Zoom optical system and security lens

Abstract

The invention discloses a zoom optical system and a security lens, and relates to the technical field of optics, the zoom optical system is provided with an object side and an image side which are oppositely arranged along the direction of an optical axis, and the zoom optical system comprises a first lens group, a diaphragm, a second lens group and an image surface which are sequentially arranged from the object side to the image side; wherein the focal power of the first lens group is negative, the focal power of the second lens group is positive, and at least one of the first lens group and the second lens group can move along the direction of the optical axis, so that the zoom optical system is zoomed. Through reasonable arrangement of structures and positions of the first lens group with negative focal power and the second lens group with positive focal power, the zoom optical system has the effects of large target surface, large aperture and small size.

Description

Technical Field

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

[0002] With the development of the security industry, the requirements for zoom lens performance are getting higher and higher. As the security monitoring system develops towards high definition, intelligence and concealment, zoom lens, as a core optical component, needs to meet the performance requirements of large aperture, large target area and small size at the same time.

[0003] However, existing technologies face multiple contradictions in this regard. In order to improve the imaging quality in low-light environments (such as night monitoring), existing security lenses usually adopt a design with a larger aperture (F number ≤ 1.8), but a large aperture requires a complex optical structure (such as increasing the number of lenses or aspherical lenses), which results in a significant increase in the size of the lens and makes it difficult to strike a balance between a large aperture and a small size. In addition, in order to adapt to high-resolution sensors, existing technologies need to expand the image surface coverage, but a large target surface design will aggravate the astigmatism and field curvature problems of the edge field of view, and cannot meet market demand. Summary of the invention

[0004] The main purpose of the present invention is to provide a zoom optical system and a security lens, aiming to provide a zoom optical system with a large target surface, a large aperture and a small volume.

[0005] To achieve the above object, the present invention provides a zoom optical system, wherein the zoom optical system has an object side and an image side that are arranged opposite to each other along an optical axis direction, and the zoom optical system comprises a first lens group, an aperture, a second lens group, and an image plane that are sequentially arranged from the object side to the image side;

[0006] Wherein, at least one of the first lens group and the second lens group can move along the optical axis direction to enable the zoom optical system to zoom.

[0007] In one embodiment, the focal length of the zoom optical system at the wide angle end is F W , the focal length F of the first lens group 100 is negative, the focal length F of the second lens group 200 is positive; the focal length satisfies:

[0008] 0.1<|F W / F 100 |<0.55, 0.1<|F W / F 200 |<1.2.

[0009] In one embodiment, the first lens group includes a first lens, a second lens, and a third lens arranged in sequence from the object side to the image side along the optical axis;

[0010] The first lens has a negative optical power, the second lens has a negative optical power, and the third lens has a positive optical power.

[0011] In one embodiment, the focal length of the first lens group is F 100 , the focal length of the first lens is F 1 , the focal length of the second lens is F2, the focal length of the third lens is F 3 , the focal length satisfies:

[0012] 0.82<|F 100 / F 1 |<1.11,0.59<|F 100 / F 2 |<0.80,0.56<|F 100 / F 3 |<0.76.

[0013] In one embodiment, the second lens group includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens arranged in sequence from the object side to the image side along the optical axis;

[0014] Among them, the optical focal power of the fourth lens is positive, the optical focal power of the fifth lens is negative, the optical focal power of the sixth lens is positive, the optical focal power of the seventh lens is negative, the optical focal power of the eighth lens is positive, the optical focal power of the ninth lens is negative, the optical focal power of the tenth lens is positive, and the optical focal power of the eleventh lens is negative.

[0015] In one embodiment, the focal length of the second lens group is F 200 , the focal length of the fourth lens is F 4 , the focal length of the fifth lens is F 5 , the focal length of the sixth lens is F 6 , the focal length of the seventh lens is F 7 , the focal length of the eighth lens is F 8 , the focal length of the ninth lens is F 9 , the focal length of the tenth lens is F 10 , the focal length of the eleventh lens is F 11 , the focal length satisfies:

[0016] 0.57<|F 200 / F 4 |<0.77,3.00<|F 200 / F 5 |<4.06, 0.97<|F 200 / F 6 |<1.31,0.76<|F 200 / F 7 |<1.03, 0.95<|F 200 / F 8 |<1.28,1.87<|F 200 / F 9 |<2.52,17.75<|F 200 / F 10 |<24.01,31.06<|F 200 / F 11 |<42.03.

[0017] In one embodiment, the first lens group includes a first lens, a second lens, and a third lens arranged in sequence from the object side to the image side along the optical axis, and the second lens and the third lens are cemented together; and / or,

[0018] The second lens group includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens arranged in sequence from the object side to the image side along the optical axis, the fifth lens and the sixth lens are cemented together, and the seventh lens, the eighth lens and the ninth lens are cemented together.

[0019] In one implementation, the fourth lens, the tenth lens, and the eleventh lens are aspherical lenses.

[0020] In one embodiment, the zoom optical system further includes a filter, and the filter is disposed between the second lens group and the image plane along the optical axis and is disposed close to the image plane.

[0021] The present invention further provides a security lens, comprising a zoom optical system, wherein the zoom optical system has an object side and an image side that are arranged opposite to each other along an optical axis direction, and the zoom optical system comprises a first lens group, an aperture, a second lens group, and an image plane that are sequentially arranged from the object side to the image side;

[0022] Wherein, at least one of the first lens group and the second lens group can move along the optical axis direction to enable the zoom optical system to zoom.

[0023] In the technical solution of the present invention, at least one of the first lens group and the second lens group moves along the optical axis toward the image side, and different positions of the two lens groups correspond to different overall focal lengths, so that the zoom optical system changes continuously from the wide-angle end to the telephoto end to achieve zooming; the aperture stop is arranged between the first lens group and the second lens group, which can adjust the field of view size, block the far-axis light, avoid the far-axis light from affecting the imaging quality, improve the image quality, and make the lens have a large light throughput, and thus have a night vision function; through the reasonable arrangement of the structure and position of the first lens group with negative optical focal length and the second lens group with positive optical focal length, the zoom optical system has the effects of large target surface, large aperture and small volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 the structures shown in these drawings without paying creative work.

[0025] Figure 1 A schematic structural diagram of an embodiment of a zoom optical system provided by the present invention;

[0026] Figure 2 for Figure 1 Schematic diagram of the field curvature / distortion curve of a medium zoom optical system at the wide-angle end;

[0027] Figure 3 for Figure 1 Schematic diagram of the field curvature / distortion curve of a medium zoom optical system at the telephoto end;

[0028] Figure 4 for Figure 1 Vertical chromatic aberration diagram of the medium zoom optical system at the wide-angle end;

[0029] Figure 5 for Figure 1 Vertical chromatic aberration diagram of the medium zoom optical system at the telephoto end.

[0030] Description of Figure Numbers:

[0031] 100. Zoom optical system; 1. First lens group; 11. First lens; 12. Second lens; 13. Third lens; 2. Second lens group; 21. Fourth lens; 22. Fifth lens; 23. Sixth lens; 24. Seventh lens; 25. Eighth lens; 26. Ninth lens; 27. Tenth lens; 28. Eleventh lens; 3. Diaphragm; 4. Filter; 5. Image plane.

[0032] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] The present invention provides a zoom optical system 100 .

[0037] First of all, it should be noted that 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 certain lens, and can also be used to characterize a system formed by multiple lenses (i.e., a lens group).

[0038] See also Figure 1In one embodiment of the present invention, the zoom optical system 100 has an object side and an image side which are arranged opposite to each other along the optical axis direction. The zoom optical system 100 includes a first lens group 1, an aperture 3, a second lens group 2 and an image plane 5 which are arranged in sequence from the object side to the image side; wherein the first lens group 1 has a negative focal power, and the second lens group 2 has a positive focal power, and at least one of the first lens group 1 and the second lens group 2 can move along the optical axis direction to enable the zoom optical system 100 to zoom.

[0039] In the technical solution of the present invention, at least one of the first lens group 1 and the second lens group 2 moves along the optical axis toward the image side, and different positions of the two lens groups correspond to different overall focal lengths, so that the zoom optical system 100 changes continuously from the wide-angle end to the telephoto end to achieve zooming; the aperture 3 is arranged between the first lens group 1 and the second lens group 2, and can adjust the field of view, block the far-axis light, avoid the far-axis light from affecting the imaging quality, improve the image quality, and make the lens have a large light throughput; through the reasonable arrangement of the structure and position of the first lens group 1 with negative optical focal power and the second lens group 2 with positive optical focal power, the zoom optical system 100 has the effects of large target surface, large aperture and small volume.

[0040] In one embodiment of the present invention, the zoom optical system 100 also includes a filter 4, which is arranged between the second lens group 2 and the image plane 5 along the optical axis and is arranged close to the image plane 5. By setting the filter 4, the filter 4 can filter out stray light and prevent the stray light from reaching the image plane 5 and interfering with normal visible light imaging, thereby improving the imaging quality.

[0041] Specifically, in one embodiment of the present invention, the focal length of the zoom optical system at the wide-angle end is FW, and the focal length of the first lens group 1 is F 100 is negative, the focal length F of the second lens group 2 200 is positive; the focal length satisfies: 0.1<|F W / F 100 |<0.55, 0.1<|FW / F 200 |<1.2; By conditionally limiting the focal length of the wide-angle end of the optical system and the focal length ratio of each lens group, the optical system can achieve a small volume and a larger zoom adjustment range to meet the requirements of shooting different scenes.

[0042] In one embodiment of the present invention, the first lens group 1 includes a first lens, a second lens 12, and a third lens 13 arranged in sequence from the object side to the image side along the optical axis; wherein the object side surface of the first lens is convex, which can introduce more light; the object side surface of the second lens 12 is concave, and the image side surface is concave; the object side surface of the third lens 13 is convex, and the image side surface is convex. By such an arrangement, the concave and convex sides of the second lens 12 and the third lens 13 complement each other, fit more closely, and have a more compact structure; in addition, it is also ensured that the optical power of the second lens 12 is negative and the optical power of the third lens 13 is positive, which controls the trend of light and improves resolution. By limiting the positive and negative optical powers of the first lens, the second lens 12, and the third lens 13 in the first lens group 1, the height of the light entering the rear group is reduced, and the aberration of the off-axis system is reduced.

[0043] Further, in an embodiment of the present invention, the focal length of the first lens group 1 is F100, the focal length of the first lens is F1, the focal length of the second lens 12 is F2, the focal length of the third lens 13 is F3, and the focal lengths satisfy: 0.82<|F 100 / F 1 |<1.11,0.59<|F 100 / F 2 |<0.80,0.56<|F 100 / F 3 |<0.76. . The lens resolution is improved by conditionally limiting the focal length ratio of each lens and the first lens group 1.

[0044] In addition, in one embodiment of the present invention, the second lens group 2 includes a fourth lens 21, a fifth lens 22, a sixth lens 23, a seventh lens 24, an eighth lens 25, a ninth lens 26, a tenth lens 27 and an eleventh lens 28 arranged in sequence from the object side to the image side along the optical axis; wherein the fourth lens 21 has a positive focal power, the fifth lens 22 has a negative focal power, the sixth lens 23 has a positive focal power, the seventh lens 24 has a negative focal power, the eighth lens 25 has a positive focal power, the ninth lens 26 has a negative focal power, the tenth lens 27 has a positive focal power, and the eleventh lens 28 has a negative focal power. By limiting the positive and negative focal powers of the lenses, the residual spherical aberration of the system is corrected, and at the same time, the light height of the off-axis field of view can be increased, so that the system has a larger target surface. In one embodiment, the target surface of the zoom optical system can reach φ10.6mm.

[0045] Furthermore, the focal length of the second lens group 2 is F 200 , the focal length of the fourth lens 21 is F 4 , the focal length of the fifth lens 22 is F 5 , the focal length of the sixth lens 23 is F6 , the focal length of the seventh lens 24 is F 7 , the focal length of the eighth lens 25 is F 8 , the focal length of the ninth lens 26 is F 9 , the focal length of the tenth lens 27 is F 10 , the focal length of the eleventh lens 28 is F 11 , the focal length satisfies: 0.57<|F 200 / F 4 |<0.77,3.00<|F 200 / F 5 |<4.06, 0.97<|F 200 / F 6 |<1.31,0.76<|F 200 / F 7 |<1.03, 0.95<|F 200 / F 8 |<1.28,1.87<|F 200 / F 9 |<2.52,17.75<|F 200 / F 10 |<24.01,31.06<|F 200 / F 11 |<42.03; By conditionally limiting the focal length ratio of each lens and the second lens group 2, the lens resolution is improved.

[0046] Specifically, in one embodiment of the present invention, the specific relationship between the focal length of the zoom optical system, the focal length of each lens group and the focal length of each lens is shown in Table 1 below.

[0047] Table 1

[0048]

[0049] In addition, in one embodiment of the present invention, the first lens group 1 includes a first lens, a second lens 12, and a third lens 13 arranged in sequence from the object side to the image side along the optical axis, and the second lens 12 and the third lens 13 are glued together; the first lens group 1 uses a single lens and two spherical lenses glued together for use, which can not only correct the chromatic aberration of the zoom optical system 100 well, but also reduce the surface sensitivity, thereby ensuring the high resolution of the system.

[0050] In addition, in one embodiment of the invention, the second lens group 2 includes a fourth lens 21, a fifth lens 22, a sixth lens 23, a seventh lens 24, an eighth lens 25, a ninth lens 26, a tenth lens 27, and an eleventh lens 28 arranged in sequence from the object side to the image side along the optical axis direction. The fifth lens 22 and the sixth lens 23 are glued together, and the seventh lens 24, the eighth lens 25 and the ninth lens 26 are glued together. By arranging the fifth lens 22 and the sixth lens 23 to be glued together, chromatic aberration is reduced while correcting light, and then the seventh lens 24, the eighth lens 25 and the ninth lens 26 are glued together, so that aberration and chromatic aberration are further reduced, thereby improving imaging quality.

[0051] It can be understood that the cemented lenses of the above two lens groups can be selected alone, or the above cemented lenses can be used in both lens groups to further improve the imaging quality.

[0052] Specifically, in an embodiment of the present invention, the fourth lens 21 , the tenth lens 27 and the eleventh lens 28 are aspherical lenses.

[0053] It can be understood that the characteristics of aspherical lenses are: the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike spherical lenses with constant curvature from the center of the lens to the periphery of the lens, aspherical lenses have better curvature radius characteristics and have the advantages of improving distortion aberration and improving astigmatism aberration. After using aspherical lenses, the aberrations that occur during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens.

[0054] Specifically, in one embodiment of the present invention, the surface shape of the aspheric lens in the optical system should satisfy the following equation:

[0055]

[0056] Among them, c is the curvature corresponding to the radius; y is the radial coordinate (its unit is the same as the lens length unit); k is the conic quadratic curve coefficient, and A, B, C, D, E, F, G... represent the second-order, fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order... aspheric coefficients respectively.

[0057] More specifically, in one embodiment of the present invention, the even-order coefficients of each aspherical surface are shown in Table 2 below, where A=0.

[0058] Table 2

[0059]

[0060] The above parameters can be used to accurately set the shape and size of the aspheric surfaces on the front and back of the lens, which can effectively correct symmetrical aberrations such as spherical aberration and field curvature.

[0061] In addition, in one embodiment of the present invention, the 11th lens 28 is provided with a vignetting setting on the edge of the mirror surface. It should be noted that vignetting refers to the phenomenon that when light enters the optical system from the edge, the light beam is partially blocked due to the physical limitations of the optical elements (such as the edge of the lens, the aperture, the frame, etc.). This phenomenon will cause the light intensity at the edge of the image to weaken, thereby producing a dark corner effect. By providing vignetting on the edge of the mirror surface of the 11th lens 28, the peripheral stray light can be blocked without affecting the brightness of the image plane, so that the center and edge of the image plane can maintain the same resolution.

[0062] Specifically, in one embodiment of the present invention, the parameters of the zoom optical system are shown in Table 3 below.

[0063] Table 3

[0064]

[0065]

[0066] It should be noted that the thickness in Table 2 refers to the distance from the center of the surface to the next surface along the optical axis direction. Taking the first lens 11 as an example, the thickness of the object side of the first lens 11 refers to the distance from the center of the first lens 11, that is, the thickness of the first lens 11; the thickness of the image side of the first lens 11 refers to the distance from the center of the image side of the first lens 11 to the center of the object side of the second lens 12, that is, the air gap between the first lens 11 and the second lens 12.

[0067] In addition, during the zooming process, the magnification data of the zoom optical system at the wide-angle end and the telephoto end are shown in Table 3 below.

[0068] Table 3

[0069]

[0070] It should be noted that the data in Table 3 represent the distance between the surface and the next surface during zooming, in millimeters (mm). In particular, the data of the image side of the eleventh lens refers to the distance between the image side of the eleventh lens and the object side of the filter 4 during zooming.

[0071] Figure 2 FIG. 4 is a schematic diagram of a field curvature / distortion curve at a wide angle end according to an embodiment of the present invention. Figure 3 FIG. 1 is a schematic diagram of a field curvature / distortion curve at the telephoto end of an embodiment of the present invention. Figure 4 is a vertical axis chromatic aberration diagram at a wide angle end according to an embodiment of the present invention, Figure 5 FIG. 1 is a diagram of vertical axial chromatic aberration at the telephoto end according to an embodiment of the present invention.

[0072] Depend on Figure 2-5It can be seen that the fixed-focus optical system provided by this embodiment has good imaging capability.

[0073] In one embodiment of the present invention, the total optical length TTL of the optical system satisfies: TTL≤51.4 mm, wherein the total optical length refers to the distance from one surface of the first lens to the image plane, so that the zoom optical system can achieve a small volume.

[0074] It can be understood that the light carrying the information of the subject can pass through the first lens 11, the second lens 12, the third lens 13, the aperture 3, the fourth lens 21, the fifth lens 22, the sixth lens 23, the seventh lens 24, the eighth lens 25, the ninth lens 26, the tenth lens 27, the eleventh lens 28, the filter 4 in sequence and finally form an image on the image plane 5.

[0075] The present invention further proposes a security lens, which includes a zoom optical system. The specific structure of the zoom optical system refers to the above-mentioned embodiment. Since the security lens adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0076] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A zoom optical system, characterized in that: The zoom optical system has an object side and an image side which are arranged opposite to each other along the optical axis direction, and the zoom optical system comprises a first lens group, an aperture, a second lens group and an image plane which are arranged in sequence from the object side to the image side; The optical power of the first lens group is negative, and the optical power of the second lens group is positive. At least one of the first lens group and the second lens group can move along the optical axis to enable the zoom optical system to zoom.

2. The zoom optical system according to claim 1, wherein: The focal length of the zoom optical system at the wide angle end is F W , the focal length F of the first lens group 100 is negative, the focal length F of the second lens group 200 is positive; the focal length satisfies: 0.1<|F W / F 100 |<0.55,0.1<|F W / F 200 |<1.2。 3. The zoom optical system according to claim 1, wherein: The first lens group includes a first lens, a second lens, and a third lens arranged in sequence from the object side to the image side along the optical axis; The first lens has a negative optical power, the second lens has a negative optical power, and the third lens has a positive optical power.

4. The zoom optical system according to claim 3, wherein: The focal length of the first lens group is F 100 , the focal length of the first lens is F1, the focal length of the second lens is F2, the focal length of the third lens is F3, and the focal lengths satisfy: 0.82<|F 100 / F1|<1.11,0.59<|F 100 / F2|<0.80,0.56<|F 100 / F3|<0.76。 5. The zoom optical system according to claim 1, wherein: The second lens group includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens which are sequentially arranged from the object side to the image side along the optical axis direction; Among them, the optical focal power of the fourth lens is positive, the optical focal power of the fifth lens is negative, the optical focal power of the sixth lens is positive, the optical focal power of the seventh lens is negative, the optical focal power of the eighth lens is positive, the optical focal power of the ninth lens is negative, the optical focal power of the tenth lens is positive, and the optical focal power of the eleventh lens is negative.

6. The zoom optical system according to claim 5, wherein: The focal length of the second lens group is F 200 The focal length of the fourth lens is F4, the focal length of the fifth lens is F5, the focal length of the sixth lens is F6, the focal length of the seventh lens is F7, the focal length of the eighth lens is F8, the focal length of the ninth lens is F9, and the focal length of the tenth lens is F 10 , the focal length of the eleventh lens is F 11 , the focal length satisfies: 0.57<|F 200 / F4|<0.77,3.00<|F 200 / F5|<4.06,0.97<|F 200 / F6|<1.31,0.76<|F 200 / F7|<1.03,0.95<|F 200 / F8|<1.28,1.87<|F 200 / F9|<2.52,17.75<|F 200 / F 10 |<24.01,31.06<|F 200 / F 11 |<42.03。 7. The zoom optical system according to claim 1, wherein: The first lens group comprises a first lens, a second lens, and a third lens arranged in sequence from the object side to the image side along the optical axis, and the second lens and the third lens are cemented together; and / or, The second lens group includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens arranged in sequence from the object side to the image side along the optical axis, the fifth lens and the sixth lens are cemented together, and the seventh lens, the eighth lens and the ninth lens are cemented together.

8. The zoom optical system according to claim 1, wherein: The fourth lens, the tenth lens, and the eleventh lens are aspherical lenses.

9. The zoom optical system according to claim 1, wherein: The zoom optical system further includes a filter, which is disposed between the second lens group and the image plane along the optical axis and close to the image plane.

10. A security lens, characterized in that: Comprising the zoom optical system as claimed in any one of claims 1 to 9.

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