Abstract:
An apparatus for driving a touchpad of a portable terminal including a second control unit controlling the touchpad in an active mode is provided. The apparatus includes a sensor unit for generating interrupt signals when pressure on the touchpad is sensed, a first control unit for outputting activating signals to activate the second control unit when the interrupt signals are input and a switching unit for transmitting the interrupt signals generated from the sensor unit to the first control unit when the second control unit is in an inactive mode. Accordingly, even though the multimedia processor embedded in the portable terminal is in an inactive mode, the multimedia processor is activated when a user presses the touchpad, thereby making it possible to process signals input by touching the touchpad, particularly, to keep the user interface. Furthermore, the multimedia processor embedded in the portable terminal can reduce the consumption of battery power required to maintain the user interface, as compared with multimedia processors maintaining operating in a conventional polling method.

Description:
PRIORITY 
       [0001]    This application claims the benefit under 35 U.S.C. 119(a) of a Korean patent application filed on Jul. 10, 2006 in the Korean Industrial Property Office and assigned Serial No. 2006-64420, and of a Korean patent application filed on May 23, 2007 in the Korean Industrial Property Office and assigned Serial No. 2007-50330, the entire disclosures of both of which are hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an apparatus for driving a touchpad of a portable terminal. More particularly, the present invention relates to an apparatus for driving a touchpad of a portable terminal, which includes the touchpad and a multimedia processor controlling the touchpad. 
         [0004]    2. Description of the Related Art 
         [0005]    Portable communication terminals have been widely used for some time. Most recently, portable terminals have tended to be multimedia devices which have the ability to perform various advanced functions. Specifically, portable terminals combined with a Portable Multimedia Player (PMP) and portable terminals which can provide a multimedia function, have been rapidly developed. These portable terminals have a multimedia processor embedded therein, which can perform a multimedia function. 
         [0006]    Portable terminals providing a multimedia function may have a touchpad that can sense input signals exerted thereon by the user&#39;s fingers, pens, and the like. The touchpad provides an efficient user interface and a more convenient method of using the multimedia functions. 
         [0007]    However, in these portable terminals having a touchpad, the embedded multimedia processor controls the touchpad with a polling method. Accordingly, battery power is unnecessarily consumed in order to keep the user interface with the touchpad active. 
         [0008]    Furthermore, when the multimedia processor enters or is converted to a sleep mode, it cannot recognize input signals from the touchpad even though the user presses the touchpad. Hence, there is a problem in that the user interface cannot be maintained with the touchpad. 
       SUMMARY OF THE INVENTION 
       [0009]    An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages occurring in the prior art and to provide at least the advantages described below. Accordingly, it is an object of the present invention to provide an apparatus for driving a touchpad of a portable terminal, which can maintain a user interface efficiently. 
         [0010]    It is another object of the present invention to provide an apparatus for driving a touchpad of a portable terminal, which can reduce consumption of electric power required to maintain a user interface. 
         [0011]    In accordance with an aspect of the present invention, an apparatus for driving a touchpad of a portable terminal is provided. The apparatus includes a sensor unit for generating interrupt signals when pressure on the touchpad is sensed, a second control unit for controlling the touchpad in an active mode, a first control unit for outputting activating signals to activate the second control unit when the interrupt signals are input and a switching unit for transmitting the interrupt signals generated from the sensor unit to the first control unit when the second control unit is in an inactive mode. 
         [0012]    In accordance with another aspect of the present invention, an apparatus for driving a touchpad of a portable terminal is provided The apparatus includes a sensor unit for generating interrupt signals when pressure on the touchpad is sensed a second control unit for controlling the touchpad in an active mode, and a first control unit for outputting activating signals to activate the second control unit when the interrupt signals are input. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The above and other aspects, features and advantages of certain exemplary embodiments of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0014]      FIG. 1  is a block diagram illustrating a portable terminal according to an exemplary embodiment of the present invention; 
           [0015]      FIG. 2  is a block diagram illustrating a detailed structure of the exemplary portable terminal shown in  FIG. 1 ; 
           [0016]      FIG. 3  is a perspective view illustrating a structure of a touchpad of a portable terminal according to an exemplary embodiment of the present invention; 
           [0017]      FIG. 4  is a block diagram illustrating a portable terminal according to an exemplary embodiment of the present invention; 
           [0018]      FIG. 5  is a block diagram illustrating a detailed structure of the exemplary portable terminal shown in  FIG. 4 ; 
           [0019]      FIG. 6  is a block diagram illustrating a portable terminal according to another exemplary embodiment of the present invention; and 
           [0020]      FIG. 7  is a block diagram illustrating a detailed structure of the exemplary portable terminal shown in  FIG. 6 . 
       
    
    
       [0021]    Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features and structures. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0022]    The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness. 
         [0023]      FIG. 1  is a block diagram illustrating a portable terminal according to an exemplary embodiment of the present invention, and  FIG. 2  is a block diagram illustrating a detailed structure of the exemplary portable terminal shown in  FIG. 1 . 
         [0024]    The portable terminal shown in  FIG. 1  includes a touchpad  110 , a sensor unit  115 , a switching unit  120 , a second control unit  130 , a key input unit  140 , a first control unit  150 , a display unit  160 , and a memory unit  170 . 
         [0025]    Referring to  FIGS. 1 and 2 , the touchpad  110  includes a small flat panel to which a pressure sensor is attached. In operation of the touchpad  110 , signals are input to the second control unit  130  when a user touches the touchpad  110  with a finger, a pen and the like. 
         [0026]    The sensor unit  115  generates interrupt signals and outputs them to the switching unit  120  upon sensing pressure on the touchpad  110 . The sensor unit may be included in the touchpad  110 . 
         [0027]    In an exemplary embodiment of the present invention, the sensor unit  115  includes a dome sheet  112  having a dome switch. The dome switch senses pressure on a window of the touchpad  110  so as to output interrupt signals to the switching unit  120 . 
         [0028]    With reference to  FIG. 3 , an exemplary structure, having the dome sheet included in the touchpad  110 , will be described hereinafter. 
         [0029]      FIG. 3  is a perspective view illustrating a structure of a touchpad of a portable terminal according to an exemplary embodiment of the present invention. 
         [0030]    Referring to  FIG. 3 , the touchpad  110  is connected to a circuit board (not shown) of the portable terminal through a ribbon cable  117 . 
         [0031]    The touchpad  110  has an opening  111  formed in a part thereof, and a dome sheet  112  including a dome switch is disposed in the opening  111 . 
         [0032]    The dome sheet  112  is connected to the touchpad  110  through a flexible printed circuit  113 , and the opening  111  is formed in the touchpad  110 . In an exemplary embodiment, the opening  111  is formed at the center of the touchpad  110 . Therefore, the dome switch outputs interrupt signals when a window, which is positioned in the touchpad  110 , is pressured so as to close a switch. 
         [0033]    Referring to  FIGS. 1 and 2 , the second control unit  130  controls the touchpad  110  in the active state, and maintains an interface between a user and the portable terminal through the touchpad  110 . 
         [0034]    When the second control unit  130  enters an inactive mode, the switching unit  120 , under the control of the first control unit  150 , connects an interrupt signal line output from the sensor unit  115  to the first control unit  150 . Therefore, the switching unit  120  can transmit an interrupt signal generated in the sensor unit  115  to the first control unit  150  through the interrupt signal line. 
         [0035]    On the other hand, when the second control unit  130  is in an active mode, the switching unit  120 , under the control of the first control unit  150 , disconnects the interrupt signal line so that the interrupt signals are not transmitted to the first control unit  150 . 
         [0036]    More specifically, if the second control unit  130  enters an inactive mode, for example a sleep mode, the second control unit  130  may notify the first control unit. The first control unit  150  then generates a control signal and enables the switching unit  120  to transmit interrupt signals output from the sensor unit  115  to the first control unit  150 . At this time, the first control unit  150  can be converted to the sleep mode after controlling the switching unit  120 . 
         [0037]    When the second control unit  130  is in an inactive mode, if an interrupt signal is generated from the sensor unit  115  and input to the first control unit  150 , the first control unit  150  outputs an activating signal to the second control unit  130  so as to activate the second control unit  130 . Then, the second control unit  130  is converted from the inactive mode to the active mode to process signals input through the touchpad  110 . 
         [0038]    On the other hand, if an interrupt signal is input into the first control unit  150  while it is in the sleep mode, the first control unit  150  is converted to the active mode. Then, the first control unit  150  outputs an activating signal to the second control unit  130  to activate the second control unit  130 , and in turn is converted to the sleep mode again. 
         [0039]    The switching unit  120  may be implemented as an analog switch in an exemplary embodiment of the present invention. 
         [0040]    In an exemplary embodiment of the present invention, the second control unit  130  includes a multimedia processor for performing a multimedia function of the portable terminal. The multimedia function refers to a function of processing various media including voices, figures, pictures, etc. 
         [0041]    The key input unit  140  includes character keys, numeric keys, various function keys, and external volume control buttons, and outputs key input signals corresponding to the user&#39;s key input to the control unit  150 . 
         [0042]    The first control unit  150  (e.g. a Mobile Station Modem (MSM) chip) controls overall operations of the portable terminal according to an exemplary embodiment of the present invention. 
         [0043]    The display unit  160  may include a Liquid Crystal Display (LCD), etc., and outputs various display data generated by the portable terminal. 
         [0044]    The memory unit  170  may include program memories and data memories, and stores a wide variety of information required to control the operation of the portable terminal according to an exemplary embodiment of the present invention. The memory unit  170  may also store various selected information based on user selection information. For example, the memory unit  170  may include a ROM for storing an operation algorithm accessed by the first control unit  150  for the overall operation of the portable terminal, and a RAM for storing data depending on control instruction in a procedure for processing data of the first control unit  150 . 
         [0045]      FIG. 4  is a block diagram illustrating a portable terminal according to an exemplary embodiment of the present invention, and  FIG. 5  is a block diagram illustrating a detailed structure of the portable terminal shown in  FIG. 4 . 
         [0046]    As illustrated, the portable terminal includes a touchpad  210 , a sensor unit  215 , a switching unit  220 , a second control unit  230 , a key input unit  240 , a first control unit  250 , a display unit  260 , and a memory unit  270 . 
         [0047]    In the structure of  FIG. 4 , functions of the key input unit  230 , the display unit  260 , and a memory unit  270  are substantially the same as functions of the key input unit  140 , the display unit  160 , and the memory unit  170  of  FIG. 1 , respectively, according to the previous exemplary embodiment of the present invention. Therefore, description of these functions will be omitted for clarity. 
         [0048]    Referring to  FIGS. 4 and 5 , the touchpad  210  includes a small flat panel to which a pressure sensor is attached. Signals are input to the second control unit  230  when the user touches the touchpad  210  with a finger, a pen and the like. 
         [0049]    The sensor unit  215  generates an interrupt signal and outputs it to the first control unit  240  upon sensing pressure on the touchpad  210 . The sensor unit  215  may be embedded or included in the touchpad  210   
         [0050]    In an exemplary embodiment of the present invention, the sensor unit  215  includes a dome sheet having a dome switch, which is substantially the same as the previous exemplary embodiment of the present invention. The dome switch senses pressure on a window of the touchpad  210  so as to output interrupt signals to the first control unit  250 . Meanwhile, a structure of the touchpad  210  including the sensor unit  215  has been already described above in  FIG. 3 . Therefore, description about this structure will be omitted. 
         [0051]    The switching unit  220  includes an analog switch according to an exemplary embodiment of the present invention. When the second control unit  230  enters an inactivate mode, the switching unit  220 , under the control of the first control unit  250 , connects an interrupt signal line output from the sensor unit  215  to the first control unit  250 . For example, referring to  FIG. 5 , the switching unit  220  is in a state A, so as to transmit interrupt signals generated in the sensor unit  215  to the first control unit  250  through an interrupt signal line. 
         [0052]    Furthermore, when the second control unit  230  is in an active mode, the switching unit  220  connects an interrupt signal line to the second control unit  230  under the control of the first control unit  250 . For example, the switching unit  220  is in a state B with reference to  FIG. 5  so as to transmit interrupt signals generated in the sensor unit  215  to the second control unit  230  through an interrupt signal line. From this point, the touchpad  210  is under the control of the second control unit  230 . 
         [0053]    In an exemplary embodiment of the present invention, the second control unit  230  may include a multimedia processor for processing multimedia including voices, pictures, and the like, similar to the above description with reference to  FIG. 1 . When the second control unit  230  is in an active state, i.e. an activate mode, the touchpad  210  is controlled by the second control unit  230  to maintain a user interface. 
         [0054]    Furthermore, when the second control unit  230  is converted from the active mode to the inactive mode, the second control unit  230  outputs a signal for notifying conversion to the inactive mode to the first control unit  250 . As a result, the first control unit  250  connects an interrupt signal line of the switching unit  220  connected with the second control unit  230  to the first control unit  250 . 
         [0055]    The first control unit  250  controls overall operations of the portable terminal according to an exemplary embodiment of the present invention. 
         [0056]    When an interrupt signal is input to the first control unit  250  from the sensor unit  215  in a state that the second control unit  230  is in an inactive mode, the first control unit  250  outputs activate signals so as to activate the second control unit  230 . The first control unit  250  also generates a control signal so as to cause the switching unit  220  to transmit interrupt signals to the second control unit  230 . Then, the second control unit  230  is converted from the inactive mode to an active mode so as to process signals input through the touchpad  210 . 
         [0057]    When interrupt signals are input to the first control unit  250  while it is in the sleep mode, the first control unit  250  is converted to the active mode. Then, the first control unit  250  outputs activating signals and is converted to the sleep mode again. 
         [0058]    The first control unit  250  determines if the second control unit  230  is in the active mode at a certain time period so as to cause the switching unit  220  to transmit the interrupt signal line. 
         [0059]    When the second control unit  230  is not in the active mode as a result of the determining, the first control unit  250  causes the switching unit  220  to transmit interrupt signals generated in the sensor unit  215  to the first control unit  250 . 
         [0060]    According to another exemplary embodiment, when signals for notifying conversion to the inactive mode are input from the second control unit  230  to the first control unit  250 , under the control of the control unit  250 , the switching unit  220  can also transmit interrupt signals generated in the sensor unit  215  to the first control unit  250 . 
         [0061]      FIG. 6  is a block diagram illustrating a portable terminal according to another exemplary embodiment of the present invention, and  FIG. 7  is a block diagram illustrating a detailed structure of the portable terminal shown in  FIG. 6 . 
         [0062]    As illustrated, the portable terminal includes a touchpad  310 , a sensor unit  315 , a second control unit  320 , a key input unit  330 , a first control unit  340 , a display unit  350 , and a memory unit  360 . 
         [0063]    In the structure of  FIG. 6 , functions of the key input unit  330 , the display unit  350 , and a memory unit  360  are substantially the same as functions of the key input unit  140 , the display unit  160 , and the memory unit  170  of  FIG. 1 , respectively, according to the previous exemplary embodiment of the present invention. Therefore, description of these functions will be omitted. 
         [0064]    Referring to  FIGS. 6 and 7 , the touchpad  310  includes a small flat panel to which a pressure sensor is attached. Signals are input to the second control unit  320  when the user touches the touchpad  310  with a finger, a pen and the like. 
         [0065]    The sensor unit  315  generates interrupt signals and outputs them to the first control unit  340  upon sensing pressure on the touchpad  310 . The sensor unit  315  may be embedded or included in the touchpad  310 . 
         [0066]    In an exemplary embodiment of the present invention, the sensor unit  315  includes a dome sheet having a dome switch, which is substantially the same as the previous exemplary embodiments of the present invention. The dome switch senses pressure on a window of the touchpad  310  so as to output interrupt signals to the first control unit  340 . Meanwhile, a structure of the touchpad  310  including the sensor unit  315  has been already described above in  FIG. 3 . Therefore description about this structure will be omitted for clarity. 
         [0067]    Under the control of the second control unit  320  in an active state, i.e. an activate mode, the touchpad  310  is controlled to maintain a user interface. 
         [0068]    In an exemplary embodiment of the present invention, the second control unit  320  may also include a multimedia processor for processing multimedia including voices and pictures, similar to the above description with reference to  FIG. 1 . The first control unit  340  can be implemented as, for example, a Mobile Station Modem (MSM) chip and controls overall operations of the portable terminal according to an exemplary embodiment of the present invention. 
         [0069]    When interrupt signals are input from the sensor unit  315  to the first control unit  340  in a state that the second control unit  320  is in the inactive mode, the first control unit  340  outputs an activating signal so as to activate the second control unit  320  which is in the inactive mode. Then, the second control unit  320  is converted from the inactive mode to the active mode to process signals input through the touchpad  310 . 
         [0070]    If the interrupt signals are input to the first control unit  340  while it is in the sleep mode, the first control unit  340  is converted to the active mode. Then, the first control unit  340  outputs an activating signal so as to activate the second control unit  320 , and is converted to the sleep mode again. 
         [0071]    When the first control unit  340 , in the sleep mode or in the active mode, receives an interrupt signal from the sensor unit  315 , it may identify if the second control unit  320  is in an active mode or a sleep mode. By identifying the state of the second control unit  320 , it may prevent output of unnecessary activating signals by determining that the activating signals need not be output. 
         [0072]    For example, when an interrupt signal is input to the first control unit  340  in a state that the second control unit  320  is in the activate mode as a result of the identification, the first control unit  340  does not output an activating signal. On the other hand, when the interrupt signals are input to the first control unit  340  in a state that the second control unit  320  is in the inactivate mode, the first control unit  340  outputs an activating signal. 
         [0073]    As described above, even though the multimedia processor embedded in the portable terminal is in an inactive mode, the multimedia processor is immediately activated when the user presses the touchpad, thereby processing signals input by pressing the touchpad, thus, maintaining the user interface. 
         [0074]    Furthermore, exemplary embodiments of the present invention can reduce the amount of battery power consumed by the multimedia processor embedded in the portable terminal in order to maintain the user interface, as compared with multimedia processors maintaining operation using a conventional polling method. 
         [0075]    While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.