sighting lens

Abstract

This application discloses an observation and aiming lens. The observation and aiming lens, along the optical axis from the object side to the image side, sequentially includes: a first lens with positive optical power, its object side being convex and its image side being concave; a second lens with positive optical power, its object side being convex and its image side being concave; a third lens with negative optical power, its object side being convex and its image side being concave; a fourth lens with positive optical power, its object side being convex and its image side being convex; a fifth lens with negative optical power, its object side being concave and its image side being concave; a sixth lens with positive optical power, its object side being convex and its image side being convex; a seventh lens with negative optical power, its object side being concave and its image side being concave; and an eighth lens with negative optical power, its object side being concave and its image side being convex; wherein the effective focal length F4 of the fourth lens and the effective focal length F of the observation and aiming lens satisfy: 0.25≤F4 / F≤0.45.

Description

Technical Field

[0001] This application relates to the field of optical components, and more specifically, to a viewing lens. Background Technology

[0002] Sighting lenses, also known as scopes or sniper scopes, allow users to see targets more clearly. Generally speaking, people have the following four main technical requirements for sighting lenses: 1) As handheld products, sighting lenses prioritize portability, requiring them to be lightweight and compact, thus necessitating miniaturization; 2) Sighting lenses are used for observing object details, where the object-side field of view is relatively small, thus requiring a longer focal length; 3) To meet the need for discerning minute details, high image quality is required; 4) To meet the needs of nighttime observation, infrared confocal focusing is required.

[0003] However, existing sighting lenses still have the following shortcomings: 1) Existing technologies cannot balance lens aperture and high image quality; 2) Existing technologies cannot balance telephoto and shorter overall length; 3) Existing technologies use narrow bands and cannot achieve infrared confocal focus. Summary of the Invention

[0004] This application provides an observation and aiming lens, which comprises, along the optical axis from the object side to the image side, the following in sequence: a first lens with positive optical power, the object side of which is convex and the image side of which is concave; a second lens with positive optical power, the object side of which is convex and the image side of which is concave; a third lens with negative optical power, the object side of which is convex and the image side of which is concave; a fourth lens with positive optical power, the object side of which is convex and the image side of which is convex; a fifth lens with negative optical power, the object side of which is concave and the image side of which is concave; a sixth lens with positive optical power, the object side of which is convex and the image side of which is convex; a seventh lens with negative optical power, the object side of which is concave and the image side of which is concave; and an eighth lens with negative optical power, the object side of which is concave and the image side of which is convex; wherein the effective focal length F4 of the fourth lens and the effective focal length F of the observation and aiming lens satisfy the condition: 0.25≤F4 / F≤0.45.

[0005] In one embodiment, the effective focal length F1 of the first lens and the effective focal length F of the observation lens satisfy: 0.85≤F1 / F≤1.15.

[0006] In one embodiment, the effective focal length F2 of the second lens and the effective focal length F of the observation lens satisfy: 0.75≤F2 / F≤0.95.

[0007] In one embodiment, the effective focal length F3 of the third lens and the effective focal length F of the observation lens satisfy: -0.45≤F3 / F≤-0.35.

[0008] In one embodiment, the effective focal length F5 of the fifth lens and the effective focal length F of the observation lens satisfy: -0.45≤F5 / F≤-0.25.

[0009] In one embodiment, the effective focal length F6 of the sixth lens and the effective focal length F of the observation lens satisfy: 0.15≤F6 / F≤0.30.

[0010] In one embodiment, the effective focal length F7 of the seventh lens and the effective focal length F of the observation lens satisfy: -0.45≤F7 / F≤-0.30.

[0011] In one embodiment, the effective focal length F8 of the eighth lens and the effective focal length F of the observation lens satisfy: -0.65≤F8 / F≤-0.40.

[0012] In one embodiment, the third lens, the fourth lens, and the fifth lens form a cemented triplet lens, and the combined focal length Fa of the third lens, the fourth lens, and the fifth lens satisfies the condition that -0.50≤Fa / F≤-0.30 with respect to the effective focal length F of the viewing lens.

[0013] In one embodiment, the sixth lens and the seventh lens form a cemented doublet lens, and the combined focal length Fb of the sixth lens and the seventh lens satisfies the condition that 0.40≤Fb / F≤0.70 with respect to the effective focal length F of the viewing lens.

[0014] In one embodiment, the combined focal length F17 of the first to seventh lenses and the effective focal length F of the observation lens satisfy: 0.70≤F17 / F≤0.85.

[0015] 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.

[0016] In one embodiment, the refractive index ND1 of the first lens satisfies: 1.90≤ND1≤1.95.

[0017] In one embodiment, the Abbe number VD2 of the second lens satisfies: 90 ≤ VD2 ≤ 100.

[0018] In one implementation, the Abbe number VD4 of the fourth lens satisfies: 90 ≤ VD4 ≤ 100.

[0019] In one embodiment, the maximum aperture Dmax of the observation lens and the distance TTL from the center of the object side of the first lens to the imaging surface of the observation lens on the optical axis satisfy: 0.45≤Dmax / TTL≤0.65.

[0020] In one embodiment, the distance TTL from the center of the object side of the first lens to the imaging surface of the viewing lens on the optical axis satisfies the following condition: 0.85≤TTL / F≤1.00.

[0021] In one implementation, the effective focal length F of the sighting lens and the entrance pupil diameter ENPD of the sighting lens satisfy the following condition: 2.0 ≤ F / ENPD ≤ 2.25.

[0022] In one embodiment, the distance BFL from the center of the image side of the eighth lens to the imaging surface of the viewing lens on the optical axis and the distance TTL from the center of the object side of the first lens to the imaging surface of the viewing lens on the optical axis satisfy: 0.10≤BFL / TTL≤0.25.

[0023] In another aspect, this application provides an electronic device. This electronic device includes a viewing lens according to this application and an imaging element for converting the optical image formed by the viewing lens into an electrical signal.

[0024] The observation and aiming lens provided in this application uses eight lenses. By reasonably setting the optical power and surface shape of each lens and reasonably allocating the focal length value of the fourth lens, the observation and aiming lens provided in this application has at least one beneficial effect such as miniaturization, high image quality, and infrared confocal focus. Attached Figure Description

[0025] Other features, objects, and advantages of this utility application will become more apparent from the following detailed description of the embodiments, taken in conjunction with the accompanying drawings. In the drawings:

[0026] Figure 1 This is a schematic diagram of the observation and aiming lens according to Embodiment 1 of this application;

[0027] Figure 2 The relative illumination curve of the viewing lens according to Embodiment 1 of this application;

[0028] Figure 3 Ray Fan diagram of the viewing lens according to Embodiment 1 of this application;

[0029] Figure 4 This is a schematic diagram of the observation and aiming lens according to Embodiment 2 of this application;

[0030] Figure 5 The relative illumination curve of the viewing lens according to Embodiment 2 of this application;

[0031] Figure 6 Ray Fan diagram of the viewing lens according to Embodiment 2 of this application;

[0032] Figure 7 This is a schematic diagram of the observation and aiming lens according to Embodiment 3 of this application;

[0033] Figure 8 The relative illumination curve of the viewing lens according to Embodiment 3 of this application;

[0034] Figure 9 Ray Fan diagram of the viewing lens according to Embodiment 3 of this application;

[0035] Figure 10 This is a schematic diagram of the observation and aiming lens according to Embodiment 4 of this application;

[0036] Figure 11 The relative illumination curve of the observation lens according to Embodiment 4 of this application; and

[0037] Figure 12 Ray Fan diagram of the viewing lens according to Embodiment 4 of this application. Detailed Implementation

[0038] To facilitate understanding of this application, a more complete description of the application will be provided below with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of the application and are not intended to limit the scope of the 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.

[0039] 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 third lens.

[0040] 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.

[0041] 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 side is called the image-side surface of the lens.

[0042] 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.

[0043] 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 a 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.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] The features, principles and other aspects of this application are described in detail below.

[0046] In an exemplary embodiment, the viewing lens includes, for example, eight lenses with 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. These eight lenses are arranged sequentially along the optical axis from the object side to the image side, and any two adjacent lenses among the first to eighth lenses may have a gap distance between them.

[0047] In an exemplary embodiment, the aiming lens may further include an aperture stop for limiting the light beam, thereby further improving the imaging quality of the aiming lens. Exemplarily, the aperture stop may be positioned between the first lens and the second lens. The aperture stop helps to concentrate the light entering the aiming lens, shorten the overall length of the optical system, reduce the maximum aperture of the aiming lens, and facilitates miniaturization and reduces the system's assembly sensitivity. However, it should be noted that the position of the aperture stop disclosed herein is merely an example and not a limitation; in alternative embodiments, the aperture stop may be positioned in other locations as needed.

[0048] In an exemplary embodiment, the viewing 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 photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS).

[0049] In an exemplary embodiment, the first lens has positive optical power, with a convex object-side surface and a concave image-side surface. The positive optical power of the first lens facilitates light collection, causing the emitted light rays to converge towards the optical axis, reducing the aperture of the rear lens and promoting miniaturization. The concave image-side surface of the first lens helps reduce the angle of incidence of axial rays on the image-side surface, minimizing spherical aberration and contributing to high image quality. Optionally, the first lens may be made of a material with a high refractive index to reduce surface curvature and aberration generation, further enhancing image quality.

[0050] In an exemplary embodiment, the second lens has positive optical power, with a convex object-side surface and a concave image-side surface. The positive optical power and concave image-side surface of the second lens reduce the angle of incidence of axial rays on the image-side surface, thereby reducing spherical aberration and contributing to high image quality. Optionally, the second lens can be combined with a low-dispersion material to reduce chromatic aberration, simplify system calibration, and further enhance image quality.

[0051] In an exemplary embodiment, the third lens has negative optical power, with its object-side surface being convex and its image-side surface being concave. The negative optical power and convex object-side surface of the third lens help to reduce the angle of incidence of on-axis rays on the object-side surface of the third lens, thereby reducing spherical aberration generated on the object-side surface and ultimately contributing to high image quality.

[0052] In an exemplary embodiment, the fourth lens has positive optical power, and both its object-side and image-side surfaces are convex. The fourth lens collectively shares the optical power, reducing surface curvature and aberrations, thus contributing to high image quality.

[0053] In an exemplary embodiment, the fifth lens has negative optical power, and both its object-side and image-side surfaces are concave. The fifth lens shares the optical power, reducing surface curvature and aberrations, thus contributing to high image quality.

[0054] In an exemplary embodiment, the third, fourth, and fifth lenses constitute a cemented triplet lens. The third lens has negative optical power in the cemented triplet lens, and works with the fourth lens to achieve apochromatic aberration, which is beneficial for achieving high image quality. The fourth lens has positive optical power in the cemented triplet lens, and can preferably be paired with a low-dispersion material to apochromatic the system, which is beneficial for achieving infrared confocal aberration; the fourth lens compensates for the on-axis chromatic aberration generated by the first lens, which is beneficial for achieving infrared confocal aberration; overall, the focal length of the cemented triplet lens is negative, generating negative spherical aberration, which compensates for the positive spherical aberration introduced by the first and second lenses, which is beneficial for achieving high image quality. The fifth lens has negative optical power in the cemented triplet lens, and works with the fourth lens to achieve apochromatic aberration, which is beneficial for achieving high image quality.

[0055] In an exemplary embodiment, the sixth lens has positive optical power, and both its object-side and image-side surfaces are convex. The sixth lens shares the optical power, reducing surface curvature and aberrations, thus contributing to high image quality.

[0056] In an exemplary embodiment, the seventh lens has negative optical power, and both its object-side and image-side surfaces are concave. The seventh lens shares the optical power, reduces surface curvature, and minimizes aberrations, which is beneficial for achieving high image quality.

[0057] In an exemplary embodiment, the sixth and seventh lenses are combined to form a cemented doublet lens, which corrects the residual chromatic aberration of the system and facilitates high image quality. The sixth lens has positive optical power in the cemented doublet lens and can be paired with a low-dispersion material to apochromatic the system, which is beneficial for achieving infrared confocal focusing. The seventh lens has negative optical power in the cemented doublet lens, which, together with the sixth lens, achieves apochromatic aberration and is beneficial for achieving high image quality. In addition, the seventh lens has negative optical power, which, together with the eighth lens, gives the rear group of the lens a greater negative optical power, while the front group from the first to the sixth lens has positive optical power. The front and rear combinations constitute the telephoto architecture of the sighting lens, reducing the overall optical length and facilitating miniaturization.

[0058] In an exemplary embodiment, the eighth lens has negative optical power, with its object-side surface being concave and its image-side surface being convex. The first to seventh lenses collectively have positive optical power, and the eighth lens, combined with the first to seventh lenses, constitutes a telephoto architecture, reducing the overall optical length and facilitating miniaturization.

[0059] In an exemplary embodiment, the observation and aiming lens according to this application satisfies the following condition: 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 observation and aiming lens. Satisfying 0.85≤F1 / F≤1.15 allows for a reasonable allocation of the focal length value of the first lens. By collecting light, the light emitted from the first lens is directed closer to the optical axis, reducing the aperture of the rear lens and facilitating miniaturization.

[0060] In an exemplary embodiment, the observation and aiming lens according to this application satisfies: 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 observation and aiming lens. Satisfying 0.75≤F2 / F≤0.95, by reasonably allocating the focal length value of the second lens and using low dispersion materials, reduces the generation of chromatic aberration, lowers the difficulty of system calibration, and is conducive to achieving high image quality.

[0061] In an exemplary embodiment, the observation lens according to this application satisfies: -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 observation lens. It also satisfies -3.7≤F3 / F≤-2.5. By rationally allocating the focal length value of the third lens, the third lens has negative optical power in the cemented lens configuration, which, combined with the fourth lens, achieves apochromatic aberration, thus contributing to high image quality.

[0062] In an exemplary embodiment, the observation and aiming lens according to this application satisfies: 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 observation and aiming lens. Satisfying 0.25≤F4 / F≤0.45, by reasonably allocating the focal length value of the fourth lens, ensures that the fourth lens has positive optical power within the cemented lens system. Combined with low-dispersion materials, this apochromatic effect on the system is beneficial for achieving infrared confocal focusing.

[0063] In an exemplary embodiment, the observation lens according to this application satisfies: -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 observation lens. Satisfying -0.45≤F5 / F≤-0.25, by reasonably allocating the focal length value of the fifth lens, allows the fifth lens to have negative optical power within the cemented lens configuration, achieving apochromatic aberration in conjunction with the fourth lens, which is beneficial for achieving high image quality.

[0064] In an exemplary embodiment, the observation and aiming lens according to this application satisfies: 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 observation and aiming lens. Satisfying 0.15≤F6 / F≤0.30, by reasonably allocating the focal length value of the sixth lens, allows the sixth lens to have positive optical power within the cemented doublet lens. Combined with low-dispersion materials, this apochromatic effect on the system is beneficial for achieving infrared confocal focusing.

[0065] In an exemplary embodiment, the observation lens according to this application satisfies: -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 observation lens. Satisfying -0.45≤F7 / F≤-0.30, by rationally allocating the focal length value of the seventh lens, the seventh lens has negative optical power in the cemented doublet lens, achieving apochromatic effect in conjunction with the sixth lens, which is beneficial for achieving high image quality. By rationally allocating the focal length value of the seventh lens, the seventh lens has negative optical power, which, in conjunction with the eighth lens, gives the rear group of the lens greater negative optical power, while the front group from the first lens to the sixth lens as a whole has positive optical power. The front and rear combinations constitute the telephoto architecture of the observation lens, reducing the overall optical length and facilitating miniaturization.

[0066] In an exemplary embodiment, the observation lens according to this application satisfies: -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 observation lens. By satisfying -0.65≤F8 / F≤-0.40 and rationally allocating the focal length value of the eighth lens, the eighth lens has negative optical power, while the first to seventh lenses as a whole have positive optical power. The eighth lens, combined with the first to seventh lenses, forms a telephoto structure, reducing the overall optical length and facilitating miniaturization.

[0067] In an exemplary embodiment, the observation lens according to this application satisfies: -0.50 ≤ Fa / F ≤ -0.30, where Fa is the combined focal length of the third, fourth, and fifth lenses, and F is the effective focal length of the observation lens. By reasonably allocating the focal length values ​​of the cemented triplet lenses, the cemented triplet lenses compensate for the on-axis chromatic aberration generated by the first lens, which is beneficial for achieving infrared confocality; at the same time, making the focal length value of the cemented triplet lenses negative generates negative spherical aberration, which compensates for the positive spherical aberration introduced by the first and second lenses, which is beneficial for achieving high image quality.

[0068] In an exemplary embodiment, the viewing lens according to this application satisfies: 0.40 ≤ Fb / F ≤ 0.70, where Fb is the combined focal length of the sixth and seventh lenses, and F is the effective focal length of the viewing lens. By reasonably allocating the focal length values ​​of the sixth and seventh lenses, the residual chromatic aberration of the system is corrected, which is beneficial to achieving high image quality.

[0069] In an exemplary embodiment, the aiming lens according to this application satisfies the following condition: 0.70≤F17 / F≤0.85, where F17 is the combined focal length of the first to seventh lenses, and F is the effective focal length of the aiming lens. Satisfying 0.70≤F17 / F≤0.85, by reasonably allocating the combined focal length values ​​of the first to seventh lenses, ensures that the focal length of the front group of lenses formed by the first to seventh lenses is positive, reducing the total optical length and facilitating miniaturization.

[0070] In an exemplary embodiment, the viewing lens according to this application satisfies: -1.75≤F17 / F8≤-1.30, where F17 is the combined focal length of the first to seventh lenses, and F8 is the effective focal length of the eighth lens. By satisfying -1.75≤F17 / F8≤-1.30 and reasonably allocating the combined focal length values ​​of the first to seventh lenses and the focal length value of the eighth lens, the focal length of the front group of lenses (formed by the first to seventh lenses) is positive, and the focal length of the rear group of lenses (formed by the eighth lens) is negative. These two elements constitute a telephoto structure, reducing the overall optical length and facilitating miniaturization.

[0071] In an exemplary embodiment, the viewing lens according to this application satisfies: 1.90≤ND1≤1.95, where ND1 is the refractive index of the first lens. By satisfying 1.90≤ND1≤1.95 and reasonably setting the refractive index of the first lens, the first lens can preferably be made of a material with a higher refractive index, reducing surface curvature, reducing aberrations, and thus contributing to achieving high image quality.

[0072] In an exemplary embodiment, the viewing lens according to this application satisfies: 90≤VD2≤100, where VD2 is the Abbe number of the second lens. Satisfying 90≤VD2≤100, by reasonably setting the Abbe number of the second lens, reduces the generation of chromatic aberration, lowers the difficulty of chromatic aberration correction in the system, and facilitates the realization of infrared confocal focusing.

[0073] In an exemplary embodiment, the viewing lens according to this application satisfies: 90≤VD4≤100, where VD4 is the Abbe number of the fourth lens. Satisfying 90≤VD4≤100, by reasonably setting the Abbe number of the fourth lens, reduces the generation of chromatic aberration, lowers the difficulty of chromatic aberration correction in the system, and is beneficial for achieving infrared confocal focusing.

[0074] In an exemplary embodiment, the aiming lens according to this application satisfies the following condition: 0.45 ≤ Dmax / TTL ≤ 0.65, where TTL is the distance on the optical axis from the center of the object-side surface of the first lens to the imaging surface of the aiming lens, and Dmax is the maximum aperture of the aiming lens. Satisfying 0.45 ≤ Dmax / TTL ≤ 0.65, within a given total system optical length, controls the maximum aperture of the aiming lens to be relatively small, which is beneficial for miniaturization.

[0075] In an exemplary embodiment, the aiming lens according to this application satisfies the following condition: 0.85 ≤ TTL / F ≤ 1.00, where F is the effective focal length of the aiming lens, and TTL is the distance along the optical axis from the center of the object-side surface of the first lens to the imaging surface of the aiming lens. Satisfying 0.85 ≤ TTL / F ≤ 1.00, under a given system focal length value, by controlling the overall optical length of the system, the overall optical length of the system is made smaller, which is beneficial for miniaturization.

[0076] In an exemplary embodiment, the aiming lens according to this application satisfies: 2.0 ≤ F / ENPD ≤ 2.25, where F is the effective focal length of the aiming lens and ENPD is the entrance pupil diameter of the aiming lens. Satisfying 2.0 ≤ F / ENPD ≤ 2.25, by controlling the size of the system's entrance pupil diameter, allows the system to have a smaller aperture value, which is beneficial for achieving a large aperture.

[0077] In an exemplary embodiment, the aiming lens according to this application satisfies: 0.10 ≤ BFL / TTL ≤ 0.25, where BFL is the distance on the optical axis from the center of the image-side surface of the eighth lens to the imaging surface of the aiming lens, and TTL is the distance on the optical axis from the center of the object-side surface of the first lens to the imaging surface of the aiming lens. Satisfying 0.10 ≤ BFL / TTL ≤ 0.25 allows the system to control the entrance pupil diameter, resulting in a smaller aperture value, which is beneficial for achieving a large aperture.

[0078] In the observation and aiming lens of this application, the third lens, the fourth lens, and the fifth lens constitute a cemented triplet lens. 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 higher Abbe number, which is beneficial for correcting chromatic aberration. The third, fourth, and fifth lenses, through the combination of materials and optical power, correct their own aberrations, which is beneficial for reducing tolerance sensitivity.

[0079] In the observation and aiming lens of this application, the sixth lens and the seventh lens form a cemented doublet lens. The sixth lens has positive optical power and the seventh lens has negative optical power. The sixth lens can be made of a material with a higher Abbe number, which is beneficial for correcting chromatic aberration. The sixth and seventh lenses, through the combination of materials and optical power, correct their own aberrations, which is beneficial for reducing tolerance sensitivity.

[0080] The observation and aiming lens of this application has a long focal length, which can meet the usage range of a telephoto lens. In an exemplary embodiment, the effective focal length F of the observation and aiming lens of this application can reach 60mm.

[0081] Optionally, in an exemplary embodiment, the viewing lens of this application may further include a filter and / or protective glass disposed between the eighth lens and the imaging surface, as needed, to filter light of different wavelengths and prevent damage to the image-side elements (e.g., chips) of the viewing lens.

[0082] In an exemplary embodiment, the first to eighth lenses can be spherical lenses or aspherical lenses. This application does not specifically limit the number of spherical and aspherical lenses; when image quality is a primary concern, the number of aspherical lenses can be increased, and even all lenses can be aspherical. Aspherical lenses are characterized by a continuously changing curvature from the lens center to the periphery. Unlike spherical lenses, which have a constant curvature from the lens center to the periphery, aspherical lenses have better radius of curvature characteristics, offering advantages in improving distortion and astigmatism. Using aspherical lenses can minimize aberrations that occur during imaging, thereby improving the lens's image quality. Optionally, the object-side and image-side surfaces of all lenses in the first to eighth lenses are spherical mirror surfaces.

[0083] The observation and aiming lens according to the above embodiments of this application can use multiple lenses, such as the eight lenses mentioned above. By reasonably allocating optical parameters such as the optical power, surface shape, center thickness of each lens, and on-axis spacing between each lens, at least one of the following can be achieved in the observation and aiming lens: long focal length, miniaturization, high image quality, and infrared confocal focus.

[0084] The aiming lens according to the above embodiments of this application can employ multiple lenses, such as the eight lenses described above. However, those skilled in the art should understand that the number of lenses constituting the lens can be changed without departing from the technical solutions claimed in this application to obtain the various results and advantages described in this specification. For example, although eight lenses are described as an example in the embodiments, the aiming lens is not limited to including eight lenses. If necessary, the aiming lens may also include other numbers of lenses. Specific embodiments of the aiming lens applicable to the above embodiments are further described below with reference to the accompanying drawings.

[0085] Example 1

[0086] The following is for reference Figure 1 A viewing lens according to Embodiment 1 of this application is described. Figure 1 A schematic diagram of the observation and aiming lens according to Embodiment 1 of this application is shown.

[0087] like Figure 1 As shown, the viewing lens includes, along the optical axis from the object side to the image side, 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. Among them, the third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens, and the sixth lens L6 and the seventh lens L7 form a cemented doublet lens.

[0088] The first lens L1 has positive optical power, with its object side S1 being convex and its image side S2 being concave.

[0089] The second lens L2 has positive optical power, with its object side S4 being convex and its image side S5 being concave.

[0090] The third lens L3 has negative optical power, with its object side S6 being convex and its image side S7 being concave.

[0091] The fourth lens L4 has positive optical power, and its object side S7 is convex, while its image side S8 is convex.

[0092] The fifth lens L5 has negative optical power, and its object side S8 is concave, as is its image side S9.

[0093] The sixth lens L6 has positive optical power, and its object side S10 is convex, and its image side S11 is convex.

[0094] The seventh lens L7 has negative optical power, and its object side S11 is concave, and its image side S12 is concave.

[0095] The eighth lens L8 has negative optical power, with its object side S13 being concave and its image side S14 being convex.

[0096] The viewing lens may also include an aperture stop STO, which may be set between the first lens L1 and the second lens L2.

[0097] Optionally, the viewing lens may also 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 can be used to correct color deviations, and can also be used to protect the image sensor chip located at the imaging surface IMA. Light from the object passes sequentially through each surface S1 to S16 and is finally imaged onto the imaging surface IMA.

[0098] Table 1 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens in the observation and aiming lens of Example 1, wherein the units of radius of curvature and thickness / distance are millimeters (mm).

[0099]

[0100]

[0101] Table 1

[0102] Figure 2 The relative illumination curve of the viewing lens in Embodiment 1 is shown, which represents the relative illumination magnitude value corresponding to different fields of view. Figure 3 A Ray Fan diagram of the observation and aiming lens of Embodiment 1 is shown, representing the aberrations corresponding to different fields of view. According to... Figure 2 and Figure 3 It can be seen that the observation and aiming lens given in Example 1 has the characteristics of high illumination and low aberration, and can achieve good imaging quality.

[0103] Example 2

[0104] The following is for reference Figure 4 A viewing lens according to Embodiment 2 of this application is described. Figure 4 A schematic diagram of the observation and aiming lens according to Embodiment 2 of this application is shown.

[0105] like Figure 4As shown, the viewing lens includes, along the optical axis from the object side to the image side, 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. Among them, the third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens, and the sixth lens L6 and the seventh lens L7 form a cemented doublet lens.

[0106] The first lens L1 has positive optical power, with its object side S1 being convex and its image side S2 being concave.

[0107] The second lens L2 has positive optical power, with its object side S4 being convex and its image side S5 being concave.

[0108] The third lens L3 has negative optical power, with its object side S6 being convex and its image side S7 being concave.

[0109] The fourth lens L4 has positive optical power, and its object side S7 is convex, while its image side S8 is convex.

[0110] The fifth lens L5 has negative optical power, and its object side S8 is concave, as is its image side S9.

[0111] The sixth lens L6 has positive optical power, and its object side S10 is convex, and its image side S11 is convex.

[0112] The seventh lens L7 has negative optical power, and its object side S11 is concave, and its image side S12 is concave.

[0113] The eighth lens L8 has negative optical power, with its object side S13 being concave and its image side S14 being convex.

[0114] The viewing lens may also include an aperture stop STO, which may be set between the first lens L1 and the second lens L2.

[0115] Optionally, the viewing lens may also 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 can be used to correct color deviations, and can also be used to protect the image sensor chip located at the imaging surface IMA. Light from the object passes sequentially through each surface S1 to S16 and is finally imaged onto the imaging surface IMA.

[0116] Table 2 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens in the observation and aiming lens of Example 2, wherein the units of radius of curvature and thickness / distance are millimeters (mm).

[0117]

[0118]

[0119] Table 2

[0120] Figure 5 The relative illumination curve of the viewing lens in Embodiment 2 is shown, which represents the relative illumination magnitude value corresponding to different fields of view. Figure 6 A Ray Fan diagram of the observation and aiming lens of Embodiment 2 is shown, representing the aberrations corresponding to different fields of view. According to... Figure 5 and Figure 6 It can be seen that the observation and aiming lens given in Example 2 has the characteristics of high illumination and low aberration, and can achieve good imaging quality.

[0121] Example 3

[0122] The following is for reference Figure 7 A viewing lens according to Embodiment 3 of this application is described. Figure 7 A schematic diagram of the observation and aiming lens according to Embodiment 3 of this application is shown.

[0123] like Figure 7 As shown, the viewing lens includes, along the optical axis from the object side to the image side, 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. Among them, the third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens, and the sixth lens L6 and the seventh lens L7 form a cemented doublet lens.

[0124] The first lens L1 has positive optical power, with its object side S1 being convex and its image side S2 being concave.

[0125] The second lens L2 has positive optical power, with its object side S4 being convex and its image side S5 being concave.

[0126] The third lens L3 has negative optical power, with its object side S6 being convex and its image side S7 being concave.

[0127] The fourth lens L4 has positive optical power, and its object side S7 is convex, while its image side S8 is convex.

[0128] The fifth lens L5 has negative optical power, and its object side S8 is concave, as is its image side S9.

[0129] The sixth lens L6 has positive optical power, and its object side S10 is convex, and its image side S11 is convex.

[0130] The seventh lens L7 has negative optical power, and its object side S11 is concave, and its image side S12 is concave.

[0131] The eighth lens L8 has negative optical power, with its object side S13 being concave and its image side S14 being convex.

[0132] The viewing lens may also include an aperture stop STO, which may be set between the first lens L1 and the second lens L2.

[0133] Optionally, the viewing lens may also 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 can be used to correct color deviations, and can also be used to protect the image sensor chip located at the imaging surface IMA. Light from the object passes sequentially through each surface S1 to S16 and is finally imaged onto the imaging surface IMA.

[0134] Table 3 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens in the observation and aiming lens of Example 3, wherein the units of radius of curvature and thickness / distance are millimeters (mm).

[0135]

[0136] Table 3

[0137] Figure 8 The relative illumination curve of the viewing lens in Example 3 is shown, which represents the relative illumination magnitude value corresponding to different fields of view. Figure 9 A Ray Fan diagram of the observation and aiming lens of Embodiment 3 is shown, representing the aberrations corresponding to different fields of view. According to... Figure 8 and Figure 9 It can be seen that the observation and aiming lens given in Example 3 has the characteristics of high illumination and low aberration, and can achieve good imaging quality.

[0138] Example 4

[0139] The following is for reference Figure 10 A viewing lens according to Embodiment 4 of this application is described. Figure 10 A schematic diagram of the observation and aiming lens according to Embodiment 4 of this application is shown.

[0140] like Figure 10 As shown, the viewing lens includes, along the optical axis from the object side to the image side, 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. Among them, the third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens, and the sixth lens L6 and the seventh lens L7 form a cemented doublet lens.

[0141] The first lens L1 has positive optical power, with its object side S1 being convex and its image side S2 being concave.

[0142] The second lens L2 has positive optical power, with its object side S4 being convex and its image side S5 being concave.

[0143] The third lens L3 has negative optical power, with its object side S6 being convex and its image side S7 being concave.

[0144] The fourth lens L4 has positive optical power, and its object side S7 is convex, while its image side S8 is convex.

[0145] The fifth lens L5 has negative optical power, and its object side S8 is concave, as is its image side S9.

[0146] The sixth lens L6 has positive optical power, and its object side S10 is convex, and its image side S11 is convex.

[0147] The seventh lens L7 has negative optical power, and its object side S11 is concave, and its image side S12 is concave.

[0148] The eighth lens L8 has negative optical power, with its object side S13 being concave and its image side S14 being convex.

[0149] The viewing lens may also include an aperture stop STO, which may be set between the first lens L1 and the second lens L2.

[0150] Optionally, the viewing lens may also 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 can be used to correct color deviations, and can also be used to protect the image sensor chip located at the imaging surface IMA. Light from the object passes sequentially through each surface S1 to S16 and is finally imaged onto the imaging surface IMA.

[0151] Table 4 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens in the viewing lens of Example 4, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0152]

[0153] Table 4

[0154] Figure 11 The relative illumination curve of the viewing lens in Example 4 is shown, which represents the relative illumination magnitude values ​​corresponding to different fields of view. Figure 12 A Ray Fan diagram of the observation and aiming lens of Embodiment 4 is shown, representing the aberrations corresponding to different fields of view. According to... Figure 11 and Figure 12 It can be seen that the observation and aiming lens given in Example 4 has the characteristics of high illumination and low aberration, and can achieve good imaging quality.

[0155] In summary, Examples 1 to 4 satisfy the relationships shown in Table 5 below.

[0156] Conditional Implementation Examples Example 1 Example 2 Example 3 Example 4 0.45≤Dmax / TTL≤0.65 0.506 0.506 0.502 0.549 0.85≤TTL / F≤1.00 0.908 0.908 0.917 0.917 2.00≤F / ENPD≤2.25 2.200 2.200 2.200 2.050 0.10≤BFL / TTL≤0.25 0.194 0.189 0.181 0.174 0.85≤F1 / F≤1.15 0.935 0.914 0.915 0.986 0.75≤F² / F≤0.95 0.820 0.823 0.838 0.816 -0.45≤F3 / F≤-0.35 -0.390 -0.391 -0.401 -0.392 0.25≤F4 / F≤0.45 0.343 0.352 0.364 0.329 -0.45≤F5 / F≤-0.25 -0.327 -0.348 -0.365 -0.307 0.15≤F6 / F≤0.30 0.214 0.218 0.228 0.192 -0.45≤F7 / F≤-0.30 -0.341 -0.334 -0.350 -0.333 -0.65≤F8 / F≤-0.40 -0.542 -0.545 -0.545 -0.447 -0.50≤Fa / F≤-0.30 -0.383 -0.398 -0.413 -0.382 0.40≤Fb / F≤0.70 0.554 0.598 0.624 0.431 0.70≤F17 / F≤0.85 0.753 0.759 0.765 0.738 -1.75≤F17 / F8≤-1.30 -1.391 -1.393 -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

[0157] Table 5

[0158] This application also provides an electronic device that may include a viewing lens according to the above embodiments of this application and an imaging element for converting the optical image formed by the viewing lens into an electrical signal.

[0159] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A sighting lens characterized in that, The observation and aiming lens, along the optical axis from the object side to the image side, includes, in sequence: The first lens with positive optical power has a convex object side and a concave image side. A second lens with positive optical power has a convex object-side surface and a concave image-side surface; A third lens with negative optical power has a convex object side and a concave image side. The fourth lens with positive optical power has a convex object-side surface and a convex image-side surface; The fifth lens with negative optical power has a concave object side and a concave image side. The sixth lens has positive optical power, with both its object-side and image-side surfaces being convex. A seventh lens with negative optical power, its object-side surface is concave, and its image-side surface is concave; and The eighth lens, possessing negative optical power, has a concave object-side surface and a convex image-side surface; among which, The effective focal length F4 of the fourth lens and the effective focal length F of the observation lens satisfy the following condition: 0.25≤F4 / F≤0.45; The effective focal length F8 of the eighth lens and the effective focal length F of the observation lens satisfy the following condition: -0.65≤F8 / F≤-0.40; The number of lenses with optical power in the observation and aiming lens is eight.

2. The viewing lens of claim 1, wherein, The effective focal length F1 of the first lens and the effective focal length F of the observation lens satisfy the following condition: 0.85≤F1 / F≤1.

15.

3. The viewing lens of claim 1, wherein, The effective focal length F2 of the second lens and the effective focal length F of the observation lens satisfy the condition: 0.75≤F2 / F≤0.

95.

4. The viewing lens of claim 1, wherein, The effective focal length F3 of the third lens and the effective focal length F of the observation lens satisfy the following condition: -0.45≤F3 / F≤-0.

35.

5. The viewing lens of claim 1, wherein, The effective focal length F5 of the fifth lens and the effective focal length F of the observation lens satisfy the following condition: -0.45≤F5 / F≤-0.

25.

6. The viewing lens of claim 1, wherein, The effective focal length F6 of the sixth lens and the effective focal length F of the observation lens satisfy the following condition: 0.15≤F6 / F≤0.

30.

7. The viewing lens of claim 1, wherein, The effective focal length F7 of the seventh lens and the effective focal length F of the observation lens satisfy the following condition: -0.45≤F7 / F≤-0.

30.

8. The sighting lens of any one of claims 1-7, wherein, The third lens, the fourth lens, and the fifth lens together form a cemented triplet lens. The combined focal length Fa of the third lens, the fourth lens, and the fifth lens satisfies the following condition with the effective focal length F of the observation lens: -0.50≤Fa / F≤-0.

30.

9. The sighting lens of any one of claims 1-7, wherein, The sixth lens and the seventh lens together form a cemented doublet lens. The combined focal length Fb of the sixth lens and the seventh lens and the effective focal length F of the observation lens satisfy the following condition: 0.40≤Fb / F≤0.

70.

10. The sighting lens of any one of claims 1-7, wherein, The combined focal length F17 of the first lens to the seventh lens and the effective focal length F of the observation lens satisfy: 0.70≤F17 / F≤0.

85.

11. The sighting lens of any one of claims 1-7, wherein, The combined focal length F17 of the first lens to the seventh lens and the effective focal length F8 of the eighth lens satisfy: -1.75≤F17 / F8≤-1.

30.

12. The sighting lens of any one of claims 1-7, wherein, The refractive index ND1 of the first lens satisfies: 1.90≤ND1≤1.

95.

13. The observation and aiming lens according to any one of claims 1-7, wherein, The Abbe number VD2 of the second lens satisfies: 90≤VD2≤100.

14. The observation and aiming lens according to any one of claims 1-7, wherein, The Abbe number VD4 of the fourth lens satisfies: 90≤VD4≤100.

15. The observation and aiming lens according to any one of claims 1-7, wherein, The maximum aperture Dmax of the observation lens and the distance TTL from the center of the object side of the first lens to the imaging surface of the observation lens on the optical axis satisfy the following condition: 0.45≤Dmax / TTL≤0.

65.

16. The observation and aiming lens according to any one of claims 1-7, wherein, The distance TTL from the center of the object side of the first lens to the imaging surface of the sighting lens on the optical axis and the effective focal length F of the sighting lens satisfy: 0.85≤TTL / F≤1.

00.

17. The observation and aiming lens according to any one of claims 1-7, wherein, The effective focal length F of the sighting lens and the entrance pupil diameter ENPD of the sighting lens satisfy the following condition: 2.0≤F / ENPD≤2.

25.

18. The observation and aiming lens according to any one of claims 1-7, wherein, The distance BFL from the center of the image side of the eighth lens to the imaging surface of the sighting lens on the optical axis and the distance TTL from the center of the object side of the first lens to the imaging surface of the sighting lens on the optical axis satisfy the following condition: 0.10 ≤ BFL / TTL ≤ 0.

25.

19. The observation and aiming lens according to claim 1, wherein, The observation and aiming lens satisfies any one of the following conditions: 0.329≤F4 / F≤0.364 0.914≤F1 / F≤0.986 0.816≤F² / F≤0.838 -0.401≤F3 / F≤-0.390, -0.365≤F5 / F≤-0.307, 0.192≤F6 / F≤0.228 -0.350≤F7 / F≤-0.333, -0.545≤F8 / F≤-0.447, -0.413≤Fa / F≤-0.382, 0.431≤Fb / F≤0.624, 0.738≤F17 / F≤0.765 -1.651≤F17 / F8≤-1.391, 1.90≤ND1≤1.92, 90≤VD2≤94.5, 90≤VD4≤94.5, 0.502≤Dmax / TTL≤0.549 0.908≤TTL / F≤0.917 2.050≤F / ENPD≤2.200 0.174≤BFL / TTL≤0.194 Wherein, F1 is the effective focal length of the first lens, F2 is the effective focal length of the second lens, F3 is the effective focal length of the third lens, 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, Fa is the combined focal length of the third, fourth, and fifth lenses, Fb is the combined focal length of the sixth and seventh lenses, F17 is the combined focal length of the first to the seventh lenses, 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 aperture of the sighting lens, TTL is the distance from the center of the object side of the first lens to the imaging surface of the sighting lens on the optical axis, ENPD is the entrance pupil diameter of the sighting lens, and BFL is the distance from the center of the image side of the eighth lens to the imaging surface of the sighting lens on the optical axis.

Images