Observing and aiming lens

Abstract

The utility model relates to an observing and aiming lens, which sequentially comprises a first lens with positive focal power, a second lens with positive focal power, a third lens with negative focal power, a fourth lens with positive focal power, a fifth lens with negative focal power, a sixth lens, a seventh lens and an eighth lens with negative focal power along an optical axis from an object side to an image side, the focal power of the sixth lens is opposite to that of the seventh lens; the second lens, the third lens, the fourth lens and the fifth lens form a first cemented lens. The sighting lens at least has one of the characteristics of small volume, long optical total length, high resolution, high image quality, capability of realizing infrared confocal sighting lens and the like.

Description

Technical Field

[0001] This utility model relates to the field of lens technology, and in particular to a viewing and aiming lens. Background Technology

[0002] Sighting lenses, also known as scopes or sniper scopes, allow users to see targets more clearly. Generally speaking, there are four main technical requirements for sighting lenses: 1) As handheld products, sighting lenses need to be lightweight and compact, thus requiring miniaturization; 2) Sighting lenses are primarily used for observing object details, therefore requiring a long focal length; 3) To meet the needs of nighttime observation, infrared confocal technology is required; 4) To meet the requirements of use in low-light conditions, sighting lenses need to achieve high resolution across a wide spectral range, thus requiring correction of wide-spectral chromatic aberration.

[0003] However, existing observation and aiming lenses still have the following shortcomings:

[0004] 1. Existing technology struggles to balance lens aperture and high image quality;

[0005] 2. Existing technologies struggle to balance a long focal length with a small size;

[0006] 3. Existing technologies make it difficult to achieve infrared confocal focusing;

[0007] 4. Existing technologies cannot achieve high resolution over a wide spectral range (430-940nm). Utility Model Content

[0008] To address the problems existing in the prior art, the purpose of this utility model is to provide a viewing and aiming lens that has at least one of the following characteristics: small size, short total optical length, high resolution, high image quality, and the ability to achieve infrared confocal focus.

[0009] To achieve the above-mentioned utility model objectives, this utility model provides an observation and aiming lens, which, along the optical axis from the object side to the image side, sequentially includes: a first lens with positive optical power, a second lens with positive optical power, a third lens with negative optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens, a seventh lens, and an eighth lens with negative optical power, wherein the optical powers of the sixth lens and the seventh lens are opposite;

[0010] The second lens, the third lens, the fourth lens, and the fifth lens constitute the first cemented lens.

[0011] According to one technical solution of this utility model, the first lens is a convex-concave lens;

[0012] The object-side surface of the second lens is convex.

[0013] The image-side surface of the third lens is concave;

[0014] The fourth lens is a convex-convex lens;

[0015] The fifth lens is a concave-convex lens;

[0016] The image-side surface of the seventh lens is convex.

[0017] The eighth lens is a concave-convex lens.

[0018] According to one technical solution of this utility model, the sixth lens and the seventh lens constitute a second cemented lens.

[0019] According to one technical solution of this utility model, the focal length value FB2 of the second cemented lens and the total focal length value F of the viewing lens satisfy the following relationship: 0.25≤FB2 / F≤0.50.

[0020] According to one technical solution of this utility model, the refractive index Nd(B2) of at least one lens in the second cemented lens satisfies the following relationship: 1.90≤Nd(B2)≤2.10.

[0021] According to one technical solution of this utility model, the Abbe number Vd(B2) of at least one lens in the second cemented lens satisfies the following relationship: 20.00≤Vd(B2)≤35.00.

[0022] According to one technical solution of this utility model, the total optical length TTL of the observation and aiming lens and the total focal length F of the observation and aiming lens satisfy the following relationship: 1.00≤TTL / F≤1.50.

[0023] According to one technical solution of this utility model, the focal length F1 of the first lens and the total focal length F of the observation lens satisfy the following relationship: 0.83≤F1 / F≤1.60.

[0024] According to one technical solution of this utility model, the focal length F2 of the second lens and the total focal length F of the viewing lens satisfy the following relationship: 0.37≤F2 / F≤1.51.

[0025] According to one technical solution of this utility model, the focal length F3 of the third lens and the total focal length F of the observation lens satisfy the following relationship: -0.41≤F3 / F≤-0.10.

[0026] According to one technical solution of this utility model, the focal length F4 of the fourth lens and the total focal length F of the observation lens satisfy the following relationship: 0.15≤F4 / F≤0.45.

[0027] According to one technical solution of this utility model, the focal length F5 of the fifth lens and the total focal length F of the observation lens satisfy the following relationship: -0.42≤F5 / F≤-0.15.

[0028] According to one technical solution of this utility model, the focal length F6 of the sixth lens and the total focal length F of the observation lens satisfy the following relationship: -1.86≤F6 / F≤0.60.

[0029] According to one technical solution of this utility model, the focal length F7 of the seventh lens and the total focal length F of the observation lens satisfy the following relationship: -1.51≤F7 / F≤0.55.

[0030] According to one technical solution of this utility model, the focal length F8 of the eighth lens and the total focal length F of the observation lens satisfy the following relationship: -0.79≤F8 / F≤-0.10.

[0031] According to one technical solution of this utility model, the focal length value FB1 of the first cemented lens and the total focal length value F of the viewing lens satisfy the following relationship: -1.82≤FB1 / F≤-0.65.

[0032] According to one technical solution of this utility model, the focal length F2 of the second lens and the focal length FB1 of the first cemented lens satisfy the following relationship: -1.71≤F2 / FB1≤-0.11.

[0033] According to one technical solution of this utility model, the combined focal length value F15 of the first lens to the fifth lens and the combined focal length value F68 of the sixth lens to the eighth lens satisfy the following relationship: 1.69≤F15 / F68≤6.00.

[0034] According to one technical solution of this utility model, the focal length F17 of the first lens to the seventh lens and the focal length F8 of the eighth lens satisfy the following relationship: -1.50≤F17 / F8≤-0.50.

[0035] According to one technical solution of this utility model, the refractive index Nd(B1) of at least one lens in the first cemented lens satisfies the following relationship: 1.75≤Nd(B1)≤1.95.

[0036] According to one technical solution of this utility model, the Abbe number Vd(B1) of at least one lens in the first cemented lens satisfies the following relationship: 19.67≤Vd(B1)≤45.00.

[0037] According to one technical solution of this utility model, the optical back focal length (BFL) of the observation and aiming lens and the optical total length (TTL) of the observation and aiming lens satisfy the following relationship: 0.14≤BFL / TTL≤0.32.

[0038] According to one technical solution of this utility model, the maximum aperture Dmax of the observation and aiming lens and the total optical length TTL of the observation and aiming lens satisfy the following relationship: 0.35≤Dmax / TTL≤0.66.

[0039] According to one technical solution of this utility model, the observation and aiming lens satisfies at least one of the following conditions:

[0040] 1.06≤TTL / F≤1.30

[0041] 0.83≤F1 / F≤1.38

[0042] 0.46≤F² / F≤1.42

[0043] -0.41≤F3 / F≤-0.19,

[0044] 0.21≤F4 / F≤0.35

[0045] -0.42≤F5 / F≤-0.23,

[0046] -1.60≤F6 / F≤0.34,

[0047] -1.3≤F7 / F≤0.34,

[0048] -0.79≤F8 / F≤-0.42,

[0049] -1.72≤FB1 / F≤-0.74,

[0050] -1.56≤F2 / FB1≤-0.26,

[0051] 2.16≤F15 / F68≤5.42

[0052] -1.43≤F17 / F8≤-0.93,

[0053] 0.3≤FB² / F≤0.48

[0054] 1.95≤Nd(B2)≤2.06,

[0055] 24.94≤Vd(B2)≤28.81,

[0056] 0.35≤Dmax / TTL≤0.51

[0057] Wherein, TTL is the total optical length of the sighting lens; F is the total focal length of the sighting lens; F1 is the focal length of the first lens; F2 is the focal length of the second lens; F3 is the focal length of the third lens; F4 is the focal length of the fourth lens; F5 is the focal length of the fifth lens; F6 is the focal length of the sixth lens; F7 is the focal length of the seventh lens; F8 is the focal length of the eighth lens; FB1 is the focal length of the first cemented lens; F15 is the combined focal length of the first to the fifth lens; and F68 is the combined focal length of the sixth to the eighth lens. Combined focal length values; F17 is the focal length value of the first lens to the seventh lens; FB2 is the focal length value of the second cemented lens composed of the sixth lens and the seventh lens; Nd(B1) is the refractive index of at least one lens in the first cemented lens; Vd(B1) is the refractive index of at least one lens in the first cemented lens; Nd(B2) is the refractive index of at least one lens in the second cemented lens; Vd(B2) is the refractive index of at least one lens in the second cemented lens; BFL is the optical back focal length of the observation lens; Dmax is the maximum aperture of the observation lens.

[0058] According to the present invention, by setting the number and focal length of the viewing lenses, the ultra-wide-angle lens can achieve at least one of the following beneficial effects: small size and short total optical length; resolution up to 4K, with the advantage of high image quality; and infrared confocal focusing. Attached Figure Description

[0059] To more clearly illustrate the embodiments of this utility model or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0060] Figure 1 This is a schematic diagram of the observation and aiming lens in Embodiment 1 of this utility model;

[0061] Figure 2 This is a Ray Fan diagram of the observation and aiming lens in Embodiment 1 of this utility model;

[0062] Figure 3 This is a schematic diagram of the observation and aiming lens in Embodiment 2 of this utility model;

[0063] Figure 4 This is a Ray Fan diagram of the viewing and aiming lens in Embodiment 2 of this utility model;

[0064] Figure 5This is a schematic diagram of the observation and aiming lens in Embodiment 3 of this utility model;

[0065] Figure 6 This is a Ray Fan diagram of the viewing and aiming lens in Embodiment 3 of this utility model;

[0066] Figure 7 This is a schematic diagram of the observation and aiming lens in Embodiment 4 of this utility model;

[0067] Figure 8 This is a Ray Fan diagram of the viewing and aiming lens in Embodiment 4 of this utility model;

[0068] Figure 9 This is a schematic diagram of the observation and aiming lens in Embodiment 5 of this utility model;

[0069] Figure 10 Ray Fan diagram of the viewing and aiming lens in Embodiment 5 of this utility model;

[0070] Figure 11 This is a schematic diagram of the observation and aiming lens in Embodiment Six of this utility model;

[0071] Figure 12 This is a Ray Fan diagram of the observation and aiming lens in Embodiment Six of this utility model. Detailed Implementation

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] like Figures 1 to 12 As shown, an embodiment of this utility model 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 with positive optical power, a second lens L2 with positive optical power, a third lens L3 with negative optical power, a fourth lens L4 with positive optical power, a fifth lens L5 with negative optical power, a sixth lens L6, a seventh lens L7, an eighth lens L8 with negative optical power, and an image plane IMA. The optical powers of the sixth lens L6 and the seventh lens L7 are opposite.

[0080] In this embodiment of the present invention, the first lens L1 is a convex-concave lens with positive optical power. The positive optical power of the first lens L1 causes the light rays emitted from the first lens L1 to be closer to the optical axis, reducing the aperture of the rear lens and facilitating miniaturization. The convex-concave shape of the first lens L1 allows the incident angle of light rays on the object side of the first lens L1 to be smaller, reducing the aberrations generated by the first lens L1 and facilitating the achievement of high image quality.

[0081] The object-side surface of the second lens L2 is convex and has positive optical power. The convexity of the object-side surface of the second lens L2 reduces the angle of incidence of on-axis rays on the image-side surface of the second lens L2, thereby reducing spherical aberration generated on the image-side surface and contributing to high image quality. The positive optical power of the second lens L2, combined with the third lens L3, fourth lens L4, and fifth lens L5, enables the correction of apochromatic and spherical aberration, further contributing to high image quality and broad-spectrum apochromatic correction.

[0082] The image-side surface of the third lens L3 is concave and has negative optical power. The concave image-side surface of the third lens L3 helps to reduce aberrations and achieve high image quality. The negative optical power of the third lens L3, together with the second lens L2, the fourth lens L4 and the fifth lens L5, can correct apochromatic and spherical aberration, which is beneficial to achieving high image quality and also beneficial to wide-spectrum apochromatic correction.

[0083] The fourth lens L4 is a convex-convex lens with positive optical power. Both the object side and the image side of the fourth lens L4 are convex, which share the optical power, reduce the surface curvature, reduce the generation of aberrations, and help to achieve high image quality. The fourth lens L4 has positive optical power and, together with the second lens L2, the third lens L3 and the fifth lens L5, can achieve the correction of apochromatic and spherical aberration, which is conducive to achieving high image quality.

[0084] The fifth lens L5 is a concave lens with negative optical power. Both the object side and the image side of the fifth lens L5 are concave, which share the optical power, reduce the surface curvature, and reduce the generation of aberrations, which is conducive to achieving high image quality. The fifth lens L5 has negative optical power, and together with the second lens L2, the third lens L3 and the fourth lens L4, it can correct apochromatic and spherical aberration, which is conducive to achieving high image quality.

[0085] The sixth lens, L6, can be a convex-convex, plano-convex, or plano-concave lens. The object-side and image-side surfaces of the sixth lens, L6, share the optical power, reducing surface curvature and aberrations, thus contributing to high image quality. Its optical power can be set to positive or negative. The seventh lens, L7, has a convex image-side surface, which helps correct field curvature, astigmatism, and other off-axis aberrations, achieving high image quality.

[0086] The sixth lens L6 and the seventh lens L7 have opposite optical powers; the sixth lens L6 and the seventh lens L7 have positive or negative optical powers, and when they work together, they can achieve apochromatic aberration, which is beneficial for achieving high image quality.

[0087] The eighth lens L8 is a concave-convex lens with negative optical power. The shape of the eighth lens L8 is concave-convex and crescent-shaped, which is beneficial to the aberration of the optical lens and achieves high resolution. The eighth lens L8 has negative optical power and, together with the first lens L1 to the seventh lens L7 with positive optical power, forms a telephoto structure, which reduces the total optical length and is conducive to miniaturization.

[0088] In this embodiment of the invention, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 constitute the first cemented lens. The second lens L2 and the fourth lens L4, which have positive optical power, are made of materials with smaller Abbe numbers, thereby reducing chromatic aberration and achieving high image quality.

[0089] In this embodiment of the present invention, the sixth lens L6 and the seventh lens L7 form a second cemented lens. The combination of positive and negative optical power is beneficial to reducing chromatic aberration and to achieving infrared confocality. The doublet lens formed by the sixth lens L6 and the seventh lens L7 has an overall convex or concave-convex shape, which is beneficial to reducing aberration and achieving high image quality.

[0090] In some embodiments of this invention, the total optical length (TTL) of the aiming lens and the total focal length (F) of the aiming lens satisfy the following relationship: 1.00 ≤ TTL / F ≤ 1.50, and more preferably 1.06 ≤ TTL / F ≤ 1.30. Under a given system focal length, by controlling the total optical length of the aiming lens, the total optical length of the aiming lens can be made smaller, which is beneficial for miniaturizing the aiming lens.

[0091] In some embodiments of this invention, the focal length F1 of the first lens L1 and the total focal length F of the viewing lens satisfy the following relationship: 0.83 ≤ F1 / F ≤ 1.60, and more preferably 0.83 ≤ F1 / F ≤ 1.38. By rationally allocating the focal length of the first lens L1, large-angle incident light rays are converged into the optical system, reducing the aperture of the rear lens, which is beneficial for expanding the field of view and achieving miniaturization.

[0092] In some embodiments of this invention, the focal length F2 of the second lens L2 and the total focal length F of the viewing lens satisfy the following relationship: 0.37 ≤ F2 / F ≤ 1.51, and more preferably 0.46 ≤ F2 / F ≤ 1.42. By rationally allocating the focal length of the second lens L2, the second lens L2 achieves positive optical power in the four-layer cemented lens, realizing apochromatic aberration and contributing to high image quality.

[0093] In some embodiments of this invention, the focal length F3 of the third lens L3 and the total focal length F of the viewing lens satisfy the following relationship: -0.41≤F3 / F≤-0.10, and more preferably -0.41≤F3 / F≤-0.19. By rationally allocating the focal length of the third lens, the third lens L3 has a negative optical power in the first cemented lens, achieving apochromatic aberration and thus contributing to high image quality.

[0094] In some embodiments of this invention, the focal length F4 of the fourth lens L4 and the total focal length F of the observation lens satisfy the following relationship: 0.15 ≤ F4 / F ≤ 0.45, and more preferably 0.21 ≤ F4 / F ≤ 0.35. By rationally allocating the focal length values ​​of the fourth lens, the fourth lens L4 is paired with the second lens L2, the third lens L3, and the fifth lens L5 to achieve apochromatic aberration, which is beneficial for achieving high image quality.

[0095] In some embodiments of this invention, the focal length F5 of the fifth lens L5 and the total focal length F of the observation lens satisfy the following relationship: -0.42 ≤ F5 / F ≤ -0.15, and more preferably -0.42 ≤ F5 / F ≤ -0.23. By rationally allocating the focal length values ​​of the fifth lens, the fifth lens L5 is paired with the second lens L2, the third lens L3, and the fourth lens L4 to achieve apochromatic aberration, which is beneficial for achieving high image quality.

[0096] In some embodiments of this invention, the focal length F6 of the sixth lens L6 and the total focal length F of the viewing lens satisfy the following relationship: -1.86 ≤ F6 / F ≤ 0.60, and more preferably -1.60 ≤ F6 / F ≤ 0.34. By rationally allocating the focal length of the sixth lens L6, the sixth lens L6 has positive optical power in the cemented doublet lens, and works with the seventh lens L7 to achieve apochromatic effect, which is beneficial for achieving high image quality.

[0097] In some embodiments of this invention, the focal length F7 of the seventh lens L7 and the total focal length F of the viewing lens satisfy the following relationship: -1.51 ≤ F7 / F ≤ 0.55, and more preferably -1.3 ≤ F7 / F ≤ 0.34. By rationally allocating the focal length of the seventh lens L7, the seventh lens L7 has negative optical power in the cemented doublet lens, which, together with the sixth lens L6, corrects off-axis chromatic aberration, thus contributing to achieving high image quality.

[0098] In some embodiments of this invention, the focal length F8 of the eighth lens L8 and the total focal length F of the viewing lens satisfy the following relationship: -0.79 ≤ F8 / F ≤ -0.10, and more preferably -0.79 ≤ F8 / F ≤ -0.42. By reasonably controlling the focal length of the eighth lens L8, the focal length of the eighth lens L8 is matched with the focal lengths of the first seven lenses, which helps to reduce the overall length of the optical system and achieve miniaturization.

[0099] In some embodiments of this invention, the focal length FB1 of the first cemented lens and the total focal length F of the viewing lens satisfy the following relationship: -1.82 ≤ FB1 / F ≤ -0.65, and more preferably -1.72 ≤ FB1 / F ≤ -0.74. By rationally allocating the ratio of the focal length of the first cemented lens to the system focal length, it is beneficial to achieve wide-spectrum apochromatic aberration and high image quality.

[0100] In some embodiments of this invention, the focal length F2 of the second lens L2 and the focal length FB1 of the first cemented lens satisfy the following relationship: -1.71 ≤ F2 / FB1 ≤ -0.11, and more preferably -1.56 ≤ F2 / FB1 ≤ -0.26. By reasonably allocating the ratio of the focal length of the second lens L2 to that of the first cemented lens, the second lens L2 achieves a light-gathering effect, thereby ensuring bright light transmission.

[0101] In some embodiments of this invention, the combined focal length F15 of the first lens L1 to the fifth lens L5 and the combined focal length F68 of the sixth lens L6 to the eighth lens L8 satisfy the following relationship: 1.69 ≤ F15 / F68 ≤ 6.00, and more preferably 2.16 ≤ F15 / F68 ≤ 5.42. By rationally allocating the combined focal length values ​​of the first five lenses and the last three lenses, the light transition is smooth, which helps to reduce aberrations and improve optical imaging quality.

[0102] In some embodiments of this invention, the focal length F17 of the first lens L1 to the seventh lens L7 and the focal length F8 of the eighth lens L8 satisfy the following relationship: -1.50 ≤ F17 / F8 ≤ -0.50, and more preferably -1.43 ≤ F17 / F8 ≤ -0.93. By reasonably controlling the ratio of the combined focal length of the first lens L1 to the seventh lens L7 to the focal length of the eighth lens L8, it is beneficial to reduce the total optical length, thereby achieving miniaturization.

[0103] In some embodiments of this invention, the focal length FB2 of the second cemented lens and the total focal length F of the viewing lens satisfy the following relationship: 0.25≤FB2 / F≤0.50, and more preferably 0.3≤FB2 / F≤0.48. By rationally allocating the focal length of the cemented doublet lenses, it is beneficial to correct off-axis chromatic aberration, achieve infrared confocal focus, and improve optical imaging quality.

[0104] In some embodiments of this invention, the refractive index Nd(B1) of at least one lens in the first cemented lens satisfies the following relationship: 1.75 ≤ Nd(B1) ≤ 1.95. By rationally allocating the refractive index of the first cemented lens, the chromatic aberration of the lens is effectively corrected, which is beneficial for achieving infrared confocal focusing.

[0105] In some embodiments of this invention, the Abbe number Vd(B1) of at least one lens in the first cemented lens satisfies the following relationship: 19.67 ≤ Vd(B1) ≤ 45.00. By rationally allocating the Abbe number of the first cemented lens, the generation of chromatic aberration is effectively reduced, which is beneficial for achieving infrared confocal focusing.

[0106] In some embodiments of this invention, the refractive index Nd(B2) of at least one lens in the second cemented lens satisfies the following relationship: 1.90 ≤ Nd(B2) ≤ 2.10, and more preferably 1.95 ≤ Nd(B2) ≤ 2.06. By rationally distributing the refractive index of the second cemented lens, chromatic aberration of the lens is effectively corrected, which is beneficial for achieving infrared confocal focusing.

[0107] In some embodiments of this invention, the Abbe number Vd(B2) of at least one lens in the second cemented lens satisfies the following relationship: 20.00 ≤ Vd(B2) ≤ 35.00, and more preferably 24.94 ≤ Vd(B2) ≤ 28.81. By rationally allocating the Abbe number of the second cemented lens, the generation of chromatic aberration is effectively reduced, which is beneficial for achieving infrared confocal focusing.

[0108] In some embodiments of this invention, the optical back focal length (BFL) of the aiming lens and the total optical length (TTL) of the aiming lens satisfy the following relationship: 0.14 ≤ BFL / TTL ≤ 0.32. Controlling the system's optical back focal length facilitates the miniaturization of the system.

[0109] In some embodiments of this invention, the maximum aperture Dmax of the aiming lens and the total optical length TTL of the aiming lens satisfy the following relationship: 0.35≤Dmax / TTL≤0.66, and more preferably 0.35≤Dmax / TTL≤0.51. With a fixed total optical length, controlling the maximum aperture of the system results in a smaller maximum aperture, which is beneficial for miniaturization.

[0110] The following six specific embodiments are given based on the above-described configuration of this utility model to specifically describe the optical lens according to this utility model. The optical lens according to this utility model has a total of eight lenses. Each cemented surface of the cemented lens is designated as one surface, plus the aperture stop STO, the protective glass CG, and the image plane IMA, for a total of 16 surfaces. The aperture stop STO is located between the first lens L1 and the second lens L2. For ease of description, each lens surface, aperture stop STO, and protective glass CG is numbered S1, S2 to S16.

[0111] The data for the six sets of examples are shown in Table 1 below:

[0112]

[0113]

[0114] Table 1

[0115] 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.

[0116] Example 1

[0117] Figure 1 This is a schematic diagram of the observation and aiming lens in Embodiment 1 of this utility model;

[0118] Figure 2 This is a Ray Fan diagram of the observation and aiming lens in Embodiment 1 of this utility model.

[0119] 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-convex lens with positive optical power, the seventh lens L7 is a concave-convex lens with negative optical power, and the eighth lens L8 is a concave-convex lens with negative optical power.

[0120] The second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 form the first cemented lens, which is a four-cemented lens; the sixth lens L6 and the seventh lens L7 form the second cemented lens, which is a two-cemented lens. The aperture stop STO is positioned between the first lens L1 and the second lens L2.

[0121] 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.

[0122]

[0123]

[0124] Table 2

[0125] In Example 1, the total focal length F of the observation lens is 40.008mm, and the half-image height of the observation lens is 4.56mm.

[0126] Combination Figure 1 and Figure 2 As shown in Tables 1 and 2 above, this embodiment is a sighting lens that has at least one of the following characteristics: small volume and short total optical length, high resolution (up to 4K), high image quality, and the ability to achieve infrared confocal focus.

[0127] Example 2

[0128] Figure 3 This is a schematic diagram of the observation and aiming lens in Embodiment 2 of this utility model;

[0129] Figure 4 This is a Ray Fan diagram of the observation and aiming lens in Embodiment 2 of this utility model.

[0130] 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-convex lens with positive optical power, the seventh lens L7 is a concave-convex lens with negative optical power, and the eighth lens L8 is a concave-convex lens with negative optical power.

[0131] The second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 form the first cemented lens, which is a four-cemented lens; the sixth lens L6 and the seventh lens L7 form the second cemented lens, which is a two-cemented lens. The aperture stop STO is positioned between the first lens L1 and the second lens L2.

[0132] 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.

[0133]

[0134]

[0135] Table 3

[0136] In Example 2, the total focal length F of the observation lens is 39.996mm, and the half-image height of the observation lens is 4.56mm.

[0137] Combination Figure 3 and Figure 4 As shown in Tables 1 and 3 above, this second embodiment is a sighting lens that has at least one of the following characteristics: small volume and short total optical length, high resolution (up to 4K), high image quality, and the ability to achieve infrared confocal focus.

[0138] Example 3

[0139] Figure 5 This is a schematic diagram of the observation and aiming lens in Embodiment 3 of this utility model;

[0140] Figure 6 This is a Ray Fan diagram of the observation and aiming lens in Embodiment 3 of this utility model.

[0141] In Embodiment 3, the first lens L1 is a convex-concave lens with positive optical power, the second lens L2 is a convex-convex lens with positive optical power, the third lens L3 is a concave-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 plano-convex lens with positive optical power, the seventh lens L7 is a concave-convex lens with negative optical power, and the eighth lens L8 is a concave-convex lens with negative optical power.

[0142] The second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 form the first cemented lens, which is a four-cemented lens; the sixth lens L6 and the seventh lens L7 form the second cemented lens, which is a two-cemented lens. The aperture stop STO is positioned between the first lens L1 and the second lens L2.

[0143] 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.

[0144]

[0145]

[0146] Table 4

[0147] In Example 3, the total focal length F of the observation lens is 39.991mm, and the half-image height of the observation lens is 4.56mm.

[0148] Combination Figure 5 and Figure 6As shown in Tables 1 and 4 above, this third embodiment is a sighting lens that has at least one of the following characteristics: small volume and short total optical length, high resolution (up to 4K), high image quality, and the ability to achieve infrared confocal focus.

[0149] Example 4

[0150] Figure 7 This is a schematic diagram of the observation and aiming lens in Embodiment 4 of this utility model;

[0151] Figure 8 This is a Ray Fan diagram of the viewing and aiming lens in Embodiment 4 of this utility model.

[0152] In Embodiment 4, the first lens L1 is a convex-concave lens with positive optical power, the second lens L2 is a convex-convex lens with positive optical power, the third lens L3 is a concave-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 plano-concave lens with negative optical power, the seventh lens L7 is a convex-convex lens with positive optical power, and the eighth lens L8 is a concave-convex lens with negative optical power.

[0153] The second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 form the first cemented lens, which is a four-cemented lens; the sixth lens L6 and the seventh lens L7 form the second cemented lens, which is a two-cemented lens. The aperture stop STO is positioned between the first lens L1 and the second lens L2.

[0154] 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.

[0155] Surface serial number Surface type radius of curvature R Thickness d Refractive index Nd Abbe number Vd S1 spherical 27.383 2.892 1.946 17.94 S2 spherical 58.804 0.100 S3(STO) spherical Infinity 3.500 S4 spherical 23.000 4.053 1.834 37.21 S5 spherical -64.272 0.950 1.699 30.05 S6 spherical 7.746 6.842 1.593 68.34 S7 spherical -21.685 0.950 1.847 23.78 S8 spherical 17.877 10.849 S9 spherical Infinity 0.800 1.487 70.44 S10 spherical 30.281 2.617 2.003 28.32 S11 spherical -18.259 1.547 S12 spherical -14.297 0.800 1.648 33.85 S13 spherical -319.818 7.101 S14 spherical Infinity 1.500 1.517 64.20 S15 spherical Infinity 4.500 S16(IMA) spherical Infinity 0.000

[0156] Table 5

[0157] In Example 4, the total focal length F of the observation lens is 40.002mm, and the half-image height of the observation lens is 4.56mm.

[0158] Combination Figure 7 and Figure 8 As shown in Tables 1 and 5 above, this fourth embodiment is a sighting lens that has at least one of the following characteristics: small volume and short total optical length, high resolution (up to 4K), high image quality, and the ability to achieve infrared confocal focus.

[0159] Example 5

[0160] Figure 9 This is a schematic diagram of the observation and aiming lens in Embodiment 5 of this utility model;

[0161] Figure 10 This is a Ray Fan diagram of the viewing and aiming lens in Embodiment 5 of this utility model.

[0162] In Embodiment 5, the first lens L1 is a convex-concave lens with positive optical power, the second lens L2 is a convex-planar lens with positive optical power, the third lens L3 is a plano-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 plano-concave lens with negative optical power, the seventh lens L7 is a convex-convex lens with positive optical power, and the eighth lens L8 is a concave-convex lens with negative optical power.

[0163] The second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 form the first cemented lens, which is a four-cemented lens; the sixth lens L6 and the seventh lens L7 form the second cemented lens, which is a two-cemented lens. The aperture stop STO is positioned between the first lens L1 and the second lens L2.

[0164] 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.

[0165] Surface serial number Surface type radius of curvature R Thickness d Refractive index Nd Abbe number Vd S1 spherical 32.675 2.307 2.003 28.32 S2 spherical 104.186 3.303 S3(STO) spherical Infinity 5.000 S4 spherical 18.779 2.850 1.593 68.34 S5 spherical Infinity 0.600 1.654 39.54 S6 spherical 7.499 4.971 1.593 68.34 S7 spherical -38.243 0.600 1.805 25.46 S8 spherical 17.663 12.723 S9 spherical Infinity 0.600 1.487 70.44 S10 spherical 19.305 3.000 2.003 28.32 S11 spherical -25.097 3.113 S12 spherical -15.466 0.600 1.847 23.78 S13 spherical -173.421 3.686 S14 spherical Infinity 1.350 1.517 64.20 S15 spherical Infinity 4.500 S16(IMA) spherical Infinity 0.000

[0166] Table 6

[0167] In Example 5, the total focal length F of the observation lens is 40.001mm, and the half-image height of the observation lens is 4.56mm.

[0168] Combination Figure 9 and Figure 10 As shown in Tables 1 and 6 above, this fifth embodiment is a sighting lens that has at least one of the following characteristics: small volume and short total optical length, high resolution (up to 4K), high image quality, and the ability to achieve infrared confocal focus.

[0169] Example 6

[0170] Figure 11 This is a schematic diagram of the observation and aiming lens in Embodiment Six of this utility model;

[0171] Figure 12 This is a Ray Fan diagram of the observation and aiming lens in Embodiment Six of this utility model.

[0172] In Embodiment Six, 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 plano-concave lens with negative optical power, the seventh lens L7 is a convex-convex lens with positive optical power, and the eighth lens L8 is a concave-convex lens with negative optical power.

[0173] The second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 form the first cemented lens, which is a four-cemented lens; the sixth lens L6 and the seventh lens L7 form the second cemented lens, which is a two-cemented lens. The aperture stop STO is positioned between the first lens L1 and the second lens L2.

[0174] Table 7 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.

[0175] Surface serial number Surface type radius of curvature R Thickness d Refractive index Nd Abbe number Vd S1 spherical 32.648 2.263 1.923 18.90 S2 spherical 95.492 5.921 S3(STO) spherical Infinity 5.000 S4 spherical 15.563 2.928 1.744 44.90 S5 spherical 162.637 0.600 1.808 22.70 S6 spherical 9.067 4.361 1.593 68.34 S7 spherical -22.062 0.600 1.741 27.76 S8 spherical 16.360 10.618 S9 spherical Infinity 0.600 1.523 58.66 S10 spherical 18.942 2.268 2.001 25.43 S11 spherical -24.105 2.691 S12 spherical -15.422 0.600 1.743 49.22 S13 spherical -1333.971 4.699 S14 spherical Infinity 1.350 1.517 64.20 S15 spherical Infinity 4.500 S16(IMA) spherical Infinity 0.000

[0176] Table 7

[0177] In Example 6, the total focal length F of the observation lens is 40.002mm, and the half-image height of the observation lens is 4.56mm.

[0178] Combination Figure 11 and Figure 12 As shown in Tables 1 and 7 above, this sixth embodiment is a sighting lens that has at least one of the following characteristics: small volume and short total optical length, high resolution (up to 4K), high image quality, and the ability to achieve infrared confocal focus.

[0179] 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 utility model involved in this application is not limited to the 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 viewing and aiming lens, characterized in that, Along the optical axis from the object side to the image side, the lens comprises, in sequence: a first lens (L1) with positive optical power, a second lens (L2) with positive optical power, a third lens (L3) with negative optical power, a fourth lens (L4) with positive optical power, a fifth lens (L5) with negative optical power, a sixth lens (L6), a seventh lens (L7) with negative optical power, and an eighth lens (L8) with negative optical power. The optical powers of the sixth lens (L6) and the seventh lens (L7) are opposite. The second lens (L2), the third lens (L3), the fourth lens (L4), and the fifth lens (L5) constitute the first cemented lens.

2. The observation and aiming lens according to claim 1, characterized in that, The first lens (L1) is a convex-concave lens; The object-side surface of the second lens (L2) is convex; The image-side surface of the third lens (L3) is concave; The fourth lens (L4) is a convex-convex lens; The fifth lens (L5) is a concave-convex lens; The image-side surface of the seventh lens (L7) is convex; The eighth lens (L8) is a concave-convex lens.

3. The observation and aiming lens according to claim 1, characterized in that, The sixth lens (L6) and the seventh lens (L7) together form the second cemented lens.

4. The observation and aiming lens according to claim 3, characterized in that, The focal length FB2 of the second cemented lens and the total focal length F of the viewing lens satisfy the following relationship: 0.25≤FB2 / F≤0.

50.

5. The observation and aiming lens according to claim 3, characterized in that, The refractive index Nd(B2) of at least one lens in the second cemented lens satisfies the following relationship: 1.90≤Nd(B2)≤2.

10.

6. The observation and aiming lens according to claim 3, characterized in that, The sixth lens (L6) and the seventh lens (L7) form a second cemented lens, and the Abbe number Vd(B2) of at least one lens in the second cemented lens satisfies the following relationship: 20.00≤Vd(B2)≤35.

00.

7. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The total optical length TTL of the sighting lens and the total focal length F of the sighting lens satisfy the following relationship: 1.00≤TTL / F≤1.

50.

8. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length F1 of the first lens (L1) and the total focal length F of the viewing lens satisfy the following relationship: 0.83≤F1 / F≤1.

60.

9. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length F2 of the second lens (L2) and the total focal length F of the viewing lens satisfy the following relationship: 0.37≤F2 / F≤1.

51.

10. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length F3 of the third lens (L3) and the total focal length F of the observation lens satisfy the following relationship: -0.41≤F3 / F≤-0.

10.

11. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length F4 of the fourth lens (L4) and the total focal length F of the observation lens satisfy the following relationship: 0.15≤F4 / F≤0.

45.

12. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length F5 of the fifth lens (L5) and the total focal length F of the observation lens satisfy the following relationship: -0.42≤F5 / F≤-0.

15.

13. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length F6 of the sixth lens (L6) and the total focal length F of the observation lens satisfy the following relationship: -1.86≤F6 / F≤0.

60.

14. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length F7 of the seventh lens (L7) and the total focal length F of the observation lens satisfy the following relationship: -1.51≤F7 / F≤0.

55.

15. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length F8 of the eighth lens (L8) and the total focal length F of the observation lens satisfy the following relationship: -0.79≤F8 / F≤-0.

10.

16. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length FB1 of the first cemented lens and the total focal length F of the viewing lens satisfy the following relationship: -1.82≤FB1 / F≤-0.

65.

17. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal length F2 of the second lens (L2) and the focal length FB1 of the first cemented lens satisfy the following relationship: -1.71≤F2 / FB1≤-0.

11.

18. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The combined focal length F15 of the first lens (L1) to the fifth lens (L5) and the combined focal length F68 of the sixth lens (L6) to the eighth lens (L8) satisfy the following relationship: 1.69≤F15 / F68≤6.

00.

19. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The focal lengths F17 of the first lens (L1) to the seventh lens (L7) and the focal length F8 of the eighth lens (L8) satisfy the following relationship: -1.50≤F17 / F8≤-0.

50.

20. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The refractive index Nd(B1) of at least one lens in the first cemented lens satisfies the following relationship: 1.75≤Nd(B1)≤1.

95.

21. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The Abbe number Vd(B1) of at least one lens in the first cemented lens satisfies the following relationship: 19.67≤Vd(B1)≤45.

00.

22. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The optical back focal length (BFL) of the sighting lens and the optical total length (TTL) of the sighting lens satisfy the following relationship: 0.14≤BFL / TTL≤0.

32.

23. The observation and aiming lens according to any one of claims 1 to 6, characterized in that, The maximum aperture Dmax of the sighting lens and the total optical length TTL of the sighting lens satisfy the following relationship: 0.35≤Dmax / TTL≤0.

66.

24. The observation and aiming lens according to claim 1, characterized in that, The observation and aiming lens must meet at least one of the following conditions: 1.06≤TTL / F≤1.30 0.83≤F1 / F≤1.38 0.46≤F² / F≤1.42 -0.41≤F3 / F≤-0.19, 0.21≤F4 / F≤0.35 -0.42≤F5 / F≤-0.23, -1.60≤F6 / F≤0.34, -1.3≤F7 / F≤0.34, -0.79≤F8 / F≤-0.42, -1.72≤FB1 / F≤-0.74, -1.56≤F2 / FB1≤-0.26, 2.16≤F15 / F68≤5.42 -1.43≤F17 / F8≤-0.93, 0.3≤FB² / F≤0.48 1.95≤Nd(B2)≤2.06, 24.94≤Vd(B2)≤28.81, 0.35≤Dmax / TTL≤0.51 Wherein, TTL is the total optical length of the sighting lens; F is the total focal length of the sighting lens; F1 is the focal length of the first lens (L1); F2 is the focal length of the second lens (L2); F3 is the focal length of the third lens (L3); F4 is the focal length of the fourth lens (L4); F5 is the focal length of the fifth lens (L5); F6 is the focal length of the sixth lens (L6); F7 is the focal length of the seventh lens (L7); F8 is the focal length of the eighth lens (L8); FB1 is the focal length of the first cemented lens; F15 is the combined focal length of the first lens (L1) to the fifth lens (L5); F68 is the focal length of the sixth lens (L8). The combined focal length of the lens from lens (L6) to the eighth lens (L8); F17 is the focal length of the first lens (L1) to the seventh lens (L7); FB2 is the focal length of the second cemented lens composed of the sixth lens (L6) and the seventh lens (L7); Nd (B1) is the refractive index of at least one lens in the first cemented lens; Vd (B1) is the refractive index of at least one lens in the first cemented lens; Nd (B2) is the refractive index of at least one lens in the second cemented lens; Vd (B2) is the refractive index of at least one lens in the second cemented lens; BFL is the optical back focal length of the sighting lens; Dmax is the maximum aperture of the sighting lens.

Images