Condensing lens and preparation method and application thereof
By coating a SiO2 transition layer on an arc-shaped substrate and spin-coating an ITO thin film, the problems of uniformity and adhesion of the coating on the focusing lens were solved, achieving efficient and low-cost improvement in optical performance, and enhancing the light focusing accuracy and lens stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-19
- Publication Date
- 2026-04-10
AI Technical Summary
Existing methods for coating condenser lenses on curved substrates suffer from poor uniformity, insufficient adhesion, and high cost. Traditional processes are difficult to adapt to curved surfaces, resulting in low light focusing accuracy and short lifespan.
An ITO thin film is formed by coating a SiO2 transition layer on an arc substrate and then spin-coating it in two stages. By combining a specific precursor solution ratio and annealing treatment, the uniformity and adhesion of the film layer are optimized. The solution process reduces equipment requirements and costs.
It improves the light transmittance and optical flux of the condenser lens, reduces light reflection loss, and enhances the optical application effect and service life.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of condensing lens technology, and specifically relates to a condensing lens, its preparation method and application. Background Technology
[0002] As a core component of an optical system, condenser lenses are primarily used to converge and diverge light sources, thereby increasing the luminous flux of the optical path. Their optical performance and structural stability directly affect the overall performance of the optical system. Therefore, it is necessary to optimize key properties such as transmittance and adhesion by depositing functional thin films on the lens surface. However, most existing condenser lenses use curved substrates to meet the requirements of light convergence. The curved structure differs significantly from traditional planar substrates, leading to numerous unsolvable problems in the practical application of existing coating technologies.
[0003] First, it is difficult to guarantee the uniformity and adhesion of the coating on curved substrates. Traditional coating methods mostly rely on vacuum adsorption to fix the substrate, but the curved surface structure of curved substrates cannot achieve stable vacuum adsorption, causing the substrate to wobble easily during the coating process. At the same time, the process parameters of planar coating cannot be adapted to the curvature changes of the curved surface, resulting in uneven spreading of the functional film on the substrate surface, with large thickness differences between the edge and center areas, and poor adhesion. This directly affects the light focusing accuracy of the condenser lens and leads to disordered light path propagation.
[0004] Secondly, the adhesion between the film layer and the curved substrate is insufficient, making it prone to peeling and cracking. In the existing technology, some solutions directly deposit functional thin films on the surface of the curved substrate without considering the surface energy matching between the substrate and the film. This results in weak interfacial bonding between the film and the substrate. During subsequent use or heat treatment, the internal stress caused by the material difference cannot be released, which in turn causes the film layer to crack and peel off, seriously affecting the service life of the condenser lens.
[0005] In addition, existing coating processes suffer from high costs and poor versatility. For example, traditional coating methods such as magnetron sputtering require complex vacuum equipment and specialized targets, resulting in large equipment investments, high maintenance costs, and low target utilization, making them unsuitable for large-scale mass production. At the same time, these processes have poor adaptability to curved substrates, making it difficult to achieve precise coating for condenser lenses with different curvatures, thus limiting their application range. Summary of the Invention
[0006] The present invention aims to improve at least one technical problem in the prior art.
[0007] The first aspect of this invention provides a method for preparing a condensing lens, wherein the substrate of the condensing lens is an arc-shaped substrate; the preparation method includes the following steps: Obtain the arc-shaped substrate, and coat the light-concentrating side surface of the arc-shaped substrate with SiO2 to form a transition layer; A first precursor liquid is spin-coated onto the surface of the transition layer, followed by annealing to obtain the condensing lens. The spin coating includes a first spin coating and a second spin coating. The rotation speed of the first spin coating is 300 r / min to 400 r / min, and the spin coating time is 9 s to 12 s. The rotation speed of the second spin coating is 2000 r / min to 3000 r / min, and the spin coating time is 30 s to 40 s. The annealing temperature is 300℃~400℃, and the annealing time is 1h~2h; The preparation of the first precursor solution includes the following steps: Indium nitrate and tin acetate were mixed at a mass ratio of indium to tin of 9:1 to obtain the first mixture; The first mixture is added to a first mixed solution of ethylene glycol monomethyl ether, monoethanolamine and H2O2 in a volume ratio of 1:(0.1~0.2):(0.05~0.08), mixed well, and aged for no less than 24 hours to obtain the first precursor solution.
[0008] The core of the condenser lens fabrication method provided in this application is to address the issues of poor adhesion and uniformity of the coating on the curved substrate of the condenser lens. Simultaneously, it optimizes the process to improve the quality and control the cost of the functional thin film. This method ultimately forms an ITO (Indium Tin Oxide Film) thin film on the surface of the condenser lens by spin-coating a first precursor liquid and annealing. As a key functional layer, the ITO film significantly optimizes the core performance of the condenser lens. The ITO film itself possesses excellent transparency properties, which, combined with the flat and dense structure fabricated by this process, effectively increases light transmittance, significantly improving the light transmittance of the condenser lens. This allows more light energy to be focused through the lens, ensuring sufficient light flux. Simultaneously, the ITO film reduces light reflection loss on the lens surface, avoiding glare interference from reflected light, making the light focusing of the condenser lens more precise, reducing light path disturbances, and thus improving the optical application effect of the condenser lens.
[0009] This application first coats the focusing side surface of the curved substrate with SiO2 to form a transition layer. This transition layer provides a smooth and suitable surface for the deposition of the ITO thin film, effectively improving the adhesion between the ITO thin film and the curved substrate. The SiO2-coated transition layer acts as an inert layer, adjusting the substrate surface energy and making it easier for the subsequent first precursor solution to wet the substrate. This avoids solution aggregation or uneven spreading due to surface energy mismatch, thereby improving film formation efficiency. Simultaneously, it improves the interface state between the ITO thin film and the curved substrate, reducing stress caused by material differences between the film and the curved substrate (materials such as glass, polymer, or crystalline materials), and lowering the risk of ITO thin film cracking. After the transition layer is formed, the first precursor solution is spin-coated onto its surface and annealed to obtain the focusing lens. The spin-coating is divided into two stages: a first spin-coating and a second spin-coating. This dynamic spin-coating design is the core of ensuring the uniformity of film formation on the curved surface. In this process, the first spin coating allows the first precursor solution to fully diffuse on the focusing side surface and transition layer of the curved substrate, spreading gradually from the center to the edge, avoiding localized accumulation or incomplete coverage of the solution due to the curvature of the curved surface. The subsequent second spin coating, with its higher rotation speed, utilizes centrifugal force to ensure uniform solution distribution and control film thickness, while simultaneously removing excess solvent from the solution to prevent prolonged solvent retention that could lead to pores or streaks in the film. Compared to traditional methods such as magnetron sputtering, this application employs a solution-based process, which offers advantages such as lower process temperature and easier control. The prepared films exhibit uniformity at the molecular or atomic scale, high quality, and high purity. Furthermore, it eliminates the need for complex equipment and targets, has lower equipment and environmental requirements, and results in lower preparation costs.
[0010] In this application, the preparation of the first precursor solution involves precise proportioning design. Indium nitrate and tin acetate are mixed at a mass ratio of indium to tin of 9:1 to form the first mixture. This ratio ensures that the subsequently formed ITO film possesses excellent optical properties and structural stability. The first mixture is prepared using ethylene glycol monomethyl ether, monoethanolamine, and H2O2. Ethylene glycol monomethyl ether has high polarity, a low boiling point, and good fluidity, which can fully dissolve indium nitrate and tin acetate, facilitating the formation of stable MOM bonds. Monoethanolamine acts as a stabilizer, promoting the full dissolution of raw materials and maintaining chemical equilibrium. The addition of H2O2 plays a crucial optimization role. During the subsequent annealing process, H2O2 decomposes, and the generated hydroxide ions can combine with micro-defects such as oxygen vacancies in the ITO film, promoting the migration of atomic groups on the ITO film surface. At the same time, it accelerates the rapid decomposition of organic residues in the precursor solution. This not only makes the ITO film surface smoother and reduces the thickness of the surface rough layer, but also effectively lowers the optimal annealing temperature, reduces surface defects in the ITO film, and further improves the performance of the ITO film.
[0011] In this application, the annealing temperature range can meet the requirements of ITO grain refinement, making the internal structure of the film more flat and dense, while also avoiding damage to the curved substrate or film layer caused by excessive temperature with the help of H2O2. During the annealing process, the internal stress of the ITO film is released, and the structural stability is further improved.
[0012] The first mixture is added to the first mixed solution at a mass concentration of 0.1 g / mL to 0.3 g / mL.
[0013] The dosage of the first precursor solution is 50 μL / cm³. 2 ~100μL / cm 2 .
[0014] Preferably, the annealing is carried out in the atmosphere of a first mixed gas, which is a mixture of argon and oxygen in a volume ratio of 19:1.
[0015] Argon, as an inert gas, can effectively isolate the outside air during the annealing process, preventing the curved substrate and the formed film from being over-oxidized. At the same time, it provides a stable environment for the refinement growth of ITO grains and reduces the interference of external impurities on the film structure. The addition of an appropriate amount of oxygen can replenish the oxygen elements that may be missing during the film formation process, effectively reducing micro-defects such as oxygen vacancies inside the ITO film, further promoting the migration of atomic groups and the decomposition of organic residues, making the ITO film structure more complete.
[0016] The formation of the transition layer includes the following steps: The second precursor liquid is spin-coated on the light-concentrating side surface of the arc-shaped substrate at a speed of 300 r / min to 500 r / min for 10 s to 20 s, and then dried to form the transition layer. The preparation of the second precursor solution includes the following steps: Tetraethyl orthosilicate, ethanol, and water were mixed in a volume ratio of 1:3:0.5, and 0.1% polyvinylpyrrolidone was added. The mixture was stirred at 70℃~85℃ for 24 hours to obtain the second precursor solution.
[0017] The dosage of the second precursor solution is 30 μL / cm³. 2 ~80μL / cm 2 .
[0018] Preferably, the arc-shaped substrate is obtained after cleaning and drying.
[0019] A second aspect of the present invention provides a condensing lens prepared by the above-described method for preparing a condensing lens.
[0020] The third aspect of the present invention provides the application of the above-described condenser lens in white light interferometer imaging.
[0021] The beneficial effects of this invention are as follows: This invention breaks through the technical bottleneck of poor uniformity and insufficient film adhesion of traditional arc-shaped surface coating. Through the synergistic design of dual-stage dynamic spin coating and composite film layer, it not only ensures the uniform spreading and tight adhesion of the film layer on the arc-shaped substrate surface, but also achieves the organic unity of interface adaptation and functional enhancement, effectively improving the overall performance stability and optical application effect of the condenser lens. Detailed Implementation
[0022] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.
[0023] Example 1 A method for preparing a focusing lens includes the following steps: Obtain an arc-shaped substrate (made of glass), ultrasonically clean the arc-shaped substrate, and then repeatedly clean it with methanol, ethanol and deionized water, and then air dry it. The second precursor solution was spin-coated onto the focusing side surface of the curved substrate at 350 r / min for 15 s (the amount of the second precursor solution was 50 μL / cm). 2 (), and dry at 120°C to form a transition layer; The first precursor solution was spin-coated onto the surface of the transition layer (the amount of the first precursor solution was 80 μL / cm). 2 First, spin-coat at 350 r / min for 10 s, then spin-coat at 2500 r / min for 40 s, and anneal at 350℃ for 2 h (annealing is carried out in an atmosphere of argon and oxygen mixed gas with a volume ratio of 19:1) to obtain a condenser lens.
[0024] The preparation of the first precursor solution includes the following steps: Indium nitrate and tin acetate were mixed at a mass ratio of indium to tin of 9:1 to obtain the first mixture; A first mixture (mass concentration of 0.2 g / mL) was added to a first mixture of ethylene glycol monomethyl ether, monoethanolamine and H2O2 in a volume ratio of 1:0.15:0.06, mixed well and aged for 24 h to obtain the first precursor solution.
[0025] The preparation of the second precursor solution includes the following steps: Tetraethyl orthosilicate, ethanol, and water were mixed in a volume ratio of 1:3:0.5, and 0.1% polyvinylpyrrolidone was added. The mixture was stirred at 80°C for 24 hours to obtain the second precursor solution.
[0026] Example 2 A method for preparing a focusing lens includes the following steps: Obtain an arc-shaped substrate (made of glass), ultrasonically clean the arc-shaped substrate, and then repeatedly clean it with methanol, ethanol and deionized water, and then air dry it. The second precursor solution was spin-coated at 500 r / min for 20 s on the focusing side surface of the curved substrate (the amount of the second precursor solution was 80 μL / cm). 2 (), and dry at 120°C to form a transition layer; The first precursor solution was spin-coated onto the surface of the transition layer (the amount of the first precursor solution was 100 μL / cm). 2 First, spin-coat at 400 r / min for 12 s, then spin-coat at 3000 r / min for 40 s, and anneal at 380℃ for 1.5 h (annealing is carried out in an atmosphere of argon and oxygen mixed gas with a volume ratio of 19:1) to obtain a condenser lens.
[0027] The preparation of the first precursor solution includes the following steps: Indium nitrate and tin acetate were mixed at a mass ratio of indium to tin of 9:1 to obtain the first mixture; A first mixture (mass concentration of 0.3 g / mL) was added to a first mixture of ethylene glycol monomethyl ether, monoethanolamine and H2O2 in a volume ratio of 1:0.2:0.08, mixed well and aged for 24 h to obtain the first precursor solution.
[0028] The preparation of the second precursor solution includes the following steps: Tetraethyl orthosilicate, ethanol, and water were mixed in a volume ratio of 1:3:0.5, and 0.1% polyvinylpyrrolidone was added. The mixture was stirred at 85°C for 24 hours to obtain the second precursor solution.
[0029] Example 3 A method for preparing a focusing lens includes the following steps: Obtain an arc-shaped substrate (made of glass), ultrasonically clean the arc-shaped substrate, and then repeatedly clean it with methanol, ethanol and deionized water, and then air dry it. The second precursor solution was spin-coated at 300 r / min for 10 s on the focusing side surface of the curved substrate (the amount of the second precursor solution was 30 μL / cm). 2 (), and dry at 120°C to form a transition layer; A first precursor solution (50 μL / cm³) was spin-coated onto the surface of the transition layer. 2 First, spin-coat at 300 r / min for 9 s, then spin-coat at 2000 r / min for 30 s, and anneal at 330℃ for 2 h (annealing is carried out in an atmosphere of argon and oxygen mixed gas with a volume ratio of 19:1) to obtain a condenser lens.
[0030] The preparation of the first precursor solution includes the following steps: Indium nitrate and tin acetate were mixed at a mass ratio of indium to tin of 9:1 to obtain the first mixture; A first mixture (mass concentration of 0.1 g / mL) was added to a first mixture of ethylene glycol monomethyl ether, monoethanolamine and H2O2 in a volume ratio of 1:0.1:0.05, mixed well, and aged for 24 h to obtain the first precursor solution.
[0031] The preparation of the second precursor solution includes the following steps: Tetraethyl orthosilicate, ethanol, and water were mixed in a volume ratio of 1:3:0.5, and 0.1% polyvinylpyrrolidone was added. The mixture was stirred at 70°C for 24 hours to obtain the second precursor solution.
[0032] Comparative Example 1 A method for preparing a condenser lens differs from Example 1 in that the first precursor solution is spin-coated at 2500 r / min for only 40 s. Everything else is the same as in Example 1.
[0033] Comparative Example 2 A method for preparing a focusing lens differs from Example 1 in that the first mixture is ethylene glycol monomethyl ether and monoethanolamine in a volume ratio of 1:0.15, and does not contain H2O2. Everything else is the same as in Example 1.
[0034] Comparative Example 3 A method for preparing a focusing lens differs from Example 1 in that: a first precursor liquid is directly spin-coated onto the focusing side surface of an arc-shaped substrate, without the step of forming a transition layer. Otherwise, it is the same as Example 1.
[0035] Comparative Example 4 A method for preparing a focusing lens differs from Example 1 in that the volume ratio of ethylene glycol monomethyl ether, monoethanolamine, and H2O2 in the first mixture is 1:0.15:0.03. Everything else is the same as in Example 1.
[0036] Comparative Example 5 A method for preparing a focusing lens differs from Example 1 in that the volume ratio of ethylene glycol monomethyl ether, monoethanolamine, and H2O2 in the first mixture is 1:0.15:0.15. Everything else is the same as in Example 1.
[0037] Comparative Example 6 A method for preparing a condenser lens differs from Example 1 in that: the spin coating of the first precursor liquid is first performed at 350 r / min for 10 s, followed by spin coating at 1000 r / min for 40 s. All other steps are the same as in Example 1.
[0038] Comparative Example 7 A method for preparing a condenser lens differs from Example 1 in that: the spin coating of the first precursor liquid is first performed at 350 r / min for 10 s, followed by spin coating at 4000 r / min for 40 s. All other steps are the same as in Example 1.
[0039] The following performance tests were performed on the condenser lenses prepared in the embodiments and comparative examples of this application: Light transmittance test: measured by spectrophotometer (average value of 380nm~780nm band). Film thickness deviation test: A step meter was used for testing. The ITO functional layer area of each condenser lens was selected, and 5 test points were evenly selected on the sample surface (1 point in the center and 4 points evenly distributed at the edges). The ITO functional layer thickness at each point was measured sequentially using the step meter. The thickness values at each point were recorded and the average film thickness was calculated. Then the film thickness deviation was calculated (film thickness deviation = (maximum thickness value - minimum thickness value) / average film thickness × 100%). Finally, the proportion of the maximum deviation to the average film thickness was calculated as the film thickness deviation test result. Imaging effect test: The test was conducted by constructing a simulated optical converging light path, which consisted of: a diverging light source (wavelength 380nm~780nm), a condenser lens holder, and a receiving screen (50cm away from the condenser lens). Each condenser lens was installed on the holder in sequence, and the distance between the light source and the lens was adjusted to 30cm. The light source was then turned on. The shape of the converged light spot was observed through the receiving screen to determine the concentration of the light spot (whether it is uniform and without obvious diffusion). At the same time, the presence of reflected glare in the light path was observed to comprehensively evaluate the imaging effect.
[0040] The test results are shown in Table 1. Comparative Example 8 in Table 1 is an untreated curved substrate.
[0041] Table 1 Based on the data in Table 1, compared with Example 1, Comparative Example 1 only uses a single-speed spin coating for its first precursor solution, which cannot achieve gradient spreading and precise control of film thickness on the surface of the curved substrate, resulting in uneven stress distribution and increased surface defects within the film layer; Compared with Example 1, Comparative Example 2 does not contain H2O2 in its first precursor solution, which cannot repair micro-defects such as oxygen vacancies in the film through hydroxide ions generated by H2O2 decomposition during annealing, nor can it accelerate the decomposition of residual organic matter in the precursor solution, resulting in decreased film density; Compared with Example 1, Comparative Example 3 does not have a transition layer, which cannot adjust the surface energy of the curved substrate, cannot optimize the interfacial compatibility between the ITO film and the curved substrate, and affects the subsequent ITO film formation quality; Comparative Example 4 and... Compared to Example 1, the volume ratio of H2O2 in Comparative Example 5 is too low, failing to fully utilize its defect repair and organic matter decomposition functions. Compared to Example 1, the volume ratio of H2O2 in Comparative Example 5 is too high, leading to excessive oxidation during annealing and disrupting the integrity of the ITO film's lattice structure. Compared to Example 1, the spin-coating speed in Comparative Example 6 is insufficient, failing to remove excess solvent from the precursor solution through sufficient centrifugal force, resulting in a thicker film with increased internal solvent residue, which easily leads to stress concentration and defects during subsequent annealing. Compared to Example 1, the spin-coating speed in Comparative Example 7 is too high, with excessive centrifugal force causing rapid loss of the first precursor solution, preventing the formation of a complete and uniform ITO film, resulting in a thinner film prone to pinholes and other defects. The aforementioned comparative examples, deviating from the core process parameters, component ratios, or structural design of this application, result in insufficient ITO film uniformity, increased internal defects, and weakened interfacial bonding, ultimately significantly affecting the optical performance and structural stability of the condenser lens, failing to achieve improved light transmittance and glare suppression.
[0042] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.
[0043] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a condenser lens, characterized in that, The substrate of the condenser lens is an arc-shaped substrate; the preparation method includes the following steps: Obtain the arc-shaped substrate, and coat the light-concentrating side surface of the arc-shaped substrate with SiO2 to form a transition layer; A first precursor liquid is spin-coated onto the surface of the transition layer, followed by annealing to obtain the condensing lens. The spin coating includes a first spin coating and a second spin coating. The rotation speed of the first spin coating is 300 r / min to 400 r / min, and the spin coating time is 9 s to 12 s. The rotation speed of the second spin coating is 2000 r / min to 3000 r / min, and the spin coating time is 30 s to 40 s. The annealing temperature is 300℃~400℃, and the annealing time is 1h~2h; The preparation of the first precursor solution includes the following steps: Indium nitrate and tin acetate were mixed at a mass ratio of indium to tin of 9:1 to obtain the first mixture; The first mixture is added to a first mixed solution of ethylene glycol monomethyl ether, monoethanolamine and H2O2 in a volume ratio of 1:(0.1~0.2):(0.05~0.08), mixed well, and aged for no less than 24 hours to obtain the first precursor solution.
2. The method for preparing a condenser lens according to claim 1, characterized in that, The first mixture is added to the first mixture at a mass concentration of 0.1 g / mL to 0.3 g / mL.
3. The method for preparing a condenser lens according to claim 2, characterized in that, The dosage of the first precursor solution was 50 μL / cm. 2 ~100μL / cm 2 .
4. The method for preparing a condenser lens according to claim 1, characterized in that, The annealing is carried out in the atmosphere of a first mixed gas, which is a mixture of argon and oxygen in a volume ratio of 19:
1.
5. The method for preparing a condenser lens according to claim 1, characterized in that, The formation of the transition layer includes the following steps: The second precursor liquid is spin-coated on the light-concentrating side surface of the arc-shaped substrate at a speed of 300 r / min to 500 r / min for 10 s to 20 s, and then dried to form the transition layer. The preparation of the second precursor solution includes the following steps: Tetraethyl orthosilicate, ethanol, and water were mixed in a volume ratio of 1:3:0.5, and 0.1% polyvinylpyrrolidone was added. The mixture was stirred at 70℃~85℃ for 24 hours to obtain the second precursor solution.
6. The method for preparing a condenser lens according to claim 5, characterized in that, The dosage of the second precursor solution is 30 μL / cm. 2 ~80μL / cm 2 .
7. A focusing lens, characterized in that, It is prepared by the method of any one of claims 1-6.
8. The application of the condenser lens as described in claim 7 in white light interferometer imaging.