Zoom lens

Abstract

A zoom lens comprising, in order from the object side to the image side along the optical axis, a first lens group having negative refractive power, which includes at least three negative lenses and at least one positive lens; a second lens group having positive refractive power, which includes at least two negative lenses and at least two positive lenses; a third lens group having negative refractive power, which includes at least two negative lenses and at least one positive lens; and a fourth lens group having positive refractive power, which includes at least three negative lenses and at least two positive lenses; wherein, in a zooming process from a wide-angle end to a telephoto end, the first lens group moves along the optical axis from the object side to the image side, the second lens group moves along the optical axis from the image side to the object side, the third lens group moves along the optical axis from the image side to the object side to jointly realize continuous zooming from the wide-angle end to the telephoto end with the first lens group and the second lens group, and the fourth lens group moves along the optical axis from the image side to the object side to compensate for a shift in the image plane position during the continuous zooming.

Description

Technical Field

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

[0002] With the development of modern society and the advancement of science and technology, zoom optical systems have been widely used in all aspects of life, such as security monitoring and intelligent transportation. Zoom lenses are characterized by their ability to adapt to the needs of different scenarios, and their market demand is constantly increasing, leading to increasingly higher requirements for the optical performance and product stability of zoom lenses.

[0003] Current zoom lenses mainly suffer from the following problems:

[0004] 1. The imaging target surface is small, resulting in low image resolution;

[0005] 2. The wide-angle end has an insufficient angle, limiting the monitoring range;

[0006] 3. Zoom lenses exhibit significant distortion at certain angles;

[0007] 4. The lens uses a large number of lenses and has a large size, making it difficult to meet the design requirements for miniaturization. Summary of the Invention

[0008] According to an embodiment of this application, a zoom lens is provided, comprising, in sequence along the optical axis from the object side to the image side: a first lens group having negative optical power, comprising at least three negative lenses and at least one positive lens; a second lens group having positive optical power, comprising at least two negative lenses and at least two positive lenses; a third lens group having negative optical power, comprising at least two negative lenses and at least one positive lens; and a fourth lens group having positive optical power, comprising at least two negative lenses and at least two positive lenses; wherein, during the zooming process from the wide-angle end to the telephoto end, the first lens group moves along the optical axis from the object side to the image side, the second lens group moves along the optical axis from the image side to the object side, the third lens group moves along the optical axis from the image side to the object side to achieve continuous zooming from the wide-angle end to the telephoto end together with the first lens group and the second lens group, and the fourth lens group moves along the optical axis from the image side to the object side to compensate for the shift in image plane position during continuous zooming.

[0009] In some embodiments, the first lens group includes four lenses along the optical axis from the object side to the image side: the first lens has negative optical power; the second lens has negative optical power; the third lens has negative optical power; and the fourth lens has positive optical power.

[0010] In some embodiments, the second lens group includes four lenses along the optical axis from the object side to the image side: the first lens has negative optical power; the second lens has positive optical power; the third lens has positive optical power; and the fourth lens has negative optical power.

[0011] In some embodiments, the third lens group includes three lenses along the optical axis from the object side to the image side: the first lens has negative optical power; the second lens has positive optical power; and the third lens has negative optical power.

[0012] In some embodiments, the fourth lens group includes five lenses along the optical axis from the object side to the image side: the first lens has positive optical power; the second lens has negative optical power; the third lens has negative optical power; the fourth lens has positive optical power; and the fifth lens has negative optical power.

[0013] In some embodiments, the fourth lens group includes six lenses along the optical axis from the object side to the image side: the first lens has positive optical power; the second lens has negative optical power; the third lens has negative optical power; the fourth lens has positive optical power; the fifth lens has negative optical power; and the sixth lens has negative optical power.

[0014] In some embodiments, the first lens group includes at least one set of cemented lenses.

[0015] In some embodiments, the second lens group includes at least one set of positive cemented lenses.

[0016] In some embodiments, the third lens group includes at least one set of positive cemented lenses.

[0017] In some embodiments, the fourth lens group includes at least two sets of cemented lenses.

[0018] In some implementations, the effective focal length FG1 of the first lens group and the effective focal length FW of the zoom lens in the wide-angle state satisfy: -2.3≤FG1 / FW≤-2.0.

[0019] In some implementations, the effective focal length FG1 of the first lens group and the effective focal length FT of the zoom lens in telephoto mode satisfy: -0.8≤FG1 / FT≤-0.6.

[0020] In some implementations, the effective focal length FG2 of the second lens group and the effective focal length FW of the zoom lens in wide-angle mode satisfy: 6.0≤FG2 / FW≤7.1.

[0021] In some implementations, the effective focal length FG2 of the second lens group and the effective focal length FT of the zoom lens in telephoto mode satisfy: 2.0≤FG2 / FT≤2.5.

[0022] In some implementations, the effective focal length FG3 of the third lens group and the effective focal length FW of the zoom lens in wide-angle mode satisfy: -13.3≤FG3 / FW≤-7.5.

[0023] In some implementations, the effective focal length FG4 of the fourth lens group and the effective focal length FW of the zoom lens in wide-angle mode satisfy: 2.7≤FG4 / FW≤3.4.

[0024] In some implementations, the effective focal length FG4 of the fourth lens group and the effective focal length FT of the zoom lens in telephoto mode satisfy the following condition: 0.9 ≤ FG4 / FT ≤ 1.2.

[0025] In some implementations, the effective focal length FW of the zoom lens in wide-angle mode and the effective focal length FT of the zoom lens in telephoto mode satisfy: 2.9≤FT / FW≤3.1.

[0026] In some implementations, the effective focal length FW of the zoom lens in wide-angle mode and the total optical length TTL-W of the zoom lens in wide-angle mode satisfy: 0≤FW / TTL-W≤0.1.

[0027] In some implementations, the effective focal length FT of the zoom lens in telephoto mode and the total optical length TTL-T of the zoom lens in telephoto mode satisfy: 0.2≤FT / TTL-T≤0.4.

[0028] In some embodiments, the effective focal length F1 of the positive cemented lens in the first lens group and the effective focal length FG1 of the first lens group satisfy: -36.5≤F1 / FG1≤-6.2.

[0029] In some embodiments, the effective focal length F2 of the positive cemented lens in the second lens group and the effective focal length FG2 of the second lens group satisfy: 0.6≤F2 / FG2≤2.4.

[0030] In some embodiments, the effective focal length F4 of the second set of cemented lenses in the fourth lens group and the effective focal length FG4 of the fourth lens group satisfy: 0.8≤F4 / FG4≤2.0.

[0031] In some implementations, the refractive index Nd3 of the lenses in the third lens group satisfies: 1.8 ≤ Nd3 ≤ 2.0.

[0032] In some implementations, the effective focal length FW of the zoom lens in wide-angle mode and the holographic height H of the zoom lens satisfy the following condition: 0.4 ≤ FW / H ≤ 0.6.

[0033] In some implementations, the back focal length BFL-W of the zoom lens in wide-angle mode and the effective focal length FW of the zoom lens in wide-angle mode satisfy: 1.8≤BFL-W / FW≤2.4.

[0034] In some implementations, the maximum optical aperture DMAX of the zoom lens and the total optical length TTL-T of the zoom lens in telephoto mode satisfy: 0.3≤DMAX / TTL-T≤0.4.

[0035] In some embodiments, the first lens group includes four lenses along the optical axis from the object side to the image side: the object side of the first lens is convex and the image side is concave; the image side of the second lens is concave; both the object side and the image side of the third lens are concave; and the object side of the fourth lens is convex.

[0036] In some embodiments, the second lens group includes four lenses along the optical axis from the object side to the image side: the object side of the first lens is convex and the image side is concave; both the object side and the image side of the second lens are convex; both the object side and the image side of the third lens are convex; and the object side of the fourth lens is concave.

[0037] In some embodiments, the third lens group includes three lenses along the optical axis from the object side to the image side: the object side of the first lens is concave and the image side is convex; both the object side and the image side of the second lens are convex; and the object side of the third lens is concave.

[0038] In some embodiments, the fourth lens group includes five lenses along the optical axis from the object side to the image side: the object side and image side of the first lens are both convex; the object side of the second lens is concave and the image side is convex; the object side of the third lens is convex and the image side is concave; the object side and image side of the fourth lens are both convex; and the object side and image side of the fifth lens are both concave.

[0039] In some embodiments, the fourth lens group includes six lenses arranged along the optical axis from the object side to the image side: the object side and image side of the first lens are both convex; the object side of the second lens is concave and the image side is convex; the object side of the third lens is convex and the image side is concave; the object side and image side of the fourth lens are both convex; the object side of the fifth lens is concave and the image side is convex; and the object side and image side of the sixth lens are both concave.

[0040] The zoom lens provided according to the embodiments of this application adopts a zoom lens architecture with three zoom groups (negative, positive, and negative) combined with a positive focusing group. Through the allocation of the number of lenses and optical power in each lens group and the surface design, it is beneficial to reduce the overall length of the system on the one hand, and can effectively correct chromatic aberration, aberration and distortion on the other hand, thus meeting at least one of the design requirements of high resolution, wide angle, low distortion and large target surface. Attached Figure Description

[0041] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0042] Figure 1A A schematic diagram of the zoom lens at the wide-angle end according to Embodiment 1 of this application is shown;

[0043] Figure 1B A schematic diagram of the zoom lens at the telephoto end according to Embodiment 1 of this application is shown;

[0044] Figure 2A A schematic diagram of the zoom lens at the wide-angle end according to Embodiment 2 of this application is shown;

[0045] Figure 2B A schematic diagram of the zoom lens at the telephoto end according to Embodiment 2 of this application is shown;

[0046] Figure 3A A schematic diagram of the zoom lens at the wide-angle end according to Embodiment 3 of this application is shown;

[0047] Figure 3B A schematic diagram of the zoom lens at the telephoto end according to Embodiment 3 of this application is shown;

[0048] Figure 4A A schematic diagram of the zoom lens at the wide-angle end according to Embodiment 4 of this application is shown;

[0049] Figure 4B A schematic diagram of the zoom lens at the telephoto end according to Embodiment 4 of this application is shown;

[0050] Figure 5A A schematic diagram of the zoom lens at the wide-angle end according to Embodiment 5 of this application is shown; and

[0051] Figure 5B A schematic diagram of the zoom lens at the telephoto end according to Embodiment 5 of this application is shown. Detailed Implementation

[0052] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0053] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the first lens.

[0054] 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.

[0055] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0056] 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.

[0057] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0058] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other. The following embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application.

[0059] The features, principles and other aspects of this application are described in detail below.

[0060] refer to Figure 1A and Figure 1B As shown, a zoom lens according to this application includes, arranged sequentially along the optical axis from the object side to the image side: a first lens group G1 with negative optical power, a second lens group G2 with positive optical power, a third lens group G3 with negative optical power, and a fourth lens group G4 with positive optical power.

[0061] Among them, the first lens group G1 is the first zoom group. The first lens group moves along the optical axis from the object side to the image side, which can realize continuous zoom of the lens from the wide-angle end to the telephoto end. Moreover, the first lens group G1 reduces the aperture of the rear lens by converging light and collecting light from a large field of view, which is beneficial to meet the requirements of a large field of view and also to balance the distortion of the system.

[0062] The second lens group G2 is the second zoom group. During the zoom process of the zoom lens from the wide-angle end to the telephoto end, the second lens group G2 moves along the optical axis from the image side to the object side. The second lens group G2 has a large amount of travel movement and undertakes the main zoom function.

[0063] The third lens group G3 is the third zoom group. During the zoom process of the zoom lens from the wide-angle end to the telephoto end, the third lens group G3 moves along the optical axis from the image side to the object side. Together with the first lens group G1 and the second lens group G2, it realizes continuous zoom from the wide-angle end to the telephoto end. The third lens group G3 helps to maintain the stability of the focal length during the zoom process, and at the same time, it can make the outgoing light smooth and reduce the generation of aberrations.

[0064] The fourth lens group G4 is the focusing group (compensation group). During the zoom process of the zoom lens from the wide-angle end to the telephoto end, the fourth lens group G4 moves along the optical axis from the image side to the object side. It mainly undertakes the function of image plane compensation. It can compensate for the shift of the image plane position during the continuous zoom of the lens, thereby ensuring the image quality of the lens body during continuous zoom.

[0065] In an exemplary embodiment, the first lens group G1 includes at least three negative lenses and at least one positive lens; the second lens group G2 includes at least two negative lenses and at least two positive lenses; the third lens group G3 includes at least two negative lenses and at least one positive lens; and the fourth lens group G4 includes at least three negative lenses and at least two positive lenses.

[0066] In some embodiments, the first lens group G1 includes four lenses arranged along the optical axis from the object side to the image side: the first lens has negative optical power, with a convex object side and a concave image side; the second lens has negative optical power, with a concave image side; the third lens has negative optical power, with both the object side and image side being concave; and the fourth lens has positive optical power, with a convex object side. Preferably, the first lens is a glass aspherical lens, which helps to balance system distortion and improve image quality; the convex object side and concave image side of the first lens, when combined with a high refractive index material, help to reduce the front-end diameter of the system; the concave image side of the second lens, in conjunction with the first lens, helps to further reduce the front-end diameter of the optical system.

[0067] In some embodiments, the first lens group includes at least one set of positive cemented lenses, which is beneficial for correcting chromatic aberration of the system and improving image quality. For example, the third and fourth lenses in the first lens group G1 can constitute a set of cemented lenses with positive optical power, and through reasonable material matching, the purpose of correcting axial chromatic aberration can be achieved.

[0068] In some embodiments, the second lens group G2 includes four lenses along the optical axis from the object side to the image side: the first lens has negative optical power, the object side is convex, and the image side is concave; the second lens has positive optical power, and both the object side and the image side are convex; the third lens has optical power, and both the object side and the image side are convex; and the fourth lens has optical power, and the object side is concave.

[0069] In some embodiments, the second lens group G2 includes at least one set of positive cemented lenses. For example, the first and second lenses in the second lens group can form a set of cemented lenses with positive optical power, which is beneficial for correcting system chromatic aberration and improving resolution.

[0070] In some embodiments, the third lens group G3 includes three lenses arranged along the optical axis from the object side to the image side: the first lens has negative optical power, with a concave object side and a convex image side; the second lens has positive optical power, with both the object side and image side being convex; and the third lens has negative optical power, with a concave object side. The concave object side and convex image side of the first lens facilitate the collection of light rays emitted from the second lens group, allowing the light rays to smoothly enter the third lens group, which is beneficial for image quality stability.

[0071] In some embodiments, the third lens group G3 includes at least one set of cemented lenses. For example, the second and third lenses in the third lens group can form a set of cemented lenses with positive optical power, which can reduce the tolerance sensitivity of the lens and is beneficial for correcting chromatic aberration.

[0072] In some embodiments, the fourth lens group G4 includes five lenses along the optical axis from the object side to the image side: the first lens has positive optical power and both the object side and the image side are convex; the second lens has negative optical power and both the object side and the image side are concave; the third lens has negative optical power and both the object side and the image side are concave; the fourth lens has positive optical power and both the object side and the image side are convex; and the fifth lens has negative optical power and both the object side and the image side are concave.

[0073] In some other embodiments, the fourth lens group G4 includes six lenses along the optical axis from the object side to the image side: the first lens has positive optical power and both the object side and the image side are convex; the second lens has negative optical power and both the object side and the image side are concave; the third lens has negative optical power and both the object side and the image side are concave; the fourth lens has positive optical power and both the object side and the image side are convex; the fifth lens has negative optical power and both the object side and the image side are concave; and the sixth lens has negative optical power and both the object side and the image side are concave.

[0074] In some embodiments, the fourth lens group G4 may include at least two sets of positive cemented lenses. For example, the first and second lenses of the fourth lens group may form a first set of cemented lenses with positive optical power. The arrangement of the first set of cemented lenses is beneficial to improving the focus compensation efficiency and correcting system chromatic aberration. The third and fourth lenses, or the third to fifth lenses of the fourth lens group may form a second set of cemented lenses with positive optical power. The arrangement of the second set of cemented lenses is beneficial to correcting residual aberrations generated during zooming. While correcting system field curvature, the angle of the principal ray reaching the image plane is made positive, thereby avoiding vignetting.

[0075] In some implementations, the last lens of the fourth lens group G4 (the lens closest to the image side) is a glass aspherical lens, which helps to balance the various aberrations introduced by the cemented lens and improve the image quality.

[0076] In an exemplary embodiment, the zoom lens can satisfy the following condition: -2.3≤FG1 / FW≤-2.0, where FG1 is the effective focal length value of the first lens group, and FW is the effective focal length value of the zoom lens in the wide-angle state. By reasonably controlling the focal length of the first lens group and the focal length of the zoom lens at the wide-angle end, it is beneficial to converge large-angle incident light rays into the optical system, effectively expanding the field of view of the optical system, so that the field of view at the wide-angle end satisfies FOV_w≥100°.

[0077] In an exemplary embodiment, the zoom lens can satisfy the following condition: -0.8 ≤ FG1 / FT ≤ -0.6, where FG1 is the effective focal length value of the first lens group, and FT is the effective focal length value of the zoom lens in the telephoto state. By reasonably controlling the focal length of the first lens group and the focal length of the zoom lens at the telephoto end, it is beneficial to reduce the spherical aberration and distortion of the zoom lens in the telephoto state.

[0078] In an exemplary embodiment, the zoom lens can satisfy the following condition: 6.0 ≤ FG2 / FW ≤ 7.1, where FG2 is the effective focal length value of the second lens group, and FW is the effective focal length value of the zoom lens in wide-angle mode. By reasonably controlling the focal length value of the second lens group, it is beneficial to achieve imaging performance while ensuring the required zoom ratio during zooming.

[0079] In an exemplary embodiment, the zoom lens can satisfy the following condition: 2.0 ≤ FG2 / FT ≤ 2.5, where FG2 is the effective focal length value of the second lens group, and FT is the effective focal length value of the zoom lens in telephoto mode. Satisfying this condition, and controlling the focal length value of the zoom group, which bears the main zoom function, within a reasonable range, helps to reduce the movement distance during the transition from wide-angle to telephoto mode, thus limiting the overall optical length of the zoom lens.

[0080] In an exemplary embodiment, the zoom lens can satisfy the following condition: -13.3 ≤ FG3 / FW ≤ -7.5, where FG3 is the effective focal length value of the third lens group, and FW is the effective focal length value of the zoom lens in wide-angle mode. By reasonably controlling the focal length value of the third lens group, the required zoom ratio during zooming is guaranteed.

[0081] In an exemplary embodiment, the zoom lens can satisfy the following condition: 2.7 ≤ FG4 / FW ≤ 3.4, where FG4 is the effective focal length value of the fourth lens group, and FW is the effective focal length value of the zoom lens in wide-angle mode. By reasonably controlling the focal length value of the fourth lens group, the lens can compensate for the image plane during continuous zooming, allowing light to smoothly exit onto the image plane, which helps to reduce CRA, correct distortion, and achieve large target area imaging.

[0082] In an exemplary embodiment, the zoom lens can satisfy the following condition: 0.9 ≤ FG4 / FT ≤ 1.2, where FG4 is the effective focal length value of the fourth lens group, and FT is the effective focal length value of the zoom lens in telephoto mode. Satisfying this condition prevents the refractive power of the focusing group from becoming too strong, which is beneficial for controlling spherical aberration at the telephoto end and for achieving high resolution.

[0083] In an exemplary embodiment, the zoom lens can satisfy the following condition: 2.9 ≤ FT / FW ≤ 3.1, where FW is the effective focal length value of the zoom lens in wide-angle mode, and FT is the effective focal length value of the zoom lens in telephoto mode. By reasonably controlling the ratio of the focal length value at the telephoto end to the focal length value at the wide-angle end of the zoom lens, it is beneficial to achieve zoom from the wide-angle end to the telephoto end, realizing a small-magnification zoom.

[0084] In an exemplary embodiment, the zoom lens can satisfy the following condition: 0≤FW / TTL-W≤0.1, where FW is the effective focal length of the zoom lens in wide-angle mode, and TTL-W is the total optical length of the zoom lens in wide-angle mode. Satisfying this condition can control the overall system length, avoid the overall length of the optical system becoming too long, and achieve both miniaturization and weight reduction.

[0085] In an exemplary embodiment, the zoom lens can satisfy the following condition: 0.2 ≤ FT / TTL-T ≤ 0.4, where FT is the effective focal length of the zoom lens in telephoto mode, and TTL-T is the total optical length of the zoom lens in telephoto mode. By satisfying this condition, and given a fixed system focal length at the telephoto end, the total optical length of the system can be controlled to be smaller, which is beneficial for miniaturization.

[0086] In an exemplary embodiment, the zoom lens can satisfy the following condition: -36.5≤F1 / FG1≤-6.2, where F1 is the effective focal length of the cemented lens in the first lens group, and FG1 is the effective focal length of the first lens group. Satisfying this condition, by setting a set of cemented lenses in the first lens group and combining them with materials of different refractive indices (high and low), helps to correct chromatic aberration in the system and improve image quality.

[0087] In an exemplary embodiment, the zoom lens can satisfy the following condition: 0.6 ≤ F2 / FG2 ≤ 2.4, where F2 is the effective focal length of the cemented lens in the second lens group, and FG2 is the effective focal length of the second lens group. Satisfying this condition, and setting a set of cemented lenses in the second lens group, is beneficial for balancing various aberrations.

[0088] In an exemplary embodiment, the zoom lens can satisfy the following condition: 0.8 ≤ F4 / FG4 ≤ 2.0, where F4 is the effective focal length value of the second group of cemented lenses in the fourth lens group, and FG4 is the effective focal length value of the fourth lens group. Satisfying this condition, by setting cemented lenses in the fourth lens group, helps to balance chromatic aberration and reduce the tolerance sensitivity of the group.

[0089] In an exemplary embodiment, the zoom lens can satisfy the following condition: 1.8 ≤ Nd3 ≤ 2.0, where Nd3 is the refractive index of the lens in the third lens group. By satisfying this condition and appropriately selecting the lens material, chromatic aberration can be effectively corrected while simultaneously correcting distortion.

[0090] In an exemplary embodiment, the zoom lens can satisfy the following condition: 0.4 ≤ FW / H ≤ 0.6, where FW is the effective focal length of the zoom lens in wide-angle mode, and H is the total image height of the zoom lens. By satisfying this condition, and given a fixed total optical length of the system, optimizing the system image height results in a larger image height value, which is beneficial for achieving a large target surface, increasing the size of the sensor suitable for the zoom lens, and consequently improving the imaging quality of the zoom lens.

[0091] In an exemplary embodiment, the zoom lens can satisfy the following condition: 1.8 ≤ BFL-W / FW ≤ 2.4, where BFL-W is the back focal length of the zoom lens in wide-angle mode, and FW is the effective focal length of the zoom lens in wide-angle mode. Satisfying this condition ensures system performance while limiting the overall system length within a certain range.

[0092] In an exemplary embodiment, the zoom lens can satisfy the following condition: 0.3 ≤ DMAX / TTL-T ≤ 0.4, where DMAX is the maximum optical aperture of the zoom lens, and TTL-T is the total optical length of the zoom lens in telephoto mode. Satisfying this condition, by controlling the size of the maximum light-gathering aperture, is beneficial for adjusting the light within the zoom lens and also for achieving lens miniaturization.

[0093] In an exemplary embodiment, the zoom lens may further include an aperture stop, for example, the aperture stop may be disposed between the second lens group G2 and the third lens group G3, with a fixed position relative to the image plane.

[0094] In an exemplary embodiment, the zoom lens may further include a protective glass or filter for protecting the photosensitive element located on the imaging plane.

[0095] In an exemplary embodiment, the object-side or image-side surface of at least one lens in the zoom lens can be aspherical. Aspherical lenses have better radius of curvature characteristics, which has the advantage of improving distortion aberration and astigmatism aberration. By using aspherical lenses, aberrations that occur during imaging can be eliminated as much as possible, thereby improving image quality.

[0096] In an exemplary embodiment, the use of a zoom lens in conjunction with a glass aspherical lens helps to correct distortion, chromatic aberration, aberrations, etc. of the zoom lens.

[0097] The zoom lens according to the embodiments of this application can simultaneously meet the requirements of a large field of view (FOV ≥ 100° at the wide-angle end) and a large target area (maximum imaging target area can reach 25.56mm). This is beneficial for achieving wide-angle characteristics and acquiring more scene information.

[0098] The zoom lens according to the embodiments of this application can achieve low distortion while satisfying the wide-angle characteristics, with an absolute value of distortion of <12% at the wide-angle end and an absolute value of distortion of <0.6% at the telephoto end, thereby increasing the application scenarios of the zoom lens.

[0099] The zoom lens according to the embodiments of this application is beneficial in reducing the overall system length and can effectively correct chromatic aberration, aberration and distortion, thus meeting the requirements of high resolution (8K resolution).

[0100] The following describes in further detail, with reference to the accompanying drawings, specific embodiments of the zoom lens applicable to the above-described embodiments.

[0101] Example 1

[0102] The following is for reference Figure 1A and Figure 1B A zoom lens according to Embodiment 1 of this application is described.

[0103] like Figure 1A and Figure 1B As shown, the zoom lens of this embodiment includes, in sequence along the optical axis from the object side to the image side: a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4. The zoom lens of this embodiment includes a total of 17 lenses L1 to L17, wherein the first lens group G1 has negative optical power and includes 4 lenses L1-L4; the second lens group G2 has positive optical power and includes 4 lenses L5-L8; the third lens group G3 has negative optical power and includes 3 lenses L9-L11; and the fourth lens group G4 has positive optical power and includes 6 lenses L12-L17.

[0104] In this embodiment, during the zoom process from wide-angle to telephoto, the first lens group G1 moves along the optical axis from the object side to the image side, the second lens group G2 moves along the optical axis from the image side to the object side, the third lens group G3 moves along the optical axis from the image side to the object side to achieve continuous zoom from wide-angle to telephoto together with the first lens group G1 and the second lens group G2, and the fourth lens group G4 moves along the optical axis from the image side to the object side to compensate for the shift in image plane position during continuous zoom.

[0105] In this embodiment, the first lens L1 in the first lens group G1 is preferably a glass aspherical surface, which is beneficial to balance the distortion of the system and improve the imaging quality. The object side of the first lens L1 is convex and the image side is concave. Combined with a high refractive index material, it is beneficial to reduce the front port diameter of the system. The image side of the second lens L2 is concave. Combined with the first lens L1, it is beneficial to further reduce the front port diameter of the system.

[0106] In this embodiment, the object side of the first lens (ninth lens L9) in the third lens group G3 is concave and the image side is convex, which is beneficial for collecting light rays emitted from the second lens group and allowing the light rays to enter the third lens group smoothly, which is beneficial for image quality stability.

[0107] In this embodiment, the third lens L3 and the fourth lens L4 in the first lens group G1 constitute a cemented doublet with positive optical power, which is beneficial for correcting chromatic aberration in the system and improving image quality.

[0108] The fifth lens L5 and the sixth lens L6 in the second lens group G2 form a cemented doublet with positive optical power, which is beneficial for correcting chromatic aberration in the system and improving resolution.

[0109] The tenth lens L10 and the eleventh lens L11 in the third lens group G3 form a cemented doublet with positive optical power, which can reduce the tolerance sensitivity of the lens and is beneficial for correcting chromatic aberration.

[0110] The fourth lens group G4 includes two sets of cemented lenses. The twelfth lens L12 and the thirteenth lens L13 form a cemented doublet with positive optical power; simultaneously, the fourteenth lens L14, the fifteenth lens L15, and the sixteenth lens L16 form a cemented triplet with positive optical power. By incorporating two sets of cemented lenses, the fourth lens group improves focus compensation efficiency and corrects system chromatic aberration. The second set of cemented lenses helps correct residual aberrations generated during zooming. While correcting system field curvature, it also ensures that the principal ray angle reaching the image plane is positive, preventing vignetting.

[0111] In this embodiment, the last lens L17 of the fourth lens group is preferably a glass aspherical lens, which is beneficial for balancing various aberrations introduced by the cemented lens and improving imaging quality.

[0112] In this embodiment, an aperture stop STO may be provided between the second lens group G2 and the third lens group G3, and the position of the aperture stop STO relative to the image plane is fixed.

[0113] In this embodiment, the zoom lens may further include a filter CG for protecting the photosensitive element located on the imaging surface (IMA). Light from the object passes sequentially through the optical surfaces surf1 to surf31 and is finally imaged onto the imaging surface surf32.

[0114] Table 1 shows some basic parameters of each lens in the zoom lens of this embodiment, including surface type, radius of curvature, thickness, refractive index of the material, and Abbe number. The units for radius of curvature and thickness / distance are millimeters (mm).

[0115]

[0116]

[0117] Table 1

[0118] As can be seen from Table 1, in this embodiment, the curvature radius R of the object side surface surf3 of the second lens L2, the image side surface surf7 of the fourth lens L4, and the image side surface surf20 of the eleventh lens L11 is relatively large. The shape of these surfaces can be convex, concave, or flat, and no specific limitation is made in this application.

[0119] In this embodiment, the object-side surface and image-side surface of the first lens L1 and the seventeenth lens L17 of the zoom lens are both aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0120]

[0121] Where z 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 (that is, 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 correction coefficient of the i-th order of the aspherical surface.

[0122] Table 2 shows the conic coefficient (k) and higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror in this embodiment. 10 A 12 and A 14 .

[0123] Number / Coefficient k A4 A6 A8 A10 A12 A14 surf1 0.50 3.99E-07 -8.78E-09 1.65E-11 -1.88E-14 1.19E-17 -3.30E-21 surf2 -1.17 1.72E-05 5.23E-10 2.58E-12 3.15E-14 -1.23E-19 1.63E-26 surf28 -24.68 -3.70E-05 -3.60E-08 1.88E-10 -1.49E-12 -4.00E-23 7.60E-29 surf29 18.75 2.67E-05 -1.71E-07 1.03E-09 -4.48E-12 -1.43E-22 5.72E-27

[0124] Table 2

[0125] Table 3 shows the zoom data of the zoom lens in this embodiment at the wide-angle and telephoto ends:

[0126] Face number Thickness / Distance Wide-angle end telephoto end surf7 T1 44.90 0.30 surf14 T2 15.77 6.34 surf20 T3 8.17 0.20 surf29 T4 21.01 54.12

[0127] Table 3

[0128] According to Embodiment 1 of this application, the zoom lens has an effective focal length (FW) of 12.245mm in wide-angle mode and an effective focal length (FT) of 36.117mm in telephoto mode; the total optical length (TTL-W) is 175mm in wide-angle mode and 146.115mm in telephoto mode; the absolute value of optical distortion is less than 12% in wide-angle mode and less than 0.6% in telephoto mode. Therefore, the zoom lens provided in Embodiment 1 can achieve low distortion and has good aberration correction capability, thus presenting good image quality.

[0129] Example 2

[0130] The following is for reference Figure 2A and Figure 2B This application describes a zoom lens according to Embodiment 2. For the sake of brevity, descriptions similar to those in Embodiment 1 will be omitted in Embodiment 2 and the following embodiments.

[0131] like Figure 2A and Figure 2B As shown, the zoom lens in this embodiment includes a first lens group G1 to a fourth lens group G4. Unlike embodiment 1, the zoom lens in this embodiment includes a total of 16 lenses L1 to L16, of which the fourth lens group G4 includes 5 lenses L12 to L16. Except for the fourth lens group G4, the optical power and the number of lenses included in each of the other lens groups are the same as in embodiment 1, and will not be described again here.

[0132] In this embodiment, the fourth lens group G4 includes two sets of positive cemented lenses, wherein the twelfth lens L12 and the thirteenth lens L13 form a cemented doublet with positive optical power; at the same time, the fourteenth lens L14 and the fifteenth lens L15 form a cemented doublet with positive optical power.

[0133] Table 4 shows some basic parameters of each lens in the zoom lens of this embodiment, including surface type, radius of curvature, thickness, refractive index of the material, and Abbe number. The units for radius of curvature and thickness / distance are millimeters (mm).

[0134] Face number Surface type radius of curvature Thickness / Distance Refractive index Nd Abbe number Vd surf1 aspherical 61.531 2.20 1.85 40.1 surf2 aspherical 19.175 12.12 surf3 spherical 721.403 1.00 1.49 70.4 surf4 spherical 42.947 7.23 surf5 spherical -60.825 2.31 1.50 81.6 surf6 spherical 42.706 6.00 1.94 33.2 surf7 spherical -743.711 T1 surf8 spherical 78.676 1.00 1.81 22.7 surf9 spherical 34.636 3.62 1.61 44.1 surf10 spherical -362.364 0.10 surf11 spherical 116.872 3.04 1.77 27.5 surf12 spherical -55.223 0.10 surf13 spherical -59.786 1.00 1.81 22.7 surf14 spherical 1588.735 T2 surf15 (STO) spherical Infinity 2.20 surf16 spherical -53.093 1.00 1.91 28.9 surf17 spherical -1443.515 0.12 surf18 spherical 60.726 4.92 1.81 25.5 surf19 spherical -23.777 1.00 1.90 31.3 surf20 spherical -4.26E+04 T3 surf21 spherical 22.543 8.96 1.50 81.6 surf22 spherical -19.148 1.00 1.52 64.2 surf23 spherical -133.961 0.10 surf24 spherical 19.056 1.26 1.82 46.6 surf25 spherical 12.425 8.58 1.50 81.6 surf26 spherical -32.294 0.20 surf27 aspherical -31.31 4.35 1.85 40.1 surf28 aspherical 68.112 T4 surf29 spherical Infinity 0.80 1.52 64.2 surf30 spherical Infinity 6.00 surf31(IMA) spherical Infinity 0.00

[0135] Table 4

[0136] As can be seen from Table 4, in this embodiment, the radius of curvature R of the image-side surface surf14 of the eighth lens L8 and the image-side surface surf20 of the eleventh lens L11 of the zoom lens is relatively large. The shape of these two surfaces can be convex, concave or flat, and no specific limitation is made in this application.

[0137] In this embodiment, the object-side surface and image-side surface of the first lens L1 and the sixteenth lens L16 of the zoom lens are both aspherical, and the surface shape of each aspherical lens can be defined by formula (1) given in the above embodiment 1.

[0138] Table 5 shows the conic coefficient (k) and higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror in this embodiment. 10 A 12 and A 14 .

[0139] Number / Coefficient k A4 A6 A8 A10 A12 A14 surf1 -0.63 2.79E-06 -1.37E-08 2.44E-11 -2.08E-14 6.46E-18 6.31E-22 surf2 -1.17 1.80E-05 -2.68E-09 -6.66E-12 6.54E-14 -2.17E-23 3.71E-28 surf27 -13.05 -1.04E-05 -8.62E-08 -1.29E-10 7.19E-13 3.51E-24 4.87E-28 surf28 31.18 7.13E-05 -2.95E-07 7.63E-10 -4.97E-12 3.24E-24 4.93E-28

[0140] Table 5

[0141] Table 6 shows the zoom data of the zoom lens in this embodiment at the wide-angle and telephoto ends:

[0142] Face number Thickness / Distance Wide-angle end telephoto end surf7 T1 46.22 0.20 surf14 T2 19.72 7.77 surf20 T3 10.71 0.20 surf28 T4 18.13 48.11

[0143] Table 6

[0144] According to Embodiment 2 of this application, the zoom lens has an effective focal length (FW) of 12.291 mm in wide-angle mode and an effective focal length (FT) of 36.258 mm in telephoto mode; the total optical length (TTL-W) is 175 mm in wide-angle mode and 136.492 mm in telephoto mode; the absolute value of optical distortion is less than 12% in wide-angle mode and less than 0.3% in telephoto mode. Therefore, the zoom lens provided in Embodiment 2 can achieve low distortion and has good aberration correction capability, thus presenting good image quality.

[0145] Example 3

[0146] The following is for reference Figure 3A and Figure 3B Description of a zoom lens according to Embodiment 3 of this application.

[0147] like Figure 3A and Figure 3B As shown, the zoom lens of this embodiment includes a first lens group G1 to a fourth lens group G4 arranged sequentially from the object side to the image side along the optical axis, comprising a total of 16 lenses L1 to L16. The optical power and the number of lenses included in each lens group are the same as in Embodiment 2, and will not be described again here.

[0148] Table 7 shows some basic parameters of each lens in the zoom lens of this embodiment, including surface type, radius of curvature, thickness, refractive index of the material, and Abbe number. The units for radius of curvature and thickness / distance are millimeters (mm).

[0149]

[0150]

[0151] Table 7

[0152] As can be seen from Table 7, in this embodiment, the radius of curvature R of the image side surface surf20 of the eleventh lens L11 of the zoom lens is relatively large. The shape of this surface can be convex, concave or flat, and this application does not specifically limit it.

[0153] In this embodiment, the object-side surface and image-side surface of the first lens L1 and the sixteenth lens L16 of the zoom lens are both aspherical, and the surface shape of each aspherical lens can be defined by formula (1) given in the above embodiment 1.

[0154] Table 8 shows the conic coefficient (k) and higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror in this embodiment. 10 A 12 and A 14 .

[0155] Number / Coefficient k A4 A6 A8 A10 A12 A14 surf1 -0.81 1.33E-07 -6.56E-09 1.40E-11 -1.64E-14 1.08E-17 -3.16E-21 surf2 -1.42 2.22E-05 -3.52E-09 4.68E-12 3.41E-14 -7.53E-22 1.62E-26 surf27 -17.69 -3.79E-05 4.33E-08 -5.76E-10 1.46E-12 -4.00E-23 7.63E-29 surf28 17.97 2.52E-05 -9.00E-08 1.11E-11 -1.16E-12 -1.43E-22 5.71E-27

[0156] Table 8

[0157] Table 9 shows the zoom data of the zoom lens in this embodiment at the wide-angle and telephoto ends:

[0158] Face number Thickness / Distance Wide-angle end telephoto end surf7 T1 46.46 0.20 surf14 T2 16.15 9.76 surf20 T3 12.62 0.20 surf28 T4 19.43 50.86

[0159] Table 9

[0160] According to Embodiment 3 of this application, the zoom lens has an effective focal length (FW) of 12.264 mm in wide-angle mode and an effective focal length (FT) of 36.178 mm in telephoto mode; the total optical length (TTL-W) is 175 mm in wide-angle mode and 141.355 mm in telephoto mode; the absolute value of optical distortion is less than 12% in wide-angle mode and less than 0.4% in telephoto mode. Therefore, the zoom lens provided in Embodiment 3 can achieve low distortion and has good aberration correction capability, thus presenting good image quality.

[0161] Example 4

[0162] The following is for reference Figure 4A and Figure 4B The zoom lens according to Embodiment 4 of this application is described.

[0163] like Figure 4A and Figure 4B As shown, the zoom lens of this embodiment includes a first lens group G1 to a fourth lens group G4 arranged sequentially from the object side to the image side along the optical axis, comprising a total of 16 lenses L1 to L16. The optical power and the number of lenses included in each lens group are the same as in Embodiment 2, and will not be described again here.

[0164] Table 10 shows some basic parameters of each lens in the zoom lens of this embodiment, including surface type, radius of curvature, thickness, refractive index of the material, and Abbe number. The units for radius of curvature and thickness / distance are millimeters (mm).

[0165] Face number Surface type radius of curvature Thickness / Distance Refractive index Nd Abbe number Vd surf1 aspherical 53.952 2.82 1.85 40.1 surf2 aspherical 17.113 13.33 surf3 spherical -331.227 1.00 1.49 70.4 surf4 spherical 65.102 5.47 surf5 spherical -66.464 2.38 1.50 81.6 surf6 spherical 42.439 5.83 1.95 32.3 surf7 spherical -2521.144 T1 surf8 spherical 93.768 1.00 1.81 22.7 surf9 spherical 36.072 3.95 1.61 44.1 surf10 spherical -206.426 0.10 surf11 spherical 98.346 3.11 1.78 45.0 surf12 spherical -67.173 1.15 surf13 spherical -72.295 1.00 1.84 43.0 surf14 spherical 1050.077 T2 surf15 (STO) spherical Infinity 2.20 surf16 spherical -47.098 1.00 1.89 27.4 surf17 spherical -324.61 0.10 surf18 spherical 75.695 4.09 1.81 22.7 surf19 spherical -29.709 1.00 1.89 30.0 surf20 spherical 8361.135 T3 surf21 spherical 22.517 8.43 1.50 81.6 surf22 spherical -21.347 1.11 1.59 61.3 surf23 spherical -72.999 0.10 surf24 spherical 20.135 1.53 surf25 spherical 12.377 8.93 1.50 81.6 surf26 spherical -28.687 0.17 surf27 aspherical -34.503 5.47 1.85 40.1 surf28 aspherical 58.003 T4 surf29 spherical Infinity 0.80 1.52 64.2 surf30 spherical Infinity 6.00 surf31(IMA) spherical Infinity 0.00

[0166] Table 10

[0167] As can be seen from Table 10, in this embodiment, the radius of curvature R of the image-side surface surf7 of the fourth lens L4, the image-side surface surf14 of the eighth lens L8, and the image-side surface surf20 of the eleventh lens L11 of the zoom lens are relatively large. The shapes of these surfaces can be convex, concave, or flat, and are not specifically limited in this application.

[0168] In this embodiment, the object-side surface and image-side surface of the first lens L1 and the sixteenth lens L16 of the zoom lens are both aspherical, and the surface shape of each aspherical lens can be defined by formula (1) given in the above embodiment 1.

[0169] Table 11 shows the conic coefficient (k) and higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror in this embodiment. 10 A 12 and A 14 .

[0170] Number / Coefficient k A4 A6 A8 A10 A12 A14 surf1 -0.92 6.07E-08 -1.03E-08 2.18E-11 -2.40E-14 1.38E-17 -3.16E-21 surf2 -1.88 3.69E-05 -3.45E-08 4.60E-11 6.45E-15 -4.87E-21 -5.59E-27 surf27 -15.54 -4.03E-05 1.10E-07 -9.78E-10 2.55E-12 6.06E-23 1.38E-27 surf28 21.75 3.17E-05 -1.37E-07 1.17E-10 -4.19E-12 -1.76E-22 7.89E-27

[0171] Table 11

[0172] Table 12 shows the zoom data of the zoom lens in this embodiment at the wide-angle and telephoto ends:

[0173] Face number Thickness / Distance Wide-angle end telephoto end surf7 T1 44.39 0.20 surf14 T2 19.67 9.33 surf20 T3 11.82 0.20 surf28 T4 17.04 47.81

[0174] Table 12

[0175] According to Embodiment 4 of this application, the zoom lens has an effective focal length (FW) of 12.232 mm in wide-angle mode and an effective focal length (FT) of 36.082 mm in telephoto mode; the total optical length (TTL-W) is 175 mm in wide-angle mode and 139.61 mm in telephoto mode; the absolute value of optical distortion is less than 12% in wide-angle mode and less than 0.03% in telephoto mode. Therefore, the zoom lens provided in Embodiment 4 can achieve low distortion and has good aberration correction capability, thus presenting good image quality.

[0176] Example 5

[0177] The following is for reference Figure 5A and Figure 5B The zoom lens according to Embodiment 5 of this application is described.

[0178] like Figure 5A and Figure 5B As shown, the zoom lens of this embodiment includes a first lens group G1 to a fourth lens group G4 arranged sequentially from the object side to the image side along the optical axis, comprising a total of 16 lenses L1 to L16. The optical power and the number of lenses included in each lens group are the same as in Embodiment 2, and will not be described again here.

[0179] Table 13 shows some basic parameters of each lens in the zoom lens of this embodiment, including surface type, radius of curvature, thickness, refractive index of the material, and Abbe number. The units for radius of curvature and thickness / distance are millimeters (mm).

[0180]

[0181]

[0182] Table 13

[0183] As can be seen from Table 13, in this embodiment, the radius of curvature R of the image side surface surf20 of the eleventh lens L11 of the zoom lens is relatively large. The shape of this surface can be convex, concave or flat, and this application does not specifically limit it.

[0184] In this embodiment, the object-side surface and image-side surface of the first lens L1 and the sixteenth lens L16 of the zoom lens are both aspherical, and the surface shape of each aspherical lens can be defined by formula (1) given in the above embodiment 1.

[0185] Table 14 shows the conic coefficient (k) and higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror in this embodiment. 10 A 12 and A 14 .

[0186] Number / Coefficient k A4 A6 A8 A10 A12 A14 surf1 -1.55 -8.54E-07 -7.05E-09 1.58E-11 -1.86E-14 1.22E-17 -3.51E-21 surf2 -1.70 3.30E-05 -2.43E-08 2.90E-11 2.22E-15 5.89E-18 -6.69E-27 surf27 -14.46 -4.76E-05 1.81E-07 -1.20E-09 2.93E-12 6.24E-23 1.37E-27 surf28 17.55 2.50E-05 -9.32E-08 1.71E-11 -5.55E-12 -1.77E-22 7.89E-27

[0187] Table 14

[0188] Table 15 shows the zoom data of the zoom lens in this embodiment at the wide-angle and telephoto ends:

[0189] Face number Thickness / Distance Wide-angle end telephoto end surf7 T1 40.65 0.20 surf14 T2 10.69 0.70 surf20 T3 12.31 0.31 surf28 T4 16.20 46.49

[0190] Table 15

[0191] According to Embodiment 5 of this application, the zoom lens has an effective focal length (FW) of 12.217 mm in wide-angle mode and an effective focal length (FT) of 35.933 mm in telephoto mode; the total optical length (TTL-W) is 175 mm in wide-angle mode and 140.846 mm in telephoto mode; the absolute value of optical distortion is less than 12% in wide-angle mode and less than 0.2% in telephoto mode. Therefore, the zoom lens provided in Embodiment 5 can achieve low distortion and has good aberration correction capability, thus presenting good image quality.

[0192] In summary, the lenses in Embodiments 1 to 5 satisfy the conditions shown in Table 16 below.

[0193] Conditional / Example 1 2 3 4 5 -2.3≤FG1 / FW≤-2.0 -2.074 -2.177 -2.171 -2.129 -2.068 -0.8≤FG1 / FT≤-0.6 -0.703 -0.738 -0.736 -0.722 -0.703 6.0≤FG2 / FW≤7.1 6.043 6.356 6.034 6.049 6.693 2.0 ≤ FG2 / FT ≤ 2.5 2.049 2.155 2.046 2.051 2.276 -13.3≤FG3 / FW≤-7.5 -7.698 -11.204 -9.297 -9.876 -13.151 2.7≤FG4 / FW≤3.4 2.808 2.969 2.949 2.878 2.928 0.9 ≤ FG4 / FT ≤ 1.2 0.952 1.006 1.000 0.976 0.995 2.9 ≤ FT / FW ≤ 3.1 2.950 2.950 2.950 2.950 2.941 0≤FW / TTL-W≤0.1 0.070 0.070 0.070 0.070 0.070 0.2 ≤ FT / TTL - T ≤ 0.4 0.247 0.266 0.256 0.258 0.255 -36.5≤F1 / FG1≤-6.2 -36.412 -10.024 -7.349 -9.832 -9.410 0.6 ≤ F² / FG² ≤ 2.4 1.775 2.027 2.302 2.199 0.933 0.8 ≤ F4 / FG4 ≤ 2.0 1.877 0.875 0.875 0.923 1.787 0.4 ≤ FW / H ≤ 0.6 0.479 0.481 0.480 0.479 0.478 1.8 ≤ BFL - w / FW ≤ 2.4 2.271 2.029 2.139 1.949 1.882 0.3≤DMAX / TTL-T≤0.4 0.356 0.381 0.368 0.372 0.369

[0194] Table 16

[0195] 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 zoom lens, characterized in that, Along the optical axis from the object side to the image side, the sequence includes: A first lens group with negative optical power; A second lens group with positive optical power; A third lens group with negative optical power; and A fourth lens group with positive optical power; In the process of zooming from wide-angle to telephoto, the first lens group moves from the object side to the image side along the optical axis, the second lens group moves from the image side to the object side along the optical axis, the third lens group moves from the image side to the object side along the optical axis to achieve continuous zooming from wide-angle to telephoto together with the first lens group and the second lens group, and the fourth lens group moves from the image side to the object side along the optical axis to compensate for the shift in image plane position during the continuous zooming process. The first lens group contains four lenses with optical power, arranged along the optical axis from the object side to the image side: the first lens has negative optical power; the second lens has negative optical power; the third lens has negative optical power; and the fourth lens has positive optical power. The second lens group contains four lenses with optical power, arranged along the optical axis from the object side to the image side: the first lens has negative optical power; the second lens has positive optical power; the third lens has positive optical power; and the fourth lens has negative optical power. The third lens group contains three lenses with optical power, arranged along the optical axis from the object side to the image side: the first lens has negative optical power; the second lens has positive optical power; and the third lens has negative optical power. The fourth lens group comprises five lenses with optical power, arranged along the optical axis from the object side to the image side: the first lens has positive optical power; the second lens has negative optical power; the third lens has negative optical power; the fourth lens has positive optical power; and the fifth lens has negative optical power. Alternatively, the fourth lens group comprises six lenses with optical power, arranged along the optical axis from the object side to the image side: the first lens has positive optical power; the second lens has negative optical power; the third lens has negative optical power; the fourth lens has positive optical power; the fifth lens has negative optical power; and the sixth lens has negative optical power. The zoom lens has four lens groups with optical power. The first lens group includes at least one set of cemented lenses; The effective focal length F1 of the positive cemented lens in the first lens group and the effective focal length FG1 of the first lens group satisfy: -36.5≤F1 / FG1≤-6.

2.

2. The zoom lens according to claim 1, wherein, The second lens group includes at least one set of cemented lenses.

3. The zoom lens according to claim 1, wherein, The third lens group includes at least one set of cemented lenses.

4. The zoom lens according to claim 1, wherein, The fourth lens group includes at least two sets of cemented lenses.

5. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FG1 of the first lens group and the effective focal length FW of the zoom lens in wide-angle mode satisfy: -2.3≤FG1 / FW≤-2.

0.

6. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FG1 of the first lens group and the effective focal length FT of the zoom lens in telephoto mode satisfy: -0.8≤FG1 / FT≤-0.

6.

7. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FG2 of the second lens group and the effective focal length FW of the zoom lens in wide-angle mode satisfy: 6.0≤FG2 / FW≤7.

1.

8. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FG2 of the second lens group and the effective focal length FT of the zoom lens in telephoto mode satisfy the following condition: 2.0 ≤ FG2 / FT ≤ 2.

5.

9. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FG3 of the third lens group and the effective focal length FW of the zoom lens in wide-angle mode satisfy the following condition: -13.3≤FG3 / FW≤-7.

5.

10. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FG4 of the fourth lens group and the effective focal length FW of the zoom lens in wide-angle mode satisfy the following condition: 2.7≤FG4 / FW≤3.

4.

11. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FG4 of the fourth lens group and the effective focal length FT of the zoom lens in telephoto mode satisfy the following condition: 0.9 ≤ FG4 / FT ≤ 1.

2.

12. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FW of the zoom lens in wide-angle mode and the effective focal length FT of the zoom lens in telephoto mode satisfy the following condition: 2.9 ≤ FT / FW ≤ 3.

1.

13. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FW of the zoom lens in wide-angle mode and the total optical length TTL-W of the zoom lens in wide-angle mode satisfy: 0≤FW / TTL-W≤0.

1.

14. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FT of the zoom lens in telephoto mode and the total optical length TTL-T of the zoom lens in telephoto mode satisfy the following condition: 0.2≤FT / TTL-T≤0.

4.

15. The zoom lens according to claim 2, wherein, The effective focal length F2 of the positive cemented lens in the second lens group and the effective focal length FG2 of the second lens group satisfy: 0.6≤F2 / FG2≤2.

4.

16. The zoom lens according to claim 4, wherein, The effective focal length F4 of the second set of cemented lenses in the fourth lens group and the effective focal length FG4 of the fourth lens group satisfy the following condition: 0.8 ≤ F4 / FG4 ≤ 2.

0.

17. The zoom lens according to any one of claims 1-4, wherein, The refractive index Nd3 of the lenses in the third lens group satisfies: 1.8≤Nd3≤2.

0.

18. The zoom lens according to any one of claims 1-4, wherein, The effective focal length FW of the zoom lens in wide-angle mode and the holographic height H of the zoom lens satisfy the following condition: 0.4≤FW / H≤0.

6.

19. The zoom lens according to any one of claims 1-4, wherein, The back focal length BFL-W of the zoom lens in wide-angle mode and the effective focal length FW of the zoom lens in wide-angle mode satisfy the following condition: 1.8≤BFL-W / FW≤2.

4.

20. The zoom lens according to any one of claims 1-4, wherein, The maximum optical aperture DMAX of the zoom lens and the total optical length TTL-T of the zoom lens in telephoto mode satisfy the following condition: 0.3≤DMAX / TTL-T≤0.

4.

21. The zoom lens according to any one of claims 1-4, wherein, In the first lens group, along the optical axis from the object side to the image side: The object side of the first lens is convex, and the image side is concave. The image-side surface of the second lens is concave; The object-side and image-side surfaces of the third lens are both concave. The object-side surface of the fourth lens is convex.

22. The zoom lens according to any one of claims 1-4, wherein, In the second lens group, along the optical axis from the object side to the image side: The object side of the first lens is convex, and the image side is concave. The object-side and image-side surfaces of the second lens are both convex. The object-side and image-side surfaces of the third lens are both convex. The object-side surface of the fourth lens is concave.

23. The zoom lens according to any one of claims 1-4, wherein, In the third lens group, along the optical axis from the object side to the image side: The object side of the first lens is concave, and the image side is convex. The object-side and image-side surfaces of the second lens are both convex. The object-side surface of the third lens is concave.

24. The zoom lens according to any one of claims 1-4, wherein, The fourth lens group contains five lenses with optical power, arranged along the optical axis from the object side to the image side: The object-side and image-side surfaces of the first lens are both convex. The object side of the second lens is concave, and the image side is convex. The object side of the third lens is convex, and the image side is concave. The object-side and image-side surfaces of the fourth lens are both convex. The object-side and image-side surfaces of the fifth lens are both concave.

25. The zoom lens according to any one of claims 1-4, wherein, The fourth lens group comprises six lenses with optical power, arranged along the optical axis from the object side to the image side: The object-side and image-side surfaces of the first lens are both convex. The object side of the second lens is concave, and the image side is convex. The object side of the third lens is convex, and the image side is concave. The object-side and image-side surfaces of the fourth lens are both convex. The object-side surface of the fifth lens is concave, and the image-side surface is convex. The object-side and image-side surfaces of the sixth lens are both concave.

26. The zoom lens according to claim 1, wherein, The zoom lens satisfies any one of the following conditions: -2.177≤FG1 / FW≤-2.068, -0.738≤FG1 / FT≤-0.703, 6.034≤FG2 / FW≤6.693 2.046≤FG2 / FT≤2.276 -13.151≤FG3 / FW≤-7.698, 2.808≤FG4 / FW≤2.969 0.952≤FG4 / FT≤1.006 2.941≤FT / FW≤2.950 0.070≤FW / TTL-W≤0.1 0.247≤FT / TTL-T≤0.266 -36.412≤F1 / FG1≤-7.349, 0.933≤F2 / FG2≤2.302, 0.875≤F4 / FG4≤1.877 1.81≤Nd3≤1.95, 0.478≤FW / H≤0.481 1.882≤BFL-W / FW≤2.271 0.356≤DMAX / TTL-T≤0.381 Wherein, FW is the effective focal length of the zoom lens in wide-angle mode, FT is the effective focal length of the zoom lens in telephoto mode, FG2 is the effective focal length of the second lens group, FG3 is the effective focal length of the third lens group, FG4 is the effective focal length of the fourth lens group, TTL-W is the total optical length of the zoom lens in wide-angle mode, TTL-T is the total optical length of the zoom lens in telephoto mode, the second lens group includes at least one set of cemented lenses, F2 is the effective focal length of the cemented lenses in the second lens group, the fourth lens group includes at least two sets of cemented lenses, F4 is the effective focal length of the second set of cemented lenses in the fourth lens group, Nd3 is the refractive index of the lenses in the third lens group, H is the full image height of the zoom lens, BFL-W is the back focal length of the zoom lens in wide-angle mode, and DMAX is the maximum optical aperture of the zoom lens.

Images