Patent ID: 12197068

DETAIL DESCRIPTION OF EMBODIMENTS

In order to make those skilled in the art better understand the technical solutions of the embodiments of the present disclosure, a display substrate and a manufacture method thereof, a display panel, and a display module will be described in further detail with reference to the accompanying drawings and specific embodiments of the present disclosure.

The embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, but the embodiments shown may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

Embodiments of the present disclosure are not limited to the embodiments shown in the drawings, but include modifications of configurations formed based on manufacturing processes. Accordingly, the regions in the drawings are schematic, and the shapes of the regions shown in the drawings show specific shapes of the regions and are not intended to be limited thereto.

In reflective liquid crystal displays (i.e., LCDs), a reflective layer is generally formed in an array substrate. The array substrate and a color filter substrate are aligned to form a cell, and a liquid crystal layer is disposed between the array substrate and the color filter substrate to form a liquid crystal display panel. In order to avoid poor display caused by insufficient light of an external environment, a light source may be disposed on a side of the color filter substrate away from the array substrate. Light emitted from the light source irradiates the array substrate, is reflected by the reflective layer, passes through the color filter substrate, and exits to a display side of the liquid crystal display panel. Such a light source is referred to as a front light source.

The reflective layer can be formed as a continuous convex structure that is developed with the goal of a Lambertian-like reflective structure. The Lambertian body refers to a phenomenon that incident energy is uniformly reflected in all directions, that is, the incident energy is reflected isotropically over the entire hemispherical space with an incident point as a center of the hemispherical space, which is called diffuse reflection or isotropic reflection, and the entire diffuser is called the Lambertian body. The light reflected by the Lambertian reflective structure has good brightness uniformity, good contrast ratio, and wide range of emitted light. If the reflective layer is formed into an ideal Lambertian-like reflective structure, the brightness uniformity, the contrast ratio and the viewing angle range of the reflective liquid crystal display panel can be improved.

Aiming at the problems of insufficient reflectivity, small viewing angle, poor contrast ratio, and low front brightness of the existing reflective LCD, the present disclosure focus on developing a Lambertian-like reflective structure that can improve viewing angle, brightness uniformity and contrast ratio.

Aiming at the problems of insufficient reflectivity, small viewing angle, poor contrast ratio and low front brightness of the existing reflective LCD, an embodiment of the present disclosure provides a display substrate. As shown inFIG.1andFIG.2, the display substrate includes a driver backplane2, a reflective structure3and a pixel electrode4on the driver backplane2. The reflective structure3and the pixel electrode4are sequentially disposed away from the driver backplane2along a thickness direction of the driver backplane2; the pixel electrode4is connected to the driver backplane2through the reflective structure3; the surface of the reflective structure3away from the driver backplane2is a reflective surface. The reflective surface includes a plurality of arc surfaces31each of which is convex towards a direction away from the driver backplane2. The plurality of arc surfaces31are continuously arranged, and any two adjacent arc surfaces31are connected to each other.

The driver backplane2includes a base substrate1and a transistor21on a side of the base substrate1proximal to the reflective structure3. The transistor21includes a gate electrode210, an active layer211, a first electrode212and a second electrode213. A first via-hole30is formed in the reflective structure3, and the pixel electrode4is connected to the second electrode213through the first via-hole30. The first electrode212and the second electrode213are respectively disposed at two ends of the active layer211and both connected to the active layer211. When the transistor21is turned on, the first electrode212and the second electrode213are electrically connected to each other; and when the transistor21is turned off, the first electrode212is electrically disconnected from the second electrode213.

It should be noted that, the arc surfaces31being continuously arranged means that any two adjacent arc surfaces31can be directly connected to each other to form a non-arc surface connection surface as shown inFIG.1. Or alternatively in an actual process, concave arc surfaces as shown inFIG.2are formed in regions between any two adjacent arc surfaces31of the arc surfaces31continuously arranged.

Optionally, as shown inFIG.3, the arc surface31includes a first sub-portion311and a second sub-portion312surrounding the first sub-portion311. The first sub-portion311is connected to the second sub-portion312. The first sub-portion311is a part of a sphere. A pitch between vertexes of the first sub-portions311of any two adjacent arc surfaces31is smaller than a diameter D of the sphere or the spherical surface where the first sub-portion311is located. The second sub-portions312of any two adjacent arc surfaces31are connected to each other. The vertex of the first sub-portion311is the vertex of the arc surface31.

Optionally, the second sub-portions312of any two adjacent arc surfaces31are spliced together to form a concave arc surface protruding along a direction opposite to the convex direction of the first sub-portion311. The concave arc surface is formed in the actual process.

Optionally, the arc surfaces31are arranged in an array.

In an embodiment, the display substrate and the counter substrate are aligned to form a cell with a liquid crystal layer disposed therebetween, so as to form a liquid crystal display panel. A light source is located on a side of the counter substrate away from the display substrate. During the display process, light emitted by the light source (i.e., the front light source) irradiates towards the display substrate, is reflected by the reflective surface of the reflective structure3, and emits through the counter substrate towards to the display side, so that display of the display panel can be realized.

Since the continuously arranged arc surfaces31serve as the reflective surface, the reflective structure3can make the distribution curve of the light intensity of the light reflected by the reflective surface when the incident light with various incident angles is incident on the reflective surface approach a cosine function, with an incident angle of the incident light being an included angle between the incident light and a normal line of the display substrate. That is, the distribution curve of the light intensity of the light reflected when the incident light with various incident angles is incident on the reflective surface presents a normal distribution, as shown inFIG.4, which is substantially consistent with the Lambertian reflective curve, so that the reflective structure3can be formed as the Lambertian-like reflective structure. The Lambertian-like reflective structure can realize that the light intensity of the diffused light along various directions is always proportional to the cosine function of the incident angle regardless of the direction of the incident light, so that the light from various directions has the same luminance, and thus, not only the brightness uniformity and the contrast ratio of the display panel including the display substrate can be improved, but also the viewing angle and the display effect of display panel including the display substrate can be improved because the incident light in various directions, after passing through the reflective surface, can form diffuse reflective light along a direction perpendicular to a plane where tangent lines on the arc surfaces are located. The reflected light inFIG.4has two distribution curves of the light intensity, one of which is a distribution curve of the light intensity of the reflected light in a direction perpendicular to the plane of the display substrate, and the other is a distribution curve of the light intensity of the reflected light in a direction parallel to the plane of the display substrate. An X-coordinate of the distribution curve of the light intensity of the reflected light inFIG.4represents coordinates for position points of the display panel along a span direction of the viewing angle (i.e., a direction parallel to a straight line where pupils of both eyes of a viewer are located when the viewer normally views the display panel).

Optionally, as shown inFIG.5, the arc surfaces31has the same size, and an orthographic projection of each of the arc surfaces31on the base substrate has a shape of a circle.

Further optionally, as shown inFIG.5, the plurality of arc surfaces31may be continuously arranged along any two different directions, that is, a first straight-line direction P1and a second straight-line direction P2. A pitch between vertexes of any two adjacent arc surfaces31along the first straight-line direction P1and along the second straight-line direction P2is a first distance1. The vertexes of any two adjacent arc surfaces31along the first straight-line direction P1are spaced apart from each other along the second straight-line direction P2by ¼ to ⅔ of the first distance1. A vertex of the arc surface31is the highest point of the arc surface, that is, the point on the arc surface which is farthest from the base substrate1in the direction perpendicular to the base substrate1. With the arrangement, continuous tight connection between the arc surfaces31can be ensured, so that a better Lambertian-like reflective structure can be formed, and the viewing angle, the brightness uniformity and the contrast ratio of the display panel including the display substrate can be further improved.

It should be noted that, as shown inFIG.6, a plurality of arc surfaces may also be continuously arranged in an array. Along the row direction X of the array, any two adjacent rows of arc surfaces31may also be aligned in one-to-one correspondence manner, respectively; and along the column direction Y of the array, any two adjacent columns of arc surfaces31can also be aligned in one-to-one correspondence manner, respectively. With such an arrangement, although the continuity between the arc surfaces31is inferior to that in the above arrangement, the Lambertian-like reflective structure can also be formed to some extent, thereby improving the viewing angle, the brightness uniformity, and the contrast ratio of the display panel using the display substrate.

Optionally, the pitch between the vertexes of the adjacent arc surfaces31is greater than 0 μm and less than or equal to 10 μm. With such pitch, a better Lambertian-like reflective structure can be formed, thereby being beneficial to the uniformity of the display brightness of the display substrate at various viewing angles.

Optionally, a proportion of the pitch between the vertexes of the first sub-portions of the adjacent arc surfaces31to the curvature radius of the first sub-portion ranges from 0.9:1 to 1.6:1. Preferably, the optimum proportion of the pitch between the vertexes of the first sub-portions of the adjacent arc surfaces31to the curvature radius of the first sub-portion is 1.41:1. The curvature radius of the first sub-portion is a radius of the spherical surface.FIG.7shows, with experiments, the distribution curve of the light intensity of the light reflected when the incident light with the incident angle of 0° is incident on the reflective surface of the reflective structure3in a case where the pitch between the vertexes of the first sub-portions of the adjacent arc surfaces31to the curvature radius r of the first sub-portion has various ratios. There are two distribution curves of the light intensity of the reflected light, one of which is a distribution curve of the light intensity of the reflected light perpendicular to the plane where the display substrate is located, and the other is a distribution curve of the light intensity of the reflected light parallel to the plane where the display substrate is located. As can be seen fromFIG.7, when the proportion of the pitch between the vertexes of the first sub-portions of the adjacent arc surfaces31to the curvature radius r of the first sub-portion is 1.41:1, the distribution curve of the light intensity of the light reflected when the incident light with the incident angle of 0° is incident on the reflective surface of the reflective structure3approximates a cosine function, that is, the distribution curve of the light intensity of the light reflected when the incident light with the incident angle of 0° is incident on the reflective surface of the reflective structure3presents a normal distribution, with the incident angle of the incident light being an included angle between the incident light and a normal line of the display substrate. The distribution curve of the light intensity of the light reflected is substantially consistent with the Lambertian reflective curve. Therefore, the reflective structure3can be formed as the Lambertian-like reflective structure. The Lambertian-like reflective structure can realize that the light intensity of the diffused light along various directions is always proportional to the cosine function of the incident angle regardless of the direction of the incident light. Therefore, the lights from various directions has the same luminance, and thus not only the brightness uniformity and the contrast ratio of the display panel including the display substrate can be improved, but also the viewing angle of the display panel including the display substrate can be improved.

Optionally, an opening caliber D of the arc surface31is greater than or equal to 2 μm and less than or equal to 20 μm. An arch height h of the arc surface31is greater than 0 m and less than or equal to 3 μm. The arch height h of the arc surface31and the opening caliber D of the arc surface31can be calculated according to the pitch between the vertexes of the adjacent arc surfaces31and the proportion of the pitch between the vertexes of the adjacent arc surfaces31to the curvature radius of the arc surface31. For example, when the arc surface31is a hemispherical surface, D=1.41 Pitch; h=r. As shown inFIG.7, the opening caliber D of the arc surface31is a maximum size of an opening of the arc surface31, the opening of the arc surface31is on a side of the arc surface31proximal to the base substrate1, and an arch height h of the arc surface31is a shortest distance from a vertex (i.e., a highest point) of the arc surface31to a plane where the opening is located.

As shown inFIG.8, with the reflective surface in the embodiment, when light emitted from the front light source is incident on the reflective surface, incident light with an incident angle of 42° or less can reach the air interface7(i.e., the surface on the display side of the display panel) and exit out. The incident light with the incident angle larger than 42° may be totally reflected by the reflective surface; the incident light with the incident angle larger than 42° may be scattered by the reflective surface and finally become small-angle light which can reach the air interface7and emit out, so that light loss can be prevented, and the display brightness of the display panel adopting the display substrate can be improved.FIG.9shows display luminances of various pixels at different viewing angles in a range from 90° on the left to 90° on the right, when a certain light (i.e. an incident light in a certain direction) emitted from a light source is incident on the display substrate of the display panel. As can be seen fromFIG.9, with the reflective surface of the reflective structure3, the display brightness at different viewing angles of various pixels at different positions can be is basically the same, and thus not only the brightness uniformity and the contrast ratio of the display panel including the display substrate can be improved, but also the viewing angle of display panel including the display substrate can be improved.

Optionally, as shown inFIG.1, the reflective structure3includes a first sub-layer32and a second sub-layer33. The first sub-layer32and the second sub-layer33are stacked sequentially along a direction away from the driver backplane2. The surface of the second sub-layer33away from the first sub-layer32is a reflective surface. The surface of the first sub-layer32in contact with the second sub-layer33matches the second sub-layer33in size and shape.

Optionally, the first sub-layer32is made of resin material; the second sub-layer33is made of a reflective metal material, for example, indium tin oxide, a stack layer of silver and indium tin oxide, or an aluminum neodymium alloy. The material of the first sub-layer32enables the reflective surface of the reflective structure3is formed through common exposure process, development process and high-temperature reflow process without relatively complex processes such as a semi-mask process, so that the manufacture cost and the process difficulty can be reduced. The material of the second sub-layer33can promote good reflection of light, which is beneficial for better reflective display.

Optionally, the display substrate further includes a planarization layer5. The planarization layer5is on a side of the reflective structure3away from the driver backplane2and on a side of the pixel electrode4proximal to the driver backplane2. The surface of the planarization layer5away from the driver backplane2is a planarized surface. A second via-hole51is formed in the planarization layer5. An orthographic projection of the second via-hole51on the base substrate1is spaced apart or offset from an orthographic projection of the first via-hole30on the base substrate1. The pixel electrode4is connected to the second electrode213through the second via-hole51and the reflective structure3. The planarization layer5is made of transparent resin material, so that the light from the front light source can be irradiated the reflective surface of the reflective structure3after the light passes through the planarization layer for realizing reflective display.

Optionally, inFIG.1, the display substrate further includes a gate line, a data line, and a storage electrode8. The gate line and the gate electrode210are disposed in the same layer, and the gate line is connected to the gate electrode210. A signal for controlling the transistor21to be turned on is input to the gate electrode210through the gate line. The data line and the first electrode212are disposed in the same layer, and the data line is connected to the first electrode212. A data signal is provided to the pixel electrodes4through the data line. The storage electrode8includes a first electrode plate81and a second electrode plate82opposite to each other. The first electrode plate81is disposed in the same layer as the first electrode plate212, and the second electrode plate82is disposed in the same layer as the gate electrode210. The transistor21controls the pixel electrode4to be turned on and off. A pixel voltage signal is input to the first electrode plate81, and a common voltage signal is input to the second electrode plate82. The first electrode plate81and the second electrode plate82of the storage electrode8form a storage capacitor for storing a charging voltage supplied to the pixel electrode4from the data line, so as to ensure that the voltage of the pixel electrode4can be held during display.

The liquid crystal alignment layer is formed on a side of the pixel electrode4away from the base substrate by performing rubbing and aligning processes on a coated liquid crystal alignment film. The reflective surface of the reflective structure3includes a plurality of arc surfaces31, which causes the liquid crystal alignment film formed above the pixel electrode4to be uneven, that is, the surface of the liquid crystal alignment film may have a height different greatly at different positions. When the liquid crystal alignment layer is formed by rubbing the liquid crystal alignment film subsequently, the uneven surface of the liquid crystal alignment film causes poor rubbing and the light leakage phenomenon in the display. With the planarization layer5, the reflective surface of the reflective structure3can be planarized, so that the light leakage phenomenon due to the liquid crystal alignment layer formed above the pixel electrode4subsequently can be avoided, and thus the light leakage of display can be further avoided. In addition, if the orthographic projection of the first via-hole30on base substrate1overlaps the orthographic projection of the second via-hole51on base substrate1, that is, the first via-hole30and the second via-hole51are formed as a sleeve hole, which means that a position of the first via-hole30corresponds to a position of the second via-hole51and an orthographic projection of the first via-hole30on the base substrate1coincides with or overlaps an orthographic projection of the second via-hole51on the base substrate1. After the display substrate and the counter substrate are aligned to form a cell, there is a cell gap of 5 μm to 6 μm at the via-holes, which results in that the cell thickness of the liquid crystal display panel at the via-holes is 5 μm to 6 μm much greater than the cell thickness of liquid crystal display panel at other positions except the sleeve hole, and in turn results in a delay in deflecting the liquid crystal by the electric field, and further results in the light leakage in the dark state. In the embodiment, since the first via-hole30is spaced apart from the second via-hole51, the cell gap at the via-holes in the pixel can be decreased, for example, the cell gap at the via-holes can be decreased to 1.3 μm from 6 μm, and the risk of light leakage in the dark state can be reduced, and the yield rate of the display panel including the display substrate can be improved. Since the orthographic projection of the first via-hole30on the base substrate1does not overlap the orthographic projection of the second via-hole51on the base substrate1, the difficulty of the manufacture process and manufacture yield of the display substrate can be improved.

Optionally, as shown inFIG.10, the display substrate includes a plurality of pixel electrodes4arranged in an array. The pixel electrodes4are made of a transparent electrode material (e.g., ITO), therefore the pixel electrodes4can transmit light. The second sub-layer33includes a plurality of sub-portions330independent of each other and in one-to-one correspondence with the plurality of pixel electrodes4. Both of the orthographic projections of the first via-hole30and the second via-hole51on the base substrate1fall within the orthographic projection of a corresponding pixel electrode4on the base substrate1. The plurality of sub-portions330are independent of each other, that is, the plurality of sub-portions330are insulated from each other. An area of the orthographic projection of each of the sub-portion330on the base substrate1may be larger than an area of the orthographic projection of a corresponding pixel electrode4on the base substrate1, and the orthographic projection of the sub-portions330on the base substrate1covers the entire orthographic projection of the corresponding pixel electrode4on the base substrate1. Alternatively, an area of the orthographic projection of each of the sub-portions330on the base substrate1may be equal to an area of the orthographic projection of a corresponding pixel electrode4on the base substrate1, and the orthographic projection of the sub-portion330on the base substrate1coincides with the orthographic projection of the corresponding pixel electrode4on the base substrate1. In short, as long as it is ensured that all the light from the front light source transmitted into the display substrate after passing through the pixel electrode4can be irradiated on the reflective surface of the reflective structure3.

Further optionally, as shown inFIG.11, each of the sub-portions330includes a first region3301and a second region3302independent of each other, that is, the first region3301and the second region3302are spaced apart, insulated, and disconnected from each other. The orthographic projections of the first via-hole30and the second via-hole51on the base substrate1fall within an orthographic projection of a corresponding first region3301on the base substrate1. That is, the pixel electrode4is electrically connected to the second electrode of the transistor through the second via-hole51, the first via-hole30and the first region3301.

Optionally, as shown inFIG.12, all of the data lines9respectively connected to the pixel electrodes4, the transistors21connected to the pixel electrodes4, the gate lines10connected to the gate electrodes of the transistors21, the common electrode lines12in parallel to and disposed in the same layer as the gate lines10, and the storage capacitors11for storing the voltages of the pixel electrodes4in the display substrate are located within the orthographic projection of the pixel electrodes4on the base substrate1. In the pixel region where the pixel electrode4is located, the reflective surface of the reflective structure realizes reflective display, therefore in the pixel region, the film layers below the reflective structure may not be required to transmit light, and the film layers cannot transmit light and wirings may all be arranged in the pixel region without affecting the normal display of the display substrate. Optionally, a column of pixel electrodes4may correspond to n data lines9(e.g., n is a positive integer greater than or equal to 2), and various pixel electrodes4in the column of pixel electrodes4correspond to different gate lines10. During driving display, the same scanning signal may be input to the n gate lines10, so that the n pixel electrodes4in the same column of pixel electrodes4may be charged simultaneously, therefore the refresh rate of the display panel can be effectively improved.FIG.12shows a case where a column of pixel electrodes4corresponds to four data lines9. Specifically, for the same column of pixel electrodes4, a first data line9may correspond to the (1, 8, 9, . . . , 8m, and 8 m+1)throws of pixel electrodes, a second data line9may correspond to the (2, 7, 10, . . . , 8 m−1, and 8 m+2)throws of pixel electrodes, a third data line9may correspond to the (3, 6, 11, . . . , 8 m−2, and 8 m+3)throws of pixel electrodes, and a fourth data line9may correspond to the (4, 5, 12, . . . , 8 m−3, and 8 m+4)throws of pixel electrodes, wherein m is an integer greater than or equal to zero. For example, by inputting the same scan signal to the 1st, 2nd, 3rd, and 4throws of gate lines10, the pixel electrodes4in the 1st, 2nd, 3rdand 4throws can be charged at the same time, thereby significantly increasing the refresh rate. Further, since the reflective display substrate does not need a backlight, the opaque metal signal lines may be disposed in the pixel region without affecting the influence on the aperture ratio of the pixels.

Based on the above structure of the display substrate, an embodiment further provides a method for manufacturing the display substrate, including forming a driver backplane; and forming a reflective structure and a pixel electrode on the driver backplane such that the reflective structure and the pixel electrode are sequentially disposed away from the driver backplane along a thickness direction of the driver backplane and the pixel electrode is connected to the driver backplane through the reflective structure. The formation of the reflective structure includes forming a reflective surface. The formation of the reflective surface includes forming a plurality of arc surfaces each of which protrudes towards a direction away from the driver backplane, such that the arc surfaces are continuously arranged and any two adjacent arc surfaces are connected to each other.

The formation of the reflective structure includes sequentially forming a first sub-layer and a second sub-layer on the driver backplane. The surface of the second sub-layer away from the first sub-layer is the reflective surface. The formation of the first sub-layer includes steps S01to S03.

At step S01, a resin material layer is coated.

At step S02, an exposure process and a development process are performed on the resin material layer by using a mask plate with a first light-transmitting pattern to form a plurality of first patterns.

The resin material layer is made of a positive material. A part of the resin material layer corresponding to the first light-transmitting pattern of the mask plate is removed after the exposure and development processes, and the other part of the transparent resin material layer corresponding to regions of the mask plate except the first light-transmitting pattern is retained to form the first patterns each of which is a rudiment of the arc surface. As shown inFIG.13(a, b, c), each of the first patterns6has a shape of a square, a circle, a regular hexagon, or a regular octagon. The plurality of first patterns6are the same in size and shape, and the first patterns6are arranged in an array. The plurality of first patterns6are continuously arranged along any two different directions, i.e., a first straight-line direction P1and a second straight-line direction P2. A pitch between the centers of any two adjacent first patterns6along each of the first straight-line direction P1and the second straight-line direction P2is a second distance1′, and the centers of the any two adjacent first patterns6along the first straight-line direction P1are spaced apart from each other or staggered from each other by ¼ to ⅔ of the second distance1′ along the second straight-line direction P2. In a case where the first patterns6are arranged by the exposure process as shown inFIG.13, transmittance curves of the exposure light along the first straight-line direction L1, the second straight-line direction L2and the third straight-line direction L3are as shown inFIG.14. No high transmittance platform of the exposure light appears along the first straight-line direction L1, the second straight-line direction L2, and the third straight-line direction L3, therefore continuous compact arrangement of the arc surfaces formed subsequently can be realized, a good Lambertian-like reflective structure can be formed, and the viewing angle range, the brightness uniformity and the contrast ratio of the display panel adopting the display substrate can be further improved.

As shown inFIG.15(a, b, andc), along the row direction of the array, any two adjacent rows of the first patterns6may also be respectively aligned in a one-to-one correspondence manner; and along the column direction of the array, any two adjacent columns of the first patterns6may also be respectively aligned in a one-to-one correspondence manner. In a case where the first patterns6are arranged by the exposure process as shown inFIG.15, transmittance curves of the exposure light along the first straight-line direction L1, the second straight-line direction L2and the third straight-line direction L3are as shown inFIG.16. A high transmittance platform of the exposure light appears along the third straight-line direction L3, which is not conducive to realizing the continuous compact arrangement of the arc surfaces formed subsequently. Although the arc surfaces formed subsequently based on the first patterns6inFIG.15are less continuous than the situation that the first patterns6are arranged in a staggered manner, a Lambertian-like reflective structure can be formed to a certain extent, therefore the viewing angle, the brightness uniformity and the contrast ratio of the display panel adopting the display substrate can be improved.

InFIG.14andFIG.16, the first patterns6are disposed in an array in a planar coordinate system formed by a transverse X-axis and a longitudinal Y-axis. A row direction of the array formed by the first patterns6is the X-axis direction, and a column direction of the array formed by the first patterns6is the Y-axis direction. The first straight-line direction L1is the column direction of the array formed by the first patterns6, the second straight-line direction L2is the row direction of the array formed by the first patterns6, and the third straight-line direction L3is a diagonal direction of the array formed by the first patterns6. The diagonal direction is a diagonal direction of the square formed by arranging the first patterns6or a direction of a symmetry axis direction, between the row direction and the column direction of the array formed by the first patterns6, of the regular hexagon formed by arranging the first patterns6. The transmittance platform represents light transmittance of exposure light passing through the first light-transmitting pattern of the mask plate (i.e., other regions except for the regions on the mask plate for forming the first patterns6). The high transmittance platform represents that exposure light passing through the first light-transmitting pattern of the mask plate has a high light transmittance. Since each of the gaps (corresponding to the first light-transmitting pattern of the mask plate), arranged along the first straight-line direction L1, the second straight-line direction L2and the third straight-line direction L3, between any two first patterns6arranged in a staggered manner inFIG.14is small, the high-transmittance platform of the exposure light cannot be formed for the first patterns6arranged in a staggered manner inFIG.14, and thus continuous compact arrangement of the arc surfaces formed subsequently can be realized, and a good Lambertian-like reflective structure can be formed. However, since each of the gaps (corresponding to the first light-transmitting pattern of the mask plate), arranged along the third straight-line direction L3, between any two first patterns6arranged in an aligned manner inFIG.16is greater, a high-transmittance platform of the exposure light can be formed along the third straight-line direction L3for the first patterns6arranged in an aligned manner inFIG.16, and the subsequently formed arc surfaces are less continuous than the arrangement of the first patterns6inFIG.14.

It should be noted that the first via-hole and the first patterns may be formed through the a single patterning process. For example, by providing a second light-transmitting pattern in the same mask plate with the first light-transmitting pattern, a part of the transparent resin material layer corresponding to the second light-transmitting pattern of the mask plate is removed after exposure and development processes are performed on the transparent resin material layer, so as to form a pattern of the first via-hole. Alternatively, after the first patterns are formed, a pattern of the first via-hole can also be formed by providing a second light-transmitting pattern in another mask plate, and a part of the material corresponding to the second light-transmitting pattern of another mask plate is removed after exposure and development processes are performed on the material.

Optionally, when the transparent resin material layer is exposed, the light transmittance of the exposure light passing through the first light-transmitting pattern of the mask plate is in a range of 40% to 60%. The intensity simulation of the exposure light show that the smaller the first light-transmitting pattern is, the smaller the gray scale of the exposure light can be realized. The continuous compact arc surfaces can be formed by keeping the light transmittance of the exposure light in a range of 40% to 60%.

At step S03, a reflow process is performed on the first patterns at a temperature of 230° C. to 250° C. to form the arc surfaces.

The first patterns are protruding structures with clear edges and corners, and upper surfaces of the first patterns are flat surfaces. The protruding structures can be melted at the temperature of 230° C. to 250° C. and flow into grooves between the protruding structures under the action of gravity, so that the upper surfaces of the protruding structures with the clear edges and corners form the arc surfaces.

The formation of the second sub-layer includes: depositing a reflective metal layer on the first sub-layer. The formed reflective metal layer matches a surface of the first sub-layer in contact with the reflective metal layer in size and shape.

The display substrate is provided with the reflective structure in which the arc surfaces are arranged continuously as the reflective surface, the reflective structure can enable the light intensity distribution curve of the light reflected when the incident light with various incident angles is incident on the reflective surface to be proximal to a cosine function. That is, the distribution curve of the light intensity of the light reflected when the incident light with various incident angles is incident on the reflective surface presents a normal distribution, which is substantially consistent with the Lambertian reflective curve, so that the reflective structure3can be formed as the Lambertian-like reflective structure, which can realize that the light intensity of the diffused light along various directions is always proportional to the cosine function of the incident angle regardless of the direction of the incident light, so that the light from various directions has the same luminance, and thus not only the brightness uniformity and the contrast ratio of the display panel including the display substrate can be improved, but also the viewing angle of display panel including the display substrate can be improved, and thus the display effect of display panel including the display substrate can be improved.

An embodiment of the present disclosure further provides a display panel, which includes the display substrate in any one of the above embodiments. The display panel further includes a counter substrate facing the display substrate, with a liquid crystal layer disposed between the display substrate and the counter substrate.

In the display substrate in any one of above-mentioned embodiments, not only the brightness uniformity and the contrast ratio of the display panel can be improved, but also the viewing angle of the display panel can be enlarged, and moreover the display effect of the display panel can be improved.

An embodiment of the present disclosure further provides a display module, which includes the display panel in any one of above embodiments and a light source. The light source is disposed on the light-emitting side of the display panel, and the light-emitting surface of the light source faces the light-emitting side of the display panel.

The light source includes micro light-emitting diodes (Micro-LEDs) arranged in an array.

In the display panel in any one of above-mentioned embodiments, not only the brightness uniformity and the contrast ratio of the display module can be improved, but also the viewing angle of the display module can be enlarged, and moreover the display effect of the display module can be improved.

The display module provided by the embodiments of the present disclosure can be any product or component with a display function, such as an LCD panel, an LCD television, a display, a mobile phone, a navigator and the like.

It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the present disclosure, and these changes and modifications are within the scope of the present disclosure.