eyepiece lens

Abstract

The utility model relates to an eyepiece lens, in the direction from object side to image side along the optical axis, sequentially include: the first lens of positive refractive power, the second lens of positive refractive power, the third lens of negative refractive power, the fourth lens of positive refractive power, the fifth lens of positive or negative refractive power, the second lens is convex-concave type lens. The eyepiece lens of the utility model has at least one of the characteristics of long exit pupil distance (up to 46mm), long back focal length (up to 7mm), miniaturization and low cost.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of imaging lens, especially to an eyepiece lens. BACKGROUND

[0002] In the field of modern science and technology, optical instruments play a crucial role, and as the key component of microscopes, telescopes, virtual reality devices, and gun sights, the performance of eyepieces directly affects the use effect of the entire instrument.

[0003] From the historical development, the design and manufacture of eyepieces have evolved with the progress of optical theory and technology. Early eyepiece designs mainly focused on meeting the basic imaging magnification function, with relatively simple structure and limited application scenarios. With the development of scientific research and the development of military, entertainment and other industries, the requirements for optical instruments are increasing, and the functions of eyepieces are also expanding.

[0004] In the field of microscopes, from simple biological observation to fine research on viruses, bacteria and other small objects, the eyepiece is required to provide high-resolution, high-contrast imaging to assist researchers in accurate analysis. The development of telescopes has higher requirements for the long-distance imaging and clarity of eyepieces, whether for astronomical observation or military reconnaissance, the eyepiece needs to maintain good performance in different environments. The rise of virtual reality devices has given eyepieces new missions, which need to provide immersive visual experience for users, involving field of view, aberration correction and other technical challenges.

[0005] For special optical instruments such as gun sights, the eyepiece needs to adapt to complex combat environments and quickly and accurately provide clear target images for the shooter. The design of the eyepiece with a display screen requires the eyepiece to effectively magnify the image received by the display screen to ensure the accuracy of shooting.

[0006] With the increase of use and use scenarios, we find that the existing eyepiece still has the following problems:

[0007] 1. The exit pupil distance of the eyepiece lens in the prior art is still small, which cannot meet the use of some special scenarios;

[0008] 2. The back focal length of the eyepiece lens in the prior art is still small, resulting in insufficient space for the rear structure, which has the risk of interference;

[0009] 3. High cost, not conducive to consumers or customers with large demand;

[0010] 4. Large volume, cannot meet the requirements of small and light optical instruments.

[0011] Therefore, designing an eyepiece lens with one of the characteristics of long exit pupil distance, low cost, miniaturization, long back focal length and the like is still an urgent problem to be solved. Utility model content

[0012] To solve the problems in the prior art, the utility model provides an eyepiece lens with at least one of the characteristics of long exit pupil distance, low cost, miniaturization, long back focal length and the like.

[0013] To achieve the utility model purpose, the utility model provides an eyepiece lens, in the direction from the object side to the image side along the optical axis, sequentially comprising:

[0014] The first lens with positive refractive power, the second lens with positive refractive power, the third lens with negative refractive power, the fourth lens with positive refractive power, the fifth lens with positive or negative refractive power;

[0015] The second lens is a convex-concave lens.

[0016] According to one of the utility model technical schemes, the object side surface of the first lens is a convex surface, the third lens is a convex-concave lens, the object side surface of the fourth lens is a convex surface,

[0017] The fifth lens is a convex-concave lens with positive refractive power or a concave-convex lens with negative refractive power.

[0018] According to one of the utility model technical schemes, the second lens, the third lens and the fourth lens form a three-cemented lens.

[0019] According to one of the utility model technical schemes, the third lens and the fourth lens form a double-cemented lens.

[0020] According to one of the utility model technical schemes, the first lens, the second lens, the third lens and the fourth lens are all spherical lenses.

[0021] The fifth lens is an aspherical lens.

[0022] According to one of the utility model technical schemes, the effective focal length F1 of the first lens and the effective focal length F of the eyepiece lens satisfy the following relationship: 1.5 ≤ F1 / F ≤ 3.5.

[0023] According to one of the utility model technical schemes, the effective focal length F2 of the second lens and the effective focal length F of the eyepiece lens satisfy the following relationship: 1.8 ≤ F2 / F ≤ 3.5.

[0024] According to one of the utility model technical schemes, the effective focal length F3 of the third lens and the effective focal length F of the eyepiece lens satisfy the following relationship: -2 ≤ F3 / F ≤ -0.8.

[0025] According to one of the technical solutions of the utility model, the effective focal length F4 of the fourth lens and the effective focal length F of the eyepiece lens satisfy the following relationship: 0.5 <= F4 / F <= 1.5.

[0026] According to one of the technical solutions of the utility model, the combined focal length F234 of the second lens, the third lens and the fourth lens and the effective focal length F of the eyepiece lens satisfy the following relationship: 1.2 <= F234 / F <= 2.5.

[0027] According to one of the technical solutions of the utility model, the effective focal length F1 of the first lens and the effective focal length F2 of the second lens satisfy the following relationship: 0.5 <= F1 / F2 <= 2.

[0028] According to one of the technical solutions of the utility model, the optical total length TTL of the eyepiece lens and the effective focal length F satisfy the following relationship: 1.2 <= TTL / F <= 2.5.

[0029] According to one of the technical solutions of the utility model, the effective focal length F of the eyepiece lens and the back focal length BFL satisfy the following relationship: 0.2 <= BFL / F <= 1.

[0030] According to one of the technical solutions of the utility model, the Abbe number vd3 of the third lens satisfies the following relationship: 10 <= vd3 <= 30;

[0031] The Abbe number vd4 of the fourth lens satisfies the following relationship: 15 <= vd4 <= 50.

[0032] According to one of the technical solutions of the utility model, the refractive index nd2 of the second lens satisfies the following relationship: 1.63 <= nd2 <= 2;

[0033] The refractive index nd3 of the third lens satisfies the following relationship: 1.8 <= nd3 <= 2.04;

[0034] The refractive index nd4 of the fourth lens satisfies the following relationship: 1.7 <= nd4 <= 2.1.

[0035] According to one of the technical solutions of the utility model, the curvature radius R21 of the object side of the second lens and the curvature radius R22 of the image side satisfy the following relationship: 0.2 <= R21 / R22 <= 0.5.

[0036] According to one of the technical solutions of the utility model, the curvature radius R31 of the object side of the third lens and the curvature radius R32 of the image side satisfy the following relationship: 2 <= R31 / R32 <= 5.

[0037] According to one of the technical solutions of the utility model, the curvature radius R41 of the object side surface of the fourth lens and the curvature radius R42 of the image side surface satisfy the following relationship: -0.11 <= R41 / R42 <= 0.15.

[0038] According to one of the technical solutions of the utility model, the center thickness D1 of the first lens, the center thickness D2 of the second lens, the center thickness D3 of the third lens, the center thickness D4 of the fourth lens, the center thickness D5 of the fifth lens and the optical total length TTL of the eyepiece lens satisfy the following relationship: 1 <= (D1+D2+D3+D4+D5) / F <= 2.

[0039] According to one of the technical solutions of the utility model, the eyepiece lens at least satisfies one of the following conditions:

[0040] 2.14 <= F1 / F <= 3.01,

[0041] 2.12 <= F2 / F <= 2.83,

[0042] -1.57 <= F3 / F <= -0.97,

[0043] 0.84 <= F4 / F <= 1.03,

[0044] 1.36 <= F234 / F <= 2.03,

[0045] 0.92 <= F1 / F2 <= 1.12,

[0046] 1.68 <= TTL / F <= 1.85,

[0047] 0.34 <= BFL / F <= 0.49,

[0048] 23.75 <= vd4 <= 42.75,

[0049] 1.63 <= nd2 <= 1.93,

[0050] 1.91 <= nd3 <= 2.04,

[0051] 1.82 <= nd4 <= 2.06,

[0052] 0.31 <= R21 / R22 <= 0.43,

[0053] 3.26 <= R31 / R32 <= 4.61,

[0054] -0.1 <= R41 / R42 <= 0.1,

[0055] 1.23 <= (D1+D2+D3+D4+D5) / F <= 1.42,

[0056] Wherein, TTL is the total optical length of the eyepiece lens, F is the effective focal length of the eyepiece lens, BFL is the back focal length of the eyepiece lens, F1 is the effective focal length of the first lens, F2 is the effective focal length of the second lens, F3 is the effective focal length of the third lens, F4 is the effective focal length of the fourth lens, F234 is the combined focal length of the second lens, the third lens and the fourth lens, vd4 is the Abbe number of the fourth lens, nd2 is the refractive index of the second lens, nd3 is the refractive index of the third lens, nd4 is the refractive index of the fourth lens, R21 is the curvature radius of the object side of the second lens, R22 is the curvature radius of the image side of the second lens, R31 is the curvature radius of the object side of the third lens, R32 is the curvature radius of the image side of the third lens, R41 is the curvature radius of the object side of the fourth lens, R42 is the curvature radius of the image side of the fourth lens, D1 is the central thickness of the first lens, D2 is the central thickness of the second lens, D3 is the central thickness of the third lens, D4 is the central thickness of the fourth lens, D5 is the central thickness of the fifth lens.

[0057] According to the scheme of the present application, by setting the eyepiece lens to include five lenses, and setting the refractive powers of the first to fifth lenses to be positive, positive, negative, positive and positive or negative respectively, the present application can take into account both long exit pupil distance and long back focal length, and has the advantages of miniaturization and low cost. The eyepiece lens of the present application has at least one of the characteristics of long exit pupil distance (up to 46mm), long back focal length (up to 7mm), miniaturization and low cost. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0059] Figure 1 is a structural schematic view of the eyepiece lens of example one in the present application;

[0060] Figure 2 is a structural schematic view of the eyepiece lens of example two in the present application;

[0061] Figure 3 is a structural schematic view of the eyepiece lens of example three in the present application;

[0062] Figure 4 is a structural schematic view of the eyepiece lens of example four in the present application;

[0063] Figure 5 Figure 3 is a structural schematic diagram of an eyepiece lens according to an embodiment of the present application;

[0064] Figure 6 Figure 4 is a structural schematic diagram of an eyepiece lens according to another embodiment of the present application. DETAILED DESCRIPTION

[0065] For a better understanding of the present application, various aspects of the present application will be described in greater detail below with reference to the accompanying drawings. It is to be understood that these detailed descriptions are merely descriptive of exemplary embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0066] It should be noted that, in the present specification, the expressions first, second, third, and the like are used only to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the first lens without departing from the teachings of the present application.

[0067] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0068] In the present specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0069] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when describing the embodiments of the present application, the use of "may" indicates that "one or more embodiments of the present application". Also, the expression "exemplary" is intended to mean example or illustrative.

[0070] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0071] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other. The following embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application.

[0072] like Figures 1 to 6 As shown, an embodiment of this utility model provides an eyepiece lens, which, along the optical axis from the object side to the image side, sequentially includes: an aperture stop STO, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a protective flat glass CG, wherein the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are all spherical lenses.

[0073] The object-side surface of the first lens L1 is convex and has positive optical power. This can prevent the light entering the optical system from being too divergent, which is conducive to the smoothing of the light path behind, balancing some chromatic aberration and coma in the system, and is also beneficial for the correction of field curvature at different object distances.

[0074] The second lens L2 is a convex-concave lens with positive optical power, and it is crescent-shaped, which is beneficial for the correction of astigmatism and field curvature.

[0075] The third lens L3 is a convex-concave lens with negative optical power. When used in conjunction with the second lens L2 and the fourth lens L4, it can effectively correct the field curvature and chromatic aberration of the eyepiece lens, while also reducing the tolerance sensitivity of the eyepiece lens.

[0076] The fourth lens L4 has a convex object side with positive optical power, which allows light rays from different fields of view to be spatially staggered to correct transverse aberration. It also facilitates the convergence of light rays, allowing more light to enter the eyepiece lens, ensuring light throughput, and thus improving relative illumination.

[0077] In some embodiments of this utility model, the second lens L2, the third lens L3, and the fourth lens L4 form a cemented triplet lens.

[0078] In some embodiments of this utility model, the third lens L3 and the fourth lens L4 form a cemented doublet lens.

[0079] The fifth lens L5 is an aspherical lens, and the fifth lens L5 is a convex-concave lens with positive refractive power or a concave-convex lens with negative refractive power, which is beneficial to correcting residual chromatic aberration of the system.

[0080] In some embodiments of the utility model, the effective focal length F1 of the first lens L1 and the effective focal length F of the eyepiece lens satisfy the following relationship: 1.5≤F1 / F≤3.5, preferably 2.14≤F1 / F≤3.01; by reasonably controlling the ratio of the effective focal length F1 of the first lens L1 and the effective focal length F of the eyepiece lens, it can avoid the light entering the optical system too much divergence, which is beneficial to the gentle trend of the rear light, can balance the partial chromatic aberration and coma of the system, and is beneficial to the correction of field curvature under different object distances.

[0081] In some embodiments of the utility model, the effective focal length F2 of the second lens L2 and the effective focal length F of the eyepiece lens satisfy the following relationship: 1.8≤F2 / F≤3.5, preferably 2.12≤F2 / F≤2.83; by reasonably controlling the ratio of the effective focal length F2 of the second lens L2 and the effective focal length F of the eyepiece lens, it is beneficial to the correction of chromatic aberration and field curvature of the system.

[0082] In some embodiments of the utility model, the effective focal length F3 of the third lens L3 and the effective focal length F of the eyepiece lens satisfy the following relationship: -2≤F3 / F≤-0.8, preferably -1.57≤F3 / F≤-0.97; by reasonably distributing the effective focal length F3 of the third lens L3, the field curvature and chromatic aberration of the system can be effectively corrected, and the system tolerance sensitivity can be reduced.

[0083] In some embodiments of the utility model, the effective focal length F4 of the fourth lens L4 and the effective focal length F of the eyepiece lens satisfy the following relationship: 0.5≤F4 / F≤1.5, preferably 0.84≤F4 / F≤1.03; by reasonably controlling the effective focal length F4 of the fourth lens L4, the different field light rays can be overlapped in space to correct the vertical aberration, and it is beneficial to the convergence of light rays, so that more light rays enter the eyepiece lens, ensure the light flux, and improve the relative luminance.

[0084] In some embodiments of the utility model, the combined focal length F234 of the second lens L2, the third lens L3 and the fourth lens L4 and the effective focal length F of the eyepiece lens satisfy the following relationship: 1.2≤F234 / F≤2.5, preferably 1.36≤F234 / F≤2.03; by reasonably controlling the combined focal length F234 of the second lens L2, the third lens L3 and the fourth lens L4, it is beneficial to the correction of axial and vertical chromatic aberration of the system.

[0085] In some embodiments of the utility model, effective focal length F1 of first lens L1 and effective focal length F2 of second lens L2 satisfy following relation: 0.5≤F1 / F2≤2, preferably, 0.92≤F1 / F2≤1.12;By reasonable setting the ratio of effective focal length F1 of first lens L1 and effective focal length F2 of second lens L2, it is favorable to reduce lens assembly core, tilt tolerance, improve production yield.

[0086] In some embodiments of the utility model, the optical total length TTL of the eyepiece lens and the effective focal length F satisfy the following relationship: 1.2≤TTL / F≤2.5, preferably, 1.68≤TTL / F≤1.85;By reasonably controlling the optical total length of the eyepiece lens, it is beneficial to realize the miniaturization of the lens.

[0087] In some embodiments of the utility model, the effective focal length F of the eyepiece lens and the back focal length BFL satisfy the following relationship: 0.2≤BFL / F≤1, preferably, 0.34≤BFL / F≤0.49;By reasonably controlling the back focal length of the eyepiece lens, enough structural allowance can be left for the rear end of the lens to avoid interference risk during assembly.

[0088] In some embodiments of the utility model, the Abbe number vd3 of the third lens L3 satisfies the following relationship: 10≤vd3≤30;The Abbe number vd4 of the fourth lens L4 satisfies the following relationship: 15≤vd4≤50, preferably, 23.75≤vd4≤42.75;By reasonably allocating the Abbe number of the cemented lens, the chromatic aberration of the lens can be effectively corrected, and the imaging quality of the optical system is improved.

[0089] In some embodiments of the utility model, the refractive index nd2 of the second lens L2 satisfies the following relationship: 1.63≤nd2≤2, preferably, 1.63≤nd2≤1.93;The refractive index nd3 of the third lens L3 satisfies the following relationship: 1.8≤nd3≤2.04, preferably, 1.91≤nd3≤2.04;The refractive index nd4 of the fourth lens L4 satisfies the following relationship: 1.7≤nd4≤2.1, preferably, 1.82≤nd4≤2.06;By reasonably allocating the refractive index of the cemented lens, the light ray trend can be effectively controlled, so that the light rays converge gently to the rear end system, and the system tolerance sensitivity is reduced.

[0090] In some embodiments of the utility model, the curvature radius R21 of the object side of the second lens L2 and the curvature radius R22 of the image side satisfy the following relationship: 0.2≤R21 / R22≤0.5, preferably, 0.31≤R21 / R22≤0.43;By reasonably controlling the curvature radius of the second lens L2, the refractive power of the second lens L2 can be effectively controlled, the light ray turning trend is slowed down, the difficulty of aberration correction is reduced, and the resolving power of the eyepiece lens is improved.

[0091] In some embodiments of the utility model, the curvature radius R31 of the object side of third lens L3 and the curvature radius R32 of the image side satisfy the following relationship: 2≤R31 / R32≤5, preferably, 3.26≤R31 / R32≤4.61; by reasonable control of the curvature radius of third lens L3, different wavelengths of light can effectively reach different divergence angles, which is conducive to correcting system chromatic aberration.

[0092] In some embodiments of the utility model, the curvature radius R41 of the object side of fourth lens L4 and the curvature radius R42 of the image side satisfy the following relationship: -0.11≤R41 / R42≤0.15, preferably, -0.1≤R41 / R42≤0.1; by reasonable control of the curvature radius of fourth lens L4, light rays can be effectively converged, more light rays can enter the eyepiece lens, the luminous flux is ensured, and the relative luminance is improved.

[0093] In some embodiments of the utility model, the center thickness D1 of first lens L1, the center thickness D2 of second lens L2, the center thickness D3 of third lens L3, the center thickness D4 of fourth lens L4, the center thickness D5 of fifth lens L5 and the optical total length TTL of the eyepiece lens satisfy the following relationship: 1≤(D1+D2+D3+D4+D5) / F≤2, preferably, 1.23≤(D1+D2+D3+D4+D5) / F≤1.42; by reasonably restricting the center thickness of each lens, the difficulty of aberration correction can be reduced, the lens processing precision is ensured, the tolerance of the optical element is reduced, the lens production yield is improved, and miniaturization is realized.

[0094] Wherein, the entrance pupil is the effective aperture of the incident light beam, and the image formed by the aperture stop to the front optical system, the entrance pupil and the exit pupil correspond to each other;

[0095] The entrance pupil position is the position point of the image formed by the aperture stop to the front optical system, and the calculation of the entrance pupil position is to regard the center of the aperture stop as an object point, and the ray tracing is carried out to the front optical system, and the intersection coordinates of the point on the optical axis are obtained, and the distance from the first lens surface is usually taken as the entrance pupil distance.

[0096] The exit pupil position is the position point of the image formed by the aperture stop to the rear optical system, and the calculation of the exit pupil position is to regard the center of the aperture stop as an object point, and the ray tracing is carried out to the rear optical system, and the intersection coordinates of the point on the optical axis are obtained, and the distance from the last lens surface is usually taken as the exit pupil distance.

[0097] The following six specific embodiments are given according to the above setting of the utility model to specifically explain the eyepiece lens according to the utility model. The eyepiece lens according to the utility model has five lenses in total, each cemented surface of the cemented lenses is recorded as a surface, plus the diaphragm STO, the protection glass CG and the image surface IMA, and the total number of surfaces is 12 or 13. Among them, the diaphragm STO is arranged before the first lens L1.

[0098] The data of the six embodiments are as follows in Table 1:

[0099] Conditional expression Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 1.5 ≤ F1 / F ≤ 3.5 2.288 2.954 2.260 2.190 2.258 2.190 1.8 ≤ F2 / F ≤ 3.5 2.343 2.773 2.292 2.170 2.295 2.199 -2 ≤ F3 / F ≤ -0.8 -1.060 -1.513 -1.037 -1.037 -1.029 -1.150 0.5 ≤ F4 / F ≤ 1.5 0.908 0.952 0.903 0.968 0.894 0.980 1.2 ≤ F234 / F ≤ 2.5 1.761 1.414 1.776 1.978 1.772 1.703 0.5 ≤ F1 / F2 ≤ 2 0.976 1.065 0.986 1.009 0.984 0.996 1.2 ≤ TTL / F ≤ 2.5 1.791 1.737 1.789 1.747 1.778 1.753 0.2 ≤ BFL / F ≤ 1 0.411 0.435 0.406 0.397 0.403 0.397 10 ≤ vd3 ≤ 30 16.500 17.500 16.500 16.500 16.500 16.500 15 ≤ vd4 ≤ 50 40.800 33.900 39.200 23.800 42.700 42.700 1.63 ≤ nd2 ≤ 2 1.880 1.680 1.880 1.880 1.880 1.880 1.8 ≤ nd3 ≤ 2.04 1.990 1.960 1.980 1.980 1.980 1.980 1.7 ≤ nd4 ≤ 2.1 1.880 2.010 1.880 1.880 1.870 1.870 0.2 ≤ R21 / R22 ≤ 0.5 0.380 0.373 0.365 0.371 0.367 0.380 2 ≤ R31 / R32 ≤ 5 4.326 3.315 4.515 4.372 4.553 4.328 -0.11 ≤ R41 / R42 ≤ 0.15 -0.050 -0.060 -0.049 0.098 -0.048 -0.055 1 ≤ (D1+D2+D3+D4+D5) / F ≤ 2 1.362 1.282 1.366 1.336 1.347 1.323

[0100] Table 1

[0101] The utility model will be described in detail below in combination with the drawings and specific embodiments, and the embodiments cannot be described one by one here, but the embodiments of the utility model are not limited to the following embodiments.

[0102] Embodiment one

[0103] Figure 1 The structure diagram of the eyepiece lens of embodiment one in the utility model.

[0104] In embodiment one, the first lens L1 is a convex-convex lens with positive refractive power, the second lens L2 is a convex-concave lens with positive refractive power, the third lens L3 is a convex-concave lens with negative refractive power, the fourth lens L4 is a convex-convex lens with positive refractive power, and the fifth lens L5 is a convex-concave lens with positive refractive power.

[0105] The second lens L2, the third lens L3 and the fourth lens L4 form three cemented lenses.

[0106] Table 2 lists the related parameters of each lens in the eyepiece lens of the embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd of material and Abbe number Vd.

[0107] Surface number Surface type Curvature radius R Thickness d Refractive index Nd Abbe number Vd S1 (STO) Spherical Infinity 46.000 S2 Spherical 60.055 5.314 2.000 28.30 S3 Spherical -121.652 0.150 S4 Spherical 23.984 5.308 1.880 40.80 S5 Spherical 63.120 0.900 1.990 16.50 S6 Spherical 14.592 8.782 1.880 40.80 S7 Spherical -291.699 0.150 S8 Aspherical 85.560 3.002 1.640 23.50 S9 Aspherical 100.000 4.332 S10 Spherical Infinity 1.800 1.519 64.20 S11 Spherical Infinity 0.900 S12 (IMA) Spherical Infinity

[0108] Table 2

[0109] Table 3 lists the aspheric coefficients of each aspheric lens of the optical lens of the embodiment, including: the quadratic surface constant K of the surface, the fourth-order aspheric coefficient A4, the sixth-order aspheric coefficient A6, the eighth-order aspheric coefficient A8, the tenth-order aspheric coefficient A10, the twelfth-order aspheric coefficient A12 and the fourteenth-order aspheric coefficient A14. 10 12 14 16

[0110] Surface number K [A4] [A6] [A8] A 10 ]]> A 12 ]]> A 14 ]]> A 16 ]] S8 2.663 -3.12E-05 -1.34E-07 -8.28E-11 -2.13E-12 1.85E-14 0.00E+00 0.00E+00 S9 51.536 6.36E-05 -8.44E-07 -2.94E-10 3.01E-12 3.90E-14 0.00E+00 0.00E+00 ​​​​

[0111] Table 3

[0112] In combination Figure 1 In addition to the above and as shown in Tables 1-3, in Example One, the eyepiece lens has an image height of 10.4mm, a field of view of 32.69°, a total optical length TTL of 30.638mm, a back focal length BFL of 7.032mm, and an exit pupil distance of 46mm. The long exit pupil distance design allows for a safe eye relief distance and is suitable for use in certain special scenarios.

[0113] Example One is an eyepiece lens that has at least one of the following characteristics: long exit pupil distance (46mm), low cost, miniaturization (up to 31mm), long back focal length, etc.

[0114] Example Two

[0115] Figure 2 FIG. 1 is a schematic diagram of the structure of an eyepiece lens according to Example Two of the present application.

[0116] In Example Two, the first lens L1 is a convex-concave lens with positive refractive power, the second lens L2 is a convex-concave lens with positive refractive power, the third lens L3 is a convex-concave lens with negative refractive power, the fourth lens L4 is a convex-convex lens with positive refractive power, and the fifth lens L5 is a convex-concave lens with positive refractive power.

[0117] The second lens L2, the third lens L3, and the fourth lens L4 form a triple cemented lens.

[0118] Table 4 lists the relevant parameters of each lens in the eyepiece lens of the present example, including: surface type, curvature radius R, thickness d, refractive index Nd of the material, and Abbe number Vd.

[0119] Surface number Surface type Curvature radius R Thickness d Refractive index Nd Abbe number Vd S1 (STO) Spherical Infinity 46.000 S2 Spherical 39.986 4.968 2.000 28.30 S3 Spherical 150.122 0.100 S4 Spherical 22.356 5.503 1.680 95.10 S5 Spherical 60.000 0.799 1.960 17.50 S6 Spherical 18.102 8.324 2.010 33.90 S7 Spherical -300.000 0.268 S8 Aspherical 90.000 3.288 1.640 23.50 S9 Aspherical 93.703 5.064 S10 Spherical Infinity 1.800 1.519 64.20 S11 Spherical Infinity 0.900 S12 (IMA) Spherical Infinity

[0120] Table 4

[0121] Table 5 lists the aspherical coefficients of each aspherical lens in the optical lens of the present example, including: the quadratic surface constant K of the surface, the fourth-order aspherical coefficient A4, the sixth-order aspherical coefficient A6, the eighth-order aspherical coefficient A8, the tenth-order aspherical coefficient A10, the twelfth-order aspherical coefficient A12, and the fourteenth-order aspherical coefficient A14. 10 12 14 16

[0122] Surface number K [A4] [A6] [A8] A 10 ]]> A 12 ]]> A 14 ]]> A 16 ]]> S8 2.663 -3.49E-05 -9.80E-08 -3.94E-11 -1.88E-12 1.53E-14 0.00E+00 0.00E+00 S9 51.536 7.50E-05 -8.64E-07 -8.29E-10 5.36E-13 6.28E-14 0.00E+00 0.00E+00

[0123] Table 5

[0124] In combination Figure 2 ​​​​As shown in Table 1, Table 4 and Table 5, in the embodiment two, the eye lens has an image height of 10.4mm, a field angle of 33.08°, a total optical length TTL of 31.014mm, a back focal length BFL of 7.764mm, and a pupil distance of 46mm. The long pupil distance design can leave enough eye safety working distance and facilitate the use in some special scenes.

[0125] The embodiment two is an eye lens having at least one of the following characteristics: long pupil distance (46mm), low cost, miniaturization (31mm), long back focal length, etc.

[0126] Embodiment three

[0127] Figure 3 The structure of the eye lens in the embodiment three is shown in the figure.

[0128] In the embodiment three, the first lens L1 is a convex-convex lens with positive refractive power, the second lens L2 is a convex-concave lens with positive refractive power, the third lens L3 is a convex-concave lens with negative refractive power, the fourth lens L4 is a convex-convex lens with positive refractive power, and the fifth lens L5 is a convex-concave lens with positive refractive power.

[0129] The second lens L2, the third lens L3 and the fourth lens L4 form a three-lens cemented lens.

[0130] Table 6 lists the related parameters of each lens in the eye lens of the embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd of the material and Abbe number Vd.

[0131] Surface number Surface type Curvature radius R Thickness d Refractive index Nd Abbe number Vd S1 (STO) Spherical Infinity 46.000 S2 Spherical 58.310 5.449 2.000 29.80 S3 Spherical -129.996 0.166 S4 Spherical 23.969 5.295 1.880 53.10 S5 Spherical 65.692 1.196 1.980 16.50 S6 Spherical 14.551 8.780 1.880 39.20 S7 Spherical -300.004 0.136 S8 Aspherical 84.343 2.946 1.640 23.50 S9 Aspherical 97.289 4.330 S10 Spherical Infinity 1.800 1.519 64.20 S11 Spherical Infinity 0.900 S12 (IMA) Spherical Infinity

[0132] Table 6

[0133] Table 7 lists the aspheric coefficients of each aspheric lens in the optical lens of the embodiment, including: the quadratic surface constant K of the surface, the fourth-order aspheric coefficient A4, the sixth-order aspheric coefficient A6, the eighth-order aspheric coefficient A8, the tenth-order aspheric coefficient A10, the twelfth-order aspheric coefficient A12 and the fourteenth-order aspheric coefficient A14. 10 12 14 16

[0134]

[0135]

[0136] Table 7

[0137] In combination with Figure 3 ​​​​As shown in Table 1, Table 6 and Table 7, in Example Three, the eyepiece lens has an image height of 10.4mm, a field of view of 31.97°, a total optical length TTL of 30.998mm, a back focal length BFL of 7.030mm, and an exit pupil distance of 46mm. The long exit pupil distance design can leave sufficient eye safety working distance and facilitate use in some special scenarios.

[0138] The eyepiece lens of Example Three has at least one of the following characteristics: long exit pupil distance (46mm), low cost, miniaturization (up to 31mm), long back focal length, etc.

[0139] Example Four

[0140] Figure 4 FIG. 1 is a structural schematic diagram of the eyepiece lens of Example Four of the present application.

[0141] In Example Four, the first lens L1 is a convex-convex lens with positive refractive power, the second lens L2 is a convex-concave lens with positive refractive power, the third lens L3 is a convex-concave lens with negative refractive power, the fourth lens L4 is a convex-concave lens with positive refractive power, and the fifth lens L5 is a convex-concave lens with positive refractive power.

[0142] The second lens L2, the third lens L3 and the fourth lens L4 form a triple cemented lens.

[0143] Table 8 lists the related parameters of each lens in the eyepiece lens of the present example, including: surface type, curvature radius R, thickness d, refractive index Nd of the material, and Abbe number Vd.

[0144] Surface number Surface type Curvature radius R Thickness d Refractive index Nd Abbe number Vd S1 (STO) Spherical Infinity 46.000 S2 Spherical 56.853 5.209 2.010 42.70 S3 Spherical -129.978 0.049 S4 Spherical 23.841 5.339 1.880 23.90 S5 Spherical 64.335 1.367 1.980 16.50 S6 Spherical 14.715 8.810 1.880 23.80 S7 Spherical 150.000 0.193 S8 Aspherical 19.999 2.985 1.640 23.50 S9 Aspherical 103.676 4.356 S10 Spherical Infinity 1.800 1.519 64.20 S11 Spherical Infinity 0.900 S12 (IMA) Spherical Infinity

[0145] Table 8

[0146] Table 9 lists the aspherical coefficients of each aspherical lens in the optical lens of the present example, including: the quadratic surface constant K of the surface, the fourth-order aspherical coefficient A4, the sixth-order aspherical coefficient A6, the eighth-order aspherical coefficient A8, the tenth-order aspherical coefficient A10, the twelfth-order aspherical coefficient A12, and the fourteenth-order aspherical coefficient A14. 10 12 14 16

[0147] Surface number K [A4] [A6] [A8] A 10 ]]> A 12 ]]> A 14 ]]> A 16 ]]> S8 46.527 -1.26E-04 8.93E-07 -8.57E-10 -1.03E-11 -3.92E-14 0.00E+00 0.00E+00 S9 -80.002 1.55E-04 -3.81E-06 2.87E-08 1.00E-10 -1.23E-12 0.00E+00 0.00E+00

[0148] Table 9

[0149] In combination with Figure 4 ​​​​As shown in Table 1, Table 8 and Table 9, in the embodiment four, the eyepiece lens has an image height of 10.4mm, a field of view angle of 32.02°, a total optical length TTL of 31.007mm, a back focal length BFL of 7.056mm, and a pupil distance of 46mm. The long pupil distance design can leave enough eye safety working distance and facilitate the use in some special scenes.

[0150] The embodiment four is an eyepiece lens having at least one of the following characteristics: long pupil distance (46mm), low cost, miniaturization (up to 31mm), long back focal length, etc.

[0151] Embodiment five

[0152] Figure 5 The embodiment five is an eyepiece lens.

[0153] In the embodiment five, the first lens L1 is a convex-convex lens with positive refractive power, the second lens L2 is a convex-concave lens with positive refractive power, the third lens L3 is a convex-concave lens with negative refractive power, the fourth lens L4 is a convex-convex lens with positive refractive power, and the fifth lens L5 is a convex-concave lens with positive refractive power.

[0154] The third lens L3 and the fourth lens L4 form a doublet lens.

[0155] Table 10 lists the related parameters of each lens in the eyepiece lens of the embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd of the material, and Abbe number Vd.

[0156]

[0157]

[0158] Table 10

[0159] Table 11 lists the aspheric coefficients of each aspheric lens in the optical lens of the embodiment, including: the quadratic surface constant K of the surface, the fourth-order aspheric coefficient A4, the sixth-order aspheric coefficient A6, the eighth-order aspheric coefficient A8, the tenth-order aspheric coefficient A10, the twelfth-order aspheric coefficient A12, and the fourteenth-order aspheric coefficient A14. 10 12 14 16

[0160] Surface number K [A4] [A6] [A8] A 10 ]]> A 12 ]]> A 14 ]]> A 16 ]]> S9 -80.000 -1.00E-04 6.67E-07 -6.97E-10 -6.39E-12 -9.24E-15 0.00E+00 0.00E+00 S10 -54.016 1.25E-04 -3.74E-06 3.03E-08 8.81E-11 -1.41E-12 0.00E+00 0.00E+00

[0161] Table 11

[0162] In combination with Figure 5 ​​​​As shown in Table 1, Table 10 and Table 11, in the embodiment five, the image height of the eyepiece lens is 10.4mm, the field of view angle is 31.99°, the total optical length TTL is 30.996mm, the back focal length BFL is 7.022mm, the exit pupil distance can reach 46mm, and the design of the long exit pupil distance can leave sufficient eye safety working distance and facilitate use in some special scenes.

[0163] The embodiment five is one of the eyepiece lenses having at least one of the characteristics of long exit pupil distance (46mm), low cost, miniaturization (up to 31mm), long back focal length, etc.

[0164] Embodiment six

[0165] Figure 6 The embodiment six is an eyepiece lens.

[0166] In the embodiment six, the first lens L1 is a convex-convex lens with positive refractive power, the second lens L2 is a convex-concave lens with positive refractive power, the third lens L3 is a convex-concave lens with negative refractive power, the fourth lens L4 is a convex-convex lens with positive refractive power, and the fifth lens L5 is a concave-convex lens with negative refractive power.

[0167] The third lens L3 and the fourth lens L4 form a double cemented lens.

[0168] Table 12 lists the related parameters of each lens in the eyepiece lens of the embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd of the material, and Abbe number Vd.

[0169]

[0170]

[0171] Table 12

[0172] Table 13 lists the aspheric coefficients of each aspheric lens in the optical lens of the embodiment, including: the quadratic surface constant K of the surface, the fourth-order aspheric coefficient A4, the sixth-order aspheric coefficient A6, the eighth-order aspheric coefficient A8, the tenth-order aspheric coefficient A10, the twelfth-order aspheric coefficient A12, and the fourteenth-order aspheric coefficient A14. 10 12 14 16

[0173] Surface number K [A4] [A6] [A8] A 10 ]]> A 12 ]]> A 14 ]]> A 16 ]]> 9 -75.655 -4.66E-05 9.17E-07 -2.95E-10 -9.24E-12 -6.06E-14 0.00E+00 0.00E+00 10 -74.934 1.46E-04 -2.34E-06 3.64E-08 6.82E-11 -1.30E-12 0.00E+00 0.00E+00

[0174] Table 13

[0175] In combination with Figure 6 Surface number ​​​​As shown in Table 1, Table 12 and Table 13, in Example 6, the eyepiece lens has an image height of 10.4 mm, a field of view of 31.03°, a total optical length TTL of 31.001 mm, a back focal length BFL of 7.024 mm, and an exit pupil distance of 46 mm. The long exit pupil distance design can leave sufficient eye safety working distance and facilitate use in some special scenarios.

[0176] The eyepiece lens of Example 6 has at least one of the following characteristics: long exit pupil distance (46 mm), low cost, miniaturization (up to 31 mm), long back focal length, etc.

[0177] The above description is merely preferred embodiments of the present application and a description of the technical principles of the application. It should be understood by those skilled in the art that the scope of the utility model disclosed in the present application is not limited to the technical solutions formed by the specific combinations of the above technical features, and also covers other technical solutions formed by any combinations of the above technical features or equivalent features without departing from the concept of the utility model. For example, the above features can be replaced with technical features disclosed in the present application (but not limited to) having similar functions to form technical solutions.

Claims

1. An eyepiece lens characterized by, In the direction from the object side to the image side along the optical axis, in order: a first lens (L1) with positive refractive power, a second lens (L2) with positive refractive power, a third lens (L3) with negative refractive power, a fourth lens (L4) with positive refractive power, and a fifth lens (L5) with positive or negative refractive power; the second lens (L2) is a convex-concave lens; the second lens (L2), the third lens (L3), and the fourth lens (L4) form a triple cemented lens; or the third lens (L3) and the fourth lens (L4) form a double cemented lens.

2. The eyepiece lens of claim 1, wherein the object side surface of the first lens (L1) is a convex surface, the third lens (L3) is a convex-concave lens, and the object side surface of the fourth lens (L4) is a convex surface, the fifth lens (L5) is a convex-concave lens with positive refractive power or a concave-convex lens with negative refractive power.

3. The eyepiece lens of claim 1, wherein the first lens (L1), the second lens (L2), the third lens (L3), and the fourth lens (L4) are all spherical lenses; the fifth lens (L5) is an aspherical lens.

4. The eyepiece lens of any one of claims 1-3, wherein, the effective focal length F1 of the first lens (L1) and the effective focal length F of the eyepiece lens satisfy the following relationship: 1.5≤F1 / F≤3.

5.

5. The eyepiece lens of any one of claims 1-3, wherein, the effective focal length F2 of the second lens (L2) and the effective focal length F of the eyepiece lens satisfy the following relationship: 1.8≤F2 / F≤3.

5.

6. The eyepiece lens of any one of claims 1-3, wherein, the effective focal length F3 of the third lens (L3) and the effective focal length F of the eyepiece lens satisfy the following relationship: -2≤F3 / F≤-0.

8.

7. The eyepiece lens of any one of Claims 1-3, wherein, the effective focal length F4 of the fourth lens (L4) and the effective focal length F of the eyepiece lens satisfy the following relationship: 0.5≤F4 / F≤1.

5.

8. The eyepiece lens of any one of claims 1-3, wherein, the combined focal length F234 of the second lens (L2), the third lens (L3), and the fourth lens (L4) and the effective focal length F of the eyepiece lens satisfy the following relationship: 1.2≤F234 / F≤2.

5.

9. The eyepiece lens of any one of Claims 1-3, wherein, the effective focal length F1 of the first lens (L1) and the effective focal length F2 of the second lens (L2) satisfy the following relationship: 0.5≤F1 / F2≤2.

10. The eyepiece lens of any one of Claims 1-3, wherein, the total optical length TTL of the eyepiece lens and the effective focal length F satisfy the following relationship: 1.2≤TTL / F≤2.

5.

11. The eyepiece lens of any one of Claims 1-3, wherein, the effective focal length F of the eyepiece lens and the back focal length BFL satisfy the following relationship: 0.2≤BFL / F≤1.

12. The eyepiece lens of any one of Claims 1-3, wherein, the Abbe number vd3 of the third lens (L3) satisfies the following relationship: 10≤vd3≤30; the Abbe number vd4 of the fourth lens (L4) satisfies the following relationship: 15≤vd4≤50.

13. The eyepiece lens of any one of Claims 1-3, wherein, the refractive index nd2 of the second lens (L2) satisfies the following relationship: 1.63≤nd2≤2; the refractive index nd3 of the third lens (L3) satisfies the following relationship: 1.8≤nd3≤2.04; the refractive index nd4 of the fourth lens (L4) satisfies the following relationship: 1.7≤nd4≤2.

1.

14. The eyepiece lens of any of claims 1-3, wherein, the curvature radius R21 of the object side surface of the second lens (L2) and the curvature radius R22 of the image side surface satisfy the following relationship: 0.2≤R21 / R22≤0.

5.

15. The eyepiece lens of any of claims 1-3, wherein, The radius of curvature R31 of the object side surface of the third lens (L3) and the radius of curvature R32 of the image side surface satisfy the following relationship: 2≤R31 / R32≤5.

16. The eyepiece lens of any of claims 1-3, wherein, The radius of curvature R41 of the object side surface of the fourth lens (L4) and the radius of curvature R42 of the image side surface satisfy the following relationship: -0.11≤R41 / R42≤0.

15.

17. The eyepiece lens of any one of Claims 1-3, wherein, The center thickness D1 of the first lens (L1), the center thickness D2 of the second lens (L2), the center thickness D3 of the third lens (L3), the center thickness D4 of the fourth lens (L4), the center thickness D5 of the fifth lens (L5), and the total track length TTL of the objective lens satisfy the following relationship: 1≤(D1+D2+D3+D4+D5) / F≤2.

18. The eyepiece lens of claim 1, wherein, The objective lens satisfies at least one of the following conditions: 2.14≤F1 / F≤3.01, 2.12≤F2 / F≤2.83, -1.57≤F3 / F≤-0.97, 0.84≤F4 / F≤1.03, 1.36≤F234 / F≤2.03, 0.92≤F1 / F2≤1.12, 1.68≤TTL / F≤1.85, 0.34≤BFL / F≤0.49, 23.75≤vd4≤42.75, 1.63≤nd2≤1.93, 1.91≤nd3≤2.04, 1.82≤nd4≤2.06, 0.31≤R21 / R22≤0.43, 3.26≤R31 / R32≤4.61, -0.1≤R41 / R42≤0.1, 1.23≤(D1+D2+D3+D4+D5) / F≤1.42, wherein TTL is the total optical length of the eyepiece lens, F is the effective focal length of the eyepiece lens, BFL is the back focal length of the eyepiece lens, F1 is the effective focal length of the first lens (L1), F2 is the effective focal length of the second lens (L2), F3 is the effective focal length of the third lens (L3), F4 is the effective focal length of the fourth lens (L4), F234 is the combined focal length of the second lens (L2), the third lens (L3) and the fourth lens (L4), vd4 is the Abbe number of the fourth lens (L4), nd2 is the refractive index of the second lens (L2), nd3 is the refractive index of the third lens (L3), nd4 is the refractive index of the fourth lens (L4), R21 is the radius of curvature of the object side surface of the second lens (L2), R22 is the radius of curvature of the image side surface of the second lens (L2), R31 is the radius of curvature of the object side surface of the third lens (L3), R32 is the radius of curvature of the image side surface of the third lens (L3), R41 is the radius of curvature of the object side surface of the fourth lens (L4), R42 is the radius of curvature of the image side surface of the fourth lens (L4), D1 is the center thickness of the first lens (L1), D2 is the center thickness of the second lens (L2), D3 is the center thickness of the third lens (L3), D4 is the center thickness of the fourth lens (L4), D5 is the center thickness of the fifth lens (L5).

Images