Patent Publication Number: US-2023136083-A1

Title: Liquid crystal display panel and method of manufacturing the same

Description:
BACKGROUND OF INVENTION 
     Field of Invention 
     The present application relates to a field of display panels, and in particular to a liquid crystal display panel and a manufacturing method thereof. 
     Description of Prior Art 
     With the development of digital technology, liquid crystal display products have been widely used in various aspects of daily life, and the requirements for thinner and lighter liquid crystal display modules have gradually increased. 
     In the prior art, the liquid crystal display module adopts a structure of a liquid crystal display panel and a backlight module. The traditional edge-lit backlight module is usually composed of independent optical films such as a reflective sheet, a light guide plate, a diffuser sheet, and a prism sheet, whose assembly process is complicated, and it is difficult to achieve lighter and thinner modules. 
     Therefore, there is a need to develop a new type of liquid crystal display panel to overcome the defects of the prior art. 
     SUMMARY OF INVENTION 
     An object of the present invention is to provide a liquid crystal display panel, which can solve the problem that the liquid crystal display panel in the prior art is difficult to achieve lightness and thinness. 
     In order to achieve the above object, the present invention provides a liquid crystal display panel, including a pixel area, and further including: a glass substrate serving as a light guide plate; a reflective layer disposed on a side of the light guide plate; a grating structure disposed on a side of the light guide plate away from the reflective layer, and corresponding to the pixel area; a planarization layer disposed on a side of the grating structure away from the light guide plate; and a thin-film transistor layer disposed on a side of the planarization layer away from the light guide plate. 
     Further, in other embodiments, the pixel area includes a plurality of pixel units, each of the pixel units has a plurality of sub-pixels; the grating structure has a plurality of grating units, each of the grating units has a sub-grating and corresponds to one of the pixel units; and in the pixel units and the grating units corresponding to the pixel units, each of the sub-gratings corresponds to one of the sub-pixels. 
     Further, in other embodiments, the sub-pixels include a red sub-pixel, a green sub-pixel, and a blue sub-pixel, and the sub-grating in each of the sub-pixels includes a plurality of layers with a same thickness; wherein thicknesses and refractive indexes of the layers of the sub-gratings in a red sub-pixel area, a green sub-pixel area, and a blue sub-pixel area are different; and emission wavelengths of the sub-gratings in the red sub-pixel area, the green sub-pixel area, and the blue sub-pixel area are controlled according to the Bragg equation: 2dsinθ=nλ, where d is a thickness of the layers of each of the sub-gratings, θ is an incident angle of incident light, n is a refractive index of the layers of each of the sub-gratings, λ is an emission wavelength, and the emission light wavelength of each of the sub-gratings is controlled by adjusting the thickness of the layers of each of the sub-gratings, the incident angle of the incident light, and the refractive index of the layers of each of the sub-gratings. 
     Further, in other embodiments, each of the sub-gratings in the red sub-pixel area emits light with a wavelength of 580 nm-660 nm, each of the sub-gratings in the green sub-pixel area emits light with a wavelength of 500 nm-580 nm, and each of the sub-gratings in the blue sub-pixel area emits light with a wavelength of 440 nm-500 nm. 
     Further, in other embodiments, the liquid crystal display panel further includes a light-shielding layer disposed between the sub-gratings. 
     Further, in other embodiments, the liquid crystal display panel further includes a light source disposed facing toward a sidewall of the glass substrate. 
     Further, in other embodiments, the liquid crystal display panel further includes a lower polarizer disposed on a side of the thin-film transistor layer away from the planarization layer; a liquid crystal layer disposed on a side of the lower polarizer away from the thin-film transistor layer; a second glass substrate disposed on a side of the liquid crystal layer away from the lower polarizer; and an upper polarizer disposed on a side of the second glass substrate away from the liquid crystal layer. 
     In order to achieve the above object, the present invention also provides a method of manufacturing the liquid crystal display panel of the present invention, wherein the liquid crystal display panel includes a pixel area, and the method of manufacturing the liquid crystal display panel includes the following steps: provide a glass substrate serving as a light guide plate; preparing a reflective layer on a side of the light guide plate; preparing a grating structure on a side of the light guide plate away from the reflective layer, wherein a position of the grating structure corresponds to the pixel area; preparing a planarization layer on a side of the grating structure away from the light guide plate; and preparing a thin-film transistor layer on a side of the planarization layer away from the light guide plate. 
     Further, in other embodiments, the grating structure is made of silicon oxide, the silicon oxide is doped with a photosensitive material, and the grating structure is prepared by chemical vapor deposition. 
     Further, in other embodiments, the pixel area includes a plurality of pixel units, each of the pixel units has a plurality of sub-pixels; the grating structure has a plurality of grating units, each of the grating units has a sub-grating and corresponds to one of the pixel units; and in the pixel units and the grating units corresponding to the pixel units, each of the sub-gratings corresponds to one of the sub-pixels. 
     Further, in other embodiments, the sub-pixels include a red sub-pixel, a green sub-pixel, and a blue sub-pixel, and the sub-grating in each of the sub-pixels includes a plurality of layers with a same thickness; wherein thicknesses and refractive indexes of the layers of the sub-gratings in a red sub-pixel area, a green sub-pixel area, and a blue sub-pixel area are different; and emission wavelengths of the sub-gratings in the red sub-pixel area, the green sub-pixel area, and the blue sub-pixel area are controlled according to the Bragg equation: 2dsinθ=nλ, where d is a thickness of the layers of each of the sub-gratings, θ is an incident angle of incident light, n is a refractive index of the layers of each of the sub-gratings, λ is an emission wavelength, and the emission light wavelength of each of the sub-gratings is controlled by adjusting the thickness of the layers of each of the sub-gratings, the incident angle of the incident light, and the refractive index of the layers of each of the sub-gratings. 
     The step of preparing the grating structure includes: depositing a silicon oxide film doped with photosensitive material on the side of the light guide plate away from the reflective layer, and fabricating the sub-gratings in the red sub-pixel area, the green sub-pixel area, and the blue sub-pixel area through exposure, development, and etching.. 
     Further, in other embodiments, each of the sub-gratings in the red sub-pixel area emits light with a wavelength of 580 nm-660 nm, each of the sub-gratings in the green sub-pixel area emits light with a wavelength of 500 nm-580 nm, and each of the sub-gratings in the blue sub-pixel area emits light with a wavelength of 440 nm-500 nm. 
     Further, in other embodiments, between preparing the grating structure and preparing the planarization layer, the method of manufacturing the liquid crystal display panel further includes: preparing a light-shielding layer between the sub-gratings, and the light-shielding layer is made of an opaque material or a light-reflecting material. 
     Further, in other embodiments, after the step of preparing the thin-film transistor layer, the method of manufacturing the liquid crystal display panel further includes: preparing a lower polarizer disposed on a side of the thin-film transistor layer away from the planarization layer; preparing a liquid crystal layer disposed on a side of the lower polarizer away from the thin-film transistor layer; preparing a second glass substrate disposed on a side of the liquid crystal layer away from the lower polarizer; and preparing an upper polarizer disposed on a side of the second glass substrate away from the liquid crystal layer. 
     Compared with the prior art, beneficial effects of the present invention are that: the present invention provides a liquid crystal display panel and a method of manufacturing the same, wherein by forming a grating on an upper surface of a glass substrate, and adjusting a thickness, an angle of light incidence, and a refractive index of sub-gratings, to allow the gratings in red, green, and blue sub-pixel areas to transmit red, green, and blue light respectively, the gratings that can transmit red, green, and blue light can replace the existing red and green color resists, and a light-shielding layer between the gratings can replace the existing black matrix, so that the liquid crystal display panel does not need to be provided with a color filter substrate, thereby reducing an overall thickness of the liquid crystal display panel. 
     Further, the glass substrate in the array substrate is configured to serve as a light guide plate, thus further reducing the thickness of the liquid crystal display panel. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The following detailed description of specific implementations of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application obvious. 
         FIG.  1    is a schematic structural diagram of a liquid crystal display panel provided by an embodiment of the present invention. 
         FIG.  2    is a flowchart of a method of manufacturing a liquid crystal display panel provided by an embodiment of the present invention. 
     
    
    
     Elements in the drawings are designated by reference numerals listed below. 
     LCD panel- 100 ; reflective layer- 10 ; glass substrate- 20 ; grating structure- 30 ; sub-grating- 31 ; light-shielding layer- 40 ; planarization layer- 50 ; thin-film transistor layer- 60 ; lower polarizer- 70 ; liquid crystal layer- 80 ; second glass substrate- 21 ; upper polarizer- 90 ; red sub-pixel - 101 ; green sub-pixel - 102 ; blue sub-pixel - 103 . 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The technical solutions in the embodiments of the present application will be clearly and completely described in the following with reference to the accompanying drawings in the embodiments. It is apparent that the described embodiments are only a part of the embodiments of the present application, and not all of them. All other embodiments obtained by a person skilled in the art based on the embodiments of the present application without creative efforts are within the scope of the present application. 
     In the present invention, unless otherwise expressly stated and limited, the formation of a first feature over or under a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. Moreover, the first feature “above”, “over” and “on” the second feature includes the first feature directly above and above the second feature, or merely indicating that the first feature is at a level higher than the second feature. The first feature “below”, “under” and “beneath” the second feature includes the first feature directly below and obliquely below the second feature, or merely the first feature has a level lower than the second feature. 
     The following disclosure provides many different embodiments or examples for realizing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and/or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and/or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the present applications of other processes and/or the use of other materials. 
     An embodiment of the present invention provides a liquid crystal display panel. Referring to  FIG.  1   ,  FIG.  1    is a schematic structural diagram of a liquid crystal display panel  100  provided by this embodiment. The liquid crystal display panel  100  includes a pixel area, a reflective layer  10 , a glass substrate  20 , a grating structure  30 , a light-shielding layer  40 , a planarization layer  50 , a thin-film transistor layer  60 , a lower polarizer  70 , a liquid crystal layer  80 , a second glass substrate  21 , an upper polarizer  90 , and a light source (not shown). 
     The glass substrate  20  is used as a light guide plate, the light source is disposed on a side of the light guide plate; the reflective layer  10  is coated on a lower surface of the glass substrate  20 ; the grating structure  30  is disposed above the light guide plate, a position of the grating structure  30  corresponds to the pixel area; the light-shielding layer  40  is disposed between the grating structure  30 ; the planarization layer  50  is disposed on the grating structure  30 ; the thin-film transistor layer  60  is disposed on the planarization layer  50 ; the lower polarizer  70  is disposed on the thin-film transistor layer  60 ; the liquid crystal layer  80  is disposed on the lower polarizer  70 ; the second glass substrate  21  is disposed on the liquid crystal layer  80 ; and the upper polarizer  90  is disposed on a side of the second glass substrate  21  away from the liquid crystal layer  80 . 
     The glass substrate  20  in the array substrate is configured to serve as a light guide plate, which can reduce a thickness of the liquid crystal display panel  100 . 
     The pixel area includes a number of pixel units, each of the pixel units has a plurality of sub-pixels; the grating structure  30  has a plurality of grating units, each of the grating units has a sub-grating  31  and corresponds to one of the pixel units; and in the pixel units and the grating units corresponding to the pixel units, each of the sub-gratings  31  corresponds to one of the sub-pixels. 
     The sub-pixels include a red sub-pixel  101 , a green sub-pixel  102 , and a blue sub-pixel  103 , and the sub-grating  31  in each of the sub-pixels includes a plurality of layers with a same thickness. Thicknesses and refractive indexes of the layers of the sub-gratings  31  in a red sub-pixel area  101 , a green sub-pixel area  102 , and a blue sub-pixel area  103  are different; and emission wavelengths of the sub-gratings  31  in the red sub-pixel area  101 , the green sub-pixel area  102 , and the blue sub-pixel area  103  are controlled according to the Bragg equation: 2dsinθ=nλ, where d is a thickness of the layers of each of the sub-gratings  31 , θ is an incident angle of incident light, n is a refractive index of the layers of each of the sub-gratings  31 , λ is an emission wavelength, and the emission light wavelength of each of the sub-gratings  31  is controlled by adjusting the thickness of the layers of each of the sub-gratings  31 , the incident angle of the incident light, and the refractive index of the layers of each of the sub-gratings  31 . 
     Each of the sub-gratings  31  in the red sub-pixel area  101  emits light with a wavelength of 580 nm-660 nm, each of the sub-gratings  31  in the green sub-pixel  102  area emits light with a wavelength of 500 nm-580 nm, and each of the sub-gratings  31  in the blue sub-pixel  103  area emits light with a wavelength of 440 nm-500 nm. 
     By forming a grating on the upper surface of the glass substrate  20 , the wavelength of the emitted light of the grating is controlled by adjusting the diffraction surface spacing, incident ray angle and diffraction order, 
     By forming a grating on an upper surface of a glass substrate, and adjusting a diffraction surface spacing, incident ray angle, and diffraction order to control a wavelength of emitted light of the grating, the gratings in red, green, and blue sub-pixel areas can transmit red, green, and blue light respectively, the gratings that can transmit red, green, and blue light can replace the existing red and green color resists, and a light-shielding layer between the gratings can replace the existing black matrix, so that the liquid crystal display panel does not need to be provided with a color filter substrate, thereby reducing an overall thickness of the liquid crystal display panel. 
     An embodiment of the present invention also provides a method of manufacturing the liquid crystal display panel  100  provided by the present invention. The liquid crystal display panel  100  includes a pixel area. Referring to  FIG.  2   ,  FIG.  2    shows a flow chart of a method of manufacturing the liquid crystal display panel, including the step 1 to step 5. 
     Step 1: providing a glass substrate  20  configured to serve as a light guide plate; 
     Step 2: preparing a reflective layer  10  on a side of the light guide plate; 
     Step 3: preparing a grating structure  30  on a side of the light guide plate away from the reflective layer  10 , wherein a position of the grating structure  30  corresponds to the pixel area; 
     The grating structure  30  is made of silicon oxide, the silicon oxide is doped with a photosensitive material, and the grating structure  30  is prepared by chemical vapor deposition. 
     The pixel area includes a plurality of pixel units, each of the pixel units has a plurality of sub-pixels; the grating structure  30  has a plurality of grating units, each of the grating units has a sub-grating and corresponds to one of the pixel units; and in the pixel units and the grating units corresponding to the pixel units, each of the sub-gratings corresponds to one of the sub-pixels. 
     The sub-pixels include a red sub-pixel  101 , a green sub-pixel  102 , and a blue sub-pixel  103 , and the sub-grating  31  in each of the sub-pixels includes a plurality of layers with a same thickness; wherein thicknesses and refractive indexes of the layers of the sub-gratings in a red sub-pixel area  101 , a green sub-pixel area  102 , and a blue sub-pixel area  103  are different; and emission wavelengths of the sub-gratings  31  in the red sub-pixel area  101 , the green sub-pixel area  102 , and the blue sub-pixel area  103  are controlled according to the Bragg equation: 2dsinθ=nλ, where d is a thickness of the layers of each of the sub-gratings, θ is an incident angle of incident light, n is a refractive index of the layers of each of the sub-gratings  31 , λ is an emission wavelength, and the emission light wavelength of each of the sub-gratings  31  is controlled by adjusting the thickness of the layers of each of the sub-gratings  31 , the incident angle of the incident light, and the refractive index of the layers of each of the sub-gratings  31 . 
     The step of preparing the grating structure  30  includes: depositing a silicon oxide film doped with photosensitive material on the side of the light guide plate away from the reflective layer  10 , and fabricating the sub-gratings  31  in the red sub-pixel area  101 , the green sub-pixel area  102 , and the blue sub-pixel area  103  through exposure, development, and etching. 
     Each of the sub-gratings  31  in the red sub-pixel area  101  emits light with a wavelength of 580 nm-660 nm, each of the sub-gratings  31  in the green sub-pixel area  102  emits light with a wavelength of 500 nm-580 nm, and each of the sub-gratings  31  in the blue sub-pixel area  103  emits light with a wavelength of 440 nm-500 nm. 
     Step 4: preparing a planarization layer  50  on a side of the grating structure  30  away from the light guide plate; and 
     Step 5: preparing a thin-film transistor layer  60  on a side of the planarization layer  50  away from the light guide plate. 
     Between preparing the grating structure  30  and preparing the planarization layer  50 , the method of manufacturing the liquid crystal display panel further includes preparing a light-shielding layer  40  between the sub-gratings, and the light-shielding layer  40  is made of an opaque material or a light-reflecting material. 
     After the step of preparing the thin-film transistor layer  60 , the method of manufacturing the liquid crystal display panel further includes step 6 to step 9. 
     Step 6: preparing the lower polarizer  70  on a side of the thin-film transistor layer  60  away from the planarization layer  50 . 
     Step 7: preparing the liquid crystal layer  80  on a side of the lower polarizer  70  away from the thin-film transistor layer  60 . 
     Step 8: preparing the second glass substrate  21  on a side of the liquid crystal layer  80  away from the lower polarizer  70 . 
     Step 9: preparing he upper polarizer  90  on a side of the second glass substrate  21  away from the liquid crystal layer  80 . 
     Beneficial effects of the present invention are that: the present invention provides a liquid crystal display panel and a method of manufacturing the same, wherein by forming a grating on an upper surface of a glass substrate, and adjusting a thickness, an angle of light incidence, and a refractive index of sub-gratings, to allow the gratings in red, green, and blue sub-pixel areas to transmit red, green, and blue light respectively, the gratings that can transmit red, green, and blue light can replace the existing red and green color resists, and a light-shielding layer between the gratings can replace the existing black matrix, so that the liquid crystal display panel does not need to be provided with a color filter substrate, thereby reducing an overall thickness of the liquid crystal display panel. 
     Further, the glass substrate in the array substrate is configured to serve as a light guide plate, thus further reducing the thickness of the liquid crystal display panel. 
     In the above embodiments, the descriptions of each embodiment have their own emphasis. The parts that are not described in detail in an embodiment can be referred to the detailed descriptions in other embodiments above, which will not be repeated herein for brevity. 
     The liquid crystal display panel and the method of manufacturing the same provided in the embodiments of the present application have been described in detail above. Specific examples are used in this document to explain the principles and implementation of the present invention. The descriptions of the above embodiments are only for understanding the method of the present invention and its core ideas, to help understand the technical solution of the present application and its core ideas, and a person of ordinary skill in the art should understand that it can still modify the technical solution described in the foregoing embodiments, or equivalently replace some of the technical features. Such modifications or replacements do not depart the spirit of the corresponding technical solutions beyond the scope of the technical solutions of the embodiments of the present application.