Patent Publication Number: US-2015075960-A1

Title: Touch panel

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 102133385, filed on Sep. 14, 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 more particularly to a touch panel having a hot key design. 
     2. Description of Related Art 
     In the era of information explosion, people view effectiveness as a valuable quality. Therefore, as for smart terminal products such as hand-held electronic devices including smart phones or tablet computers, not only having multiple functions and light and thin appearances, users also expect to execute required functions in a short time and switch between each application quickly when using the smart terminal products. Among the aforementioned functions, the functions (for example, editing text messages, querying calling records, or returning from/to the home page) that are frequently used by the users are even more important. 
     In order to fulfill the above requirements, taking smart phones or tablet computers for example, recent manufacturers of the smart terminal products commonly configure shortcut keys or hot keys in a decoration area of a smart phone or a tablet computer at the beginning of the product design. Generally, in the process of making the shortcut keys or the hot keys, it is required to carve part of a decoration layer located in the decoration area out to form an opening having a predetermined contour, such that this predetermined pattern contours of the shortcut keys or the hot keys are visible on the a touch panel. In addition, touch electrodes are disposed on the corresponding shortcut keys or hot keys, which allow the users to operate the smart phone or the tablet computer more intuitively. 
     However, since the decoration layer is formed on the surface of the substrate of the touch panel and has a certain thickness, there will be a height difference between the upper surface of the decoration layer near the aforementioned opening and the surface of the substrate of the touch panel. As a result, when manufacturing the touch electrodes corresponding to the shortcut keys or the hot keys, disconnection of the touch electrodes may occur due to the aforementioned height difference, which leads to a problem such as malfunction of the touching function corresponding to the shortcut key or the hot key or delay of the touching reaction. 
     SUMMARY OF THE INVENTION 
     Accordingly, the invention provides a touch panel having an improved layout of a conductive electrode structure so as to prevent the problem such as malfunction of a touching function or delay of a touching reaction due to disconnection of the touch electrode structure. 
     The touch panel of the invention includes a substrate, at least one decoration layer, and a conductive electrode structure. The decoration layer is disposed on at least one side of the substrate and has at least one hot key area. The hot key area includes a hot key pattern area and a hot key touching area. The hot key touching area is located on at least one side of the hot key pattern area without overlapping each other. The decoration layer has at least one recess disposed in the hot key pattern area. The conductive electrode structure is disposed on the decoration layer. The conductive electrode structure is located in the hot key touching area, and an orthogonal projection of the conductive electrode structure on the substrate and an orthogonal projection of the recess on the substrate do not overlap with each other. 
     The touch panel of the invention includes a substrate, at least one decoration layer, and a conductive electrode structure. The decoration layer is disposed on at least one side of the substrate and has at least one hot key area. The hot key area includes a hot key pattern area and a hot key touching area. The hot key touching area is located on at least one side of the hot key pattern area without overlapping each other. The decoration layer has at least one recess disposed in the hot key pattern area. The conductive electrode structure is disposed on the decoration layer. The conductive electrode structure is located in the hot key touching area, wherein the conductive electrode structure is located out of the recess. 
     In an embodiment of the invention, the aforementioned decoration layer includes at least one ink layer, at least one photoresist layer, or a combination thereof. 
     In an embodiment of the invention, the aforementioned conductive electrode structure is formed by a one layer electrode. 
     In an embodiment of the invention, the aforementioned recess is a hot key pattern opening. 
     In an embodiment of the invention, the conductive electrode structure includes a first electrode and a second electrode, and the contour of the first electrode and the contour of the second electrode are at least partially complementary to each other. 
     In an embodiment of the invention, each of the first electrode and the second electrode includes a main electrode and a plurality of sub electrodes connecting to the main electrode, and the sub electrodes of the first electrode and the sub electrodes of the second electrode are arranged alternately. 
     In an embodiment of the invention, each of the sub electrodes of the first electrode extends toward the second electrode, and each of the sub electrodes of the second electrode extends toward the first electrode. 
     In an embodiment of the invention, the conductive electrode structure further includes a first extending electrode. The first extending electrode is connected to the first electrode and extends to the peripheral area of the hot key pattern area, and a part of the contour of the first extending electrode and the contour of the hot key pattern opening are complementary to each other. 
     In an embodiment of the invention, the conductive electrode structure further includes a second extending electrode. The second extending electrode is connected to the second electrode and extends to the peripheral area of the hot key pattern area, and a part of the contour of the second extending electrode and the contour of the hot key pattern opening are complementary to each other. 
     In an embodiment of the invention, the conductive electrode structure includes a first electrode, a second electrode, and a virtual electrode. The first electrode and the second electrode surround the hot key pattern area, and each of the first electrode and the second electrode includes a main electrode and a plurality of sub electrodes connected to the main electrode. The virtual electrode is located between the first electrode and the second electrode and located in the hot key pattern area. 
     In an embodiment of the invention, the virtual electrode includes a plurality of virtual sub electrodes, and a part of the virtual sub electrodes extend toward the first electrode while the other part of the virtual sub electrodes extend toward the second electrode. The plurality of virtual electrodes is located outside of the hot key pattern area. 
     In an embodiment of the invention, the part of the virtual sub electrodes are arranged alternately with the sub electrodes of the first electrode, while the other part of the virtual sub electrodes are arranged alternately with the sub electrodes of the second electrode. 
     In an embodiment of the invention, the contour of the part of the virtual sub electrodes and the contour of the hot key pattern opening are complementary to each other. 
     In an embodiment of the invention, the conductive electrode structure is connected to an external circuit. 
     In an embodiment of the invention, the recess includes a colored ink layer therein. 
     In an embodiment of the invention, the recess includes an ink layer having a low optical density. 
     In an embodiment of the invention, the ink layer having the low optical density has an optical density that is less than 2.5. 
     To sum up, in the touch panel of the invention, the hot key touching area is located on at least one side of the hot key pattern area without overlapping each other. The conductive electrode structure is disposed on the decoration layer and located in the hot key touching area. The contours of the first electrode and the second electrode of the conductive electrode structure are complementary to each other or selectively complementary to the contour of the recess. Therefore, the layout of the conductive electrode structure skirts the recess, so that the problem such as the malfunction of the touch function or the delay of the touching reaction due to the disconnection of the conductive electrode structure can be avoided. 
     To make the above features and advantages of the present invention more comprehensible, several embodiments accompanied with drawings are described in detail as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a schematic view of a touch panel according to an embodiment of the invention. 
         FIG. 2A  is a schematic view of partial layout of the conductive electrode structure located in an area A of  FIG. 1 . 
         FIG. 2B  is a cross-sectional schematic view along a line I-I of  FIG. 2A . 
         FIG. 2C  is a cross-sectional schematic view of a conductive electrode structure according to another embodiment of the invention. 
         FIG. 2D  is a partial layout schematic diagram of the conductive electrode structure according to another embodiment of the invention. 
         FIG. 3A  to  FIG. 3E  are partial layout schematic diagrams of conductive electrode structures according to other embodiments of the invention. 
         FIG. 4  is a partial layout schematic diagram of a conductive electrode structure according to another embodiment of the invention. 
         FIG. 5  is a partial layout schematic diagram of a conductive electrode structure according to yet another embodiment of the invention. 
         FIG. 6A  and  FIG. 6B  are partial layout schematic diagrams of a conductive electrode structure according to still another embodiment of the invention. 
         FIG. 7A  is a partial layout schematic diagram of a conductive electrode structure according to further another embodiment of the invention. 
         FIG. 7B  is a schematic cross-sectional view along a line J-J of  FIG. 7A . 
         FIG. 8  and  FIG. 9  are partial layout schematic diagrams of conductive electrode structures according to other possible embodiments of the invention. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1  is a schematic view of a touch panel according to an embodiment of the invention.  FIG. 2A  is a schematic view of partial layout of the conductive electrode structure located in an area A of  FIG. 1 .  FIG. 2B  is a cross-sectional schematic view along a line I-I of  FIG. 2A . For the purpose of clarity, sizes, relative sizes and shapes of each element, each layer, and each area may be appropriately exaggerated in  FIG. 2B . Please refer to  FIG. 1 ,  FIG. 2A , and  FIG. 2B . In the present embodiment, a touch panel  100  includes a substrate  110 , at least one decoration layer  120 , and a conductive electrode structure  130 . To be more specific, the substrate  110  is, for example, a touch module of a smart phone or a tablet computer or a cover substrate of an electronic device. The cover substrate is capable of covering and protecting the touch module or the electronic device and may be, for example, a light transmissive glass substrate or 1 acrylic substrate. In addition, the cover substrate may also have a strengthening or embellishment function achieved with the surface thereof being chemically or physically processed, but the invention is not limited thereto. 
     In the present embodiment, the decoration layer  120  is disposed on the substrate  110 , as shown in  FIG. 2B . The decoration layer  120  is, for example, a multi-layer structure formed by stacking an ink layer  120   a  and a photoresist layer  120   b  in order. For example, the decoration layer  120  may also be a single-layer structure formed by an ink layer having a high optical density (OD) or a photoresist layer with high optical density (OD), whose optical density (OD) is preferably greater than 2.5. Additionally, in other embodiments that are not shown, the decoration layer  120  may also be a multi-layer structures or a single-layer structure formed by stacking either one of the ink layers  120   a  of the photoresist layer  120   b,  but the invention is not limited thereto. 
     The decoration layers  120  may be disposed on at least one side of the substrate  100 , but the invention is not limited thereto. For example, as shown in  FIG. 1 , the decoration layer  120  may be disposed on the peripheral area of the substrate  100  to define an operating area AA that is substantially a rectangular shape. An electrode structure applied to a driving/sensing function may be disposed on the operating area AA. Alternatively, the touch panel  100  may also be equipped with a sensing component used for sensing a touch operation of a user in the operating area AA. However, the invention is not intent to limit that the operating area AA has to be provided with the driving/sensing function, and in other embodiments, the operating area AA may merely be a light transmissive area without having a touching function. 
     Specifically, the ink layer  120   a  may be formed on substrate  110  through a process such as a gravure printing process, a screen printing process, a flexographic printing process, an offset printing, a reverse printing process, an ink jet printing process, and the like. On the other hand, the photoresist layer  120   b  may be formed on the ink layer  120   a  by one of the aforementioned printing processes or solely formed on the substrate  110 . The photoresist layer  120   b  may be, for example, a black ink layer having a high optical density so as to effectively reduce light transmittance. In other words, by disposing the decoration layer  120  on the substrate  110 , the user may be prevented from directly seeing through the circuit layout in the peripheral area of the touch panel  100 . 
     Referring to  FIG. 2A  and  FIG. 2B , at least a hot key area  120   c  is disposed on the decoration layer  120 , and each hot key area  120   c  further includes a hot key pattern area  121  and a hot key touching area  122 . The hot key touching area  122  is located on at least one side of the hot key pattern area  121  (in the present embodiment, an example where the hot key pattern area  121  is surrounded by hot key touching area  122  is illustrated) without overlapping each other, and the decoration layer  120  has at least one recess  121   a  disposed in the hot key pattern area  121 . 
     On the other hand, the conductive electrode structure  130  is disposed on the decoration layer  120 . The conductive electrode structure  130  is located in the hot key touching area  122 , and an orthogonal projection of the conductive electrode structure  130  on the substrate  110  and an orthogonal projection of the recess  121   a  on the substrate  110  do not overlap with each other. More specifically, the orthogonal projections of the conductive electrode  130  and the recess  121   a  are formed on the substrate  110  along an auxiliary projection direction P, and the auxiliary projection direction P is perpendicular to the substrate  110 . In other words, the conductive electrode structure  130  is located out of the recess  121   a  and does not extend into the recess  121   a . The hot key pattern area  121  substantially surrounds the rectangular region around the recess  121   a  (as shown in  FIG. 2A ). The rectangular region here is only an example for the purpose of illustration, and in other embodiments, the contour and the area of the hot key pattern area  121  may vary with different designs. 
     In detail, the recess  121   a  may be, for example, a hot key pattern opening, and the contour of the hot key pattern opening is defined by the region in the hot key pattern area  121  with no decoration layer  120  formed on the substrate  110 . Herein, a house icon used for returning to the home page is illustrated as an example of the hot key pattern opening, which construes no limitations in the invention. In other possible embodiments, the hot key pattern opening may also be any other predetermined function key such as a return arrow icon, a magnifier icon, or the like. 
     Please continue to refer to  FIG. 2A  and  FIG. 2B . In the present embodiment, the conductive electrode structure  130  is formed by a one layer electrode, and the conductive electrode structure  130  includes a first electrode  140  and a second electrode  150 . In other words, the first electrode  140  and the second electrode  150  are formed on the same layer to meet the trend toward lightness and slimness of the touch panel. Certainly, manufacturing the conductive electrode structure  130  using one layer electrode also facilitates in simplifying the manufacturing process, shortening the processing period, and lowering down the cost. In the present embodiment, the first electrode  140  is, for example, a driving electrode, the second electrode  150  is, for example, a sensing electrode, and the first electrode  140  and the second electrode  150  can be made of the same material or different materials, such as metal, conductive oxide (e.g., indium tin oxide), conductive polymer, or other conductive materials. On the other hand, the conductive electrode structure  130  is connected to a circuit (not shown), which may be used to provide driving signals to first electrode  140  and receive sensing signals from second electrode  150 . Certainly, in other possible embodiments, the first electrode  140  may be, for example, a driving electrode, and the second electrode  150  may be, for example, a sensing electrode, such that the aforementioned circuit may be used for providing driving signals to first electrode  140  and receiving sensing signals from the second electrode  150 . 
     Specifically, the touch panel  100  of the present embodiment may be, for example, a mutual-capacitance type touch panel, and namely, a mutual capacitance effect is formed between the first electrode  140  and the second electrode  150 . When no touch event occurs, the circuit obtains a constant equivalent mutual capacitance. However, when a touch event occurs, the equivalent mutual capacitance between the first electrode  140  and the second electrode  150  is changed and is obtained by the circuit, such that through calculations, an exact location where the touch event occurs may be determined according to the calculation of the capacitance change. 
     In order to make the sensing of the touch event more precise, the contour of the first electrode  140  and the contour of the second electrode  150  are at least partially complementary to each other. As shown in  FIG. 2A , in the present embodiment, the first electrode  140  and the second electrode  150  respectively include main electrodes  141 ,  151  and a plurality of sub electrodes  142 ,  152  which are connected to the corresponding main electrodes  141 ,  151  to present two mutually engaged comb-like electrodes without contacting each other, and thereby, the mutual capacitance effect between the first electrode  140  and the second electrode  150  is increased. In other words, the sub electrodes  142  of the first electrode  140  and the sub electrodes  152  of the second electrode  150  are arranged alternately, and therein, each of the sub electrodes  142  extends toward the second electrode  150  along a direction A1, and each of the sub electrodes  152  extends toward the first electrode  140  along a direction A1. 
     In detail, a first gap G1 exists between each two adjacent sub electrodes  142  and  152 , and a second gap G2 exists between each two adjacent main electrodes  141  and  151 . On the other hand, a third gap G3 exists between each adjacent sub electrode  152  and main electrode  141 , and a fourth gap G4 exists between each adjacent sub electrode  142  and main electrode  151 . The aforementioned gaps are preferably 20-500 microns, and more preferably 200-300 microns. 
     In short, with the aforementioned layout of the conductive electrode structure  130 , not only the problem such as malfunction of the touching function or delay of the touching reaction due to disconnection of the touch electrode structure  130  can be resolved, but also the mutual capacitance between the first electrode  140  and the second electrode  150  can further be increased, such that the hot key pattern area  121  on the touch panel  100  can have better touch sensitivity. 
     In addition, please refer to  FIG. 2B . Since the recess  121   a  is an opening formed by penetrating through the decoration layer  120 , a colored-ink layer may be additionally deposited to cover the recess  121   a,  such that the colored-ink layer may cover or partially cover the hot key touching area  122 . 
       FIG. 2C  is a cross-sectional schematic view of a conductive electrode structure according to another embodiment of the invention. More specifically, the recess  121   a  is not limit to be the aforementioned aspect of the embodiment above. For example, referring to  FIG. 2C , an ink layer  120   a  having a low optical density (i.e., an optical density less than 2.5) may be disposed in the recess  121   a.  In such disposition, a user may still be able to see the contour of the hot key pattern opening, such as the house icon for returning to home page shown in  FIG. 2A  or other predetermined functional key icons, in the periphery of the substrate  110 . In the present embodiment, the ink layer  120   a  in the recess  121   a  is a one layer structure as an example for the purpose of illustration. However, as long as the user is able to see the contour of the hot key pattern opening in the periphery of the substrate  110 , in other embodiments, the ink layer  120   a  in the recess  121   a  may also be a multi-layer structure, which is not limited in the invention. 
       FIG. 2D  is a partial layout schematic diagram of the conductive electrode structure according to another embodiment of the invention. Please refer to  FIG. 2D .  FIG. 2D  illustrates a conductive electrode structure  130 ′ that is different from the conductive electrode structure  130  in  FIG. 2A  are in the following aspects. In the present embodiment, the hot key pattern area  121  is located in a semi-enclosed region having an opening formed by the second electrode  150 , and the second electrode  150  is located in a semi-enclosed region having an opening formed by the first electrode  140 . More specifically, the opening of the semi-enclosed region formed by the first electrode  140  is connected through with the opening of the semi-enclosed region formed by the second electrode  150 . With the layout of the conductive electrode structure  130 ′, the same technical effect presented in the previous embodiments can also be achieved. The location of the opening shown in  FIG. 2C  is only an example for illustration, and does not construe any limitation to the invention. In other embodiments, the location of the opening of the semi-enclosed region formed by the first electrode  140  and the location of the opening of the semi-enclosed region formed by the second electrode  150  may vary with different designs. 
       FIGS. 3A to 3E  are partial layout schematic diagrams of conductive electrode structures according to other embodiments of the invention. Please refer to  FIG. 3A , illustrating a conductive electrode structure  130   a.  In the present embodiment, the contour of first electrode  140  and the contour of second electrode  150  of the conductive electrode structure  130   a  are also partially complementary to each other. More specifically, the first electrode  140  has a convex part  142   a  extending toward the second electrode  150 , and the convex part  142   a  is substantially a triangle shape. The second electrode  150  has a concave part  152   a  corresponding to the convex part  142   a,  such that the convex part  142   a  may be contained therein. The convex part  142   a  and the concave part  152   a  are engaged with each other without being contacting each other. In other words, a gap also exists between the first electrode  140  and the second electrode  150 , and the gap is preferably 20-500 microns, and more preferably 200-300 microns. With the layout of the conductive electrode structure  130   a,  the same technical effect presented in the previous embodiments can also be achieved. 
     Please refer to  FIG. 3B  illustrating a conductive electrode structure  130   b.  In the present embodiment, the contour of first electrode  140  and the contour of second electrode  150  of the conductive electrode structure  130   b  are also partially complementary to each other. More specifically, the first electrode  140  and the second electrode  150  respectively include plate sub electrodes  142   b  and  152   b  that are corresponding to each other. The plate sub electrodes  142   b  are located on two sides of two plate sub electrodes  152   b,  while the hot key pattern area  121  and the hot key pattern opening are located between the two plate sub electrodes  152   b.    
     More specifically, the hot key pattern area  121  and the hot key pattern opening are simultaneously surrounded by the first electrode  140  and the second electrode  150 , while the first electrode  140  and the second electrode  150  are engaged with and separated from each other by a gap therebetween without contacting each other, wherein the gap is preferably 20-500 microns and more preferably 200-300 microns. With the layout of the conductive electrode structure  130   b,  the same technical effect presented in the previous embodiments can also be achieved. 
     Please refer to  FIG. 3C  illustrating a conductive electrode structure  130   c.  In the present embodiment, the contour of first electrode  140  and the contour of second electrode  150  in conductive electrode structure  130   c  are also partially complementary to each other. More specifically, the first electrode  140  has a dentate sub electrode  142   c  which extending toward the second electrode  150 , and the second electrode  150  has a dentate sub electrode  152   c  extending toward the first electrode  140 . The dentate sub electrodes  142   c  and  152   c  are arranged alternately. 
     More specifically, the hot key pattern area  121  and the hot key pattern opening are surrounded by the second electrode  150 , and the first electrode  140  is located outside the second electrode  150 . The first electrode  140  and the second electrode  150  are engaged with and separated from each other by a gap therebetween without contacting each other, wherein the gap is preferably 20-500 microns, and more preferably 200-300 microns. With the layout of the conductive electrode structure  130   c,  the same technical effect presented in the previous embodiments can also be achieved. 
     Please refer to  FIG. 3D  illustrating a conductive electrode structure  130   d  including a first electrode  140   d  and a second electrode  150   d.  The conductive electrode structure  130   d  of  FIG. 3D  and the conductive electrode structure  130   c  of  FIG. 3C  are different in the following aspects. In the present embodiment, the first electrode  140   d  has a wave-like sub electrode  142   d  extending toward the second electrode  150   d,  the second electrode  150   d  includes a wave-like sub electrode  152   d  extending toward the first electrode  140   d,  and the wave-like sub electrodes  142   d  and  152   d  are arranged alternately. With the layout of the conductive electrode structure  130   d,  the same technical effect presented in the previous embodiments can also be achieved. 
     Please refer to  FIG. 3E  illustrating a conductive electrode structure  130   e  including a first electrode  140   e  and a second electrode  150   e.  The conductive electrode structure  130   e  of  FIG. 3E  and the conductive electrode structure  130  of  FIG. 2A  are different in the following aspect. In the present embodiment, the sub electrodes  142   e  of the first electrode  140  extend toward second electrode  150  along the direction A2 and the sub electrodes  152   e  of second electrode  150  extend toward the first electrode  140  along the direction A2, respectively, and the direction A2 is perpendicular to the direction A1. With the layout of the conductive electrode structure  130   e,  the same technical effect presented in the previous embodiments can be achieved. 
       FIG. 4  is a partial layout schematic diagram of a conductive electrode structure according to another embodiment of the invention. Please refer to  FIG. 2A  and  FIG. 4  simultaneously.  FIG. 4  illustrates a conductive electrode structure  130   f  that is different from the conductive electrode structure  130  of  FIG. 2A  in the following aspects. In the present embodiment, the conductive electrode structure  130   f  further includes a first extending electrode  143  connected to the first electrode  140  and extending to the peripheral area of the hot key pattern area  121 , and the contour of the first extending electrode  143  and the contour of the hot key pattern opening are partially complementary to each other. More specifically, the hot key pattern area  121  is, for example, a region defined along the contour of the hot key pattern opening. 
     That is to say, by skirting the layout of the hot key pattern opening, the first electrode  140  further extends to a semi-enclosed region having an opening that is formed by the second electrode  150  with the first extending electro  143 , wherein the sub electrodes  142  and  152  in the hot key area  120   c  are arranged alternately, and the first extending electrode  143  is parallel to the second electrode  150  in the hot key area  120   c . Therefore, along the direction A1, a plurality of parallel electric field lines M are produced between the first electrode  140  and the second electrode  150  and between the first extending electrode  143  and the second electrode  150 . On the other hand, along the direction A2, a plurality of electric field lines M may also be produced between two adjacent sub electrodes  142  and  152 . In such disposition, not only efficiency of the fringe capacitance in the hot key area  120   c  can be improved, but a sensing range of the hot key area  120   c  may also be increased. As a result, not only the same mutual-capacitance effect presented in the previous embodiments can be achieved, but also the sensing capability of the hot key area  120   c  may be significantly increased to achieve better touch sensitivity. 
       FIG. 5  is a partial layout schematic diagram of a conductive electrode structure according to yet another embodiment of the invention. Please refer to  FIG. 4  and  FIG. 5  simultaneously.  FIG. 5  illustrates a conductive electrode structure  130   g  that is different from the conductive electrode structure  130   f  of  FIG. 4  in the following aspect. In the present embodiment, the conductive electrode structure  130   g  further includes a second extending electrode  153  connected to the second electrode  150  and extending to the peripheral area of the hot key pattern area  121 , the contour of the second extending electrode  153  and the contour of the hot key pattern opening are partially complementary to each other. The hot key pattern area  121  of the present embodiment may also be, for example, the region defined along the contour of the hot key pattern opening. In other words, with the layout skirting the hot key pattern opening, the second electrode  150  further extends to a semi-enclosed region formed by the second electrode  150  with the second extending electrode  153 , and the same technical effect of the aforementioned conductive electrode structure  130   f  can also be achieved. 
       FIG. 6A  and  FIG. 6B  are partial layout schematic diagrams of a conductive electrode structure according to still another embodiment of the invention. Please refer to  FIG. 2A  and  FIG. 6A  simultaneously.  FIG. 6A  illustrates a conductive electrode structure  130   h  that is different in the following aspect. In the present embodiment, the conductive electrode structure  130   h  further includes a virtual electrode  160  located between the first electrode  140  and the second electrode  150  in the hot key pattern area  120 . More specifically, the virtual electrode  160  may be, for example, a floating electrode having no substantial signal connection or spatially contact with the first electrode  140  and the second electrode  150 . The virtual electrode  160  may be made of, for example, indium tin oxide (ITO) or any conductive material of which the first electrode  140  and the second electrode  150  are made. 
     In the present embodiment, the virtual electrode  160  also utilizes a layout skirting the hot key pattern opening so as to prevent disconnection. For example, the contour of the virtual electrode  160  and the contour of the hot key pattern opening are partially complementary to each other. It is to be mentioned that since the virtual electrode  160  has no substantial signal connection with the first electrode  140  and the second electrode  150 , the contour of the virtual electrode  160  and the contour of the hot key pattern opening are also unnecessarily complementary to each other. That is to say, even though the virtual electrode  160  is separated into a plurality of blocks due to the hot key pattern opening during the process of forming the virtual electrode  160  in the hot key pattern area  121 , the effect of improving of the sensing capability of the conductive electrode structure  130   h  will not be affected. 
     On the other hand, the virtual electrode  160  has a plurality of virtual sub electrodes  161  and  162 . The virtual sub electrodes  161  extend toward the first electrode  140  along the direction A1, the virtual sub electrodes  162  extend toward the second electrode  150  along the direction A1, and the virtual sub electrodes  161  and  162  are located outside the hot key pattern area  121 . Furthermore, the part of the virtual sub electrodes  161  and the sub electrodes  142  of the first electrode  140  are arranged alternately, and the other part of the virtual sub electrodes  162  and the sub electrodes  152  of the second electrode  150  are arranged alternately. Therefore, as shown in FIG. 
       6 A, a plurality of parallel electric field lines M with an offset relative to the direction A1 is produced between the virtual sub electrode  162  and the second electrode  150  and between the sub electrode  152  and the virtual electrode  160 . On the other hand, along the direction A2, a plurality of electric field lines M are produced between the adjacent sub electrode  152  and virtual sub electrode  162 . With the layout, not only the effect of the fringe capacitance between the first electrode  140  and the second electrode  150  can be improved, but also the sensing range of the periphery of the hot key pattern area  121  can be further increased. 
     In short, with the layout of disposing the virtual electrodes  160  between the first electrode  140  and the second electrode  150 , not only the same mutual-capacitance effect presented in the previous embodiments can be achieved, but also the effect of the fringe capacitance efficiency between the first electrode  140  and the second electrode  150  in the hot key pattern area  121  can be increased, such that the sensing capacity of the hot key pattern area  121  can be improved to achieve better touch sensitivity. 
     On the other hand, as shown in  FIG. 6B , it illustrates a conductive electrode structure  130   h ′ that is different from the conductive electrode structure  130   h  of  FIG. 6A  in the following aspect. The virtual electrode  160  in the conductive electrode structure  130   h ′ may include a plurality of block virtual sub electrodes  163  arranged in an array, wherein each of the virtual sub electrodes  163  is not connected to each other, and the virtual sub electrodes  161  and  162  are also not connected to the virtual sub electrodes  163 . In such disposition, the same technical efficiency presented in the previous embodiments can also be achieved. 
     In the present embodiment, the virtual sub electrodes  163  are illustrated as in a rectangular shape, but construes no limitations to the invention, and in other possible embodiments, the virtual sub electrodes  163  may also be arranged in an array in any other polygonal, circular or elliptic structure that are not connected to each other, or alternatively, in any other rectangular, polygonal, circular or elliptic structure, in which at least a part of the virtual sub electrodes  163  are connected to each other, irregularly arranged and but not connected to each other, or irregularly arranged and connected to each other, which construe no limitations to the invention. 
     It is to be mentioned that even though the virtual electrode  160  illustrated as being located between the first electrode  140  and the second electrode  150  in the aforementioned embodiment as an example, the virtual electrode  160  is also unnecessarily located between the first electrode  140  and the second electrode  150  in other embodiments depending on different layout designs the electrode structure designs. In other words, any embodiment with the disposition of the virtual electrode  160  in the hot key pattern area  121  that can lead to significant improvement of the sensitivity capacity in the hot key pattern area  121  shall be considered as falling within the scope of the invention. 
       FIG. 7A  is a partial layout schematic diagram of a conductive electrode structure according to further another embodiment of the invention.  FIG. 7B  is a schematic cross-sectional view along a line J-J of  FIG. 7A . Therein, the substrate  110  and the decoration layer  120  are omitted for the purpose of clear description. Please refer to  FIG. 6A  and  FIG. 7A  simultaneously.  FIG. 7A  a conductive electrode structure  130   i  that is different from the conductive electrode structure  130   h  in  FIG. 6A  in the following aspect. In the present embodiment, a par of sub electrodes  142  and  152  of the conductive electrode structure  130   i  are stacked on the virtual electrode  160  to enhance conductivity of the electric field lines between the first electrode  140  and the second electrode  150  disposed in the periphery of the hot key pattern area  121 . 
     More specifically, as shown in  FIG. 7B , an insulation layer  170  is disposed between the virtual electrode  160  and the first and the second electrodes  140 ,  150 , such that a part of the electrodes  142  and  152  stacked on the virtual electrode  160  are separated from the virtual electrode  160 . Thereby, the occurrence of short circuit between the first and the second electrodes  140 ,  150  and the virtual electrode  160  can be prevented. On the other hand, in other possible embodiments, the layout of the virtual electrode  160  of the conductive electrode structure  130   i  may also be adjusted with reference to the layout design depicted in  FIG. 6B , which is not limited in the invention. 
     In general, in other embodiments that are not shown, the layouts of the conductive electrode structures illustrated in  FIG. 4A ,  FIG. 5 ,  FIG. 6A ,  FIG. 6B , and  FIG. 7A  may also be adjusted with reference the layouts of the conductive electrode structures illustrated in  FIG. 3A  through  FIG. 3E , and in the aforementioned possible layouts of the conductive electrode structure, the sensing capability of the hot key pattern area can be effectively improved to achieve better touch sensitivity. 
       FIG. 8  and  FIG. 9  are partial layout schematic diagrams of conductive electrode structures according to other possible embodiments of the invention. The invention does not limit that the conductive electrode structure has to be the layout of mutual capacitance effect, and in other possible embodiments, a conductive electrode structure  130   j  may be, for example, a layout of self-capacitance effect having the hot key pattern area  121  located in an enclosed region surrounded by the conductive electrode structure  130   j,  of which the layout is illustrated in  FIG. 8 . In other words, with the driving design of the self-capacitance effect, the same conductive electrode structure  130   j  may also perform touch operations of signal driving and sensing. The conductive electrode structure  130   j  is connected to an external circuit (not shown) to provide driving signals and receive sensing signals. 
     In addition, as shown in  FIG. 9 , it also illustrates a conductive electrode structure  130   k  of a self-capacitance effect layout. The conductive electrode structure  130   k  of  FIG. 9  is different from the conductive electrode structure  130   j  of  FIG. 8  in the following aspect. In the present embodiment, the hot key pattern area  121  is located in a semi-enclosed region having an opening that is surrounded by the conductive electrode structure  130   k.  Under such arrangement, the conductive electrode structure  130   k  can achieve the same technical effect as the conductive electrode structure  130   j  does. 
     It is to be mentioned that the conductive electrode structures  130   j  and  130   k  may also selectively include the virtual electrodes  160  shown in  FIG. 6A  and  FIG. 6B  or other suitable virtual electrodes in the hot key pattern area  121  to enhance the sensing capability of the conductive electrode structures  130   j  and  130   k  of the self-capacitance effect layout. 
     To sum up, in the touch panel of the invention, the hot key touching area is located on at least one side of the hot key pattern area without overlapping with each other, and the conductive electrode structure is disposed on the decoration layer and located in the hot key touching area. The contours of the first electrode and the second electrode of the conductive electrode structure are complementary to each other, and both are also both also complementary to the contour of the hot key pattern opening. Therefore, the layout of the conductive electrode structure skirts the hot key pattern opening so as to prevent the problem such as malfunction or the delay of the touching function due to disconnection of the conductive electrode structure passing through the hot key pattern opening. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of the invention provided they fall within the scope of the following claims and their equivalents.