Observing and aiming lens

Abstract

The utility model discloses an observing and aiming lens. The sighting lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an object side to an image side along an optical axis, the second lens has positive focal power; the third lens has negative focal power; the fourth lens has positive focal power; the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface; the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a concave surface; the object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens is a convex surface; the distance TTL from the center of the object side surface of the first lens to the imaging surface of the observing and aiming lens on the optical axis and the effective focal length F of the observing and aiming lens meet the condition that TTL / F is larger than or equal to 0.85 and smaller than or equal to 1.00.

Description

Technical Field

[0001] The present application relates to the field of optical elements, and more specifically, to a sighting lens. Background Art

[0002] The sighting lens is also called a sighting lens and a sniper scope, which allows the user to see the target more clearly. Overall, people have the following four technical requirements for the sighting lens: 1) As a handheld product, the sighting lens pays more attention to portability, requiring the lens weight and volume to be small enough, so the requirement of miniaturization is put forward; 2) The sighting lens is used to observe the details of objects, and the object side field of view is small, so the lens needs to have a longer focal length; 3) In order to meet the need to distinguish tiny details, the sighting lens is required to have high image quality; 4) In order to meet the needs of night observation, the sighting lens is required to have infrared confocal.

[0003] However, the sighting lens in the prior art still has the following shortcomings: 1) It is difficult for the prior art to take into account both the lens aperture and high image quality; 2) It is difficult for the prior art to achieve both long focus and shorter total length; 3) The prior art uses a narrow band and it is difficult to achieve infrared confocality. Utility Model Content

[0004] On one hand, the present application provides a viewing and aiming lens, which includes, in order from the object side to the image side along the optical axis: 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, whose object side surface is concave and whose image side surface is concave; a sixth lens with positive optical power, whose object side surface is convex and whose image side surface is convex; a seventh lens with negative optical power, whose object side surface is concave and whose image side surface is concave; and an eighth lens with negative optical power, whose object side surface is concave and whose image side surface is convex; wherein a distance TTL from the center of the object side surface of the first lens to the imaging surface of the viewing and aiming lens on the optical axis and an effective focal length F of the viewing and aiming lens satisfy the following ratio: 0.85≤TTL / F≤1.00.

[0005] In one embodiment, the object-side surface of the first lens is convex, and the image-side surface is concave.

[0006] In one embodiment, the object-side surface of the second lens is convex, and the image-side surface is concave.

[0007] In one embodiment, the object-side surface of the third lens is convex, and the image-side surface is concave.

[0008] In one embodiment, the object-side surface of the fourth lens is convex, and the image-side surface is convex.

[0009] In one embodiment, the effective focal length F1 of the first lens and the effective focal length F of the aiming lens satisfy: 0.85≤F1 / F≤1.15.

[0010] In one embodiment, the effective focal length F2 of the second lens and the effective focal length F of the aiming lens satisfy: 0.75≤F2 / F≤0.95.

[0011] In one embodiment, the effective focal length F3 of the third lens and the effective focal length F of the aiming lens satisfy: -0.45≤F3 / F≤-0.35.

[0012] In one embodiment, the effective focal length F4 of the fourth lens and the effective focal length F of the aiming lens satisfy: 0.25≤F4 / F≤0.45.

[0013] In one embodiment, the effective focal length F5 of the fifth lens and the effective focal length F of the aiming lens satisfy: -0.45≤F5 / F≤-0.25.

[0014] In one embodiment, the effective focal length F6 of the sixth lens and the effective focal length F of the aiming lens satisfy: 0.15≤F6 / F≤0.30.

[0015] In one embodiment, the effective focal length F7 of the seventh lens and the effective focal length F of the aiming lens satisfy: -0.45≤F7 / F≤-0.30.

[0016] In one embodiment, the effective focal length F8 of the eighth lens and the effective focal length F of the aiming lens satisfy: -0.65≤F8 / F≤-0.40.

[0017] In one embodiment, the third lens, the fourth lens and the fifth lens form a triplet lens, and the combined focal length Fa of the third lens, the fourth lens and the fifth lens and the effective focal length F of the aiming lens satisfy: -0.50≤Fa / F≤-0.30.

[0018] In one embodiment, the sixth lens and the seventh lens form a doublet lens, and the combined focal length Fb of the sixth lens and the seventh lens and the effective focal length F of the aiming lens satisfy: 0.40≤Fb / F≤0.70.

[0019] In one embodiment, the combined focal length F17 of the first lens to the seventh lens and the effective focal length F of the aiming lens satisfy: 0.70≤F17 / F≤0.85.

[0020] In one embodiment, the combined focal length F17 of the first to seventh lenses and the effective focal length F8 of the eighth lens satisfy: -1.75≤F17 / F8≤-1.30.

[0021] In one embodiment, the refractive index ND1 of the first lens satisfies: 1.90≤ND1≤1.95.

[0022] In one embodiment, the Abbe number VD2 of the second lens satisfies: 90≤VD2≤100.

[0023] In one embodiment, the Abbe number VD4 of the fourth lens satisfies: 90≤VD4≤100.

[0024] In one embodiment, the maximum light transmission full aperture Dmax of the aiming and viewing lens and the distance TTL from the center of the object side surface of the first lens to the imaging surface of the aiming and viewing lens on the optical axis satisfy: 0.45≤Dmax / TTL≤0.65.

[0025] In one embodiment, the effective focal length F of the aiming and viewing lens and the entrance pupil diameter ENPD of the aiming and viewing lens satisfy: 2.0≤F / ENPD≤2.25.

[0026] In one embodiment, a distance BFL from the center of the image side surface of the eighth lens to the imaging surface of the aiming lens on the optical axis and a distance TTL from the center of the object side surface of the first lens to the imaging surface of the aiming lens on the optical axis satisfy: 0.10≤BFL / TTL≤0.25.

[0027] Another aspect of the present application provides an electronic device, which includes a sighting lens provided by the present application and an imaging element for converting an optical image formed by the sighting lens into an electrical signal.

[0028] The sighting and aiming lens provided by the present application adopts eight lenses. By reasonably setting the optical focal length of each lens and the surface shape of some lenses, the total optical length of the system is controlled under a certain system focal length value, so that the total optical length of the system is short. The sighting and aiming lens provided by the present application has at least one beneficial effect of miniaturization, high image quality, infrared confocality, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features, purposes and advantages of the present utility model will become more apparent through the detailed description of the following embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0030] Figure 1 Schematic diagram of the structure of the aiming and viewing lens according to Embodiment 1 of the present application;

[0031] Figure 2 is a relative illumination curve of the aiming and viewing lens according to Example 1 of the present application;

[0032] Figure 3 is a Ray Fan diagram of the aiming and viewing lens according to Example 1 of the present application;

[0033] Figure 4Schematic diagram of the structure of the aiming and viewing lens according to Embodiment 2 of the present application;

[0034] Figure 5 is a relative illumination curve of the aiming and viewing lens according to Embodiment 2 of the present application;

[0035] Figure 6 is a Ray Fan diagram of the aiming and viewing lens according to Embodiment 2 of the present application;

[0036] Figure 7 Schematic diagram of the structure of the aiming and viewing lens according to Embodiment 3 of the present application;

[0037] Figure 8 is a relative illumination curve of the aiming and viewing lens according to Example 3 of the present application;

[0038] Fig. 9 is a Ray Fan diagram of the aiming and viewing lens according to Example 3 of the present application;

[0039] Fig.10 Schematic diagram of the structure of the aiming and viewing lens according to Embodiment 4 of the present application;

[0040] Fig.11 is a relative illumination curve of the aiming and viewing lens according to embodiment 4 of the present application; and

[0041] Fig.12 It is a Ray Fan diagram of the aiming lens according to Example 4 of the present application. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and do not limit the scope of the present application in any way. Throughout the specification, the same figure numbers refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0043] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0044] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0045] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface 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 of the lens, and the surface of each lens closest to the imaging side is called the image side of the lens.

[0046] It should also be understood that the terms "comprises", "including", "having", "includes" 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. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0047] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0048] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] The features, principles and other aspects of the present application are described in detail below.

[0050] In an exemplary embodiment, the sighting lens includes, for example, eight lenses having optical power, namely, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The eight lenses are arranged in sequence from the object side to the image side along the optical axis, and any two adjacent lenses from the first lens to the eighth lens may have a spacing distance therebetween.

[0051] In an exemplary embodiment, the sighting lens may further include an aperture for limiting the light beam to further improve the imaging quality of the sighting lens. Exemplarily, the aperture may be disposed between the first lens and the second lens. The aperture is conducive to converging the light entering the sighting lens, shortening the total length of the optical system, reducing the maximum aperture of the sighting lens, and is conducive to miniaturization and reducing the assembly sensitivity of the system. However, it should be noted that the position of the aperture disclosed herein is only an example and not a limitation; in alternative embodiments, the aperture may also be disposed at other positions according to actual needs.

[0052] In an exemplary embodiment, the sighting lens may further include a photosensitive element disposed on the image side of the eighth lens. Optionally, the photosensitive element disposed on the image side of the eighth lens may be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

[0053] In an exemplary embodiment, the first lens has positive focal power, and its object side surface is convex and its image side surface is concave. The first lens has positive focal power, which is conducive to collecting light, so that the light emitted by the first lens is close to the optical axis, reducing the aperture of the rear lens, and facilitating miniaturization; the image side surface of the first lens is concave, which helps to reduce the incident angle of the axial light on the image side surface of the first lens, reduce the spherical aberration generated by the image side surface of the first lens, and facilitate high image quality. Optionally, the first lens selects a material with a larger refractive index to reduce the surface curvature and reduce the generation of aberrations, which is conducive to achieving high image quality.

[0054] In an exemplary embodiment, the second lens has positive power, its object side surface is convex, and its image side surface is concave. The second lens has positive power, and its image side surface is concave, which can reduce the incident angle of the axial light on the image side surface of the second lens, reduce the spherical aberration generated on the image side surface of the second lens, and help achieve high image quality. Optionally, the second lens can be matched with a low dispersion material to reduce the generation of chromatic aberration, reduce the difficulty of system correction, and help achieve high image quality.

[0055] In an exemplary embodiment, the third lens has negative optical power, its object side surface is convex, and its image side surface is concave. The third lens has negative optical power, and its object side surface is convex, which is conducive to reducing the incident angle of axial light on the object side surface of the third lens, reducing the spherical aberration generated by the object side surface of the third lens, and thus facilitating the realization of high image quality.

[0056] In an exemplary embodiment, the fourth lens has positive refractive power, and its object side surface is convex, and its image side surface is convex. The fourth lens shares the refractive power, reduces the surface curvature, reduces the generation of aberrations, and is conducive to achieving high image quality.

[0057] In an exemplary embodiment, the fifth lens has negative optical power, and its object side surface and image side surface are both concave. The fifth lens shares the optical power, reduces the surface curvature, reduces the generation of aberrations, and is conducive to achieving high image quality.

[0058] In an exemplary embodiment, the third lens, the fourth lens and the fifth lens form a triplet lens. The third lens has a negative optical power in the triplet lens, and cooperates with the fourth lens to achieve apochromatism, which is conducive to achieving high image quality. The fourth lens has a positive optical power in the triplet lens, and can be preferably matched with a low-dispersion material to perform apochromatism on the system, which is conducive to achieving infrared confocality; the fourth lens compensates for the axial chromatic aberration produced by the first lens, which is conducive to achieving infrared confocality; overall, the focal length value of the triplet lens is negative, which produces negative spherical aberration, compensates for the positive spherical aberration introduced by the first lens and the second lens, and is conducive to achieving high image quality. The fifth lens has a negative optical power in the triplet lens, and cooperates with the fourth lens to achieve apochromatism, which is conducive to achieving high image quality.

[0059] In an exemplary embodiment, the sixth lens has positive refractive power, and its object side surface and image side surface are both convex. The sixth lens shares the refractive power, reduces the surface curvature, reduces the generation of aberrations, and is conducive to achieving high image quality.

[0060] In an exemplary embodiment, the seventh lens has negative optical power, and its object side surface and image side surface are both concave. The seventh lens shares the optical power, reduces the surface curvature, reduces the generation of aberrations, and is conducive to achieving high image quality.

[0061] In an exemplary embodiment, the sixth lens and the seventh lens are combined into a doublet lens to correct the residual chromatic aberration of the system, which is conducive to achieving high image quality. The sixth lens has positive focal length in the doublet lens, and can be used with low dispersion materials to perform apochromatization on the system, which is conducive to achieving infrared confocal. The seventh lens has negative focal length in the doublet lens, and cooperates with the sixth lens to achieve apochromatization, which is conducive to achieving high image quality; in addition, the seventh lens has negative focal length in the doublet lens, and can be used with the sixth lens to achieve apochromatization, which is conducive to achieving high image quality. Seven lenses It has negative optical power, and together with the eighth lens the rear group of the lens has a larger negative optical power, while the front group of the first to sixth lenses has a positive optical power as a whole. The front and rear combination constitutes the telephoto structure of the sighting lens, which reduces the total optical length and is conducive to miniaturization.

[0062] In an exemplary embodiment, the eighth lens has negative optical power, its object side surface is concave, and its image side surface is convex. The first to seventh lenses have positive optical power as a whole, and the eighth lens is combined with the first to seventh lenses to form a telephoto architecture, which reduces the total optical length and is conducive to miniaturization.

[0063] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 0.85≤F1 / F≤1.15, where F1 is the effective focal length of the first lens, and F is the effective focal length of the sighting lens. Satisfying 0.85≤F1 / F≤1.15, the focal length value of the first lens is reasonably allocated, and by collecting light, the light emitted by the first lens is made close to the optical axis direction, reducing the aperture of the rear lens, which is conducive to miniaturization.

[0064] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 0.75≤F2 / F≤0.95, where F2 is the effective focal length of the second lens, and F is the effective focal length of the sighting lens. Satisfying 0.75≤F2 / F≤0.95, by reasonably allocating the focal length value of the second lens and matching low-dispersion materials, the generation of chromatic aberration is reduced, the difficulty of system correction is reduced, and high image quality is achieved.

[0065] In an exemplary embodiment, the sighting lens according to the present application may satisfy: -0.45≤F3 / F≤-0.35, where F3 is the effective focal length of the third lens, and F is the effective focal length of the sighting lens. -3.7≤F3 / F≤-2.5 is satisfied, and by reasonably allocating the focal length value of the third lens, the third lens has a negative focal power in the triplet lens, and cooperates with the fourth lens to achieve achromatic aberration, which is conducive to achieving high image quality.

[0066] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 0.25≤F4 / F≤0.45, where F4 is the effective focal length of the fourth lens, and F is the effective focal length of the sighting lens. Satisfying 0.25≤F4 / F≤0.45, by reasonably allocating the focal length value of the fourth lens, the fourth lens has positive focal power in the triplet lens, and with low dispersion materials, the system is apochromatic, which is conducive to achieving infrared confocal.

[0067] In an exemplary embodiment, the sighting lens according to the present application may satisfy: -0.45≤F5 / F≤-0.25, where F5 is the effective focal length of the fifth lens, and F is the effective focal length of the sighting lens. Satisfying -0.45≤F5 / F≤-0.25, by reasonably allocating the focal length value of the fifth lens, the fifth lens has a negative focal power in the triplet lens, and cooperates with the fourth lens to achieve apochromatism, which is conducive to achieving high image quality.

[0068] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 0.15≤F6 / F≤0.30, where F6 is the effective focal length of the sixth lens, and F is the effective focal length of the sighting lens. Satisfying 0.15≤F6 / F≤0.30, by reasonably allocating the focal length value of the sixth lens, the sixth lens has positive focal power in the double cemented lens, and with low dispersion materials, the system is apochromatic, which is conducive to achieving infrared confocal.

[0069] In an exemplary embodiment, the sighting lens according to the present application may satisfy: -0.45≤F7 / F≤-0.30, where F7 is the effective focal length of the seventh lens, and F is the effective focal length of the sighting lens. Satisfying -0.45≤F7 / F≤-0.30, by reasonably allocating the focal length value of the seventh lens, the seventh lens has a negative focal power in the double cemented lens, and cooperates with the sixth lens to achieve apochromatism, which is conducive to achieving high image quality; by reasonably allocating the focal length value of the seventh lens, the seventh lens has a negative focal power, and cooperates with the eighth lens to make the rear lens group have a larger negative focal power, while the front group of the first lens to the sixth lens has a positive focal power as a whole, and the front and rear combination constitutes the telephoto structure of the sighting lens, which reduces the total optical length and is conducive to miniaturization.

[0070] In an exemplary embodiment, the sighting lens according to the present application may satisfy: -0.65≤F8 / F≤-0.40, where F8 is the effective focal length of the eighth lens, and F is the effective focal length of the sighting lens. Satisfying -0.65≤F8 / F≤-0.40, by reasonably allocating the focal length value of the eighth lens, the eighth lens has a negative focal power, the first lens to the seventh lens as a whole have a positive focal power, and the eighth lens and the first lens to the seventh lens are combined to form a telephoto architecture, which reduces the total optical length and is conducive to miniaturization.

[0071] In an exemplary embodiment, the sighting lens according to the present application may satisfy: -0.50≤Fa / F≤-0.30, where Fa is the combined focal length of the third lens, the fourth lens, and the fifth lens, and F is the effective focal length of the sighting lens. By reasonably allocating the focal length values ​​of the triplet lens, the triplet lens compensates for the axial chromatic aberration produced by the first lens, which is conducive to achieving infrared confocality; at the same time, the focal length value of the triplet lens is made negative, generating negative spherical aberration, compensating for the positive spherical aberration introduced by the first lens and the second lens, which is conducive to achieving high image quality.

[0072] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 0.40≤Fb / F≤0.70, where Fb is the combined focal length of the sixth lens and the seventh lens, and F is the effective focal length of the sighting lens. By reasonably allocating the focal length values ​​of the sixth lens and the seventh lens, the residual chromatic aberration of the system is corrected, which is conducive to achieving high image quality.

[0073] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 0.70≤F17 / F≤0.85, where F17 is the combined focal length of the first lens to the seventh lens, and F is the effective focal length of the sighting lens. Satisfying 0.70≤F17 / F≤0.85, by reasonably allocating the combined focal length values ​​of the first lens to the seventh lens, the focal length value of the front lens group composed of the first lens to the seventh lens is positive, reducing the total optical length, which is conducive to miniaturization.

[0074] In an exemplary embodiment, the sighting lens according to the present application may satisfy: -1.75≤F17 / F8≤-1.30, wherein F17 is the combined focal length of the first lens to the seventh lens, and F8 is the effective focal length of the eighth lens. Satisfying -1.75≤F17 / F8≤-1.30, by reasonably allocating the combined focal length value of the first lens to the seventh lens and the focal length value of the eighth lens, the focal length value of the front lens group formed by the first lens to the seventh lens is positive, and the focal length value of the rear lens group formed by the eighth lens is negative, and the two form a telephoto architecture, reducing the total optical length, which is conducive to miniaturization.

[0075] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 1.90≤ND1≤1.95, where ND1 is the refractive index of the first lens. When 1.90≤ND1≤1.95 is satisfied, by reasonably setting the refractive index of the first lens, the first lens may preferably be made of a material with a larger refractive index, reduce the surface curvature, reduce the generation of aberrations, and facilitate the realization of high image quality.

[0076] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 90≤VD2≤100, where VD2 is the Abbe number of the second lens. When 90≤VD2≤100 is satisfied, the Abbe number of the second lens is reasonably set to reduce the generation of chromatic aberration, reduce the difficulty of chromatic aberration correction of the system, and facilitate the realization of infrared confocal.

[0077] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 90≤VD4≤100, where VD4 is the Abbe number of the fourth lens. When 90≤VD4≤100 is satisfied, the Abbe number of the fourth lens is reasonably set to reduce the generation of chromatic aberration, reduce the difficulty of chromatic aberration correction of the system, and facilitate the realization of infrared confocal.

[0078] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 0.45≤Dmax / TTL≤0.65, wherein TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the sighting lens on the optical axis, and Dmax is the maximum clear aperture of the sighting lens. When 0.45≤Dmax / TTL≤0.65 is satisfied, under a certain system optical total length, the maximum clear aperture of the sighting lens is controlled to be smaller, which is conducive to miniaturization.

[0079] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 0.85≤TTL / F≤1.00, where F is the effective focal length of the sighting lens, and TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the sighting lens on the optical axis. When 0.85≤TTL / F≤1.00 is satisfied, under a certain system focal length value, the total optical length of the system is controlled so that the total optical length of the system is small, which is conducive to miniaturization.

[0080] In an exemplary embodiment, the sighting lens according to the present application may satisfy: 2.0≤F / ENPD≤2.25, where F is the effective focal length of the sighting lens, and ENPD is the entrance pupil diameter of the sighting lens. When 2.0≤F / ENPD≤2.25 is satisfied, the system has a smaller aperture value by controlling the size of the entrance pupil diameter, which is conducive to achieving a large aperture.

[0081] In an exemplary embodiment, the aiming lens according to the present application may satisfy: 0.10≤BFL / TTL≤0.25, where BFL is the distance from the center of the image side surface of the eighth lens to the imaging surface of the aiming lens on the optical axis, and TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the aiming lens on the optical axis. When 0.10≤BFL / TTL≤0.25 is satisfied, the system has a smaller aperture value by controlling the size of the entrance pupil diameter, which is conducive to achieving a large aperture.

[0082] In the sighting lens of the present application, the third lens, the fourth lens and the fifth lens form a triplet lens, wherein the third lens has negative optical power, the fourth lens has positive optical power, and the fifth lens has negative optical power. The fourth lens can be made of a material with a larger Abbe number, which is beneficial for correcting chromatic aberration; the third lens, the fourth lens and the fifth lens correct their own aberrations by matching materials and optical power, which is beneficial for reducing tolerance sensitivity.

[0083] In the sighting lens of the present application, the sixth lens and the seventh lens form a double-cemented lens, the sixth lens has positive optical power, and the seventh lens has negative optical power, wherein the sixth lens can be selected from a material with a larger Abbe number, which is conducive to correcting chromatic aberration; the sixth lens and the seventh lens correct their own aberrations by matching materials and optical power, which is conducive to reducing tolerance sensitivity.

[0084] The sighting and aiming lens of the present application has a longer focal length, which can meet the use range of a telephoto lens. In an exemplary embodiment, the effective focal length F of the sighting and aiming lens of the present application can reach 60 mm.

[0085] Optionally, in an exemplary embodiment, as needed, the aiming and viewing lens of the present application may further include a filter and / or a protective glass disposed between the eighth lens and the imaging plane to filter light with different wavelengths and prevent damage to the image-side element (e.g., chip) of the aiming and viewing lens.

[0086] In an exemplary embodiment, the first lens to the eighth lens may be a spherical lens or an aspherical lens. The present application does not specifically limit the specific number of spherical lenses and aspherical lenses. When focusing on imaging quality, the number of aspherical lenses can be increased, or even all lenses use aspherical lenses. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery. Unlike a spherical lens with a constant curvature from the center of the lens to the periphery, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical lens, the aberration that occurs during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens. Optionally, the object side and image side of all lenses from the first lens to the eighth lens are spherical mirror surfaces.

[0087] The sighting and aiming lens according to the above-mentioned embodiment of the present application may adopt multiple lenses, for example, the eight lenses mentioned above, and by reasonably allocating optical parameters such as the focal length, surface shape, center thickness of each lens, and on-axis spacing between each lens, at least one of the long focal length, miniaturization, high image quality, and infrared confocality of the sighting and aiming lens can be achieved.

[0088] The sighting lens according to the above-mentioned embodiment of the present application may adopt multiple lenses, such as eight lenses as described above. However, those skilled in the art should understand that, without departing from the technical solution claimed for protection in the present application, the number of lenses constituting the lens may be changed to obtain the various results and advantages described in this specification. For example, although eight lenses are described as an example in the embodiment, the sighting lens is not limited to including eight lenses. If necessary, the sighting lens may also include other numbers of lenses. The following further describes a specific embodiment of the sighting lens applicable to the above-mentioned embodiment with reference to the accompanying drawings.

[0089] Example 1

[0090] The following reference Figure 1 The aiming lens according to Embodiment 1 of the present application is described. Figure 1 A schematic structural diagram of a viewing and aiming lens according to Embodiment 1 of the present application is shown.

[0091] like Figure 1 As shown, the aiming lens 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 and an eighth lens L8 in order from the object side to the image side along the optical axis. Among them, the third lens L3, the fourth lens L4 and the fifth lens L5 form a triplet lens, and the sixth lens L6 and the seventh lens L7 form a doublet lens.

[0092] The first lens L1 has positive refractive power, an object-side surface S1 of which is convex, and an image-side surface S2 of which is concave.

[0093] The second lens L2 has positive refractive power, an object-side surface S4 thereof is convex, and an image-side surface S5 thereof is concave.

[0094] The third lens L3 has negative refractive power, and its object-side surface S6 is convex, and its image-side surface S7 is concave.

[0095] The fourth lens L4 has positive refractive power, and its object-side surface S7 is convex, and its image-side surface S8 is convex.

[0096] The fifth lens L5 has negative refractive power, and its object-side surface S8 is concave and its image-side surface S9 is concave.

[0097] The sixth lens L6 has positive refractive power, and its object-side surface S10 is convex, and its image-side surface S11 is convex.

[0098] The seventh lens L7 has negative refractive power, and its object-side surface S11 is concave, and its image-side surface S12 is concave.

[0099] The eighth lens L8 has negative refractive power, and its object-side surface S13 is concave, and its image-side surface S14 is convex.

[0100] The aiming lens may further include a stop STO. The stop STO may be disposed between the first lens L1 and the second lens L2.

[0101] Optionally, the sighting lens may further include a filter CG having an object side surface S15 and an image side surface S16 and / or a protective glass (not shown) having an object side surface and an image side surface. The filter CG and / or the protective glass may be used to correct color deviation, and the filter CG and / or the protective glass may also be used to protect an image sensor chip located at the imaging surface IMA. Light from the object sequentially passes through each surface S1 to S16 and is finally imaged on the imaging surface IMA.

[0102] Table 1 shows the radius of curvature, thickness / distance, refractive index and Abbe number of each lens of the aiming lens of Example 1, wherein the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0103]

[0104]

[0105] Table 1

[0106] Figure 2 The relative illumination curve of the aiming lens of Example 1 is shown, which indicates the relative illumination values ​​corresponding to different fields of view. Figure 3 The Ray Fan diagram of the aiming lens of Example 1 is shown, which indicates the aberrations corresponding to different fields of view. Figure 2 and Figure 3It can be seen that the viewing and aiming lens provided in Example 1 has the characteristics of high illumination and low aberration, and can achieve good imaging quality.

[0107] Example 2

[0108] The following reference Figure 4 The aiming lens according to Embodiment 2 of the present application is described. Figure 4 A schematic structural diagram of a viewing and aiming lens according to Embodiment 2 of the present application is shown.

[0109] like Figure 4 As shown, the aiming lens 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 and an eighth lens L8 in order from the object side to the image side along the optical axis. Among them, the third lens L3, the fourth lens L4 and the fifth lens L5 form a triplet lens.

[0110] The first lens L1 has positive refractive power, an object-side surface S1 of which is convex, and an image-side surface S2 of which is concave.

[0111] The second lens L2 has positive refractive power, an object-side surface S4 thereof is convex, and an image-side surface S5 thereof is concave.

[0112] The third lens L3 has negative refractive power, and its object-side surface S6 is convex, and its image-side surface S7 is concave.

[0113] The fourth lens L4 has positive refractive power, and its object-side surface S7 is convex, and its image-side surface S8 is convex.

[0114] The fifth lens L5 has negative refractive power, and its object-side surface S8 is concave and its image-side surface S9 is concave.

[0115] The sixth lens L6 has positive refractive power, and its object-side surface S10 is convex, and its image-side surface S11 is convex.

[0116] The seventh lens L7 has negative refractive power, and its object-side surface S12 is concave, and its image-side surface S13 is concave.

[0117] The eighth lens L8 has negative refractive power, and its object-side surface S14 is concave, and its image-side surface S15 is convex.

[0118] The aiming lens may further include a stop STO. The stop STO may be disposed between the first lens L1 and the second lens L2.

[0119] Optionally, the sighting lens may further include a filter CG having an object side surface S16 and an image side surface S17 and / or a protective glass (not shown) having an object side surface and an image side surface. The filter CG and / or the protective glass may be used to correct color deviation, and the filter CG and / or the protective glass may also be used to protect an image sensor chip located at the imaging surface IMA. Light from the object sequentially passes through each surface S1 to S17 and is finally imaged on the imaging surface IMA.

[0120] Table 2 shows the radius of curvature, thickness / distance, refractive index and Abbe number of each lens of the aiming lens of Example 2, wherein the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0121]

[0122]

[0123] Table 2

[0124] Figure 5 The relative illumination curve of the aiming lens of Example 2 is shown, which indicates the relative illumination values ​​corresponding to different fields of view. Figure 6 The Ray Fan diagram of the aiming lens of Example 2 is shown, which indicates the aberrations corresponding to different fields of view. Figure 5 and Figure 6 It can be seen that the viewing and aiming lens provided in Example 2 has the characteristics of high illumination and low aberration, and can achieve good imaging quality.

[0125] Example 3

[0126] The following reference Figure 7 The aiming lens according to Embodiment 3 of the present application is described. Figure 7 A schematic structural diagram of a viewing and aiming lens according to Embodiment 3 of the present application is shown.

[0127] like Figure 7 As shown, the aiming lens 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 and an eighth lens L8 in order from the object side to the image side along the optical axis. Among them, the third lens L3, the fourth lens L4 and the fifth lens L5 form a triplet lens, and the sixth lens L6 and the seventh lens L7 form a doublet lens.

[0128] The first lens L1 has positive refractive power, an object-side surface S1 of which is convex, and an image-side surface S2 of which is concave.

[0129] The second lens L2 has positive refractive power, an object-side surface S4 thereof is convex, and an image-side surface S5 thereof is concave.

[0130] The third lens L3 has negative refractive power, and its object-side surface S6 is convex, and its image-side surface S7 is concave.

[0131] The fourth lens L4 has positive refractive power, and its object-side surface S7 is convex, and its image-side surface S8 is convex.

[0132] The fifth lens L5 has negative refractive power, and its object-side surface S8 is concave and its image-side surface S9 is concave.

[0133] The sixth lens L6 has positive refractive power, and its object-side surface S10 is convex, and its image-side surface S11 is convex.

[0134] The seventh lens L7 has negative refractive power, and its object-side surface S11 is concave, and its image-side surface S12 is concave.

[0135] The eighth lens L8 has negative refractive power, and its object-side surface S13 is concave, and its image-side surface S14 is convex.

[0136] The aiming lens may further include a stop STO, and the stop STO may be disposed between the first lens L1 and the second lens L2.

[0137] Optionally, the sighting lens may further include a filter CG having an object side surface S15 and an image side surface S16 and / or a protective glass (not shown) having an object side surface and an image side surface. The filter CG and / or the protective glass may be used to correct color deviation, and the filter CG and / or the protective glass may also be used to protect an image sensor chip located at the imaging surface IMA. Light from the object sequentially passes through each surface S1 to S16 and is finally imaged on the imaging surface IMA.

[0138] Table 3 shows the radius of curvature, thickness / distance, refractive index and Abbe number of each lens of the aiming lens of Example 3, wherein the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0139]

[0140] Table 3

[0141] Figure 8 The relative illumination curve of the aiming lens of Example 3 is shown, which indicates the relative illumination values ​​corresponding to different fields of view. Fig. 9 The Ray Fan diagram of the aiming lens of Example 3 is shown, which indicates the aberrations corresponding to different fields of view. Figure 8 and Fig. 9 It can be seen that the viewing and aiming lens provided in Example 3 has the characteristics of high illumination and low aberration, and can achieve good imaging quality.

[0142] Example 4

[0143] The following reference Fig.10The aiming lens according to Embodiment 4 of the present application is described. Fig.10 A schematic structural diagram of a viewing and aiming lens according to Embodiment 4 of the present application is shown.

[0144] like Fig.10 As shown, the aiming lens 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 and an eighth lens L8 in order from the object side to the image side along the optical axis. Among them, the third lens L3, the fourth lens L4 and the fifth lens L5 form a triplet lens, and the sixth lens L6 and the seventh lens L7 form a doublet lens.

[0145] The first lens L1 has positive refractive power, an object-side surface S1 of which is convex, and an image-side surface S2 of which is concave.

[0146] The second lens L2 has positive refractive power, an object-side surface S4 thereof is convex, and an image-side surface S5 thereof is concave.

[0147] The third lens L3 has negative refractive power, and its object-side surface S6 is convex, and its image-side surface S7 is concave.

[0148] The fourth lens L4 has positive refractive power, and its object-side surface S7 is convex, and its image-side surface S8 is convex.

[0149] The fifth lens L5 has negative refractive power, and its object-side surface S8 is concave and its image-side surface S9 is concave.

[0150] The sixth lens L6 has positive refractive power, and its object-side surface S10 is convex, and its image-side surface S11 is convex.

[0151] The seventh lens L7 has negative refractive power, and its object-side surface S11 is concave, and its image-side surface S12 is concave.

[0152] The eighth lens L8 has negative refractive power, and its object-side surface S13 is concave, and its image-side surface S14 is convex.

[0153] The aiming lens may further include a stop STO. The stop STO may be disposed between the first lens L1 and the second lens L2.

[0154] Optionally, the sighting lens may further include a filter CG having an object side surface S15 and an image side surface S16 and / or a protective glass (not shown) having an object side surface and an image side surface. The filter CG and / or the protective glass may be used to correct color deviation, and the filter CG and / or the protective glass may also be used to protect an image sensor chip located at the imaging surface IMA. Light from the object sequentially passes through each surface S1 to S16 and is finally imaged on the imaging surface IMA.

[0155] Table 4 shows the radius of curvature, thickness / distance, refractive index and Abbe number of each lens of the aiming lens of Example 4, wherein the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0156]

[0157] Table 4

[0158] Fig.11 The relative illumination curve of the aiming lens of Example 4 is shown, which indicates the relative illumination values ​​corresponding to different fields of view. Fig.12 The Ray Fan diagram of the aiming lens of Example 4 is shown, which indicates the aberrations corresponding to different fields of view. Fig.11 and Fig.12 It can be seen that the viewing and aiming lens provided in Example 4 has the characteristics of high illumination and low aberration, and can achieve good imaging quality.

[0159] In summary, Examples 1 to 4 respectively satisfy the relationship shown in Table 5 below.

[0160] Conditional formula\Example Example 1 Example 2 Example 3 Example 4 0.45≤Dmax / TTL≤0.65 0.506 0.539 0.502 0.549 0.85≤TTL / F≤1.00 0.908 0.933 0.917 0.917 2.00≤F / ENPD≤2.25 2.200 2.050 2.200 2.050 0.10≤BFL / TTL≤0.25 0.194 0.170 0.181 0.174 0.85≤F1 / F≤1.15 0.935 1.030 0.915 0.986 0.75≤F2 / F≤0.95 0.820 0.844 0.838 0.816 -0.45≤F3 / F≤-0.35 -0.390 -0.397 -0.401 -0.392 0.25≤F4 / F≤0.45 0.343 0.333 0.364 0.329 -0.45≤F5 / F≤-0.25 -0.327 -0.319 -0.365 -0.307 0.15≤F6 / F≤0.30 0.214 0.249 0.228 0.192 -0.45≤F7 / F≤-0.30 -0.341 -0.413 -0.350 -0.333 -0.65≤F8 / F≤-0.40 -0.542 -0.570 -0.545 -0.447 -0.50≤Fa / F≤-0.30 -0.383 -0.399 -0.413 -0.382 0.40≤Fb / F≤0.70 0.554 0.555 0.624 0.431 0.70≤F17 / F≤0.85 0.753 0.782 0.765 0.738 -1.75≤F17 / F8≤-1.30 -1.391 -1.373 -1.404 -1.651 1.90≤ND1≤1.95 1.92 1.92 1.92 1.92 90≤VD2≤100 94.5 94.5 94.5 94.5 90≤VD4≤100 94.5 94.5 94.5 94.5

[0161] Table 5

[0162] The present application also provides an electronic device, which may include a viewing lens according to the above-mentioned embodiment of the present application and an imaging element for converting an optical image formed by the viewing lens into an electrical signal.

[0163] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A sighting lens, characterized in that: The aiming lens includes, in order from the object side to the image side along the optical axis: a first lens having positive optical power; a second lens having positive optical power; a third lens having negative optical power; a fourth lens having positive refractive power; a fifth lens having negative optical power, whose object-side surface is concave and whose image-side surface is concave; a sixth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is convex; a seventh lens element having negative optical power, whose object-side surface is concave and whose image-side surface is concave; and The eighth lens with negative optical power has a concave object side surface and a convex image side surface; wherein, A distance TTL from the center of the object-side surface of the first lens to the imaging surface of the aiming and viewing lens on the optical axis and an effective focal length F of the aiming and viewing lens satisfy: 0.85≤TTL / F≤1.

00.

2. The sighting lens according to claim 1, characterized in that: The object side surface of the first lens is convex, and the image side surface is concave; The object side surface of the second lens is convex, and the image side surface is concave; The object side surface of the third lens is convex, and the image side surface is concave; The object side surface of the fourth lens is convex, and the image side surface is convex.

3. The sighting lens according to claim 1, characterized in that: The effective focal length F1 of the first lens and the effective focal length F of the aiming lens satisfy: 0.85≤F1 / F≤1.

15.

4. The sighting lens according to claim 1, characterized in that: The effective focal length F2 of the second lens and the effective focal length F of the aiming lens satisfy: 0.75≤F2 / F≤0.

95.

5. The sighting lens according to claim 1, characterized in that: The sighting lens satisfies one of the following conditions: -0.45≤F3 / F≤-0.35, 0.25≤F4 / F≤0.45, -0.45≤F5 / F≤-0.25, 0.15≤F6 / F≤0.30, -0.45≤F7 / F≤-0.30, -0.65≤F8 / F≤-0.40, Among them, F3 is the effective focal length of the third lens, F4 is the effective focal length of the fourth lens, F5 is the effective focal length of the fifth lens, F6 is the effective focal length of the sixth lens, F7 is the effective focal length of the seventh lens, F8 is the effective focal length of the eighth lens, and F is the effective focal length of the aiming and viewing lens.

6. The sighting lens according to any one of claims 1 to 5, characterized in that: The third lens, the fourth lens and the fifth lens form a triplet lens. The combined focal length Fa of the third lens, the fourth lens and the fifth lens and the effective focal length F of the aiming lens satisfy: -0.50≤Fa / F≤-0.

30.

7. The sighting lens according to any one of claims 1 to 5, characterized in that: The sixth lens and the seventh lens form a doublet lens, The combined focal length Fb of the sixth lens and the seventh lens and the effective focal length F of the aiming lens satisfy the following: 0.40≤Fb / F≤0.

70.

8. The aiming lens according to any one of claims 1 to 5, characterized in that: The combined focal length F17 of the first lens to the seventh lens and the effective focal length F of the aiming lens satisfy: 0.70≤F17 / F≤0.

85.

9. The aiming lens according to any one of claims 1 to 5, characterized in that: A combined focal length F17 of the first to seventh lenses and an effective focal length F8 of the eighth lens satisfy: -1.75≤F17 / F8≤-1.

30.

10. The sighting lens according to any one of claims 1 to 5, characterized in that: The sighting lens satisfies one of the following conditions: 1.90≤ND1≤1.95,90≤VD2≤100,90≤VD4≤100,0.45≤Dmax / TTL≤0.65,2.0≤F / ENPD≤2.25,0.10≤BFL / TTL≤0.25, Wherein, ND1 is the refractive index of the first lens, VD2 is the Abbe number of the second lens, VD4 is the Abbe number of the fourth lens, Dmax is the maximum clear aperture of the aiming and viewing lens, TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the aiming and viewing lens on the optical axis, F is the effective focal length of the aiming and viewing lens, ENPD is the entrance pupil diameter of the aiming and viewing lens, and BFL is the distance from the center of the image side surface of the eighth lens to the imaging surface of the aiming and viewing lens on the optical axis.

Images