WO2006001557A1

WO2006001557A1 - Wireless charging pad and battery pack using radio frequency identification technology

Info

Publication number: WO2006001557A1
Application number: PCT/KR2004/002263
Authority: WO
Inventors: Chun-Kil Jung; Yoon-Sang Kook
Original assignee: Hanrim Postech Co., Ltd.
Priority date: 2004-06-25
Filing date: 2004-09-07
Publication date: 2006-01-05
Also published as: KR20050122669A; KR200361755Y1; KR100564256B1

Abstract

The present invention relates to a wireless charging pad and a battery pack, to which a radio frequency identification technology is applied, which can detect the charged status of the battery pack in real time, and which includes a means for detecting devices placed on the wireless charging pad. Thus effectively coping with the case where a plurality of battery packs, or an object that cannot be charged, is placed on the wireless charging pad.

Description

DESCRIPTION

WIRELESS CHARGING PAD AND BATTERY PACK USING RADIO FREQUENCY IDENTIFICATION TECHNOLOGY

Technical Field The present invention relates, in general, to a wireless charging pad and a battery pack to which a radio frequency identification technology is applied and, more particularly, to a wireless charging pad and a battery- pack, to which a radio frequency identification technology is applied, which can detect the charged status of the battery pack in real time, and which includes a means for detecting devices placed on the wireless charging pad, thus effectively coping with the case where a plurality of battery packs, or an object that cannot be charged, is placed on the wireless charging pad.

Background Art Recently, with the development of communication and information processing technologies, the use of portable devices that are convenient to carry, such as a mobile phone, is increasing, and with the development of technologies, new model terminals having improved efficiency are continuously popularized. To charge such portable devices, a contact type charging method is used, or a non-contact type charging method in which a battery is charged using magnetic coupling without electrical contact is used so as to overcome the problem of the contact type charging method that is attributable to the exposure of contact terminals to an outside. As for technology corresponding to a non-contact charger, a method of charging a battery through wireless communication between a battery pack and a charging device using magnetic cores is disclosed in Korean Unexamined Pat. Pub. No. 2002-0035242 entitled "Non-contact Charging Device for Battery of Portable Device using Inductive Coupling, " and a method of solving a problem of a magnetic core using a transformer formed in such a way that coils are wound on a Printed Circuit Board (PCB) is disclosed in Korean Unexamined Pat. Pub. No. 2002-0057469 entitled "Thin PCB Transformer without Core and Non-contact Battery Charger using PCB Transformer." The present applicant proposed the technology in which a wireless charging pad for functioning as a wireless charger was constructed and the battery pack of a portable device was charged in a non-contact manner by placing the battery pack on the wireless charging pad through "Non- contact Battery Charging System capable of Multi-Charging and Method of Designing Core Block" (Korean Pat. application No. 2004-21335) . However, in the prior art, the wireless charging pad could not detect the charged status of the battery pack in real time and a means for detecting devices placed on the wireless charging pad was not implemented, so that a problem arises in that the prior art is difficult to cope with the case where a plurality of battery packs, or an object that cannot be charged, is placed on a wireless charging pad.

Description of Drawings FIG. 1 is a view showing the construction of a battery pack charged by a wireless charging pad in a non- contact manner, according to the present invention; FIG. 2 is a view showing the entire construction of a non-contact battery charging system composed of the wireless charging pad and the battery pack, according to the present invention; FIGS. 3 to 5 are views illustrating the components of the wireless charging pad or battery pack, according to the present invention; FIG. 6 is a view showing a method of generating a magnetic field based on the switching patterns of the wireless charging pad, according to the present invention; FIG. 7 is a view showing the size expansion of the wireless charging pad according to the number of charging devices, according to the present invention; FIG. 8 is a view showing the detailed construction of the non-contact battery charging system composed of the wireless charging pad and the battery pack, according to the present invention; FIG. 9 is a flowchart showing a method of charging a battery using the wireless charging pad of FIG. 8; FIGS. 10 and 11 are views showing the equivalent circuits of series and parallel resonant converters, respectively, provided to the wireless charging pad of the present invention; FIGS. 12 to 17 are views showing the operation of a half-bridge series resonant converter provided to the wireless charging pad of the present invention, according to modes; FIG. 18 is a view showing the voltage and current waveforms of a transformer according to the gate signal of the half-bridge series resonant converter provided to the wireless charging pad of the present invention; FIG. 19 is a view showing the rotating directions of a magnetic field according to the operation of the half- bridge series resonant converter provided to the wireless charging pad of the present invention, according to modes; FIGS. 20 to 23 are views showing the rectifying circuits of a charging receiver module according to the present invention; FIG. 24 is a view showing the construction of a controller provided to the wireless charging pad of the present invention; and FIG. 25 is a view showing the flow of an RF signal between the wireless charging pad and the battery pack according to the present invention.

Disclosure

Technical Problem Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a wireless charging pad and a battery pack, to which a radio frequency identification technology is applied, which can detect the charged status of the battery pack in real time, and which includes a means for detecting devices placed on the wireless charging pad, thus effectively coping with the case where a plurality of battery packs, or an object that cannot be charged, is placed on the wireless charging pad.

Technical Solution In order to accomplish the above objects, the present invention provides a wireless charging pad (200) for charging a battery pack (100) mounted on a portable device in a non-contact manner, to which a radio frequency identification technology is applied, including a controller (240) for switching to an active mode and controlling drive circuits (220 and 220' ) while standing by in an energy saving mode when access of the battery pack (100) is detected, for transmitting a Radio Frequency (RF) carrier signal to the battery pack (100) in the active mode, receiving RF data, which is modulated and includes wireless identification information and charged status information of the battery pack (100) , through a reader antenna (RA) in response to the RF carrier signal, and indicating the charged status of the battery pack (100) , and for switching to the energy saving mode again when charging of the battery pack (100) is completed; the drive circuits (220 and 220' ) for switching two primary coils (Pcoill and Pcoil2) under control of the controller (240) ; and a primary-side transformer formed by constructing a pad core, which is adapted to generate induced electromotive force through switching of the drive circuits (220 and 220' ) and charge the battery pack (100) , and which is formed by connecting a plurality of small cobalt-based amorphous metallic or ferrite planar cores in a square or rectangular shape, and winding two primary coils (Pcoill and Pcoil2) on the pad core in directions perpendicular to each other. Preferably, the controller (240) may read wireless identification information and charged status information of each of battery packs (100) in order in which the battery packs (100) are placed, indicate charged status of each battery pack (100) , and switch to the energy saving mode when charging of all the battery packs (100) are completed, and therefore, fully charged status may be established. Preferably, the controller (240) may include an oscillator (241) for generating an oscillation signal of a certain frequency; an antenna driver (242) for using the oscillation signal of the oscillator (241) as a clock, monitoring the access of the battery pack (100) by transmitting the RF carrier signal to an outside through the reader antenna (RA) and monitoring whether a return signal exists, and wirelessly receiving RF data, which is modulated and includes the wireless identification information and charged status information of the battery pack (100) , in response to the RF carrier signal when the battery pack (100) makes access; a demodulator (243) for demodulating the RF data received by the antenna driver (242); a filter and amplification unit (244) for filtering the wireless identification information and charged status information from the demodulated data and amplifying the filtered information; a data decoder (245) for decoding the wireless identification information and the charged status information received by the filter and amplification unit (244); and a display unit (247) for displaying the data decoded by the data decoder (245) . Preferably, the drive circuits (220 and 220') may include two half-bridge series-parallel resonant converters to control the primary coils (Pcoill and Pcoil2) perpendicular to each other, and switch the primary coils (Pcoill and Pcoil2) at a frequency higher than a resonant point so that switching patterns of the primary coils (Pcoill and Pcoil2) have a phase difference of 90 degrees, thus allowing linkage flux to vary while rotating in a sequence of 180°→ 135°→ 90°→ 45°→ 0°→ -45°→ -90°→ -135°, and thereby, generating a magnetic field that rotates by 360 degrees. Preferably, the wireless charging pad may further include an electromagnetic wave filter (250) combined with a power input terminal to block electromagnetic waves from Alternating Current (AC) power input; an AC/Direct Current (DC) conversion circuit (210) for receiving the AC power, the electromagnetic waves of which are blocked, from the electromagnetic wave filter (250) and rectifying the AC power into DC power; and a flyback converter (210' ) connected to the AC/DC conversion circuit (210) and the controller (240) to accumulate power while a transistor is turned on and transmit the accumulated power to the controller (240) when the transistor is turned off so as to drive the drive circuits (220 and 220') . Preferably, the wireless charging pad (200) may include input ports that are combined with at least one of an AC adapter, a Universal Serial Bus (USB) port and a cigar lighter jack for a vehicle. The present invention provides a battery pack (B) mounted on a portable device to be charged by a wireless charging pad (A) in a non-contact manner, to which a radio frequency identification technology is applied, including a charging receiver module (110) formed of an amorphous metallic planar core and two secondary coils (Scoill and Scoil2), which are wound on the planar core in vertical and horizontal directions, to induce power through magnetic coupling with the wireless charging pad (200) ; a charging protection circuit module (120) combined with the charging receiver module (110) and the battery (BAT) to record charged status information generated by periodically monitoring charged status of the battery (BAT) in an Radio Frequency Identification (RFID) tag (130) , and to control whether to charge or discharge the battery (BAT) by selectively supplying or blocking the power induced to the charging receiver module (110) to the battery (BAT); the RFID tag (130) combined with the charging protection circuit module (120) to store wireless identification information of the battery (BAT) , to periodically record the charged status information, and to generate and modulate RF data including the wireless identification information and charged status information of the battery (BAT) and transmit the modulated RF data to the wireless charging pad (200) when an RF carrier signal is transmitted from the wireless charging pad (200) through a tag antenna (TA) ; and the battery (BAT) to be charged under control of the protection circuit (124) . Preferably, the wireless charging pad may further include an amorphous metallic electromagnetic protector (140) for minimizing a rise in temperature of the battery (BAT) attributable to frequency interference, which is caused by radio signals or induced electromotive force in a magnetic field, or attributable to inductive heating, by magnetically blocking a gap between the battery (BAT) and the charging receiver module (110) . Preferably, the wireless charging pad may further include a battery casing (150) manufactured using a cool polymer to perform an operation of emitting heat generated due to charging while admitting the induced electromotive force, and to entirely surround a structure that is formed by assembling the components. Preferably, the charging protection circuit module (120) may include rectifying circuits 121 and 121' for rectifying the power induced to the charging receiver module (110) and supplying the rectified power to a charging control circuit (122) ; the charging control circuit (122) combined with the rectifying circuits (121 and 121' ) to supply the power rectified by the rectifying circuits (121 and 121') to a fuel gauge (123) under On/Off control of the RFID tag (130); the fuel gauge (123) for supplying the power supplied from the charging control circuit (122) to the battery (BAT) through a protection circuit (124), and generating the charged status information while monitoring the charged status of the battery (BAT) , and periodically recording the charged status information in the RFID tag (130) ; and the protection circuit (124) combined with the fuel gauge (123) and the battery (BAT) to protect the battery (BAT) by controlling whether to charge or discharge according to the charged status of the battery (BAT) . Preferably, the rectifying circuits (121 and 121') may be series-parallel resonant center tap half-bridge rectifying circuits using an output of a single center tap rectifying diode and an output filter capacitor, or series- parallel resonant full-bridge rectifying circuits using an output of a full-bridge rectifying diode and an output filter capacitor. Preferably, the RFID tag (130) may include a clock extraction unit (131) for extracting a clock from the RF carrier signal wirelessly received from the wireless charging pad (200) ; a sequencer (132) for inspecting an sequence of arranged data extracted from the clock extraction unit (131) and transmitting a control signal to a data encoder (133); the data encoder (133) for receiving the wireless identification information and charged status information of the battery (BAT) from a tag (135) when the control signal is transmitted from the sequencer (132), and transmitting the wireless identification information and charged status information to a data modulator (136) after coding the wireless identification information and charged status information; the data modulator (136) for generating RF data generated by modulating the data received from the data encoder (133) , and wirelessly transmitting the RF data to the wireless charging pad (200) ; Read Only Memory (ROM) (134) for recording the wireless identification information and charged status information therein; and the tag (135) for reading the wireless identification information and charged status information of the battery (BAT) stored in the ROM (134), and transmitting the wireless identification information and charged status information to the data encoder (133) . Preferably, the wireless identification information may correspond to one of a product name of the battery (BAT) , a serial number of the battery (BAT) and a user identification number that is stored in the RFID tag (130) through communication between a body of a portable device, on which the battery pack (100) is mounted, and the battery pack (100) . Preferably, the RF carrier signal may be a signal that accesses an RFID signal stored in the battery pack (100) using a carrier signal in High Frequency (HF) (3 to 30 MHz) or Ultra High Frequency (UHF) (300 to 3000 MHz) bands.

Advantageous Effects As described above, the present invention is advantageous in that there is provided a wireless charging pad and a battery pack, to which a radio freguency identification technology is applied, which can detect the charged status of the battery pack in real time, and which includes a means for detecting devices placed on the wireless charging pad, thus effectively coping with the case where a plurality of battery packs, or an object that cannot be charged, is placed on the wireless charging pad.

Best Mode Preferred embodiments of the present invention are described in detail with reference to the attached drawings below, but detailed descriptions of related well-known functions and construction may be omitted if the detailed descriptions are determined to make the gist of the present invention unclear. FIG. 1 is a view showing the entire construction of a battery pack charged by a wireless charging pad in a non- contact manner, according to the present invention. Referring to FIG. 1, a battery pack 100 includes a charging receiver module 110 provided with secondary coils Scoill and Scoil2 to receive induced electromotive force from a primary-side wireless charging pad 200 (refer to FIG. 2), a charging protection circuit module 120 and a battery BAT having fuel gauge and charging functions, an RFID tag 130 (refer to FIG. 2) and a tag antenna TA adapted to transmit and receive radio signals, and an electromagnetic protector 140 that is an amorphous metal- based electromagnetic interference shield for magnetically isolating the battery BAT and the charging receiver module 110 so that the battery BAT does not affect the inductive coupling between the receiver module 110 and the wireless charging pad 200 (refer to FIG. 2) . The electromagnetic protector 140 is made of an amorphous metal-based magnetic material to remove frequency interference in a magnetic field attributable to radio signals and induced electromotive force, and generally functions to minimize a rise in temperature of the battery BAT in a magnetic field attributable to inductive heating caused by a metallic battery casing, so that the electromagnetic protector 140 must be inserted. The battery pack 100 may further include the battery casing 150 for surrounding all the components, such as the charging receiver module 110, the charging protection circuit module 120, the battery BAT and the electromagnetic protector 140, combined into a single structure. In this case, the battery casing 150 is manufactured using a cool polymer material, such as cobalt or nickel, so that the battery casing 150 functions to pass the induced electromotive force or electromagnetic waves, and emit heat generated inside the battery casing 150 due to charging. FIG. 2 is a view showing the construction of a non- contact battery charging system composed of the wireless charging pad and the battery pack, according to the present invention. Referring to FIG. 2, the non-contact battery charging system composed of the wireless charging pad and the battery pack separately comprises the wireless charging pad 200 adapted to function as a non-contact charger and the battery pack 100 charged with power provided by the wireless charging pad 200. A separative transformer is provided between ' the wireless charging pad 200 and the battery pack 100 so that a primary side of the transformer is provided in the wireless charging pad 200 and a secondary side of the transformer is provided in the battery pack 100. The battery pack 100 includes the charging receiver module 110, the charging protection circuit module 120, the RFID tag 130, the tag antenna TA and the battery BAT that constitute the secondary side of the transformer. The charging receiver module 110 receives the power induced from the wireless charging pad 200 and supplies the power to the charging protection circuit module 120. The charging protection circuit module 120 having fuel gauge and charging functions includes rectifying circuits 121 and 121' for rectifying the power supplied from the charging receiver module 110 by performing AC/DC conversion, a switch mode charging control circuit 122 for charging the battery BAT made of lithium ion or lithium polymer at Constant Voltage (CV) and Constant Current (CC) , and a protection circuit 124 for detecting the charged status of the battery BAT and determining whether to supply or block the power supplied to the battery BAT from the charging control circuit 122 so as to protect the battery BAT. The charging protection circuit module 120 is constructed in such a way that the output of the charging receiver module 110 is the input of the rectifying circuits 121 and 121' and the output of the rectifying circuits 121 and 121' is connected to the input of the switch mode charging control circuit 122. Furthermore, the output of the charging control circuit 122 is connected to a fuel gauge 123, and the fuel gauge 123 is connected to the protection circuit 124 that protects the battery BAT from excessive charging and excessive current. Such components are mounted in the battery pack 100 of a portable device, and can be applied to a hard pack or an inner pack according to the type of the battery pack 100. The wireless charging pad 200 functioning as a non- contact charger has various input ports having DC inputs, so that the wireless charging pad 200 can be used in connection with various types of external power sources (e.g., the output of an AC adapter, a USB port of a computer, cigar lighter jack of a vehicle, etc.) . In the wireless charging pad 200, the primary side of the transformer is provided, switching loss is reduced through zero voltage and zero current soft switching by switching at a frequency higher than a resonant point using a half- bridge resonant converter, and linkage flux is induced to the battery pack 100 of a portable device that constitutes a secondary side. Furthermore, the wireless charging pad 200 has a function of detecting the wireless identification information of the battery BAT and indicating charged status information on the wireless charging pad 200 through radio communication when the battery pack 100 equipped with the charging receiver module 110 is placed on the wireless charging pad 200, and a function of entering a shutdown mode and an energy saving mode when an object other than a battery pack 100 is placed on the wireless charging pad 200. Furthermore, when a plurality of portable devices is placed on the wireless charging pad 200, the wireless charging pad 200 reads the wireless identification information (e.g., personal phone numbers, etc.) stored in the RFID tag 130, indicates the wireless identification information on the wireless charging pad 200, indicates charged status, and indicates charging completion status on the wireless charging pad 200 after receiving information on the completion of charging from the battery pack 100. The RFID tag 130 and the tag antenna TA function to interface with the fuel gauge 123 that controls the charged status information of the battery BAT and transmit the charged status information of the battery BAT to the wireless charging pad 200 in a radio data form using a radio frequency in HF (13.56MHz) or UHF (900MHz) bands. The RFID tag 130 includes a memory block and a logic block, and stores the wireless identification information, such as a product name, a serial number and a user identification number (e.g., personal telephone number), therein. In this case, the user identification number is stored in the memory block of the RFID tag 130 through the communication between the terminal body of the portable device and the battery pack 100. FIGS. 3 and 4 are views illustrating the components of the wireless charging pad and the battery pack according to the present invention, respectively. Referring to FIG. 3, the wireless charging pad 200 according to the present invention includes a controller 240 for reading the RFID tag and controlling charging, drive circuits 220 and 220' , and primary coils Pcoill and Pcoil2. The wireless charging pad 200 may include various input ports having DC inputs, and generates the switching patterns of the primary coils Pcoill and Pcoil2 through the drive circuits 220 and 220' , respectively, and performs a control function of detecting portable devices placed on the wireless charging pad 200 and indicating the energy saving mode and the charged status of each of the portable devices. The drive circuits 220 and 220' are On/Off switching devices for switching the primary coils Pcoill and Pcoil2, respectively, each of which is composed of an upper switch and a lower switch. The drive circuits 220 and 220' are each constructed using a half-bridge or full- bridge resonant converter (serial, parallel or serial- parallel resonant converter) . Referring to FIG. 4, in the wireless charging pad 200 according to the present invention, the primary side of the transformer is constructed in such way that the two primary coils Pcoill and Pcoil2 are wound on a planar core, which is formed by combining small cobalt-based amorphous metallic cores, such as Co, Fe, Ni, B and Si, or ferrite cores in various shapes, in directions perpendicular to each other as shown in FIG. 4. In this case, the switching patterns perform switching so that a phase difference of 90 degrees occurs between the two primary coils Pcoill and Pcoil2. Accordingly, induced energy can be received regardless of the location of the portable device that is placed on the wireless charging pad 200 and has the battery pack 100 equipped with the charging receiver module 100. The input form of the wireless charging pad 200 is described below. A control power source supplies the driving power of the controller 240 and the drive circuits 220 and 220' using a flyback converter in a 110/220 V direct drive fashion. In the resonant converter, DC power obtained by rectifying AC power in a 110/220 V switching fashion is always set to a 110 V input condition. DC power (12, 24, 48 V) is generated using the flyback converter for free voltages ranging from 86 to 265 V and is used as the input power of the resonant converter, and forms the driving power of the controller 240 and the drive circuits 220 and 220' using a regulator. The controller 240 performs both a function of reading an RFID tag and a function of controlling charging. The construction of the controller 240 is described below. First, a controller 240 is provided to detect the battery pack 100 equipped with the charging receiver module 110 and control charging. Wireless identification information, such as the product code and serial number of the battery BAT, and charged status information are read from the RFID tag 130 of the battery pack 100 through the controller 240. Furthermore, when the battery pack 100 equipped with the charging receiver module 110 is placed on the wireless charging pad 200 while the controller 240 in a sleep mode is maintained in a standby mode (energy saving mode: below 1 W) and monitors the battery pack 100, the controller 240 wakes up and switches to an active mode to generate induced electromotive force by controlling the drive circuits 220 and 220' , starts to charge the battery pack 100, and indicates the charged status of the battery pack 100. When the charging of the battery pack 100 is completed, the wireless charging pad 200 switches from the active mode to the energy saving mode again to save energy. Second, when a plurality of battery packs 100 each equipped with a charging receiver modules 110 is placed on the wireless charging pad 200, wireless identification information stored in the RFID tags 130 of the battery packs 100 is read in order in which the battery packs 100 are placed. Furthermore, a fully charged battery pack 100 is indicated by a green Light Emitting Diode (LED) and a discharged battery pack 100 is indicated by a red LED. When the battery pack 100 is fully charged, the LED switches from red to green by receiving the wireless identification information of the RFID tag 130 so that the charged status is indicated by the wireless charging pad 200. The construction of the drive circuits 220 and 220' is described below. Two resonant converters control perpendicularly arranged primary coils Pcoill and Pcoil2, respectively, and the primary coils Pcoill and Pcoil2 are switched at a frequency higher than a resonant point so that the switching patterns of the primary coils have a phase difference of 90 degrees. Accordingly, linkage flux rotates by 360 degrees in eight steps, thus enabling the battery pack 100 to be charged regardless of the location of the battery pack 100. The construction of the primary side of the transformer is described below. A single square or rectangular pad core is formed by connecting a plurality of small planar cores, is surrounded by an insulation tape, is provided with a coil wound thereon in a vertical direction, and is insulated by an insulation tape. Furthermore, the pad core is provided with a coil wound thereon in a horizontal direction and is insulated by an insulation tape, thus manufacturing the primary side of a planar transformer. In this case, the coil may be formed into a bobbinless type and be inserted into the pad core in vertical and horizontal directions. The charging receiver module 110 is operated as the secondary side of the transformer. FIG. 5 is a view showing the charging receiver module 110. The charging receiver module 110 is manufactured in such a way that a plurality of cobalt-based amorphous metallic cores is stacked to form a single planar core, and secondary coils Scoill and Scoil2 are wound on the single planar core in vertical and horizontal directions, respectively. In this case, the planar core is made of an amorphous metal-based material that has high magnetic permeability (>80,000) and a non-breakable characteristic. In the charging receiver module 110, the magnitude of induced electromotive force varies according to a function of the number of stacked cores forming the planar core, the sectional area of the planar core and the number of windings of the coils. The charging receiver module 110 has a load curve in which voltage is inversely proportional to current. FIG. 6 is a view showing a method of generating a magnetic field depending on the switching patterns of the wireless charging pad according to the present invention. In the wireless charging pad 200, a magnetic field rotates by 360 degrees in the case where current is applied by successively switching regions in the sequence of a first region—» a second region-* a third region—» a fourth region—> a fifth region—> a sixth region—> a seventh region—» an eighth region at a predetermined frequency, thus enabling a portable device equipped with the charging receiver module 110 to be charged regardless of the location and direction of the portable device when the portable device is placed on the wireless charging pad 200 (the magnetic field is rotated by 180°→ 135°→ 90°→ 45°-» 0°→ -45°→ -90°→ -135°) . In this case, the drive circuits 220 and 220' include two half-bridge series-parallel resonant converters to control the perpendicularly arranged primary coils Pcoill and Pcoil2, respectively, and switch the primary coils Pcoill and Pcoil2 at a frequency higher than a resonant point so that the switching patterns of the primary coils Pcoill and Pcoil2 have a phase difference of 90 degrees, thus allowing linkage flux to vary while rotating by 360 degrees in the sequence of 180°—> 135°—> 90°→ 45°→ 0°→ -45°→ -90°→ -135°, and thereby, generating a magnetic field that rotates by 360 degrees. FIG. 7 is a view showing the size^' expansion of the wireless charging pad according to the number of charging devices, according to the present invention. In a process of forming a pad core constituting the wireless charging pad 200, a wireless charging pad 200 having a desired size and shape can be formed by combining a plurality of small cobalt-based metallic or ferrite planar cores. For example, a pad core is formed by combining m cores in a longitudinal direction and n cores in a transverse direction according to the number of portable devices desired to be charged. FIG. 8 is a view showing the detailed construction of a non-contact battery charging system composed of the wireless charging pad and the battery pack according to the present invention. As shown in FIG. 8, a primary-side wireless charging pad 200 and a secondary-side battery pack 100 equipped with the charging receiver module 110 are magnetically combined with each other. The primary-side wireless charging pad 200 includes a power input terminal, an AC/DC conversion circuit 210, a controller 240 for detecting wireless identification information transmitted from the secondary side, two half- bridge serial-parallel resonant converters, drive circuits 220 and 220' for generating a magnetic field by generating control signals for controlling the two primary coils Pcoill and Pcoil2, respectively, a primary-side transformer constructed by winding the two primary coils Pcoill and Pcoil2 on the pad core in vertical and horizontal directions, respectively, and inductive couplers 230 and 230' formed by providing L_r and L₁' to the corresponding primary-side transformer. Furthermore, the primary-side wireless charging pad 200 may further include an electromagnetic wave filter 250 connected to the power input terminal for the purpose of blocking the electromagnetic waves of input AC power, and a flyback converter 210' connected to the AC/DC conversion circuit 210 for receiving the AC power, the electromagnetic waves of which are blocked, from the electromagnetic wave filter 250 and rectifying the AC power into DC power and the controller 240 for the purpose of accumulating power while an equipped transistor is turned on and transmitting the accumulated power to the controller 240 when the equipped transistor is turned off so as to enable the drive circuits 220 and 220' to be driven. The secondary-side battery pack 100 includes a receiver module 110 composed of an amorphous metallic planar core and two secondary coils Scoill and Scoil2 that are wound on the planar core in vertical and horizontal directions, respectively, to be magnetically combined with the wireless charging pad 100, thus inducing induced electromotive force; a charging protection circuit module 120 for generating charged status information by periodically monitoring the charged status of a battery BAT, recording the generated charged status information in an RFID tag 130 and controlling whether to charge or discharge the battery BAT by selectively supplying or blocking the power, which is induced to the charging receiver module 110, to the battery BAT under the On/Off control of the RFID tag 130; the RFID tag 130 combined with the charging protection circuit module 120 to store the wireless identification information of the battery BAT and periodically record the charged status information therein, generate and modulate RFID data including the wireless identification information and charged status information of the battery BAT and transmit the modulated RFID data to the wireless charging pad 200 in response to an RFID carrier signal transmitted from the wireless charging pad 200 through a tag antenna TA; and the battery BAT to be charged under the control of the protection circuit 124. The charging protection circuit module 120 may include rectifying circuits 121 and 121' adapted to rectify the power induced to the charging receiver module 110 and supply the rectified power to a charging control circuit 122, the charging control circuit 122 combined with the rectifying circuits 121 and 121' to supply the power, rectified by the rectifying circuits 121 and 121' under the On/Off control of the RFID tag 130, to a fuel gauge 123, the fuel gauge 123 adapted to supply the power supplied from the charging control circuit 122 to the battery BAT through the protection circuit 124, and generate the charged status information by monitoring the charged status of the battery BAT and periodically record the charged status information in the RFID tag 130, and the protection circuit 124 combined with the fuel gauge 123 and the battery BAT to protect the battery BAT by controlling whether to charge or discharge in accordance with the charged status of the battery BAT. When the RFID carrier signal is transmitted from the wireless charging pad 200 through the tag antenna TA, the RFID tag 130 generates and modulates RFID data that includes previously stored wireless identification information of the battery BAT and charged status information, which is periodically recorded through the fuel gauge 123, in response to the RFID carrier signal, and transmits the modulated RFID data to the wireless charging pad 200. In this case, the RFID tag 130 is composed of a memory block and a logic block. The memory block can be implemented using ROM 134 in which the wireless identification information and the charged status information are recorded. It is preferable to use Electrically Erasable and Programmable Read Only Memory (EEPROM) as the ROM 134. The logic block can be implemented using a clock extraction unit 131 for extracting a clock from the RFID carrier signal that is wirelessly received from the wireless charging pad 200, a sequencer 132 for inspecting the sequence of arranged data extracted from the clock extraction unit 131 and transmitting a control signal to a data encoder 133, the data encoder 133 for receiving the wireless identification information and charged status information of the battery BAT from a tag 135 when the control signal is transmitted from the sequencer 132, encoding the received information and transmitting the encoded information to a data modulator 136, the data modulator 136 for generating the modulated RFID data by modulating the data received from the data encoder 133 and wirelessly transmitting the modulated RFID data to the wireless charging pad 200, and the tag 135 for reading the wireless identification information and charged status information of the battery BAT stored in the ROM 134 and transmitting the wireless identification information and charged status information to the data encoder 133. FIG. 9 is a flowchart showing a method of charging a battery through the wireless charging pad of FIG. 8. The method of charging a battery using the wireless charging pad 200 according to the present invention is described with reference to FIG. 9 below. Step SlOO) First, when the secondary-side battery pack 100 is placed on the primary-side wireless charging pad 200, the primary-side wireless charging pad 200 generates an RFID carrier signal and inspects an object placed on the wireless charging pad 200. Step SIlO) If, as a result of the inspection, the object does not contain information indicating that the object is a battery pack 100 equipped with a charging receiver module 110, the primary-side wireless charging pad 200 always enters an energy saving mode. Step S120) If, as a result of the inspection, the object contains information indicating that the object is a battery pack 100 equipped with a charging receiver module 110, the wireless charging pad 200 wakes up to detect wireless identification information and starts charging control. Step S130) Wireless identification information about the battery pack 100 of each of various portable devices is displayed, and whether the battery pack 100 is in charging status or fully charged status is indicated after receiving charged status information. The battery 100 in fully charged status that indicates charging is completed is indicated by a green LED, and the battery 100 being charged is indicated by a red LED. Step S140) When the fully charged status in which the charging of all the battery packs 100 are completed is established, the wireless charging pad 200 collects the wireless identification information and enters a standby mode, that is, the energy saving mode. FIGS. 10 and 11 are views showing the equivalent circuits of series and parallel resonant converters provided to the wireless charging pad according to the present invention. FIGS. 10 and 11 are views showing the equivalent circuits of a separative transformer that has a gap between the wireless charging pad 200 and the battery pack 100. In a non-contact type charging method in which energy is transmitted using the magnetic coupling of the transformer, the primary side of the transformer is included in the wireless charging pad 200 functioning as a non-contact charger and the secondary side of the transformer is included in the battery pack 100, so that a gap exists between the primary and secondary sides, thus causing inefficiency in energy transmission because a coupling coefficient and magnetizing inductance are reduced and leakage inductance is increased. Besides, it is problematic in that it is difficult to electrically transmit output information to a primary-side controller at the time of controlling feedback. In the present invention, in order to overcome the disadvantages of the separative transformer and effectively transmit energy, a half-bridge serial resonant converter is applied to the primary side of the transformer. The serial resonant converter applied to the primary side of the transformer reduces the influence of leakage inductance on the primary side of the separative transformer, thus enabling effective energy transmission. The self-inductance L₁ and L₂ are measured in such a way that a secondary-side module is opened and primary-side inductance is measured, and the leakage inductance L₁₁ and L₁₂ are measured in such a way that a secondary-side module is shorted and primary-side inductance is measured. Mutual inductance L_M is calculated in such a way that impedance L_p is measured by connecting the primary and secondary sides in parallel, impedance L₃ is measured by connecting the primary and secondary sides in series, and the measured impedance L_p and L₅ are substituted for L_p and L₃ of Equation 1,

L» = ^L _P ^~ ⁽i;

The magnetizing inductance L_1n is measured using Equations 2 to 4,

(N₁ : number of primary windings, N₂: number of secondary windings)

Jt = -γ^= (3)

L_n = L₁ - L_n, L₁₂ = L₂ - NL_M (4)

Voltage imposed in the primary side of the transformer is applied to the primary side of the transformer through the voltage distribution of L₁₁ and L_i2 , and is transmitted to the secondary side based on a winding ratio. The secondary-side voltage is transmitted to the actual secondary side of the transformer through the voltage distribution of L₁₂ and secondary-side load, so that the voltage gain is lower than that of an ideal transformer. Furthermore, if the coupling coefficient is low, the magnetizing inductance L_m of the transformer is low, so that current flowing to the primary side of the transformer is not transmitted to the secondary side of the transformer through L₁₂, but is circulated and transmitted to the first side of the transformer again through the magnetizing inductance L_m that has lower impedance. That is, in order to supply current required by the load, input current must be large. If the primary-side current increases, continuity loss in a switch increases, thus causing the efficiency of a system to decrease. Accordingly, in order to increase the efficiency of the system by reducing the primary-side current, the coupling coefficient of the transformer must be increased. In the non-contact charger, the primary- and secondary-side cores are separated by a gap, and winding areas are also separated. Furthermore, the gap is located in a path through which magnetic flux passes, so that magnetic resistance is increased, thus lowering the magnetic flux density inside the cores. When a large gap exists between the primary- and secondary-side cores, magnetic flux density is expressed by Equation 5,

(B : magnetic flux density, N : number of windings, I : current flowing through transformer, l_f : length of magnetic path of core, l_g : length of magnetic path in gap, μ_f : magnetic permeability of core, μ_o : magnetic permeability of gap)

The magnetic flux density, when the gap does not exist, is expressed by Equation 6,

μ_fNI B_f = ^- » B_f (6) The magnetic permeability of the core is considerably larger than that of air, and the size of the gap is relatively larger than that of the core, so that the magnetic flux density in the case where the gap does not exist has a value considerably higher than that in the case where the gap is large. As a result, in the case of a transformer having a large gap, it is difficult for saturation status to occur inside the core, and also local saturation status is not generated easily. Accordingly, with respect to the shape of a core, a narrow section or protrusion is allowed. Furthermore, the magnetic flux density in the core is low, so that core loss due to hysteresis is also low. Since the gap is large, the magnetic resistance is increased, so that the inductance of the core is decreased. Accordingly, in order to obtain required magnetizing inductance, the number of windings is increased and a wider winding area is required as a result. The magnetizing inductance L_m may be expressed by Equation 7,

_Lm .^!L₁. !L₁HJL, . Hi ₍₇₎ W₂ W₂ R- R, (R_n, : magnetic resistance, N₁ : number of primary windings, N₂ : number of secondary windings, L_M : mutual inductance) That is, since the magnetic resistance R_m is large, the number of windings is increased to obtain the required magnetizing inductanceL_M . Generally, the difference between the primary- and secondary-side voltages of a non- contact charger is large, so that a difference in the winding ratio is also large. As a result, since the winding areas of the primary and secondary sides are different and the difference between the winding ratios is large, the shapes of the primary- and secondary-side cores are generally asymmetric. Most leakage magnetic flux is generated in the gap existing between the primary- and secondary-side cores, so that a section area of the cores opposite to each other must be large to increase the coupling coefficient in the transformer. However, in the case of a transformer used in the non-contact charger, the volume and weight of the secondary-side core are limited because the secondary-side core is located inside the battery pack, so that the section area of the cores opposite to each other is also limited. However, in the present invention, a planar pad core, the section area of which is large in considerations of limited volume and weight, is used. FIGS. 12 to 17 are views showing the operation of the half-bridge serial resonant converter provided to the wireless charging pad of the present invention, according to modes. FIGS. 12 to 17 are views showing the operation of the half-bridge serial resonant converter (upper converter) , according to modes. In FIG. 12, when Q₁ is turned on, current L₁ flows to a transformer through the switch Q₁. In FIG. 13, when the switch Q₁ is turned off, the current L₁ flows while discharging the parallel capacitor of a switch Q₂ and charging the parallel capacitor of the switch Q₁. In FIG. 14, when the voltage of the switch Q₂ is zero (the voltage of the switch Q₁ is input voltage) , the current L₁ flows through the parallel diode of the switch Q₂, and the voltage of the switch Q₂ remains at zero. Furthermore, if the switch Q² is turned on before the direction of the current L₁ is reversed, Zero Voltage Switching (ZVS) is achieved in the switch Q₂. In FIG. 15, when the direction of the current L₁ is reversed, the current L₁ flows through the switch Q². In FIG. 16, when the switch Q² is turned off, the current L₁ flows while discharging the parallel capacitor of the switch Q¹ and charging the parallel capacitor of the switch Q². In FIG. 17, when the voltage of the switch Q² is zero (the voltage of the switch Q² is the input voltage) , the current L₁ flows through the parallel diode of the switch Q¹, and the voltage of the switch Q¹ remains at zero. Furthermore, when the switch Q¹ is turned on before the direction of the current is restored, the ZVS is achieved in the switch Q¹. In order to achieve the ZVS of the switch Q², the magnitude of the current i_: at the time of being changed from FIG. 12 to FIG. 13 must be large enough so that the energy of a magnetic circuit depending on the current L₁ can charge or discharge the parallel capacitor, and the gate signal of the switch Q² must be provided before the direction of the current I₁ is reversed. The switch Q¹ can achieve the ZVS using the same principle. In this case, a resonant frequency considerably affects efficiency. The switching frequency is operated at a frequency close to the resonant frequency, so that the core loss and gap loss of the transformer are reduced if the resonant frequency is low. However, the loss may be increased because magnetic current, that is, the primary- side current of the transformer, is increased. Accordingly, the switching loss attributable to the ZVS is reduced by selecting a switching frequency higher than the resonant frequency. FIG. 18 is a view showing the voltage and current waveforms of the transformer according to the gate signal of the half-bridge series resonant converter provided in the wireless charging pad of the present invention. Referring to FIG. 18, square wave voltage identical to the input voltage is applied to the transformer by the gate signals of the switches Q¹ and Q², and sine wave current identical to the current I₁ flows to the transformer through the resonant circuit. FIG. 19 is a view showing the rotating directions of the magnetic field according to the operation of the half- bridge series resonant converter provided in the wireless charging pad of the present invention, according to modes. FIG. 20 is a view showing the rotating directions of the magnetic field generated according to the operation of the half-bridge series resonant converter according to modes. Accordingly, since the magnetic field rotates by 360 degrees, induced electromotive force can be transmitted to the secondary side regardless of the location and direction of the battery pack 100 when the battery pack 100 eguipped with the charging receiver module 110 is placed on the wireless charging pad 200. FIGS. 20 to 23 are views showing the rectifying circuits of the charging receiver module according to the present invention. Referring to FIGS. 20 to 23, the secondary-side charging receiver module 110 transmits power through a series-parallel resonant center tap half-bridge rectifying circuit that uses the output of a single center tap rectifying diode and an output filter capacitor, or through a series-parallel resonant full-bridge rectifying circuit that uses the output of a full-bridge rectifying diode and an output filter capacitor. FIG. 24 is a view showing the construction of a controller provided in the wireless charging pad of the present invention. The controller 240 provided in the wireless charging pad 200 of the present invention determines whether a battery pack 100 is placed on the wireless charging pad 200, reads wireless identification information, which is stored in the RFID tag 130, from the battery pack 100 if the battery pack 100 is placed, determines whether the battery pack 100 needs to be charged or how many battery packs 100 are placed, and generates a drive control signal and indicates the charged status of each of the battery packs at the same time. Referring to FIG. 24, the controller 240 provided in the wireless charging pad 200 of the present invention may include an oscillator 241 for generating an oscillation signal of a certain frequency, an antenna driver 242, a demodulator 243 for demodulating RF data received by the antenna driver 242, a filter and amplification unit 244 for filtering wireless identification information and charged status information from the demodulated data and amplifying the filtered information, a data decoder 245 for decoding the wireless identification information and charged status information received by the filter and amplification unit 244, a driver control unit 246 for performing mode conversion according to the charged status based on the decoded data, a display unit 247 for displaying the data decoded by the data decoder 245, a timer 248, and a reset unit 249. The antenna driver 242 uses the oscillation signal of the oscillator 241 as a clock, monitors the access of the battery pack 100, and wirelessly receives RF data, which is modulated and includes the wireless identification information and charged status information of the battery pack 100, in response to an RF carrier signal through the reader antenna RA when the battery pack 100 makes access. In this case, a polling method of periodically transmitting the RF carrier signal to the outside through the reader antenna RA and monitoring whether a return signal exists can be applied as a method of the antenna driver 242 monitoring the access of the battery pack 100. Furthermore, in the case where a plurality of battery packs 100 is placed, the controller 240 reads the wireless identification information and charged status information of each of the battery packs 100 in order in which the battery packs 100 are placed, indicates the charged status of each of the battery packs 100, and switches from an active mode to an energy saving mode when all the battery packs 100 are completely charged, and thereby, the fully charged status is established. FIG. 25 is a view showing the flow of the RF signal between the wireless charging pad and the battery pack according to the present invention. Referring to FIG. 25, when the controller 240 accesses the RFID tag 130 in the battery pack 100 equipped with the charging receiver module 110 to access information on the battery BAT using a carrier frequency in HF (3 to 30 MHz) or UHF (300 to 3000 MHz) bands, the battery information stored in the memory block of the RFID tag 130 is transmitted to the wireless charging pad 200 in a modulated RF signal form. The present invention may be modified in various forms without departing from the basic concept of the invention according to the demands of those skilled in the art.

Claims

1. A wireless charging pad (200) for charging a battery pack (100) mounted on a portable device in a non- contact manner, to which a radio frequency identification technology is applied, comprising: a controller (240) for switching to an active mode and controlling drive circuits (220 and 220' ) while standing by in an energy saving mode when access of the battery pack (100) is detected, for transmitting a Radio Frequency (RF) carrier signal to the battery pack (100) in the active mode, receiving RF data, which is modulated and includes wireless identification information and charged status information of the battery pack (100), through a reader antenna (RA) in response to the RF carrier signal, and indicating the charged status of the battery pack (100) , and for switching to the energy saving mode again when charging of the battery pack (100) is completed; the drive circuits (220 and 220') for switching two primary coils (Pcoill and Pcoil2) under control of the controller (240) ; and a primary-side transformer formed by constructing a pad core, which is adapted to generate induced electromotive force through switching of the drive circuits (220 and 220') and charge the battery pack (100), and which is formed by connecting a plurality of small cobalt-based amorphous metallic or ferrite planar cores in a square or rectangular shape, and winding two primary coils (Pcoill and Pcoil2) on the pad core in directions perpendicular to each other.

2. The wireless charging pad according to claim 1, wherein the controller (240) reads wireless identification information and charged status information of each of battery packs (100) in order in which battery packs (100) are placed, indicates charged status of each battery pack (100) , and switches to the energy saving mode when charging of all the battery packs (100) are completed, and therefore, fully charged status is established.

3. The wireless charging pad according to claim 1 or 2, wherein the controller (240) comprises an oscillator (241) for generating an oscillation signal of a certain frequency; an antenna driver (242) for using the oscillation signal of the oscillator (241) as a clock, monitoring the access of the battery pack (100) by transmitting the RF carrier signal to an outside through the reader antenna (RA) and monitoring whether a return signal exists, and wirelessly receiving RF data, which is modulated and includes the wireless identification information and charged status information of the battery pack (100) , in response to the RF carrier signal when the battery pack (100) makes access; a demodulator (243) for demodulating the RF data received by the antenna driver (242); a filter and amplification unit (244) for filtering the wireless identification information and charged status information from the demodulated data and amplifying the filtered information; a data decoder (245) for decoding the wireless identification information and the charged status information received by the filter and amplification unit (244); and a display unit (247) for displaying the data decoded by the data decoder (245) .

4. The wireless charging pad according to claim 1, wherein the drive circuits (220 and 220' ) include two half- bridge series-parallel resonant converters to control the primary coils (Pcoill and Pcoil2) perpendicular to each other, and switch the primary coils (Pcoill and Pcoil2) at a frequency higher than a resonant point so that switching patterns of the primary coils (Pcoill and Pcoil2) have a phase difference of 90 degrees, thus allowing linkage flux to vary while rotating in a sequence of 180°—> 135°→ 90°—> 45°→ 0°→ -45°→ -90°→ -135°, and thereby, generating a magnetic field that rotates by 360 degrees.

5. The wireless charging pad according to claim 1, further comprising: an electromagnetic wave filter (250) combined with a power input terminal to block electromagnetic waves from Alternating Current (AC) power input; an AC/Direct Current (DC) conversion circuit (210) for receiving the AC power, the electromagnetic waves of which are blocked, from the electromagnetic wave filter (250) and rectifying the AC power into DC power; and a flyback converter (210' ) connected to the AC/DC conversion circuit (210) and the controller (240) to accumulate power while a transistor is turned on and transmit the accumulated power to the controller (240) when the transistor is turned off so as to drive the drive circuits (220 and 220') .

6. The wireless charging pad according to claim 1, wherein the wireless charging pad (200) includes input ports that are combined with at least one of an AC adapter, a Universal Serial Bus (USB) port and a cigar lighter jack for a vehicle.

7. The wireless charging pad according to claim 1, wherein the wireless identification information corresponds to one of a product name of the battery (BAT) , a serial number of the battery (BAT) and a user identification number that is stored in an Radio Frequency Identification (RFID) tag (130) through communication between a body of a portable device, on which the battery pack (100) is mounted, and the battery pack (100) .

8. The wireless charging pad according to claim 1, wherein the RF carrier signal is a signal that accesses an RFID signal stored in the battery pack (100) using a carrier signal in High Frequency (HF) (3 to 30 MHz) or Ultra High Frequency (UHF) (300 to 3000 MHz) bands.

9. A battery pack (B) mounted on a portable device to be charged by a wireless charging pad (A) in a non-contact manner, to which a radio frequency identification technology is applied, comprising: a charging receiver module (110) formed of an amorphous metallic planar core and two secondary coils (Scoill and Scoil2) , which are wound on the planar core in vertical and horizontal directions, to induce power through magnetic coupling with the wireless charging pad (200) ; a charging protection circuit module (120) combined with the charging receiver module (110) and the battery (BAT) to record charged status information generated by periodically monitoring charged status of the battery (BAT) in an RFID tag (130) , and to control whether to charge or discharge the battery (BAT) by selectively supplying or blocking the power induced to the charging receiver module (110) to the battery (BAT); the RFID tag (130) combined with the charging protection circuit module (120) to store wireless identification information of the battery (BAT) , to periodically record the charged status information, and to generate and modulate RF data including the wireless identification information and charged status information of the battery (BAT) and transmit the modulated RF data to the wireless charging pad (200) when an RF carrier signal is transmitted from the wireless charging pad (200) through a tag antenna (TA) ; and the battery (BAT) to be charged under control of the protection circuit (124) .

10. The wireless charging pad according to claim 9, further comprising an amorphous metallic electromagnetic protector (140) for minimizing a rise in temperature of the battery (BAT) attributable to frequency interference, which is caused by radio signals or induced electromotive force in a magnetic field, or attributable to inductive heating, by magnetically blocking a gap between the battery (BAT) and the charging receiver module (110) .

11. The wireless charging pad according to claim 9 or 10, further comprising a battery casing (150) manufactured using a cool polymer to perform an operation of emitting heat generated due to charging while admitting the induced electromotive force, and to entirely surround a structure that is formed by assembling the components.

12. The wireless charging pad according to claim 9, wherein the charging protection circuit module (120) comprises: rectifying circuits 121 and 121' for rectifying the power induced to the charging receiver module (110) and supplying the rectified power to a charging control circuit (122); the charging control circuit (122) combined with the rectifying circuits (121 and 121' ) to supply the power rectified by the rectifying circuits (121 and 121') to a fuel gauge (123) under On/Off control of the RFID tag (130); the fuel gauge (123) for supplying the power supplied from the charging control circuit (122) to the battery (BAT) through a protection circuit (124) , and generating the charged status information while monitoring the charged status of the battery (BAT) , and periodically recording the charged status information in the RFID tag (130) ; and the protection circuit (124) combined with the fuel gauge (123) and the battery (BAT) to protect the battery (BAT) by controlling whether to charge or discharge according to the charged status of the battery (BAT) .

13. The wireless charging pad according to claim 12, wherein the rectifying circuits (121 and 121' ) are series- parallel resonant center tap half-bridge rectifying circuits using an output of a single center tap rectifying diode and an output filter capacitor, or series-parallel resonant full-bridge rectifying circuits using an output of a full-bridge rectifying diode and an output filter capacitor.

14. The wireless charging pad according to claim 9, wherein the RFID tag (130) comprises: a clock extraction unit (131) for extracting a clock from the RF carrier signal wirelessly received from the wireless charging pad (200) ; a sequencer (132) for inspecting an sequence of arranged data extracted from the clock extraction unit (131) and transmitting a control signal to a data encoder (133) ; the data encoder (133) for receiving the wireless identification information and charged status information of the battery (BAT) from a tag (135) when the control signal is transmitted from the sequencer (132), and transmitting the wireless identification information and charged status information to a data modulator (136) after coding the wireless identification information and charged status information; the data modulator (136) for generating RF data generated by modulating the data received from the data encoder (133) , and wirelessly transmitting the RF data to the wireless charging pad (200); Read Only Memory (ROM) (134) for recording the wireless identification information and charged status information therein; and the tag (135) for reading the wireless identification information and charged status information of the battery (BAT) stored in the ROM (134), and transmitting the wireless identification information and charged status information to the data encoder (133) .

15. The wireless charging pad according to claim 9, wherein the wireless identification information corresponds to one of a product name of the battery (BAT) , a serial number of the battery (BAT) and a user identification number that is stored in the RFID tag (130) through communication between a body of a portable device, on which the battery pack (100) is mounted, and the battery pack (100) .

16. The wireless charging pad according to claim 9, wherein the RF carrier signal is a signal that accesses an RFID signal stored in the battery pack (100) using a carrier signal in HF (3 to 30 MHz) or UHF (300 to 3000 MHz) bands.