Patent Publication Number: US-2009237357-A1

Title: Method And Cursor-Generating Device For Generating A Cursor Extension On A Screen Of An Electronic Device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of Taiwanese application no. 097110350, filed on Mar. 24, 2008. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a method and cursor-generating device for generating a cursor extension on a screen of an electronic device. 
     2. Description of the Related Art 
     A conventional electronic device, which includes a touchscreen, allows selection of an object, such as an icon or a menu item, displayed on the touchscreen with the use of a stylus or the user&#39;s finger. Many users prefer to use their fingers to save the time and effort required to retrieve and handle the stylus. However, selection of the objects with the use of a finger is slow and is error prone. Two pointing techniques have been proposed heretofore to address these issues. 
     In the first pointing technique, as illustrated in  FIG. 1 , when a tip of a user&#39;s finger  1  is detected on a touchscreen (not shown), and when the tip of the user&#39;s finger  1  overlaps multiple objects  11 , a cursor extension  10  is generated on the touchscreen, which thereafter may be moved to select one of the objects  11 . 
     In the second pointing technique, called Shift, as illustrated in  FIG. 2 , when a tip of a user&#39;s finger  1  is detected on a touchscreen (not shown), and when the tip of the user&#39;s finger  1  overlaps multiple objects  11 , a window  20  is generated on the touchscreen. The window  20  shows the overlapped objects, and a cursor extension  21 , which thereafter may be moved to select one of the objects, e.g., the object  22 , shown in the window  20 . 
     The aforementioned two conventional pointing techniques are disadvantageous in that the tip of the user&#39;s finger  1  has to be moved along the touchscreen in order to move the cursor extension  11 ,  21 . Moreover, the two conventional pointing techniques do not resolve the issue of the difficulty in selecting an object on the edge of the touchscreen. 
     SUMMARY OF THE INVENTION 
     Therefore, the main object of the present invention is to provide a method for generating a cursor extension on a screen of an electronic device that can overcome the aforesaid drawbacks of the prior art. 
     Another object of the present invention is to provide a cursor-generating device for generating a cursor extension on a screen of an electronic device that can overcome the aforesaid drawbacks of the prior art. 
     According to an aspect of the present invention, a method for generating a cursor extension on a screen of an electronic device comprises the steps of: 
     A) detecting presence of at least one touched spot on a touchpad of the electronic device; and 
     B) deciding whether to generate the cursor extension based on an attribute of the at least one touched spot detected in step A). 
     According to another aspect of the present invention, a cursor-generating device is adapted for generating a cursor extension on a screen of an electronic device, and comprises a detecting unit that is adapted to be coupled to a touchpad of the electronic device and that is operable so as to detect presence of at least one touched spot on the touchpad, and a processing unit that is coupled to the detecting unit, that is adapted to be coupled to the screen, and that is operable so as to decide whether to enable generation of the cursor extension on the screen based on an attribute of the at least one touched spot detected by the detecting unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which: 
         FIG. 1  is a schematic diagram illustrating a conventional pointing technique for generating and moving a cursor extension; 
         FIG. 2  is a schematic diagram illustrating another conventional pointing technique for generating and moving a cursor extension; 
         FIG. 3  is a block diagram of the preferred embodiment of a cursor-generating device according to this invention; 
         FIG. 4  is a schematic diagram illustrating a cursor extension generated by the preferred embodiment; 
         FIGS. 5A to 5C  are flow charts of the preferred embodiment of a method for generating a cursor extension to be implemented using the cursor-generating device shown in  FIG. 3  according to this invention; 
         FIGS. 6 to 9  are schematic diagrams illustrating states where a cursor extension is generated; and 
         FIGS. 10 to 12  are schematic diagrams illustrating states where the cursor extension is moved. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 3 and 4 , the preferred embodiment of a cursor-generating device  400  according to this invention is shown to include a detecting unit  41  and a processing unit  42 . 
     The cursor-generating device  400  of this invention is applicable to an electronic device  4  that includes a screen  43 , such as a liquid crystal display (LCD), and a touchpad  40 , such as a planar or a non-planar capacitive touchpad. 
     The electronic device  4  may be a notebook computer, a personal digital assistant (PDA), a mobile phone, or a global positioning system (GPS). 
     The cursor-generating device  400  is used to generate a cursor extension on the screen  43  to thereby assist a user of the touchpad  40  to select an object (not shown) (e.g., a key of a virtual keyboard, an icon, an item in a menu, etc.) displayed on the screen  43 . 
     In this embodiment, the screen  43  and the touchpad  40  constitute a touchscreen. That is, the touchpad  40  is mounted on the screen  43 . In an alternative embodiment, the screen  43  and the touchpad  40  are separated from each other. 
     The detecting unit  41  is connected electrically to the touchpad  40 , and is operable so as to detect presence of at least one touched spot  80  impressed by a user&#39;s finger on the touchpad  40 . In this embodiment, the detecting unit  41  is a touch controller implemented in a hardware circuit. 
     The processing unit  42 , which includes a microprocessor (not shown), is connected electrically to the detecting unit  41  and the screen  43 , and is operable so as to decide whether to enable generation of a cursor extension on the screen  43  based on an attribute of the at least one touched spot  80  detected by the detecting unit  41 , in a manner that will be described hereinafter. 
     In this embodiment, the cursor extension generated on the screen  43  includes a symbol  81 , and a line  82  that extends between the symbol  81  and a position on the screen  43  that corresponds to the touched spot  80  detected by the detecting unit  41 . 
     The preferred embodiment of a method for generating the cursor extension to be implemented using the aforementioned cursor-generating device  400  according to this invention will now be described with further reference to  FIGS. 5A to 5C . 
     In step  50 , the detecting unit  41  detects at least one touched spot  80  on the touchpad  40  of the electronic device  4 . Thereafter, the detecting unit  41  sends coordinates of the at least one touched spot  80  detected thereby to the processing unit  42 . 
     In step  51 , when the processing unit  42  determines that the number of the touched spots  80  on the touchpad  40  detected in step  50  is one, the flow proceeds to step  52 . Otherwise, the flow proceeds to step  62 . 
     In step  52 , when the processing unit  42  determines that the touched spot  80  detected in step  50  remains on the touchpad  40  for a time duration that exceeds a predetermined threshold, e.g., two seconds, the flow proceeds to step  53 . Otherwise, the flow proceeds to step  65 . 
     In this step, the processing unit  42  activates a timer (not shown) that measures the time duration within which the touched spot  80  remains on the touchpad  40  upon receipt of the coordinates of the touched spot  80  sent by the detecting unit  41 . 
     In step  53 , the processing unit  42  generates a cursor extension. Thereafter, the flow proceeds to step  54 . 
     In step  62 , as illustrated in  FIG. 6 , when the processing unit  42  determines that the number of the touched spots  80  on the touchpad  40  detected in step  50  is two, the flow proceeds to step  63 . Otherwise, the flow is terminated. 
     In step  63 , when the processing unit  42  determines that the number of the touched spots  80  on the touchpad  40  detected in step  50  changes from two to one, i.e., one of the touched spots  80  vanishes, and that the change in the number of the touched spots  80  on the touchpad  40  occurs within a predetermined time period, e.g., one second, the flow proceeds to step  64 . Otherwise, the flow is terminated. 
     In step  64 , the processing unit  42  generates the cursor extension. Thereafter, the flow proceeds to step  54 . 
     In this step, as illustrated in  FIG. 7 , the cursor extension is generated at a position on the screen  43  that corresponds to a vanished one of the touched spots  80 , and is manipulated through a remaining one of the touched spots  80  on the touchpad  40 . 
     In step  65 , as illustrated in  FIG. 8 , when the processing unit  42  determines that the number of the touched spots  80  on the touchpad  40  detected in step  50  changes from one to two, the flow proceeds to step  66 . Otherwise, the flow proceeds to step  52 . 
     In step  66 , the processing unit  42  generates the cursor extension. Thereafter, the flow proceeds to step  54 . 
     In this step, as illustrated in  FIG. 9 , the cursor extension is generated at a position on the screen  43  that corresponds to an initial one of the touched spots  80  detected in step  50  and is manipulated through a latter one of the touched spots  80  detected in step  50 . 
     In step  54 , when the processing unit  42  determines a change in an area of the touched spot  80  detected in step  50  on the touchpad  40 , the flow proceeds to step  55 . Otherwise, the flow proceeds to step  56 . 
     For example, in this step, the processing unit  42  may determine an increase or a decrease of approximately 10 mm 2  from the previous area of the touched spot  80  on the touchpad  40 . 
     In step  55 , the processing unit  42  adjusts a distance between the symbol  81  of the cursor extension generated in step  53 ,  64 , or  66  and a position on the screen  43  that corresponds to the touched spot  80  detected in step  50  on the touchpad  40  based on the change in the area of the touched spot  80  determined in step  54 . 
     In this step, as illustrated in  FIG. 10 , the processing unit  42  lengthens or shortens the line  82  of the cursor extension to thereby adjust the distance between the symbol  81  of the cursor extension and the position on the screen  43  that corresponds to the touched spot  80 . 
     In step  56 , when the processing unit  42  determines a change in an angular orientation of the touched spot  80  detected in step  50  on the touchpad  40 , the flow proceeds to step  57 . Otherwise, the flow proceeds to step  58 . 
     For example, in this step, the processing unit  42  may determine a 20-degree change in the angular orientation of the touched spot  80  on the touchpad  40 . 
     In step  57 , the processing unit  42  moves the cursor extension generated in step  53 ,  64 , or  66  in a direction that corresponds to the change in the angular orientation of the touched spot  80  determined in step  56 . Thereafter, the flow proceeds to step  58 . 
     For example, as illustrated in  FIG. 11 , the processing unit  42  may change the direction of the cursor extension by 20 degrees or a multiple of 20 degrees, such as 100 degrees. 
     In step  58 , the detecting unit  41  detects presence of another touched spot  80  on the touchpad  40 . 
     In step  59 , when the processing unit  42  determines that a position on the screen  43  that corresponds to the touched spot  80  detected in step  58  overlaps a position of the cursor extension generated in step  53 ,  64 , or  66 , the flow proceeds to step  60 . Otherwise, the flow proceeds to step  61 . 
     In step  60 , the processing unit  42  adjusts a distance and a relative direction between the cursor extension generated in step  53 ,  64 , or  66  and a position on the screen  43  that corresponds to the touched spot  90  detected in step  50  based on the touched spot  80  detected in step  58 . 
     For example, as illustrated in  FIG. 12 , when the processing unit  42  determines that the touched spot  80  detected in step  58  is moved upwardly toward the left, the processing unit  42  moves the symbol  81  of the cursor extension to a position on the screen  43  that corresponds to the touched spot  80  detected in step  58 . 
     In step  61 , when the processing unit  42  determines that the cursor extension overlaps an object and that the touched spot  80  detected in step  50  vanishes, the flow is terminated. Otherwise, the flow goes back to step  54 . 
     It is noted that, in this embodiment, aside from the time duration within which the touched spot  80  detected in step  50  remains on the touchpad  40  and the change in the number of the touched spots  80  detected in step  50 , the cursor extension is likewise generated when an area of the touched spot  80  detected in step  50  exceeds a corresponding predetermined threshold. 
     Furthermore, in an alternative embodiment, instead of a capacitive touchpad, the touchpad  40  of the electronic device  4  may be an optical touchpad. In this case, the optical touchpad  40  captures an image of a touched spot  80  thereon, which is thereafter detected by the detecting unit  41 . The processing unit  42  may adjust a distance between a cursor extension generated on the screen  43  and a position on the screen  43  that corresponds to the touched spot  80  on the touchpad  40  based on the change in an area of the image of the touched spot  80  detected by the detecting unit  41 . In addition, the processing unit  42  may move the cursor extension generated on the screen  43  in a direction that corresponds to an angular orientation of the image of the touched spot  80  detected by the detecting unit  41 . 
     It has thus been shown that, unlike the conventional pointing techniques, which require movement of a user&#39;s finger along a touchscreen in order to move a cursor extension, this invention permits movement of the cursor extension by simply changing an angular orientation of the touched spot  80  on the touchpad  40  and varying an area of the touched spot  80  on the touchpad  40 . As such, selection of objects displayed on the screen  43 , even those objects that are on the edge of the screen  43 , is relatively easy, fast, and accurate. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.