A positive defocused eyeglass lens and design method thereof

Abstract

The present application provides a positive defocused spectacle lens and a design method thereof. The lens has a first optical surface and a second optical surface arranged opposite to each other, the second optical surface is close to the user's eye side, and a ring-shaped or circular aspheric microlens array is arranged in the middle of the first optical surface, and the aspheric microlens array includes: a compound microlens. The positive defocused spectacle lens can correct the refractive error of the central vision of the human eye, and can also improve the strabismus imaging quality of the multiple microlenses used to form the peripheral myopic defocus of the retina, thereby improving the adaptation difficulty problem commonly existing in multi-point positive defocused spectacle lenses.

Description

Technical Field

[0001] The present application belongs to the field of optical technology and relates to a positive defocus type eyeglass lens and a design method thereof. Background Art

[0002] Nowadays, technology is developing rapidly, and electronic products have become an indispensable tool for people every day. Excessive use of eyes, especially long-term use of electronic products, has become an important cause of myopia. According to a research report by the World Health Organization, there are as many as 600 million myopic patients in China, and the myopia rate among young people ranks first in the world. China has become the world's largest country with myopia. Therefore, refractive correction is urgent.

[0003] Due to hyperopic defocus or myopic defocus, the human eye will grow toward the back or front of the retina, causing the eye axis to grow or shorten, and the refractive state of the eyeball to develop in the opposite direction. On the basis of refractive correction, functional eyeglasses that can suppress human eye refractive errors have emerged. For example, positive defocus eyeglasses designed with microlens arrays can effectively solve the problem of eye axis growth or shortening. This type of eyeglasses slows down the progression of myopia in adolescents by 59%.

[0004] Chinese invention patent CN104678572 B discloses a spectacle lens, in which a number of circular small area lenses with a diameter of about 0.8mm to 2mm are arranged in different areas to form a second refractive area. While visually distinguishing the image formed by the first refractive power, the development of myopia is suppressed by the image obtained in front of the retina by the second refractive area. In the above scheme, it can be seen from the embodiment that the circular microlens used to form the second refractive area is a spherical surface, and the image is slightly blurred. During the fitting process, the proportion of users feeling uncomfortable wearing is relatively high. Summary of the invention

[0005] In order to overcome the above-mentioned defects, the purpose of the present application is to propose a positive defocus type eyeglass lens and a design method thereof.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] A positive defocused spectacle lens, the lens having a main lens structure and an aspherical microlens array; the main lens structure is provided as a first optical surface and a second optical surface arranged oppositely; the second optical surface is close to the user's eye side, and a ring-shaped or circular aspherical microlens array is arranged in the middle of the first optical surface, and the aspherical microlens array includes: a compound microlens. In this way, the positive defocused spectacle lens using an aspherical microlens array can suppress the refractive error of the eye while improving the imaging quality, ensuring sufficient visibility and a good wearing feeling.

[0008] Preferably, the diameter of the microlens is between 0.8 mm and 2 mm.

[0009] Preferably, the diameter of the aspherical microlens is between 0.9 mm and 1.5 mm.

[0010] The present application provides a method for designing a positive defocus eyeglass lens, the method comprising:

[0011] S1. Calculate the main focal length F of the eyeglass lens;

[0012] S2. Based on the calculation formula: f = Fd, calculate the focal length f of the microlens array,

[0013] Where, d is the focal plane distance difference;

[0014] S3. Calculate the radius of curvature r of the microlens based on the radius of curvature r2 of the second optical surface of the eyeglass lens, the focal length f of the microlens array, and the material refractive index n;

[0015] S4. Establish a microlens array model and optimize the surface of each ring zone.

[0016] Preferably, step S4 includes:

[0017] A microlens array model is established according to the position, diameter, curvature radius r, material refractive index n and curvature radius r2 of the second optical surface of the microlens. The spectacle lenses designed by this method can correct the refractive error of the central vision of the human eye and improve the adaptation difficulty commonly found in multi-point forward defocus lenses.

[0018] Preferably, step S4 further includes: when optimizing a single microlens in the array,

[0019] Based on the aberrations formed by the main lens structure, the positions of the microlenses in different annular zones, and the angular orientation, the surface is optimized with the goal of minimizing the spherical aberration of the focusing point.

[0020] Preferably, the design method of the forward defocused eyeglass lens also includes: calculating the human eye perceived luminosity of each annular zone microlens according to the position and angular orientation of the microlenses in different annular zones and according to an imaging system with a far point spherical surface 25 mm away from the lens, and reversely calculating and confirming the actual vertex luminosity of the different microlenses in each annular zone according to the unified human eye perceived luminosity of each annular zone.

[0021] Beneficial Effects

[0022] The positive defocused spectacle lens proposed in the present application has the following features:

[0023] 1) Better imaging quality. While correcting the refractive error of the center of the macula, the imaging quality of the microlens array in each peripheral ring zone is improved, and the adaptation difficulty problem that is common in current positive defocus lenses is improved.

[0024] 2) No additional production difficulty is added. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1a is an imaging optical path diagram of a spherical microlens according to an embodiment of the present application,

[0026] Figure 1b is an imaging optical path diagram of the aspheric microlens of an embodiment of the present application,

[0027] Figure 2 Schematic diagram of the optical path of the main lens structure and micro-lens of an embodiment of the present application.

[0028] Figure 3 This is a cross-sectional view of a spectacle lens according to an embodiment of the present application.

[0029] Figure 4 This is a plan view of a spectacle lens according to an embodiment of the present application.

[0030] Figure 5 A magnified detail of the microlens array of an eyeglass lens.

[0031] Among them, 1. the first optical surface, that is, the object side surface; 2. the second optical surface, that is, the eye side surface; 3. the first refractive area; 4. the microlens area. DETAILED DESCRIPTION

[0032] The above scheme is further described below in conjunction with specific examples. It should be understood that these examples are used to illustrate the present application and are not limited to the scope of the present application. The implementation conditions adopted in the examples can be further adjusted as the conditions of the specific manufacturer, and the unspecified implementation conditions are usually the conditions in conventional experiments.

[0033] The present application provides a positive defocused spectacle lens, which has a first optical surface and a second optical surface arranged oppositely, and a ring-shaped or circular aspheric microlens array is arranged in the middle of the first optical surface, and the aspheric microlens array includes: a plurality of microlenses. The positive defocused spectacle lens can correct the refractive error of the central vision of the human eye, and can also improve the strabismus imaging quality of the plurality of microlenses used to form the peripheral myopic defocus of the retina, thereby improving the adaptation difficulty problem commonly existing in multi-point positive defocused lenses.

[0034] Next, the forward defocused spectacle lens and the design method thereof proposed in the present application will be described in conjunction with the accompanying drawings.

[0035] like Figure 1a The imaging optical path diagram of the spherical microlens is shown in Figure 2. Figure 1bThe figure shows the imaging optical path of the aspherical microlens. As can be seen from the figure, the spherical aberration caused by the microlens with a spherical structure is relatively large, and the spot diagram is large, resulting in poor imaging quality. The spherical aberration caused by the microlens with an aspherical structure is relatively small, and the smaller the spot diagram, the better the imaging quality.

[0036] Figure 2 Schematic diagram of the optical path of the focal plane (primary focal plane) of the main lens structure and the focal plane (secondary focal plane) of the microlens of the lens according to the embodiment of the present application.

[0037] The figure shows the positional relationship between the primary focal plane generated by the main lens structure and the secondary focal plane generated by the microlens, wherein the secondary focal plane is approximately 5 mm to 10 mm in front of the primary focal plane (ie, the retina).

[0038] Figure 3 This is a cross-sectional view of a spectacle lens according to an embodiment of the present application.

[0039] The spectacle lens is a spectacle lens with an aspherical microlens structure, and comprises a first optical surface 1 (ie, an object-side surface) and a second optical surface 2 (ie, an eye-side surface) which are arranged opposite to each other.

[0040] The first optical surface 1 is provided with an aspherical microlens array 11, which includes a plurality of microlenses arranged in a circular ring. In this embodiment, the diameter of the microlens is between 0.8 mm and 2 mm. Preferably, the diameter of the aspherical microlens is between 0.9 mm and 1.5 mm.

[0041] like Figure 4 The figure is a schematic plan view of a spectacle lens according to an embodiment of the present application at one viewing angle.

[0042] The eyeglass lens comprises: a first refractive area 3 and a microlens area 4 of an aspherical microlens array.

[0043] In this embodiment, the material refractive index of the eyeglass lens is n, the radius of curvature of the first optical surface 1 is r1, the radius of curvature of the second optical surface 2 is r2, and the focal length is F.

[0044] Next, the design method of the above-mentioned lens is described.

[0045] The design approach includes:

[0046] S1. Calculate the main focal length F of the eyeglass lens,

[0047] In this step, the main focal length F is obtained based on the known material refractive index n of the eyeglass lens, and the curvature radii r1 and r2 of the first optical surface 1 and the second optical surface 2 .

[0048] Since the optical thickness of the eyeglass lens is very small, it can be considered that the lens spacing is close to 0, so the focal length formula of the lens can be rewritten as:

[0049]

[0050] From formula (2), it can be seen that the main focal length F of the lens is related to the curvature radii r1 and r2 of the first optical surface 1 and the second optical surface 2 of the lens, as well as the material refractive index n. Since these parameters are known, the focal length of the main lens structure, i.e., the main focal length F, can be calculated based on these known parameters;

[0051] S2. Get the focal length f of the microlens array

[0052] f=Fd (3)

[0053] Depend on Figure 2 Formula (3) can be derived. According to actual use requirements, the focal plane distance difference d can be obtained. According to the main focal length F of the lens and the focal plane distance difference d, the focal length f of the microlens array can be calculated by formula (3);

[0054] S3. Get the radius of curvature r of the microlens

[0055] In this step, according to the curvature radius r2 of the second optical surface 2, the focal length f of the microlens array, and the material refractive index n, the curvature radius r of the microlens can be calculated by substituting into formula (2) again;

[0056] S4. Build a microlens array model and optimize the surface

[0057] In this step, a microlens array model is established according to the position, diameter, curvature radius r, material refractive index n and curvature radius r2 of the second optical surface 2 of the microlens.

[0058] When optimizing a single microlens in the array, the aberrations formed by the superimposed main lens structure and the positions and angles of the microlenses in different annular zones are considered simultaneously, and the surface is optimized with the goal of minimizing the spherical aberration of the focusing point.

[0059] In addition, according to the position and angle of the microlenses in different annular zones, the human eye perceived luminosity of each annular zone microlens is calculated according to the imaging system with the far point spherical surface 25 mm away from the lens, and the luminosity of each annular zone is reversely calculated and confirmed according to the unified human eye perceived luminosity of each annular zone.

[0060] When the optical axis of the aspheric surface is the Z axis, the aspheric surface equation is:

[0061]

[0062] In formula (1), Z is the vector height, r is the distance from any point on the aspheric surface to the origin, k is the quadratic constant, and c is the curvature of the vertex. When k = 0, it is a spherical equation; when K is not equal to zero, it is an aspheric equation. In the implementation of the present application, since the aperture of the system is small and the focal length is long, it is not necessary to add higher-order terms to meet the design requirements.

[0063] The spectacle lenses designed by this method are positive defocus spectacle lenses with aspheric microlens arrays, which can correct the refractive error of the central vision of the human eye and improve the squint imaging quality of the multiple microlenses used to form the peripheral myopic defocus of the retina, thereby improving the adaptation difficulties commonly found in multi-point positive defocus lenses.

[0064] Next, the above-mentioned design method is described in conjunction with a specific implementation method.

[0065] Embodiment 1:

[0066] Assuming that the human eye is myopic 300 degrees, the refractive index n of the eyeglass lens is known to be 1.597 (nominal refractive index 1.6), the curvature radius r1 of the first optical surface is 392.76 mm, and the curvature radius r2 of the second optical surface is 131.2 mm. According to formula (2), the main focal length of the lens can be obtained to be 328.35 mm.

[0067] Get the radius of curvature r of the microlens:

[0068] If the focal plane needs to be advanced by 5 mm, the focal length of the microlens array is 323.35 mm, and the calculated curvature radius r of the microlens is 405.26 mm.

[0069] If the focal plane needs to be advanced by 10 mm, the focal length of the microlens array is 318.35 mm, and the radius of curvature r of the microlens is calculated to be 419 mm;

[0070] Embodiment 2:

[0071] Assuming that the human eye is myopic 400 degrees, the refractive index n of the eyeglass lens is known to be 1.499 (nominal refractive index 1.49), the curvature radius r1 of the first optical surface is 457.8 mm, and the curvature radius r2 of the second optical surface is 98 mm. According to formula (2), the main focal length of the lens can be obtained to be 254.47 mm.

[0072] Get the radius of curvature r of the microlens:

[0073] If the focal plane needs to be moved back by 5 mm, the focal length of the microlens array is 259.47 mm, and the calculated radius of curvature of the microlens is 427.58 mm.

[0074] If the focal plane needs to be moved back 10 mm, the focal length of the microlens array is 264.47 mm, and the radius of curvature of the microlens is calculated to be 402.02 mm;

[0075] Next, according to the position, diameter, curvature radius r, material refractive index n of the microlens and curvature radius r2 of the second optical surface 2, a microlens array model is established, and each annular zone surface is optimized.

[0076] In this embodiment, when optimizing a single microlens in the array, the aberrations formed by the superimposed main lens structure and the positions and angles of the microlenses in different annular zones are considered simultaneously, and the surface is optimized with the goal of minimizing the spherical aberration of the focus point.

[0077] In addition, according to the position and angle of the microlenses in different annular zones, the human eye perceived luminosity of each annular zone microlens is calculated according to the imaging system with the far point spherical surface 25 mm away from the lens, and the luminosity of each annular zone is confirmed by reverse calculation according to the unified human eye perceived luminosity of each annular zone.

[0078] The above embodiments are only for illustrating the technical concept and features of the present application, and their purpose is to enable people familiar with the technology to understand the content of the present application and implement it accordingly, and they cannot be used to limit the protection scope of the present application. Any equivalent transformation or modification made according to the spirit of the present application shall be included in the protection scope of the present application.

Claims

1. A method for designing a positive defocused eyeglass lens, wherein the eyeglass lens comprises a main lens structure and an aspherical microlens array; the main lens structure is provided with a first optical surface and a second optical surface arranged opposite to each other; The second optical surface is close to the user's eye side, and a ring-shaped or circular aspheric microlens array is disposed in the middle of the first optical surface. The aspheric microlens array includes: Compound microlens; characterized in that the design method includes: S1. Calculate the main focal length F of the eyeglass lens; Based on calculation Get the main focal length F, Wherein, n is the refractive index of the material, r1 is the radius of curvature of the first optical surface, and r2 is the radius of curvature of the second optical surface; S2. Based on the calculation formula: f = Fd, calculate the focal length f of the microlens array, Where, d is the focal distance difference; S3. Calculate the equivalent radius of curvature r of the microlens based on the radius of curvature r2 of the second optical surface of the eyeglass lens, the focal length f of the microlens array, and the material refractive index n; S4. Establish a microlens array model and optimize the surface of each ring zone; A microlens array model is established according to the position, diameter, equivalent radius of curvature r, material refractive index n and radius of curvature r2 of the second optical surface of the microlens; When optimizing a single aspheric microlens in the array, the aberrations formed by the main lens structure, the positions and angular orientations of the aspheric microlenses in different annular zones are used to optimize the surface with the goal of minimizing the spherical aberration of the focusing point. According to the positions and angular orientations of the microlenses in different annular zones and the imaging system with the far point spherical surface 25 mm away from the lens, the human eye perceived luminosity of each annular zone microlens is calculated, and the actual vertex luminosity of the different microlenses in each annular zone is reversely calculated and confirmed based on the unified human eye perceived luminosity of each annular zone.

2. The method for designing a positive defocused eyeglass lens according to claim 1, wherein: The secondary focal plane generated by the aspherical microlens array is 5 mm to 10 mm in front of the primary focal plane generated by the lens.

3. The method for designing a positive defocused eyeglass lens according to claim 1, wherein: The outer side of the aspherical microlens array is a refraction area.

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