Observation lens

Abstract

The present application relates to a sighting lens, which comprises, in order from the object side to the image side along the optical axis, a first lens with positive refractive power, a second lens with positive refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, a fifth lens with negative refractive power, a sixth lens with positive refractive power, a seventh lens with positive refractive power, an eighth lens with negative refractive power, and a ninth lens with positive refractive power; the effective focal length F6 of the sixth lens and the effective focal length F of the sighting lens satisfy the following relationship: 0.2 <= F6 / F <= 2.0; the effective focal length F7 of the seventh lens and the effective focal length F of the sighting lens satisfy the following relationship: 0.09 <= F7 / F <= 0.30. The sighting lens of the present application has at least one of the following characteristics: super-telephoto, miniaturization, wide spectrum (430nm-940nm), high resolution, low chromatic aberration, good thermal stability (-30-70 DEG C), total field illumination >=99%, lens chief ray angle CRA <1.0 DEG.

Description

Technical Field

[0001] This invention relates to the field of imaging lens technology, and more particularly to a viewing lens. Background Technology

[0002] With the continuous advancement of optical technology, the manufacturing process of optical lenses and optical theory have made significant progress. This laid the foundation for the development of sighting lenses. Sighting lenses, also called scopes or sniper scopes, allow users to see targets more clearly.

[0003] Sighting lenses need to be used in various complex environments, thus adaptability technologies for different environments are constantly evolving, which places higher demands on sighting lenses. First, as handheld products, portability is paramount; the lens's weight and size must be sufficiently small, thus requiring miniaturization. Second, sighting lenses are used to observe object details, resulting in a narrow object-side field of view, necessitating a longer focal length. Third, to meet the need for discerning minute details, high image quality and low ghosting are required. Fourth, to meet the requirements of low-light conditions such as dusk and dawn, the lens must provide high resolution across a wide spectrum (430nm–940nm), thus requiring wide-spectrum chromatic aberration correction. Furthermore, to cope with harsh weather conditions such as fog, rain, and snow, waterproof, anti-fog, and shock-resistant technologies are also incorporated into the design and manufacturing of sighting lenses, ensuring stable performance in various complex environments and providing users with clear and accurate target observation.

[0004] The following shortcomings still exist in the current market for observation and aiming lenses:

[0005] 1. Existing sighting lenses struggle to balance lens diameter and high image quality;

[0006] 2. Existing observation and aiming lenses cannot achieve both telephoto capabilities and a shorter overall optical length;

[0007] 3. Existing observation and aiming lenses use narrow bands to achieve high resolution across a wide spectrum of 430nm to 940nm;

[0008] 4. Existing observation and aiming lenses have limited room for ghosting optimization, making it difficult to achieve high image quality.

[0009] Therefore, designing a viewing lens with one of the following characteristics—ultra-long focal length, miniaturization, wide spectrum, and high resolution—has become a market trend. Summary of the Invention

[0010] To address the problems existing in the prior art, the present invention aims to provide a viewing and aiming lens that has at least one of the following characteristics: ultra-long focal length, miniaturization, wide spectrum, and high resolution.

[0011] To achieve the above-mentioned objective, the present invention provides a viewing lens, comprising, along the optical axis from the object side to the image side, the following components in sequence:

[0012] The first lens with positive optical power, the second lens with positive optical power, the third lens with negative optical power, the fourth lens with positive optical power, the fifth lens with negative optical power, the sixth lens with positive optical power, the seventh lens with positive optical power, the eighth lens with negative optical power, and the ninth lens with positive optical power.

[0013] The effective focal length F6 of the sixth lens and the effective focal length F of the observation lens satisfy the following relationship: 0.2≤F6 / F≤2.0;

[0014] The effective focal length F7 of the seventh lens and the effective focal length F of the observation lens satisfy the following relationship: 0.09≤F7 / F≤0.30.

[0015] According to one technical solution of the present invention, the first lens is a convex-concave lens, the second lens is a convex-concave lens, the third lens is a convex-concave lens, the object side of the fourth lens is a convex surface, and the image side of the fifth lens is a concave surface.

[0016] According to one technical solution of the present invention, the image-side surface of the seventh lens is convex, the eighth lens is a concave-concave lens, and the object-side surface of the ninth lens is convex.

[0017] According to one technical solution of the present invention, the third lens, the fourth lens, and the fifth lens form a cemented triplet lens, or

[0018] The third lens, the fourth lens, the fifth lens, and the sixth lens together form a four-cemented lens.

[0019] According to one technical solution of the present invention, the combined focal length Fa of the three-cemented lens or the four-cemented lens and the effective focal length F of the observation lens satisfy the following relationship: -1.69≤Fa / F≤-0.14.

[0020] According to one technical solution of the present invention, the seventh lens and the eighth lens form a cemented doublet lens.

[0021] According to one technical solution of the present invention, the combined focal length Fb of the doublet lens and the effective focal length F of the viewing lens satisfy the following relationship: -0.30≤Fb / F≤-0.09.

[0022] According to one technical solution of the present invention, the effective focal length F1 of the first lens and the effective focal length F of the observation lens satisfy the following relationship: 0.6≤F1 / F≤1.5.

[0023] According to one technical solution of the present invention, the effective focal length F2 of the second lens and the effective focal length F of the observation lens satisfy the following relationship: 0.4≤F2 / F≤1.1.

[0024] According to one technical solution of the present invention, the effective focal length F3 of the third lens and the effective focal length F of the observation lens satisfy the following relationship: -0.7≤F3 / F≤-0.2.

[0025] According to one technical solution of the present invention, the effective focal length F4 of the fourth lens and the effective focal length F of the observation lens satisfy the following relationship: 0.18≤F4 / F≤0.50.

[0026] According to one technical solution of the present invention, the effective focal length F5 of the fifth lens and the effective focal length F of the observation lens satisfy the following relationship: -0.4≤F5 / F≤-0.1.

[0027] According to one technical solution of the present invention, the effective focal length F8 of the eighth lens and the effective focal length F of the observation lens satisfy the following relationship: -0.15≤F8 / F≤-0.02.

[0028] According to one technical solution of the present invention, the combined effective focal length F16 of the first lens to the sixth lens and the effective focal length F of the observation lens satisfy the following relationship: 0.4≤F16 / F≤0.7.

[0029] According to one technical solution of the present invention, the refractive index ND1 of the first lens satisfies the following relationship: 1.85≤ND1≤1.98.

[0030] According to one technical solution of the present invention, the Abbe number VD4 of the fourth lens satisfies the following relationship: 60≤VD4≤100.

[0031] According to one technical solution of the present invention, the effective focal length F of the observation lens and the entrance pupil diameter ENPD satisfy the following relationship: 2.9≤F / ENPD≤3.1.

[0032] According to one technical solution of the present invention, the maximum aperture Dmax of the observation and aiming lens and the total optical length TTL satisfy the following relationship: 0.39≤Dmax / TTL≤0.50.

[0033] According to one technical solution of the present invention, the total optical length (TTL) and back focal length (BFL) of the observation and aiming lens satisfy the following relationship: 0.1 ≤ BFL / TTL ≤ 0.3.

[0034] According to one technical solution of the present invention, the radius of curvature R32 of the image side surface of the third lens and the radius of curvature R52 of the image side surface of the fifth lens satisfy the following relationship: 0.12≤R32 / R52≤1.2.

[0035] According to one technical solution of the present invention, the observation and aiming lens satisfies at least one of the following conditions:

[0036] 0.68≤F1 / F≤1.33

[0037] -0.55≤F3 / F≤-0.22,

[0038] 0.20≤F4 / F≤0.41

[0039] 0.49≤F16 / F≤0.68

[0040] 75.46≤VD4≤94.36

[0041] 0.16≤BFL / TTL≤0.30

[0042] Wherein, TTL is the total optical length of the sighting lens, F is the effective focal length of the sighting lens, BFL is the back focal length of the sighting lens, F1 is the effective focal length of the first lens, F3 is the effective focal length of the third lens, F4 is the effective focal length of the fourth lens, F16 is the combined effective focal length of the first lens to the sixth lens, and VD4 is the Abbe number of the fourth lens.

[0043] According to the present invention, by setting the observation and aiming lens to include nine lenses, and setting the optical power of the first lens to the eighth lens to be positive optical power, positive optical power, negative optical power, positive optical power, negative optical power, positive optical power, positive optical power, negative optical power, and positive optical power respectively, and by reasonably configuring the ratio of the effective focal length of the seventh lens to the observation and aiming lens, the observation and aiming lens of the present invention has at least one of the following characteristics: ultra-long focal length, miniaturization, wide spectrum (430nm~940nm), high resolution, low chromatic aberration, good thermal stability (-30~70℃), full field of view illuminance ≥99%, and principal ray incident angle CRA <1.0°. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0045] Figure 1This is a schematic diagram of the observation and aiming lens in Embodiment 1 of the present invention;

[0046] Figure 2 This is a relative illumination diagram of the observation and aiming lens in Embodiment 1 of the present invention;

[0047] Figure 3 This is a lateral ray fan pattern of the observation and aiming lens in Embodiment 1 of the present invention;

[0048] Figure 4 This is a schematic diagram of the observation and aiming lens in Embodiment 2 of the present invention;

[0049] Figure 5 This is a relative illumination diagram of the viewing lens in Embodiment 2 of the present invention;

[0050] Figure 6 This is the lateral ray fan pattern of the observation and aiming lens in Embodiment 2 of the present invention;

[0051] Figure 7 This is a schematic diagram of the observation and aiming lens in Embodiment 3 of the present invention;

[0052] Figure 8 This is a relative illumination diagram of the observation and aiming lens in Embodiment 3 of the present invention;

[0053] Figure 9 This is the lateral ray fan pattern of the observation and aiming lens in Embodiment 3 of the present invention;

[0054] Figure 10 This is a schematic diagram of the observation and aiming lens in Embodiment 4 of the present invention;

[0055] Figure 11 This is a relative illumination diagram of the viewing lens in Embodiment 4 of the present invention;

[0056] Figure 12 This is the lateral ray fan pattern of the observation and aiming lens in Embodiment 4 of the present invention;

[0057] Figure 13 This is a schematic diagram of the observation and aiming lens in Embodiment 5 of the present invention;

[0058] Figure 14 This is a relative illumination diagram of the viewing lens in Embodiment 5 of the present invention;

[0059] Figure 15 This is the lateral ray fan pattern of the observation and aiming lens in Embodiment 5 of the present invention. Detailed Implementation

[0060] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0061] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the first lens.

[0062] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0063] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0064] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0065] 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.

[0066] 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.

[0067] like Figures 1 to 15 As shown, an embodiment of the present invention provides an observation and aiming lens, which, along the optical axis from the object side to the image side, sequentially includes: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, and a protective flat glass CG, wherein the first lens L1 to the ninth lens L9 are all spherical lenses.

[0068] The first lens L1 has positive optical power, a convex object-side surface, and a concave image-side surface. The positive optical power of the first lens L1 facilitates light collection, causing the emitted light rays to converge towards the optical axis, reducing the aperture of the rear lens and thus contributing to miniaturization. The concave image-side surface of the first lens L1 helps reduce the angle of incidence of on-axis rays on the image-side surface, minimizing spherical aberration and promoting high image quality.

[0069] Optionally, the first lens L1 is made of a material with a high refractive index, which can reduce the surface curvature and reduce the generation of aberrations, thereby helping to achieve high image quality.

[0070] The second lens L2 has positive optical power, a convex object-side surface, and a concave image-side surface. This reduces the angle of incidence of on-axis rays on the image-side surface of the second lens L2, thereby reducing spherical aberration and contributing to high image quality. The second lens L2 can be paired with a low-dispersion material to reduce chromatic aberration, simplify system calibration, and further enhance image quality.

[0071] In some embodiments of the present invention, the third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens, or

[0072] The third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 together form a four-cemented lens.

[0073] The third lens L3 has negative optical power, a convex object-side surface, and a concave image-side surface. This helps to reduce the angle of incidence of on-axis rays on the object-side surface of the third lens L3, thereby reducing spherical aberration generated by the object-side surface of the third lens L3 and contributing to high image quality. The negative optical power of the third lens L3 in the cemented lens, combined with the fourth lens L4, achieves apochromatic aberration, which is beneficial for achieving high image quality.

[0074] The fourth lens L4 has positive optical power and a convex object-side surface. The fourth lens L4 shares the optical power, reducing surface curvature and aberrations, thus contributing to high image quality. In cemented lenses, the fourth lens L4's positive optical power allows for optimal pairing with low-dispersion materials to apochromatic the system, facilitating infrared confocalization and high / low temperature correction. Furthermore, the fourth lens L4 compensates for on-axis chromatic aberration generated by the first lens L1, promoting broadband chromatic aberration correction and achieving even higher image quality.

[0075] The fifth lens L5 has negative optical power and a concave image side. By sharing the optical power, the fifth lens L5 reduces surface curvature, minimizing aberrations and contributing to high image quality. In a cemented lens, the negative optical power of the fifth lens L5, combined with the fourth lens L4, achieves apochromatic aberration, further enhancing image quality. Optionally, the third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented third lens. The negative focal length of the cemented third lens generates negative spherical aberration, compensating for the positive spherical aberration introduced by the first lens L1 and the second lens L2, thus contributing to high image quality.

[0076] The sixth lens L6 has positive optical power, which reduces the angle of incidence of on-axis rays on the image side of the sixth lens L6, thereby reducing spherical aberration generated on the image side of the sixth lens L6 and contributing to high image quality. Optionally, the sixth lens L6 can be combined with a low-dispersion material to form a cemented four-element lens with the third lens L3, the fourth lens L4, and the fifth lens L5. The focal length of the cemented four-element lens is negative, producing negative spherical aberration, which compensates for the positive spherical aberration introduced by the first lens L1 and the second lens L2, contributing to high image quality and reducing system tolerance sensitivity.

[0077] In some embodiments of the present invention, the combined focal length Fa of the cemented triplet or cemented quadruplet lens and the effective focal length F of the observation lens satisfy the following relationship: -1.69 ≤ Fa / F ≤ -0.14. By reasonably allocating the focal length values ​​of the cemented triplet or cemented quadruplet lenses, the cemented lens group can compensate for the on-axis chromatic aberration generated by the first lens L1, which is beneficial for achieving infrared confocality; at the same time, making the focal length value of the cemented lens negative, generating negative spherical aberration, can compensate for the positive spherical aberration introduced by the first lens L1 and the second lens L2, which is beneficial for achieving high image quality.

[0078] In some embodiments of the present invention, the seventh lens L7 and the eighth lens L8 form a cemented doublet lens.

[0079] The seventh lens L7 has positive optical power, and its image side is convex while its object side can be either convex or concave. The seventh lens L7 and the eighth lens L8 are combined to form a cemented doublet, which can correct the remaining off-axis chromatic aberration of the system and is beneficial for achieving high image quality.

[0080] The eighth lens L8 has negative optical power, and its object side and image side are both concave. The eighth lens L8 has negative optical power in a cemented doublet, and when combined with the seventh lens L7, it achieves apochromatic effect, which is beneficial for achieving high image quality.

[0081] In some embodiments of the present invention, the combined focal length Fb of the cemented doublet lens and the effective focal length F of the sighting lens satisfy the following relationship: -0.30≤Fb / F≤-0.09. By rationally allocating the focal length values ​​of the cemented doublet lens group composed of the seventh lens L7 and the eighth lens L8, off-axis residual chromatic aberration can be corrected, which is beneficial to achieving high image quality.

[0082] The ninth lens, L9, has positive optical power, a convex object-side surface, and an image-side surface that can be concave or flat. The ninth lens can be made of materials with low dispersion, which can correct residual chromatic aberration in the system and contribute to achieving high image quality.

[0083] The first lens L1 to the sixth lens L6 together with the rear group form a telephoto structure, reducing the total optical length and facilitating miniaturization.

[0084] In some embodiments of the present invention, the effective focal length F1 of the first lens L1 and the effective focal length F of the observation lens satisfy the following relationship: 0.6≤F1 / F≤1.5, preferably, 0.68≤F1 / F≤1.33; by reasonably allocating the focal length value of the first lens L1, the first lens L1 can collect light, so that the light emitted from the first lens L1 is closer to the optical axis, which is beneficial to reducing the aperture of the rear lens and realizing miniaturization.

[0085] In some embodiments of the present invention, the effective focal length F2 of the second lens L2 and the effective focal length F of the observation lens satisfy the following relationship: 0.4≤F2 / F≤1.1; by reasonably allocating the focal length value of the second lens L2 and using low dispersion material, the generation of chromatic aberration can be reduced, the system calibration difficulty can be reduced, and high image quality can be achieved.

[0086] In some embodiments of the present invention, the effective focal length F3 of the third lens L3 and the effective focal length F of the observation lens satisfy the following relationship: -0.7≤F3 / F≤-0.2, preferably -0.55≤F3 / F≤-0.22; by reasonably allocating the focal length value of the third lens L3, the third lens L3 has negative optical power in the cemented triplet or cemented quadruplet lens, and works with the fourth lens L4 to achieve apochromatic effect, which is beneficial to achieving high image quality.

[0087] In some embodiments of the present invention, the effective focal length F4 of the fourth lens L4 and the effective focal length F of the observation lens satisfy the following relationship: 0.18≤F4 / F≤0.50, preferably, 0.20≤F4 / F≤0.41; by reasonably allocating the focal length value of the fourth lens L4, the fourth lens L4 has positive optical power in the cemented triplet or cemented quadruplet lens, and with the low dispersion material, the system is apochromatic, which is beneficial to achieving infrared confocal lens.

[0088] In some embodiments of the present invention, the effective focal length F5 of the fifth lens L5 and the effective focal length F of the observation lens satisfy the following relationship: -0.4≤F5 / F≤-0.1; by reasonably allocating the focal length value of the fifth lens L5, the fifth lens L5 has negative optical power in the cemented triplet or cemented quadruplet lens, and works with the fourth lens L4 to achieve apochromatic effect, which is beneficial to achieving high image quality.

[0089] In some embodiments of the present invention, the effective focal length F6 of the sixth lens L6 and the effective focal length F of the observation lens satisfy the following relationship: 0.2≤F6 / F≤2.0; by reasonably allocating the focal length value of the sixth lens L6, the sixth lens L6 has positive optical power in the four-cement lens, and with the low dispersion material, the system is apochromatic, which is beneficial to achieving infrared confocal.

[0090] In some embodiments of the present invention, the effective focal length F7 of the seventh lens L7 and the effective focal length F of the observation lens satisfy the following relationship: 0.09≤F7 / F≤0.30; by reasonably allocating the focal length value of the seventh lens L7, the seventh lens L7 has positive optical power in the cemented doublet lens, and with the low dispersion material, the system is apochromatic, which is beneficial to achieving infrared confocal.

[0091] In some embodiments of the present invention, the effective focal length F8 of the eighth lens L8 and the effective focal length F of the observation lens satisfy the following relationship: -0.15≤F8 / F≤-0.02; the eighth lens L8 has negative optical power in the cemented doublet lens, and works with the seventh lens L7 to achieve apochromatic effect, which is beneficial to achieving high image quality.

[0092] In some embodiments of the present invention, the combined effective focal length F16 of the first lens L1 to the sixth lens L6 and the effective focal length F of the observation lens satisfy the following relationship: 0.4≤F16 / F≤0.7, preferably, 0.49≤F16 / F≤0.68; by reasonably allocating the combined effective focal length of the first lens L1 to the sixth lens L6, so that it forms a telephoto architecture with the rear group, it is beneficial to reduce the total optical length and achieve miniaturization.

[0093] In some embodiments of the present invention, the refractive index ND1 of the first lens L1 satisfies the following relationship: 1.85≤ND1≤1.98; by reasonably setting the refractive index of the first lens L1, the first lens L1 can preferably be made of a material with a larger refractive index, reduce the surface curvature, reduce the generation of aberrations, and facilitate the achievement of high image quality.

[0094] In some embodiments of the present invention, the Abbe number VD4 of the fourth lens L4 satisfies the following relationship: 60≤VD4≤100, preferably 75.46≤VD4≤94.36; by reasonably setting the Abbe number of the fourth lens L4, the fourth lens L4 can preferably be made of a material with a larger Abbe number, which is beneficial for chromatic aberration and high and low temperature correction, achieving non-defocusing within a temperature range of -30 to 70℃, while reducing infrared defocusing and improving the resolution of visible and infrared light.

[0095] In some embodiments of the present invention, the effective focal length F of the sighting lens and the entrance pupil diameter ENPD satisfy the following relationship: 2.9≤F / ENPD≤3.1; by controlling the size of the system entrance pupil diameter, the system has a smaller aperture value, which is beneficial to achieving a large aperture.

[0096] In some embodiments of the present invention, the maximum aperture Dmax of the viewing lens and the total optical length TTL satisfy the following relationship: 0.39≤Dmax / TTL≤0.50; under a certain total optical length of the system, by controlling the maximum aperture of the system, the maximum aperture of the system is made smaller, which is beneficial to miniaturization.

[0097] In some embodiments of the present invention, the total optical length (TTL) and back focal length (BFL) of the viewing lens satisfy the following relationship: 0.1 ≤ BFL / TTL ≤ 0.3, preferably 0.16 ≤ BFL / TTL ≤ 0.30. On the basis of miniaturization, by controlling the optical back focal length of the system, it is beneficial to take into account cameras with different interfaces, improve the versatility of the lens, and at the same time help to reserve space for the installation of optical components.

[0098] In some embodiments of the present invention, the radius of curvature R32 of the image side surface of the third lens L3 and the radius of curvature R52 of the image side surface of the fifth lens L5 satisfy the following relationship: 0.12≤R32 / R52≤1.2; by reasonably controlling the radius of curvature of the image side surface of the third lens L3 and the image side surface of the fifth lens L5, it is beneficial to smooth the incident light rays and reduce the risk of strong energy ghost images caused by off-axis edge rays.

[0099] The following five specific embodiments of the observation and aiming lens according to the present invention are given to specifically illustrate the observation and aiming lens according to the present invention. The observation and aiming lens according to the present invention has a total of nine lenses, each cemented surface of the cemented lens is referred to as one surface, plus the protective glass CG and the image plane IMA, for a total of 17 or 18 surfaces. Among them, the aperture stop STO is disposed between the first lens L1 and the second lens L2.

[0100] The data for the five sets of examples are shown in Table 1 below:

[0101] Conditional expression Example 1 Example 2 Example 3 Example 4 Example 5 0.6 ≤ F1 / F ≤ 1.5 1.271 0.811 0.837 0.907 0.734 0.4 ≤ F² / F ≤ 1.1 0.671 0.540 0.534 0.848 0.712 -0.7≤F3 / F≤-0.2 -0.500 -0.301 -0.273 -0.398 -0.343 0.18≤F4 / F≤0.50 0.298 0.282 0.238 0.333 0.271 -0.4≤F5 / F≤-0.1 -0.283 -0.228 -0.170 -0.204 -0.343 0.2≤F6 / F≤2.0 0.775 0.547 0.358 0.298 1.932 0.09≤F7 / F≤0.30 0.215 0.143 0.151 0.194 0.187 -0.15≤F8 / F≤-0.02 -0.083 -0.072 -0.091 -0.098 -0.083 -1.69≤Fa / F≤-0.14 -0.510 -0.245 -0.193 -0.853 -0.507 -0.30≤Fb / F≤-0.09 -0.142 -0.164 -0.246 -0.200 -0.151 0.4 ≤ F16 / F ≤ 0.7 0.548 0.617 0.625 0.582 0.591 1.85≤ND1≤1.98 1.923 1.923 1.923 1.923 1.923 60≤VD4≤100 75.510 81.610 75.510 81.610 94.520 2.9 ≤ F / ENPD ≤ 3.1 3.000 3.000 3.000 3.000 3.000 0.39≤Dmax / TTL≤0.50 0.440 0.440 0.440 0.441 0.445 0.1 ≤ BFL / TTL ≤ 0.3 0.220 0.250 0.221 0.220 0.218 0.12 ≤ R3² / R5² ≤ 1.2 0.664 0.671 0.900 1.009 0.176

[0102] Table 1

[0103] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The embodiments cannot be described in detail here, but the embodiments of the present invention are not limited to the following embodiments.

[0104] Example 1

[0105] Figure 1 This is a schematic diagram of the observation and aiming lens in Embodiment 1 of the present invention;

[0106] Figure 2 This is a relative illumination diagram of the observation and aiming lens in Embodiment 1 of the present invention;

[0107] Figure 3 This is a lateral ray fan pattern of the observation and aiming lens in Embodiment 1 of the present invention.

[0108] In Embodiment 1, the first lens L1 is a convex-concave lens with positive optical power, the second lens L2 is a convex-concave lens with positive optical power, the third lens L3 is a convex-concave lens with negative optical power, the fourth lens L4 is a convex-convex lens with positive optical power, the fifth lens L5 is a concave-concave lens with negative optical power, the sixth lens L6 is a convex-concave lens with positive optical power, the seventh lens L7 is a convex-convex lens with positive optical power, the eighth lens L8 is a concave-concave lens with negative optical power, and the ninth lens L9 is a convex-flat lens with positive optical power.

[0109] The first lens L1 to the ninth lens L9 are all spherical lenses; the aperture STO is located between the first lens L1 and the second lens L2.

[0110] The third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens; the seventh lens L7 and the eighth lens L8 form a cemented doublet lens.

[0111] Table 2 lists the relevant parameters of each lens in the observation and aiming lens of this embodiment, including: surface type, radius of curvature R, thickness d, refractive index Nd of the material and Abbe number Vd.

[0112] Surface serial number Surface type radius of curvature R Thickness d Refractive index Nd Abbe number Vd S1 spherical 163.892 4.387 1.923 20.9 S2 spherical 535.010 4.000 STO aperture Infinity -3.900 S3 spherical 65.638 9.998 1.593 68.3 S4 spherical 365.967 0.970 S5 spherical 72.149 2.503 1.750 35.0 S6 spherical 36.138 14.315 1.550 75.5 S7 spherical -283.118 2.000 1.805 25.5 S8 spherical 54.389 11.039 S9 spherical 39.131 4.124 1.870 20.0 S10 spherical 52.393 39.699 S11 spherical 121.874 3.363 1.785 25.7 S12 spherical -46.106 2.000 1.954 32.3 S13 spherical 24.639 19.329 S14 spherical 36.485 3.172 1.673 32.2 S15 spherical Infinity 30.999 S16 spherical Infinity 1.500 1.517 64.2 S17 spherical Infinity 0.500 IMA Image Infinity - -

[0113] Table 2

[0114] Combination Figures 1 to 3 As shown in Tables 1 and 2 above, in Embodiment 1, the absolute value of the distortion of the viewing lens is 0.01%, the half field of view is 1.18°, the half image height is 4.08, and the total optical length (TTL) is 150mm.

[0115] This embodiment is a sighting lens that has at least one of the following characteristics: ultra-long focal length, miniaturization, wide spectrum (430nm~940nm), high resolution, low chromatic aberration, good thermal stability (-30~70℃), full field of view illumination ≥99%, and lens principal ray incident angle CRA<1.0°.

[0116] Example 2

[0117] Figure 4 This is a schematic diagram of the observation and aiming lens in Embodiment 2 of the present invention;

[0118] Figure 5 This is a relative illumination diagram of the viewing lens in Embodiment 2 of the present invention;

[0119] Figure 6 This is a lateral ray fan pattern of the observation and aiming lens in Embodiment 2 of the present invention.

[0120] In Embodiment 2, the first lens L1 is a convex-concave lens with positive optical power, the second lens L2 is a convex-concave lens with positive optical power, the third lens L3 is a convex-concave lens with negative optical power, the fourth lens L4 is a convex-convex lens with positive optical power, the fifth lens L5 is a concave-concave lens with negative optical power, the sixth lens L6 is a convex-concave lens with positive optical power, the seventh lens L7 is a convex-convex lens with positive optical power, the eighth lens L8 is a concave-concave lens with negative optical power, and the ninth lens L9 is a convex-concave lens with positive optical power.

[0121] The first lens L1 to the ninth lens L9 are all spherical lenses; the aperture STO is located between the first lens L1 and the second lens L2.

[0122] The third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens; the seventh lens L7 and the eighth lens L8 form a cemented doublet lens.

[0123] Table 3 lists the relevant parameters of each lens in the observation and aiming lens of this embodiment, including: surface type, radius of curvature R, thickness d, refractive index Nd of the material and Abbe number Vd.

[0124] Surface serial number Surface type radius of curvature R Thickness d Refractive index Nd Abbe number Vd S1 spherical 120.540 5.718 1.923 20.9 S2 spherical 603.896 4.000 STO aperture Infinity -3.900 S3 spherical 49.463 11.160 1.589 61.3 S4 spherical 208.291 0.100 S5 spherical 101.842 2.039 1.801 35.0 S6 spherical 32.387 15.140 1.497 81.6 S7 spherical -165.291 5.790 1.808 22.7 S8 spherical 48.289 3.788 S9 spherical 42.632 5.073 1.923 20.9 S10 spherical 69.551 40.296 S11 spherical 112.370 4.165 1.847 23.8 S12 spherical -30.255 3.706 1.954 32.3 S13 spherical 26.756 12.232 S14 spherical 36.102 3.125 1.673 32.2 S15 spherical 607.552 35.566 S16 spherical Infinity 1.500 1.517 64.2 S17 spherical Infinity 0.500 IMA Image Infinity - -

[0125] Table 3

[0126] Combination Figures 4 to 6 As shown in Tables 1 and 3 above, in Embodiment 2, the absolute value of the distortion of the viewing lens is 0.05%, the half field of view is 1.18°, the half image height is 4.08, and the total optical length (TTL) is 150mm.

[0127] This second embodiment is a sighting lens that has at least one of the following characteristics: ultra-long focal length, miniaturization, wide spectrum (430nm~940nm), high resolution, low chromatic aberration, good thermal stability (-30~70℃), full field of view illumination ≥99%, and lens principal ray incident angle CRA<1.0°.

[0128] Example 3

[0129] Figure 7 This is a schematic diagram of the observation and aiming lens in Embodiment 3 of the present invention;

[0130] Figure 8 This is a relative illumination diagram of the observation and aiming lens in Embodiment 3 of the present invention;

[0131] Figure 9 This is a lateral ray fan pattern of the observation and aiming lens in Embodiment 3 of the present invention.

[0132] In Embodiment 3, the first lens L1 is a convex-concave lens with positive optical power, the second lens L2 is a convex-concave lens with positive optical power, the third lens L3 is a convex-concave lens with negative optical power, the fourth lens L4 is a convex-convex lens with positive optical power, the fifth lens L5 is a concave-concave lens with negative optical power, the sixth lens L6 is a convex-concave lens with positive optical power, the seventh lens L7 is a convex-convex lens with positive optical power, the eighth lens L8 is a concave-concave lens with negative optical power, and the ninth lens L9 is a convex-concave lens with positive optical power.

[0133] The first lens L1 to the ninth lens L9 are all spherical lenses; the aperture STO is located between the first lens L1 and the second lens L2.

[0134] The third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens; the seventh lens L7 and the eighth lens L8 form a cemented doublet lens.

[0135] Table 4 lists the relevant parameters of each lens in the observation and aiming lens of this embodiment, including: surface type, radius of curvature R, thickness d, refractive index Nd of the material and Abbe number Vd.

[0136]

[0137]

[0138] Table 4

[0139] Combination Figures 7 to 9 As shown in Tables 1 and 4 above, in Embodiment 3, the absolute value of the distortion of the viewing lens is 0.07%, the half field of view is 1.18°, the half image height is 4.08, and the total optical length (TTL) is 150mm.

[0140] This third embodiment is a sighting lens that has at least one of the following characteristics: ultra-long focal length, miniaturization, wide spectrum (430nm~940nm), high resolution, low chromatic aberration, good thermal stability (-30~70℃), full field of view illumination ≥99%, and lens principal ray incident angle CRA<1.0°.

[0141] Example 4

[0142] Figure 10 This is a schematic diagram of the observation and aiming lens in Embodiment 4 of the present invention;

[0143] Figure 11 This is a relative illumination diagram of the viewing lens in Embodiment 4 of the present invention;

[0144] Figure 12 This is a lateral ray fan pattern of the observation and aiming lens in Embodiment 4 of the present invention.

[0145] In Embodiment 4, the first lens L1 is a convex-concave lens with positive optical power, the second lens L2 is a convex-concave lens with positive optical power, the third lens L3 is a convex-concave lens with negative optical power, the fourth lens L4 is a convex-concave lens with positive optical power, the fifth lens L5 is a convex-concave lens with negative optical power, the sixth lens L6 is a convex-concave lens with positive optical power, the seventh lens L7 is a concave-convex lens with positive optical power, the eighth lens L8 is a concave-concave lens with negative optical power, and the ninth lens L9 is a convex-flat lens with positive optical power.

[0146] The first lens L1 to the ninth lens L9 are all spherical lenses; the aperture STO is located between the first lens L1 and the second lens L2.

[0147] The third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 form a cemented four-layer lens; the seventh lens L7 and the eighth lens L8 form a cemented two-layer lens.

[0148] Table 5 lists the relevant parameters of each lens in the observation and aiming lens of this embodiment, including: surface type, radius of curvature R, thickness d, refractive index Nd of the material and Abbe number Vd.

[0149]

[0150]

[0151] Table 5

[0152] Combination Figures 10 to 12 As shown in Tables 1 and 5 above, in Embodiment 4, the absolute value of the distortion of the viewing lens is 0.06%, the half field of view is 1.18°, the half image height is 4.08, and the total optical length (TTL) is 150mm.

[0153] This fourth embodiment is a sighting lens that has at least one of the following characteristics: ultra-long focal length, miniaturization, wide spectrum (430nm~940nm), high resolution, low chromatic aberration, good thermal stability (-30~70℃), full field of view illumination ≥99%, and lens principal ray incident angle CRA<1.0°.

[0154] Example 5

[0155] Figure 13 This is a schematic diagram of the observation and aiming lens in Embodiment 5 of the present invention;

[0156] Figure 14 This is a relative illumination diagram of the viewing lens in Embodiment 5 of the present invention;

[0157] Figure 15 This is the lateral ray fan pattern of the observation and aiming lens in Embodiment 5 of the present invention.

[0158] In Embodiment 5, the first lens L1 is a convex-concave lens with positive optical power, the second lens L2 is a convex-concave lens with positive optical power, the third lens L3 is a convex-concave lens with negative optical power, the fourth lens L4 is a convex-convex lens with positive optical power, the fifth lens L5 is a concave-concave lens with negative optical power, the sixth lens L6 is a concave-convex lens with positive optical power, the seventh lens L7 is a concave-convex lens with positive optical power, the eighth lens L8 is a concave-concave lens with negative optical power, and the ninth lens L9 is a convex-concave lens with positive optical power.

[0159] The first lens L1 to the ninth lens L9 are all spherical lenses; the aperture STO is located between the first lens L1 and the second lens L2.

[0160] The third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens; the seventh lens L7 and the eighth lens L8 form a cemented doublet lens.

[0161] Table 6 lists the relevant parameters of each lens in the observation and aiming lens of this embodiment, including: surface type, radius of curvature R, thickness d, refractive index Nd of the material and Abbe number Vd.

[0162] Surface serial number Surface type radius of curvature R Thickness d Refractive index Nd Abbe number Vd S1 spherical 72.615 6.630 1.923 20.9 S2 spherical 152.174 4.666 STO aperture Infinity 0.100 S3 spherical 60.560 8.069 1.613 44.1 S4 spherical 190.575 0.100 S5 spherical 88.739 2.000 1.728 28.3 S6 spherical 31.467 17.935 1.438 94.5 S7 spherical -79.162 2.000 1.805 25.5 S8 spherical 178.574 4.793 S9 spherical -113.958 3.290 1.523 58.6 S10 spherical -73.448 45.496 S11 spherical -126.918 3.460 1.801 35.0 S12 spherical -24.336 2.000 1.729 54.7 S13 spherical 24.798 13.733 S14 spherical 36.665 3.079 1.673 32.2 S15 spherical 5479.318 30.648 S16 spherical Infinity 1.500 1.517 64.2 S17 spherical Infinity 0.500 IMA Image Infinity - -

[0163] Table 6

[0164] Combination Figures 13 to 15As shown in Tables 1 and 6 above, in Embodiment 5, the absolute value of the distortion of the viewing lens is 0.06%, the half field of view is 1.17°, the half image height is 4.08, and the total optical length (TTL) is 150mm.

[0165] This fifth embodiment is a sighting lens that has at least one of the following characteristics: ultra-long focal length, miniaturization, wide spectrum (430nm~940nm), high resolution, low chromatic aberration, good thermal stability (-30~70℃), full field of view illumination ≥99%, and lens principal ray incident angle CRA<1.0°.

[0166] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A sighting lens, characterized by, In the direction from the object side to the image side along the optical axis, in order, include: 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, a fifth lens (L5) with negative refractive power, a sixth lens (L6) with positive refractive power, a seventh lens (L7) with positive refractive power, an eighth lens (L8) with negative refractive power, and a ninth lens (L9) with positive refractive power, and the total number of lenses with refractive power is nine; An effective focal length F6 of the sixth lens (L6) and an effective focal length F of the viewing and sighting lens satisfy the following relationship: 0.298≤F6 / F≤2.

0. An effective focal length F7 of the seventh lens (L7) and the effective focal length F of the viewing and sighting lens satisfy the following relationship: 0.09≤F7 / F≤0.

30.

2. The viewing lens of claim 1, wherein The first lens (L1) is a convex-concave lens, the second lens (L2) is a convex-concave lens, the third lens (L3) is a convex-concave lens, the object side surface of the fourth lens (L4) is a convex surface, and the image side surface of the fifth lens (L5) is a concave surface.

3. The viewing lens of claim 1, wherein The image side surface of the seventh lens (L7) is a convex surface, the eighth lens (L8) is a concave-concave lens, and the object side surface of the ninth lens (L9) is a convex surface.

4. The viewing optic of claim 1, wherein, The third lens (L3), the fourth lens (L4), and the fifth lens (L5) form a three-lens cemented lens, or The third lens (L3), the fourth lens (L4), the fifth lens (L5), and the sixth lens (L6) form a four-lens cemented lens.

5. The viewing optic of claim 4, wherein, A combined focal length Fa of the three-lens cemented lens or the four-lens cemented lens and the effective focal length F of the viewing and sighting lens satisfy the following relationship: -1.69≤Fa / F≤-0.

14.

6. The viewing lens of claim 1, wherein, The seventh lens (L7) and the eighth lens (L8) form a two-lens cemented lens.

7. The viewing optic of claim 6, wherein, A combined focal length Fb of the two-lens cemented lens and the effective focal length F of the viewing and sighting lens satisfy the following relationship: -0.30≤Fb / F≤-0.

09.

8. The viewing lens of any one of claims 1-7, wherein, An effective focal length F1 of the first lens (L1) and the effective focal length F of the viewing and sighting lens satisfy the following relationship: 0.6≤F1 / F≤1.

5.

9. The viewing optic of any of claims 1-7, wherein, An effective focal length F2 of the second lens (L2) and the effective focal length F of the viewing and sighting lens satisfy the following relationship: 0.4≤F2 / F≤1.

1.

10. The viewing optic of any of claims 1-7, wherein, An effective focal length F3 of the third lens (L3) and the effective focal length F of the viewing and sighting lens satisfy the following relationship: -0.7≤F3 / F≤-0.

2.

11. The viewing optic of any of claims 1-7, wherein, An effective focal length F4 of the fourth lens (L4) and the effective focal length F of the viewing and sighting lens satisfy the following relationship: 0.18≤F4 / F≤0.

50.

12. The viewing optic of any of claims 1-7, wherein, An effective focal length F5 of the fifth lens (L5) and the effective focal length F of the viewing and sighting lens satisfy the following relationship: -0.4≤F5 / F≤-0.

1.

13. The sighting lens of any one of claims 1-7, wherein, An effective focal length F8 of the eighth lens (L8) and the effective focal length F of the viewing and sighting lens satisfy the following relationship: -0.15≤F8 / F≤-0.

02.

14. The viewing optic of any of claims 1-7, wherein, A combination effective focal length F16 of the first lens (L1) to the sixth lens (L6) and an effective focal length F of the sighting lens satisfy the following relationship: 0.4≤F16 / F≤0.

7.

15. The viewing optic of any of claims 1-7, wherein, A refractive index ND1 of the first lens (L1) satisfies the following relationship: 1.85≤ND1≤1.

98.

16. The viewing optic of any of claims 1-7, wherein, An Abbe number VD4 of the fourth lens (L4) satisfies the following relationship: 60≤VD4≤100.

17. The viewing optic of any of claims 1-7, wherein, An effective focal length F of the sighting lens and an entrance pupil diameter ENPD satisfy the following relationship: 2.9≤F / ENPD≤3.

1.

18. The viewing optic of any of claims 1-7, wherein, A maximum light passing full aperture Dmax of the sighting lens and an optical total length TTL satisfy the following relationship: 0.39≤Dmax / TTL≤0.

50.

19. The viewing optic of any of claims 1-7, wherein, An optical total length TTL of the sighting lens and a back focal length BFL satisfy the following relationship: 0.1≤BFL / TTL≤0.

3.

20. The viewing optic of any of claims 1-7, wherein, A curvature radius R32 of an image side surface of the third lens (L3) and a curvature radius R52 of an image side surface of the fifth lens (L5) satisfy the following relationship: 0.12≤R32 / R52≤1.

2.

21. The viewing optic of claim 1, wherein, The sighting lens at least satisfies one of the following conditions: 0.68≤F1 / F≤1.33, -0.55≤F3 / F≤-0.22, 0.20≤F4 / F≤0.41, 0.49≤F16 / F≤0.68, 75.46≤VD4≤94.36, 0.16≤BFL / TTL≤0.30, wherein TTL is an optical total length of the sighting lens, F is an effective focal length of the sighting lens, BFL is a back focal length of the sighting lens, F1 is an effective focal length of the first lens (L1), F3 is an effective focal length of the third lens (L3), F4 is an effective focal length of the fourth lens (L4), F16 is a combination effective focal length of the first lens (L1) to the sixth lens (L6), and VD4 is an Abbe number of the fourth lens (L4).

Images