Fresnel lens, manufacturing method and virtual display device

Abstract

The application discloses a Fresnel lens, a manufacturing method and a virtual display device. The Fresnel lens of one embodiment comprises a lens body, a tooth-shaped part at a first end of the lens body, and an arc-shaped part at a second end of the lens body. The tooth-shaped part comprises a first tooth-shaped structure and a plurality of second tooth-shaped structures arranged around the first tooth-shaped structure. Each second tooth-shaped structure comprises a first tooth surface and a second tooth surface, and the first tooth surface is away from the center of the orthographic projection of the lens body. Each second tooth-shaped structure further comprises a first shielding layer fixed to the second tooth surface. The arc-shaped part further comprises a first convex structure and a fixed end around the first convex structure, and the fixed end extends to intersect with the side wall of the lens body in the horizontal direction.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of display technology. More particularly, it relates to a Fresnel lens, a manufacturing method and a virtual display device. BACKGROUND

[0002] Virtual reality (VR) and augmented reality (AR) are the main application scenarios of near-eye display technology, which is becoming an important way for people to obtain information. At present, the mainstream near-eye display optical technology mainly includes: waveguide display, free-form surface display and integrated imaging light field display schemes, each of which has its own advantages and disadvantages. Waveguide display is sensitive to incident light wavelength and is prone to color dispersion; waveguide light coupling structure also has a dispersion effect on external light, and "ghost image" and other phenomena may occur during wearing. The free-form surface display scheme has a large overall size, and it is difficult to balance the large field of view and the size of the device; the integrated imaging light field display is difficult to realize the transmission of external light, and the AR augmented reality display effect is poor.

[0003] In the existing VR optical scheme, the straight-through aspheric lens group has the advantages of low design and processing difficulty, high light efficiency (> 50%), and no stray light, but the total length is thick (> 35mm), which is not conducive to product thinning. Pancake (thin pancake) type has the advantages of better imaging quality and thinner total system length (≤ 30mm), but the light efficiency is lower (< 25%), and there are ghost images and other phenomena. The straight-through Fresnel lens group is expected to have the advantages of high light efficiency of the straight-through aspheric lens group and the relatively thin advantage of the Pancake system. Since the straight-through Fresnel lens group has a Fresnel lens, the Fresnel lens has an invalid surface, and the invalid surface will have stray light, which will affect the imaging quality, as shown in Figure 1a SUMMARY

[0004] The purpose of the present application is to provide a Fresnel lens, a manufacturing method and a virtual display device to solve at least one of the problems in the prior art.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] The first aspect of the present application provides a Fresnel lens, which comprises:

[0007] an arc-shaped portion located at the second end portion,

[0008] wherein the tooth-shaped portion comprises a first tooth-shaped structure and a plurality of second tooth-shaped structures arranged in sequence around the first tooth-shaped structure;

[0009] The second tooth-shaped structure comprises a first tooth surface and a second tooth surface, and the first tooth surface is away from the center of the orthographic projection of the lens body relative to the second tooth surface; ​

[0010] Each of the second tooth-shaped structures further comprises a first shielding layer fixed on the second tooth surface;

[0011] The arc-shaped portion further comprises:

[0012] a first protruding structure, a protruding surface of the first protruding structure extending protruding from the first end portion to the second end portion; and

[0013] a fixed end surrounding the first protruding structure, the fixed end extending to intersect with the side wall of the lens body in a horizontal direction.

[0014] Optionally, the first tooth-shaped structure further comprises a second protruding structure, a protruding surface of the second protruding structure extending protruding from the second end portion to the second end portion, the protruding surface being arc-shaped or an inflection point structure at a position perpendicular to an axis of the center of the lens body.

[0015] Optionally, in a horizontal direction from the first tooth-shaped structure to the second tooth-shaped structure, a tooth-shaped width of the first tooth-shaped structure in the horizontal direction is the same;

[0016] or

[0017] in a vertical direction from the second end portion to the first end portion, tooth-shaped heights of the first tooth-shaped structure and the second tooth-shaped structure are the same.

[0018] Optionally, the Fresnel lens further comprises a second shielding layer arranged on the side wall of the lens body, a height of the second shielding layer in a vertical direction is equal to a height of the side wall of the lens body in the vertical direction.

[0019] Optionally, the first shielding layer is a carbon black or an organic black material.

[0020] Optionally, the Fresnel lens further comprises an arc-shaped portion at the second end portion, wherein the arc-shaped portion further comprises:

[0021] a first protruding structure, a protruding surface of the first protruding structure extending protruding from the first end portion to the second end portion; and

[0022] a fixed end surrounding the first protruding structure, the fixed end extending to intersect with the side wall of the lens body in a horizontal direction.

[0023] The second aspect of the present application provides a method for manufacturing the Fresnel lens as the first aspect of the present application, the method comprising:

[0024] forming an arc-shaped portion on the second end portion of the lens body;

[0025] A tooth-shaped portion is formed on a first end of the lens body, the tooth-shaped portion comprising a first tooth-shaped structure and a plurality of second tooth-shaped structures arranged in sequence around the first tooth-shaped structure, the first tooth-shaped structure coinciding with the center of the orthographic projection of the lens body, and the second tooth-shaped structure comprising a first tooth surface and a second tooth surface;

[0026] The forming of the second tooth-shaped structure comprises forming a first shielding layer on the second tooth surface by using a 3D printing process.

[0027] Optionally, the forming of the first shielding layer on the second tooth surface by using a 3D printing process further comprises:

[0028] The fixture is used to fix the Fresnel lens on a printing table of a 3D printing device;

[0029] Position data of the Fresnel lens after being fixed on the printing table is acquired, the position data comprising coordinate data of the second tooth surface in the orthographic projection of the lens body;

[0030] The position data is used to control a printing needle head of the 3D printing device to form an ink material layer of the first shielding layer on the second tooth surface;

[0031] The ink material layer is solidified to form the first shielding layer.

[0032] Optionally, the second tooth-shaped structure further comprises a transition surface of an arc-shaped structure connecting the first tooth surface and the second tooth surface, the center of the transition surface being towards the second end,

[0033] The controlling of the printing needle head of the 3D printing device to form the ink material layer of the first shielding layer on the second tooth surface by using the position data further comprises:

[0034] The printing needle head is controlled to move above the second tooth surface;

[0035] The inclination angle of the printing needle head is controlled to change the angle of the printing included angle formed by the printing needle head and the second tooth surface.

[0036] Optionally, the method further comprises forming a second shielding layer on the side wall of the lens body, the height of the second shielding layer in the vertical direction being equal to the height of the side wall of the lens body in the vertical direction.

[0037] The third aspect of the present application provides a virtual display device, the virtual display device comprising the Fresnel lens of the first aspect of the present application.

[0038] The present application has the following beneficial effects:

[0039] The embodiment of the present application sets a shielding layer on the invalid second tooth surface, uses the shielding layer to shield the stray light generated by the Fresnel lens, reduces the stray light, and improves the imaging effect. BRIEF DESCRIPTION OF DRAWINGS

[0040] The specific embodiments of the present application are further described in detail below with reference to the accompanying drawings.

[0041] Figure 1a And Figure 1b A schematic diagram of stray light of a Fresnel lens group of the related embodiments is shown.

[0042] Figure 2 A structural schematic diagram of the Fresnel lens of one embodiment of the present application is shown.

[0043] Figure 3 A schematic diagram of the imaging effect of the Fresnel lens is shown. Figure 2 A schematic diagram of the imaging effect of the Fresnel lens is shown.

[0044] Figure 4 A structural schematic diagram of the second tooth shape structure of one optional embodiment of the present application is shown.

[0045] Figure 5 A structural schematic diagram of the second shielding layer of one optional embodiment of the present application is shown.

[0046] Figure 6 And Figure 7 A structural schematic diagram of the Fresnel lens of different embodiments of the present application is shown.

[0047] Figure 8 A structural schematic diagram of the arc-shaped part of one optional embodiment of the present application is shown.

[0048] Figure 9 A flowchart of the manufacturing method of the Fresnel lens of another embodiment of the present application is shown.

[0049] Figure 10 A flowchart of the manufacturing method of step S931 of the embodiment of the present application is shown.

[0050] Figure 11a And Figure 11b Positional schematic diagrams of the printing needle vertically and obliquely arranged of the embodiment of the present application are shown.

[0051] Figure 12 And Figure 13 A clamp structure for fixing the Fresnel lens of the embodiment of the present application is shown. DETAILED DESCRIPTION

[0052] For a clearer explanation of the present application, the present application will be further described below with embodiments and accompanying drawings. Like components are denoted by the same reference numerals in the drawings. It should be understood by those skilled in the art that the specific description below is illustrative rather than limiting, and the protection scope of the present application should not be limited thereby.

[0053] The ineffective surface of the Fresnel lens is in the order of microns, and it is currently difficult to directly and accurately shield the ineffective surface of the Fresnel lens. However, if the ineffective surface is not shielded, stray light will be generated as shown in Figure 1a , which seriously affects the imaging quality. In view of this, the embodiments of the present application propose a Fresnel lens, a manufacturing method and a virtual display device.

[0054] As shown in Figure 2 , the first embodiment of the present application proposes a Fresnel lens, which comprises:

[0055] a lens body 10 comprising a first end portion 11 and a second end portion 12 arranged oppositely, in one specific example, the lens body of the present embodiment is a columnar structure, that is, it has a certain thickness in the vertical direction;

[0056] a tooth-shaped portion 20 located at the first end portion 11; and

[0057] an arc-shaped portion 30 located at the second end portion 12;

[0058] wherein the tooth-shaped portion 20 comprises a first tooth-shaped structure 21 and a plurality of second tooth-shaped structures 22 arranged in sequence around the first tooth-shaped structure 21, in one specific example, the first tooth-shaped structure 21 coincides with the center of the orthographic projection of the lens body 10, it is worth noting that when the orthographic projection of the lens body 10 in the horizontal plane is a non-standard structure, the center of the orthographic projection of the lens body 10 in the present embodiment is an approximate center position;

[0059] the second tooth-shaped structure 22 comprises:

[0060] a first tooth surface 221; and

[0061] a second tooth surface 222, the first tooth surface 221 is away from the center of the orthographic projection of the lens body 10 relative to the second tooth surface 222;

[0062] each second tooth-shaped structure 22 further comprises a first shielding layer 223 fixed on the second tooth surface 222.

[0063] In the embodiment of the present application, the first tooth surface 221 is an effective surface, and the second tooth surface 222 is an effective surface. In the embodiment of the present application, the shielding layer is arranged on the ineffective second tooth surface 222, the shielding layer is used to shield the stray light generated by the Fresnel lens, the stray light is reduced, and the imaging effect is improved.

[0064] In one specific example, the imaging effect of the Fresnel lens before improvement is shown in FIG. 1, and the imaging effect of the Fresnel lens after improvement is shown in FIG. 2. Figure 1b As shown in FIG. 2, the imaging effect of the Fresnel lens is shown in FIG. 2. Figure 1b As shown in FIG. 1, the imaging effect of the Fresnel lens is shown in FIG. 1. Figure 3 As shown in FIG. 2, the imaging effect of the Fresnel lens with the first shielding layer 223 in the embodiment of the present application is shown in FIG. 2, and the stray light of the Fresnel lens imaging shown in FIG. 2 is obviously improved. Figure 3 As shown in FIG. 2, the imaging effect of the Fresnel lens with the first shielding layer 223 in the embodiment of the present application is shown in FIG. 2, and the stray light of the Fresnel lens imaging shown in FIG. 2 is obviously improved.

[0065] In one optional embodiment, as shown in FIG. 3, the second tooth structure 22 further includes a transition surface 224 of an arc-shaped structure connecting the first tooth surface 221 and the second tooth surface 222, and a center of the arc-shaped structure of the transition surface 224 is towards the second end portion 12. Figure 4 In one specific example, the arc radius of the transition surface 224 is 10-30 microns, and preferably 20 microns as shown in FIG. 3. Figure 4

[0066] In the embodiment of the present application, the junction of the first tooth surface 221 and the second tooth surface 222 is limited to an arc-shaped structure. In the embodiment, the arc surface of the arc-shaped structure is bent in the direction from the first tooth surface 221 to the second tooth surface 222 and in the direction from the second end portion 12 to the first end portion 11. The height of the arc surface of the transition surface 224 close to the first tooth surface 221 from the upper surface of the first end portion 11 is greater than the height of the arc surface of the transition surface 224 close to the second tooth surface 222 from the upper surface of the first end portion 11. That is, the bend of the arc-shaped structure is downward. For the first tooth surface 221, the transition surface 224 can block the material forming the first shielding layer 223 from flowing to the first tooth surface 221, and has a blocking effect. For the second tooth surface 222, the transition surface 224 can make the material forming the first shielding layer 223 flow along the transition surface 224 to the second tooth surface 222, thereby improving the flowability of the material of the first shielding layer 223 and further ensuring the shielding effect.

[0067] In one optional embodiment, as shown in FIG. 4, the Fresnel lens further includes a second shielding layer 40 arranged on the side wall of the lens body 10, and the height of the second shielding layer 40 in the vertical direction is equal to the height of the side wall of the lens body 10 in the vertical direction. Figure 5

[0068] ​​In the technical scheme that the second tooth surface 222 is shielded by the first shielding layer 223, the side wall of the Fresnel lens is designed in the embodiment of the present application, and the side wall of the lens body 10 is shielded by the second shielding layer 40, so that the influence of stray light at the position of the side wall is further improved, and the imaging quality is improved.

[0069] In an optional embodiment, the first shielding layer 223 is carbon black or organic black material, and the second shielding layer 40 is organic or inorganic black material in the series of acrylic. Through the arrangement, the first shielding layer 223 and the second shielding layer 40 both have good shielding effect.

[0070] In an optional embodiment, the first shielding layer 223 is formed by using 3D printing technology. Since the 3D printing technology can realize micron-level process processing, the first shielding layer 223 with good covering effect can be formed on the second tooth surface 222. In order to save the manufacturing process, the second shielding layer 40 can also be formed by using 3D printing technology.

[0071] In an optional embodiment, as shown in Figure 6 and Figure 7 , the first tooth structure 21 further includes a second protruding structure 211, a protruding surface of the second protruding structure 211 protrudes from the second end portion 12 to the direction of the second end portion 12, and the protruding surface is arc-shaped or an inflection point structure at the position of the axis perpendicular to the center of the lens body 10 (for example, at the dotted line position shown in Figure 6 .

[0072] In the embodiment, as shown in Figure 6 and Figure 7 , the first tooth structure 21 of the embodiment of the present application is located at the center position of the lens body 10, the second tooth structure 22 is a circular ring protrusion surrounding the second protruding structure 211 in turn, and the first tooth structure 21 is a solid protruding structure. For different structures, the structures of the protruding surfaces are not the same.

[0073] In an optional embodiment, as shown in Figure 6 , in the horizontal direction from the first tooth structure 21 to the second tooth structure 22, the tooth width of the first tooth structure 21 in the horizontal direction is the same, that is, the Fresnel lens of the embodiment of the present application is an equal-interval structure. In a specific example, as shown in Figure 6 , in the direction from the second tooth structure 22 to the first tooth structure 21, that is, in the direction from the center of the Fresnel lens to the outside, the height of each first tooth structure 21 gradually increases, and the height of the second tooth structure 22 is less than the minimum width of all the first tooth structures 21.

[0074] In another optional embodiment, as shown inFigure 7 As shown, the tooth height of the first tooth structure 21 and the second tooth structure 22 is the same in the vertical direction from the second end 12 to the first end 11. That is, the Fresnel lens of the embodiment of the present application is of equal height structure, and in one specific example, as shown in the figure, the tooth height of the first tooth structure 21 and the second tooth structure 22 is the same in the vertical direction from the second end 12 to the first end 11. Figure 7 As shown, the width of the first tooth structure 21 gradually decreases in the direction from the second tooth structure 22 to the first tooth structure 21, that is, in the direction from the center of the Fresnel lens to the outside, and the width of the second tooth structure 22 is greater than the maximum width of all the first tooth structures 21.

[0075] In an alternative embodiment, as shown, the arc-shaped portion 30 further comprises: Figure 8 As shown, the arc-shaped portion 30 further comprises:

[0076] a first protruding structure 31, a protruding surface of the first protruding structure 31 extending protruding in the direction from the first end 11 to the second end 12; and

[0077] a fixed end 32 surrounding the first protruding structure 31, the fixed end 32 extending to intersect with the side wall of the lens body 10 in the horizontal direction, and the surface of the fixed end 32 away from the second end 12 is a horizontal surface.

[0078] When the first blocking layer 223 is formed on the side of the second end 12, the surface with height difference formed by the fixed end 32 and the first protruding structure 31 of the embodiment of the present application can realize the fixation of the Fresnel lens.

[0079] Based on the above design, the imaging effect of the Fresnel lens of the embodiment of the present application is improved, and has a wide application prospect.

[0080] Another embodiment of the present application proposes a method for manufacturing the Fresnel lens as described in the above embodiments of the present application, as shown, the method comprises: Figure 9 As shown, the method comprises:

[0081] S91, forming an arc-shaped portion 30 on the second end 12 of the lens body 10;

[0082] S93, forming a tooth-shaped portion 20 on the first end 11 opposite to the second end 12, the tooth-shaped portion 20 comprising a first tooth structure 21 and a plurality of second tooth structures 22 arranged in sequence around the first tooth structure 21, the first tooth structure 21 coinciding with the center of the orthographic projection of the lens body 10, and the second tooth structure 22 comprising a first tooth surface 221 and a second tooth surface 222;

[0083] In step S93, the forming of the second tooth structure 22 includes step S931, i.e., forming a first shielding layer 223 on the second tooth surface 222 by using a 3D printing process.

[0084] The 3D printing technology used in this embodiment can realize micron-level processing, thereby forming the first shielding layer 223 on the second tooth surface 222 with good coverage, and the Fresnel lens structure with improved stray light is formed through the above steps.

[0085] In an optional embodiment, as shown in FIG. 9, step S931 of forming the first shielding layer 223 on the second tooth surface 222 by using a 3D printing process further includes: Figure 10

[0086] S9311, fixing the Fresnel lens on a printing table of a 3D printing device by using a clamp. In this step, the Fresnel lens to be printed with the first shielding layer 223 of the second tooth surface 222 is fixed on the printing table by using the clamp to prevent errors caused by relative movement of the Fresnel lens during printing. For example, the first protruding structure 31 and the fixed end 32 of the embodiment of the present application can fix the Fresnel lens on the printing table to avoid movement errors.

[0087] S9313, obtaining position data of the Fresnel lens, the position data including coordinate data of the second tooth surface 222 in the orthographic projection of the lens body 10. In this step, the position data can be relative data, for example, taking the printing table as the coordinate system and taking the position of the Fresnel lens relative to the printing table as the position data, or the position data can be absolute data, for example, taking the position of the second tooth surface 222 of the Fresnel lens relative to the lens body 10 as the position data. As shown in FIG. 8, the coordinate of the top of the second tooth surface 222 in the direction away from the second end 12 and perpendicular to the surface of the lens body 10 is the initial position of the printing needle, and the position data is input into the 3D printing table device to plan the path of 3D printing. Figure 2

[0088] S9315, controlling the printing needle of the 3D printing device to form an ink material layer of the first shielding layer 223 on the second tooth surface 222 by using the position data.

[0089] During printing, the printing needle carries the printing ink, and the ink in the printing needle is sprayed under the driving of the printing control device. As shown in FIG. 10, the printing needle sprays the ink to the position of the second tooth surface 222 to be printed, so that the ink material with light shielding performance is sprayed on the second tooth surface 222. Figure 11a

[0090] ​​​Based on the foregoing embodiments, when the second toothed structure 22 of the present invention further includes a transition surface 224 of an arc-shaped structure connecting the first toothed surface 221 and the second toothed surface 222, in an optional embodiment, step S9315 "the step of controlling the printing needle of the 3D printing device to form an ink material layer of the first shielding layer 223 on the second toothed surface 222 using the position data" further includes:

[0091] Control the printing needle to move above the second tooth surface 222;

[0092] The tilt angle α of the printing needle is controlled to change the angle of the printing angle formed between the printing needle and the second tooth surface 222.

[0093] In other words, such as Figure 11b As shown, the present invention sets the tilt angle α of the printing needle, which enables the ink material of the printing needle to be accurately sprayed to the position of the transition surface 224. The structure of the transition surface 224 prevents the ink material from flowing to the first tooth surface 221, thereby affecting the light emission effect of the first tooth surface 221. Furthermore, the structure of the transition surface 224 allows the ink material to flow to the second tooth surface 222 more quickly, achieving the accurate coverage effect of the first shielding layer 223 on the second tooth surface 222.

[0094] In an optional embodiment, when the angle between the printing needle and the vertical direction is 20°-80°, the printing needle is tilted. When the tilt angle α is preferably 30°, and the ink outlet of the printing needle is located 0.05-1 mm above the junction of the first tooth surface 221 and the second tooth surface 222, preferably 0.1 mm above, the printing needle and the transition surface 224 have optimal positioning effect, and the ink material jet has optimal flowability.

[0095] S9317. The ink material layer is cured to form the first shielding layer 223.

[0096] In this step, the ink material printed on the second toothed surface 222 is photocured using an ultraviolet lamp, thereby ensuring a firm bond between the light-shielding ink material and the second toothed surface 222. In an optional embodiment, the tooth width of the first toothed surface is 40µm-1cm, the viscosity of the printing ink is between 10000-30000mPa·s, the diameter of the printing needle is 2-30µm, the transmittance of the printing ink material to visible light is <0.1%, the width of the first shielding layer 223 in the direction from the first toothed structure 21 and the second toothed structure 22 (i.e., the printing linewidth of the first shielding layer 223) is ≤30µm, and in the curing process, the wavelength of the ultraviolet lamp is 350-400nm, and the curing time is 5-40s, which can effectively fix the first shielding layer 223 and the second toothed surface 222.

[0097] Figure 12 and Figure 13 The fixture structure of the fixed Fresnel lens of the embodiment of the application is shown, in an alternative embodiment, the fixture comprises a fixed base 61, the fixed base 61 is horizontal near the bottom surface of the printing table, the fixed base 61 is provided with a groove structure 611 corresponding to the Fresnel lens body 10 at the top away from the printing table, for example, the groove depth of the groove structure 611 is less than the overall height of the Fresnel lens, that is, less than the distance between the vertex of the second tooth surface 222 of the Fresnel lens and the outermost protruding position of the first protruding structure 31, so that the first tooth structure 21 of the Fresnel lens is exposed to the upper surface of the printing table for 3D printing.

[0098] In a specific example, as shown in Figure 12 and Figure 13 The groove surface of the groove structure 611 of the fixture and the end surface of the fixed end 32 of the Fresnel lens and the protruding surface of the first protruding structure 31 are correspondingly arranged, so as to realize the fixation of the Fresnel lens and reduce the processing error.

[0099] In an alternative embodiment, as shown in Figure 12 and Figure 13 The fixture further comprises a vertically arranged abutting portion 62 arranged on the surface of the fixed base 61, the surface of the fixed base 61 is a fan ring structure in orthographic projection, further realizing the fixation of the side wall of the Fresnel lens 1.

[0100] In an alternative embodiment, as shown in Figure 12 and Figure 13 The fixture 60 further comprises an adjusting portion 63 arranged opposite to the abutting portion 62, for example, the adjusting portion 63 can be Figure 12 The magnetic adjusting structure shown in Figure 13 The bolt adjusting structure shown in, further ensuring the fixation stability of the Fresnel lens.

[0101] In a specific example, as shown in Figure 12 When the adjusting portion 63 is a magnetic adjusting structure, the adjusting portion 63 comprises a first magnet 631 arranged inside the fixed base 61 and a second magnet 632 arranged on the surface of the fixed base 61, the surface of the fixed base 61 is a fan ring structure in orthographic projection, the position of the Fresnel lens is fine-tuned by adjusting the relative position between the first magnet 631 and the second magnet 632 to change the magnetic force.

[0102] In another specific example, as shown in Figure 13As shown, when the adjusting part 63 is a screw adjusting structure, the adjusting part 63 comprises a moving block 633 on the surface of the fixed base 61 and a locking part 634 on the side wall of the moving block 633 away from the abutting part 62, and the position of the Fresnel lens 1 is finely adjusted by adjusting the locking degree of the locking part 634.

[0103] In an optional embodiment, as shown in Figure 13 As shown, the side wall of the moving block 633 away from the abutting part 62 is provided with an elastic layer 65 to buffer the locking force and protect the Fresnel lens.

[0104] In an optional embodiment, the groove structure 611 is provided with an air extraction hole, and after the Fresnel lens 1 is placed in the groove structure 611, the gap between the convex surface of the first convex structure and the groove structure is extracted through the air extraction hole, and the fixing of the Fresnel lens is further realized.

[0105] The person skilled in the art can select a corresponding clamp according to the actual application to realize the fixing of the Fresnel lens, which will not be described here.

[0106] It is worth noting that the specific embodiments of the Fresnel lens manufacturing method of the embodiment of the present application can refer to the Fresnel lens of the foregoing embodiments, which will not be described here.

[0107] In an optional embodiment, the method further comprises forming a second shielding layer 40 on the side wall of the lens body 10, and the height of the second shielding layer 40 in the vertical direction is equal to the height of the side wall of the lens body 10 in the vertical direction. This step realizes Figure 5 As shown, the structure of the second shielding layer 40 further improves the influence of stray light at the position of the side wall and improves the imaging quality. In a specific example, the structure design of the second shielding layer 40 can be realized by using a coating process or the like.

[0108] Another embodiment of the present application provides a virtual display device, which comprises the Fresnel lens as described above, and the Fresnel lens of the embodiment of the present application can be used as a lens group, for example, applied to a virtual reality device or an augmented reality device to improve the imaging effect.

[0109] In the description of the application, the relative terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation without necessarily requiring or implying any such actual relationship or order between such entities or operations. Moreover, the terms "comprising", "including", or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without more limitations, an element defined by an expression "comprising a..." does not exclude the existence of additional identical elements in the process, method, article, or apparatus including the stated elements.

[0110] Obviously, the above-described embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation manners of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and it is impossible to enumerate all the implementation manners here. Any obvious changes or variations derived from the technical solutions of the present application are still within the protection scope of the present application.

Claims

1. A Fresnel lens, characterized in that, The Fresnel lens includes: The lens body includes a first end and a second end disposed opposite to each other; and The toothed portion located at the first end, The arc-shaped portion located at the second end, The toothed portion includes a first toothed structure and a plurality of second toothed structures arranged sequentially around the first toothed structure; The second tooth structure includes a first tooth surface and a second tooth surface, wherein the first tooth surface is located away from the center of the orthogonal projection of the lens body relative to the second tooth surface; Each of the second tooth-shaped structures further includes a first shielding layer fixed to the second tooth surface; The arc-shaped portion also includes: A first protrusion structure, wherein the protruding surface of the first protrusion structure extends protruding from the first end to the second end; and The fixed end surrounds the first protrusion structure and extends horizontally to intersect with the sidewall of the lens body; The Fresnel lens further includes a second shielding layer disposed on the sidewall of the lens body, the height of the second shielding layer in the vertical direction being equal to the height of the sidewall of the lens body in the vertical direction; The second shielding layer is formed using 3D printing technology.

2. The Fresnel lens according to claim 1, characterized in that, The first tooth-shaped structure further includes a second protrusion structure. The protrusion surface of the second protrusion structure extends from the second end toward the second end and the protrusion surface is arc-shaped or has an inflection point structure at an axis position perpendicular to the center of the lens body.

3. The Fresnel lens according to claim 2, characterized in that, In the horizontal direction from the first tooth structure to the second tooth structure, the tooth width of the first tooth structure is the same in the horizontal direction; or In the vertical direction from the second end to the first end, the tooth heights of the first tooth structure and the second tooth structure are the same.

4. The Fresnel lens according to claim 1, characterized in that, The first shielding layer is made of carbon black or organic black material.

5. A method for manufacturing a Fresnel lens as described in any one of claims 1-4, characterized in that, The method includes: An arcuate portion is formed at the second end of the lens body; A toothed portion is formed on the first end of the lens body. The toothed portion includes a first toothed structure and a plurality of second toothed structures arranged sequentially around the first toothed structure. The second toothed structure includes a first tooth surface and a second tooth surface. The formation of the second tooth structure includes forming a first shielding layer on the surface of the second tooth using a 3D printing process.

6. The manufacturing method according to claim 5, characterized in that, The step of forming a first shielding layer on the second tooth surface using 3D printing technology further includes: The Fresnel lens is fixed to the printing table of the 3D printing equipment using a clamp. The position data of the Fresnel lens after it is fixed to the printing table is obtained, and the position data includes the coordinate data of the orthographic projection of the second tooth surface onto the lens body; The position data is used to control the printing needle of the 3D printing device to form an ink material layer of the first shielding layer on the second tooth surface; The ink material layer is cured to form the first shielding layer.

7. The manufacturing method according to claim 6, characterized in that, The second tooth structure further includes a transition surface of an arc-shaped structure connecting the first tooth surface and the second tooth surface, the center of which faces the second end side. The ink material layer used to control the printing needle of the 3D printing device to form a first shielding layer on the second tooth surface using the position data further includes: Control the printing needle to move above the second tooth surface; The tilt angle of the printing needle is controlled to change the printing angle formed between the printing needle and the second tooth surface.

8. The manufacturing method according to claim 5, characterized in that, The method further includes forming a second shielding layer on the sidewall of the lens body, wherein the height of the second shielding layer in the vertical direction is equal to the height of the sidewall of the lens body in the vertical direction.

9. The manufacturing method according to claim 5, characterized in that, In the direction from the first tooth structure to the second tooth structure, the tooth width of the first tooth surface is 40um-1cm, and the printed line width of the shielding layer is ≤30um.

10. The manufacturing method according to claim 6, characterized in that, The diameter of the printing needle is 2-30 μm, and the viscosity of the ink material stored in the printing needle is 10000-30000 mPa·s.

11. A virtual display device, characterized in that, The virtual display device includes a Fresnel lens as described in any one of claims 1-4.

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