Patent Publication Number: US-2023152623-A1

Title: Liquid crystal display panel and method for making same, and display device

Description:
FIELD 
     The subject matter herein generally relates to displays, particularly relates to a liquid crystal display panel, a method for making the liquid crystal display panel, and a display device having the liquid crystal display panel. 
     BACKGROUND 
     When viewing a flat liquid crystal display from different directions, brightness, contrast, and colors of the display will be different from different viewing angles. When viewing the display screen with a sight line perpendicular to the display screen, the display effect is good and true. When squinting at the display screen, the picture contrast is low, and the color is poor. 
     A curved screen is more ergonomic than a flat screen, all parts of the ergonomic screen being an equal distance from the screen. However, a method of making a liquid crystal display curved screen is generally to bend a flat liquid crystal display panel to match a backlight plate with a certain curvature. However, due to an uneven stress of the glass substrate of the bent liquid crystal display panel and an inconsistent curvature of the thin film transistor substrate and the color filter substrate, the middle front viewing display effect of the liquid crystal display is also good; but squinting at the display screen still has a low contrast and poor color. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the present technology will now be described, by way of embodiments only, with reference to the attached figures. 
         FIG.  1 A  is a sectional view of a liquid crystal display panel according to one embodiment of the present disclosure. 
         FIG.  1 B  is a sectional view of a glass substrate according to one embodiment of the present disclosure. 
         FIG.  1 C  is a top view of a glass substrate according to one embodiment of the present disclosure. 
         FIG.  2 A  is a sectional view of a liquid crystal display panel according to another embodiment of the present disclosure. 
         FIG.  2 B  is a sectional view of a glass substrate according to another embodiment of the present disclosure. 
         FIG.  2 C  is a top view of a glass substrate according to another embodiment of the present disclosure. 
         FIG.  3    shows a display device according to one embodiment of the present disclosure. 
         FIG.  4    is a flowchart of a method for making a liquid crystal display panel according to one embodiment of the present disclosure. 
         FIG.  5    is a flowchart of a method for making a liquid crystal display panel according to another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure. 
     The term “coupled” is defined as coupled, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently coupled or releasably coupled. The term “comprising” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the like. 
       FIG.  1 A  illustrates a liquid crystal display panel  10 A. The liquid crystal display panel  10 A includes a color filter substrate  100 , a liquid crystal layer  200 , a thin film transistor substrate  300 , and a frame  400 . The thin film transistor substrate  300  is opposite to the color filter substrate  100 . The liquid crystal layer  200  is between the color filter substrate  100  and the thin film transistor substrate  300 . The frame  400  surrounds the liquid crystal layer  200  and connects to edges of both the thin film transistor substrate  300  and the color filter substrate  100  to maintain a certain distance between the thin film transistor substrate  300  and the color filter substrate  100 . In addition, the frame  400  can also seal the liquid crystal layer  200  to prevent a leakage of liquid crystal and entry of external pollutants. 
     As shown in  FIG.  1 A  and  FIG.  1 C , the liquid crystal display panel  10 A includes a display area  410  and a non-display area  420  surrounding the display area  410 . The frame  400  is located in the non-display area  420 . 
     The color filter substrate  100  includes a glass substrate  110 , a black matrix  120  on the glass substrate  110 , a color filter layer  130  on the glass substrate  110 , and a protecting layer  140  covering both the color filter layer  130  and the black matrix  120 . 
     The color filter layer  130  includes red filter layers  131 , green filter layers  132 , and blue filter layers  133  on the glass substrate  110 . The red filter layers  131 , the green filter layers  132 , and the blue filter layers  133  are spaced apart from each other and configured to filter out light having specific ranges of wavelengths from a white light source, so that light of different colors can be displayed. 
     The black matrix  120  is located between and surrounds the red filter layers  131 , the green filter layers  132 , and the blue filter layers  133  to absorb critical light of adjacent filter layers, reduce the color mixing interference between pixels, and prevent the deterioration of color contrast. On the other hand, the black matrix  120  is also formed at a position of the glass substrate  110  corresponding to the non-display area  420  to shade light in the non-display area  420 . 
     As shown in  FIG.  1 B  and  FIG.  1 C , a surface of the glass substrate  110  having the color filter layer  130  defines a plurality of grooves  111  having different depths in the display area  410 . Adjacent grooves  111  have different depths and each groove  111  has a constant depth. The depths of the grooves  111  gradually increase in a direction from an edge region  411  of the display area  410  towards a center region  412  of the display area  410 . A width L of each groove  111  is in a range of 0.8 cm-1.2 cm, and a depth difference between two adjacent grooves  111  is in a range of 0.1 μm-1 μm. 
     The width L of the grooves  111  and the number of grooves  111  in  FIG.  1 B  and  FIG.  1 C  do not reflect a true scale of the liquid crystal display panel, but are used only for the purpose of schematically explaining the content of the present disclosure. The number and distribution of the red filter layers  131 , the green filter layers  132 , and the blue filter layers  133  in the groove  111  in  FIG.  1 A  do not reflect a true situation of the color filter substrate  100 , but are used only for the purpose of schematically explaining the content of this disclosure. A shape of the boundary between adjacent grooves  111  in  FIG.  1 C  does not reflect a true surface morphology of the glass substrate  110  and is only intended to schematically illustrate the content of the present disclosure. 
     In some embodiments, in the above liquid crystal display panel  10 A, the width L of each groove  111  is 1 cm, and the depth difference between two adjacent grooves  111  is 0.1 μm. 
     In some embodiments, in the above liquid crystal display panel  10 A, the width L of each groove  111  is 1 cm, and the depth difference between two adjacent grooves  111  is 1 μm. 
     The black matrix  120  and the color filter layer  130  are distributed in the grooves  111 , and the protective layer  140  covers the color filter layer  130  and the black matrix  120 . Corresponding to the grooves  111  having different depths, a thickness of the protective layer  140  is constant overall, so a surface of the protective layer  140  adjacent to the liquid crystal layer  200  is consistent with the surface of grooves  111 , and the liquid crystal layer  200  follows the same general contours as the depths of the grooves  111 . That is, corresponding to the grooves  111  having different depths on the surface of the glass substrate  110 , the thickness of the liquid crystal layer  200  gradually increases in the direction from the edge region  411  of the display area  410  towards the center region  412  of the display area  410 . 
     The liquid crystal display panel  10 A is suitable for the situation in which the viewer look at horizontally. When the viewer&#39;s sight line falls from the center region  412  of the display area  410  to the edge region  411  of the display area  410 , the thickness of the liquid crystal layer  200  becomes less, and the display angle of the liquid crystal display panel  10 A becomes greater, which makes up for the difference in display caused by the change of viewing angle, and improves the low contrast and poor color when squinting. 
       FIG.  2 A  illustrates another liquid crystal display panel  10 B. The liquid crystal display panel  10 B includes a color filter substrate  100 , a liquid crystal layer  200 , a thin film transistor substrate  300 , and a frame  400 . The thin film transistor substrate  300  is arranged opposite to the color filter substrate  100 . The liquid crystal layer  200  is between the color filter substrate  100  and the thin film transistor substrate  300 . The frame  400  surrounds the liquid crystal layer  200  and connects to edges of both the thin film transistor substrate  300  and the color filter substrate  100 . 
     As shown in  FIG.  2 A  and  FIG.  2 C , the liquid crystal display panel  10 B includes a display area  410  and a non-display area  420  surrounding the display area  410 . The frame  400  is located in the non-display area  420 . 
     The color filter substrate  100  includes a glass substrate  110 , a black matrix  120  on the glass substrate  110 , a color filter layer  130  on the glass substrate  110 , and a protecting layer  140  covering both the color filter layer  130  and the black matrix  120 . 
     The color filter layer  130  includes red filter layers  131 , green filter layers  132 , and blue filter layers  133  on the glass substrate  110 . The red filter layers  131 , the green filter layers  132 , and the blue filter layers  133  are spaced apart from each other and configured to filter out light having specific ranges of wavelengths from a white light source, so that light of different colors can be displayed. 
     The black matrix  120  is located between and surrounds the red filter layers  131 , the green filter layers  132 , and the blue filter layers  133 , to absorb critical light of adjacent filter layers, reduce the color mixing interference between pixels, and not allow deterioration of color contrast. On the other hand, the black matrix  120  is also formed at a position of the glass substrate  110  corresponding to the non-display area  420  to shade light in the non-display area  420 . 
     As shown in  FIG.  2 B  and  FIG.  2 C , a surface of the glass substrate  110  having the color filter layer  130  defines a plurality of grooves  111  having different depths in the display area  410 . The grooves  111  have different depths and each groove  111  has a constant depth. The depths of the grooves  111  gradually increases in a direction from a first side  413  of the display area  410  towards a second side  414  of the display area  410  opposite to the first side  413 . A width L of each groove  111  is in a range of 0.8 cm-1.2 cm, and a depth difference between two adjacent grooves  111  is 0.1 μm-1 μm. In some embodiments, the first side  413  is the upper side (for example, a side close to an upper edge of the liquid crystal display panel  10 B), and the second side  414  is the lower side (for example, a side close to a lower edge of the liquid crystal display panel  10 B) when viewing the liquid crystal display panel  10 B. 
     The width L of the grooves  111  and the number of grooves  111  in  FIG.  2 B  and  FIG.  2 C  do not reflect a true scale of the liquid crystal display panel, but are only for the purpose of schematically explaining the content of the present disclosure. The number and distribution of the red filter layers  131 , the green filter layers  132  and the blue filter layers  133  in the groove  111  in  FIG.  2 A  do not reflect a true situation of the color filter substrate  100 , but are only for the purpose of schematically explaining the content of this disclosure. A shape of boundary between adjacent grooves  111  in  FIG.  2 C  does not reflect a true surface morphology of the glass substrate  110  and is only intended to schematically illustrate the content of the present disclosure. 
     In some embodiments, in the above liquid crystal display panel  10 B, the width L of each groove  111  is 1 cm, and the depth difference between two adjacent grooves  111  is 0.1 μm. 
     In some embodiments, in the above liquid crystal display panel  10 B, the width L of each groove  111  is 1 cm, and the depth difference between two adjacent grooves  111  is 1 μm. 
     The black matrix  120  and the color filter layer  130  are distributed in the grooves  111 , and the protective layer  140  covers the color filter layer  130  and the black matrix  120 . Corresponding to the grooves  111  having different depths, a thickness of the protective layer  140  is generally constant, so a surface of the protective layer  140  adjacent to the liquid crystal layer  200  is consistent with the surface of grooves  111 , and a thickness of the liquid crystal layer  200  maintains and follows the contours of the depths of the grooves  111 . That is, corresponding to the grooves  111  having different depths on the surface of the glass substrate  110 , the thickness of the liquid crystal layer  200  gradually increases in the direction from the first side  413  of the display area  410  towards the second side  414  of the display area  410 . 
     The liquid crystal display panel  10 A is suitable for the situation in which the viewer looks upwards. When the liquid crystal display panel  10 B is suspended on a wall for example, the first side  413  of the display area  410  is farther away from the observer than the second side  414  of the display area  410 . When the observer&#39;s sight line falls from the second side  414  of the display area  410  to the first side  413  of the display area  410 , the thickness of the liquid crystal layer  200  becomes less, and the display angle of the liquid crystal display panel  10 B becomes greater, which makes up for the difference in display caused by the change of viewing angle, and improves low contrast and poor color when the viewer is looking upwards. 
       FIG.  3    illustrates a display device  20 . The display device  20  includes the above-mentioned liquid crystal display panel  10 A/ 10 B and a backlight module  500 . The backlight module  500  is located on a side of the liquid crystal display panel  10 A/ 10 B away from the display surface. 
     The display device  20  has the same advantages as the liquid crystal display panel compared with the prior art. 
     A method for making the above liquid crystal display panel is also provided. The method for making the liquid crystal display panel includes: providing a glass substrate; defining a plurality of grooves having different depths on a surface of the glass substrate, and corresponding to the positions of the grooves having different depths, a thickness of the liquid crystal layer and the depths of the grooves maintain the same general contours. 
     As shown in  FIG.  4   , a method for making the liquid crystal display panel includes the following steps. 
     Step S 11 , providing and cleaning a glass plate having opposite plane surfaces. 
     Step S 12 , bending the glass plate so that the opposite surfaces of the glass plate form a concave surface and a convex surface respectively. 
     Step S 13 , adding etching solutions to the concave surface of the glass plate. 
     Step S 14 , using etching solutions having different amounts or concentrations to different positions of the concave surface of the glass plate to form a plurality of grooves having different depths on the concave surface of the glass plate. Grooves formed at a position with more etching solution or higher concentration of etching solution are deeper, and grooves formed at the position with less etching solution or lower concentration of etching solution are shallower. 
     Step S 15 , bending the glass plate to make the convex surface a plane, and the glass plate forms a glass substrate. 
     Step S 16 , cleaning the glass substrate. 
     Step S 17 , forming a black matrix in the plurality of grooves of the glass substrate. 
     Step S 18 , forming a color filter layer in the plurality of grooves of the glass substrate. The color filter layer includes red filter layers, green filter layers, and blue filter layer, and the filter layers are spaced apart from each other by the black matrix. 
     Step S 19 , forming a protective layer on the black matrix and the color filter layer. A thickness of the protective layer is generally constant. Thus far, a color filter substrate is formed. 
     Step S 20 , aligning a thin film transistor substrate with the color filter substrate, and forming a frame on opposite edges of the color filter substrate and the thin film transistor substrate, so that the color filter substrate and the thin film transistor substrate are aligned and adhered together. The frame has an injection port. 
     Step S 21 , injecting liquid crystal molecules between the color filter substrate and the thin film transistor substrate through the injection port of the frame to form a liquid crystal layer whose thickness changes with the depths of the grooves of the glass substrate. 
     Step S 22 , sealing the injection port. 
     Another method for making the above liquid crystal display panel is also provided. The method includes: forming a glass substrate, the surface of the glass substrate is provided with a plurality of grooves having different depths, the surface corresponds to the positions of the grooves having different depths, the thickness of the liquid crystal layer maintains the same general contours as the depths of the grooves. 
     As shown in  FIG.  5   , a method for making the liquid crystal display panel includes the following steps. 
     Step S 101 , providing a glass plate having opposite plane surfaces, and cleaning the glass plate. 
     Step S 102 , adding grinding fluid between a grinding machine table and the surface of the glass plate. The grinding fluid is nano diamond grinding fluid. 
     Step S 103 , grinding a surface of the glass plate to form a plurality of grooves having different depths on the surface of the glass plate to form a glass substrate. The pressures between the grinding machine table and different positions of the glass plate are made to be different by using grinding machine tables having different curvature. 
     Step S 104 , cleaning the glass substrate. 
     Step S 105 , forming a black matrix in the grooves of the glass substrate. 
     Step S 106 , forming a color filter layer in the grooves of the glass substrate. The color filter layer includes red filter layers, green filter layers, and blue filter layers, and the filter layers are spaced apart from each other by the black matrix. 
     Step S 107 , forming a protective layer on the black matrix and the color filter layer. A thickness of the protective layer is generally constant. Thus far, a color filter substrate is formed. 
     Step S 108 , aligning a thin film transistor substrate with the color filter substrate, and forming a frame on opposite edges of the color filter substrate and the thin film transistor substrate, so that the color filter substrate and the thin film transistor substrate are aligned and adhered together. The frame has an injection port. 
     Step S 109 , injecting liquid crystal molecules between the color filter substrate and the thin film transistor substrate through the injection port of the frame to form a liquid crystal layer whose thickness changes with the depths of the grooves of the glass substrate. 
     Step S 110 , sealing the injection port. 
     The nano diamond grinding fluid is formed by uniformly dispersing diamond powder in water, which has dispersion stability, is suitable for ultra precision polishing, and can meet the requirements of optical glass and gemstones for machining accuracy. The nano diamond grinding fluid can improve the quality of the machined surface while maintaining a high grinding rate. 
     It is to be understood, even though information and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only; changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present embodiments to the full extent indicated by the plain meaning of the terms in which the appended claims are expressed.