Optical element with parameterized optical structure

Abstract

The invention provides an optical element with parameterized optical structures. The element comprises a reference plane and a plurality of optical structures closely arranged on the reference plane in an array mode. Each optical structure is composed of a parallelogram reference sub-surface, a convex cubic pyramid and a concave cubic pyramid, wherein the convex cubic pyramid and the concave cubic pyramid are constructed by taking two equilateral triangles of the reference sub-surface as bottom surfaces respectively. By defining the characteristic angle parameters between the reflecting surfaces of the convex cubic pyramid and the concave cubic pyramid and the reference plane and the characteristic length parameters of the equilateral triangles forming the reference sub-surfaces, accurate description and control of the optical structure and the array layout thereof are realized. The characteristic angle parameters are preferably configured, so that the optical structure can present the set retroreflection illuminance distribution. Besides, the invention further provides a plurality of optimization algorithms to efficiently and accurately configure characteristic angle parameters, and the optical element can be used as a retroreflection device and has wide application prospects and important practical value.

Description

Technical Field

[0001] This invention relates to the field of retroreflective optics, and in particular to an optical element composed of an optical structure arranged in a seamless array on a reference plane. Through specific parametric design, this structure achieves excellent retroreflective performance and a specific illuminance distribution. Background Technology

[0002] Retroreflective optical structures, as a special type of optical element, are widely used in traffic signs, safety equipment, and nighttime visibility enhancement. Their core function is to reflect incident light rays in a direction almost opposite to their incident path, thus achieving a highly efficient retroreflective effect. However, traditional retroreflective structures have certain design limitations, particularly in achieving specific retroreflective illuminance distributions.

[0003] First, most current retroreflective structures are based on fixed geometries and layouts, lacking flexibility and adjustability, making it difficult to achieve complex retroreflective illumination distributions. In practical applications, retroreflectors often need to provide specific lighting patterns or designs to enhance visual effects or meet specific functional requirements. However, existing retroreflective structures, due to design limitations, cannot effectively achieve this goal.

[0004] Secondly, the lack of an effective parametric representation method is another significant factor hindering the development of retroreflective structures. Parametric design is a powerful tool that can abstract design elements into adjustable parameters and optimize design performance by adjusting these parameters. However, in the design of retroreflective structures, an effective parametric representation method has not yet been established, making it difficult for designers to systematically explore and optimize retroreflective performance.

[0005] Furthermore, the relationship between the random distribution of parameters and the retroreflective illuminance distribution of array retroreflective structures has not been fully explored and studied. In practical applications, due to manufacturing errors and material inhomogeneities, the parameters of retroreflectors often exhibit a certain degree of randomness. However, a deep understanding of the relationship between this randomness and the retroreflective illuminance distribution is currently lacking. This prevents designers from accurately predicting and controlling the actual performance of retroreflectors, limiting further improvements in their performance. Summary of the Invention

[0006] The core objective of this invention is to provide an optical element with a parameterized optical structure that overcomes the limitations of traditional retroreflective structures, achieving excellent retroreflective performance and a specific illuminance distribution. To achieve this goal, this invention proposes a parameterized cubic pyramid retroreflective optical structure design and, by introducing a set of parameterized expression methods, realizes the precise description and control of the optical structure and its array layout.

[0007] Specifically, the optical element of the present invention includes a reference plane and multiple optical structures formed on the reference plane. These optical structures are arranged closely in an array on the reference plane, collectively forming the main body of the optical element. Each optical structure consists of a parallelogram reference sub-plane formed by splicing two equilateral triangles, and a convex cubic pyramid and a concave cubic pyramid constructed with the two equilateral triangles as their bases, respectively. This unique design allows the optical structure to have abundant reflecting surfaces and included angle parameters, making it possible to achieve a predetermined retroreflective illuminance distribution.

[0008] The angles formed between the three reflecting surfaces of the convex cubic pyramid and the reference plane are defined as characteristic angle parameters i1, j1, and k1, respectively, while the angles formed between the three reflecting surfaces of the concave cubic pyramid and the reference plane are defined as characteristic angle parameters i2, j2, and k2, respectively. These characteristic angle parameters represent important design freedoms in this invention. By optimally configuring these parameters, the optical structure can exhibit a predetermined retroreflective illuminance distribution. Specifically, different configurations of the characteristic angle parameters result in different light reflection paths and illuminance distributions. Therefore, by precisely adjusting these parameters, specific retroreflective illuminance distribution requirements can be achieved.

[0009] In addition to the basic characteristic angle parameters, this invention provides several preferred features, further enriching the design freedom and application range of optical elements. For example, both convex and concave cubic pyramids can be designed as PG solid angle units to enhance optical performance. A PG solid angle unit is a solid angle structure with excellent optical performance, capable of more effectively reflecting incident light rays back along their incident path. Designing convex and concave cubic pyramids as PG solid angle units can further enhance the retroreflective performance of optical elements.

[0010] Furthermore, the side length of the equilateral triangle constituting the reference sub-plane is set as a characteristic length parameter Λ. This parameter facilitates precise control of the size and shape of the optical structure, thereby achieving more accurate optical performance control. The characteristic length parameter Λ is preferably in the range of 0.01mm-1.0mm to meet the needs of different application scenarios. By adjusting the characteristic length parameter Λ, the retroreflective performance and illuminance distribution of the optical structure can be further fine-tuned.

[0011] Furthermore, the included angles between adjacent reflecting surfaces in convex and concave cubic pyramids are defined as characteristic angle parameters. These characteristic angle parameters further enrich the design freedom of optical structures, enabling optical elements to achieve more diverse illumination distributions. Specifically, the included angles between adjacent reflecting surfaces in a convex cubic pyramid are defined as characteristic angle parameters α1, β1, and γ1, while the included angles between adjacent reflecting surfaces in a concave cubic pyramid are defined as characteristic angle parameters α2, β2, and γ2. The characteristic angle parameters of each cubic pyramid are determined by its characteristic angle parameters; therefore, by adjusting the characteristic angle parameters, the characteristic included angle parameters can be indirectly adjusted, thereby achieving precise control over the performance of the optical structure.

[0012] The optimal configuration of characteristic angle parameters not only ensures that the illuminance distribution of optical elements presents a predetermined image but also meets diverse application requirements. For example, in traffic signs, a specific illuminance distribution can be achieved by optimizing the characteristic angle parameters, improving the visibility and safety of the signs. Furthermore, the characteristic angle parameters of both convex and concave cubic pyramids can be assigned independently, increasing design flexibility. In practical applications, the characteristic angle parameters of convex and concave cubic pyramids can be adjusted independently according to specific needs to achieve the optimal retroreflective illuminance distribution.

[0013] Furthermore, convex and concave cubic pyramids can also have deflection and / or tilt angles. Setting deflection and tilt angles can further expand the application range of optical elements. For example, in applications requiring reflection at a specific angle, this can be achieved by setting deflection and / or tilt angles. By adjusting the deflection and tilt angles, the reflection path of light on the optical structure can be changed, thereby achieving more flexible control over retroreflection performance.

[0014] To achieve efficient and accurate design, this invention provides methods for optimizing feature angle parameters, including the steepest descent method, Newton's method, and the L-BFGS algorithm. These methods can quickly find the optimal feature angle parameter configuration, enabling the optical element to exhibit a predetermined retroreflective illuminance distribution. Specifically, the steepest descent method is an iterative optimization algorithm that approximates the optimal solution by continuously adjusting the feature angle parameters; Newton's method is a gradient-based optimization algorithm that finds the optimal solution by calculating the gradient of the objective function; and the L-BFGS algorithm is a quasi-Newton method that accelerates the optimization process by approximating the Hessian matrix. Each method has its advantages, and the appropriate method can be selected for optimization design based on specific needs and computational resources.

[0015] Finally, the optical element of this invention can be used as a retroreflective device, with broad application prospects. For example, it can be applied to improve visibility and safety in areas such as traffic signs, personal protective equipment, and vehicle markings. By precisely adjusting key parameters such as characteristic angle parameters, specific retroreflective illuminance distributions and excellent retroreflective performance can be achieved, thereby meeting the needs of various application scenarios.

[0016] This invention achieves the following technical effects through parametric design:

[0017] This invention introduces a parametric design method to achieve precise description and control of the optical structure and its array layout. By adjusting key parameters such as characteristic angle parameters, the performance of the retroreflector can be optimized to achieve a specific retroreflective illumination distribution. This provides an effective solution to the fixed and non-adjustable nature of existing retroreflective structure designs.

[0018] The optical element proposed in this invention consists of a seamless array of optical structures laid out on a reference plane. Through specific parametric design, it achieves excellent retroreflective performance and a specific illuminance distribution. This enables the retroreflective optical element to provide a more uniform and symmetrical illuminance distribution in practical applications, enhancing visual effects and user experience.

[0019] This invention delves into the relationship between the random distribution of array retroreflective structural parameters and the retroreflective illuminance distribution. This research provides a theoretical foundation and practical guidance for further improving the performance of retroreflectors. By understanding and controlling the influence of the random distribution of parameters on the retroreflective illuminance distribution, the actual performance of retroreflectors can be predicted and controlled more accurately.

[0020] In summary, this invention proposes an optical structure based on parametric design. This structure achieves precise description and control of the optical structure and its array layout by introducing a set of parametric expression methods. By adjusting key parameters such as characteristic angle parameters, the performance of the retroreflector can be optimized and a specific retroreflective illuminance distribution can be achieved. Furthermore, this invention explores the relationship between the random distribution of array retroreflective structure parameters and the retroreflective illuminance distribution, providing a theoretical basis and practical guidance for further improving the performance of the retroreflector. In addition, the retroreflector of this structure also has stronger light emission characteristics, typically exhibiting a retroreflectivity greater than 0.9. This invention has broad application prospects and significant practical value in the field of retroreflective optics. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0022] Figure 1 This is a plan view of the retroreflector in Embodiment 1, which includes an optical structure.

[0023] Figure 1a This is a perspective view of the retroreflector in Embodiment 1, which includes an optical structure.

[0024] Figure 2 yes Figure 1 A three-dimensional diagram of the optical structure.

[0025] Figure 2a yes Figure 2 Top view of the optical structure Figure 1 .

[0026] Figure 2b yes Figure 2 Top view of the optical structure Figure 2 .

[0027] Figure 3 This is a partial view of the expanded range of the retroreflector in Embodiment 1.

[0028] Figure 3a yes Figure 3 Illumination diagram displayed in a Cartesian coordinate system.

[0029] Figure 4 This is a partial view of the retroreflector in Embodiment 1, with its range further expanded.

[0030] Figure 4a yes Figure 4 Illuminance diagram displayed in polar coordinates.

[0031] Figure 5 This is a stereoscopic view of the retroreflector in another embodiment, and its illuminance diagram in a Cartesian coordinate system. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] Unless otherwise defined, the technical or scientific terms used in this patent document shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this patent specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an," "a," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" indicate that the element or object preceding "comprising" encompasses the element or object listed following "comprising" or its equivalents, and do not exclude other elements or objects. Terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are used only to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. These terms are only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a set orientation, or be constructed and operated in a set orientation, and therefore should not be construed as a limitation of the invention.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, features in the following embodiments can be combined with each other.

[0037] The following is a detailed description of specific embodiments of the optical structure based on parametric design of the present invention. The present invention aims to achieve precise control of retroreflective illuminance distribution by finely adjusting characteristic angle parameters, characteristic included angle parameters, and characteristic length parameters, thereby improving retroreflective performance to meet application needs in fields such as traffic safety and outdoor advertising.

[0038] In this embodiment, based on a parametrically designed optical structure, the retroreflector achieves flexible design and optimization by setting characteristic angle parameters, characteristic included angle parameters, and characteristic length parameters. In practical applications, these parameters can be flexibly adjusted according to specific needs and scenarios to obtain the best retroreflection effect. Furthermore, this invention employs optimization techniques such as characteristic included angle deviation design, normal distribution design, and symmetry design to further improve the optical performance and practical application effect of the retroreflector.

[0039] Specifically, this embodiment provides an optical element with a parameterized optical structure, including a reference plane and multiple optical structures formed on the reference plane. The multiple optical structures are arranged in an array on a common reference plane, such as... Figure 1 and Figure 2 As shown, the optical structure includes a parallelogram reference sub-plane formed by two equilateral triangles, and a convex cubic pyramid and a concave cubic pyramid constructed with the two equilateral triangles as their bases, respectively. The angles formed between the three reflecting surfaces (1a, 1b, 1c) of the convex cubic pyramid and the reference plane are defined as characteristic angle parameters i1, j1, and k1, respectively. The angles formed between the three reflecting surfaces (2a, 2b, 2c) of the concave cubic pyramid and the reference plane are defined as characteristic angle parameters i2, j2, and k2, respectively. A preferred configuration of the characteristic angle parameters enables the retroreflector to exhibit a uniform retroreflective illuminance distribution, or for specific images such as QR codes, etc. Figure 3 , 3a As shown in 4a.

[0040] Furthermore, the characteristic angle parameters i1, j1, and k1 of the convex cubic pyramid are positive, while the characteristic angle parameters i2, j2, and k2 of the concave cubic pyramid are negative. The two reflecting surfaces of the convex cubic pyramid and its adjacent concave cubic pyramid sharing a common baseline have characteristic angle parameters with similar values. When the characteristic angle parameters of adjacent reflecting surfaces sharing a common baseline are the same, they coincide, and the convex and concave cubic pyramids together form a trihedral cubic pyramid. However, in this embodiment, the characteristic angle parameters of the adjacent reflecting surfaces of the convex and concave cubic pyramids sharing a common baseline are different, thus the six-sided optical structure formed by the two trihedral cubic pyramids has a wider range of degrees of freedom.

[0041] It should be noted that in the field of retroreflective optics, a cubic pyramid prism is a corner cut from a cube, consisting of three mutually perpendicular right-angled facets, with the base typically being an equilateral triangle. The three reflecting faces of the pyramid prism are equivalent to the three adjacent faces of the cube, each a right-angled face, allowing light to return along its original path after three total internal reflections inside the prism. When light is incident on the cubic pyramid, it is reflected by the three reflecting faces and returns along the same path as the incident light. This characteristic makes cubic pyramids widely used in optics and engineering, especially in applications requiring precise control of the light reflection path. In this invention, the characteristic included angle parameter of the convex and concave cubic pyramids is not an absolute 90°, but rather has a slight deviation from 90°, typically no greater than 1°. In this embodiment, the deviation of the characteristic included angle parameter can be adjusted using a characteristic angle parameter.

[0042] I. Optical Structure Design

[0043] Parallelogram reference subplane design

[0044] like Figure 1 and Figure 2 As shown, in this embodiment, the substrate of the optical structure is a parallelogram array unit, which is composed of two equilateral triangles joined together. The side length of the equilateral triangle is set as a characteristic length parameter Λ, used to control the size of the optical structure. The value of Λ ranges from 0.01 mm to 1.0 mm. In this embodiment, Λ is set to 0.1 mm to ensure that the optical structure has appropriate size and array density. In other embodiments, it can also be 0.2 mm, while in some cases, such as bicycle taillights, outdoor display devices, etc., Λ can be appropriately increased to 1.0 mm or greater.

[0045] By adjusting Λ, the size and array density of the optical structure can be flexibly controlled, thereby optimizing the overall performance of the retroreflector. A smaller Λ value allows for increased array density, which helps to achieve a finer illumination distribution; while a larger Λ value is suitable for scenarios requiring a large area of ​​retroreflection.

[0046] Convex and concave cubic pyramid designs

[0047] Based on the parallelogram reference plane, a convex cubic pyramid and a concave cubic pyramid are constructed with two equilateral triangles as their bases, respectively. The convex and concave cubic pyramids extend to both sides of the reference plane. The angles formed between the three reflecting surfaces of the convex cubic pyramid and the reference plane are defined as characteristic angle parameters i1, j1, and k1, respectively, and the angles formed between the three reflecting surfaces of the concave cubic pyramid and the reference plane are defined as characteristic angle parameters i2, j2, and k2, respectively. In this embodiment, since the cubic pyramid is a PG solid angle unit, the characteristic angle parameters can be set according to actual needs to achieve a specific retroreflection illuminance distribution. The PG solid angle element, which is part of the structured surface of the solid angle element, can be alternatively or additionally described as a solid angle element having at least one non-dihedral edge, which: (1) is not parallel to the reference plane along which the structured surface extends; and (2) is substantially parallel to the adjacent non-dihedral edges of the adjacent solid angle element. Compared with the truncated solid angle unit, it exhibits higher total light return performance. This structure can more effectively reflect incident light back along its incident path, thus having wide application value in the fields of transportation and personal safety. A PG solid angle unit typically consists of three reflective surfaces, as illustrated in Chinese patent CN105359009A, where these surfaces are arranged in a specific geometry to form a solid angle structure. Each reflective surface is precisely designed and manufactured to ensure that light is reflected along a predetermined path. Furthermore, PG solid angle units may also have special design features, such as tilted surfaces, skew angles, or tilt angles, to further optimize their optical performance. Skew angles are generally used to describe the degree of deviation of the solid angle unit from a reference plane extending in a direction perpendicular to the column, while tilt angles are generally used to describe the degree of deviation of the solid angle unit from a reference plane extending in a column direction.

[0048] Each cubic pyramid contains three reflecting surfaces, and the included angles between adjacent reflecting surfaces are defined as characteristic angle parameters α, β, and γ. Specifically, the included angles between adjacent reflecting surfaces in the convex cubic pyramid are defined as characteristic angle parameters α1, β1, and γ1, respectively, and the included angles between adjacent reflecting surfaces in the concave cubic pyramid are defined as characteristic angle parameters α2, β2, and γ2, respectively. These characteristic angle parameters directly affect the light reflection effect of the retroreflector. By adjusting the geometry of the cubic pyramid, such as changing the size of the apex angle or the tilt angle of the reflecting surfaces, the characteristic angle parameters can be optimized to achieve a better light reflection effect. The characteristic angle parameters of each cubic pyramid are determined by its characteristic angle parameters.

[0049] Furthermore, in some applications, such as traffic signs, to achieve uniform brightness and a certain degree of beamwidth, multiple nonorthogonality (MNO) needs to be introduced. This allows for slight deviations in the three characteristic angles of each cubic pyramid; that is, each of the three characteristic angles of each cubic pyramid deviates from its theoretical value, and these deviations are within a certain range. Specifically, influenced by the characteristic angle parameters, the characteristic angle deviation can be less than a certain value, such as 0.1°, and the characteristic angle deviation, influenced by the characteristic angle deviation, also follows a normal distribution with a variance of a certain value, such as 0.1°, to ensure that the retroreflector exhibits uniform light return characteristics and stable optical performance.

[0050] It should be noted here that, in order to improve the divergence shape and light reflection performance of the retroreflector, tilt and deflection angles can be introduced into the cubic pyramid. The design of the tilt and deflection angles helps to introduce multiple nonorthogonality (MNO), thereby improving the divergence shape and light reflection performance of the retroreflector and further enhancing its optical performance.

[0051] II. Optimization Process for Parameter Optimization

[0052] To achieve a specific illuminance distribution (such as a QR code, specific text, or signage), fine-tuning of the characteristic angle parameters is required. This implementation method employs one or more optimization algorithms, including the steepest descent method, Newton's method, and L-BFGS algorithm, for parameter optimization. The specific steps are as follows:

[0053] Define target performance metrics: Based on application requirements, define target performance metrics for the retroreflector, including retroreflectivity, uniformity of retroreflected illuminance distribution, and specific illuminance distribution shape (such as a QR code). These metrics will serve as constraints for the optimization algorithm.

[0054] Establish a simulation model: Using optical design or simulation software, establish an optical model of the optical structure. Set different combinations of characteristic angle parameters in the model to simulate retroreflection performance. Evaluate whether the retroreflector meets the target performance indicators through simulation results.

[0055] Parameter optimization: One or more optimization algorithms, such as the steepest descent method, Newton's method, and L-BFGS algorithm, are used to adjust and optimize the feature angle parameters. These optimization algorithms can find parameter combinations close to the optimal solution in a relatively short time. During the optimization process, the retroreflection performance is evaluated based on simulation results to determine whether it meets the target specifications, and the feature angle parameters are adjusted accordingly. The iterative process is repeated until the optimal parameter combination is found.

[0056] Optimal Parameter Distribution: During the optimization process, it was found that retroreflection performance is superior when the characteristic angle parameters exhibit a normal distribution around a certain central value. Therefore, the optimal distribution of characteristic angle parameters should ensure that the characteristic angles exhibit a normal distribution around a specific angle (such as the theoretical value). Simultaneously, to maintain the continuity and smoothness of the retroreflection illuminance distribution, the variance of the normal distribution should be limited to a small range (e.g., less than 0.5°).

[0057] In this embodiment, the characteristic angle parameters i1, j1, k1 and i2, j2, k2, after being adjusted by the optimization algorithm, exhibit a normal distribution within the range of 55°±1°, and the variance of the normal distribution is precisely controlled to be around 0.1°. This parameter distribution method enables the retroreflector to present a clear and uniform illumination distribution in practical applications.

[0058] In this embodiment, optical structures can be fabricated in a mold using precision machining techniques (such as nanoimprinting and photolithography). During the fabrication process, processing precision and surface roughness must be strictly controlled to ensure the optical performance of the structure. Simultaneously, the fabricated optical structures must undergo quality inspection to remove defective products.

[0059] III. Performance Testing

[0060] The fabricated retroreflector undergoes performance testing to evaluate whether its performance meets the design requirements. Specific testing includes:

[0061] 3.1 Retroreflectivity Test

[0062] The retroreflectivity of the retroreflector is measured using instruments such as a photometer to ensure it is not less than 0.9 to meet high-efficiency performance requirements. Retroreflectivity testing should be conducted under standard light sources and observation conditions to ensure the accuracy and comparability of the test results.

[0063] 3.2 Retroreflection Illuminance Distribution Test

[0064] The retroreflective illuminance distribution of the retroreflector under different incident and observation angles was measured using optical measurement equipment. Its performance was evaluated to determine whether it met the set illuminance distribution requirements and whether it possessed excellent performance characteristics such as continuous smooth distribution and symmetry. During the testing process, special attention should be paid to the clarity and legibility of specific illuminance distribution shapes, such as QR codes.

[0065] 3.3 Durability Test

[0066] The retroreflector undergoes weathering and abrasion resistance tests to evaluate its stability and reliability in real-world usage environments. Durability tests should simulate various harsh conditions in actual use scenarios to ensure the retroreflector maintains good performance during long-term use.

[0067] refer to Figure 1-4aThe image shows how to design a retroreflector that can achieve a uniform illuminance distribution.

[0068] (1) Determine the overall size and shape of the retroreflector and the required uniform illumination distribution characteristics.

[0069] (2) Based on the characteristics of uniform illuminance distribution, design the characteristic length parameters L and characteristic angle parameters i1, j1, k1 and i2, j2, k2 of the optical structure. Gradually adjust these parameters through numerical simulation and experimental verification until the desired uniform illuminance distribution effect is achieved. In this process, optimization algorithms such as Newton's steepest descent method can be used to optimize the parameters to improve efficiency and accuracy.

[0070] (3) Arrange and combine the designed optical structures to form a complete retroreflector array layout. During the arrangement process, ensure that the gaps between the optical structures are as small as possible to improve the overall retroreflection performance. At the same time, consider the characteristics of uniform illuminance distribution and optimize the layout to ensure that the illuminance distribution on the entire retroreflector surface is uniform and consistent.

[0071] (4) Optimize and adjust the overall structure and performance of the retroreflector to ensure its effectiveness and stability in practical applications. Perform numerical simulations and experimental verification on the optimized retroreflector to confirm that its performance meets the design requirements.

[0072] The illuminance distribution of the cubic pyramid designed using the above optimization methods can exhibit C2, C3, and C6 symmetry characteristics. Figure 4a The symmetry feature of C6 is shown. In another embodiment, such as Figure 5 As shown, the illuminance distribution of a cubic pyramid can also be non-uniform, but the brightness at reflective locations is basically uniform.

[0073] The following is another specific embodiment illustrating how to design a retroreflector capable of displaying the illumination distribution of a QR code, specifically including the following design steps:

[0074] (1) Determine the overall size and shape of the retroreflector, as well as the size and resolution of the required QR code illumination distribution. Select an appropriate feature length parameter L as the basic size of the optical structure according to actual needs.

[0075] (2) Design the characteristic angle parameters i1, j1, k1 and i2, j2, k2 of the optical structure based on the characteristics of the QR code illuminance distribution. Gradually adjust these parameters using numerical simulation and experimental verification methods until the desired QR code illuminance distribution effect is achieved. In this process, optimization algorithms such as Newton's steepest descent method can be used to optimize the parameters to improve efficiency and accuracy.

[0076] (3) Arrange and combine the designed optical structures to form a complete retroreflector array layout. During the arrangement process, ensure that the gaps between the optical structures are as small as possible to improve the overall retroreflection performance. At the same time, optimize the layout by considering the integrity and recognizability of specific illumination distribution shapes such as QR codes.

[0077] (4) Optimize and adjust the overall structure and performance of the retroreflector to ensure its effectiveness and stability in practical applications. Perform numerical simulations and experimental verification on the optimized retroreflector to confirm that its performance meets the design requirements.

[0078] As can be seen from the above description of specific embodiments, the present invention optimizes the performance of retroreflectors through parametric design, realizing the optical design of retroreflective structures with specific illuminance distributions, which has broad application prospects and market potential. It should be noted that the above embodiments are merely illustrative and not intended to limit the scope of protection of the present invention. Those skilled in the art can make various modifications and improvements without departing from the spirit and essence of the present invention, all of which should be included within the scope of protection of the present invention.

Claims

1. An optical element having parameterized optical structures, comprising a reference plane, and a plurality of optical structures formed on the reference plane, the plurality of optical structures being closely arranged in an array on the reference plane; characterized in that, The optical structure comprises: a reference sub-face formed by two equilateral triangles and shaped as a parallelogram; and a convex cube corner pyramid and a concave cube corner pyramid respectively constructed with the two equilateral triangles as their base faces; wherein the included angles between the three reflecting faces of the convex cube corner pyramid and the reference plane are defined as characteristic angular parameters i1, j1 and k1 respectively, and the included angles between the three reflecting faces of the second set of faces and the reference plane are defined as characteristic angular parameters i2, j2 and k2 respectively; the preferred configuration of the characteristic angular parameters enables the optical structure to exhibit a set retro-reflective luminance distribution.

2. The optical element according to claim 1, characterized in that The convex cube corner pyramid and the concave cube corner pyramid are both PG cube corner units.

3. The optical element according to claim 1 or 2, characterized in that, The edge length of the equilateral triangle constituting the reference sub-face is set as a characteristic length parameter Λ.

4. The optical element according to claim 3, characterized in that The characteristic length parameter Λ ranges from 0.01 mm to 1.0 mm.

5. The optical element according to claim 1, characterized by The included angles between the adjacent reflecting faces in the convex cube corner pyramid are defined as characteristic included angle parameters α1, β1 and γ1 respectively, and the included angles between the adjacent reflecting faces in the concave cube corner pyramid are defined as characteristic included angle parameters α2, β2 and γ2 respectively.

6. The optical element according to claim 5, characterized by The characteristic included angle parameters of each cube corner pyramid are determined by its characteristic angular parameters.

7. The optical element of claim 1, wherein The preferred configuration of the characteristic angular parameters enables the optical element to exhibit a set image.

8. The optical element according to claim 1 or 7, characterized by The characteristic angular parameters i1, j1 and k1 of the convex cube corner pyramid and the characteristic angular parameters i2, j2 and k2 of the concave cube corner pyramid can be independently assigned values.

9. The optical element of claim 1, wherein, The convex cube corner pyramid and the concave cube corner pyramid have a declination angle and / or an inclination angle.

10. The optical element of claim 1, wherein The method for the preferred configuration of the characteristic angular parameters is one or several of the steepest descent method, the Newton method and the L-BFGS algorithm.

11. The optical element of claim 1, wherein The optical element is a retro-reflector.

12. The optical element of claim 1, wherein, The two reflecting faces of the convex cube corner pyramid and its adjacent concave square corner pyramid share a base line and have characteristic angular parameters with similar values.

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