Abstract:
Two wireless earbuds include controllers, receivers, transmitters and firmware. One earbud establishes a primary wireless communication connection to an electronic device such as a smart phone, and a secondary wireless communication connection to a second earbud. Power monitors, signal strength monitors, synchronized clocks, and power management hardware and/or software may trigger a switching condition to occur. Each switching condition causes the reversal of the roles of the first and second earbuds so as to increase the operating life of the paired earbuds before they need to be recharged by balancing their respective power consumption when in use. Each switching condition may also cause the reversal of the roles of the first and second earbuds so as to avoid the disconnection of communication with the electronic device and/or evenly distribute battery usage.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application Ser. No. 61/108,690, filed Jan. 28, 2015, the contents of which are incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    This disclosure relates to wireless earbuds, and more particularly relates to wireless earbuds with reciprocating leader and follower configuration. 
         [0003]    Wireless earbuds are a convenient way to eliminate the issues associated with physical user connection to audio signal producing devices. The existing wireless headphones in the marketplace are tethered such that one of the earbuds (the “leader”) contains an embedded receiver, microchip, battery and control functions and is linked wirelessly to the data producing device (i.e. a cellular phone playing music). The second earbud (the “follower”) receives electrical charge and data from the first earbud via physical wiring. In this way, one of the earbuds may be considered to be primary, and the other secondary. In addition to “leader/follower” or “primary/secondary,” such a configuration is sometimes also called a “master/slave” or “primary/replica” configuration. 
         [0004]    In a truly wireless earbud configuration, there is no physical wiring at all. The leader earbud contains the same components described previously. The follower earbud may be identical to the leader earbud and (a) contains its own internal battery for power, and (b) receives data transmitted wirelessly from the first earbud because it is not physically connected to the leader. 
         [0005]    In a system with two identical wireless earbuds where one is a follower and the other is the leader, the leader earbud holds primary connection to the original data source. This means that the leader earbud is actively (i) receiving signals from the phone or other electronic device from which it receives transmissions, (ii) transmitting signals to the phone, and (ii) simultaneously transmitting signals to the follower earbud. Given that the leader earbud is actively transmitting and receiving more data, and its internal microchip is producing more calculations, the leader earbud consumes more electrical energy than the follower earbud. Because the earbuds are intended for use in pairs, this creates a problem for the user because the leader earbud will exhaust its electrical energy while the follower earbud still has significant electrical energy remaining. 
         [0006]    This document describes a system that may address the issues described above. 
       SUMMARY 
       [0007]    In an embodiment, an earbud set includes two earbuds: a leader earbud and a follower earbud, each having a transmitter, a receiver, and a controller. The leader earbud is configured to establish a primary communication connection with a remote electronic device and a secondary communication connection with the follower earbud. In such configuration, the leader earbud can transmit/receive audio or data to/from the remote electronic device, process received audio or data, and transmit a part of the audio or data to the follower earbud. The leader earbud may also receive data from the follower earbud and pass on to the remote electronic device. The leader earbud is also capable of detecting a switching condition, and if a switching condition has occurred, sending a signal to the follower earbud to establish a primary communication connection with the remote electronic device, and terminating its own primary communication connection with the remote electronic device, thus to relinquish the leader role and become a follower earbud. The follower earbud may be configured to receive a switching signal, and in response to receiving the switching signal, establish a primary communication connection with the remote electronic device and assume a leader role. 
         [0008]    Optionally, each of the two earbuds in the set may be configured to include at least some components that are identical. An earbud, once taking the leader role, may detect that a switching condition has occurred, and in response, send a signal to the other earbud to establish or re-establish the primary communication connection with the remote electronic device, and terminate its own communication connection with the remote electronic device, thus to relinquish the leader role and become a follower earbud. 
         [0009]    There may be various ways to detect that a switching condition has occurred. In one embodiment, each earbud includes a power monitor that is configured to detect a battery charge level in the earbud, and the switching condition may be indicative of a difference between a battery charge level in the leader earbud and a battery charge level in the follower earbud. Using this switching condition, the earbud that has the most remaining battery charge will be the leader and the other earbud the follower. The switching condition may also be indicative of a decrease of a battery charge level in the leader earbud as compared to a previous battery charge level. The system also may include a clock circuit, and the switching condition may also be indicative of an elapsed period of time since a previous switching has occurred, or may occur at a fixed frequency. 
         [0010]    Alternatively and/or additionally, each of the earbuds in the set may also include an antenna control that can be configured as a communication signal monitor to detect the level of communication signal strength, such as Bluetooth signal strength, received by the earbud for a communication connection with the remote electronic device. In one embodiment, the switching condition is indicative of the difference between the level of communication signal strength in the leader and follower earbuds. Using this switching condition, the earbud that receives the strongest signal for communicating with the remote electronic device will be the leader and the other earbud the follower. The switching condition may also be indicative of a decrease of the level of communication signal strength by at least a threshold amount as compared to a previous communication signal strength level in the leader earbud. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  illustrates diagrams of various electrical components within a set of wireless audio earbuds. 
           [0012]      FIG. 2  illustrates diagrams of select components and microchips contained within the earbuds from  FIG. 1 . 
           [0013]      FIG. 3  is a diagram of the wireless data connection between the earbuds from  FIG. 1  and a mobile computing device according to one embodiment. 
           [0014]      FIG. 4  illustrates a relationship between the two earbuds in  FIG. 1  according to one embodiment. 
           [0015]      FIG. 5  illustrates a reverse relationship between the two earbuds in  FIG. 1  according to one embodiment. 
           [0016]      FIG. 6  illustrates a diagram of reversal between a leader earbud and a follower earbud according to one embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    As used in this document, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. As used in this document, the term “comprising” means “including, but not limited to.” 
         [0018]    The term “connected,” when used to refer to a relationship between two earbuds or between an earbud and an electronic device, refers to a configuration in which the two items have established a communication link by which they may exchange signals containing data. The link may be a near-field or short-range communication link, such as may occur when two devices “pair” using a Bluetooth or other communications protocol. 
         [0019]    Each of the terms “electronic device,” “remote electronic device,” “mobile electronic device” and “mobile computing device” refers to a computing device that includes a processor and non-transitory, computer-readable memory. The memory may contain programming instructions in the form of a software application or firmware that, when executed by the processor, causes the device to be in wireless communication with another device or peripherals, such as a headset or earbud, and perform various processing operations according to the programming instructions. Examples of suitable devices include portable electronic devices such as smartphones, personal digital assistants, cameras, tablet devices, remote controllers, electronic readers, personal computers, media players, satellite navigation devices and the like. The wireless communication can be in various protocols such as Wi-Fi, Bluetooth, NFC (Near Field Communication), other RF- or infrared-based protocols or the like, or other wireless protocols, now known or later developed. 
         [0020]    Each of the terms “earbud” and “earphone” refers to a device designed to fit within the ear of a human, and which emits audio signals that the earbud receives from an electronic device. Examples of earbuds include ear-anchored headphones, audio headsets with microphones, and in-ear speakers. Examples of earphones include in-ear headphones, hearing aids and the like. Earbuds or earphones also may include or be components of other audio devices such as wireless headsets, in-ear monitors and the like. 
         [0021]    The “leader” earbud in a set of earbuds is the earbud with primary Bluetooth or NFC connection with an audio and/or data transmitting/receiving electronic device. The “follower” earbud is an earbud that receives and/or transmits signal from/to a leader earbud, and that is not directly connected or in communication with the audio/data transmitting/receiving electronic device. 
         [0022]    The embodiments described in this document may help eliminate the inconvenience of additional charging cables, wires, and tethered earbuds by providing a configuration of two truly wireless earbuds, with optimized battery life and signal reception for the pair. 
         [0023]    This patent document incorporates by reference the following patent disclosures in full: (i) U.S. Provisional Patent Application No. 61/942,698, filed Feb. 21, 2014; (ii) U.S. Pat. No. 8,891,800; (iii) U.S. patent application Ser. No. 14/510,539, filed Oct. 9, 2014; and (iv) U.S. Pat. No. 9,148,717, filed Jan. 23, 2015. 
         [0024]    With reference to  FIG. 1 , an earbud pair or earbud set contains two individual earbuds  11  and  13  that contain earbud batteries  18  and  38  which serve as the primary power source for the earbuds  11  and  13 . The earbud batteries  18  and  38  may be non-rechargeable as available commercially off-the-shelf. In one embodiment, the earbud batteries  18  and  38  may be rechargeable batteries and may be charged through direct current, induction, or other near-field charging methods. The earbuds  11  and  13  may also contain one or more micro-controllers or processors  80  and  90 , antennas  24  and  44 , and other components such as transmitters and receivers. These components, including the micro-controllers or processors, are electrically coupled, such as mounted on and electrically connected via a circuit on each earbud&#39;s respective printed circuit board (PCB)  82  and  92 , so that the micro-controllers or processors  80  and  90  can control various other components in order to communicate with another earbud or a remote electronic device. These various electrical components and circuitry in each earbud are powered primarily by the earbud batteries  18  and  38 . Antennas  24  and  44  provide earbuds  11  and  13  with the ability to communicate with each other or with a remote electronic device, e.g. a mobile smart phone, wirelessly, such as using Bluetooth, or near-field communication capabilities. 
         [0025]    The earbuds  11  and  13  may be configured to receive signals via antennas wirelessly, where the signals may contain data representing digital audio such as voice or music, and/or control signals for causing the microcontrollers  80  and  90  to perform certain control operations. In one embodiment, each of the controllers  80  and  90  receives audio signals, processes the received audio signals and then passes the processed signals on via the electrical circuit to speakers  20  and  40 , which in turn produce audible sound. The earbuds  11  and  13  may also include one or more microphones  16 ,  26  and  36 ,  46 , which are electrically mounted on or connected to each earbud&#39;s respective circuit  82  or  92 . Microphones may include either analog or digital, or other varieties. In one embodiment, the controllers  80  or  90  can be configured to cause the microphones  16 ,  26  and  36 ,  46  to capture sound, process the captured audio signals and transmit the audio signals to an external source device such as a smart mobile phone. 
         [0026]    The earbuds may also contain earbud tips  30  and  50 , which are coupled to acoustic components of speakers  20  and  40 . In one embodiment, the earbud tips  30  and  50  are configured to contact the user&#39;s ear canals and allow audible sounds to travel from the speakers  20  and  40  to a user&#39;s ears. The earbud tips  30  and  50  may be made from a soft material such as silicone, rubber, resin, photopolymer, foam and the like. In one embodiment, the earbud tips can be produced by injection molding or anatomically customized for a user&#39;s ear canal via  3 D scanning and/or printing. 
         [0027]    In one embodiment, the earbuds may also contain grips  12  and  32 , which provide a means for a user to grasp and remove them from the user&#39;s ears. As grips do not need to contact a user&#39;s ears, they may be made of any plastic such as polycarbonate, polypropylene, polyvinyl chloride, photopolymer, resin, metal, alloy and the like, and available in a variety of hues. The earbuds  11  and  13  may also contain electrical connectors/conductors, such as leads or prongs that can be used for charging or communicating with other devices. 
         [0028]    With reference to  FIG. 2 , select components from the earbud set, i.e. earbuds  11  and  13  in  FIG. 1  are shown. The earbuds may contain components such as one or more transmitters and receivers (which may be integrated into a single transceiver device or provided as separate components), Bluetooth and/or WiFi interfaces, RAM, Flash memory, MMUs, as well as embedded software stored in non-transitory computer readable medium for audio signal processing (CODECs), interface management, clock synchronization, power monitoring, power control, antenna reception signal monitoring and a host of other functions. 
         [0029]    With further reference to  FIG. 2 , in an non-limiting example, earbuds  11  and  13  ( FIG. 1 ) of the earbud set can each have an antenna control system  51  and  59  that can be configured to establish a wireless communication connection between the two earbuds via antennas  24  and  44 . In one embodiment, the wireless communication connection can be a Wi-Fi channel or a Bluetooth channel. In one embodiment, each earbud can contain a power monitor system  55  and  56  that can be configured to detect the battery charge level in each earbud, such as remnant charge within batteries  18  and  38 . The detected battery charge level may be stored in a memory installed in each earbud for later retrieval. In one embodiment, the two earbuds may also each contain a synchronized clock circuit  62  and  66  for each respective controller to share, so that any connection change and audio signal processing between the two earbuds may be coordinated appropriately. 
         [0030]    Each earbud can also include a power monitor system  55  and  56  that can be configured to monitor the changes in battery charge level. In one embodiment, a power monitor system in one earbud  55  may obtain the battery charge level of the earbud from the power control system  54 . Additionally, the power monitor system  55  may also obtain the battery charge level of the other earbud in the pair from the power control system of that other earbud  58  via the wireless communication connection between the two earbuds. For example, during the wireless communication between the two earbuds, the reading of each earbud&#39;s battery charge level can be processed by its respective controller and included in a data packet that will be transmitted to the other earbud. The controller of the receiving earbud may receive the data packet wirelessly and decode the battery charge level from the received data packet and pass it to its own power monitor system. Alternatively and/or additionally, the battery charge level of one earbud may be transmitted to the other earbud via other communication protocols, in either digital or analog. 
         [0031]    In one embodiment, the power monitor system  55  and  56  may be configured to constantly or periodically monitor the changes in battery charge level and determine whether a switching condition has occurred. The switching condition may indicate a significant change of conditions, such as the battery charge level or antenna reception signal strength that may affect the continued operation of the earbuds. The occurrence or detection of a switching condition may cause the roles or relationship of the two earbuds to reverse. For example, when the power monitor systems  55  and  56  detect a significant difference in remnant charge of batteries  18  and  38 , a switching condition may have occurred, indicating an imbalance of remaining battery charges between the two earbuds that may warrant the roles of the two earbuds to switch. 
         [0032]    In one embodiment, the antenna control system  51  and  59  in each of the earbuds can be configured to detect the antenna reception signal strength of each respective earbud for a particular wireless connection, such as to a target or host remote electronic device. For example, each earbud can detect one or multiple Bluetooth target devices (e.g. a remote electronic device or a smart mobile phone) within its reception range and can measure the reception signal strength for each of the connections corresponding to one or more target devices. 
         [0033]    Alternatively and/or additionally, each earbud may contain an antenna monitor system  53  and  57 , which can be configured to monitor the changes of antenna reception signal strength. An antenna monitor system in one earbud  53  may obtain the antenna reception signal strength of the earbud from the antenna control system  51 . The antenna monitor system  53  may also obtain the reception signal strength of the other earbud in the pair from the antenna monitor system of that earbud  57  via the wireless communication connection between the two earbuds. For example, during the wireless communication between the two earbuds, the reading of each earbud&#39;s antenna reception signal strength level can be processed by its respective controller and included in a data packet that will be transmitted to the other earbud. The controller of the receiving earbud may receive the data packet wirelessly and decode the antenna reception signal strength level from the received data packet and pass it to its own antenna monitor system. 
         [0034]    Alternatively and/or additionally, the antenna reception signal strength level of one earbud may be transmitted to the other earbud via other communication protocols, in either digital or analog Similar to power monitor system  55  and  56 , antenna monitor system  53  and  57  can be configured to constantly or periodically monitor the changes of antenna reception signal strength level of the two earbuds and determine whether a switching condition has been met, which condition may warrant the roles of the two earbuds to switch. 
         [0035]    With reference to  FIG. 3 , the relationship between the two earbuds is now explained according to one embodiment. While the two earbuds are in wireless communication connection with each other, only one of the two earbuds, such as earbud  11 , is directly connected to a remote electronic device (smart phone  52 ) wirelessly, such as via Bluetooth, to receive signals from or transmit signals to the remote electronic device. Therefore, earbud  11  is called the leader. The signals carried over through the primary wireless communication connection between the leader earbud and the remote electronic device may contain audio and/or data to be transmitted by the leader to the follower earbud. The signals may also include audio and/or data to be received from the follower earbud by the remote electronic device, such as audios captured by the follower earbud&#39;s microphone. In one embodiment, a secondary wireless communication connection is established between earbuds  11  and  13 , which is used to transmit/receive signals between the two earbuds. 
         [0036]    In one embodiment, when the leader earbud  11  receives signals from the remote electronic device  52 , its controller  80  may process the signals and play the signals in its appropriate format on its speaker  20 , such as an audio in MP3 format. If the signals are meant to be played on the other earbud, such as the right channel of a stereo music, the leader earbud  11  transmits the signals to the follower earbud  13  via its established secondary wireless communication connection, such as a Bluetooth connection. Alternatively and/or additionally, the follower earbud  13  may transmit signals back to earbud  11  (e.g., audio captured by microphones  36  and  46  or other control signal/data), and in response, the leader earbud  11  may process the signals received from the follower earbud  13  and transmit to the remote electronic device, as needed. 
         [0037]    In one embodiment, when the follower earbud  13  receives signals from the leader earbud  11 , it may operate in a similar manner as earbud  11 . For example, the controller of earbud  13 , i.e.  90 , processes the received signals and determines if the signals are audio that should be played to its speaker  40 . In one embodiment, the follower earbud  13  may also determine if the signals received from the leader earbud  11  contains a control signal or data. For example, the follower earbud  13  may receive a switching signal indicating that a switching condition has occurred and now that the roles of the leader earbud and follower earbud need to reverse. In response to receiving the switching signal, the controller of the follower earbud  90  may perform appropriate operations or cause various components to perform appropriate operations. For example, the controller  90  may cause the antenna control  59  ( FIG. 2 ) to establish a primary connection with the remote electronic device  52 . 
         [0038]    In one embodiment, the leader and follower earbuds are made of identical components and the assignment of leader and follower may be random. In another embodiment, the assignment of leader and follower can be based upon which earbud is first powered on. In another embodiment, the assignment can be based on which earbud initially has the most remaining battery charge. In another embodiment, the assignment can be based on which earbud has the strongest antenna reception signal strength level for a communication connection to the same target or remote electronic device. 
         [0039]    With reference to  FIG. 4 , now the switching of the roles of leader and follower earbuds is explained. In a non-limiting example, earbud  11  may begin as the leader, establish a primary wireless communication connection, such as a Bluetooth connection, with a smart phone  52 , and is configured to transmit signals/data received from the smart phone  52  to the controller  90  of the follower earbud  13 , via antennas  24  and  44  and a secondary communication connection. When the power monitor  55  or  56  of either earbud detects that a switching condition has occurred, the controller of leader earbud  11  may determine to reverse the leader and follower relationship of earbuds  11  and  13 . 
         [0040]    The switching condition indicates that a significant condition has occurred that may warrant a switching of roles of the earbuds in order for the earbud set to continue operating at its optimal performance. For example, a switching condition may be indicative of a threshold drop in the remaining charge level of the battery of one of the earbuds. In another example, the switching condition may be indicative of the existence of a threshold difference (e.g., 25%) in the level of remain battery charges in the two earbuds and when the battery charge level of the leader earbud is lower than that of the follower earbud. This 25% differential represents an example of a threshold, is arbitrary and may be set at any percentage determined sufficient. In another example, the switching condition may be indicative of an elapse of a threshold period of time since a previous switching has occurred, for example, the most recent switching. In one embodiment, the elapse of the threshold period of time may be based on the synchronized clock  62  and  60 . For example, synchronized clocks  62  and  60  may communicate elapsed timing to the power monitor system  55  and  56  at fixed intervals (e.g., every 10 elapsed minutes or any percentage or period determined sufficient) to reverse the leader and follower relationship. 
         [0041]    Alternatively and/or additionally, the switching condition may be indicative of a threshold drop in the antenna reception signal strength in the leader earbud for the primary communication with the remote electronic device. In one embodiment, the switching condition may also be indicative of the existence of a threshold difference between the antenna reception signal strength of each of the two earbud antennas (e.g., 20 db) for a corresponding communication connection with the remote electronic device and when the antenna reception signal strength of the leader earbud is weaker than that of the follower earbud. In other words, if the antenna monitor system ( 53  or  57  in  FIG. 2 ) determines that the primary communication connection between the leader earbud and the remote electronic device becomes weaker, or significantly weaker than it would be between the follower earbud and the remote electronic device, then the antenna monitor system may trigger a switching condition. In response, the controller of the leader earbud may trigger a reversal between the leader and follower earbuds. In the event that the antenna reception signal strength of the earbuds fluctuates, the above disclosed switching condition may permit the earbud pair or set to operate at its strongest performance. 
         [0042]    With reference to  FIG. 5 , once a switching condition is detected, the roles of earbuds  11  and  13  are now reversed, making earbud  11  the follower and earbud  13  the leader. This reversal is achieved by the termination of primary wireless communication connection to the smart phone  52  by earbud  11 , establishment of primary connection to smart phone  52  by earbud  13 , and the beginning of a direct wireless communication connection between earbud  13  (as leader) and the smart phone  52 . The system may do this using any suitable sequence. For example, a diagram showing the switching is described as below according to one embodiment. 
         [0043]    With reference to  FIG. 6 , in a non-limiting example, earbud  11  starts off as the leader earbud and has established primary communication connection  600  with the remote electronic device  52 . Earbud  11  is also in a secondary communication connection  601  with the follower earbud  13  to transmit and receive signals or data to/from earbud  13 . When a switching condition has occurred  602 , earbud  11  sends a switching signal to the follower earbud  13  to indicate that a switching is to occur. In response, earbud  13  initiates and establishes a new primary communication connection  604  with the remote electronic device  52 , and sends back an acknowledgment signal  605  to earbud  11  indicating that earbud  13  is now ready to be the leader earbud. Alternatively and/or additionally, earbud  11  may receive an acknowledgment signal  606  from the remote electronic device  52  indicating that another earbud has established a new primary connection and is ready to take over. Upon receiving the acknowledgement, earbud  11  may now terminate the original primary connection  607  with the remote electronic device  52 , and the data transmission between the remote electronic device  52  and earbud  11  is now handed-over  608  to the new primary communication connection between earbud  13  and the remote electronic device  52 . Now, earbud  13  is acting as a leader and earbud  11  as a follower, which is in a secondary communication connection  609  with the leader earbud  13 . 
         [0044]    As can be appreciated by a person ordinarily skilled in the art, there can be various ways to achieve the reversal without departing from the essence of the inventive concepts disclosed in this document. In one embodiment, the hand-shaking/acknowledgement signals may be optional. For example, once the leader earbud has sent out the switching signal to the follower earbud, it may not need to wait for acknowledgment from the follower earbud or the remote electronic device. Instead, it may start terminating the primary communication connection with the remote electronic device and indicate to the remote electronic device that the primary communication connection will be switched to another earbud. Upon receiving the termination request, the remote electronic device may wait for the other earbud to initiate and request a connection, and only upon successful establishment of the new communication connection with the new earbud does the remote electronic device acknowledge the termination request from the leader earbud. In another example, the leader earbud may first terminate the primary communication connection with the remote electronic device, and then send a signal to the follower earbud to establish a new primary communication connection between the follower earbud and the remote electronic device. This simplified signaling may cause a brief loss of signals during the reversal because of lack of hand-shaking. On the other hand, this approach can achieve fast switching with no or minimal latency, and it may be practically reliable when the earbuds are idle or when data communication in the primary communication connection is not time critical. 
         [0045]    The above-disclosed features and functions, as well as alternatives, may be combined into many other different systems or applications. Various components may be implemented in hardware or software or embedded software. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements may be made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.