An ophthalmic lens system having a multi-scale optical microstructure array

Abstract

The present application relates to the technical field of optical system, and discloses an ophthalmic lens system with a multi-scale optical microstructure array, which comprises a refractive first optical microstructure unit with a first focal length and a diffractive second optical microstructure unit with a second focal length; the first and second optical microstructure units are arranged on an optical area in a non-periodic spatial layout, and the layout has a non-uniform spatial density that changes according to a radial position, the central area is biased to the second optical microstructure unit, and the peripheral area is biased to the first optical microstructure unit; the present application converts out-of-focus energy into unstructured background glow by using the non-periodic layout, realizes passive adaptation of light energy distribution to the pupil by using the non-uniform density, and compensates for chromatic dispersion by means of the mixed unit and the non-periodic layout.

Description

TECHNICAL FIELD

[0001] The application relates to an ophthalmic lens system with a multi-scale optical microstructure array, and belongs to the technical field of optical systems. BACKGROUND

[0002] At present, it is a key technical task to provide multifocal functions for ophthalmic applications, such as simultaneously meeting the needs of distance and near vision. The mainstream technical way to achieve this goal is to rely on the design and manufacture of microstructure arrays on the surface of optical components, such as diffractive optical components or microlens arrays, which use these structures to divide the incident light wavefront into different focal points. In order to ensure the predictability of optical design and the stability of manufacturing process, the design of the above-mentioned microstructure array has long relied on a core design method, that is, periodic arrangement, such as concentric ring band or regular grid layout. However, this dependence on periodicity also introduces an inherent constraint in optical physics. According to the principle of Fourier optics, the off-focus energy of any periodic structure when processing light waves must be structured in space and will produce coherent superposition at a certain spatial frequency. This physical property causes the off-focus energy to be concentrated to form a clear and high-energy density focal ring or diffraction order, which constitutes the physical root of visual interference artifacts.

[0003] In the face of this problem, the improvement ideas in the field are mostly concentrated in optimization within the periodic framework, such as through more complex grating profile design or phase control technology, trying to compensate or suppress the structured off-focus energy that has already been formed. A specific embodiment of this idea is to divide the optical area into concentric ring band areas with different functions, trying to match different visual needs in a partition compensation way. For example, Chinese invention patent CN120762223A discloses a microstructure lens and glasses, which tries to compensate the relative peripheral refractive power by setting a first optical zone with single effect stimulation and a second optical zone with multiple effect stimulation. However, the essence of this design idea has not deviated from the underlying framework of periodicity or regional structure. The different functional areas such as the clear area, the first optical zone and the second optical zone still rely on the rigid division of concentric ring bands. This clear functional boundary and regular layout within the area will also introduce new structured diffraction effects in physical principles, causing the off-focus energy to coherently superimpose at certain spatial positions such as the area boundary, forming interfering transition rings or halos. However, these methods do not deviate from the basis of periodic design, and their essence is to compensate for an already existing physical artifact rather than prevent it from forming from the source. This not only increases the complexity of optical design, but also often fails to achieve ideal results in all working conditions.

[0004] The prior art method has an inherent technical contradiction between realizing the multi-focal function and suppressing the structured artifact, and the limitations are: 1. The periodic layout relied on by the mainstream design determines that the defocus energy is necessarily structured in physical principle, which is the root cause of the interference artifact; 2. The subsequent compensation design idea increases the system complexity, but does not fundamentally change the structured nature of the defocus energy. Therefore, how to provide an optical assembly system, the structural design of which can change the distribution form of the defocus energy from the physical source, so that it realizes the multi-scale optical function while fundamentally changing the defocus energy into a non-structured spatial decorrelation form to avoid the formation of structured artifacts, becomes a technical problem to be solved by the present application. SUMMARY

[0005] The present application provides an ophthalmic lens system with a multi-scale optical microstructure array, which mainly aims to solve the problem that the existing optical assembly system generally relies on periodic microstructure layout, resulting in the defocus energy necessarily being structured in physical level, and then forming an interference artifact.

[0006] To achieve the above purpose, the present application provides an ophthalmic lens system with a multi-scale optical microstructure array, which comprises:

[0007] a lens body defining an optical area;

[0008] a first optical microstructure unit arranged on the optical area, the first optical microstructure unit being configured as a refractive optical unit with a first focal length; and a second optical microstructure unit arranged on the optical area, the second optical microstructure unit being configured as a diffractive optical unit with a second focal length;

[0009] The first optical microstructure unit and the second optical microstructure unit are arranged on the optical area in a non-periodic spatial layout; and the non-periodic spatial layout has a non-uniform spatial density, the relative number density of the first optical microstructure unit and the second optical microstructure unit varying according to the radial position thereof on the optical area;

[0010] The optical area includes a central area and a peripheral area surrounding the central area; in the central area, the number density of the second optical microstructure unit is higher than that of the first optical microstructure unit; and in the peripheral area, the number density of the first optical microstructure unit is higher than that of the second optical microstructure unit.

[0011] Preferably, at least one of the first optical microstructure units and the second optical microstructure units has at least one optical surface configured as an aspheric surface; the aspheric surface is determined by an optical design software based on a preset tilt angle, and a pre-compensation aberration introduced by the aspheric surface is configured to offset the coma caused by off-axis incidence when the system is tilted.

[0012] Preferably, the aperiodic spatial layout is generated based on a random lattice; the first optical microstructure units and the second optical microstructure units are configured as polygonal units with different shapes and sizes, and the polygonal units are formed based on the random lattice as a nucleation point for Voronoi tessellation; the polygonal units seamlessly fill the optical region.

[0013] Preferably, the aperiodic spatial layout is a random or pseudo-random spatial layout.

[0014] Preferably, the aperiodic spatial layout is generated based on a blue noise algorithm.

[0015] Preferably, the aperiodic spatial layout is generated based on a Poisson disc sampling algorithm.

[0016] Preferably, the first focal length is set to a focal length corresponding to distance vision, and the second focal length is set to a focal length corresponding to near vision.

[0017] Preferably, the diameter of the central region is set to a range of 2.0 mm to 3.5 mm, and the outer diameter of the peripheral region is set to a range of 5.0 mm to 6.5 mm.

[0018] Preferably, the non-uniform spatial density follows a preset radial density function; wherein r is a radial position coordinate measured from the center of the optical region, D1(r) is the number density of the first optical microstructure units at the radial position coordinate r, and D2(r) is the number density of the second optical microstructure units at the radial position coordinate r; the radial density function is configured such that D1(r) < D2(r) in the central region and D1(r) > D2(r) in the peripheral region.

[0019] Preferably, the central region and the peripheral region further include a transition region; in the transition region, the relative ratio between the number density D1(r) of the first optical microstructure units and the number density D2(r) of the second optical microstructure units is a monotonic function of the radial position coordinate r.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] 1、The system layout adopted by the present application arranges microstructure units with first optical characteristics and microstructure units with second optical characteristics on an optical area in a non-periodic spatial layout. This non-periodic structure design avoids the coherent superposition of defocus energy at specific frequencies in space caused by periodic structures when processing defocus light, and instead forms spatially uncorrelated non-coherent superposition of defocus energy on the focal plane. This change in physical properties converts the energy that would have formed a structured halo into a non-structured uniform background glow, thereby changing the distribution of defocus energy from an optical physics perspective.

[0022] 2、On the basis of the non-periodic spatial layout, the present application further designs the layout to have a non-uniform spatial density, so that the relative number density of the first optical microstructure units and the second optical microstructure units changes according to the radial position on the optical area. This structure design causes the overall light energy distribution ratio of the optical system to change passively when facing different sizes of incident pupils, for example, corresponding to physiological pupil changes under different lighting conditions. For example, when the pupil contracts through only the central area, the system can focus on presenting the effect of the second optical characteristics. When the pupil expands to cover the peripheral area, the system automatically introduces the optical characteristics of the peripheral area, for example, focusing on the first optical characteristics, so that a static optical component obtains adaptive optical characteristics for dynamic working conditions.

[0023] 3、The present application also cooperatively designs the non-periodic spatial layout and the optical surface morphology of the microstructure units, that is, at least one of the first optical microstructure units or the second optical microstructure units has an aspherical surface or a freeform surface. This specific optical surface morphology is configured to compensate for the off-axis aberration introduced when the optical system is tilted or decentered during actual installation or wearing. This design enables the micro units constituting the array to have the ability to correct aberrations of off-axis incident light, thereby ensuring that the non-structured background glow generated by the non-periodic layout, such as the uniform characteristics of the first effect, is maintained under non-ideal centering conditions, avoiding degradation into new structured spots due to off-axis aberration pollution. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 It is a schematic diagram of the functional architecture of the non-periodic microstructure array of the present application.

[0025] Fig. 2 It is a comparison chart of the defocus energy distribution of the periodic and non-periodic layouts of the present application.

[0026] Fig. 3 It is a flowchart of the design, manufacture, and performance verification of the optical system of the present application. DETAILED DESCRIPTION

[0027] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and should not be used to limit the protection scope of the present application.

[0028] An ophthalmic lens system with a multi-scale optical microstructure array, one of the core optical system architectures is built on a lens body that defines an optical area, the optical area is arranged with two kinds of microstructure units that are completely different in optical properties but work together in spatial layout, namely the first optical microstructure unit with the first focal length of the refractive type, and the second optical microstructure unit with the second focal length of the diffractive type, the two units together constitute a composite array for realizing multi-scale optical function, through systematic optical design of the spatial layout, unit density, and unit itself optical form of the array, it is used to deal with the structured artifacts problem caused by relying on periodic structure in the prior art; in the design practice of the optical system, the traditional periodic microstructure array with concentric ring band or regular grid layout will inevitably produce coherent superposition at a certain frequency in space according to the Fourier optical principle when dealing with defocus light, forming a clear profile, high energy density focal ring or diffraction order, these structured defocus energy is identified as an interfering halo in visual perception; in order to change the distribution form of defocus energy from the physical source, the core optical mechanism adopted by the present scheme is that the first optical microstructure unit and the second optical microstructure unit are arranged on the optical area in a non-periodic spatial layout, this non-periodic structure design, for example, a random or pseudo-random spatial layout, is equivalent to a random spatial filter in optical effect, which makes the wavefront from each defocus unit spatially uncorrelated on the focal plane, they will not be coherently superimposed at a certain position, but form incoherent superposition, this change in physical properties makes the energy that originally forms structured halos be transformed into a non-structured, spatially uniform background glow.

[0029] In the specific engineering practice of implementing the aperiodic layout, in order to ensure that the layout has excellent uniformity in statistics, and to avoid the aggregation effect in small scales due to insufficient random sampling, the aperiodic spatial layout can be generated based on a specific optical design algorithm. In a preferred embodiment, the layout is generated based on a blue noise algorithm, or the layout is generated based on a Poisson disk sampling algorithm, both of which can ensure that the sampling points maintain a minimum distance, thereby ensuring the local uniformity of the microstructure units in spatial distribution while introducing randomness. This local uniformity plays a key role in realizing the background glow, and it avoids the aggregation effect (Clustering) or voids (Voids) in spatial distribution caused by simple random sampling in optical physics. Such aggregation and voids correspond to low-frequency noise components sensitive to the human visual system in the spatial frequency domain. When the out-of-focus energy distribution contains such low-frequency noise, it will appear as uneven mottling or speckle in visual perception, which constitutes new visual interference. In contrast, the blue noise or Poisson disk sampling algorithm of the present application generates a dot matrix with noise energy mainly concentrated in the high-frequency region in the spatial frequency domain, and there is an energy void in the low-frequency region sensitive to the human eye. This makes the out-of-focus energy converted into a truly uniform background glow without low-frequency mottling in space. The noise characteristics (high frequency) of this glow are naturally smoothed and averaged on the retina after passing through the optical system of the human eye (lens, etc.), so that it is identified as a negligible, uniform background glow or mist in visual perception, ensuring the visual friendliness of unstructured artifacts. After obtaining the coordinate points of the aperiodic layout, in order to realize seamless filling of the optical area, the first optical microstructure unit and the second optical microstructure unit can be constructed as multiple polygonal units with different shapes and sizes. These polygonal units are formed based on random dot arrays as crystal nucleus points for Voronoi tessellation division. This Voronoi tessellation structure enables all units to seamlessly fill the optical area, and the double randomness in position and shape further enhances the spatial decorrelation characteristics of the out-of-focus energy, ensuring that the background glow remains highly uniform even under small pupils, i.e., small sampling windows.

[0030] Furthermore, the optical system also faces an objective problem arising from the real application environment, that is, the size of the entrance pupil faced by the ophthalmic lens system, which is the physiological pupil of the human eye, is dynamically variable. For example, the pupil dilates in low light and constricts in bright light. It is difficult for a static and uniformly distributed microstructure array to achieve optimal light energy distribution under all working conditions. To solve this dynamic adaptation problem of the optical system, the present solution further designs the non-periodic spatial layout to have a non-uniform spatial density. Among them, the relative number density of the first optical microstructure unit and the second optical microstructure unit varies according to its radial position in the optical region. The optical region is divided into a central region and a peripheral region surrounding the central region. The first focal length is set to a focal length corresponding to distant vision, and the second focal length is set to a focal length corresponding to near vision. Given that the pupil constricts in bright light and the demand for near vision increases, while the pupil dilates in low light and the demand for distant vision dominates, the optical system is configured as follows: in the central region, the number density of the second optical microstructure unit (near focus) is higher than that of the first optical microstructure unit (distant focus); while in the peripheral region, the number density of the first optical microstructure unit (distant focus) is higher than that of the second optical microstructure unit (near focus). This design enables a static optical component to acquire the passive adaptation ability to dynamic working conditions. When the pupil constricts and only passes through the central region, the system automatically focuses on the near-focus function. When the pupil dilates to cover the peripheral region, a large number of distant-focus units from the peripheral region are activated, and the overall light energy distribution of the system is passively and automatically shifted to the distant-focus function.

[0031] When determining the key parameters of the above-mentioned partitioned optical structure, the diameter of the central region is set to an interval that matches the typical constriction range of the physiological pupil in bright light, for example, within the range of 2.0 mm to 3.5 mm; the outer diameter of the peripheral region corresponds to the pupil dilation range in low light and is, for example, set within the range of 5.0 mm to 6.5 mm; the relative density change of the two types of units follows a preset radial density function. Among them, r is the radial position coordinate measured from the center of the optical region, D1(r) is the number density of the first optical microstructure unit at the radial position coordinate r, D2(r) is the number density of the second optical microstructure unit at the radial position coordinate r. The radial density function is configured as follows: in the central region, D1(r) < D2(r); in the peripheral region, D1(r) > D2(r); to avoid sudden changes in light energy distribution between different regions, a transition region may also be included between the central region and the peripheral region. In the transition region, the relative ratio between D1(r) and D2(r) is a monotonic function of the radial position coordinate r.

[0032] In determining the preset radial density functions D1(r) and D2(r) followed by the non-uniform spatial density, the specific engineering procedures can include: first, setting the light energy distribution targets under at least two key working conditions, for example, under a 3.0 mm aperture diameter (simulating bright light), the energy proportion target of the focal plane corresponding to the second focal length f2 is set to 65% to 70%, and under a 6.0 mm aperture diameter (simulating dark light), the energy proportion target of the focal plane corresponding to the first focal length f1 is set to 65% to 70%; second, constructing a parameterized radial function P2(r) = D2(r) / (D1(r) + D2(r)) for representing the relative number density of the second optical microstructure unit (near focus), which at least includes a radial coordinate parameter r0 for defining the center position of the transition region and a slope parameter k for defining the steepness of the transition; finally, in the optical design software system, taking r0 and k as optimization variables, and the energy proportion targets of the above two working conditions as optimization constraint conditions, through iterative calculation, a specific value of r0 and k is determined which can make the simulation light energy distribution result deviate from the preset target value by the minimum, so as to uniquely determine the radial density functions D1(r) and D2(r).

[0033] In generating the microstructure array combining non-periodic layout and non-uniform density, the specific physical structure implementation procedures can include: first, based on a preset total unit density function, a set of non-periodic crystal nucleus point coordinates is generated on the entire optical area by using the blue noise algorithm or the Poisson disk sampling algorithm; second, taking the set of crystal nucleus points as a reference, the Voronoi tessellation algorithm is executed to generate a geometric grid data composed of multiple polygonal units with different shapes and sizes, which fills the optical area without gaps; third, each polygonal unit in the grid is traversed to obtain the radial coordinate r i of the geometric centroid of the polygonal unit, and the target probability P2(r i ) of the second optical microstructure unit (near focus) at this position is calculated according to the radial density function determined in the previous step; fourth, a pseudo-random number R in the interval (0, 1) is compared with the target probability P2(r i ), if R < P2(r i ), the mask data of the polygonal unit is constructed as a diffractive optical unit, otherwise, it is constructed as a refractive optical unit, until all units are assigned types, thereby generating the final digitized mask data.

[0034] In addition, the optical system must also take into account the off-axis aberration problem introduced by the inevitable tilt or decentration of the lens under real installation or wearing conditions. This off-axis incidence, especially coma, will pollute the uniform background glow produced by the aperiodic layout and degrade it into new structured spots. To ensure the robustness of the optical system under off-axis working conditions, the micro-units constituting the array are functionally designed. That is, at least one of the first optical micro-structure unit and the second optical micro-structure unit has at least one optical surface configured as an aspheric surface. The surface morphology of the aspheric surface is determined by optimizing a preset tilt angle (for example, a simulated 5-degree installation tilt) using optical design software (such as ZEMAX or CODEV). The pre-compensation aberration introduced by the surface morphology is configured to exactly offset the coma generated by off-axis incidence when the system is tilted. This design enables the micro-units constituting the array to have the ability to correct off-axis aberration, thereby ensuring that the uniformity of the unstructured background glow produced by the aperiodic layout is maintained under non-ideal centering conditions.

[0035] In the optimization of aspherical optical surface profile to compensate for off-axis aberration, the optimization procedure in optical design software is based on a multi-constrained optimization merit function configured to minimize coma generated by off-axis incidence at a preset tilt angle such as 5 degrees, for example, by minimizing Zernike coma coefficients Z7 or Z8 of a specific field of view, while iterating high-order coefficients of aspherical surface as optimization variables, and the iteration process is subject to at least two key performance constraints: one is that the Strehl ratio of the main focal spot energy concentration degree of the focal plane corresponding to the first focal length f1 and the focal plane corresponding to the second focal length f2 must be maintained above a preset performance baseline such as 0.8 when the system is not tilted (0 degrees); the second is that the intensity distribution modulation depth of the background glow area formed by the out-of-focus energy must be constrained below a preset low threshold such as 0.05 in the non-tilted working condition to maintain the uniformity of the glow; finally, the optical system design also utilizes the hybrid characteristics of non-periodic layout to solve the dispersion problem under multi-spectral (white light) illumination, and the refractive optical unit in the optical assembly usually has positive dispersion, while the diffractive optical unit has strong negative dispersion with opposite characteristics; this scheme utilizes this physical characteristic, designs the first optical microstructure unit as a refractive optical unit, and the second optical microstructure unit as a diffractive optical unit, both of which participate in non-periodic layout, and under this optical system configuration, the non-periodic spatial layout functions as a dispersion mixer: it spatially mixes the two units with opposite dispersion characteristics on a microscopic scale, so that the positive dispersion from the refractive unit and the negative dispersion from the diffractive unit are statistically compensated on the focal plane.

[0036] Example 1: In one specific application scenario, an ophthalmic lens system with a multi-scale array of optical microstructures is applied to a typical working condition with stringent requirements on optical performance, namely night driving; this working condition requires the user to maintain clear distance vision while dealing with the interference from high-contrast light sources such as oncoming vehicle headlights; in this dark environment, the user's physiological pupil dilates to a diameter of, for example, 6.0 mm, which size causes the incident light to cover both the central and peripheral regions of the optical area; at this time, two key design features of the optical system are activated and work together, first, for distance vision tasks, the light passing through the peripheral region of the pupil mainly interacts with the optical microstructure units in the peripheral region, given that the peripheral region is configured to have a high number density of first optical microstructure units, i.e. units corresponding to the distance vision focal length, the light energy from this large-area peripheral region is focused to the far focal point; this part of the light energy is superimposed with the light energy focused by the first optical microstructure units in the central region, so that the proportion of the total light energy received by the system allocated to the far focal point is automatically increased, thereby providing the required distance vision clarity for night driving.

[0037] Secondly, for the interfering light from the oncoming vehicle headlights, the microstructure units in the system that are in a defocused state, i.e. the second optical microstructure units mainly distributed in the central region, i.e. units corresponding to the near vision focal length, also act on it, but since the microstructure units of the system all follow a non-periodic spatial layout, the energy generated by these defocused units forms a spatially uncorrelated incoherent superposition in the focal plane, rather than being focused into a structured light halo with clear contours; the result of the operation of this optical system in this specific working condition is that the user obtains distance vision with optimized light energy distribution, while the defocused energy excited by the strong light source is converted into a layer of unstructured low-contrast background glow, which is considered as negligible background noise at the physiological perception level, rather than an interfering, high-contrast false signal, thereby addressing the visual interference problem of multifocal optical systems in dark high-contrast scenes.

[0038] Example 2: To objectively quantify the optical properties of the ophthalmic lens system with multi-scale optical microstructure array, an optical testing platform was built, which includes a collimated laser for simulating an infinite point light source, a precision adjustment stand for mounting the test lens, a variable precision diaphragm for simulating the physiological pupil, and a charge-coupled device (CCD) image sensor set at the focal plane for collecting the light intensity distribution, with a pixel pitch of 5.0 microns; three groups of optical lenses with the same base material and the same focal length (the first focal length f1 is set to be far focus, and the second focal length f2 is set to be near focus) were prepared in this test: control group A, whose surface has traditional periodic concentric ring band microstructure; inventive sample group B, whose surface has non-periodic spatial layout of microstructure units with uniform spatial density as described in the detailed description; and inventive sample group C, whose surface has non-periodic spatial layout of microstructure units with non-uniform spatial density, with a central region diameter of 3.0 mm, the number density of the second optical microstructure units in this region is higher than that of the first optical microstructure units, and in the peripheral region of 3.0 mm to 6.0 mm diameter, the number density of the first optical microstructure units is higher than that of the second optical microstructure units; Test 1: Quantitative comparison of off-focus energy spatial distribution morphology, the diameter of the variable precision diaphragm was set to 5.0 mm to simulate the pupil state in dark light; control group A and inventive sample group B were placed on the adjustment stand respectively, with the CCD sensor located at the focal plane corresponding to the first focal length f1 of each lens, the collimated laser was started to illuminate, and the point spread function (PSF) image of each lens on the focal plane was collected and recorded; then, the collected PSF image data was processed, a one-dimensional light intensity distribution curve was extracted from the radial direction of the light spot center point, and the peak intensity (percentage relative to the main focus spot peak) of the secondary light ring or background glow formed by the off-focus energy and the light intensity distribution modulation depth (calculated as the standard deviation of the light intensity distribution) of the glow region were calculated, see Table 1.

[0039] Table 1: Comparative data table for off-focus energy spatial distribution characteristics.

[0040]

[0041] Referring to Table 1, the test data of the control group A (periodic layout) shows that it produces a secondary light ring with a peak intensity of 14.8% on the focal plane, and the modulation depth of the glow area is 0.41, indicating that the off-focus energy is concentrated in a specific spatial position, forming a structured distribution; the off-focus energy peak intensity of the sample group B (uniform non-periodic layout) of the application is not higher than 0.9%, and the modulation depth is 0.04, the data shows that the non-periodic spatial layout effectively decorrelates the off-focus energy in space, making its distribution form a layer of low-amplitude, uniform background glow; Test two: response characteristics of light energy distribution to system diaphragm diameter, using the same optical test platform, respectively test the light energy distribution ratio of the sample group B (uniform non-periodic) and the sample group C (non-uniform non-periodic) of the application under different diaphragm diameters; the first working condition (simulating bright light) sets the diaphragm diameter to 3.0mm, and the second working condition (simulating dark light) sets the diaphragm diameter to 6.0mm; under each working condition, the total light energy converging on the focal plane corresponding to the first focal length f1 and the total light energy converging on the focal plane corresponding to the second focal length f2 are measured and calculated respectively, and the percentage of the two is calculated.

[0042] Table 2: is a data table of far / near focal light energy distribution ratio under different system diaphragm diameters.

[0043]

[0044] Referring to Table 2, the far / near focal light energy distribution ratio of the sample group B (uniform layout) of the application maintains at about 50%:50% under 3.0mm and 6.0mm diaphragms; the sample group C (non-uniform layout) of the application has a light energy distribution ratio of 31.1% (far) : 68.9% (near) under 3.0mm diaphragm; when the diaphragm is expanded to 6.0mm, the light energy distribution ratio changes to 69.5% (far) : 30.5% (near); the test data shows that using a non-periodic spatial layout with non-uniform spatial density (such as the sample group C of the application), the light energy distribution ratio of the optical assembly system changes with the change of the incident pupil diameter, and the energy distribution is focused on the near focal point under small pupil and on the far focal point under large pupil.

[0045] Example 3: This example describes an ophthalmic lens system with a multi-scale optical microstructure array, such as Figs. 1 to 3 , which includes a lens having a front surface and a back surface, and a plurality of optical microstructures disposed on the front surface of the lens. Fig. 1As shown, the incident light enters the microstructure array arrangement layer, which is composed of refractive type first optical microstructure units with a first focal length for distance vision and diffractive type second optical microstructure units with a second focal length for near vision. The arrangement layer adopts a non-periodic spatial layout, which functions to convert out-of-focus energy into unstructured background glow to achieve structured artifact elimination. At the same time, the layout has a non-uniform spatial density, which functions to achieve passive adaptation of light energy distribution to the pupil. In addition, the unit structure design adopts an aspherical optical surface morphology to compensate for the off-axis coma introduced by system tilt to maintain optical performance under tilt conditions. The mixed use of refractive positive dispersion and diffractive negative dispersion units in the unit type achieves mixed unit dispersion compensation, which is statistically complementary to reduce overall dispersion. Finally, through light energy distribution optimization, a multifocal output with distance / near focal energy distribution optimization and no structured halo interference is achieved.

[0046] As shown in Fig. 2 The periodic layout shown by the dashed line in the graph has a high-intensity light ring with a peak value of nearly 15% at a radial position of 0.5 mm, indicating that the out-of-focus energy is highly concentrated. The non-periodic layout shown by the solid line in the graph has an optical intensity below 1% at all radial positions, showing a low-amplitude diffuse distribution, verifying the function of converting out-of-focus energy into unstructured background glow. As shown in Fig. 3 As shown, the optical design software system generates digital mask data for the microstructure units through the blue noise / Poisson disk algorithm module and the Voronoi tessellation segmentation program based on input data such as distance / near vision focal length requirements, and uses the aspherical coma compensation optimization module for aberration compensation. Precise manufacturing and processing equipment etches or forms a microstructure array on the lens body (substrate) based on the data to realize the physical structure and produce the lens to be tested. The optical performance test platform simulates pupil changes using a variable precision diaphragm, uses a point spread function PSF acquisition module and a light energy distribution proportion analyzer to verify the characteristics of the physical product, and generates a test report data containing peak intensity, modulation depth and energy proportion. The data can be fed back to the design system for design parameter correction.

[0047] Example 4: To further illustrate the difference in the defocus energy distribution pattern between the non-periodic spatial layout and the prior art periodic layout, the following comparative test was conducted. The comparative test was used to compare the difference in the defocus energy spatial distribution pattern between the optical lens using the non-periodic spatial layout and the optical lens using the traditional periodic spatial layout. The test conditions and test procedures were the same as those in Example 2 Test 1. The control group A had the traditional periodic concentric ring band microstructure layout as in Example 2, and the sample group B of the present application had the uniform non-periodic spatial layout as in Example 2. The base material, the first focal length f1, the second focal length f2, and the microstructure unit type of the two groups of lenses were set to be consistent. During the test, the variable precision diaphragm diameter was set to 5.0 mm, and the control group A and the sample group B of the present application were tested respectively. The collimated laser was started to illuminate, and the point spread function image was collected at the focal plane corresponding to the first focal length f1 of each lens by using the CCD image sensor. Then the collected image data was processed, the one-dimensional radial light intensity distribution was extracted, and the peak intensity of the secondary light ring or the background glow formed by the defocus energy was calculated in percentage of the main focal spot peak intensity, and the modulation depth of the glow region light intensity distribution was calculated in standard deviation of the light intensity distribution. The results are shown in Table 3.

[0048] Table 3: Comparative data table of defocus energy spatial distribution characteristics under different layout modes.

[0049]

[0050] Referring to Table 3, the test measured that the control group A (periodic layout) formed a clear secondary light ring structure with a peak intensity of 14.8% of the main focal spot at the focal plane corresponding to the first focal length f1, and the modulation depth of the glow region light intensity distribution was 0.41, indicating that the defocus energy presented a highly concentrated structured pattern in space. The sample group B (uniform non-periodic layout) of the present application had a peak intensity of the defocus energy on the focal plane not higher than 0.9% of the main focal spot under the same test conditions, and the modulation depth of the glow region light intensity distribution was 0.04, and the energy presented a low-amplitude, diffuse non-structured background glow distribution. The test data of the comparative test showed that under the condition that all other conditions were the same except the microstructure unit layout mode, the periodic layout led to the defocus energy concentrated to form a structured halo, and the non-periodic spatial layout converted the defocus energy into a non-structured background glow.

[0051] Example 5: To verify the compensation effect of the aspherical optical microstructure unit on the off-axis aberration under the system tilt working condition, a simulation test was carried out by using an optical simulation software; two optical system models were constructed, model one (control) adopted the uniform non-periodic spatial layout of the sample group B of the application in example 2, but the surface morphology of the microstructure unit was set as a spherical surface; model two (test) also adopted the layout of the sample group B of the application, but the surface morphology of the microstructure unit was set as an aspherical surface, and the aspherical surface parameter was determined after coma compensation optimization for a preset 5-degree tilt angle; in the simulation, the two models were both set to be tilted by 5 degrees relative to the optical axis, parallel light was used for incidence, and the point spread function (PSF) was recorded at the focal plane corresponding to the first focal length f1; the PSF data was analyzed, and the symmetry and uniformity of the morphology of the background glow formed by the out-of-focus energy were particularly focused on; the simulation results showed that the background glow of model one (spherical unit) under the tilt condition presented a clear asymmetric morphology, which was a comet-like tail, indicating that there was an uncompensated coma; the background glow of model two (aspherical unit) under the same tilt condition remained good symmetry and uniformity, and its morphology was close to that of the unstructured glow without tilt, indicating that the aspherical design effectively compensated the off-axis coma introduced by the tilt, and maintained the optical performance of the non-periodic layout under the off-axis working condition.

[0052] Example 6: To verify the effect of the Voronoi tessellation structure in maintaining the uniformity of the background glow under small pupil conditions, a simulation test was continued by using an optical simulation software; two optical system models were constructed, model three (control) adopted the uniform non-periodic spatial layout of the sample group B of the application in example 2, the microstructure unit was set as a uniform square, and there was a non-optical function gap between the units; model four (test) adopted the same random point array to generate Voronoi tessellation units, so that the unit shapes were not the same and the optical area was seamlessly filled; in the simulation, a circular diaphragm with a diameter of 2.0 mm was used to simulate the small pupil state, and was placed at the center in front of the model, parallel light was used for incidence, and the point spread function (PSF) passing through the diaphragm area was recorded at the focal plane corresponding to the first focal length f1; the PSF data was analyzed, the spatial standard deviation of the light intensity in the background glow area (after excluding the main focal spot) was calculated, so as to quantify the uniformity of the glow; the simulation results showed that the light intensity standard deviation of the background glow area of model three (square unit) under the 2.0 mm small pupil was 0.09, which showed a certain spatial non-uniformity and presented a mottled feeling; the light intensity standard deviation of the background glow area of model four (Voronoi unit) under the same condition was 0.03, which was lower than that of model three, indicating that the Voronoi tessellation structure improved the statistical uniformity of the non-periodic layout under small sample size (small pupil) through shape randomness and seamless filling, suppressed the statistical aggregation effect, and made the background glow still maintain a high uniformity under the condition of small bright pupil.

[0053] It is apparent for a person skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but that the present application can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit the present application, and although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the spirit and scope of the present application.

Claims

1. An ophthalmic lens system having a multi-scale array of optical microstructures, characterized in that, The system comprises: a lens body defining an optical zone; first optical microstructure units arranged on the optical zone, the first optical microstructure units being configured as refractive optical units having a first focal length; and second optical microstructure units arranged on the optical zone, the second optical microstructure units being configured as diffractive optical units having a second focal length; the first optical microstructure units and the second optical microstructure units are collectively arranged on the optical zone in a non-periodic spatial layout; and the non-periodic spatial layout has a non-uniform spatial density, the relative number density of the first optical microstructure units and the second optical microstructure units varying according to their radial position on the optical zone; the optical zone comprises a central zone and a peripheral zone surrounding the central zone; in the central zone, the number density of the second optical microstructure units is higher than that of the first optical microstructure units; and in the peripheral zone, the number density of the first optical microstructure units is higher than that of the second optical microstructure units; wherein at least one of the first optical microstructure units and the second optical microstructure units has at least one optical surface configured as an aspheric surface; the surface form of the aspheric surface is determined by optimizing a preset tilt angle using optical design software, and the pre-compensation aberration introduced by the surface form is configured to offset the coma generated by off-axis incidence when the system is tilted; the non-periodic spatial layout is generated based on a blue noise algorithm or a Poisson disc sampling algorithm.

2. The ophthalmic lens system having a multi-scale array of optical microstructures of claim 1, wherein, the non-periodic spatial layout is generated based on a random point array; the first optical microstructure units and the second optical microstructure units are configured as polygonal units of different shapes and sizes, the polygonal units being formed by Voronoi tessellation based on the random point array as nucleation points; and the polygonal units seamlessly cover the optical zone.

3. The ophthalmic lens system having a multi-scale array of optical microstructures of claim 1, wherein, the non-periodic spatial layout is a random or pseudo-random spatial layout.

4. The ophthalmic lens system having a multi-scale array of optical microstructures of claim 1, wherein, the first focal length is set as a focal length corresponding to distance vision, and the second focal length is set as a focal length corresponding to near vision.

5. The ophthalmic lens system having a multi-scale array of optical microstructures of claim 1, wherein, the diameter of the central zone is set to be in the range of 2.0 mm to 3.5 mm, and the outer diameter of the peripheral zone is set to be in the range of 5.0 mm to 6.5 mm.

6. The ophthalmic lens system having a multi-scale array of optical microstructures of claim 1, wherein, the non-uniform spatial density follows a preset radial density function; wherein r is a radial position coordinate measured from the center of the optical zone, D1(r) is the number density of the first optical microstructure units at the radial position coordinate r, and D2(r) is the number density of the second optical microstructure units at the radial position coordinate r; the radial density function is configured such that in the central zone, D1(r) < D2(r), and in the peripheral zone, D1(r) > D2(r).

7. The ophthalmic lens system having a multi-scale array of optical microstructures of claim 6, wherein, the central zone and the peripheral zone further comprise a transition zone; in the transition zone, the relative proportion between the number density D1(r) of the first optical microstructure units and the number density D2(r) of the second optical microstructure units is a monotonic function of the radial position coordinate r.

Images