Abstract:
A detection method for detecting a touch point on a touch panel is provided. The detection method includes: (1) providing a touch panel which is capable of being divided into even unit regions; (2) defining a plurality of unit regions as a detection region by a control unit; (3) detecting the detection region to obtain a position of the touch point in the corresponding unit region by a driving unit; (4) when the detecting is failed to obtain the position, re-defining the number of unit regions consisting of the detection region by the control unit; and (5) when the position is detected, memorizing the position into a memory unit. The number of unit regions defined in the step (4) is equal to a half of the number of unit regions defined in the step (2).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Taiwan application Serial No. 99123621 filed Jul. 19, 2010, the subject matter of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a detection method, and more particularly to a detection method for a touch panel to detect touch points by scanning divided regions. 
         [0004]    2. Description of the Related Art 
         [0005]      FIG. 1  shows a conventional capacitive touch panel. Referring to  FIG. 1 , a capacitive touch panel  1  comprises a plurality of driving lines X 1 -Xn and a plurality of sensing lines Y 1 -Ym. The driving lines X 1 -Xn interlaces with the sensing lines Y 1 -Tm, and one set of the interlaced driving line and sensing line corresponds to one sensing cell. For example, the interlaced driving line X 1  and the sensing line Y 1  corresponds to one sensing cell DC 10 . The touch panel  1  mainly comprises two conductive layers. The driving lines X 1 -Xn are formed on one conductive layer, while the sensing lines Y 1 -Ym are formed on the other conductive layer. Generally, during the detection of touch points, the driving lines X 1 -Xn are scanned one by one. When one driving line is scanned, voltage signals on the sensing lines Y 1 -Ym are read out sequentially, and it is determined whether the corresponding sensing cells have been touched to serve as touch points according to the read voltage signals. 
         [0006]    Assume that reading out the voltage signal of one sensing line takes one unit of time. For the detection of touch points during one frame, it takes n*m units of time. When above detection method for detecting touch points is applied in a touch panel with a large area, much time is consumed for the scanning operation of the driving lines in a non-touch region and the reading operation of the voltage signals on the sensing lines. Thus, the time for detecting touch points is increased, and more hardware resource is used. 
         [0007]    Thus, it is desired to provide a detection method which can efficiently detect touch points for shortening a detection time and decreasing hardware resource consumption. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    An exemplary embodiment of a detection method for detecting a touch point on a touch panel is provided. The detection method comprises (1) providing a touch panel which is capable of being divided into even unit regions; (2) defining a plurality of unit regions as a detection region by a control unit; (3) detecting the detection region to obtain a position of the touch point in the corresponding unit region by a driving unit; (4) when the detecting is failed to obtain the position, re-defining the number of unit regions consisting the detection region by the control unit; and (5) when the position is detected, memorizing the position into a memory unit. The number of unit regions defined in the step (4) is equal to a half of the number of unit regions defined in the step (2). 
         [0009]    An exemplary embodiment of a touch device for controlling a touch penal is provided. The touch panel connecting a plurality of driving lines and a plurality of sensing lines. The driving lines interlace with the sensing lines, and each set of the interlaced driving line and sensing line corresponds to a sensing cell. Each driving line corresponds to a unit region. The touch device comprises a control unit and a driving unit. The control unit initially defines a plurality of unit regions as a detection region. The driving unit is coupled to the control unit and detects the detection region to obtain a position of a touch point in the corresponding unit region. When the driving unit detects the position, the control unit memorizes the position into a memory unit. When the driving unit does not the position, the control unit re-defines the number of unit regions consisting of the detection region. The re-defined number of unit regions is equal to a half of the initial-defined number of unit regions defined by the control unit. 
         [0010]    A detailed description is given in the following embodiments with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
           [0012]      FIG. 1  shows a conventional capacitive touch panel; 
           [0013]      FIG. 2  shows an exemplary embodiment of a touch device; 
           [0014]      FIGS. 3A-3C  are diagrams showing driving-line groups according to an exemplary embodiment; 
           [0015]      FIG. 4  shows an exemplary embodiment of the signal processing unit in  FIG. 2 ; and 
           [0016]      FIG. 5  is a flow chart of an exemplary embodiment of a detection method. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. 
         [0018]    Touch devices are provided. In an exemplary embodiment of a touch device in  FIG. 2 , a touch device  2  comprises a touch panel  20 , driving units  21  and  22 , a signal processing unit  23 , a control unit  24 , and a memory unit  25 . The touch panel  20  connects a plurality of driving lines and a plurality of sensing lines Y 1 -Y 10 . In the embodiment, 16 sixteen driving lines X 1 -X 16  and ten sensing lines Y 1 -Y 10  are given as an example for description. However, the number of the driving lines and the number of sensing lines are not limited to the above example and determined according to system requirements. The driving lines X 1 -X 16  interlace with the sensing lines Y 1 -Y 10 , and one set of the interlaced driving line and sensing line corresponds to one sensing cell. For example, the set of the interlaced driving line X 1  and the sensing line Y 1  corresponds to a sensing cell DC 20 . The driving unit  21  is coupled to the driving lines X 1 -X 16  and scans the driving lines X 1 -X 16  according to a control signal S 21 . The driving unit  22  is coupled to the sensing lines Y 1 -Y 10  and reads out voltage signals on the sensing lines Y- 1 T 10  according to a control signal S 22 . In the embodiment, the region corresponding to one of the driving lines X 1 -X 16  is referred as a unit region. Thus, the touch panel  20  comprises even unit regions. 
         [0019]    When one driving line is scanned by the driving unit  21 , the driving unit  22  reads out the voltage signals on the sensing lines Y 1 -Y 10 , and the signal processing unit  23  receives these voltage signals to determine whether the sensing cells corresponding to the scanned driving line and the sensing lines Y 1 -Y 10  have been touched. The signal processing unit  23  generates a detection signal S 23  according to the determination result. Accordingly, the control unit  24  can generate the control signals S 21  and S 22  according to the detection signal S 23  representing the determination result and also control the driving units  21  and  22  to perform the scanning operation of the sequent driving line and the reading operation of the voltage signals on the sensing lines. 
         [0020]    When it is desired to detect whether one sensing cell in the touch panel  20  has been touched to serve as a touch point, the touch device  2  performs a detection operation to one driving-line group among the driving lines X 1 -X 16 . For example, referring to  FIGS. 2 and 3A , the touch device  2  performs a detection operation to one driving-line group GX 1  composed by the driving lines X 1 -X 8 . In other words, according to the embodiment of the invention, the touch panel  20  is divided into a plurality of sensing regions to increase detection efficiency of the touch panel. The touch device  2  performs the detection operation to a sensing region R 1  of the touch panel  20  which corresponds to the driving-line group GX 1 . 
         [0021]    Referring to  FIG. 3B , in the detection operation of the driving-line group GX 1 , the control unit  24  defines the driving-line group GX 1  as a main driving-line group. The control unit  24  generates the control signal S 21  according to the detection signal S 23  to control the driving unit  21  to sequentially scan a subordinate driving-line group SX 1 , which comprises the driving lines X 1 -X 4 , in the main driving-line group GX 1 . The control unit  24  defines the region, which corresponds to the subordinate driving-line group SX 1 , in the touch panel  20  as a detection region SR 1 . The detection region SR 1  comprises the corresponding unit regions of the driving lines X 1 -X 4 ; that is four unit regions. The control unit  24  also generates the control signal S 22  to control the driving unit  22  to read out the voltage signals on the sensing lines Y 1 -Y 10 . In detail, when the driving unit  21  scans one driving line (such as the driving line X 1 ) in the subordinate driving-line group SX 1  according to the control signal S 21 , the driving unit  22  reads out the voltage signals on the sensing lines Y 1 -Y 10  according to the control signal S 22 , and the signal processing unit  23  receives the read voltage signals to determine whether one of the sensing cells which correspond to the scanned driving line X 1  and the sensing lines Y 1 -Y 10  has been touched. Then, when the driving unit  21  sequentially scans the next driving line X 2  in the subordinate driving-line group SX 1  according to the control signal S 21 , the driving unit  22  reads out the voltage signals on the sensing lines Y 1 -Y 10  according to the control signal S 22 , and the signal processing unit  23  receives the read voltage signals to determine whether one of the sensing cells which correspond to the scanned driving line X 2  and the sensing lines Y 1 -Y 10  has been touched. By performing the scanning operation to the driving lines X 1 -X 4  in the subordinate driving-line group SX 1  and the reading operation of the voltage signals to the sensing lines Y 1 -Y 10 , the signal processing unit  23  can determine whether one of the sensing cells which correspond to the scanned driving lines X 1 -X 4  and the sensing lines Y 1 -Y 10  has been touched. That is, the signal processing unit  23  can detect whether one touch point has occurred in the detection region SR 1 . 
         [0022]    When the signal processing unit  23  determines that one of the sensing cells corresponding to the scanned driving lines X 1 -X 4  and the sensing lines Y 1 -Y 10  has been touched (that is one touch point has occurred in the detection region SR 1 ), the signal processing unit  23  generates the detection signal S 23  to the control unit  24 , so that the control unit  24  memorizes the position of the touched sensing cell in the corresponding unit region in the detection region SR 1  into the memory unit  25  (that is the control unit  24  memorizes the position of the touch point in the corresponding unit region into the memory unit  25 ). Moreover, the touch device  2  stops performing the detection operation to the driving-line group GX 1 , and the detection procedure of touch points is finished. When the touch device  2  performs the next detection procedure of touch points, a detection operation is performed to the sensing region which is not detected in the previous detection procedure of touch points (that is in a sensing region R 2  corresponding to a driving-line group GX 2  in the embodiment). 
         [0023]    When the signal processing unit  23  determines that the sensing cells corresponding to the scanned driving lines X 1 -X 4  and the sensing lines Y 1 -Y 10  have not been touched (that is there is no touch point in the detection region SR 1 ), the touch device  2  performs a detection operation to a subordinate driving-line group SX 2  composed by the driving lines X 5 -X 8 . 
         [0024]    Referring to  FIG. 3C , in the detection operation of the subordinate driving-line group SX 2 , the control unit  24  defines the subordinate driving-line group SX 2  as a main driving-line group. The control unit  24  generates the control signal S 21  according to the detection signal S 23  to control the driving unit  21  to sequentially scan a subordinate driving-line group SX 21  in the main driving-line group SX 2  which comprises the driving lines X 5 -X 6 . The control unit  24  defines the region, which corresponds to the subordinate driving-line group SX 21 , in the touch panel  20  as a detection region SR 21 . The detection region SR 21  comprises the corresponding unit regions of the driving lines X 5 -X 6 ; that is two unit regions. The control unit  24  also generates the control signal S 22  to control the driving unit  22  to read out the voltage signals on the sensing lines Y 1 -Y 10 . By performing the scanning operation to the driving lines X 5 -X 6  in the subordinate driving-line group SX 21  and the reading operation of the voltage signals to the sensing lines Y 1 -Y 10 , the signal processing unit  23  can determine whether one of the sensing cells which correspond to the scanned driving lines X 5 -X 6  and the sensing lines Y 1 -Y 10  has been touched. That is, the signal processing unit  23  can detect whether one touch point has occurred in the detection region SR 21 . When the signal processing unit  23  determines that one of the sensing cells corresponding to the scanned driving lines X 5 -X 6  and the sensing lines Y 1 -Y 10  has been touched (that is one touch point has occurred in the detection region SR 21 ), the signal processing unit  23  generates the detection signal S 23  to the control unit  24 , so that the control unit  24  memorizes the position of the touched sensing cell in the corresponding unit region in the detection region SR 1  into the memory unit  25  (that is the control unit  24  memorizes the position of the touch point in the corresponding unit region into the memory unit  25 ). Moreover, the touch device  2  stops performing the detection operation to the subordinate driving-line group SX 2 . Then, the touch device  2  can be switched to perform a detection operation to the driving-line group GX 2 . When the signal processing unit  23  determines that the sensing cells corresponding to the scanned driving lines X 5 -X 6  and the sensing lines Y 1 -Y 10  have not been touched (that is there is no touch point in the detection region SR 21 ), the touch device  2  performs a detection operation to a subordinate driving-line group SX 22  composed by the driving lines X 7 -X 8 . 
         [0025]    According to  FIGS. 3B-3C , in the detection operation of the driving-line group GX 1 , the detection region SR 1  comprises four unit regions respectively corresponding to the driving lines X 1 -X 4 , and in the detection operation of the subordinate driving-line group SX 2 , the detection region SR 21  comprises two unit regions respectively corresponding to the driving lines X 5 -X 6 . Accordingly, when no touch point is detected in the detection region SR 1 , the number of unit regions consisting of the detection region SR 21  which is detected sequentially is equal to a half of the number of unit regions consisting of the detection region SR 1 . 
         [0026]    According to the above description, by repeatedly defining a main driving-line group (that is a detection region) to repeatedly perform a detection operation, it can be detected whether one of the sensing cells which correspond the driving lines X 1 -X 8  and the sensing lines Y 1 -Y 10  has been touched. When the control unit  24  determines that the touch device  2  did not detect one touched sensing cell after the touch panel  2  performed the detection operations by a predetermined number, the driving unit  21  scans the driving lines which have not experienced a detection operation yet according to the control signal S 21  to detect whether one of the corresponding sensing cells has been touched. If no touched sensing cell is detected, the touch device  2  performs the same detection operation of the driving-line group GX 1  to the driving-line group GX 2  composed by the driving lines X 9 -X 16 . In other words, the touch device  2  performs the detection operation to the sensing region R 2  of the touch panel  20  corresponding to the driving-line group GX 2 . 
         [0027]    For example, assume that the predetermined number is equal to two. When the control unit  24  determines that the touch device  2  did not detect one touched sensing cell after the touch panel  2  performed the detection operation for two times (that is the number of detecting times is equal to two; one detection operation for the driving-line group GX and the other detection operation for the subordinate driving-line group SX 2 ), the driving unit  21  scans the subordinate driving-line group SX 22  according to the control signal S 21  to detect whether one of the corresponding sensing cells has been touched. If no touched sensing cell is detected, the touch device  2  performs the same detection operation of the driving-line group GX 1  to the driving-line group GX 2  composed by the driving lines X 9 -X 16 . If it is detected that one of the sensing cells which correspond to the subordinate driving-line group SX 22  has been touched, the signal processing unit  23  generates the detection signal S 23  to the control unit  24 , so that the control unit  24  memorizes the position of the touched sensing cell in the corresponding unit region in the detection region SR 12  into the memory unit  25  (that is the control unit  24  memorizes the position of the touch point in the corresponding unit region into the memory unit  25 ). The touch device  2  then can be switched to perform a detection operation to the driving-line group GX 2 . 
         [0028]    Thus, by repeatedly defining a man driving-line group in the driving-lines group GX 2  to repeatedly perform a detection operation, it can be detected whether one of the sensing cells which correspond to the driving lines X 9 -X 16  and the sensing lines Y 1  Y 10  has been touched. 
         [0029]    The above predetermined number is set as two for an example of the embodiment without limitation. The predetermined number can be determined according to system requirements and size of applied touch panels. 
         [0030]    In the embodiment, the number of driving lines in the driving-line group GX 1  is equal to the number of driving lines in the driving-line group GX 2 . Moreover, for each detection operation, one main driving-line group is divided into two subordinate driving-line groups, and the number of driving lines in one subordinate driving-line group is equal to the number of driving lines in the other subordinate driving-line group. 
         [0031]    In other embodiments, the area of the detection region R 1  corresponding to the driving-line group GX 1  is equal to the area of the detection region R 2  corresponding to the driving-line group GX 2 . 
         [0032]    According to the above embodiment, the driving lines X 1 -X 16  are divided into several groups. When the touch panel  2  desires to detect whether one sensing cell in the touch panel  20  has been touched, the control unit  24  controls the driving unit  21  to perform a detection operation to one driving-line group each time until one touched sensing cell is detected. Thus, each time when the touch device  2  desires to detect whether one sensing cell in the touch panel  20  has been touched, the control unit  24  does not require scanning all of the driving lines X 1 -X 16 ; thereby shortening detection duration and degrading resource consumption. 
         [0033]      FIG. 4  shows an exemplary embodiment of the signal processing unit  23  in  FIG. 1 . Referring to  FIG. 4 , the signal processing unit  23  comprises an amplifier (AMP)  40 , an analog-to-digital converter (ADC)  41 , and a comparator (COMP)  42 . When one driving lines is scanned, the amplifier  40  receives and amplifies the voltage signals from the sensing lines Y 1 -Y 10  sequentially. The ADC  41  converts the voltage signals of each sensing line from the analog format to the digital format for back-end digital circuits. When one driving line is scanned, the comparator  42  compares the voltage signals of the sensing lines with one reference voltage signal Vref and determines whether the corresponding sensing cell has been touched according to the comparison result to generate the detection signal S 23 . Accordingly, the control unit  24  generates the control signals S 21  and S 22  according to the detection signal S 23 , so that the driving unit  21  performs a scanning operation to the corresponding driving line, and the driving unit  22  performs a reading operation the corresponding sensing line. 
         [0034]      FIG. 5  is a flow chart of an exemplary embodiment of a detection method. The detection method of  FIG. 5  may be applied to the touch device  2  of  FIG. 2 . First, the touch panel  20  is divided into two sensing regions R 1  and R 2  (Step S 50 ). A detection operation is performed to the sensing region R 1  to detect a touch point (Step S 51 ). In the detection operation, the sensing region R 1  is defined as a main region (Step S 52 ). The main region R 1  is divided into two regions SR 1  and SR 2 , and the region SR 1  is defined as a detection region (Step S 53 ). The detection region SR 1  comprises the corresponding unit regions of the driving lines X 1 -X 4 ; that is, four unit regions. Then, it is detected whether one touch point has occurred in the detection region SR 1  (Step S 54 ). When one touch point has occurred in the detection region SR 1  (that is the position of the touch point is detected), the position of the touch point in the corresponding unit region in the detection region SR 1  is memorized (Step S 55 ), and a detection operation is performed to the sensing region R 2  (Step S 59 ). Then, the detection method returns to Step S 52 . When no touch point has occurred in the detection region SR 1  (that is the detecting is failed), it is determined whether the number of times of performing a detection operation (hereafter “the number of detecting times”) is equal to a predetermined number (Step S 56 ). In the embodiment, the predetermined number is set as two. Since the number of detecting times is one (to the sensing region R 1 ) which is less than the predetermined number, a detection operation is performed to the region SR 2  (Step S 60 ). 
         [0035]    At this time, the detection method returns to Step S 52 , and the region SR 2  is defined as a main region (Step S 52 ). The main region SR 1  is divided into two regions SR 21  and SR 22 , and the region SR 21  is defined as a detection region (Step S 53 ). The detection region SR 21  comprises the corresponding unit regions of the driving lines X 5 -X 6 ; that is, two unit regions. Then, it is detected whether one touch point has occurred in the detection region SR 21  (Step S 54 ). When one touch point has occurred in the detection region SR 21 , the position of the touch point in the corresponding unit region in the detection region SR 21  is memorized (Step S 55 ), and a detection operation is performed to the sensing region R 2  (Step S 59 ). Then, the detection method returns to Step S 52 . When no touch point has occurred in the detection region SR 21 , in Step S 56 , it is determined that the number of detecting times is equal to two (one detection operation for the sensing region R 1 , and the other detection operation for the region SR 2 ) which is equal to the predetermined number. Then, it is detected whether one touch point has occurred in the other region SR 22  of the main region SR 2  (Step S 57 ). When no touch point has occurred in the region SR 22 , a detection operation is performed to the sensing region R 2  (Step S 59 ), and then the detection method returns to Step S 52 . When one touch point has occurred in the region SR 22 , the position of the touch point in the corresponding unit region in the region SR 22  is memorized (Step S 58 ). Then, a detection operation is performed to the sensing region R 2  (Step S 59 ), and then the detection method returns to Step S 52 . 
         [0036]    In the above embodiment, the area of the sensing region R 1  is equal to the area of the sensing region R 2 . Moreover, for each detection operation (Step S 52 -Step S 60 ), one main region is divided into two regions, and the area of one region is equal to the area of the region. 
         [0037]    According to the above embodiment, the touch panel  20  is divided into several regions. When the touch device  2  desires to detect whether one sensing cell in the touch panel  20  has been touched, the control unit  24  controls the driving unit  21  to scan one driving-line group without scanning all of the driving lines X 1 -X 16  one by one; thereby shortening detection duration and degrading resource consumption. 
         [0038]    While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.