Abstract:
A touch control device and a method thereof are disclosed. A driving voltage is applied to a first conductive layer of the touch control device. A second conductive layer is connected via scanning lines to a scan sensing circuit. To detect the location where a touch or depression occurs, the scan sensing circuit repeatedly and sequentially scans first ends of multiple elongate conductive strips that constitute the second conductive layer. The coordinates of the location of the depression is determined on the basis of the scanning result that the scan sensing circuit performs over the elongate conductive strips of the second conductive layer and the voltage that the first conductive layer applies to one or more of the elongate conductive strips of the second conductive layer that correspond to the location of the depression. The second ends of the elongate conductive strips of the second conductive layer can also be connected to the scan sensing circuit via scanning lines to allow the scan sensing circuit to perform scanning operation over the first and second ends of the elongate conductive strips of the second conductive layer in a sequential and repeated manner.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a touch control device, and in particular to a sequentially-scanning touch control device and a method thereof. 
       BACKGROUND OF THE INVENTION 
       [0002]    A conventional touch panel includes a glass substrate having a top surface coated with a layer of transparent conductor, such as ITO conductive layer. The glass substrate and the transparent conductive layer together form a piece of electrically conductive glass panel. The electrically conductive glass panel is provided with another glass substrate or film arranged thereabove, and the another glass substrate or film is coated, on a bottom surface thereof, with a transparent conductive layer, corresponding to the transparent conductive layer of the glass panel. Insulation spacers are arranged between the transparent conductive layers of the glass panel and the film to space the transparent conductive layers. 
       SUMMARY OF THE INVENTION 
       [0003]    Various designs and constructions of touch control panels or touch control devices are available currently, each using different scanning techniques and calculations to determine the location of a touch or depression of the touch control device. However, each known technique has its own drawbacks. For example, some touch control panels require complicated circuit structure for detecting the location of the depression, and some use very complicated processes and calculation formulas to determine the location of the depression. 
         [0004]    Thus, an objective of the present invention is to provide a touch control device, wherein a location of a depression can be easily detected and determined by a micro-controller by simply carrying out sequential scanning operation at one or both ends of one of two conductive layers of the touch control device, while maintaining a uniform electrical potential or establishing a potential gradient on the other one of the conductive layers. 
         [0005]    Another objective of the present invention is to provide a method for detecting a location of a depression by sequentially scanning terminal ends of elongate conductive strips on a specific side or both sides of conductive layers of a touch control device, wherein sequential scanning operation is performed over the ends of the elongate conductive strips of a specific side or both sides and a micro-controller determines the location of the depression based on the voltage detected at the elongate conductive strips. 
         [0006]    In accordance with the present invention, a solution to the above problems resides in that a driving voltage, which is a uniform electrical potential or a gradient of potential, is applied to a first conductive layer of a touch control device. A second conductive layer is connected at one end or both ends thereof, to a scan sensing circuit via scanning lines. To detect the location where a touch or depression occurs, the scan sensing circuit repeatedly and sequentially scans first ends of multiple elongate conductive strips that constitute the second conductive layer. The coordinates of the location of the depression is determined on the basis of the scanning result that the scan sensing circuit performs over the elongate conductive strips of the second conductive layer and the voltage that the first conductive layer applies to one or more of the elongate conductive strips of the second conductive layer that correspond to the location of the depression. 
         [0007]    In accordance with the present invention, the detection of the location of the depression is carried out by performing scanning operation over one end or both end of each elongate conductive strip of a conductive layer of the touch control device and thus the control of the scanning operation and the scanning circuit required for the scanning operation are both simple. Further, in the calculation and determination of the location of the depression, the micro-controller only needs to work on simple formula for calculating voltage to detect the location of the depression on the elongate conductive strip. Compared to the known techniques, the present invention is advantageous in easy and efficient calculation and simple circuit construction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof and the best mode for carrying out the present invention, with reference to the attached drawings, in which: 
           [0009]      FIG. 1  illustrates a system block diagram of a touch control device in accordance with a first embodiment of the present invention; 
           [0010]      FIG. 2  shows a conductive layer formed on a first substrate of the touch control device opposing a second conductive layer formed on a second substrate of the touch control device when the first and second substrates are assembled together, the first and second substrates being spaced from each other by a plurality of insulation spacers; 
           [0011]      FIG. 3  shows a sequence table that a scan sensing circuit of the touch control device of the present invention takes to sequentially scan first ends of elongate conductive strips of the second conductive layer of the touch control device of the present invention; 
           [0012]      FIG. 4  shows a system block diagram of a touch control device in accordance with a second embodiment of the present invention; 
           [0013]      FIG. 5  shows a sequence table that a scan sensing circuit of the touch control device of the present invention takes to sequentially scan first and second ends of elongate conductive strips of a second conductive layer of the touch control device in accordance with the second embodiment of the present invention; 
           [0014]      FIG. 6  shows a system block diagram of a touch control device in accordance with a third embodiment of the present invention; 
           [0015]      FIG. 7  shows a potential gradient established in a first conductive layer of the touch control device in accordance with the third embodiment illustrated in  FIG. 6 ; 
           [0016]      FIG. 8  shows a system block diagram of a touch control device in accordance with a fourth embodiment of the present invention; 
           [0017]      FIG. 9  shows a system block diagram of a touch control device in accordance with a fifth embodiment of the present invention; 
           [0018]      FIG. 10  shows the spatial relationship of a first conductive layer formed on a first substrate of the touch control device in accordance with the fifth embodiment illustrated in  FIG. 9  with respect to a second conductive layer formed on a second substrate when the first and second substrates are assembled together; 
           [0019]      FIG. 11  shows a system block diagram of a touch control device in accordance with a sixth embodiment of the present invention; 
           [0020]      FIG. 12  shows a system block diagram of a touch control device in accordance with a seventh embodiment of the present invention 
           [0021]      FIG. 13  shows a potential gradient established in a first conductive layer of the touch control device in accordance with the seventh embodiment illustrated in  FIG. 12 ; and 
           [0022]      FIG. 14  shows a system block diagram of a touch control device in accordance with an eighth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    With reference to the drawings and in particular to  FIG. 1 , which illustrates a system block diagram of a touch control device in accordance with a first embodiment of the present invention, the touch control device, which is generally designated at  100 , comprises a first substrate  1  and a second, opposite substrate  2 . The first substrate  1  has a bottom surface on which a first conductive layer  10  is formed in a continuous planar structure. The second substrate  2  has a top surface on which a second conductive layer  21  is formed. For the state-of-art technology of touch control panels, it is often to coat a layer of transparent conductor, such as ITO conductive layer, on a surface of a glass substrate to serve as both the continuous planar structure of the first conductive layer  10  and the second conductive layer  21 . 
         [0024]      FIG. 2  shows the continuous planar structure of the first conductive layer  10  opposing the second conductive layer  2  when the first and second substrates  1 ,  2  are assembled together. The first and second substrates  1 ,  2  are spaced from each other by a plurality of insulation spacer  3 . 
         [0025]    The continuous planar structure of the first conductive layer  10  is formed by uniformly coating a transparent conductive layer on the bottom surface of the first substrate  1  and a driving voltage V of a preset voltage level is applied from a driving voltage supply circuit  4  to the continuous planar structure of the first conductive layer  10  to thereby establish a uniform electric potential on the continuous planar structure of the first conductive layer  10 . 
         [0026]    The second conductive layer  21  is comprised of a plurality of elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn, which are electrically insulated and substantially parallel to each other. Each elongate conductive strip Y 1 , Y 2 , Y 3 , . . . , Yn is extended in a first direction Y on the top surface of the second substrate  2 . 
         [0027]    Each elongate conductive strip Y 1 , Y 2 , Y 3 , . . . , Yn of the second conductive layer  2  has a first end Y 1   a , Y 2   a , Y 3   a , . . . , Yna, which is connected to a scan sensing circuit  6  by scanning lines  61 , an example being a conventional multiplexer. Each elongate conductive strip Y 1 , Y 2 , Y 3 , . . . , Yn of the second conductive layer  2  also has a second end Y 1   b , Y 2   b , Y 3   b , . . . , Ynb, which is set in an open condition. A micro-controller  5  controls, via a scan control signal S 2 , the scan sensing circuit  6  to carry out sequential scanning over the first end Y 1   a , Y 2   a , Y 3   a , . . . , Yna of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn to detect physical engagement of any one of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn with the continuous planar structure of the first conductive layer  10 , as being physically depressed or actuated, and the location or the actuation/depression. 
         [0028]      FIG. 3  shows a sequence table that the scan sensing circuit  6  takes to sequentially scan the first ends Y 1   a , Y 2   a , Y 3   a , . . . , Yna of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn. At the first time point t 11 , the scan sensing circuit  6  first carries out scanning over the first end Y 1   a  of the elongate conductive strip Y 1 . Then, at the second time point t 12 , the first end Y 2   a  of the elongate conductive strip Y 2  is scanned, and at the third time point t 13 , the first end Y 3   a  of the elongate conductive strip Y 3  is scanned. The scanning operation is repeated in sequence for each of the elongate conductive strips and finally, at the nth time point t 1   n , the first end Yna of the elongate conductive strip Yn is scanned. Once the cycle of scanning is completed, the previous process is repeated again for sequentially scanning the ends of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn. 
         [0029]    The scanning operation that the scan sensing circuit  6  performs over the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn of the second conductive layer  21  provides a scan sensing signal S 3 , which is converted by an analog-to-digital converter  7  into a digital scan sensing signal, and the digital scan sensing signal is applied to the micro-controller  5 . 
         [0030]    When the surface of the first substrate  1  is depressed, the continuous planar structure of the first conductive layer  1  is forced to engage the second conductive layer  21  at the location or point where the depression occurs. Thus, according to the location of the depression, the continuous planar structure of the first conductive layer  10  applies the driving voltage V to the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn of the second conductive layer  21  that correspond to the location of the depression. The micro-controller  5  bases on the scan sensing signal S 3  that is generated by the scanning operation carried out on the elongated conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn of the second conductive layer  2  by the scan sensing circuit  6  to calculate and determine the coordinates of X and Y axes of the location of the depression. 
         [0031]    For example, when a user touches and depresses down the continuous planar structure of the first conductive layer  10  to cause engagement with the third elongate conductive strip Y 3  of the second conductive layer  21 , the driving voltage V that is present on the continuous planar structure of the first conductive layer  10  is applied to the third elongate conductive strip Y 3  of the second conductive layer  21 . 
         [0032]    When the scan sensing circuit  6  scans over the third elongate conductive strip Y 3  of the second conductive layer  21 , it can be determined that the location of the depression by the user is on the third elongate conductive strip Y 3 . Then the micro-controller  5  bases on the voltage that is caused by the driving voltage V and is detected at the first end Y 3   a  of the third elongate conductive strip Y 3  to calculate and determine the X, Y coordinates of the location of the depression by the user. 
         [0033]      FIG. 4  shows a system block diagram of a touch control device  100   a  in accordance with a second embodiment of the present invention. The second embodiment (touch control device  100   a ) is substantially identical to the first embodiment (touch control device  100 ) with the exception that besides the first ends Y 1   a , Y 2   a , Y 3   a , . . . , Yna of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn of the second conductive layer  21  being connected to the scan sensing circuit  6  via the scanning lines  61 , the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn also have second ends Y 1   b , Y 2   b , Y 3   b , . . . , Ynb that are connected to the scan sensing circuit  6  by other scanning lines  61   a . Thus, the scan sensing circuit  6  can carry out scanning operation, in a sequential manner, over the first ends Y 1   a , Y 2   a , Y 3   a , . . . , Yna and the second ends Y 1   b , Y 2   b , Y 3   b , . . . , Ynb of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn, respectively via the scanning lines  61 ,  61   a , in order to detect the engagement of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn with respect to the continuous planar structure of the first conductive layer  10  due to being touched and depressed, as well as the location of the depression. 
         [0034]      FIG. 5  shows a sequence table that the scan sensing circuit  6  takes to sequentially scan the first ends Y 1   a , Y 2   a , Y 3   a , . . . , Yna and the second ends Y 1   b , Y 2   b , Y 3   b , . . . , Ynb of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn. The scan sensing circuit  6  carries out scanning operation over the first ends Y 1   a , Y 2   a , Y 3   a , . . . , Yna of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn in sequence at different time points t 11 , t 12 , t 13 , . . . , t 1   n , and then sequentially scans the second ends Y 1   b , Y 2   b , Y 3   b , . . . , Ynb of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn at different time points t 21 , t 22 , t 23 , . . . , t 2   n . Once a cycle of scanning operation over the ends of the elongate conductive strips is completed, the whole scanning operation is repeated to once again sequentially scanning the first and second ends of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn. 
         [0035]      FIG. 6  shows a system block diagram of a touch control device  100   b  in accordance with a third embodiment of the present invention. The third embodiment (touch control device  10   b ) is substantially identical to the first embodiment (touch control device  100 ) and the difference between the two embodiments resides in that in the touch control device  100   b  of the third embodiment, the driving voltage V of a preset voltage level is applied to an end of the continuous planar structure of the first conductive layer  10  and an opposite end of the continuous planar structure of the first conductive layer  10  is grounded via a grounding line G, whereby a potential gradient is established on the continuous planar structure of the first conductive layer  10 , as illustrated in  FIG. 7 . 
         [0036]      FIG. 8  shows a system block diagram of a touch control device  100   c  in accordance with a fourth embodiment of the present invention. The fourth embodiment (touch control device  100   c ) is substantially identical to the second embodiment (touch control device  100   a ) illustrated in  FIG. 4  and the difference between the two embodiments resides in that in the touch control device  100   c  of the fourth embodiment, the driving voltage V of a preset voltage level is applied to an end of the continuous planar structure of the first conductive layer  10  and an opposite end of the continuous planar structure of the first conductive layer  10  is grounded via a grounding line G, whereby a potential gradient is established on the continuous planar structure of the first conductive layer  10 . 
         [0037]      FIG. 9  shows a system block diagram of a touch control device  100   d  in accordance with a fifth embodiment of the present invention. The fifth embodiment (touch control device  100   d ) is substantially identical to the first embodiment (touch control device  100 ) illustrated in  FIG. 1  and the difference between the two embodiments resides in that in the touch control device  100   d  of the fifth embodiment, the continuous planar structure of the first conductive layer  10  of the touch control device  100  of the first embodiment is replaced by a first conductive layer  11  having a structure composed of elongated conductive strips. The first conductive layer  11  comprises a plurality of elongate conductive strips X 1 , X 2 , X 3 , . . . , Xn that together is equivalent to the continuous planar structure adopted in the previous embodiments. The elongate conductive strips X 1 , X 2 , X 3 , . . . , Xn are electrically insulated and substantially parallel to each other. Each of the elongate conductive strips X 1 , X 2 , X 3 , . . . , Xn extends in a second direction X on the bottom surface of the first substrate  1  and each elongate conductive strip X 1 , X 2 , X 3 , . . . , Xn has opposite first and second ends. For example, the ends of the elongate conductive strip X 1  are first end X 1   a  and second end X 1   b.    
         [0038]      FIG. 10  illustrates the spatial relationship of the first conductive layer  11  with respect to the second conductive layer  21  when the first and second substrates  1 ,  2  shown in  FIG. 9  are assembled together. The first and second substrates  1 ,  2  are spaced from each other by insulation spacer  3 . 
         [0039]      FIG. 11  shows a system block diagram of a touch control device  10   e  in accordance with a sixth embodiment of the present invention. The sixth embodiment (touch control device  100   e ) is substantially identical to the fifth embodiment (touch control device  100   d ) illustrated in  FIG. 9  and the difference between the two embodiments resides in that besides the first ends Y 1   a , Y 2   a , Y 3   a , . . . , Yna of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn of the second conductive layer  21  being connected to the scan sensing circuit  6  via the scanning lines  61 , the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn also have second ends Y 1   b , Y 2   b , Y 3   b , . . . , Ynb that are connected to the scan sensing circuit  6  by other scanning lines  61   a . Thus, the scan sensing circuit  6  can carry out scanning operation, in a sequential manner, over the first ends Y 1   a , Y 2   a , Y 3   a , . . . , Yna and the second ends Y 1   b , Y 2   b , Y 3   b , . . . , Ynb of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn, respectively via the scanning lines  61 ,  61   a , in order to detect the engagement of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn with respect to the continuous planar structure of the first conductive layer  10  due to being touched and depressed, as well as the location of the depression. 
         [0040]      FIG. 12  shows a system block diagram of a touch control device  100   f  in accordance with a seventh embodiment of the present invention. The seventh embodiment (touch control device  100   f ) is substantially identical to the fifth embodiment (touch control device  100   d ) illustrated in  FIG. 9  and the difference between the two embodiments resides in that in the touch control device  100   f  of the seventh embodiment, the driving voltage V of a preset voltage level is applied to the first end X 1   a , X 2   a , X 3   a , . . . , Xna of each elongate conductive strip X 1 , X 2 , X 3 , . . . , Xn and the second end X 1   b , X 2   b , X 3   b , . . . , Xnb of the elongate conductive strip is grounded via a grounding line G, whereby a potential gradient is established on each elongate conductive strip X 1 , X 2 , X 3 , . . . , Xn, as illustrated in  FIG. 13 . 
         [0041]      FIG. 14  shows a system block diagram of a touch control device  10   g  in accordance with an eighth embodiment of the present invention. The eighth embodiment (touch control device  100   g ) is substantially identical to the seventh embodiment (touch control device  100   f ) illustrated in  FIG. 12  and the difference between the two embodiments resides in that besides the first ends Y 1   a , Y 2   a , Y 3   a , . . . , Yna of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn of the second conductive layer  21  being connected to the scan sensing circuit  6  via the scanning lines  61 , the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn also have second ends Y 1   b , Y 2   b , Y 3   b , . . . , Ynb that are connected to the scan sensing circuit  6  by other scanning lines  61   a . Thus, the scan sensing circuit  6  can carry out scanning operation, in a sequential manner, over the first ends Y 1   a , Y 2   a , Y 3   a , . . . , Yna and the second ends Y 1   b , Y 2   b , Y 3   b , . . . , Ynb of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn, respectively via the scanning lines  61 ,  61   a , in order to detect the engagement of the elongate conductive strips Y 1 , Y 2 , Y 3 , . . . , Yn with respect to the elongate-strip structure of the first conductive layer  11  due to being touched and depressed, as well as the location of the depression. 
         [0042]    Although the present invention has been described with reference to the preferred embodiments thereof, as well as the best mode for carrying out the present invention, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.