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 display screen side;Light is emitted from micro display screen, after converging once by the second lens group, then enter human eye by the first lens group, form image;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 sequentially arranged by a piece of positive lens, a piece of negative lens and a piece of negative lens, and the second lens group is arranged by a piece of positive lens, a piece of negative lens, a piece of positive lens and a piece of negative lens.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, allowing for better improvement in the overall imaging quality of the optical system. However, this also results in a significantly 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 optical systems composed of multiple lenses, achieving good manufacturability. However, their optical systems use positive power optical systems and various coordination relationships between lens groups, failing to achieve the conversion between real image optics and virtual image optical paths. Therefore, the degree of freedom of the entire optical system is greatly reduced, and the ideal optical effect cannot be achieved. The stray light generated is also unacceptable, reducing 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 micro-display screen; light emitted from the micro-display screen 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 consists of one positive lens and one negative lens, and the second lens group consists of one positive lens, one negative lens, one positive lens, and one negative lens arranged sequentially; 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.

[0011] Among them, F1 / F and F2 / F satisfy the following relations (1) and (2) respectively:

[0012] -1.66≤F1 / F≤-1.38(1);

[0013] -1.8≤F2 / F≤-1.07(2);

[0014] 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):

[0015] 0.12≤M / L≤0.18(3);

[0016] 0.32≤W / L≤0.40 (4).

[0017] The visual optical system of the present invention includes a first lens group comprising a first eye-side lens group composed of a first lens and a second lens, and a second eye-side lens group composed of a third lens. The first eye-side lens group has positive optical 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):

[0018] 0.60≤f11 / F1≤0.80(7);

[0019] The second eye-side lens group 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):

[0020] -2.32≤f12 / F1≤-0.84 (8).

[0021] The visual optical system of the present invention includes a second lens group comprising a first object-side lens group consisting of a fourth lens and a fifth lens; the fourth lens is a positive lens with a focal length of f21; the fifth lens is a negative lens with a focal length of f22; the first object-side lens group has positive optical power with a focal length of f2; and f21, f22 and f2 satisfy the following relationships (9) and (10):

[0022] 0.88≤f21 / f2≤1.23 (9);

[0023] -70.02≤f22 / f2≤-5.38 (10).

[0024] The visual optical system of the present invention includes a second object-side lens group comprising a sixth lens and a seventh lens; the sixth lens is a positive lens with a focal length of f31; the seventh lens is a negative lens with a focal length of f32; the second object-side lens group has a focal length of f3; f31, f32 and f3 satisfy the following relationships (11) and (12);

[0025] -0.4≤f31 / f3≤0.59 (11);

[0026] -0.41≤f32 / f3≤0.13 (12).

[0027] In the visual optical system of the present invention, M / W satisfies the following relationship (5):

[0028] 0.30≤M / W≤0.55 (5).

[0029] The visual optical system of the present invention comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0030] The visual optical system of the present invention comprises a first eye-side lens group with positive optical power formed by the first lens and the second lens, and a second eye-side lens group with negative optical power formed by the third lens, wherein the first eye-side lens group and the second eye-side lens group together form a first lens group with positive optical power; a fourth lens and the fifth lens form a first object-side lens group with positive optical power, and a sixth lens and the seventh lens form a second object-side lens group with negative optical power, wherein the first object-side lens group and the second object-side lens group together form a second lens group with positive optical power.

[0031] In the visual optical system of the present invention, F1 / F and F2 / F respectively satisfy the following relationships (11) and (21):

[0032] -1.54≤F1 / F≤-1.40 (11);

[0033] -1.55≤F2 / F≤-1.41 (21).

[0034] In the visual optical system of the present invention, the M / L and W / L respectively satisfy the following relationships (31) and (41).

[0035] 0.14≤M / L≤0.16 (31);

[0036] 0.36≤W / L≤0.38 (41).

[0037] 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 relation (42):

[0038]

[0039] 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.

[0040] 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.

[0041] The beneficial effects of this invention are as follows: by employing a reasonable lens combination relationship 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 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

[0042] 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:

[0043] Figure 1 This is a schematic diagram of the visual optical system of Embodiment 1 of the present invention;

[0044] Figure 2 This is a schematic diagram of the optical transfer function (MTF) of the visual optical system in Embodiment 1 of the present invention;

[0045] Figure 3 This is a schematic diagram of the diffuse spot of the visual optical system in Embodiment 1 of the present invention;

[0046] Figure 4a , Figure 4b These are schematic diagrams of field curvature and distortion of the visual optical system according to Embodiment 1 of the present invention;

[0047] Figure 5 This is a schematic diagram of the visual optical system of Embodiment 2 of the present invention;

[0048] Figure 6 This is a schematic diagram of the optical transfer function (MTF) of the visual optical system in Embodiment 2 of the present invention;

[0049] Figure 7 This is a schematic diagram of the diffusion spot of the visual optical system in Embodiment 2 of the present invention;

[0050] Figure 8a , Figure 8b These are schematic diagrams of field curvature and distortion of the visual optical system according to Embodiment 2 of the present invention;

[0051] Figure 9This is a schematic diagram of the visual optical system of Embodiment 3 of the present invention;

[0052] Figure 10 This is a schematic diagram of the optical transfer function (MTF) of the visual optical system in Embodiment 3 of the present invention;

[0053] Figure 11 This is a schematic diagram of the diffusion spot of the visual optical system in Embodiment 3 of the present invention;

[0054] Figure 12a , Figure 12b These are schematic diagrams of field curvature and distortion of the visual optical system according to Embodiment 3 of the present invention. Detailed Implementation

[0055] 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.

[0056] 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 a miniature display screen; light emitted from the miniature display screen is converged once by the second lens group, then passes 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 consists of one positive optical power lens and one negative optical power lens, and the second lens group consists of one positive lens, one negative lens, one positive lens, and one negative lens arranged sequentially; 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.

[0057] Among them, F1 / F, F2 / F, M / L, and W / L satisfy the following relationships (1), (2), (3), and (4), respectively:

[0058] -1.66≤F1 / F≤-1.38 (1);

[0059] -1.8≤F2 / F≤-1.07 (2);

[0060] 0.12≤M / L≤0.18 (3);

[0061] 0.32≤W / L≤0.40 (4).

[0062] The possible values ​​for F1 / F are -1.66, -1.65, -1.63, -1.60, -1.54, -1.53, -1.50, -1.49, -1.48, -1.47, -1.45, -1.43, -1.42, -1.41, -1.40, -1.39, and -1.38, etc.; the possible values ​​for F2 / F are -1.8, -1.7, -1.61, -1.58, -1.57, -1.56, -1.55, -1.54, and -1.5. 3. The possible values ​​for M / L are 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, etc., and the possible values ​​for W / L are 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, etc.

[0063] The embodiments of this invention construct a large field-of-view, large-aperture, negative focal length visual optical system through a reasonable lens combination relationship, which greatly increases the optimization freedom of the optical system and significantly improves the imaging quality of the entire optical system. It achieves indicators such as a 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 this invention can achieve a larger field of view, higher image quality, lower distortion, and better mass production, which greatly improves the competitiveness of the product.

[0064] 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.

[0065] Furthermore, the aforementioned visual optical system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. Specifically, the first and second lenses form a first eye-side lens group with positive optical power, the third lens forms a second eye-side lens group with negative optical power, and the first and second eye-side lens groups together form a first lens group with positive optical power; the fourth and fifth lenses form a first object-side lens group with positive optical power, the sixth and seventh lenses form a second object-side lens group with negative optical power, and the first and second object-side lens groups together form a second lens group with positive optical power.

[0066] Furthermore, the above F1 / F, F2 / F, M / L, and W / L satisfy the following relationships (11), (21), (31), and (41), respectively:

[0067] -1.54≤F1 / F≤-1.40 (11);

[0068] -1.55≤F2 / F≤-1.41 (21);

[0069] 0.14≤M / L≤0.16 (31);

[0070] 0.36≤W / L≤0.38 (41).

[0071] 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):

[0072] 0.30≤M / W≤0.55 (5).

[0073] The M / W ratio can be 0.30, 0.32, 0.35, 0.40, 0.44, 0.45, 0.47, 0.48, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, etc.

[0074] In a further embodiment, the first lens group of the visual optical system includes a first eye-side lens group composed of a first lens and a second lens, and a second eye-side lens group composed of a third lens. The first eye-side lens group has positive optical 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):

[0075] 0.60≤f11 / F1≤0.80 (7);

[0076] The second eye-side lens group 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):

[0077] -2.32≤f12 / F1≤-0.84 (8).

[0078] The possible values ​​for f11 / F1 are 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.68, 0.71, 0.74, 0.78, 0.79, and 0.80. The possible values ​​for f12 / F1 are -2.32, -2.31, -2.30, -2.29, -2.28, -2.27, -2.26, -2.05, -1.97, -1.87, -1.75, -1.65, -1.57, -1.43, -1.35, -1.23, -1.13, -1.05, -0.98, -0.91, and -0.84.

[0079] In a further embodiment, the second lens group of the visual optical system comprises a first object-side lens group consisting of a fourth lens and a fifth lens; the fourth lens is a positive lens with a focal length of f21; the fifth lens is a negative lens with a focal length of f22; the first object-side lens group has positive optical power with a focal length of f2; f21, f22 and f2 satisfy the following relationships (9) and (10):

[0080] 0.88≤f21 / f2≤1.23 (9);

[0081] -70.02≤f22 / f2≤-5.38 (10).

[0082] Among them, f21 / f2 can take values ​​of 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.0, 1.04, 1.1, 1.13, 1.20, 1.21, 1.22, 1.23, etc.; f22 / f2 can take values ​​of -70.02, -68.23, -65.01, -60.23, -59.4, -54.23, -46.01, -37.23, -25.01, -19.23, -18.01, -14.55, -11.23, -5.90, -5.55, -5.38, etc.

[0083] In a further embodiment, the second lens group of the visual optical system includes a second object-side lens group consisting of a sixth lens and a seventh lens; the fifth lens is a positive lens with a focal length of f31; the sixth lens is a negative lens with a focal length of f32; the focal length of the second object-side lens group is f3; f31, f32 and f3 satisfy the following relationships (6) and (61):

[0084] -0.4≤f31 / f3≤0.59 (6);

[0085] -0.41≤f32 / f3≤0.13 (61).

[0086] Among them, f31 / f3 can take values ​​of -0.4, -0.35, -0.24, -0.14, 0.3, 0.33, 0.39, 0.42, 0.46, 0.55, 0.58, 0.65, 0.72, 0.84, 0.85, etc.; f32 / f3 can take values ​​of -0.41, -0.4, -0.23, -0.21, -0.20, -0.19, -0.10, -0.04, 0.01, 0.08, 0.11, 0.12, 0.13, etc.

[0087] 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 (42):

[0088]

[0089] 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.

[0090] The principles, schemes, and display results of the above-mentioned visual optical system will be further explained below through more specific embodiments.

[0091] In the following embodiments, the aperture stop EYE can be the exit pupil of the visual optical system, a virtual light-emitting aperture. When the pupil of the human eye is at the aperture stop position, the best imaging effect can be observed. The miniature image display IMMG is the image plane of the visual optical system.

[0092] [Example 1]

[0093] The optical path structure of the visual optics system in this embodiment is as follows: Figure 1 As shown; the optical path structure data is shown in Table 1a, and the aspherical coefficients are shown in Table 1b below:

[0094] Table 1a

[0095]

[0096] Table 1b

[0097]

[0098]

[0099] like Figure 1 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), the fourth lens (L4), the fifth lens (L5), the sixth lens (L6), and the seventh lens (L7). Lenses L1-L7 sequentially have: a first surface 111, a second surface 112, a third surface 113, a fourth surface 114, a fifth surface 115, a sixth surface 116, a seventh surface 201, an eighth surface 202, a ninth surface 203, a tenth surface 204, an eleventh surface 301, a twelfth surface 302, a thirteenth surface 303, and a fourteenth surface 304. The surface parameters of each lens are shown in the table above.

[0100] In this system, the first lens L1 and the second lens L2 form a first eye-side lens group M1 with positive optical power, and the third lens L3 forms a second eye-side lens group M2 with negative optical power. The first eye-side lens group M1 and the second eye-side lens group M2 together form a first lens group with positive optical power. The fourth lens L4 and the fifth lens L5 form a first object-side lens group W1 with positive optical power, and the sixth lens L6 and the seventh lens L7 form a second object-side lens group W2 with negative optical power. The first object-side lens group W1 and the second object-side lens group W2 together form a second lens group with positive optical power.

[0101] 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 -12.62, the focal length F1 of the first lens group is 20, and the focal length F2 of the second lens group is 13.45. The total length L of the visual optical system is 138.98, the total length M of the first lens group is 24.53, and the total length W of the second lens group is 44.44. The focal length f11 of the first eye-side lens group M1 is 11.95, the focal length f12 of the second eye-side lens group M2 is -16.71, the focal length f2 of the first object-side lens group W1 is 29.66, and the focal length f3 of the second object-side lens group W2 is -36.38. Among them, the fourth lens L4 has a focal length of f21 of 26.06, the fifth lens L5 has a focal length of f22 of -159.46, the sixth lens L6 has a focal length of f31 of 14.57, and the seventh lens L7 has a focal length of f32 of -4.9.

[0102] Appendix Figure 2 Appendix Figure 3 Appendix Figure 4a and attached Figure 4b 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, respectively, which show that the optical system has high imaging quality, very small field curvature, and optical distortion while ensuring a large field of view.

[0103] [Example 2]

[0104] The optical path structure of the visual optics system in this embodiment is as follows: Figure 5 As shown; the optical path structure data is shown in Table 2a, and the aspherical coefficients are shown in Table 2b.

[0105] Table 2a

[0106]

[0107]

[0108] Table 2b

[0109]

[0110] like Figure 5 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), the fourth lens (L4), the fifth lens (L5), the sixth lens (L6), and the seventh lens (L7). Lenses L1-L7 sequentially have: a first surface 111, a second surface 112, a third surface 113, a fourth surface 114, a fifth surface 115, a sixth surface 116, a seventh surface 201, an eighth surface 202, a ninth surface 203, a tenth surface 204, an eleventh surface 301, a twelfth surface 302, a thirteenth surface 303, and a fourteenth surface 304. The surface parameters of each lens are shown in the table above.

[0111] In this system, the first lens L1 and the second lens L2 form a first eye-side lens group M1 with positive optical power, and the third lens L3 forms a second eye-side lens group M2 with negative optical power. The first eye-side lens group M1 and the second eye-side lens group together form a first lens group with positive optical power. The fourth lens L4 and the fifth lens L5 form a first object-side lens group W1 with positive optical power, and the sixth lens L6 and the seventh lens L7 form a first object-side lens group W2 with negative optical power. The first object-side lens group W1 and the first object-side lens group W2 together form a second lens group with positive optical power.

[0112] 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 -14.54, the focal length F1 of the first lens group is 20, and the focal length F2 of the second lens group is 23.5. The total length L of the visual optical system is 161.9, the total length M of the first lens group is 24.4, and the total length W of the second lens group is 62.8. The focal length f11 of the first eye-side lens group M1 is 15.47, the focal length f12 of the second eye-side lens group M2 is -26.73, the focal length f2 of the first object-side lens group W1 is 38.13, and the focal length f3 of the second object-side lens group W2 is 61.65. Among them, the fourth lens L4 has a focal length of f21 of 34, the fifth lens L5 has a focal length of f22 of -298.95, the sixth lens L6 has a focal length of f31 of 15.91, and the seventh lens L7 has a focal length of f32 of -13.04.

[0113] Appendix Figure 6 Appendix Figure 7 Appendix Figure 8a and attached Figure 8b The figures are the optical transfer function (MTF) curve, the speckle diagram, the field curvature, and the distortion diagram of the visual optical system of the present invention, respectively, which reflect that the optical system has high imaging quality, very small field curvature, and optical distortion while ensuring a large field of view.

[0114] [Example 3]

[0115] The optical path structure of the visual optics system in this embodiment is as follows: Figure 9 As shown; the optical path structure data is shown in Table 3a, and the aspherical coefficients are shown in Table 3b.

[0116] Table 3a

[0117]

[0118]

[0119] Table 3b

[0120]

[0121] like Figure 9 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), the fourth lens (L4), the fifth lens (L5), the sixth lens (L6), and the seventh lens (L7). Lenses L1-L7 sequentially have: a first surface 111, a second surface 112, a third surface 113, a fourth surface 114, a fifth surface 115, a sixth surface 116, a seventh surface 201, an eighth surface 202, a ninth surface 203, a tenth surface 204, an eleventh surface 301, a twelfth surface 302, a thirteenth surface 303, and a fourteenth surface 304. The surface parameters of each lens are shown in the table above.

[0122] In this system, the first lens L1 and the second lens L2 form a first eye-side lens group M1 with positive optical power, and the third lens L3 forms a second eye-side lens group M2 with negative optical power. The first eye-side lens group M1 and the second eye-side lens group together form a first lens group with positive optical power. The fourth lens L4 and the fifth lens L5 form a first object-side lens group W1 with positive optical power, and the sixth lens L6 and the seventh lens L7 form a second object-side lens group W2 with negative optical power. The first object-side lens group W1 and the second object-side lens group W2 together form a second lens group with positive optical power.

[0123] 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 -10.64, the focal length F1 of the first lens group is 17.62, and the focal length F2 of the second lens group is 19.13. The total length L of the visual optical system is 158, the total length M of the first lens group is 18.9, and the total length W of the second lens group is 63.34. The focal length f11 of the first eye-side lens group M1 is 14.17, the focal length f12 of the second eye-side lens group M2 is -40.92, the focal length f2 of the first object-side lens group W1 is 48.86, and the focal length f3 of the second object-side lens group W2 is 27.16. Among them, the fourth lens L4 has a focal length f21 of 60.19, the fifth lens L5 has a focal length f22 of -3421.3, the sixth lens L6 has a focal length f31 of 16.1, and the seventh lens L7 has a focal length f32 of -11.

[0124] Appendix Figure 10 Appendix Figure 11 Appendix Figure 12a and attached Figure 12b 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, respectively, which show that the optical system has high imaging quality, very small field curvature, and optical distortion while ensuring a large field of view.

[0125] 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.

[0126] 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.

[0127] In summary, the embodiments of the present invention, by employing a reasonable lens combination relationship 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 and significantly improve the imaging quality of the entire optical system. This achieves indicators such as a large field of view, high image resolution, low distortion, and small field curvature for the visual optical system. Furthermore, near-eye display devices 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 capabilities, greatly enhancing product competitiveness. Compared with existing technologies, the visual optical system of this embodiment does not require a set of reflective optical surfaces; instead, it can achieve similar optical effects using only traditional spherical or aspherical lenses, greatly improving the freedom and size of the optical system.

[0128] 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, include: The first lens group is closer to the human eye, and the second lens group is closer to the micro-display screen. Light emitted from the miniature display screen converges once through the second lens group, then passes 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 consists of a positive lens, a negative lens, and a negative lens arranged in sequence, and the second lens group consists of a positive lens, a negative lens, a positive lens, and a negative lens arranged in sequence. 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: -1.66≤F1 / F≤-1.38(1); -1.8≤F2 / F≤-1.07 (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: 0.12≤M / L≤0.18(3); 0.32≤W / L≤0.40 (4).

3. The visual optical system according to claim 1, characterized in that, The first lens group includes a first eye-side lens group composed of a first lens and a second lens, and a second eye-side lens group composed of a third lens. The first eye-side lens group has positive optical 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): 0.60≤f11 / F1≤0.80(7); The second eye-side lens group 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): -2.32≤f12 / F1≤-0.84 (8).

4. The visual optical system according to claim 1, characterized in that, The second lens group includes a first object-side lens group consisting of a fourth lens and a fifth lens; the fourth lens is a positive lens with a focal length of f21; the fifth lens is a negative lens with a focal length of f22; the first object-side lens group has positive optical power with a focal length of f2; f21, f22 and f2 satisfy the following relationships (9) and (10): 0.88≤f21 / f2≤1.23 (9); -70.02≤f22 / f2≤-5.38 (10).

5. The visual optical system according to claim 1, characterized in that, The second lens group includes a second object-side lens group consisting of a sixth lens and a seventh lens; the sixth lens is a positive lens with a focal length of f31; the seventh lens is a negative lens with a focal length of f32; the focal length of the second object-side lens group is f3; f31, f32 and f3 satisfy the following relationships (6) and (61); -0.4≤f31 / f3≤0.59 (6); -0.41≤f32 / f3≤0.13 (61).

6. The visual optical system according to claim 2, characterized in that, M / W satisfies the following relationship (5): 0.30≤M / W≤0.55 (5).

7. The visual optical system according to claim 1, characterized in that, The visual optical system consists of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

8. The visual optical system according to claim 7, characterized in that, The first lens and the second lens form a first eye-side lens group with positive optical power, and the third lens forms a second eye-side lens group with negative optical power. The first eye-side lens group and the second eye-side lens group together form the first lens group with positive optical power. The fourth lens and the fifth lens form a first object-side lens group with positive optical power, and the sixth lens and the seventh lens form a second object-side lens group with negative optical power. The first object-side lens group and the second object-side lens group together form a second lens group with positive optical power.

9. The visual optical system according to claim 1, characterized in that, The F1 / F and F2 / F satisfy the following relations (11) and (21) respectively: -1.54≤F1 / F≤-1.40(11); -1.55≤F2 / F≤-1.41 (21).

10. The visual optical system according to claim 2, characterized in that, The M / L and W / L satisfy the following relationships (31) and (41), respectively. 0.14≤M / L≤0.16(31); 0.36≤W / L≤0.38 (41).

11. The visual optical system according to any one of claims 1-10, characterized in that, The optical surface types in the lens group include even-order aspherical surface types, satisfying relation (42): 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.

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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