Optical lens

Abstract

This application discloses an optical lens. The optical lens, along its optical axis from the object side to the image side, sequentially comprises: a first lens with negative optical power, its object side being convex and its image side being concave; a second lens with negative optical power, its object side being convex and its image side being concave; a third lens with negative optical power, its object side being concave and its image side being concave; a fourth lens with positive optical power, its object side being convex; a fifth lens with positive optical power, its object side being convex and its image side being convex; 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 positive optical power, its object side being convex and its image side being convex; wherein the effective focal length F6 of the sixth lens, the effective focal length F7 of the seventh lens, and the effective focal length F of the optical lens satisfy: 0.3≤|(F6+F7)| / F≤0.9.

Description

Technical Field

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

[0002] With the advancement of technology, fisheye lenses have become increasingly sophisticated in design. Modern fisheye lenses can capture more realistic images and have undergone significant technological improvements to address distortion issues, such as multi-element optical lens designs and traveling metering. Currently, fisheye lenses have become an essential product for almost all lens manufacturers. Simultaneously, due to the widespread adoption and development of panoramic imaging technology, fisheye lenses are finding increasingly wider applications in VR, AR, and panoramic photography.

[0003] However, most fisheye lenses on the market currently have the following problems:

[0004] 1. Most ultra-wide-angle lenses on the market achieve image quality at the expense of distortion;

[0005] 2. Ultra-wide-angle lenses on the market that can meet image quality requirements often have very small apertures, making them unsuitable for dark environments such as nighttime or rainy days.

[0006] Therefore, there is an urgent need in the market for an ultra-wide-angle lens that can achieve a large aperture, high resolution, and infrared confocal focus. Summary of the Invention

[0007] This application provides an optical lens comprising, along the optical axis from the object side to the image side, the following components in sequence: a first lens with negative optical power, having a convex object side and a concave image side; a second lens with negative optical power, having a convex object side and a concave image side; a third lens with negative optical power, having a concave object side and a concave image side; a fourth lens with positive optical power, having a convex object side; a fifth lens with positive optical power, having a convex object side and a convex image side; a sixth lens with positive optical power, having a convex object side and a convex image side; a seventh lens with negative optical power, having a concave object side and a concave image side; and an eighth lens with positive optical power, having a convex object side and a convex image side; wherein the effective focal length F6 of the sixth lens, the effective focal length F7 of the seventh lens, and the effective focal length F of the optical lens satisfy the following condition: 0.3 ≤ |(F6+F7)| / F ≤ 0.9.

[0008] In one embodiment, the effective focal length F1 of the first lens and the effective focal length F of the optical lens satisfy: -13.2≤F1 / F≤-9.0.

[0009] In one embodiment, the effective focal length F2 of the second lens and the effective focal length F of the optical lens satisfy: -3.0≤F2 / F≤-2.4.

[0010] In one embodiment, the effective focal length F2 of the second lens, the effective focal length F3 of the third lens, and the effective focal length F of the optical lens satisfy: 0≤|(F3-F2)| / F≤0.9.

[0011] In one embodiment, the effective focal length F3 of the third lens and the effective focal length F of the optical lens satisfy: -3.7≤F3 / F≤-2.5.

[0012] In one embodiment, the effective focal length F4 of the fourth lens and the effective focal length F of the optical lens satisfy: 3.2≤F4 / F≤3.8.

[0013] In one embodiment, the effective focal length F5 of the fifth lens and the effective focal length F of the optical lens satisfy: 3.2≤F5 / F≤3.8.

[0014] In one embodiment, the effective focal length F6 of the sixth lens and the effective focal length F of the optical lens satisfy: 2.5≤F6 / F≤3.1.

[0015] In one embodiment, the effective focal length F7 of the seventh lens and the effective focal length F of the optical lens satisfy: -2.4≤F7 / F≤-1.9.

[0016] In one embodiment, the combined focal length F67 of the sixth and seventh lenses satisfies the following condition with respect to the effective focal length F of the optical lens: -30.2 ≤ F67 / F ≤ -10.6.

[0017] In one embodiment, the effective focal length F8 of the eighth lens and the effective focal length F of the optical lens satisfy: 3.6≤F8 / F≤5.2.

[0018] In one embodiment, the combined focal length Fa of the first lens, the second lens, the third lens and the fourth lens satisfies the effective focal length F of the optical lens: -2.4≤Fa / F≤-1.5.

[0019] In one embodiment, the combined focal length Fb of the fifth, sixth, seventh, and eighth lenses and the effective focal length F of the optical lens satisfy the condition: 2.6 ≤ Fb / F ≤ 3.0.

[0020] In one embodiment, the combined focal length Fa of the first lens, the second lens, the third lens and the fourth lens and the combined focal length Fb of the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -1.0≤Fa / Fb≤-0.4.

[0021] In one embodiment, the center thickness CT6 of the sixth lens on the optical axis and the center thickness CT7 of the seventh lens on the optical axis satisfy: 3.1≤CT6 / CT7≤4.4.

[0022] In one embodiment, the maximum aperture D1 of the first lens and the distance TTL from the center of the object side of the first lens to the imaging surface of the optical lens on the optical axis satisfy: 0.7≤D1 / TTL≤1.1.

[0023] In one embodiment, the optical lens further includes an aperture stop disposed between the fourth lens and the fifth lens, wherein the distance TTL from the center of the object side of the first lens to the imaging surface of the optical lens on the optical axis, the distance T4 from the image side of the fourth lens to the aperture stop on the optical axis, and the center thickness CT4 of the fourth lens on the optical axis satisfy: 13.3≤TTL / (T4+CT4)≤17.1.

[0024] In one embodiment, the distance D12 from the center of the image side of the first lens to the center of the object side of the second lens on the optical axis, the distance D45 from the center of the image side of the fourth lens to the center of the object side of the fifth 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 optical lens on the optical axis satisfy: 0≤(D12+D45) / TTL≤0.3.

[0025] In one embodiment, the distance TTL from the center of the object side of the first lens to the imaging plane of the optical lens on the optical axis satisfies the following condition: 14.7≤TTL / F≤15.5.

[0026] In one embodiment, the distance BFL from the center of the image side of the eighth lens to the imaging surface of the optical 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 optical lens on the optical axis satisfy: 0.1≤BFL / TTL≤0.3.

[0027] In another aspect, this application provides an electronic device. This electronic device includes an optical lens according to this application and an imaging element for converting an optical image formed by the optical lens into an electrical signal.

[0028] The optical lens provided in this application is an eight-element ultra-wide-angle lens. By reasonably setting the optical power and surface shape of each lens and balancing the optical power of the sixth and seventh lenses, it is beneficial to achieve the lens's performance in the infrared state, so that the optical lens provided in this application has at least one beneficial effect such as ultra-wide-angle, large aperture, high resolution, and infrared confocal. Attached Figure Description

[0029] 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:

[0030] Figure 1 This is a schematic diagram of the structure of an optical lens according to Embodiment 1 of this application;

[0031] Figure 2 This is a schematic diagram of the structure of an optical lens according to Embodiment 2 of this application;

[0032] Figure 3 This is a schematic diagram of the structure of an optical lens according to Embodiment 3 of this application; and

[0033] Figure 4 This is a schematic diagram of the structure of an optical lens according to Embodiment 4 of this application. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] The features, principles and other aspects of this application are described in detail below.

[0042] In an exemplary embodiment, the optical 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.

[0043] In an exemplary embodiment, the sixth lens and the seventh lens are cemented together to form a cemented lens.

[0044] In an exemplary embodiment, the optical lens may further include an aperture stop for limiting the light beam, thereby further improving the imaging quality of the optical lens. Exemplarily, the aperture stop may be positioned between the fourth and fifth lenses. The aperture stop helps to concentrate the light entering the optical lens, shorten the overall length of the optical system, reduce the maximum aperture of the optical lens, facilitate miniaturization, and reduce the system's assembly sensitivity. However, it should be noted that the positions of the aperture stop disclosed herein are merely examples and not limitations; in alternative embodiments, the aperture stop may be positioned in other locations as needed.

[0045] In an exemplary embodiment, the optical 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).

[0046] In an exemplary embodiment, the first lens has negative optical power, with its object-side surface being convex and its image-side surface being concave. This configuration of the first lens can effectively collect light from a large field of view, which is beneficial for tracing the large field of view light entering the optical system to the rear optical system, thereby reducing the incident angle of the rear light.

[0047] In an exemplary embodiment, the second lens has negative optical power, with its object-side surface being convex and its image-side surface being concave. This configuration of the second lens can effectively share the negative optical power of the first lens and also achieve re-deflection of incident light rays at larger angles, which is beneficial for tracking light rays at the rear.

[0048] In an exemplary embodiment, the third lens has negative optical power, with both its object-side and image-side surfaces being concave. This configuration of the third lens deflects the incident light rays to balance the angle of incidence. Simultaneously, its shape increases the aperture to adjust the optical path and enhance peripheral brightness.

[0049] In an exemplary embodiment, the fourth lens has positive optical power and its object-side surface is convex. The fourth lens can effectively suppress the light rays incident from the front end, making the light rays easier to track.

[0050] In an exemplary embodiment, the fifth lens has positive optical power, and both its object-side and image-side surfaces are convex. This configuration of the fifth lens can compensate for the negative lens at the front, which is beneficial for aberration correction and thus improves image quality. At the same time, it can also suppress large-angle light rays near the aperture stop, adjust the light path, and optimize tolerances.

[0051] In an exemplary embodiment, the sixth lens has positive optical power, and both its object-side and image-side surfaces are convex. This arrangement of the sixth lens allows for better control of incident light near the aperture stop, enabling more light to enter the rear lens.

[0052] In an exemplary embodiment, the seventh lens has negative optical power, and both its object-side and image-side surfaces are concave. This configuration of the seventh lens effectively compensates for the sixth lens, achieving aberration compensation.

[0053] In an exemplary embodiment, the sixth and seventh lenses are cemented lenses with positive and negative optical powers. These lenses can not only correct chromatic aberration well, but also effectively reduce the impact of tolerances.

[0054] In an exemplary embodiment, the eighth lens has positive optical power, and both its object-side and image-side surfaces are convex. This configuration of the eighth lens is beneficial for correcting the additional negative optical power of the front lens. In addition, the eighth lens is preferably an aspherical lens, which can correct for edge field-of-view distortion, thereby improving the resolving power of the lens.

[0055] In an exemplary embodiment, the optical lens according to this application satisfies: 0.3 ≤ |(F6+F7)| / F ≤ 0.9, where F6 is the effective focal length of the sixth lens, F7 is the effective focal length of the seventh lens, and F is the effective focal length of the optical lens. Satisfying 0.3 ≤ |(F6+F7)| / F ≤ 0.9, under a given system focal length value, by controlling the optical power of the sixth and seventh lenses, it is beneficial to balance the distribution of the optical power of the sixth and seventh lenses, and simultaneously improve the lens performance in infrared conditions.

[0056] In an exemplary embodiment, the optical lens according to this application satisfies: -13.2 ≤ F1 / F ≤ -9.0, where F1 is the effective focal length of the first lens and F is the effective focal length of the optical lens. Satisfying -13.2 ≤ F1 / F ≤ -9.0 ensures manufacturability while effectively collecting light from a large field of view, which is beneficial for controlling transverse chromatic aberration at a large field of view and also meets the imaging requirements of an ultra-wide-angle lens.

[0057] In an exemplary embodiment, the maximum field of view (FOV) of the optical lens according to this application satisfies: FOV ≥ 185°.

[0058] In an exemplary embodiment, the optical lens according to this application satisfies: -3.0 ≤ F2 / F ≤ -2.4, where F2 is the effective focal length of the second lens and F is the effective focal length of the optical lens. By satisfying -3.0 ≤ F2 / F ≤ -2.4 and reasonably controlling the focal length value of the second lens, the negative optical power of the first lens can be effectively shared, which is beneficial for light to enter the system more smoothly.

[0059] In an exemplary embodiment, the optical lens according to this application satisfies: 0 ≤ |(F3-F2)| / F ≤ 0.9, where F2 is the effective focal length of the second lens, F3 is the effective focal length of the third lens, and F is the effective focal length of the optical lens. Satisfying 0 ≤ |(F3-F2)| / F ≤ 0.9 helps to widen the beam width, allowing large-angle light rays to be fully transmitted to the rear optical system after passing through the third lens, thereby obtaining a wider field of view and higher relative illumination.

[0060] In an exemplary embodiment, the optical lens according to this application satisfies: -3.7 ≤ F3 / F ≤ -2.5, where F3 is the effective focal length of the third lens and F is the effective focal length of the optical lens. Satisfying -3.7 ≤ F3 / F ≤ -2.5 helps to balance the angle of incidence while also slightly diverging the light beam after passing through the second lens to obtain a higher light transmission.

[0061] In an exemplary embodiment, the optical lens according to this application satisfies: 3.2 ≤ F4 / F ≤ 3.8, where F4 is the effective focal length of the fourth lens and F is the effective focal length of the optical lens. Satisfying 3.2 ≤ F4 / F ≤ 3.8 is beneficial for compensating for the negative optical power of the third lens, effectively reducing the primary aberrations caused by the third lens, and also mitigating changes in the shape of the fifth lens.

[0062] In an exemplary embodiment, the optical lens according to this application satisfies: 3.2 ≤ F5 / F ≤ 3.8, where F5 is the effective focal length of the fifth lens and F is the effective focal length of the optical lens. Satisfying 3.2 ≤ F5 / F ≤ 3.8 can effectively compensate for the negative optical power of the first, second, and third lenses. At the same time, it also helps to improve the spherical aberration and coma caused by the first to fourth lenses, thereby improving the imaging quality of the optical system.

[0063] In an exemplary embodiment, the optical lens according to this application satisfies: 2.5 ≤ F6 / F ≤ 3.1, where F6 is the effective focal length of the sixth lens and F is the effective focal length of the optical lens. Satisfying 2.5 ≤ F6 / F ≤ 3.1 can effectively control the incident light near the aperture stop, which is beneficial for light tracking, making the light entering the seventh lens more stable, and can also optimize aberrations.

[0064] In an exemplary embodiment, the optical lens according to this application satisfies: -2.4≤F7 / F≤-1.9, where F7 is the effective focal length of the seventh lens and F is the effective focal length of the optical lens. Satisfying -2.4≤F7 / F≤-1.9 is beneficial for compensating for the optical power of the front lens and also optimizes aberrations.

[0065] In an exemplary embodiment, the sixth lens and the seventh lens are cemented together to form a cemented lens. The combined focal length F67 of the sixth and seventh lenses satisfies the condition that -30.2 ≤ F67 / F ≤ -10.6 with the effective focal length F of the optical lens. The cemented lens is beneficial for correcting chromatic aberration and reducing the sensitivity caused by tolerance.

[0066] In an exemplary embodiment, the optical lens according to this application satisfies: 3.6 ≤ F8 / F ≤ 5.2, where F8 is the effective focal length of the eighth lens and F is the effective focal length of the optical lens. Satisfying 3.6 ≤ F8 / F ≤ 5.2 is beneficial for correcting the optical power of the front lens and correcting edge field-of-view distortion, so that it can better meet the imaging requirements.

[0067] In an exemplary embodiment, the optical lens according to this application can satisfy: -2.4≤Fa / F≤-1.5, where Fa is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, and F is the effective focal length of the optical lens.

[0068] In an exemplary embodiment, the optical lens according to this application can satisfy: 2.6≤Fb / F≤3.0, where Fb is the combined focal length of the fifth lens, the sixth lens, the seventh lens and the eighth lens, and F is the effective focal length of the optical lens.

[0069] In an exemplary embodiment, the optical lens according to this application satisfies: -1.0 ≤ Fa / Fb ≤ -0.4, where Fa is the combined focal length of the first, second, third, and fourth lenses, and Fb is the combined focal length of the fifth, sixth, seventh, and eighth lenses. Reasonably controlling the focal length ratio between the two groups helps balance the optical power of the front and rear groups, improving ray tracing efficiency. Satisfying -1.0 ≤ Fa / Fb ≤ -0.4 also benefits the distortion correction of the ultra-wide-angle lens, while effectively reducing off-axis wide beam aberrations and field curvature, positively impacting edge image quality. Furthermore, it helps correct the field curvature generated by the first to fourth lenses before the aperture stop.

[0070] In an exemplary embodiment, the optical lens according to this application satisfies: 3.1 ≤ CT6 / CT7 ≤ 4.4, where CT6 is the center thickness of the sixth lens on the optical axis, and CT7 is the center thickness of the seventh lens on the optical axis. By controlling the center thicknesses of the sixth and seventh lenses, the lens thickness sensitivity can be appropriately reduced, effectively correcting field curvature and distortion of the optical system, and improving the imaging quality of the optical system across the entire field of view.

[0071] In an exemplary embodiment, the optical lens according to this application satisfies: 0.7 ≤ D1 / TTL ≤ 1.1, where D1 is the maximum aperture of the first 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 optical lens. By satisfying 0.7 ≤ D1 / TTL ≤ 1.1 and controlling the head aperture and overall length of the lens, the optical system can be made more miniaturized.

[0072] In an exemplary embodiment, the optical lens according to this application satisfies: 13.3 ≤ TTL / (T4+CT4) ≤ 17.1, 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 optical lens, T4 is the distance on the optical axis from the image-side surface of the fourth lens to the aperture stop, and CT4 is the center thickness of the fourth lens on the optical axis. Satisfying 13.3 ≤ TTL / (T4+CT4) ≤ 17.1 reasonably increases the distance between the aperture stop and the fourth lens, as well as the center thickness of the fourth lens, so that the rear group (fifth to eighth lenses) is further away from the aperture stop. This facilitates the reasonable entry of incident light rays after the aperture stop into the rear group lenses, and also increases the imaging height on the imaging surface.

[0073] In an exemplary embodiment, the optical lens according to this application satisfies: 0 ≤ (D12 + D45) / TTL ≤ 0.3, where D12 is the distance on the optical axis from the center of the image-side surface of the first lens to the center of the object-side surface of the second lens, D45 is the distance on the optical axis from the center of the image-side surface of the fourth lens to the center of the object-side surface of the fifth 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 optical lens. By satisfying 0 ≤ (D12 + D45) / TTL ≤ 0.3, the image quality of the lens can be effectively improved by adjusting the distances between the first and second lenses and between the fourth and fifth lenses.

[0074] In an exemplary embodiment, the optical lens according to this application satisfies: 14.7 ≤ TTL / F ≤ 15.5, 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 optical lens, and F is the effective focal length of the optical lens. Satisfying 14.7 ≤ TTL / F ≤ 15.5 is beneficial for shortening the total length (i.e., total optical length) TTL of the lens, and also helps to avoid problems such as poor overall lens performance due to an excessively small TTL / f ratio, thereby improving the lens's compatibility.

[0075] In an exemplary embodiment, the optical lens according to this application satisfies the following condition: 0.1 ≤ BFL / TTL ≤ 0.3, 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 optical 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 optical lens. By satisfying 0.1 ≤ BFL / TTL ≤ 0.3 and controlling the ratio of optical back focus to total optical length, interference between the lens and the chip due to insufficient back focus can be avoided, thus preventing an impact on the overall image quality of the lens.

[0076] In an exemplary embodiment, the optical lens of this application may be made of a hybrid material of glass and plastic. For example, it may consist of 4 glass lenses and 4 plastic lenses. The glass-plastic hybrid material is beneficial to improving the reliability of the optical system and to balancing the high and low temperature performance of the optical lens, so as to achieve high imaging quality in the range of -40℃ to +80℃.

[0077] Optionally, in an exemplary embodiment, the optical 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 optical lens.

[0078] 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 the second, third, fourth, and eighth lenses are aspherical.

[0079] The optical 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 ultra-wide-angle, large aperture, high resolution, and infrared confocal properties of the optical lens can be achieved.

[0080] In an exemplary embodiment, the aperture number Fno of the optical lens according to this application is 1.8, which enables the optical lens to have a large aperture characteristic while also increasing the light throughput.

[0081] In an exemplary embodiment, the CRA (chief ray angle) of the optical lens according to this application can meet the following requirement: CRA≤13°, which can be adapted to a variety of large-area image sensors and has broad application prospects and high market competitiveness.

[0082] The optical lens according to the above embodiments of this application may 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 have been described as an example in the embodiments, the optical lens is not limited to including eight lenses. If desired, the optical lens may also include other numbers of lenses. Specific embodiments of the optical lens applicable to the above embodiments are further described below with reference to the accompanying drawings.

[0083] Example 1

[0084] The following is for reference Figure 1 An optical lens according to Embodiment 1 of this application is described. Figure 1 A schematic diagram of the structure of an optical lens according to Embodiment 1 of this application is shown.

[0085] like Figure 1 As shown, the optical lens, along the optical axis from the object side to the image side, includes, in sequence, 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. The sixth lens L6 and the seventh lens L7 form a cemented lens.

[0086] The first lens L1 has negative optical power, with its object side S1 being convex and its image side S2 being concave.

[0087] The second lens L2 has negative optical power, with its object side S3 being convex and its image side S4 being concave.

[0088] The third lens L3 has negative optical power, and its object side S5 is concave, as is its image side S6.

[0089] The fourth lens L4 has positive optical power, with its object side S7 being convex and its image side S8 being concave.

[0090] The fifth lens L5 has positive optical power, and its object side S10 is convex, and its image side S11 is convex.

[0091] The sixth lens L6 has positive optical power, and its object side S12 is convex, and its image side S13 is convex.

[0092] The seventh lens L7 has negative optical power, and its object side S13 is concave, and its image side S14 is concave.

[0093] The eighth lens L8 has positive optical power, and its object side S15 is convex, and its image side S16 is convex.

[0094] The optical lens may also include an aperture stop STO, which may be positioned between the fourth lens L4 and the fifth lens L5.

[0095] Optionally, the optical lens may also include a filter CG having an object-side surface S17 and an image-side surface S18 and / or a protective glass (not shown) having both an object-side surface and an image-side surface. The filter CG and / or the protective glass can be used to correct color aberrations, and can also protect the image sensor chip located at the imaging surface IMA. Light from the object passes sequentially through surfaces S1 to S18 and is ultimately imaged onto the imaging surface IMA.

[0096] Table 1 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens in the optical lens of Example 1, wherein the units of radius of curvature and thickness / distance are millimeters (mm).

[0097]

[0098] Table 1

[0099] In Example 1, the object-side and image-side surfaces of the second, third, fourth, and eighth lenses are aspherical mirror surfaces, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0100]

[0101] Where x is the distance vector from the vertex of the aspherical surface at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 gives the conic coefficient k and higher-order coefficients A4, A6, A8, A16 that can be used for the aspherical mirrors S3-S8, S15-S16 in Example 1. 10 A 12 A 14 and A 16 .

[0102] Face number k A4 A6 A8 A10 A12 A14 A16 S3 0.00 7.65E-04 -6.34E-05 3.42E-06 -9.65E-08 1.26E-09 -1.93E-12 -7.08E-14 S4 -0.76 5.66E-04 3.74E-04 -7.15E-05 2.71E-06 4.14E-07 2.39E-08 -6.14E-09 S5 -0.20 -4.18E-03 1.68E-03 -1.95E-04 1.40E-05 4.69E-07 -1.34E-07 4.53E-09 S6 -63.39 -3.11E-04 9.95E-04 6.02E-05 -2.90E-05 1.03E-05 -1.58E-06 2.14E-07 S7 -3.93 1.05E-02 8.23E-04 8.60E-05 -4.60E-06 8.40E-07 4.88E-07 2.16E-07 S8 0.00 1.31E-02 9.53E-04 3.70E-04 -4.92E-05 4.87E-06 -3.28E-07 1.97E-06 S15 2.59 -1.92E-03 1.62E-04 -1.88E-05 1.15E-06 -4.24E-08 5.84E-10 -4.73E-11 S16 0.31 2.47E-03 -4.35E-05 1.47E-05 -1.68E-06 4.57E-09 9.40E-09 -4.58E-10

[0103] Table 2

[0104] Example 2

[0105] The following is for reference Figure 2 An optical lens according to Embodiment 2 of this application is described. In this embodiment and the following embodiments, for the sake of brevity, descriptions similar to those in Embodiment 1 will be omitted. Figure 2 A schematic diagram of the structure of an optical lens according to Embodiment 2 of this application is shown.

[0106] like Figure 2 As shown, the optical lens, along the optical axis from the object side to the image side, includes, in sequence, 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. The sixth lens L6 and the seventh lens L7 form a cemented lens.

[0107] The first lens L1 has negative optical power, with its object side S1 being convex and its image side S2 being concave.

[0108] The second lens L2 has negative optical power, with its object side S3 being convex and its image side S4 being concave.

[0109] The third lens L3 has negative optical power, and its object side S5 is concave, as is its image side S6.

[0110] The fourth lens L4 has positive optical power, and its object side S7 is convex, while its image side S8 is convex.

[0111] The fifth lens L5 has positive optical power, and its object side S10 is convex, and its image side S11 is convex.

[0112] The sixth lens L6 has positive optical power, and its object side S12 is convex, and its image side S13 is convex.

[0113] The seventh lens L7 has negative optical power, and its object side S13 is concave, and its image side S14 is concave.

[0114] The eighth lens L8 has positive optical power, and its object side S15 is convex, and its image side S16 is convex.

[0115] The optical lens may also include an aperture stop STO, which may be positioned between the fourth lens L4 and the fifth lens L5.

[0116] Optionally, the optical lens may also include a filter CG having an object-side surface S17 and an image-side surface S18 and / or a protective glass (not shown) having both an object-side surface and an image-side surface. The filter CG and / or the protective glass can be used to correct color aberrations, and can also protect the image sensor chip located at the imaging surface IMA. Light from the object passes sequentially through surfaces S1 to S18 and is ultimately imaged onto the imaging surface IMA.

[0117] Table 3 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens in the optical lens of Example 2, wherein the units of radius of curvature and thickness / distance are millimeters (mm).

[0118]

[0119] Table 3

[0120] Table 4 shows the higher-order coefficients that can be used for each aspherical mirror in Example 2, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0121] Face number k A4 A6 A8 A10 A12 A14 A16 S3 0.00 6.80E-04 -5.89E-05 3.37E-06 -9.83E-08 1.28E-09 -1.07E-12 -8.11E-14 S4 -0.72 7.64E-04 1.87E-04 -4.20E-05 2.49E-06 1.90E-07 1.68E-08 -3.61E-09 S5 0.06 -4.46E-03 1.63E-03 -1.98E-04 1.47E-05 5.78E-07 -1.27E-07 3.37E-09 S6 -26.54 1.19E-03 7.12E-04 4.55E-05 -2.94E-05 9.22E-06 -1.58E-06 3.18E-07 S7 -4.98 8.93E-03 4.76E-04 8.17E-05 -2.65E-05 2.25E-06 8.81E-07 1.65E-08 S8 0.00 1.00E-02 4.11E-04 3.09E-04 -3.98E-05 3.04E-06 -2.47E-06 1.17E-06 S15 2.80 -2.21E-03 2.35E-04 -1.94E-05 1.28E-06 -3.47E-08 -1.24E-09 2.59E-11 S16 0.04 2.01E-03 -1.52E-05 1.95E-05 -1.65E-06 -3.59E-09 9.50E-09 -4.80E-10

[0122] Table 4

[0123] Example 3

[0124] The following is for reference Figure 3 An optical lens according to Embodiment 3 of this application is described. Figure 3 A schematic diagram of the structure of an optical lens according to Embodiment 3 of this application is shown.

[0125] like Figure 3 As shown, the optical lens, along the optical axis from the object side to the image side, includes, in sequence, 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. The sixth lens L6 and the seventh lens L7 form a cemented lens.

[0126] The first lens L1 has negative optical power, with its object side S1 being convex and its image side S2 being concave.

[0127] The second lens L2 has negative optical power, with its object side S3 being convex and its image side S4 being concave.

[0128] The third lens L3 has negative optical power, and its object side S5 is concave, as is its image side S6.

[0129] The fourth lens L4 has positive optical power, and its object side S7 is convex, while its image side S8 is convex.

[0130] The fifth lens L5 has positive optical power, and its object side S10 is convex, and its image side S11 is convex.

[0131] The sixth lens L6 has positive optical power, and its object side S12 is convex, and its image side S13 is convex.

[0132] The seventh lens L7 has negative optical power, and its object side S13 is concave, and its image side S14 is concave.

[0133] The eighth lens L8 has positive optical power, and its object side S15 is convex, and its image side S16 is convex.

[0134] The optical lens may also include an aperture stop STO, which may be positioned between the fourth lens L4 and the fifth lens L5.

[0135] Optionally, the optical lens may also include a filter CG having an object-side surface S17 and an image-side surface S18 and / or a protective glass (not shown) having both an object-side surface and an image-side surface. The filter CG and / or the protective glass can be used to correct color aberrations, and can also protect the image sensor chip located at the imaging surface IMA. Light from the object passes sequentially through surfaces S1 to S18 and is ultimately imaged onto the imaging surface IMA.

[0136] Table 5 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens in the optical lens of Example 3, wherein the units of radius of curvature and thickness / distance are millimeters (mm).

[0137]

[0138]

[0139] Table 5

[0140] Table 6 shows the higher-order coefficients that can be used for each aspherical mirror in Example 2, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0141] Face number k A4 A6 A8 A10 A12 A14 A16 S3 0.00 9.87E-04 -7.28E-05 3.42E-06 -8.42E-08 1.03E-09 -5.13E-12 2.18E-14 S4 -0.76 1.00E-03 2.12E-04 -1.36E-05 -3.30E-06 2.69E-07 6.70E-08 -6.24E-09 S5 0.25 -4.36E-03 1.86E-03 -2.22E-04 9.70E-06 1.15E-06 -4.11E-08 -8.31E-09 S6 -16.57 3.16E-03 1.33E-03 -4.67E-05 -8.18E-05 1.74E-05 6.68E-07 -8.05E-08 S7 -4.13 9.36E-03 7.56E-04 -1.87E-06 -5.09E-05 6.95E-06 2.28E-06 -2.49E-07 S8 0.00 1.01E-02 3.80E-04 3.16E-04 -4.74E-05 4.37E-06 -2.57E-06 1.20E-06 S15 2.25 -2.27E-03 2.58E-04 -1.83E-05 9.06E-07 -2.91E-08 2.55E-09 -1.01E-10 S16 -0.35 2.13E-03 -3.23E-05 1.88E-05 -1.61E-06 9.66E-09 7.54E-09 -2.85E-10

[0142] Table 6

[0143] Example 4

[0144] The following is for reference Figure 4 An optical lens according to Embodiment 4 of this application is described. Figure 4 A schematic diagram of the structure of an optical lens according to Embodiment 4 of this application is shown.

[0145] like Figure 4 As shown, the optical lens, along the optical axis from the object side to the image side, includes, in sequence, 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. The sixth lens L6 and the seventh lens L7 form a cemented lens.

[0146] The first lens L1 has negative optical power, with its object side S1 being convex and its image side S2 being concave.

[0147] The second lens L2 has negative optical power, its object side S3 is convex, and its image side S4 is concave.

[0148] The third lens L3 has negative optical power, and its object side S5 is concave, as is its image side S6.

[0149] The fourth lens L4 has positive optical power, and its object side S7 is convex, while its image side S8 is convex.

[0150] The fifth lens L5 has positive optical power, and its object side S10 is convex, and its image side S11 is convex.

[0151] The sixth lens L6 has positive optical power, and its object side S12 is convex, and its image side S13 is convex.

[0152] The seventh lens L7 has negative optical power, and its object side S13 is concave, and its image side S14 is concave.

[0153] The eighth lens L8 has positive optical power, and its object side S15 is convex, and its image side S16 is convex.

[0154] The optical lens may also include an aperture stop STO, which may be positioned between the fourth lens L4 and the fifth lens L5.

[0155] Optionally, the optical lens may also include a filter CG having an object-side surface S17 and an image-side surface S18 and / or a protective glass (not shown) having both an object-side surface and an image-side surface. The filter CG and / or the protective glass can be used to correct color aberrations, and can also protect the image sensor chip located at the imaging surface IMA. Light from the object passes sequentially through surfaces S1 to S18 and is ultimately imaged onto the imaging surface IMA.

[0156] Table 7 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens in the optical lens of Example 4, wherein the units of radius of curvature and thickness / distance are millimeters (mm).

[0157]

[0158] Table 7

[0159] Table 8 shows the higher-order coefficients that can be used for each aspherical mirror in Example 4, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0160] Face number k A4 A6 A8 A10 A12 A14 A16 S3 0.00 8.61E-04 -7.51E-05 3.70E-06 -9.51E-08 1.17E-09 -4.17E-12 -2.04E-14 S4 -0.75 1.03E-03 3.95E-04 -6.76E-05 1.23E-06 3.69E-07 4.03E-08 -4.92E-09 S5 -0.29 -3.32E-03 1.72E-03 -2.76E-04 1.50E-05 1.37E-06 -8.58E-08 -5.74E-09 S6 -19.33 1.43E-03 1.03E-03 -5.37E-05 -7.89E-05 1.05E-05 6.82E-07 -6.91E-08 S7 -3.56 1.01E-02 9.16E-04 1.37E-04 -1.58E-05 2.54E-07 -4.64E-07 2.73E-07 S8 0.00 1.20E-02 1.17E-03 4.66E-04 -4.13E-05 7.31E-06 6.31E-07 4.74E-07 S15 2.31 -1.78E-03 1.34E-04 -2.23E-05 9.49E-07 -3.94E-08 5.50E-10 -1.74E-10 S16 0.26 2.35E-03 -6.37E-05 1.63E-05 -2.05E-06 -1.25E-08 1.10E-08 -5.13E-10

[0161] Table 8

[0162] In summary, Examples 1 to 4 satisfy the relationships shown in Table 9 below.

[0163]

[0164]

[0165] Table 9

[0166] This application also provides an electronic device that may include an optical lens according to the above embodiments of this application and an imaging element for converting an optical image formed by the optical lens into an electrical signal.

[0167] 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. An optical lens, characterized in that, The optical lens comprises, along the optical axis from the object side to the image side, the following in sequence: The first lens with negative optical power has a convex object side and a concave image side. A second lens with negative optical power has a convex object side and a concave image side. A third lens with negative optical power has a concave object side and a concave image side. The fourth lens has positive optical power and its object side is convex. The fifth lens with positive optical power has a convex object-side surface and a convex image-side surface; 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 positive optical power, has a convex object-side surface and a convex image-side surface; among which, The optical lens has eight lenses with optical power. The effective focal length F6 of the sixth lens, the effective focal length F7 of the seventh lens, and the effective focal length F of the optical lens satisfy: 0.3≤|(F6+F7)| / F≤0.9; The effective focal length F2 of the second lens, the effective focal length F3 of the third lens, and the effective focal length F of the optical lens satisfy: 0≤|(F3-F2)| / F≤0.9; The effective focal length F1 of the first lens and the effective focal length F of the optical lens satisfy: -13.2≤F1 / F≤-9.

0.

2. The optical lens according to claim 1, wherein, The effective focal length F2 of the second lens and the effective focal length F of the optical lens satisfy: -3.0≤F2 / F≤-2.

4.

3. The optical lens according to claim 1, wherein, The effective focal length F3 of the third lens and the effective focal length F of the optical lens satisfy the following condition: -3.7≤F3 / F≤-2.

5.

4. The optical lens according to claim 1, wherein, The effective focal length F4 of the fourth lens and the effective focal length F of the optical lens satisfy the following condition: 3.2≤F4 / F≤3.

8.

5. The optical lens according to claim 1, wherein, The effective focal length F5 of the fifth lens and the effective focal length F of the optical lens satisfy the following condition: 3.2≤F5 / F≤3.

8.

6. The optical lens according to claim 1, wherein, The effective focal length F6 of the sixth lens and the effective focal length F of the optical lens satisfy the following condition: 2.5≤F6 / F≤3.

1.

7. The optical lens according to claim 1, wherein, The effective focal length F7 of the seventh lens and the effective focal length F of the optical lens satisfy the following condition: -2.4≤F7 / F≤-1.

9.

8. The optical lens according to claim 1, wherein, The sixth lens and the seventh lens are cemented together to form a cemented lens. The combined focal length F67 of the sixth lens and the seventh lens satisfies the following condition with respect to the effective focal length F of the optical lens: -30.2≤F67 / F≤-10.

6.

9. The optical lens according to claim 1, wherein, The effective focal length F8 of the eighth lens and the effective focal length F of the optical lens satisfy the following condition: 3.6≤F8 / F≤5.

2.

10. The optical lens according to any one of claims 1-9, wherein, The combined focal length Fa of the first lens, the second lens, the third lens, and the fourth lens satisfies the following condition with respect to the effective focal length F of the optical lens: -2.4 ≤ Fa / F ≤ -1.

5.

11. The optical lens according to any one of claims 1-9, wherein, The combined focal length Fb of the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length F of the optical lens satisfy the following condition: 2.6 ≤ Fb / F ≤ 3.

0.

12. The optical lens according to any one of claims 1-9, wherein, The combined focal length Fa of the first lens, the second lens, the third lens, and the fourth lens and the combined focal length Fb of the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: -1.0 ≤ Fa / Fb ≤ -0.

4.

13. The optical lens according to any one of claims 1-9, wherein, The center thickness CT6 of the sixth lens on the optical axis and the center thickness CT7 of the seventh lens on the optical axis satisfy the following condition: 3.1≤CT6 / CT7≤4.

4.

14. The optical lens according to any one of claims 1-9, wherein, The maximum aperture D1 of the first lens and the distance TTL from the center of the object side of the first lens to the imaging surface of the optical lens on the optical axis satisfy: 0.7≤D1 / TTL≤1.

1.

15. The optical lens according to any one of claims 1-9, wherein, The optical lens also includes an aperture stop positioned between the fourth lens and the fifth lens. The distance TTL from the center of the object side of the first lens to the imaging surface of the optical lens on the optical axis, the distance T4 from the image side of the fourth lens to the aperture on the optical axis, and the center thickness CT4 of the fourth lens on the optical axis satisfy: 13.3≤TTL / (T4+CT4)≤17.

1.

16. The optical lens according to any one of claims 1-9, wherein, The distance D12 from the center of the image side of the first lens to the center of the object side of the second lens on the optical axis, the distance D45 from the center of the image side of the fourth lens to the center of the object side of the fifth 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 optical lens on the optical axis satisfy: 0≤(D12+D45) / TTL≤0.

3.

17. The optical lens according to any one of claims 1-9, wherein, The distance TTL from the center of the object side of the first lens to the imaging surface of the optical lens on the optical axis satisfies the following condition: 14.7≤TTL / F≤15.

5.

18. The optical lens according to any one of claims 1-9, wherein, The distance BFL from the center of the image side of the eighth lens to the imaging surface of the optical 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 optical lens on the optical axis satisfy the following condition: 0.1 ≤ BFL / TTL ≤ 0.

3.

19. The optical lens according to claim 1, wherein, The optical lens also includes an aperture stop placed between the fourth lens and the fifth lens; The optical lens satisfies at least one of the following: 0.611≤|(F6+F7)| / F≤0.801; -13.067≤F1 / F≤-9.146; -2.898≤F2 / F≤-2.532; 0.060≤|(F3-F2)| / F≤0.8 03; -3.335≤F3 / F≤-2.689; 3.348≤F4 / F≤3.589; 3.334≤F5 / F≤3.426; 2.685≤F6 / F≤2.906; -2.105≤F7 / F ≤-2.046;-14.043≤F67 / F≤-10.720;3.695≤F8 / F≤4.163;-1.904≤Fa / F≤-1.605;2.718≤Fb / F≤2.858;- 0.701≤Fa / Fb≤-0.569; 3.253≤CT6 / CT7≤4.225; 0.880≤D1 / TTL≤0.970; 13.546≤TTL / (T4+CT4)≤16.978; 0.124≤(D12+D45) / TTL≤0.195; 14.834≤TTL / F≤15.298; 0.1 ≤ BFL / TTL ≤ 0.154; Wherein, F4 is the effective focal length of the fourth lens, F5 is the effective focal length of the fifth lens, F8 is the effective focal length of the eighth lens, F67 is the combined focal length of the sixth and seventh lenses, Fa is the combined focal length of the first, second, third, and fourth lenses, Fb is the combined focal length of the fifth, sixth, seventh, and eighth lenses, CT6 is the center thickness of the sixth lens on the optical axis, CT7 is the center thickness of the seventh lens on the optical axis, D1 is the maximum aperture of the first lens, and TT... L is the distance from the center of the object side of the first lens to the imaging surface of the optical lens on the optical axis; T4 is the distance from the image side of the fourth lens to the aperture on the optical axis; CT4 is the center thickness of the fourth lens on the optical axis; D12 is the distance from the center of the image side of the first lens to the center of the object side of the second lens on the optical axis; D45 is the distance from the center of the image side of the fourth lens to the center of the object side of the fifth lens on the optical axis; and BFL is the distance from the center of the image side of the eighth lens to the imaging surface of the optical lens on the optical axis.

Images