Patent Publication Number: US-2011069006-A1

Title: Method and system for detecting a finger contact on a touchpad

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims foreign priority benefits under 35 U.S.C.§119 of Chinese Patent Application Serial No. 200910190235.0, filed on Sep. 18, 2009, the content of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present invention relates generally to a touchpad, and more particularly to a scrolling method for touchpad. 
     BACKGROUND 
     Although the keyboard remains a primary input device of a computer, the prevalence of graphical user interfaces (GUIs) may require use of a mouse or other pointing device such as a trackball, joystick, touchpad or the like. 
     Touchpads are commonly used on portable electronic devices due to their compact size.  FIG. 1  shows a conventional touchpad  10 , on which three regions are divided for a cursor control region  11 , a horizontal scroll region  12  and a vertical scroll region  13 . In operation, cursor control and scrolling control are performed on their respective, specific regions. For example, when a user wants to move a cursor on a corresponding window, the user operates on the cursor control region  11 . To view portions of documents outside a user interface window, the user may operate the corresponding scroll regions to scroll the documents upward, downward, leftward or rightward. 
     SUMMARY OF THE INVENTION 
     According to one exemplary embodiment of the invention, a method for executing a scroll control operation on a touchpad includes detecting a first simultaneous execution of a first operation executed by a first pointing object, and a second operation executed twice in succession by a second pointing object. The first operation includes detecting a presence of the first pointing object on the touchpad. The second operation includes a contact with the touchpad by the second pointing object, followed by lifting the second pointing object off the touchpad subsequently. The method further includes triggering a scroll control function in response to the detection of the first simultaneous execution of the first operation and the two successive second operations. 
     According to another exemplary embodiment of the invention, a device for executing a scroll control operation on a touchpad comprises a sensing unit and a processing unit. The sensing unit is configured to detect a first simultaneous execution of a first operation executed by a first pointing object and a second operation executed twice in succession by a second pointing object. The first operation includes a contact with the touchpad by the first pointing object. The second operation includes a contact with the touchpad by the second pointing object, followed by lifting the second pointing object off the touchpad subsequently. The processing unit is configured to trigger the scroll control operation in response to the detection of the first simultaneous execution of the first operation and the two successive second operations. 
     According to another exemplary embodiment of the invention, a method for executing a scroll control operation on a touchpad includes predefining at least a first region and a second region on the touchpad, the first region and the second region associated with a first scrolling direction and a second scrolling direction, respectively. The method further includes detecting a presence of a first pointing object on the touchpad and detecting an operation executed twice in succession by a second pointing object in the presence of the first pointing object, the operation including a contact with the touchpad by the second pointing object, followed by lifting the second pointing object off the touchpad subsequently. The method further includes triggering a scroll control operation in the respective scrolling direction in response to the detection of the two successive operations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. The embodiments illustrated in the figures of the accompanying drawings herein are by way of example and not by way of limitation. In the drawings: 
         FIG. 1  illustrates a touchpad device according to the prior art; 
         FIG. 2  is a flow chart describing a method for executing a scroll control operation on a touchpad device according to one exemplary embodiment of the present invention; 
         FIG. 3A  and  FIG. 3B  are schematic diagrams describing a scroll control operation on a touchpad device according to one exemplary embodiment of the present invention; 
         FIG. 4  is a schematic diagram describing terminating a scrolling control operation on a touchpad device according to another exemplary embodiment of the present invention; 
         FIG. 5  is a schematic diagram describing a scrolling control operation on a touchpad device according to another exemplary embodiment of the present invention; 
         FIG. 6  is a schematic diagram describing a scrolling control operation on a touchpad device according to another exemplary embodiment of the present invention; and 
         FIG. 7  is a schematic diagram describing a scrolling control operation on a touchpad device according to another exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. For example, a number of components or objects may be described herein in the singular, plural or as being “at least one” or “one or more.” It should be understood, however, that notwithstanding any particular quantity with which a component or object may be described herein, unless explicitly stated otherwise, the component or object may be in any of a number of different quantities, from the singular to the plural. Like numbers refer to like elements throughout. 
       FIG. 2  is a flow chart describing a method for executing a scroll control operation on a touchpad according to one exemplary embodiment of the present invention (“exemplary” as used herein referring to “serving as an example, instance or illustration”). Referring to  FIG. 2 , the execution process may start at step S 202  and proceed to detecting a first operation at step S 204 . In the first operation, a first pointing object, e.g., a first finger, may come into contact with the touchpad, which may be sensed and detected by a sensing unit. During the execution of the first operation, two successive second operations may be executed at step S 206 . In executing the second operation, the sensing unit may sense and detect a second pointing object, e.g., a second finger, quickly touching the touchpad and lifting off the touchpad. If the first operation and the two successive second operations are simultaneously detected at step S 208 , a scroll control function may be triggered by a processing unit at step S 210 . On the other hand, if the first operation and the two successive second operations are not simultaneously executed, the process will jump to step S 220  to terminate the execution process. If the scroll control function is triggered at step S 208 , the surface of the touchpad that receives the execution process may then be switched from providing cursor control function to provide the scroll control function. An indication of a user initiating a scroll operation over the touchpad is then received and detected at step S 212 . In response to the user&#39;s initiation, the scroll operation is accordingly executed on the touchpad at step S 214 . Then user may be able to operate corresponding scroll regions to scroll documents upward, downward, leftward or rightward. When a termination operation is detected by the processing unit at step S 216 , i.e., another simultaneous execution of the first operation and the two successive second operations is detected again, or a sliding operation on the touchpad is detected by the sensing unit at step S 216 , the scroll control function may be terminated by the processing unit at step S 218 . The execution process is then terminated at step S 220 . If no termination operation is detected at step S 216 , the procedure may proceed to step S 212 . 
       FIG. 3A  and  FIG. 3B  are schematic diagrams describing a scroll control operation on a touchpad  30  according to one exemplary embodiment of the present invention. As illustrated in  FIG. 3A , a first pointing object  31  (e.g., a first finger) is resting on the touchpad  30 , which is accordingly referred as “a first operation” executed by the first finger  31 . The first finger  31  in contact with the touchpad  30  may be sensed and detected by a sensing unit (not shown). In  FIG. 3B , a second pointing object  32  (e.g., a second finger) is placed on the touchpad  30 , followed by lifting the second pointing object  32  off the touchpad  30 . This operation, accordingly referred as “a second operation,” may be executed twice in succession in the presence of the first finger  31  in contact with the touchpad  30 . The two successive second operations are also referred as tapping twice or double click. Detection of the simultaneous execution of the first operation and the two successive second operations may then trigger the scroll control function. 
     In one exemplary embodiment, the scroll control function may be terminated by another simultaneous execution of the first operation and the two successive second operations. In another exemplary embodiment, as shown in  FIG. 4 , sliding a finger on the touchpad  30  from a first place  33  to a second place  34  in any direction, for example, directions A, B, C and D, may terminate the scroll control function. 
       FIG. 5  is a schematic diagram describing a scrolling control operation on a touchpad  30  according to another exemplary embodiment of the present invention. As illustrated in  FIG. 5 , a first region  41  and a second region  42  are predefined on the touchpad  30 . Each of the first region  41  and the second region  42  is associated with a respective scrolling direction. For instances, the first region  41  may be associated with an upward scrolling direction  51  on a user interface  50 . The second region  42  may be associated with a downward scrolling direction  52  on the user interface  50 . In operation, when a user rests a first finger on the first region  41  and double clicks by a second finger in the same region, the scroll control function associated with the first region  41  may be triggered. The first region  41  that may be provided cursor control function is then switched to provide the scroll control function. The touchpad  30  may sense operations on its surface by a sensing unit (not shown) and may communicate with a processing unit (not shown) using varieties of communication protocols, such as a PS/2 protocol or a USB protocol. 
       FIG. 6  is a schematic diagram describing a scrolling control operation on a touchpad device according to another exemplary embodiment of the present invention. As illustrated in  FIG. 6 , four regions,  41 ,  42 ,  43 , and  44  are predefined on the touchpad  30 . Similar to what described in  FIG. 5 , each of the four regions may be associated with a respective scrolling direction on the user interface  50 . For instances, region  41  may be associated with upward scrolling direction  51 . Region  42  may be associated with downward scrolling direction  52 . Region  43  may be associated with leftward scrolling direction  53 . Region  44  may be associated with rightward scrolling direction  54 . In operation, when a user places a first finger on one of the four regions, and double click in the same region, the scroll control function associated with this specific region may be triggered. 
       FIG. 7  is a schematic diagram describing a scrolling control operation on a touchpad device according to another exemplary embodiment of the present invention. Similar to  FIG. 6 , the four main regions  41 ,  42 ,  43 ,  44  are predefined on the touchpad  30 . Each region is associated with a scrolling direction on the user interface  50 . In this embodiment, each of the four regions is further divided into two sub-regions, thereby providing different scrolling rates in one direction. For an instance, the first region  41  may be further divided into two sub-regions  411  and  412 . Accordingly, sub-region  411  and sub-region  412  may provide different scrolling rates in upward direction  51 . 
     According to one aspect of the present invention, the touchpad may include, for example, a sensing unit and a processing unit. When a user&#39;s first finger is resting on the touchpad, the contact with the touchpad may be sensed by the sensing unit, which may be embodied in a number of different manners, such as in the form of a touch-sensitive surface. The sensing unit may simultaneously sense the user&#39;s second finger double clicks. The processing unit may trigger the scroll control function in response to the placement of the first finger simultaneous with the second finger&#39;s double clicks. The processing unit may be embodied in a number of different manners, such as a CPU (Central Processing Unit), microprocessor, coprocessor, controller and/or various other processing devices including integrated circuits such as ASIC (Application Specification Integrated Circuit), FPGA (Field Programmable Gate Array) or the like. As will be appreciated, the processing unit may include or otherwise be configured to communicate with memory, such as volatile memory and/or non-volatile memory, which may store data received or calculated by the processing unit, and may also store one or more software applications, instructions or the like for the processing unit to perform functions associated with operation of the device in accordance with exemplary embodiments of the present invention. 
     All or a portion of the system of the present invention, such as all or portions of the processing unit, generally operates under control of a computer program product. The computer program product for performing the methods of embodiments of the present invention includes a computer-readable storage medium, such as the non-volatile storage medium, and computer-readable program code portions, such as a series of computer instructions, embodied in the computer-readable storage medium. 
     It will be appreciated by those skilled in the art that changes could be made to the examples described above without departing from the broad inventive concept. It is understood, therefore, that this invention is not limited to the particular examples disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.