A zoom lens, a camera module and an electronic device

Abstract

Embodiments of the present application provide a zoom lens, a camera module and an electronic device. The zoom lens comprises: first, second and third lens groups arranged in order from the object side to the image side along the optical axis; the first and third lens groups have negative optical power, and the second lens group has positive optical power; the first lens group is a fixed group, the second lens group is a zoom group capable of moving along the optical axis, and moves from the first end close to the object side to the second end close to the image side, thereby realizing optical zoom of the zoom lens from the telephoto end to the wide-angle end; and the third lens group is a compensation group capable of moving along the optical axis; in the first, second and third lens groups: the total number of lenses with optical power is M, the number of aspheric surfaces is N, M≤7, and N≥8; the second lens group comprises at least two lenses, at least one of the two lenses has negative optical power, and the Abbe number V thereof is ≤40. The zoom lens of the embodiments of the present application has the advantages of simple structure, miniaturization and thinness, and can realize continuous zooming.

Description

[0001] This application claims priority to Chinese patent application filed on September 30, 2021, with application number 202111161927.X and entitled "A zoom lens, camera module and electronic device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of optical imaging, and more particularly to a zoom lens, a camera module, and an electronic device. Background Technology

[0003] With the increasing demands for mobile phone photography and the improvement in image quality of mobile phone camera modules, a single focal length lens and digital zoom are no longer sufficient to meet consumer needs. Most flagship phones on the market now feature mid-to-long telephoto cameras (3X / 5X), such as periscope lenses with up to 10x optical zoom, achieved by incorporating two to three wide-angle and telephoto lenses respectively. Because the optical elements within existing lens modules are generally arranged along the central axis of the lens barrel, the large number of lenses results in a longer overall length, hindering miniaturization and thinning, and also increasing costs. Furthermore, current high-magnification optical zoom in mobile phones is mostly "jump-like" zoom, combined with algorithm-based digital zoom to achieve hybrid optical zoom, but it cannot achieve continuous zoom, thus failing to better meet user needs. Summary of the Invention

[0004] This application provides a zoom lens, a camera module, and an electronic device. The zoom lens can achieve high-magnification continuous zoom with a single lens, and contains fewer lenses, has a simple structure, which is conducive to miniaturization and thinning, while also reducing costs.

[0005] Therefore, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, embodiments of this application provide a zoom lens, the zoom lens comprising: a first lens group, a second lens group, and a third lens group arranged sequentially along the optical axis from the object side to the image side; the first lens group and the third lens group have negative optical power, and the second lens group has positive optical power; the first lens group is a fixed group, the second lens group is a zoom group movable between a first end and a second end along the optical axis, the first end being closer to the object side and the second end being closer to the image side, the second lens group moving from the first end to the second end to achieve optical zoom of the zoom lens from a telephoto end to a wide-angle end, and the third lens group is a compensation group movable along the optical axis, the compensation group being used to compensate for the image plane position. The offset is adjusted to maintain image clarity; the first lens group and the third lens group each include at least one lens; the second lens group includes at least two lenses, at least one of the two lenses having negative optical power, and the Abbe number of the lens with negative optical power in the second lens group is V, where V≤40; each lens includes two opposing surfaces, at least one of the two surfaces being a lens surface, the lens surface being a curved surface that is convex or concave along the optical axis of the zoom lens, in the first lens group, the second lens group and the third lens group: the total number of lenses with optical power is M, the total number of aspherical lens surfaces is N, where M is an integer less than or equal to 7, and N is an integer greater than or equal to 8.

[0007] In the above scheme, the zoom lens includes three lens groups, with the total number of lenses in the three lens groups being less than or equal to 7 and the number of aspherical surfaces being greater than or equal to 8. By selecting the configuration of each group and the optical power of the lenses, and making reasonable use of aspherical surfaces, and in conjunction with the Abbe number of at least one lens with negative optical power in the second lens group, the zoom lens can achieve high image quality while meeting certain magnification and telephoto requirements, realizing continuous zoom. At the same time, the zoom lens contains fewer lenses and has a simpler structure, which is conducive to miniaturization and thinning, and can reduce costs.

[0008] In one possible implementation, the zoom lens further includes an aperture stop located between the second lens group and the third lens group. The aperture stop reduces stray light in the zoom lens, thereby improving image quality. The aperture stop can be an aperture stop and / or a field stop. Alternatively, the aperture stop can be located in other positions depending on operational requirements.

[0009] In one possible implementation, the focal length of the second lens group is f2, and the focal length of the telephoto end of the zoom lens is ft, satisfying: 0.10 ≤ |f2 / ft| ≤ 0.5. By limiting the range of optical power values ​​for the second lens group, the image quality after zooming can be improved.

[0010] In one possible implementation, the focal length of the third lens group is f3, and the focal length of the telephoto end of the zoom lens is ft, satisfying: 0.10 ≤ |f3 / ft| ≤ 0.5. By limiting the range of optical power of the third lens group, the image quality after zooming can be improved.

[0011] In one possible implementation, the ratio of the total optical length (TTL) of the zoom lens to the focal length (ft) at the telephoto end of the zoom lens, TTL / ft, ranges from 0.8 to 1.2. By limiting the compression ratio of the system, i.e., the range of the ratio TTL / ft, the zoom capability of the system can be improved. TTL / ft can be one of 0.8, 0.9, 1.0, 1.1, and 1.2. Of course, other values ​​of TTL / ft can be selected according to actual needs.

[0012] In one possible implementation, the ratio IH / ft of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens ranges from 0.02 ≤ IH / ft ≤ 0.2. This improves the zoom capability of the system. IH / ft can be one of 0.02, 0.05, 0.1, 0.15, and 0.2. Of course, other values ​​of IH / ft can be selected according to actual needs.

[0013] In one possible implementation, the first lens group includes a first lens and a second lens; the second lens group includes a third lens and a fourth lens; the third lens group includes a fifth lens and a sixth lens, M=6; the first lens, the third lens, and the fifth lens have positive optical power; the second lens, the fourth lens, and the sixth lens have negative optical power; the lens surfaces of the first lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are aspherical, N=10; the aperture value F# of the zoom lens ranges from 2.8 ≤ F# ≤ 5. By utilizing the matching of optical power, the image quality after zooming is improved, and the continuity of zooming is ensured.

[0014] In one possible implementation, the first lens group includes a first lens; the second lens group includes a second lens and a third lens, and the third lens group includes a fourth lens and a fifth lens, M=5; the first lens, the third lens, and the fifth lens have negative optical power; the second lens and the fourth lens have positive optical power; the lens surfaces of the second lens, the third lens, the fourth lens, and the fifth lens are aspherical, N=8; the aperture value F# of the zoom lens ranges from 2.8 ≤ F# ≤ 5. By utilizing optical power matching, the image quality after zooming is improved, ensuring zoom continuity.

[0015] In one possible implementation, the first lens group includes a first lens and a second lens; the second lens group includes a third lens and a fourth lens; the third lens group includes a fifth lens, M=5; the first lens and the third lens have positive optical power; the second lens, the fourth lens, and the fifth lens have negative optical power; the lens surfaces of the first lens, the third lens, the fourth lens, and the fifth lens are aspherical, N=8; the aperture value F# of the zoom lens ranges from 3.5≤F#≤5.75. By utilizing the matching of optical power, the image quality after zooming is improved, and the continuity of zooming is ensured.

[0016] In one possible implementation, the first lens group includes a first lens and a second lens; the second lens group includes a third lens and a fourth lens; the third lens group includes a fifth lens, a sixth lens, and a seventh lens, M=7; the first lens, the third lens, the fifth lens, and the seventh lens have positive optical power; the second lens, the fourth lens, and the sixth lens have negative optical power; the lens surfaces of the first lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are aspherical, N=10; the aperture value F# of the zoom lens ranges from 2.93≤F#≤5.5. By utilizing the matching of optical power, the image quality after zooming is improved, and the continuity of zooming is ensured.

[0017] In one possible implementation, the lens in the zoom lens is symmetrical along a first axis of symmetry and a second axis of symmetry, respectively, and the first axis of symmetry and the second axis of symmetry are perpendicular. The maximum dimension of the lens in the zoom lens along the extension direction of the first axis of symmetry is smaller than the maximum dimension along the extension direction of the second axis of symmetry. In this implementation, an I-cut lens can be used, that is, the lens can be a part of a circle. Specifically, the arcuate edges on opposite sides of the circle can be cut along the second axis of symmetry, i.e., the diameter direction, to form a straight line, while the other two sides of the circle remain arcuate edges. This makes the maximum dimension of the lens in the first axis of symmetry direction, such as the height direction, smaller than the maximum dimension in the second axis of symmetry direction, such as the width direction, thereby reducing the module height, for example, the vertical height is less than 6mm.

[0018] Secondly, embodiments of this application provide a camera module, the camera module including a photosensitive element and a zoom lens provided in the first aspect above, the photosensitive element being located on the image side of the zoom lens, wherein the zoom lens is used to receive light reflected by the object being photographed and project it onto the photosensitive element, and the photosensitive element is used to convert the light into an image signal.

[0019] In one possible implementation, the camera module further includes a prism or a reflector to change the direction of the light path, allowing the light passing through the prism or reflector to propagate along the extension direction of the optical axis of the zoom lens. This creates a light path deflection, achieving a periscope-like optical path. For example, multiple lenses of the zoom lens can be arranged along the thickness direction of the electronic device, such as a mobile phone, so that the thickness of the phone is greater than the sum of the thicknesses of the multiple lenses. By adding a prism or reflector, the multiple lenses of the zoom lens can be arranged along the extension direction of the plane on which the phone is located. The prism or reflector can change the light incident perpendicular to the thickness direction of the phone to be arranged along the extension direction of the phone's surface. With proper arrangement, it can propagate along the extension direction of the optical axis of the zoom lens.

[0020] Thirdly, embodiments of this application provide an electronic device, the electronic device including a driver chip and the camera module provided in the second aspect above, the driver chip being used to drive the camera module. Attached Figure Description

[0021] The accompanying drawings used in the description of the embodiments or prior art are briefly introduced below.

[0022] Figure 1A This is a schematic diagram of the zoom lens at the wide-angle end provided in the first embodiment of this application;

[0023] Figure 1B This is a schematic diagram of the zoom lens at the telephoto end provided in the first embodiment of this application;

[0024] Figure 1C for Figure 1A The diagram shows the defocus curve of a zoom lens at the wide-angle end;

[0025] Figure 1D for Figure 1A The diagram shows the lateral chromatic aberration curve of a zoom lens at the wide-angle end.

[0026] Figure 1E for Figure 1A The distortion curve of the zoom lens at the wide-angle end is shown below;

[0027] Figure 2A This is a schematic diagram of the zoom lens at the wide-angle end provided in the second embodiment of this application;

[0028] Figure 2B This is a schematic diagram of the zoom lens at the telephoto end provided in the second embodiment of this application;

[0029] Figure 2C for Figure 2A The diagram shows the defocus curve of a zoom lens at the wide-angle end;

[0030] Figure 2D for Figure 2A The diagram shows the lateral chromatic aberration curve of a zoom lens at the wide-angle end.

[0031] Figure 2E for Figure 2A The distortion curve of the zoom lens at the wide-angle end is shown below;

[0032] Figure 3A This is a schematic diagram of the zoom lens at the wide-angle end provided in the third embodiment of this application;

[0033] Figure 3B This is a schematic diagram of the zoom lens at the telephoto end provided in the third embodiment of this application;

[0034] Figure 3C for Figure 3A The diagram shows the defocus curve of a zoom lens at the wide-angle end;

[0035] Figure 3D for Figure 3A The diagram shows the lateral chromatic aberration curve of a zoom lens at the wide-angle end.

[0036] Figure 3E for Figure 3A The distortion curve of the zoom lens at the wide-angle end is shown below;

[0037] Figure 4A This is a schematic diagram of the zoom lens at the wide-angle end provided in the fourth embodiment of this application;

[0038] Figure 4B This is a schematic diagram of the zoom lens at the telephoto end provided in the fourth embodiment of this application;

[0039] Figure 4C for Figure 4A The diagram shows the defocus curve of a zoom lens at the wide-angle end;

[0040] Figure 4D for Figure 4A The diagram shows the lateral chromatic aberration curve of a zoom lens at the wide-angle end.

[0041] Figure 4E for Figure 4A The distortion curve of the zoom lens at the wide-angle end is shown below;

[0042] Figure 5A This is a schematic diagram of the zoom lens at the wide-angle end provided in the fifth embodiment of this application;

[0043] Figure 5B This is a schematic diagram of the zoom lens at the telephoto end provided in the fifth embodiment of this application;

[0044] Figure 5C for Figure 5AThe diagram shows the defocus curve of a zoom lens at the wide-angle end;

[0045] Figure 5D for Figure 5A The diagram shows the lateral chromatic aberration curve of a zoom lens at the wide-angle end.

[0046] Figure 5E for Figure 5A The distortion curve of the zoom lens at the wide-angle end is shown. Detailed Implementation

[0047] To better understand this application, various aspects of the present application will be described in more detail with reference to embodiments. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of the present 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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 formal sense unless expressly so specified herein.

[0053] The abbreviations and key terms used in the embodiments of this application are described in detail below:

[0054] F#: F-number, the ratio of the lens's focal length to its entrance pupil diameter. A smaller F# means more light enters the lens in the same amount of time; a larger F# results in a shallower depth of field, blurring the background and creating an effect similar to a telephoto lens.

[0055] EFL: effective focal length, the effective focal length of a lens;

[0056] TTL: total track length, the total length from the lens head to the image plane, is the main factor that determines the camera height;

[0057] IH: image height, the radius of the imaging circle, half-image height;

[0058] FOV: Field of view;

[0059] MIC: maximum image circle diameter;

[0060] BFL: back focal length;

[0061] MTF: Modulation transfer function / modulation contrast, a measure of system imaging quality;

[0062] Chief ray: The ray that passes through the center of the entrance pupil and exit pupil of the system;

[0063] CRA: chief ray angle, the angle of incidence of the chief ray on the image plane;

[0064] ASP: asphere

[0065] T: tangential, meridian, the surface determined by the optical axis and the principal ray;

[0066] S: sagittal, the plane that passes through the principal ray and is perpendicular to the meridional plane;

[0067] R: radius of curvature;

[0068] LP: line pair;

[0069] Wide-angle end: The shortest focal length of the lens, i.e., the short focal length end, the lens has the largest angle of view, used for shooting close-ups, especially large-scale close-ups;

[0070] Telescopic end: The longest focal length of the lens, also known as the telephoto end. It has the smallest angle of view and is used to shoot distant scenes, especially close-ups.

[0071] Temperature drift: The offset between the optimal image plane of the system at a certain temperature and the optimal image plane at room temperature.

[0072] Positive focal length: A lens or lens group has a positive focal length and a light-gathering effect;

[0073] Negative optical power: A lens or lens group has a negative focal length and a light-diverging effect;

[0074] Focal power: the reciprocal of the lens's focal length.

[0075] 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.

[0076] There are currently three ways to achieve zoom in mobile phone cameras, but they are not limited to the following:

[0077] The first option involves using a periscope telephoto camera and multi-camera algorithm zoom. The algorithm relays digital zoom to achieve high-magnification hybrid zoom. This option includes a large number of cameras and has a complex algorithm.

[0078] The second option is an external retractable zoom design. This option offers more flexibility in optical design. However, it results in a larger size, which is not conducive to miniaturizing the phone; the lens protrudes from the body when taking photos, disrupting the overall appearance of the phone, and is less waterproof and dustproof, leading to lower reliability.

[0079] The third option is to use a double-prism zoom design. In this design, the first prism has a lens on the outside, which is relatively thick. The volume space is limited, and the effective focal length distribution range is relatively small.

[0080] Of the three solutions mentioned above, achieving zoom functionality involves a large number of lenses and / or a large overall size, which limits the future trend of miniaturization, thinning, and high image quality in mobile phone lenses, thus restricting the competitiveness of zoom optical systems. Furthermore, current high-magnification optical zoom in mobile phones is mostly "skip-like" zoom, combined with algorithm-based digital zoom to achieve hybrid optical zoom, but it cannot achieve continuous zoom, failing to better meet user needs.

[0081] In view of this, embodiments of this application provide a zoom lens, a camera module, and an electronic device. By configuring the optical power of each component and lens, rationally utilizing aspherical surfaces, and employing lenses with specific optical properties in conjunction with each other in terms of focal length, refractive index, total optical length of the lens system, on-axis thickness, and radius of curvature, the zoom system can meet certain magnification and telephoto requirements while achieving high image quality. It can perform continuous zooming, and includes fewer lenses, resulting in a simple structure that facilitates miniaturization and thinning, while also reducing costs. The electronic device can be, for example, a portable device such as a mobile phone, tablet computer, or monitor. Furthermore, an I-cut lens can be used, where the lens is a portion of a circle. Specifically, the arcuate edges on opposite sides of the circle are cut into straight lines along the second axis of symmetry, i.e., the diameter direction, while the other two sides of the circle remain arcuate. This makes the maximum size of the lens in the first axis of symmetry direction (height direction) smaller than the maximum size in the second axis of symmetry direction (width direction), thereby reducing the module height.

[0082] The electronic device, such as a mobile phone, may include a driver chip and a camera module. The driver chip drives the camera module. The camera module may include a photosensitive element and a zoom lens. The side of the zoom lens facing the object is called the object side of the zoom lens, and the side of the zoom lens that forms the image is called the image side. The photosensitive element is located on the image side of the zoom lens. The zoom lens is used to receive light reflected from the object being photographed and project it onto the photosensitive element, which is used to convert the light into an image signal.

[0083] The specific structure of the zoom lens provided in the embodiments of this application will be described in detail below. Based on the need for miniaturization and continuous zoom capability, the embodiments of this application design a miniaturized continuous zoom optical system, i.e., a zoom lens, comprising a front fixed group, a zoom group, and a compensation group. This lens can be applied to shooting and recording images on smart terminals, such as scenarios where lenses from portable electronic products like mobile phones, tablets, and monitors are used to shoot external videos and photos, including various shooting applications at different magnifications and focal lengths. It is understood that these embodiments are merely exemplary, and this application has many other implementation methods.

[0084] Specifically, the zoom lens of this application embodiment includes a front fixed group (i.e., a first lens group G1) with negative optical power, a zoom group (i.e., a second lens group G2) with positive optical power, and a compensation group (i.e., a third lens group G3) with negative optical power. The second lens group G2 moves from the image side to the object side, realizing zoom from the wide-angle end to the telephoto end, and can perform continuous zoom. The optical magnification range / zoom range can be, for example, 1.5x-2.5x. The third lens group G3 is used to compensate for the offset of the image plane position to maintain image sharpness. The offset of the image plane position can be caused by the zoom group during the zoom process or by changes in the external temperature. The first lens group G1 and the third lens group G3 may each include at least one lens. The second lens group G2 includes at least two lenses, of which at least one is a negative lens (i.e., a lens with negative optical power), and the Abbe number V of the negative lens is ≤40.

[0085] Each lens comprises two opposing surfaces, at least one of which is a lens surface. The lens surface is a curved surface that protrudes or recedes along the optical axis of the zoom lens, participating in image formation and aberration correction. Specifically, light entering the lens is refracted on the lens surface, and its path is altered by the curved shape of the lens surface. By changing the path of the incident light through the lens surface, the incident light can converge or diverge accordingly, thus participating in image formation. Through the sequential divergence or convergence of the incident light by multiple lens surfaces in the zoom lens, optical imaging is achieved. The lens surface can be aspherical or non-aspherical. In the first lens group G1, the second lens group G2, and the third lens group G3: the total number of lenses with optical power is M, and the total number of aspherical lens surfaces is N, where M is an integer less than or equal to 7, and N is an integer greater than or equal to 8.

[0086] Figure 1A This is a schematic diagram of the zoom lens at the wide-angle end provided in the first embodiment of this application. Figure 1B This is a schematic diagram of the zoom lens at the telephoto end according to the first embodiment of this application. Figure 1A and Figure 1BAs shown, the zoom lens of the first embodiment of this application includes a first lens group G1, a second lens group G2, and a third lens group G3 arranged sequentially along the optical axis from the object side to the image side. Figure 1A and Figure 1B In the middle, from left to right, the objects side and the image side are shown respectively. On the image side of the third lens group G3, the filter L7 and the imaging surface are also shown.

[0087] The zoom lens comprises three lenses: a first lens group G1 (which can be a two-element lens with negative optical power), a second lens group G2 (which can be a two-element lens with positive optical power), and a third lens group G3 (which can be a two-element lens with negative optical power). Specifically, the first lens group G1 includes a first lens L1 and a second lens L2. The second lens group G2 includes a third lens L3 and a fourth lens L4. The third lens group G3 includes a fifth lens L5 and a sixth lens L6. Therefore, the total number of lenses with optical power is M = 6. The first lens L1, third lens L3, and fifth lens L5 have positive optical power. The second lens L2, fourth lens L4, and sixth lens L6 have negative optical power. The lens surfaces of the first lens L1, third lens L3, fourth lens L4, fifth lens L5, and sixth lens L6 are aspherical, with N = 10. The lens surface of the second lens L2 can be spherical. This zoom lens can include 10 aspherical surfaces and 2 spherical surfaces.

[0088] Furthermore, the ratio of the focal length f1 of the first lens group G1 to the focal length ft of the zoom lens at the telephoto end is |f1 / ft| = 0.74; the ratio of the focal length f2 of the second lens group G2 to the focal length ft of the zoom lens at the telephoto end is |f2 / ft| = 0.33; the Abbe number V of the fourth lens L4 with negative optical power in the two-element second lens group G2 is 19.98; and the ratio of the focal length f3 of the third lens group G3 to the focal length ft of the zoom lens at the telephoto end is |f3 / ft| = 0.724.

[0089] The ratio of the focal length ft of each lens to the telephoto end of the zoom lens can be as follows: the focal length f of the first lens L1 L1 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L1 / ft|=0.966; the focal length f of the second lens L2 L2 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L2 / ft|=0.4; the focal length f of the third lens L3 L3 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L3 / ft|=0.227; the focal length f of the fourth lens L4 L4 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L4 / ft|=0.519; the focal length f of the fifth lens L5 L5 The ratio of the focal length ft at the telephoto end of the zoom lens to |fL5 / ft|=0.343. The focal length f of the sixth lens L6. L6 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L6 / ft|=0.235.

[0090] Furthermore, the aperture value F# of a zoom lens can range from 2.8 to F# to 5. The ratio of the total optical length (TTL) of the zoom lens to its focal length (ft) at the telephoto end (TTL / ft) can be 0.981, and the ratio of the maximum image height (IH) of the zoom lens to its focal length (ft) at the telephoto end (IH / ft) can be 0.107. In one example, the effective focal length of the zoom lens at the wide-angle end is fs = 11.99mm, and the effective focal length at the telephoto end is ft = 27.99mm.

[0091] The zoom lens may also include an aperture stop (not shown in the figure), located between the second lens group G2 and the third lens group G3. Specifically, the aperture stop may be positioned close to the third lens group G3, and the aperture stop does not move during zooming of the zoom lens. Figure 1A and Figure 1B As shown, the lenses L1-L6 and the aperture stop of the zoom lens in the first embodiment are arranged in sequence, with surfaces labeled S1, S2, S3, S4, S5, S6, S7, S8, STOP (aperture stop S9, not shown in the figure), S10… It should be noted that only… Figure 1A The labels on the surfaces of each lens, L1-L6, are S1, S2, ... Figure 1B The surface markings of lenses L1-L6 can be found in the reference section. Figure 1A As shown, that is Figure 1A and Figure 1B The surface markings of each lens L1-L6 are consistent.

[0092] "Center thickness Th" refers to the distance along the optical axis between the surface and its adjacent downstream surface. A "downstream surface" is a surface closer to the image side than "the surface." For example, the center thickness Th of surface S2 of the first lens is the distance along the optical axis between surface S2 and surface S3; the center thickness Th of surface S5 of the third lens is the distance along the optical axis between surface S5 and surface S6 of the fourth lens. An exemplary specific value for the radius of curvature R, center thickness Th, refractive index Nd, and Abbe number Vd of each lens L1-L6 and filter L7 can be found in Table 1 below. The second lens group G2 and the third lens group G3 can be moved along the optical axis to change the overall focal length of the zoom lens, simultaneously causing changes in the air gap between some surfaces, i.e., the center thickness Th. D1, D2, D3, and D4 are the center thickness Th values ​​corresponding to the zoom lens changing to four different focal lengths, respectively. In other words, when the zoom lens as a whole has a first focal length, the center thickness Th is D1; ​​when the zoom lens as a whole has a second focal length, the center thickness Th is D2; when the zoom lens as a whole has a third focal length, the center thickness Th is D3; and when the zoom lens as a whole has a fourth focal length, the center thickness Th is D4.

[0093]

[0094] Table 1. Radius of curvature, refractive index, Abbe number, and center thickness of each lens at different focal lengths.

[0095] It should be noted that in Table 1, blank spaces indicate that there are no specific requirements for the numerical values; "inf" stands for Infinity, which means a plane.

[0096] Furthermore, in the first embodiment of this application, all even-order aspherical surface types z can be defined using, but are not limited to, the following aspherical formulas:

[0097]

[0098] Where z is the sagitta of the aspherical surface, r is the radial coordinate of the aspherical surface, c is the spherical curvature at the vertex of the aspherical surface, K is the quadratic surface constant, and A4, A6, A8, A10, and A12 are aspherical coefficients. The quadratic surface constants and aspherical coefficients of the surfaces of each lens in the first embodiment of this application are shown in Table 2 below.

[0099]

[0100] Table 2. Aspherical coefficients of each lens

[0101] As shown in Table 2, the zoom lens of the first embodiment of this application contains a total of 10 aspherical surfaces. The two surfaces S3 and S4 of L2 are spherical. The aspherical coefficient is calculated according to the following rules: taking the values ​​in the first row as an example, -7.35E-06 = -7.35 × 10-6 -4.38E-07 = -4.38 × 10 -7 -3.10E-08 = -3.10 × 10 -8 -1.29E-09 = -1.29 × 10 -9 .

[0102] The effects achievable by the zoom lens of the first embodiment of this application can be seen in Table 3 below.

[0103] Optical parameters Focal length f 11.99-27.99mm F value 2.8-5 Like high IMH 3mm TTL 27.45mm Design wavelength 650nm, 610nm, 555nm, 510nm, 470nm

[0104] Table 3. Effects achievable with zoom lenses

[0105] The following is for reference. Figure 1C , Figure 1D and Figure 1E Taking the wide-angle end of a zoom lens as an example, we will introduce the defocus amount, lateral chromatic aberration value and distortion. The defocus curve, lateral chromatic aberration curve and distortion of the zoom lens at the telephoto end are similar to those of the zoom lens at the wide-angle end.

[0106] Figure 1C for Figure 1A The diagram shows the defocus curve of a zoom lens at the wide-angle end. (See also...) Figure 1C As shown, the horizontal axis represents the defocus amount, and the vertical axis represents the value of the modulation transfer function (MTF), with the unit being lp / mm (line pairs per mm). According to the simulation results of the image quality (125 lp / mm) under different fields of view shown by the defocus curve, it can be seen that when the defocus amount is 0, the MTF values ​​in the T and R directions are mostly above 0.7, where the R direction is along the radius of curvature.

[0107] Figure 1D for Figure 1A The diagram shown illustrates the lateral chromatic aberration curve of a zoom lens at the wide-angle end, as follows: Figure 1D As shown, the horizontal axis represents the chromatic aberration value, and the vertical axis represents the field of view / image height. Examples are provided for colored light with wavelengths of 650nm, 555nm, and 470nm. Figure 1D It can be seen that the color difference value of light is small at different wavelengths.

[0108] Figure 1E for Figure 1A The distortion curve shown is for a zoom lens at the wide-angle end. (See diagram.) Figure 1E As shown, the horizontal axis represents distortion, and the vertical axis represents the field of view / image height, indicating the difference between the image distortion and the ideal shape. Figure 1E In the meantime, due to the small distortion, the distortion curve basically coincides with the vertical axis, so the zoom lens can control the distortion to within 5% at the wide-angle end.

[0109] Figure 2A This is a schematic diagram of the zoom lens at the wide-angle end provided in the second embodiment of this application. Figure 2B This is a schematic diagram of the zoom lens at the telephoto end according to the second embodiment of this application. Figure 2A and 2B As shown, the zoom lens of the second embodiment of this application may have the same number of lenses, the same type of optical power of each lens, and the same range of aperture value F# as the zoom lens of the first embodiment of this application. The differences between the zoom lens of the second embodiment of this application and the zoom lens of the first embodiment of this application are as follows:

[0110] The ratio of the focal length f1 of the first lens group G1 to the focal length of the zoom lens at the telephoto end, |f1 / ft|, is 0.591; the ratio of the focal length f2 of the second lens group G2 to the focal length ft of the zoom lens at the telephoto end, |f2 / ft|, is 0.358; the Abbe number V of the fourth lens L4, which has negative optical power in the two-element second lens group G2, is 19.24; the ratio of the focal length f3 of the third lens group G3 to the focal length ft of the zoom lens at the telephoto end, |f3 / ft|, is 24.8.

[0111] Wherein, the focal length f of the first lens L1 L1 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L1 / ft|=0.603; the focal length f of the second lens L2 L2 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L2 / ft|=0.264; the focal length f of the third lens L3 L3 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L3 / ft|=0.217; the focal length f of the fourth lens L4 L4 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L4 / ft|=0.354; the focal length f of the fifth lens L5 L5 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L5 / ft|=0.538; the focal length f of the sixth lens L6 L6 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L6 / ft|=0.404.

[0112] In addition, the ratio of the total optical length TTL of the zoom lens to the focal length ft at the telephoto end of the zoom lens, TTL / ft, can be 1.004; the ratio of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens, IH / ft, can be 0.1.

[0113] In one example, the effective focal length of the zoom lens at the wide-angle end is fs = 11.5mm, and the effective focal length of the zoom lens at the telephoto end is ft = 30mm.

[0114] The zoom lens may also include an aperture stop (not shown in the figure), located between the second lens group G2 and the third lens group G3. Specifically, the aperture stop may be positioned close to the third lens group G3, and the aperture stop does not move during zooming of the zoom lens. Figure 2A and Figure 2B As shown, the lenses L1-L6 and the aperture stop of the zoom lens in the second embodiment are arranged in sequence, with surfaces labeled S1, S2, S3, S4, ..., STOP (aperture stop, S9), S10... It should be noted that only... Figure 2A The labels on the surfaces of each lens, L1-L6, are S1, S2, ... Figure 2B The surface markings of lenses L1-L6 can be found in the reference section. Figure 2A As shown, that is Figure 2A and Figure 2B The surfaces of all lenses are labeled uniformly. The radii of curvature R, center thickness Th, refractive index Nd, and Abbe number Vd of each lens L1-L6 and filter L7 are shown in Table 4. The second lens group G2 and the third lens group G3 can be moved along the optical axis to change the overall focal length of the zoom lens, simultaneously altering the air gap between some surfaces, i.e., the center thickness Th. D1, D2, D3, and D4 represent the center thickness Th values ​​corresponding to four different focal lengths of the zoom lens.

[0115]

[0116]

[0117] Table 4. Radius of curvature, refractive index, Abbe number, and center thickness of each lens at different focal lengths.

[0118] It should be noted that in Table 4, blank spaces indicate that there are no specific requirements for the numerical values; "inf" stands for Infinity, which means a plane.

[0119] Furthermore, in the second embodiment of this application, all even-order aspherical surface types z can be defined using, but are not limited to, the following aspherical formulas:

[0120]

[0121] Where z is the sagitta of the aspherical surface, r is the radial coordinate of the aspherical surface, c is the spherical curvature at the vertex of the aspherical surface, K is the quadratic surface constant, and A4, A6, A8, A10, and A12 are aspherical coefficients. The quadratic surface constants and aspherical coefficients of the surfaces of each lens in the second embodiment of this application are shown in Table 5 below.

[0122]

[0123] Table 5. Aspherical coefficients of each lens

[0124] As shown in Table 5, the zoom lens of the second embodiment of this application contains a total of 10 aspherical surfaces. The two surfaces S3 and S4 of L2 are spherical surfaces. The calculation rules for the aspherical coefficients in Table 5 can be found in Table 2.

[0125] The effects achievable by the zoom lens of the second embodiment of this application can be seen in Table 6 below.

[0126] Optical parameters Focal length f 11.5-30mm F value 2.8-5

[0127] Like high IMH 3mm TTL 30mm Design wavelength 650nm, 610nm, 555nm, 510nm, 470nm

[0128] Table 6. Effects achievable with zoom lenses

[0129] The following is for reference. Figure 2C , Figure 2D and Figure 2E Taking the wide-angle end of a zoom lens as an example, we will introduce the defocus amount, lateral chromatic aberration value and distortion. The defocus curve, lateral chromatic aberration curve and distortion of the zoom lens at the telephoto end are similar to those of the zoom lens at the wide-angle end.

[0130] Figure 2C for Figure 2A The diagram shows the defocus curve of a zoom lens at the wide-angle end. (See also...) Figure 2C As shown, the horizontal axis represents the defocus amount, and the vertical axis represents the value of the modulation transfer function (MTF), with the unit being lp / mm (line pairs per mm). According to the simulation results of the image quality (125 lp / mm) under different fields of view shown by the defocus curve, it can be seen that when the defocus amount is 0, the MTF values ​​in the T and R directions are mostly above 0.4, where the R direction is along the radius of curvature.

[0131] Figure 2D for Figure 2A The diagram shown illustrates the lateral chromatic aberration curve of a zoom lens at the wide-angle end, as follows: Figure 2D As shown, the horizontal axis represents the chromatic aberration value, and the vertical axis represents the field of view / image height. Examples are provided for colored light with wavelengths of 650nm, 555nm, and 470nm. Figure 2D It can be seen that the color difference value of light is small at different wavelengths.

[0132] Figure 2E for Figure 2A The distortion curve shown is for a zoom lens at the wide-angle end. (See diagram.) Figure 2EAs shown, the horizontal axis represents distortion, and the vertical axis represents the field of view / image height, indicating the difference between the image distortion and the ideal shape. Figure 2E In the meantime, due to the small distortion, the distortion curve basically coincides with the vertical axis, so the zoom lens can control the distortion to within 5% at the wide-angle end.

[0133] Figure 3A This is a schematic diagram of the zoom lens at the wide-angle end provided in the third embodiment of this application. Figure 3B This is a schematic diagram of the zoom lens at the telephoto end according to the third embodiment of this application. Figure 3A and 3B As shown, the zoom lens of the third embodiment of this application includes a first lens group G1, a second lens group G2, and a third lens group G3 arranged sequentially along the optical axis from the object side to the image side. Figure 3A and Figure 3B In the middle, from left to right, the objects side and the image side are shown respectively. On the image side of the third lens group G3, the filter L6 and the imaging surface are also shown.

[0134] The zoom lens comprises three lenses: a first lens group G1 (a single-element lens with negative optical power), a second lens group G2 (a two-element lens with positive optical power), and a third lens group G3 (a two-element lens with negative optical power). Specifically, the first lens group G1 includes a first lens L1. The second lens group G2 includes a second lens L2 and a third lens L3, and the third lens group G3 includes a fourth lens L4 and a fifth lens L5. That is, the total number of lenses with optical power M = 5. The first lens L1, third lens L3, and fifth lens L5 have negative optical power; the second lens L2 and fourth lens L4 have positive optical power. The lens surfaces of the second lens L2, third lens L3, fourth lens L4, and fifth lens L5 are aspherical, and N = 8. The lens surface of the first lens L1 can be spherical. This zoom lens may include 8 aspherical surfaces and 2 spherical surfaces.

[0135] Furthermore, the ratio of the focal length f1 of the first lens group G1 to the focal length ft of the zoom lens at the telephoto end is |f1 / ft| = 1.217; the ratio of the focal length f2 of the second lens group G2 to the focal length ft of the zoom lens at the telephoto end is |f2 / ft| = 0.4; the Abbe number V of the third lens L3, which has negative optical power in the two-element second lens group G2, is 19.24; and the ratio of the focal length f3 of the third lens group G3 to the focal length ft of the zoom lens at the telephoto end is |f3 / ft| = 0.778.

[0136] The ratio of the focal length ft of each lens to the telephoto end of the zoom lens can be as follows: the focal length f of the first lens L1 L1 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L1 / ft|=1.216; the focal length f of the second lens L2 L2The ratio of the focal length ft at the telephoto end of the zoom lens to |f L2 / fl|=0.273; the focal length f of the third lens L3 L3 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L3 / fl|=0.594; the focal length f of the fourth lens L4 L4 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L4 / fl|=0.492; the focal length f of the fifth lens L5 L5 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L5 / f|=0.299.

[0137] Furthermore, the aperture value F# of a zoom lens can range from 2.8 to F# to 5; the ratio of the total optical length (TTL) of the zoom lens to its focal length (ft) at the telephoto end (TTL / ft) can be 1.02; and the ratio of the maximum image height (IH) of the zoom lens to its focal length (ft) at the telephoto end (IH / ft) can be 0.12. In one example, the effective focal length of the zoom lens at the wide-angle end is fs = 12mm, and the effective focal length at the telephoto end is ft = 25mm.

[0138] The zoom lens may also include an aperture stop (not shown in the figure), located between the second lens group G2 and the third lens group G3. The aperture stop may be positioned close to the third lens group G3 and does not move during zooming of the zoom lens. Figure 3A and Figure 3B As shown, the lenses L1-L5 and the aperture stop of the zoom lens in the third embodiment are arranged in sequence, with surfaces labeled S1, S2, S3, S4, ..., STOP (aperture stop S7), S8... It should be noted that only... Figure 3A The surface designations of each lens L1-L5 are marked with S1, S2, ... Figure 3B The surface markings of each lens L1-L5 can be found by referring to... Figure 3A As shown, that is Figure 3A and Figure 3B The surfaces of all lenses L1-L5 are labeled identically. The radii of curvature R, center thickness Th, refractive index Nd, and Abbe number Vd of each lens L1-L5 and filter L6 are shown in Table 7. The second lens group G2 and the third lens group G3 can be moved along the optical axis to change the overall focal length of the zoom lens, simultaneously altering the air gap between some surfaces, i.e., the center thickness Th. D1, D2, D3, and D4 represent the center thickness Th values ​​corresponding to four different focal lengths of the zoom lens.

[0139]

[0140] Table 7. Radius of curvature, refractive index, Abbe number, and center thickness of each lens at different focal lengths.

[0141] It should be noted that in Table 7, blank spaces indicate that there are no specific requirements for the numerical values; "inf" stands for Infinity, which means a plane.

[0142] In addition, the quadratic surface constants and aspherical coefficients of the surfaces of each lens in the third embodiment of this application are shown in Table 8 below.

[0143]

[0144]

[0145] Table 8. Aspherical coefficients of each lens

[0146] In the third embodiment of this application, all even-order aspherical surface types z can be defined using, but are not limited to, the following aspherical formulas:

[0147]

[0148] Where z is the aspherical elevation, r is the radial coordinate of the aspherical surface, c is the spherical curvature at the vertex of the aspherical surface, K is the quadratic surface constant, and A4, A6, A8, A10, and A12 are aspherical coefficients. As shown in Table 8, the zoom lens of the third embodiment of this application contains a total of 8 aspherical surfaces. The two surfaces S1 and S2 of L1 are spherical surfaces. The calculation rules for the values ​​of the aspherical coefficients in Table 8 can be found in Table 2.

[0149] The effects achievable by the zoom lens of the third embodiment of this application can be seen in Table 9 below.

[0150] Optical parameters Focal length f 12-25mm F value 2.8-5 Like high IMH 3mm TTL 25mm Design wavelength 650nm, 610nm, 555nm, 510nm, 470nm

[0151] Table 9. Effects achievable with zoom lenses

[0152] The following is for reference. Figure 3C , Figure 3D and Figure 3E Taking the wide-angle end of a zoom lens as an example, we will introduce the defocus amount, lateral chromatic aberration value and distortion. The defocus curve, lateral chromatic aberration curve and distortion of the zoom lens at the telephoto end are similar to those of the zoom lens at the wide-angle end.

[0153] Figure 3C for Figure 3A The diagram shows the defocus curve of a zoom lens at the wide-angle end. (See also...) Figure 3CAs shown, the horizontal axis represents the defocus amount, and the vertical axis represents the value of the modulation transfer function (MTF), with the unit being lp / mm (line pairs per mm). According to the simulation results of the image quality (125 lp / mm) under different fields of view shown by the defocus curve, it can be seen that when the defocus amount is 0, the MTF values ​​in the T and R directions are mostly above 0.5, where the R direction is along the radius of curvature.

[0154] Figure 3D for Figure 3A The diagram shown illustrates the lateral chromatic aberration curve of a zoom lens at the wide-angle end, as follows: Figure 3D As shown, the horizontal axis represents the chromatic aberration value, and the vertical axis represents the field of view / image height. Examples are provided for colored light with wavelengths of 650nm, 555nm, and 470nm. Figure 3D It can be seen that the color difference value of light is small at different wavelengths.

[0155] Figure 3E for Figure 3A The distortion curve shown is for a zoom lens at the wide-angle end. (See diagram.) Figure 3E As shown, the horizontal axis represents distortion, and the vertical axis represents the field of view / image height, indicating the difference between the image distortion and the ideal shape. Figure 3E In the meantime, due to the small distortion, the distortion curve basically coincides with the vertical axis, so the zoom lens can control the distortion to within 5% at the wide-angle end.

[0156] Figure 4A This is a schematic diagram of the zoom lens at the wide-angle end provided in the fourth embodiment of this application. Figure 4B This is a schematic diagram of the zoom lens at the telephoto end according to the fourth embodiment of this application. Figure 4A and 5B As shown, the optical lens according to Embodiment 4 of the application includes a first lens group G1, a second lens group G2, and a third lens group G3 arranged sequentially along the optical axis from the object side to the image side. Figure 4A and Figure 4B In the middle, from left to right, the object side to the image side is shown. On the image side of the third lens group G3, the filter L6 and the imaging surface are also shown.

[0157] The zoom lens comprises a first lens group G1, which can be a two-element lens with negative optical power; a second lens group G2, which can be a two-element lens with positive optical power; and a third lens group G3, which can be a single-element lens with negative optical power. Specifically, the first lens group G1 includes a first lens L1 and a second lens L2; ​​the second lens group G2 includes a third lens L3 and a fourth lens L4; and the third lens group G3 includes a fifth lens L5. That is, the total number of lenses with optical power M = 5. The first lens L1 and the third lens L3 have positive optical power; the second lens L2, the fourth lens L4, and the fifth lens L5 have negative optical power. The lens surfaces of the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are aspherical, with N = 8. The lens surface of the second lens L2 can be spherical. This zoom lens can include 8 aspherical surfaces and 2 spherical surfaces.

[0158] Furthermore, the ratio of the focal length f1 of the first lens group G1 to the focal length ft of the zoom lens at the telephoto end is |f1 / ft| = 0.796; the ratio of the focal length f2 of the second lens group G2 to the focal length ft of the zoom lens at the telephoto end is |f2 / ft| = 0.419; the Abbe number V of the fourth lens L4 with negative optical power in the two-element second lens group G2 is 19.24; and the ratio of the focal length f3 of the third lens group G3 to the focal length ft of the zoom lens at the telephoto end is |f3 / ft| = 1.072.

[0159] The ratio of the focal length ft of each lens to the telephoto end of the zoom lens can be as follows: the focal length f of the first lens L1 L1 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L1 / ft|=1.607; the focal length f of the second lens L2 L2 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L2 / ft|=0.559; Focal length f of the third lens L3 L3 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L3 / ft|=0.314; the focal length f of the fourth lens L4 L4 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L4 / ft|=1.243; the focal length f of the fifth lens L5 L5 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L5 / ft|=1.072.

[0160] In addition, the aperture value F# of the zoom lens can be in the range of 3.5≤F#≤5.75; the ratio of the total optical length TTL of the zoom lens to the focal length ft at the telephoto end of the zoom lens, TTL / ft, can be 1.164; the ratio of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens, IH / ft, can be 0.12.

[0161] In one example, the effective focal length of the zoom lens at the wide-angle end is fs = 12mm, and the effective focal length of the zoom lens at the telephoto end is ft = 25mm.

[0162] The zoom lens may also include an aperture stop located between the second lens group G2 and the third lens group G3. The aperture stop may be positioned close to the third lens group G3 and does not move during zooming. Figure 4A and Figure 4B As shown, the lenses L1-L5 and the aperture stop of the zoom lens in the fourth embodiment are arranged in sequence, with surfaces labeled S1, S2, S3, S4, ..., STOP (aperture stop S9), S10... It should be noted that only... Figure 4A The surface designations of each lens L1-L5 are marked with S1, S2, ... Figure 4B The surface markings of each lens L1-L5 can be found by referring to... Figure 4A As shown, that is Figure 4A and Figure 4B The surfaces of all lenses L1-L5 are labeled identically. The radii of curvature R, center thickness Th, refractive index Nd, and Abbe number Vd of each lens L1-L5 and filter L6 are shown in Table 10. The second lens group G2 and the third lens group G3 can be moved along the optical axis to change the overall focal length of the zoom lens, simultaneously altering the air gap between some surfaces, i.e., the center thickness Th. D1, D2, D3, and D4 represent the center thickness Th values ​​corresponding to four different focal lengths of the zoom lens.

[0163]

[0164]

[0165] Table 10. Radius of curvature, refractive index, Abbe number, and center thickness of each lens at different focal lengths.

[0166] It should be noted that in Table 10, blank spaces indicate that there are no specific requirements for the numerical values; "inf" stands for Infinity, which means a plane.

[0167] Furthermore, in the fourth embodiment of this application, all even-order aspherical surface types z can be defined using, but are not limited to, the following aspherical formulas:

[0168]

[0169] Where z is the sagitta of the aspherical surface, r is the radial coordinate of the aspherical surface, c is the spherical curvature at the vertex of the aspherical surface, K is the quadratic surface constant, and A4, A6, A8, A10, and A12 are aspherical coefficients. The quadratic surface constants and aspherical coefficients of the surfaces of the lenses in the fourth embodiment of this application are shown in Table 11 below.

[0170]

[0171] Table 11. Aspherical coefficients of each lens

[0172] As shown in Table 11, the zoom lens of the fourth embodiment of this application contains a total of 8 aspherical surfaces. The two surfaces S3 and S4 of L2 are spherical surfaces. The calculation rules for the aspherical coefficients in Table 11 can be found in Table 2.

[0173] The effects that the zoom lens of the fourth embodiment of this application can achieve are shown in Table 12 below.

[0174] Optical parameters Focal length f 12-25mm F value 3.55-5.75 Like high IMH 3mm TTL 30.13mm Design wavelength 650nm, 610nm, 555nm, 510nm, 470nm

[0175] Table 12. Effects achievable with zoom lenses

[0176] The following is for reference. Figure 4C , Figure 4D and Figure 4E Taking the wide-angle end of a zoom lens as an example, we will introduce the defocus amount, lateral chromatic aberration value and distortion. The defocus curve, lateral chromatic aberration curve and distortion of the zoom lens at the telephoto end are similar to those of the zoom lens at the wide-angle end.

[0177] Figure 4C for Figure 4A The diagram shows the defocus curve of a zoom lens at the wide-angle end. (See also...) Figure 4C As shown, the horizontal axis represents the defocus amount, and the vertical axis represents the value of the modulation transfer function (MTF), with the unit being lp / mm (line pairs per mm). According to the simulation results of the image quality (125 lp / mm) under different fields of view shown by the defocus curve, it can be seen that when the defocus amount is 0, the MTF values ​​in the T and R directions are mostly above 0.5, where the R direction is along the radius of curvature.

[0178] Figure 4D for Figure 4A The diagram shown illustrates the lateral chromatic aberration curve of a zoom lens at the wide-angle end, as follows: Figure 4D As shown, the horizontal axis represents the chromatic aberration value, and the vertical axis represents the field of view / image height. Examples are provided for colored light with wavelengths of 650nm, 555nm, and 470nm. Figure 4D It can be seen that the color difference value of light is small at different wavelengths.

[0179] Figure 4E for Figure 4A The distortion curve of the zoom lens at the wide-angle end is shown below. Figure 4E As shown, the horizontal axis represents distortion, and the vertical axis represents the field of view / image height, indicating the difference between the image distortion and the ideal shape. Figure 4E In the meantime, due to the small distortion, the distortion curve basically coincides with the vertical axis, so the zoom lens can control the distortion to within 5% at the wide-angle end.

[0180] Figure 5A This is a schematic diagram of the zoom lens at the wide-angle end provided in the fifth embodiment of this application. Figure 5B This is a schematic diagram of the zoom lens at the telephoto end according to the fifth embodiment of this application. Figure 5A and 5B As shown, the zoom lens of the fifth embodiment of this application includes a first lens group G1, a second lens group G2, and a third lens group G3 arranged sequentially along the optical axis from the object side to the image side. Figure 5A and Figure 5B In the middle, from left to right, the objects side and the image side are shown respectively. On the image side of the third lens group G3, the filter L8 and the imaging surface are also shown.

[0181] The zoom lens comprises three lenses: a first lens group G1 (two-element, negative optical power), a second lens group G2 (two-element, positive optical power), and a third lens group G3 (three-element, negative optical power). Specifically, the first lens group G1 includes a first lens L1 and a second lens L2. The second lens group G2 includes a third lens L3 and a fourth lens L4. The third lens group G3 includes a fifth lens L5, a sixth lens L6, and a seventh lens L7. Therefore, the total number of lenses with optical power is M = 7. Lenses L1, L3, L5, and L7 have positive optical power. Lenses L2, L4, and L6 have negative optical power. The lens surfaces of lenses L1, L3, L4, L5, and L6 are aspherical, with N = 10. That is, two lens surfaces of the second lens L2 and two lens surfaces of the seventh lens L7 can be spherical. This zoom lens can include 10 aspherical surfaces and 4 spherical surfaces.

[0182] Furthermore, the ratio of the focal length f1 of the first lens group G1 to the focal length ft of the zoom lens at the telephoto end is |f1 / ft| = 0.665; the ratio of the focal length f2 of the second lens group G2 to the focal length ft of the zoom lens at the telephoto end is |f2 / ft| = 0.306; the Abbe number V of the fourth lens L4, which has negative optical power in the two-element second lens group G2, is 31.3; and the ratio of the focal length f3 of the third lens group G3 to the focal length ft of the zoom lens at the telephoto end is |f3 / ft| = 0.647.

[0183] The ratio of the focal length ft of each lens to the telephoto end of the zoom lens can be as follows: the focal length f of the first lens L1 L1 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L1 / ft|=0.563; the focal length f of the second lens L2 L2 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L2 / ft|=0.266; the focal length f of the third lens L3 L3 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L3 / ft|=0.204; the focal length f of the fourth lens L4 L4 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L4 / ft|=0.398; the focal length f of the fifth lens L5 L5 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L5 / ft|=0.294; the focal length f of the sixth lens L6 L6 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L6 / ft|=0.167; the focal length f of the seventh lens L7 L7 The ratio of the focal length ft at the telephoto end of the zoom lens to |f L7 / ft|=0.91.

[0184] In addition, the aperture value F# of the zoom lens can be in the range of 2.93≤F#≤5.5; the ratio of the total optical length TTL of the zoom lens to the focal length ft at the telephoto end of the zoom lens, TTL / ft, can be 1.1; the ratio of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens, IH / ft, can be 0.103.

[0185] In one example, the effective focal length of the zoom lens at the wide-angle end is fs = 11.5mm, and the effective focal length of the zoom lens at the telephoto end is ft = 29mm.

[0186] The zoom lens may also include an aperture stop located between the second lens group G2 and the third lens group G3. The aperture stop may be positioned close to the third lens group G3 and does not move during zooming. Figure 5A and Figure 5B As shown, the lenses L1-L7 and the aperture stop of the zoom lens in the fifth embodiment are arranged in sequence, with surfaces labeled S1, S2, S3, S4, ..., STOP (aperture stop S9), S10... It should be noted that only... Figure 5A The surface numbers of each lens L1-L7 are marked as S1, S2, ... Figure 5B The surface markings of lenses L1-L7 can be found by referring to... Figure 5A As shown, that is Figure 5A and Figure 5B The surfaces of all lenses L1-L7 are labeled identically. The radii of curvature R, center thickness Th, refractive index Nd, and Abbe number Vd of each lens L1-L7 and filter L8 are shown in Table 13. The second lens group G2 and the third lens group G3 can be moved along the optical axis to change the overall focal length of the zoom lens, simultaneously altering the air gap between some surfaces, i.e., the center thickness Th. D1, D2, D3, and D4 represent the center thickness Th values ​​corresponding to four different focal lengths of the zoom lens.

[0187]

[0188]

[0189] Table 13. Radius of curvature, refractive index, Abbe number, and center thickness of each lens at different focal lengths.

[0190] It should be noted that in Table 13, blank spaces indicate that there are no specific requirements for the numerical values; "inf" stands for Infinity, which means a plane.

[0191] Furthermore, in the fifth embodiment of this application, all even-order aspherical surface types z can be defined using, but are not limited to, the following aspherical formulas:

[0192]

[0193] Where z is the sagitta of the aspherical surface, r is the radial coordinate of the aspherical surface, c is the spherical curvature at the vertex of the aspherical surface, K is the quadratic surface constant, and A4, A6, A8, A10, and A12 are aspherical coefficients. The quadratic surface constants and aspherical coefficients of the surfaces of the lenses in the fifth embodiment of this application are shown in Table 14 below.

[0194]

[0195] Table 14. Aspherical coefficients of each lens

[0196] As shown in Table 14, the zoom lens of the fifth embodiment of this application includes 10 aspherical surfaces. The two surfaces S3 and S4 of L2 and the two surfaces S14 and S15 of L7 are spherical surfaces. The calculation rules for the aspherical coefficients in Table 14 can be found in Table 2.

[0197] The effects achievable by the zoom lens of the fifth embodiment of this application are shown in Table 15 below.

[0198] Optical parameters Focal length f 11.5-29mm F value 2.93-5.5 Like high IMH 3mm TTL 31.9mm Design wavelength 650nm, 610nm, 555nm, 510nm, 470nm

[0199] Table 15. Effects achievable with zoom lenses

[0200] The following is for reference. Figure 5C , Figure 5D and Figure 5E Taking the wide-angle end of a zoom lens as an example, we will introduce the defocus amount, lateral chromatic aberration value and distortion. The defocus curve, lateral chromatic aberration curve and distortion of the zoom lens at the telephoto end are similar to those of the zoom lens at the wide-angle end.

[0201] Figure 5C for Figure 5A The diagram shows the defocus curve of a zoom lens at the wide-angle end. (See also...) Figure 5C As shown, the horizontal axis represents the defocus amount, and the vertical axis represents the value of the modulation transfer function (MTF), with the unit being lp / mm (line pairs per mm). According to the simulation results of the image quality (125 lp / mm) under different fields of view shown by the defocus curve, it can be seen that when the defocus amount is 0, the MTF values ​​in the T and R directions are mostly above 0.6, where the R direction is along the radius of curvature.

[0202] Figure 5D for Figure 5A The diagram shown illustrates the lateral chromatic aberration curve of a zoom lens at the wide-angle end, as follows: Figure 5D As shown, the horizontal axis represents the chromatic aberration value, and the vertical axis represents the field of view / image height. Examples are provided for colored light with wavelengths of 650nm, 555nm, and 470nm. Figure 5D It can be seen that the color difference value of light is small at different wavelengths.

[0203] Figure 5E for Figure 5A The distortion curve shown is for a zoom lens at the wide-angle end. (See diagram.) Figure 5E As shown, the horizontal axis represents distortion, and the vertical axis represents the field of view / image height, indicating the difference between the image distortion and the ideal shape. Figure 5E In the meantime, due to the small distortion, the distortion curve basically coincides with the vertical axis, so the zoom lens can control the distortion to within 5% at the wide-angle end.

[0204] In summary, in the embodiments of this application, in the first lens group G1, the second lens group G2, and the third lens group G3: the total number of lenses with optical power is M, where M is an integer less than or equal to 7, meaning the zoom lens includes a maximum of 7 lenses, thus having a maximum of 7 × 2 = 14 surfaces. The total number of aspherical lens surfaces N can be an integer greater than or equal to 8. Because the three lens groups include a relatively small number of lenses M, the zoom lens structure is simple, facilitating miniaturization and thinning, while also reducing costs. Furthermore, the zoom lens can use I-cut lenses (with a vertical height, for example, less than 6 mm), reducing the lens module height and further aiding in miniaturization. For example, the diameter of the first lens can be less than 9 mm, suitable for miniaturized lenses in mobile phones, enabling continuous zoom within the miniaturized lens.

[0205] The ratio of the total optical length (TTL) of the zoom lens to the focal length (ft) at the telephoto end of the zoom lens, TTL / ft, can range from 0.8 to 1.2. Specifically, TTL / ft can be one of 0.8, 0.9, 1.0, 1.1, or 1.2. Of course, other values ​​of TTL / ft can be selected according to actual needs. For example, in the first embodiment, the ratio of the total optical length TTL of the zoom lens to the focal length ft at the telephoto end of the zoom lens, TTL / ft, can be 0.981; in the second embodiment, the ratio of the total optical length TTL of the zoom lens to the focal length ft at the telephoto end of the zoom lens, TTL / ft, can be 1.004; in the third embodiment, the ratio of the total optical length TTL of the zoom lens to the focal length ft at the telephoto end of the zoom lens, TTL / ft, can be 1.02; in the fourth embodiment, the ratio of the total optical length TTL of the zoom lens to the focal length ft at the telephoto end of the zoom lens, TTL / ft, can be 1.164; and in the fifth embodiment, the ratio of the total optical length TTL of the zoom lens to the focal length ft at the telephoto end of the zoom lens, TTL / ft, can be 1.1.

[0206] The ratio IH / ft of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens can range from 0.02 ≤ IH / ft ≤ 0.2. Specifically, IH / ft can be one of 0.02, 0.05, 0.1, 0.15, and 0.2. Of course, other values ​​of IH / ft can also be selected according to actual needs. For example, in the first embodiment, the ratio IH / ft of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens can be 0.107; in the second embodiment, the ratio IH / ft of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens can be 0.1; in the third embodiment, the ratio IH / ft of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens can be 0.12; in the fourth embodiment, the ratio IH / ft of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens can be 0.12; in the fifth embodiment, the ratio IH / ft of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens can be 0.103.

[0207] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A zoom lens, characterized in that, include: The first lens group (G1), the second lens group (G2), and the third lens group (G3) are arranged sequentially along the optical axis from the object side to the image side. The first lens group (G1) and the third lens group (G3) have negative optical power, and the second lens group (G2) has positive optical power; The first lens group (G1) is a fixed group, and the second lens group (G2) is a zoom group that can move along the optical axis between a first end and a second end. The first end is closer to the object side, and the second end is closer to the image side. The second lens group (G2) moves from the first end to the second end to realize the optical zoom of the zoom lens from the telephoto end to the wide-angle end. The third lens group (G3) is a compensation group that can move along the optical axis. The compensation group is used to compensate for the offset of the image plane position to maintain image clarity. The first lens group (G1) and the third lens group (G3) each include at least one lens; the second lens group (G2) includes at least two lenses, at least one of which has negative optical power, and the Abbe number of the lens with negative optical power in the second lens group (G2) is V, where V ≤ 40; each lens includes two opposing surfaces, at least one of which is a lens surface, which is a curved surface that is convex or concave along the optical axis of the zoom lens; in the first lens group (G1), the second lens group (G2), and the third lens group (G3): the total number of lenses with optical power is M, the total number of aspherical lens surfaces is N, where M is an integer less than or equal to 7, and N is an integer greater than or equal to 8; The first lens group (G1) includes a first lens (L1) and a second lens (L2); the second lens group (G2) includes a third lens (L3) and a fourth lens (L4); the third lens group (G3) includes a fifth lens (L5) and a sixth lens (L6), M=6; The first lens (L1), the third lens (L3), and the fifth lens (L5) have positive optical power; the second lens (L2), the fourth lens (L4), and the sixth lens (L6) have negative optical power. The lens surfaces of the first lens (L1), the third lens (L3), the fourth lens (L4), the fifth lens (L5), and the sixth lens (L6) are aspherical, and N=10; the aperture value F# of the zoom lens ranges from 2.8 to 5. Alternatively, the first lens group (G1) includes a first lens (L1); the second lens group (G2) includes a second lens (L2) and a third lens (L3), and the third lens group (G3) includes a fourth lens (L4) and a fifth lens (L5), M=5; The first lens (L1), the third lens (L3), and the fifth lens (L5) have negative optical power; the second lens (L2) and the fourth lens (L4) have positive optical power. The lens surfaces of the second lens (L2), the third lens (L3), the fourth lens (L4), and the fifth lens (L5) are aspherical, and N=8; the aperture value F# of the zoom lens ranges from 2.8 to 5. Alternatively, the first lens group (G1) includes a first lens (L1) and a second lens (L2); the second lens group (G2) includes a third lens (L3) and a fourth lens (L4); the third lens group (G3) includes a fifth lens (L5), M=5; The first lens (L1) and the third lens (L3) have positive optical power; the second lens (L2), the fourth lens (L4), and the fifth lens (L5) have negative optical power. The lens surfaces of the first lens (L1), the third lens (L3), the fourth lens (L4), and the fifth lens (L5) are aspherical, and N=8; the aperture value F# of the zoom lens ranges from 3.5 to 5.

75. Alternatively, the first lens group (G1) includes a first lens (L1) and a second lens (L2); the second lens group (G2) includes a third lens (L3) and a fourth lens (L4); the third lens group (G3) includes a fifth lens (L5), a sixth lens (L6), and a seventh lens (L7), where M=7; The first lens (L1), the third lens (L3), the fifth lens (L5), and the seventh lens (L7) have positive optical power; the second lens (L2), the fourth lens (L4), and the sixth lens (L6) have negative optical power. The lens surfaces of the first lens (L1), the third lens (L3), the fourth lens (L4), the fifth lens (L5), and the sixth lens (L6) are aspherical, and N=10; the aperture value F# of the zoom lens ranges from 2.93≤F#≤5.

5.

2. The zoom lens according to claim 1, characterized in that, The zoom lens also includes an aperture stop located between the second lens group (G2) and the third lens group (G3).

3. The zoom lens according to claim 1 or 2, characterized in that, The focal length of the second lens group (G2) is f2, and the focal length of the telephoto end of the zoom lens is ft, satisfying: 0.10≤|f2 / ft|≤0.

5.

4. The zoom lens according to claim 1 or 2, characterized in that, The focal length of the third lens group (G3) is f3, and the focal length of the telephoto end of the zoom lens is ft, satisfying: 0.10≤|f3 / ft|≤0.

5.

5. The zoom lens according to claim 1 or 2, characterized in that, The ratio of the total optical length TTL of the zoom lens to the focal length ft at the telephoto end of the zoom lens, TTL / ft, has a range of 0.8 ≤ TTL / ft ≤ 1.

2.

6. The zoom lens according to claim 1 or 2, characterized in that, The ratio of the maximum image height IH of the zoom lens to the focal length ft at the telephoto end of the zoom lens, IH / ft, has a range of 0.02 ≤ IH / ft ≤ 0.

2.

7. The zoom lens according to claim 1 or 2, characterized in that, The lens in the zoom lens is symmetrical along a first axis of symmetry and a second axis of symmetry, respectively, and the first axis of symmetry and the second axis of symmetry are perpendicular to each other. The maximum dimension of the lens in the zoom lens along the extension direction of the first axis of symmetry is smaller than the maximum dimension along the extension direction of the second axis of symmetry.

8. A camera module, characterized in that, The device includes a photosensitive element and a zoom lens as described in any one of claims 1 to 7, wherein the photosensitive element is located on the image side of the zoom lens, and the zoom lens is used to receive light reflected from the object being photographed and project it onto the photosensitive element, and the photosensitive element is used to convert the light into an image signal.

9. The camera module according to claim 8, characterized in that, The camera module also includes a prism or a reflector to change the direction of the light path, so that the light after passing through the prism or the reflector can propagate along the extension direction of the optical axis of the zoom lens.

10. An electronic device, characterized in that, It includes a driver chip and a camera module as described in claim 8 or 9, wherein the driver chip is used to drive the camera module.

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