Abstract:
This is directed to systems and methods for detecting the insertion of a plug in a device port without physically contacting the plug. For example, systems and methods are provided for detecting the insertion of an audio plug into an audio jack without using physical contacts placed in the periphery of the audio jack. In some embodiments, an electrically conductive element (e.g., a circuit board trace) can be provided on a surface of the port or within the port wall. When a metallic or conductive plug is inserted into the port, the plug can interact with the conductive element and cause a change in capacitance or induction detected by appropriate circuitry coupled to the conductive element. In some embodiments, an optical sensor can be used to detect a plug placed in a port. In some embodiments, the electronic device can detect distinguishable attributes associated with the contact between the electrical contact of plug and port contacts using an appropriate sensor (e.g., a microphone or an accelerometer).

Description:
BACKGROUND OF THE INVENTION 
     This is directed to detecting a plug placed in an electronic device without physically contacting the plug. 
     Many electronic devices provide functionality via accessories coupled to the electronic devices using a plug. For example, media players can include a jack into which an audio plug can be inserted to provide audio from the device to a speaker or headphone connected to the jack. As another example, laptop and desktop computers can include USB ports for receiving USB accessories such as input mechanisms (e.g., a keyboard and mouse), peripheral devices (e.g., a printer), storage media (e.g., external hard or solid state drives), or any other suitable accessory providing additional functionality to the device. 
     To provide the additional functionality, an electronic device may first detect the accessory device plug inserted into an appropriate aperture of the device and enable a state associated with the detected accessory device. One typical manner to detect a plug is to provide spring arms or other components in the device aperture that are placed in physical contact with the plug upon insertion of the plug. For example, an audio jack can include two or more conductive spring arms operative to create an electrically conductive connection with an inserted plug. A circuit can then detect that the two or more conductive spring arms have been shorted to determine that a plug was inserted in the device. 
     As the size of devices is reduced, however, space may not be available to provide spring arms or components for physically contacting a plug. Alternatively, the spring arms or components can limit the overall size of the electronic device. In addition, the physical contact of between the spring arms or other components and the plug can be a source of failure (e.g., fatigue failure after a particular number of plug insertion-removal cycles). 
     SUMMARY OF THE INVENTION 
     This is directed to systems and methods for detecting a plug without physically contacting the plug. 
     A plug can be inserted in a jack or other port to provide enhanced functionality to the electronic device. As the device manages its operations and resources, it may selectively enable particular functions associated with different ports based on the type or number of connected peripheral devices. For example, a media playback device can be in a first state in which media playback is enabled when an audio plug is detected in a jack, and in a second state in which media playback is prevented when no audio plug is detected in the jack. This may require the electronic device to first determine when a plug is inserted in a device port. 
     The electronic device can use any suitable approach for detecting a plug in a port without physically contacting the plug. In some embodiments, one or more of a capacitance sensor and an inductive sensor can be used to detect a plug. For example, an electronic device can include a capacitive trace placed within a port wall or adjacent to a port wall. As a plug is inserted in the port, the capacitance detected from the capacitive trace can change to indicate the presence of a conductive material near the trace. As another example, an electronic device can include an inductive trace placed within a port wall or adjacent to a port wall. When a conductive plug (e.g., a metallic audio plug) is placed in the port, the inductance detected from the inductive trace can change, indicating the presence of conductive material within the plug. The size and location of the capacitive or inductive traces can be selected based on the precision of the detector, the amount of plug material inserted adjacent to the trace within the port, or any other suitable criteria. 
     In some embodiments, the electronic device can instead or in addition use an optical sensing mechanism to detect the presence of a plug in a port. For example, the port wall can include one or more apertures through which an emitter can emit radiation that reflects off of the plug and back to a detector, which detects the reflected radiation. In some cases, the detector can be operative to identify particular radiation reflected from the plug. For example, the detector can be operative to identify a particular wavelength radiation (e.g., light waves reflected in particular manner off a polished plug (e.g., an audio plug). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of the present invention, its nature and various advantages will be more apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a cross-sectional view of an illustrative audio plug placed in an audio jack and detected using contacts; 
         FIG. 2  is a cross-sectional view of an illustrative plug placed in a port and detected using a capacitive sensor in accordance with one embodiment of the invention; 
         FIG. 3  a cross-sectional view of an illustrative plug placed in a port and detected using an inductive sensor in accordance with one embodiment of the invention; 
         FIG. 4  is a cross-sectional view of an illustrative plug placed in a port and detected using an optical sensor in accordance with one embodiment of the invention; and 
         FIG. 5  is a schematic view of an audio plug inserted into an audio jack in accordance with one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In some devices, an audio plug is detected in an audio jack using spring arms or contacts that come into contact with a portion of the audio plug.  FIG. 1  is a cross-sectional view of an illustrative audio plug placed in an audio jack and detected using contacts. Device  100  can include jack  102  operative to receive plug  110 . Jack  102  can include arms  104  and  106  placed on opposite sides of jack  102  such that a portion of plug  110  contacts both arms  104  and  106  when plug  110  is inserted in jack  102 . Circuit  108  can couple arms  104  and  106  such that circuit  108  is closed when plug  110  connects arms  104  and  106 . When circuit  108  detects that it is closed, the electronic device can enable communications with a peripheral device of plug  110  (e.g., change the state of the device). This approach, however, requires a physical and electrically conductive contact between plug  110  and both arms  104  and  106 . 
     To remove the space required by arms  104  and  106 , other approaches can be used to detect a plug.  FIG. 2  is a cross-sectional view of an illustrative plug placed in a port and detected using a capacitive sensor in accordance with one embodiment of the invention. Device  200  can include port  202  operative to receive plug  210  (e.g., in a port receptacle). To detect the insertion or removal of plug  210 , port  202  can include at least one conductive element  220  deposited on the exposed surface of port  202  to form a capacitive sensor. As plug  210  moves past element  220  when it is inserted in port  202 , the capacitance of element  220  can change. Detector  224 , which can be coupled to element  220  via path  222 , can detect the change in capacitance, and provide an indication to a processor. In some embodiments, conductive element  220  can be positioned within the wall of port  202  (e.g., not exposed to plug  210 ), or on or adjacent to the hidden surface of the port wall. For example, conductive element  220  can include a conductive trace in a circuit board located adjacent to the port wall. In response to the output of detector  224 , a processor of the electronic device can change the state or mode of the device. 
     Conductive element  220  can be positioned along any suitable portion of port  202 . For example, conductive element  220  can be positioned near the opening of port  202 , or near the closed end of port  202  (e.g., near the inner-most portion of port  202  that plug  210  can reach). As another example, several conductive elements  220  can be distributed along the surface of port  202 . By placing a conductive element  220  near the inner-most portion of port  202 , detector  224  may be able to detect plug  210  only when it is fully inserted in port  202 , and thus reduce user frustration due to improper detection of an incompletely inserted plug. Alternatively, the electronic device can provide different functionality based on how deep the plug is inserted in the port (e.g., the processor can provide no microphone support for partially inserted audio plugs). If several conductive elements  220  are provided along the length of port  202 , detector  224  may be operative to identify the particular elements  220  opposite which plug  210  is positioned, and monitor the detected change in adjacent elements to determine whether a plug is being inserted or removed from port  202 . 
       FIG. 3  a cross-sectional view of an illustrative plug placed in a port and detected using an inductive sensor in accordance with one embodiment of the invention. Device  300  can include port  302  operative to receive plug  310 . To detect the insertion or removal of plug  310 , port  302  can include at least one inductive element  320  deposited on the exposed surface of port  302  to form an inductive sensor. Inductive element  320  can include any suitable wire, coil, or other conductive component forming a circuit. As plug  310  moves past element  320  when it is inserted in port  302 , the inductance of a circuit including inductive element  320  can change. Detector  324 , which can be coupled to element  320  via path  322 , can then detect the change in inductance. In some embodiments, inductive element  320  can be positioned within the wall of port  302  (e.g., not exposed to plug  310 ), or on or adjacent to the hidden surface of the port wall. For example, conductive element  320  can include a conductive trace in a circuit board located adjacent to the port wall (e.g., a trace forming a loop adjacent to the port wall). The size or orientation of conductive element  320  can be selected based on any suitable criteria, including for example the size of the plug inserted in port  302 , the amount or density of conductive material in the plug, and the precision of detector  324 . 
     Inductive element  320  can be positioned along any suitable portion of port  302 . For example, inductive element  320  can be positioned near the opening of port  302 , or near the closed tip of port  302  (e.g., near the inner-most portion of port  302  that plug  310  can reach). As another example, several inductive elements  320  can be distributed along the surface of port  302 . By placing an inductive element  320  near the distal-most portion of port  302  (i.e., the portion of port  302  that is furthest from the plug opening), detector  324  may be able to detect plug  310  only when it is fully inserted in port  302 , and thus reduce user frustration due to an improperly inserted plug. Alternatively, the electronic device can provide different levels of functionality based on how deep the plug is inserted in the port (e.g., no microphone support for partially inserted audio plugs). If several inductive elements  320  are distributed along the length of port  302 , detector  324  may be operative to identify the particular elements  320  opposite which plug  310  is positioned, and monitor the detected change in adjacent elements to determine whether a plug is being inserted or removed from port  302 . 
       FIG. 4  is a cross-sectional view of an illustrative plug placed in a port and detected using an optical sensor in accordance with one embodiment of the invention. Device  400  can include port  402  operative to receive plug  410 . To detect the insertion or removal of plug  410 , port  402  can include at least one optical path  422  providing a conduit between optical sensor  424  and the inside of port  402 . Optical path  422  can include any suitable connecting mechanism allowing light waves or other radio waves to be directed between port  402  and optical sensor  424 , such as a light tube, a fiber optic cable, an aperture (e.g., a hollow tube), or any other connecting mechanism or conduit. Optical sensor  424  can include one or both of an emitter for emitting radio waves at a particular frequency (e.g., a light emitting diode emitting light waves at a particular frequency or frequency range) and a detector for detecting light waves reflected from a surface (e.g., from plug  410 ). As plug  410  moves past optical path  422 , radiation emitted by optical sensor  424  can travel along optical path  422 , reflect off of plug  410 , and travel back through optical path  422  to optical sensor  424  for detection. The optical properties of plug  410  and the inner surface of port  402  can be different such that the radiation reflected back to optical sensor  424  changes in a measurable manner when plug  410  is inserted in port  402 . For example, plug  410  can be polished, while the inner surface of port  402  can be non-reflective, such that the amount of radiation reflected by plug  410  is larger than the amount of radiation reflected by the inner surface of port  402  (e.g., when no plug is present). As another example, the shapes of plug  410  and of the inner surface of port  402  can reflect radiation in different manners (e.g., one diffuses more radiation than the other, or one reflects radiation away from optical path  422 ), such that a measurable difference in reflected radiation can be detected. 
     Optical path  422  can be positioned along any suitable portion of port  402 . For example, optical path  422  can be positioned near the opening of port  402 , or near the closed tip of port  402  (e.g., near the inner-most portion of port  402  that plug  410  can reach). As another example, several optical paths  422  can be distributed along the surface of port  402 . By placing an optical path  422  near the distal-most portion of port  402  (i.e., the portion of port  402  that is furthest from the plug opening), optical sensor  424  may be able to detect plug  410  only when it is fully inserted in port  402 , and thus reduce user frustration due to an improperly inserted plug. Alternatively, the electronic device can provide different functionality based on how deep the plug is inserted in the port (e.g., no microphone support for partially inserted audio plugs). If several optical paths  422  are provided, detector  424  may be operative to identify the particular elements  420  opposite which plug  410  is positioned, and monitor the detected change in adjacent elements to determine whether a plug is being inserted or removed from port  402 . 
     In some embodiments, the electronic device can detect the insertion or removal of a plug in a port using sensors that are not directly connected or related to the plug, but have other primary uses in the electronic device. In particular, the electronic device can include one or more sensors operative to detect particular attributes of the plug insertion or removal process (e.g., detect events caused by the plug insertion or removal). For example, a plug can include several contact regions operative to contact corresponding port regions and form electrically conductive paths between the plug and the port. Using the electrically conductive paths, the electronic device and accessory device associated with plug can transfer data or power in the course of the operation of each device. As the contact regions of the plug come into physical contact with the corresponding port regions, one or more detectable events can occur. For example, the physical contact between contact regions of the plug and port can generate a distinguishable vibration or motion detectable by an accelerometer of the device. As another example, the physical contact can generate one or more audible and distinguishable sounds or sequence of sounds detectable by a microphone of the electronic device. 
     The following example will serve to illustrate the detection of a plug using an accelerometer or a microphone in the context of an audio plug inserted into an audio jack.  FIG. 5  is a schematic view of an audio plug inserted into an audio jack in accordance with one embodiment of the invention. Device  500  can include audio jack  501  operative to receive audio plug  510 . To provide data from the electronic device to the speakers coupled to audio plug  510 , audio jack  501  can include several contacts  502 ,  504 ,  506  and  508  operative to contact corresponding portions of audio plug  510 . Contacts  502 ,  504 ,  506  and  508  can be biased away from the surface of jack  501  to ensure that each of the contacts is placed in contact and remains in contact with plug  510  when it is inserted in the jack. In particular, each of the contacts can be positioned such that it is elastically deformed when plug  510  is inserted in the jack and thus retained against plug  510 . 
     Plug  510  can include several conductive regions  512 ,  514 ,  516  and  518 , each operative to conduct different signals (e.g., left audio, right audio, ground, and microphone signals). Each of contacts  502 ,  504 ,  506 , and  508  can be associated with a particular corresponding conductive region of plug  510  (e.g., contact  502  with region  512 , contact  504  with region  514 , contact  506  with region  516 , and contact  508  with region  518 ). When plug  510  is initially introduced into jack  501 , region  518  may first come into contact with contacts  502 ,  504 , and  506  before finally reaching contact  508  (e.g. due to the biasing of the contacts). Similarly, regions  514  and  516  can come into contact with other contacts of plug  510  than the one with which the region is associated. The succession of impacts between contacts and jack regions with which the contacts are not associated can define a sufficiently unique or distinguishable sequence of vibrations or sounds that an accelerometer or microphone, respectively, can detect and identify. Alternatively, a single, particular contact between a contact region and a contact (e.g., contact region  516  and contact  504 , or contact region  516  and associated contact  506 ) can be sufficiently unique or distinguishable for the device to detect the insertion of audio plug  510  in audio jack  501 . 
     The above-described embodiments of the present invention are presented for purposes of illustration and not of limitation, and the present invention is limited only by the claims which follow.