Preparation method of liquid crystal dual-mode dual-channel imaging lens

Abstract

The method is mainly applied to the technical field of optical device preparation. The invention discloses a preparation method of a liquid crystal dual-mode dual-channel imaging lens. The preparation method comprises the following steps: acquiring a phase pattern, and dividing the phase pattern into a plurality of sub-patterns; two matched transparent substrates are obtained, the surfaces of the two transparent substrates are spin-coated with a photo-alignment agent to form an alignment layer, and the two transparent substrates are packaged in a face-to-face mode to form a liquid crystal box with a hollow cavity; the liquid crystal box is placed on a platform deck capable of moving horizontally, a spatial light modulator is combined with a polarization ultraviolet light source, the platform deck is moved to conduct exposure on phase areas in all the sub-patterns one by one, and therefore a continuous phase orientation structure is formed on the working face of the liquid crystal box in a mask photoetching mode; after exposure is completed, filling the liquid crystal box with a filler of a liquid crystal material; and packaging the filled liquid crystal box to obtain the liquid crystal dual-mode dual-channel imaging lens. Limitation of a traditional liquid crystal imaging device preparation process is broken through, and the liquid crystal dual-mode dual-channel imaging lens is efficiently prepared with high precision.

Description

Technical Field

[0001] This invention relates to the field of optical device fabrication technology, specifically to a method for fabricating a liquid crystal dual-mode dual-channel imaging lens. Background Technology

[0002] Liquid crystal imaging devices, with their advantages of fast electro-optical response, low power consumption, and programmable control, have become core components in fields such as spatial light modulation, dynamic holography, and adaptive optics. Their core function relies on the precise control of the spatial orientation of liquid crystal molecules to construct a phase distribution that meets specific wavefront modulation requirements. Existing fabrication techniques mainly revolve around the processing of the alignment layer, with typical methods including mechanical triboelectric alignment and optically controlled alignment.

[0003] It is worth noting that although microstructure metasurface devices can achieve high-precision phase structures through electron beam lithography, their reliance on rigid substrates makes them incompatible with the electrically tunable characteristics of liquid crystals. Furthermore, the vacuum environment and point-by-point exposure mechanism of electron beam lithography also face bottlenecks such as low efficiency and high cost in large-area fabrication. In summary, the fabrication process of traditional liquid crystal imaging devices presents a fundamental contradiction between large-size working surfaces and high-resolution complex orientation distributions: either area is sacrificed to maintain accuracy, or accuracy is sacrificed for efficiency. It is impossible to efficiently and accurately fabricate micro / nano phase structures with complex, high-resolution, multi-order polarization orientation distributions on the centimeter-scale working surface of a single device, severely hindering the practical application of liquid crystal dual-mode imaging devices. Summary of the Invention

[0004] This invention provides a method for fabricating a liquid crystal dual-mode dual-channel imaging lens, which breaks through the limitations of traditional liquid crystal imaging device fabrication processes and fabricates a liquid crystal dual-mode dual-channel imaging lens with high efficiency and high precision.

[0005] This invention provides a method for fabricating a liquid crystal dual-mode dual-channel imaging lens, the method comprising: Obtain a phase pattern and divide the phase pattern into multiple sub-patterns; Two matching transparent substrates are obtained, a photo-aligning agent is spin-coated on the surfaces of the two transparent substrates to form an alignment layer, and the two transparent substrates are encapsulated face to face to form a liquid crystal cell with a hollow cavity. The liquid crystal cell is placed on a movable stage, and a spatial light modulator is used in combination with a polarized ultraviolet light source. The stage is moved to expose the phase regions in each sub-pattern one by one, thereby forming a continuous phase alignment structure on the working surface of the liquid crystal cell by photomask lithography. After exposure, the liquid crystal material is filled into the liquid crystal cell; The filled liquid crystal cell is then encapsulated to obtain a liquid crystal dual-mode dual-channel imaging lens.

[0006] Optionally, the step of obtaining two matching transparent substrates, spin-coating a photo-alignment agent onto the surfaces of the two transparent substrates to form an alignment layer, and encapsulating the two transparent substrates face-to-face to form a liquid crystal cell with a hollow cavity includes: A conductive layer is formed by coating the surfaces of the two transparent substrates respectively; The transparent substrate coated with the conductive layer is cleaned and dried. After cleaning and drying, a photo-aligning agent is coated onto the conductive layer of each transparent substrate and then heat-treated to form an alignment layer. Spacers are sprayed onto the alignment layer, and then two substrates are aligned, bonded, and encapsulated to form the liquid crystal cell, wherein a hollow cavity with a predetermined thickness and size is formed inside the liquid crystal cell.

[0007] Optionally, the conductive layer is an indium tin oxide conductive layer.

[0008] Optionally, the cleaning and drying process of the transparent substrate coated with the conductive layer includes: The transparent substrate covered with the conductive layer was ultrasonically cleaned sequentially with deionized water, ethanol and acetone, with each cleaning session lasting 15 minutes. The cleaned substrate was then dried at 120°C for 30 minutes.

[0009] Optionally, specific embodiments of coating a photo-alignment agent onto the conductive layer of each of the transparent substrates and forming an alignment layer through heat treatment include: A photo-aligning agent in solution is spin-coated onto the substrate surface, wherein the photo-aligning agent in solution is a mixed solution of a photo-aligning agent and dimethylformamide as a solvent; The coated substrate was then heated at 110°C for 5 minutes to evaporate the solvent in the mixed solution and form a uniform alignment layer.

[0010] Optionally, the spacer is a spherical spacer with a diameter of 4 μm.

[0011] Optionally, acquiring the phase pattern and dividing the phase pattern into multiple sub-patterns includes: The phase pattern is divided into pixel arrays to form multiple sub-patterns of the same size; Each sub-pattern is divided into multiple orientation steps, and each orientation step has a mapping relationship with the target polarization orientation angle; For each of the sub-patterns, an exposure pattern corresponding to each of the orientation steps is generated, wherein the exposure pattern is used to guide the formation of a continuously distributed phase structure during the exposure process.

[0012] Optionally, the exposure process, in which the liquid crystal cell is placed on a movable stage and an exposure region in each sub-pattern is performed one by one by using a spatial light modulator combined with a polarized ultraviolet light source, includes: A digital micromirror device is used as a spatial light modulator, and a dynamic exposure pattern corresponding to the orientation order in each of the sub-patterns is generated through the spatial light modulator. The stage is controlled to translate along at least two orthogonal directions by a predetermined step size, so that the exposure area of ​​the liquid crystal cell is sequentially aligned with the position corresponding to each sub-pattern; For each of the sub-patterns, linearly polarized ultraviolet light of a predetermined wavelength is used as the light source to expose each of the orientation steps for a predetermined time, so as to use the light-controlled orientation reaction to write the preset phase information into the orientation layer.

[0013] The present invention has at least the following beneficial effects: This technical solution overcomes the limitations of traditional liquid crystal imaging devices through an innovative fabrication process. First, the phase pattern is divided into sub-patterns, and point-by-point exposure using a translational stage and spatial light modulator combined with a polarized ultraviolet light source achieves high-precision phase alignment structure fabrication, solving the problem of precise phase alignment control in traditional processes. Second, a hollow cavity is formed by face-to-face encapsulation of a transparent substrate, followed by filling and encapsulation with liquid crystal material, avoiding problems such as uneven liquid crystal material filling or contamination in traditional processes, thus improving fabrication efficiency and product quality. Then, through mask lithography and stage movement techniques, seamless large-size phase imaging is achieved, meeting the requirements of microscopic imaging for fully receiving low-frequency information from the Fourier plane. Overall, this method achieves efficient and high-precision fabrication of a liquid crystal dual-mode dual-channel imaging lens, improving imaging quality and device performance. Attached Figure Description

[0014] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0015] Figure 1 This is a flowchart of the fabrication process of a liquid crystal dual-mode dual-channel imaging lens; Figure 2 This is a flowchart of step S101 in the fabrication method of a liquid crystal dual-mode dual-channel imaging lens; Figure 3 This is a flowchart of step S102 in the fabrication method of a liquid crystal dual-mode dual-channel imaging lens; Figure 4 This is a flowchart of the exposure process in the fabrication method of a liquid crystal dual-mode dual-channel imaging lens; Figure 5This is a schematic diagram illustrating the fabrication process of a liquid crystal dual-mode dual-channel imaging lens. Figure 6 This is a schematic diagram of the splicing method for manufacturing large-area liquid crystal dual-mode dual-channel imaging lenses using a splicing photolithography process; Figure 7 This is a schematic diagram of the phase structure of a liquid crystal dual-mode dual-channel imaging lens under a cross polarizer, as observed by a polarizing microscope. Figure 8 This is a schematic diagram of the phase structure of a liquid crystal dual-mode dual-channel imaging lens under a parallel polarizer, as observed by a polarization microscope. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0017] Please refer to Figure 1 , Figure 1 This is a flowchart of the fabrication process of a liquid crystal dual-mode dual-channel imaging lens.

[0018] This embodiment provides a method for fabricating a liquid crystal dual-mode dual-channel imaging lens, including: S101. Obtain the phase pattern and divide the phase pattern into multiple sub-patterns.

[0019] S102. Obtain two matching transparent substrates, spin-coat a photo-alignment agent on the surfaces of the two transparent substrates to form an alignment layer, and encapsulate the two transparent substrates face to face to form a liquid crystal cell with a hollow cavity.

[0020] S103. The liquid crystal cell is placed on a movable stage. A spatial light modulator is used in combination with a polarized ultraviolet light source. The stage is moved to expose the phase regions in each sub-pattern one by one, thereby forming a continuous phase alignment structure on the working surface of the liquid crystal cell by photomask lithography.

[0021] S104. After exposure, fill the liquid crystal cell with liquid crystal material.

[0022] S105. The filled liquid crystal cell is encapsulated to obtain a liquid crystal dual-mode dual-channel imaging lens.

[0023] It is understood that the fabrication method in this embodiment mainly includes three key steps: phase design and segmentation, liquid crystal cell substrate fabrication, and light-controlled alignment exposure. This innovative fabrication process overcomes the limitations of traditional liquid crystal imaging devices. First, the phase pattern is divided into sub-patterns, and a translational stage and spatial light modulator are used in conjunction with a polarized ultraviolet light source for point-by-point exposure, achieving high-precision phase alignment structure fabrication and solving the problem of precise phase alignment control in traditional processes. Second, a hollow cavity is formed by face-to-face encapsulation of a transparent substrate, followed by filling and encapsulation with liquid crystal material. This avoids problems such as uneven liquid crystal material filling or contamination in traditional processes, improving fabrication efficiency and product quality. Overall, this method achieves efficient and high-precision fabrication of a liquid crystal dual-mode dual-channel imaging lens, improving imaging quality and device performance, and ensuring a large device size (12.2472 mm × 12.2472 mm) and high precision (3.78 μm × 3.78 μm pixels).

[0024] Please refer to Figure 2 , Figure 2 This is a flowchart of step S101 in a method for fabricating a liquid crystal dual-mode dual-channel imaging lens.

[0025] In some embodiments, step S101 includes: S201. Divide the phase pattern into pixel arrays to form multiple sub-patterns of the same size.

[0026] S202. Each sub-pattern is divided into multiple orientation steps, and each orientation step has a mapping relationship with the target polarization orientation angle.

[0027] S203. For each sub-pattern, generate an exposure pattern corresponding to each orientation level, wherein the exposure pattern is used to guide the formation of a continuously distributed phase structure during the exposure process.

[0028] In some embodiments, the phase pattern has 3240×3240 pixels, and the phase pattern is divided into 9 sub-phases of 4.0824 mm×4.0824 mm. Each sub-phase is divided into 36 orders (each order has a 5° polarization orientation angle). An exposure pattern is generated by a digital micromirror device (DMD) to ensure seamless stitching of large-size phases.

[0029] Understandably, this embodiment refines the exposure process by dividing the phase pattern into sub-patterns of equal size according to the pixel array and further dividing it into multiple orientation steps, with each orientation step mapped to the target polarization orientation angle. The generated exposure pattern can precisely guide the formation of a continuously distributed phase structure, effectively improving the uniformity and accuracy of the phase structure. This improvement significantly enhances the optical performance of the imaging lens, achieves higher-precision phase control, further overcomes the limitations of traditional fabrication processes, and improves imaging quality and device performance.

[0030] Please refer to Figure 3 , Figure 3 This is a flowchart of step S102 in the fabrication method of a liquid crystal dual-mode dual-channel imaging lens.

[0031] In some embodiments, step S102 includes: S301. Coating the surfaces of the two transparent substrates respectively to form a conductive layer.

[0032] S302. Clean and dry the transparent substrate covered with the conductive layer.

[0033] S303. After cleaning and drying, a photo-alignment agent is coated onto the conductive layer of each transparent substrate and then heat-treated to form an alignment layer.

[0034] S304. A spacer is sprayed onto the alignment layer, and then the two substrates are aligned, bonded, and encapsulated into a liquid crystal cell, forming a hollow cavity with a predetermined thickness and size inside the liquid crystal cell.

[0035] Understandably, this embodiment ensures a clean substrate surface and good conductivity by coating a conductive layer onto the transparent substrate and then cleaning and drying it, providing a stable foundation for subsequent processes. Coating a photo-alignment agent onto the conductive layer and then heat-treating it to form an alignment layer allows for precise control of the liquid crystal molecule orientation, improving image quality. Spraying a spacer followed by alignment and encapsulation precisely controls the thickness and dimensions of the liquid crystal cell, ensuring the uniformity and stability of the hollow cavity. These improvements significantly enhance the fabrication precision and reliability of the liquid crystal cell, further improving the performance and quality of the liquid crystal dual-mode dual-channel imaging lens and strengthening its application advantages in high-precision imaging.

[0036] In some embodiments, the conductive layer is an indium tin oxide conductive layer.

[0037] In some embodiments, the spacer is a spherical spacer with a diameter of 4 μm.

[0038] In some embodiments, step S302 includes: The transparent substrate with the conductive layer was ultrasonically cleaned sequentially with deionized water, ethanol and acetone, with each cleaning lasting 15 minutes; the cleaned substrate was then dried at 120°C for 30 minutes.

[0039] In some embodiments, the specific implementation of coating a photo-alignment agent onto the conductive layer of each transparent substrate and then heat-treating it to form an alignment layer includes: A photo-aligning agent in solution is spin-coated onto the substrate surface. The photo-aligning agent in solution is a mixture of a photo-aligning agent and dimethylformamide as a solvent. The coated substrate is then heated at 110°C for 5 minutes to evaporate the solvent in the mixture and form a uniform alignment layer.

[0040] In some embodiments, the spin coating method specifically involves preparing a 0.5 wt% SD1 alignment agent solution (the solvent being dimethylformamide DMF) and spin coating it onto the ITO glass surface at a rotation speed of 2500 r / min.

[0041] Please refer to Figure 4 , Figure 4 This is a flowchart of the exposure process in the fabrication method of a liquid crystal dual-mode dual-channel imaging lens.

[0042] In some embodiments, the exposure process, in which the liquid crystal cell is placed on a movable stage and a spatial light modulator is used in conjunction with a polarized ultraviolet light source to expose the phase regions in each sub-pattern one by one by moving the stage, includes: S401. A digital micromirror device is used as a spatial light modulator, and a dynamic exposure pattern corresponding to the orientation level in each sub-pattern is generated through the spatial light modulator.

[0043] S402. Control the stage to translate along at least two orthogonal directions in predetermined steps, so that the exposure area of ​​the liquid crystal cell is sequentially aligned with the position corresponding to each sub-pattern.

[0044] S403. For each sub-pattern, linearly polarized ultraviolet light of a predetermined wavelength is used as the light source to expose each orientation step for a predetermined time, so as to use the light-controlled orientation reaction to write the preset phase information into the orientation layer.

[0045] In some embodiments, DMD maskless lithography is used to expose nine sub-phases sequentially with 405 nm linearly polarized ultraviolet light: the displacement stage is translated along the x and y axes (step size 4.0824 mm), and each exposure lasts for 30 seconds. The liquid crystal molecules are guided to align according to the design orientation through photochemical reaction, and the triple phase information is written into the alignment layer.

[0046] Optionally, the light-controlled orientation exposure adopts a step-by-step alignment strategy: the size of a single micromirror in the DMD is 7.56 μm × 7.56 μm, and the exposure pattern is projected onto the liquid crystal surface through a 2× magnification imaging system, so that the actual pixel size matches the design value of 3.78 μm × 3.78 μm, thereby improving phase accuracy.

[0047] Understandably, in this embodiment, a digital micromirror device is used as a spatial light modulator, which can dynamically generate exposure patterns corresponding to the orientation steps in the sub-patterns, achieving precise phase information writing. By controlling the stage to translate along orthogonal directions, the exposure areas of each sub-pattern are ensured to be precisely aligned sequentially, avoiding errors associated with traditional exposure methods. Each orientation step is exposed using linearly polarized ultraviolet light of a predetermined wavelength, combined with photo-controlled orientation reactions, achieving efficient and high-precision phase structure fabrication. These improvements significantly enhance the optical performance of the imaging lens, further breaking through the limitations of traditional processes, and improving imaging quality and device reliability.

[0048] Please refer to Figure 5 , Figure 5 This is a schematic diagram illustrating the fabrication process of a liquid crystal dual-mode dual-channel imaging lens.

[0049] like Figure 5 As shown, this scheme also provides an embodiment of another method for fabricating a liquid crystal dual-mode dual-channel imaging lens. In this embodiment, two clean ITO conductive glasses are first prepared. A 0.5% wt SD1 mixed solution (using dimethylformamide DMF as solvent) is spin-coated onto the upper surfaces of the two glasses at a speed of 2500 r / min. The glasses are then placed on a heating stage at 110°C for 5 min to evaporate the solvent and form an SD1 film. For one of the glasses spin-coated with SD1, a 4 μm spacer is uniformly sprayed onto the surface, and then the two glasses are rapidly face-to-face encapsulated. In the experiment, the designed phase is exposed using a DMD digital mask lithography system. The size of a single pixel projected by the DMD chip is 3.78 μm. Since the pixel size of the phase is 3240×3240, the exposed phase area is a square with a side length of 12.2472 mm. The phase is divided into 9 parts, each part starting from... arrive To ensure uniformity, the image is divided into 36 steps, each part being a square, with a designed phase side length of 4.0824 mm for each image. A polarization angle of 5 degrees is applied to each step, and the exposure time for each image is 20 seconds. After the final exposure, E7 liquid crystal material is filled into the oriented liquid crystal cell, and the two sides are sealed with adhesive to complete the fabrication.

[0050] Please refer to Figure 6 , Figure 6This is a schematic diagram of the splicing method for manufacturing large-area liquid crystal dual-mode dual-channel imaging lenses using a splicing photolithography process.

[0051] like Figure 6 As shown, the liquid crystal dual-mode imaging lens has a focal length of 100 mm, physical dimensions of 12.2472 mm × 12.2472 mm, and an exposure resolution of 3240 × 3240 pixels. The unit size of each light-aligned LC pixel is 3.78 μm × 3.78 μm. In the experiment, the resolution of the digital mask lithography system was 1920 × 1080, and the size of each micromirror was 7.56 μm × 7.56 μm. Accordingly, the exposure mode corresponding to the liquid crystal dual-mode imaging lens was divided into a 3 × 3 array of 9 sub-regions, each with a resolution of 1080 × 1080 pixels. The phases of each part were stitched together by translating along the x and y axes using a stage, and then sequentially loaded onto the DMD digital mask lithography system for step-by-step exposure.

[0052] Please refer to Figure 7 , 8 The phase structure of the liquid crystal dual-mode dual-channel imaging lens prepared by the above-described method, observed under a polarization microscope with a cross polarizer, is as follows: Figure 7 As shown, the phase structure observed under a parallel polarizer is as follows: Figure 8 As shown. Figure 7 and Figure 8 The structural details of the liquid crystal dual-mode imaging lens are shown, observed using a polarizing microscope under crossed and parallel polarizing filters. At 10x magnification, the phase details of the liquid crystal device are clearly resolved, indicating a high degree of precision achieved during manufacturing.

[0053] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices. It should be understood that in this application, “at least one” means one or more, and “more than one” means two or more.

[0054] Although the description of this application has been quite detailed and particularly focused on several of the described embodiments, it is not intended to limit itself to any of these details or embodiments or any particular embodiment. Rather, it should be considered as effectively covering the intended scope of this application by referring to the appended claims and taking into account the prior art, which provides for a broad possible interpretation of these claims. Furthermore, the foregoing description of this application with respect to embodiments foreseeable by the inventors is intended to provide a useful description, and non-substantial modifications to this application that have not yet been foreseen may still represent equivalent modifications.

Claims

1. A method for fabricating a liquid crystal dual-mode dual-channel imaging lens, characterized in that, The method includes: Obtain a phase pattern and divide the phase pattern into multiple sub-patterns; Two matching transparent substrates are obtained, a photo-aligning agent is spin-coated on the surfaces of the two transparent substrates to form an alignment layer, and the two transparent substrates are encapsulated face to face to form a liquid crystal cell with a hollow cavity. The liquid crystal cell is placed on a movable stage, and a spatial light modulator is used in combination with a polarized ultraviolet light source. The stage is moved to expose the phase regions in each sub-pattern one by one, thereby forming a continuous phase alignment structure on the working surface of the liquid crystal cell by photomask lithography. After exposure, the liquid crystal material is filled into the liquid crystal cell; The filled liquid crystal cell is then encapsulated to obtain a liquid crystal dual-mode dual-channel imaging lens.

2. The method according to claim 1, characterized in that, The process of obtaining two matching transparent substrates, spin-coating a photo-alignment agent onto the surfaces of the two transparent substrates to form an alignment layer, and encapsulating the two transparent substrates face-to-face to form a liquid crystal cell with a hollow cavity includes: A conductive layer is formed by coating the surfaces of the two transparent substrates respectively; The transparent substrate coated with the conductive layer is cleaned and dried. After cleaning and drying, a photo-aligning agent is coated onto the conductive layer of each transparent substrate and then heat-treated to form an alignment layer. Spacers are sprayed onto the alignment layer, and then two substrates are aligned, bonded, and encapsulated to form the liquid crystal cell, wherein a hollow cavity with a predetermined thickness and size is formed inside the liquid crystal cell.

3. The method according to claim 2, characterized in that, The conductive layer is an indium tin oxide conductive layer.

4. The method according to claim 3, characterized in that, The cleaning and drying process for the transparent substrate coated with the conductive layer includes: The transparent substrate covered with the conductive layer was ultrasonically cleaned sequentially with deionized water, ethanol and acetone, with each cleaning session lasting 15 minutes. The cleaned substrate was then dried at 120°C for 30 minutes.

5. The method according to claim 2, characterized in that, Specific embodiments of coating a photo-alignment agent onto the conductive layer of each of the transparent substrates and forming an alignment layer by heat treatment include: A photo-aligning agent in solution is spin-coated onto the substrate surface, wherein the photo-aligning agent in solution is a mixed solution of a photo-aligning agent and dimethylformamide as a solvent; The coated substrate was then heated at 110°C for 5 minutes to evaporate the solvent in the mixed solution and form a uniform alignment layer.

6. The method according to claim 2, characterized in that, The spacer is a spherical spacer with a diameter of 4 μm.

7. The method according to any one of claims 1 to 6, characterized in that, The step of acquiring a phase pattern and dividing the phase pattern into multiple sub-patterns includes: The phase pattern is divided into pixel arrays to form multiple sub-patterns of the same size; Each sub-pattern is divided into multiple orientation steps, and each orientation step has a mapping relationship with the target polarization orientation angle; For each of the sub-patterns, an exposure pattern corresponding to each of the orientation steps is generated, wherein the exposure pattern is used to guide the formation of a continuously distributed phase structure during the exposure process.

8. The method according to claim 7, characterized in that, The exposure process, in which the liquid crystal cell is placed on a movable stage and an exposure region in each sub-pattern is performed one by one by using a spatial light modulator combined with a polarized ultraviolet light source, includes: A digital micromirror device is used as a spatial light modulator, and a dynamic exposure pattern corresponding to the orientation order in each of the sub-patterns is generated through the spatial light modulator. The stage is controlled to translate along at least two orthogonal directions by a predetermined step size, so that the exposure area of ​​the liquid crystal cell is sequentially aligned with the position corresponding to each sub-pattern; For each of the sub-patterns, linearly polarized ultraviolet light of a predetermined wavelength is used as a light source to expose each of the orientation steps for a predetermined time, so as to use the light-controlled orientation reaction to write the preset phase information into the orientation layer.

Images