Fresnel lens, manufacturing method and virtual display device

Abstract

The invention discloses a Fresnel lens, a manufacturing method and a virtual display device. The Fresnel lens of one embodiment comprises a lens body, a first lens and a second lens, wherein the lens body comprises a first end part and a second end part which are oppositely arranged; the tooth-shaped part is positioned at the first end part; the arc-shaped part is positioned at the second end part; wherein the tooth-shaped part comprises a first tooth-shaped structure and a plurality of second tooth-shaped structures which are arranged around the first tooth-shaped structure in sequence; the second tooth-shaped structure comprises a first tooth surface and a second tooth surface, and the first tooth surface is far away from the center of the orthographic projection of the lens body relative to the second tooth surface; each second tooth-shaped structure further comprises a first shielding layer fixed to the second tooth face, the arc-shaped part further comprises a first protruding structure and a fixing end surrounding the first protruding structure, and the fixing end extends in the horizontal direction to intersect with the side wall of the lens body.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and more specifically, to a Fresnel lens, a manufacturing method and a virtual display device. Background Art

[0002] Near-eye display technology, with virtual reality (VR) and augmented reality (AR) as the main application scenarios, is becoming an increasingly important way for people to obtain information. At present, the mainstream near-eye display optical technologies mainly include: waveguide display, free-form surface display and integrated imaging light field display. These solutions have their own advantages and disadvantages. Waveguide display is sensitive to the wavelength of incident light and is prone to dispersion; the waveguide light coupling structure also has a dispersion effect on external light, and "ghost images" and other phenomena will appear during wearing. The overall size of the free-form surface display solution is large, 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 achieve the transmission of external light, and the AR augmented reality display effect is poor.

[0003] Among the existing VR optical solutions, the straight-through aspheric lens group has the advantages of low design and processing difficulty, high light efficiency (>50%), and no stray light. However, the total length of the system is thick (>35mm), which is not conducive to the thinness of the product. The Pancake type has the advantages of better imaging quality and thin system length (≤30mm), but the light efficiency is low (<25%), and there are phenomena such as ghosting. The straight-through Fresnel lens group is expected to have the advantages of both the high light efficiency of the straight-through aspheric lens group and the thinness of the Pancake type 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. The stray light will affect the imaging quality, such as Figure 1a shown. Summary of the invention

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

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A first aspect of the present invention provides a Fresnel lens, the Fresnel lens comprising:

[0007] The arc portion located at the second end portion,

[0008] Wherein, the tooth-shaped portion includes a first tooth-shaped structure and a plurality of second tooth-shaped structures sequentially arranged around the first tooth-shaped structure;

[0009] The second tooth-shaped structure includes a first tooth surface and a second tooth surface, wherein the first tooth surface is farther away from the center of the orthographic projection of the lens body than the second tooth surface;

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

[0011] The arc portion further comprises:

[0012] a first protruding structure, a protruding surface of the first protruding structure extending protrudingly in a direction from the first end portion toward the second end portion; and

[0013] The fixing end surrounds the first protrusion structure, and the fixing end extends in a horizontal direction to intersect with a side wall of the lens body.

[0014] Optionally, the first tooth-shaped structure further includes a second protruding structure, a protruding surface of the second protruding structure extends and protrudes from the second end portion toward the second end portion, and the protruding surface is an arc-shaped or inflection point structure at an axial position perpendicular to the center of the lens body.

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

[0016] or

[0017] In a vertical direction from the second end to the first end, the first toothed structure and the second toothed structure have the same tooth height.

[0018] Optionally, the Fresnel lens further comprises a second shielding layer arranged on the side wall of the lens body, and a height of the second shielding layer in the 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 carbon black or organic black material.

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

[0021] A first protruding structure, a protruding surface of the first protruding structure protrudes in a direction extending from the first end toward the second end; and

[0022] The fixing end surrounds the first protrusion structure, and the fixing end extends in a horizontal direction to intersect with a side wall of the lens body.

[0023] A second aspect of the present invention provides a method for manufacturing the Fresnel lens according to the first aspect of the present invention, the method comprising:

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

[0025] A toothed portion is formed on a first end portion of the lens body, the toothed portion comprising a first toothed structure and a plurality of second toothed structures sequentially arranged around the first toothed structure, the first toothed structure coincides with the center of the orthographic projection of the lens body at the center of the orthographic projection of the lens body, and the second toothed structure comprises a first toothed surface and a second toothed surface;

[0026] Wherein, forming the second tooth-shaped structure includes forming a first shielding layer on the second tooth surface by using a 3D printing process.

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

[0028] Fixing the Fresnel lens to a printing table of a 3D printing device using a clamp;

[0029] Acquire position data of the Fresnel lens after being fixed on the printing table, wherein the position data includes coordinate data of the orthographic projection of the second tooth surface on the lens body;

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

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

[0032] Optionally, the second tooth-shaped structure further includes a transition surface of an arc-shaped structure connecting the first tooth surface and the second tooth surface, and the center of the transition surface faces the second end.

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

[0034] Controlling the printing needle to move above the second tooth surface;

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

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

[0037] A third aspect of the present invention provides a virtual display device, comprising the Fresnel lens according to the first aspect of the present invention.

[0038] The beneficial effects of the present invention are as follows:

[0039] In the embodiment of the present invention, a shielding layer is provided on the invalid second tooth surface, and the shielding layer is used to shield the stray light generated by the Fresnel lens, thereby reducing the stray light and improving the imaging effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0041] Figure 1a and Figure 1b A schematic diagram showing stray light defects of a Fresnel lens assembly of a related embodiment is shown;

[0042] Figure 2 A schematic structural diagram of a Fresnel lens according to an embodiment of the present invention;

[0043] Figure 3 Shows Figure 2 Schematic diagram of the imaging effect of the Fresnel lens shown;

[0044] Figure 4 A schematic structural diagram showing a second tooth-shaped structure of an optional embodiment of the present invention;

[0045] Figure 5 A schematic diagram showing the structure of a second shielding layer according to an optional embodiment of the present invention;

[0046] Figure 6 and Figure 7 Schematic diagrams showing the structures of Fresnel lenses according to different embodiments of the present invention;

[0047] Figure 8 A schematic diagram showing the structure of an arc portion of an optional embodiment of the present invention;

[0048] Fig. 9 A flow chart showing a method for manufacturing a Fresnel lens according to another embodiment of the present invention;

[0049] Fig.10 A flowchart of the manufacturing method of step S931 of an embodiment of the present invention is shown;

[0050] Fig.11a and Fig.11b Schematic diagrams showing the positions of the printing needle in the embodiment of the present invention when it is vertically and obliquely arranged;

[0051] Fig.12 and Fig.13 The figure shows a fixture structure for fixing a Fresnel lens according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to explain the present invention more clearly, the present invention is further described below in conjunction with embodiments and drawings. Similar components in the drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and the protection scope of the present invention should not be limited thereto.

[0053] The ineffective surface of the Fresnel lens is at the um level. Currently, it is difficult to directly and accurately block the ineffective surface of the Fresnel lens. However, if the ineffective surface is not blocked, the following will occur: Figure 1a The stray light shown seriously affects the imaging quality. In view of this, the embodiment of the present invention provides a Fresnel lens, a manufacturing method and a virtual display device.

[0054] like Figure 2 As shown, the first embodiment of the present invention provides a Fresnel lens, and the Fresnel lens includes:

[0055] A lens body 10, wherein the lens body 10 comprises a first end portion 11 and a second end portion 12 which are arranged opposite to each other. In a specific example, the lens body of this embodiment is a columnar structure, that is, it has a certain thickness in the vertical direction;

[0056] a toothed portion 20 located at the first end portion 11; and

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

[0058] The tooth-shaped portion 20 includes a first tooth-shaped structure 21 and a plurality of second tooth-shaped structures 22 sequentially arranged around the first tooth-shaped structure 21. In a specific example, the center of the orthographic projection of the lens body 10 of 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 on the horizontal plane is a non-standard structure, the center of the orthographic projection of the lens body 10 described in this embodiment is an approximate central position.

[0059] The second toothed structure 22 comprises:

[0060] A first tooth surface 221; and

[0061] a second tooth surface 222, wherein 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 of the second tooth-shaped structures 22 further includes a first shielding layer 223 fixed on the second tooth surface 222 .

[0063] In the embodiment of the present invention, 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 invention, a shielding layer is provided on the invalid second tooth surface 222, and the shielding layer is used to shield the stray light generated by the Fresnel lens, thereby reducing the stray light and improving the imaging effect.

[0064] In a specific example, the imaging effect of the Fresnel lens before improvement is as follows: Figure 1b As shown, Figure 1b The imaging effect shows obvious stray light, such as Figure 3 FIG. 2 shows the imaging effect of the Fresnel lens with the first shielding layer 223 according to an embodiment of the present invention. It can be clearly seen that Figure 3 The stray light of the Fresnel lens imaging shown is improved, which shows that the Fresnel lens of the embodiment of the present invention has a wide range of application prospects.

[0065] In an optional embodiment, if Figure 4 As shown, the second tooth structure 22 further includes a transition surface 224 of an arc structure connecting the first tooth surface 221 and the second tooth surface 222, and the center of the transition surface 224 faces the second end 12. In a specific example, the arc radius of the transition surface 224 is 10-30 microns, preferably Figure 4 20 μm shown.

[0066] The embodiment of the present invention limits the junction of the first tooth surface 221 and the second tooth surface 222 to an arc-shaped structure. In this embodiment, the arc surface of the arc-shaped structure is a bend in the direction from the first tooth surface 221 to the second tooth surface 222 and in the direction from the second end 12 to the first end 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 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 11. In other words, the bend of the arc-shaped structure is a downward bend. For the first tooth surface 221, the transition surface 224 can block the material forming the first shielding layer 223 from flowing toward the first tooth surface 221, and has a blocking effect. For the second tooth surface 222, the transition surface 224 can enable the material forming the first shielding layer 223 to flow along the transition surface 224 to the second tooth surface 222, thereby improving the fluidity of the material of the first shielding layer 223 and further ensuring the shielding effect.

[0067] In an alternative embodiment, Figure 5 As shown, the Fresnel lens further includes a second shielding layer 40 disposed 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.

[0068] In this embodiment, based on the technical solution of shielding the second tooth surface 222 with the first shielding layer 223, the present invention designs the side wall of the Fresnel lens, and shields the side wall of the lens body 10 with the second shielding layer 40, so as to further improve the influence of stray light at the side wall position and improve the imaging quality.

[0069] In an optional embodiment, the first shielding layer 223 is carbon black or an organic black material, and the second shielding layer 40 is an organic or inorganic black material of the acrylic series. With this configuration, both the first shielding layer 223 and the second shielding layer 40 have good shielding effects.

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

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

[0072] In this embodiment, Figure 6 and Figure 7 As shown, the first tooth-shaped structure 21 of the embodiment of the present invention is located at the center of the lens body 10, the second tooth-shaped structure 22 is a circular protrusion that surrounds the second protrusion structure 211 in sequence, and the first tooth-shaped structure 21 is a solid protrusion structure. For different structures, the structure of the protrusion surface is not the same.

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

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

[0075] In an optional embodiment, if Figure 8 As shown, the arc portion 30 also includes:

[0076] A first protruding structure 31, wherein a protruding surface of the first protruding structure 31 extends and protrudes from the first end 11 toward the second end 12; and

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

[0078] When the first shielding layer 223 is formed on one side of the second end portion 12 , the surface with a height difference formed by the fixing end 32 and the first protruding structure 31 in the embodiment of the present invention can realize the fixing of the Fresnel lens.

[0079] Based on the above design, the imaging effect of the Fresnel lens of the embodiment of the present invention is improved and has broad application prospects.

[0080] Another embodiment of the present invention provides a method for manufacturing the Fresnel lens of the above embodiment of the present invention, such as Fig. 9 As shown, the method includes:

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

[0082] S93, forming a toothed portion 20 on the first end portion 11 opposite to the second end portion 12, the toothed portion 20 comprising a first toothed structure 21 and a plurality of second toothed structures 22 sequentially arranged around the first toothed structure 21, the first toothed structure 21 coincides with the center of the orthographic projection of the lens body 10 at the center of the orthographic projection of the lens body 10, and the second toothed structure 22 comprises a first toothed surface 221 and a second toothed surface 222;

[0083] Among them, the step of “forming the second tooth-shaped structure 22 ” in step S93 includes step S931 , namely, “forming a first shielding layer 223 on the second tooth surface 222 by using a 3D printing process”.

[0084] The embodiment of this invention can realize micron-level processing by 3D printing technology, so as to form a first shielding layer 223 with good covering effect on the second tooth surface 222. The Fresnel lens structure with improved stray light is formed through the above steps.

[0085] In an optional embodiment, if Fig.10 As shown, step S931 "forming a first shielding layer 223 on the second tooth surface 222 by using a 3D printing process" further includes:

[0086] S9311. Fix the Fresnel lens to the printing table of the 3D printing device using a clamp. In this step, the Fresnel lens that needs to print the first shielding layer 223 of the second tooth surface 222 is fixed to the printing table by a clamp to prevent errors caused by relative movement of the Fresnel lens during the printing process. Exemplarily, the first protruding structure 31 and the fixed end 32 of the embodiment of the present invention can fix the Fresnel lens to the printing table to avoid movement errors.

[0087] S9313, obtaining the position data of the Fresnel lens, the position data including the coordinate data of the orthographic projection of the second tooth surface 222 on the lens body 10. In this step, the position data may 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 may be absolute data, for example, taking the position of the second tooth surface 222 of the Fresnel lens relative to its own lens body 10 as the position data. Figure 2 As shown, the coordinates 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 are the initial position of the printing needle. The position data is input into the 3D printer to plan the 3D printing path.

[0088] S9315, using the position data to control 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.

[0089] During the printing process, the printing needle carries the printing ink. Under the drive of the printing control device, the ink in the printing needle will be ejected. Based on the description of the second tooth-shaped structure 22 in the above embodiment, as shown in FIG. Fig.11a As shown, the printing needle sprays ink toward 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 .

[0090] Based on the foregoing embodiment, when the second tooth-shaped structure 22 of the embodiment of the present invention further includes a transition surface 224 of an arc-shaped structure connecting the first tooth surface 221 and the second tooth surface 222, in an optional embodiment, step S9315 "using the position data to control 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" further includes:

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

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

[0093] That is to say, Fig.11b As shown, the present invention sets the inclination angle α of the printing needle, through which the ink material of the printing needle can be accurately sprayed to the position of the transition surface 224, and the structure of the transition surface 224 is used to prevent the ink material from flowing to the first tooth surface 221, so as to affect the light emitting effect of the first tooth surface 221, and the structure of the transition surface 224 can make the ink material flow to the second tooth surface 222 faster, so as to achieve the accurate covering effect of the first shielding layer 223 on the second tooth surface 222.

[0094] In an optional embodiment, when the angle between the print needle and the vertical direction is 20°-80°, the print needle is tilted, and the tilt angle α is preferably 30°. When the ink outlet of the print 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 print needle and the transition surface 224 have the optimal position effect, and the injection of the ink material has the optimal fluidity.

[0095] S9317, curing the ink material layer to form the first shielding layer 223.

[0096] In this step, the ink material printed on the second tooth surface 222 is photocured by an ultraviolet lamp, so that the light-shielding ink material is firmly combined with the second tooth surface 222. In an optional embodiment, the tooth width of the first tooth surface is 40um-1cm, the viscosity of the printing ink is between 10000-30000mPa·s, the diameter of the printing needle is 2-30um, the transmittance of the printing ink material to visible light is less than 0.1%, the width of the first shielding layer 223 in the direction from the first tooth structure 21 and the second tooth structure 22, that is, the print line width of the first shielding layer 223 is ≤30um, and in the curing process, the wavelength of the ultraviolet lamp is 350-400nm, and the curing time is 5-40s, which can achieve effective fixation of the first shielding layer 223 and the second tooth surface 222.

[0097] Fig.12 and Fig.13 The fixture structure for fixing the Fresnel lens according to an embodiment of the present invention is shown. In an optional embodiment, the fixture includes a fixed base 61, the bottom surface of the fixed base 61 close to the printing table is a horizontal plane, and the top of the fixed base 61 away from the printing table is provided with a groove structure 611 corresponding to the Fresnel lens body 10. Exemplarily, 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 toothed structure 21 of the Fresnel lens is exposed above the printing table for 3D printing.

[0098] In a specific example, if Fig.12 and Fig.13 As shown, 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 convex surface of the first convex structure 31 are arranged correspondingly, so as to fix the Fresnel lens and reduce the processing error.

[0099] In an optional embodiment, if Fig.12 and Fig.13 As shown, the fixture further includes a vertically arranged abutment portion 62 arranged on the surface of the fixed base 61 , and the orthographic projection of the abutment portion 62 on the surface of the fixed base 61 is a fan-ring structure, which further implements the fixation of the side wall of the Fresnel lens 1 .

[0100] In an optional embodiment, if Fig.12 and Fig.13 As shown, the clamp 60 further includes an adjusting portion 63 disposed opposite to the abutting portion 62. For example, the adjusting portion 63 may be Fig.12 The magnetic force adjustment structure shown can also be Fig.13 The bolt adjustment structure shown further ensures the fixing stability of the Fresnel lens.

[0101] In a specific example, if Fig.12 As shown, when the adjustment part 63 is a magnetic adjustment structure, the adjustment part 63 includes a first magnet 631 arranged inside the fixed base 61 and a second magnet 632 located on the surface of the fixed base 61. The orthographic projection of the second magnet 632 on the surface of the fixed base 61 is a fan-ring structure. The magnetic force is changed by adjusting the relative position between the first magnet 631 and the second magnet 632 to fine-tune the position of the Fresnel lens.

[0102] In another specific example, Fig.13As shown, when the adjustment portion 63 is a bolt adjustment structure, the adjustment portion 63 includes a moving block 633 located on the surface of the fixed base 61 and a locking portion 634 arranged on the side wall of the moving block 633 away from the abutment portion 62. The position of the Fresnel lens 1 is fine-tuned by adjusting the locking degree of the locking portion 634.

[0103] In an optional embodiment, in Fig.13 As shown, an elastic layer 65 is provided on the side wall of the moving block 633 facing the abutting portion 62 to buffer the locking force, thereby protecting the Fresnel lens.

[0104] In an optional embodiment, the groove structure 611 is provided with an exhaust hole. After the Fresnel lens 1 is placed in the groove structure 611, the exhaust hole is used to exhaust air from the gap formed by the convex surface of the first convex structure and the groove structure, thereby further fixing the Fresnel lens.

[0105] Those skilled in the art select corresponding clamps to fix the Fresnel lens according to actual applications, which will not be described in detail here.

[0106] It is worth noting that the specific embodiment of the method for manufacturing the Fresnel lens of the embodiment of the present invention can refer to the Fresnel lens of the aforementioned embodiment, which will not be described in detail 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, wherein 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 The structure of the second shielding layer 40 shown further improves the stray light effect at the side wall position and improves the imaging quality. In a specific example, the structural design of the second shielding layer 40 can be achieved by using a coating process or other methods.

[0108] Another embodiment of the present invention provides a virtual display device, which includes the Fresnel lens as described above. The Fresnel lens of the embodiment of the present invention can be used as a lens group, for example, in a virtual reality device or an augmented reality device to improve imaging effects.

[0109] In the description of the present invention, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0110] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A Fresnel lens, characterized in that: The Fresnel lens comprises: A lens body including a first end and a second end that are oppositely disposed; and a toothed portion located at the first end portion, The arc portion located at the second end portion, Wherein, the tooth-shaped portion includes a first tooth-shaped structure and a plurality of second tooth-shaped structures sequentially arranged around the first tooth-shaped structure; The second tooth-shaped structure includes a first tooth surface and a second tooth surface, wherein the first tooth surface is farther away from the center of the orthographic projection of the lens body than the second tooth surface; Each of the second tooth-shaped structures further includes a first shielding layer fixed on the second tooth surface; The arc portion further comprises: A first protruding structure, a protruding surface of the first protruding structure protrudes in a direction extending from the first end toward the second end; and The fixing end surrounds the first protrusion structure, and the fixing end extends in a horizontal direction to intersect with a side wall of the lens body.

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

3. The Fresnel lens according to claim 2, characterized in that: In a horizontal direction from the first tooth-shaped structure to the second tooth-shaped structure, the tooth-shaped widths of the first tooth-shaped structure in the horizontal direction are the same; or In a vertical direction from the second end to the first end, the first toothed structure and the second toothed structure have the same tooth height.

4. The Fresnel lens according to claim 1, characterized in that: The Fresnel lens further includes a second shielding layer disposed on the side wall of the lens body, and the height of the second shielding layer in the vertical direction is equal to the height of the side wall of the lens body in the vertical direction.

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

6. A method for manufacturing a Fresnel lens as claimed in any one of claims 1 to 5, characterized in that: The method comprises: forming an arc portion on the second end portion of the lens body; A toothed portion is formed on the first end of the lens body, the toothed portion comprising a first toothed structure and a plurality of second toothed structures sequentially arranged around the first toothed structure, the second toothed structure comprising a first toothed surface and a second toothed surface; Wherein, forming the second tooth-shaped structure includes forming a first shielding layer on the second tooth surface by using a 3D printing process.

7. The manufacturing method according to claim 6, characterized in that: The forming of the first shielding layer on the second tooth surface by using the 3D printing process further comprises: Fixing the Fresnel lens to a printing table of a 3D printing device using a clamp; Acquire position data of the Fresnel lens after being fixed on the printing table, the position data including coordinate data of the orthographic projection of the second tooth surface on the lens body; Using the position data, control a printing needle of the 3D printing device to form an ink material layer of a first shielding layer on the second tooth surface; The ink material layer is cured to form the first shielding layer.

8. The method according to claim 7, characterized in that: The second tooth-shaped structure further includes a transition surface of an arc-shaped structure connecting the first tooth surface and the second tooth surface, wherein the center of the transition surface faces the second end portion. The step of controlling the printing needle of the 3D printing device by using the position data to form the ink material layer of the first shielding layer on the second tooth surface further comprises: Controlling the printing needle to move above the second tooth surface; The inclination angle of the printing needle is controlled to change the printing angle formed by the printing needle and the second tooth surface.

9. The manufacturing method according to claim 6, characterized in that: The method further includes forming a second shielding layer on the side wall of the lens body, wherein a height of the second shielding layer in the vertical direction is equal to a height of the side wall of the lens body in the vertical direction.

10. The manufacturing method according to claim 6, characterized in that: In the direction from the first tooth-shaped structure to the second tooth-shaped structure, the tooth-shaped width of the first tooth surface is 40um-1cm, and the printing line width of the shielding layer is ≤30um.

11. The manufacturing method according to claim 7, characterized in that: The diameter of the printing needle is 2-30 um, and the viscosity of the ink material stored in the printing needle is 10000-30000 mPa·s.

12. A virtual display device, characterized in that: The virtual display device comprises a Fresnel lens as claimed in any one of claims 1 to 5.

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