Patent Publication Number: US-2019196263-A1

Title: Display panel and display device

Description:
RELATED APPLICATIONS 
     This application is a continuation application of PCT Patent Application No. PCT/CN2018/073060, filed Jan. 17, 2018, which claims the priority benefit of Chinese Patent Application No. 201711435849.1, filed Dec. 26, 2017, which is herein incorporated by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The disclosure relates to a display technical field, and more particularly to a display panel and a display device. 
     BACKGROUND 
     With the progress of optoelectronic and semiconductor technologies, the development of flat panel displays has also been driven. In many flat panel displays, Liquid Crystal Display (LCD) has advantages of high space utilization efficiency, low power consumption, zero radiation, low electromagnetic interference, and many other superior features, and has become the mainstream of the market. 
     LCD usually includes a liquid crystal panel and a backlight module. The backlight module provides light to the liquid crystal panel so that the liquid crystal panel displays an image. However, in a conventional liquid crystal display device with a single liquid crystal panel, the display contrast of which is low, and the light leakage is also serious. 
     SUMMARY 
     A technical problem to be solved by the disclosure is to provide a display panel and a display device with significantly improved contrast. 
     An objective of the present invention is to provide a display panel, which includes a first liquid crystal panel and a second liquid crystal panel. The first and second liquid crystal panels both have VA (vertical alignment) display modes, the first and second liquid crystal panels are disposed face to face, and the first liquid crystal panel is disposed on the second liquid crystal panel. 
     Further, the first liquid crystal panel includes a first lower polarizer, a first liquid crystal cell and a first upper polarizer. The first lower polarizer is disposed on the second liquid crystal panel, the first liquid crystal cell is disposed on the first lower polarizer, and the first upper polarizer is disposed on the first liquid crystal cell. 
     Further, the first liquid crystal cell includes a first color filter substrate, a first array substrate, and a first liquid crystal layer. The first color filter substrate is disposed in between the first upper polarizer and the first lower polarizer, the first array substrate is disposed in between the first color filter substrate and the first lower polarizer, the first array substrate and the first color filter substrate are assembled cassette-to-cassette, and the first liquid crystal layer is disposed in between the first array substrate and the first color filter substrate. 
     Further, the second liquid crystal panel includes a second lower polarizer, a second liquid crystal cell, and a second upper polarizer. The second liquid crystal cell is disposed on the second lower polarizer, the second upper polarizer is disposed on the second liquid crystal cell, and the first lower polarizer is disposed on the second upper polarizer. 
     Further, the second liquid crystal cell includes a second color filter substrate, a second array substrate, and a second liquid crystal layer. The second color filter substrate is disposed in between the second upper polarizer and the second lower polarizer, the second array substrate is disposed in between the second color filter substrate and the second lower polarizer, the second array substrate and the second color filter substrate are assembled cassette-to-cassette, and the second liquid crystal layer is disposed in between the second array substrate and the second color filter substrate. 
     Further, the contrast of the display panel is 27000 times to that of the first liquid crystal panel or the second liquid crystal panel. 
     According to another aspect of the present invention, the disclosure further provides a display device, which comprises the above display panel, and the backlight module is faced to the second lower polarizer. 
     Further, the backlight module is a direct-type backlight module or an edge-type backlight module, 
     Beneficial effects of the present invention: the invention is to use the stacking structure of dual liquid crystal panels so as to significantly improve the contrast of the display panel, and a rate of light leakage of the display panel can also be sharply decreased. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Accompanying drawings are for providing further understanding of the abovementioned and other objectives, features, and advantages of the embodiments of the present invention. In the figures: 
         FIG. 1  is a structural schematic view of a display panel according to an embodiment of the disclosure; and 
         FIG. 2  is a structural schematic view of a liquid crystal display device according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention is described in details below with references to the accompanying drawings and specific embodiments. However, it is embodied in many different forms and embodiments of the present invention, and the present invention should not be construed as limited to the particular embodiments set forth herein. Rather, these embodiments in order to explain the principles of the invention and its practical application to thereby enable others skilled in the art to understand the invention for various embodiments and various modifications as suited to the particular use contemplated. 
     In the drawings for device clarity, thicknesses of layers and regions are exaggerated to. The same reference numerals throughout the specification and the drawings may be used to denote like or same elements. 
     It is understood that, although the terms may be used herein “first,” “second,” etc., to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. 
       FIG. 1  is a structural schematic view of a display panel according to an embodiment of the disclosure. 
     As shown in  FIG. 1 , a display panel  1000  according to an embodiment of the present invention includes a first liquid crystal panel  100  and a second liquid crystal panel  200 . The first liquid crystal panel  100  and the second liquid crystal panel  200  both have VA display modes, the first liquid crystal panel  100  and the second liquid crystal panel  200  are disposed face to face, and the first liquid crystal panel  100  is fixed on the second liquid crystal panel  200 . 
     In a preferred embodiment of the present invention, the first liquid crystal panel  100  and the second liquid crystal panel  200  are the same, and each sub-pixel of the first liquid crystal panel  100  is accurately aligned to each sub-pixel of the second liquid crystal panel  200  during the fixation of the first liquid crystal panel  100  and the second liquid crystal panel  200 . Thus shadow would not occur when displaying images. 
     The following Table 1 shows stimulation data of the display panel  1000  and the first liquid crystal panel  100  or the second liquid crystal panel  200 . 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Results of Stimulation 
               
            
           
           
               
               
               
               
            
               
                   
                 Brightness of 
                 Brightness of 
                   
               
               
                 Type 
                 White Screen 
                 Black Screen 
                 Contrast 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 First liquid crystal panel 
                 3782.6 
                 0.132223 
                 28608 
               
               
                 100 or second liquid crystal 
               
               
                 panel 200 
               
               
                 Display panel 1000 
                 3114.7 
                 0.000004 
                 778675000 
               
               
                   
               
            
           
         
       
     
     From the above Table 1, it shows the contrast of the first liquid crystal panel  100  or the second liquid crystal panel  200  is 28608, and the contrast of the display panel  1000  is 27219 times to the contrast of the first liquid crystal panel  100  or the second liquid crystal panel  200 . Therefore, the contrast of the display panel  1000  is significantly improved. Moreover, after testing, the light leakage rate of the display panel  1000  is decreased by 3 hundred thousand times than the light leakage rate of the first liquid crystal panel  100  or the second liquid crystal panel  200 . 
     Further, in the embodiment, the first liquid crystal panel  100  includes a first lower polarizer  110 , a first liquid crystal cell  120  and a first upper polarizer  130 . More specifically, the first lower polarizer  110  is disposed on the second liquid crystal panel  200 , the first liquid crystal cell  120  is disposed on the first lower polarizer  110 , and the first upper polarizer  130  is disposed on the first liquid crystal cell  120 . In the embodiment, relationship between absorptions axes of the first upper polarizer  130  and the first lower polarizer  110  is depending on the normally black mode or normally white mode of the first liquid crystal panel  100 , and the invention is not limited herein. 
     In addition, as an implementation of the present invention, the first liquid crystal cell  120  includes a first color filter substrate  121 , a first array substrate  122 , and a first liquid crystal layer  123 . More specifically, the first color filter substrate  121  is disposed in between the first upper polarizer  130  and the first lower polarizer  110 , the first array substrate  122  is disposed in between the first color filter substrate  121  and the first lower polarizer  110 , the first array substrate  122  and the first color filter substrate  121  are assembled cassette-to-cassette, and the first liquid crystal layer  123  is disposed in between the first array substrate  122  and the first color filter substrate  121 . 
     Herein, the first color filter substrate  121  can include essential components such as color filter, black matrix, etc. . . . And the first array substrate  122  can include essential components such as thin film transistors, pixel electrodes, etc. . . . The first liquid crystal layer  123  includes a great number of liquid crystal molecules. The liquid crystal molecules are deflected according to the applied voltage to allow light pass through or not. Or as another implementation of the present invention, the color filter is fabricated on the first array substrate  122  to form a COA (color filter on array) substrate. 
     Furthermore, in the embodiment, the second liquid crystal panel  200  includes a second lower polarizer  210 , a second liquid crystal cell  220 , and a second upper polarizer  230 . More specifically, the second liquid crystal cell  220  is disposed on the second lower polarizer  210 , the second upper polarizer  230  is disposed on the second liquid crystal cell  220 , and the first lower polarizer  110  is disposed on the second upper polarizer  230 . In this embodiment, relationship between absorptions axes of the second upper polarizer  230  and the second lower polarizer  210  is depending on the normally black mode or normally white mode of the second liquid crystal panel  200 ; however the invention is not limited herein. 
     In addition, as an implementation of the present invention, the second liquid crystal cell  220  includes a second color filter substrate  221 , a second array substrate  222 , and a second liquid crystal layer  223 . More specifically, the second color filter substrate  221  is disposed in between the second upper polarizer  230  and the second lower polarizer  210 , the second array substrate  222  is disposed in between the second color filter substrate  221  and the second lower polarizer  210 , the second array substrate  222  and the second color filter substrate  221  are assembled cassette-to-cassette, and the second liquid crystal layer  223  is disposed in between the second array substrate  222  and the second color filter substrate  221 . 
     Herein, the second color filter substrate  221  can include essential components, such as color filter, black matrix, etc. . . . And the second array substrate  222  can include essential components, such as thin film transistors, pixel electrodes, etc. . . . The second liquid crystal layer  223  includes a great number of liquid crystal molecules. The liquid crystal molecules are deflected according to the applied voltage to allow light pass through or not. Or as another implementation of the present invention, the color filter is fabricated on the first array substrate  222  to form a CGA (color filter on array) substrate. 
       FIG. 2  is a structural schematic view of a display device according to an embodiment of the disclosure. 
     As shown in  FIG. 2 , a display device according to an embodiment of the present invention includes the display panel  1000  and a backlight module  2000 . The backlight module  2000  and the liquid crystal panel  1000  are disposed opposite to each other, so that the backlight module  2000  can proved light to the liquid crystal panel  1000  to display. Further, the backlight module  2000  is faced to the second lower polarizer  210 . 
     Moreover, in the embodiment, the backlight module  2000  is a direct-type backlight module or an edge-type backlight module, but the present invention is not limited herein. 
     In conclusion, the invention is to use the stacking structure of dual liquid crystal panels so as to significantly improve the contrast of the display panel, and a rate of light leakage of the display panel can also be sharply decreased. 
     While shown already with reference to specific embodiments and description in the disclosure, those skilled in the art will appreciate that: without departing from the spirit and scope of the invention being indicated by the claims and their equivalents, various changes in form and detail can be made and should be included in the protection scope of the application.