Abstract:
A mobile device, particularly a wireless headset, includes a cord to which an earpiece is fixed and a module having a spring-actuated retractor reel into which the cord is retracted for storage. A fastener on the module makes the device wearable. A rotary encoder generates a position data output according to the rotational position of the reel, and a controller receives the position data output from the sensor, and, in response, controls a function such as placing the device in an on-hook or off-hook state.

Description:
TECHNICAL FIELD 
     The present invention relates generally to mobile devices, and more particularly to mobile devices with cord retractors. 
     BACKGROUND OF THE INVENTION 
     Mobile devices, such as cellular telephones, personal data assistants (PDAs), media players etc., continue to increase in popularity. To maintain this trend, manufacturers continue to explore ways to make mobile devices appeal to a larger part of the population. One object of the invention is to address a need for improvements in the ease of use of such devices, by automating aspects of their operation to make performing different functions with the device simpler or more intuitive. 
     Headsets are used with many mobile devices to free-up a user&#39;s hands leaving them free to perform other tasks, such as driving, etc and are also advantageous in noisy environments. As a result, headsets increase the convenience of using a mobile device. With many mobile devices, the audio signal is outputted through a headset having one or more earpieces connected by an electrical cord to an output jack on the device. An improvement to this is to have a cord retractor in the device, as this provides many advantages. It allows for convenient storage of the cord, it allows a variable length of cord to be deployed as required to avoid snagging, tangling, or like problems and it also prevents headsets from being misplaced when not utilized or when not plugged into the mobile device. Another area of focus with mobile devices is hands-free wireless communications where headsets communicate with a local mobile device via a local wireless network. Such headsets have elements in common with other mobile audio devices, but a particular application is telephone communications. A further object of the invention is to address a need for improvements in the ease of use of audio devices of this type. 
     DISCLOSURE OF THE INVENTION 
     According to one aspect of the present invention there is provided a mobile device comprising: a cord having inner and outer sections; a retractor into which the cord is retracted for storage, the retractor including a fixture holding the inner section; a sensor adapted to generate a position data output related to the position of the fixture; a controller that receives the position data output from the sensor, and, in response, controls a function of the device. 
     Preferably the device comprises a portable audio device for providing an audio output signal, the retractor comprises a reel for winding up the cord and spring means for biasing the reel to wind the cord onto the reel; the sensor comprises a rotary encoder that generates the position data output according to the rotational position of the reel, the cord comprises flexible conductors for transmitting the audio output signal, and further comprising an earpiece coupled to the outer section of the cord for projecting audible signals to a user in response to the audio output signal. 
     Alternatively, for instance, the cord may provide a tether for securing a stylus to the mobile device. The mobile device may include a stylus-operated input, such as a touch-sensitive pad, for inputting text into the device. The sensor may comprise a two-position switch actuated by the cord to move between a first position when the cord is extended and a second position when the cord is retracted. The function of the device controlled by the controller in response to the position data output determined by the controller according to the position of the switch may include actuation of the touch-sensitive pad so as to display input from the pad upon a screen of the device. 
     Preferably the function of the device comprises activating or deactivating the audio device to transmit the audio output signal to the earpiece. Optionally, if the audio device further includes a main speaker, the function of the device includes activating or deactivating the main speaker. 
     Preferably the mobile audio device is adapted for two-way telephone communication and comprises a wireless headset having a microphone for receiving audible signals from a user, a wireless interface to interface the earpiece and microphone with a terminal, and wherein the function of the device comprises automatically placing the wireless headset in an on-hook or off-hook mode in response to the position data output. 
     Preferably the mobile audio device has an associated housing in which the reel, spring means, microphone and wireless interface are disposed, the rotary encoder comprises a non-contact sensor, and fastening means on the housing for securing the housing to a user. Preferably the fastening means includes a spring clip, most preferably the clip having teeth for engaging teeth on the housing. Alternatively, the fastening means may include an aperture in the housing for fastening a lanyard, or the like. 
     Optionally the device further includes a plurality of teeth circumferentially spaced about the reel, a pawl slidably fixed in the housing and moveable between an engaged position in engagement with the teeth to prevent the spring winding in the cord while allowing the cord to be extended from the reel, and a disengaged position allowing the spring to retract the cord and a button mounted to the housing for moving the pawl between the engaged and disengaged positions. Optionally, other known ratchet-type mechanisms for allowing unwinding of a retractor reel and selectively latching to prevent winding up of the reel may be employed. 
     Preferably the rotary encoder comprises at least one discontinuity provided in a circumferential surface on the reel and a Hall-effect sensor arranged with respect to the at least one discontinuity so as to enable each one of the at least one discontinuities to exert a characteristic magnetic influence upon the Hall-effect sensor during reel rotation. It will be appreciated that other types of non-contact sensor, such as optical sensors, may be employed to provide the position data output. 
     Preferably the reel further includes slip rings through which the audio output signal is transmitted and each one of the at least one rotor discontinuities further comprises a recessed area formed in one of the slip rings. Each one of the at least one rotor discontinuities may exhibit magnetic properties. 
     In another aspect the invention provides a mobile device comprising a mobile terminal and a wireless headset having a microphone for receiving audible signals from a user, a wireless interface to interface the earpiece and microphone with the mobile terminal, and wherein the function of the device comprises automatically connecting or disconnecting communication between the mobile terminal and the wireless headset in response to the position data output. 
     The mobile terminal may not include a speaker and microphone and therefore be incapable of communicating audible signals with a user except in conjunction with the wireless headset. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: 
         FIG. 1  is a schematic front view of a headset according to an exemplary embodiment of the invention. 
         FIG. 2  is a schematic side view of the headset of  FIG. 1 . 
         FIG. 3  is a schematic block diagram of the headset of  FIG. 1 . 
         FIG. 4  is a schematic of the reel of the headset of  FIG. 1 , showing the latching mechanism. 
         FIG. 5  is a fragmentary section along a plane obliquely intersecting the plane AA in  FIG. 1 . 
         FIG. 6  illustrates an exemplary method of operating the headset of  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1-3  illustrate an exemplary mobile device comprising a wireless headset  10  according to the present invention, having an earpiece  11  fixed to a cord  12  retractable from a housing  13 . While the present invention is described in terms of a wireless headset  10  for telephone use, those skilled in the art will appreciate that the present invention is not limited to telephone communication, and is applicable to wireless headsets for use with any device. Likewise the headset itself may include a device such as a cellular telephone, a Media Player, a Personal Digital Assistant (PDA), a conventional laptop and/or palmtop computer, or any other mobile device that is used with an earpiece. 
     The wireless headset  10  is a hands-free communication device that enables a user to communicate with a cellular telephone using a wireless interface. In exemplary embodiments, the wireless interface comprises a short-range wireless network, particularly a Bluetooth® network. A Bluetooth® network is a radio interface that enables two or more wireless devices to communicate wirelessly over a short-range. However, the present invention is not limited to Bluetooth® networks and is applicable to any wireless interface with a wireless headset  10 . 
     The wireless headset  10  generally includes an earpiece  11  for projecting audible signals to a user, a microphone  14  for receiving audible signals from the user, and a fastener for securing the wireless headset  10  to the person or clothing of a user, such as a spring-closed pivoted clip  15 . A release button  16  is mounted to the housing  13 , together with a multi-function push-button  17  for controlling functions such as pairing with the cellular telephone. A slider control  18  is provided for audio output volume control and, like the multi-function push-button  17  is associated with the headset controller  21 . 
     In  FIG. 3  each illustrated electronic component of wireless headset  10  is shown as a separate element or block, however, those skilled in the art will appreciate that two or more of these electronic components may be combined into a single microprocessor, application specific integrated circuit, or other suitable circuit. 
     The wireless headset  10  includes headset electronics  20  including a headset controller  21  for controlling the headset electronics  20 , and which may include a processor and memory for storing data. A battery  22  provides power to the headset electronics  20 . Headset electronics  20  further include an earpiece  11  for projecting audible signals to a user, microphone  14  for receiving audible signals from the user, and an audio circuit  23 . Audio circuit  23  processes audio signals received from the cellular telephone according to known methods, and provides the processed audio signals to earpiece  11  for projection to the user. Audio circuit  23  further processes audible signals received by microphone  14  according to known methods, and forwards the processed audio signals to the cellular telephone. As discussed further below, audio circuit  23  transmits/receives audio signals to/from the cellular telephone via a wireless interface. To that end, headset electronics  20  further include a wireless transmitter, such as a Bluetooth® transceiver  24  and antenna  25  for communicating with the cellular telephone via the wireless interface according to instructions provided by headset controller  21 . The cooperation between the headset controller  21 , Bluetooth® transceiver  24  and the cellular terminal with which it communicates are conventional, except as described herein, and so are not described in detail. 
     The audio circuit  23  transmits an audio output signal via conductors  27  to contacts  28  which maintain contact with the slip rings  29  fixed to the reel  30 . The retractor reel  30  for winding up the cord  12  rotates about an axis  32  concentric with the release button  16 . A spiral wound spring  31  is received in an annular recess in the reel  30  and has one end connected to the reel, and the other end connected to the housing so that the spring  31  biases the reel  30  to wind the cord  12 . A Hall-effect sensor  35  lies adjacent the reel  30 , and is connected via a sensor circuit  34  to the controller  21 , thereby providing in this application an off-hook detector for the headset. 
     As best seen in  FIG. 4 , the slip rings  29  include outer and inner slip rings  29   a  and  29   b , concentric with axis  32  and formed as by etching on a printed circuit board substrate (not shown). In the outer periphery of the outer slip ring  29   a  a lobe is formed in which apertures are provided, thereby providing a discontinuity  36  in a circumferential surface on the reel  30 . The discontinuity  36  exerts a characteristic magnetic influence upon the Hall-effect sensor  35  during reel rotation, providing a rotary encoder that generates the position data output according to the rotational position of the reel which is transmitted to the headset controller  21 . 
     The reel  30  further includes an integral ratchet wheel including a plurality of teeth  37  circumferentially spaced about the reel, the teeth being tapered to cooperate with a pawl  38  slidably fixed in the housing  13 . The pawl  38  is moveable between the engaged position shown, where it engages with the teeth  37  to prevent the spring  31  winding in the cord  12 , while at the same time allowing the cord  12  to be extended from the reel  31 , and a disengaged position (not shown) allowing the spring  31  to retract the cord  12 . The pawl  38  has a tapered face  40  and abuts a first spring  39  urging the pawl to engage the teeth  37 . The release button  16  is abutted by a second spring  41  which slidably urges the button  16  out of the housing  13 . A tapered face  42  on the button  16  is complementary to the face  40  with which it engages when the button  16  is pressed to move the pawl  38  to its disengaged position. 
     Referring now to  FIG. 6 , an exemplary method of operation of the off-hook detector of the headset will be described. Headset electronics  20  begins the headset detection loop (Block  300 ) at any appropriate time, i.e. when headset electronics  20  powers up. The headset controller  21  then determines if the headset  10  is in an off-hook mode (Block  301 ). In the off-hook mode the headset is off-hook, indicating a call is in progress, i.e., a call has been answered or made, in which case the audio circuit  23  is activated, transmitting an audio output signal to the earpiece  11 . If not in the off-hook mode the headset is in an on-hook mode, ready to receive or make a call, in which case the audio circuit  23  is deactivated, and therefore unable to transmit an audio output signal to the earpiece  11 . If the controller  21  determines that the headset is not in an off-hook mode (as, for instance, immediately following power up) the controller  21  determines if an activation signal has been received from the sensor circuit  34  (Block  302 ). The activation signal may comprise a predetermined number of pulses received from the Hall-effect sensor  35  and counted by the controller. If an activation signal has been received from the sensor circuit  34 , the controller  21  activates the audio circuit  23  to put the headset  10  in an off-hook mode—for instance, to answer a call (Block  303 ). If the controller  21  (at Block  301 ) determines that the headset  10  is in an off-hook mode, the controller  10  then determines whether a de-activation signal has been received from the sensor circuit  34  (Block  304 ). The deactivation signal may comprise the same predetermined number of pulses received from the Hall-effect sensor  35  as the activation signal, or a different number of pulses. If a deactivation signal has been received from the sensor circuit  34 , the controller  21  deactivates the audio circuit  23  to put the headset  10  in a on-hook mode—for instance, to end a call (Block  305 ). 
     The above discloses a wireless headset  10  that is effective and efficient in operational use particularly for performing a telephone call over a local wireless network, by automatically putting the device in an on-hook or off-hook state, upon extension of the cord  12  from the retractor or winding up of the cord  12  into the retractor. This simplifies the operation of the device and allows it to be readily used, without need to be versed in an operation technique. Moreover, the device may be economically constructed and has an overall simple design which minimizes manufacturing costs. 
     Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.