the wireless power. 
         [0018]    In particular, the non-contact power receiving apparatus may receive the wireless power signal from the non-contact power transmission apparatus, compare the received signal with a reference voltage, and create a pulse signal based on a duty rate that is set depending upon the comparison result and transmits the created signal to the non-contact power transmission apparatus, which in turn controls the intensity of the transmitted wireless power signal in correspondence with the transmitted pulse signal. 
         [0019]    Further, the non-contact power receiving apparatus may include an ID transmitter for transmitting and receiving code data of an AC signal, modulated in an AC modulation manner, via the secondary core, and the noncontact power transmission apparatus may include a feedback circuit unit for extracting the code data of the AC signal from a DC signal applied to the primary core when the code data are received by the primary core. 
         [0020]    Preferably, the non-contact power receiving apparatus may include a capacitor, connected in parallel with the power receiving core side of the secondary core to remove a DC signal component. 
         [0021]    More preferably, the non-contact power receiving apparatus may further include a MOSFET serially connected with the capacitor, and the ID transmitter inputs the operation voltage of the MOSFET to a gate terminal of the MOSFET in correspondence with the duty rate set depending on the comparison result. 
         [0022]    Further, the feedback circuit unit may include an RC filter circuit electrically connected with one end of the primary core to remove the DC signal component, and an amplifying circuit having an OP-AMP electrically connected with the RC filter circuit. 
         [0023]    Further, the primary core may include first and second power transmission core sides and has a multilayered structure having an overlapping region in which the first and second power transmission core sides partially overlap each other. 
         [0024]    According to another aspect of the present invention, the non-contact power transmission apparatus may include a transmission module having a primary core wirelessly sending out a wireless power signal to a noncontact power receiving apparatus having a secondary core, the transmission module including a body case; a board provided in the body case and having a control module for sending out the wireless power signal; a shielding plate provided on an upper portion of the board; first and second power transmission core sides provided on an upper portion of the shielding plate such that they are electrically connected with the control module, the first and second power transmission core sides partially overlapping each other; a light-emitting device for displaying the charging state provided on a side of the body case such that it is electrically connected with the control module; and a cover, which is coupled to the body case and on which the noncontact power receiving apparatus is placed. 
         [0025]    Particularly, at least one of the first and second power transmission core sides may be formed into a bent form and the first and second power transmission core sides are of a multi-layered structure in which the region of the first core side, which overlaps the second core side, is laid on or below the region of the second core side, which overlaps the first core side. 
         [0026]    Preferably, the overlapping region may be larger than the width of the wireless power receiving core of the wireless non-contact power receiving apparatus and smaller than the widths of the first and second power transmission core sides. 
         [0027]    Further, the transmission module may include a fitting along which another transmission module detachably slides. 
         [0028]    Further, the body case may be a support for a monitor. 
         [0029]    Further, the transmission module may further include a power cable connected to the power supply port provided in a monitor and through which the power for operating the monitor is supplied. 
         [0030]    Preferably, the power cable may be connected to a branching power cable, which supplies a regular power source to the monitor. 
         [0031]    Further, the transmission module may include on another side of the body case a connection terminal to be connected to a connection boat for an Optical Disk Drive (ODD) of a monitor, the connection terminal being electrically connected with the control module mounted on the board. 
         [0032]    According to the above-mentioned construction, the present invention can accurately determine the kind of object that is placed on the charging deck of the non-contact power transmission apparatus and, only when a non-contact power receiving apparatus is placed on the power transmission apparatus, allows the power transmission and data communication to take place, thereby having the effect of preventing damage by foreign substances from occurring to a device. 
         [0033]    Further, even when the amplitude of a signal is small under the loading conditions of DC load modulation, the present invention makes smooth data communication possible, thereby accurately determining the state of the receiver side and efficiently controlling the transmitted power. 
         [0034]    Further, the primary core of the non-contact power transmission apparatus, which transmits a power signal using an induced magnetic field, is formed into a thin, planar spiral core structure provided not on a ritz core, but on a PCB core so that it can be easily mounted in a noncontact power transmission apparatus such as a non-contact charger, thereby increasing the ease of adaptation of the primary core to various products. Still further, the primary core is constituted in a multi-layered structure, so that a charging operation can always be carried out regardless of where the non-contact power transmission apparatus, such as a portable electronic device, is moved on the charging deck. 
         [0035]    Further, the power supplied to the noncontact power receiving apparatus is measured and the output power of the wireless power signal output from the two different cores is controlled and corrected depending upon the measurement result, thereby allowing the charging operation to be conducted stably. 
         [0036]    The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]      FIG. 1  is a schematic configuration view of a non-contact power transmission apparatus in accordance with the present invention; 
           [0038]      FIG. 2  is a detailed configuration view of another example of a non-contact power transmission apparatus in accordance with the present invention; 
           [0039]      FIG. 3  is a circuit diagram of exemplary major parts of the non-contact power transmission apparatus illustrated in  FIG. 1 ; 
           [0040]      FIG. 4  is a graphical diagram illustrating an exemplary feedback signal which is detected via a primary core and indicates the kind of object placed on the non-contact power transmission apparatus of  FIG. 1 ; 
           [0041]      FIG. 5  is a circuit diagram of exemplary major parts of the non-contact power transmission apparatus of  FIG. 1 ; 
           [0042]      FIG. 6  is a graphical diagram illustrating a charging voltage of the non-contact power receiving apparatus of  FIG. 1  and exemplary transmitted/received signals for controlling charging; 
           [0043]      FIGS. 7 to 9  are flow diagrams illustrating exemplary methods of controlling the non-contact power transmission apparatus in accordance with the present invention; 
           [0044]      FIGS. 10 and 11  are flow diagrams illustrating exemplary methods of controlling the noncontact power receiving apparatus in accordance with the present invention; 
           [0045]      FIG. 12  is a configuration view of the construction of an exemplary primary core of the non-contact power transmission apparatus in accordance with the present invention; 
           [0046]      FIG. 13  is a configuration view explaining the step S 117  of  FIG. 9  and the step S 214  of  FIG. 11 ; 
           [0047]      FIG. 14  is a configuration view of the construction of another exemplary primary core of the non-contact power transmission apparatus in accordance with the present invention; 
           [0048]      FIG. 15  is an exploded perspective view illustrating the concept of a transmission module, in which major parts of the non-contact power transmission apparatus are formed into a module in accordance with the present invention; 
           [0049]      FIGS. 16 and 17  are views illustrating the state of the transmission module of  FIG. 15  in use; 
           [0050]      FIGS. 18 to 20  are views illustrating the state of another transmission module in use; and 
           [0051]      FIG. 21  is a view illustrating the state of still another transmission module in use. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0052]    Reference will now be made in detail to various embodiments of the present invention (s), examples of which are illustrated in the accompanying drawings and described below. While the invention (s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention (s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0053]    The non-contact power transmission apparatus of the present invention is variously applicable, and preferred embodiments thereof will now be described in detail with reference to the accompanying drawings. 
         [0054]      FIG. 1  illustrates a wireless power transmission system which includes the non-contact power transmission apparatus  100  of the present invention for sending out a wireless power signal and a non-contact power receiving apparatus  200  receiving the wireless power signal and charging a battery cell with it. 
         [0055]    The non-contact power transmission apparatus  100  includes a primary core  110 , an identifier  120 , a wireless power transmission controller  130 , a switching controller  140 , an operating driver  150 , a series resonance converter  160 , and a feedback circuit  170 . 
         [0056]    The primary core  110  consists of first and second power transmission core sides  111  and  112 , which are connected in parallel with the series resonance converter  160 . 
         [0057]    The identifier  120  detects a change in the load of the primary core  110  and determines whether the change is induced by the non-contact power receiving apparatus  200  or not. Thus, the identifier serves both to detect the change in the load and to analyze and process a data signal code of an AC signal of the signals transmitted from the non-contact power receiving apparatus  200 . 
         [0058]    The wireless power transmission controller  130  receives and checks the determination result from the identifier  120 , and, if the change in the load is induced by the non-contact power receiving apparatus  200 , sends out a power control signal to the operating driver  150  via the primary core  110  to transmit the wireless power signal. 
         [0059]    Then, the controller  130  analyzes and processes the data signal filtered by the identifier  120  and correspondingly controls the operating driver  150 . In addition, the controller creates a data signal (e.g. an ID asking signal) and transmits it to the non-contact power receiving apparatus  200  via the primary core  110 . 
         [0060]    The switching controller  140  controls the switching operation of first and second switches  141  and  142 , which are connected between the series resonance circuit  160  and the first power transmission core side  111  and between the series resonance circuit and the second power transmission core side  112 , respectively. 
         [0061]    The operating driver  150  controls the operation of the series resonance converter  160  depending upon the intensity of the wireless power signal that is to be transmitted. 
         [0062]    The series resonance converter  160  creates a transmission power source for creating a wireless power signal to be transmitted under the control of the operating driver  150 , and supplies it to the primary core  110 . 
         [0063]    That is, when the wireless power transmission controller  130  transmits a power control signal for transmitting a wireless power signal, which has a required power value, to the operating driver  150 , the operating driver  150  controls the operation of the series resonance converter  160  to correspond to the transmitted power control signal, and the series resonance converter  160  applies to the primary core  110  a transmission power source, which corresponds to the required power value, under the control of the operating driver  150 , thereby transmitting a wireless power signal having the required intensity. 
         [0064]    When the code data of an AC signal is received by the primary core  110 , the feedback circuit  170  extracts the code data of the AC signal from a DC signal applied to the primary core  110 . As illustrated in  FIG. 3 , the feedback circuit  170  includes an RC filter circuit section  171 , which is electrically connected with ends of the first and second power transmission core sides  111  and  112  of the primary core  110  to remove a DC signal component (low frequency component), and an amplifying circuit section  172 , which has an OP-AMP that is electrically connected with the RC filter circuit section. 
         [0065]    That is, the low frequency signal, which is a DC signal component, is removed by the RC filter circuit section  171  and the extracted AC signal component is amplified by the amplifying circuit section. 
         [0066]    Thus, it is possible to transmit and receive a low-amplitude signal. 
         [0067]    The non-contact power receiving apparatus  200  to be supplied with power by receiving the wireless power signal includes a power receiving core side  211  of a secondary core  210 , which creates induced power using the transmitted wireless power signal; a rectifier  220 , which rectifies the induced power; and a battery cell module  230 , which charges a battery cell with the rectified power. 
         [0068]    This battery module  230  includes a protection circuit, such as an overvoltage and overcurrent preventing circuit, a temperature detecting circuit and the like, and a charging management module, which collects and processes information such as the charged state of the battery cell or the like. 
         [0069]    The non-contact power receiving apparatus  200  further includes a wireless power receiver controller  240 , which checks the current induced to the power receiving core  211  of the secondary core  210  and requests the control of the intensity of a wireless power signal based on the information on the charging of the battery cell, which is collected and processed by the battery cell module  230 , and an ID transmitter  250 , which, via the secondary core  210 , transmits and receives the code data of an AC signal modulated in an AC modulation manner. 
         [0070]    As illustrated in  FIG. 5 , the non-contact power receiving apparatus  200  further includes a capacitor C, which is connected in parallel with the power receiving core  211  of the secondary core  210  to remove a DC signal component, and a MOSFET, in which a drain terminal is serially connected with the capacitor. 
         [0071]    The MOSFET performs on/off control under the control of the ID transmitter  250 . The ID transmitter  250  inputs the operation voltage of the MOSFET to the gate terminal of the MOSFET in correspondence with a duty rate, which is set to correspond to the control request for the intensity of the wireless power signal by the wireless power receiver controller  240 . 
         [0072]    That is, when the ID transmitter  250  inputs an on-signal and an off-signal, which correspond to the operation voltage, to the gate terminal, the MOSFET creates and outputs a pulse width modulated (PWM) signal corresponding to voltage input to the gate terminal, and the PWM signal is transmitted to the non-contact power transmission apparatus  100  via the power receiving core  211 . 
         [0073]    The detailed embodiment of the non-contact power transmission apparatus  100  is illustrated in  FIG. 2 . 
         [0074]    In the figure, the non-contact power transmission apparatus  100  is supplied with power, via a power supply port  181 , from an adapter supplied with a regular power source, a power source of a USB port of a portable terminal such as a notebook, or the like. 
         [0075]    The apparatus  100  further includes a current detector  191  that detects the internal current of the apparatus  100 , and a temperature detector  192  that detects the internal temperature of the apparatus  100  during the charging process, so that if overheating, overvoltage or overcurrent occurs, the operation can be stopped. 
         [0076]    The battery cell module  230  of the noncontact power receiving apparatus  200  further includes a charging circuit  231  for charging a battery cell, a gauge circuit  232 , for checking the charged quantity, and a charging monitoring circuit  233 , for monitoring the charging state. 
         [0077]    A display  193  is further provided to display the state of operation of the non-contact power transmission apparatus  100  and the charging state of the non-contact power receiving apparatus  200 . 
         [0078]    The method of charging a non-contact charging system using the core structure for the wireless power transmission will now be described. 
         [0079]    First, the operation of the non-contact power transmission apparatus  100  will be described with reference to  FIGS. 7 to 9 . A standby mode is maintained, wherein the switching controller  140  of the apparatus  100  keeps the first and second switches  141  and  142  in an OFF state, and the identifier  120  detects the change in load of the first and second power transmission core sides  111  and  112  of the primary core  110  (S 101 ). 
         [0080]    In the standby mode S 101 , when the noncontact power receiving apparatus  200  is placed on the noncontact power transmission apparatus  100 , a change in the magnetic field of the first and second power transmission core sides  111  and  112  occurs, and the identifier  120  detects the change (S 102 ). 
         [0081]    When the change in the load is detected, the identifier  120  informs the wireless power transmission controller  130  of this, and, as illustrated in  FIG. 4 , the controller  130  measures the delay in the receipt of the response signal (a reflected signal in the case where a foreign substance is present) by the primary core  110  with reference to the transmitted signal fref (S 103 ). 
         [0082]    When the delay in the receipt of the response signal is measured, the measured time is compared with a reference time (“Tfb” in  FIG. 4 ) (S 104 ). If the measured time is longer than the reference time (S 105 ) (“Tfb 1 ” in  FIG. 4 ), it is determined that a normal non-contact power receiving apparatus  200  is present (S 106 ), whereas, if the measured time is shorter than the reference time (“Tfb 2 ” in  FIG. 4 ), it is determined that a foreign substance is present (S 107 ). 
         [0083]    The determination is a primary determination reference, and the following identification process also helps distinguish between foreign substances and non-contact power receiving apparatus. 
         [0084]    When it is first determined that an object is a non-contact power receiving apparatus  200  based on a signal received via the identifier  120 , the wireless power transmission controller  130  transmits, via the primary core  110 , a signal requesting a header ID (S 108 ). 
         [0085]    Here, the header ID means a code on a header of an ID code. 
         [0086]    Meanwhile, as illustrated in  FIG. 10 , in the standby mode for charging a battery cell (S 201 ), when the header ID requesting signal is received (S 202 ), the noncontact power receiving apparatus  200  transmits the header ID code via the power receiving core  211  (S 203 ). 
         [0087]    When the header ID code is received in the primary core  110 , the identifier  120  determines that the object is the non-contact power receiving apparatus  200 , and, if no response signal is received, the identifier determines that the object is a metallic foreign substance (S 109 ). 
         [0088]    If the object is determined to be a foreign substance, a user is informed that the foreign substance is detected, using letters or illumination via an output device such as an LCD or an LED (S 111 ). If the object is determined to be a non-contact power receiving apparatus  200 , a signal requesting a full ID is transmitted via the primary core  110  (S 110 ). 
         [0089]    Here, the full ID means the full code of an ID code. 
         [0090]    Meanwhile, in the standby mode for charging a battery cell (S 201 ), when the full ID requesting signal is received (S 202 ), as illustrated in  FIG. 10 , the non-contact power receiving apparatus  200  transmits the full ID code via the power receiving core  211  (S 203 ). 
         [0091]    When the full ID code is received, the identifier  120  checks this (S 112 ). When a normal ID code is received, the identifier transmits a wireless power signal to the non-contact power receiving apparatus  200  (S 113 ). 
         [0092]    When the received ID code is not normal, the user is informed of the occurrence of an ID error (S 114 ). 
         [0093]    Here, although some of the elements of the non-contact power transmission apparatus  100  to be operated for the transmission of an ID code requesting signal and the reception of a response signal are not explained, they have already been explained through the description of the charging system of the present invention. Further, unnecessarily repetitive explanations will of course be omitted in the following description. 
         [0094]    Meanwhile, if an ID code is received by the first power transmission core side  111 , the wireless power transmission controller  130  transmits a switching control signal to the switching controller  140  to turn on the first switch  141  and turn off the second switch  142 , and transmit the power control signal to the operating driver  150 , thereby sending out a wireless power signal via the first power transmission core side  111 . 
         [0095]    Here, the output power of the transmitted wireless power signal is transmitted corresponding to a reference power value, which corresponds to a voltage which can be induced into the input voltage (e. g. 4.5V to 5.5V) required by the non-contact power receiving apparatus  200 . 
         [0096]    If an ID code is received to the second power transmission core side  112 , the wireless power transmission controller  130  transmits a switching control signal to the switching controller  140  to turn off the first switch  141  and turn on the second switch  142 , and transmit the power control signal to the operating driver  150 , thereby sending out a wireless power signal via the second power transmission core side  112 . 
         [0097]    If the power receiving core  211  is positioned in the overlapping region shown in  FIG. 12 , when the first and second power transmission core sides  111  and  112  receive an ID at the same time, the wireless power transmission controller  130  transmits a switching control signal to the switching controller  140  to turn on the first and second switches  141  and  142  and transmits a power control signal to the operating driver  150 , thereby transmitting a wireless power signal via the first and second power transmission core sides  111  and  112 . 
         [0098]    Here, when the first and second power transmission core sides  111  and  112  respectively transmit the wireless power signal with output power corresponding to a reference power value, excessive voltage can be induced to the power receiving core  211 . 
         [0099]    Thus, in the case where the first and second power transmission core sides  111  and  112  receive the ID at the same time, it is preferred that the wireless power signal be transmitted while the sum of the output power of the first power transmission core side  111  and the output power of the second power transmission core side  112  is controlled to correspond to the reference power value. 
         [0100]    When the wireless power signal is received by the non-contact power receiving apparatus  200  according to the above process (S 204 ), the non-contact power receiving apparatus  200  charges a battery cell using electrical energy induced to the power receiving core  211  (S 205 ). 
         [0101]    As illustrated in  FIG. 11 , the non-contact power receiving apparatus  200  checks the charging state of the battery cell (S 206 ) and ascertains whether or not the battery cell is fully charged (S 207 ) and whether or not a gauge has changed (S 210 ). Then, in order to accomplish stable charging, which is an object of the present invention, the apparatus  200  detects voltage induced to the power receiving core  211  and determines if the detected voltage is within the range of the input voltage (e.g. 4.5V to 5.5V) that is required for the charging operation (S 213  and S 215 ). 
         [0102]    As a result of the checking, if the battery cell is fully charged (S 207 ), the battery cell module  230  transmits, to the non-contact power transmission apparatus  100  via the ID transmitter  240 , a power off code, modulated in an AC modulation manner (S 208 ), and terminates the charging operation (S 209 ), and, if the gauge is changed (S 210 ), a gauge code is transmitted (S 211 ). 
         [0103]    As a result of the determination, if the induced voltage is not within the set range, the non-contact power receiving apparatus  200  transmits a power control requesting signal to the non-contact power transmission apparatus  100 . 
         [0104]    For example, as illustrated in  FIG. 13 , if the power receiving core  211  is moved outside and voltage is induced which is lower than the set range (S 213 ), a power up code is transmitted (S 214 ), and if the power receiving core  211  is positioned in the overlapping region of  FIG. 12  and voltage, which is higher than the set range, is induced to the power receiving core  211  by the wireless power signal simultaneously transmitted from the first and second power transmission core sides  111  and  112  (S 215 ), a power down code is transmitted (S 216 ). 
         [0105]    When the respective codes are transmitted as such, the non-contact power receiving apparatus  200  monitors the intensity and other characteristics of the wireless power signal transmitted from the non-contact power transmission apparatus  100  (S 212 ). 
         [0106]    When the power control code is received by the primary core  110  of the non-contact power transmission apparatus  100  (S 115 ), the feedback circuit  170  extracts a corresponding code from a signal (a transmitted power signal of a DC component and a code signal of a received AC component) induced to the primary core ( 110 ). 
         [0107]    The wireless power transmission controller  130  receives and analyzes the extracted code, and if the code is the power off code (S 116 ), or if the battery is fully charged (S 120 ), the wireless power transmission controller  130  displays a fully charged state via LED or LCD ((S 117 ). If the code is the gauge code (S 118 ), the charging state is output (S 119 ); if the code is the power up code (S 121 ), the output power of the corresponding power transmission core is increased (S 122 ); and if the code is the power down code (S 123 ), the output power of the corresponding power transmission core is reduced (S 124 ). 
         [0108]    For example, as illustrated in  FIG. 6 , if sensing voltage (Vsense in  FIG. 5 ) branching from a voltage (DC in  FIG. 5 ) for charging a battery cell is lower than a reference voltage (Vset), the ID transmitter  250  inputs a pulse signal with a duty rate that is larger than a duty rate corresponding to the reference voltage, to the gate terminal of the MOSFET. The MOSFET creates a power up code and transmits it to the non-contact power transmission apparatus  100  while performing ON and OFF operations in correspondence with the pulse signal input to the gate terminal, and a wireless power signal to be transmitted is received to the wireless power receiver controller  240  after the delay time (Td) passes. 
         [0109]    Here, ‘Tx’ and ‘Rx’ in  FIG. 5  indicate the transmission and reception of a signal from and to the noncontact power transmission apparatus  100 . 
         [0110]    The wireless power transmission controller  130  of the non-contact power transmission apparatus  100  calculates a corrected power value corresponding to the received power control requesting signal (respective core signals), applies the corrected power value to the reference power value and transmits a wireless power signal via at least one of the first and second power transmission core sides  111  and  112 , so that stable charging can be performed irrespective of the position of the non-contact power receiving apparatus  200 . 
         [0111]    Meanwhile, the primary core  110  of the noncontact power transmission apparatus  100  transmitting a wireless power signal using a wireless power transmission method, as shown in  FIG. 12 , comprises the first and second power transmission core sides  111  and  112  and a shielding section  115 .  FIG. 12  illustrates that the power receiving core  211  of the secondary core  210  is moved on the first and second power transmission core sides  111  and  112 . 
         [0112]    The first and second power transmission core sides  111  and  112  are formed in a PCB pattern type, and include a first single region, which belongs only to the first power transmission core side  111 , a second single region, which belongs only to the second power transmission core side  112 , and an overlapping region, where the first and second power transmission core sides  111  and  112  overlap each other. 
         [0113]    Thus, even when the power receiving core  211  of the secondary core  210  is moved, as shown in  FIG. 12 , power can be continuously supplied. 
         [0114]    Further, it is preferred that the width W 1  of the overlapping region where the first and second power transmission core sides  111  and  112  overlap each other be set greater than the width W 2  of the power receiving core  211 , so that even when the power receiving core  211  is moved, it remains within the receiving range of the wireless power signal by the first or second power transmission core sides  111  or  112 . 
         [0115]    Meanwhile, the shape and construction of the above-mentioned primary core  110  and the first and second power transmission core sides  111  and  112  may be variously modified by a person skilled in the art. 
         [0116]    For example, the power transmission core  300  of the primary core shown in  FIG. 14  may include a double-structured induction section (no reference number) of upper and lower core layers  310  and  330  on a PCB base  340 . 
         [0117]    The induction section comprises a power transmission (PT)-PCB core having a planar spiral core structure (PSCS). That is, the PT-PCB core is formed such that a single-layered or multi-layered copper planar spiral core is formed on a PCP (PCB having a Copper Clad Laminate (CCL), Flexible CCL (FCCL) or the like). 
         [0118]    The upper and lower core layers  310  and  330  are each composed of upper unit cores  311  and lower unit cores  331 . The unit cores may be modified into structures such as a circle, an oval, a triangle, a rectangle, a polygon or the like by a person skilled in the art. In  FIG. 14 , a pentagonal core structure is illustrated. 
         [0119]    The upper and lower unit cores  311  and  331  are composed of copper, and a PSR coating layer  320  is formed between the upper and lower core layers  310  and  330  in order to protect them (from damage, corrosion or the like). 
         [0120]    Here, if an Electroless Gold Plating Layer (EGPL) is formed on the upper and lower core layers  310  and  330 , the efficiency of the induced magnetic field is improved, so that the power transmission rate can be generally improved. 
         [0121]    Under the PCB base  340 , a Hanrim Postech Electro-magnetic Shield (HPES)  350  is provided in order to prevent an electronic device of an appliance from being influenced by the induced magnetic field. The HPES  350  consists of a shield panel  351 , a shield mesh  352 , and a metal film  353 , which are sequentially laminated on one another. 
         [0122]    Here, the shield panel  351  is composed of 25 parts to 55 parts by weight of polyurethane with 55 parts to 75 parts by weight of sendust, wherein sendust is a highly permeable alloy composed of aluminum, silicon, iron or the like, so that the transmission shield panel is constructed using the combination of high shielding performance sendust and polyurethane. 
         [0123]    Meanwhile, if the composition of sendust is below 55 parts by weight, the shielding performance may be degraded, whereas if it is more than 75 parts by weight, the performance is not improved in proportion with the input quantity. 
         [0124]    The shield mesh  352  serves to reduce the occurrence of eddy current by induced electromotive force created by the induced magnetic field, and is made up of a net-type structured polyester coated with an eddy current reduction composition composed of 35 parts to 45 parts by weight of Zn with 55 parts to 65 parts by weight of Ni, the net structure being made of metal net of 100 meshes to 200 meshes, preferably 135 meshes. 
         [0125]    The metal film  353  consists of Al and serves to finally block the magnetic field from the lowermost side of the HPES  350  so that it does not affect a circuit or the like. 
         [0126]    When the layer is composed of the plurality of unit cores, the wireless power transmission controller  130  can control the respective unit cores individually so that it is obvious that the series resonance converter  160  is constituted in correspondence with the respective unit cores. 
         [0127]    The non-contact power transmission apparatus  100  can be activated by power supplied from a regular power source, a USB port of a notebook, etc. That is, it can be activated by power from various kinds of electronic devices. 
         [0128]    Reference will now be made to the non-contact power transmission apparatus  100  of the present invention when actually adapted to electronic devices. 
         [0129]      FIG. 15  is an exploded perspective view illustrating the concept of a transmission module  10  in which major parts of the non-contact power transmission apparatus  100  are formed into a module in accordance with the present invention, wherein the transmission module includes a body case  11 , a board  12 , a shielding plate  13 , a first power transmission core  14 , a second power transmission core  15 , and a cover  16 . 
         [0130]    The body case  11  includes a hollow section (not designated), in which all of the remaining elements are housed, and a power supply connector (not shown) via which a typical external power source is supplied. 
         [0131]    The board  12  comprises a printed circuit board (PCB), in which the respective elements of the noncontact power transmission apparatus  100  shown in  FIG. 1  are mounted in a module form. 
         [0132]    The shielding plate  13  serves to protect electronic elements on the board  12  from the effects of the wireless power signal transmitted by the first and second power transmission core sides  14  and  15 . It may be made of various kinds of materials and have various constructions, as determined by a person skilled in the art. 
         [0133]    The first and second power transmission core sides  14  and  15  are formed in a PCB pattern and have a double-core structure, in which two core sides partially overlap each other, as illustrated in  FIG. 15 , the two core sides respectively transmitting the wireless power signal. 
         [0134]    The cover  16  is coupled to the upper portion of the body case  11  so that the non-contact power receiving apparatus, such as a portable terminal P, a battery pack B or the like, is placed thereon. The cover is composed of a material through which the wireless power signals from the first and second power transmission core sides  14  and  15  can be transmitted out. 
         [0135]    A light emitting diode (LED)  11   a  is provided on a side of the body case  11  to display the charging state of the non-contact power receiving apparatus. 
         [0136]    As shown in  FIG. 15 , the transmission module  10  with overlapping double cores comprises two different transmission modules  10  and  10 , which are arranged such that one transmission module  10 ′ is provided with a fitting  11   b′,  along which another transmission module  10  detachably slides, thereby enabling simultaneous charging of both the portable terminal P and the battery pack B, as shown in  FIG. 16 . 
         [0137]    In the case in which only the portable terminal P is charged, as illustrated in  FIG. 17 , the transmission module  10  for charging the battery pack B is moved into the other transmission module  10 ′, thereby saving space. 
         [0138]    Here, unexplained reference number  11   a′  denotes a light emitting diode provided on a side of another transmission module  10 ′. 
         [0139]    Meanwhile, since the case exists in which the non-contact power receiving apparatus  200 , such as the battery pack B, is occasionally moved during the charging process, as shown in  FIG. 16 , in order to allow the charging process to be conducted stably even if the apparatus  200  moves in this way, the first and second power transmission core sides  14  and  15  are provided in an overlapping form. 
         [0140]    That is, the first and second power transmission core sides  14  and  15 , which are the primary cores provided in the transmission module  10  for transmitting a wireless power signal, are arranged on the shielding plate  13  such that they have a first single region of only the first power transmission core side  14 , a second single region of only the second power transmission core side  15 , and an overlapping region, in which the first and second power transmission core sides  14  and  15  overlap each other. 
         [0141]    Thus, even if the portable terminal P or the battery pack B is moved as shown in  FIG. 16 , power can be continuously supplied. 
         [0142]    Meanwhile, the transmission module  10  of the non-contact power transmission apparatus  100  can be adapted to a monitor M or the like as shown in  FIGS. 18 to 20 . 
         [0143]    That is, a transmission module  10 ″ may be provided in which the body case  11  of  FIG. 1  is used as a monitor support  11 ″ and the board  12 , the shielding plate  13 , the first and second power transmission core sides  14  and  15 , and the cover  16  are provided in the space near the monitor support  11 ″, so that, as shown in  FIG. 19 , a portable terminal P is placed on the cover  16  and a battery in the portable terminal P is charged. A light emitting diode (LED)  11   a″  is provided on a side of the monitor support  11 ″ to display the charging state of the non-contact power receiving apparatus  100 . 
         [0144]    Further, the transmission module  10  of the present invention is connected with a power supply port Ma, which is provided on a side of the monitor M, via a power cable C, so that it can be supplied with driving power distributed from the monitor M. 
         [0145]    Further, as illustrated in  FIG. 20 , the transmission module  10  can be directly supplied with regular power by connecting a power cable C to a connection terminal, which branches from a power cable C′ that supplies regular power to the monitor M. 
         [0146]    Further, as illustrated in  FIG. 21 , a connection terminal T is provided on another side of the body case such that it is connected to a connection port Na of an optical disk drive (ODD) of a notebook N, whereby drive power of the transmission module Na can be supplied through the connection port Na. 
         [0147]    As set forth before, the transmission module  10  constituted to be connected with the monitor M and the notebook N is provided with a power supply unit (not shown) depending upon the power source that is supplied according to the state of use, but this power supply unit is not limited to any specific form, and may be variously configured according to the kinds of input power sources and demand by a person skilled in the art. 
         [0148]    In describing the respective embodiments, while like parts have been denoted with like numerals, in the case of describing like parts as different parts for the convenience of explanation, such as when clearly dividing or individually explaining the respective embodiments, they have been denoted with different numerals. 
         [0149]    The non-contact charging system including the non-contact power transmission apparatus of the present invention has been described above. It is understood that the technical construction of the present invention may be modified to have different forms without departing from the spirit and essential features of the present invention by those skilled in the art. 
         [0150]    Therefore, the above-mentioned embodiments are provided only for illustrative purposes in all aspects, but are not limited thereto. It should be construed that the scope of the present invention is defined not by the above detailed description, but by the appended claims, and that the described embodiments and all variations or modifications that can be deduced from equivalents interpreted from the claims fall within the scope of the present invention.