CN114280708A

CN114280708A - Fresnel lens, optical module and virtual reality device

Info

Publication number: CN114280708A
Application number: CN202210033604.0A
Authority: CN
Inventors: 黄海涛; 董瑞君; 白家荣; 韩娜; 李宝曼; 武玉龙; 王晨如; 栗可; 崔钊; 于勇; 马占山
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2022-01-12
Filing date: 2022-01-12
Publication date: 2022-04-05

Abstract

The embodiment of the disclosure provides a Fresnel lens, an optical module and a virtual reality device. Fresnel lens, including first side and second side, at least first side is provided with a plurality of sawtooth structure, and at least one sawtooth structure includes effective surface, invalid surface and loading surface, and the loading surface is connected between effective surface and invalid surface, and Fresnel lens's center is kept away from for invalid surface to the effective surface, and the loading surface is the flat surface, and the plane perpendicular to Fresnel lens's center axis in loading surface place, Fresnel lens still includes the light barrier, and the light barrier is located the loading surface. According to the Fresnel lens, a part of light can be prevented from being emitted from the invalid surface after being incident from the valid surface, so that the quantity of the light emitted from the invalid surface is reduced, formed stray light is reduced, and the light imaging quality is improved.

Description

Fresnel lens, optical module and virtual reality device

Technical Field

The utility model relates to a show technical field, especially relate to a fresnel lens, optical module and virtual reality device.

Background

Near-eye display technologies using Virtual Reality (VR) and Augmented Reality (AR) as main application scenes are becoming more and more important ways for people to acquire information. Currently, the mainstream near-eye display optical technology mainly includes: the waveguide display is sensitive to the wavelength of incident light and is easy to generate chromatic dispersion; the waveguide optical coupling structure also has a dispersion effect on external light, and ghost images and other phenomena can occur in the wearing process. The overall size of the free-form surface display scheme is large, and the large field angle and the device size are difficult to balance; the integrated imaging light field display is difficult to realize the permeation of external light, and the AR augmented reality display effect is poor.

In the existing VR optical scheme, products which are light, thin and high in light efficiency exist, but stray light exists in the products, and imaging quality is influenced.

Disclosure of Invention

The disclosed embodiment provides a Fresnel lens, an optical module and a virtual reality device, so as to solve or alleviate one or more technical problems in the prior art.

As a first aspect of the embodiments of the present disclosure, an embodiment of the present disclosure provides a fresnel lens, including a first side and a second side that are disposed opposite to each other, where at least the first side is provided with a plurality of saw-toothed structures, at least one of the saw-toothed structures includes an effective surface, an ineffective surface, and a bearing surface, where the bearing surface is connected between the effective surface and the ineffective surface, the effective surface is away from a center of the fresnel lens relative to the ineffective surface, the bearing surface is a flat surface, a plane where the bearing surface is located is perpendicular to a central axis of the fresnel lens, and the fresnel lens further includes a light blocking layer, where the light blocking layer is located on the bearing surface.

In some possible implementations, the width of the light blocking layer is configured to prevent light incident from the active surface from exiting the inactive surface.

In some possible implementations, the width of the carrying surface ranges from greater than 0 to less than or equal to 10 μm.

In some possible implementations, the light blocking layer extends from an edge of the bearing surface near the inactive surface toward an edge near the active surface;

the orthographic projection range of the light blocking layer on the bearing surface is positioned in the bearing surface; or the orthographic projection range of the light blocking layer on the bearing surface is superposed with the bearing surface.

In some possible implementations, the bearing surfaces of at least two saw-tooth structures are located on the same plane; alternatively, the bearing surfaces of the sawtooth structures are located on different planes.

In some possible implementations, the light blocking layer is also disposed on the inactive side.

In some possible implementation manners, the material of the light blocking layer is a black resin material, and the optical density value of the material of the light blocking layer is 0-5.

In some possible implementations, the light blocking layer has a thickness in a range of 0 to 2 μm.

As a second aspect of the embodiments of the present disclosure, an embodiment of the present disclosure provides an optical module, including a plurality of pieces of fresnel lenses according to any one of the above, where centers of the plurality of pieces of fresnel lenses are located on a same straight line.

In some possible implementation manners, the number of the multiple fresnel lenses is three, and the multiple fresnel lenses are respectively a first fresnel lens, a second fresnel lens and a third fresnel lens, the second fresnel lens is located between the first fresnel lens and the third fresnel lens, the first side of the first fresnel lens deviates from the second fresnel lens, the first side of the third fresnel lens faces the second fresnel lens, and the second side of the first fresnel lens and the second side of the second fresnel lens are glued with each other.

In some possible implementation manners, the distance between the third Fresnel lens and the second Fresnel lens is 0-8 mm.

As a second aspect of the embodiments of the present disclosure, an embodiment of the present disclosure provides a virtual reality apparatus, including:

the Fresnel lens comprises a display module and the Fresnel lens, wherein the first side of the Fresnel lens faces the display module; alternatively, the first and second electrodes may be,

including display module assembly and optical module as above any, the first side of fresnel lens who is close to display module assembly is towards the display module assembly.

According to the technical scheme of the embodiment of the disclosure, the bearing surface is arranged on the sawtooth-shaped structure of the Fresnel lens, and the light blocking layer is arranged on the bearing surface, so that a part of light can be prevented from being emitted from the invalid surface after being incident from the valid surface, the quantity of the light emitted from the invalid surface is reduced, the formed stray light is reduced, and the light imaging quality is improved.

The foregoing summary is provided for the purpose of description only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present disclosure will be readily apparent by reference to the drawings and following detailed description.

Drawings

In the drawings, like reference numerals refer to the same or similar parts or elements throughout the several views unless otherwise specified. The figures are not necessarily to scale. It is appreciated that these drawings depict only some embodiments in accordance with the disclosure and are not to be considered limiting of its scope.

FIG. 1 is a schematic cross-sectional view of a Fresnel lens;

FIG. 2 is a schematic diagram of an optical path of a Fresnel lens in a virtual reality device;

FIG. 3 is a schematic cross-sectional structure diagram of a Fresnel lens according to an embodiment of the disclosure;

FIG. 4 is a schematic cross-sectional structure view of a Fresnel lens according to another embodiment of the present disclosure;

FIG. 5 is a schematic cross-sectional view of a Fresnel lens according to another embodiment of the present disclosure;

FIG. 6 is a schematic cross-sectional view of a Fresnel lens according to another embodiment of the present disclosure;

FIG. 7 is a schematic diagram of a virtual reality device employing an optical module according to an embodiment of the disclosure;

FIG. 8 is a graph of a modulation transfer function of an optical module according to an embodiment of the present disclosure.

Description of reference numerals:

10. a Fresnel lens; 11. a first side; 12. a second side; 13. a light-emitting surface; 20. a saw-toothed structure; 21. an effective surface; 22. an invalid face; 23. a bearing surface; 40. and a light blocking layer.

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments may be modified in various different ways, and different embodiments may be combined arbitrarily without departing from the spirit or scope of the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

In the virtual reality device, the through-type aspheric lens group has the advantages of low design and processing difficulty, high luminous efficiency (> 80%), no stray light and the like, but the thickness is large (>35mm), and the product is not light and thin. The refraction and reflection type imaging device has the advantages of better imaging quality and thinner thickness (less than or equal to 30mm), but has lower light efficiency (less than 25 percent), ghost and other phenomena. The through type Fresnel lens set has the advantages of high light efficiency of the through type aspheric lens set and light and thin refraction and reflection type system. However, the straight-through fresnel lens group has a fresnel lens, and the fresnel lens has an ineffective surface, so that stray light is generated, and the stray light affects the imaging quality.

Fig. 1 is a schematic cross-sectional structure diagram of a fresnel lens. In the common lens, the refraction of light only occurs on the surface of the lens, the fresnel lens is formed by removing redundant optical materials in the common lens on the basis of the common lens and only preserving the curvature of part of the surface of the fresnel lens, and a plurality of concentric circles from small to large are recorded on the surface of the fresnel lens, as shown in fig. 1. Therefore, the Fresnel lens is lighter and thinner than a common head and neck.

As shown in fig. 1, the fresnel lens includes a first side 11 and a second side 12, the first side 11 may face the light source, and the second side 12 is disposed opposite the first side 11. The first side 11 of the fresnel lens is provided with a plurality of sawtooth structures 20, the sawtooth structures 20 comprise effective surfaces 21 and ineffective surfaces 22, the effective surfaces 21 are connected with the ineffective surfaces 22, the effective surfaces 21 and the ineffective surfaces 22 are the sides of the sawtooth structures 20, and the effective surfaces 21 are far away from the center of the fresnel lens relative to the ineffective surfaces 22. The second side 12 of the fresnel lens is provided with a light-emitting surface 13, and the light-emitting surface 13 is a spherical surface or an aspheric surface. In practice, the width of each sawtooth-shaped structure 20 may be equal to form equally spaced Fresnel lenses; alternatively, the height of each sawtooth-shaped structure 20 may be equal to form a Fresnel lens of equal tooth height. In practical applications, the size of the sawtooth-shaped structure in the fresnel lens can be set reasonably according to needs, and is not limited herein.

Fig. 2 is a schematic diagram of an optical path of a fresnel lens in a virtual reality device. As shown in fig. 2, the light 1 generated by the display module 50 enters the fresnel lens 10 from the effective surface 21, is refracted in the sawtooth structure 20a, and exits from the light exit surface 13 to enter human eyes. However, a part of the light generated by the display module, for example, the light 2, enters the fresnel lens from the edge of the effective surface 21 close to the ineffective surface 22, is refracted in the sawtooth-shaped structure 20a and then exits from the ineffective surface 22, enters the adjacent sawtooth-shaped structure 20b, is refracted for the second time in the sawtooth-shaped structure 20b, and then exits from the light exit surface 13 and enters human eyes.

As can be seen from fig. 2, the light ray 1 passes through the fresnel lens with a single refraction, and the light ray 2 passes through the non-effective surface 22 with a double refraction. The light passing through the inactive surface 22 of the saw-toothed structure 20 is likely to form stray light, and therefore, the light 2 is likely to form stray light, which affects the imaging quality and reduces the user experience.

Fig. 3 is a schematic cross-sectional structure diagram of a fresnel lens according to an embodiment of the present disclosure. As shown in fig. 3, the fresnel lens may include a first side 11 and a second side 12, the first side 11 may face the light source, and the second side 12 is disposed opposite the first side 11. At least the first side 11 is provided with a plurality of serrations 20, at least one serration 20 may comprise an active surface 21, an inactive surface 22 and a bearing surface 23, the active surface 21 and the inactive surface 22 being sides of the serration 20, the bearing surface 23 being connected between the active surface 21 and the inactive surface 22, the active surface 21 being remote from the centre of the fresnel lens with respect to the inactive surface 22. The support surface 23 may be a flat surface, and the plane of the support surface 23 is perpendicular to the central axis OO' of the fresnel lens. The fresnel lens may further include a light blocking layer 40, and the light blocking layer 40 is located on the carrying surface 23. Optionally, when a vertex angle exists between the effective surface 21 and the ineffective surface 22 of the first side 11, the vertex angle is flattened to obtain the bearing surface 23.

In the fresnel lens in the embodiment of the disclosure, by arranging the bearing surface 23 and arranging the light blocking layer 40 on the bearing surface 23, a part of light can be prevented from being emitted from the ineffective surface 22 after being incident from the effective surface 21, so that the quantity of light emitted from the ineffective surface 22 is reduced, the formed stray light is reduced, and the light imaging quality is improved.

Note that each of the sawtooth structures 20 is closed around the center of the fresnel lens. The serration structure 20 may be in the shape of a closed ring, such as a circular ring, an ellipse, etc., or the serration structure 20 may be in the shape of a closed polygon, such as a quadrangle, a pentagon, etc.

In one embodiment, the active surface 21 may be planar, as shown in fig. 3.

Fig. 4 is a schematic cross-sectional structure diagram of a fresnel lens according to another embodiment of the present disclosure. In another embodiment, as shown in fig. 4, the effective surface 21 may be an arc-shaped surface.

The second side 12 is exemplarily provided with a light emitting surface 13, and the light emitting surface 13 is a spherical surface or an aspherical surface, for example, the light emitting surface 13 may be a plane.

In one embodiment, as shown in fig. 3, the width of the light blocking layer 40 is configured to prevent light incident from the active surface 21 from exiting from the inactive surface 22. For example, in fig. 3, the width of the light blocking layer 40 is w, so that the light 3 incident from the effective surface 21 is refracted in the saw-tooth structure 20 and then does not exit from the ineffective surface 22, thereby preventing the light incident from the effective surface 21 from passing through the ineffective surface 22 and avoiding stray light.

In this context, the width of a is the dimension of a in the direction perpendicular to the direction of extension of the saw-tooth like structure.

In one embodiment, as shown in FIG. 3, the width w of the carrying surface 23 ranges from greater than 0 to less than or equal to 10 μm (inclusive). The width of the carrying surface 23 may be any value between 0 and 10 μm, for example, one of 5 μm, 8 μm, 9 μm, 10 μm, and the like. The width of the carrying surface 23 is set to be greater than 0 and less than or equal to 10 μm, which is advantageous for forming the carrying surface 23. Compared with the conventional Fresnel lens, the width of the bearing surface 23 is set to be 0-10 mu m, so that the area of the effective surface 21 is not reduced too much, enough light can enter the Fresnel lens through the effective surface 21, and the brightness and the display effect of the virtual reality device are ensured.

In one embodiment, the light-blocking layer 40 extends from the edge of the carrying surface 23 close to the inactive surface 22 toward the edge close to the active surface 21, and the orthographic projection range of the light-blocking layer 40 on the carrying surface 23 is located in the carrying surface 23.

In one embodiment, the light-blocking layer 40 extends from the edge of the carrying surface 23 close to the inactive surface 22 toward the edge close to the active surface 21, and the orthographic projection range of the light-blocking layer 40 on the carrying surface 23 coincides with the carrying surface 23. In this way, the light-blocking layer 40 can completely cover the bearing surface 23, and light can be prevented from being incident on the fresnel lens from the bearing surface 23. Moreover, by reasonably setting the width of the bearing surface 23, and the width of the light blocking layer 40 is the same as that of the bearing surface 23, most or even all light rays which may pass through the ineffective surface 22 can be prevented from being incident on the fresnel lens, and stray light caused by the light rays passing through the ineffective surface 22 is avoided.

In one embodiment, in order to facilitate forming the light-blocking layer 40 on the supporting surface 23, a plurality of grooves may be disposed on the supporting surface 23 to increase the adhesion of the light-blocking layer 40 on the supporting surface 23.

Fig. 5 is a schematic cross-sectional structure diagram of a fresnel lens according to another embodiment of the present disclosure. In one embodiment, as shown in fig. 5, the light blocking layer 40 may also be disposed on the inactive surface 22. When the light blocking layer 40 is disposed on the inactive surface 22, even if the light in the sawtooth structure 20 is emitted to the inactive surface 22, the light blocking layer 40 can prevent the light from being emitted from the inactive surface 22 due to the light blocking layer 40 disposed on the inactive surface 22, so as to avoid stray light.

For example, the thickness of the light-blocking layer disposed on the carrying surface 23 may be different from the thickness of the light-blocking layer disposed on the inactive surface 22. The thickness of the light-blocking layer disposed on the inactive surface 22 may be less than or equal to the thickness of the light-blocking layer disposed on the carrying surface 23.

In one embodiment, the bearing surfaces 23 of at least two serrations are in the same plane. For example, in FIG. 3, the bearing surface 23a of the sawtooth structure is located on the same plane as the bearing surface 23b of the other sawtooth structure.

Illustratively, the fresnel lens may be a fresnel lens of equal tooth height.

Fig. 6 is a schematic cross-sectional structure diagram of a fresnel lens according to another embodiment of the present disclosure. In one embodiment, as shown in FIG. 6, the bearing surfaces 23 of each serration are located in different planes. For example, in FIG. 6, the bearing surfaces 23 of each serration 20 are located in different planes.

It should be noted that, since the sawtooth-shaped structures 20 are closed-loop shapes around the center of the fresnel lens, the sawtooth-shaped structures located on both sides of the center are symmetrical in the schematic cross-sectional structure of the fresnel lens.

Illustratively, the fresnel lens may be an equally spaced fresnel lens.

In one embodiment, the material of the light blocking layer 40 may be an opaque metal, such as any one or more of silver (Ag), copper (Cu), aluminum (Al), titanium (Ti), and molybdenum (Mo).

In one embodiment, the material of the light blocking layer 40 may be a black resin material. The light blocking layer 40 made of the material can be formed on the bearing surface by adopting a coating process, so that the preparation process of the Fresnel lens is simplified. Illustratively, the optical density value (OD) of the material of the light blocking layer 40 may be 0 to 5/μm. The optical density value of the material of the light blocking layer 40 may be any value of 0 to 5/μm, for example, one value of 1, 2, 3, 4, 5. The light-blocking layer made of the material has better light-blocking effect.

In one embodiment, as shown in fig. 3, the thickness of the light-blocking layer 40 may range from 0 to 2 μm, i.e., the thickness of the light-blocking layer 40 is greater than 0 and less than or equal to 2 μm. Illustratively, the thickness of the light blocking layer 40 may be 1.1 μm.

It should be noted that, in practical applications, the type of the fresnel lens may be appropriately selected according to needs, for example, the fresnel lens may be a fresnel lens with an equal tooth height or a fresnel lens with an equal pitch, and is not particularly limited herein.

It should be noted that the first side of the fresnel lens shown herein is provided with the sawtooth-shaped structures in the embodiments of the present disclosure, and it is understood that in practical applications, the sawtooth-shaped structures in the embodiments of the present disclosure may also be provided on the second side as needed, and is not limited herein.

Based on the inventive concept of the foregoing embodiments, an embodiment of the present disclosure further provides an optical module, where the optical module may include a plurality of fresnel lenses in any embodiment of the present disclosure, and centers of the plurality of fresnel lenses are located on the same straight line.

In one embodiment, the number of the fresnel lenses is three, and the fresnel lenses are respectively a first fresnel lens, a second fresnel lens and a third fresnel lens, the second fresnel lens is located between the first fresnel lens and the third fresnel lens, the first side of the first fresnel lens is away from the second fresnel lens, the first side of the third fresnel lens faces the second fresnel lens, and the second side of the first fresnel lens and the second side of the second fresnel lens are glued to each other.

The optical module in the embodiments of the present disclosure will be further described with reference to specific applications. Fig. 7 is a schematic diagram of a virtual reality device employing an optical module according to an embodiment of the disclosure.

As shown in fig. 7, the optical module may include three pieces of fresnel lenses in any embodiment of the disclosure, namely, a first fresnel lens 10a, a second fresnel lens 10b and a third fresnel lens 10c, and centers of the three fresnel lenses are located on the same straight line. The second fresnel lens 10b is located between the first fresnel lens 10a and the third fresnel lens 10c, the first side 11a of the first fresnel lens 10a deviates from the second fresnel lens 10b and faces the display module 50, the first side 11b of the second fresnel lens 10b deviates from the display module 50, the second side of the first fresnel lens 10a and the second side of the second fresnel lens 10b are glued to each other, and the first side 11c of the third fresnel lens 10c faces the second fresnel lens 10b and displays the display module 50. The light emitted from the display module 50 enters the optical module through the first side 11c of the first fresnel lens 10a, and then exits through the second side 12c of the third fresnel lens 10c to enter human eyes.

In one embodiment, the distance d1 between the third Fresnel lens 10c and the second Fresnel lens 10b may be 0-8 mm (inclusive), and d1 may be any value from 0-8 mm, for example, d1 may be one of 2mm, 4mm, 6mm, and 8 mm.

FIG. 8 is a graph of a modulation transfer function of an optical module according to an embodiment of the present disclosure. As shown in fig. 7 and 8, the three-piece fresnel lens can achieve the effects of a focal length of 18.7mm, a total system length of 25mm, a field of view (FOV) of 70 °, and an Eye box of 8 × 8 mm.

The embodiment of the present disclosure further provides a virtual reality device, which includes a display module and a fresnel lens in any one of the embodiments of the present disclosure, wherein the first side of the fresnel lens faces the display module.

The embodiment of the present disclosure further provides a virtual reality apparatus, as shown in fig. 7, including a display module 50 or an optical module in any embodiment of the present disclosure, where a first side of a fresnel lens close to the display module 50 faces the display module 50, for example, in fig. 7, the first side of the first fresnel lens faces the optical module 50.

The virtual reality device of the embodiment of the disclosure can realize light weight, thinness and high luminous efficiency of products, and stray light is reduced by arranging the bearing surface on the sawtooth-shaped structure of the Fresnel lens and arranging the light blocking layer on the bearing surface, so that the light imaging quality of the whole system is improved.

In the description of the present specification, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present disclosure and to simplify the description, but are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present disclosure.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present disclosure, "a plurality" means two or more unless specifically limited otherwise.

In the present disclosure, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integral; the connection can be mechanical connection, electrical connection or communication; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present disclosure can be understood by those of ordinary skill in the art as appropriate.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise the first and second features being in direct contact, or may comprise the first and second features being in contact, not directly, but via another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The above disclosure provides many different embodiments or examples for implementing different features of the disclosure. The components and arrangements of specific examples are described above to simplify the present disclosure. Of course, they are merely examples and are not intended to limit the present disclosure. Moreover, the present disclosure may repeat reference numerals and/or reference letters in the various examples, which have been repeated for purposes of simplicity and clarity and do not in themselves dictate a relationship between the various embodiments and/or arrangements discussed.

While the present disclosure has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. The Fresnel lens is characterized by comprising a first side and a second side which are arranged oppositely, wherein the first side is provided with a plurality of saw-toothed structures, at least one of the saw-toothed structures comprises an effective surface, an ineffective surface and a bearing surface, the bearing surface is connected between the effective surface and the ineffective surface, the effective surface is far away from the center of the Fresnel lens relative to the ineffective surface, the bearing surface is a flat surface, the plane of the bearing surface is perpendicular to the central shaft of the Fresnel lens, the Fresnel lens further comprises a light blocking layer, and the light blocking layer is located on the bearing surface.

2. The fresnel lens according to claim 1, wherein a width of the light blocking layer is configured to prevent light rays incident from the effective surface from exiting from the ineffective surface.

3. Fresnel lens according to claim 1, characterised in that the width of the carrying surface ranges from more than 0 to less than or equal to 10 μm.

4. The fresnel lens according to claim 1, wherein the light blocking layer extends from an edge of the carrying surface near the inactive surface toward an edge near the active surface;

5. The fresnel lens according to claim 1, wherein the bearing surfaces of at least two of the sawtooth-shaped structures are located in the same plane; or the bearing surfaces of the sawtooth structures are positioned on different planes.

6. The fresnel lens according to claim 1, wherein the light blocking layer is further provided on the inactive surface.

7. The Fresnel lens according to any one of claims 1 to 6, wherein the light blocking layer is made of a black resin material, and the light blocking layer is made of a material having an optical density of 0 to 5.

8. The Fresnel lens according to any one of claims 1 to 6, wherein the light blocking layer has a thickness in a range of 0 to 2 μm.

9. An optical module comprising a plurality of fresnel lenses according to any one of claims 1 to 8, the fresnel lenses being centered on a common line.

10. The optical module as recited in claim 9, wherein the number of the fresnel lenses is three, and the fresnel lenses are a first fresnel lens, a second fresnel lens and a third fresnel lens, respectively, the second fresnel lens is located between the first fresnel lens and the third fresnel lens, a first side of the first fresnel lens is away from the second fresnel lens, a first side of the third fresnel lens is toward the second fresnel lens, and a second side of the first fresnel lens and a second side of the second fresnel lens are glued to each other.

11. The optical module of claim 10, wherein the distance between the third Fresnel lens and the second Fresnel lens is 0-8 mm.

12. A virtual reality apparatus, comprising:

a display module and a fresnel lens according to any one of claims 1 to 8, a first side of the fresnel lens facing the display module; alternatively, the first and second electrodes may be,

comprising a display module and an optical module according to any one of claims 9-11, a first side of the fresnel lens adjacent to the display module facing the display module.