CN116224477A - Lens assembly based on Fresnel structure - Google Patents

Abstract

The invention discloses a lens component based on a Fresnel structure, which relates to the technical field of myopia or presbyopia lens components or VR lens components, and comprises a substrate, a coating layer and a protective layer in sequence; the substrate is provided with a first surface and a second surface which are oppositely arranged, the first surface comprises a plurality of concentric circles, and the centers of the concentric circles are coincident with the center of the first surface; the diameters of the concentric rings gradually increase outwards along the center of the first surface, and are distributed on the first surface; steps are formed between adjacent concentric rings along the thickness direction of the substrate; and a coating layer uniformly applied to the first surface. The use of coating layers of different refractive indices n can result in a unitary lens assembly of different refractive powers D. The lens subassembly can further process for the preparation includes near-sighted eyepiece or presbyopic eyepiece or VR eyepiece, and the wearer wears the eyepiece that the lens subassembly made in this application, can both improve the comfort level of wearing for a long time, alleviates with eyestrain, promotes user experience.

Description

Lens assembly based on Fresnel structure

Technical Field

The invention relates to the technical field of spectacle lens components, in particular to a lens component based on a Fresnel structure.

Background

With the development of society, the popularization of consumer electronics and the lesson pressure of primary and secondary school students are great, the vision disorder problem after presbyopia of old people is caused, the myopia rate of primary school students is increased year by year, and the myopia problem of teenagers and the presbyopia problem of old people are becoming the most prominent human care problem in China, and therefore, a lens assembly capable of effectively preventing myopia or presbyopia is needed.

Some glasses lens components or VR ocular lens capable of inhibiting myopia growth or inhibiting presbyopia are made of resin lens components, glass lens components or other materials, and are characterized in that the higher the power is, the thicker the lens components are. The lens assembly, when assembled with the frame, also provides a heavier weight with increasing power, which increases the fatigue that occurs during use of the glasses by teenagers and older people.

Accordingly, the prior art has the above-mentioned drawbacks, and improvements are required.

Disclosure of Invention

In order to solve the technical problems, the invention provides a lens assembly with a Fresnel structure and an eyepiece comprising the lens assembly, wherein the lens assembly only maintains the Fresnel structure with refraction to the maximum extent, so that an optical beam entering from one side surface of the lens assembly is emitted from the other side surface of the lens assembly after passing through the Fresnel structure, and compared with the existing common myopia lens assembly or presbyopic lens assembly, the lens assembly has less optical path loss, clearer imaging and thinner and lighter lens assembly. The myopia lens component or the presbyopic lens component manufactured by the lens component can improve the comfort level of wearing for a long time, relieve the eyestrain and meet the design requirements of miniaturization and light weight of eyepiece products.

According to the present invention, there is provided a lens assembly comprising, in order, a substrate, a coating layer and a protective layer; the substrate is provided with a first surface and a second surface which are oppositely arranged, the first surface comprises a plurality of concentric circular rings, and the centers of the plurality of concentric circular rings are coincident with the center of the first surface; the diameters of the plurality of concentric rings gradually increase outwards along the center of the first surface and are distributed on the first surface, and steps are formed between adjacent concentric rings along the thickness direction of the substrate;

the lens assembly further includes a coating layer uniformly applied to the first surface, the coating layer being optionally made of a different refractive index n material, the coating layer of different refractive index n producing a lens assembly of different refractive power value D.

Further, the first surface comprises a plurality of concentric rings arranged in a fresnel structure.

Further, the coating layer is completely attached to the object side surface having the fresnel structure and uniformly fills the steps of the fresnel structure, and the steps are the same in height in the thickness direction of the substrate.

Further, the fresnel structure is provided as a spherical or aspherical surface.

Further, the second surface of the substrate is designed as a plane or free-form surface.

Further, when the diopter of the lens assembly satisfies:

when the focal length EFL of the substrate satisfies 20mm < EFL < 60mm, and the refractive index n of the coating layer satisfies: n is more than 1.2 and less than 1.9; when the diopter of the lens assembly satisfies: />

When the focal length EFL of the substrate satisfies-60 mm < EFL < -20mm, and the refractive index n of the coating layer satisfies: n is more than 1.3 and less than 1.9。

Further, the refractive index of the coating layer shown satisfies the following with the refractive index n0 of the substrate 1 shown: 0.81 < n/n0 < 1.36.

Further, the second surface of the substrate may be configured with a different radius of curvature R2, and by varying the radius of curvature R2 of the second surface, a lens assembly of different diopter values D may be produced.

Further, the protective layer is disposed on the coating layer for protecting the lens assembly from breakage and contamination caused by an external environment.

Further, the protective layer, the coating layer and the substrate are coupled to form a planar lens assembly or a plano-convex lens assembly or a plano-concave lens assembly.

Further, the coating layer comprises an ultraviolet glue.

Further, the thermal expansion coefficients of the coating layer, the substrate, and the protective layer are uniform.

By adopting the scheme, the invention has the beneficial effects that: compared with an eyepiece made of a common optical lens assembly, such as a pair of myopia glasses, presbyopic glasses or VR glasses, the phenomenon that corners are darkened and blurred can occur in the use process, particularly the degree is high, the lens assembly is thicker, light can be weakened by light propagation in the lens assembly with thicker edges, blurred and darkened imaging can occur easily under the condition of insufficient light conditions, and only the Fresnel structure with refraction can be reserved to the maximum extent. The myopia glasses or presbyopic glasses or VR glasses manufactured by the lens components can effectively reduce the mounting load of a wearer, improve the comfort level of wearing for a long time, relieve the eyestrain and meet the design of miniaturization and light weight of eyepiece products.

Drawings

For a clearer description of an embodiment or of a technical solution in the prior art, the drawings used in the description of the embodiment or of the prior art will be briefly introduced below, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a Fresnel structure-based lens assembly according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a lens assembly comprising a substrate, a coating layer and a protective layer sandwiched therebetween according to one embodiment of the present invention;

FIG. 3 is a schematic diagram of a Fresnel structure formed by Fresnel the surface of a spherical convex lens assembly according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a Fresnel structure formed by Fresnel the surface of a spherical concave lens assembly according to an embodiment of the present invention;

the legend above shows: 100. a lens assembly; 1. a substrate; 2. a coating layer; 3. a protective layer; 11. a first surface; 12. a second surface; 13. a plurality of concentric rings; 14. a step.

Detailed Description

In order that the invention may be readily understood, a more particular description thereof will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "first surface" and "second surface" are used herein as opposed to two sides of a substrate, and the fresnel structure is formed on the first surface of the substrate, and one of the first surface and the second surface may be disposed opposite the human eye, and these similar expressions are for the purpose of clarity only and do not limit the overall inventive concept of the present invention. In the drawings, like elements are designated by like reference numerals.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

As shown in fig. 1 and 2, the present invention provides a fresnel lens assembly 100 sequentially comprising a substrate 1, a coating layer 2 and a protective layer 3, wherein the substrate 1 has a first surface 11 and a second surface 12 disposed opposite to each other, and the second surface 12 of the substrate 1 is designed as a plane or a free-form surface. The first surface 11 of the substrate 1 comprises a plurality of concentric rings 13, the centers of the plurality of concentric rings 13 are coincident with the center of the first surface 11, and the diameters of the plurality of concentric rings 13 sequentially increase outwards along the center of the first surface 11 and are uniformly distributed on the first surface 11 of the substrate 1; a step 14 is formed between adjacent concentric rings 13 in the thickness direction of the substrate 1.

Further, the plurality of concentric rings 13 on the first surface 11 may be designed as fresnel structures.

It is to be noted that "fresnel structure" in the present application refers to a structure obtained by dividing one spherical surface or an aspherical surface into a plurality of concentric rings and arranging them into steps formed in a cross-sectional view, and has a radius of curvature equal to that of the original spherical surface or aspherical surface. Fig. 3 shows a schematic diagram of how the fresnel structure is formed for the surface fresnel of the spherical convex lens assembly, and fig. 4 shows a schematic diagram of how the fresnel structure is formed for the surface fresnel of the spherical concave lens assembly. Wherein the height of the steps 14 between the concentric rings is uniform, which facilitates a more uniform application of the coating layer 2 to the fresnel structure and a uniform thickness of the application.

According to the fresnel lens assembly design method in combination with the freeform design concept, a plurality of concentric rings 13 are machined on the first surface 11 of the substrate 1 by a known molding method or the like, for example, injection molding or die casting, and finally a fresnel structure is formed on the first surface 11 of the substrate 1, in which case the fresnel structure is an integrally formed structure with the substrate 1, as shown in fig. 2. For the wearer, if the wearer wears the myopia glasses or presbyopic glasses or VR glasses manufactured by adopting the lens assembly 100 for a long time, the mounting load of the wearer is easier to be lightened, the comfort level of wearing for a long time can be improved, the eyestrain is relieved, and the light and thin and miniaturized design of the product is met.

In other embodiments, the sheet material having fresnel structures may also be provided on the substrate 1 by means of lamination. Thus, the sheet material with the fresnel structure may be different from the material of the substrate 1, without depending on the material of the substrate 1, the sheet material design of the fresnel structure is more flexible.

In the present application, the material of the substrate 1 may be a heat curable resin, such as PMMA (polymethyl methacrylate, polymethyl methacrylate, also called acryl or plexiglass), or PC (Polycarbonate). The effective focal length EFL of the substrate 1 (Effective Focal Length, center-to-focus distance of the substrate 1) satisfies: EFL of 20mm < 60mm or EFL of-60 mm < 20mm.

Further, as shown in fig. 1, the coating layer 2 is uniformly applied to the first surface 11 of the substrate 1, i.e., a coating layer 2 is applied to the fresnel surface. The coating liquid is applied to the fresnel surface so that the coating liquid fills uniformly in the steps 14 formed between the concentric rings, and after drying, a transparent solid-state coating layer 2 is formed, completely adhering to the substrate 1 having the fresnel structure. Drying may be performed by a drying process such as air drying, ultraviolet exposure, heat drying. The coating layer 2 is made of transparent optical materials, so that the light transmittance is not affected, a myopia lens assembly 100 which is suitable for a myopic user can be manufactured according to different functional requirements of the lens assembly, the protective layer 3 and the coating layer 2 are coupled with the substrate 1 to form a plano-concave lens assembly (the side close to eyeballs is concave), a myopic wearer wears myopic spectacles made of the myopia lens assembly 100, the wearing is lighter, the imaging is clearer, and the deterioration of myopia is effectively inhibited; alternatively, if the presbyopic lens assembly 100 adapted to a presbyopic user needs to be manufactured, the protective layer 3 and the coating layer 2 are coupled with the substrate 1 to form a convex lens assembly (convex on the side close to the eyeball), so that the wearing is lighter, the imaging is clearer, and the deterioration of presbyopia is effectively suppressed. When the protective layer 3, the coating layer 2 and the substrate 1 are coupled to form a planar lens assembly, a plano-convex lens assembly or a plano-concave lens assembly, the lens assembly 100 based on the fresnel structure can be one of one or more layers in the eyepiece of the VR device, so that the design requirements of miniaturization and thinness of the wearable device can be effectively met, and the diopter for correcting vision can be simultaneously provided, so that the personalized requirements of users can be met.

It should be noted that, in the process of coupling the protective layer 3, the coating layer 2 and the substrate 1 to form a planar lens assembly, a plano-concave lens assembly or a plano-convex lens assembly, the fresnel surface uniformly covered with the coating layer 2 is always located at one side of the plane of the lens assembly, so as to facilitate compact coating of the coating layer 2, and avoid bubbles or uneven phenomena during the coating process.

The coating layer 2 also prevents oil dirt or dust from the air from accumulating in the steps 14 of the fresnel structure and affecting the sharpness of the lens assembly 100.

Because the refractive power of each user's eyes is different, a specialized optometry can be used to formulate optical lens assemblies of different refractive power values, in this application, by applying a coating of a predetermined refractive index n to a first surface of the fresnel base layer 1, obtaining a first predetermined refractive power value of the base layer 1 and/or processing a radius of curvature of a second surface of the base layer 1 to obtain a second predetermined refractive power value of the second surface, the first predetermined refractive power value and the second predetermined refractive power value interacting to ultimately obtain the desired refractive power value of the lens assembly 100. Specifically, in some embodiments, in order to meet the personalized requirements of the user, the coating layer 2 may be made of a plurality of transparent optical materials having different refractive indexes n, the lens assemblies 100 having different refractive values D may be produced by presetting the refractive index n of the coating layer 2, and applying the coating layer 2 having different refractive indexes n onto the substrate 1 to configure the lens assemblies 100 having different refractive values D.

Specifically, the diopter calculation formula including the base 1 and the coating layer 2 is as follows:

D＝(n0-n)/R0*1000

where n0 is the refractive index of the substrate 1, n is the refractive index of the coating layer 2, R0 is the radius of curvature of the Fresnel structure, and D is the diopter of the overall lens assembly.

According to some embodiments of the present application, in the fresnel structure combined with freeform surface design process, the substrate 1 with fresnel surface is designed to have an initial diopter value +26d and an initial radius of curvature r0= -19mm, when the application of the coating layer 2 with refractive index n of 1.586 results in the lens assembly 100 with a first preset diopter value of-5.0D after the fresnel structure; when the coating layer 2 having a refractive index n of 1.53 is applied, a lens assembly 100 having a first predetermined diopter value of-2.0D is obtained after the fresnel structure, as shown in fig. 4.

According to other embodiments of the present application, the second surface 12 of the substrate 1 may also be processed to have a different radius of curvature R2 to generate a second predetermined diopter value, and the lens assembly 100 may be configured to generate a different diopter value.

After the processing step described above, a lens assembly is obtained with a first preset diopter value of-5.0D, -2.0D, optionally the radius of curvature R2 of the second surface 12 of the substrate 1 is reworked, the second surface yielding a second preset diopter value +2.0D, in which case the final diopter value of-3.0D, 0.0D of the lens assembly 100 is obtained after interaction of the first preset diopter value and the second preset diopter value.

The correlation between the parameters is shown in table 1 below:

TABLE 1

Note that, when the diopter of the lens assembly satisfies:

when the focal length EFL of the substrate satisfies 20mm < EFL < 60mm, and the refractive index n of the coating layer satisfies: n is more than 1.2 and less than 1.9; when the diopter of the lens assembly satisfies: />

When the focal length EFL of the substrate satisfies-60 mm < EFL < -20mm, and the refractive index n of the coating layer satisfies: n is more than 1.3 and less than 1.9. In some embodiments, the coating layer 2 is made of an optical glue, preferably an ultraviolet glue.

In the above embodiment, the refractive index n of the illustrated coating layer 2 and the refractive index n0 of the illustrated substrate 1 satisfy: 0.81 < n/n0 < 1.36, and can better meet the design requirements of the light and thin lens assembly 100 and can also have ideal diopter for correcting vision according to the requirements of users.

In some embodiments of the present application, the coating layer 2 is formed into a solid protective film with hardness by applying a curable coating liquid material to the fresnel surface, and drying and curing the curable coating liquid material, and the coating optical material can increase the light transmittance, wear resistance, scratch resistance and wiping resistance of the lens assembly. In this case, the coating layer 2 not only has the step of sufficiently filling and adhering to the irregularities on the fresnel surface of the substrate 1, but also serves to protect the entire lens assembly 100 after drying (in this embodiment, the lens assembly 100 includes the substrate 1 and the coating layer 2), improving shatter resistance and service life of the lens assembly 100.

Wherein the thickness of the substrate 1 is not more than 1.5mm; the thickness of the coating layer 2 is not more than 0.5mm. In order to make the lens assembly 100 in the use environment between cold and hot alternation, the deformation of the lens assembly caused by the internal stress generated by the expansion and contraction of the lens assembly 100 is avoided, and gaps are generated among the substrate 1, the coating layer 2 and the protective layer 3 to influence the refraction effect of the lens assembly, so that the thermal expansion coefficients of the coating layer 2, the substrate 2 and the protective layer 3 are designed to be consistent.

It should be noted that, as shown in fig. 2, in order to further improve the overall shatter resistance of the lens assembly 100, the inventors of the present application may add a protective layer 3 outside the substrate 1 and the coating layer 2, enhance the protective performance of the coating layer 2, and improve the shatter resistance and the service life of the lens assembly 100. The protective layer 3 may also be transparent, and is preferably made of tempered glass, so that the substrate 1, the coating layer 2 and the protective layer 3 form a sandwich structure in this embodiment. In the process of applying the liquid coating layer 2, the interaction between the protective layer 3 and the substrate 1 not only can ensure that the liquid coating layer 2 is applied on the first surface 11 of the substrate 1 more uniformly and more smoothly, but also can ensure that the whole sandwich structure of the lens assembly 100 is more suitable for further processing the lens assembly 100 so as to meet different application situations of the lens assembly 100, such as surface hardening coating treatment, cutting processing and other process treatments.

To sum up, compare in adopting the lens subassembly of ordinary area correction refraction degree, the phenomenon that the corner darkens, fuzzy in the use, especially degree is high, lens subassembly is thicker, light propagates in lens subassembly that lens subassembly edge is thicker and can make light weaken, under the not enough circumstances of light condition, the formation of image that appears blurring and darken easily, the lens subassembly of fresnel structure is adopted in this application, furthest only remains the fresnel structure that takes place the refraction, lens subassembly with fresnel structure in the formation application. The myopia glasses or presbyopic glasses or VR glasses prepared by adopting the lens component based on the Fresnel structure can improve the comfort level of wearing for a long time, relieve the eyestrain and meet the design requirements of light weight, thinness and miniaturization.

The above-described features are continuously combined with each other to form various embodiments not listed above, and are regarded as the scope of the present invention described in the specification; and, it will be apparent to those skilled in the art from this disclosure that modifications and variations can be made without departing from the scope of the invention defined in the appended claims.

Claims (13)

1. A lens assembly comprising, in order, a substrate, a coating layer and a protective layer;

the substrate is provided with a first surface and a second surface which are oppositely arranged, the first surface comprises a plurality of concentric rings, and the centers of the concentric rings are coincident with the center of the first surface; the diameters of the plurality of concentric rings gradually increase outwards along the center of the first surface and are distributed on the first surface, and steps are formed between adjacent concentric rings along the thickness direction of the substrate;

the coating layer is uniformly coated on the first surface, the coating layer can be made of materials with different refractive indexes n, and the lens components with different refractive index values D can be produced by the coating layers with different refractive indexes n.

2. The lens assembly of claim 1, wherein the first surface comprises a plurality of concentric rings arranged in a fresnel structure.

3. The lens assembly of claim 2, wherein the coating layer completely conforms to the first surface having fresnel structures and uniformly fills steps of the fresnel structures, the steps being the same in height along the thickness direction of the substrate.

4. The lens assembly of claim 2, wherein the fresnel structure is provided as a spherical or aspherical surface.

5. The lens assembly of claim 1, wherein the second surface of the substrate is designed as a planar or free-form surface.

6. The lens assembly of claim 4, wherein when the diopter of the lens assembly satisfies:

in the time-course of which the first and second contact surfaces,the focal length EFL of the substrate satisfies 20mm < EFL < 60mm, and the refractive index n of the coating layer satisfies: n is more than 1.2 and less than 1.9; when the diopter of the lens assembly satisfies: />

When the focal length EFL of the substrate satisfies-60 mm < EFL < -20mm, and the refractive index n of the coating layer satisfies: n is more than 1.3 and less than 1.9.

7. The lens assembly of claim 6, wherein the refractive index n of the coating layer and the refractive index n0 of the substrate satisfy: 0.81 < n/n0 < 1.36.

8. The lens assembly of claim 4, wherein the second surface of the substrate is configurable to a different radius of curvature R2, and wherein varying the radius of curvature R2 of the second surface results in a lens assembly of different diopter value D.

9. The lens assembly of claim 1, wherein the protective layer is disposed on the coating layer for protecting the lens assembly from breakage and contamination by an external environment.

10. The lens assembly of claim 9, wherein the coating layer is formed from an adhesive configured to adhere the substrate and the protective layer.

11. The lens assembly of claim 9, wherein the protective layer, coating layer and substrate are coupled to form a planar lens assembly or a plano-convex lens assembly or a plano-concave lens assembly.

12. The lens assembly of claim 11, wherein the coating layer comprises an ultraviolet glue.

13. The lens assembly of claim 1, wherein the coating layer, the substrate, and the protective layer have coefficients of thermal expansion.

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