Large field of view, large aperture, negative focal length, visual optical system and near-eye display device

Abstract

The present application relates to a kind of big field of view big aperture negative focal length visual optical system and near-eye display device, visual optical system includes: the first lens group close to human eye side and the second lens group close to micro image display side;Light is emitted from micro image display, after converging once by the second lens group, then by the first lens group into human eye, form image;Visual optical system total focal length is negative, the first lens group and the second lens group both have positive refractive power, the first lens group is made of positive lens, and the second lens group is made of positive lens and negative lens;Or, the first lens group and the second lens group are made of positive lens and negative lens respectively.The present application uses big field of view big aperture negative focal length visual optical system, greatly increases the optimization degree of freedom of optical system, greatly improves the imaging quality of entire optical system, realizes the big field angle of visual optical system, high image resolution, low distortion, small field curvature and other indexes, greatly improves the competitiveness of product.

Description

Technical Field

[0001] This invention relates to the field of near-eye display optics technology, and more specifically, to a large field of view, large aperture, negative focal length visual optical system and near-eye display device. Background Technology

[0002] Near-eye display devices use optical imaging technologies to guide the video image light emitted by a miniature image display (such as a transmissive or reflective liquid crystal display, an organic electroluminescent device, or a DMD device) to the user's pupil, thereby creating a virtual, magnified image within the user's near-eye range and providing the user with intuitive and visual image, video, and text information.

[0003] With the continuous advancement of optical technology, the market demand for near-eye display devices is also changing rapidly. Amidst the emergence of various new optical imaging structures, a negative focal length relay optical structure has stood out. This structure is a visual optical system composed of multiple lenses, similar to microscope and telescope optics. Like these, it focuses light emitted from an object into a real image and then creates a virtual image to reach the observation side. However, unlike microscopes and telescopes, this structure guides video image light emitted from a miniature image display (e.g., transmissive or reflective liquid crystal displays, organic light-emitting diodes, DMD devices) to the user's pupil, thereby realizing a virtual, magnified image within the user's near-eye range, providing intuitive and visual images, videos, and text information. This type of optical structure offers greater design flexibility and can significantly improve the imaging quality of the entire optical system. However, this also results in a much heavier overall optical system compared to existing display systems on the market.

[0004] Currently, many papers have proposed their own different optical system designs based on this optical structure.

[0005] For example, Patent Document 1 (Chinese Patent Publication No. CN 103988111 B) and Patent Document 2 (Chinese Patent Publication No. CN107683432 B) respectively adopted an optical system composed of multiple lenses, which achieved good manufacturability. However, their optical systems adopted positive power optical systems and various coordination relationships between various lens groups, which failed to realize the conversion between real image optics and virtual image optical paths. Therefore, the degree of freedom of the entire optical system was greatly reduced, and the ideal optical effect could not be achieved. The stray light generated was also unacceptable, which reduced the contrast of the optical system and the user experience.

[0006] Patent document 3 (Chinese Patent Publication No. CN 103217782 A) and patent document 4 (Chinese Patent Publication No. CN103605205 ​​A) disclose a visual optical system composed of multiple lenses, which achieves performance indicators such as large field of view, high image quality, and low distortion. However, this visual optical system largely relies on only a few sets of positive optical power lens groups, and the optical power of the entire optical system is also positive, resulting in the entire optical light being focused in a single direction. There are not enough optical lenses and working distances to correct the effect of the entire optical system.

[0007] Patent document 5 (Chinese Patent Publication No. CN113325566B) discloses a visual optical system composed of multiple lenses. It is also a negative focal length visual optical system composed of positive optical power, and it also achieves the effect of a large field of view. However, this invention requires a set of reflective optical surfaces to achieve its optical effect, which greatly hinders the design of the optical system and increases the size of the optical system.

[0008] Therefore, there is a need to provide an optical system that is more effective and more suitable for mass production, addressing the aforementioned shortcomings of existing technologies. Summary of the Invention

[0009] The technical problem to be solved by the present invention is that the existing optical systems have poor image quality, distortion, insufficient field of view, heavy weight, and poor mass production. In view of the defects of the prior art, the present invention provides a large field of view, large aperture, negative focal length visual optical system and near-eye display device.

[0010] The technical solution adopted by this invention to solve its technical problem is as follows: A large field of view, large aperture, negative focal length visual optical system is constructed, comprising: a first lens group near the human eye and a second lens group near the miniature image display; light emitted from the miniature image display passes through the second lens group once, then through the first lens group and enters the human eye to form an image; the total focal length of the visual optical system is negative, and both the first and second lens groups have positive optical power; the first lens group is composed of positive lenses, and the second lens group is composed of positive and negative lenses; or, both the first and second lens groups are composed of positive and negative lenses respectively; the total focal length of the visual optical system is F, the focal length of the first lens group is F1, and the focal length of the second lens group is F2. Among them, F1 / F and F2 / F satisfy the following relations (1) and (2) respectively: -9.6 ≤F1 / F≤ -0.89 (1) -0.4≤F2 / F≤-3.38 (2)。

[0011] The visual optical system of the present invention has a total length of L, a total length of M for the first lens group, and a total length of W for the second lens group; wherein M / L and W / L satisfy the following relationships (3) and (4), respectively: 0.19≤M / L≤0.41 (3; 0.1≤W / L≤0.29 (4).

[0012] In the visual optical system of the present invention, the first lens group includes a first lens and a second lens; the first lens has positive power, and the ratio of its focal length f11 to the focal length F1 of the first lens group, f11 / F1, satisfies the following relationship (7): 0.36≤f11 / F1≤1.37 (7) The second lens has negative optical power, and the ratio of its focal length f12 to the focal length F1 of the first lens group, f12 / F1, satisfies the following relationship (81): -92.79≤f12 / F1≤-0.48 (8)。

[0013] In the visual optical system of the present invention, the first lens group includes a first lens and a second lens; the first lens has positive power, and the ratio of its focal length f11 to the focal length F1 of the first lens group, f11 / F1, satisfies the following relationship (71): 0.38≤f11 / F1≤1.26 (71) The second lens has negative optical power, and the ratio of its focal length f12 to the focal length F1 of the first lens group, f12 / F1, satisfies the following relationship (81): -11.96≤f12 / F1≤-1.9 (81).

[0014] In the visual optical system of the present invention, the second lens group is composed of a third lens and a fourth lens; the third lens has positive power, and the ratio of its focal length f21 to the focal length F2 of the second lens group, f21 / F2, satisfies the following relationship (9): 0.78≤f21 / F2≤1 (9; The fourth lens has negative optical power, and the ratio of its focal length f22 to the focal length F2 of the second lens group, f22 / F2, satisfies the following relationship (10): -8.67≤f22 / F2≤-2.47 (10).

[0015] In the visual optical system of the present invention, the second lens group is composed of a third lens and a fourth lens; the third lens has positive power, and the ratio of its focal length f21 to the focal length F2 of the second lens group, f21 / F2, satisfies the following relationship (91): 0.8≤f21 / F2≤0.89 (91; The fourth lens has negative optical power, and the ratio of its focal length f22 to the focal length F2 of the second lens group, f22 / F2, satisfies the following relationship (101): -2.93≤f22 / F2≤-2.79 (101).

[0016] In the visual optical system of the present invention, M / W satisfies the following relationship (5): 1.41≤M / W≤2.21 (5).

[0017] In the visual optical system of the present invention, F1 / F and F2 / F respectively satisfy the following relationships (11) and (21): -2.07 ≤F1 / F≤ -1.8 (11) -1.52≤F2 / F≤-1.32 (21).

[0018] In the visual optical system of the present invention, M / L and W / L respectively satisfy the following relationships (31) and (41): 0.19≤M / L≤0.23 (31; 0.1≤W / L≤0.13 (41).

[0019] In the visual optical system of the present invention, the M / W ratio satisfies the following relationship (51): 1.54≤M / W≤1.98 (51).

[0020] The visual optical system of the present invention, wherein the optical surface type of the lens group includes an even-order aspherical surface type, satisfying the relation (102): (102); Where z is the sag of the optical surface, c is the curvature at the vertex of the aspherical surface, K is the aspherical coefficient, a2, a4, a6, a8, ... are coefficients of each order, and r is the distance coordinate from the point on the surface to the optical axis of the lens system.

[0021] The present invention also provides a near-eye display device, comprising a large field of view, large aperture, negative focal length visual optical system as described in any of the preceding claims.

[0022] The beneficial effects of this invention are as follows: by using a combination of positive and negative lenses or a combination of positive and negative lenses to construct a large field of view, large aperture, and negative focal length visual optical system, the optimization freedom of the optical system is greatly increased, the imaging quality of the entire optical system is greatly improved, and the visual optical system achieves indicators such as a large field of view, high image resolution, low distortion, and small field curvature. Moreover, the near-eye display device designed using the visual optical system of this invention can achieve a larger field of view, higher image quality, lower distortion, and better mass production, greatly improving the competitiveness of the product. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort: Figure 1 This is a schematic diagram of the optical transfer function (MTF) of the visual optical system in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the diffuse spot of the visual optical system in Embodiment 1 of the present invention; Figure 3a , Figure 3b These are schematic diagrams of field curvature and distortion of the visual optical system according to Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the optical transfer function (MTF) of the visual optical system in Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the diffusion spot of the visual optical system in Embodiment 2 of the present invention; Figure 6a , Figure 6b These are schematic diagrams of field curvature and distortion of the visual optical system according to Embodiment 2 of the present invention; Figure 7 This is a schematic diagram of the visual optical system of Embodiment 3 of the present invention; Figure 8 This is a schematic diagram of the optical transfer function (MTF) of the visual optical system in Embodiment 3 of the present invention; Figure 9 This is a schematic diagram of the diffusion spot of the visual optical system in Embodiment 3 of the present invention; Figure 10a , Figure 10b These are schematic diagrams of field curvature and distortion of the visual optical system according to Embodiment 3 of the present invention; Figure 11 This is a schematic diagram of the visual optical system of Embodiment 4 of the present invention; Figure 12This is a schematic diagram of the optical transfer function (MTF) of the visual optical system in Embodiment 4 of the present invention; Figure 13 This is a schematic diagram of the diffuse spot of the visual optical system in Embodiment 4 of the present invention; Figure 14a , Figure 14b These are schematic diagrams of field curvature and distortion of the visual optical system according to Embodiment 4 of the present invention; Figure 15 This is a schematic diagram of the visual optical system of Embodiment 5 of the present invention; Figure 16 This is a schematic diagram of the optical transfer function (MTF) of the visual optical system in Embodiment 5 of the present invention; Figure 17 This is a schematic diagram of the diffuse spot of the visual optical system in Embodiment 5 of the present invention; Figure 18a , Figure 18b This is a schematic diagram of field curvature and distortion of the visual optical system of Embodiment 5 of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0025] A large field-of-view, large aperture, negative focal length visual optical system is constructed, comprising: a first lens group near the human eye and a second lens group near the miniature image display; light emitted from the miniature image display passes through the second lens group once, then through the first lens group and enters the human eye to form an image; the total focal length of the visual optical system is negative, and both the first and second lens groups have positive optical power; the first lens group is composed of positive lenses, and the second lens group is composed of positive and negative lenses; or, the first and second lens groups are each composed of positive and negative lenses respectively; the total focal length of the visual optical system is F, the focal length of the first lens group is F1, the focal length of the second lens group is F2, the total length of the visual optical system is L, the total length of the first lens group is M, and the total length of the second lens group is W; wherein, F1 / F, F2 / F, M / L, and W / L satisfy the following relationships (1), (2), (3), and (4) respectively: -9.6 ≤F1 / F≤ -0.89 (1) -3.38≤F2 / F≤-0.4 (2; 0.19≤M / L≤0.41 (3; 0.1≤W / L≤0.29 (4).

[0026] The possible values ​​for F1 / F are -9.6, -8.6, -8.3, -8.2, -7.9, -7.6, -6.8, -7.6, -5.2, -4.8, -3.6, -2.2, -2.07, -1.87, -1.8, -1.6, -1.2, -0.8, -0.89, etc.; the possible values ​​for F2 / F are -3.38, -3.2, -2.8, -2.6, -1.52, etc. -1.32, -1.44, -1.2, -0.8, -0.89, -0.4, etc.; M / L can take values ​​of 0.19, 0.24, 0.23, 0.26, 0.33, 0.36, 0.38, 0.41, etc.; W / L can take values ​​of 0.1, 0.11, 0.13, 0.14, 0.17, 0.20, 0.21, 0.23, 0.24, 0.27, 0.29, etc.

[0027] More preferably, F1 / F, F2 / F, M / L, and W / L satisfy the following relationships (11), (21), (31), and (41), respectively: -2.07 ≤F1 / F≤ -1.8 (11) -1.52≤F2 / F≤-1.32 (21; 0.19≤M / L≤0.23 (31; 0.1≤W / L≤0.13 (41).

[0028] This invention employs a combination of positive and negative lenses, or positive and negative lenses, to construct a large field-of-view, large-aperture, negative-focal-length visual optical system. This significantly increases the optimization freedom of the optical system, greatly improves the imaging quality of the entire system, and achieves indicators such as a large field of view, high image resolution, low distortion, and low field curvature. Furthermore, near-eye display devices designed using this invention's visual optical system can achieve a larger field of view, higher image quality, lower distortion, and better mass production capabilities, greatly enhancing product competitiveness.

[0029] Compared with the prior art, the visual optical system of this embodiment does not require a set of reflective optical surfaces, but can achieve similar optical effects simply by using traditional spherical or aspherical lenses, which greatly improves the degree of freedom and size of the optical system.

[0030] In a further embodiment, the ratio of the total length W of the second lens group to the total length M of the first lens group in the visual optical system, M / W, satisfies the following relationship (5): 1.41≤M / W≤2.21 (5).

[0031] The possible values ​​for M / W are 1.41, 1.5, 1.54, 1.7, 1.81, 1.83, 1.91, 1.98, 2.01, 2.11, 2.18, and 2.21.

[0032] More preferably, M / W satisfies the following relationship (51): 1.54≤M / W≤1.98 (51) In a further embodiment, the first lens group of the visual optical system includes a first lens and a second lens. The first lens has positive power, and the ratio of its focal length f11 to the focal length F1 of the first lens group, f11 / F1, satisfies the following relationship (7): 0.36≤f11 / F1≤1.37 (7)。

[0033] The possible values ​​for f11 / F1 are 0.36, 0.38, 0.4, 0.48, 0.52, 0.55, 0.56, 1.26, 1.31, and 1.37.

[0034] More preferably, the ratio of its focal length f11 to the total focal length F of the visual optical system, f11 / F1, satisfies the following relationship (71): 0.38≤f11 / F1≤1.26 (71).

[0035] In a further embodiment, the second lens of the visual optical system has negative optical power, and the ratio of its focal length f12 to the focal length F1 of the first lens group, f12 / F1, satisfies the following relationship (8): -92.79≤f12 / F1≤-0.48 (8)。

[0036] The possible values ​​for f12 / F1 are -92.79, -80.09, -72.49, -65.41, -55.79, -45.09, -42.71, -33.96, -22.71, -13.96, -11.71, -08.96, and -0.48.

[0037] More preferably, the ratio of its focal length f12 to the focal length F1 of the first lens group, f12 / F1, satisfies the following relationship (81): -11.96≤f12 / F1≤-1.9 (81).

[0038] In a further embodiment, the second lens group of the visual optical system consists of a third lens and a fourth lens; the third lens has positive power, and the ratio of its focal length f21 to the focal length F2 of the second lens group, f21 / F2, satisfies the following relationship (9): 0.78≤f21 / F2≤1 (9).

[0039] The possible values ​​for f12 / F2 are 0.78, 0.71, 0.65, 0.54, 0.43, 0.36, 0.32, 0.28, 0.11, and 1.

[0040] More preferably, the ratio of its focal length f21 to the focal length of the second lens group f21 / F2 satisfies the following relationship (91): 0.8≤f21 / F2≤0.89 (91).

[0041] In a further embodiment, the fourth lens of the visual optics system has negative optical power, and the ratio of its focal length f22 to the focal length F2 of the second lens group, f22 / F2, satisfies the following relationship (10): -8.67≤f22 / F2≤-2.47 (10).

[0042] The possible values ​​for f22 / F2 are -8.67, -7.79, -6.43, -5.79, -4.93, -3.79, -2.93, and -2.47.

[0043] More preferably, the ratio of its focal length f22 to the focal length F2 of the second lens group, f22 / F2, satisfies the following relationship (101): -2.93≤f22 / F2≤-2.79 (101).

[0044] In a further embodiment, the optical surface type of the lens group in the visual optics system includes an even-order aspherical surface type, satisfying relation (102): (102); Where z is the sag of the optical surface, c is the curvature at the vertex of the aspherical surface, K is the aspherical coefficient, a2, a4, a6, a8, ... are coefficients of each order, and r is the distance coordinate from the point on the surface to the optical axis of the lens system.

[0045] The principles, schemes, and display results of the above-mentioned visual optical system will be further explained below through more specific embodiments.

[0046] In the following embodiments, the aperture stop (EYE) can be the exit pupil of the visual optical system, a virtual light-emitting aperture. The best imaging effect can be observed when the human eye's pupil is at the aperture stop position. The micro-image display (IMG) is the image plane of the visual optical system.

[0047] The optical path structure data of the visual optical system in this embodiment are shown in Table 1a, and the aspherical coefficients are shown in Table 1b. Table 1a

[0048] Table 1b

[0049] From the human eye observation side to the miniature image display side (from left to right), the lenses are arranged in sequence as follows: human eye (EYE), first lens L1, second lens L2, third lens L3, and fourth lens L4. Lenses L1-L4 sequentially possess the following surfaces: first surface 111, second surface 112, third surface 113, fourth surface 114, fifth surface 201, sixth surface 202, seventh surface 203, and eighth surface 204. The surface parameters of each lens are shown in the table above.

[0050] The first lens L1 has positive optical power, and the second lens L2 has negative optical power. Together, the first lens L1 and the second lens L2 form a first lens group with positive optical power. The third lens L3 has positive optical power, and the fourth lens L4 has negative optical power. Together, the third lens L3 and the fourth lens L4 form a second lens group with positive optical power.

[0051] In this embodiment, the total focal length of the visual optical system is negative. Both the first and second lens groups of the visual optical system have positive optical power. The total focal length F of the system is -15.76, the focal length F1 of the first lens group is 14.03, and the focal length F2 of the second lens group is 6.25. The total length L of the visual optical system is 57.87, the total length M of the first lens group is 23.64, and the total length W of the second lens group is 16.76. The focal length f11 of the first lens L1 is 17.74, the focal length f12 of the second lens L2 is -1301.8, the focal length f21 of the third lens L3 is 6.26, and the focal length f22 of the fourth lens L4 is negative.

[0052] Appendix Figure 1 Appendix Figure 2 Appendix Figure 3a and attached Figure 3b The figures are the optical transfer function (MTF) curve, speckle diagram, field curvature, and distortion diagram of the visual optical system in this embodiment. They show that, under the premise of ensuring a large field of view, the MTF diagram has a resolution value greater than 0.58 at 10 lp. From the above data, it can be concluded that the optical system has high imaging quality and very small field curvature and optical distortion.

[0053] [Example 2] The optical path structure data of the visual optical system in this embodiment are shown in Table 2a, and the aspherical coefficients are shown in Table 2b. Table 2a

[0054] Table 2b

[0055] From the human eye observation side to the miniature image display side (from left to right), the lenses are arranged in sequence as follows: human eye (EYE), first lens L1, second lens L2, third lens L3, and fourth lens L4. Lenses L1-L4 sequentially possess the following surfaces: first surface 111, second surface 112, third surface 113, fourth surface 114, fifth surface 201, sixth surface 202, seventh surface 203, and eighth surface 204. The surface parameters of each lens are shown in the table above.

[0056] In this system, the first lens L1 has positive optical power, and the second lens L2 has negative optical power. Together, the first lens L1 and the second lens L2 form a first lens group with positive optical power. The first lens L1 is a positive lens, and the second lens L2 is a negative lens. The third lens L3 is a positive lens, and the fourth lens L4 is a negative lens. Together, the third lens L3 and the fourth lens L4 form a second lens group with positive optical power.

[0057] In this embodiment, the total focal length F of the visual optical system is negative. Both the first and second lens groups of the visual optical system have positive optical power. The total focal length F of the system is -3. The focal length F1 of the first lens group is 28.8, and the focal length F2 of the second lens group is 10.15. The total length L of the visual optical system is 171.32, the total length M of the first lens group is 38.58, and the total length W of the second lens group is 17.48. The focal length f11 of the first lens L1 is 39.44, the focal length f12 of the second lens L2 is -13.9, the focal length f21 of the third lens L3 is 8.09, and the focal length f22 of the fourth lens L4 is negative.

[0058] Appendix Figure 4 Appendix Figure 5 Appendix Figure 6a and attached Figure 6b The figures are the optical transfer function (MTF) curve, the blur pattern, the field curvature, and the distortion diagram of the visual optical system of the present invention, respectively. They show that, under the premise of ensuring a large field of view, the MTF diagram has a resolution value greater than 0.7 at 10 lp. From the above data, it can be concluded that, compared with Example 1, changing different lens focal lengths can result in better high-quality imaging, smaller field curvature, and less optical distortion.

[0059] [Example 3] The optical path structure of the visual optical system in this embodiment is as follows: Figure 7 As shown; the optical path structure data is shown in Table 3a, and the aspherical coefficients are shown in Table 3b. Table 3a

[0060] Table 3b

[0061] like Figure 7As shown, from the human eye observation side to the miniature image display side (from left to right), the lenses are, in sequence, the human eye (EYE), the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4. Lenses L1-L4 sequentially have: a first surface 111, a second surface 112, a third surface 113, a fourth surface 114, a fifth surface 201, a sixth surface 202, a seventh surface 203, and an eighth surface 204. The surface parameters of each lens are shown in the table above.

[0062] In this design, the first lens L1 has positive optical power, and the second lens L2 has negative optical power. Together, the first lens L1 and the second lens L2 form a first lens group with positive optical power; the first lens L1 is a positive lens, and the second lens L2 is a negative lens. The third lens L3 is a positive lens, and the fourth lens L4 is a negative lens; together, the third lens L3 and the fourth lens L4 form a second lens group with positive optical power.

[0063] In this embodiment, the total focal length of the visual optical system is negative. Both the first and second lens groups of the visual optical system have positive optical power. The total focal length F of the system is -20.7, the focal length F1 of the first lens group is 42.86, the focal length F2 of the second lens group is 31.53, the total length L of the visual optical system is 227.26, the total length M of the first lens group is 43.8, and the total length W of the second lens group is 28.51. The focal length f11 of the first lens L1 is 15.49, the focal length f12 of the second lens L2 is -81.58, the focal length f21 of the third lens L3 is 25.69, and the focal length f22 of the fourth lens L4 is negative.

[0064] Appendix Figure 8 Appendix Figure 9 Appendix Figure 10a and attached Figure 10b The figures are the optical transfer function (MTF) curve, the blur pattern, the field curvature, and the distortion diagram of the visual optical system in this embodiment. They show that, under the premise of ensuring a large field of view, the MTF diagram has a resolution value greater than 0.9 at 10 lp. From the above data, it can be concluded that, compared with embodiments 1 and 2, changing different lens focal lengths can result in better high-quality imaging, smaller field curvature, and less optical distortion.

[0065] [Example 4] The optical path structure of the visual optics system in this embodiment is as follows: Figure 11 As shown; the optical path structure data is shown in Table 4a, and the aspherical coefficients are shown in Table 4b. Table 4a

[0066] Table 4b

[0067] like Figure 11 As shown, from the human eye observation side to the miniature image display side (from left to right), the lenses are, in sequence, the human eye (EYE), the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4. Lenses L1-L4 sequentially have: a first surface 111, a second surface 112, a third surface 113, a fourth surface 114, a fifth surface 201, a sixth surface 202, a seventh surface 203, and an eighth surface 204. The surface parameters of each lens are shown in the table above.

[0068] In this design, the first lens L1 has positive optical power, and the second lens L2 has negative optical power. Together, the first lens L1 and the second lens L2 form a first lens group with positive optical power; the first lens L1 is a positive lens, and the second lens L2 is a negative lens. The third lens L3 is a positive lens, and the fourth lens L4 is a negative lens; together, the third lens L3 and the fourth lens L4 form a second lens group with positive optical power.

[0069] In this embodiment, the total focal length of the visual optical system is negative. Both the first and second lens groups of the visual optical system have positive optical power. The total focal length F of the system is -22.796, the focal length F1 of the first lens group is 42.71, and the focal length F2 of the second lens group is 30.03. The total length L of the visual optical system is 231.85, the total length M of the first lens group is 44.5, and the total length W of the second lens group is 24.59. The focal length f11 of the first lens L1 is 16.35, the focal length f12 of the second lens L2 is -115.6, the focal length f21 of the third lens L3 is 26.85, and the focal length f22 of the fourth lens L4 is negative.

[0070] Appendix Figure 12 Appendix Figure 13 Appendix Figure 14a and attached Figure 14b The figures are the optical transfer function (MTF) curve, the blur pattern, the field curvature, and the distortion diagram of the visual optical system in this embodiment. They show that, under the premise of ensuring a large field of view, the MTF diagram has a resolution value greater than 0.9 at 10 lp. From the above data, it can be concluded that, compared with embodiments 1 and 2, changing different lens focal lengths can result in better high-quality imaging, smaller field curvature, and less optical distortion.

[0071] [Example 5] The optical path structure of the visual optics system in this embodiment is as follows: Figure 15 As shown; the optical path structure data is shown in Table 5a, and the aspherical coefficients are shown in Table 5b. Table 5a

[0072] Table 5b

[0073] like Figure 15 As shown, from the human eye observation side to the miniature image display side (from left to right), the lenses are, in sequence, the human eye (EYE), the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4. Lenses L1-L4 sequentially have: a first surface 111, a second surface 112, a third surface 113, a fourth surface 114, a fifth surface 201, a sixth surface 202, a seventh surface 203, and an eighth surface 204. The surface parameters of each lens are shown in the table above.

[0074] In this design, the first lens L1 has positive optical power, and the second lens L2 has negative optical power. Together, the first lens L1 and the second lens L2 form a first lens group with positive optical power; the first lens L1 is a positive lens, and the second lens L2 is a negative lens. The third lens L3 is a positive lens, and the fourth lens L4 is a negative lens; together, the third lens L3 and the fourth lens L4 form a second lens group with positive optical power.

[0075] In this embodiment, the total focal length of the visual optical system is negative. Both the first and second lens groups of the visual optical system have positive optical power. The total focal length F of the system is -24.76, the focal length F1 of the first lens group is 44.56, the focal length F2 of the second lens group is 35.64, the total length L of the visual optical system is 235.24, the total length M of the first lens group is 45.56, and the total length W of the second lens group is 23.06. The focal length f11 of the first lens L1 is 17.76, the focal length f12 of the second lens L2 is -532.87, the focal length f21 of the third lens L3 is 27.88, and the focal length f22 of the fourth lens L4 is negative.

[0076] Appendix Figure 16 Appendix Figure 17 Appendix Figure 18a and attached Figure 18b The figures are the optical transfer function (MTF) curve, the speckle diagram, the field curvature, and the distortion diagram of the visual optical system in this embodiment. They show that, under the premise of ensuring a large field of view, the MTF diagram has a resolution value greater than 0.78 at 10 lp. From the above data, it can be concluded that the optical system has high imaging quality and very small field curvature and optical distortion.

[0077] In another embodiment of the present invention, a near-eye display device is also constructed, including the visual optical system as described in any of the foregoing embodiments, and further including a binocular display host for simultaneous viewing of a magnified image by both eyes, a forehead support assembly that contacts the forehead for wear and fixation; and a flip-connecting mechanism that connects the binocular display host and the forehead support assembly, and presents the binocular display host in front of the human body during use; the binocular display host includes: a mounting base and two fixed frame modules slidably mounted on the mounting base, and an interpupillary distance adjustment assembly for adjusting the distance between the two fixed frame modules is provided on the mounting base; each fixed frame module is provided with an optical module, a display module, and a diopter adjustment assembly for adjusting the distance between the optical module and the display module. The optical module adopts the visual optical system structure as described in any of the foregoing embodiments.

[0078] In other embodiments of the present invention, other forms of near-eye display devices are also provided, such as monocular displays and other near-eye display devices, all of which can employ the optical systems of the foregoing embodiments of the present invention. Specific structures are not detailed here.

[0079] In summary, the embodiments of the present invention, by employing reasonable lens combinations to construct a large field of view, large aperture, and negative focal length visual optical system, greatly increase the optimization freedom of the optical system, significantly improve the imaging quality of the entire optical system, and achieve indicators such as large field of view, high image resolution, low distortion, and small field curvature of the visual optical system. Moreover, the near-eye display device designed using the visual optical system of the present invention can achieve a larger field of view, higher image quality, lower distortion, and better mass production, greatly improving the competitiveness of the product.

[0080] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A wide-field-of-view, large-aperture, negative-focal-length visual optical system, characterized in that, The visual optical system consists of a first lens group near the human eye and a second lens group near the miniature image display. Light emitted from the miniature image display converges once through the second lens group and then passes through the first lens group to enter the human eye, forming an image. The total focal length of the visual optical system is negative, and both the first and second lens groups have positive optical power. The first lens group consists of a first lens and a second lens arranged sequentially along the optical axis from the human eye side to the miniature image display side. The first lens is a positive lens with a convex surface near the human eye, and the second lens is a negative lens. The second lens group consists of a third lens and a fourth lens, arranged sequentially along the optical axis from the human eye side to the miniature image display side. The third lens is a positive lens and a biconvex lens, while the fourth lens is a negative lens. The total focal length of the visual optical system is F, the focal length of the first lens group is F1, and the focal length of the second lens group is F2. Among them, F1 / F and F2 / F satisfy the following relations (1) and (2) respectively: -9.6 ≤F1 / F≤ -0.89 (1) -3.38≤F2 / F≤-0.4 (2)。 2. The visual optical system according to claim 1, characterized in that, The total length of the visual optical system is L, the total length of the first lens group is M, and the total length of the second lens group is W; wherein, M / L and W / L satisfy the following relationships (3) and (4) respectively: 0.19≤M / L≤0.41 (3; 0.1≤W / L≤0.29 (4)。 3. The visual optical system according to claim 1, characterized in that, The ratio of the focal length f11 of the first lens to the focal length F1 of the first lens group, f11 / F1, satisfies the following relationship (7): 0.36≤f11 / F1≤1.37 (7) The ratio of the focal length f12 of the second lens to the focal length F1 of the first lens group, f12 / F1, satisfies the following relationship (8): -92.79≤f12 / F1≤-0.48 (8)。 4. The visual optical system according to claim 1, characterized in that, The ratio of the focal length f11 of the first lens to the focal length F1 of the first lens group, f11 / F1, satisfies the following relationship (71): 0.38≤f11 / F1≤1.26 (71) The ratio of the focal length f12 of the second lens to the focal length F1 of the first lens group, f12 / F1, satisfies the following relationship (81): -11.96≤f12 / F1≤-1.9 (81).

5. The visual optical system according to claim 1, characterized in that, The ratio of the focal length f21 of the third lens to the focal length of the second lens group, f21 / F2, satisfies the following relationship (9): 0.78≤f21 / F2≤1 (9; The ratio of the focal length f22 of the fourth lens to the focal length of the second lens group, f22 / F2, satisfies the following relationship (10): -8.67≤f22 / F2≤-2.47 (10).

6. The visual optical system according to claim 1, characterized in that, The ratio of the focal length f21 of the third lens to the focal length F2 of the second lens group, f21 / F2, satisfies the following relationship (91): 0.8≤f21 / F2≤0.89 (91; The ratio of the focal length f22 of the fourth lens to the focal length F2 of the second lens group, f22 / F2, satisfies the following relationship (101): -2.93≤f22 / F2≤-2.79 (101).

7. The visual optical system according to claim 2, characterized in that, M / W satisfies the following relationship (5): 1.41≤M / W≤2.21 (5).

8. The visual optical system according to claim 2, characterized in that, The F1 / F and F2 / F satisfy the following relations (11) and (21), respectively: -2.07 ≤F1 / F≤ -1.8 (11) -1.52≤F2 / F≤-1.32 (21).

9. The visual optical system according to claim 8, characterized in that, The M / L and W / L satisfy the following relationships (31) and (41), respectively: 0.19≤M / L≤0.23 (31; 0.1≤W / L≤0.13 (41).

10. The visual optical system according to claim 7, characterized in that, M / W satisfies the following relationship (51): 1.54≤M / W≤1.98 (51).

11. The visual optical system according to any one of claims 1-10, characterized in that, The optical surface types in the first lens group and the second lens group include even-order aspherical surface types, satisfying the relation (102): （102）； Where z is the elevation of the optical surface, c is the curvature at the vertex of the aspherical surface, K is the aspherical coefficient, a4, a6, a8, ... are coefficients of each order, and r is the distance coordinate from the point on the surface to the optical axis of the lens system.

12. A near-eye display device, characterized in that, It includes a large field of view, large aperture, negative focal length visual optical system as described in any one of claims 1-11.

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