Patent Publication Number: US-2016231774-A1

Title: Display module

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The application relates to a display module, and particularly relates to a display module using an optical clear adhesive layer. 
     2. Description of Related Art 
     Recently, with the continuing improvement of science and technology and the progresses of the electronic industry, electronic devices such as notebook (NB) computers, smart phones, and tablet computers are more and more common, and are developed to become more convenient, functional, and artistically designed, so as to offer the user a greater variety of choices. Due to the users&#39; increasing demands on electronic products, display modules, which play an important role in electronic products, have also become the focus of the designers. 
     The display module may output information in an electronic device in the form of images. A display module usually includes components such as a display panel, a cover plate, and an assembling frame, etc., and may optionally include an optical film or a touch unit based on the needs. In addition, when the display panel is a non-self-emitting display panel, the display module may further include a backlight module, so as to provide light to the display panel and allow the display module to display images by using electronic elements (e.g., active device or pixel array) inside the display panel. These components may be assembled together through an optical clear adhesive (OCA) layer. For example, the cover plate may be adhered to the optical film and the display panel through the optical clear adhesive. However, when a drop test is performed to the display module after the display module is assembled, a stress accumulating at a corner of the optical film tends to peel the optical film off from the optical clear adhesive layer and thus damages the display module. The reliability of the display module is thus influenced. 
     SUMMARY OF THE INVENTION 
     The application provides a display module having a preferable reliability. 
     A display module of the application includes a display panel, an optical film, a cover plate and an optical clear adhesive layer. The display panel has a display surface. The optical film is disposed on the display surface, wherein the optical film has a first surface back to the display panel, and the first surface has a plurality of edges and a plurality of corners formed by any adjacent two of the edges crossing each other. The cover plate is disposed on the first surface of the optical film and covers the first surface. The optical clear adhesive layer is disposed between the cover plate and the optical film and connected with the cover plate and the optical film, wherein the optical clear adhesive layer covers the edges of the first surface and exposes the corners and a part of regions adjacent to the corners. 
     Based on the above, in the display module of the application, the first surface of the optical film back to the display panel has the edges and the corners formed by any adjacent two of the edges crossing each other, and the optical clear adhesive layer connected with the cover plate and the optical film covers the edges of the first surface and exposes the corners and a part of the regions adjacent to the corners. In this way, the optical clear adhesive layer is not adhered to the corners of the optical film, so as to prevent the optical film and the optical clear adhesive layer from being peeled off from each other due to the stress generated at the corners when the mechanical test is performed to the display module. Accordingly, the display module of the invention has a preferable reliability. 
     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 
       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 top view illustrating a display panel according to an embodiment of the invention. 
         FIG. 2  is a schematic cross-sectional view illustrating the display panel shown in  FIG. 1  along an I-I′ line. 
         FIGS. 3 and 4  are partial schematic views illustrating display panels according to other embodiments of the invention. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
       FIG. 1  is a schematic top view illustrating a display panel according to an embodiment of the invention.  FIG. 2  is a schematic cross-sectional view illustrating the display panel shown in  FIG. 1  along an I-I′ line. Referring to  FIGS. 1 and 2 , in this embodiment, a display module  100  includes a display panel  110  (shown in  FIG. 2 ), an optical film  120 , a cover plate  130 , and an optical clear adhesive layer  140 . In addition, the display panel  110  is omitted from  FIG. 1 , and  FIGS. 1 and 2  also omit other components suitable for the display panel (e.g., an assembling frame), so as to more clearly illustrate relative relations between the optical film  120 , the cover plate  130 , and the optical clear adhesive layer  140  in the drawings. In this embodiment, the display panel  110  is a liquid crystal display (LCD) panel, an organic light emitting diode (OLED) display panel, or other suitable display panels, for example, and includes a thin film transistor (TFT) array substrate, a color filter (CF) substrate, or other components suitable for the display panel. The application does not intend to limit a type and a configuration of the display panel. Accordingly, the display panel  110  has a display surface  112 , so as to be suitable to display an image. 
     Moreover, in this embodiment, the optical film  120  is disposed on the display surface  112 . The optical film  120  is a polarizer, for example. However, in other embodiments, the optical film  120  may also be other suitable optical films, and the application does not intend to limit a type of the optical film  120 . The optical film  120  has a first surface  122  back to the display panel  110 , and the cover plate  130  is disposed on the first surface  122  of the optical film  120  and covers the first surface  122 . The optical clear adhesive layer  140  is disposed between the cover plate  130  and the optical film  120 , and is connected with the cover plate  130  and the optical film  120 . The cover plate  130  is a glass cover plate, a plastic substrate, a sapphire substrate, or other suitable cover plates, for example, and is usually disposed at an outermost layer of the display module  100  as protection. However, the application does not intend to limit a type of the cover plate  130  and whether another component is disposed at an external side of the cover plate  130 . The optical clear adhesive layer  140  is configured to adhere the cover plate  130  to the optical film  120 , and preferably extends to an external side of the optical film  120  to adhere to the cover plate  130  and the display panel  110 , as shown in  FIG. 2 . In addition, a touch unit (not shown) may be further disposed between the cover plate  130  and the display panel  110  in the display module  100  based on the needs. Based on a type of the touch unit, the touch unit may be manufactured between the cover plate  130  and the optical clear adhesive layer  140  or between the optical clear adhesive layer  140  and the display panel  110 , and may also be manufactured on an additional base material and then disposed between the cover plate  130  and the display panel  110  by using an additional adhesive layer. The application does not intend to limit a position of the touch unit and whether the touch unit is disposed or not. 
     In this embodiment, the optical clear adhesive layer  140  may not only be connect with the cover plate  130  and the optical film  120 , but also have a special design in shape to improve a reliability of the display module  100 . 
     Specifically, taking this embodiment as an example, the first surface  122  of the optical film  120  of this embodiment is rectangular. Besides, the first surface  122  has four edges  122   a  and four corners  122   b  formed by any adjacent two of the edges  122   a  crossing each other. Moreover, the corners  122   b  of the first surface  122  include a plurality of right angles. However, a shape of the optical film  120  may be adjusted based on the needs, and the application is not limited thereto. During assembling of the display module  100 , the optical film  140  covers the first surface  122  and extends to a side edge of the optical film  120  to be connected with the cover plate  130  and the display panel  110 , as shown in  FIG. 2 . In this way, the optical clear adhesive layer  140  also covers the edges  122   a  of the first surface  122  of the optical film  120 . However, the optical clear adhesive layer  140  in this embodiment exposes the corners  122   b  and a part of regions adjacent to the corners  122   b.  In other words, the optical clear adhesive layer  140  does not cover the corners  122   b  and a part of the regions adjacent to the corners  122   b,  as shown in  FIG. 1 . 
     More specifically, in this embodiment, the optical clear adhesive layer  140  has a plurality of corner portions  142 , and the corner portions  142  correspondingly expose the corners  122   b.  For example, the optical clear adhesive layer  140  of this embodiment is substantially rectangular and has four corner portions  142  respectively corresponding to the four corners  122   b  of the first surface  122 . Also, in this embodiment, edges of normal projections of the corner portions  142  on the cover plate  130  are linear. In other words, the corner portions  142  of this embodiment may be obtained to expose the corners  122   b  by cutting off the right angles corresponding to the corners  122   b  from the optical clear adhesive layer  140  substantially rectangular. In this way, when a mechanical test, such as a drop test or a roller test, is performed to the display module  100  after being assembled, and a stress accumulates at the corners  122   b,  since the optical clear adhesive layer  140  does not cover the corners  122   b,  the optical film  120  and the optical clear adhesive layer  140  are not peeled off from each other because of the stress at the corners  122   b.  Accordingly, a rate that the display module  100  passes the mechanical test is improved, and the display module  100  thus has a higher reliability. 
     However, the application does not intend to limit a shape of the corner portion  142 . For example, referring to  FIG. 3 ,  FIG. 3  is a partial schematic view illustrating a display panel according to another embodiment of the invention. In this embodiment, edges of normal projections of corner portions  142   a  on the cover plate  130  are curved, making the corners  122   b  of the first surface  122  and a part of the regions adjacent to the corners  122   b  exposed. Similarly, referring to  FIG. 4 ,  FIG. 4  is a partial schematic view illustrating a display panel according to another embodiment of the invention. In this embodiment, edges of normal projections of corner portions  142   b  on the cover plate  130  are right angles recessed inwardly toward the optical clear adhesive layer  140 , making the corners  122   b  and a part of the regions adjacent to the corners  122   b  exposed. Thus, it can be known that the application does not intend to limit shapes of the corner portions  142 ,  142   a,  and  142   b,  and the shape may be designed based on the needs, so as to correspondingly expose the corners  122   b.    
     Besides, in this embodiment, there are other designs of the optical clear adhesive layer  140  to improve the reliability of the display module. 
     Specifically, in this embodiment, the cover plate  130  has a transparent region  132  and a shielding region  134  located at an external side of the transparent region  132 . Preferably, the shielding region  134  of this embodiment may be disposed to surround the external side of the transparent region  132 . However, the invention is not limited thereto. Here, to clearly distinguish the shielding region  134  from the transparent region  132  in  FIGS. 1, 3, and 4 , the shielding region  134  is indicated with oblique lines in  FIGS. 1, 3, and 4 . The shielding region  134  may be formed by disposing a colored ink layer (not shown) having a high light shielding property or other shielding materials around a periphery of the cover plate  130 . However, the application does not intend to limit how the shielding region  134  is formed. The transparent region  132  corresponds to the display surface  112 , such that the image generated by the display panel  110  may be transmitted out of the display module  100  from the display surface  112  through the optical film  120 , the optical clear adhesive layer  140 , and the transparent region  132  of the cover plate  130 . On the contrary, the shielding region  134  may be used to shield peripheral wiring (not shown) or peripheral components (not shown) inside the display module  100 . During assembling of the display module  100 , the optical clear adhesive layer  140  is disposed in the transparent region  132  and extends to the shielding region  134 . In other words, a normal projection of the optical clear adhesive layer  140  with respect to the cover plate  130  corresponds to the transparent region  132  and extends to the shielding region  134 . Preferably, a distance d that the optical clear adhesive layer  140  extends to the shielding region  134  may be 0.6 mm or more. However, the application is not limited thereto. 
     In this way, when an autoclave process is performed during assembling of the display module  100 , since the optical clear adhesive layer  140  extends from the transparent region  132  of the cover plate  130  to the shielding region  134 , bubbles that are generated due to an overly large pressure may be prevented from moving to a region of the optical clear adhesive layer  140  near the transparent region  132 . In other words, even if bubbles are generated between the optical clear adhesive layer  140  and the cover plate  130  due to an overly large pressure in the autoclave process performed to the display module  100 , the bubbles merely stay at a periphery of the optical clear adhesive layer  140  and correspond to the shielding region  134 . Namely, a region that may generate bubbles in the periphery of the optical clear adhesive layer  140  of this embodiment is covered by the shielding layer  134 . Accordingly, in the display module  100  of this embodiment, a visual effect is not influenced by the bubbles generated during assembling of the display module  100 . Thus, the display module  100  has a preferable reliability. 
     In view of the foregoing, in the display module of the application, the first surface of the optical film back to the display panel has the edges and the corners formed by any adjacent two of the edges crossing each other, and the optical clear adhesive layer connected with the cover plate and the optical film covers the edges of the first surface and exposes the corners and a part of the regions adjacent to the corners. In this way, the optical clear adhesive layer is not adhered to the corners of the optical film, so as to prevent the optical film and the optical clear adhesive layer from being peeled off from each other due to the stress generated at the corners when the mechanical test is performed to the display module. Moreover, since the optical clear adhesive layer extends from the transparent region of the cover plate to the shielding region, bubbles may be prevented from being generated at regions of the optical clear adhesive layer adjacent to the transparent region during assembling of the display module and influencing the visual effect of the display module. Accordingly, the display module of the application has a preferable reliability. 
     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 this invention provided they fall within the scope of the following claims and their equivalents.