Zoom lens

Abstract

The invention provides a zoom lens. The zoom lens comprises a first fixed lens group, a zoom lens group, a diaphragm, a second fixed lens group and a focusing lens group which are sequentially arranged from an object space to an image space along an optical axis, the first fixed lens group comprises a first lens, a second lens and a third lens which are sequentially arranged from the object side to the image side along the optical axis, and the zoom lens group comprises a fourth lens, a fifth lens and a sixth lens which are sequentially arranged from the object side to the image side along the optical axis. The second fixed lens group comprises a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a thirteenth lens which are sequentially arranged from the object side to the image side along the optical axis; the focusing lens group comprises a fourteenth lens, a fifteenth lens and a sixteenth lens which are sequentially arranged from the object side to the image side along the optical axis; the first lens and the second lens form a balsaming lens group; the second fixed lens group comprises at least two balsaming lens groups. According to the embodiment of the invention, large aperture, small distortion and clear imaging are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and particularly to a zoom lens. Background Art

[0002] ITS (Intelligent Transport System) lenses are lenses specifically designed for image sensors. ITS lenses usually have advantages such as high resolution, low distortion, and high contrast, and can provide clear, accurate, and high-quality images. Their design fully considers various factors such as optical characteristics, mechanical structures, and electronic interfaces, and can effectively adapt to various complex environments.

[0003] Currently, most of the commonly used ITS lenses on the market are fixed-focus lenses, and their imaging quality is low, and their tolerance in harsh environments is also poor; in the face of more complex usage environments, zoom lenses have gradually become the new favorites in the ITS field. However, the types of zoom lenses applied in the ITS field on the market are extremely limited, and there are defects such as low image quality, too small focal length range, and large distortion, which cause certain difficulties in practical applications. Summary of the Invention

[0004] Embodiments of the present invention provide a zoom lens to achieve a large aperture, small distortion, and clear imaging.

[0005] Embodiments of the present invention provide a zoom lens, which includes a first fixed lens group, a varifocal lens group, a diaphragm, a second fixed lens group, and a focusing lens group arranged in sequence from the object side to the image side along the optical axis. The first fixed lens group, the second fixed lens group, and the focusing lens group have positive optical powers, and the varifocal lens group has a negative optical power;

[0006] The first fixed lens group includes a first lens, a second lens, and a third lens arranged in sequence from the object side to the image side along the optical axis. The varifocal lens group includes a fourth lens, a fifth lens, and a sixth lens arranged in sequence from the object side to the image side along the optical axis. The second fixed lens group includes a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens arranged in sequence from the object side to the image side along the optical axis. The focusing lens group includes a fourteenth lens, a fifteenth lens, and a sixteenth lens arranged in sequence from the object side to the image side along the optical axis;

[0007] The first lens and the second lens form a cemented lens group; the second fixed lens group includes at least two cemented lens groups.

[0008] Optionally, the first lens, the fourth lens, the fifth lens, the eighth lens, the tenth lens, the twelfth lens, and the fifteenth lens have negative optical powers;

[0009] The second lens, the third lens, the sixth lens, the seventh lens, the ninth lens, the eleventh lens, the thirteenth lens, the fourteenth lens, and the sixteenth lens have positive optical powers.

[0010] Optionally, the focal length of the first fixed lens group is FG1, the focal length of the zoom lens group is FG2, the focal length of the second fixed lens group is FG3, the focal length of the focusing lens group is FG4, and the focal length of the wide-angle end of the zoom lens is FW, satisfying:

[0011] 5.14 ≤ FG1 / FW ≤ 5.31;

[0012] -1.77 ≤ FG2 / FW ≤ -1.66;

[0013] 2.70 ≤ FG3 / FW ≤ 2.89;

[0014] 2.31 ≤ FG4 / FW ≤ 2.76.

[0015] Optionally, the maximum distance that the zoom lens group can move along the optical axis is S2, and the maximum distance that the focusing lens group can move along the optical axis is S4, satisfying:

[0016] 24.43 ≤ S2 / S4 ≤ 86.99.

[0017] Optionally, at least two of the eighth lens, the ninth lens, and the tenth lens form a cemented lens group, and at least two of the eleventh lens, the twelfth lens, and the thirteenth lens form a cemented lens group.

[0018] Optionally, the combined focal length of the eighth lens, the ninth lens, and the tenth lens is F8_9_10, the combined focal length of the eleventh lens, the twelfth lens, and the thirteenth lens is F11_12_13, and the focal length of the second fixed lens group is FG3, satisfying:

[0019] -0.69 ≤ F8_9_10 / FG3 ≤ -0.61;

[0020] 0.62 ≤ F11_12_13 / FG3 ≤ 0.70.

[0021] Optionally, the refractive index of the seventh lens is nd7, the Abbe number of the seventh lens is vd7, the refractive index of the sixteenth lens is nd16, and the Abbe number of the sixteenth lens is vd16, satisfying:

[0022] 1.804 ≤ nd7 ≤ 1.953;

[0023] 32.403 ≤ vd7 ≤ 46.513;

[0024] 1.680 ≤ nd16 ≤ 1.914;

[0025] 32.322 ≤ vd16 ≤ 55.222.

[0026] Optionally, the fourteenth lens and the fifteenth lens form a cemented lens group.

[0027] Optionally, the focal length of the wide-angle end of the zoom lens is FW, and the focal length of the telephoto end of the zoom lens is FT, satisfying:

[0028] 3.052 ≤ FT / FW ≤ 3.333.

[0029] Optionally, the maximum distance that the varifocal lens group can move along the optical axis is S2, and the total optical length of the zoom lens is TTL, satisfying:

[0030] 3.795 ≤ TTL / S2 ≤ 3.956.

[0031] The zoom lens provided by the embodiment of the present invention is composed of sixteen lenses. The aperture stop is located between the sixth lens and the seventh lens. By changing the positions of the varifocal lens group and the focusing lens group on the optical axis, the switching between the wide-angle end and the telephoto end of the zoom lens can be realized. Using a first fixed lens group with a positive optical power and a varifocal lens group with a negative optical power in front of the aperture stop can ensure that a large light aperture is generated after the light passes through, increase the F-number of the zoom lens, and meet the usage requirements under different conditions. In addition, using a cemented lens group in the first fixed lens group can correct the high-order chromatic aberration and spherical aberration of the zoom lens, control the aberration balance of each lens group, ensure that the structure after the light enters the aperture stop will not generate serious aberration, and improve the imaging quality of the zoom lens. Using at least two cemented lens groups in the second fixed lens group behind the aperture stop can correct the aberration at the end of the zoom lens, and cooperate with the lens group in front of the aperture stop to stabilize the imaging quality of the zoom lens. Description of the Drawings

[0032] Figure 1 is a schematic structural diagram of the zoom lens provided by Embodiment 1 of the present invention at the wide-angle end;

[0033] Figure 2 is a schematic structural diagram of the zoom lens provided by Embodiment 1 of the present invention at the telephoto end;

[0034] Figure 3 is a vertical chromatic aberration curve diagram of the zoom lens provided by Embodiment 1 of the present invention at the wide-angle end;

[0035] Figures 4 - 10 is a light fan diagram of the zoom lens provided by Embodiment 1 of the present invention at the wide-angle end;

[0036] Figure 11Axial aberration curve of the zoom lens provided in Embodiment 1 of the present invention at the wide-angle end;

[0037] Figure 12 Lateral chromatic aberration curve of the zoom lens provided in Embodiment 1 of the present invention at the telephoto end;

[0038] Figures 13 - 19 Ray fan diagram of the zoom lens provided in Embodiment 1 of the present invention at the telephoto end;

[0039] Figure 20 Axial aberration curve of the zoom lens provided in Embodiment 1 of the present invention at the telephoto end;

[0040] Figure 21 Structural schematic diagram of the zoom lens provided in Embodiment 2 of the present invention at the wide-angle end;

[0041] Figure 22 Structural schematic diagram of the zoom lens provided in Embodiment 2 of the present invention at the telephoto end;

[0042] Figure 23 Lateral chromatic aberration curve of the zoom lens provided in Embodiment 2 of the present invention at the wide-angle end;

[0043] Figures 24 - 30 Ray fan diagram of the zoom lens provided in Embodiment 2 of the present invention at the wide-angle end;

[0044] Figure 31 Axial aberration curve of the zoom lens provided in Embodiment 2 of the present invention at the wide-angle end;

[0045] Figure 32 Lateral chromatic aberration curve of the zoom lens provided in Embodiment 2 of the present invention at the telephoto end;

[0046] Figures 33 - 39 Ray fan diagram of the zoom lens provided in Embodiment 2 of the present invention at the telephoto end;

[0047] Figure 40 Axial aberration curve of the zoom lens provided in Embodiment 2 of the present invention at the telephoto end;

[0048] Figure 41 Structural schematic diagram of the zoom lens provided in Embodiment 3 of the present invention at the wide-angle end;

[0049] Figure 42 Structural schematic diagram of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end;

[0050] Figure 43 Lateral chromatic aberration curve of the zoom lens provided in Embodiment 3 of the present invention at the wide-angle end;

[0051] Figures 44 - 50The light fan diagram of the zoom lens provided in Embodiment 3 of the present invention at the wide-angle end;

[0052] Figure 51 The axial aberration curve diagram of the zoom lens provided in Embodiment 3 of the present invention at the wide-angle end;

[0053] Figure 52 The lateral chromatic aberration curve diagram of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end;

[0054] Figures 53 - 59 The light fan diagram of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end;

[0055] Figure 60 The axial aberration curve diagram of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end. Detailed implementation manners

[0056] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the convenience of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0057] Embodiment 1

[0058] Figure 1 The structural schematic diagram of the zoom lens provided in Embodiment 1 of the present invention at the wide-angle end, Figure 2 The structural schematic diagram of the zoom lens provided in Embodiment 1 of the present invention at the telephoto end, refer to Figure 1 and Figure 2 , the zoom lens includes a first fixed lens group G1, a variable magnification lens group G2, a stop STO, a second fixed lens group G3, and a focusing lens group G4 arranged in sequence along the optical axis from the object side to the image side. The first fixed lens group G1, the second fixed lens group G3, and the focusing lens group G4 have positive optical powers, and the variable magnification lens group G2 has a negative optical power.

[0059] The first fixed lens group G1 includes a first lens L1, a second lens L2, and a third lens L3 arranged in sequence along the optical axis from the object side to the image side. The variable magnification lens group G2 includes a fourth lens L4, a fifth lens L5, and a sixth lens L6 arranged in sequence along the optical axis from the object side to the image side. The second fixed lens group G3 includes a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, and a thirteenth lens L13 arranged in sequence along the optical axis from the object side to the image side. The focusing lens group G4 includes a fourteenth lens L14, a fifteenth lens L15, and a sixteenth lens L16 arranged in sequence along the optical axis from the object side to the image side.

[0060] The first lens L1 and the second lens L2 form a cemented lens group; the second fixed lens group G3 includes at least two cemented lens groups.

[0061] The zoom lens provided by the embodiment of the present invention is composed of sixteen lenses. The aperture stop STO is located between the sixth lens L6 and the seventh lens L7. By changing the positions of the varifocal lens group G2 and the focusing lens group G4 on the optical axis, the switching between the wide-angle end and the telephoto end of the zoom lens can be achieved. Using the first fixed lens group G1 with a positive optical power and the varifocal lens group G2 with a negative optical power in front of the aperture stop STO can ensure that a larger light aperture is generated after the light passes through, increase the F-number of the zoom lens, and meet the usage requirements under different conditions. In addition, using a cemented lens group in the first fixed lens group G1 can correct the high-order chromatic aberration and spherical aberration of the zoom lens, control the aberration balance of each lens group, ensure that the structure after the light enters the aperture stop STO will not generate serious aberration, and improve the imaging quality of the zoom lens. Adopting at least two cemented lens groups in the second fixed lens group G3 behind the aperture stop STO can correct the aberration at the end of the zoom lens, cooperate with the lens group in front of the aperture stop STO, and stabilize the imaging quality of the zoom lens. The usage requirements of large aperture, small distortion, and clear imaging are realized under a 1 / 1.2″ target surface in the wavelength range of 436 nm to 850 nm.

[0062] Adopting at least two cemented lens groups in the second fixed lens group G3 behind the aperture stop STO. When the light just passes through the aperture stop STO, the use of the cemented lens group can well correct the chromatic aberration, avoid the superposition of chromatic aberration at the rear end of the zoom lens, and prevent the situation that a large amount of high Abbe number materials are required to pull back at the rear end, saving costs while improving the image quality.

[0063] In addition, controlling the same aperture diameter at the three ends (including the wide-angle end, the telephoto end, and the middle focal length end) of the zoom lens can reduce the aperture range structurally, ensure that the movable lens group of the zoom lens has a longer stroke distance, achieve a higher imaging magnification or reduce the volume, and meet the usage requirements under different conditions. Among them, the movable lens group is the movable lens group, including the varifocal lens group G2 and the focusing lens group G4.

[0064] Exemplarily, the zoom lens is composed of sixteen glass spherical lenses, and the first lens L1 to the sixteenth lens L16 are glass spherical lenses.

[0065] Exemplarily, the cemented lens group used in the varifocal lens group G2 can correct the high-order chromatic aberration and spherical aberration of the zoom lens. The fifth lens L5 and the sixth lens L6 form a cemented lens group. In other embodiments, the fifth lens L5 and the sixth lens L6 can be used separately and do not form a cemented lens group.

[0066] Optionally, refer to Figure 1, the first lens L1, the fourth lens L4, the fifth lens L5, the eighth lens L8, the tenth lens L10, the twelfth lens L12, and the fifteenth lens L15 have negative optical powers. The second lens L2, the third lens L3, the sixth lens L6, the seventh lens L7, the ninth lens L9, the eleventh lens L11, the thirteenth lens L13, the fourteenth lens L14, and the sixteenth lens L16 have positive optical powers.

[0067] Exemplarily, in the first fixed lens group G1, the first lens L1 is a convex-concave lens, the second lens L2 is a biconvex lens, and the third lens L3 is a convex-concave lens. In the varifocal lens group G2, the fourth lens L4 is a biconcave lens, the fifth lens L5 is a biconcave lens, and the sixth lens L6 is a convex-concave lens. In the second fixed lens group G3, the seventh lens L7 is a biconvex lens, the eighth lens L8 is a biconcave lens, the ninth lens L9 is a biconvex lens, the tenth lens L10 is a biconcave lens, the eleventh lens L11 is a biconvex lens, the twelfth lens L12 is a biconcave lens or a concave-convex lens, and the thirteenth lens L13 is a biconvex lens or a concave-convex lens. In the focusing lens group G4, the fourteenth lens L14 is a biconvex lens, the fifteenth lens L15 is a biconcave lens, and the sixteenth lens L16 is a convex-concave lens. Among them, the object side of the convex-concave lens bulges toward the object side, and the image side of the convex-concave lens depresses toward the image side. The biconvex lens is a double convex lens. The biconcave lens is a double concave lens. The object side of the concave-convex lens depresses toward the object side, and the image side of the concave-convex lens bulges toward the image side.

[0068] Exemplarily, the position of the aperture STO at different focal lengths of the zoom lens remains consistent relative to the image plane position, and the aperture diameter is the same at different focal lengths, and at the same time satisfies: FNO ≤ 1.67; where FNO is the aperture number of the zoom lens in the full focal length range (the zoom lens with the full focal length range can simultaneously adapt to three different focal length ranges: wide angle, medium focal length, and telephoto).

[0069] Exemplarily, 1.648 ≤ FNO ≤ 1.667.

[0070] Optionally, referring to Figure 1 , the focal length of the first fixed lens group G1 is FG1, the focal length of the varifocal lens group G2 is FG2, the focal length of the second fixed lens group G3 is FG3, the focal length of the focusing lens group G4 is FG4, and the focal length of the wide-angle end of the zoom lens is FW, satisfying: 5.14 ≤ FG1 / FW ≤ 5.31; -1.77 ≤ FG2 / FW ≤ -1.66;

[0071] 2.70 ≤ FG3 / FW ≤ 2.89; 2.31 ≤ FG4 / FW ≤ 2.76. Through the reasonable matching of the focal lengths of the first fixed lens group G1, the zoom lens group G2, the second fixed lens group G3, and the focusing lens group G4, the light passes through the zoom lens relatively smoothly, and the influence of high-order aberrations on the imaging quality is corrected to a great extent.

[0072] Optionally, referring to Figure 1 , the maximum distance that the zoom lens group G2 can move along the optical axis is S2, and the maximum distance that the focusing lens group G4 can move along the optical axis is S4, satisfying: 24.43 ≤ S2 / S4 ≤ 86.99. By controlling the moving distances of the focusing lens group G4 and the zoom lens group G2, it is ensured that the volume and movement range of the focusing lens group G4 are reduced to the greatest extent, and the volume of the zoom lens is reduced to a great extent.

[0073] Optionally, referring to Figure 1 , at least two of the eighth lens L8, the ninth lens L9, and the tenth lens L10 form a cemented lens group, and at least two of the eleventh lens L11, the twelfth lens L12, and the thirteenth lens L13 form a cemented lens group. The eighth lens L8, the ninth lens L9, and the tenth lens L10 can be combined into a triple cemented lens group or used as a single lens in combination with a double cemented lens; the eleventh lens L11, the twelfth lens L12, and the thirteenth lens L13 can be combined into a triple cemented lens group or used as a single lens in combination with a double cemented lens.

[0074] Optionally, referring to Figure 1 , the combined focal length of the eighth lens L8, the ninth lens L9, and the tenth lens L10 is F8_9_10, the combined focal length of the eleventh lens L11, the twelfth lens L12, and the thirteenth lens L13 is F11_12_13, and the focal length of the second fixed lens group G3 is FG3, satisfying: -0.69 ≤ F8_9_10 / FG3 ≤ -0.61; 0.62 ≤ F11_12_13 / FG3 ≤ 0.70. When the zoom lens is composed of all-glass spherical lenses, compared with the zoom lens with aspherical lenses added, its ability to correct high-order aberrations is weaker. Therefore, in the embodiments of the present invention, using two triple cemented lens groups after the aperture STO can effectively correct the chromatic aberration and high-order aberrations generated by the front lens group, thereby improving the imaging quality of the zoom lens. In addition, the properties of glass lenses are not sensitive to temperature, and the performance of the zoom lens using all-glass lenses is more uniform under different temperature conditions, with the characteristics of stable high and low temperature performance, improving the environmental adaptability of the zoom lens. The material of the glass spherical lens is various types of glass known to those skilled in the art, and the embodiments of the present invention will not elaborate on this.

[0075] Optionally, referring to Figure 1, the refractive index of the seventh lens L7 is nd7, the Abbe number of the seventh lens L7 is vd7, the refractive index of the sixteenth lens L16 is nd16, and the Abbe number of the sixteenth lens L16 is vd16, satisfying: 1.804 ≤ nd7 ≤ 1.953; 32.403 ≤ vd7 ≤ 46.513; 1.680 ≤ nd16 ≤ 1.914; 32.322 ≤ vd16 ≤ 55.222. The correction of chromatic aberration and higher-order aberrations of the zoom lens mainly depends on the second fixed lens group G3 and the focusing lens group G4. Therefore, the material selection of the seventh lens L7, which is the first lens in the second fixed lens group G3, and the sixteenth lens L16, which is the last lens in the focusing lens group G4, is crucial. By reasonably selecting the refractive indices of the seventh lens L7 and the sixteenth lens L16, the aberrations of each group can be controlled to a certain extent, ensuring smooth light exit at the front end, ensuring resolution and image height, and improving the imaging quality of the zoom lens while ensuring illuminance.

[0076] Optionally, referring to Figure 1 , the fourteenth lens L14 and the fifteenth lens L15 form a cemented lens group. The cemented lens group in the focusing lens group G4 can correct the aberrations at the end of the zoom lens. During the zooming process, the focusing lens group G4 is responsible for focusing the zoom lens with a changing focal length. The cemented lens group can correct the chromatic aberration and higher-order aberrations generated in the focusing lens group G4, greatly reducing the aberration pressure of other groups of the zoom lens at different focal lengths. Thus, while the zoom lens focuses at the full focal range, it also has good image quality and meets the normal usage requirements.

[0077] Optionally, referring to Figure 1 , the focal length of the wide-angle end of the zoom lens is FW, and the focal length of the telephoto end of the zoom lens is FT, satisfying: 3.052 ≤ FT / FW ≤ 3.333. By controlling the focal length ratio of the wide-angle end and the telephoto end of the zoom lens, under the conditions of ensuring the zoom range and large target surface, the distortion can be controlled within a reasonable small range, meeting the requirement of small distortion of the zoom lens.

[0078] Optionally, referring to Figure 1 , the maximum distance that the zoom lens group G2 can move along the optical axis is S2, and the overall optical length of the zoom lens is TTL, satisfying: 3.795 ≤ TTL / S2 ≤ 3.956. The limitation of the zoom lens group G2 and the overall optical length of the zoom lens can compress the lens space, ensuring that the zoom lens meets the required imaging quality and zoom degree under the condition of small volume.

[0079] Exemplarily, referring to Figure 1 and Figure 2, the zoom lens may further include a flat glass CG, which is located on the side of the sixteenth lens L16 away from the first lens L1 and on the side of the sixteenth lens L16 close to the image plane, so as to protect the photosensitive chip in the imaging sensor. The photosensitive chip is used to convert the optical signal collected by the zoom lens into an electrical signal, thereby ensuring the imaging effect of the zoom lens.

[0080] In the zoom lens, the first fixed lens group G1, the variable magnification lens group G2, the second fixed lens group G3, and the focusing lens group G4 can be arranged in a lens barrel ( Figure 1 and Figure 2 not shown in the figure). The first fixed lens group G1 and the second fixed lens group G3 are fixed in position in the lens barrel. The variable magnification lens group G2 and the focusing lens group G4 can reciprocate along the optical axis in the lens barrel. Through the combined movement of the variable magnification lens group G2 and the focusing lens group G4, the focal length of the zoom lens can be continuously changed from short focal length to long focal length, ensuring that the zoom lens has high image quality at each focus position.

[0081] It can be understood that during the process of the zoom lens achieving zoom by moving the variable magnification lens group G2 and the focusing lens group G4, when the focal length is the shortest, the zoom lens is at the wide-angle end, and when the focal length is the longest, the zoom lens is at the telephoto end. At the wide-angle end and the telephoto end, the zoom lens has different focal lengths and optical powers, and also has different forms.

[0082] Table 1 shows a set of design values of the zoom lens in Embodiment 1

[0083]

[0084] Table 1 shows a set of design values of the zoom lens in Embodiment 1. The specific numerical values can be adjusted according to product requirements and are not a limitation on the embodiments of the present invention. The zoom lens shown in Table 1 can be Figure 1 and Figure 2As shown. A lens generally includes two surfaces, and each surface is a refracting surface. The surface numbers in Table 1 are numbered according to the surfaces of each lens. Among them, surface number 1 represents the front surface (i.e., the object side surface) of the first lens L1, surface number 2 represents the rear surface (i.e., the image side surface) of the first lens L1, and so on, which will not be elaborated here. The radius of curvature represents the degree of curvature of the lens surface. A positive radius of curvature value indicates that the center of curvature is on the side of the surface close to the image plane IMA, that is, a positive value represents that the surface bends towards the image plane IMA side; a negative radius of curvature value represents that the center of curvature is on the side of the surface far from the image plane IMA, that is, a negative value represents that the surface bends towards the object plane side. "Infinity" in the radius of curvature column represents that the surface is a plane and the radius of curvature is infinite, with the unit of mm. The values in the thickness column represent the central axial distance from the current surface to the next surface, with the unit of mm. The refractive index column represents the refractive index of the medium between the current surface and the next surface, representing the ability of the material between the current surface and the next surface to deflect light. The space in the refractive index column is the refractive index of air, and the refractive index of air is 1. The Abbe number represents the dispersion characteristic of the material between the current surface and the next surface to light, and the space represents that the current position is air.

[0085] Table 2 Design values of the zoom intervals of the zoom lens in Embodiment 1

[0086]

[0087] Exemplarily, in Embodiment 1, the maximum diameter that the image plane size of the zoom lens can reach at the wide-angle end is 13.1 mm, and the maximum diameter that the image plane size of the zoom lens can reach at the telephoto end is 13.1 mm. The focal length (i.e., FW) of the zoom lens at the wide-angle end is 15.00 mm, and the focal length (i.e., FT) of the zoom lens at the telephoto end is 50.00 mm. The zoom lens is applicable to the wavelength band of 436 nm to 850 nm at the wide-angle end and the telephoto end. The overall optical length (i.e., TTL) of the zoom lens at the wide-angle end and the telephoto end is 124 mm.

[0088] Exemplarily, in Embodiment 1, the FNO of the zoom lens at the wide-angle end is 1.648, and the FNO of the zoom lens at the telephoto end is 1.652. FG1 / FW = 5.31, FG2 / FW = -1.66, FG3 / FW = 2.70, FG4 / FW = 2.31, S2 / S4 = 86.99, F8_9_10 / FG3 = -0.69, F11_12_13 / FG3 = 0.70, FT / FW = 3.33, TTL / S2 = 3.956.

[0089] Figure 3 This is the lateral chromatic aberration curve graph of the zoom lens provided in Embodiment 1 of the present invention. Refer to Figure 3, the vertical direction represents the field of view, 0 represents on the optical axis, and the vertex in the vertical direction represents the maximum field of view; the main wavelength is 546.07 nm, and the horizontal direction represents the offset relative to the main wavelength, with the unit of micrometer (um). From Figure 3 It can be seen that the lateral chromatic aberrations of different wavelengths are all controlled within a small range, indicating that the lateral chromatic aberration of this zoom lens at the wide-angle end is well controlled and can meet the application requirements under normal conditions.

[0090] Figures 4 - 10 This is the ray fan diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end. Refer to Figures 4 - 10 , the ray fan diagram is one of the commonly used evaluation methods by current optical designers. The abscissa is the normalized beam aperture, and the ordinate is the lateral aberration. Ideally, each curve should completely coincide with the horizontal axis. At this time, all rays at this field of view are focused at the same point on the image plane; the ordinate can also represent the maximum dispersion range of the beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberrations of different wavelengths but also represent the magnitude of the lateral chromatic aberration. From Figures 4 - 10 It can be seen that at each field of view at the wide-angle end of this zoom lens, each wavelength is well close to the horizontal axis, indicating that the lateral aberrations of each wavelength are well corrected. In addition, the curves of each color do not show obvious dispersion, indicating that this zoom lens also has good correction for chromatic aberration and meets the usage requirements of this zoom lens.

[0091] Figure 11 This is the axial aberration curve diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end. Refer to Figure 11 , the vertical direction represents the normalization of the aperture, 0 represents on the optical axis, and the vertex in the vertical direction represents the maximum pupil radius; the main wavelength is 546.07 nm, and the horizontal direction represents the offset relative to the main wavelength, with the unit of millimeter (mm). From Figure 11 It can be seen that the axial aberrations of the normalized apertures of different wavelengths from 0.3 to 1.0 are all controlled within a reasonable range, indicating that the axial aberration of this zoom lens at the wide-angle end is well controlled and meets the usage requirements.

[0092] Figure 12 This is the lateral chromatic aberration curve diagram of the zoom lens provided in the first embodiment of the present invention at the telephoto end. Refer to Figure 12 , the lateral chromatic aberration of the zoom lens at the telephoto end is well controlled and can meet the application requirements under normal conditions.

[0093] Figures 13 - 19 This is the ray fan diagram of the zoom lens provided in the first embodiment of the present invention at the telephoto end. Refer to Figures 13 - 19, at the telephoto end of this zoom lens, each field of view at each wavelength is better close to the abscissa, indicating that the vertical aberration at each wavelength is well corrected. In addition, the curves of each color do not show obvious dispersion, indicating that this zoom lens also has good correction for chromatic aberration and meets the usage requirements of this zoom lens.

[0094] Figure 20 This is the axial aberration curve diagram of the zoom lens provided in the first embodiment of the present invention at the telephoto end. Refer to Figure 20 , the axial aberrations of different wavelengths with a normalized aperture of 0.3 - 1.0 are all controlled within a reasonable range, indicating that the axial aberration of this zoom lens at the telephoto end is well controlled and meets the usage requirements.

[0095] Embodiment 2

[0096] Similarities with the above embodiments will not be elaborated here.

[0097] Table 3 shows a set of design values of the zoom lens in Embodiment 2

[0098]

[0099] Table 3 shows a set of design values of the zoom lens in Embodiment 2, and the specific numerical values can be adjusted according to product requirements, which is not a limitation to the embodiments of the present invention. The zoom lens shown in Table 3 can be Figure 21 and Figure 22 as shown in. On the basis of Embodiment 1, Embodiment 2 splits some cemented lens groups, and Table 3 has more surfaces than Table 1.

[0100] Table 4 shows the zoom interval design values of the zoom lens in Embodiment 2

[0101]

[0102] Exemplarily, in Embodiment 2, the maximum diameter that the image plane size of the zoom lens can reach at the wide-angle end is 13.1 mm, and the maximum diameter that the image plane size can reach at the telephoto end is 13.1 mm. The focal length of the zoom lens at the wide-angle end (i.e., FW) is 15.1 mm, and the focal length at the telephoto end (i.e., FT) is 50.00 mm. The zoom lens is applicable to the wavelength band of 436 nm - 850 nm at the wide-angle end and the telephoto end. The overall optical length (i.e., TTL) of the zoom lens at the wide-angle end and the telephoto end is 124 mm.

[0103] Exemplarily, in Embodiment 2, the FNO of the zoom lens at the wide-angle end is 1.651, and the FNO at the telephoto end is 1.649. FG1 / FW = 5.14, FG2 / FW = -1.74, FG3 / FW = 2.89, FG4 / FW = 2.76, S2 / S4 = 29.32, F8_9_10 / FG3 = -0.61, F11_12_13 / FG3 = 0.62, FT / FW = 3.311, TTL / S2 = 3.795.

[0104] Figure 23 The vertical chromatic aberration curve graph of the zoom lens provided in Embodiment 2 of the present invention at the wide-angle end, refer to Figure 23 , the vertical direction represents the field of view, 0 represents on the optical axis, and the vertex in the vertical direction represents the maximum field of view; the main wavelength uses 546.07 nm, and the horizontal direction represents the offset relative to the main wavelength, with the unit of micrometer (um). It can be seen from Figure 23 that the vertical chromatic aberrations of different wavelengths are all controlled within a small range, indicating that the vertical chromatic aberration of this zoom lens at the wide-angle end is well controlled and can meet the application requirements under normal conditions.

[0105] Figures 24 - 30 The ray fan diagram of the zoom lens provided in Embodiment 2 of the present invention at the wide-angle end, refer to Figures 24 - 30 , the ray fan diagram is one of the commonly used evaluation methods by current optical designers. The abscissa is the normalized beam aperture, and the ordinate is the vertical aberration. Ideally, each curve should completely coincide with the horizontal coordinate axis. At this time, all rays in this field of view are focused at the same point on the image plane; the ordinate can also be expressed as the maximum dispersion range of the beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberrations of different wavelengths, but also represent the magnitude of the vertical chromatic aberration. It can be known from Figures 24 - 30 that each wavelength of this zoom lens at the wide-angle end is well close to the horizontal coordinate, indicating that the vertical aberrations of each wavelength are well corrected. In addition, the curves of each color do not have obvious dispersion, indicating that this zoom lens also has good correction for chromatic aberration and meets the usage requirements of this zoom lens.

[0106] Figure 31 The axial aberration curve graph of the zoom lens provided in Embodiment 2 of the present invention at the wide-angle end, refer to Figure 31 , the vertical direction represents the normalization of the aperture, 0 represents on the optical axis, and the vertex in the vertical direction represents the maximum pupil radius; the main wavelength uses 546.07 nm, and the horizontal direction represents the offset relative to the main wavelength, with the unit of millimeter (mm). It can be seen from Figure 31 that the axial aberrations of different wavelengths with a normalized aperture of 0.3 - 1.0 are all controlled within a reasonable range, indicating that the axial aberration of this zoom lens at the wide-angle end is well controlled and meets the usage requirements.

[0107] Figure 32 This is the vertical chromatic aberration curve graph of the zoom lens provided in the second embodiment of the present invention at the telephoto end. Refer to Figure 32 , the vertical chromatic aberration of the zoom lens at the telephoto end is well controlled, which can meet the application requirements under normal conditions.

[0108] Figures 33 - 39 This is the light fan graph of the zoom lens provided in the second embodiment of the present invention at the telephoto end. Refer to Figures 33 - 39 , at each field of view of this zoom lens at the telephoto end, each wavelength is well close to the abscissa, indicating that the vertical aberration of each wavelength is well corrected. In addition, the curves of each color do not show obvious dispersion, indicating that this zoom lens also has good correction for chromatic aberration and meets the usage requirements of this zoom lens.

[0109] Figure 40 This is the axial aberration curve graph of the zoom lens provided in the second embodiment of the present invention at the telephoto end. Refer to Figure 40 , the axial aberrations of different wavelengths with a normalized aperture of 0.3 - 1.0 are all controlled within a reasonable range, indicating that the axial aberration of this zoom lens at the telephoto end is well controlled and meets the usage requirements.

[0110] Embodiment Three

[0111] Similarities with the above embodiments will not be elaborated here.

[0112] Table 5 shows a set of design values of the zoom lens in Embodiment Three

[0113]

[0114] Table 5 shows a set of design values of the zoom lens in Embodiment Three. The specific numerical values can be adjusted according to product requirements and are not a limitation to the embodiments of the present invention. The zoom lens shown in Table 5 can be Figure 41 and Figure 42 as shown in

[0115] Table 6 shows the zoom interval design values of the zoom lens in Embodiment Three

[0116]

[0117] Exemplarily, in Embodiment Three, the maximum diameter that the image plane size of the zoom lens can reach at the wide-angle end is 13.1 mm, and the maximum diameter that the image plane size of the zoom lens can reach at the telephoto end is 13.1 mm. The focal length of the zoom lens at the wide-angle end (i.e., FW) is 15.21 mm, and the focal length of the zoom lens at the telephoto end (i.e., FT) is 49.99 mm. The zoom lens is applicable to the wavelength band of 436 nm - 850 nm at the wide-angle end and the telephoto end. The overall optical length (i.e., TTL) of the zoom lens at the wide-angle end and the telephoto end is 124 mm.

[0118] Exemplarily, in the third embodiment, the FNO of the zoom lens at the wide-angle end is 1.667, and the FNO at the telephoto end is 1.652. FG1 / FW = 5.23, FG2 / FW = -1.77, FG3 / FW = 2.88, FG4 / FW = 2.64, S2 / S4 = 38.59, F8_9_10 / FG3 = -0.65, F11_12_13 / FG3 = 0.64, FT / FW = 3.052, TTL / S2 = 3.832.

[0119] Figure 43 The vertical chromatic aberration curve diagram of the zoom lens provided in the third embodiment of the present invention at the wide-angle end, refer to Figure 43 , the vertical direction represents the field of view, 0 represents on the optical axis, and the vertex in the vertical direction represents the maximum field of view; the main wavelength is 546.07 nm, and the horizontal direction represents the offset relative to the main wavelength, with the unit of micrometer (um). It can be seen from Figure 43 that the vertical chromatic aberrations of different wavelengths are all controlled within a small range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end is well controlled and can meet the application requirements under normal conditions.

[0120] Figures 44 - 50 The ray fan diagram of the zoom lens provided in the third embodiment of the present invention at the wide-angle end, refer to Figures 44 - 50 , the ray fan diagram is one of the commonly used evaluation methods by current optical designers. The abscissa is the normalized beam aperture, and the ordinate is the vertical aberration. Ideally, each curve should completely coincide with the horizontal axis, and at this time all rays in this field of view focus on the same point on the image plane; the ordinate can also represent the maximum dispersion range of the beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberrations of different wavelengths, but also represent the magnitude of the vertical chromatic aberration. It can be known from Figures 44 - 50 that each wavelength of this zoom lens at the wide-angle end is well close to the horizontal axis in each field of view, indicating that the vertical aberrations of each wavelength are well corrected. In addition, the curves of each color do not show obvious dispersion, indicating that this zoom lens also has good correction for chromatic aberration and meets the usage requirements of this zoom lens.

[0121] Figure 51 The axial aberration curve diagram of the zoom lens provided in the third embodiment of the present invention at the wide-angle end, refer to Figure 51 , the vertical direction represents the normalization of the aperture, 0 represents on the optical axis, and the vertex in the vertical direction represents the maximum pupil radius; the main wavelength is 546.07 nm, and the horizontal direction represents the offset relative to the main wavelength, with the unit of millimeter (mm). It can be seen from Figure 51 that the axial aberrations of different wavelengths with a normalized aperture of 0.3 - 1.0 are all controlled within a reasonable range, indicating that the axial aberration of the zoom lens at the wide-angle end is well controlled and meets the usage requirements.

[0122] Figure 52 This is the vertical chromatic aberration curve graph of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end. Refer to Figure 52 , the vertical chromatic aberration of the zoom lens at the telephoto end is well controlled, which can meet the application requirements under normal conditions.

[0123] Figures 53 - 59 This is the light fan diagram of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end. Refer to Figures 53 - 59 , at the telephoto end of this zoom lens, each wavelength at each field of view is well close to the abscissa, indicating that the vertical aberration of each wavelength is well corrected. In addition, the curves of each color do not have obvious dispersion, indicating that this zoom lens also has good correction for chromatic aberration and meets the usage requirements of this zoom lens.

[0124] Figure 60 This is the axial aberration curve graph of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end. Refer to Figure 60 , the axial aberrations of different wavelengths with a normalized aperture of 0.3 - 1.0 are all controlled within a reasonable range, indicating that the axial aberration of this zoom lens at the telephoto end is well controlled and meets the usage requirements.

[0125] Note that the above is only the preferred embodiment of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here. Various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to only the above embodiments. Without departing from the concept of the present invention, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A zoom lens, characterized in that, It includes a first fixed lens group, a zoom lens group, a diaphragm, a second fixed lens group, and a focusing lens group arranged in sequence from the object side to the image side along the optical axis. The first fixed lens group, the second fixed lens group, and the focusing lens group have positive optical powers, and the zoom lens group has a negative optical power; The first fixed lens group includes a first lens, a second lens, and a third lens arranged in sequence from the object side to the image side along the optical axis. The zoom lens group includes a fourth lens, a fifth lens, and a sixth lens arranged in sequence from the object side to the image side along the optical axis. The second fixed lens group includes a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens arranged in sequence from the object side to the image side along the optical axis. The focusing lens group includes a fourteenth lens, a fifteenth lens, and a sixteenth lens arranged in sequence from the object side to the image side along the optical axis; The first lens and the second lens form a cemented lens group; the second fixed lens group includes at least two cemented lens groups.

2. The zoom lens according to claim 1, wherein The first lens, the fourth lens, the fifth lens, the eighth lens, the tenth lens, the twelfth lens, and the fifteenth lens have negative optical powers; The second lens, the third lens, the sixth lens, the seventh lens, the ninth lens, the eleventh lens, the thirteenth lens, the fourteenth lens, and the sixteenth lens have positive optical powers.

3. The zoom lens according to claim 1, wherein The focal length of the first fixed lens group is FG1, the focal length of the zoom lens group is FG2, the focal length of the second fixed lens group is FG3, the focal length of the focusing lens group is FG4, and the focal length of the wide-angle end of the zoom lens is FW, satisfying: ； ； ； 。 4. The zoom lens according to claim 1, characterized in that, The maximum distance that the zoom lens group can move along the optical axis is S2, and the maximum distance that the focusing lens group can move along the optical axis is S4, satisfying: 。 5. The zoom lens according to claim 1, characterized in that, At least two of the eighth lens, the ninth lens, and the tenth lens form a cemented lens group, and at least two of the eleventh lens, the twelfth lens, and the thirteenth lens form a cemented lens group.

6. The zoom lens according to claim 5, characterized in that, The combined focal length of the eighth lens, the ninth lens, and the tenth lens is F8_9_10, the combined focal length of the eleventh lens, the twelfth lens, and the thirteenth lens is F11_12_13, and the focal length of the second fixed lens group is FG3, satisfying: ； 。 7. The zoom lens according to claim 1, characterized in that, The refractive index of the seventh lens is nd7, the Abbe number of the seventh lens is vd7, the refractive index of the sixteenth lens is nd16, and the Abbe number of the sixteenth lens is vd16, satisfying: ； ； ； 。 8. The zoom lens according to claim 1, wherein The fourteenth lens and the fifteenth lens form a cemented lens group.

9. The zoom lens according to claim 1, wherein The focal length of the wide-angle end of the zoom lens is FW, and the focal length of the telephoto end of the zoom lens is FT, satisfying: 。 10. The zoom lens according to claim 1, characterized in that, The maximum distance that the zoom lens group can move along the optical axis is S2, and the overall optical length of the zoom lens is TTL, satisfying: 。

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