Patent Publication Number: US-2010123853-A1

Title: Liquid crystal display panel and apparatus comprising the same

Description:
CLAIM OF PRIORITY 
     This application claims priority to Chinese Patent Application No. 200810202773.2 filed on Nov. 14, 2008. 
     FIELD OF THE INVENTION 
     The present invention relates to a liquid crystal display panel and an apparatus comprising the same, and more particularly, to a liquid crystal display panel and an apparatus comprising the same which can improve problems of light leaking and panel fracture. 
     BACKGROUND OF THE INVENTION 
     Liquid crystal displays (LCDs) have been widely applied in electrical products due to the rapid progress of optical and semiconductor technologies. With their advantages of high image quality, compact size, light weight, low driving voltage, low power consumption and various applications, LCDs have been introduced to be utilized in portable computers, mobile phones, personal digital assistants, and color televisions and are becoming the mainstream display apparatus. 
     Referring to  FIG. 7 , a cross-section view showing a conventional liquid crystal display is presented herein. Currently, an LCD is composed of a backlight module  910  and a liquid crystal panel  920 , and the backlight module  910  is configured to provide the backlight for the liquid crystal panel  920 . The liquid crystal panel  920  includes a color filter (CF) substrate  921 , a thin film transistor (TFT) array substrate  922 , an upper polarizer  923  and a lower polarizer  924 . The CF substrate  921  is disposed opposite to TFT substrate  922 , wherein a liquid crystal layer (not shown) is disposed between the CF substrate  921  and the TFT substrate  922 . The upper polarizer  923  is disposed outside the CF substrate  921 , and the lower polarizer  924  is disposed outside the TFT substrate  922 . 
     Referring to  FIG. 7  again, it is generally understood that the area of the TFT substrate  922  is larger than the area of the CF substrate  921  so as to form a bonding area  925  on the surrounding of TFT substrate  922 . The bonding area  925  is not covered by the CF substrate  921  for mounting driving devices  901 , such as a driving chip, a driving IC or a flexible printed circuit (FPC), thereon. At this time, a shading tape  926  with adhesive capability is needed to be adhered on the surrounding of the TFT substrate  922  for preventing the light of the backlight module  910  from leaking to a non-display area of the liquid crystal panel  920 . 
     However, the adhering process of the shading tape  926  needs labor effort and time, thereby increasing manufacturing cost and time. Furthermore, when mounting the driving devices  901  on the bonding area  925  of the TFT substrate  922 , the liquid crystal panel  920  is placed on a supporting platform of a bonding tool (not shown) for supporting. At this time, if there is a particle between the supporting platform and the liquid crystal panel  920 , it is susceptible to lead to defects such as scratches or a fracture of the liquid crystal panel  920 . 
     SUMMARY OF THE INVENTION 
     Therefore, an aspect of the present invention is to provide a liquid crystal display panel and an apparatus comprising the same, thereby enlarging an area of a polarizer to reduce the use of the shading tape for improving the light leaking problem. 
     Another aspect of the present invention is to provide a liquid crystal display panel and an apparatus comprising the same, thereby preventing that the substrate of the display panel to directly contact with the supporting platform of the bonding tool when mounting an electric device, and thus preventing defects such as scratches or a fracture of the liquid crystal panel. 
     Another aspect of the present invention is to provide a liquid crystal display panel and an apparatus comprising the same, thereby reducing the peeling problem between a polarizer and a substrate. 
     Another aspect of the present invention is to provide a liquid crystal display panel and an apparatus comprising the same, thereby preventing that particles from a bonding area or other sources go into a backlight module of the apparatus. 
     According to an embodiment of the present invention, the liquid crystal display panel comprises a first substrate, a second substrate, a liquid crystal layer and a first polarizer. The first substrate includes a first side face and a bonding area, wherein the bonding area is adjacent to the first side face and configured to mount at least one electric device. The liquid crystal layer is disposed between the first substrate and the second substrate. The first polarizer is disposed at the outside of the first substrate, wherein the first polarizer includes a second side face, and the second side face of the first polarizer and the first side face of the first substrate are positioned at the same side of the liquid crystal display panel, and the second side face is positioned between the first side face and the bonding area, and there is a predetermined distance between the first side face and the second side face. 
     According to another embodiment of the present invention, the liquid crystal display apparatus comprises a backlight module and a liquid crystal display panel. The backlight module has a lighting area. The liquid crystal display panel is disposed opposite to the backlight module, wherein the liquid crystal display panel comprises a first substrate, a second substrate, a liquid crystal layer and a first polarizer. The first substrate includes a first side face. The liquid crystal layer is disposed between the first substrate and the second substrate. The first polarizer is disposed at the outside of the first substrate, wherein the first polarizer includes a second side face, and the second side face of the first polarizer and the first side face of the first substrate are positioned at the same side of the liquid crystal display panel, and the second side face is positioned between the first side face and the lighting area, and there is a predetermined distance between the first side face and the second side face. 
     According to another embodiment of the present invention, the liquid crystal display apparatus comprises a backlight module and a liquid crystal display panel. The backlight module has a lighting area. The liquid crystal display panel is disposed opposite to the backlight module, wherein the liquid crystal display panel comprises a first substrate, a second substrate, a liquid crystal layer and a first polarizer. The liquid crystal layer is disposed between the first substrate and the second substrate. The first polarizer is disposed at the outside of the first substrate and at least covers the lighting area of the backlight module, and does not exceed or flushing with the first substrate. 
     Therefore, with the use of the liquid crystal display panel and the LCD apparatus disclosed in the embodiments of the present invention, the backlight leaking problem can be improved to reduce the use of the shading tape, and the panel of the invention can prevent that the substrate directly contacts with the supporting platform of the bonding tool when mounting the electric device, thereby preventing the defects such as scratches or the fracture of the liquid crystal panel and enhancing product yield and quality. Furthermore, the particles from a bonding area or other sources can be prevented from going into the backlight module of the LCD apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a cross-section view showing a liquid crystal display panel and a backlight module according to a first embodiment of the present invention; 
         FIG. 2  is a partially cross-section view showing a liquid crystal display panel according to the first embodiment of the present invention; 
         FIG. 3A  through  FIG. 3D  show the position relation between a first substrate, a first polarizer and a lighting area according to the first embodiment of the present invention; 
         FIG. 4  is a cross-section view showing a liquid crystal display panel according to a second embodiment of the present invention; 
         FIG. 5  is a cross-section view showing an assembly of the liquid crystal display panel and the backlight module according to the second embodiment of the present invention; and 
         FIG. 6A  through  FIG. 6D  show the position relation between the first substrate, the first polarizer, and a lighting area, according to the second embodiment of the present invention. 
         FIG. 7  is a cross-section view showing a conventional liquid crystal display. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In order to make the illustration of the present invention more explicit and complete, the following description is stated with reference to  FIG. 1  through  FIG. 7 . 
     Referring to  FIG. 1 , a cross-section view showing a liquid crystal display panel and a backlight module according to a first embodiment of the present invention is presented herein. The liquid crystal display panel  100  of the present invention is disposed opposite to a backlight module  200 , thereby forming an LCD apparatus. The backlight module  200  may be an edge lighting backlight module or a bottom lighting backlight module, wherein the backlight module  200  may include an optical element assembly  210  for backlight efficiency and optical improvement. The optical element assembly  210  may include a diffuser, a light guide, a prism sheet, a turning prism sheet, a brightness enhancement film, a dual brightness enhancement film, a diffused reflective polarizer film or any combination thereof. The backlight module  200  may further include at least one light source (not shown), such as a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), a light emitting diode (LED), an organic light emitting diode (OLED) or an electro-luminescence (EL) device for providing backlight for the liquid crystal display panel  100 . 
     Referring to  FIG. 1  again, in the present embodiment, the LCD apparatus may further comprise a back plate  300  and a frame  400  to carry and assemble the liquid crystal display panel  100  and the backlight module  200 . The frame  400  is disposed on the back plate  300  and includes panel supporting portions  401  for supporting the liquid crystal display panel  100 . The backlight module  200  further includes a lighting area  201  which is an area thereof not covered by the component that would shield light such as the frame  400 , thereby providing backlight for the panel  100 . 
     Referring to  FIG. 2 , a partially cross-section view showing a liquid crystal display panel according to the first embodiment of the present invention is presented herein. The liquid crystal display panel  100  comprises a first substrate  110 , a second substrate  120 , a liquid crystal layer  130 , a first polarizer  140  and a second polarizer  150 . The liquid crystal layer  130  is disposed between the first substrate  110  and the second substrate  120  and sealed by a sealant  135 . The first polarizer  140  is disposed at the outside of the first substrate  110  opposite to the liquid crystal layer  130 . The second polarizer  150  is disposed at the outside of the second substrate  120  opposite to the liquid crystal layer  130 . 
     Referring to  FIG. 2  again, the first substrate  110  of the present embodiment may include a plurality of driving devices (not shown), such as TFTs, configured to drive the twist of the liquid crystal molecules (not shown), thereby forming a TFT array substrate. At this time, the first substrate  110  may include a pixel electrode layer  111 , a first alignment layer  112 , a plurality of gate lines (not shown), a plurality of data lines (not shown), a first side face  113  and a bonding area  114 , wherein the gate lines and the data lines are intersected vertically to form a display area (not shown) for display images. The pixel electrode layer  111  and the first alignment layer  112  are disposed at the inside of the first substrate  110  (the side faced to the liquid crystal layer  130 ) in series. The pixel electrode layer  111  is preferably made of transparent and electrically-conductive material, such as ITO, IZO, AZO, GZO, TCO or ZnO. The bonding area  114  is formed on one side of the display area, adjacent to the first side face  113  and configured to mount at least one electric device  115  thereon, such as a driving chip, a driving IC or an FPC. 
     It is worth mentioning that the driving devices may be disposed on the second substrate  120  in some embodiments and not limited to be disposed on the first substrate. 
     Referring to  FIG. 2  again, the second substrate  120  may include a black matrix layer  121 , a common electrode layer  122  and a second alignment layer  123  disposed on the inside of the second substrate  120  (the side faced to the liquid crystal layer  130 ). A plurality of color filter layers (not shown) which are made of color resist material and pervious to light may be formed in the black matrix layer  121 , and thus the second substrate  120  can be a CF substrate. The material of the black matrix layer  121  may be metal (such as chromium), graphite or polymeric material. The common electrode layer  122  is preferably made of transparent and electrically-conductive material, such as ITO, IZO, AZO, GZO, TCO or ZnO. 
     It is worth mentioning that the color filter layers and the common electrode layer  122  may be disposed on the first substrate  110 , such as color filter on array (COA) in some embodiments and not limited to be disposed on the second substrate  120 . 
     Referring to  FIG. 1  and  FIG. 3A  through  FIG. 3D ,  FIG. 3A  through  FIG. 3D  show the position relation between the first substrate, the first polarizer and a lighting area according to the first embodiment of the present invention. Referring to  FIG. 1  and  FIG. 3A , when the liquid crystal display panel  100  and the backlight module  200  are assembled, the first polarizer  140  of the liquid crystal display panel  100  at least covers the lighting area  201  of the backlight module  200  but does not exceed or flush with the first substrate  110 , i.e. the area of first polarizer  140  is preferably larger or equal to the area of the lighting area  201  and less than the area of the first substrate  110 . Therefore, the first polarizer  140  can cover the lighting area  201  of the backlight module  200 , thereby improving the light leaking problem of the backlight module  200 . Furthermore, particles from the bonding area  114  or other sources can be prevented from going into the backlight module  200 . The first polarizer  140  includes a second side face  141  corresponding to the first side face  113  of the first substrate  110 . That is, the first side face  113  of the first substrate  110  and the second side face  141  of the first polarizer  140  are positioned at the same side of the liquid crystal display panel  100  adjacent to the bonding area  114 , and the second side face  141  is further positioned between the first side face  113  and the lighting area  201 , and there is a predetermined distance d 1  (such as 2 mm˜3 mm) between the second side face  141  and the first side face  113 , i.e. the second side face  141  does not exceed or flush with the first side face  113 . A distance D 1  between the first side face  113  and the lighting area  201  may be 2 mm˜3 mm. At this time, other side faces  142 ,  143  and  144  may flush with the edge of the lighting area  201  (referring to  FIG. 3C  and  FIG. 3D ), the edge of the first substrate  110  (referring to  FIG. 3A ), or positioned between the edge of the lighting area  201  and the edge of the first substrate  110  (referring to  FIG. 3B ). Furthermore, in  FIG. 3C , the second side face  141  of the first polarizer  140  may also flush with the edge of the lighting area  201 . In  FIG. 3D , the second side face  141  of the first polarizer  140  may flush with the edge of the bonding area  114 . 
     It is worth mentioning that there is a predetermined distance between the second side face  141  of the first polarizer  140  and the first side face  113  of the first substrate  110 , i.e. the second side face  141  does not flush with the first side face  113 . Therefore, the liquid crystal display panel  100  of the present embodiment can reduce the peeling problem between the first polarizer  140  and the first substrate  110 , thereby enhancing process and product yield. 
     Referring to  FIG. 4 , a cross-section view showing a liquid crystal display panel according to a second embodiment of the present invention is presented herein. The liquid crystal display panel  100  of the present embodiment comprises the first substrate  110 , the second substrate  120 , the liquid crystal layer  130 , the first polarizer  140   a  and the second polarizer  150 . The first substrate  110  has the first side face  113  and the bonding area  114 , and the bonding area  114  is formed adjacent to the first side face  113  configured to mount at least one electric device  115  thereon. The liquid crystal layer  130  is disposed between the first substrate  110  and the second substrate  120  and sealed by dispensing a sealant  135 . The first polarizer  140   a  is disposed at the outside of the first substrate  110  opposite to the liquid crystal layer  130 , wherein the first polarizer  140   a  includes a second side face  141   a . The second side face  141   a  and the first side face  113  are positioned at the same side of the liquid crystal display panel  100 , and there is a predetermined distance d 2  (such as 100 μm˜200 μm) between the second side face  141   a  and the first side face  113 . The second polarizer  150  is disposed on the outside of the second substrate  120  and opposite to the liquid crystal layer  130 . 
     Referring to  FIG. 5  and  FIG. 6A  through  FIG. 6D ,  FIG. 5  is a cross-section view showing an assembly of the liquid crystal display panel and the backlight module according to the second embodiment of the present invention, and  FIG. 6A  through  FIG. 6D  show the position relation between the first substrate, the first polarizer and a lighting area according to the second embodiment of the present invention. Referring to  FIG. 5  and  FIG. 6A  again, in the present embodiment, the first polarizer  140   a  of the liquid crystal display panel  100  preferably further covers the bonding area  114  of the first substrate  110 , but does not exceed or flush with the first substrate  110 , i.e. the area of the first polarizer  140   a  is larger than or equal to the total area of the lighter area  201  and the bonding area, and less than the area of the first substrate  110 . Therefore, the first polarizer  140   a  with a lower hardness than that of the first substrate  110  (usually composed of glass) can cover the bonding area  114  of the first substrate  110  to prevent that the backside of the first substrate  110  directly contacts with the supporting platform of the bonding tool (not shown) when mounting the electric device  115 , thereby preventing defects such as scratches or a fracture of the liquid crystal panel  100  due to the particles existing between the liquid crystal panel  100  and the supporting platform. At this time, the second side face  141   a  of the first polarizer  140   a  is positioned between the first side face  113  and the bonding area  114 , and there is another predetermined distance d 2  (such as 100 μm˜200 μm) between the second side face  141   a  and the first side face  113 , i.e. the second side face  141   a  does not exceed or flush with the first side face  113 . The predetermined distance D 2  between the first side face  113  and the bonding area  114  may be 100 μm˜200 μm. At this time, other side faces  142   a ,  143   a , and  144   a  of the first polarizer  140   a  may flush with the edge of the lighting area  201  (referring to  FIG. 6C  and  FIG. 6D ), flush with the edge of the first substrate  110  (referring to  FIG. 6A ), or positioned between the lighting area  201  and the first substrate  110  (referring to  FIG. 6B ). 
     Therefore, the liquid crystal display panel and the LCD apparatus of the present invention can enlarge the area of the polarizer to reduce the use of the shading tape and to improve the backlight leaking problem, thereby reducing labor effort, process time and cost. Furthermore, the panel of the invention can prevent that the substrate directly contacts with the supporting platform of the bonding tool when mounting the electric device, thereby preventing the defects such as scratches or the fracture of the liquid crystal panel, enhancing product yield and quality and reducing unnecessary cost lost. 
     As is understood by a person skilled in the art, the foregoing embodiments of the present invention are strengths of the present invention rather than limiting of the present invention. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures.