Zoom lens

Abstract

The application discloses a zoom lens, comprising, along an optical axis, a focusing lens group, a zoom lens group and a fixed lens group arranged in sequence from an object plane to an image plane, the focusing lens group having negative refractive power, the zoom lens group having positive refractive power, and the fixed lens group having positive refractive power, the focusing lens group comprising, from the object plane to the image plane, a first lens, a second lens, a third lens and a fourth lens arranged in sequence; the zoom lens group comprising, from the object plane to the image plane, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens arranged in sequence; and the fixed lens group comprising a tenth lens. The zoom lens provided by the embodiment of the application adopts a three-group-element structure, uses ten lenses, sets the number of lenses in the three lens groups, and further limits the refractive power matching of the three lens groups and the ten lenses, so that a high-image-quality zoom lens with small size, large aperture, infrared and high-low temperature confocal functions is realized, and can be used in cooperation with a 1 / 1.8'' chip.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical devices, in particular to a zoom lens. BACKGROUND

[0002] In the field of security and protection, zoom lenses have been widely used due to their long shooting distance and large shooting angle. With the development of technology, cameras are gradually developing towards miniaturization and refinement, which also puts forward higher requirements for zoom lenses.

[0003] At present, 1 / 1.8" chips have gradually become the mainstream chips on the market and are widely used in various security monitoring products, but traditional zoom lenses are usually suitable for 1 / 2.7" chips and are difficult to use in a wide range of environments, and traditional zoom lenses also have the problems of small aperture, large volume, infrared and high and low temperature non-cofocus. SUMMARY

[0004] The present application provides a zoom lens to realize a small volume, large aperture, infrared and high and low temperature focus high image quality zoom lens, and can be used with 1 / 1.8" chips.

[0005] The present application provides a zoom lens, comprising a focusing lens group, a zoom lens group and a fixed lens group arranged in order along the optical axis from the object plane to the image plane;

[0006] The fixed lens group is fixedly arranged, and the focusing lens group and the zoom lens group are movably arranged along the optical axis;

[0007] The focusing lens group has negative refractive power, the zoom lens group has positive refractive power, and the fixed lens group has positive refractive power;

[0008] The focusing lens group comprises a first lens, a second lens, a third lens and a fourth lens arranged in order from the object plane to the image plane; the first lens has negative refractive power, the second lens has positive refractive power, the third lens has negative refractive power, and the fourth lens has positive refractive power;

[0009] The zoom lens group comprises a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens arranged in order from the object plane to the image plane; the fifth lens has positive refractive power, the sixth lens has negative refractive power, the seventh lens has positive refractive power, the eighth lens has negative refractive power, and the ninth lens has positive refractive power;

[0010] The fixed lens group comprises a tenth lens, and the tenth lens has positive refractive power.

[0011] Optionally, the zoom lens further comprises a diaphragm, which is located in the optical path between the fifth lens and the sixth lens.

[0012] Optionally, the sixth lens and the seventh lens constitute a cemented lens group.

[0013] Optionally, the focal length of the focusing lens group is F1, the focal length of the zoom lens group is F2, the focal length of the fixed lens group is F3, and the focal length of the zoom lens at the telephoto end is FT.

[0014] -0.51≤F1 / FT≤-0.49;

[0015] 0.51≤F2 / FT≤0.53;

[0016] 2.10≤F3 / FT≤7.80.

[0017] Optionally, the maximum movable distance of the zoom lens group is S2, the distance from the optical axis center of the object side surface of the first lens to the image surface when the zoom lens is at the telephoto end is TTLT, and the distance from the optical axis center of the image side surface of the tenth lens to the image surface is BFL.

[0018] 0.34≤S2 / TTLT≤0.36, 4.3≤S2 / BFL≤4.4.

[0019] Optionally, the second lens, the third lens, the fourth lens, the fifth lens, the eighth lens, the ninth lens, and the tenth lens are all plastic aspherical lenses.

[0020] The first lens, the sixth lens, and the seventh lens are all glass spherical lenses.

[0021] Optionally, the focal length of the tenth lens is EFL10, and the focal length of the zoom lens at the wide-angle end is FW.

[0022] 10.0≤EFL10 / FW≤38.50.

[0023] Optionally, the total focal length of the eighth lens and the ninth lens is EFL89, and the focal length of the zoom lens group is F2.

[0024] 4.99<EFL89 / F2<7.10.

[0025] Optionally, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT.

[0026] 4.9≤FT / FW≤5.1.

[0027] Optionally, the object side surface of the first lens is a convex surface, and the image side surface is a concave surface.

[0028] The object side surface of the second lens is a convex surface, and the image side surface is a concave surface.

[0029] The object side surface of the third lens is a central convex surface, and the image side surface is a central concave surface.

[0030] The object side surface of the fourth lens is a convex surface, and the image side surface is a convex surface.

[0031] The object side surface of the fifth lens is a convex surface.

[0032] The object side surface of the sixth lens is a convex surface, and the image side surface is a concave surface.

[0033] The object side surface of the seventh lens is a convex surface.

[0034] The object side surface of the eighth lens is a convex surface, and the image side surface is a concave surface.

[0035] The object side surface of the ninth lens is a convex surface.

[0036] The object side surface of the tenth lens is a convex surface, and the image side surface is a concave surface.

[0037] The zoom lens provided by the embodiment of the present application adopts a three-group element structure, uses 10 lenses, sets the number of lenses in the three lens groups, and further limits the focal power matching of the three lens groups and the 10 lenses, so that the total optical length TTL of the zoom lens satisfies TTL≤61.5 mm, high-performance imaging is realized from 436 nm to 850 nm waveband on a 1 / 1.8″ target surface, the aperture number F / # at the wide-angle end can reach 1.6, the aperture number F / # at the long-focus end can reach 4.2, so that a small-volume, large-aperture, infrared and high-low-temperature confocal high-image-quality zoom lens is realized, and can be used with a 1 / 1.8″ chip.

[0038] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0040] Figure 1 A structural schematic diagram of a zoom lens provided by the embodiment of the present application at a wide-angle end.

[0041] Figure 2 Structure schematic view of a zoom lens at a long focal end according to an embodiment of the present application;

[0042] Figure 3 Structure schematic view of another zoom lens at a wide angle end according to an embodiment of the present application;

[0043] Figure 4 Structure schematic view of another zoom lens at a long focal end according to an embodiment of the present application;

[0044] Figure 5 Structure schematic view of another zoom lens at a wide angle end according to an embodiment of the present application;

[0045] Figure 6 Structure schematic view of another zoom lens at a long focal end according to an embodiment of the present application;

[0046] Figure 7 VVC curve of the zoom lens at a wide angle end according to the first embodiment of the present application;

[0047] Figure 8 VVC curve of the zoom lens at a long focal end according to the first embodiment of the present application;

[0048] Figure 9 Light ray fan chart of the zoom lens at a wide angle end according to the first embodiment of the present application;

[0049] Figure 10 Light ray fan chart of the zoom lens at a long focal end according to the first embodiment of the present application;

[0050] Figure 11 Axial aberration curve of the zoom lens at a wide angle end according to the first embodiment of the present application;

[0051] Figure 12 Axial aberration curve of the zoom lens at a long focal end according to the first embodiment of the present application;

[0052] Figure 13 VVC curve of the zoom lens at a wide angle end according to the second embodiment of the present application;

[0053] Figure 14 VVC curve of the zoom lens at a long focal end according to the second embodiment of the present application;

[0054] Figure 15 Light ray fan chart of the zoom lens at a wide angle end according to the second embodiment of the present application;

[0055] Figure 16 Light ray fan chart of the zoom lens at a long focal end according to the second embodiment of the present application;

[0056] Figure 17 Axial aberration curve diagram of the zoom lens provided for the second embodiment of the present application at the wide-angle end;

[0057] Figure 18 Axial aberration curve diagram of the zoom lens provided for the second embodiment of the present application at the long-focus end;

[0058] Figure 19 Axial aberration curve diagram of the zoom lens provided for the third embodiment of the present application at the wide-angle end;

[0059] Figure 20 Axial aberration curve diagram of the zoom lens provided for the third embodiment of the present application at the long-focus end;

[0060] Figure 21 Axial aberration curve diagram of the zoom lens provided for the third embodiment of the present application at the wide-angle end;

[0061] Figure 22 Axial aberration curve diagram of the zoom lens provided for the third embodiment of the present application at the long-focus end;

[0062] Figure 23 Axial aberration curve diagram of the zoom lens provided for the third embodiment of the present application at the wide-angle end;

[0063] Figure 24 Axial aberration curve diagram of the zoom lens provided for the third embodiment of the present application at the long-focus end. DETAILED DESCRIPTION

[0064] In order to make the personnel in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0065] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to the process, method, product or device.

[0066] Figure 1 A structure schematic diagram of a zoom lens at a wide-angle end provided by an embodiment of the present application is shown in the figure, Figure 2 A structure schematic diagram of a zoom lens at a long-focus end provided by an embodiment of the present application is shown in the figure; Figure 3 A structure schematic diagram of another zoom lens at a wide-angle end provided by an embodiment of the present application is shown in the figure, Figure 4 A structure schematic diagram of another zoom lens at a long-focus end provided by an embodiment of the present application is shown in the figure; Figure 5 A structure schematic diagram of still another zoom lens at a wide-angle end provided by an embodiment of the present application is shown in the figure, Figure 6 A structure schematic diagram of still another zoom lens at a long-focus end provided by an embodiment of the present application is shown in the figure; Figures 1-6 As shown in the figure, the zoom lens provided by the embodiment of the present application comprises, in order along the optical axis from the object plane to the image plane, a focusing lens group G1, a zoom lens group G2 and a fixed lens group G3. The fixed lens group G3 is fixedly arranged, and the focusing lens group G1 and the zoom lens group G2 are movably arranged along the optical axis direction. The focusing lens group G1 has negative refractive power, the zoom lens group G2 has positive refractive power, and the fixed lens group G3 has positive refractive power. The focusing lens group G1 comprises, in order from the object plane to the image plane, a first lens L1, a second lens L2, a third lens L3 and a fourth lens L4; the first lens L1 has negative refractive power, the second lens L2 has positive refractive power, the third lens L3 has negative refractive power, and the fourth lens L4 has positive refractive power. The zoom lens group G2 comprises, in order from the object plane to the image plane, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a ninth lens L9; the fifth lens L5 has positive refractive power, the sixth lens L6 has negative refractive power, the seventh lens L7 has positive refractive power, the eighth lens L8 has negative refractive power, and the ninth lens L9 has positive refractive power. The fixed lens group G3 comprises a tenth lens L10, and the tenth lens L10 has positive refractive power.

[0067] Specifically, as shown in the figure, Figures 1-6 The zoom lens provided by the embodiment of the present application comprises, in order along the optical axis from the object plane to the image plane, a focusing lens group G1 with negative refractive power, a zoom lens group G2 with positive refractive power and a fixed lens group G3 with positive refractive power.

[0068] Among them, the focusing lens group G1, the zoom lens group G2 and the fixed lens group G3 can be arranged in a lens barrel (not shown in the figure), but are not limited thereto.

[0069] Further, the fixed lens group G3 can be fixed in position in the lens barrel, so that the fixed lens group G3 is immovable relative to the image plane.

[0070] The focusing lens group G1 and the zoom lens group G2 can reciprocally move along the optical axis in the lens barrel, wherein moving the zoom lens group G2 can play a zooming role, and moving the focusing lens group G1 can play a focusing role, and by changing the positions of the focusing lens group G1 and the zoom lens group G2 on the optical axis, the switching of the zoom lens between the wide-angle end and the telephoto end can be realized.

[0071] In the process of realizing zooming by changing the positions of the focusing lens group G1 and the zoom lens group G2 on the optical axis, the zoom lens is at the wide-angle end when the focal length is the shortest, and is at the telephoto end when the focal length is the longest, and the zoom lens has different focal lengths and optical powers at the wide-angle end and the telephoto end.

[0072] Specifically, the optical power is equal to the difference between the converging degree of the image-side light beam and the converging degree of the object-side light beam, which represents the ability of the optical system to bend light rays. The greater the absolute value of the optical power, the stronger the bending ability of the light rays, and the smaller the absolute value of the optical power, the weaker the bending ability of the light rays. When the optical power is positive, the refraction of the light rays is convergent; when the optical power is negative, the refraction of the light rays is divergent. The optical power can be used to represent a certain refractive surface of a lens (i.e., a surface of the lens), a certain lens, or a system (i.e., a lens group) formed by multiple lenses.

[0073] In the embodiment of the present application, the optical power of the focusing lens group G1 is negative, which can ensure that the light rays form a larger aperture before entering the diaphragm, thereby increasing the aperture of the lens, and further improving the performance of the lens in low light conditions and enhancing the brightness and clarity of the image.

[0074] The optical power of the zoom lens group G2 is positive, so that after the light rays pass through the focusing lens group G1 of the focusing lens group G1, the light rays are appropriately converged by the zoom lens group G2 to adjust the light ray path, ensure that the light rays can enter the subsequent structure, and better control the degree of contraction of the light rays in the subsequent structure to adapt to different focal length requirements.

[0075] The optical power of the fixed lens group G3 is positive, which can finally focus the light rays adjusted by the first two lens groups on the imaging sensor, ensure that the light rays can be accurately focused when reaching the imaging sensor, and realize clear imaging.

[0076] The focusing lens group G1, the zoom lens group G2 and the fixed lens group G3 adopt a negative-positive-positive refractive power matching, and the light rays can be reasonably converged and diverged when passing through each lens group, so as to ensure that the light rays are not deflected too much, but smoothly pass through the entire lens system, and at the same time, the light rays have a larger aperture before entering the diaphragm, so that the light rays can smoothly pass through even if the diaphragm opening is large, and aberration is not generated due to sudden contraction, thereby allowing the lens to work at a larger aperture, which is beneficial to increase the aperture of the lens.

[0077] With reference to the foregoing Figures 1-6 The number of lenses with refractive power in the focusing lens group G1 can be 4, wherein the focusing lens group G1 can be composed of a first lens L1 with negative refractive power, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power and a fourth lens L4 with positive refractive power.

[0078] The first lens L1 has negative refractive power, which can expand the beam of incident light, so that more light rays can enter the subsequent lens group, thereby being beneficial to realize a larger aperture.

[0079] The second lens L2 to the fourth lens L4 adopt a positive-negative-positive refractive power matching, which is beneficial to control the light path and make it more smoothly pass through the subsequent lens group.

[0080] With reference to the foregoing Figures 1-6 The number of lenses with refractive power in the zoom lens group G2 can be 5, wherein the zoom lens group G2 can be composed of a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power, a seventh lens L7 with positive refractive power, an eighth lens L8 with negative refractive power and a ninth lens L9 with positive refractive power.

[0081] The fifth lens L5 to the ninth lens L9 adopt a positive-negative-positive-negative-positive refractive power matching, which not only helps the smooth transmission of light, but also can adjust the aberration of the lens to a certain extent, especially in the area near the diaphragm, the fifth lens L5 has positive refractive power and plays a role in converging light rays, which cooperates with the focusing lens group G1 to avoid reflection and other forms of stray light at the diaphragm position, ensure the aberration balance and high-low temperature performance stability of the lens, ensure that the lens can maintain stable resolving power in different temperature environments, and at the same time, the balance of aberration can be maintained during zooming, which ensures the consistency of image quality of the lens at different focal lengths and improves the overall imaging quality.

[0082] In addition, the sixth lens L6 has a negative focal power, and the seventh lens L7 has a positive focal power, which complement each other, can correct the focusing position difference of light rays of different wavelengths without changing the overall optical system focal length, ensure that the lens can form a clear image in a wide wavelength band of 436nm to 850nm, and can meet the needs of day and night monitoring.

[0083] With reference to the foregoing Figures 1-6 , the number of lenses with focal power in the fixed lens group G3 can be 1, wherein the fixed lens group G3 can be composed of the tenth lens L10 with a positive focal power.

[0084] The tenth lens L10 is the last lens in the entire lens and is located closest to the image plane (imaging sensor), and the tenth lens L10 has a positive focal power and plays a role in converging light rays, which can finally focus the light rays adjusted by the first two lens groups (i.e., the focusing lens group G1 and the zoom lens group G2) on the imaging sensor, ensure that the light rays can be incident at the best angle when reaching the sensor, reduce light loss and chromatic aberration, and at the same time, can eliminate high-order aberrations of the lens, expand the target surface (size) of the lens, so that the lens can match a larger size imaging sensor, which is beneficial to improve the image quality and meet the use requirements in more application scenarios.

[0085] In the embodiment of the application, three groups of lens structures are adopted, and 10 lenses are used. By setting the number of lenses in the three lens groups and further limiting the focal power matching of the three lens groups and the 10 lenses, the total optical length TTL of the zoom lens satisfies TTL≤61.5mm, and high-performance imaging from 436nm to 850nm waveband on a 1 / 1.8″ target surface is realized. The aperture number F / # at the wide-angle end can reach 1.6, and the aperture number F / # at the telephoto end can reach 4.2, so that a small volume, large aperture, infrared and high-low temperature confocal high-image-quality zoom lens is realized, and can be used with a 1 / 1.8″ chip.

[0086] As a feasible implementation manner, with reference to the foregoing Figure 3 and Figure 4 , the zoom lens further comprises a stop STO, and the stop STO is located in the optical path between the fifth lens L5 and the sixth lens L6.

[0087] The stop STO is arranged in the optical path between the fifth lens L5 and the sixth lens L6, and is located in the inside of the zoom lens group G2, so that the light rays can be effectively controlled when passing through the stop, and unnecessary stray light and reflection can be avoided. At the same time, when the zoom lens group G2 moves, the stop STO moves together with the zoom lens group G2, so that the movable range of the zoom lens group G2 can be significantly increased, which not only can improve the zoom ratio, but also can ensure clear imaging in the entire zoom range.

[0088] As a feasible implementation, with continuous reference to Figures 1-6 The sixth lens L6 and the seventh lens L7 form a cemented lens group g1.

[0089] Wherein, when the light passes through the stop, a certain higher-order aberration will be generated, and the cemented lens can have a certain inhibitory effect on the higher-order aberration such as chromatic aberration.

[0090] As shown in Figures 1-6 The sixth lens L6 and the seventh lens L7 are cemented, so that the first lens through which the light passes after passing through the stop STO is the cemented lens group g1, so that the chromatic aberration of the light passing through the stop STO can be better corrected, and the lens can form a clear image in the wavelength range of 436nm to 850nm. At the same time, it can also avoid the situation that the aberration is too large when the light propagates to the tail end of the lens and cannot be corrected, for example, it can avoid the situation that the chromatic aberration is superimposed at the tail end of the lens, which requires a large amount of high Abbe number material to correct the chromatic aberration at the tail end, thereby saving cost while ensuring the relative luminance and imaging quality of the lens.

[0091] At the same time, by cementing the sixth lens L6 and the seventh lens L7, the air gap between the sixth lens L6 and the seventh lens L7 can be effectively reduced, thereby further reducing the total length of the lens.

[0092] In addition, by cementing the sixth lens L6 and the seventh lens L7, the air interface can be reduced, thereby reducing the reflection loss, and the assembly components between the sixth lens L6 and the seventh lens L7 can be reduced, thereby simplifying the assembly process during lens manufacturing, reducing cost, and reducing the influence of the tilt / offset tolerance of the lens generated during assembly on the zoom lens, thereby improving the stability of the zoom lens.

[0093] As a feasible implementation, the focal length of the focusing lens group is F1, the focal length of the zoom lens group is F2, the focal length of the fixed lens group is F3, and the focal length of the zoom lens at the long focal end is FT. Wherein, -0.51≤F1 / FT≤-0.49; 0.51≤F2 / FT≤0.53; 2.10≤F3 / FT≤7.80.

[0094] Wherein, by further limiting the focal length of each lens group, the focal power of each lens can be reasonably matched, the light can pass through the zoom lens more smoothly, and the higher-order aberration of the zoom lens can be corrected to a greater extent, thereby improving the imaging quality.

[0095] As a feasible implementation, a maximum movable distance of the zoom lens group G2 is S2, a distance from an optical axis center of an object side surface of the first lens L1 to an image surface when the zoom lens is at a long focal end is TTLT, and a distance from an optical axis center of an image side surface of the tenth lens L10 to the image surface is BFL; wherein 0.34≤S2 / TTLT≤0.36, and 4.3≤S2 / BFL≤4.4.

[0096] The maximum movable distance S2 of the zoom lens group G2 refers to a distance between a closest position to the image surface and a farthest position to the image surface of the zoom lens group G2 in the zoom lens during movement.

[0097] The distance TTLT from the optical axis center of the object side surface of the first lens L1 to the image surface when the zoom lens is at the long focal end refers to an overall optical length of the zoom lens at the long focal end.

[0098] The distance BFL from the optical axis center of the image side surface of the tenth lens L10 to the image surface refers to a back focus of the zoom lens.

[0099] In the embodiment, the maximum movable distance S2 of the zoom lens group G2 and the overall optical length TTLT of the zoom lens at the long focal end satisfy 0.34≤S2 / TTLT≤0.36, and the maximum movable distance S2 of the zoom lens group G2 and the back focus BFL of the zoom lens satisfy 4.3≤S2 / BFL≤4.4, which ensures that the zoom lens group G2 can effectively move during zooming, realizes zooming from a wide angle to a long focal, and thus a larger zoom ratio can be realized without significantly increasing the overall length of the lens, so that the lens can provide high-quality imaging in a wider focal range.

[0100] Meanwhile, by controlling the position of the zoom lens group G2, the reciprocating movement of the focusing lens group G1 can be indirectly controlled, so that the movement of the zoom lens group G2 and the focusing lens group G1 does not occupy too much overall length of the lens, greatly reduces the size of the lens, and expands the use scenarios of the lens.

[0101] As a feasible implementation, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the eighth lens L8, the ninth lens L9, and the tenth lens L10 are all plastic aspherical lenses. The first lens L1, the sixth lens L6, and the seventh lens L7 are all glass spherical lenses.

[0102] Specifically, the zoom lens provided by the embodiment of the present application contains at least three spherical lenses, which helps to reduce the cost and is easy to manufacture. The spherical lenses adopt glass lenses, which can have a higher refractive index and a lower dispersion, and can provide stable optical performance in a wide waveband range, especially in the visible light and infrared light waveband. Meanwhile, the glass material has a lower thermal expansion coefficient, and can maintain stable resolving power in different temperature environments, and is particularly suitable for scenes requiring all-weather work.

[0103] Further, at least one plastic aspheric lens exists in the focusing lens group G1 and the zoom lens group G2 of the zoom lens, which can effectively reduce aberration, especially high-order aberration such as field curvature, distortion, coma and high-order spherical aberration, thereby improving the imaging quality of the entire zoom lens.

[0104] It should be noted that one of the main factors affecting the imaging quality of the lens is the aberration of the lens itself. In the zoom lens, since the lens groups need to move relatively, only controlling the aberration of the lens in a certain state cannot meet the requirement of clear imaging in the entire zoom range.

[0105] In the embodiment, the aspheric lens is added to each lens group, which can make the aberration of each state of the lens be in a relatively balanced state, thereby effectively correcting the aberration in the entire zoom range and ensuring good imaging quality at different focal lengths. Meanwhile, the uniformly distributed aspheric lenses can better coordinate the optical performance of the entire lens system, reduce the accumulation of local aberration, and through the overall correction of the lens, the effect of clear imaging in the entire waveband can also be achieved.

[0106] It should be noted that the aspheric lens generally has a good correcting effect on the aberration of the lens. The tenth lens L10 uses a plastic aspheric lens to control the high-order aberration of the light at the tail end of the lens, thereby further improving the image quality. In addition, the use of the aspheric lens at the tail end of the lens can more finely control the exit angle of the light in the lens, expand the target surface (size) of the lens, and improve the matching degree of the lens and the imaging sensor.

[0107] From the cost aspect, the aspheric lens adopts a plastic lens, which can reduce the cost on the one hand, and reduce the weight of the lens on the other hand, so as to meet the requirements of a wider range of use.

[0108] In addition, the two types of materials, glass and plastic, can compensate for each other. The glass lens and the plastic lens are used in the lens in a matched form, which can better balance the resolving power of the lens at high and low temperatures, ensure that the lens maintains good resolving power in a wide temperature range of-40℃ to 80℃, and realize high and low temperature focusing.

[0109] As a feasible implementation, a focal length of the tenth lens L10 is EFL10, and a focal length of the zoom lens at the wide-angle end is FW; wherein, 10.0≤EFL10 / FW≤38.50.

[0110] The tenth lens L10 is the last lens in the entire lens and is located closest to the image plane (imaging sensor), by setting the focal length EFL10 of the tenth lens L10 and the focal length FW of the zoom lens at the wide-angle end to satisfy 10.0≤EFL10 / FW≤38.50, the high-order aberration of the light at the tail end of the lens can be controlled, and the image quality is further improved; at the same time, the exit angle of the light in the lens can also be more finely controlled, ensuring that the light can be incident at the best angle when reaching the sensor, reducing light loss and chromatic aberration, expanding the target surface (size) of the lens, so that the lens can match a larger size imaging sensor, and meet the use requirements in more application scenarios.

[0111] As a feasible implementation, the total focal length of the eighth lens L8 and the ninth lens L9 is EFL89, and the focal length of the zoom lens group G2 is F2; wherein, 4.99

[0112] The total focal length EFL89 of the eighth lens L8 and the ninth lens L9 refers to the total focal length of the lens group composed of the eighth lens L8 and the ninth lens L9.

[0113] In this embodiment, by controlling the ratio of the total focal length EFL89 of the eighth lens L8 and the ninth lens L9 to the focal length F2 of the zoom lens group G2, the advancing trend of the light can be controlled to a greater extent, the target surface is maximized while the image quality is guaranteed, and more chip use requirements are met.

[0114] In addition, by controlling the refractive power of the tail end lens in the zoom lens group G2, the risk of stray light can be minimized, and the imaging quality of the lens is improved.

[0115] As a feasible implementation, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the long-focus end is FT; wherein, 4.9≤FT / FW≤5.1.

[0116] FT / FW can be understood as the zoom ratio, by limiting the ratio range between the focal length FT of the zoom lens at the long-focus end and the focal length FW at the wide-angle end, the zoom range and focal length range of the lens can be controlled, so that the lens can meet the use requirements under more conditions.

[0117] As a feasible implementation, the object side surface of the first lens L1 is convex, and the image side surface is concave. The object side surface of the second lens L2 is convex, and the image side surface is concave. The object side surface of the third lens L3 is central convex, and the image side surface is central concave. The object side surface of the fourth lens L4 is convex, and the image side surface is convex. The object side surface of the fifth lens L5 is convex. The object side surface of the sixth lens L6 is convex, and the image side surface is concave. The object side surface of the seventh lens L7 is convex. The object side surface of the eighth lens L8 is convex, and the image side surface is concave. The object side surface of the ninth lens L9 is convex. The object side surface of the tenth lens L10 is convex, and the image side surface is concave.

[0118] The surface shape of the lens affects the propagation direction of the light, determines how the light is bent when passing through the lens, and further affects the maximum aperture and light throughput of the lens, and the imaging quality and characteristics.

[0119] In the embodiment, by reasonably matching the surface shapes of the lenses, the light path is smoother when passing through the entire zoom lens, unnecessary reflection and absorption are reduced, the light throughput and imaging quality are improved, the optical performance indicators (such as large target surface, small volume, large aperture, infrared and high-low temperature confocal, etc.) are met, and the required optical performance indicators are met.

[0120] With reference to Figures 1-6 , as a feasible implementation, the zoom lens further includes a flat glass CG located on the image side surface side of the tenth lens L10. The flat glass CG can protect the photosensitive chip in the imaging sensor. The photosensitive chip is used to convert the light signal collected by the zoom lens into an electrical signal, and then generate a digital image or video through a series of processing steps, thereby ensuring the imaging effect of the zoom optical system.

[0121] In some cases, the flat glass CG can also be used to correct specific aberrations or filter unnecessary light. The embodiment of the present application does not make specific limitations in this regard.

[0122] The specific embodiments of the zoom lens applicable to the above embodiments will be further described below with reference to the accompanying drawings.

[0123] Embodiment one

[0124] As shown in Figure 1 and Figure 2 , the zoom lens provided by the first embodiment of the present application includes a focusing lens group G1, a zoom lens group G2 and a fixed lens group G3 arranged in order along the optical axis from the object plane to the image plane.

[0125] The fixed lens group G3 is fixedly arranged, and the focusing lens group G1 and the zoom lens group G2 are movably arranged along the optical axis.

[0126] The focusing lens group G1 includes, in order from the object side to the image side, a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4.

[0127] The zoom lens group G2 includes, in order from the object side to the image side, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9.

[0128] The fixed lens group G3 includes a tenth lens L10.

[0129] The sixth lens L6 and the seventh lens L7 form a cemented lens group g1, and a flat glass CG is located on the image side of the tenth lens L10.

[0130] Table 1 details the specific optical physical parameters of each lens in the zoom lens provided by the first embodiment of the present application in one possible implementation, and the zoom lens in Table 1 corresponds to the zoom lens shown in FIG. 1. Figure 1 and Figure 2 The zoom lens shown in FIG. 1.

[0131] Table 1: Design values of optical physical parameters of the zoom lens

[0132]

[0133]

[0134] The surface numbers in Table 1 are numbered according to the surface order of each lens, wherein "1" represents the object side surface of the first lens, "2" represents the image side surface of the first lens, and the like; "STO" represents the stop of the zoom lens; the radius of curvature represents the bending degree of the corresponding lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, wherein "INF" indicates that the surface is a flat surface with an infinite radius of curvature; the thickness represents the center axial distance from the current surface to the next surface; the material (nd) is the refractive index, which represents the deflection ability of the material between the current surface and the next surface to the light; the space represents that the current position is air with a refractive index of 1; the material (vd) is the Abbe number, which represents the chromatic dispersion characteristics of the material between the current surface and the next surface to the light; and "IMA" represents the image surface of the zoom lens.

[0135] Table 2 represents the values of the zoom interval of the zoom lens in Table 1 at the wide-angle end and the telephoto end.

[0136] The zoom interval is the interval value of the lens at the wide-angle end and the telephoto end.

[0137] Table 2: Design values of the zoom interval of the zoom lens

[0138] Wide angle end Telephoto end Zoom interval 1 24.2601 0.2408 Zoom interval 2 0.1454 20.2863

[0139] In the embodiment, the aspherical conic coefficients of the aspherical lens in the zoom lens can be defined by the following aspherical equation, but are not limited to the following expression:

[0140]

[0141] wherein Z is the axial distance of the curved surface at a position with a height of r perpendicular to the optical axis to the vertex of the surface; c represents the curvature at the vertex of the aspherical surface; k is the fitting conic coefficient; a2, a4, a6, a8, a10, a12, and a14 are the high-order aspherical coefficients of the second order, the fourth order, the sixth order, the eighth order, the tenth order, the twelfth order, and the fourteenth order of the corresponding aspherical surface, respectively; and a20, a30, a40, a50, a60, a70, a80, a90, and a100 are the high-order terms of the corresponding aspherical surface. 10 12 14 i i

[0142] For example, Table 3 details the aspherical conic coefficients of each lens in Embodiment I in a possible implementation.

[0143] Table 3: Design values of aspherical conic coefficients of each lens in the zoom lens

[0144]

[0145]

[0146] The value of k in Table 3 represents the numerical value of the best fitting conic coefficient of the aspherical surface.

[0147] The zoom lens of Embodiment I can achieve the following technical indexes:

[0148] Table 4: Technical indexes of the zoom lens

[0149] Wide angle end Telephoto end Image surface size (mm) Φ8.812 Φ8.812 Focal length (mm) 4.764 23.599 Waveband (nm) 436-850 436-850 Total optical length (mm) 61.4117 57.5332

[0150] Figure 7 Figure 1 is the sagittal chromatic aberration diagram of the zoom lens provided by Embodiment I of the present application at the wide-angle end, wherein the horizontal axis represents the relative shift of the main wavelength, and the unit is micrometers (μm); the vertical axis represents the field of view, and 0 represents the optical axis; the vertex of the vertical axis represents the maximum image height; and the main wavelength uses 546.07 nm. Figure 8 Figure 2 is the sagittal chromatic aberration diagram of the zoom lens provided by Embodiment I of the present application at the long-focus end, wherein the horizontal axis represents the relative shift of the main wavelength, and the unit is micrometers (μm); the vertical axis represents the field of view, and 0 represents the optical axis; the vertex of the vertical axis represents the maximum image height; and the main wavelength uses 546.07 nm. Figure 7 Figure 8 Figures 3 and 4 show the sagittal chromatic aberration curves of the zoom lens at the wide-angle end and the long-focus end at the infinite object distance, respectively; the vertical axis represents the field of view, and 0 represents the optical axis; the vertex of the vertical axis represents the maximum image height; the main wavelength uses 546.07 nm; and the horizontal axis represents the relative shift of the main wavelength, and the unit is micrometers (μm). Figure 7 Figure 8 ​​​​​​​It can be seen that the axial chromatic aberration of different wavelengths is controlled in a small range, which shows that the axial chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is well controlled, and the application requirement in a normal state can be met.

[0151] Figure 9 The ray fan diagram of the zoom lens provided by the embodiment one of the present application at the wide-angle end, Figure 10 The ray fan diagram of the zoom lens provided by the embodiment one of the present application at the long-focus end, the ray fan diagram is one of the evaluation methods commonly used by optical designers at present, the ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the axial chromatic aberration. In the diagram, the ray fan diagrams of the zoom lens at the wide-angle end and the long-focus end under the infinite distance are shown, the horizontal coordinate in a single diagram is the normalized beam aperture in the x direction and the y direction, and the vertical coordinate is the axial aberration, the vertical coordinate in a single diagram can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. In an ideal case, each curve should be completely coincident with the horizontal coordinate axis, at this time, all the light beams in the field of view are focused on the same point on the image plane. From Figure 9 and Figure 10 It can be seen that the axial chromatic aberration of different wavelengths is controlled in a small range, which shows that the axial chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is well controlled, and the application requirement in a normal state can be met.

[0152] Figure 11 The axial aberration curve diagram of the zoom lens provided by the embodiment one of the present application at the wide-angle end, Figure 12 The axial aberration curve diagram of the zoom lens provided by the embodiment one of the present application at the long-focus end, wherein the axial aberration curve of the lens can better represent the state of the spherical aberration and other parameters of the optical system under different wavelength conditions, the vertical direction in the diagram represents the normalization of the aperture, 0 represents on the optical axis, and the top represents the maximum pupil radius; the horizontal direction represents the offset amount relative to the ideal focus point, and the unit is millimeter (mm). From Figure 11 and Figure 12 It can be seen that the axial chromatic aberration of different wavelengths is controlled in a small range, which shows that the axial chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is well controlled, and the application requirement in a normal state can be met.

[0153] Embodiment two

[0154] As shown in Figure 3 and Figure 4 The zoom lens provided by the embodiment two of the present application comprises, in sequence along the optical axis from the object plane to the image plane, a focusing lens group G1, a zoom lens group G2 and a fixed lens group G3.

[0155] The fixed lens group G3 is fixedly arranged, and the focusing lens group G1 and the zoom lens group G2 are arranged to move along the optical axis direction.

[0156] The focusing lens group G1 comprises a first lens L1, a second lens L2, a third lens L3 and a fourth lens L4 arranged in sequence from the object plane to the image plane.

[0157] The zoom lens group G2 comprises a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a ninth lens L9 arranged in sequence from the object plane to the image plane.

[0158] The fixed lens group G3 comprises a tenth lens L10.

[0159] The sixth lens L6 and the seventh lens L7 form a cemented lens group g1, the diaphragm STO is located in the optical path between the fifth lens L5 and the sixth lens L6, and the flat glass CG is located on the image side of the tenth lens L10.

[0160] Table 5 details the specific optical physical parameters of each lens in the zoom lens provided in the second embodiment of the present application in a feasible implementation manner, and the zoom lens in Table 5 corresponds to the zoom lens shown in Table 1. Figure 3 and Figure 4 The zoom lens shown in Table 2.

[0161] Table 5: Design values of optical physical parameters of the zoom lens

[0162] Surface number Surface type Curvature radius Thickness Material (nd) Material (vd) 1 Sphere 102.321 0.500 1.70 55.53 2 Sphere 9.851 3.000 3 Asphere 11.493 1.600 1.54 55.71 4 Asphere 11.132 2.442 5 Asphere 9.924 1.405 1.54 55.71 6 Asphere 5.028 1.197 7 Asphere 29.304 2.620 1.66 20.38 8 Asphere -61.620 Zoom interval 1 9 Asphere 8.167 5.000 1.50 81.56 10 Asphere -93.994 0.869 STO Sphere INF -0.809 12 Sphere 14.678 1.199 1.85 30.06 13 Sphere 6.196 3.002 1.46 90.27 14 Sphere -553.446 0.080 15 Asphere 8.447 4.000 1.64 23.92 16 Asphere 6.010 1.499 17 Asphere 15.993 2.218 1.54 55.71 18 Asphere 43.204 Zoom interval 2 19 Asphere -21.292 1.485 1.63 24.64 20 Asphere -12.796 2.800 CG Sphere INF 0.700 1.52 64.20 22 Sphere INF 1.300 IMA Sphere INF 0.000

[0163] The surface numbers in Table 5 are numbered according to the surface order of each lens, wherein "1" represents the object side surface of the first lens, "2" represents the image side surface of the first lens, and the like; "STO" represents the diaphragm of the zoom lens; the radius of curvature represents the bending degree of the corresponding lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, wherein "INF" indicates that the surface is a flat surface with an infinite radius of curvature; the thickness represents the center axis distance from the current surface to the next surface; the material (nd) is the refractive index, which represents the deflection ability of the material between the current surface and the next surface to the light; the space represents that the current position is air with a refractive index of 1; the material (vd) is the Abbe number, which represents the chromatic dispersion characteristics of the material between the current surface and the next surface to the light; "IMA" represents the image plane of the zoom lens.

[0164] Table 6 shows the numerical values of the zoom interval of the zoom lens in Table 5 at the wide-angle end and the telephoto end.

[0165] The zoom interval is the interval value of the lens at the wide-angle end and the telephoto end.

[0166] Table 6: Design values of the zoom interval of the zoom lens

[0167] Wide angle end Telephoto end Zoom interval 1 23.3351 0.2845 Zoom interval 2 0.4866 21.1348

[0168] In this embodiment, the aspherical conic coefficient of the aspherical lens in the zoom lens can be defined by the following aspherical formula, but is not limited to the following representation:

[0169]

[0170] Where Z is the axial distance from the vertex of the surface at a position perpendicular to the optical axis at a height r; c represents the curvature at the vertex of the aspherical surface; k is the fitting conic coefficient; a2, a4, a6, a8, a 10 a 12 and a 14 For the higher-order aspheric coefficients corresponding to the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth orders of aspheric surfaces, a i r i These can be combined to form higher-order terms for the corresponding aspherical surfaces.

[0171] For example, Table 7 details the aspherical conic coefficients of each lens in this embodiment two according to a feasible implementation.

[0172] Table 7 Design values ​​of aspheric conic coefficient for each lens in zoom lenses.

[0173]

[0174]

[0175] The k value in Table 7 represents the magnitude of the best-fit conic coefficient for the aspherical surface. The zoom lens of this second embodiment can achieve the following technical specifications:

[0176] Table 8 Technical Specifications of Zoom Lenses

[0177]

[0178]

[0179] Figure 13 This is a transverse chromatic aberration diagram of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention. Figure 14 This is a transverse chromatic aberration diagram of a zoom lens at the telephoto end provided in Embodiment 2 of the present invention, wherein... Figure 13 and Figure 14 The diagram shows the transverse chromatic aberration curves of a zoom lens at infinity at both the wide-angle and telephoto ends. The vertical axis represents the field of view, with 0 indicating the optical axis. The vertex on the vertical axis represents the maximum image height. The dominant wavelength is 546.07 nm, and the horizontal axis represents the offset relative to the dominant wavelength, expressed in micrometers (μm). Figure 13 andFigure 14 It can be seen that the axial chromatic aberration of different wavelengths is controlled in a small range, which shows that the axial chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is well controlled, and the application requirement in a normal state can be met.

[0180] Figure 15 The ray fan diagram of the zoom lens provided by the second embodiment of the present application at the wide-angle end, Figure 16 The ray fan diagram of the zoom lens provided by the second embodiment of the present application at the long-focus end, the ray fan diagram is one of the commonly used evaluation methods by optical designers at present, the ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the axial chromatic aberration. In the diagram, the ray fan diagrams of the zoom lens at the wide-angle end and the long-focus end under the infinite distance are shown, the horizontal coordinate in a single diagram is the normalized beam aperture in the x direction and the y direction, and the vertical coordinate is the axial aberration, the vertical coordinate in a single diagram can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. In an ideal case, each curve should be completely coincident with the horizontal coordinate axis, at this time, all the light beams in the field of view are focused on the same point on the image plane. From Figure 15 and Figure 16 It can be seen that the axial chromatic aberration of different wavelengths is controlled in a small range, which shows that the axial chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is well controlled, and the application requirement in a normal state can be met.

[0181] Figure 17 The axial aberration curve diagram of the zoom lens provided by the second embodiment of the present application at the wide-angle end, Figure 18 The axial aberration curve diagram of the zoom lens provided by the second embodiment of the present application at the long-focus end, the axial aberration curve of the lens can better represent the state of the spherical aberration and other parameters of the optical system under different wavelength conditions, the vertical direction in the diagram represents the normalization of the aperture, 0 represents on the optical axis, and the top represents the maximum pupil radius; the horizontal direction represents the offset amount relative to the ideal focus point, and the unit is millimeter (mm). From Figure 17 and Figure 18 It can be seen that the axial chromatic aberration of different wavelengths is controlled in a small range, which shows that the axial chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is well controlled, and the application requirement in a normal state can be met.

[0182] Embodiment three

[0183] As shown in Figure 5 and Figure 6 The zoom lens provided by the third embodiment of the present application comprises, in sequence along the optical axis from the object plane to the image plane, a focusing lens group G1, a zoom lens group G2 and a fixed lens group G3.

[0184] The fixed lens group G3 is fixedly arranged, and the focusing lens group G1 and the zoom lens group G2 are arranged to move along the optical axis direction.

[0185] The focusing lens group G1 includes a first lens L1, a second lens L2, a third lens L3 and a fourth lens L4 arranged in sequence from an object plane to an image plane.

[0186] The zoom lens group G2 includes a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a ninth lens L9 arranged in sequence from the object plane to the image plane.

[0187] The fixed lens group G3 includes a tenth lens L10.

[0188] The sixth lens L6 and the seventh lens L7 form a cemented lens group g1, and a flat glass CG is located on the image side of the tenth lens L10.

[0189] Table 9 details the specific optical physical parameters of each lens in the zoom lens provided by the third embodiment of the present application in a feasible implementation manner, and the zoom lens in Table 9 corresponds to the zoom lens shown in Table 8. Figure 5 and Figure 6 .

[0190] Table 9: Design values of optical physical parameters of the zoom lens

[0191]

[0192]

[0193] The surface number in Table 9 is numbered according to the surface order of each lens, wherein "1" represents the object side surface of the first lens, "2" represents the image side surface of the first lens, and the like; "STO" represents the diaphragm of the zoom lens; the curvature radius represents the bending degree of the corresponding lens surface, the positive value represents that the surface is bent to the image side, and the negative value represents that the surface is bent to the object side, wherein "INF" indicates that the surface is a plane, and the curvature radius is infinite; the thickness represents the central axis distance from the current surface to the next surface; the material (nd) is the refractive index, which represents the deflection ability of the material between the current surface and the next surface to the light; the space represents that the current position is air, and the refractive index is 1; the material (vd) is the Abbe number, which represents the dispersion characteristics of the material between the current surface and the next surface to the light; the space represents that the current position is air; and "IMA" represents the image plane of the zoom lens.

[0194] Table 10 represents the numerical values of the zoom interval of the zoom lens in Table 9 at the wide-angle end and the long-focus end.

[0195] Wherein, the zoom interval is the interval value of the lens at the wide-angle end and the long-focus end.

[0196] Table 10 Design values of zoom interval of the zoom lens

[0197] Wide angle end Telephoto end Zoom interval 1 23.6551 0.2499 Zoom interval 2 0.1389 20.6992

[0198] In the present embodiment, the aspheric conic coefficients of the aspheric lenses in the zoom lens can be defined by the following aspheric formula, but are not limited to the following representation:

[0199]

[0200] wherein Z is the axial distance of the curved surface at a position along the optical axis and perpendicular to the optical axis height r to the vertex of the surface; c represents the curvature at the vertex of the aspheric surface; k is the fitting conic coefficient; a2, a4, a6, a8, a10, a12, and a14 are the high-order aspheric coefficients of the second order, the fourth order, the sixth order, the eighth order, the tenth order, the twelfth order, and the fourteenth order of the corresponding aspheric surface, respectively; and a2r, a4r, a6r, a8r, a10r, a12r, and a14r are the high-order terms of the corresponding aspheric surface. 10 12 14 i i

[0201] For example, Table 11 details the aspheric conic coefficients of each lens in the present embodiment three in a possible implementation.

[0202] Table 11 Design values of aspheric conic coefficients of each lens in the zoom lens

[0203]

[0204]

[0205] The value of k in Table 11 represents the numerical value of the best fitting conic coefficient of the aspheric surface.

[0206] The zoom lens of the present embodiment three can achieve the following technical indexes:

[0207] Table 12 Technical indexes of the zoom lens

[0208] Wide angle end Telephoto end Image surface size (mm) Φ8.812 Φ8.812 Focal length (mm) 4.754 23.789 Waveband (nm) 436-850 436-850 Total optical length (mm) 60.3873 57.5424

[0209] Figure 19 The sagittal chromatic aberration diagram of the zoom lens provided by the present embodiment three at the wide-angle end is shown in FIG. 6, Figure 20 The sagittal chromatic aberration diagram of the zoom lens provided by the present embodiment three at the long-focus end is shown in FIG. 7, wherein, Figure 19 Figure 20 ​​​​​​The vertical axial chromatic aberration curves of the zoom lens at the wide-angle end and the long-focus end are shown, the vertical direction represents the field of view, 0 represents on the optical axis, and the top of the vertical direction represents the maximum image height; the main wavelength uses 546.07 nm, the horizontal direction represents the offset of the relative main wavelength, and the unit is microns (μm). It can be seen from the figures that Figure 19 and Figure 20 It can be seen that the vertical axial chromatic aberration of different wavelengths is controlled in a small range, which shows that the vertical axial chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is well controlled, and can meet the application requirements under the normal state.

[0210] Figure 21 The ray fan diagram of the zoom lens provided by the third embodiment of the present application at the wide-angle end, Figure 22 The ray fan diagram of the zoom lens provided by the third embodiment of the present application at the long-focus end, the ray fan diagram is one of the commonly used evaluation methods by optical designers at present, and the ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also represent the size of the vertical axial chromatic aberration. In the figures, the ray fan diagrams of the zoom lens at the wide-angle end and the long-focus end at infinity are shown, the horizontal coordinate of a single figure is the normalized beam aperture in the x direction and the y direction, and the vertical coordinate is the vertical axial aberration. The vertical coordinate in a single image can also represent the maximum dispersion range of the light beam on the ideal image plane. In an ideal case, each curve should be completely coincident with the horizontal coordinate axis, at which time all the light beams in the field of view are focused on the same point on the image plane. From the figures Figure 21 and Figure 22 It can be seen that the vertical axial aberration of each wavelength of the zoom optical system is well corrected, in addition, the curves of each color are not obviously dispersed, which shows that the zoom optical system also has good correction for chromatic aberration, and can meet the use requirements of the zoom optical system.

[0211] Figure 23 The axial aberration curve of the zoom lens provided by the third embodiment of the present application at the wide-angle end, Figure 24 The axial aberration curve of the zoom lens provided by the third embodiment of the present application at the long-focus end, wherein the axial aberration curve of the lens can better represent the state of the spherical aberration and other parameters of the optical system under different wavelength conditions, the vertical direction in the figure represents the normalization of the aperture, 0 represents on the optical axis, and the top represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus point, and the unit is millimeters (mm). From the figures Figure 23 and Figure 24 It can be seen that the axial aberration of different wavelengths 0.3-1.0 normalized apertures is within a reasonable range, in addition, there is no obvious chromatic aberration between visible light and infrared light at the 0.5-0.9 pupil position, which realizes the effect of clear image in the full wavelength band.

[0212] In order to make the above-mentioned embodiments more clear, Table 13 details the specific optical physical parameters of each lens in the zoom lens provided by the first to third embodiments of the present application.

[0213] Table 13 Design values of optical physical parameters of the zoom lens

[0214]

[0215]

[0216] The above detailed description does not constitute a limitation on the protection scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A zoom lens, characterized in that, It includes a focusing lens group, a zoom lens group, and a fixed lens group arranged sequentially along the optical axis from the object plane to the image plane; The fixed lens group is fixedly installed, while the focusing lens group and the zoom lens group are movable along the optical axis. The focusing lens group has negative optical power, the zoom lens group has positive optical power, and the fixed lens group has positive optical power; The focusing lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged sequentially from the object plane to the image plane; the first lens has negative optical power, the second lens has positive optical power, the third lens has negative optical power, and the fourth lens has positive optical power. The zoom lens group includes a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially from the object plane to the image plane; the fifth lens has positive optical power, the sixth lens has negative optical power, the seventh lens has positive optical power, the eighth lens has negative optical power, and the ninth lens has positive optical power. The fixed lens group includes a tenth lens, which has positive optical power; The zoom lens has 10 lenses with optical power. The focal length of the focusing lens group is F1, the focal length of the zoom lens group is F2, the focal length of the fixed lens group is F3, and the focal length of the zoom lens at the telephoto end is F1. -0.51≤F1 / FT≤-0.49; 0.51≤F2 / FT≤0.53; 2.10≤F3 / FT≤7.

80.

2. The zoom lens according to claim 1, characterized in that, The zoom lens also includes an aperture stop, which is located in the optical path between the fifth lens and the sixth lens.

3. The zoom lens according to claim 1, characterized in that, The sixth lens and the seventh lens form a cemented lens group.

4. The zoom lens according to claim 1, characterized in that, The maximum movable distance of the zoom lens group is S2, the distance from the center of the optical axis on the object side of the first lens to the image plane when the zoom lens is at the telephoto end is TTLT, and the distance from the center of the optical axis on the image side of the tenth lens to the image plane is BFL. 0.34≤S2 / TTLT≤0.36, 4.3≤S2 / BFL≤4.

4.

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

6. The zoom lens according to claim 1, characterized in that, The focal length of the tenth lens is EFL10, and the focal length of the zoom lens at the wide-angle end is FW. 10.0≤EFL10 / FW≤38.

50.

7. The zoom lens according to claim 1, characterized in that, The total focal length of the eighth lens and the ninth lens is EFL89, and the focal length of the zoom lens group is F2. 4.99 < EFL89 / F2 < 7.

10.

8. The zoom lens according to claim 1, characterized in that, The zoom lens has a focal length of FW at the wide-angle end and a focal length of FT at the telephoto end. 4.9≤FT / FW≤5.

1.

9. The zoom lens according to claim 1, characterized in that, The object-side surface of the first lens is convex, and the image-side surface is concave. The object-side surface of the second lens is convex, and the image-side surface is concave. The object-side surface of the third lens is a central convex surface, and the image-side surface is a central concave surface; The object-side surface of the fourth lens is convex, and the image-side surface is also convex. The object-side surface of the fifth lens is convex. The object-side surface of the sixth lens is convex, and the image-side surface is concave. The object-side surface of the seventh lens is convex. The object-side surface of the eighth lens is convex, and the image-side surface is concave. The object-side surface of the ninth lens is convex. The object-side surface of the tenth lens is convex, and the image-side surface is concave.

Images