Patent Publication Number: US-2015085209-A1

Title: Touch display device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a touch display device. More particularly, the present invention relates to a touch display device utilizing a flexible sensor film to achieve narrow border or borderless appearance of the touch display device. 
     2. Description of the Prior Art 
       FIG. 1  illustrates the conventional touch display device. As shown in  FIG. 1 , a conventional touch display device  1  generally includes an liquid crystal display (LCD) module  10 , a touch panel module  12  stacked on the LCD module  10 , a protective cover  14  stacked on the touch panel module  12 , and a system mechanism part  16  enclosing the above components. The touch panel module  12  is fixed to the LCD module  10  through the adhesive layer  121 . The protective cover  14  is fixed to the touch panel module  12  through the adhesive layer  122 . 
     The above-described touch display device still has several shortcomings. For example, the size of touch panel module  12  is often greater than the LCD module  10 , while the size of the frame  102  of the LCD module  10  and the system mechanism part  16  is greater than touch panel module  12 , resulting in a bulky appearance. In addition, the ink layer  142  of the protective cover  14  is required to consider the metal frame  102  of the LCD module  10  and peripheral traces of the touch panel module  12 . Therefore, the prior art touch display device  1  cannot achieve the narrow border appearance. Furthermore, the size of the mask for the manufacture of the sensor layer of the touch panel module  12  is only applicable to a single panel type, and cannot be shared. 
     SUMMARY OF THE INVENTION 
     Therefore, a primary object of the present invention is to provide an improved structure of the touch display device, which has a flexible sensor layer, and can achieve a narrow border or borderless appearance. 
     According to one embodiment of the invention, a touch display device includes a liquid crystal display (LCD) panel, a flexible sensor layer disposed on the LCD panel, a cover lens disposed on the flexible sensor layer, a first adhesive layer disposed between the flexible sensor layer and the LCD panel, a second adhesive layer disposed between the flexible sensor layer and the cover lens, and a system mechanism part enclosing at least the LCD panel, the flexible sensor layer, the first adhesive layer, and the second adhesive layer. 
     According to one embodiment of the invention, the LCD panel is an open-cell LCD panel. The touch display device further comprising a backlight unit disposed under the open-cell LCD panel. 
     According to one embodiment of the invention, the system mechanism part is coupled to the cover lens and a lower part to thereby enclose at least the LCD panel, the flexible sensor layer, the first adhesive layer, and the second adhesive layer. 
     According to one embodiment of the invention, the flexible sensor layer comprises a peripheral region and edge traces in the peripheral region. The peripheral region is bent to a position that is in close proximity to a sidewall of the LCD panel. The peripheral region is bent such that the peripheral region is perpendicular to a top surface of the LCD panel. The peripheral region is adhered to an interior surface of the system mechanism part through the second adhesive layer. 
     According to one embodiment of the invention, no ink layer is disposed along a lower perimeter of the cover lens. 
     According to one embodiment of the invention, the system mechanism part is composed of plastic, metal, glass, or a composite material. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates the conventional touch display device. 
         FIG. 2  is a schematic, cross-sectional diagram showing a touch display device according to one embodiment of the invention. 
         FIG. 3  is a schematic, cross-sectional diagram showing a touch display device according to another embodiment of the invention. 
         FIG. 4  is a schematic, cross-sectional diagram showing a touch display device according to still another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 2  is a schematic, cross-sectional diagram showing a touch display device according to one embodiment of the invention. As shown in  FIG. 2 , the touch display device  2  of the invention may comprise an open-cell liquid crystal display (LCD) panel  20 , a backlight unit (BLU)  21  disposed under the open-cell LCD panel  20 , a flexible sensor film  22  disposed above the open-cell LCD panel  20 , a cover lens  24  disposed on the flexible sensor film  22 , a first adhesive layer  221  disposed between the flexible sensor film  22  and the open-cell LCD panel  20 , a second adhesive layer  222  disposed between the flexible sensor film  22  and the cover lens  24 , and a system mechanism part  26  coupled to the cover lens  24 . The system mechanism part  26  and a lower part  28  together enclose the above-described components. 
     According to one embodiment of the invention, the flexible sensor film  22  comprises a peripheral region  22   a.  Edge traces (not shown) may be disposed within the peripheral region  22   a.  According to one embodiment of the invention, the peripheral region  22   a  is a bent portion of the flexible sensor film  22 , which is disposed in close proximity to the sidewalls of the open-cell LCD panel  20 . According to one embodiment of the invention, the peripheral region  22   a  may be bent to a vertical position such that the peripheral region  22   a  is substantially perpendicular to the top surface of the open-cell LCD panel  20 . However, the invention is not limited to such angle configuration. According to one embodiment of the invention, the peripheral region  22   a  may be adhered to the interior surface of the system mechanism part  26  through the second adhesive layer  222 . 
     According to one embodiment of the invention, because the peripheral region  22   a  is bent to a position that is in close proximity to the sidewalls of the open-cell LCD panel  20 , an ink layer can be skipped or omitted from the lower peripheral surface of the cover lens  24 , to thereby achieving an inkless design. One advantage of the inkless design is that the spared ink screen printing process can simplify the manufacture steps, reduce the materials used, and thereby reducing production cost. Further, the problem of uncured adhesive under shadow can be solved, thereby improving the yield. In addition, the inkless design makes the size of visible area (VA) about the size of the cover lens  24 . 
     According to one embodiment of the invention, the stack structure of the above-described touch display device  2  is fully compatible with current Advanced Direct Bonding (ADB) processes. Therefore, the manufacture process is simplified and the production cost can be reduced. Because the flexible sensor layer  22  is incorporated, it is possible to support a panel down to a certain size. It is advantageous to use the present invention because of the high compatibility and the low cost of the mask. 
     According to one embodiment of the invention, the stack structure of the above-described touch display device  2  can reduce the overall thickness and can achieve further thickness reduction demand. 
     According to one embodiment of the invention, depending upon the design requirements and the demand of the function and appearance of the device, the system mechanism part  26  may be composed of plastic, metal, glass, or composite materials, but not limited thereto. For example, the system mechanism part  26  may be composed of polycarbonate (PC), which can constitute integrated fully flat plane appearance with the cover lens by using insert molding processes. 
     According to embodiments of the invention, the system mechanism part  26  may be integrated by upper frame integration system or hinge-up to achieve the effect of the fully flat plane. 
       FIG. 3  is a schematic, cross-sectional diagram showing a touch display device according to another embodiment of the invention. As shown in  FIG. 3 , the components of the touch display device  2 ′ according to another embodiment are similar to that depicted in  FIG. 2 . The difference is that, as shown in  FIG. 3 , a side bottom  260  is disposed on the sidewall  26   a  of the system mechanism part  26  of the touch display device  2 ′. According to another embodiment, the side bottom  260  corresponds to the peripheral region  22   a  that is bent to a position in close proximity to the sidewalls of the open-cell LCD panel  20 . According to another embodiment, the side button  260  may be a touch function key or a physical button, but not limited thereto. 
       FIG. 4  is a schematic, cross-sectional diagram showing a touch display device according to still another embodiment of the invention, wherein an exemplary stitched capacitor-type touch display device  3  with a narrow border design due to the use of the flexible sensor layer is shown. As shown in  FIG. 4 , the stitched capacitor-type touch display device  3  comprises at least a first touch display device  3   a  and a second touch display device  3   b  disposed in close proximity to the first touch display device  3   a.  For the sake of simplicity, the system mechanism parts or casings are omitted in the figure. 
     The first touch display device  3   a  may comprise an LCD module  30   a,  a flexible sensor film  32   a  disposed above the LCD module  30   a , a cover lens  34   a  disposed on the flexible sensor film  32   a,  an adhesive layer  321   a  disposed between the flexible sensor film  32   a  and the LCD module  30   a,  and an adhesive layer  322   a  disposed between the flexible sensor film  32   a  and the cover lens  34   a.    
     The second touch display device  3   b  may comprise an LCD module  30   b,  a flexible sensor film  32   b  disposed above the LCD module  30   b , a cover lens  34   b  disposed on the flexible sensor film  32   b,  an adhesive layer  321   b  disposed between the flexible sensor film  32   b  and the LCD module  30   b,  and an adhesive layer  322   b  disposed between the flexible sensor film  32   b  and the cover lens  34   b.    
     The peripheral region  32   a ′ of the flexible sensor film  32   a  and the peripheral region  32   b ′ of the flexible sensor film  32   b  are bent to a position that is in close proximity to the sidewalls of the LCD module  30   a  and the LCD module  30   b.  More specifically, the peripheral region  32   a ′ and the peripheral region  32   b ′ are bent to the gap between the metal frame  302   a  of the LCD module  30   a  and the metal frame  302   b  of the LCD module  30   b.  Therefore, the width of the ink layer  342   a  disposed along the lower perimeter of the cover lens  34   a  and the width of the ink layer  342   b  disposed along the lower perimeter of the cover lens  34   b  can be minimized. As shown in  FIG. 4 , the combined capacitor-type touch display device  3  has a frame width d that is equal to the combination of the widths of the ink layer  342   a  and the ink layer  342   b.    
       FIG. 4  also demonstrates the comparison between the visible area and the active areas. The visible areas of the cover lens  34   a  and the cover lens  34   b  are denoted as “CL VA”, the active areas of the flexible sensor film  32   a  and the flexible sensor film  32   b  are denoted as “FS AA”, while the active areas of the LCD module  30   a  and the LCD module  30   b  are denoted as “LCM AA”. According to the embodiment of the invention, the dimension of FS AA of the flexible sensor film  32   a  and the flexible sensor film  32   b  is greater than the dimension of CL VA of the cover lens  34   a  and the cover lens  34   b.  The dimension of CL VA of the cover lens  34   a  and the cover lens  34   b  is greater than the dimension of LCM AA of the LCD module  30   a  and the LCD module  30   b.    
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.