PATENT DOCUMENT

Publication Number: US-8098838-B2
Application Number: US-27721908-A
Country: US
Kind Code: B2

Title: Detecting the repositioning of an earphone using a microphone and associated action

Abstract:
A system detects the repositioning of an earphone that is worn by a user, and changes an operation mode of a host coupled to the earphone. Within the earphone is a pressure transducer that detects a pressure change caused by the repositioning of the earphone. A signaling mechanism sends a repositioning detection signal to the host in response to a signal from the pressure transducer indicating the detection of the pressure change.

Claims:
1. An apparatus comprising:
 an earphone that is to be coupled to a host; 
 a pressure transducer within the earphone; and 
 a microphone; and 
 a signaling mechanism coupled to the microphone and the pressure transducer, the signaling mechanism to send to the host a repositioning detection signal representing a pressure change detected by the pressure transducer, the pressure change responsive to repositioning of the earphone, wherein the signaling mechanism is to generate the repositioning detection signal for transmission to the host, the repositioning detection signal generated as a distinct direct current (DC) voltage level upon detection that the microphone is not in use, and as a supersonic distinct alternating current (AC) frequency sequence upon detecting that the microphone is in use. 
 
     
     
       2. The apparatus of  claim 1 , wherein the signaling mechanism comprises a signal generator to generate the supersonic distinct AC frequency sequence as the repositioning detection signal, the supersonic distinct AC frequency sequence to be superimposed on a microphone signal generated by the microphone for transmission to the host. 
     
     
       3. The apparatus of  claim 1 , wherein the supersonic distinct AC frequency sequence is in the range 75 kHz-300 kHz. 
     
     
       4. The apparatus of  claim 1 , wherein the signaling mechanism comprises:
 a host interface to transmit a unique voltage level that identifies an occurrence of the repositioning detection signal. 
 
     
     
       5. The apparatus of  claim 1 , further comprising:
 the host; and 
 an earphone interface within the host to receive the repositioning detection signal and to change an operation mode of the host upon receipt of the repositioning detection signal. 
 
     
     
       6. The apparatus of  claim 1 , further comprising:
 one or more buttons coupled to the signaling mechanism, the signaling mechanism to generate a button press signal when one of the buttons is pressed, the button press signal to be transmitted to the host through a same wire as the repositioning detection signal. 
 
     
     
       7. The apparatus of  claim 1 , wherein the host comprises:
 a media player, which is to pause playing a media file in response to the repositioning detection signal indicating that the earphone has been removed from an ear. 
 
     
     
       8. The apparatus of  claim 1 , wherein the host comprises:
 a media player, which is to resume playing a media file in response to the repositioning detection signal indicating that the earphone has been inserted into an ear. 
 
     
     
       9. The apparatus of  claim 1 , further comprising:
 a plurality of wires to connect the signaling mechanism and the earphone with the host, the plurality of wires to carry audio signals from the host to the earphone, and the repositioning detection signal from the earphone to the host. 
 
     
     
       10. A method comprising:
 detecting a pressure change within an earphone, the pressure change responsive to repositioning of the earphone, wherein the earphone is coupled to a microphone; 
 in response to the pressure change, generating a repositioning detection signal to a host that is coupled to the earphone, the repositioning detection signal generated as a distinct direct current (DC) voltage level upon detection that the microphone is not in use, and as a supersonic distinct alternating current (AC) frequency sequence upon detection that the microphone is in use; and 
 sending the repositioning detection signal to the host to cause the host to change an operating mode. 
 
     
     
       11. The method of  claim 10 , further comprising:
 generating the repositioning detection signal as a unique voltage level in response to the pressure change; and 
 transmitting the unique voltage level to the host via a conductive wire. 
 
     
     
       12. The method of  claim 10 , further comprising:
 generating the repositioning detection signal as the supersonic distinct AC frequency sequence in response to the pressure change; 
 superimposing the supersonic distinct AC frequency sequence on an audible signal generated by the microphone that is coupled to the earphone; and 
 transmitting the superimposed supersonic and audio signals to the host through a conductive wire. 
 
     
     
       13. The method of  claim 10 , further comprising:
 transmitting the repositioning detection signal through a same wire as an audible signal generated by the microphone. 
 
     
     
       14. The method of  claim 10 , further comprising:
 causing a media player in the host to pause playing a media file in response to the repositioning detection signal indicating that the earphone has been removed from an ear. 
 
     
     
       15. The method of  claim 10 , further comprising:
 causing a media player in the host to resumes playing a media file in response to the repositioning detection signal indicating that the earphone has been inserted into an ear. 
 
     
     
       16. A system comprising:
 means for detecting a pressure change within an earphone that is coupled to a microphone; 
 means for generating a repositioning detection signal generated as a distinct direct current (DC) voltage level upon detecting that the microphone is not in use, and as a supersonic distinct alternating current (AC) frequency sequence upon detecting that the microphone is in use; and 
 means for sending the repositioning detection signal representing the pressure change to a host, the pressure change responsive to repositioning of the earphone. 
 
     
     
       17. The system of  claim 16 , further comprising:
 means for generating a uniquely identifiable signal as the repositioning detection signal, the uniquely identifiable signal to be transmitted to the host, through a single wire, with a microphone signal generated by the microphone.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to an earphone. More particularly, this invention relates to detecting the repositioning of an earphone that is worn by a user. 
     BACKGROUND 
     Earphones (also known as earbuds or headphones) are widely used for listening to audio sources for recreation. An earphone contains a receiver (a small speaker) that is held close to the user&#39;s ear to convert electric signals into sound. Earphones can be connected to an audio source, such as an audio amplifier or a media player, which resides in stationary equipment (e.g., a CD or DVD player, a home theater, a personal computer, etc.), or in a portable device (e.g., a digital audio player, an MP3 player, a mobile phone, a personal digital assistant, etc.). 
     An earphone may be combined or integrated with a microphone to form a headset, that is used for two-way communications through a host device, such as a cellular phone, or a desktop or laptop computer executing voice over IP (Internet Protocol) software. The headset can communicate with the host device through either a wired connection or a wireless link. 
     SUMMARY OF THE INVENTION 
     A method and system for detecting the repositioning of an earphone is described herein. The system comprises an earphone assembly (earphone) that is to be coupled to a host. Within the earphone is a pressure transducer that detects a pressure change caused by the repositioning of the earphone against the user&#39;s ear. Upon detection of the pressure change, the pressure transducer transmits a signal to a signaling mechanism that is also outside the host. The signaling mechanism sends a repositioning detection signal to the host in response to the signal from the pressure transducer. The repositioning detection signal may be superimposed on a microphone output audio signal when it is transmitted to the host. 
     Upon receipt of the repositioning detecting signal, the host changes its operation mode. In one scenario, the host may include a media player that is connected to the earphone and is playing music through the earphone. The player pauses music playing when the repositioning detecting signal indicates removal of the earphone from the user&#39;s ear. The media player may automatically resume music playing when the repositioning detecting signal indicates that the earphone has been re-inserted into the user&#39;s ear or is otherwise “at the ear.” In another scenario, the host may include a telephone module which automatically switches to speakerphone mode when the repositioning detecting signal indicates the removal of the earphone from the user&#39;s ear. The telephone module may switch back to receiver mode (handset mode) when the repositioning detecting signal indicates that the earphone has resumed its at-the-ear position. It is understood that other scenarios, involving different operation modes of the host, may also utilize the repositioning detection signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
         FIG. 1  illustrates one embodiment of an earphone assembly communicating with a host by wires. 
         FIG. 2  illustrates an embodiment of an I/O port of a host through which a wired connection can be established between the host and the earphone assembly. 
         FIG. 3  illustrates an embodiment of a signaling module as part of a wired headset assembly. 
         FIG. 4  illustrates another embodiment of an earphone assembly that communicates with a host using a wireless connection. 
         FIG. 5  illustrates a flow diagram of a method for detecting the repositioning of an earphone according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an embodiment of an earphone assembly  100  and a wired headset  101 , connected to a host  120  that contains a signal source, such as a media player  121 . Earphone assembly  100 , in this example, includes a pair of earpieces  110  to be held close to a user&#39;s ears. Earpieces  110  may be held inside the ears (such as earbuds or in-the-ear earphones), or outside but in close proximity of the ears. When placed in the ears, earpieces  110  may be positioned outside the ear canals, or within the ear canals with the ear canals entirely or partially sealed. In the embodiment shown in  FIG. 1 , earpieces  110  are connected to host  120  by wires (or cables). The wires carry electric signals representative of sound (audio signals) into earpieces  110 . One end of the wires has a plug (not shown) to be plugged into a mating jack  125  of host  120 . Each earpiece  110  contains an earphone receiver  113 , which can also be referred to as an earphone speaker, for converting the electric signal into sound to be heard by the user. 
     According to one embodiment of the present invention, each of earpieces  110  also contains a pressure transducer  115  that converts a pressure change in the ear into a voltage or current change. The pressure change may be produced by removing earpiece  110  from, or placing earpiece  110  against or into, the user&#39;s ear that wears the earpiece. In one embodiment, pressure transducer  115  is a microphone, such as an MEMS (Micro-Electro-Mechanical Systems) microphone that detects an ambient pressure change. 
     In the embodiment, pressure transducer  115  generates a transducer signal to carry a voltage change to host  120 . The transducer signal can be sent to host  120  through a dedicated wire, or can be multiplexed with or superimposed on an audio signal, in the same wire that carries electric audio signals (e.g., music) from or to the host  120 . 
     In the embodiment shown in  FIG. 1 , the transducer signal carrying the voltage change is sent from the earphone assembly  100  to a microphone assembly  130  of the headset  101 , through a separate wire (separate from the wire for the left receiver and the wire for the right receiver). The microphone assembly  130  then forwards the transducer signal to host  120  in the same or a different signaling format. In one embodiment, microphone assembly  130  comprises a microphone  131  for converting a sound (e.g., the user&#39;s speech) into electric signals for transmission to host  120 . The microphone assembly  130  also comprises a signaling module  132  for generating a repositioning detection signal in response to the transducer signal, and one or more buttons  133  that can be programmed to control specific tasks. For example, buttons  133  can be used to turn on/off the microphone  131 , signal the host to adjust the volume of the music it is playing through the earphone assembly  100 , or disconnect an ongoing telephone call. A button press signal is generated and transmitted to host  120  by the signaling module  132 , when one of buttons  133  is pressed. 
     In one embodiment, the repositioning detection signal is transmitted to host  120  on the same wire as the electric signal generated by microphone  131  (referred to as a microphone signal). The frequency of the microphone signal falls in an audible frequency range. Signaling module  132  may transmit the repositioning detection signal as a DC voltage level when microphone  131  is not present or is not in use. When microphone  131  is in use, signaling module  132  may transmit the repositioning detection signal as a supersonic AC signal which is superimposed on the microphone signal. An embodiment of signaling module  132  will be described in greater detail with reference to  FIG. 3 . 
     In one embodiment, host  120  comprises a media player  121 , a wired earphone interface  122 , and a battery  123 . In alternative embodiments, host  120  may comprise some, but not all of the components shown in  FIG. 1 . For example, although battery  123  is shown in  FIG. 1 , it is understood that host  120  may be a desktop computer or a stationary device that is powered by a standard electric outlet instead of a battery. Host  120  may be, for example, a personal computer (PC), a mobile phone, a palm-sized computing device, a personal digital assistant (PDA), a media playing device such as an iPod™ device, or a gaming device. 
     Media player  121  may be viewed as a source of the electric audio signal that will be delivered to the input of the earphone receiver  113 . In one embodiment, media player  121  is a software program for playing streamed or stored multimedia files, such as audio and video files. Examples of a software media player include the following brands of personal computer application programs: iTunes™, Windows Media Player, Quicktime, and RealPlayer. Alternatively, media player  121  may comprise dedicated hardware, or a combination of dedicated hardware and software such as an iPod™ player. 
     Wired earphone interface  122  converts a digital audio signal into an analog audio signal for transmission to earphone assembly  100 . Wired earphone interface  122  also receives the repositioning detection signal, as a distinct or unique voltage level or a supersonic signal, and invokes a change in the operation mode of media player  121  or host  120 . For example, media player  121  can be paused when it is in a play mode, or can resume playing when it is in a pause mode. Host  120  can switch from a receiver mode into a speaker mode, or vice versa, upon receipt of the repositioning detection signal. Wired earphone interface  122  is powered and controlled by host  120 . 
     The connection between the wired headset  101  and the wired earphone interface  122  of the host  120  may be through an I/O port  220 , depicted in  FIG. 2 . I/O port  120  may be located in jack  125  of  FIG. 1 . In this embodiment, four lines or wires are shown to pass through I/O port  220 . A first line (labeled “R”)  231  carries electric audio signal representative of sound to the right earpiece  110 , and a second line (labeled “L”)  232  carries electric audio signal representative of sound to the left earpiece  110 . The output signals on these two lines may be different for stereophonic sound, or may be the same for monotonic sound. A third line (labeled “MIC”)  233  carries the microphone signal, and one or more button press signals, into host  120 . MIC line  233  also provides power to microphone assembly  130 . A fourth line (labeled “GRN”)  234  provides a ground voltage to microphone assembly  130 . In this embodiment, the repositioning detection signal is carried by the MIC line  233  in accordance with the technique described below in connection with  FIG. 3 . 
       FIG. 2  also illustrates an embodiment of the components within wired earphone interface  122 . In this embodiment, wired earphone interface  122  includes a host module  250 , a decoder  260 , and an I 2 C interface  270 . Host module  250  provides regulated downstream power to signaling module  132  and microphone  131 . Decoder  260  decodes the button press signal and the repositioning detection signal (from microphone assembly  130 ), and provides the decoded information to host  120  via an interface, e.g., an I2 C interface  270 . The decoded information causes host  120  to change its operation mode or to perform other pre-programmed tasks according to the pressed button. 
       FIG. 3  illustrates a block diagram of an embodiment of signaling module  132 . Signaling module  132  includes a host interface  310 , a microphone interface  320 , a button interface  330  and a tone generator  340 . Host interface  310  communicates with host  120  via MIC line  233  and GRN line  234  (of  FIG. 2 ). In this embodiment, it is not necessary for R line  231  and L line  232  to enter signaling module  132 , as the destination for the sound signals on these lines is earphone assembly  110 . Via MIC line  233 , host interface  310  sends the microphone signal, the button press signal and the repositioning detection signal to host  120 , and receives power from host  120 . The power from host  120  is used to power up or bias the microphone  131  and operate the signaling module  132 . Via GND line  234 , host interface  310  receives a ground voltage from host  120 . 
     Microphone interface  320  receives signals from microphone  131  and forwards the microphone signal to host  120  via host interface  310 . Microphone interface  320  also detects the presence and usage of microphone  131 , and provides an indication to host interface  310  as to whether microphone  131  is present or in use. Button interface  330  is coupled to a switch-resistor network  350 , which includes a series of resistors, each coupled to a switch. The switches are controlled by buttons  133 , except that one of the switches is controlled by the transducer signal. Button interface  330  forwards the detection of a button press and the detection of a transducer signal to host interface  310 . 
     When microphone  131  is not in use or is not present, signaling module  132  enters a button mode, in which the press of buttons and the presence of a transducer signal are transmitted to host  120  through MIC line  233  using discrete voltage levels. During operation in the button mode, signaling module  132  operates as a pass through element, which connects switch-resistor network  350  onto MIC line  233 . When one of buttons  133  is pressed, the DC voltage level on MIC line  233  is changed and detected by wired earphone interface  122  of host  120 . A distinct DC voltage level is generated when a different button is pressed. When a transducer signal is received, another distinct DC voltage level is generated to provide a repositioning detection signal to host  120 . In one embodiment, when a change of the DC level on MIC line  233  is detected, wired earphone interface  122  translates the frequency sequence into a button press or a repositioning of an earphone. Wired earphone interface  122  places the translated result in registers and sets an interrupt. Host  120  reads these registers to determine into which operation mode the host should change. 
     Still referring to  FIG. 3 , when microphone interface  320  detects the presence of a microphone signal, e.g. speech pick up, signaling module  132  enters a tone mode. During operation in the tone mode, tone generator  340  generates a discrete frequency (AC) sequence onto MIC line  233  in response to the detection of a button press or the detection of a transducer signal. The frequency sequence is unique to each button press. When a transducer signal is received, another unique frequency sequence is generated to provide a repositioning detection signal to host  120 . Wired earphone interface  122  of the host  120  ( FIG. 1 ) detects and uses the frequency sequence on MIC line  233  to determine the occurrence of a specific button press or a repositioning of the earphone. When a distinct frequency sequence is detected on MIC line  233 , wired earphone interface  122  translates the frequency sequence into a button press or a repositioning of the earphone. Wired earphone interface  122  places the translated result in registers and sets an interrupt. Host  120  reads these registers to determine into which operation mode the host should change. 
     In one embodiment, when a button is pressed or a transducer signal is received, tone generator  340  generates a supersonic frequency sequence between 75 kHz and 300 kHz. A unique frequency sequence is used for the press of each button and the repositioning detection signal. The supersonic signals can be easily separated from the audible signal generated by microphone  131 . 
       FIG. 4  illustrates another embodiment of an earphone assembly  400 , which may also be viewed as a wireless headset which communicates with a host  420  using a radio frequency (RF) or infra-red (IR) transmission link. Signals transmitted on this wireless link can be encoded according to a wireless protocol, such as FM, Bluetooth or Wi-Fi. In this embodiment, earphone assembly  400  comprises an earpiece  410  for delivering audio signals to a user&#39;s ear. When placed in the ears, earpieces  410  may be positioned outside the ear canals, or within the ear canals with the ear canals entirely or partially sealed. Earpiece  410  includes an earphone receiver  413 , which can also be referred to as an earphone speaker, for converting the electric signal into sound to be heard by the user. Earpiece  410  is physically connected to a microphone  431 , which picks up the user&#39;s speech, as a microphone signal, and transmits the microphone signal to a signaling module  432  in earpiece  410 . Signaling module  432  encodes the microphone signal into a encoded data sequence and modulates a host-bound wireless signal with such a sequence, according to a standard wireless protocol. 
     Earpiece  410  also includes a pressure transducer  415  (e.g., a microphone), which is similar or the same as pressure transducer  115  of  FIG. 1 . When a user removes earpiece  410 , or re-inserts earpiece  410  into the ear, pressure transducer  415  detects a pressure change in the ear. Pressure transducer  415  converts the pressure change into an electric signal (referred to as a transducer signal), and sends the transducer signal to signaling module  432 . In response to the transducer signal, signaling module  432  generates a repositioning detection signal to host  420 , via a wireless interface that transmits the signal using a predetermined wireless protocol. For example, signaling module  432  can insert a pre-designated data sequence in the host-bound wireless signal to indicate the presence of the repositioning detection signal. 
     Host  420  has an antenna  425  for receiving the repositioning detection signal, and for transmitting audio signals (e.g., music) to earpiece  410 , via a wireless link. Host  420  includes a media player  421 , a wireless earphone interface  422  to demodulate the received, host-bound wireless signal to extract the repositioning detection signal, and a battery  423 . Media player  421  may be similar or the same as media player  121  of  FIG. 1 . Host  420  may be powered by battery  423 , or may be powered by a standard power cord that plugs into an electric outlet. 
     Upon detection of the repositioning detection signal, wireless earphone interface  422  decodes the signal and sends the decoded information to host  420 . In response to the decoded information, the host  420  changes an operation mode of media player  421  or host  420 . For example, media player  421  may be paused when it is in a play mode, or may resume playing when it is in a pause mode. Host  420  may switch from a receiver mode into a speaker mode, or vice versa, upon receipt of the repositioning detection signal. 
       FIG. 5  shows a flow diagram of a method  500  for detecting the repositioning of an earphone according to one embodiment of the present invention. Method  500  may be performed by hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), software (such as instructions on a computer readable storage medium executable by a processing device), or a combination thereof. In one embodiment, method  500  is performed by earphone assembly  100  and signaling module  122  of  FIG. 1 , or earphone assembly  400  of  FIG. 4 . 
     At block  510 , a pressure transducer (e.g., pressure transducer  115  of  FIG. 1  or pressure transducer  415  of  FIG. 4 ) within an earphone assembly detects a pressure change responsive to the repositioning of one or both of the earpieces. At block  520 , the pressure transducer converts the pressure change into an electric signal (i.e., the transducer signal). At block  530 , the pressure transducer sends the transducer signal to a signaling mechanism, such as signaling module  132  of  FIG. 3  or signaling module  432  of  FIG. 4 . At block  540 , the signaling mechanism generates a repositioning detection signal in response to the transducer signal. At block  550 , the signaling mechanism transmits the repositioning detection signal to a host (e.g., host  120  of  FIG. 1  or host  420  of  FIG. 4 ). In response to the repositioning detection signal, the host changes an operation mode of the host or a media player within the host. 
     An embodiment of the invention may be a machine-readable medium having stored thereon instructions which cause a programmable processor to perform operations as described above. A “machine-readable” medium may include a computer-readable storage medium and any medium that can store or transfer information. Examples of a machine readable medium include a ROM, a floppy diskette, a CD-ROM, a DVD, flash memory, hard drive, an optical disk or similar medium. In other embodiments, the operations might be performed by specific hardware components that contain hardwired logic. Those operations might alternatively be performed by any combination of programmed computer components and custom hardware components. 
     The applications of the present invention have been described largely by reference to specific examples and in terms of particular allocations of functionality to certain hardware and/or software components. However, those of skill in the art will recognize that automatically detecting the repositioning of an earphone, and responding to it by changing operation of the host, can also be made by software and hardware that distribute the functions of embodiments of this invention differently than herein described. Such variations and implementations are understood to be made without departing from the broader spirit and scope of the invention as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

Metadata:
Filing Date: 20081124
Publication Date: 20120117
Grant Date: 20120117
Priority Date: 20081124
Inventors: LEE JAE HAN
SANDER WENDELL B.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R1/1041", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/1041", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R2420/07", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2201/107", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2201/107", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2420/07", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 41531798