Abstract:
A digitizing tablet is provided, comprising: a display surface with a digitizer which detects a location of a front tip of a digitizing stylus, a pen sensor configured to detect the digitizing stylus being placed flatly on the display surface and, in response, to transmit a detecting signal, and a controller electrically coupled to the pen sensor. The controller is configured to execute instructions for: receiving the detecting signal from the pen sensor; and placing the digitizing tablet into a suspend mode upon receipt of the detecting signal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to tablet computers and, more specifically, to placing the tablet computer into a suspended mode. 
         [0002]    Digitizing tablet computers and devices (hereinafter “tablets”) allow a user to use a digitizing stylus-type input device to interact with a surface of the tablet by drawing, writing, selecting, etc. Circuitry inside the tablet detects the stylus action and transmits appropriate commands to computing circuitry. 
         [0003]    Tablets are typically turned off or placed in a sleep or suspend mode using a hard or soft switch. A user may also enter settings to allow the tablet to enter the suspend mode automatically after a predetermined time. Thus, to reduce power consumption when not using the tablet, a user must take an affirmative action to place the tablet in the suspend mode or wait for the tablet to do so automatically. 
         [0004]    Therefore, it can be seen that there is a need for a more efficient way to place a tablet into its suspend mode. 
       SUMMARY 
       [0005]    In one aspect, a digitizing tablet is provided, comprising: a display surface with a digitizer which detects a location of a front tip of a digitizing stylus; a pen sensor configured to detect the digitizing stylus being placed flatly on the display surface and, in response, transmits a detecting signal; and a controller electrically coupled to the pen sensor, the controller configured to execute instructions for: receiving the detecting signal from the pen sensor and placing the digitizing tablet into a suspend mode upon receipt of the detecting signal. 
         [0006]    In another aspect, a digitizing tablet is provided, comprising: a display surface; and a controller electrically coupled to transmitting and receiving circuitry, the controller configured to execute instructions for: sending a command to the transmitting circuitry to transmit an electromagnetic wave; receiving a first message from the receiving circuitry; determining if the first message from the receiving circuitry is indicative of simultaneous detection of electromagnetic induction from two locations of the digitizing stylus; and placing the digitizing tablet into a suspend mode upon receipt of simultaneous detection of electromagnetic induction from the two locations of the digitizing stylus 
         [0007]    In another aspect, a digitizing tablet system is provided, comprising: a digitizing stylus, comprising: first capacitive-inductive (LC) circuitry in a first location of the digitizing stylus; and second LC circuitry in a second location of the digitizing stylus; and a digitizing tablet, comprising: a display; transmitting circuitry; receiving circuitry; a controller electrically coupled to the display and the transmitting and receiving circuitry; a processor within the controller; and a memory. The memory is configured to store instructions executable by the processor for: sending a command to the transmitting circuitry to transmit an electromagnetic wave; receiving a first message from the receiving circuitry; determining if the first message from the receiving circuitry is indicative of detection of electromagnetic induction from the first and second LC circuitries of the digitizing stylus; if the first message from the receiving circuitry is not indicative of detection of electromagnetic induction from the first and second LC circuitries of the digitizing stylus, waiting to receive a second message from the receiving circuitry; and if the first message from the receiving circuitry is indicative of simultaneous detection of electromagnetic induction from the first and second LC circuitries of the digitizing stylus, placing the digitizing tablet into a suspend mode. 
         [0008]    In a further aspect, a computer program product stored on non-transitory computer readable media executable by a programmable processor is provided, the computer program product having computer readable code embodied therein and comprising instructions for: receiving a first message from receiving circuitry; determining if the first message from the receiving circuitry is indicative of simultaneous detection of electromagnetic induction from two locations of a digitizing stylus; if the first message from the receiving circuitry is not indicative of simultaneous detection of electromagnetic induction from the two locations of the digitizing stylus, waiting to receive a second message from the receiving circuitry; and if the first message from the receiving circuitry is indicative of simultaneous detection of electromagnetic induction from the two locations of the digitizing stylus, placing the digitizing tablet into a suspend mode. 
         [0009]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a top view of a stylus input tablet and digitizing stylus according to an exemplary embodiment; 
           [0011]      FIG. 2  is a block diagram of control circuitry of the tablet and stylus of  FIG. 1  according to an exemplary embodiment; 
           [0012]      FIG. 3  is a block diagram of the control circuitry of  FIG. 2  illustrating the tablet activating a radio frequency (RF) transmission; 
           [0013]      FIG. 4  is a side perspective view of the tablet and stylus of  FIG. 1  with the stylus placed on the surface of the tablet; 
           [0014]      FIG. 5  is a block diagram of the control circuitry of  FIG. 2  illustrating the response by the stylus to the RF transmission; 
           [0015]      FIG. 6  is a block diagram of the control circuitry of  FIG. 2  illustrating the tablet receiving electromagnetic induction from two locations on the stylus; 
           [0016]      FIG. 7  is a flow chart of a method according to an exemplary embodiment; 
           [0017]      FIG. 8  is a flow chart of a method according to another exemplary embodiment; 
           [0018]      FIG. 9  is a flow chart of a method according to still another exemplary embodiment; and 
           [0019]      FIG. 10  is another block diagram of the control circuitry of the tablet and stylus of  FIG. 1  according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0020]    The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles, since the scope of the embodiments is best defined by the appended claims. 
         [0021]    Various inventive features are described below that can each be used independently of one another or in combination with other features. 
         [0022]    Broadly, exemplary embodiments provide apparatus and methods for placing a digitizing tablet computer into a suspend or sleep mode. More specifically, exemplary embodiments provide a tablet and stylus-type input device that may allow the tablet to enter a suspend mode when the stylus is placed on the display surface of the tablet. 
         [0023]      FIG. 1  is a top view of a digitizing tablet computer (“tablet”)  10  and a stylus-type input device (“stylus” or “pen”)  30  according to an exemplary embodiment. As illustrated in  FIG. 2 , the tablet  10  may include a display surface  12 , a controller  14 , transmitting circuitry  16  and a pen sensor or receiving circuitry  18  electrically coupled to the controller  14 . The controller  14  may include a processor  20  and a memory  22  configured to store computing instructions to be executed by the processor  20 . The stylus  30  may include any type of circuitry that can detect and respond to the transmitting circuitry  16 , such as passive capacitive-inductive (LC) circuitries  32  and  34  at two locations. In the FIGs., the LC circuitries  32 ,  34  are shown located in the front tip end and the back eraser end, respectively, of the stylus  30 . 
         [0024]    In operation, the controller  14  may transmit a command to the transmitting circuitry  16  to transmit an electromagnetic wave  24  ( FIG. 3 ). When the stylus  30  is laid on the display surface  12  of the tablet  10  ( FIG. 4 ), the LC circuitry  32  and  34  in the stylus  30  may both respond with LC resonance ( FIG. 5 ) causing electromagnetic induction or waves  36  ( FIG. 6 ). The electromagnetic induction  32  and  34  from both locations of the stylus  30  may be received by the pen sensor or receiving circuitry  18  in the tablet. The controller  14  may receive a detecting signal or message from the receiving circuitry  18  and terminate the transmission of the electromagnetic wave  24 . If the controller  14  determines that the received message indicates that the receiving circuitry  18  doesn&#39;t detect electromagnetic induction  36  from both LC circuitries  32  and  34  simultaneously, such as if the stylus  30  is not on the surface  12 , the controller  14  waits for another message from the receiving circuitry  18 . Otherwise, if the controller  14  determines that the received message indicates that the receiving circuitry  18  detects electromagnetic induction  36  from both LC circuitries  32  and  34  simultaneously, indicating that the stylus  30  has been laid on the surface  12 , the controller  14  may place the tablet  10  into a low power, suspend mode. Subsequently, when the controller  14  receives a message from the receiving circuitry  18 , or stops transmitting the detecting signal, indicative of the absence of the detection of the electromagnetic induction  36  from one or both LC circuitries  32  and  34  because the stylus  30  has been removed from the surface  12 , the controller  14  may wake the tablet and exits the suspend mode. 
         [0025]    Referring to the flowchart of  FIG. 7 , instructions stored in the memory  22  and executable by the processor  20  may begin by initiating a background task when the tablet controller  14  is booted (step  700 ). The controller  14  may wait to receive electromagnetic waves from the stylus  30  (step  702 ). When electromagnetic waves are received, the report identification (ID) may be checked (step  704 ) and a determination may be made whether the LC circuitry  32 ,  34  in both locations of the stylus  30  has been detected (step  706 ). If not, the controller  14  may continue to wait (step  702 ). If the LC circuitry  32 ,  34  in both locations of the stylus  30  has been detected (step  706 ), the controller  14  puts the tablet  10  into the suspend mode ( 708 ). 
         [0026]    In one embodiment ( FIG. 8 ), while in the suspend mode (point A), the controller  14  continues to wait to receive a stylus-detect message (step  800 ). When a message is received, the report ID is checked (step  802 ) and a determination may be made whether the electromagnetic induction  36  from LC circuitry  32  and  34  from both locations of the stylus  30  continues to be detected (step  804 ). If so, as when the stylus  30  remains on the surface  12 , the controller  14  may continue to wait (step  800 ). If the electromagnetic induction  36  from both locations of the stylus  30  has not been detected (step  804 ), as when the stylus  30  has been removed from the display surface  12 , the controller  14  wakens the tablet  10  from the suspend mode ( 806 ) and the controller  14  returns (point B) to waiting for a stylus message ( FIG. 7 , step  702 ). 
         [0027]    When the tablet  10  is in a slanted position, for example being laid on a slanting tablet stand on a desk, the stylus  30  may roll off of the display surface  12  once after the stylus  30  is placed flatly on the display surface  12 . In a further variation of the embodiment, the controller  14  detects whether the stylus  30  has been removed from the display surface  12  by a user, or the stylus  30  has rolled out from the display surface  12 . The controller  14  continuously monitors position change of the electromagnetic induction  36  from both location of the stylus  30 . When the electromagnetic induction  36  from both location of the stylus  30  is lost after approaching an edge of the display surface, the controller  14  may determine that the stylus  30  has rolled off of the display surface  12 , and the controller  14  does not waken the tablet  10  from the suspend mode. 
         [0028]    In another embodiment ( FIG. 9 ), once the tablet  10  has been placed in the suspend mode by detecting that the stylus  30  is against the display surface  12 , the controller  14  may deactivate the receiving circuitry  18  or otherwise ignore signals from the receiving circuitry  18  so that the stylus  30  may be removed without causing the tablet  10  to waken. Thus, if the tablet  10  is being held at an angle, the user may touch the stylus  30  to the display  12  to trigger the suspend mode (point A). The controller  14  may deactivate the receiving circuitry  18  (step  900 ). When a manual wake signal is detected by the controller  14  (step  902 ), such as when the user presses the power switch, the controller  14  may wake the tablet  10  from the suspend mode ( 904 ) and the controller  14  returns (point B) to waiting for a stylus message ( FIG. 7 , step  702 ). In this manner, the user may remove the stylus  30  from the display surface  12  without having to hold or lay the tablet  10  in a horizontal position to keep the stylus  30  from rolling off of the display surface  12 . 
         [0029]    In another embodiment, the tablet  10  may include a pressure-sensitive touch panel, which detects the area of touching object by detecting the pressure given by the touching object. 
         [0030]    In an alternative embodiment ( FIG. 10 ), the stylus  30  may include a passive capacitive-inductive (LC) circuitry  35  in the middle of a rod of the stylus  30 . In operation, when the stylus  30  is laid flat on the display surface  12  of the tablet  10 , the LC circuitry  35  in the middle of the stylus  30  may respond with LC resonance causing electromagnetic induction. The electromagnetic induction from the middle location of the stylus  30  may be received by the receiving circuitry  18  in the tablet  10 . The controller  14  may receive a signal or message from the receiving circuitry  18 . If the controller  14  determines that the received message indicates that the receiving circuitry  18  does not detect electromagnetic induction from the LC circuitry  35 , the controller  14  waits for another message from the receiving circuitry  18 . Otherwise, if the controller  14  determines that the received message indicates that the receiving circuitry  18  detects electromagnetic induction from the LC circuitry  35 , indicating that the stylus  30  has been laid on the display surface  12 , the controller  14  may place the tablet  10  into a low power, suspend mode. 
         [0031]    It is important to note that while the present invention has been described in the context of a fully functioning system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a non-transitory computer readable storage medium of instructions and a variety of forms and that the present invention applies regardless of the particular type of storage media actually used to carry out the distribution. 
         [0032]    It should be understood, of course, that the foregoing relate to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.