Patent Publication Number: US-2015060255-A1

Title: Touch panel

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 102131578, filed on Sep. 2, 2013. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is related to a touch panel, and particularly to a touch panel with a multi-touch function. 
     2. Description of Related Art 
     In current information era, touch panels have been introduced to replace conventional keyboards or mice to serve as input devices of many information technology (IT) products. Among them, a touch display device capable of performing both a touch function and a display function is one of the most popular products at present. 
     Currently, the touch panels are roughly classified into resistive, capacitive, infrared, and ultrasonic touch panels, wherein the resistive touch panels and the capacitive touch panels are most common. When it comes to the capacitive touch panels, they are gradually favored by the market due to a multi-touch feature that provides a more user-friendly operation mode. However, for the purpose of achieving the multi-touch function, sometimes it is necessary to increase channels of a driver IC of the touch panel so as to differentiate between touch points. As a result, manufacturing cost of the touch panel is increased. Therefore, how to achieve the multi-touch function with a limited cost is worth studying in the field of touch panels. 
     SUMMARY OF THE INVENTION 
     The invention provides a touch panel that achieves the multi-touch function by making use of arrangement manners and electrical connection manners of electrodes without a need to significantly increase the number of channels of a driver IC, and thus has an advantage of cost saving. 
     A touch panel of the invention includes a substrate and a plurality of touch sensitive units. The touch sensitive units are arranged in sequence on the substrate. Each touch sensitive unit includes a first electrode set and a second electrode set. The first electrode set includes a plurality of first electrodes. The first electrodes are arranged in sequence along a first direction and are separated by a first space between one another. The second electrode set is located beside the first electrode set and includes a plurality of second electrodes. The second electrodes are arranged in sequence along the first direction and are separated by a second space between one another. One of a width of each second electrode and a width of each first electrode is increased along the first direction, and the other one is decreased along the first direction, wherein at least one second space is not aligned to at least one first space so that an extended trajectory of the at least one second space passes through one of the first electrodes. Two adjacent first electrodes are electrically independent and two adjacent second electrodes are electrically independent. 
     In an embodiment of the invention, the width of each first electrode is increased along the first direction, and a maximum width of the n-th first electrode is smaller than a minimum width of the (n+1)-th first electrode, wherein n is a positive integer. 
     In an embodiment of the invention, the width of each second electrode is decreased along the first direction, and a minimum width of the m-th second electrode is larger than a maximum width of the (m+1)-th second electrode, wherein m is a positive integer. 
     In an embodiment of the invention, the (2n−1)-th first electrodes are electrically connected together, and the 2n-th first electrodes are electrically connected together, wherein n is a positive integer. 
     In an embodiment of the invention, the touch panel further includes a driver IC, a plurality of first wires, a plurality of second wires, a plurality of third wires and a plurality of fourth wires. The driver IC, the first wires, the second wires, the third wires and the fourth wires are disposed on the substrate. Each first wire is connected between the driver IC and the first electrode having a minimum width in each first electrode set. Each second wire is connected between the driver IC and the first electrode having a maximum width in each first electrode set. Each third wire is connected between the driver IC and the second electrode having a maximum width in each second electrode set. Each fourth wire is connected between the driver IC and the second electrode having a minimum width in each second electrode set. 
     In an embodiment of the invention, the (2m−1)-th second electrodes are electrically connected together, and the 2m-th second electrodes are electrically connected together, wherein m is a positive integer. 
     In an embodiment of the invention, the 2m-th second electrode in the k-th touch sensitive unit is electrically connected to the (2m−1)-th second electrode in the (k+1)-th touch sensitive unit, wherein k is a positive integer. 
     In an embodiment of the invention, the (2m−1)-th second electrode in the k-th touch sensitive unit is electrically connected to the 2m-th second electrode in the (k+1)-th touch sensitive unit, wherein k is a positive integer. 
     In an embodiment of the invention, the touch panel further includes a driver IC and a plurality of wires. The driver IC and the wires are disposed on the substrate, wherein the second electrodes in the k-th touch sensitive unit and in the (k+1)-th touch sensitive unit that are electrically connected to one another are connected to the driver IC via one of the wires. 
     In an embodiment of the invention, none of the second spaces is aligned to the first spaces. 
     In an embodiment of the invention, the touch sensitive units are arranged in sequence along a second direction, and the second direction intersects the first direction. 
     In an embodiment of the invention, a stair-shaped variation is exhibited in the widths of each first electrode and each second electrode. 
     In an embodiment of the invention, a wave-shaped variation is exhibited in the widths of each first electrode and each second electrode. 
     In an embodiment of the invention, a linear variation is exhibited in the widths of each first electrode and each second electrode. 
     In an embodiment of the invention, the substrate is any substrate in a display. 
     In an embodiment of the invention, the substrate is any one of a color filter substrate, an encapsulation plate and a cover lens. 
     In an embodiment of the invention, the substrate is any one of a glass substrate, a plastic substrate and a film substrate. 
     In an embodiment of the invention, the first electrodes and the second electrodes include a metal mesh consisting of a plurality of metal fine lines. 
     Based on the above, in each touch sensitive unit of the invention, the electrodes in the first electrode set are separated by the first spaces and the electrodes in the second electrode set are separated by the second spaces, wherein at least one second space is not aligned to the first spaces so that the extended trajectory of the at least one second space passes through one of the first electrodes. Accordingly, each first electrode corresponds to two second electrodes. When position points at which a user touches lie on the two second electrodes that correspond to the same first electrode, different touch points are differentiated according to the two different second electrodes. 
     In addition, two adjacent first electrodes are electrically independent and two adjacent second electrodes are electrically independent. Thus, when the user touches the two adjacent second electrodes that correspond to the same first electrode at the same time, the touch points are effectively differentiated. By making use of the arrangement manners and electrical connection manners of the electrodes, the touch panel of the invention achieves the multi-touch function without the need to significantly increase the number of channels of a driver IC, and thus has an advantage of cost saving. 
     To make the above features and advantages of the invention more comprehensible, embodiments accompanied with drawings are described in detail as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a touch panel according to an embodiment of the invention. 
         FIG. 2  is a schematic view of a touch panel according to another embodiment of the invention. 
         FIG. 3  is a schematic view of a touch panel according to another embodiment of the invention. 
         FIG. 4  is a schematic view of a touch panel according to another embodiment of the invention. 
         FIG. 5A  and  FIG. 5B  are embodiments of first electrodes and second electrodes in a touch sensitive unit. 
     
    
    
     DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS 
       FIG. 1  is a schematic view of a touch panel according to an embodiment of the invention. Referring to  FIG. 1 , a touch panel  100  includes a substrate  110  and a plurality of touch sensitive units  120 . The touch sensitive units  120  are arranged in sequence on the substrate  110 . Each touch sensitive unit  120  includes a first electrode set  122  and a second electrode set  124 . The first electrode set  122  includes a plurality of first electrodes  1222 . The first electrodes  1222  are arranged in sequence along a first direction D1 and are separated by a first space G1 between one another. The second electrode set  124  is located beside the first electrode set  122  and includes a plurality of second electrodes  1242 . The second electrodes  1242  are arranged in sequence along the first direction D1 and are separated by a second space G2 between one another. One of a width W of each second electrode  1242  and the width W of each first electrode  1222  is increased along the first direction D1, and the other one is decreased along the first direction D1. 
     It should be noted that the present embodiment illustrates an example in which each first electrode set  122  includes two first electrodes  1222  and each second electrode set  124  includes four second electrodes  1242 . However, the invention is not limited thereto. The number of the first electrodes  1222  in the first electrode set  122  and the number of the second electrodes  1242  in the second electrode set  124  may be adjusted as needed. In addition, the present embodiment illustrates an example in which the width W of each first electrode  1222  is increased along the first direction D1, and the width W of each second electrode  1242  is decreased along the first direction D1. However, the invention is not limited thereto. In other embodiments, it may be that the width of the second electrode  1242  is increased along the first direction D1, and the width of the first electrode  1222  is decreased along the first direction D1. As illustrated in  FIG. 1 , at least one second space G2 is not aligned to at least one first space G1 so that a virtual extended trajectory of the at least one second space G2 passes through one of the first electrodes  1222 . 
     The touch sensitive units  120  in the present embodiment are arranged in sequence along a second direction D2, and the second direction D2 intersects the first direction D1. Each touch sensitive unit  120  includes the same elements. Moreover, the elements in each touch sensitive unit  120  are arranged in the same manner and have the same electrical connection relationships. In the following, a multi-touch function of the touch panel  100  is described by illustrating a single touch sensitive unit  120  of the touch panel  100 . 
     As illustrated in  FIG. 1 , in the present embodiment, the (2m−1)-th second electrodes  1242  in each second electrode set  124  are electrically connected together via a connecting wire  190 A, and are connected to a driver IC  140  via a third wire  170 . The 2m-th second electrodes  1242  are electrically connected together via a connecting wire  190 B, and are connected to the driver IC  140  via a fourth wire  180 . m is a positive integer. Meanwhile, the two first electrodes  1222  are electrically independent from each other. In other words, two adjacent first electrodes  1222  are electrically independent and two adjacent second electrodes  1242  are electrically independent. 
     In the touch sensitive unit  120 , at least one second space G2 is not aligned to the first space G1. Accordingly, a first electrode  1222 A corresponds to two different second electrodes  1242 A and  1242 B, and a first electrode  1222 B corresponds to two different second electrodes  1242 C and  1242 D. When a user touches two touch points P1 and P2 at the same time, the touch points P1 and P2 are differentiated according to signals of the different second electrodes  1242 A and  1242 B. Or, when the user touches two touch points P3 and P4 at the same time, the touch points P3 and P4 are differentiated according to signals of the different second electrodes  1242 C and  1242 D. 
     In addition, although the second electrode  1242 A and the second electrode  1242 C are electrically connected to each other, when the user touches the touch points P1 and P3 at the same time, the touch points P1 and P3 are identified as different touch points according to the electrically independent first electrode  1222 A and first electrode  1222 B. Similarly, when the user touches the touch points P2 and P4, although the second electrode  1242 B and the second electrode  1242 D are electrically connected to each other, the touch points P2 and P4 are identified as different touch points according to the electrically independent first electrode  1222 A and first electrode  1222 B. Based on the above, the touch panel  100  in the present embodiment achieves the multi-touch function by making use of the arrangement manners and the electrical connection manners of the electrodes  1222  and  1242 . In terms of the present embodiment, one touch sensitive unit  120  of the touch panel  100  is able to simultaneously sense at least the signals of the four touch points P1, P2, P3 and P4. 
     As illustrated in  FIG. 1 , the width W of each first electrode  1222  in the touch sensitive unit  120  is increased along the first direction D1, and a maximum width of the n-th first electrode  1222  is smaller than a minimum width of the (n+1)-th first electrode  1222 , wherein n is a positive integer. Moreover, the width W of each second electrode  1242  is decreased along the first direction D1, and a minimum width of the m-th second electrode  1242  is larger than a maximum width of the (m+1)-th second electrode  1242 , wherein m is a positive integer. In other words, an entire width of the first electrode set  122  in each touch sensitive unit  120  is progressively increased along the first direction D1, and an entire width of the second electrode set  124  is progressively decreased along the first direction D1. 
     The present embodiment illustrates an example in which the first electrode set  122  and the second electrode set  124  are in the shape of two complementary triangles, and hypotenuses of the two triangles are disposed opposed to each other. For example, in a single touch sensitive unit  120  of the touch panel  100 , positions of the four touch points P1, P2, P3 and P4 correspond respectively to patterns of the first electrode  1222  and of the second electrode  1242  having different area ratios, thus generating different signal values. Therefore, the positions of the touch points P1, P2, P3 and P4 along the first direction D1 are determined according to size of the signal values. 
     In addition, in the present embodiment, the touch panel  100  further includes the driver IC  140 , a plurality of first wires  150 , a plurality of second wires  160 , a plurality of the third wires  170  and a plurality of the fourth wires  180 . The driver IC  140 , the first wires  150 , the second wires  160 , the third wires  170  and the fourth wires  180  are disposed on the substrate  110 . The first wires  150  and the second wires  160  are respectively located at two opposing sides of the first electrode set  122 , wherein each first wire  150  is connected between the driver IC  140  and the first electrode  1222  having a minimum width in each first electrode set  122 . Moreover, each second wire  160  is connected between the driver IC  140  and the first electrode  1222  having a maximum width in each first electrode set  122 . 
     The third wires  170  and the fourth wires  180  are respectively located at two opposing sides of the second electrode set  124 , wherein each third wire  170  is connected between the driver IC  140  and the second electrode  1242  having a maximum width in each second electrode set  124 . Moreover, each fourth wire  180  is connected between the driver IC  140  and the second electrode  1242  having a minimum width in each second electrode set  124 . Accordingly, the electrodes  1222  and  1242  transmit signals to the driver IC  140  via the corresponding wires  150 ,  160 ,  170  and  180 . It is worth mentioning that a patterned decorative layer (not illustrated) is selectively disposed around the substrate  110  to cover the wires  150 ,  160 ,  170  and  180 , and that a portion of the touch sensitive unit  120  mounts the patterned decorative layer and overlaps the same. 
     In a single touch sensitive unit  120  of the touch panel  100 , for example, the second electrode  1242 A in the second electrode set  124  is electrically connected to the second electrode  1242 C, and the third wire  170  is connected between the driver IC  140  and the second electrode  1242 A having the maximum width in the second electrode set  124 . Accordingly, the second electrode  1242 A and the second electrode  1242 C are simultaneously connected to the driver IC  140  via the third wire  170 . Similarly, the second electrode  1242 B in the second electrode set  124  is electrically connected to the second electrode  1242 D, and the fourth wire  180  is connected between the driver IC  140  and the second electrode  1242 D having the minimum width in the second electrode set  124 . Accordingly, the second electrode  1242 B and the second electrode  1242 D are simultaneously connected to the driver IC  140  via the fourth wire  180 . In such electrical connection manner, the touch panel  100  in the present embodiment achieves the multi-touch function without significantly increasing the number of the wires. Accordingly, the number of channels of the driver IC  140  is decreased, thus providing the advantage of cost reduction. 
     In the present embodiment, materials of the first electrode  1222  and the second electrode  1242  may be transparent conductive substances, such as indium tin oxides (ITO), indium zinc oxides (IZO), aluminum zinc oxides (AZO), silver nanowires, graphene and so on. Or, the materials of the first electrode  1222  and the second electrode  1242  may be metal, or may also be a stack of metal and the transparent conductive substances, such as silver/ITO/silver. In addition, materials of the first wires  150 , the second wires  160 , the third wires  170  and the fourth wires  180  may be transparent conductive substances or metal. In addition, the aforementioned electrodes may be in the form of a continuous film, such as an ITO film, or in the form of a mesh (e.g. metal mesh). The mesh consists of, for example, a plurality of metal fine lines. Widths of the metal fine lines are, for example, in a range of 1 micron to 30 microns. Moreover, in the electrode in the form of a metal mesh, an opening between the fine lines is much wider than the line widths of the fine lines. As a result, a light transmittance of the metal mesh electrode reaches above 75%. In addition, the present embodiment illustrates an example in which both the first electrode  1222  and the second electrode  1242 , and even the wires  150 - 180  as well as the connecting wires  190 A and  190 B are manufactured on the same surface of the substrate  110 . However, the invention is not limited thereto. 
     The reference numerals and a part of the contents in the previous embodiment are used in the following embodiments, in which identical reference numerals indicate identical or similar components, and repeated description of the same technical contents is omitted. For a detailed description of the omitted parts, reference can be found in the previous embodiment, and no repeated description is contained in the following embodiments. 
       FIG. 2  is a schematic view of a touch panel according to another embodiment of the invention. The embodiment of  FIG. 2  is similar to the embodiment of  FIG. 1 . The two embodiments differ in that in the embodiment of  FIG. 2 , second electrodes  2242  in two adjacent touch sensitive units  220  have an electrical connection relationship therebetween. Referring to  FIG. 2 , in each touch sensitive unit  220 , the (2m−1)-th second electrodes  2242  are electrically connected together via a connecting wire  290 A, and the 2m-th first electrodes  2222  are electrically connected together via a connecting wire  290 B, wherein m is a positive integer. In addition, the 2m-th second electrode  2242  in the k-th touch sensitive unit  220  is electrically connected to the (2m−1)-th second electrode  2242  in the (k+1)-th touch sensitive unit  220  via a connecting wire  290 C, wherein k is a positive integer. 
     Referring to  FIG. 2 , for example, the first second electrode  2242 A in each touch sensitive unit  220  is electrically connected to the third second electrode  2242 C via the connecting wire  290 A, and the second electrode  2242 B is electrically connected to the fourth second electrode  2242 D via the connecting wire  290 B. Moreover, the second second electrode  2242 B and the fourth second electrode  2242 D in the first touch sensitive unit  220  are electrically connected to the first second electrode  2242 A and the third second electrode  2242 C in the second touch sensitive unit  220  via the connecting wire  290 C. Similarly, the second second electrode  2242 B and the fourth second electrode  2242 D in the second touch sensitive unit  220  are electrically connected to the first second electrode  2242 A and the third second electrode  2242 C in the third touch sensitive unit  220 . 
     In addition, in the present embodiment, the touch panel  200  further includes the driver IC  140 , a plurality of fifth wires  250 , a plurality of sixth wires  260 , a plurality of seventh wires  270  and an eighth wire  280 . The driver IC  140 , the fifth wires  250 , the sixth wires  260 , the seventh wires  270  and the eighth wire  280  are disposed on the substrate  110 . As illustrated in  FIG. 2 , each fifth wire  250  is connected between the driver IC  140  and the first electrode  2222  having a minimum width in each first electrode set  222 . Moreover, each sixth wire  260  is connected between the driver IC  140  and the first electrode  2222  having a maximum width in each first electrode set  222 . Each seventh wire  270  is connected between the driver IC  140  and the second electrode  2242  having a minimum width in each second electrode set  224 . The eighth wire  280  is connected between the driver IC  140  and the second electrode  2242  having a maximum width in one of the second electrode set  224 . Accordingly, the electrodes  2222  and  2242  transmit signals to the driver IC  140  via the corresponding wires  250 ,  260 ,  270  and  280 . Particularly, the second electrodes  2242  in the k-th touch sensitive unit  220  and in the (k+1)-th touch sensitive unit  220  that are electrically connected to one another are connected to the driver IC  140  simply via one of the seventh wires  270 . 
     In the present embodiment, the second electrodes  2242  in different touch sensitive units  220  have an electrical connection relationship therebetween. Accordingly, the seventh wire  270  simultaneously connects a plurality of the second electrodes  2242  in different touch sensitive units  220  to the driver IC  140 . In such electrical connection manner, the touch panel  200  in the present embodiment achieves the multi-touch function while effectively decreasing the number of the wires. Accordingly, the number of channels of the driver IC  140  is decreased, thus providing the advantage of cost reduction. 
       FIG. 3  is a schematic view of a touch panel according to another embodiment of the invention. The embodiment of  FIG. 3  is similar to the embodiment of  FIG. 2 . The two embodiments differ mainly in that the (2m−1)-th second electrode  3242  in the k-th touch sensitive unit  320  is electrically connected to the 2m-th second electrode  3242  in the (k+1)-th touch sensitive unit  320 , wherein k is a positive integer. In other words, in the embodiment of  FIG. 2 , the second second electrode  2242 B and the fourth second electrode  2242 D in the first touch sensitive unit  220  are electrically connected to the first second electrode  2242 A and the third second electrode  2242 C in the second touch sensitive unit  220 . In the embodiment of  FIG. 3 , the first second electrode  3242 A and the third second electrode  3242 C in the first touch sensitive unit  320  are electrically connected to the second second electrode  3242 B and the fourth second electrode  3242 D in the second touch sensitive unit  320 . 
     In addition, in the present embodiment, a touch panel  300  further includes the driver IC  140 , a plurality of fifth wires  350 , a plurality of sixth wires  360 , a plurality of seventh wires  370  and a plurality of eighth wires  380 . The driver IC  140 , the fifth wires  350 , the sixth wires  360 , the seventh wires  370  and the eighth wires  380  are disposed on the substrate  110 . As illustrated in  FIG. 3 , the fifth wires  350  are connected between the driver IC  140  and first electrodes  3222  having a minimum width in a first electrode set  322 . Moreover, the sixth wires  360  are connected between the driver IC  140  and the first electrodes  3222  having a maximum width in the first electrode set  322 . The seventh wires  370  are connected between the driver IC  140  and the second electrodes  3242  having a minimum width in a part of second electrode sets  324 . The eighth wires  380  are connected between the driver IC  140  and the second electrodes  3242  having a maximum width in a part of the second electrode sets  324 . Accordingly, the electrodes  3222  and  3242  transmit signals to the driver IC  140  via the corresponding wires  350 ,  360 ,  370  and  380 . Particularly, the second electrodes  3242  in the k-th touch sensitive unit  320  and in the (k+1)-th touch sensitive unit  320  that are electrically connected to one another are connected to the driver IC  140  simply via one of the eighth wires  380 . 
       FIG. 4  is a schematic view of a touch panel according to another embodiment of the invention. The embodiment of  FIG. 4  is similar to the embodiment of  FIG. 1 . The two embodiments differ in the electrical connection relationship between the first electrodes in the first electrode set, and relative positions of the first electrodes and the second electrodes. It should be noted that the present embodiment illustrates an example in which each first electrode set  422  includes four first electrodes  4222  and each second electrode set  424  includes four second electrodes  4242 . However, the invention is not limited thereto. The number of the first electrodes  4222  in the first electrode set  422  and the number of the second electrodes  4242  in the second electrode set  424  may be adjusted as needed. 
     Referring to  FIG. 4 , in the present embodiment, none of the second spaces G2 is aligned to the first spaces G1. Moreover, the second spaces G2 and the first spaces G1 are arranged alternately. In a single touch sensitive unit  420 , for example, with such arrangement, except for the last first electrode  4222 D in the first electrode set  422 , each first electrode  4222  faces two second electrodes  4242 , while each second electrode  4242  faces two first electrodes  4222 . In addition, in the present embodiment, the (2n−1)-th first electrodes  4222  in each first electrode set  422  are electrically connected together via a connecting wire  490 C, and the 2n-th first electrodes  4222  are electrically connected together via a connecting wire  490 D, wherein n is a positive integer. In other words, in the embodiment of  FIG. 1 , only the second electrodes  1242  in the second electrode set  124  have an electrical connection relationship therebetween, whereas in the present embodiment, not only the second electrodes  4242  in the second electrode set  424  are electrically connected together via connecting wires  490 A and  490 B, but also the first electrodes  4222  in the first electrode set  422  have an electrical connection relationship therebetween. 
     Please refer to  FIG. 4 . In the following, the multi-touch function of a touch panel  400  is described by illustrating a single touch sensitive unit  420  of the touch panel  400 . When the user touches touch points P5 to P11 at the same time, at each of the touch points P5 to P11, one of the first electrodes  4222  and one of the second electrodes  4242  are respectively touched. Combinations of the first electrodes  4222  and the second electrodes  4242  touched at each of the touch points P5 to P11 are not repeated. For example, when the user touches the touch point P5, he or she touches a first electrode  4222 A and a second electrode  4242 A at the same time; when the user touches the touch point P6, he or she touches the first electrode  4222 A and a second electrode  4242 B at the same time. When the user touches the touch point P7, he or she touches a first electrode  4222 B and the second electrode  4242 B at the same time; when the user touches the touch point P8, he or she touches the first electrode  4222 B and a second electrode  4242 C at the same time. By the user touching the first electrodes  4222  and the second electrodes  4242  in different combinations when touching the touch points P5 to P11 at the same time, the touch points P5 to P11 are differentiated according to signals of the different electrodes  4222  and  4242 . 
     In addition, two adjacent first electrodes  4222  are electrically independent and two adjacent second electrodes  4242  are electrically independent. Accordingly, when the user touches two adjacent second electrodes  4242  that correspond to the same first electrode  4222  at the same time, or touches two first electrodes  4222  that correspond to the same second electrode  4242  at the same time, the touch points are effectively differentiated. For example, when the user touches the touch point P5, he or she touches the first electrode  4222 A and the second electrode  4242 A at the same time; when the user touches the touch point P6, he or she touches the first electrode  4222 A and the second electrode  4242 B at the same time. Although the touch points P5 and P6 both correspond to the first electrode  4222 A, the touch points P5 and P6 correspond to the different second electrodes  4242 A and  4242 B. Moreover, the second electrode  4242 A is electrically independent from the second electrode  4242 B. Thus, the touch points P5 and P6 are identified as different touch points. Based on the above, the touch panel  400  in the present embodiment achieves the multi-touch function. In terms of the present embodiment, one touch sensitive unit  420  of the touch panel  400  is able to simultaneously sense at least the signals of the seven touch points P5, P6, P7, P8, P9, P10 and P11. 
     In addition, in the present embodiment, the touch panel  400  further includes the driver IC  140 , a plurality of the first wires  150 , a plurality of the second wires  160 , a plurality of the third wires  170  and a plurality of the fourth wires  180 . The driver IC  140 , the first wires  150 , the second wires  160 , the third wires  170  and the fourth wires  180  are disposed on the substrate  110 . The wires  150 - 180  are arranged in the same way as in the embodiment of  FIG. 1 , and thus descriptions thereof are omitted. It should be noted that in the present embodiment, the first electrode  4222 A is electrically connected to a first electrode  4222 C. Accordingly, the first electrode  4222 A and the first electrode  4222 C are simultaneously connected to the driver IC  140  via the first wire  150 . Similarly, the first electrode  4222 B and the first electrode  4222 D are simultaneously connected to the driver IC  140  via the second wire  160 . In such electrical connection manner, the touch panel  400  in the present embodiment achieves the multi-touch function while effectively decreasing the number of the wires. Accordingly, the number of channels of the driver IC  140  is decreased, thus providing the advantage of cost reduction. 
       FIG. 5A  and  FIG. 5B  are embodiments of first electrodes and second electrodes in a touch sensitive unit. The previous embodiments illustrate examples in which whole outlines of the first electrode set and the second electrode set in the touch sensitive unit are both in the form of triangles. However, the first electrode set and the second electrode set may be in other forms. As illustrated in  FIG. 5A , the whole outlines of a first electrode set  522 A and a second electrode set  524 A in a touch sensitive unit  520 A include respectively a hypotenuse E1 and a hypotenuse E2. The hypotenuse E1 and the hypotenuse E2 are disposed opposed to each other and are both zigzag-shaped. Or, as illustrated in  FIG. 5B , the whole outlines of a first electrode set  522 B and a second electrode set  524 B in a touch sensitive unit  520 B include respectively a hypotenuse E3 and a hypotenuse E4. The hypotenuse E3 and the hypotenuse E4 are disposed opposed to each other and are both wave-shaped. That is to say, in addition to the hypotenuses mentioned in the above embodiments that show a linear variation, a stair-shaped variation or a wave-shaped variation is exhibited in the widths of the first electrode sets  522 A,  522 B and the second electrode sets  524 A,  524 B. In addition, the first electrode set and the second electrode set may both have a plurality of protrusions and a plurality of recesses. Moreover, the protrusions of the first electrode set protrude into the recesses of the second electrode set, while the protrusions of the second electrode set protrude into the recesses of the first electrode set. In addition, a virtual electrode may be disposed between two adjacent touch sensitive units, between the first spaces and between the second spaces. The virtual electrodes are manufactured together with the wires and are formed on the substrate of the touch panel. The first spaces do not necessarily have the same width, and may have different widths. The same situation exists in the second spaces. 
     It is worth mentioning that the substrate in the aforementioned embodiments may be any substrate in a display, such as a filter substrate in a liquid crystal display or an encapsulation plate of an organic light emitting diode (OLED) display, but is not limited thereto. In addition, the substrate may be a cover lens, and a material thereof may be glass, sapphire or hard plastic. The substrate may also be a soft film material, such as a PET film or Polyimide film, but is not limited thereto. 
     In summary, in each touch sensitive unit of the invention, the electrodes in the first electrode set are separated by the first spaces and the electrodes in the second electrode set are separated by the second spaces, wherein at least one second space is not aligned to the first space(s) so that the extended trajectory of the at least one second space passes through one of the first electrodes. Accordingly, one first electrode corresponds to two second electrodes. When the user touches the two second electrodes that correspond to the same first electrode, the different touch points are differentiated according to the two different second electrodes. 
     In addition, two adjacent first electrodes are electrically independent and two adjacent second electrodes are electrically independent. Thus, when the user touches the two adjacent second electrodes that correspond to the same first electrode at the same time, or touches the two adjacent first electrodes that correspond to the same second electrode at the same time, the touch points are effectively differentiated according to the characteristic of electrical independence. By making use of the arrangement manners and the electrical connection manners of the electrodes, the touch panel of the invention achieves the multi-touch function without the need to significantly increase the number of channels of a driver IC, and thus has the advantage of cost saving. Of course, in addition to adopting the methods described in the aforementioned embodiments, a part of two adjacent first electrodes or/and two adjacent second electrodes may achieve electrical independence by an exclusive wire arranged for each electrode. 
     Moreover, the first electrodes in each first electrode set are electrically connected to one another, and the second electrodes in each second electrode set are electrically connected to one another. Or, the second electrodes in two adjacent touch sensitive units are electrically connected to one another. Accordingly, in the touch panel of the invention, the same wire is used to connect between a control IC and a plurality of the first electrodes that are electrically connected to one another, or the same wire is used to connect between the control IC and a plurality of the second electrodes that are electrically connected to one another. Based on the above, the touch panel of the invention achieves the multi-touch function without increasing the number of the wires, and thus has the advantage of cost saving. 
     Although the invention has been described with reference to the above embodiments, it will be apparent to one of ordinary skill in the art that modifications to the described embodiments may be made without departing from the spirit of the invention. Accordingly, the scope of the invention will be defined by the attached claims and not by the above detailed descriptions.