Zoom lens

Abstract

The zoom lens comprises a focusing lens group, a zoom lens group and a fixed lens group which are sequentially arranged from an object plane to an image plane along an optical axis, the focusing lens group has negative focal power, the zoom lens group has positive focal power, and the fixed lens group has positive focal power. The focusing lens group comprises a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged from an object plane to an image plane; the zoom lens group comprises a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens which are sequentially arranged from the object plane to the image plane; the fixed lens group includes a tenth lens. According to the zoom lens provided by the embodiment of the invention, a three-component structure is adopted, ten lenses are used, the number of the lenses in the three lens groups is set, and the focal power matching of the three lens groups and the ten lenses is further limited, so that the high-image-quality zoom lens which is small in size, large in aperture, infrared and confocal at high and low temperatures is realized, and the zoom lens can be matched with a 1 / 1.8 ''chip for use.

Description

Technical Field

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

[0002] In the field of security, zoom lenses have been widely used due to their advantages of long shooting distance and wide shooting angle. With the development of technology, cameras are gradually moving towards miniaturization and refinement, which also puts forward more stringent 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” chip is difficult to use in a wide range of environments, and traditional zoom lenses also have problems such as small aperture, large size, and non-confocality in infrared and high and low temperatures. Summary of the invention

[0004] The present invention provides a zoom lens to realize a high-image-quality zoom lens with a small size, a large aperture, infrared and high and low temperature confocality, and can be used in conjunction with a 1 / 1.8" chip.

[0005] The present invention provides a zoom lens, comprising a focus lens group, a zoom lens group and a fixed lens group which are sequentially arranged along an optical axis from an object plane to an image plane;

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

[0007] 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;

[0008] The focusing lens group comprises a first lens, a second lens, a third lens and a fourth lens arranged in sequence from the object plane to the image plane; the first lens has a negative optical power, the second lens has a positive optical power, the third lens has a negative optical power, and the fourth lens has a positive optical 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 sequence from the object plane to the image plane; the fifth lens has positive focal power, the sixth lens has negative focal power, the seventh lens has positive focal power, the eighth lens has negative focal power, and the ninth lens has positive focal power;

[0010] The fixed lens group includes a tenth lens having positive optical power.

[0011] Optionally, the zoom lens further includes an aperture stop, and the aperture stop is located in the optical path between the fifth lens and the sixth lens.

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

[0013] Optionally, the focal length of the focus 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, and when the zoom lens is at the telephoto end, the distance from the optical axis center of the object side surface of the first lens to the image plane is TTLT, and the distance from the optical axis center of the image side surface of the tenth lens to the image plane 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 convex, and the image side surface is concave;

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

[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 convex, and the image side surface is convex;

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

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

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

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

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

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

[0037] The zoom lens provided in the embodiment of the present invention adopts a three-component structure and uses 10 lenses. By setting the number of lenses in 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 band is achieved under a 1 / 1.8″ target surface. 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, thereby realizing a high-image quality zoom lens with a small size, a large aperture, infrared and high and low temperature confocality, and can be used with a 1 / 1.8″ chip.

[0038] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 A schematic diagram of the structure of a zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of the structure of a zoom lens at the telephoto end provided by an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of the structure of another zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0043] Figure 4 A schematic diagram of the structure of another zoom lens at the telephoto end provided by an embodiment of the present invention;

[0044] Figure 5 A schematic diagram of the structure of another zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0045] Figure 6 A schematic diagram of the structure of another zoom lens at the telephoto end provided by an embodiment of the present invention;

[0046] Figure 7 A vertical axis chromatic aberration diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end;

[0047] Figure 8 A vertical axis chromatic aberration diagram of the zoom lens provided in the first embodiment of the present invention at the telephoto end;

[0048] Fig. 9 A light fan diagram of the zoom lens at the wide-angle end provided in the first embodiment of the present invention;

[0049] Fig.10 A light fan diagram of the zoom lens at the telephoto end provided by the first embodiment of the present invention;

[0050] Fig.11 An axial aberration curve diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end;

[0051] Fig.12 An axial aberration curve diagram of the zoom lens at the telephoto end provided by the first embodiment of the present invention;

[0052] Fig.13 A vertical axis chromatic aberration diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end;

[0053] Fig.14 A vertical axis chromatic aberration diagram of the zoom lens provided in the second embodiment of the present invention at the telephoto end;

[0054] Fig.15 A light fan diagram of the zoom lens at the wide-angle end provided in the second embodiment of the present invention;

[0055] Fig.16 A light fan diagram of the zoom lens at the telephoto end provided by the second embodiment of the present invention;

[0056] Fig.17 An axial aberration curve diagram of the zoom lens at the wide-angle end provided in the second embodiment of the present invention;

[0057] Fig.18 An axial aberration curve diagram of the zoom lens at the telephoto end provided by the second embodiment of the present invention;

[0058] Fig.19 A vertical axis chromatic aberration diagram of the zoom lens provided in Embodiment 3 of the present invention at the wide-angle end;

[0059] Fig. 20 A vertical axis chromatic aberration diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention;

[0060] Fig.21 A light fan diagram of the zoom lens at the wide-angle end provided in the third embodiment of the present invention;

[0061] Fig. 22 A light fan diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention;

[0062] Fig.23 This is an axial aberration curve diagram of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

[0063] Fig.24 This is an axial aberration curve diagram of the zoom lens provided in Embodiment 3 of the present invention at the telephoto end. DETAILED DESCRIPTION

[0064] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0065] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

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

[0067] Specifically, Figure 1-Figure 6 As shown, the zoom lens provided by the embodiment of the present invention is arranged in sequence from the object side to the image side along the optical axis: a focus lens group G1 with negative optical power, a zoom lens group G2 with positive optical power, and a fixed lens group G3 with positive optical power.

[0068] The focus lens group G1 , the zoom lens group G2 and the fixed lens group G3 may be arranged in one lens barrel (not shown in the figure), but it is not limited thereto.

[0069] Furthermore, the position of the fixed lens group G3 can be fixed in the lens barrel so that the fixed lens group G3 does not move relative to the image plane.

[0070] The focus lens group G1 and the zoom lens group G2 can move back and forth along the optical axis in the lens barrel, wherein moving the zoom lens group G2 can achieve a zooming effect, and moving the focus lens group G1 can achieve a focusing effect. By changing the positions of the focus lens group G1 and the zoom lens group G2 on the optical axis, the zoom lens can be switched between the wide-angle end and the telephoto end.

[0071] Among them, in the process of achieving zooming by changing the positions of the focus 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. At the wide-angle end and the telephoto end, the zoom lens has different focal lengths and optical focal powers.

[0072] Specifically, the focal length is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam, and it characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal length, the stronger the ability to bend light, and the smaller the absolute value of the focal length, the weaker the ability to bend light. When the focal length is a positive number, the refraction of light is convergent; when the focal length is a negative number, the refraction of light is divergent. The focal length can be used to characterize a refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a lens, or can be used to characterize a system formed by multiple lenses (i.e., a lens group).

[0073] In the embodiment of the present invention, the focal length of the focusing lens group G1 is negative, which can ensure that the light forms a larger aperture before entering the aperture, thereby increasing the aperture of the lens, which can not only improve the performance of the lens under low light conditions, but also enhance the brightness and clarity of the image.

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

[0075] The optical focal length of the fixed lens group G3 is positive, and the light adjusted by the first two lens groups can be finally focused onto the imaging sensor, ensuring that the light can be accurately focused when reaching the imaging sensor to achieve clear imaging.

[0076] Among them, the focusing lens group G1, the zoom lens group G2 and the fixed lens group G3 adopt a negative-positive-positive optical focal power combination. The light can be reasonably converged and diverged when passing through each lens group, ensuring that the light will not be deflected too much, but pass through the entire lens system smoothly. At the same time, it can also ensure that the light has a larger aperture before entering the aperture. Even if the aperture opening is large, the light can pass smoothly without causing aberrations due to sudden contraction, thereby allowing the lens to work at a larger aperture, which is conducive to increasing the aperture of the lens.

[0077] Continue to refer Figure 1-Figure 6 The number of lenses with optical focal length 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 optical focal length, a second lens L2 with positive optical focal length, a third lens L3 with negative optical focal length, and a fourth lens L4 with positive optical focal length.

[0078] The first lens L1 has a negative optical power, which can expand the light beam of the incident light, so that more light can enter the subsequent lens group, thereby facilitating the realization of a larger aperture.

[0079] The second lens L2 to the fourth lens L4 adopt a positive-negative-positive optical power combination, which is beneficial to controlling the light path so that it passes through the subsequent lens groups more smoothly.

[0080] Continue to refer Figure 1-Figure 6 The number of lenses with optical focal length 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 optical focal length, a sixth lens L6 with negative optical focal length, a seventh lens L7 with positive optical focal length, an eighth lens L8 with negative optical focal length, and a ninth lens L9 with positive optical focal length.

[0081] Among them, the fifth lens L5 to the ninth lens L9 adopt a positive-negative-positive-negative-positive optical power combination, which not only helps to smoothly transmit light, but also can adjust the aberration of the lens to a certain extent, especially in the area near the aperture. The fifth lens L5 has positive optical power and plays a role in converging light. It cooperates with the focusing lens group G1 to avoid reflection and other forms of stray light at the aperture position, ensure the aberration balance and high and low temperature performance stability of the lens, ensure that the lens can maintain stable resolution in different temperature environments, and maintain aberration balance during zooming, ensuring the image quality consistency of the lens at different focal lengths and improving the overall imaging quality.

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

[0083] Continue to refer Figure 1-Figure 6 The number of lenses with optical power in the fixed lens group G3 may be one, wherein the fixed lens group G3 may be composed of a tenth lens L10 with positive optical power.

[0084] Among them, the tenth lens L10 is the last lens in the entire lens and is located closest to the image plane (imaging sensor). The tenth lens L10 has positive optical power and plays the role of converging light. It can finally focus the light adjusted by the first two lens groups (i.e., focus lens group G1 and zoom lens group G2) onto the imaging sensor, ensuring that the light can be incident at the best angle when reaching the sensor, reducing light loss and chromatic aberration, and at the same time eliminating the high-level aberrations of the lens and expanding the lens target surface (size), so that the lens can match a larger imaging sensor, which is beneficial to improving image quality and meeting the usage requirements in more application scenarios.

[0085] In the embodiment of the present invention, a three-component structure is adopted, and 10 lenses are used. By setting the number of lenses in the three lens groups and further limiting the optical focal length 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 band is achieved under a 1 / 1.8″ target surface. 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, thereby realizing a high-image quality zoom lens with a small size, large aperture, infrared and high and low temperature confocality, and can be used with a 1 / 1.8″ chip.

[0086] As a feasible implementation method, continue to refer to Figure 3 and Figure 4 The zoom lens also includes an aperture STO, which is located in the optical path between the fifth lens L5 and the sixth lens L6.

[0087] Among them, the aperture STO is set in the optical path between the fifth lens L5 and the sixth lens L6, so that it is located inside the zoom lens group G2, which can ensure that the light can be effectively controlled when passing through the aperture, avoiding unnecessary stray light and reflection. At the same time, when the zoom lens group G2 moves, the aperture STO will move with the zoom lens group G2, so that the movable range of the zoom lens group G2 can be significantly increased, which can not only improve the zoom ratio, but also ensure clear imaging within the entire zoom range.

[0088] As a feasible implementation method, continue to refer to Figure 1-Figure 6 , the sixth lens L6 and the seventh lens L7 form a cemented lens group g1.

[0089] Among them, when light passes through the aperture, certain high-order aberrations will be generated, and the cemented lens can have a certain inhibitory effect on high-order phase aberrations such as chromatic aberration.

[0090] like Figure 1-Figure 6 As shown, the sixth lens L6 and the seventh lens L7 are glued together, so that the lens that the light passes through first after passing through the aperture STO is the glued lens group g1, so that the chromatic aberration of the light passing through the aperture STO can be corrected well, ensuring that the lens forms a clear image in the 436nm to 850nm band. At the same time, it can also avoid the aberration being too large and unable to be corrected when the light propagates to the rear end of the lens, for example, it can avoid the situation where the chromatic aberration is superimposed at the rear end of the lens, resulting in the need for a large amount of high Abbe number materials at the rear end to correct the chromatic aberration, thereby saving costs while ensuring the relative illumination and imaging quality of the lens.

[0091] At the same time, gluing the sixth lens L6 and the seventh lens L7 together can also effectively reduce the air gap between the sixth lens L6 and the seventh lens L7, thereby further reducing the overall length of the lens.

[0092] In addition, gluing the sixth lens L6 and the seventh lens L7 together can also reduce the air interface, thereby reducing the reflection loss, and can also reduce the number of assembly components between the sixth lens L6 and the seventh lens L7, simplifying the assembly procedure in the lens manufacturing process, reducing costs, and reducing the influence of lens tolerances such as tilt / eccentricity generated during the assembly process on the zoom lens, thereby improving the stability of the zoom lens.

[0093] As a feasible implementation, the focal length of the focus 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. Among them, -0.51≤F1 / FT≤-0.49; 0.51≤F2 / FT≤0.53; 2.10≤F3 / FT≤7.80.

[0094] Among them, by further limiting the focal length of each lens group, it is possible to achieve a reasonable combination of the optical power of each lens, so that light can pass through the zoom lens more smoothly, and at the same time, the high-level aberrations of the zoom lens can be corrected to a greater extent, thereby improving the imaging quality.

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

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

[0097] When the zoom lens is at the telephoto end, the distance TTLT from the optical axis center of the object-side surface of the first lens L1 to the image plane refers to the total optical length of the zoom lens at the telephoto end.

[0098] The distance BFL from the optical axis center of the image-side surface of the tenth lens L10 to the image plane is referred to as the back focus of the zoom lens.

[0099] In this embodiment, the maximum movable distance S2 of the zoom lens group G2 and the total optical length TTLT of the zoom lens at the telephoto end are set to 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, ensuring that the zoom lens group G2 can move effectively during the zooming process to achieve the zoom function from wide angle to telephoto, thereby achieving a larger zoom ratio without significantly increasing the total length of the lens, so that the lens can provide high-quality imaging within a wider focal length range.

[0100] At the same time, by controlling the position of the zoom lens group G2, the focus lens group G1 can be indirectly controlled to move back and forth, so that the movement of the zoom lens group G2 and the focus lens group G1 will not occupy too much of the total length of the lens, greatly reducing the size of the lens and expanding 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 invention includes at least three spherical lenses, which helps to reduce costs and is easy to manufacture. The spherical lens uses a glass lens, which can have a higher refractive index and lower dispersion, and can provide stable optical performance in a wide band, especially in the visible light and infrared light bands. At the same time, the glass material has a low thermal expansion coefficient and can maintain stable resolution in different temperature environments, which is particularly suitable for scenes that require all-weather work.

[0103] Furthermore, there is at least one plastic aspherical lens in the focus lens group G1 and the zoom lens group G2 of the zoom lens, which can effectively reduce aberrations, especially high-order aberrations 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 a lens is the aberration of the lens itself. In a zoom lens, since each lens group needs to move relative to each other, controlling only the lens aberration in a certain state cannot meet the demand for clear imaging within the entire zoom range.

[0105] In this embodiment, aspheric lenses are added to each lens group, so that the aberration of each lens configuration is in a relatively balanced state, so that the aberration can be effectively corrected in the entire zoom range, ensuring that good imaging quality can be maintained at different focal lengths. At the same time, the evenly distributed aspheric lenses can better coordinate the optical performance of the entire lens system, reduce local aberration accumulation, and achieve clear imaging in the entire band through overall lens correction.

[0106] It should be noted that aspherical lenses generally have a good corrective effect on lens aberrations. The use of a plastic aspherical lens in the tenth lens L10 can control the high-order aberrations of light at the rear end of the lens, further improving image quality. In addition, the use of an aspherical lens at the rear end of the lens can more finely control the exit angle of light in the lens, expand the lens target surface (size), and improve the matching degree between the lens and the imaging sensor.

[0107] From a cost perspective, aspherical lenses use plastic lenses, which can reduce costs on the one hand and reduce the weight of the lens on the other hand, making it meet a wider range of usage requirements.

[0108] In addition, glass and plastic are two types of materials that can compensate for each other. Using a combination of glass and plastic lenses in the lens can better balance the resolution of the lens under high and low temperature conditions, ensuring that the lens maintains good resolution in a wide temperature range of -40°C to 80°C, and achieving high and low temperature confocality.

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

[0110] Among them, 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 aberrations of light at the rear end of the lens can be controlled to further improve the image quality; at the same time, the exit angle of light in the lens can also be controlled more finely to ensure that the light can be incident at the optimal angle when it reaches the sensor, reduce light loss and chromatic aberration, expand the lens target surface (size), so that the lens can match a larger imaging sensor and meet the usage requirements in more application scenarios.

[0111] As a feasible implementation manner, 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<EFL89 / F2<7.10.

[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 formed by combining 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 forward trend of light can be controlled to a large extent, thereby ensuring image quality while maximizing the target surface and meeting more chip usage requirements.

[0114] In addition, by controlling the optical focal length of the rear lens in the zoom lens group G2, the risk of stray light can be minimized and the imaging quality of the lens can be improved.

[0115] As a feasible implementation manner, 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; wherein 4.9≤FT / FW≤5.1.

[0116] Among them, 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 telephoto 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 usage requirements under more conditions.

[0117] As a feasible implementation manner, 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 a central convex surface, and the image side surface is a central concave surface. 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] Among them, the surface shape of the lens affects the propagation direction of light and determines how the light bends when passing through the lens, which in turn affects the maximum aperture and light transmittance of the lens, as well as the quality and characteristics of the imaging.

[0119] In this embodiment, by reasonably matching the surface shapes of each lens, while meeting the optical focal requirements of each lens and achieving the required optical performance indicators (such as large target surface, small size, large aperture, infrared and high and low temperature confocality, etc.), the path of light can be made smoother when passing through the entire zoom lens, reducing unnecessary reflections and absorption, which is beneficial to improving light throughput and imaging quality.

[0120] Continue to refer Figure 1-Figure 6 As a feasible implementation, the zoom lens may further include a flat glass CG, which is located on the image side of the tenth lens L10. The flat glass CG can protect a photosensitive chip in the imaging sensor, wherein the photosensitive chip is used to convert the light signal collected by the zoom lens into an electrical signal, which can then be used to generate a digital image or video from the electrical signal through a series of processing steps, thereby ensuring the imaging effect of the zoom optical system.

[0121] In some cases, the flat glass CG may also be used to correct specific aberrations or filter out unnecessary light, which is not specifically limited in the embodiment of the present invention.

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

[0123] Embodiment 1

[0124] like Figure 1 and Figure 2 As shown, the zoom lens provided in the first embodiment of the present invention comprises a focus lens group G1, a zoom lens group G2 and a fixed lens group G3 which are sequentially arranged along the optical axis from the object plane to the image plane.

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

[0126] The focusing lens group G1 includes a first lens L1, a second lens L2, a third lens L3 and a fourth lens L4 which are arranged in sequence from an object plane to an image plane.

[0127] 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 which are arranged in sequence from the object plane to the image plane.

[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 the flat glass CG is located on the image-side surface of the tenth lens L10.

[0130] Table 1 describes in detail the specific optical and physical parameters of each lens in the zoom lens provided in Example 1 of the present invention in a feasible implementation manner. The zoom lens in Table 1 corresponds to Figure 1 and Figure 2 Zoom lens shown.

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

[0132]

[0133]

[0134] The surface numbers in Table 1 are numbered according to the order of the surfaces of each lens, where "1" represents the object side of the first lens, "2" represents the image side of the first lens, and so on; "STO" represents the aperture of the zoom lens; the radius of curvature represents the degree of curvature 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, where "INF" indicates that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the material (nd) is the refractive index, which represents the light deflection ability of the material between the current surface and the next surface, and a blank space represents that the current position is air with a refractive index of 1; the material (vd) is the Abbe number, which represents the dispersion characteristics of the light between the current surface and the next surface, and a blank space represents that the current position is air; "IMA" represents the image surface of the zoom lens.

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

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

[0137] Table 2 Design values ​​of zoom intervals of zoom lenses

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

[0139] In this embodiment, the aspheric cone coefficient of the aspheric lens in the zoom lens can be defined by the following aspheric formula, but is not limited to the following expression method:

[0140]

[0141] Where Z is the axial distance from the surface at a height r perpendicular to the optical axis to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; k is the fitting cone coefficient; a2, a4, a6, a8, a 10 、a 12 and a 14 is the high-order aspheric coefficient of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth order corresponding to the aspheric surface, a i r i The combination becomes the high-order terms corresponding to the aspherical surface.

[0142] Exemplarily, Table 3 describes in detail the aspheric cone coefficients of each lens in the first embodiment in a feasible implementation manner.

[0143] Table 3 Design values ​​of aspheric cone coefficients of each lens in the zoom lens

[0144]

[0145]

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

[0147] The zoom lens of the first embodiment can achieve the following technical indicators:

[0148] Table 4 Technical specifications of zoom lenses

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

[0150] Figure 7 The vertical axis chromatic aberration diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end is shown in FIG. Figure 8 This is a vertical axis chromatic aberration diagram of the zoom lens at the telephoto end provided by the first embodiment of the present invention, wherein: Figure 7 and Figure 8 The vertical axis chromatic aberration curve of the zoom lens at the wide-angle end and the telephoto end at infinite object distance is shown. The vertical axis represents the field of view, 0 represents the optical axis, and the vertical axis vertex represents the maximum image height. The main wavelength is 546.07nm, and the horizontal axis represents the offset relative to the main wavelength in micrometers (μm). Figure 7 and Figure 8It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a small range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end and the telephoto end is well controlled and can meet the application requirements under normal conditions.

[0151] Fig. 9 This is a light fan diagram of the zoom lens at the wide-angle end provided in the first embodiment of the present invention. Fig.10 The light fan diagram of the zoom lens at the telephoto end provided in the first embodiment of the present invention is one of the evaluation methods commonly used by optical designers. The light fan diagram can not only reflect the monochromatic aberrations of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Among them, the figure shows the light fan diagram of the zoom lens at the wide-angle end and the telephoto end at infinite object distance. The horizontal axis in a single figure is the normalized beam aperture in the x-direction and the y-direction, and the vertical axis is the vertical axis aberration. The vertical axis in a single image can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. Ideally, each curve should completely coincide with the horizontal axis. At this time, all light rays in the field of view are focused on the same point on the image plane. By Fig. 9 and Fig.10 It can be seen that the vertical axis aberration of each wavelength of the zoom optical system is well corrected. In addition, the curves of each color do not have obvious dispersion, which shows that the zoom optical system also has good correction of chromatic aberration and can meet the use requirements of the zoom optical system.

[0152] Fig.11 This is an axial aberration curve diagram of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention, Fig.12 This is a graph of the axial aberration curve of the zoom lens at the telephoto end provided in the first embodiment of the present invention, wherein the axial aberration curve of the lens can better show the state of parameters such as spherical aberration of the optical system under different wavelength conditions. The vertical direction in the graph represents the normalization of the aperture, 0 represents the optical axis, and the vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Fig.11 and Fig.12 It can be seen that the axial aberrations of normalized apertures of different wavelengths from 0.3 to 1.0 are all within a reasonable range. In addition, at the pupil position of 0.5-0.9, there is no obvious chromatic aberration between visible light and infrared light, which meets the basic requirements for clear imaging at night and achieves clear imaging in the full band.

[0153] Embodiment 2

[0154] like Figure 3 and Figure 4 As shown, the zoom lens provided by the second embodiment of the present invention comprises a focus lens group G1, a zoom lens group G2 and a fixed lens group G3 which are sequentially arranged along the optical axis from the object plane to the image plane.

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

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

[0157] 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 which are arranged in sequence from the object plane to the image plane.

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

[0159] The sixth lens L6 and the seventh lens L7 form a cemented lens group g1, the aperture 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 describes in detail the specific optical and physical parameters of each lens in the zoom lens provided in Example 2 of the present invention in a feasible implementation manner. The zoom lens in Table 5 corresponds to Figure 3 and Figure 4 Zoom lens shown.

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

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

[0163] The surface numbers in Table 5 are numbered according to the order of the surfaces of each lens, where "1" represents the object side of the first lens, "2" represents the image side of the first lens, and so on; "STO" represents the aperture of the zoom lens; the radius of curvature represents the degree of curvature 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, where "INF" indicates that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the material (nd) is the refractive index, which represents the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air with a refractive index of 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 light, and a blank space represents that the current position is air; "IMA" represents the image surface of the zoom lens.

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

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

[0166] Table 6 Design values ​​of zoom intervals of zoom lenses

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

[0168] In this embodiment, the aspheric cone coefficient of the aspheric lens in the zoom lens can be defined by the following aspheric formula, but is not limited to the following expression method:

[0169]

[0170] Where Z is the axial distance from the surface at a height r perpendicular to the optical axis to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; k is the fitting cone coefficient; a2, a4, a6, a8, a 10 、a 12 and a 14 is the high-order aspheric coefficient of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth order corresponding to the aspheric surface, a i r i The combination becomes the high-order terms corresponding to the aspherical surface.

[0171] Exemplarily, Table 7 describes in detail the aspheric cone coefficient of each lens in the second embodiment in a feasible implementation manner.

[0172] Table 7 Design values ​​of aspheric cone coefficients of each lens in the zoom lens

[0173]

[0174]

[0175] The k value in Table 7 represents the numerical value of the best fitting cone coefficient of the aspheric surface. The zoom lens of the second embodiment can achieve the following technical indicators:

[0176] Table 8 Technical specifications of zoom lenses

[0177]

[0178]

[0179] Fig.13 The vertical axis chromatic aberration diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end is shown in FIG. Fig.14 This is a vertical axis chromatic aberration diagram of the zoom lens at the telephoto end provided by the second embodiment of the present invention, wherein: Fig.13 and Fig.14 The vertical axis chromatic aberration curve of the zoom lens at the wide-angle end and the telephoto end at infinite object distance is shown. The vertical axis represents the field of view, 0 represents the optical axis, and the vertical axis vertex represents the maximum image height. The main wavelength is 546.07nm, and the horizontal axis represents the offset relative to the main wavelength in micrometers (μm). Fig.13 and Fig.14 It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a small range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end and the telephoto end is well controlled and can meet the application requirements under normal conditions.

[0180] Fig.15 This is a light fan diagram of the zoom lens at the wide-angle end provided by the second embodiment of the present invention, Fig.16 The light fan diagram of the zoom lens at the telephoto end provided in the second embodiment of the present invention is one of the evaluation methods commonly used by optical designers. The light fan diagram can not only reflect the monochromatic aberrations of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Among them, the figure shows the light fan diagram of the zoom lens at the wide-angle end and the telephoto end at infinite object distance. The horizontal axis in a single figure is the normalized beam aperture in the x-direction and the y-direction, and the vertical axis is the vertical axis aberration. The vertical axis in a single image can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. Ideally, each curve should completely coincide with the horizontal axis. At this time, all light rays in the field of view are focused on the same point on the image plane. By Fig.15 and Fig.16 It can be seen that the vertical axis aberration of each wavelength of the zoom optical system is well corrected. In addition, the curves of each color do not have obvious dispersion, which shows that the zoom optical system also has good correction of chromatic aberration and can meet the use requirements of the zoom optical system.

[0181] Fig.17 The axial aberration curve diagram of the zoom lens at the wide-angle end provided in the second embodiment of the present invention is as follows: Fig.18 This is an axial aberration curve diagram of the zoom lens at the telephoto end provided in the second embodiment of the present invention, wherein the axial aberration curve of the lens can better show the state of parameters such as spherical aberration of the optical system under different wavelength conditions. The vertical direction in the figure represents the normalization of the aperture, 0 represents the optical axis, and the vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Fig.17 and Fig.18 It can be seen that the axial aberrations of normalized apertures of different wavelengths from 0.3 to 1.0 are all within a reasonable range. In addition, at the pupil position of 0.5-0.9, there is no obvious chromatic aberration between visible light and infrared light, which meets the basic requirements for clear imaging at night and achieves clear imaging in the full band.

[0182] Embodiment 3

[0183] like Figure 5 and Figure 6 As shown, the zoom lens provided by the third embodiment of the present invention comprises a focus lens group G1, a zoom lens group G2 and a fixed lens group G3 which are sequentially arranged along the optical axis from the object plane to the image plane.

[0184] The fixed lens group G3 is fixedly arranged, and the focus lens group G1 and the zoom lens group G2 are movably arranged 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 which are 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 which are 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 the flat glass CG is located on the image-side surface of the tenth lens L10.

[0189] Table 9 describes in detail the specific optical and physical parameters of each lens in the zoom lens provided in Example 3 of the present invention in a feasible implementation manner. The zoom lens in Table 9 corresponds to Figure 5 and Figure 6 Zoom lens shown.

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

[0191]

[0192]

[0193] The surface numbers in Table 9 are numbered according to the order of the surfaces of each lens, where "1" represents the object side of the first lens, "2" represents the image side of the first lens, and so on; "STO" represents the aperture of the zoom lens; The radius of curvature represents the degree of curvature 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, where "INF" indicates that the surface is a plane and the radius of curvature is infinite; Thickness represents the central axial distance from the current surface to the next surface; Material (nd) is the refractive index, which represents the ability of the material between the current surface and the next surface to deflect light, and a blank space represents that the current position is air with a refractive index of 1; Material (vd) is the Abbe number, which represents the dispersion characteristics of the material between the current surface and the next surface to light, and a blank space represents that the current position is air; "IMA" represents the image surface of the zoom lens.

[0194] Table 10 shows the values ​​of the zoom intervals of the zoom lens in Table 9 at the wide-angle end and the telephoto end.

[0195] The zoom interval refers to the different interval values ​​of the lens at the wide-angle end and the telephoto end.

[0196] Table 10 Design values ​​of zoom intervals of zoom lenses

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

[0198] In this embodiment, the aspheric cone coefficient of the aspheric lens in the zoom lens can be defined by the following aspheric formula, but is not limited to the following expression method:

[0199]

[0200] Where Z is the axial distance from the surface at a height r perpendicular to the optical axis to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; k is the fitting cone coefficient; a2, a4, a6, a8, a 10 、a 12 and a 14 is the high-order aspheric coefficient of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth order corresponding to the aspheric surface, a i r i The combination becomes the high-order terms corresponding to the aspherical surface.

[0201] Exemplarily, Table 11 describes in detail the aspheric cone coefficients of each lens in the third embodiment in a feasible implementation manner.

[0202] Table 11 Design values ​​of aspheric cone coefficients of each lens in zoom lens

[0203]

[0204]

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

[0206] The zoom lens of the third embodiment can achieve the following technical indicators:

[0207] Table 12 Technical specifications of zoom lenses

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

[0209] Fig.19 This is a vertical axis chromatic aberration diagram of the zoom lens provided in the third embodiment of the present invention at the wide-angle end, Fig. 20 This is a vertical axis chromatic aberration diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention, wherein: Fig.19 and Fig. 20The vertical axis chromatic aberration curve of the zoom lens at the wide-angle end and the telephoto end at infinite object distance is shown. The vertical axis represents the field of view, 0 represents the optical axis, and the vertical axis vertex represents the maximum image height. The main wavelength is 546.07nm, and the horizontal axis represents the offset relative to the main wavelength in micrometers (μm). Fig.19 and Fig. 20 It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a small range, indicating that the vertical chromatic aberration of the zoom lens at the wide-angle end and the telephoto end is well controlled and can meet the application requirements under normal conditions.

[0210] Fig.21 This is a light fan diagram of the zoom lens at the wide-angle end provided in the third embodiment of the present invention. Fig. 22 The light fan diagram of the zoom lens at the telephoto end provided in the third embodiment of the present invention is one of the evaluation methods commonly used by optical designers. The light fan diagram can not only reflect the monochromatic aberrations of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Among them, the figure shows the light fan diagram of the zoom lens at the wide-angle end and the telephoto end at infinite object distance. The horizontal axis in a single figure is the normalized beam aperture in the x-direction and the y-direction, and the vertical axis is the vertical axis aberration. The vertical axis in a single image can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. Ideally, each curve should completely coincide with the horizontal axis. At this time, all light rays in the field of view are focused on the same point on the image plane. By Fig.21 and Fig. 22 It can be seen that the vertical axis aberration of each wavelength of the zoom optical system is well corrected. In addition, the curves of each color do not have obvious dispersion, which shows that the zoom optical system also has good correction of chromatic aberration and can meet the use requirements of the zoom optical system.

[0211] Fig.23 This is an axial aberration curve diagram of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention, Fig.24 This is a graph of the axial aberration curve of the zoom lens at the telephoto end provided in the third embodiment of the present invention, wherein the axial aberration curve of the lens can better show the state of parameters such as spherical aberration of the optical system under different wavelength conditions. The vertical direction in the graph represents the normalization of the aperture, 0 represents the optical axis, and the vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Fig.23 and Fig.24 It can be seen that the axial aberrations of normalized apertures of different wavelengths from 0.3 to 1.0 are all within a reasonable range. In addition, at the pupil position of 0.5-0.9, there is no obvious chromatic aberration between visible light and infrared light, achieving a clear imaging effect in the full band.

[0212] In order to explain the above embodiments more clearly, Table 13 details the specific optical and physical parameters of each lens in the zoom lens provided in Embodiments 1 to 3 of the present invention.

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

[0214]

[0215]

[0216] The above specific implementations do not constitute a limitation on the protection scope of the present invention. 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 substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A zoom lens, characterized in that: It includes a focus lens group, a zoom lens group and a fixed lens group which are arranged in sequence from the object plane to the image plane along the optical axis; The fixed lens group is fixedly arranged, and the focus lens group and the zoom lens group are movably arranged along the optical axis direction; 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 comprises a first lens, a second lens, a third lens and a fourth lens arranged in sequence from the object plane to the image plane; the first lens has a negative optical power, the second lens has a positive optical power, the third lens has a negative optical power, and the fourth lens has a positive optical power; The zoom lens group comprises a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens arranged in sequence from the object plane to the image plane; the fifth lens has positive focal power, the sixth lens has negative focal power, the seventh lens has positive focal power, the eighth lens has negative focal power, and the ninth lens has positive focal power; The fixed lens group includes a tenth lens having positive optical power.

2. The zoom lens according to claim 1, wherein: The zoom lens further includes an aperture stop located in an optical path between the fifth lens and the sixth lens.

3. The zoom lens according to claim 1, wherein: The sixth lens and the seventh lens form a cemented lens group.

4. The zoom lens according to claim 1, wherein: The focal length of the focus 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; -0.51≤F1 / FT≤-0.49; 0.51≤F2 / FT≤0.53; 2.10≤F3 / FT≤7.

80.

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

4.

6. The zoom lens according to claim 1, wherein: 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.

7. The zoom lens according to claim 1, wherein: 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.

8. The zoom lens according to claim 1, wherein: 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.

9. The zoom lens according to claim 1, wherein: 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; 4.9≤FT / FW≤5.

1.

10. The zoom lens according to claim 1, wherein: 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 convex; The object side surface of the fifth lens is a convex surface; 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 a convex surface; 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 a convex surface; The object side surface of the tenth lens is convex, and the image side surface is concave.

Images