Abstract:
A sense device for a capacitive touch control display is disclosed. The sense device includes a plurality of sense channels paralleled to each other, each of the sense channel including a first sense electrode having a first geometric figure for outputting a first sense signal, a second sense electrode having a second geometric figure for outputting a second sense signal, and a third sense electrode formed between the first sense electrode and the second sense electrode for outputting a third sense signal. An operation unit of the capacitive touch control display determines a plurality of touch positions according to the first sense signal, the second sense signal and the third sense signal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a sense device and a capacitive touch control display, and more particularly, to a sense device and a capacitive touch control display capable of detecting multiple touch positions. 
         [0003]    2. Description of the Prior Art 
         [0004]    A touch control display device has been widely utilized among electrical products. The touch control display device includes a display panel and a transparent touch panel. Through attachment of the display panel to the transparent touch panel, the touch control display device can realize functions of touch control as well as display. Nowadays, capacitive touch control is the most popular technique. 
         [0005]    Please refer to  FIG. 1 , which is a schematic diagram of a traditional capacitive touch control display  10  disclosed by U.S. Pat. No. 4,087,625. In  FIG. 1 , the capacitive touch control display  10  comprises a sense device  100 , an operation unit  102  a flexible circuit board (not shown in figure). The sense device  100  is interlaced by Indium Tin Oxide (ITO) to form sense channels or sense array on its surface. As shown in  FIG. 1 , each sense channel is realized by a single-layer of paired triangles for respectively outputting sense signals S 1 -S N  and D 1 -D N  to the operation unit  102  via the flexible circuit board. Further more, when a human body (object) touches the touch control display device  10 , the human body and the sense array form a coupling capacitor to sense capacitance changes of the coupling capacitor, such that the sense signals S 1 -S N  and D 1 -D N  outputted by the sense electrodes may change to accordingly compute a touch coordinate in X and Y directions. In short, the structure of the paired triangles provides a solution simplifying two-layer sense array into a single-layer sense array. By utilizing the single-layer sense array, a complex production process can be simplified, and production costs effectively controlled. 
         [0006]    Further more, U.S. Patent Application Number 2010/0309167 A1 discloses another type of sense device  20 . Please refer to  FIG. 2 , which is a schematic diagram of the traditional sense device  200 . Comparing with the sense device  100  shown in  FIG. 1 , the sense device  200  adjusts the number of paired triangles to realize the single-layer sense array structure. As shown in  FIG. 2 , the sense electrodes of each sense channel are realized by three pairs of triangles. 
         [0007]    However, the sense device shown in  FIG. 1  or  FIG. 2  can merely detect one touch position at one time, if the user touches two touch positions at a single sense channel of the sense device  100  or  200 , the operation unit  102  may recognize coordinates of one of the two touch positions according to the sense signals S 1 -S N  and D 1 -D N . Therefore, how to utilize the single-layer sense array to detect multiple touch positions has become a goal in the industry. 
       SUMMARY OF THE INVENTION 
       [0008]    It is therefore an object of the present invention to provide a sense device and a capacitive touch control display capable of detecting multiple touch positions. 
         [0009]    The present invention discloses a sense device for a capacitive touch control display comprising a plurality of sense channels paralleled to each other, each of the sense channel comprising a first sense electrode having a first geometric figure for outputting a first sense signal, a second sense electrode having a second geometric figure for outputting a second sense signal, and a third sense electrode formed between the first sense electrode and the second sense electrode for outputting a third sense signal, wherein an operation unit of the capacitive touch control display determines a plurality of touch positions according to the first sense signal, the second sense signal and the third sense signal. 
         [0010]    The present invention further discloses a capacitive touch control display comprising a sense device comprising a plurality of sense channels paralleled to each other, each of the sense channel comprising a first sense electrode having a first geometric figure for outputting a first sense signal, a second sense electrode having a second geometric figure for outputting a second sense signal, and a third sense electrode formed between the first sense electrode and the second sense electrode for outputting a third sense signal, and an operation unit for determining a plurality of touch positions according to the first sense signal, the second sense signal and the third sense signal. 
         [0011]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic diagram of a traditional capacitive touch control display. 
           [0013]      FIG. 2  is a schematic diagram of a traditional sense device. 
           [0014]      FIG. 3  is a schematic diagram of a sense device according to an embodiment of the present invention. 
           [0015]      FIG. 4  is a schematic diagram of a sense device according to another embodiment of the present invention. 
           [0016]      FIG. 5  is a schematic diagram illustrating the touch positions detected by the operation unit shown in  FIG. 3  cooperating with the sense device shown in  FIG. 3  and the sense device shown in  FIG. 4 . 
           [0017]      FIG. 6  is a schematic diagram of a sense device according to another embodiment of the present invention. 
           [0018]      FIG. 7  is a schematic diagram of a sense device according to another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Please refer to  FIG. 3 , which is a schematic diagram of a sense device  300  according to an embodiment of the present invention. The sense device  300  may be substituted for the sense device  100  in the capacitive touch control display. The sense device  300  comprises sense channels CH 1 -CH N  and an operation unit  302 . Each of the sense channels CH 1 -CH N  is paralleled to each other and has the same structure. As shown in  FIG. 3 , each of the sense channels CH 1 -CH N  comprises three sense electrodes, for example, the sense channel CH 1  comprises sense electrodes A 1 , B 1  and C 1 , the sense channel CH 2  comprises sense electrodes A 2 , B 2  and C 2 , . . . , and the sense channel CH N  comprises sense electrodes A N , B N  and C N . In detail, the sense electrode may have a specific geometric figure. Take the sense channel CH 1  in  FIG. 3  for example, the sense electrode B 1  is an equilateral triangle and the same as the sense electrode C 1 , while the sense electrode A 1  is formed between the sense electrode B 1  and the sense electrode C 1 . The sense electrodes A 1 -A N , B 1 -B N  and C 1 -C N  are respectively used for sensing whether the sense device  300  is touched by a human body to output sense signals S A1   - S AN , S B1 -S BN  and S C1 -S CN  to the operation unit  302 . The operation unit  302  is used for computing touch positions according to signal differences ΔS A1 −ΔS AN , ΔS B1 −ΔS BN  and ΔS C1 −ΔS CN  of the sense signals S A1 -S AN , S B1 -S BN  and S C1 -S CN  before and during the sense device  300  is touched by the human body. 
         [0020]    In such a structure, if two fingers of a user simultaneously touch one sense channel, e.g. the sense channel CH 1 , the operation unit  302  may obtain the signal differences ΔS A1 , ΔS B1  and ΔS C1  by comparing the sense signals S A1 , S B1  and S C1  before and during the sense device  300  is touched by the human body, so as to compute two touch positions TP 1  and TP 2 . 
         [0021]    In operation, if the operation unit  302  computes one of the signal differences ΔS A1 , ΔS B1  and AS C1  corresponding to the sense signals S A1 , S B1  and S C1  as greater than a threshold value, the operation unit  302  may notice a touch event at the sense channel CH 1  and obtain coordinates of the touch positions TP 1  and TP 2  in X direction according to a coordinate of the sense channel CH 1  in X direction. 
         [0022]    Meanwhile, if the signal differences ΔS A1 , ΔS B1  of the sense signals S A1 , S B1  before and during the touch event are both greater than the threshold value, the operation unit  302  may compute a coordinate of the touch position TP 1  in +Y direction according to the signal differences ΔS A1 , ΔS B1  of the sense signals S A1 , S B1  before and during the touch events. Specifically, the closer the touch position close to the center of the sense channel CH 1 , i.e. the center between +Y and −Y directions, the greater touch area of the sense electrode A 1 , and the greater signal difference ΔS A1  of the sense signal S A1  before and during the touch event. In contrast, the farther the touch position is away from the center of the sense electrode CH 1 , the greater touch area of the sense electrode B 1 , and the greater the signal difference ΔS B1  of the sense signal S B1  before and during the touch event. As a result, the operation unit  302  may compute the coordinate of the touch position TP 1  in the +Y direction according to the signal differences ΔS A1 , ΔS B1  of the sense signals S A1 , S B1  before and during the touch event. 
         [0023]    On the other hand, if the signal differences ΔS A1 , ΔS C1  of the sense signals S A1 , S C1  before and during the touch events are both greater than the threshold value, the operation unit  302  may compute the coordinate of the touch position TP 2  in the −Y direction according to the signal differences ΔS A1 , ΔS C1  of the sense signals S A1 , S C1  before and during the touch events. Similarly, the closer the touch position close to the center of the sense channel CH 1 , i.e. the center between the +Y and −Y directions, the greater touch area of the sense electrode A 1 , and the greater signal difference ΔS A1  of the sense signal S A1  before and during the touch event. In contrast, the farther the touch position is away from the center of the sense electrode CH 1 , the greater touch area of the sense electrode C 1 , and the greater the signal difference ΔS C1  of the sense signal S C1  before and during the touch event. As a result, the operation unit  302  may compute the coordinate of the touch position TP 2  in the −Y direction according to the signal differences ΔS A1 , ΔS C1  of the sense signals S A1 , S C1  before and during the touch event. 
         [0024]    In short, the sense device  300  of the present invention may generate sense signals by the three sense electrodes of each sense channel, such that the sense device  300  may detect multiple touch positions at once with a structure of a single-layer sense array. 
         [0025]    Moreover, in order to improve sensitivities of the sense electrodes B 1 -B N  and C 1 -C N  to detect the touch positions, preferably, the sense electrodes B 1 -B N  and C 1 -C N  may have the same geometric figure and the same area. For example, please refer to  FIG. 3  and  FIG. 4  at the same time,  FIG. 4  is a schematic diagram of a sense device  400  according to another embodiment of the present invention. Take channel CH 1  for instance, the geometric figure of the sense electrodes B 1  and C 1  in  FIG. 3  is an equilateral triangle with the same area. In  FIG. 4 , the geometric figure of the sense electrodes B 1     —     4  and C 1     —     4  is a convex saw-tooth formed by connecting two equilateral triangles side by side, such that the sensitivities of the sense electrodes A 1     —     4 , B 1     —     4  and C 1     —     4  may be more even, and improve an accuracy of the sense device  400  for detecting the coordinate of the touch position in the +Y and −Y directions. 
         [0026]    Please refer to  FIG. 5 , which is a schematic diagram illustrating the touch positions detected by the operation unit  302  cooperating with the sense device  300  and  400 . Assume that the user slides a horizontal line, i.e. touch position TP REAL  denoted with a solid line, from the coordinate h of the X direction along the +Y direction on the sense devices  300  and  400 , respectively. The operation unit  302  computes the touch position TP 3  denoted with a dash line according to the sense signals S A1  and S B1  outputted by the sense device  300 . The operation unit  302  computes the touch position TP 4  denoted with a dotted line according to the sense signals S A1     —     4  and S B1     —     4  outputted by the sense device  400 . As shown in  FIG. 5 , if most of the touch position TP REAL  lies in the area of the sense electrode B 1  and only small part of the touch position TP REAL  lies in the area of the sense electrode A 1 , the signal difference ΔS B1  of the sense signal S B1  may be much greater than the signal difference ΔS A1  of the sense signal S A1  before and during the touch event, such that the touch position TP 3  computed by the operation unit  302  may be greater than the coordinate h, which causes the sense device  300  may have greater coordinate errors in the +Y direction. In comparison, the touch position TP REAL  may be located evenly between the areas of the sense electrodes A 1     —     4  and B 1     —     4  since the areas of the sense electrodes A 1     —     4  and B 1     —     4  are more evenly distributed than the areas of the sense electrodes A 1  and B 1 . As a result, the signal differences ΔS A1     —     4  and ΔS B1     —     4  of the sense signals S A1     —     4  and S B1     —     4  before and during the touch event may be even, such that the touch position TP 4  computed by the operation unit  302  may be close the real touch position TP REAL  and the sense device  400  may have smaller coordinate errors in the +Y and −Y directions. 
         [0027]    On the other hand, the geometric figures of the sense electrodes B 1  and C 1  in the sense channel CH 1  and the geometric figures of the sense electrodes B 1     —     4  and C 1     —     4  in the sense channel CH 1-4  maybe different. For example, please refer to  FIG. 6 , which is a schematic diagram of a sense device  600  according to an embodiment of the present invention. In  FIG. 6 , the geometric figure of the sense electrode B 1     —     6  is an equilateral triangle, and the geometric figure of the sense electrode C 1     —     6  is a concave saw-tooth corresponding to the equilateral triangle of the sense electrode B 1     —     6 , wherein the area of the sense electrode B 1     —     6  is preferably equal to the area of the sense electrode C 1     —     6 . In such a structure, the sense electrodes B 1     —     6  and C 1     —     6  may have the same sensitivity though those geometric figures are different. 
         [0028]    Please refer to  FIG. 7 , which is a schematic diagram of a sense device  700  according to an embodiment of the present invention. As shown in  FIG. 7 , the sense electrode B 1     —     7  and the sense electrode B 1     —     4  have the same geometric figure, which is a convex saw-teeth formed by connecting a plurality of equilateral triangles side by side. The geometric figure of the sense electrode C 1     —     7  is derived from the geometric figure of the sense electrode C 1     —     6 , the geometric figure of the sense electrode C 1     —     7  is concave saw-teeth corresponding to the geometric figure of the sense electrode B 1     —     7 , and is formed by connecting a plurality of concave saw-teeth side by side. Likewise, the sense electrodes A 1     —     7 , B 1     —     7  and C 1     —     7  may have the same sensitivity thought their geometric figures are different. Also, the areas of the sense electrodes A 1   —7 , B 1     —     7  and C 1     —     7  are more evenly distributed than the areas of the sense electrodes A 1     —     6 , B 1     —     6  and C 1     —     6  to detect the touch coordinate precisely. 
         [0029]    To sum up, the traditional sense devices  100  and  200  may only detect a single touch position at once. In comparison, the sense devices  300 ,  400 ,  600  and  700  of the present invention may detect multiple touch positions simultaneously. Furthermore, sense electrode of the sense device may have various geometric figures to reach different levels of coordinate accuracy. As a result, the present invention may achieve multiple touch detection and well coordinate accuracy with the simple structure of the single-layer sense array. 
         [0030]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.