Quantum dot lens group, preparation method thereof, backlight module and display device

Abstract

The invention discloses a quantum dot lens group, a preparation method thereof, a backlight module and a display device, and belongs to the technical field of display. The invention discloses a preparation method of a quantum dot lens group. The preparation method comprises the following steps: providing photoresist mixed with quantum dots; and performing two-photon photoetching processing on the photoresist according to a preset target lens group structure to obtain the quantum dot lens group. According to the invention, the quantum dots are directly integrated in the lens structure of the lens group, and the contradiction between the light and thin requirements of equipment and the improvement of the optical performance is effectively overcome.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and in particular, to a quantum dot lens group, a preparation method thereof, a backlight module, and a display device. Background Art

[0002] With the popularization of LED (Light Emitting Diode) lighting technology, while traditional LED lamps provide efficient lighting, they also expose the problem of excessive blue light. As an emerging light-emitting material, quantum dot technology exhibits unique advantages. Quantum dots are nanoscale semiconductor materials that can generate visible light with a pure spectrum through photoluminescence or electroluminescence. Their quantum size effect and quantum confinement effect enable full-spectrum coverage from blue light to near-infrared by regulating the size of quantum dots, providing a new technical path for solving the LED blue light problem.

[0003] Generally, the application of quantum dots in optoelectronic devices mainly focuses on the preparation of quantum dot films or quantum dot plates. However, these solutions require an increase in the thickness of the backlight module, which is contrary to the trend of thinning of display devices, and also affects the overall aesthetics and portability of the device. Summary of the Invention

[0004] The main purpose of the present application is to provide a quantum dot lens group, a preparation method thereof, a backlight module, and a display device. The present application realizes the direct integration of quantum dots into the lens structure of the lens group, effectively overcoming the contradiction between the requirement of device thinning and the improvement of optical performance.

[0005] To achieve the above object, an embodiment of the present application provides a method for preparing a quantum dot lens group, including the following steps:

[0006] Provide a photoresist mixed with quantum dots;

[0007] According to a preset target lens group structure, perform two-photon lithography on the photoresist to obtain a quantum dot lens group.

[0008] In one embodiment, before the step of performing two-photon lithography on the photoresist according to the preset lens group structure, the method further includes:

[0009] Determine the target lens group structure according to preset optical performance parameters.

[0010] In one embodiment, the step of determining the target lens group structure according to the preset optical performance parameters includes:

[0011] Determine the actual input light field according to the light source information;

[0012] Determine the ideal output light field according to the optical performance parameters;

[0013] Determine the actual wavefront information according to the actual input light field, the simulated lens group structure, and the ray tracing function;

[0014] Determine the ideal wavefront information according to the ideal output light field, the simulated lens group structure, and the ray tracing function;

[0015] Determine the target lens group structure according to the actual wavefront information and the ideal wavefront information.

[0016] In one embodiment, the step of determining the target lens group structure according to the actual wavefront information and the ideal wavefront information includes:

[0017] Determine the objective function according to the difference between the actual wavefront information and the ideal wavefront information;

[0018] Dynamically adjust the simulated lens group structure until the objective function meets the preset error condition to obtain the target lens group structure.

[0019] In one embodiment, after the step of obtaining the quantum dot lens group, it further includes:

[0020] Prepare a water and oxygen barrier film on the light-emitting surface of at least one lens of the quantum dot lens group.

[0021] In one embodiment, the step of performing two-photon lithography on the photoresist according to the preset target lens group structure to obtain the quantum dot lens group includes:

[0022] Establish a lens group model corresponding to the target lens group structure;

[0023] Perform two-photon lithography on the photoresist according to the lens group model to obtain the quantum dot lens group.

[0024] In one embodiment, after the step of performing two-photon lithography on the photoresist, it further includes:

[0025] Remove the uncured photoresist through a developing process.

[0026] The embodiment of the present application further provides a quantum dot lens group, and the quantum dot lens group is obtained by the quantum dot lens group preparation method as described above.

[0027] In one embodiment, the quantum dot lens group includes at least one quantum dot lens, and the quantum dot lens includes: a resin layer, wherein the resin layer includes a plurality of embedded quantum dots.

[0028] In one embodiment, a water and oxygen barrier film is provided on the light-emitting surface of at least one quantum dot lens of the quantum dot lens group.

[0029] In one embodiment, multiple quantum dot lenses of the quantum dot lens group are combined through a bracket.

[0030] An embodiment of the present application further provides a backlight module, which includes a quantum dot lens group prepared by the method for preparing a quantum dot lens group as described above, or the quantum dot lens group as described above.

[0031] An embodiment of the present application further provides a display device, which includes a quantum dot lens group prepared by the method for preparing a quantum dot lens group as described above, or the quantum dot lens group as described above.

[0032] One or more technical solutions proposed in the embodiments of the present application have at least the following technical effects: providing a method for preparing a quantum dot lens group, performing two-photon lithography on a photoresist mixed with quantum dots through a preset target lens group structure to obtain a quantum dot lens group. The present application realizes the direct integration of quantum dots into the lens structure of the lens group through two-photon lithography technology, avoiding the problem of increased thickness of the backlight module caused by adding a quantum dot film and / or a quantum dot plate. At the same time, through two-photon lithography technology, high-precision processing can also be achieved, enabling flexible design and precise control of the shape structure and optical curvature of the quantum dot lens, meeting diverse beam shaping requirements, and effectively overcoming the contradiction between the requirements of device thinning and the improvement of optical performance. Description of the Drawings

[0033] Figure 1 It is a schematic flow chart of the method for preparing a quantum dot lens group according to the embodiment of the present application;

[0034] Figure 2 It is a schematic structure of the quantum dot lens group according to the embodiment of the present application Figure 1 ;

[0035] Figure 3 It is a schematic structure of the quantum dot lens group according to the embodiment of the present application Figure 2 ;

[0036] Figure 4 It is a schematic structure of the quantum dot lens group according to the embodiment of the present application Figure 3 ;

[0037] Figure 5 It is a schematic flow chart of a more complete embodiment of the method for preparing a quantum dot lens group according to the embodiment of the present application.

[0038] The realization, functional characteristics and advantages of the purpose of the present application will be further described with reference to the embodiments and the drawings.

[0039] Description of Reference Numerals

[0040] 10. Substrate; 20. Bracket; 21. First bracket; 22. Second bracket;

[0041] 30. Wafer; 40. Quantum dot lens; 401. First lens; 402. Second lens;

[0042] 41. Quantum dots; 42. Photoresist; 50. Water and oxygen barrier film. Detailed Implementation Modes

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. For those not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are followed. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0044] Hereinafter, the embodiments of the quantum dot lens group, its preparation method, backlight module, and display device of the present application are specifically disclosed with appropriate reference to the drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where the detailed descriptions of well-known matters and the repeated descriptions of actually identical structures are omitted. This is to prevent the following descriptions from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following descriptions are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter recited in the claims.

[0045] The "ranges" disclosed in this application are defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include or exclude the end values and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a specific parameter, ranges of 60 to 110 and 80 to 120 are also contemplated. In addition, if the minimum range values of 1 and 2 are listed, and if the maximum range values of 3, 4, and 5 are listed, the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise stated, the numerical range "a to b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0 to 5" means that all real numbers between "0 to 5" are fully listed herein, and "0 to 5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0046] If there is no special instruction, all embodiments and optional embodiments of this application can be combined with each other to form new technical solutions.

[0047] If there is no special instruction, all technical features and optional technical features of this application can be combined with each other to form new technical solutions.

[0048] If there is no special instruction, all steps of this application can be carried out sequentially or randomly, preferably sequentially. For example, if a method includes steps (a) and (b), it means that the method can include steps (a) and (b) carried out sequentially, or can also include steps (b) and (a) carried out sequentially. For example, if it is mentioned that the method may further include step (c), it means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c), or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0049] If there is no special instruction, the "including" and "comprising" mentioned in this application mean open-ended or can also be closed-ended. For example, "including" and "comprising" can mean that other components not listed can also be included or comprised, or can also mean only including or comprising the listed components.

[0050] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) while B is true (or exists); or both A and B are true (or exist).

[0051] To make the above objects, features, and advantages of this application more obvious and understandable, the technical solutions of this application will be further described below in conjunction with the accompanying drawings and embodiments. However, this application is not limited to the listed embodiments, and should also include any other well-known changes within the scope of the rights required by this application.

[0052] As used herein, the term "one embodiment" or "embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of this application. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or selectively exclusive embodiments from other embodiments.

[0053] To better understand the technical solutions of this application, the following will be described in detail in conjunction with the drawings of the specification and specific implementation manners.

[0054] In the conventional technology, the preparation methods of quantum dot lens arrays mainly include two schemes: one is the injection molding method, in which the colloid mixed with quantum dots is injected into the lens model, but this method is applicable to large-sized lenses and is difficult to meet the requirements of small display devices; the other is to coat the quantum dot film on the surface of the wafer or the lower surface of the lens, use blue light to excite the quantum dot film to generate white light, and then perform beam shaping through the lens. However, this scheme requires the collaborative use of the quantum dot film and the lens, and it is difficult to achieve precise control of the optical curvature only by the quantum dot material.

[0055] In the embodiments of this application, through a preset target lens array structure, two-photon lithography processing is performed on the photoresist mixed with quantum dots to obtain a quantum dot lens array. This application realizes the direct integration of quantum dots into the lens structure of the lens array through two-photon lithography technology, avoiding the problem of increased thickness of the backlight module caused by adding a quantum dot film and / or a quantum dot plate. At the same time, through two-photon lithography technology, high-precision processing can also be achieved, enabling flexible design and precise control of the shape structure and optical curvature of the quantum dot lens, meeting the diverse beam shaping requirements, and effectively overcoming the contradiction between the requirements of device thinning and the improvement of optical performance. By directly processing a micron-level quantum dot lens array on the surface of the wafer, blue light can directly excite the quantum dots in the quantum dot lens array to generate high-purity white light, thus replacing the long quantum plate or quantum film scheme and significantly improving the color gamut range and picture quality.

[0056] The first embodiment of the present application provides a method for preparing a quantum dot lens group. Refer to Figure 1 , which includes the following steps:

[0057] Step S10: Provide a photoresist mixed with quantum dots;

[0058] In a feasible embodiment, the quantum dots and the photoresist are uniformly mixed to obtain a photoresist mixed with quantum dots, which is used as the substrate for each lens in the quantum dot lens group.

[0059] Optionally, the quantum dots include: red light quantum dots and / or green light quantum dots.

[0060] Optionally, the quantum dots include at least one of II-VI group compounds (such as cadmium sulfide, cadmium selenide, cadmium telluride, zinc selenide, etc.), III-V group compounds (such as indium phosphide, indium arsenide, etc.), IV-VI group compounds (such as lead sulfide, lead selenide, etc.), and perovskite quantum dots (such as CsPbI3, etc.).

[0061] Optionally, the substrate of the photoresist includes at least one of IP-S photoresist, IP-DIP photoresist, zirconia hybrid photoresist, TP-EO cationic photoresist, acrylate photoresist, and epoxy resin photoresist.

[0062] Optionally, the substrate of the photoresist includes: IP-S photoresist and / or IP-DIP photoresist.

[0063] IP-S photoresist is a high-resolution photoresist designed for two-photon lithography. It can achieve high-precision 3D structure manufacturing at extremely small scales, with a resolution reaching the sub-micron level. It is suitable for manufacturing complex micro-nano structures such as microlenses and photonic crystals, and has high mechanical strength and stability after curing.

[0064] IP-DIP photoresist is a negative photoresist used for two-photon lithography. It forms a cross-linked structure after exposure, has high mechanical strength and thermal stability, is suitable for manufacturing 3D structures that require high stability and durability, and can maintain the structural integrity in a high-temperature environment.

[0065] Step S20: According to the preset target lens group structure, perform two-photon lithography on the photoresist to obtain a quantum dot lens group.

[0066] In a feasible embodiment, according to the preset target lens group structure, use two-photon lithography technology to perform lithography on the photoresist mixed with quantum dots to obtain a quantum dot lens group, where the quantum dot lens group includes at least one quantum dot lens.

[0067] Two-Photon Lithography (TPL) is a micro-nano processing technology based on nonlinear optical effects, which uses the Two-Photon Absorption (TPA) process to achieve the fabrication of high-precision three-dimensional micro-nano structures. Its core principle is that when a femtosecond laser is focused inside a photosensitive material, only at the focal point where the photon density is high enough can two-photon absorption be triggered, thereby triggering the polymerization reaction of the photosensitive material. This nonlinear effect enables two-photon lithography technology to achieve precise material processing at extremely small spatial scales, with high resolution, deep penetration depth, and true three-dimensional processing capabilities. Two-photon lithography technology can directly perform three-dimensional processing inside the material. By controlling the movement path of the laser focus, micro-nano structures of arbitrary shapes can be fabricated, including complex quantum dot lens arrays. By dynamically adjusting the laser power and focus position, the size and shape of voxels (volume pixels) can be precisely controlled, thereby achieving precise control of the optical curvature of the lens.

[0068] Exemplarily, referring to Figure 2 , the quantum dot lens array includes a quantum dot lens 40. A wafer 30 and a bracket 20 are arranged on one side surface of a substrate 10, and a photoresist 42 mixed with quantum dots 41 is arranged on one side surface of the wafer 30. According to the target lens array structure, the photoresist 42 is subjected to two-photon lithography treatment to obtain the quantum dot lens 40 in the quantum dot lens array.

[0069] It can be understood that a lens refers to a structure capable of beam shaping, such as various metasurface structures or phase masks. Therefore Figure 2 the lens shape shown is only a schematic diagram, and the actual lens shape can be adjusted according to requirements, which is not limited in this embodiment.

[0070] In a feasible implementation manner, in step S20, the step of subjecting the photoresist to two-photon lithography treatment according to a preset target lens array structure to obtain a quantum dot lens array includes:

[0071] Step S21, establishing a lens array model corresponding to the target lens array structure;

[0072] In a feasible embodiment, according to the target lens array structure, its corresponding lens array model is established.

[0073] Optionally, the target lens array structure may be the structural parameters corresponding to the target lens array. For example, it includes at least one of the lens surface height, radial coordinate, curvature, radius of curvature, conic constant, aspheric coefficient, the spacing between the lenses included in the lens array, and the relative position between the lenses.

[0074] Optionally, the target lens array structure is imported into three-dimensional modeling software to obtain the corresponding three-dimensional lens array model.

[0075] Step S22: According to the lens group model, perform two-photon lithography on the photoresist to obtain a quantum dot lens group.

[0076] In a feasible embodiment, according to the lens group model, determine the lithography path, and use two-photon lithography technology to perform lithography on the photoresist mixed with quantum dots based on the lithography path to obtain a quantum dot lens group.

[0077] Optionally, import the target lens group structure into 3D modeling software, export it as an STL (STereoLithography) format file, import the STL file into the corresponding software for layer slicing processing to generate a code program recognizable by the two-photon processing software, then set the exposure energy and scanning speed, and use a two-photon lithography machine to process quantum dot lenses on the surface of the photoresist mixed with quantum dots, so that the photoresist is formed during the processing to form a micron-scale quantum dot lens group with a complex curved surface structure.

[0078] Optionally, the quantum dot lens group includes at least one quantum dot lens, and the quantum dot lens includes: a resin layer, where the resin layer includes a plurality of embedded quantum dots. The resin layer is the functional layer formed by lithography of the photoresist.

[0079] In this embodiment, by establishing a lens group model, the shape, curvature, and other optical parameters of the lens can be accurately designed in a virtual environment to ensure that it meets specific optical performance requirements. During the modeling process, numerical simulation and optical theory can be combined to optimize the geometric structure of the lens and reduce errors in actual processing.

[0080] In a feasible implementation manner, after the step of performing two-photon lithography on the photoresist in step S20, it further includes:

[0081] Step S23: Remove the uncured photoresist through a developing process.

[0082] In a feasible embodiment, after performing two-photon lithography on the photoresist mixed with quantum dots, remove the uncured photoresist through a developing process to obtain a quantum dot lens group.

[0083] Optionally, the developing process is a key step in lithography technology, which is used to remove the uncured photoresist, so as to form the required three-dimensional pattern on the wafer surface. Its core principle is to dissolve a specific area of the photoresist (the exposed area of positive photoresist or the non-exposed area of negative photoresist) through the developer, and finally replicate the pattern on the mask plate onto the wafer.

[0084] In a feasible implementation manner, after the step of obtaining a quantum dot lens group in step S20, it further includes:

[0085] Step S30: Prepare a water and oxygen barrier film on the light-emitting surface of at least one lens of the quantum dot lens group.

[0086] In a feasible embodiment, a water and oxygen barrier film is prepared on the light-emitting surface of at least one lens of the quantum dot lens group, so as to effectively isolate the penetration of water and oxygen, prevent the oxidation or degradation of quantum dots, and at the same time keep the optical performance of the lens unaffected.

[0087] Optionally, spray a water and oxygen barrier film on the light-emitting surface of at least one lens of the quantum dot lens group.

[0088] Exemplarily, refer to Figure 3 , the quantum dot lens group includes a quantum dot lens 40. A wafer 30 and a bracket 20 are arranged on one side surface of the substrate 10, and a photoresist 42 mixed with quantum dots 41 is arranged on one side surface of the wafer 30. According to the target lens group structure, two-photon lithography processing is performed on the photoresist 42 to obtain the quantum dot lens 40 in the quantum dot lens group, and a water and oxygen barrier film 50 is prepared on the light-emitting surface of the quantum dot lens 40, so as to effectively isolate the penetration of water and oxygen, prevent the oxidation or degradation of the quantum dots 41, and at the same time keep the optical performance of the quantum dot lens 40 unaffected.

[0089] Exemplarily, for application scenarios that require higher light type control accuracy, a second lens structure can be introduced in the optical simulation to form a lens group together with the first lens. Refer to Figure 4, the quantum dot lens group includes a first lens 401 and a second lens 402, and the arrow direction represents the light propagation direction. During the preparation of the quantum dot lens group, a wafer 30 and a first bracket 21 can be arranged on one side surface of the substrate 10, and a photoresist 42 mixed with quantum dots 41 can be arranged on one side surface of the wafer 30. According to the target lens group structure, the photoresist 42 is subjected to two-photon lithography to obtain the first lens 401 in the quantum dot lens group, and a water and oxygen barrier film 50 is prepared on the light-emitting surface of the first lens 401, so as to effectively isolate the penetration of water and oxygen, prevent the oxidation or degradation of the quantum dots 41, and at the same time keep the optical performance of the quantum dot lens 40 unaffected. Further, a second bracket 22 is arranged on the light-emitting side of the first lens 401, and a photoresist 42 mixed with quantum dots 41 is arranged on the light-emitting side of the second bracket 22. According to the target lens group structure, the photoresist 42 is subjected to two-photon lithography to obtain the second lens 402 in the quantum dot lens group, and a water and oxygen barrier film 50 is prepared on the light-emitting surface of the second lens 402. By arranging multiple lenses in the quantum dot lens group, the light can be shaped more finely. For example, the first lens 401 can initially focus or scatter the light, and the second lens 402 can further adjust the shape and direction of the light beam to make it more meet the requirements of specific applications. By reasonably designing the parameters of the two lenses (such as curvature, thickness, material refractive index, etc.), the brightness distribution of the outgoing light spot can be made more uniform and meet the requirements of complex optical performance.

[0090] Optionally, according to the requirements of beam shaping, the number of lenses in the quantum dot lens group is not limited to two, and multiple lenses can be combined and processed above the wafer.

[0091] In this embodiment, through the preset target lens group structure, the photoresist mixed with quantum dots is subjected to two-photon lithography to prepare a quantum dot lens group. The present application realizes the direct integration of quantum dots into the lens structure of the lens group through two-photon lithography technology, avoiding the problem of increased thickness of the backlight module caused by adding a quantum dot film and / or a quantum dot plate. At the same time, through two-photon lithography technology, high-precision processing can also be achieved, flexible design can be realized, and the shape structure and optical curvature of the quantum dot lens can be precisely controlled to meet the diverse beam shaping requirements, effectively overcoming the contradiction between the requirements of device thinning and the improvement of optical performance. By directly processing a micron-level quantum dot lens group on the wafer surface, blue light can directly excite the quantum dots in the quantum dot lens group to generate high-purity white light, thus replacing the long quantum dot plate or quantum dot film solution, and significantly improving the color gamut range and picture quality.

[0092] Based on the above first embodiment, a second embodiment of the preparation method of the quantum dot lens group of the present application is proposed. In this embodiment, before the step S20 of performing two-photon lithography on the photoresist according to the preset lens group structure, the following steps are further included:

[0093] Step S11, determine the target lens group structure according to the preset optical performance parameters.

[0094] In a feasible embodiment, simulate according to the preset optical performance parameters to determine the target lens group structure.

[0095] Optionally, the optical performance parameters can be the target optical performance parameters of the quantum dot lens group. For example, they include: divergence angle, illumination height, light intensity distribution, etc.

[0096] Optionally, based on the optical performance parameters, modeling and optimization can be carried out through optical simulation software, and finally the specific structural parameters of the lens group are determined.

[0097] In a feasible implementation manner, step S11, the step of determining the target lens group structure according to the preset optical performance parameters includes:

[0098] Step S111, determine the actual input light field according to the light source information;

[0099] In a feasible embodiment, determine the actual input light field according to the light source information, where the input light field refers to the intensity, phase and direction distribution of light before entering the lens or other optical elements. It contains all the information of light before entering the optical system, including the wavelength, polarization state, light intensity distribution and the direction of light rays, etc.

[0100] Optionally, a near-field distribution photometer can be used to measure the luminous surface characteristics map of the light source (such as an LED wafer), obtain the brightness and chromaticity distribution maps of the light source at different angles, and convert them into the light ray distribution information of the light source as the actual input light field.

[0101] Step S112, determine the ideal output light field according to the optical performance parameters;

[0102] In a feasible embodiment, determine the ideal output light field according to the optical performance parameters of the quantum dot lens group, where the output light field refers to the intensity, phase and direction distribution of light formed at the output end of the optical system after being processed by the lens or other optical elements. It is the result of the modulation of the input light field by the optical system (such as a lens), and contains information such as the light intensity distribution, phase change and the direction of light rays after passing through the lens.

[0103] Optionally, according to the optical performance parameters, determine the light intensity distribution map at the specified position on the output surface as the ideal output light field.

[0104] Step S113, determine the actual wavefront information according to the actual input light field, the simulated lens group structure and the ray tracing function;

[0105] In a feasible embodiment, according to the actual input light field, the simulated lens group structure, and the ray tracing function, the actual wavefront information is determined, where the actual wavefront refers to the actual distribution of light rays in space after passing through the quantum dot lens group. It is formed by the refraction and focusing effects of the actual input light field through the lens. Therefore, the shape and distribution of the actual wavefront depend on the optical characteristics of the lens, such as parameters like curvature and aspheric coefficient, while the ray tracing function simulates the propagation path and wavefront distribution of light rays starting from the light source and passing through the lens.

[0106] Optionally, the input light field propagates forward using the ray tracing function and reaches the position of the quantum dot lens to obtain the actual wavefront information.

[0107] Optionally, a simulated lens group structure can be preset and simulated by adjusting the simulated lens group structure to obtain a target lens group structure that meets the optical performance parameters.

[0108] Optionally, the lens in the simulated lens group structure can be selected as an aspheric lens, and the formula for its structure-related parameters is:

[0109]

[0110] where z(r) is the lens surface height; is the radial coordinate; c is the curvature, (c = 1 / R, R is the radius of curvature); k is the conic constant; W i is the aspheric coefficient.

[0111] Step S114, according to the ideal output light field, the simulated lens group structure, and the ray tracing function, determine the ideal wavefront information;

[0112] In a feasible embodiment, according to the ideal output light field, the simulated lens group structure, and the ray tracing function, the ideal wavefront information is determined, where the ideal wavefront information is the information on the propagation state that light rays should have on the lens surface assuming no machining errors, uniform material, and perfection of the lens. It reflects the performance of the optical system under ideal conditions.

[0113] Optionally, the output light field propagates backward using the ray tracing function and reaches the position of the quantum dot lens to obtain the ideal wavefront information.

[0114] Step S115, according to the actual wavefront information and the ideal wavefront information, determine the target lens group structure.

[0115] In a feasible embodiment, during the lens design process, the goal is to make the actual wavefront as close as possible to the ideal wavefront. Therefore, based on the actual wavefront information and the ideal wavefront information, the simulated lens group structure can be dynamically adjusted to obtain the target lens group structure.

[0116] In a feasible implementation manner, in step S115, the step of determining the target lens group structure according to the actual wavefront information and the ideal wavefront information includes:

[0117] Step A10, determining an objective function according to the difference between the actual wavefront information and the ideal wavefront information;

[0118] Step A20, dynamically adjusting the simulated lens group structure until the objective function meets a preset error condition, and obtaining the target lens group structure.

[0119] In a feasible embodiment, an objective function is determined according to the difference between the actual wavefront information and the ideal wavefront information, and then by dynamically adjusting the parameters corresponding to the simulated lens group structure, the objective function meets the preset error condition, where the error condition can represent the error that the difference between the actual wavefront information and the ideal wavefront information needs to meet, and then the target lens group structure is obtained.

[0120] Optionally, the actual wavefront A i and the ideal wavefront B i can be obtained at the quantum dot lens position through the optical path difference formula, and the difference OPD between them is:

[0121] OPD(x,y) = A i (x,y) - B i (x,y)

[0122] where (x, y) represents the coordinates corresponding to the quantum dot lens position; and then the root mean square error is used as the objective function RMS:

[0123]

[0124] Furthermore, the gradient descent method can be used to continuously and dynamically adjust the parameters corresponding to the simulated lens group structure, such as lens curvature, aspheric coefficient, etc., so that the actual wavefront and the target wavefront are as matched as possible according to the following formula:

[0125] A i (x,y) = B i (x,y) + ε

[0126] where ε is the allowable error range, and a suitable value can be selected and substituted.

[0127] Optionally, to assist in understanding the above technical solution, the following uses a relatively complete embodiment of this application for illustration, referring to Figure 5, Step B10: Mix quantum dots with photoresist to obtain photoresist mixed with quantum dots; Step B20: Determine the target lens group structure according to the target optical performance parameters; Step B30: Establish a lens group model corresponding to the lens group structure; Step B40: Convert the lens group model into a code program recognizable by two-photon processing software; Step B50: Use two-photon photoresist to process the photoresist mixed with quantum dots; Step B60: Remove the uncured photoresist through development to obtain a quantum dot lens group; Step B70: Prepare a water and oxygen barrier film to prevent the oxidation or degradation of quantum dots while keeping the optical performance of the lens unaffected.

[0128] In this embodiment, through the above simulation method, the shape, curvature, and other optical parameters of the lens can be accurately designed in a virtual environment to ensure that it meets specific optical performance requirements and reduce errors in actual processing.

[0129] The third embodiment of the present application also provides a quantum dot lens group, which is obtained by the quantum dot lens group preparation method as described above.

[0130] Optionally, referring to Figure 2 , the quantum dot lens group includes at least one quantum dot lens 40, and the quantum dot lens 40 includes: a resin layer composed of photoresist 42, and the resin layer includes a plurality of embedded quantum dots 41.

[0131] Optionally, the resin layer is a kind of photolithography layer, that is, a functional layer obtained by two-photon lithography technology. Two-photon lithography technology can also achieve high-precision processing, realize flexible design, and can accurately control the shape structure and optical curvature of the quantum dot lens to meet diverse beam shaping requirements, effectively overcoming the contradiction between the requirements of device thinning and the improvement of optical performance.

[0132] Optionally, a water and oxygen barrier film is provided on the light-emitting surface of at least one quantum dot lens of the quantum dot lens group. Through the setting of the water and oxygen barrier film, the penetration of water and oxygen is effectively isolated, preventing the oxidation or degradation of quantum dots while keeping the optical performance of the lens unaffected.

[0133] Optionally, multiple quantum dot lenses of the quantum dot lens group are combined through a bracket.

[0134] Exemplarily, referring to Figure 4 , the quantum dot lens group includes a first lens 401 and a second lens 402, and the second lens 402 is disposed on the light-emitting side of a second bracket 22 on the light-emitting side of the first lens 401. The combination of multiple lenses is realized through the bracket, so that the light can be shaped more finely; and by reasonably designing the parameters of the two lenses (such as curvature, thickness, material refractive index, etc.), the brightness distribution of the outgoing light spot can be made more uniform and meet complex optical performance requirements.

[0135] The beneficial effects of the quantum dot lens group provided by the embodiments of the present application are the same as those of the quantum dot lens group preparation method provided by the above embodiments, and other technical features in the quantum dot lens group are the same as those disclosed in the above embodiment method, which will not be elaborated here.

[0136] The fourth embodiment of the present application also provides a backlight module, including a quantum dot lens group prepared by the quantum dot lens group preparation method as described above.

[0137] The beneficial effects of the backlight module provided by the embodiments of the present application are the same as those of the quantum dot lens group preparation method provided by the above embodiments, and other technical features in the backlight module are the same as those disclosed in the above embodiment method, which will not be elaborated here.

[0138] The fifth embodiment of the present application also provides a display device, including a quantum dot lens group prepared by the quantum dot lens group preparation method as described above.

[0139] The beneficial effects of the display device provided by the embodiments of the present application are the same as those of the quantum dot lens group preparation method provided by the above embodiments, and other technical features in the display device are the same as those disclosed in the above embodiment method, which will not be elaborated here.

[0140] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the patent protection scope of the present application.

Claims

1. A method for preparing a quantum dot lens assembly, characterized in that: The method comprises the following steps: providing a photoresist mixed with quantum dots; According to the preset target lens group structure, the photoresist is subjected to two-photon lithography processing to obtain a quantum dot lens group.

2. The method for preparing a quantum dot lens assembly according to claim 1, characterized in that: Before the step of performing two-photon lithography on the photoresist according to the preset lens group structure, the method further includes: The target lens group structure is determined according to preset optical performance parameters.

3. The method for preparing a quantum dot lens assembly according to claim 2, characterized in that: The step of determining the target lens group structure according to the preset optical performance parameters comprises: Determine the actual input light field according to the light source information; Determining an ideal output light field according to the optical performance parameters; Determining actual wavefront information according to the actual input light field, the simulated lens group structure and the ray tracing function; Determining ideal wavefront information according to the ideal output light field, the simulated lens group structure and the ray tracing function; The target lens group structure is determined according to the actual wavefront information and the ideal wavefront information.

4. The method for preparing a quantum dot lens assembly according to claim 3, characterized in that: The step of determining the target lens group structure according to the actual wavefront information and the ideal wavefront information comprises: Determining an objective function according to a difference between the actual wavefront information and the ideal wavefront information; The simulated lens group structure is dynamically adjusted until the objective function meets a preset error condition to obtain the target lens group structure.

5. The method for preparing a quantum dot lens assembly according to claim 1, characterized in that: The step of performing two-photon lithography on the photoresist according to the preset target lens group structure to obtain the quantum dot lens group comprises: Establishing a lens group model corresponding to the target lens group structure; According to the lens group model, the photoresist is subjected to two-photon lithography processing to obtain the quantum dot lens group.

6. A quantum dot lens assembly, characterized in that: The quantum dot lens group is prepared by the method for preparing a quantum dot lens group according to any one of claims 1 to 5.

7. The quantum dot lens assembly according to claim 6, characterized in that: The quantum dot lens group includes at least one quantum dot lens, and the quantum dot lens includes: a resin layer, wherein the resin layer includes a plurality of embedded quantum dots.

8. The quantum dot lens assembly according to claim 6, characterized in that: A water and oxygen barrier film is provided on the light-emitting surface of at least one quantum dot lens of the quantum dot lens group.

9. The quantum dot lens assembly according to claim 6, characterized in that: The multiple quantum dot lenses in the quantum dot lens group are combined by a bracket.

10. A backlight module, characterized in that: The backlight module comprises a quantum dot lens group manufactured by the method for manufacturing a quantum dot lens group as claimed in any one of claims 1 to 5, or a quantum dot lens group as claimed in any one of claims 6 to 9.

11. A display device, characterized in that: The display device comprises a quantum dot lens group manufactured by the method for manufacturing a quantum dot lens group as claimed in any one of claims 1 to 5, or a quantum dot lens group as claimed in any one of claims 6 to 9.

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