Abstract:
The present disclosure generally relates to a radiofrequency communication device. The radiofrequency communication device has a rechargeable battery for mobile use and the charging contacts needs specific requirement for volume minimization and user convenience. Additional electrical circuit or integrated chip are also applied for radiofrequency communication and charging control.

Description:
FIELD 
       [0001]    The present disclosure herein generally relates to charging electrodes and the applications thereof. 
       BACKGROUND 
       [0002]    Wireless connection among electronic devices is getting popular, because the electronic components become more and more compact and the wireless communication technology are well developed. However, the antenna of a wireless electronic device has physical requirements restricting the minimization of wireless electronic devices. Furthermore, the wireless electronic device needs a battery and electrical contacts for recharging and it is impracticable for user behavior if the electrical contacts are designed too small. In addition, a prominent electrical contact is prompt to be short circuited and bad for aesthetics. For another example, a compact electronic device with an antenna may have a problem to accommodate both charging electrodes and an antenna in a limited space where the charging electrodes may have interference effects to the antenna. 
         [0003]    In the present disclosure, the problems described above can be solved. The examples shown in the present disclosure are mostly around an earphone and may be applied to other wireless electronic devices. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Implementations of the present technology will now be described, by way of example only, with reference to the attached figures. 
           [0005]      FIG. 1A  is an example of a radiofrequency communication device communicating with a wireless terminal. 
           [0006]      FIG. 1B  is an example of two radiofrequency communication devices communicating with a wireless terminal. 
           [0007]      FIG. 2A  shows the oblique front view of an example that a housing of a radiofrequency communication device is an earphone housing. 
           [0008]      FIG. 2B  shows the oblique back view of an example that a housing of a radiofrequency communication device is an earphone housing. 
           [0009]      FIG. 3A  is a block diagram of a radiofrequency communication device. 
           [0010]      FIG. 3B  is an exploded view of an example of a radiofrequency communication device. 
           [0011]      FIG. 4A  is a block diagram of a radiofrequency communication device. 
           [0012]      FIG. 4B  is an exploded view of an example of a radiofrequency communication device. 
           [0013]      FIG. 5  is an example of a radiofrequency communication device comprising a master earphone and a slave earphone and the master earphone communicates with a wireless terminal and the slave earphone. 
           [0014]      FIG. 6A  is an oblique view of an example of a close loop monopole antenna electrode.  FIG. 6B  is an oblique view of an example of an open loop monopole antenna electrode.  FIG. 6C  is an oblique view of an example of a close loop dipole antenna electrode.  FIG. 6D  is an oblique view of an example of an open loop dipole antenna electrode. 
           [0015]      FIG. 7  is a block diagram of an example of a radiofrequency communication device as an wireless earphone. 
           [0016]      FIG. 8  is a block diagram of a rechargeable system comprising a rechargeable device and a charging case. The dotted line indicates the electrical connection when the rechargeable device is recharged by the charging case. 
           [0017]      FIG. 9A  is a lateral view of an example of a rechargeable system comprising a wireless earphone and a charging case comprising a drawer assembly and a containing box.  FIG. 9B  is an oblique view of an example of a rechargeable system comprising two wireless earphones and a charging case comprising a drawer assembly and a containing box. 
           [0018]      FIG. 10A  shows a wireless earphone is to be coupled to the dock electrodes assembled on a dock base. 
           [0019]      FIG. 10B  shows a wireless earphone is to be coupled to the dock electrodes assembled on a dock base. 
           [0020]      FIG. 11  shows the working states of the wireless earphone transitioning between different working states. 
           [0021]      FIG. 12  shows the working states of the wireless earphone transitioning between different working states by corresponding input modes. 
           [0022]      FIG. 13  shows the input modes trigger media control function under media state. 
           [0023]      FIG. 14A  shows the input modes trigger phone call control function under phone call state when incoming call. 
           [0024]      FIG. 14B  shows the input modes trigger phone call control function under phone call state when active call. 
           [0025]      FIG. 15A  shows a charging case having an external power connection port, a first charging indicator and a second charging indicator. 
           [0026]      FIG. 15B  shows an enlarged view of the external power connection port, the first charging indicator and a second charging indicator. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein. 
         [0028]    Several definitions that apply throughout this disclosure will now be presented. 
         [0029]    The term “electrode” refers to an electrical conductor and does not limit the shape, material, or function of an electrode to any specific form of electrode. The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like. 
         [0030]    The present disclosure is described in relation to a radiofrequency communication device and the applications thereof. 
         [0031]    The radiofrequency communication device may comprise an antenna electrode, a charging electrode, a transceiver module, a charge controller, a battery, and a housing. 
         [0032]    An antenna electrode is an antenna having capability of coupling to an electrode of a battery charger. The antenna electrode may be manufactured by printed circuit technology or by winding and/or welding an electrical conductive wire. The antenna electrode also have a function as an antenna. An antenna is an electrical device which converts electromagnetic wave into electrical power or converts electrical power into electromagnetic wave. The electrical power and the electromagnetic wave carry electrical signals for communication purpose. An antenna receives electrical power from a transceiver module through a transmission line, creates an oscillating electromagnetic field, and then transmits electromagnetic wave. Conversely, an antenna receives electromagnetic wave, converts into electrical power, and deliver the electrical power to a transceiver module through a transmission line. Said electromagnetic wave may have radiofrequency for specific application. For example, Industrial Scientific Medical (ISM) Bands are reserved internationally for communication or other purposes without regulatory limitation. Popular communication standards includes Bluetooth and Wi-Fi, which have frequency range around 2.4 GHz. 
         [0033]    A charging electrode is configured to form electrical contact pairs with an antenna electrode. The electrical contact pairs provide electrical connection between the rechargeable battery and the battery charger. A rechargeable battery may be an alkaline battery, a silver battery, a zinc-air battery, a mercury battery, a lithium battery or the like. The rechargeable battery may be a button battery. A rechargeable battery is capable of providing electrical power for the electrical components in a radiofrequency communication device. 
         [0034]    A transceiver module is configured to transmit or receive electrical signals from an antenna. The transceiver module may be connected to the antenna through a transmission line to convey electrical signals. The transceiver module may be an integrated electrical system with multiple functional parts and configured to receive electromagnetic signals and to process the received signals into audio signals for the speaker. The electromagnetic signals may have the frequency within Industrial Scientific Medical Band (ISM band), such as 2.4 GHz. Usually, Wi-Fi, Bluetooth, or other proprietary protocol used for the communication between a radiofrequency communication module and a wireless terminal. The transceiver module may comprise multiple electrical components integrated on a printed circuit board, or integrated in a chip scale package. 
         [0035]    A charge controller is configured to modulate the electrical properties, for example, electrical current or electrical voltage, during charging process. Also, a charge controller may prevent circuit from electrical overload. The charge controller may be configured as a charge integrated circuit. 
         [0036]    A battery is configured to provide electrical power for an earphone. The battery may be a primary battery or a secondary battery. Preferably, a secondary battery is ideal for rechargeability, sufficient energy density, fast charging, and safety. For example, lithium ion battery is suitable for most portable electronic devices. A battery in the earphone features small volume and steady discharge voltage, and a battery in the earphone case features large capacity. 
         [0037]    As shown in  FIG. 1A , the radiofrequency communication device  100  is configured to communicate with a wireless terminal  300 . The radiofrequency communication device  100  is an electronic device configured to communicating with a wireless terminal  300  through radiofrequency communication. The radiofrequency communication device  100  may comprise an antenna electrode, a charging electrode, a transceiver module, a charge controller, a rechargeable battery, and a housing. The electronic device may be a wireless earphone, an active stylus pen, a remote controller, or a pointer. In the present disclosure, the radiofrequency communication device is able to transmit or receive data via an antenna electrode and to recharge the rechargeable battery via the antenna electrode and the charging electrode. The wireless terminal  300  comprises at least a processor for managing data and controlling other electronic components of the wireless terminal; a storage for storing data; and a wireless communication module for transmitting the data to and from the radiofrequency communication device. The data may be multimedia files, such as video or audio files, or may be control signals. The wireless terminal may be a wireless storage, a wireless router, a wireless server, or an audio content providing device. 
         [0038]    As shown in  FIG. 1B , the radiofrequency communication device  100   a  may also communicate with another radiofrequency communication device  100   b . The radiofrequency communication device  100   a  may transmit or receive data to or from the other radiofrequency communication device  100   b  via an antenna electrode. In one example, the radiofrequency communication devices are earphones. The radiofrequency communication device  100   a  and the other radiofrequency communication device  100   b  may receive the audio data via radiofrequency communication from the wireless terminal  350 , respectively. Furthermore, the radiofrequency communication device  100   a  may send control signals to the other radiofrequency communication device  100   b  so that the two radiofrequency communication devices  100   a ,  100   b  may deliver synchronized music or voice according to the audio data. In another example, the radiofrequency communication devices  100   a ,  100   b    
         [0039]    In the example as shown in  FIGS. 2A and 2B , the housing of the radiofrequency communication device is an earphone housing. An in-ear earphone may comprise at least a transceiver module, a speaker, a battery and an in-ear earphone housing. An earphone is configured to have a wireless connection to an audio content providing device. An audio content providing device is able to generate or acquire audio data and transmit the audio data through wireless connection. The audio data may be the audio part of multi-media data. For example, the audio data may be the audio part of a video clip or a video streaming data. The audio data may be a recorded sound, such as a voice or music. The audio data may be generated from voice phone call or video phone call by a smart phone or from a multimedia program by a media center, for example a smart phone, a television, a personal computer or a sound system. 
         [0040]    In one example as shown in  FIG. 3A , a radiofrequency communication device comprise an antenna electrode  101 , a charging electrode  105 , a transceiver module  110 , a charge controller  120 , and a battery  130 . The antenna electrode  101  is configured to be coupled to the transceiver module  110  to receive or transmit the electrical power from or to the transceiver module  110 . The antenna electrode  101  and the charging electrode  105  are coupled to the charge controller  120 . The charging controller  120  receives the electrical power from the antenna electrode  101  and the charging electrode  105  and delivers the electrical power to the rechargeable battery  130 . When the radiofrequency communication device  100  is in use to communicate with a wireless terminal, the transceiver module  110  transmits or receives the electrical signals from the antenna electrode  101  and the antenna electrode  101  transmits or receives electromagnetic wave to or from the wireless terminal. When the radiofrequency communication device  100  is in use to recharge the battery  130 , the charge controller  120  protects the transceiver module  110  from the electric currents from the antenna electrode  101  and the charging electrode  105  and stably recharge the battery  130 . 
         [0041]    In one example as shown in  FIG. 3B , a radiofrequency communication device is a wireless earphone. The wireless earphone comprises a transceiver module  110 ; a charge controller  120 ; a charging electrode  105  coupled to the charge controller  120 ; an antenna electrode  101  coupled to the transceiver module  110  and the charge controller  120 ; a battery  130  coupled to the charge controller  120 ; and a housing  160 . The housing  160  is a wireless earphone housing. The earphone housing  160  accommodates the antenna electrode  101 , the charging electrode  102 , the transceiver module  110 , the charge controller  120 , and the battery  130 . 
         [0042]    In one example as shown in  FIG. 4A , a radiofrequency communication device comprise an antenna electrode  101 , a charging electrode  105 , a transceiver module  110 , a charge controller  120 , a rechargeable battery  130 , and a switching module  150 . The switching module  150  is configured to change the electrical connection between the electrical components according to input signal. The input signal may be electrical current, electrical potential difference, or signal frequency. The switching module may be an electromechanical switch or a solid state switch, such as an integrated circuit or a relay. The antenna electrode  101  is coupled to the switching module  150 . The switching module  150  is configured to determine whether the radiofrequency communication device is under charging process or communication process. During charging process, the switching module  150  allows the electrical connection between the antenna electrode  101  and charge controller  120 , and inhibits the electrical connection between the antenna electrode  101  and the transceiver module  110 . During communication process, the switching module  150  allows the electrical connection between the antenna electrode  101  and the transceiver module  110  to receive or transmit the electrical power from or to the transceiver module  110 , and inhibits the electrical connection between the antenna electrode  101  and charge controller  120 . The charging electrode  102  is coupled to the charge controller  120 . The charging controller  120  receives the electrical power from the antenna electrode  101  and the charging electrode  105  and delivers the electrical power to the rechargeable battery  130 . When the radiofrequency communication device  100  is in use to receive signals from a wireless terminal, the switching module  150  may sense the radiofrequency signals from the antenna electrode  101  and allow the radiofrequency signals to reach the transceiver module  110 . Similarly, when the radiofrequency communication device  100  is in use to transmit signals to a wireless terminal, the switching module  150  may allow the radiofrequency signals from the transceiver module  110  to the antenna electrode  101 . When the radiofrequency communication device  100  is in use to recharge the battery  130 , the switching module  150  protects the transceiver module  110  from the electric currents from the antenna electrode  101  and the charging electrode  105  and stably recharge the battery  130 . 
         [0043]    In one example as shown in  FIG. 4B , a radiofrequency communication device is a wireless earphone. The wireless earphone comprise an antenna electrode  101 , a charging electrode  105 , a transceiver module  110 , a charge controller  120 , a battery  130 , a switching module  150 , and a housing  160 . The housing  160  is a wireless earphone housing. The earphone housing  160  accommodates the antenna electrode  101 , the charging electrode  105 , the transceiver module  110 , the charge controller  120 , the battery  130  and the switching module  150 . 
         [0044]    In one example as shown in  FIG. 5 , the radiofrequency communication device is a pair of earphones comprising a master earphone  201  and a slave earphone  202 . Herein, the wireless terminal  300  is an audio content providing device. The master earphone comprises a first transceiver module; a first charge controller; a first charging electrode coupled to the first charge controller; an first antenna electrode coupled to the first transceiver module and the first charge controller; a first battery coupled to the first charge controller; and a first earphone housing. The slave earphone comprises a second transceiver module; a second charge controller; a second charging electrode coupled to the second charge controller; an second antenna electrode coupled to the second transceiver module and the second charge controller; a second battery coupled to the second charge controller; and a second earphone housing. The master earphone is coupled to the slave earphone via the first antenna electrode and the second antenna electrode. 
         [0045]    The master earphone  201  is capable of communicating with the audio content providing device  350  and the slave earphone  202 . In the example, the master earphone  201  is the left earphone and the slave earphone  202  is the right earphone. The master earphone  201  is configured to receive the audio data from the audio content providing device and convey the audio data to the slave earphone  202 . Also, the master earphone may send control signals to the slave earphone to reduce bilateral audio latency and to optimize the sound effects. The master earphone  201  may be able to synchronize the master earphone  201  and the slave earphone  202  to eliminate sound playing delay. 
         [0046]    In one example, the master earphone  201  may serve as an audio crossover to assign the stereo audio channels to the master earphone  201  and the slave earphone  202 , so that earphone may play a certain part of the audio data. In some examples, the earphones having microphones provide stereo audio recording. The earphone set may have wireless communication between the left earphone and the right earphone to ensure short signal latency. The earphone set is connected with an audio content providing device. The earphone set is connected with an audio content providing device. The wireless connection between the earphone set and the audio content providing device or the wireless connection within the earphone set provides audio streaming or data communication. The audio content providing device may be a mobile phone, a laptop, a television, a video game machine, or a sound system. 
         [0047]    The antenna electrode may be configured as a monopole antenna, a dipole antenna, a closed loop antenna or an open loop antenna. The perimeter of the antenna is configured to match the designated wavelength of electromagnetic wave. The typical length of perimeter is equal to the wavelength or one quarter of the wavelength. In one example, the perimeter of a loop antenna may be substantially 30.59 millimeter in order to receive 2.45 GHz radiofrequency signals. It is contemplated that the perimeter may be tolerated a range of variation to meet optimal radiation efficiency. Also, the shape of a loop antenna may be circular, elliptical, rectangular, or other geometric shape. Furthermore, the feed point connecting the transmission line(s) and the antenna may be located arbitrarily on the antenna and not limited to the examples shown in the figures. 
         [0048]    As shown in  FIG. 6A-6B , the loop antenna may be a monopole antenna. In  FIG. 6A , the monopole antenna may be a closed loop antenna. In one example, the internal perimeter may be around twenty millimeter to thirty-five millimeter and the external perimeter may be twenty-five to forty millimeter, while the external perimeter is greater than the internal perimeter In  FIG. 6B , the monopole antenna may be a closed loop antenna an open loop antenna. As shown in  FIG. 6C-6D , the loop antenna may be a dipole antenna. In  FIG. 6C , the dipole antenna may be a closed loop antenna. In  FIG. 6D , the dipole antenna may be an open loop antenna. It is contemplated that the impedance of the antenna should be matched with the transceiver module under certain working conditions. 
         [0049]    In one example as shown in  FIG. 7 , a radiofrequency communication device  100  is a wireless earphone. The wireless earphone comprises an antenna electrode  101 , a charging electrode  105 , a transceiver module  110 , a charge controller  120 , and a battery  130 . The wireless earphone comprises a transceiver module  110 ; a charge controller  120 ; a charging electrode  105  coupled to the charge controller  120 ; an antenna electrode  101  coupled to the transceiver module  110  and the charge controller  120 ; a battery  130  coupled to the charge controller  120 ; and a housing  160 . The antenna electrode  101  is coupled to the transceiver module  110  via a match circuit  173  to ensure that the impedance between the antenna electrode  101  and the transceiver module  110 . The antenna electrode  101  is coupled to the charger controller  120  via a bias T circuit  174  to shunt the direct electric current to the charger controller  120  when the wireless earphone  100  is in use to recharge the battery  130 . The bias T circuit  174  may also be coupled to the transceiver module  110  to shunt the radiofrequency current to the transceiver module  110 . In some examples, the bias T circuit  174  may be replaced with a switching module and the switching module is coupled to the transceiver module  110 . 
         [0050]    The wireless earphone may further comprise a microcontroller  181 , a memory (read-only memory  182 , random access memory  183 ), a digital signal processor  184 , baseband module  185 , an input/output device  186 , an audio interface  187 , a user interface  170 , a microphone  140 , a speaker  145 , a crystal clock  175 , and a protection circuit  176 . In one example, many electronic components may be embedded on a printed circuit board as a radiofrequency module  180  for ease of mass production and volume minimization of the wireless earphone. The user interface  170  may comprise a button  171  configured to receive user input and a light indicator  172  configured to deliver indicating signals. The microphone  140  may be coupled to the audio interface  187  to receive environmental sound or the user&#39;s voice. The audio interface  187  may have noise cancellation function to eliminate ambient noise so that the speaker  145  is capable of delivering high quality sound or may amplify certain frequency range of sound, for example, human speech. With the microphone  140 , the wireless earphone  100  may serve as a wireless intercom, a hearing aid or a sound amplifying device. 
         [0051]    Charging contacts are essential electrical interfaces for restoring battery energy of an electronic device. The charging contacts are configured to couple the electronic device to a power source. People still confront many problems when using an electronic device with charging contacts. For example, most electronic devices have to be place in a specific direction to fit a charging dock and thus forms an adequate electrical connections between a rechargeable battery in the electronic device and a battery charger. Such a directional limitation may lead to inconvenience, bad user experience, and even charge failure. 
         [0052]    A rechargeable system comprises a rechargeable device and a charging case. The rechargeable device comprises a battery, a charge controller, a first charging contact, a second charging contact and a device housing. The battery is coupled to a charge controller and the charge controller is coupled to the first charging contact and the second charging contact. The charging case may comprise a battery charger, a first dock electrode, a second dock electrode and a case housing. The battery charger is coupled to the first dock electrode and the second dock electrode. When the rechargeable system is under charging process, the rechargeable device is coupled to the charging case via the first charging contact, the second charging contact, the first dock electrode, and the second dock electrode, wherein the first charging contact is coupled to the first dock electrode and the second charging contact is coupled to the second dock electrode. 
         [0053]    The charging case is configured to recharge the battery of a rechargeable device. The battery charger may comprise a power management module, a rechargeable battery or an external power connection port. The external power connection port is configured to receive external power to recharge the rechargeable battery. For example, the external power connection port is a universal serial bus (USB) port or a micro-USB port. The case housing comprises at least a dock base to provide mechanical connection to device housing of the rechargeable device and fix the position of the first dock electrode and the second dock electrode. The first dock electrode and the second dock electrode provide electrical connection to the rechargeable device. The case housing may further comprises a dock rack to support and stabilize the device housing. The case housing may further comprises a drawer assembly and a containing box, wherein the drawer assembly, comprising the dock base and the dock rack, is configured to be accommodated by the containing box. 
         [0054]    As shown in  FIG. 8 , a charging module may comprise a first charging contact  251 , a second charging contact  252 , a first dock electrode  261 , a second dock electrode  262 , a charge controller  120 , a battery  130 , and a battery charger  270 . The first charging contact  251  and the second charging contact  252  are coupled to the cathode or the anode of the charge controller  120 . The first dock electrode  261  and the second dock electrode  262  are coupled to the cathode and the anode of the battery charger  140 . The dot lines indicate electrical connections between the first charging contact  251  and the first dock electrode  261 , or between the second charging contact  252  and the second dock electrode  262  when a charging circuit is complete. 
         [0055]    In one example as shown in  FIG. 9A , a rechargeable system comprises a rechargeable device  250  and a charging case  260 , wherein the rechargeable device  250  is a wireless earphone and the charging case  260  comprising a drawer assembly  281  and a containing box  286 . The drawer assembly  281  comprising a dock rack  283  and a dock base  282 . The dock rack  283  has a neck portions  284  to support the device housing of the rechargeable device  250 . In the example, the dock rack  283  may have two neck portions  284  for two rechargeable device  250 . The charging case  260  is shown with an open position and one earphone is located on the dock rack  283  of the drawer assembly  281 . 
         [0056]    In  FIG. 9B , the charging dock is a directionless charging dock compatible with the directionless charging port of the earphone. The electrodes of the charging dock and the electrodes of the charging port are arranged in radial symmetry. As a result, the user may place the earphone on the charging dock in an arbitrary direction. 
         [0057]    As shown in  FIG. 10A , a charging module may comprise a first charging contact  251 , a second charging contact  252 , a first dock electrode  261 , a second dock electrode  262 , and a third dock electrode  263 . The first charging contact  251  may be a conductive pin with a spring cushion to ensure electrical connection to the first dock electrode  251 . The second charging contact  252  is configured in a circular shape around the first charging contact  251 . There may be a circular shape insulation wall prevents the first charging contact  251  and the second charging contact  252  from short circuit. Also, the insulation wall may provide mechanical support so that the location of the first dock electrode  261  is correctly in contact with the first charging contact  251  and not biased from the center of the second charging contact  252 . One of the second dock electrode  262 , and the third dock electrode  263  is ensured to have electrical connection to the second charging contact  252 . As a result, the charging module completes a charging circuit in regardless of the direction. 
         [0058]    As shown in  FIG. 10B , a charging module may comprise a first charging contact  251 , a second charging contact  252 , a first dock electrode  261 , a second dock electrode  262 , and a battery charger  270 . The first charging contact  251  may be a conductive pin with a spring cushion to ensure electrical connection to the first dock electrode  251 . The second charging contact  252  is configured in a circular shape with an open gap  258 . The second dock electrode  262  and the width  268  of the second dock electrode  262  is equal to or larger than the open gap  258  of the second charging contact. There may be a circular shape insulation wall prevents the first charging contact  251  and the second charging contact  252  from short circuit. Also, the insulation wall may provide mechanical support so that the location of the first dock electrode  261  is correctly in contact with the first charging contact  251  and not biased from the center of the second charging contact  252 . The second dock electrode  262  is ensured to have electrical connection to the second charging contact  252 . As a result, the charging module completes a charging circuit in regardless of the direction. 
         [0059]    A user interface may be a user input module or a user output module. The user input module is configured to receive the user input by mechanical force. In one example, the user input module may be a control button located on the body of an earphone. A control button may be a push-button or a toggle switch. The user output module is configured to send out visual, audio or vibrational signals to inform the user with the states of the earphone. In one example, the visual output module may be a light emitting diode (LED). In one example, the speaker may also have the function to inform the user. The speaker may deliver a voice message, “device pairing”, when the earphone is at device pairing state. 
         [0060]    Input modes are applicable with the presentation of a control button. An input mode comprise a certain duration of a mechanical input disposed on a control button. Within present disclosure, a press is defined as a control button being activated in a certain period of time. Preferably, a control button is activated when a mechanical force is disposed on the control button and thus the underlying electrical circuit is connected. A control button is inactivated when a mechanical force is removed from the control button. 
         [0061]    An input mode is the combination of a certain duration of activation and inactivation of the control button. An input mode may be a short input, a long input, a very long input, or an extra-long input. In one example, a short input indicates the control button is activated shorter than a duration of 0.5 seconds. A double input indicates the control button is activated with two consequent short inputs spaced with a short duration of inactivation of the control button, for example 0.5 seconds. A long input indicates the control button is activated around two seconds. A very-long input indicates the control button is activated with a duration of three to four seconds. An extra-long input indicates the control button is activated with a duration of six to seven seconds. 
         [0062]    An input mode may switch the earphone from a working state to anther working state. When an input mode is recognized by the microcontroller, the state of the earphone may be switch to a certain working state. A working state of an earphone may be a power-on state, a power-off state, a device pairing state, a media state, a phone call state. Power-off state indicates the power of the earphone is inactive or stays low consumption for reserving battery energy. Power-on state indicates the earphone is ready for connection with an audio content providing device. Media state indicates the earphone is connecting with an audio content providing device having an active multi-media application. Phone call state indicates the earphone is connecting audio data from an audio content providing device having a phone connection. Device pairing state indicates the earphone is seeking for the connection with an audio content providing device. 
         [0063]    An input mode may trigger a certain function under corresponding state. A function may be a media control function, such as content switching, volume adjustment, media-play, or media-pause, or may be a phone call control function, such as call answering, call rejection, or call cancelling. 
         [0064]    In one example as shown in  FIG. 11 , one working state of the earphone may switch to another working state. In one example, the earphone may start at power-off state and may be switched to device paring state or power-on state. The earphone at power-on state may be switched to media state or phone call state. The earphone at media state may be switched to phone call state and may be switched back to media state. All working states may be switched to power-off state. 
         [0065]    In one example as shown in  FIG. 12 , one working state of the earphone may switch to another working state by an input mode. In one example, the earphone at power-off state may be switched to device paring state by extra-long input or may be switched to power-on state by very-long input. The earphone at power-on state may be switched to media state by short input when media source presented. All working states may be switched to power-off state by very-long input. 
         [0066]    In one example as shown in  FIG. 13 , an input mode may trigger a media control function under media state. A media control function may be content switching, volume adjustment, media-play, or media-pause. A short input may trigger media-play function when a media content is available to play or when a media content is paused. A short input may trigger media-pause function when a media content is playing. A long input may trigger content switching function when a media content is playing. Content switching function may forward the media content to next section or backward the media content to previous section. For example, a long input applied on the control button of the right earphone forwards to the next song, and a long input applied on the control button of the left earphone backwards the previous song. A double input may trigger volume adjustment function to adjust audio volume. For example, a double input applied on the control button of the right earphone increases audio volume, and a long input applied on the control button of the left earphone decrease audio volume. 
         [0067]    In one example as shown in  FIGS. 14A and 14B , an input mode may trigger a phone call control function under phone call state. A phone call control function may be call answering, call rejection, call canceling, and volume adjustment. When an incoming call ( FIG. 14A ), a short input triggers call answering function, a long input triggers call rejection function, and a double input triggers volume adjustment function. When active call ( FIG. 14B ), a short input triggers call canceling function, and a double input triggers volume adjustment function. 
         [0068]    In one example as shown in  FIGS. 15A and 15B , the charging case has a first charging indicator and a second charging indicator. In one example, the earphone case has a USB port for power charge. When the charging case is connected to a power source with a USB wire, the earphone case may have or may not have the earphone on the charging dock.  FIG. 15B  is the enlarged view of the dotted line region in  FIG. 15A . In one example, the earphone case has charging indicators. The charging indicators may be a case charging indicator and an earphone charging indicator. The case charging indicator may show the corresponding charging status, such as “not charging”, “under charging”, or “charging complete”. The earphone charging indicator may show the corresponding battery status of the earphones. 
         [0069]    The embodiments shown and described above are only examples. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.