A method for manufacturing a microlens, a privacy display panel, and a privacy display device

Abstract

The embodiment of the present application discloses a preparation method of a microlens, a privacy display panel and a privacy display device, wherein the preparation method of the microlens comprises forming a lens material layer covering a substrate on the substrate; patterning the lens material layer to form an array-distributed microlens intermediate structure, wherein the microlens intermediate structure comprises a plurality of sub-microlens intermediate structures with different thicknesses, and the thickness of each sub-microlens intermediate structure gradually increases in a direction from far to near to a center point of the microlens intermediate structure; heating the microlens intermediate structure to make the microlens intermediate structure reflow to form a semispherical microlens structure; and cooling the semispherical microlens structure to form the microlens. After the microlens material is laid, the microlens structure comprising a plurality of sub-microlens intermediate structures with different thicknesses is patterned, the prepared microlens has a standard appearance, and the optical performance of the microlens is improved.

Description

Technical Field

[0001] This invention relates to the field of display technology. More specifically, it relates to a method for fabricating a microlens, a privacy display panel, and a privacy display device. Background Technology

[0002] With the continuous development of display technology, display screens are being used more and more widely. In certain special circumstances, such as when processing confidential company information or entering personal information on a mobile phone, we hope to protect our privacy and prevent others from peeping at this sensitive data.

[0003] In related technologies, in order to achieve privacy protection, black matrix blocking technology is used to limit the light emission angle, and a microlens layer is subsequently prepared to significantly improve the light emission efficiency from the front and reduce light leakage from the side, thereby improving privacy protection performance.

[0004] The morphology of microlenses is crucial to their performance. Existing fabrication methods produce microlenses with trapezoidal morphologies, resulting in microlenses with low optical properties. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a microlens, a privacy display panel, and a privacy display device, so as to solve at least one of the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a method for fabricating a microlens, the method comprising:

[0008] A lens material layer covering the substrate is formed on the substrate;

[0009] The lens material layers are patterned to form an array of distributed microlens intermediate structures, wherein,

[0010] The microlens intermediate structure includes multiple sub-microlens intermediate structures with different thicknesses, and the thickness of each sub-microlens intermediate structure gradually increases from the farthest point to the center of the microlens intermediate structure.

[0011] The intermediate structure of the microlens is heated so that it reflows to form a hemispherical microlens structure.

[0012] The hemispherical microlens structure is cooled to form a microlens.

[0013] This invention provides a method for fabricating microlenses. After laying microlens material, a microlens intermediate structure is patterned to form a microlens intermediate structure comprising multiple sub-microlens intermediate structures with different thicknesses. The thickness of each sub-microlens intermediate structure gradually increases from the farthest point to the center of the microlens intermediate structure. After a hot reflow process, a standard hemispherical microlens structure is formed. The fabricated microlens has a standard morphology, thereby improving the optical performance of the microlens and the reliability of the product.

[0014] In one possible implementation, the diameter of the microlens is greater than or equal to 10 micrometers.

[0015] This method increases the size of the microlens, and the diameter of the fabricated microlens is greater than or equal to 10 micrometers, which can collect more incident light and further enhance the light extraction efficiency.

[0016] In one possible implementation, the lens material layer is made of a negative photoresist material mixed with refractive particles, having a refractive index greater than or equal to 1.6.

[0017] In this implementation, the lens material layer is a negative photoresist material with a refractive index greater than or equal to 1.6 and mixed with refractive particles. The microlens is prepared using a high-refractive-index material, which further improves the light extraction efficiency.

[0018] In one possible implementation, the temperature at which the intermediate structure of the microlens is heated is greater than or equal to 50 degrees Celsius and less than or equal to 100 degrees Celsius.

[0019] In this implementation, the temperature of the hot reflow process is controlled between 50 and 100 degrees Celsius, which avoids damage to the lens material and other materials caused by high temperatures. At the same time, it allows the material to achieve appropriate fluidity, promoting the formation of the microlens structure. By precisely controlling the heating temperature, the microlens achieves the expected hemispherical structure after the hot reflow process without damaging other components, thereby improving its ability to transmit and focus light and ensuring the reliability of the product.

[0020] In one possible implementation, the thickness difference between the intermediate structures of two adjacent sub-microlenses is the same.

[0021] This implementation ensures that the thickness difference between the intermediate structures of two adjacent sub-microlenses is the same, thereby making the thickness of the intermediate structures of multiple sub-microlenses in the intermediate structure of the microlens uniformly change. This further ensures that the intermediate structure of the microlens forms a uniform hemispherical shape after the hot reflow process, thus improving the optical quality and consistency of the microlens.

[0022] In one possible implementation, the sub-microlens intermediate structure includes a cylindrical first sub-microlens intermediate structure and other annular sub-microlens intermediate structures surrounding the first sub-microlens intermediate structure.

[0023] In one possible implementation, the difference in radius between the intermediate structures of two adjacent sub-microlenses is the same.

[0024] This implementation ensures that the radius difference between the intermediate structures of two adjacent sub-microlenses is the same, so that the multiple intermediate structures of sub-microlenses with different thicknesses in the intermediate structure of the microlens are evenly distributed. This further ensures that the intermediate structure of the microlens forms a uniform hemispherical shape after the hot reflow process, thereby improving the optical quality and consistency of the microlens.

[0025] In one possible implementation, the intermediate structures of two adjacent sub-microlenses are seamlessly connected.

[0026] In this implementation, the intermediate structures of multiple sub-microlenses are seamlessly connected, further ensuring that the intermediate structures of the microlenses form a uniform hemispherical shape after the low-temperature hot reflow process, thereby improving the optical performance and consistency of the microlenses, and increasing production efficiency and product quality stability.

[0027] A second aspect of the present invention provides a privacy display panel, the privacy display panel comprising:

[0028] A privacy display substrate includes multiple sub-pixels formed on a substrate, each sub-pixel having a light-emitting area;

[0029] A microlens layer located on the light-emitting side of the display substrate, the microlens layer comprising microlens structures corresponding one-to-one with the light-emitting areas of each sub-pixel;

[0030] The orthographic projection of the microlens structure on the display substrate at least partially overlaps with the orthographic projection of the corresponding sub-pixel light-emitting area on the display substrate, and the microlens layer is formed by the preparation method provided in the first aspect of the present invention;

[0031] as well as

[0032] A dimming layer located on the side of the microlens layer away from the display substrate has a refractive index lower than that of the microlens layer.

[0033] This implementation improves the light output of the display panel by forming a microlens layer and a dimming layer on the privacy display substrate. The refractive index of the dimming layer is lower than that of the microlens layer. Furthermore, the microlens layer is prepared using the method provided in the first aspect of this invention, resulting in a standard morphology, which further improves the light output of the display panel, enhances the light output efficiency of the display panel, and ensures the privacy display of the display panel.

[0034] In one possible implementation, the material of the microlens layer is a negative photoresist material mixed with refractive particles, having a refractive index greater than or equal to 1.6.

[0035] The refractive index of the dimming layer is less than or equal to 1.41.

[0036] In this implementation, the microlens layer is made of a high-refractive-index material with a refractive index greater than 1.6, which improves the light extraction efficiency of the display panel. Combined with the low-refractive-index dimming layer, it enhances the reflectivity of the optical devices. Furthermore, it can modulate large-angle light into positive output, further enhancing the light extraction efficiency of the privacy display panel and improving its brightness.

[0037] A third aspect of the present invention provides a privacy display device, the privacy display device comprising the privacy display substrate provided in the second aspect of the present invention.

[0038] The beneficial effects of this invention are as follows:

[0039] The microlens fabrication method provided by this invention involves laying microlens material and then patterning it to form a microlens intermediate structure comprising multiple sub-microlens intermediate structures of different thicknesses. The thickness of each sub-microlens intermediate structure gradually increases from the farthest point to the center of the microlens intermediate structure. After a hot reflow process, a standard hemispherical microlens structure can be formed, resulting in a microlens with a standard morphology and thus improving the optical performance of the microlens. Attached Figure Description

[0040] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0041] Figure 1 This diagram illustrates a process flow diagram of a microlens fabrication method provided in the prior art.

[0042] Figure 2 A schematic diagram of the structure of a mask provided by the prior art is shown.

[0043] Figure 3 Show Figure 1 A schematic diagram of the microlens obtained by the fabrication method shown.

[0044] Figure 4 This diagram illustrates a flow chart of a microlens fabrication method provided by an embodiment of the present invention.

[0045] Figure 5 This is a top view of a microlens intermediate structure provided in an embodiment of the present invention.

[0046] Figure 6 Show Figure 4 A schematic diagram of the microlens obtained by the fabrication method shown.

[0047] Figure 7 This diagram illustrates the structure of a mask provided in an embodiment of the present invention.

[0048] Figure 8 This diagram illustrates the structure of the patterned area of ​​a mask provided in an embodiment of the present invention. Detailed Implementation

[0049] In this disclosure, "on," "formed on," and "set on" can indicate that one layer is directly formed or set on another layer, or that one layer is indirectly formed or set on another layer, meaning that there are other layers between the two layers.

[0050] It should be noted that although the terms "first," "second," etc., may be used herein to describe various components, members, elements, regions, layers, and / or parts, these components, members, elements, regions, layers, and / or parts should not be limited by these terms. Rather, these terms are used to distinguish one component, member, element, region, layer, and / or part from another. Thus, for example, the first component, first member, first element, first region, first layer, and / or first part discussed below may be referred to as a second component, second member, second element, second region, second layer, and / or second part without departing from the teachings of this disclosure.

[0051] In the prior art, the methods for fabricating microlenses are as follows: Figure 1 As shown, this includes depositing microlens material 20 on substrate 10, using methods such as... Figure 2 The mask shown is exposed and developed to form multiple cylindrical initial microlenses 201 arranged at intervals. The mask includes multiple light-transmitting areas 801, each with a diameter greater than or equal to 4 micrometers. Thermal reflow is then used to form the final microlens 202. The fabricated microlens 202 is shown in the image. Figure 3 As shown, its shape resembles a truncated cone.

[0052] The inventors discovered that as the requirements for the light emission efficiency of display panels increase, the size of the microlenses that need to be produced also needs to be increased. However, the existing microlens manufacturing process is not suitable for the fabrication of large-size microlenses. Specifically, the microlens layer is generally fabricated above the light-emitting layer, which requires low-temperature hot reflow during the fabrication of the microlens. Furthermore, the microlenses are made of high-refractive-index materials, and due to the special properties of the microlens materials, their fluidity is insufficient at low temperatures. As a result, the initial cylindrical microlenses with a diameter of 4 micrometers or more tend to form a frustum shape rather than a hemispherical shape after processing by the low-temperature hot reflow process. This deviation from the ideal design in terms of geometry affects their optical performance.

[0053] In view of this, the first embodiment of the present invention provides a method for preparing a microlens, such as... Figure 4 As shown, including

[0054] A lens material layer 40 covering the substrate is formed on the substrate 30;

[0055] The patterned lens material layer 40 forms an array of distributed microlens intermediate structures 401, wherein...

[0056] The microlens intermediate structure 401 includes multiple sub-microlens intermediate structures 4011 with different thicknesses. The thickness of each sub-microlens intermediate structure 4011 gradually increases in the direction X from the center point of the microlens intermediate structure 401 to the center point of the microlens intermediate structure 401.

[0057] The intermediate structure 401 of the microlens is heated so that the intermediate structure 401 of the microlens is reflowed to form a hemispherical microlens structure 402.

[0058] The hemispherical microlens structure 402 is cooled to form a microlens.

[0059] In this embodiment, after laying the microlens material, a microlens intermediate structure is patterned to form a microlens intermediate structure including multiple sub-microlens intermediate structures with different thicknesses. The thickness of each sub-microlens intermediate structure gradually increases from far to near the center point of the microlens intermediate structure. After the hot reflow process, a standard hemispherical microlens structure is formed, and the microlens morphology of the prepared microlens is standard, thereby improving the optical performance of the microlens.

[0060] In one possible implementation, the lens material layer 40 is a negative photoresist material mixed with refractive particles, having a refractive index greater than or equal to 1.6, for example, 1.7 or 1.9.

[0061] Specifically, the refracting particles are inorganic particles, such as silicon dioxide nanoparticles, titanium dioxide nanoparticles, aluminum oxide nanoparticles, metal nanoparticles, or zinc oxide nanoparticles.

[0062] In this implementation, the lens material layer is a negative photoresist material with a refractive index greater than or equal to 1.6 and mixed with refractive particles. The microlens is prepared using a high-refractive-index material, which further improves the light extraction efficiency.

[0063] Optionally, the thickness of the lens material layer 40 is greater than or equal to 4 micrometers and less than or equal to 7 micrometers, for example, 5 micrometers or 6 micrometers.

[0064] In one possible implementation, the diameter of each microlens is greater than or equal to 10 micrometers, for example, 12 micrometers or 14 micrometers.

[0065] The microlenses prepared by this method have a diameter of 10 micrometers or more. Larger microlenses can collect more incident light and further enhance light extraction efficiency.

[0066] In one possible implementation, the diameter of each microlens is greater than or equal to 10 micrometers, and the thickness of each microlens is greater than or equal to 4 micrometers and less than or equal to 7 micrometers.

[0067] This implementation increases the size of the microlens, and the fabricated microlens have a diameter greater than or equal to 10 micrometers and a thickness greater than or equal to 4 micrometers and less than or equal to 7 micrometers, which can collect more incident light and further enhance the light extraction efficiency.

[0068] In one possible implementation, the temperature at which the microlens intermediate structure 401 is heated is greater than or equal to 50 degrees Celsius and less than or equal to 100 degrees Celsius.

[0069] Specifically, since lens materials may lose transparency at high temperatures, and microlens layers are generally formed on substrates containing chips, high-temperature environments can damage the substrate and sensitive components in the chips, such as the light-emitting material layer, further reducing the light-emitting performance of the display panel. Therefore, the temperature of the hot reflow is controlled at 50 to 100 degrees Celsius, for example, 50, 60, 65, 70, 80, 90 or 100 degrees Celsius.

[0070] In this implementation, the temperature range of the hot reflow process is 50 to 100 degrees Celsius, which avoids damage to the lens material and other materials caused by high temperature, while making the material achieve appropriate fluidity and promoting the formation of the microlens structure. By precisely controlling the heating temperature, the microlens can achieve the expected hemispherical structure after the hot reflow process without damaging other devices, thereby improving its ability to transmit and focus light and ensuring the reliability of the product.

[0071] In a specific example, firstly, a 3-micrometer-thick lens material layer is deposited on the surface of the encapsulation layer of the privacy display substrate. The lens material layer is a negative photoresist doped with refractive particles. The lens material layer is exposed and cured, and then cleaned with a developer to remove residual lens material, forming a spaced microlens intermediate structure 401. The product is then placed in a reflow oven at 100 degrees Celsius for hot reflow, so that the microlens intermediate structure 401 directly forms a hemispherical microlens structure 402.

[0072] In one possible implementation, the thickness difference between the intermediate structures 4011 of two adjacent sub-microlenses is the same.

[0073] This implementation ensures that the thickness difference between two adjacent sub-microlens intermediate structures 4011 is the same, thereby making the thickness of multiple sub-microlens intermediate structures 4011 in the microlens intermediate structure change uniformly. This further ensures that the microlens intermediate structure forms a uniform hemispherical shape after the hot reflow process, thereby improving the optical quality and consistency of the microlens.

[0074] Specifically, such as Figure 6As shown, the microlens is a hemispherical microlens, and its orthographic projection on the substrate is a circle. The sub-microlens intermediate structure 4011 includes multiple concentric rings with decreasing radii and a concentric cylinder surrounded by the concentric ring with the smallest radius. Here, the radius refers to the outer diameter of the concentric ring. The orthographic projection of the sub-microlens intermediate structure 4011 on the substrate corresponds to the orthographic projection of the hemispherical microlens on the substrate. Furthermore, the multiple first microlenses are seamlessly connected and have different aperture ratios.

[0075] In one possible implementation, the sub-microlens intermediate structure 4011 includes a cylindrical sub-microlens intermediate structure and other annular sub-microlens intermediate structures surrounding the sub-microlens intermediate structure.

[0076] Specifically, such as Figure 5 As shown, the sub-microlens intermediate structure 4011 includes a cylindrical first sub-microlens intermediate structure 40111, an annular second sub-microlens intermediate structure 40112 surrounding the first sub-microlens intermediate structure 40111, and a third sub-microlens intermediate structure 40113 surrounding the second sub-microlens intermediate structure 40112.

[0077] In one possible implementation, the intermediate structures 4011 of two adjacent sub-microlenses are seamlessly connected.

[0078] In this implementation, the multiple sub-microlens intermediate structures 4011 are seamlessly connected, further ensuring that the microlens intermediate structures form a uniform hemispherical shape after the low-temperature hot reflow process, thereby improving the optical performance and consistency of the microlenses, and improving production efficiency and product quality stability.

[0079] In one possible implementation, the difference in radius between the intermediate structures 4011 of two adjacent sub-microlenses is the same.

[0080] This implementation ensures that the radius difference between two adjacent sub-microlens intermediate structures 4011 is the same, so that multiple sub-microlens intermediate structures 4011 with different thicknesses in the microlens intermediate structure are evenly distributed. This further ensures that the microlens intermediate structure forms a uniform hemispherical shape after the hot reflow process, thereby improving the optical quality and consistency of the microlens.

[0081] In one possible implementation, by means of, Figure 7 , 8 The mask shown exposes and develops the laid microlens material to form the intermediate structure of the microlens.

[0082] This method forms the intermediate structure of the microlens in one step through exposure and development using a mask, which simplifies the fabrication process, improves fabrication efficiency and product quality, and increases the lifespan of the display panel while improving the optical performance of the microlens.

[0083] In one possible implementation, such as Figure 7 , 8 As shown, the photomask includes a light-shielding plate, which includes a plurality of patterned areas 60 and a light-shielding area surrounding the patterned areas 60.

[0084] The pattern area 60 includes multiple sub-pattern areas 601 with different aperture ratios. The aperture ratio of each sub-pattern area 601 gradually increases in the direction Y from the center point of the pattern area 60, thereby controlling the transmittance of light rays during exposure to gradually increase in the direction Y near the center of the pattern area 60, and the thickness of the retained microlens material gradually decreases from the center to the outside.

[0085] Specifically, multiple openings are formed on the light-shielding plate using techniques such as photolithography, electron beam etching, and ion beam etching.

[0086] Specifically, the material of the light-shielding plate is, for example, quartz, glass, or metal.

[0087] In one possible implementation, each sub-pattern area 601 has a first opening 70 on its light-shielding plate; two adjacent sub-pattern areas 601 are seamlessly connected.

[0088] The distribution density of the first opening 70 on the sub-pattern area 601 that is far from the center point of the pattern area 60 is less than the distribution density of the first opening 70 on the sub-pattern area 601 that is close to the center point of the pattern area 60.

[0089] Specifically, the diameter of each first opening 70 is greater than or equal to 2 micrometers and less than or equal to 7 micrometers. The greater the distribution density of the first openings 70 in the sub-pattern region 601, the greater the transmittance of the corresponding region, and the greater the thickness of the sub-microlens intermediate structure 4011 corresponding to the sub-pattern region 601 in the microlens intermediate structure formed by exposure through the mask. The smaller the distribution density of the first openings 70 in the sub-pattern region 601, the smaller the transmittance of the corresponding region, and the lower the thickness of the sub-microlens intermediate structure 4011 corresponding to the sub-pattern region 601 in the microlens intermediate structure formed by exposure through the mask.

[0090] It should be noted that this implementation does not specifically limit the shape of the first opening 70. The shape of the first opening 70 may be, for example, a circle, an ellipse, a rectangle, a triangle, a hexagon, etc.

[0091] In one possible implementation, such as Figure 8 As shown, the opening area of ​​the first opening 70 on the sub-pattern area 601 that is far from the center point of the pattern area 60 is smaller than the opening area of ​​the first opening 70 on the sub-pattern area 601 that is close to the center point of the pattern area 60.

[0092] Specifically, the shape of the first opening 70 is, for example, circular, and the diameter of each first opening 70 is greater than or equal to 2 micrometers and less than or equal to 7 micrometers.

[0093] Optionally, the opening area and distribution density of the first opening 70 on the sub-pattern area 601 away from the center point of the pattern area 60 are smaller than the opening area and distribution density of the first opening 70 on the sub-pattern area 601 close to the center point of the pattern area 60.

[0094] In one possible implementation, the pattern area 60 of the mask is circular, including a first sub-pattern area centered at the center point of the pattern area 60, and other annular sub-pattern areas surrounding the first sub-pattern area and concentric with the first sub-pattern area.

[0095] Specifically, there are 60 interconnected pattern areas with different transmittance.

[0096] In one possible implementation, the difference in aperture ratio between two adjacent sub-pattern regions 601 is the same.

[0097] This implementation ensures that the difference in aperture ratio between two adjacent sub-pattern areas 601 is the same, thereby making the difference in thickness between two adjacent sub-microlens intermediate structures 4011 in the microlens intermediate structure formed by the exposure lens material layer 40 the same. This results in a uniform thickness variation among the multiple sub-microlens intermediate structures 4011 in the microlens intermediate structure, further ensuring that the microlens intermediate structure forms a uniform hemispherical shape after the hot reflow process, thus improving the optical quality and consistency of the microlens.

[0098] In one possible implementation, the difference in radius between two adjacent sub-pattern regions 601 is the same.

[0099] This implementation ensures that the radius difference between two adjacent sub-pattern areas 601 is the same, thus making the thickness difference between two adjacent sub-microlens intermediate structures 4011 in the microlens intermediate structure formed by the exposure lens material layer 40 the same. This results in a uniform thickness variation among the multiple sub-microlens intermediate structures 4011 in the microlens intermediate structure, further ensuring that the microlens intermediate structure forms a uniform hemispherical shape after the thermal reflow process, thereby improving the optical quality and consistency of the microlens.

[0100] Another embodiment of this disclosure provides a privacy display panel, the privacy display panel comprising:

[0101] A privacy display substrate includes multiple sub-pixels formed on a substrate, each sub-pixel having a light-emitting area;

[0102] A microlens layer located on the light-emitting side of the display substrate, the microlens layer comprising microlens structures corresponding one-to-one with the light-emitting areas of each sub-pixel; the orthographic projection of the microlens structure onto the display substrate at least partially overlaps with the orthographic projection of the corresponding sub-pixel light-emitting area onto the display substrate; the microlens layer is formed using the above-described fabrication method; and

[0103] The dimming layer is located on the side of the microlens layer away from the display substrate. The refractive index of the dimming layer is less than that of each microlens structure in the microlens layer.

[0104] This implementation method forms a microlens layer and a dimming layer on the privacy display substrate. The refractive index of the dimming layer is lower than that of the microlens layer, which increases the light output of the display panel. Furthermore, the lens layer is prepared using the above-mentioned method and is a standard hemispherical microlens, which further improves the light output efficiency of the display panel and ensures the privacy display of the display panel.

[0105] In one possible implementation, the material of the microlens layer is a negative photoresist material mixed with refractive particles, with a refractive index greater than or equal to 1.6.

[0106] The refractive index of the dimming layer is less than or equal to 1.41.

[0107] Specifically, the refracting particles are inorganic particles, such as silicon dioxide nanoparticles, titanium dioxide nanoparticles, aluminum oxide nanoparticles, metal nanoparticles, or zinc oxide nanoparticles.

[0108] In this implementation, the microlens layer is made of a high-refractive-index material with a refractive index greater than 1.6, which further improves the light extraction efficiency of the display panel. Combined with a dimming layer with a refractive index less than or equal to 1.41, it enhances the reflectivity of the optical device. Furthermore, it can modulate large-angle light into positive output, thereby enhancing the light extraction efficiency of the privacy display panel and increasing its brightness.

[0109] In one possible implementation, the diameter of each microlens is greater than or equal to 10 micrometers, and the thickness of the microlens layer is greater than or equal to 4 micrometers and less than or equal to 7 micrometers.

[0110] This implementation increases the size of the microlens. The microlens of the privacy display panel has a diameter greater than or equal to 10 micrometers and a thickness greater than or equal to 4 micrometers and less than or equal to 7 micrometers, and has a standard shape. The large-sized microlens can collect more incident light, further enhancing the light emission efficiency of the privacy display panel and improving the light efficiency.

[0111] In one possible implementation, the display substrate includes:

[0112] A pixel defining layer, wherein the pixel defining layer is provided with a second opening for defining the light-emitting area;

[0113] A first electrode layer and a light-emitting layer are formed in the second opening of the pixel defining layer;

[0114] A second electrode layer covering the light-emitting layer;

[0115] An optical path confinement layer is located on the pixel boundary layer. The optical path confinement layer is provided with a third opening. The orthographic projection of the third opening on the pixel boundary layer covers the orthographic projection of the second opening on the pixel boundary layer.

[0116] In one possible implementation, the optical path limiting layer is a reflective layer formed on one side of the pixel defining layer. The light emitted from the light-emitting layer is reflected after reaching the reflective layer through the pixel defining layer, thereby limiting the emission angle of the pixel.

[0117] In this implementation, the light path limiting layer is a reflective layer disposed on one side surface of the pixel defining layer. Part of the light emitted from the light-emitting layer is emitted through the third opening, while the other part of the light entering the pixel defining layer is reflected by the reflective layer covering the pixel defining layer. The reflective layer prevents the light from escaping from the corresponding part of the pixel defining layer, thereby limiting the emission angle of the light from the pixel unit and achieving privacy protection.

[0118] Specifically, the reflective layer is made of opaque metallic materials, such as mercury and molybdenum.

[0119] In one possible implementation, the optical path confinement layer is a light-shielding layer formed on one side of the pixel defining layer, and the light-shielding layer is, for example, made of a black matrix material.

[0120] In this implementation, the light path limiting layer is a light-shielding layer disposed on one side surface of the pixel defining layer. Part of the light emitted from the light-emitting layer is emitted through the third opening, while the other part of the light entering the pixel defining layer is absorbed by the light-shielding layer covering the pixel defining layer. The reflective layer prevents the light from escaping from the corresponding part of the pixel defining layer, thereby limiting the emission angle of the light from the pixel unit and achieving privacy protection display.

[0121] In one possible implementation, the display substrate is an OLED display substrate, and also includes...

[0122] Substrate and driving circuit layer formed on substrate;

[0123] For example, the substrate can be made of materials such as glass or quartz. The OLED display substrate may also include a barrier layer and a buffer layer located between the substrate and the driving circuit layer. For example, the barrier layer and the buffer layer can be formed on the entire surface of the substrate. For example, the barrier layer can be made of inorganic insulating materials such as silicon oxide, silicon nitride, or silicon oxynitride, and the buffer layer can also be made of inorganic insulating materials such as silicon oxide, silicon nitride, or silicon oxynitride. The barrier layer helps to prevent water and oxygen from entering the OLED from the bottom. The buffer layer improves the quality of subsequent material deposition.

[0124] The driving circuit layer, also known as the thin-film transistor (TFT) layer, includes an active layer formed on a buffer layer using a patterning process; a gate insulating layer (GI) formed on the active layer by deposition or other methods; the gate of the TFT formed on the gate insulating layer using a patterning process; a dielectric layer (ILD) formed on the gate by deposition or other methods; a source / drain metal layer formed on the dielectric layer; and a second planarization layer (PLN) covering the source / drain metal layer and the exposed dielectric layer. The source / drain metal layer forms the source and drain of the TFT. For example, the source is electrically connected to the active layer through a via in the dielectric layer. The active layer can be made of materials such as polysilicon and metal oxides. The gate insulating layer can be made of inorganic insulating materials such as silicon oxide, silicon nitride, or silicon oxynitride. The dielectric layer can also be made of inorganic insulating materials such as silicon oxide, silicon nitride, or silicon oxynitride. The gate material includes metals or alloys such as aluminum, titanium, and cobalt. The second planarization layer is, for example, an organic material.

[0125] The first electrode is, for example, an anode, which is a metal oxide such as ITO or IZO, or a metal or alloy of Ag, Al, or Mo. The first electrode is electrically connected to the drain through a via in the second planarization layer. The pixel defining layer is, for example, made of an organic material. The second electrode is, for example, a cathode covering the light-emitting layer. The cathode is, for example, formed on the entire surface of the OLED display substrate. The cathode material may include metals such as Mg, Ca, Li, or Al, or alloys of Mg, Ca, Li, or Al, or metal oxides such as IZO or ZTO, or conductive organic materials such as PEDOT / PSS (poly(3,4-ethylenedioxythiophene / polystyrene sulfonate)).

[0126] The OLED display substrate also includes a coating layer (TFE) located on the second electrode and the light path confinement layer. For example, the coating layer may include a first inorganic coating layer, an organic coating layer, and a second inorganic coating layer. For example, the first and second inorganic coating layers may be formed by deposition or other methods. The organic coating layer may be formed by inkjet printing. For example, the first and second inorganic coating layers may be formed using inorganic materials such as silicon nitride, silicon oxide, or silicon oxynitride, while the organic coating layer may be formed using organic materials such as polyimide (PI) or epoxy resin. Thus, the first inorganic coating layer, the organic coating layer, and the second inorganic coating layer form a composite coating layer, which provides multiple layers of protection for the functional structure of the display panel, resulting in better coating performance.

[0127] Another embodiment of this disclosure provides a privacy display device, including a privacy display panel provided in the above embodiments.

[0128] The privacy display device can be any product or component with a display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or in-vehicle TV. This embodiment does not limit this.

[0129] Obviously, the above embodiments of this disclosure are merely examples for clearly illustrating this disclosure, and are not intended to limit the implementation of this disclosure. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all implementation methods here. Any obvious variations or modifications derived from the technical solutions of this disclosure are still within the protection scope of this disclosure.

Claims

1. A method for preparing a microlens, characterized in that, include A lens material layer covering the substrate is formed on the substrate; The lens material layers are patterned to form an array of distributed microlens intermediate structures, wherein, The microlens intermediate structure includes multiple sub-microlens intermediate structures with different thicknesses, and the thickness of each sub-microlens intermediate structure gradually increases from the farthest point to the center of the microlens intermediate structure. The intermediate structure of the microlens is heated so that it reflows to form a hemispherical microlens structure. The hemispherical microlens structure is cooled to form a microlens; The patterning of the lens material layer to form an array of microlens intermediate structures includes: exposing and developing the lens material layer through a mask to form the array of microlens intermediate structures. The photomask includes a light-shielding plate, which includes multiple patterned areas and a light-shielding area surrounding the patterned areas; The pattern area includes multiple sub-pattern areas with different aperture ratios, and the aperture ratio of each sub-pattern area gradually increases from the farthest point to the center of the pattern area.

2. The preparation method according to claim 1, characterized in that, The diameter of the microlens is greater than or equal to 10 micrometers.

3. The preparation method according to claim 1, characterized in that, The lens material layer is made of a negative photoresist material mixed with refractive particles, and its refractive index is greater than or equal to 1.

6.

4. The preparation method according to claim 1, characterized in that, The temperature at which the intermediate structure of the microlens is heated is greater than or equal to 50 degrees Celsius and less than or equal to 100 degrees Celsius.

5. The preparation method according to claim 1, characterized in that, The thickness difference between the intermediate structures of two adjacent sub-microlenses is the same.

6. The preparation method according to claim 1, characterized in that, The sub-microlens intermediate structure includes a cylindrical first sub-microlens intermediate structure and other annular sub-microlens intermediate structures surrounding the first sub-microlens intermediate structure.

7. The preparation method according to claim 6, characterized in that, The difference in radius between the intermediate structures of two adjacent sub-microlenses is the same.

8. The preparation method according to claim 6, characterized in that, The intermediate structure between two adjacent sub-microlenses is seamlessly connected.

9. A privacy display panel, characterized in that, The privacy display panel includes A privacy display substrate includes multiple sub-pixels formed on a substrate, each sub-pixel having a light-emitting area; A microlens layer located on the light-emitting side of the display substrate, the microlens layer comprising microlens structures corresponding one-to-one with the light-emitting areas of each sub-pixel; The orthogonal projection of the microlens structure on the display substrate at least partially overlaps with the orthogonal projection of the corresponding sub-pixel light-emitting area on the display substrate, and the microlens layer is formed by the preparation method according to any one of claims 1-7; as well as A dimming layer located on the side of the microlens layer away from the display substrate has a refractive index lower than that of the microlens layer.

10. The privacy display panel according to claim 9, characterized in that, The microlens layer is made of a negative photoresist material mixed with refractive particles, and its refractive index is greater than or equal to 1.

6. The refractive index of the dimming layer is less than or equal to 1.

41.

11. A privacy display device, characterized in that, Includes the privacy display panel as described in any one of claims 9-10.

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