A zoom lens

Abstract

The embodiment of the present application discloses a zoom lens. The zoom lens comprises a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power and a fourth lens group with positive refractive power arranged in sequence along an optical axis from an object side to an image side, the second lens group and the fourth lens group move along the optical axis during zooming; the first lens group comprises a first lens, a second lens and a third lens; the second lens group comprises a fourth lens, a fifth lens and a sixth lens; the third lens group comprises a seventh lens, an eighth lens, a ninth lens and a tenth lens; and the fourth lens group comprises an eleventh lens, a twelfth lens, a thirteenth lens and a fourteenth lens. The zoom lens provided by the embodiment of the present application uses 14 lenses, can realize a high-performance zoom lens with an angle of view from about 18° to 50° on a 1 / 1.8 inch CMOS target surface, and meets the imaging requirements under the environment of-40℃ to 80℃.

Description

Technical Field

[0001] The present invention relates to lens technology, and more particularly to a zoom lens. Background Technology

[0002] In the security field, zoom lenses are widely used because their focal length is variable, allowing users to obtain images at various magnification levels according to their needs.

[0003] With the development of technology, security products are trending towards miniaturization. As the core component of a security camera's imaging system, the size of the security lens directly determines the overall size of the camera. This places demands on the miniaturization and high-definition capabilities of the lens. Summary of the Invention

[0004] This invention provides a zoom lens, specifically a four-element zoom lens, which improves image quality while reducing lens size and achieving a large aperture. This zoom lens uses 14 elements and achieves a high-performance zoom lens with a diagonal field of view from approximately 18° to 50° on a 1 / 1.8-inch CMOS sensor, meeting imaging requirements in environments ranging from -40°C to 80°C.

[0005] This invention provides a zoom lens, comprising a first lens group with positive optical power, a second lens group with negative optical power, a third lens group with positive optical power, and a fourth lens group with positive optical power arranged sequentially along the optical axis from the object side to the image side, wherein the second lens group and the fourth lens group move along the optical axis during zooming.

[0006] The first lens group includes a first lens, a second lens, and a third lens arranged sequentially along the optical axis from the object side to the image side;

[0007] The second lens group includes a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical axis from the object side to the image side;

[0008] The third lens group includes a seventh lens, an eighth lens, a ninth lens, and a tenth lens arranged sequentially from the object side to the image side along the optical axis;

[0009] The fourth lens group includes an eleventh lens, a twelfth lens, a thirteenth lens, and a fourteenth lens arranged sequentially along the optical axis from the object side to the image side;

[0010] The first lens has negative optical power, the second lens has positive optical power, the third lens has positive optical power, the fourth lens has negative optical power, the fifth lens has negative optical power, the sixth lens has positive optical power, the seventh lens has positive optical power, the eighth lens has positive optical power, the ninth lens has positive optical power, the tenth lens has negative optical power, the eleventh lens has positive optical power, the twelfth lens has negative optical power, the thirteenth lens has positive optical power, and the fourteenth lens has positive optical power.

[0011] Optionally, the first lens and the second lens form a cemented lens, and the ninth lens and the tenth lens form a cemented lens.

[0012] Optionally, the optical power of the first lens, the second lens, the ninth lens, and the tenth lens satisfies the following:

[0013]

[0014]

[0015] in, and These represent the optical power of the cemented lens composed of the first lens and the second lens, and the cemented lens composed of the ninth lens and the tenth lens, respectively. The zoom lens's optical power at the wide-angle end is referred to as "the zoom lens's optical power".

[0016] Optionally, the optical power of the first lens to the fourteenth lens satisfies:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027] in, and These represent the optical power of the lenses with corresponding serial numbers from the first lens to the fourteenth lens. This refers to the optical power of the zoom lens at the wide-angle end. The optical power of the second lens group is... The optical power of the fourth lens group is given.

[0028] Optionally, the refractive indices of the first lens to the fourteenth lens satisfy the following:

[0029] 1.71≤n1≤1.85;

[0030] 1.41≤n²≤1.55;

[0031] 1.53≤n4≤1.73;

[0032] 1.62≤n10≤1.71;

[0033] 1.52≤n13≤1.69;

[0034] Wherein, n1, n2, n4, n10 and n13 represent the refractive indices of the lenses with corresponding serial numbers from the first lens to the fourteenth lens.

[0035] Optionally, the dispersion coefficients of the first lens to the fourteenth lens satisfy:

[0036] 17≤v1≤50;

[0037] 70≤v2≤98;

[0038] 37≤v3≤98;

[0039] 26≤v4≤88;

[0040] 53≤v5≤61.2;

[0041] 32≤v8≤65;

[0042] 65≤v11≤97;

[0043] 17≤v12≤31;

[0044] 32≤v13≤65;

[0045] Wherein, v1, v2, v3, v4, v5, v8, v11, v12 and v13 represent the dispersion coefficients of the lenses with corresponding serial numbers from the first lens to the fourteenth lens.

[0046] Optionally, the diameter D1 of the first lens and the total length TTL_W of the zoom lens at the wide-angle end satisfy the following:

[0047] D1 / TTL_W<0.446.

[0048] Optionally, the first lens, the second lens, the third lens, the fourth lens, the seventh lens, the ninth lens, the tenth lens, and the eleventh lens are all glass spherical lenses;

[0049] The fifth lens, the sixth lens, the eighth lens, the twelfth lens, the thirteenth lens, and the fourteenth lens are all plastic aspherical lenses.

[0050] Optionally, the first lens is a convex-concave lens, the second lens is a convex-concave lens, the fourth lens is a biconcave lens, the seventh lens is a biconvex lens, the eighth lens is a convex-concave lens, the ninth lens is a biconvex lens, the tenth lens is a biconcave lens, the eleventh lens is a convex-concave lens, the thirteenth lens is a concave-convex lens, and the fourteenth lens is a convex-concave lens.

[0051] Optionally, the zoom lens may also include an aperture stop;

[0052] The aperture stop is located between the sixth lens and the seventh lens.

[0053] The zoom lens provided in this invention includes a first lens group with positive optical power, a second lens group with negative optical power, a third lens group with positive optical power, and a fourth lens group with positive optical power, arranged sequentially along the optical axis from the object side to the image side. Specifically, it employs 14 lenses, a relatively small number that helps reduce the lens length. The second and fourth lens groups move along the optical axis during zooming, allowing the zoom lens to switch between wide-angle and telephoto ends. The total effective focal length of the zoom lens is continuously zoomable within the range of 10mm to 30mm. Through a rational design of the structure of each lens and the matching of optical powers, the zoom lens achieves a high-performance zoom lens with a diagonal field of view from approximately 18° to 50° on a 1 / 1.8-inch CMOS sensor, and meets imaging requirements when used in environments ranging from -40℃ to 80℃. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the structure of a zoom lens at the wide-angle end, provided in an embodiment of the present invention.

[0055] Figure 2 for Figure 1 A schematic diagram of the telephoto end of a medium zoom lens;

[0056] Figure 3 This is a spherical aberration curve at the wide-angle end of a zoom lens in this embodiment;

[0057] Figure 4This is a spherical aberration curve at the telephoto end of a zoom lens in this embodiment;

[0058] Figure 5 This is a field curvature distortion diagram of a zoom lens at the wide-angle end in this embodiment;

[0059] Figure 6 This is a field curvature distortion diagram at the telephoto end of a zoom lens in this embodiment;

[0060] Figure 7 This is a schematic diagram of another zoom lens wide-angle end provided in an embodiment of the present invention;

[0061] Figure 8 for Figure 7 A schematic diagram of the telephoto end of a medium zoom lens;

[0062] Figure 9 This is a spherical aberration curve at the wide-angle end of a zoom lens in this embodiment;

[0063] Figure 10 This is a spherical aberration curve at the telephoto end of a zoom lens in this embodiment;

[0064] Figure 11 This is a field curvature distortion diagram of a zoom lens at the wide-angle end in this embodiment;

[0065] Figure 12 This is a field curvature distortion diagram at the telephoto end of a zoom lens in this embodiment;

[0066] Figure 13 This is a schematic diagram of the structure of another zoom lens wide-angle end provided in an embodiment of the present invention;

[0067] Figure 14 for Figure 13 A schematic diagram of the telephoto end of a medium zoom lens;

[0068] Figure 15 This is a spherical aberration curve at the wide-angle end of a zoom lens in this embodiment;

[0069] Figure 16 This is a spherical aberration curve at the telephoto end of a zoom lens in this embodiment;

[0070] Figure 17 This is a field curvature distortion diagram of a zoom lens at the wide-angle end in this embodiment;

[0071] Figure 18 This is a field curvature distortion diagram at the telephoto end of a zoom lens in this embodiment. Detailed Implementation

[0072] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0073] The terminology used in the embodiments of this invention is for the purpose of describing specific embodiments only and is not intended to limit the invention. It should be noted that directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this invention. Furthermore, in the context, it should be understood that when referring to an element being formed "upper" or "lower" of another element, it can be formed not only directly "upper" or "lower" of the other element, but also indirectly "upper" or "lower" of the other element through an intermediate element. The terms "first," "second," etc., are used for descriptive purposes only and do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0074] Figure 1 This is a schematic diagram of the structure of a zoom lens at the wide-angle end, provided as an embodiment of the present invention. (Reference) Figure 1The zoom lens provided in this embodiment of the invention includes a first lens group 10 with positive optical power, a second lens group 20 with negative optical power, a third lens group 30 with positive optical power, and a fourth lens group 40 with positive optical power arranged sequentially from the object side to the image side along the optical axis. The second lens group 20 and the fourth lens group 40 move along the optical axis during zooming. The first lens group 10 includes a first lens 101, a second lens 102, and a third lens 103 arranged sequentially from the object side to the image side along the optical axis. The second lens group 20 includes a fourth lens 201, a fifth lens 202, and a sixth lens 203 arranged sequentially from the object side to the image side along the optical axis. The third lens group 30 includes a seventh lens 301, an eighth lens 302, a ninth lens 303, and a tenth lens 304 arranged sequentially from the object side to the image side along the optical axis. The fourth lens group 40 includes an eleventh lens 401, a twelfth lens 402, a thirteenth lens 403, and a fourteenth lens 404 arranged sequentially from the object side to the image side along the optical axis. The first lens 101 has negative optical power, the second lens 102 has positive optical power, the third lens 103 has positive optical power, the fourth lens 201 has negative optical power, the fifth lens 202 has negative optical power, the sixth lens 203 has positive optical power, the seventh lens 301 has positive optical power, the eighth lens 302 has positive optical power, the ninth lens 303 has positive optical power, the tenth lens 304 has negative optical power, the eleventh lens 401 has positive optical power, the twelfth lens 402 has negative optical power, the thirteenth lens 403 has positive optical power, and the fourteenth lens 404 has positive optical power.

[0075] It is understandable that optical power is the reciprocal of focal length and characterizes the ability of an optical system to deflect light. The larger the absolute value of optical power, the stronger the ability to bend light; the smaller the absolute value, the weaker the ability to bend light. When optical power is positive, the refraction of light is converging; when optical power is negative, the refraction of light is diverging. In this embodiment, the first lens group 10, the second lens group 20, the third lens group 30, and the fourth lens group 40 can be arranged in a single lens barrel. Figure 1 Within (not shown), the positions of the first lens group 10 and the third lens group 30 are fixed. The focal length of the lens is changed by moving the second lens group 20 and the fourth lens group 40. During the movement, the second lens group 20 and the fourth lens group 40 play the roles of zoom and focusing, respectively. By setting the optical power relationship of each lens group, the total effective focal length of the zoom lens can be continuously zoomed within the range of 10mm to 30mm.

[0076] In the process of zooming by moving the second lens group 20 and the fourth lens group 40, the zoom lens is located at the wide-angle end when the focal length is shortest, and at the telephoto end when the focal length is longest. At the wide-angle end and the telephoto end, the zoom lens has different focal lengths and optical powers, as well as different lengths or shapes.

[0077] The technical solution of this embodiment uses the movement of the second lens group 20 and the fourth lens group 40 along the optical axis during zooming to switch the zoom lens between the wide-angle and telephoto ends. The total effective focal length of the zoom lens is continuously zoomed within the range of 10mm to 30mm. By rationally designing the structure of each lens and the matching relationship of optical power, the zoom lens achieves a high-performance zoom lens with a diagonal field of view from approximately 18° to 50° under a 1 / 1.8-inch CMOS sensor, and meets imaging requirements in environments ranging from -40℃ to 80℃. Specifically, it uses 14 lenses, a relatively small number of lenses, which helps to reduce the lens length. By rationally matching the various lens groups and the optical power of each lens, aberration balance can be effectively achieved at each focal length, ensuring image clarity at different focal lengths. This results in high image quality within a shorter overall length limit, reducing cost and weight.

[0078] Optional, continue to refer to Figure 1 The first lens 101 and the second lens 102 form a cemented lens 100, and the ninth lens 303 and the tenth lens 304 form a cemented lens 300.

[0079] In this design, by setting the first lens 101 and the second lens 102 to form a cemented lens 100, and the ninth lens 303 and the tenth lens 304 to form a cemented lens 300, the air gap between the first lens 101 and the second lens 102, and between the ninth lens 303 and the tenth lens 304, can be effectively reduced, thereby further reducing the overall length of the lens. Furthermore, cemented lenses help reduce or eliminate chromatic aberration, allowing various aberrations in the zoom lens to be fully corrected. Under the premise of a compact structure, this improves resolution, optimizes optical performance such as distortion, and reduces light loss caused by reflections between lens elements, increasing illumination and thus improving image quality and the sharpness of the lens image. In addition, the use of cemented lenses reduces the number of assembly components between lens elements, simplifies the assembly process in lens manufacturing, reduces costs, and reduces tolerance sensitivity issues such as tilting / eccentricity of lens units during assembly.

[0080] Optionally, the optical power of the first lens 101, the second lens 102, the ninth lens 303, and the tenth lens 304 satisfies:

[0081]

[0082]

[0083] in, and These represent the optical power of the cemented lens 100 composed of the first lens 101 and the second lens 102, and the cemented lens 300 composed of the ninth lens 303 and the tenth lens 304, respectively. This refers to the optical power of a zoom lens at the wide-angle end.

[0084] By properly setting the optical power relationship between the cemented lens 100 and the zoom lens at the wide-angle end, the field of view of the zoom lens can be varied from approximately 18° to 50°. Furthermore, by properly setting the optical power relationship between the cemented lens 100, the cemented lens 300, and the zoom lens at the wide-angle end, it is beneficial for the aberration correction of the zoom lens, especially for the correction of chromatic aberration.

[0085] Optionally, the optical power of the first lens 101 to the fourteenth lens 404 satisfies:

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096] in, and These represent the optical power of the lenses with corresponding serial numbers from the first lens 101 to the fourteenth lens 404. This refers to the optical power of a zoom lens at the wide-angle end. The optical power of the second lens group 20, The optical power is 40 for the fourth lens group.

[0097] By rationally designing the optical power of each lens and and This relationship allows for a reduction in the size of zoom lenses, enabling miniaturization.

[0098] Optionally, the refractive indices of the first lens 101 to the fourteenth lens 404 satisfy the following:

[0099] 1.71≤n1≤1.85;

[0100] 1.41≤n²≤1.55;

[0101] 1.53≤n4≤1.73;

[0102] 1.62≤n10≤1.71;

[0103] 1.52≤n13≤1.69;

[0104] Wherein, n1, n2, n4, n10 and n13 represent the refractive indices of the lenses with corresponding serial numbers from the first lens 101 to the fourteenth lens 404.

[0105] Optionally, the dispersion coefficients of the first lens 101 to the fourteenth lens 404 satisfy:

[0106] 17≤v1≤50;

[0107] 70≤v2≤98;

[0108] 37≤v3≤98;

[0109] 26≤v4≤88;

[0110] 53≤v5≤61.2;

[0111] 32≤v8≤65;

[0112] 65≤v11≤97;

[0113] 17≤v12≤31;

[0114] 32≤v13≤65;

[0115] Wherein, v1, v2, v3, v4, v5, v8, v11, v12 and v13 represent the dispersion coefficients of the lenses with corresponding serial numbers from the first lens 101 to the fourteenth lens 404.

[0116] By setting the refractive index and Abbe number of each lens within a given range, the corresponding optical power range can be achieved, which helps to realize a small size, high performance, and large target surface of the lens.

[0117] Optionally, the diameter D1 of the first lens 101 and the total length TTL_W of the zoom lens at the wide-angle end satisfy the following:

[0118] D1 / TTL_W<0.446.

[0119] The distance from the center of the optical axis on the object side of the first lens 101 to the image plane is the total optical length of the zoom lens. The first lens 101 is a negative lens, used to collect as much light as possible into the lens. By limiting the ratio of D1 to TTL_W to less than 0.446, the lens aperture can be avoided from being too large, thus meeting the installation space requirements of the final product.

[0120] Optionally, the first lens 101, the second lens 102, the third lens 103, the fourth lens 201, the seventh lens 301, the ninth lens 303, the tenth lens 304, and the eleventh lens 401 are all glass spherical lenses; the fifth lens 202, the sixth lens 203, the eighth lens 302, the twelfth lens 402, the thirteenth lens 403, and the fourteenth lens 404 are all plastic aspherical lenses.

[0121] By designing the fifth lens 202, sixth lens 203, eighth lens 302, twelfth lens 402, thirteenth lens 403, and fourteenth lens 404 as aspherical lenses, advanced aberrations can be effectively corrected, improving the image quality of the lens. Furthermore, since the cost of forming aspherical lenses from plastic is far lower than that from glass, using plastic aspherical lenses can also reduce the cost of zoom lenses.

[0122] The surface profile of an aspherical lens satisfies the formula:

[0123]

[0124] Where Z represents the sag of the aspherical surface, c represents the fundamental curvature at the vertex, k represents the conic section constant, r represents the radial coordinate perpendicular to the optical axis, and a i a is the coefficient of the higher-order term. i r 2i For aspherical surfaces, the term is of higher order.

[0125] Furthermore, glass lenses are more stable at high and low temperatures. By designing the first lens 101, second lens 102, third lens 103, fourth lens 201, seventh lens 301, ninth lens 303, tenth lens 304, and eleventh lens 401 as glass spherical lenses, the stability of the lens at high and low temperatures is improved. At the same time, because glass lenses have a strong light-reflecting ability, they help to reduce the aperture of aspherical lenses, thereby reducing the design difficulty and manufacturing cost of aspherical lenses.

[0126] At the same time, the two materials, glass and plastic, can compensate for each other, balancing high and low temperatures, which makes the zoom lens have stable performance at high and low temperatures and helps to improve the environmental adaptability of the zoom lens.

[0127] The plastic aspherical lens can be made of any plastic known to those skilled in the art, and the glass spherical lens can be made of any type of glass known to those skilled in the art. This embodiment of the invention does not limit the material used.

[0128] Optionally, the first lens 101 is a convex-concave lens, the second lens 102 is a convex-concave lens, the fourth lens 201 is a biconcave lens, the seventh lens 301 is a biconvex lens, the eighth lens 302 is a convex-concave lens, the ninth lens 303 is a biconvex lens, the tenth lens 304 is a biconcave lens, the eleventh lens 401 is a convex-concave lens, the thirteenth lens 403 is a concave-convex lens, and the fourteenth lens 404 is a convex-concave lens.

[0129] By rationally setting the shape of each lens, the optical power requirements of the above embodiments can be met, while also ensuring that the entire zoom lens structure is compact and highly integrated.

[0130] Optionally, the zoom lens also includes an aperture stop 50; the aperture stop 50 is located between the sixth lens 203 and the seventh lens 301. By adding the aperture stop 50, edge light can be blocked, which helps to improve image quality.

[0131] Continue to refer to Figure 1 The zoom lens also includes a flat glass plate 60, which is disposed on the image-side side of the fourteenth lens 404. By placing a flat glass plate 60 of a certain thickness between the fourteenth lens 404 and the image plane, it serves a protective function while also filtering out unwanted stray light, thereby improving the image quality of the zoom lens. For example, the flat glass plate 60 can filter out infrared light during the day to improve the image quality of the zoom lens.

[0132] For example, Figure 2 for Figure 1 A schematic diagram of the telephoto end of a medium zoom lens is shown in Table 1. Figure 1 and Figure 2 Specific parameters of the adaptive zoom lens:

[0133] Table 1 Specific parameters of zoom lenses

[0134]

[0135]

[0136] Table 2 is... Figure 1 and Figure 2 The specific design parameters of each lens in the zoom lens are as follows:

[0137] Table 2 Design values ​​of various lens parameters for zoom lenses

[0138]

[0139]

[0140] In this designation, surface number 1 represents the front surface (the surface closer to the object side) of the first lens 101, surface number 2 represents the rear surface (the surface closer to the image side) of the first lens 101, and so on. Surface number 2 is the cemented surface between the first lens 101 and the second lens 102; surface number 18 is the cemented surface between the ninth lens 303 and the tenth lens 304; and surface numbers 28 and 29 represent the front and rear surfaces of the lens protective glass, respectively. The radius of curvature indicates the degree of curvature of the lens surface; a positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinity" indicates that the surface is planar and the radius of curvature is infinite. Thickness represents the central axial distance between the current surface and the next surface. The units for radius of curvature and thickness are millimeters. The refractive index (nd) represents the ability of the material between the current surface and the next surface to deflect light, and the Abbe number (vd) represents the dispersion characteristics of the material between the current surface and the next surface.

[0141] Table 3 shows the zoom interval values ​​in Table 2:

[0142] Table 3. One design value for zoom interval.

[0143] Wide-angle end Middle coke end telephoto end Zoom interval 1 1.039 7.284 10.606 Zoom interval 2 9.989 3.744 0.422 Zoom interval 3 1.813 0.949 2.272 Zoom interval 4 5.080 5.944 4.621

[0144] Table 4 is... Figure 1 and Figure 2 Aspherical surface parameters in medium zoom lenses:

[0145] Table 4. One design value for aspheric coefficient in fixed-focus lenses.

[0146]

[0147]

[0148] Where -1.174833E-03 indicates that the a2 coefficient of surface number 9 is -1.174833 × 10 -3 .

[0149] Figure 3 This is a spherical aberration curve at the wide-angle end of a zoom lens in this embodiment, for reference. Figure 3 The spherical aberration of the zoom lens at different wavelengths (0.656μm, 0.588μm, 0.546μm, 0.486μm and 0.436μm) is within 0.04mm, which means that the axial aberration of the zoom lens is small. Therefore, it can be seen that the zoom lens provided in this embodiment of the invention can correct aberrations well at the wide-angle end.

[0150] Figure 4 This is a spherical aberration curve at the telephoto end of a zoom lens in this embodiment, for reference. Figure 4The spherical aberration of the zoom lens at different wavelengths (0.656μm, 0.588μm, 0.546μm, 0.486μm and 0.436μm) is within 0.05mm, which means that the axial aberration of the zoom lens is small. Therefore, it can be seen that the zoom lens provided in this embodiment of the invention can also correct aberrations well at the telephoto end.

[0151] Figure 5 This is a field curvature distortion diagram at the wide-angle end of a zoom lens in this embodiment, where the left side represents field curvature and the right side represents distortion. (Reference) Figure 5 In the field curvature diagram, the horizontal axis represents the magnitude of the field curvature in mm; the vertical axis represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta. Figure 5 As can be seen, the zoom lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is relatively small. In the distortion diagram, the horizontal axis represents the magnitude of distortion as a percentage; the vertical axis represents the normalized image height, which has no unit; from... Figure 5 As can be seen, the zoom lens provided in this embodiment has an absolute distortion of about 10% at the wide-angle end, which is relatively small and meets the requirements for low distortion.

[0152] Figure 6 This is a field curvature distortion diagram at the telephoto end of a zoom lens in this embodiment, where the left side represents field curvature and the right side represents distortion. (Reference) Figure 6 In the field curvature diagram, the horizontal axis represents the magnitude of the field curvature in mm; the vertical axis represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta. Figure 6 As can be seen, the zoom lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is relatively small. In the distortion diagram, the horizontal axis represents the magnitude of distortion as a percentage; the vertical axis represents the normalized image height, which has no unit; from... Figure 6 As can be seen, the zoom lens provided in this embodiment has less than 5% distortion at the telephoto end, and the imaging distortion is small, which meets the requirements for low distortion.

[0153] In summary, by Figures 3-6 It can be seen that the zoom lens provided in the embodiments of the present invention has good imaging capabilities.

[0154] For example, Figure 7 This is a schematic diagram of another zoom lens at the wide-angle end provided in an embodiment of the present invention. Figure 8 for Figure 7 A schematic diagram of the telephoto end of a medium zoom lens is shown in Table 5. Figure 7 and Figure 8 Specific parameters of the adaptive zoom lens:

[0155] Table 5 Specific parameters of zoom lenses

[0156]

[0157] Table 6 is... Figure 7 and Figure 8 The specific design parameters of each lens in the zoom lens are as follows:

[0158] Table 6 Design values ​​of various lens parameters for zoom lenses

[0159]

[0160]

[0161] In this designation, surface number 1 represents the front surface (the surface closer to the object side) of the first lens 101, surface number 2 represents the rear surface (the surface closer to the image side) of the first lens 101, and so on. Surface number 2 is the cemented surface between the first lens 101 and the second lens 102; surface number 18 is the cemented surface between the ninth lens 303 and the tenth lens 304; and surface numbers 28 and 29 represent the front and rear surfaces of the lens protective glass, respectively. The radius of curvature indicates the degree of curvature of the lens surface; a positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinity" indicates that the surface is planar and the radius of curvature is infinite. Thickness represents the central axial distance between the current surface and the next surface. The units for radius of curvature and thickness are millimeters. The refractive index (nd) represents the ability of the material between the current surface and the next surface to deflect light, and the Abbe number (vd) represents the dispersion characteristics of the material between the current surface and the next surface.

[0162] Table 7 shows the zoom interval values ​​from Table 6:

[0163] Table 7. One design value for zoom interval.

[0164] Wide-angle end Middle coke end telephoto end Zoom interval 1 0.849 7.093 10.416 Zoom interval 2 10.275 4.030 0.708 Zoom interval 3 2.255 1.392 2.714 Zoom interval 4 5.204 6.067 4.744

[0165] Table 8 is... Figure 7 and Figure 8 Aspherical surface parameters in medium zoom lenses:

[0166] Table 8. One design value for aspheric coefficient in fixed-focus lenses.

[0167]

[0168]

[0169] Where -1.121690E-03 indicates that the a2 coefficient of surface number 9 is -1.121690 × 10 -3 .

[0170] Figure 9This is a spherical aberration curve at the wide-angle end of a zoom lens in this embodiment, for reference. Figure 9 The spherical aberration of the zoom lens at different wavelengths (0.656μm, 0.588μm, 0.546μm, 0.486μm and 0.436μm) is within 0.03mm, which means that the axial aberration of the zoom lens is small. Therefore, it can be seen that the zoom lens provided in this embodiment of the invention can correct aberrations well at the wide-angle end.

[0171] Figure 10 This is a spherical aberration curve at the telephoto end of a zoom lens in this embodiment, for reference. Figure 10 The spherical aberration of the zoom lens at different wavelengths (0.656μm, 0.588μm, 0.546μm, 0.486μm and 0.436μm) is within 0.05mm, which means that the axial aberration of the zoom lens is small. Therefore, it can be seen that the zoom lens provided in this embodiment of the invention can also correct aberrations well at the telephoto end.

[0172] Figure 11 This is a field curvature distortion diagram at the wide-angle end of a zoom lens in this embodiment, where the left side represents field curvature and the right side represents distortion. (Reference) Figure 11 In the field curvature diagram, the horizontal axis represents the magnitude of the field curvature in mm; the vertical axis represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta. Figure 11 As can be seen, the zoom lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is relatively small. In the distortion diagram, the horizontal axis represents the magnitude of distortion as a percentage; the vertical axis represents the normalized image height, which has no unit; from... Figure 11 As can be seen, the zoom lens provided in this embodiment has an absolute distortion value of about 8% at the wide-angle end, which is relatively small and meets the requirements for low distortion.

[0173] Figure 12 This is a field curvature distortion diagram at the telephoto end of a zoom lens in this embodiment, where the left side represents field curvature and the right side represents distortion. (Reference) Figure 12 In the field curvature diagram, the horizontal axis represents the magnitude of the field curvature in mm; the vertical axis represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta. Figure 12 As can be seen, the zoom lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is relatively small. In the distortion diagram, the horizontal axis represents the magnitude of distortion as a percentage; the vertical axis represents the normalized image height, which has no unit; from... Figure 12 As can be seen, the zoom lens provided in this embodiment has a distortion of less than 4% at the telephoto end, and the imaging distortion is small, which meets the requirements for low distortion.

[0174] In summary, by Figures 9-12It can be seen that the zoom lens provided in the embodiments of the present invention has good imaging capabilities.

[0175] For example, Figure 13 This is a schematic diagram of the structure of another zoom lens at the wide-angle end provided in an embodiment of the present invention. Figure 14 for Figure 13 A schematic diagram of the telephoto end of a medium zoom lens is shown in Table 9. Figure 13 and Figure 14 Specific parameters of the adaptive zoom lens:

[0176] Table 9 Specific parameters of zoom lenses

[0177]

[0178] Table 10 is... Figure 13 and Figure 14 The specific design parameters of each lens in the zoom lens are as follows:

[0179] Table 10 Design values ​​of various lens parameters for zoom lenses

[0180]

[0181]

[0182] In this designation, surface number 1 represents the front surface (the surface closer to the object side) of the first lens 101, surface number 2 represents the rear surface (the surface closer to the image side) of the first lens 101, and so on. Surface number 2 is the cemented surface between the first lens 101 and the second lens 102; surface number 18 is the cemented surface between the ninth lens 303 and the tenth lens 304; and surface numbers 28 and 29 represent the front and rear surfaces of the lens protective glass, respectively. The radius of curvature indicates the degree of curvature of the lens surface; a positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinity" indicates that the surface is planar and the radius of curvature is infinite. Thickness represents the central axial distance between the current surface and the next surface. The units for radius of curvature and thickness are millimeters. The refractive index (nd) represents the ability of the material between the current surface and the next surface to deflect light, and the Abbe number (vd) represents the dispersion characteristics of the material between the current surface and the next surface.

[0183] Table 11 shows the zoom interval values ​​from Table 10:

[0184] Table 3. One design value for zoom interval.

[0185] Wide-angle end Middle coke end telephoto end Zoom interval 1 1.043 7.287 10.609 Zoom interval 2 9.967 3.723 0.400 Zoom interval 3 1.861 0.997 2.323 Zoom interval 4 5.047 5.910 4.585

[0186] Table 12 is... Figure 13 and Figure 14 Aspherical surface parameters in medium zoom lenses:

[0187] Table 12. One design value for aspheric coefficient in fixed-focus lenses.

[0188]

[0189]

[0190] Where -1.178704E-03 indicates that the a2 coefficient of surface number 9 is -1.178704 × 10 -3 .

[0191] Figure 15 This is a spherical aberration curve at the wide-angle end of a zoom lens in this embodiment, for reference. Figure 15 The spherical aberration of the zoom lens at different wavelengths (0.656μm, 0.588μm, 0.546μm, 0.486μm and 0.436μm) is within 0.05mm, which means that the axial aberration of the zoom lens is small. Therefore, it can be seen that the zoom lens provided in this embodiment of the invention can correct aberrations well at the wide-angle end.

[0192] Figure 16 This is a spherical aberration curve at the telephoto end of a zoom lens in this embodiment, for reference. Figure 16 The spherical aberration of the zoom lens at different wavelengths (0.656μm, 0.588μm, 0.546μm, 0.486μm and 0.436μm) is within 0.04mm, which means that the axial aberration of the zoom lens is small. Therefore, it can be seen that the zoom lens provided in this embodiment of the invention can also correct aberrations well at the telephoto end.

[0193] Figure 17 This is a field curvature distortion diagram at the wide-angle end of a zoom lens in this embodiment, where the left side represents field curvature and the right side represents distortion. (Reference) Figure 17 In the field curvature diagram, the horizontal axis represents the magnitude of the field curvature in mm; the vertical axis represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta. Figure 17 As can be seen, the zoom lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is relatively small. In the distortion diagram, the horizontal axis represents the magnitude of distortion as a percentage; the vertical axis represents the normalized image height, which has no unit; from... Figure 17 As can be seen, the zoom lens provided in this embodiment has an absolute distortion value of about 8% at the wide-angle end, which is relatively small and meets the requirements for low distortion.

[0194] Figure 18 This is a field curvature distortion diagram at the telephoto end of a zoom lens in this embodiment, where the left side represents field curvature and the right side represents distortion. (Reference) Figure 18In the field curvature diagram, the horizontal axis represents the magnitude of the field curvature in mm; the vertical axis represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta. Figure 18 As can be seen, the zoom lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is relatively small. In the distortion diagram, the horizontal axis represents the magnitude of distortion as a percentage; the vertical axis represents the normalized image height, which has no unit; from... Figure 18 As can be seen, the zoom lens provided in this embodiment has a distortion of less than 6% at the telephoto end, and the imaging distortion is small, which meets the requirements for low distortion.

[0195] In summary, by Figures 15-18 It can be seen that the zoom lens provided in the embodiments of the present invention has good imaging capabilities.

[0196] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A zoom lens, characterized in that, It includes a first lens group with positive optical power, a second lens group with negative optical power, a third lens group with positive optical power, and a fourth lens group with positive optical power arranged sequentially from the object side to the image side along the optical axis. The second lens group and the fourth lens group move along the optical axis during zooming. The first lens group includes a first lens, a second lens, and a third lens arranged sequentially along the optical axis from the object side to the image side; The second lens group includes a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical axis from the object side to the image side; The third lens group includes a seventh lens, an eighth lens, a ninth lens, and a tenth lens arranged sequentially from the object side to the image side along the optical axis; The fourth lens group includes an eleventh lens, a twelfth lens, a thirteenth lens, and a fourteenth lens arranged sequentially 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, the fourth lens has negative optical power, the fifth lens has negative optical power, the sixth lens has positive optical power, the seventh lens has positive optical power, the eighth lens has positive optical power, the ninth lens has positive optical power, the tenth lens has negative optical power, the eleventh lens has positive optical power, the twelfth lens has negative optical power, the thirteenth lens has positive optical power, and the fourteenth lens has positive optical power. The zoom lens has fourteen lenses with optical power. The optical power of the second lens, the third lens, the fourth lens, the sixth lens, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens, the thirteenth lens, and the fourteenth lens satisfy the following: 0.224≤φ2 / φW≤0.293; 0.259≤φ3 / φW≤0.309; 0.725≤φ4 / φZ≤0.927; -0.369≤φ6 / φZ≤-0.260; 0.810≤φ9 / φW≤0.970; -1.481≤φ10 / φW≤-1.164; 0.821≤φ11 / φF≤0.940; -0.503≤φ12 / φF≤-0.409; 0.057≤φ13 / φF≤0.182; 0.432≤φ14 / φF≤0.483; Wherein, φ2 represents the optical power of the second lens, φ3 represents the optical power of the third lens, φ4 represents the optical power of the fourth lens, φ6 represents the optical power of the sixth lens, φ9 represents the optical power of the ninth lens, φ10 represents the optical power of the tenth lens, φ11 represents the optical power of the eleventh lens, φ12 represents the optical power of the twelfth lens, φ13 represents the optical power of the thirteenth lens, φ14 represents the optical power of the fourteenth lens, φW represents the optical power of the zoom lens at the wide-angle end, φZ represents the optical power of the second lens group, and φF represents the optical power of the fourth lens group.

2. The zoom lens according to claim 1, characterized in that, The first lens and the second lens form a cemented lens, and the ninth lens and the tenth lens form a cemented lens.

3. The zoom lens according to claim 2, characterized in that, The optical power of the cemented lens composed of the first lens and the second lens, and the optical power of the cemented lens composed of the ninth lens and the tenth lens, satisfy the following: 0.055≤(φ1-2) / φW≤0.115; -0.242≤(φ9-10) / φW≤-0.149; Wherein, φ1-2 represents the optical power of the cemented lens composed of the first lens and the second lens, and φ9-10 represents the optical power of the cemented lens composed of the ninth lens and the tenth lens.

4. The zoom lens according to claim 1, characterized in that, The refractive indices of the first lens, the second lens, the fourth lens, the tenth lens, and the thirteenth lens satisfy the following: 1.71≤n1≤1.85； 1.41≤n2≤1.55； 1.53≤n4≤1.73； 1.62≤n10≤1.71； 1.52≤n13≤1.69； Wherein, n1 represents the refractive index of the first lens, n2 represents the refractive index of the second lens, n4 represents the refractive index of the fourth lens, n10 represents the refractive index of the tenth lens, and n13 represents the refractive index of the thirteenth lens.

5. The zoom lens according to claim 1, characterized in that, The dispersion coefficients of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the eighth lens, the eleventh lens, the twelfth lens, and the thirteenth lens satisfy the following: 17≤v1≤50； 70≤v2≤98； 37≤v3≤98； 26≤v4≤88； 53≤v5≤61.2； 32≤v8≤65； 65≤v11≤97； 17≤v12≤31； 32≤v13≤65； Wherein, v1 represents the dispersion coefficient of the first lens, v2 represents the dispersion coefficient of the second lens, v3 represents the dispersion coefficient of the third lens, v4 represents the dispersion coefficient of the fourth lens, v5 represents the dispersion coefficient of the fifth lens, v8 represents the dispersion coefficient of the eighth lens, v11 represents the dispersion coefficient of the eleventh lens, v12 represents the dispersion coefficient of the twelfth lens, and v13 represents the dispersion coefficient of the thirteenth lens.

6. The zoom lens according to claim 1, characterized in that, The diameter D1 of the first lens and the total length TTL_W of the zoom lens at the wide-angle end satisfy the following: 0.390≤D1 / TTL_W<0.

446.

7. The zoom lens according to claim 1, characterized in that, The first lens, the second lens, the third lens, the fourth lens, the seventh lens, the ninth lens, the tenth lens, and the eleventh lens are all glass spherical lenses; The fifth lens, the sixth lens, the eighth lens, the twelfth lens, the thirteenth lens, and the fourteenth lens are all plastic aspherical lenses.

8. The zoom lens according to claim 7, characterized in that, The first lens is a convex-concave lens, the second lens is a convex-concave lens, the fourth lens is a biconcave lens, the seventh lens is a biconvex lens, the eighth lens is a convex-concave lens, the ninth lens is a biconvex lens, the tenth lens is a biconcave lens, the eleventh lens is a convex-concave lens, the thirteenth lens is a concave-convex lens, and the fourteenth lens is a convex-concave lens.

9. The zoom lens according to claim 1, characterized in that, The zoom lens also includes an aperture stop; The aperture stop is located between the sixth lens and the seventh lens.

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