PATENT DOCUMENT

Publication Number: US-8192234-B2
Application Number: US-79364410-A
Country: US
Kind Code: B2

Title: Audio connector control system

Abstract:
An electronic device such as a portable music player, cellular telephone, or computer may be provided with an audio jack system that allows audio plug position measurements to be made. Sensors such as optical sensors, magnetic sensors, mechanical sensors, electrical sensors, resistive sensors, and capacitive sensors may be used in monitoring the position and movement of the audio plug relative to the audio jack. A user may rotate the audio plug to control operations such as media playback operations, menu selection operations, and other activities in the electronic device. The audio jack may include flexible structures that allow the audio plug to be tilted relative to the audio jack. Capacitive sensors or other sensors may be used to monitor audio plug tilt and axial audio plug movement. This allows the audio plug to serve as a joystick for the electronic device.

Claims:
1. An electronic device that is configured to operate with an accessory that has an audio plug, comprising:
 an audio jack; and 
 a magnetic sensor that detects rotation of the audio plug when the audio plug is in the audio jack, wherein the magnetic sensor comprises an anisotropic magnetoresistance sensor. 
 
     
     
       2. The electronic device defined in  claim 1  further comprising capacitive sensor electrodes that monitor the audio plug. 
     
     
       3. The electronic device defined in  claim 2  wherein the audio jack comprises flexible members that accommodate tilting movement of the audio plug relative to the electronic device. 
     
     
       4. The electronic device defined in  claim 3  further comprising:
 storage and processing circuitry that is configured to process capacitive sensor signals from the capacitive sensor electrodes to produce joystick data corresponding to the tilting movement of the audio plug. 
 
     
     
       5. The electronic device defined in  claim 1  further comprising flexible members that sense tilting movement of the audio plug relative to the audio jack. 
     
     
       6. The electronic device defined in  claim 1  wherein the audio jack includes a tip contact, a sleeve contact, and at least one ring contact. 
     
     
       7. The electronic device defined in  claim 1  wherein the audio jack has a longitudinal axis, the electronic device comprising capacitive electrodes that measure tilting movement of the audio plug relative to the longitudinal axis and that measure axial movement of the audio plug along the longitudinal axis. 
     
     
       8. The electronic device defined in  claim 7  further comprising sensors with flexible members in the audio jack. 
     
     
       9. An electronic device that is adapted to operate with an accessory that has an audio plug, comprising:
 an audio jack; and 
 capacitive sensors that monitor the audio plug when the audio plug is inserted in the audio jack. 
 
     
     
       10. The electronic device defined in  claim 9  wherein the capacitive sensors comprise an array of capacitor electrodes distributed at different positions around the audio plug. 
     
     
       11. The electronic device defined in  claim 10  further comprising a magnetic sensor that detects rotation of the audio plug relative to the audio jack. 
     
     
       12. The electronic device defined in  claim 9  further comprising:
 at least one flexible structure in the audio jack that allows the audio plug to tilt relative to the electronic device, wherein the capacitive sensors measure the tilt. 
 
     
     
       13. The electronic device defined in  claim 12  wherein the flexible structure comprises part of a resistance sensor. 
     
     
       14. An audio jack that is adapted to receive a magnetless audio plug, comprising:
 a tip contact; 
 at least one ring contact; 
 a sleeve contact; and 
 a magnetic sensor that detects rotational motion of the magnetless audio plug relative to the audio jack. 
 
     
     
       15. The audio jack defined in  claim 14  further comprising capacitive sensors that make capacitance measurements on the audio plug. 
     
     
       16. The audio jack defined in  claim 14  wherein the audio jack has a longitudinal axis, the audio jack further comprising:
 at least one flexible structure that allows the magnetless audio plug to tilt relative to the longitudinal axis. 
 
     
     
       17. The audio jack defined in  claim 16  wherein the flexible structure comprises part of a resistance sensor. 
     
     
       18. The audio jack defined in  claim 16  further comprising a sensor that detects axial movement of the magnetless audio plug along the longitudinal axis. 
     
     
       19. The audio jack defined in  claim 14  wherein the magnetic sensor comprises an anisotropic magnetoresistance sensor.

Description:
BACKGROUND 
     This relates to control systems, and, more particularly, to control systems that allow a user to issue commands for an electronic device by manipulating an audio connector. 
     Electronic devices such as media players, cellular telephones, computers, and other electronic equipment often contain audio jacks. Accessories such as headsets have mating plugs. A user who desires to use a headset with an electronic device may connect the headset to the electronic device by inserting the headset plug into the mating audio jack on the electronic device. Miniature size (3.5 mm) phone jacks and plugs are commonly used in electronic devices such as notebook computers and media players, because audio connectors such as these are relatively compact. 
     Particularly in compact electronic devices, there is a desire to minimize the amount of space that is consumed by user interface equipment. For example, it may desirable to eliminate all but the most significant buttons and input-output ports in a compact media player. Sometimes this means eliminating buttons and controls that might be helpful to a user, but that simply will not fit within the allotted volume for the device. A designer of an electronic device is therefore often faced with competing concerns. Useful buttons and other user interface components should be included in a device to provide the user of the device with ways in which to control device operation. At the same time, space should be conserved by minimizing the number of controls that are included. Significant design compromises must often be made. 
     It would therefore be desirable to be able to provide improved ways in which to control an electronic device such as control schemes that have a minimized impact on device size. 
     SUMMARY 
     An electronic device such as a portable music player, cellular telephone, or computer may be provided with an audio jack that receives an audio plug. Audio plugs may be used in headphones and other audio accessories. When an audio plug is inserted into an audio jack, contacts in the audio plug mate with contacts in the audio jack. This allows electrical signals such as power and audio signals to be passed between the accessory and electronic device to which the accessory is attached. 
     User input for controlling an electronic device may be gathered using buttons and other user input interface devices. Audio connectors such as jacks and plugs may also be provided with sensors that allow the audio connectors to serve as a type of user input device. For example, rotation sensors may be used to detect rotation of an audio plug within a jack. Sensors may also be used to detect axial movement of an audio plug along the longitudinal axis of the audio jack or tilting movement of the audio plug relative to the jack. By processing data from these audio connector sensors, user manipulation of the position of the audio plug relative to the audio jack can serve as user input. 
     Sensors such as optical sensors, magnetic sensors, mechanical sensors, electrical sensors, resistive sensors, and capacitive sensors may be used in monitoring the position and movement of the audio plug relative to the audio jack. A user may rotate the audio plug to control operations such as media playback operations, menu selection operations, and other activities in the electronic device. The audio jack may include flexible structures that allow the audio plug to be tilted relative to the audio jack. The flexible structures can form part of a resistive sensor or other position sensor. Capacitive sensors or other sensors may be used to monitor audio plug tilt and axial audio plug movement. Sensors such that detect tilt and axial movement can be used to allow the audio plug to serve as a joystick for the electronic device. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of an illustrative electronic device that may be controlled using an audio connector control system in accordance with an embodiment of the present invention. 
         FIG. 1B  is a perspective view of another illustrative electronic device that may be controlled using an audio connector control system in accordance with an embodiment of the present invention. 
         FIG. 2  is diagram showing how an electronic device may mate with a corresponding audio accessory using a pair of matching audio connectors in accordance with an embodiment of the present invention. 
         FIG. 3  is a perspective view of a portion of an electronic device and audio accessory showing how sensors may be used in monitoring the position of the audio accessory plug relative to the electronic device jack in accordance with an embodiment of the present invention. 
         FIG. 4  is a cross-sectional side view of an illustrative optical sensor system that may be used in determining the position of an audio plug in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an illustrative magnetic sensor system that may be used in determining the position of an audio plug in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of an illustrative mechanical sensor system that may be used in determining the position of an audio plug in accordance with an embodiment of the present invention. 
         FIG. 7  is a cross-sectional side view of an illustrative electrical contact sensor system that may be used in determining the position of an audio plug in accordance with an embodiment of the present invention. 
         FIG. 8  is a cross-sectional side view of an illustrative capacitive sensor system that may be used in determining the position of an audio plug in accordance with an embodiment of the present invention. 
         FIG. 9  is a cross-sectional side view of an illustrative audio plug that has been inserted into a corresponding audio jack in an electronic device with sensors for measuring the position of the audio plug in accordance with an embodiment of the present invention. 
         FIG. 10  is a top view of an illustrative audio plug and associated capacitive sensors for measuring off-axis tilt of the audio plug in accordance with an embodiment of the present invention. 
         FIG. 11  is a cross-sectional side view of an illustrative audio plug and associated capacitive sensors in a position in which the audio plug is oriented along the longitudinal axis of an audio jack in accordance with an embodiment of the present invention. 
         FIG. 12  is a cross-sectional side view of the illustrative audio plug and associated capacitive sensors of  FIG. 11  in a position in which the audio plug has been tilted with respect to the longitudinal axis of the audio jack in accordance with an embodiment of the present invention. 
         FIG. 13  is a cross-sectional side view of an audio plug inserted into a waterproofed audio jack in accordance with an embodiment of the present invention. 
         FIG. 14  is a flow chart of illustrative steps involved in operating equipment that includes an audio connector control system in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     This relates to control systems such as control systems for electronic devices. The electronic devices in which the control systems are used may be computers, media players, handheld devices, cellular telephones, laptop computers, tablet computers, other portable electronic devices, or other electronic equipment. Arrangements in which the control systems are used in connection with portable electronic devices such as media players and cellular telephones are sometimes described herein as an example. This is, however, merely illustrative. The control systems may be used in connection with any electronic equipment. 
     The control systems may allow a user to control an electronic device by manipulating the position of an audio plug within an audio jack in the electronic device. The audio plug may be associated with an accessory such as a headset. Movement of the audio plug relative to the electronic device may be detected using sensors. By detecting the position of the audio plug relative to the electronic device, some or all desired user interface operations may be implemented without using external buttons and other controls. 
     An illustrative electronic device that may include an audio connector control system is shown in  FIG. 1A . As shown in  FIG. 1A , device  10  includes housing  12 . Housing  12 , which is sometimes referred to as a case, may be formed of any suitable materials including, plastic, glass, ceramics, composites, metal, other suitable materials, or a combination of these materials. Housing  12  may be formed using a unibody construction technique in which most or all of housing  12  is formed from a single piece of material. Housing  12  may, for example, be formed from a piece of machined or cast aluminum or stainless steel. Housing  12  may also be formed from multiple smaller housing structures (i.e., frame structures, sidewalls, peripheral bands, bezels, etc.). Unibody housing structures and housing structures formed from multiple pieces may be formed from metal, plastic, composites, or other suitable materials. 
     Device  10  may have a display such as display  14 . Display  14  may be a touch screen that incorporates capacitive touch electrodes or other touch sensitive elements. Display  14  may include image pixels formed form light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electronic ink elements, liquid crystal display (LCD) components, or other suitable image pixel structures. A cover glass member may cover the surface of display  14 . Buttons such as button  16  and speaker ports such as speaker port  18  may be formed in openings in the cover glass. Buttons and ports may also be formed in housing  12 . For example, button  20  may be formed in housing  12  and audio port (audio jack)  22  may be formed in housing  12 . 
       FIG. 1B  is a diagram of another illustrative electronic device that may use a control system based on an audio connector. In the example of  FIG. 1B , electronic device  10  has audio jack  22  mounted in housing  12 , but has few or no other additional buttons or user interface components. The illustrative device of  FIG. 1B  does not have a display, but a display may be provided in a device of the type shown in  FIG. 1B  if desired. 
     In compact devices such as device  10  of  FIG. 1A  and device  10  of  FIG. 1B , it may be desirable to minimize the amount of space consumed by buttons and other user interface devices. Because audio connector  22  is necessarily present in devices such as these (to support attachment of audio devices), there is little or no extra space requirement involved in using audio connector  22  as part of a user interface for controlling device  10 . 
     In a typical arrangement, a user inserts an audio plug into audio jack  22 . The audio plug may be associated with an accessory such as a headset. Once the audio plug has been inserted into audio jack  22 , a user of device  10  may manipulate the position of the audio plug to control device  10 . 
     An illustrative arrangement of this type is shown in  FIG. 2 . As shown in  FIG. 2 , electronic device  10  may include an audio connector such as audio jack  22 . Audio jack  22  may be, for example, a ⅛″ jack. Accessory  30  may have a corresponding audio plug (i.e., a ⅛″ plug) such as plug  38 . When a user desires to connect accessory  30  to device  10 , the user may insert plug  38  into jack  22 . 
     In the  FIG. 2  example, accessory  30  is a headset having speakers  32 , microphone  34 , and cable  36 . Cable  36  and the other circuitry of accessory  30  may be coupled to device  10  when plug  38  is inserted into jack  22 . Accessory  30  may, in general, be any device that has an associated audio connector (e.g., a set of speakers, an adapter, an extension cable, a peer device, an audio-video receiver, a television, or other consumer electronics equipment, a computer monitor, etc.). Popular device accessories include stereo headsets with microphones (e.g., for use with cellular telephones) and stereo headsets without microphones (e.g., for use with media players). 
     Electronic device  10  may have storage and processing circuitry  24 . Storage and processing circuitry  24  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 storage and processing circuitry  24  may be used to process sensor data and control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, applications specific integrated circuits, etc. 
     Storage and processing circuitry  24  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, storage and processing circuitry  24  may be used in implementing communications protocols. 
     Input-output circuitry  26  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 such as accessory  30 . Input-output devices  26  may include touch screens, displays without touch capabilities, status indicator lights, buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, speakers, input-output ports, etc. A user can control the operation of device  10  by supplying commands through such user input devices (if available). A user can also control the operation of device  10  by manipulating the position of plug  38  within jack  22 . 
     Sensors may be used in determining the position of audio plug  38  relative to audio jack  22  (and therefore the position of audio plug  38  relative to device  10 ). The sensors that are used in determining the position of plug  38  may be included in device  10  (see, e.g., sensor  28 ). The sensors that are used in determining the position of plug  38  relative to jack  22  may also be located in audio plug  38  (e.g., in shaft  46  or on jacket  50 , as shown by illustrative sensor  48  in  FIG. 2 ). Signals from these sensors may be processed using processing circuitry in accessory  30  and/or processing circuitry in device  10  (e.g., storage and processing circuitry  24 ). 
     The position of audio plug  38  may be monitored in various dimensions. For example, the rotational orientation of plug  38  may be monitored. Jack  22  may have a longitudinal axis such as axis  40 . When audio plug  38  is inserted into jack  22 , audio plug  38  may be rotated in clockwise direction  42  and counterclockwise direction  44  relative to jack  22  and housing  12 . Using sensors, the amount by which plug  38  has been rotated about rotational axis  40  can be determined. 
     If desired, jack  22  may be provided with flexible structures that allow plug  38  to tilt relative to axis  40 . These flexible structures may include elastomeric structures, springs, hinges, pivots, or other structures. Plug  38  may have a longitudinal axis. When plug  38  is tilted, the longitudinal axis of plug  38  may tilt relative to longitudinal axis  40  of audio jack  22 , as indicated by tilt angle A between axis  52  and axis  40  in  FIG. 2 . Sensors such as sensors  48  and  28  may be used in determining the value of angle A and the direction of tilt (i.e., the lateral direction in which the tip of plug  38  has been displaced relative to axis  40 ). Sensor signals from one or more sensors may be processed when determining the rotational orientation and tilt of plug  38 . 
     Audio connectors such as plug  38  and jack  22  may contain any suitable number of contacts. Audio connectors that are commonly used for handling stereo audio have a tip connector, a ring connector, and a sleeve connector and are sometimes referred to as three-contact connectors or TRS connectors. In devices such as cellular telephones, it is often necessary to convey microphone signals from the headset to the cellular telephone. In arrangements in which it is desired to handle both stereo audio signals and microphone signals (e.g., in accessories such as accessory  30  of  FIG. 2 ), an audio connector typically contains an additional ring terminal. Audio connectors such as these have a tip, two rings, and a sleeve and are therefore sometimes referred to as four-contact connectors or TRRS connectors. 
     A perspective view of a portion of device  10  in the vicinity of audio jack  22  is shown in  FIG. 10 . As shown in  FIG. 10 , audio jack  22  may contain electrical contacts T (tip), R 1  (ring  1 ), R 2  (ring  2 ), and S (sleeve). If desired, jack  22  may contain fewer contacts (e.g., two or three) or more contacts (e.g., five contacts or more than five contacts). Arrangements in which audio jack  22  has four contacts (i.e., four-contact audio connector arrangements such as the arrangement of  FIG. 3 ) are sometimes described herein as an example. 
     When audio plug  38  is inserted into audio jack  22  along longitudinal axis  40 , the contacts of audio jack  22  mate with corresponding audio contacts T, R 1 , R 2 , and S on shaft  46  of audio plug  38 . One or more sensors in device  10  such as sensor(s)  28  may be used in monitoring the position of audio plug  38 . One or more sensors (or sensor-related structures) on audio plug  38  may also (or alternatively) be used in monitoring the position of audio plug  38 . Sensor structures in audio plug  38  may be located on jacket member (see, e.g., sensor  48 A), on or under one of the contacts in plug  38  (see, e.g., sensor  48 B), or within one or more of insulating rings  54  separating respective contacts in plug (see, e.g., sensor  48 C). Contacts T, R 1 , R 2 , and S in jack  22  and plug  38  may be formed form conductive materials such as metal (e.g., stainless steel). Insulating rings  54  may be formed from a dielectric such as plastic, ceramic, glass, etc. 
     The position of audio plug  38  may be monitored using any suitable type of position sensor. Storage and processing circuitry  24  may be used in gathering and processing sensor signals. Storage and processing circuitry  24  may, in conjunction with input-output devices  26 , take appropriate actions in response to measured positions. Examples of actions that may be taken in response to motion of audio plug  38  include changes to media playback volume, changes in media playback direction (e.g., forward or reverse), changes in channel (e.g., when tuning wireless channels), track changes (e.g., to advance to the next track in an album or to return to a previous track), or other suitable media playback commands. Other actions that can be taken include turning functions on an off, adjusting the levels of device settings, making menu selections, choosing which applications to launch, etc. 
       FIG. 4  shows how the position of audio plug  38  may be monitored using an optical sensor system. In the arrangement of  FIG. 4 , light source  56  produces light  58 . Light source  56  may be a laser or light-emitting diode. Light  58  may be directed onto a textured portion of audio plug  38 , such as one or more of insulating rings  54  ( FIG. 3 ). As audio plug  38  rotates about longitudinal axis  40 , the pattern of reflected light from plug  38  (shown as light  62  in  FIG. 4 ) may be detected by optical sensor  64 . The signal from optical sensor  64  may be converted into position information by storage and processing circuitry  24 . 
     As shown in the illustrative arrangement of  FIG. 5 , the position of audio plug  38  may be monitored by using a magnetic sensor such as magnetic sensor  66  to detect magnetic fields  68  that are associated with audio plug  38 . Signals from magnetic sensor  66  may be gathered and processed by storage and processing circuitry  24 . Sensor  66  may be an anisotropic magnetoresistance (AMR) sensor of the type that is sometimes referred to as a compass in applications where the detected magnetic field is the earth&#39;s magnetic field. If desired, other magnetic sensor technologies may be used to implement sensor  66  (e.g., Hall effect sensors). 
     The magnetic field that is detected by sensor  66  may be produced by one or more permanent magnets such as magnet  70  that are embedded within audio plug  38 . To ensure backwards compatibility with audio plugs that do not include magnets (magnetless audio plugs), it may be desirable to use sensor  66  to detect parasitic magnetic fields of the type that are sometimes associated with trace magnetism in audio plug  38  or magnetic fields produced when current runs through audio plug  38 . Sensitive electronic compasses such as anisotropic magnetoresistance sensors and other magnetic sensors can detect small magnetic fields and are able to detect the rotation of audio plug  38  about axis  40  even in the absence of magnet  70 . The ability to measure the rotational orientation and movement of audio plug  38  magnetically without requiring that audio plug  38  include special magnets, electrical contacts, mechanical registration marks, or other special structures may be advantageous in environments in which compatibility with legacy equipment is desired. Magnetic sensors can, for example, measure rotational motion in magnetless audio plugs such as conventional TRRS plugs. One or more magnetic sensors (e.g., electric compasses) may be placed in the vicinity of audio plug  38  to measure magnetic fields from the audio plug if desired. 
       FIG. 6  shows how the position of audio plug  38  may be monitored using a mechanical position sensor. Mechanical sensor  72  may include a rotating wheel such as wheel  76 . Wheel  76  may be supported by a shaft such as shaft  74 . The outer surface of wheel  76  may contact the outer surface of audio plug  38 . As audio plug  38  rotates about axis  40 , wheel  76  rotates proportionally around shaft  74 . Encoder  78  detects the position of shaft  74  and generates a corresponding output. Storage and processing circuitry  24  may receive and process the output from encoder  78  to determine the position of audio plug  38 . 
     In the illustrative configuration of  FIG. 7 , audio plug  38  has electrical contacts  82 . Contacts  82  may be distributed at different respective angular positions around the circumference of audio plug  38 . When audio plug  38  is rotated, contacts  82  come into contact with springs  82  or other electrical contacts. Springs  82  may be mounted at fixed positions within audio jack  22 , so movement of audio plug  38  can be detected by monitoring the way in which contacts  80  form open and closed circuit paths with springs  82 . 
     If desired, the position of audio plug  38  may be monitored using capacitive sensors. An illustrative capacitive sensor system is shown in  FIG. 8 . As shown in  FIG. 8 , one or more electrodes such as electrodes  86  may be mounted at fixed positions within audio jack  22 . Audio plug  38  may include one or more electrodes  84  at different respective angular positions around the periphery of audio plug  38 . When an electrode on plug  38  aligns with an electrode on jack  22 , measured capacitance will generally peak. When the jack and plug electrodes are not in alignment, measured capacitance will generally drop. Capacitance changes can be measured and processed to determine the rotational orientation of plug  38  about axis  40  using storage and processing circuitry  24 . 
     If desired, capacitance sensors and other sensors may be used in measuring tilt in audio plug  38 . An illustrative audio connector control system in which audio plug tilt can be monitored is shown in  FIG. 9 . In the example of  FIG. 9 , audio plug  38  has been inserted within audio jack  22 , so that tip contact T, ring contacts R 1  and R 2 , and sleeve contact S of plug  38  contact respective contacts T, R 1 , R 2 , and S in jack  22 . Insertion sensor  90  may be used to determine when audio plug  38  is present. 
     Capacitive electrodes  88  can be oriented around some or all of the periphery of audio plug  38 . There may be, for example, an array of three or four or more than four electrodes  88  that are arranged around plug  38  at respective angular positions. In a three electrode configuration, for example, a first electrode might be centered at an angular position of 0° about axis  40 , a second electrode might be centered at an angular position of 120° about axis  40 , and a third electrode might be centered at an angular position of 240° about axis  40 . Each electrode may monitor about 5-120° of the periphery of plug  38  in this type of configuration. 
     In the  FIG. 9  example, electrodes  88  have been placed adjacent to tip contact T of plug  38 . This is merely illustrative. Electrodes  88  may be placed adjacent to other conductive portions of shaft  46  if desired (see, for example, illustrative capacitive electrode  92 , which has been placed adjacent to ring contact R 2  in audio plug  38 ). 
     Optional magnetic sensor  66  or other sensors may be used to make measurements of the rotational orientation and movement of audio plug  38 . Because electrodes  88  are evenly spaced and surround all sides of audio plug  38 , electrodes  88  can be used to monitor tilt in audio plug  38  relative to audio jack longitudinal axis  40 . If, for example, audio plug  38  tilts so that tip T (or other suitable part of shaft  46 ) moves closer to a first of three electrodes in a three electrode setup while simultaneously moving farther from the second and third electrodes, the capacitance measured with the first electrode will generally rise, while the capacitance measured with the second and third electrodes will generally fall. Storage and processing circuitry  24  can measure the capacitances at each of the electrodes and can use interpolation to determine the direction in which audio plug  38  is tilting with respect to axis  40  and to determine the magnitude of the tilt. This allows audio plug  38  to be used as a joystick in controlling electronic device  10 . 
     Electrodes  88  that are configured as shown in  FIG. 9  can detect axial movement of audio plug  38  along axis  40 . When plug  38  is moved in inward direction  100 , all electrodes  88  will generally exhibit a capacitance increase. When plug  38  is moved outwards (i.e., away from jack  22  and device  10  in direction  102 ), all electrodes  88  will generally exhibit a capacitance decrease. Inward and outward axial movement of this type may be detected separately from tilt activity or may be measured simultaneously (e.g., if a user is both tilting audio plug  38  and pushing audio plug  38  inwardly at the same time). 
     Flexible structures in audio jack  22  may be used to allow audio plug  22  to tilt and optionally exhibit axial movement. These flexible structures may be incorporated into contacts S, R 1 , R 2 , and T (e.g., by using flexible spring structures), may be incorporated into jack  22  using other springs or flexible metal members, may be implemented using flexible polymers (e.g., flexible gaskets, flexible foam, etc.), or may be implemented using other flexible structures. 
     If desired, tilt and axial movement of audio plug  38  may be detected using other (non-capacitive) sensors (e.g., piezoelectric sensors, strain gauges based on resistive thin films or surface electrodes, mechanical sensors such as plungers with encoders or other mechanisms that measure position using an array of electrical contacts, resistive sensors, magnetic sensors, optical sensors, etc.). The arrangement of  FIG. 9  includes, as an example, resistive sensors  94 . There may be any suitable number of resistive sensors  94  (e.g., four sensors  94  arranged at equally distributed angular positions about axis  40  as an example). Each sensor  94  may include a compressible foam member  96  and a resistance (resistivity) sensor  98 . Resistance sensors  98  may measure the resistance of each compressible foam member  96  and may supply resistance data to storage and processing circuitry  24  or the resistance measurement functions of sensors  94  may be incorporated into storage and processing circuitry  24 . 
     When audio plug  38  tilts in a particular direction, the foam sensor member  96  that is located along the direction of tilt will tend to be compressed. This will generally decrease its resistance without increasing the resistance of the sensor members elsewhere in the array. Axial movement will result in resistance increases from all sensors  94  in the array at the same time. By processing sensor signals from an array of circumferentially distributed sensors  94 , tilt and axial movement can be detected. 
     Resistive sensors such as sensors  94  can be used in conjunction with capacitive sensors  88  or may be used in place of capacitive sensors. If desired, members  96  may be formed from non-conductive foam or other compressible materials that do not form part of a sensor (e.g., to serve as a flexible gasket that allows audio plug  38  to tilt and reciprocate axially within audio jack  22  without serving as a sensor component). In general, any suitable number of sensor technologies may be used simultaneously. For example, one, some, or all of the sensors described in connection with  FIGS. 4 ,  5 ,  6 ,  7 ,  8 , and  9  may be used in an audio connector position sensing system. 
       FIG. 10  shows how capacitive electrodes  88  may be arranged at evenly spaced angular locations around the inner periphery of audio jack  22  and the outer periphery of audio plug  38 . In the  FIG. 10  example, there are four capacitive electrodes. Electrode  88 A is located at an angular position of 0°, electrode  88 B is located at an angular position of 90°, electrode  88 C is located at an angular position of 180°, and electrode  88 D is located at an angular position of 270°. Storage and processing circuitry  24  can detect movement of audio plug  38  by measuring the capacitance of sensors  88 A,  88 B,  88 C, and  88 D. 
     Consider, as an example, movement (e.g., tilt) in audio plug  38  that causes plug  38  to move in direction  104 . In this situation, the capacitance signals that are gathered using electrodes  88 C and  88 D will increase and the capacitance signals that are gathered using electrodes  88 B and  88 A will decrease. If, as another example, audio plug  38  tilts so that shaft  46  moves in direction  106 , the sensor signal from electrode  88 A will increase, the sensor signal from electrode  88 C will decrease, and the sensor signals from electrodes  88 B and  88 D will tend to decrease (e.g., somewhat less than the decrease exhibit by electrode  88 C). By examining the pattern of signal changes from electrodes  88  and the magnitude of each of these signal changes, storage and processing circuitry  24  can determine in which direction audio plug  38  has been tilted and by how much audio plug  38  has been tilted. 
       FIG. 11  is a side view of audio plug  38  in a configuration in which audio plug  38  has been inserted into audio jack  22 . In  FIG. 11 , audio plug  38  is in an on-axis (untilted) orientation. In this configuration, compressible members  96  are both uncompressed (unflexed) and longitudinal axis  46  of audio plug  38  is aligned with longitudinal axis  40  of  FIG. 12 . 
     A user may tilt or otherwise manipulate audio plug  38  by grasping and moving cable  36  and jacket  50  of audio plug  38 . For example, the user may tilt audio plug  38  so that shaft  46  moves in direction  106 , as shown in  FIG. 12 . As described in connection with  FIG. 10 , storage and processing circuitry  24  may detect the resulting capacitance changes on electrodes  88  (and, if members  96  are being used as movement sensors, the resulting signal changes produced by members  96 ) and can determine the value of angle A (i.e., the amount by which audio plug longitudinal axis  46  has tilted with respect to audio jack longitudinal axis  40 ). Storage and processing circuitry  24  can also determine the angular direction of the tilt (i.e., direction  106 , which corresponds to an angle of 0° in the  FIG. 10  diagram). 
       FIG. 13  is a cross-sectional side view of audio plug  38  and audio jack  22  showing how audio jack  22  may be implemented using a waterproof (water-resistant) construction. As shown in  FIG. 13 , audio jack  22  may be provided with sidewalls  108  that are sealed against the environment, thereby preventing the intrusion of dust or moisture into the interior of device  10 . Audio jack contacts T, R 1 , R 2 , and S may protrude through sidewall structure  108 . Sidewall structure  108  may be sufficiently sealed around the audio jack contacts to prevent moisture from passing from the vicinity of plug  38  to the interior of device  10 . Structure  108  may, if desired, be formed from a dielectric such as plastic with a cylindrical opening to receive plug  38 . Sensor such as magnetic sensor  66  can be mounted in the interior of device  10 , on the protected side of structure  108  (as an example). 
     Illustrative steps involved in operating an electronic device with an audio-contact-based user interface are shown in  FIG. 14 . 
     At step  110 , sensor structures in device  10  and/or sensor structures in accessory  30  (i.e., in the vicinity of plug  38 ) may be used to detect user input. As described in connection with  FIGS. 4-9 , sensors that may be used to detect input include light sensors, magnetic sensors, mechanical sensors, electrical sensors, capacitive sensors, resistive sensors, other sensors, and combinations of these sensors. Rotational activity (angular position and/or angular movement), axial activity (axial position and/or axial movement), and tilting activity (off-axis positioning and/or off-axis movement) can be detected. Storage and processing circuitry  24  may analyze sensor data in real time to detect and quantify user input that involves manipulation of audio plug. 
     If tilting activity (off-axis orientation activity) is detected, appropriate action may be taken at step  112 . For example, storage and processing circuitry  24  can interpret a tilt in audio plug  38  as a command to adjust the position of a pointer on a display, as a command to move through menu items, as a command to control media playback, etc. Tilt activity may, if desired by interpreted as 2-dimensional commands (i.e., X-Y joystick data). Tilt monitoring and processing may therefore be used to implement joystick functionality in device  10 . 
     If axial activity is detected, appropriate actions may be taken at step  116 . Examples of actions that can be taken in response to detecting that audio plug  38  has been moved axially along axis  40  include toggling the power state of device  10 , and controlling media playback (e.g., pausing or starting playback, making menu selections, etc.). 
     If clockwise rotational activity is detected, appropriate steps may be taken at step  114 . If counterclockwise rotational activity is detected, appropriate actions may be taken at step  118 . Examples of actions that may be taken in response to rotational activity include increasing and decreasing media playback volume, making menu selections, controlling media playback, etc. 
     After detecting activity and taking appropriate action, processing can return to step  110 , as indicated by line  120 . 
     During sensor signal processing, audio jack position, audio jack motion, or both position and motion data can be observed and used in determining what actions to take in device  10 . Acceleration data and other secondary data can be extracted from position and motion signals and can also be used in determining how to take actions in device  10 . Some sensors are well suited to gathering position data (e.g., mechanical sensors such as the roller-wheel sensor of  FIG. 6 ). Other sensors are well suited to gathering motion information. For example, when an magnetic sensor is used to detect rotational activity of a legacy-type magnetless audio plug that does not include a magnet or other registration features, the sensor may be particularly well suited to detecting rotational motion, rather than determining the absolute position of plug  38 . Depending on the capabilities of the sensors that are used, some configurations may be best suited to taking actions based on the absolute position of plug  38  and other configurations may be best suited to taking actions based on the speed (and, if desired, acceleration) of plug  38  (e.g., how fast a user is rotating plug  38  in the clockwise or counterclockwise direction). Combinations of these approaches may be used. For example, a magnetic sensor may be used to detect the speed with which plug  38  is rotated, a capacitive sensor array may be used to detect the absolute X-Y position of shaft  46 , and the capacitive sensor or a mechanical switch may be used to determine the axial position of plug  38 . 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20100603
Publication Date: 20120605
Grant Date: 20120605
Priority Date: 20100603
Inventors: WITTENBERG MICHAEL B.
MYERS SCOTT
PATEL PARIN
Assignee: APPLE INC
CPC Classifications: [{"code": "G01D21/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R24/58", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0362", "inventive": true, "first": false, "tree": "[]"}, {"code": "G05G1/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01D21/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "G05G1/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0362", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 45064800