PATENT DOCUMENT

Publication Number: US-11109136-B2
Application Number: US-201816167394-A
Country: US
Kind Code: B2

Title: Wireless ear buds with proximity sensors

Abstract:
Ear buds are provided that communicate wirelessly with an electronic device. To determine the current status of the ear buds and thereby take suitable action in controlling the operation of the electronic device and ear buds, the ear buds may be provided with sensor circuitry. The sensor circuitry may include proximity sensors. The ear buds may each have a housing with a main body portion that is configured to be inserted into the ear of the user and an elongated stem portion that extends from the main body portion. The proximity sensors may include sensors on the main body and sensors on the stem. The proximity sensors may be light-based sensors that emit light that passes through the housing.

Claims:
What is claimed is: 
     
       1. A wireless ear bud, comprising:
 a housing having a main body portion and a stem portion extending from the main body portion; 
 a speaker in the main body portion; 
 a first sensor in the main body portion that produces a first sensor output; 
 a second sensor in the stem portion that produces a second sensor output; and 
 control circuitry that:
 determines whether the ear bud has been placed in a user&#39;s ear using the first and second sensor outputs; and 
 determines whether the ear bud has been removed from the user&#39;s ear using the first sensor output without using the second sensor output. 
 
 
     
     
       2. The wireless ear bud defined in  claim 1  further comprising a third sensor in the main body portion that produces a third sensor output. 
     
     
       3. The wireless ear bud defined in  claim 2  further comprising a fourth sensor in the stem portion that produces a fourth sensor output. 
     
     
       4. The wireless ear bud defined in  claim 3  wherein the control circuitry determines whether the ear bud has been removed from the user&#39;s ear using the third sensor output without using the fourth sensor output. 
     
     
       5. The wireless ear bud defined in  claim 4  wherein the control circuitry determines whether the ear bud has been placed in the user&#39;s ear using the third and fourth sensor outputs. 
     
     
       6. The wireless ear bud defined in  claim 5  wherein the first sensor comprises a tragus sensor and the third sensor comprises a concha sensor. 
     
     
       7. The wireless ear bud defined in  claim 6  wherein the concha and tragus sensors comprise light-based proximity sensors. 
     
     
       8. The wireless ear bud defined in  claim 7  wherein the concha and tragus sensors each have an infrared light-emitting diode and a light detector. 
     
     
       9. The wireless ear bud defined in  claim 8  wherein the housing comprises a wall and wherein the infrared light-emitting diodes in the concha and tragus sensors emit infrared light that passes through the wall. 
     
     
       10. The wireless ear bud defined in  claim 1  further comprising an accelerometer that detects movement of the housing. 
     
     
       11. The wireless ear bud defined in  claim 1  wherein the first sensor is configured to detect the user&#39;s ear and wherein the second sensor is configured to detect a touch input from the user. 
     
     
       12. An ear bud, comprising:
 control circuitry; 
 wireless circuitry that the control circuitry uses to communicate wirelessly with an electronic device; 
 a housing having a first portion that is configured to be inserted into an ear of a user and a second portion that extends from the first portion; 
 a speaker in the first portion; 
 a first proximity sensor in the first portion; and 
 a second proximity sensor in the second portion, wherein the control circuitry determines that the ear bud has been placed in a user&#39;s ear when the first proximity sensor is covered and when the second proximity sensor is uncovered. 
 
     
     
       13. The ear bud defined in  claim 12  wherein the first and second proximity sensors are light-based proximity sensors. 
     
     
       14. The ear bud defined in  claim 13  wherein the first and second proximity sensors each include an infrared light-emitting diode that produces infrared light that passes through the housing. 
     
     
       15. The ear bud defined in  claim 14  wherein the second portion of the housing comprises an elongated stem. 
     
     
       16. The ear bud defined in  claim 12  wherein the first proximity sensor produces a first output and the second proximity sensor produces a second output, and wherein the control circuitry determines whether the ear bud has been removed from the user&#39;s ears using the first output without using the second output. 
     
     
       17. A wireless ear bud, comprising:
 a housing; 
 a speaker in the housing; 
 a first light-based sensor that produces a first output indicating whether the first light-based sensor is covered or uncovered; 
 a second light-based sensor that produces a second output indicating whether the second light-based sensor is covered or uncovered; and 
 control circuitry that determines that the ear bud has been placed in a user&#39;s ear when the first light-based sensor is covered and when the second light-based sensor is uncovered. 
 
     
     
       18. The wireless ear bud defined in  claim 17  wherein the control circuitry determines that the ear bud has been removed from the user&#39;s ear using the first output without using the second output. 
     
     
       19. The wireless ear bud defined in  claim 17  wherein the housing comprises a main body portion and a stem portion. 
     
     
       20. The wireless ear bud defined in  claim 19  wherein the first light-based sensor is located in the main body portion and the second light-based sensor is located in the stem portion. 
     
     
       21. The wireless ear bud defined in  claim 20  wherein the first light-based sensor comprises a sensor selected from the group consisting of: a tragus sensor and a concha sensor. 
     
     
       22. The wireless ear bud defined in  claim 17  wherein the first light-based sensor faces the user&#39;s ear and the second light-based sensor faces away from the user&#39;s ear.

Description:
This application is a continuation of patent application Ser. No. 15/270,445, filed Sep. 20, 2016, which claims the benefit of provisional patent application No. 62/233,848, filed Sep. 28, 2015, both of which are hereby incorporated by reference herein in their entireties. 
    
    
     BACKGROUND 
     This relates generally to electronic devices, and, more particular, to wearable electronic devices such as ear buds. 
     Cellular telephones, computers, and other electronic equipment may generate audio signals during media playback operations and telephone calls. Users often use microphones and speakers in these devices to handle telephone calls and media playback. Sometimes ear buds have cords that allow the ear buds to be plugged into an electronic device. 
     Wireless ear buds provide users with more flexibility than wired ear buds, but can be challenging to use. It is not always clear whether a wireless ear bud is located in a pocket, is resting on a table, or is in a user&#39;s ear. As a result, audio signals can sometimes be misdirected. 
     It would therefore be desirable to be able to provide improved wearable electronic devices such as improved wireless ear buds. 
     SUMMARY 
     Ear buds are provided that communicate wirelessly with an electronic device. The electronic device may be a cellular telephone, wristwatch device, or other electronic equipment. A wireless link may be established between the electronic device and the ear buds. The wireless link may be used to transfer audio information between the ear buds and the electronic device. For example, if the electronic device is being used for a cellular telephone call or media playback operations, audio associated with the cellular telephone call or media playback operations may be transferred between the electronic device and the ear buds over the wireless link. 
     The state of the ear buds may be monitored and corresponding actions taken in controlling the ear buds and electronic device. For example, if a user places an ear bud in the ear of the user in response to receiving a cellular telephone call with the electronic device, the telephone call can be automatically transferred to the ear bud. If the user removes the ear bud from the ear during a telephone call or media playback operation, the audio for the call or media playback operation can be routed to a speaker in the electronic device. 
     During use by a user, the ear buds may be stored in a case or pocket, may be rest on a table top, may be inserted into the ear of a user, or may rest in the ear of a user. To determine the current status of the ear buds and thereby take suitable action in controlling the operation of the electronic device and ear buds, the ear buds may be provided with sensor circuitry. The sensor circuitry may include proximity sensors. The ear buds may each have a main body portion that is configured to be inserted into the ear of the user and an elongated stem portion that extends from the main body portion. The proximity sensors may include sensors on the main body and sensors on the stem. 
     The proximity sensors may be light-based sensors each of which has a light source such as an infrared light-emitting diode and a corresponding light detector. Infrared light from the light-emitting diodes can pass through the housings of the ear buds. There may be two proximity sensors on the main body of each ear bud and two proximity sensors on the stem of each ear bud or other numbers of proximity sensors may be used. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative system including electronic equipment that communicates wirelessly with wearable electronic devices such as wireless ear buds in accordance with an embodiment. 
         FIG. 2  is a perspective view of an illustrative ear bud in accordance with an embodiment. 
         FIG. 3  is a side view of an illustrative ear bud located in an ear of a user in accordance with an embodiment. 
         FIGS. 4, 5, and 6  are cross-sectional side views of portions of housing wall structures for ear buds and associated light-based proximity sensors in accordance with an embodiment. 
         FIG. 7  is a flow chart of illustrative steps involved in calibrating and operating wearable electronic devices such as wireless ear buds in accordance with an embodiment. 
         FIG. 8  is a state diagram showing illustrative operations involved in determining the current state of wireless ear buds in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as a host device may have wireless circuitry. Wireless wearable electronic devices such as wireless ear buds may communicate with the host device and with each other. In general, any suitable types of host electronic device and wearable wireless electronic devices may be used in this type of arrangement. The use of a wireless host such as a cellular telephone, computer, or wristwatch may sometimes be described herein as an example. Moreover, any suitable wearable wireless electronic devices may communicate wirelessly with the wireless host. The use of wireless ear buds to communicate with the wireless host is merely illustrative. 
     A schematic diagram of an illustrative system in which a wireless electronic device host communicates wirelessly with accessory devices such as ear buds is shown in  FIG. 1 . Host electronic device  10  may be a cellular telephone, may be a computer, may be a wristwatch device or other wearable equipment, may be part of an embedded system (e.g., a system in a plane or vehicle), may be part of a home network, or may be any other suitable electronic equipment. Illustrative configurations in which electronic device  10  is a watch, computer, or cellular telephone, may sometimes be described herein as an example. 
     As shown in  FIG. 1 , electronic device  10  may have control circuitry  16 . Control circuitry  16  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  16  may be used to control the operation of device  10 . The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc. 
     Device  10  may have input-output circuitry  18 . Input-output circuitry  18  may include wireless communications circuitry  20  (e.g., radio-frequency transceivers) for supporting communications with wireless wearable devices such as ear buds  24  or other wireless wearable electronic devices via wireless links  26 . Ear buds  24  may have wireless communications circuitry  30  for supporting communications with circuitry  20  of device  10 . Ear buds  24  may also communicate with each other using wireless circuitry  30 . In general, the wireless devices that communicate with device  10  may be any suitable portable and/or wearable equipment. Configurations in which wireless wearable devices  24  are ear buds are sometimes described herein as an example. 
     Input-output circuitry in device  10  such as input-output devices  22  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  22  may include buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, displays (e.g., touch screen displays), tone generators, vibrators (e.g., piezoelectric vibrating components, etc.), cameras, sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output devices  22  and may receive status information and other output from device  10  using the output resources of input-output devices  22 . If desired, some or all of these input-output devices may be incorporated into ear buds  24 . 
     Each ear bud  24  may have control circuitry  28  (e.g., control circuitry such as control circuitry  16  of device  10 ), wireless communications circuitry  30  (e.g., one or more radio-frequency transceivers for supporting wireless communications over links  26 ), may have one or more sensors  32 , and may have additional components such as speakers  34 , microphones  36 , and accelerometers  38 . Speakers  34  may play audio into the ears of a user. Microphones  36  may gather audio data such as the voice of a user who is making a telephone call. Accelerometer  38  may detect when ear buds  24  are in motion or are at rest. 
     Control circuitry  28  on ear buds  24  and control circuitry  16  of device  10  may be used to run software on ear buds  24  and device  10 , respectively. During operation, the software running on control circuitry  28  and/or  16  may be used in gathering sensor data, user input, and other input and may be used in taking suitable actions in response to detected conditions. As an example, control circuitry  28  and  16  may be used in handling audio signals in connection with incoming cellular telephone calls when it is determined that a user has placed one of ear buds  24  in the ear of the user. Control circuitry  28  and/or  16  may also be used in coordinating operation between a pair of ear buds  24  that are paired with a common host device (e.g., device  10 ), handshaking operations, etc. 
     In some situations, it may be desirable to accommodate stereo playback from ear buds  24 . This can be handled by designating one of ear buds  24  as a primary ear bud and one of ear buds  24  as a secondary ear bud. The primary ear bud may serve as a slave device while device  10  serves as a master device. A wireless link between device  10  and the primary ear bud may be used to provide the primary ear bud with stereo content. The primary ear bud may transmit one of the two channels of the stereo content to the secondary ear bud for communicating to the user (or this channel may be transmitted to the secondary ear bud from device  10 ). Microphone signals (e.g., voice information from the user during a telephone call) may be captured by using microphone  36  in the primary ear bud and conveyed wirelessly to device  10 . 
     Sensors  32  may include strain gauge sensors, proximity sensors, ambient light sensors, touch sensors, force sensors, temperature sensors, pressure sensors, magnetic sensors, accelerometers (see, e.g., accelerometers  38 ), gyroscopes and other sensors for measuring orientation (e.g., position sensors, orientation sensors), microelectromechanical systems sensors, and other sensors. Proximity sensors in sensors  32  may emit and/or detect light and/or may be capacitive proximity sensors that generate proximity output data based on measurements by capacitance sensors (as examples). Proximity sensors may be used to detect the presence of a portion of a user&#39;s ear to ear bud  24  and/or may be triggered by the finger of a user (e.g., when it is desired to use a proximity sensor as a capacitive button or when a user&#39;s fingers are gripping part of ear bud  24  as ear bud  24  is being inserted into the user&#39;s ear). 
       FIG. 2  is a perspective view of an illustrative ear bud. As shown in  FIG. 2 , ear bud  24  may include a housing such as housing  40 . Housing  40  may have walls formed from plastic, metal, ceramic, glass, sapphire or other crystalline materials, fiber-based composites such as fiberglass and carbon-fiber composite material, natural materials such as wood and cotton, other suitable materials, and/or combinations of these materials. Housing  40  may have a main portion such as main body  40 - 1  that houses audio port  42  and a stem portion such as stem  40 - 2  or other elongated portion that extends away from main body portion  40 - 1 . During operation, a user may grasp stem  40 - 2  and, while holding stem  40 - 2 , may insert main portion  40 - 1  and audio port  42  into the ear. 
     Audio ports such as audio port  42  may be used for gathering sound for a microphone and/or for providing sound to a user (e.g., audio associated with a telephone call, media playback, an audible alert, etc.). For example, audio port  42  of  FIG. 2  may be a speaker port that allows sound from speaker  34  ( FIG. 1 ) to be presented to a user. Sound may also pass through additional audio ports (e.g., one or more perforations may be formed in housing  40  to accommodate microphone  36 ). 
     Sensor data (e.g., proximity sensor data, accelerometer data or other motion sensor data), wireless communications circuitry status information, and/or other information may be used in determining the current operating state of each ear bud  24 . Proximity sensor data may be gathered using proximity sensors located at any suitable locations in housing  40 .  FIG. 3  is a side view of ear bud  24  in an illustrative configuration in which ear bud  24  has four proximity sensors S 1 , S 2 , S 3 , and S 4 . Sensors S 1  and S 2  may be mounted in main body portion  40 - 1  of housing  40  and sensors S 3  and S 4  may be mounted on stem  40 - 2  or other mounting arrangements may be used. In the example of  FIG. 3 , there are four proximity sensors on housing  40 . More proximity sensors or fewer proximity sensors may be used in ear bud  24 , if desired. 
     Sensors S 1 , S 2 , S 3 , and S 4  may use reflected light, capacitance measurements, or other measurements to determine whether an external object is nearby. During operation, a raw sensor signal (e.g., a reflected light signal, capacitance signal, etc.) may be compared to a predetermined threshold. If the raw signal is greater than the threshold, the sensor output will be positive (i.e., an external object is in the vicinity of the sensor). If the raw signal is less than the threshold of the sensor, the sensor output will be negative (i.e., no external object is in the vicinity of the sensor). 
     As shown in  FIG. 3 , ear bud  24  may be inserted into the ear (ear  50 ) of a user, so that speaker port  42  is aligned with ear canal  48 . Ear  50  may have features such as concha  46 , tragus  45 , and antitragus  44 . Proximity sensors such as proximity sensors S 1  and S 2  may output positive signals when ear bud  24  is inserted into ear  50 . Sensor S 1  may be a tragus sensor and sensor S 2  may be a concha sensor or sensors such as sensors S 1  and/or S 2  may be mounted adjacent to other portions of ear  50 . Sensors S 3  and S 4  may be located away from ear  50 , so that sensors S 3  and S 4  output negative signals when ear bud  24  is inserted into ear  50 . 
     The status of sensors S 1 , S 2 , S 3 , and S 4  may be analyzed to help discriminate between possible usage scenarios for ear buds  24  (e.g., an ear bud is in a protective case, an ear bud is in a user&#39;s pocket, an ear bud is being held by the fingers of a user as the user is inserting the ear bud into ear  50 , ear bud  24  is in ear  50 , etc.). Based on this status information, appropriate action can be taken by ear buds  24  and electronic device  10 . 
     With one illustrative arrangement, proximity sensors in ear buds  24  may be formed using light-based proximity sensors. An illustrative light-based proximity sensor that has been mounted within housing  40  of ear bud  24  is shown in  FIG. 4 . As shown in the cross-sectional side view of  FIG. 4 , light-based proximity sensor  60  may have a substrate such as substrate  62 . Substrate  62  may be formed from a rigid printed circuit board (e.g., substrate  62  may be formed from fiberglass-filled epoxy or other rigid printed circuit board material) or may be a flexible printed circuit (e.g., substrate  62  may be formed from a flexible layer of polyimide or a sheet of other flexible polymer). Components may be mounted on substrate  62  for handling proximity sensor signals. These components may include light source  64  and light detectors  66 . 
     Light source  64  may be a light-emitting diode such as an infrared light-emitting diode that emits light  70  that is out of the visible spectrum (e.g., to avoid distracting the user). Light detector  66  may be a photodetector based on a phototransistor or photodiode and may be sensitive to the wavelength of light  70 . In the absence of ear  50  or other external object such as external object  74  (e.g., a user&#39;s finger, the interior of a pocket, a table top, etc.), light  70  will travel into free space and will not be reflected towards detector  66 . As a result, the output of sensor  60  will be negative. In the presence of ear  50  or other external object  74 , however, reflected light  72  from external object  74  will be detected by detector  66 . The output of sensor  60  in this situation will therefore be positive. Light  70  (and reflected light  72 ) may be visible light, infrared light, broad spectrum light, narrow spectrum light (e.g., light having a spectral width of less than 20 nm or less than 5 nm), may be ultraviolet light, or may be other suitable light. 
     Sensor  60  may be mounted behind a portion of housing wall  40 . In the illustrative configuration of  FIG. 4 , portions  40 D of housing wall  40  are different than portions  40 W of housing wall  40 . Portions  40 D may absorb light  70  and may therefore reduce the signal-to-noise ratio of reflected signal  72 . To enhance the signal-to-noise ratio of proximity sensor  60 , infrared-transparent materials may be used in forming windows in housing  40 . For example, portions  40 W may be infrared-transparent materials (e.g., plastic, glass, etc.), may be portions of housing  40  that include microperforations to enhance infrared light transmission (e.g., laser-drilled openings with diameters of less than 75 microns, more than 50 microns, less than 150 microns, or other suitable sizes), or may be other material or structures for enhancing the transmission of light  70  and the transmission of reflected light  72 . 
     Some of light  70  may scatter when emitted by light source  64 , so an optional light blocking structure such as structure  68  may be incorporated into sensor  60 , if desired. Structure  68  may be formed from opaque plastic, metal, or other opaque materials. Structure  68  may be formed as an integral portion of housing  40 , may be a molded plastic member on substrate  62 , may be a member that is attached to substrate  62  using adhesive or other suitable mounting arrangements, or may be any other light blocking structure. Clear polymer or other material may be interposed between light source  64  and housing  40  and may be interposed between housing  40  and light detector  66 . The illustrative configuration of  FIG. 5 , which does not include any polymer or other material between the circuitry of sensor  60  and the inner surface of housing  40 , is shown as an example. 
       FIG. 6  is a cross-sectional side view of housing  40  and sensor  60  in an illustrative configuration in which a portion of housing  40  has been locally thinned to enhance light transmission for sensor  60 . Housing  40  has a thickness of D 2  in regions of ear bud  24  that are not aligned with sensor  60 . In portions of housing  40  that are aligned with sensor  60 , housing  40  is locally thinned and has a thickness D 1  that is less than D 2 . The value of D 2  may be 450 microns, more than 300 microns, more than 700 microns, less than 2 mm, or other suitable thickness. The value of D 1  may be 150 microns, more than 100 microns, less than 400 microns, or other suitable thickness). Illustrative polymer  76  (e.g., infrared-transparent polymer) or other structures may be placed between substrate  62  and the inner surface of thinned portion  40 T of housing  40  to help secure sensor  60  to ear bud  24  or other mounting techniques may be used. 
     Some of light  70  may be scattered into detector  66  by particles or other substances in housing  40 . Calibration operations may be performed during manufacturing or during use of ear bud  24  by a user to remove this source of noise from the proximity detector signal produced by sensor  60 . Illustrative steps involved in the calibration and use of proximity sensor data in ear buds  24  is shown in  FIG. 7 . During calibration operations (step  80 ), the amount of light  70  that is being scattered back towards detector  66  by housing  40  rather than being reflected back towards detector  66  by an external object can be ascertained. In particular, the amount of light  70  that is scattered rather than being transmitted may be measured at step  82 . For example, light source  64  may be modulated using a square wave or other suitable modulating signal in the absence of an external object. When light source  64  is turned on, detector  66  can measured the scattered light signal from housing  40 . When light source  64  is turned off, detector  66  will measure background signals. Using this technique, the amount of scattered light in sensor  60  (e.g., a fraction of the amount of transmitted light  70 ) may be determined and stored in control circuitry  30  for use as calibration data (see, e.g., step  84 ). 
     At step  86 , after the calibration operations of step  80  have been performed, ear bud  24  may be used by a user while data is gathered from proximity sensors S 1 , S 2 , S 3 , and S 4  and other sensors and circuitry in ear buds  24 . The user may store ear buds  24  in a protective charging case (e.g., a case having a connector that mates with a corresponding connector on stem  40 - 2  or other portion of ear bud  24  to facilitate battery recharging operations), may store ear buds  24  in a pocket of an article of clothing or a bag, may allow ear buds  24  to rest on a surface such as a table top, may pick up and hold ear buds  24  by body  40 - 1  and/or stem  40 - 2 , may insert ear buds  24  into ears  50 , and may remove ear buds  24  from ears  50 . 
     In each of these different possible usage scenarios, there is a potential for a different set of sensors to be blocked and a potential for a corresponding different set of sensors to be unblocked. The amounts of time that the sensors are blocked and unblocked will also generally vary in different scenarios. 
     Sensors may be blocked by ears  50 , by a user&#39;s fingers, by a portion of a pocket of a case or article of clothing, by a table surface of other resting surface, etc. For example, if sensors S 1  and S 2  are positive and sensors S 3  and S 4  are negative, ear buds  24  and device  10  can conclude that ear buds  24  have been inserted into ears  50  (i.e., sensors S 1  and S 2  are now resting adjacent to ear  50  and sensors S 3  and S 4  are uncovered because the user&#39;s fingers have released the stems of ear buds  24 ). If sensors S 1 , S 2 , S 3 , and S 4  are all negative (as another example), it can be concluded that ear buds  24  are in an enclosed area such as the interior of a pocket. 
     Accelerometer data from accelerometer  38  and/or other information (e.g., information from microphone  36 ) may be used to help accurately identify usage scenarios. As an example, if accelerometer  38  indicates that ear buds  24  are not moving, it can be concluded that ear buds  24  are resting on a table or other non-moving surface. If accelerometer  38  indicates that ear buds  24  are moving, it can be assumed that ear buds  24  are not resting on a table. Clock data (e.g., time information, date information, etc.) may be used in conjunction with sensor data, communications status data (e.g., whether an incoming cellular telephone is being received by device  10 ), and other information to determine which actions should be taken by ear buds  24  and device  10 . 
     At step  88 , ear buds  24  and/or device  10  of  FIG. 1  may take suitable action based on the detected state of ear buds  24 . For example, if it is determined that a user has just placed one of ear buds  24  into ear  50  in response to an incoming cellular telephone call to device  10 , audio playback may be transferred from device  10  to that ear bud. A remote wireless link (e. g., a cellular telephone link with a wireless base station in a cellular telephone network) may be handled by device  10 . A local wireless link (link  26  of  FIG. 1 ) may be established between device  10  and ear bud  24  to allow ear bud  24  to transmit and receive audio. If it is determined that ear buds  24  are located in the pocket of a user when an incoming call is received on device  10 , the incoming call can be routed to the speaker and microphone of device  10 . 
     In yet another scenario, a user may be using ear bud  24  in ear  50  to handle a cellular telephone call. A local wireless link (link  26 ) between ear bud  24  and device  10  may be used to transmit microphone and speaker audio signals between device  10  and ear bud  24 . Device  10  may maintain a cellular telephone link with remote network equipment. If a user removes ear bud  24  from ear  50  during the telephone call, the microphone and speaker of device  10  can be switched into use so that the telephone call can be sustained even though the user is no longer using ear bud  24 . 
     In some situations, the output of sensor S 1  may be positive while sensors S 3  and S 4  are negative, indicating that ear bud  24  is in ear  50 . During media playback, audio may be streamed from device  10  to ear bud  24  and presented to the user with the speaker in ear bud  24 . Sensors S 3  and S 4  may be used as touch buttons. A user can momentarily block one or both of these sensors to advance a track, to pause a track that is currently playing, or to otherwise control media playback. As this example demonstrates, temporarily unused proximity sensors can serve as input devices. 
     To discriminate between different usage states, control circuitry  28  and/or control circuitry  16  may analyze sensor data from each of the proximity sensors in ear buds  24  and/or the sensors and other circuitry of ear buds  24  and device  10 . An illustrative state diagram showing the operation of the system of  FIG. 1  in different states is shown in  FIG. 8 . Control circuitry  28  and/or control circuitry  16  may determine the current operating state of the  FIG. 1  system (e.g., ear buds  24  and/or device  10 ) by analyzing the output of sensors S 1 , S 2 , S 3 , and S 4  and, if desired, additional sensors and sources of operational state information in ear buds  24  and device  10 . 
     In state  96 , ear bud  24  is not in ear  50 . While ear bud  24  is out of the user&#39;s ear, the status of sensors S 1 , S 2 , S 3 , and S 4  may be monitored. So long as S 1  and S 2  are not positive while S 3  and S 4  are negative, it can be concluded that ear bud  24  is remaining out of the user&#39;s ear (i.e., in state  96 ). Monitoring of S 1 , S 2 , S 3 , and S 4  may therefore continue. 
     In response to detecting a positive output from sensors S 1  and S 2  and a negative output from sensors S 3  and S 4 , it can be tentatively concluded that ear bud  24  has been placed in ear  50  in a configuration of the type shown in  FIG. 3  and that the user has released stem  40 - 2 . Operations may therefore transition to state  92  (a state representing the transition of ear bud  24  into ear  50 ), as indicated by line  110 . During state  92 , the status of sensors S 1 , S 2 , S 3 , and S 4  can be monitored to determine whether the positive state of sensors S 1  and S 2  and the negative state of sensors S 3  and S 4  will be sustained for a threshold amount of time (time T 2 ). The value of T 2  may be 0.5 seconds, more than 0.3 seconds, less than 1 second, or other suitable length of time. If any of the outputs of sensors S 1 , S 2 , S 3 , and S 4  changes during state  92 , it can be concluded that ear bud  24  is not in ear  50  and operations may transition back to state  96 , as indicated by line  112 . 
     If sensors S 1  and S 2  remain positive and sensors S 3  and S 4  remain negative for time T 2 , it can be concluded that ear bud  24  is in ear  50  and operations can transition to state  90 , as indicated by line  102 . During the monitoring operations of state  90 , the status of sensor S 1  (the tragus sensor) or sensor S 2  (the concha sensor) can be monitored and the status of sensors S 3  and S 4  can be ignored. After ear bud  24  has been placed in ear  50 , a user may move in a way that causes sensors S 3  and S 4  to produce a positive output (e.g., due to the presence of hair, a hat, or other obstructions). The output of sensors S 3  and S 4  is therefore not necessarily representative of the status of ear bud  24  during use of ear bud  24  and can be ignored when monitoring the sensors to determine the current operating state of ear bud  24 . Sensors such as sensors S 1  and S 2  are immediately adjacent to the user&#39;s ear and are therefore more representative of whether or not ear bud  24  is in the user&#39;s ear. With one illustrative configuration, sensor S 1  may be monitored and sensor S 2  may be ignored along with sensors S 3  and S 4  (e.g., because sensor S 1  is more representative of whether or not ear bud  24  is present in ear  50 ). Other sensor monitoring schemes may be used during state  90 , if desired (e.g., schemes in which S 2  is monitored but not S 1 , schemes in which S 1  and S 2  are monitored, schemes in which S 1  and S 2  are both monitored but are weighted unequally and/or are filtered using different time-dependent filters, etc.). The arrangement of state  90  of  FIG. 8  is an example. 
     In a scenario in which sensor S 1  is being monitored during state  90  while the outputs of sensors S 2 , S 3 , and S 4  are being ignored, any transition in the state of the output of sensor S 1  from positive to negative indicates that ear bud  24  is potentially being removed from ear  50 . Operations may therefore transition to state  98 , as indicated by line  104 . 
     During the operations of state  98 , ear bud  24  is believed to be transitioning out of ear  50 . In response to determining during the operations of step  98  that the S 1  sensor output has returned to positive before reaching time T 1 , operations may transition back to state  90 , as indicated by line  106  (i.e., it can be concluded that ear bud  24  is still in ear  50 ). The value of T 1  may be 0.25 seconds, less than 1 second, more than 0.1 second, or other suitable amount. The value of T 1  may be less than the value of T 2  or may be more than the value of T 2 . If the output of sensor S 1  remains negative for a predetermined threshold amount of time (e.g., more than time T 1 ), it can be concluded that ear bud  24  is out of ear  50  and operations can transition to state  96 . 
     Information from the monitoring operations and analysis operations of  FIG. 8  can be used to determine which actions to take during the operations of step  88  ( FIG. 7 ). If desired, other sensor data (e.g., accelerometer output), cellular telephone call status information (incoming call present, current call active, etc.), and/or other communications status information and operating status information may be used in determining which actions to take. The user of proximity sensor output information from sensors S 1 , S 2 , S 3 , and S 4  is merely illustrative. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20181022
Publication Date: 20210831
Grant Date: 20210831
Priority Date: 20150928
Inventors: SAULSBURY, ASHLEY N.
MCQUEEN, TRAVIS J.
Assignee: APPLE INC
CPC Classifications: [{"code": "A61B5/6803", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1016", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01V8/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1041", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1041", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R2420/07", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/6817", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R2420/07", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/1041", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/6803", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/6817", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R2420/07", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/1041", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/6803", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S7/481", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1016", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/1016", "inventive": true, "first": true, "tree": "[]"}, {"code": "A61B5/6817", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1016", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R2420/07", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/6817", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1016", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/1041", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/6803", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R2420/07", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 58407665