Patent Publication Number: US-2015077654-A1

Title: Touch panel

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 102133957, filed on Sep. 18, 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 relates to a touch panel, and more particularly, to a touch panel that improves appearance and enhances visual effects. 
     2. Description of Related Art 
     Generally, a touch panel has to be installed on a surface of an electronic product for a user to input information by touching and to operate the electronic product. Or, a touch panel is integrated into a surface of a display panel so as to provide touching and displaying functions. Nonetheless, in order to shield locations of transmission lines and a layout of circuits, a border of a touch panel is usually disposed with a light shielding material in a dark color, such as in black color. That is the reason why borders of electronic products are usually in black color which cannot satisfy a user&#39;s demand for a product appearance. 
     Furthermore, in contemporary electronic devices, signs of corporate brands or product models are often arranged on the electronic devices, which are used to show corporate images or product properties. In order to arrange a sign representing a corporate brand or a product model on a touch panel, the sign thereof must be formed directly on a cover plate by metal coating or ink printing, and then a light shielding layer and transmission lines are sequentially formed, wherein the light shielding layer is disposed between the sign and the transmission lines. However, a metal sign formed by metal coating increases manufacturing costs and complicates a process of manufacturing a touch panel. If an ink sign is formed by ink printing, glossiness of ink is inferior to glossiness of metal, and thereby overall quality of the touch panel is significantly sacrificed. 
     SUMMARY OF THE INVENTION 
     The invention provides a touch panel, which satisfies a user&#39;s demand for a product appearance and can avoid increases on manufacturing costs. 
     A touch panel of the invention has a light transmitting area and a light shielding area adjacent to the light transmitting area. The touch panel includes a cover plate, a first decoration layer, a touch-sensing element and a metal conductive layer. The first decoration layer is disposed on the cover plate and located in the light shielding area. The first decoration layer has at least one hollow area. The touch-sensing element is disposed on the cover plate and at least located in the light transmitting area. The metal conductive layer is disposed on the first decoration layer, located in the light shielding area, and surrounds the touch-sensing element, wherein a portion of the metal conductive layer surrounds the hollow area. 
     In an embodiment of the invention, the touch panel further includes a second decoration layer at least overlapping the metal conductive layer and a portion of the first decoration layer, and extending to the cover plate. 
     In an embodiment of the invention, the hollow area defines a product trademark, a function symbol or a function hole. 
     In an embodiment of the invention, the function hole is a camera hole or a sensing hole. 
     In an embodiment of the invention, a portion of metal conductive layer covers a portion of the hollow area. 
     In an embodiment of the invention, the portion of metal conductive layer covers the hollow area. 
     In an embodiment of the invention, a material of the metal conductive layer includes aluminum (Al), copper (Cu), molybdenum (Mo), or a combination thereof. 
     In an embodiment of the invention, the metal conductive layer is connected to a ground potential. 
     In an embodiment of the invention, the portion of metal conductive layer is electrically connected to the metal conductive layer. 
     In an embodiment of the invention, at least a portion of the metal conductive layer is disposed on the cover plate. 
     In an embodiment of the invention, an orthographic projection area of the metal conductive layer on the cover plate is not completely overlapped with an orthographic projection area of the first decoration layer on the cover plate. 
     In an embodiment of the invention, an orthographic projection area of the metal conductive layer on the cover plate is not overlapped with an orthographic projection area of the first decoration layer on the cover plate. 
     In light of the above, since the metal conductive layer of the invention has metallic luster, the orthographic projection area of the metal conductive layer on the cover plate is not completely overlapped or not overlapped with orthographic projection area of the first decoration layer on the cover plate, so as to provide a touch panel having a metallic annular rim. Moreover, since the hollow area of the present embodiment is covered by the metal conductive layer for a product trademark or a function symbol defined by the hollow area having metallic luster, there is no need for extra processing steps to form desired colors for the product trademark or the function symbol, and increased manufacturing costs can be avoided. 
     Several exemplary embodiments accompanied with figures are described in detail below to further describe the invention in details. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  illustrates a schematic bottom view of a touch panel according to an embodiment of the invention. 
         FIG. 2  illustrates a schematic cross-sectional view of  FIG. 1  along the line I-I′. 
         FIGS. 3A to 3C  illustrate a schematic bottom view and a schematic cross-sectional view of a hollow area of the touch panel depicted in  FIG. 1 . 
         FIG. 4  illustrates a schematic bottom view of a touch panel according to an embodiment of the invention. 
         FIG. 5  illustrates a schematic bottom view of a touch panel according to another embodiment of the invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIG. 1  illustrates a schematic bottom view of a touch panel according to an embodiment of the invention.  FIG. 2  illustrates a schematic cross-sectional view of  FIG. 1  along the line I-I′. Referring to  FIG. 1  and  FIG. 2 , in the present embodiment, a touch panel  100   a  has a light transmitting area  102  and a light shielding area  104  surrounding the light transmitting area  102 , wherein the light shielding area  104  is located at least one side of the light transmitting area  102 . The touch panel  100   a  includes a cover plate  110 , a touch-sensing element  120 , a metal conductive layer  130  and a first decoration layer  140 , wherein the metal conductive layer  130  is connected to a ground potential. 
     The touch-sensing element  120  is disposed on the cover plate  110  and at least located in the light transmitting area  102 . At least a portion of the metal conductive layer  130  is disposed on the cover plate  110 , located in the light shielding area  104  and surrounds the touch-sensing element  120 . The first decoration layer  140  is disposed on the cover plate  110  and located in the light shielding area  104 , wherein the first decoration layer  140  has at least one hollow area  142  exposing a portion of the cover plate  110  so as to define at least one pattern, such as a product trademark, a function symbol or a function hole. The function hole can be, for example, a cameral hole, a light source hole or a sensing hole. Namely, a camera lens, an LED light source, an infrared sensor or a charge-coupled device can be disposed behind the function hole, but the invention is not limited herein. When the hollow area  142  defines a product trademark, a portion of the metal conductive layer  130  covers the hollow area  142 , and when the hollow area  142  defines a camera hole, a portion of the metal conductive layer  130  is disposed at an edge of the hollow area  142 . 
     More particularly, the cover plate  110  of the present embodiment, for example, is a glass plate or a plastic plate. However, the invention is not limited herein. The touch-sensing element  120 , for example, is consisted of a plurality of first electrode series  122  and a plurality of second electrode series  124 . Each of the first electrode series  122  includes a plurality of first electrodes  122   a  and a plurality of first connecting lines  122   b  connecting the first electrodes  122   a  along one direction. Each of the second electrode series  124  includes a plurality of second electrodes  124   a  and a plurality of second connecting lines  124   b  connecting the second electrodes  124   a  along one direction. To avoid short circuit of the first electrode series  122  and the second electrode series  124 , an insulation pattern  125  between the first connecting line  122   b  and the second connecting line  124   b  is further arranged. In addition, the touch sensing-element  120  further includes a passivation layer  126  covering the first electrode series  122  and the second electrode series  124 . 
     As shown in  FIG. 2 , the first electrodes  122   a  and the second electrode series  124  of the present embodiment can be made of the same transparent conductive material. Next, the insulation pattern  125  is formed on the second connecting line  124   b.  Thereafter, the first connecting line  122   b  is formed on the insulation pattern  125 . Now, the first connecting line  122   b  is disposed on one side of the insulation layer  125  far away from the cover plate  110 , and can be made of a transparent conductive material or a metal material. However, the invention is not limited herein. In other embodiments not illustrated herein, the first connecting line  122   b  can firstly be formed on the cover plate  110  before fabricating the first electrodes  122   a  and the second electrode series  124 , and the insulation pattern  125  is formed on the first connecting line  122   b,  and then the first electrode  122   a  and the second electrode series  124  are fabricated on the cover plate  110 . Now, the first connecting line  122   b  is disposed between the insulation layer  125  and the cover plate  110 , and can be made of a transparent conductive material or a metal material. The aforesaid techniques still belongs to a technical means adoptable in the invention and falls within the protection scope of the invention. 
     Furthermore, in order to connect the first electrode series  122  and the second electrode series  124  to a driving circuit or an external circuit, the touch panel  100   a  further includes a plurality of transmission lines  160 , wherein the transmission lines  160  are disposed on the first decoration layer  140 , located in the light shielding area  104  and electrically connected to the touch-sensing element  120 . As shown in  FIG. 2 , the first electrode  122   a  extends to the first decoration layer  140  and covers a portion of the first decoration layer  140 , while the transmission line  160  covers the first electrode  122   a  to form a connection. As a result, the first decoration layer  140  can shield the transmission lines  160  to provide an aesthetic appearance of the touch panel  100   a.    
     A material of the first decoration layer  140  of the present embodiment, for example, is an ink material or a photoresist material. More specifically, referring to  FIG. 3A , when the hollow area  142  defines a product trademark, a portion of the metal conductive layer  130  is disposed within the hollow area  142  to cover a portion of the cover plate  110  exposed by the hollow area  142 . Namely, when a user sees the touch panel  100   a,  colors of the metal conductive layer  130  is displayed on the cover plate  110  through the hollow area  142 . As shown in  FIG. 1 , in the present embodiment, an area of the metal conductive layer  130  extending to the hollow area  142  is larger than an area of the hollow area  142 . In other words, the metal conductive layer  130  covers the hollow area  142  and a portion of the first decoration layer  140 . Moreover, the metal conductive layer  130  can be formed on the cover plate  110  by applying methods such as an evaporation method, a sputtering method, a screen printing method, a transfer printing method and a spraying method. A material of the metal conductive layer  130 , for example, is a material having metallic luster such as aluminum (Al), copper (Cu), molybdenum (Mo), or a combination thereof. 
     Since the metal conductive layer  130  of the present embodiment has metallic luster, colors from the metal conductive layer  130  through the hollow area  142  and the first decoration layer  140  can be seen, such that a product trademark or a function symbol defined by the hollow area  142  on the touch panel  100   a  has metallic luster and the appearance quality is enhanced. Therefore, the touch panel  100   a  of the present embodiment can satisfy the user&#39;s demand for a product configuration. In addition, since the hollow area  142  of the present embodiment is covered by the metal conductive layer  130 , there is no need for extra processing steps to form desired colors for a product trademark or a function symbol, which can avoid the increment on manufacturing costs. 
     Furthermore, referring to  FIG. 2  again, the touch panel  100   a  of the present embodiment can also further include a second decoration layer  180 , wherein the second decoration layer  180  is disposed to at least overlap the metal conductive layer  130  and a portion of the first decoration layer  140 , and extends to the cover plate  110 . Therefore, an area not shielded by the first decoration layer  140  and the metal decoration layer  130  on the light shielding area  104  is covered by the second decoration layer  180  to prevent light from leaking from the edge of the cover plate  110 . The passivation layer  126  is disposed between the second decoration layer  180  and the metal conductive layer  130  and the first decoration layer  140 . 
     It should be noted that positioning methods and structural types of the metal conductive layer  130  of the invention is not limited herein. As shown in  FIG. 3A , the metal conductive layer  130  of the present embodiment is disposed on one side of the first decoration layer  140  far away from the cover plate  110  and extends to the cover plate  110 . In other embodiments, referring to  FIG. 4 , the metal conductive layer  130  of a touch panel  100   b  is disposed on the cover plate  110 , and an orthographic projection area of the metal conductive layer  130  on the cover plate  110  is not overlapped with an orthographic projection area of a first decoration layer  140   b  on the cover plate  110 ; or, referring to  FIG. 5 , the metal conductive layer  130  of a touch panel  100   c  is disposed on the cover plate  110 , and an orthographic projection area of the metal conductive layer  130  on the cover plate  110  is not overlapped with an orthographic projection area of a first decoration layer  140   c  on the cover plate  110 , and a line width P2 of the metal conductive layer  130  in  FIG. 5  is wider than a line width P1 of the metal conductive layer  130  in  FIG. 4 . Since the metal conductive layer  130  is connected to a ground potential and an area of the metal conductive layer  130  is proportional to anti-electrostatic capability, the touch panel  100   c  has better anti-electrostatic capability than the touch panel  100   b.  Here, the line widths P1 and P2 of the metal conductive layer  130  are at least 200 micrometers, and a distance D from an edge of the metal conductive layer  130  to an edge of the cover plate  110  is, for example, at least 100 micrometers. 
     Since orthographic projection areas of the metal conductive layer  130  on the cover plate of the touch panels  100   a,    100   b  and  100   c  are not completely overlapped or not overlapped with orthographic projection areas of the first decoration layers  140 ,  140   b  and  140   c  on the cover plate  110 , so as to provide the touch panels  100   a,    100   b  and  100   c  having metallic annular rims. Moreover, since the hollow area  142  of the present embodiment is covered by the metal conductive layer  130 , a product trademark or a function symbol defined by the hollow area  142  has metallic luster. Therefore, there is no need for extra processing steps to form desired colors for the product trademark or the function symbol, and increment on manufacturing costs can be avoided. 
     In addition, referring to  FIGS. 1 ,  4  and  5 , a cameral hole can be defined by the hollow area  142 , and surrounded by the metal conductive layer  130  such that the grounded metal conductive layer  130  is configured to prevent external electrostatic from destroying internal devices through the hollow area  142 . Referring to  FIG. 3B , the metal conductive layer  130  covers the first decoration layer  140  and exposes a camera hole (i.e., a location at which the hollow area  142  is positioned); or, in other embodiments, referring to  FIG. 3C , a portion of the metal conductive layer  130  extends to the cover plate  110  inside the camera hole, so as to provide the camera hole having a pattern of metal ring. 
     In summary, since the metal conductive layer of the invention has metallic luster, a touch panel having a metallic annular rim can be provided by the metal conductive layer disposed on the cover plate. Further, the metal conductive layer covers the hollow area defining a product trademark or a function symbol to provide metallic luster on the product trademark or the function symbol. Moreover, the grounded metal conductive layer surrounds the hollow area defining a camera hole and partially overlaps with the cover plate to provide the camera hole having a pattern of metal ring and to prevent external electrostatic from destroying internal devices through the hollow area. Therefore, the touch panel of the invention can satisfy a user&#39;s demand for a product appearance and electrical requirement. Additionally, since the invention is a design that provides various kinds of visual effects through the metal conductive layer, there is no need for extra processing steps to add metallic luster, and increased manufacturing cost can be avoided. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this specification provided they fall within the scope of the following claims and their equivalents.