Patent Publication Number: US-2015065041-A1

Title: Portable device using a common antenna for both near field communication and wireless charging

Description:
TECHNICAL FIELD 
     The present invention relates to a portable device using a common antenna for both near field communication (NFC) and wireless charging, and more particularly, to a portable device using a common antenna enabling the portable device to be miniaturized and lightened by using the common antenna capable of implementing both near field communication and wireless charging. 
     BACKGROUND ART 
     In general, a portable device requires a dedicated battery charger and a dedicated adaptor which converts alternating current power into direct current power. Therefore, whenever a user purchases the portable devices, the user should purchase the dedicated battery charger and the dedicated adaptor, and as a result, the number of dedicated battery chargers and dedicated adaptors has gradually been increased and a plurality of dedicated battery chargers need to be connected to a power supply to charge the portable device, which make it even more inconvenient. 
     In order to solve the above-mentioned problems, a method of charging the portable device with power in a non-contact method, that is, a wireless charging method has been recently developed. The wireless charging method is generally classified into two methods, and one is a magnetic induction method and the other is a magnetic resonance method. The magnetic induction method is a method in which if a current flows into a primary coil of a magnetic field radiating coil pad and a magnetic field is generated accordingly, an induced current flows in a secondary coil of a receiver placed immediately on the magnetic field radiating coil pad to thereby charge the portable device. Subsequently, wireless charging is possible at distances of about several mm to several cm. In addition, the magnetic resonance method is a method in which a transmitter and a receiver for wireless charging are equipped with a resonance coil, such that when resonance frequencies of the transmitter and receiver are matched, energy is transmitted to the portable device, and when the resonance frequencies are not matched, the energy is absorbed into an electrical and magnetic field, and by using the magnetic resonance method, the charging up to several meters away is possible. 
     However, in order to use the wireless charging method for the portable device as described above, a separate antenna for wireless power transmission is required, and in addition to this, various antennas such as a Bluetooth antenna, a Wi-Fi antenna, a Long Term Evolution (LTE) antenna, a Digital Multimedia Broadcasting (DMB) antenna, an amplitude modulation (AM)/frequency modulation (FM) antenna, an antenna for NFC communication, and the like are required of the portable antenna. 
     Korean Patent No. 10-0971717 entitled “Wireless Type Charging and Data Communication Control Module for Mobile Terminal and Layout of the Same” (hereinafter, referred to as the related art 1), has disclosed a structure in which both a power receiving coil of a charging system and a loop antenna of an electronic approval system are mounted in a battery pack and a cover case of a mobile terminal, such that both a non-contact charging and an electronic approval are possible using one mobile terminal. 
     However, in accordance with the related art 1, since both the power receiving coil for the non-contact charging and the loop antenna for the electronic approval system are mounted in one mobile terminal, a thickness of the mobile terminal itself becomes thick and an area of the mobile terminal is increased, there is a problem that it is inconvenient to carry the mobile terminal despite being the mobile terminal. 
     DISCLOSURE 
     Technical Problem 
     An object of the present invention is to provide a portable device which is miniaturized, thinned, and lightened by using a common antenna capable of performing both near field communication and wireless charging to thereby reduce the number of antennas mounted in the portable device. 
     Technical Solution 
     In one general aspect, a portable device using a common antenna for both near field communication (NFC) and wireless charging includes: a common antenna part  10  transmitting and receiving near field communication and wireless charging signals; an NFC signal judgment module  100  connected to the common antenna part  10  and sensing a signal applied from the common antenna part  10  or a Tx signal generated from an NFC performing part  200  to thereby judge whether or not the signal or the Tx signal is the near field communication signal; an NFC performing part  200  connected to the NFC signal judgment module  100  and performing the near field communication according to a signal transferred from the NFC signal judgment module  100 ; and a battery part  300  connected to the NFC signal judgment module  100  and being wirelessly charged according to the control signal transferred from the NFC signal judgment module  100 . 
     The NFC signal judgment module  100  may include: a signal matching part  110  converting antenna impedance transferred through the common antenna part  10  into impedance which is suitable for both near field communication and wireless charging and transferring the near field communication signal to the NFC performing part  200  or a signal controlling part  130 ; a signal converting part  120  including a RF/DC converter  121  converting the wireless signal transferred from the signal matching part  110  into a direct current voltage and a regulator  122  uniformly supplying the direct current voltage converted by the RF/DC converter  121 ; a signal controlling part  130  judging whether or not the wireless signal is the near field communication signal; a first switch  400  controlling an operation of the NFC performing part  200  depending on a signal of the signal controlling part  130 ; and a second switch  500  controlling an operation of the battery part  300  depending on the signal of the signal controlling part  130 . 
     The signal matching part  110  may include: an NFC signal matcher  111  converting the antenna impedance transferred from the common antenna part  10  into the impedance which is suitable for the near field communication and transferring the near field communication signal to the NFC performing part  200 ; a wireless charging signal matcher  112  converting the antenna impedance transferred from the common antenna part  10  into the impedance which is suitable for the wireless charging; and a selection switch  113  transferring the near field communication signal transferred from the NFC signal matcher  111  or the wireless charging signal transferred from the wireless charging signal matcher  112  to the signal converting part  120 . 
     The selection switch  113  may re-transfer the signal to the NFC signal matcher  111  depending on the signal transferred from the signal controlling part  130 . 
     The regulator  122  may uniformly supply the direct current voltage transferred from the RF/DC converter  121  to the signal controlling part  130  or the second switch  500 . 
     The signal controlling part  130  may include: a signal demodulator  131  demodulating the wireless signal transferred from the signal matching part  110  to obtain digital information; an identification (ID) storage part  132  storing unique ID for near field communication; and a signal judgment device  133  comparing the demodulated signal transferred from the signal demodulator  131  with the unique ID stored in the ID storage part  132  or sensing the Tx signal by the near field communication transferred from the NFC performing part  200  to thereby judge whether or not the demodulated signal or the Tx signal is the near field communication signal. 
     Advantageous Effects 
     According to the present invention, the number of antennas used for the portable device may be reduced by performing the near field communication or the wireless charging by the common antenna, thereby simplifying a process of manufacturing the antenna. 
     In addition, since an area of a circuit in the portable device may be reduced by using a unified chip for both near field communication and wireless charging, production cost may be reduced. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram schematically illustrating a portable device using a common antenna for both near field communication and wireless charging according to an embodiment of the present invention. 
         FIG. 2  is a diagram schematically illustrating a portable device using a common antenna for both near field communication and wireless charging according to another embodiment of the present invention. 
         FIG. 3  is a diagram specifically illustrating the portable device using the common antenna for both near field communication and wireless charging according to the embodiment of the present invention. 
         FIG. 4  is a flow chart illustrating a method of controlling a signal which is input from a signal controlling part according to an embodiment of the present invention. 
         FIG. 5  is a flow chart illustrating a method of controlling a signal which is input from a signal controlling part according to another embodiment of the present invention. 
     
    
    
     BEST MODE 
     Hereinafter, a portable device using a common antenna for both near field communication and wireless charging according to the present invention will be described in detail with reference to the accompanying drawings. The drawings of the present invention to be described below are provided by way of example so that the idea of the present invention can be sufficiently transferred to those skilled in the art to which the present invention pertains. Therefore, the present invention is not be limited to the drawings provided below but may be modified in many different forms. In addition, like reference numerals denote like elements throughout the specification. 
     In this case, technical terms and scientific terms used in the specification have the general meaning understood by those skilled in the art to which the present invention pertains unless otherwise defined, and a description for the known function and configuration obscuring the present invention will be omitted in the following description and the accompanying drawings. 
       FIG. 1  is a diagram schematically illustrating a portable device using a common antenna for both near field communication and wireless charging according to an embodiment of the present invention. 
     A configuration of the portable device using the common antenna for both near field communication and wireless charging according to the embodiment of the present invention will be described in detail with reference to  FIG. 1 . 
     The portable device using the common antenna for both near field communication and wireless charging according to the embodiment of the present invention is configured to include a common antenna part  10 , a near field communication (NFC) signal judgment module  100 , an NFC performing part  200 , and a battery part  300 . 
     The near field communication (NFC) means a non-contact type communication technology transmitting and receiving various wireless data at a close distance, and has been widely utilized for goods information in a store, travel information for tourists, a locking apparatus for access control, and the like as well as an approval system. In addition, wireless charging according the related art means that the portable device mounted on a magnetic field radiating coil pad together with an electromotive circuit for a charger is charged through a wired charging connector without requiring a dedicated battery charger and dedicated adaptor for charging. However, according to the related art as described above, in order to perform both near field communication and wireless charging in the portable device, the respective separate antennas transmitting and receiving near field communication and wireless charging signals are required. 
     Therefore, the common antenna part  10  may simultaneously transmit and receive the near field communication (NFC) and wireless charging signals. 
     In general, the signals for both near field communication and wireless charging may use the same frequency, that is, 13.5 MHz. When the common antenna part  10  receives a wireless signal, the wireless signal may be transferred to the NFC signal judgment module  100 . 
     The NFC signal judgment module  100  may be connected to the common antenna part  10  to thereby judge whether or not the wireless signal transferred from the common antenna part  10  is a signal for near field communication, or may sense a Tx signal generated by the near field communication which is already operated in the NFC performing part  200  to thereby judge whether or not the Tx signal is the signal for near field communication. Therefore, the NFC signal judgment module  100  transfers the signal to the NFC performing part  200  in the case in which the wireless signal or the Tx signal is the signal for near field communication, and transfers the signal to the batter part  300  in the case in which the wireless signal or the Tx signal is not the signal for near field communication, thereby making it possible to wirelessly charge a battery pack. 
     The NFC signal judgment module  100  may be configured to include a signal matching part  110 , a signal converting part  120 , a signal controlling part  130 , a first switch  400 , and a second switch  500 , and the NFC signal judgment module  100  will be described in detail with reference to  FIG. 3 . 
     In this case, in order to activate the NFC performing part  200  for near field communication, the first switch  400  may be configured, and in order to activate the battery part  300  for wireless charging, the second switch  500  may be configured. Further, the first switch  400  and the second switch  500  are controlled depending on results judged by the signal controlling part  130 , and a logic part (not shown) for controlling the first switch  400  and the second switch  500  may be configured in the signal controlling part  130 . 
     The signal matching part  110  may be connected to the common antenna part  10  to thereby convert the signal transferred from the common antenna part  110 , that is, antenna impedance into impedance which is suitable for both near field communication and wireless charging. In this case, a frequency of the signal transferred through the common antenna part  10  may be generally 13.5 MHz which is equal to that used for both near field communication and wireless charging. 
     Meanwhile, even though a frequency for both near field communication and wireless charging is significantly changed, the signal matching part  110  is configured to further include an NFC signal matcher  111 , a wireless charging signal matcher  112 , and a selection switch  113 , as shown in  FIG. 2 , such that the signals which are differently input to the common antenna part  10  for both near field communication and wireless charging may be converted into appropriate impedance. That is, the signal transferred from the common antenna part  10 , that is, antenna impedance may be converted into impedance which is suitable for near field communication by the NFC signal matcher  111 , and the antenna impedance may be converted into impedance which is suitable for wireless charging by the wireless charging signal matcher  112 . 
     The selection switch  113  may select a near field communication signal transferred from the NFC signal matcher  111  and a wireless charging signal transferred from the wireless charging signal matcher  112  depending on the transferred signal to thereby transfer the selected signal to the signal converting part  120 . Further, in the case in which the selection switch  113  receives the wireless signal which is judged as a near field wireless signal by the signal controlling part  130 , it may maintain a connection with the NFC signal matcher  111  and block a connection with the wireless charging signal matcher  112 . 
     The signal converting part  120  may be configured to include a RF/DC converter  121  and a regulator  122 , wherein the RF/DC converter  121  may convert a radio frequency (RF) signal, which is a wireless signal, into a direct current voltage, and the regulator  122  may supply a voltage transferred from the RF/DC converter  121  to the signal controlling part  130  while uniformly maintaining the voltage. In addition, the regulator  122  may also stably supply a voltage which is suitable for wireless charging to the second switch  500  in order to activate the battery part  300  in the case in which the wireless charging needs to be performed, depending on the result judged by the signal controlling part  130 . 
     Further, the portable device using the common antenna according to the present invention may include at least one RF/DC converter and regulator in order to use the RF/DC converter  121  and the regulator  122  for both near field communication and wireless charging, respectively, and may include the at least one RF/DC converter and regulator outside of the NFC signal judgment module  100 , if necessary. 
     The signal controlling part  130  may sense the Tx signal which is generated and transferred by the near field communication which is already performed in the NFC performing part  200  by the wireless signal transferred from the signal matching part  110 , or may judge the wireless signal transferred from the signal matching part  110  to the signal controller  130  to thereby judge whether or not the Tx signal or the wireless signal is the near field communication. The signal controlling part  130  may activate the NFC performing part  200  or the battery part  300  depending on the judged results. That is, in other words, depending on the judged results, the signal controlling part  130  may activate the NFC performing part  200  by transferring the signal to the first switch  400  in the case in which the Tx signal or the wireless signal is judged as the near field communication signal, and may activate the battery part  300  by transferring the signal to the second switch  500  in the case in which the Tx signal or the wireless signal is judged as the wireless charging signal. 
     Further, the signal controlling part  130  may be configured to include a signal demodulator  131 , an ID storage part  132 , and a signal judgment device  133 , wherein 
     the signal demodulator  131  may use the direct current voltage applied by the RF/DC converter  121  in the signal converting part  120  as power, may demodulate the wireless signal transferred from the signal matching part  110 , and may transfer the demodulated signal to the signal judgment device  133 . 
     The ID storage part  132  may store unique ID for near field communication, and the signal judgment device  133  may compare the demodulated signal transferred from the signal demodulator  131  with ID information stored in the ID storage part  132  to thereby judge whether or not the transferred demodulated signal is the signal for near field communication. 
     Alternatively, in the case in which the Tx signal, which is transferred through the NFC performing part  200 , that is, generated by the near field communication which is already performed, is transferred, the signal judgment device  133  may sense the transferred Tx signal to thereby judge whether or not the transferred Tx signal is the signal for near field communication. 
     To this end, the signal judgment device  133  may judge whether the demodulated signal transferred from the signal demodulator  131  is not the Tx signal, which is generated and transferred by the near field communication of the NFC performing part  200  but the signal for near field communication. 
     As shown in  FIG. 4 , 
     in the case in which the signal judgment device  133  receives the demodulated signal, it activates the NFC performing part  200  by first transferring the signal to the first switch  400  before performing judgment of the demodulated signal, and deactivates the battery part  300  for wireless charging by not transferring a separate signal to the second switch  500  (S 410 ). 
     Next, it is judged whether or not the demodulated signal transferred from the signal judgment device  133  is the signal for near field communication (S 420 ). 
     In the case in which the demodulated signal is the signal for near field communication depending on the judged result, the near field communication is maintained by maintaining an active mode of the NFC performing part  200  (S 431 ), and as the near field communication is terminated, an operation of the NFC performing part  200  is terminated (S 432 ). 
     On the other hand, in the case in which the demodulated signal is not the signal for near field communication depending on the result judged by the signal judgment device  133 , that is, in the case in which the demodulated signal is the signal for wireless charging, the NFC performing part  200  is deactivated and the battery part  300  is activated by transferring the signal to the second switch  500  to thereby start the wireless charging (S 441 ). 
     After the wireless charging is maintained for a predetermined time (S 442 ), it is judged whether a charging of the portable device is completed (S 443 ). Depending on the judged results, in the case in which the charging is completed, the NFC performing part  200  is activated by again transferring the signal to the first switch  400  and an operation of the battery part  300  is terminated (S 444 ). 
     Alternatively, in another embodiment in which the signal judgment device  133  judges whether the demodulated signal transferred from the signal demodulator  131  is the signal for near field communication, 
     as shown in  FIG. 5 , 
     once the signal is transferred to the signal judgment device  133 , the NFC performing part  200  is activated by preferentially transferring the signal to the first switch (S 510 ), and 
     an activated mode of the NFC performing part  200  is maintained for a preset time (S 520 ). In this case, the preset time according to the present invention may be one second and is a set time judged to be sufficient to perform the near field communication, which is merely one embodiment of the present invention. 
     After the activated mode of the NFC performing part  200  is maintained for a preset constant time, in the case in which a predetermined time elapses, the NFC performing part  200  may be automatically deactivated, and the battery part  300  may be activated, that is, the wireless charging may be performed by transferring the signal to the second switch  500  (S 530 ). 
     In addition, once the charging is completed by the wireless charging, all functions may be initialized. 
     That is, in other words, the NFC performing part  200  is activated and the battery part  300  is deactivated. 
     In this case, the NFC performing part  200  is connected to the first switch  400  of the NFC signal judgment module  100  and transfers the signal from the signal judgment device  133  of the NFC signal judgment module  100  to the first switch  400 , thereby making it possible to perform the near field communication, and 
     the battery part  300  is also connected to the second switch  500  of the NFC signal judgment module  100  and transfers the signal from the signal judgment device  133  of the NFC signal judgment module  100  to the second switch  500 , thereby making it possible to wirelessly charge the portable device. 
     Further, the battery part  300  may be configured to include a battery protecting part (not shown) and a battery cell (not shown). The battery protecting part is provided to protect the battery cell, because there are risks such as overcharging and an overcurrent or a short circuit in the case in which the current directly flows in battery cell without a separate protection circuit when the wireless charging is performed. 
     That is, in other words, the portable device using the common antenna for both near field communication and wireless charging according to the embodiment of the present invention may transfer the wireless signal applied to the common antenna part  10  to the NFC signal judgment module  100 , and the NFC signal judgment module  100  may judge the applied signal to thereby activate the operation of the NFC performing part  200  or the battery part  300  depending on the judged results. 
     Subsequently, since the portable device using the common antenna for both near field communication and wireless charging according to the embodiment of the present invention may reduce the number of antennas by using one common antenna without using the respective separate antennas as the antenna transmitting and receiving the wireless signal to use both near field communication and wireless charging, and may simplify a configuration of a circuit and reduce an area of the circuit by using one dedicated chip for both near field communication and wireless charging, that is, the NFC signal judgment module without using a separate electromotive circuit for charging for using both near field communication and wireless charging, the portable device may be miniaturized, thinned, and lightened. 
     As described above, although the present invention has been described with reference to the embodiments and the accompanying drawings, it would be appreciated by those skilled in the art that the present invention is not limited thereto but various modifications and alterations might be made without departing from the scope defined in the claims and their equivalents. 
                             DETAILED DESCRIPTION OF MAIN ELEMENTS                                        10:    common antenna part       100:    NFC signal judgment module       110:    signal matching part       111:   NFC signal matcher       112:   wireless charging signal       113:    selection switch       120:    signal converting part       121:    RF/DC converter       122:    regulator       130:    signal controlling part       131:   signal demodulator       132:    ID storage part       133:    signal judgment device       200:    NFC performing part       300:    battery part       400:    first switch       500:    second switch                    
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