Zoom lens and monitoring camera device

Abstract

The application discloses a zoom lens and a monitoring camera equipment, the zoom lens comprises a shell and a lens group, the lens group comprises a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, a fourth lens group with positive refractive power and a fifth lens group with negative refractive power arranged in sequence from the object side to the image side, the first lens group and the fifth lens group are fixedly installed on the shell, and the second lens group, the third lens group and the fourth lens group are movably installed on the shell along the optical axis direction, in the technical scheme, the reasonable setting of the five lens groups and the conditional restriction of the wide-angle end focal length of the zoom lens and the focal length ratio of each lens group can solve the technical problem that the existing zoom lens cannot coexist with low cost, small caliber, wide angle, small distortion and large zooming.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical system design, in particular to a zoom lens applied to an outdoor monitoring system and a monitoring camera device. BACKGROUND

[0002] At present, the mainstream high-image-quality zoom monitoring lens on the market needs a lens with a large enough field of view to obtain a wider field of view, and the lens is often designed to have a wide-angle effect. The design concept of the lens with a wide-angle effect is to sacrifice the distortion of the lens to maximize the incoming light with great distortion, so that the image information of the edge area of the picture is severely compressed and cannot be distinguished, resulting in poor imaging visual quality.

[0003] In outdoor monitoring, in order to ensure that a large range of the monitored area can be clearly monitored, there is a high requirement for the distortion of the picture. The existing monitoring lens generally reduces the influence of distortion by using many glass aspherical lenses, but the manufacturing cost is high and cannot meet the market demand. SUMMARY

[0004] The main purpose of the present application is to provide a zoom lens and a monitoring camera device, which aims to solve the technical problem that the existing zoom lens cannot coexist with low cost, small aperture, wide angle, small distortion and large zoom.

[0005] To achieve the above purpose, the present application provides a zoom lens, which has an object side and an image side arranged opposite along the optical axis direction, and comprises:

[0006] a housing; and

[0007] a plurality of lens groups arranged in the housing, including a first lens group with positive focal power, a second lens group with negative focal power, a diaphragm, a third lens group with positive focal power, a fourth lens group with positive focal power, a fifth lens group with negative focal power, and a photosensitive chip arranged in sequence from the object side to the image side, wherein the first lens group and the fifth lens group are fixedly installed on the housing, the second lens group, the third lens group and the fourth lens group are movably arranged along the extension direction of the optical axis, the second lens group and the third lens group move cooperatively along the optical axis direction to adjust the focal length of the zoom lens, and the fourth lens group is movably arranged along the optical axis direction to focus the zoom lens.

[0008] Wherein, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, the focal length of the fifth lens group is f5, and the zoom lens satisfies the following conditions: 0.128 < fw / f1 < 0.173, and -0.825 < fw / f2 < -0.61, and 0.195 < fw / f3 < 0.264, and 0.272 < fw / f4 < 0.313, and -0.126 < fw / f5 < -0.093.

[0009] Optionally, the first lens group comprises, from the object side to the image side in order, a first lens with negative refractive power, a second lens with positive refractive power, a third lens with positive refractive power, and a fourth lens with positive refractive power.

[0010] The focal length of the first lens is f11, the focal length of the second lens is f12, the focal length of the third lens is f13, and the focal length of the fourth lens is f14, and the first lens group and the first lens, the second lens, the third lens, and the fourth lens satisfy the following conditions:

[0011] -0.529 < f1 / f11 < -0.391, and 0.468 < f1 / f12 < 0.633, and 0.378 < f1 / f13 < 0.511, and 0.438 < f1 / f14 < 0.593.

[0012] Optionally, the second lens group comprises, from the object side to the image side in order, a fifth lens with negative refractive power, a sixth lens with negative refractive power, and a seventh lens with positive refractive power, and the sixth lens is a glass aspherical lens.

[0013] The focal length of the fifth lens is f21, the focal length of the sixth lens is f22, and the focal length of the seventh lens is f23, and the second lens group and the fifth lens, the sixth lens, and the seventh lens satisfy the following conditions:

[0014] 0.764 < f2 / f21 < 1.033, and 0.393 < f2 / f22 < 0.531, and -0.424 < f2 / f23 < -0.313.

[0015] Optionally, the third lens group comprises, from the object side to the image side in order, an eighth lens with positive refractive power, a ninth lens with positive refractive power, a tenth lens with negative refractive power, and an eleventh lens with positive refractive power, and the eleventh lens is a glass aspherical lens.

[0016] A focal length of the eighth lens is f31, a focal length of the ninth lens is f32, a focal length of the tenth lens is f33, a focal length of the eleventh lens is f34, and the third lens group, the eighth lens, the ninth lens, the tenth lens, and the eleventh lens satisfy the following conditions:

[0017] 0.737 < f3 / f31 < 0.997, and 0.863 < f3 / f32 < 1.167, and -2.809 < f3 / f33 < -2.077, and 1.111 < f3 / f34 < 1.503.

[0018] Optionally, the fourth lens group comprises, in order from the object side to the image side, a twelfth lens with positive refractive power, a thirteenth lens with positive refractive power, and a fourteenth lens with negative refractive power.

[0019] A focal length of the twelfth lens is f41, a focal length of the thirteenth lens is f42, and a focal length of the fourteenth lens is f43, and the fourth lens group, the twelfth lens, the thirteenth lens, and the fourteenth lens satisfy the following conditions:

[0020] 0.353 < f4 / f41 < 0.477, and 0.698 < f4 / f42 < 0.944, and -0.218 < f4 / f43 < -0.161.

[0021] Optionally, the fifth lens group comprises, in order from the object side to the image side, a fifteenth lens with positive refractive power and a sixteenth lens with negative refractive power, and the sixteenth lens is a glass aspheric lens.

[0022] Optionally, the zoom lens satisfies the following condition: 0.317 < øL11 / TTL < 0.447;

[0023] wherein øL11 is an effective clear aperture of the first lens, and TTL is an optical total length of the zoom lens.

[0024] Optionally, the zoom lens satisfies the following condition: 0.233 < ΔZ1W-T / TTL < 0.329;

[0025] wherein ΔZ1W-T is a relative displacement of the second lens group when the zoom lens is at the wide-angle end position and when the zoom lens is at the telephoto end position, and TTL is an optical total length of the zoom lens. W-T

[0026] Optionally, the zoom lens satisfies the following condition: 0.099 < ΔZ2W-T / TTL < 0.14;

[0027] ​Wherein, ΔZ2W-T is the relative displacement of the third lens group when the zoom lens is at the wide-angle end position and the zoom lens is at the telephoto end position, and TTL is the total optical length of the zoom lens.

[0028] A monitoring camera device, comprising a zoom lens having an object side and an image side oppositely arranged along an optical axis direction, the zoom lens comprising:

[0029] A housing; and

[0030] A plurality of lens groups arranged in the housing, including a first lens group with positive refractive power, a second lens group with negative refractive power, a diaphragm, a third lens group with positive refractive power, a fourth lens group with positive refractive power, a fifth lens group with negative refractive power, and a photosensitive chip arranged in sequence from the object side to the image side, wherein the first lens group and the fifth lens group are fixedly installed on the housing, the second lens group, the third lens group, and the fourth lens group are movably arranged along the extension direction of the optical axis, the second lens group and the third lens group move cooperatively along the optical axis direction to adjust the focal length of the zoom lens, and the fourth lens group is movably arranged along the optical axis direction to focus the zoom lens.

[0031] Wherein, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the focal length of the fifth lens group is f5, and the zoom lens satisfies the following conditions: 0.128 < fw / f1 < 0.173, and -0.825 < fw / f2 < -0.61, and 0.195 < fw / f3 < 0.264, and 0.272 < fw / f4 ≤ 0.313, and -0.126 < fw / f5 < -0.093.

[0032] In the technical solution provided by this invention, the first lens group and the fifth lens group are fixedly installed in the housing, while the second lens group, the third lens group, and the fourth lens group are movably installed in the housing along the optical axis. The second and third lens groups are used for zooming, and the fourth lens group is used for focusing. The second and third lens groups move collaboratively along the optical axis to zoom the zoom lens from a wide-angle end to a telephoto end. Furthermore, the fourth lens group is driven by an external force to move along the optical axis in conjunction with the second and third lens groups. The zoom lens uses a focus adjustment mechanism that adjusts the position, imaging wavelength, and imaging object distance to maintain sharpness on the imaging surface during zooming. The first lens group has positive optical power, the second lens group has negative optical power, the third lens group has positive optical power, the fourth lens group has positive optical power, and the fifth lens group can have either positive or negative optical power. By rationally configuring the five lens groups and conditionally limiting the ratio of the wide-angle focal length to the focal length of each lens group, the technical problem of existing zoom lenses being unable to achieve low cost, small aperture, wide angle, low distortion, and large zoom simultaneously is solved. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the first embodiment of the zoom lens provided by the present invention when it is at the wide-angle end;

[0035] Figure 2 for Figure 1 A schematic diagram of the structure of a zoom lens at the intermediate magnification.

[0036] Figure 3 for Figure 1 A schematic diagram of the zoom lens in the telephoto end;

[0037] Figure 4 for Figure 1 Aberration diagram of a zoom lens at the wide-angle end;

[0038] Figure 5 for Figure 1 Field curvature diagram of a zoom lens at the wide-angle end;

[0039] Figure 6 for Figure 1Distortion map of the zoom lens in the present application at wide angle end;

[0040] Figure 7 For Figure 2 Spherical aberration map of the zoom lens in the present application at intermediate magnification;

[0041] Figure 8 For Figure 2 Curvature of field map of the zoom lens in the present application at intermediate magnification;

[0042] Figure 9 For Figure 2 Distortion map of the zoom lens in the present application at intermediate magnification;

[0043] Figure 10 For Figure 3 Aberration map of the zoom lens in the present application at telephoto end;

[0044] Figure 11 For Figure 3 Curvature of field map of the zoom lens in the present application at telephoto end;

[0045] Figure 12 For Figure 3 Distortion map of the zoom lens in the present application at telephoto end;

[0046] BRIEF DESCRIPTION OF DRAWINGS

[0047]

[0048] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative work under the premise that the specific working conditions are changed, belong to the scope of protection of the present application.

[0050] It should be noted that if the directionality indication is involved in the embodiments of the present application, the directionality indication is only used to explain the relative position relationship, movement condition and the like between the components in a certain specific posture, and if the specific posture is changed, the directionality indication is also changed accordingly.

[0051] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. For example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0052] At present, the mainstream high image quality zoom monitoring lens on the market needs a lens with a large enough field of view to obtain a wider field of view. The lens is often designed to have a wide-angle effect. The design concept of the lens with wide-angle effect is to sacrifice the distortion of the lens to maximize the incoming light with great distortion. Therefore, the image information of the edge area of the picture is severely compressed because of the huge deformation, which causes the imaging quality to be poor. In outdoor monitoring, in order to ensure that the large range of the monitored area can be clearly monitored, the distortion of the picture has a higher requirement. The existing monitoring lens generally reduces the influence of distortion by using many glass aspherical lenses, but the manufacturing cost is high and cannot meet the market demand.

[0053] The present application provides a zoom lens, which aims to improve the technical problem that wide angle and small distortion cannot coexist in the prior art. Please refer to Figures 1 to 12 , the specific embodiments of the zoom lens are shown in the drawings.

[0054] Figures 1 to 12 The first embodiment of the zoom lens provided by the present application.

[0055] Please refer to Figures 1 to 3The zoom lens has an object side and an image side arranged oppositely along an optical axis direction, and comprises a housing (not shown in the figure) and a plurality of lens groups, the housing is arranged along the optical axis direction, the lens groups comprise, from the object side to the image side, a first lens group 1 with positive focal power, a second lens group 2 with negative focal power, a diaphragm 6, a third lens group 3 with positive focal power, a fourth lens group 4 with positive focal power, a fifth lens group 5, and a photosensitive chip 8, and the focal power of the fifth lens group can be positive or negative, wherein the first lens group 1, the fifth lens group 5 and the photosensitive chip 8 are fixedly installed on the housing, the second lens group 2, the third lens group 3 and the fourth lens group 4 are movably installed on the housing along the optical axis direction, and the second lens group 2 and the third lens group 3 move cooperatively along the optical axis direction to make the zoom lens zoom, and the fourth lens group 4 moves along the optical axis direction to make the zoom lens focus, when the second lens group 2 and the third lens group 3 are driven by external force to move along the optical axis direction towards the image side, the zoom lens zooms from a wide-angle end to a telephoto end, and when the fourth lens group 4 is driven by external force to move along the optical axis direction corresponding to the positions, imaging wavelength and imaging object distance of the second lens group 2 and the third lens group 3, the zoom lens focuses to keep the imaging surface clear during zooming.

[0056] Moreover, the zoom lens satisfies the following conditions: 0.128 < fw / f1 < 0.173, and -0.825 < fw / f2 < -0.61, and 0.195 < fw / f3 < 0.264, and 0.272 < fw / f4 < 0.313, and -0.126 < fw / f5 < -0.093; wherein fw is the focal length of the zoom lens at the wide-angle end, f1 is the focal length of the first lens group 1, f2 is the focal length of the second lens group 2, f3 is the focal length of the third lens group 3, f4 is the focal length of the fourth lens group 4, and f5 is the focal length of the fifth lens group 5.

[0057] In the embodiment, the ratio of the focal length of the zoom lens at the wide-angle end to the focal length of each lens group is as follows: fw / f1 = 0.147; fw / f2 = -0.701; fw / f3 = 0.224; fw / f4 = 0.313; and fw / f5 = -0.107.

[0058] It should be noted that the second lens group 2, the third lens group 3 and the fourth lens group 4 can be driven by external force to move along the optical axis direction, wherein the external force driving can be driving motor driving or manual adjustment, which is not limited herein.

[0059] In the technical scheme provided by the present application, the first lens group 1 and the fifth lens group 5 are fixedly installed on the shell, and the second lens group 2, the third lens group 3 and the fourth lens group 4 are movably installed on the shell along the optical axis, wherein the second lens group 2 and the third lens group 3 are used for zooming, the fourth lens group 4 is used for focusing, the second lens group 2 and the third lens group 3 move along the optical axis to make the zoom lens zoom from the wide-angle end to the telephoto end, the fourth lens group 4 is driven by an external force to move along the optical axis to make the zoom lens keep the imaging surface clear during zooming, and the first lens group 1 has positive focal power, the second lens group 2 has negative focal power, the third lens group 3 has positive focal power, the fourth lens group 4 has positive focal power, and the fifth lens group 5 can have positive or negative focal power. Through reasonable arrangement of the five lens groups and conditional limitation of the wide-angle end focal length of the zoom lens and the focal length ratio of each lens group, the technical problem that the existing zoom lens cannot coexist with low cost, small aperture, wide angle, small distortion and large zooming is solved.

[0060] Specifically, the first lens group 1 comprises, in order from the object side to the image side, a first lens 11 with negative focal power, a second lens 12 with positive focal power, a third lens 13 with positive focal power, and a fourth lens 14 with positive focal power, and the first lens group 1 and the first lens 11, the second lens 12, the third lens 13 and the fourth lens 14 satisfy the following conditions: -0.529

[0061] More specifically, in the present embodiment, the first lens 11 is a convex-concave spherical lens with negative focal power, i.e. the object side surface of the first lens 11 is convex and the image side surface is concave, the second lens 12 is a convex-concave spherical lens with positive focal power, the third lens 13 is a convex-concave spherical lens with positive focal power, and the fourth lens 13 is a convex-concave spherical lens with positive focal power; and the focal length ratio of each lens in the first lens group is specifically as follows: f1 / f11=-0.449; f1 / f12=0.538; f1 / f13=0.435; f1 / f14=0.504;

[0062] Further, the first lens 11 and the second lens 12 are cemented to form a first cemented lens with positive focal power, and satisfy the following condition: 0.101 < f1 / f1112 < 0.075; wherein, f1 is the focal length of the first lens group 1, and f1112 is the focal length of the first cemented lens. In this way, the cemented lens is reasonably used, the optical element improves the image quality of the optical system, reduces the loss of light energy, increases the imaging clarity, protects the scale surface, and further optimizes the processing flow to meet the design requirements.

[0063] In the embodiment, the ratio of the first lens group 1 to the first cemented lens is specifically f1 / f1112 = 0.086.

[0064] Specifically, the second lens group 2 includes, from the object side to the image side, a fifth lens 21 with negative focal power, a sixth lens 22, and a seventh lens 23 with positive focal power, the sixth lens is a glass aspheric lens, and the focal power of the sixth lens can be positive or negative; and the second lens group 2 and the fifth lens 21, the sixth lens 22, and the seventh lens 23 satisfy the following conditions: 0.764 < f2 / f21 < 1.033, 0.393 < f2 / f22 < 0.531, and -0.424 < f2 / f23 < -0.313.

[0065] Wherein, f2 is the focal length of the second lens group 2, f21 is the focal length of the fifth lens 21, f22 is the focal length of the sixth lens 22, and f23 is the focal length of the seventh lens 23.

[0066] More specifically, in the embodiment, the fifth lens 21 is negative, the sixth lens 22 is a convex-concave spherical lens with negative focal power, and the seventh lens 23 is a convex-concave aspheric lens; the focal length ratio of the second lens group and each lens is as follows: f2 / f21 = 0.878; f2 / f22 = 0.451; and f2 / f23 = -0.36.

[0067] In particular, the third lens group 3 comprises, sequentially from the object side to the image side, an eighth lens 31 with positive refractive power, a ninth lens 32 with positive refractive power, a tenth lens 33 with negative refractive power, an eleventh lens 34 with positive refractive power, and the eleventh lens is a glass aspheric lens; and the third lens group 3 and the eighth lens 31, the ninth lens 32, the tenth lens 33, the eleventh lens 34 satisfy the following conditions: 0.737 < f3 / f31 < 0.997, and 0.863 < f3 / f32 < 1.167, and -2.809 < f3 / f33 < -2.077, and 1.111 < f3 / f34 < 1.503; wherein f3 is the focal length of the third lens group 3, f31 is the focal length of the ninth lens 31, f32 is the focal length of the tenth lens 32, and f33 is the focal length of the eleventh lens 33.

[0068] More specifically, in the present embodiment, the eighth lens 31 is a biconvex spherical lens with positive refractive power, the ninth lens 32 is a biconvex spherical lens with positive refractive power, the tenth lens 33 is a flat concave spherical lens with negative refractive power, and the eleventh lens 34 is a biconvex aspheric lens with positive refractive power; the focal length ratio of each lens in the third lens group 3 is as follows: f3 / f31 = 0.847; f3 / f32 = 0.992; f3 / f33 = -2.388; and f3 / f34 = 1.278.

[0069] In particular, the fourth lens group 4 comprises, sequentially from the object side to the image side, a twelfth lens 41 with positive refractive power, a thirteenth lens 42 with positive refractive power, and a fourteenth lens 43 with negative refractive power, and the fourth lens group 4 and the twelfth lens 41, the thirteenth lens 42, the fourteenth lens 43 satisfy the following conditions: 0.353 < f4 / f41 < 0.477, and 0.698 < f4 / f42 < 0.944, and -0.218 < f4 / f43 < -0.161; wherein f4 is the focal length of the fourth lens group 4, f41 is the focal length of the twelfth lens 42, f42 is the focal length of the thirteenth lens 42, f43 is the focal length of the fourteenth lens 43, f44 is the focal length of the fifteenth lens 44, and f45 is the focal length of the sixteenth lens 45.

[0070] More specifically, in the present embodiment, the twelfth lens 41 is a biconvex spherical lens with positive refractive power, the thirteenth lens 42 is a biconvex spherical lens with positive refractive power, and the fourteenth lens 43 is a biconcave-convex spherical lens with negative refractive power, and the fourth lens group 4 has a focal length ratio of each lens as follows: f4 / f41=0.406; f4 / f42=0.803; f4 / f43=-1.185.

[0071] Further, the thirteenth lens 42 and the fourteenth lens 43 form a second cemented lens by cementing, the second cemented lens has positive refractive power, and satisfies the following condition: 0.537

[0072] In the present embodiment, the specific ratio of the fourth lens group 4 and the second cemented lens is: f4 / f4344=0.617.

[0073] Specifically, in the present embodiment, the fifth lens group 5 includes a fifteenth lens 51 and a sixteenth lens 52, the sixteenth lens 52 is a glass aspheric lens, and the refractive power of the sixteenth lens 52 can be positive or negative.

[0074] More specifically, in the present embodiment, the fifteenth lens 51 is a concave-convex lens with positive refractive power, and the sixteenth lens 52 is a concave-convex lens with negative refractive power.

[0075] In this way, by reasonably allocating the refractive power of the lens, adjusting the shape and material of the glass, effectively correcting the chromatic aberration and secondary spectrum, and mutually compensating and offsetting the spherical aberration, coma, astigmatism and the like on each lens, a clear imaging effect is achieved, and the optimal correction of high-order aberration and chromatic aberration is realized.

[0076] It can be understood that the surface of the photosensitive chip 8 facing the object side is an imaging surface.

[0077] Specifically, the zoom lens further includes a diaphragm 6, and the diaphragm 6 is located between the second lens group 2 and the third lens group 3; that is, the diaphragm 6 is located between the seventh lens 23 and the eighth lens 31. In the present embodiment, the diaphragm 6 is an adjustable diaphragm, which can perform corresponding aperture scaling measures according to the change of the ambient light intensity, and the zoom lens satisfies the following condition: 0.419

[0078] In the embodiment, the ratio of the distance of the diaphragm 6 to the imaging surface to the total optical length of the zoom lens: L / TTL=0.505.

[0079] Specifically, in the embodiment, the zoom lens further comprises a filter, which is located between the fifth lens group 5 and the imaging surface, and the filter 7 is used to filter out unnecessary waveband light and stray light to reduce light noise and reduce the difficulty of subsequent photoelectric module processing part, and the filter can also be used to adjust the color degree of the final imaging object, thereby improving the imaging quality.

[0080] Specifically, the imaging surface can be understood as the surface of the photosensitive chip facing the object side, that is, the surface of the camera element such as CCD or CMOS, and more specifically, in the embodiment, the imaging surface is the surface of the CMOS solid-state camera element (the size of the CMOS in the embodiment is 1 / 1.8 inch H*V=7.8mm*4.38mm), and it can be understood that the light carrying the object information can pass through the first lens group 1, the second lens group 2, the diaphragm 6, the third lens group 3, the fourth lens group 4, the fifth lens group 5, the filter and finally image on the imaging surface.

[0081] Specifically, the zoom lens satisfies the following condition: 0.317<øL11 / TTL<0.447; wherein øL11 is the effective light aperture of the first lens 11, and TTL is the total optical length of the zoom lens.

[0082] In the embodiment, the ratio of the effective light aperture of the first lens 11 to the total optical length of the zoom lens: øL11 / TTL=0.371.

[0083] Specifically, the zoom lens satisfies the following condition: 0.233<ΔZ1W-T / TTL<0.329; wherein ΔZ1 W-T is the relative displacement of the second lens group when the zoom lens is at the wide-angle end position and when the zoom lens is at the telephoto end position, and TTL is the total optical length of the zoom lens.

[0084] In the embodiment, the ratio of the movement amount of the second lens group from the wide-angle end to the telephoto end of the zoom lens to the total optical length of the zoom lens: ΔZ1W-T / TTL=0.273;

[0085] Specifically, the zoom lens satisfies the following condition: 0.099 < ΔZ2W-T / TTL < 0.14; wherein ΔZ2W-T is the relative displacement of the third lens group when the zoom lens is at the wide-angle end position and the zoom lens is at the telephoto end position, and TTL is the total optical length of the zoom lens.

[0086] In the embodiment, the ratio of the moving amount of the third lens group when the zoom lens moves from the wide-angle end to the telephoto end to the total optical length of the zoom lens is ΔZ2W-T / TTL = 0.116.

[0087] Specifically, in the embodiment, the parameters of the zoom lens are as follows:

[0088] The wide-angle end focal length fw = 7.09 mm, the telephoto end focal length ft = 175.1 mm; the wide-angle end aperture number Fw = 1.6, the telephoto end aperture number Ft = 5.2; the wide-angle end horizontal field angle = 59°, the telephoto end half field angle = 2.5°; the optical distortion range is between -4.4% and 2%; the total optical length TTL of the zoom lens = 110 mm.

[0089] Specifically, in the embodiment, the refractive index, the radius of curvature, and the thickness interval of the lenses are as shown in the following table:

[0090] Table 1 Parameters of lenses

[0091]

[0092] Specifically, in the embodiment, the sixth lens 22, the eleventh lens 34, and the sixteenth lens 52 are aspherical glass lenses. The aspherical lenses have the following characteristics: the curvature continuously changes from the center of the lens to the periphery of the lens, which is different from the spherical lenses with constant curvature from the center of the lens to the periphery of the lens. The aspherical lenses have better radius of curvature characteristics, have the advantages of improving the distortion aberration and improving the astigmatism aberration, can eliminate the aberration as much as possible during imaging, thereby improving the imaging quality of the lens, and the lenses made of glass can reduce the influence of temperature on the optical performance of the lens.

[0093] Further, in the embodiment, the aspherical surface shape of the aspherical lens satisfies the following condition:

[0094]

[0095] ​​​​Wherein, c is the curvature corresponding to the radius, y is the radial coordinate (its unit is the same as the unit of lens length), k is the conic quadratic curve coefficient (when the k coefficient is less than -1, the surface shape curve is a hyperbola, when the k coefficient is equal to -1, it is a parabola, when the k coefficient is between -1 and 0, it is an ellipse, when the k coefficient is equal to 0, it is a circle, and when the k coefficient is greater than 0, it is a flat circle), A, B, C, D, E, F are high-order aspherical coefficients (see Table 2 below), and the shape and size of the aspherical surface of the lens object side and the image side can be set by the above parameters.

[0096] Table 2 Conic coefficient and aspherical coefficient corresponding to aspherical lens

[0097]

[0098] Table 3 Zoom data of the zoom lens at wide-angle end, intermediate magnification position, and telephoto end, respectively

[0099]

[0100] In the embodiment, please refer to Figures 1 to 3 , which are structural schematic diagrams of the zoom lens at wide-angle end, intermediate magnification position, and telephoto end, respectively; wherein, the intermediate magnification can be understood as the position diagram of each lens group in the zoom lens when the zoom lens is between the wide-angle end and the telephoto end.

[0101] Figures 4 to 6 The longitudinal aberration, field curvature, and distortion of the zoom lens at the wide-angle end are shown in the figures, respectively, wherein, the d line (λ = 588 nm), and S, T in the figures are the aberrations corresponding to the sagittal image surface and the tangential image surface, respectively.

[0102] Please refer to Figures 7 to 9 , which are the aberration diagram, field curvature diagram, and distortion diagram of the zoom lens at the intermediate magnification position, wherein, the d line (λ = 546 nm), and S, T in the figures are the aberrations corresponding to the sagittal image surface and the tangential image surface, respectively.

[0103] Please refer to Figures 10 to 12 , which are the spherical aberration diagram, field curvature diagram, and distortion diagram of the zoom lens at the telephoto end, wherein, the d line (λ = 546 nm), and S, T in the figures are the aberrations corresponding to the sagittal image surface and the tangential image surface, respectively.

[0104] From the above figures, it can be seen that the spherical aberration, field curvature, and distortion of the zoom lens in the embodiment at the intermediate magnification position, wide-angle end, and telephoto end can be well corrected.

[0105] As shown in the above figures, the spherical aberration, field curvature and distortion of the zoom lens in the embodiment can be well corrected at the intermediate magnification, wide-angle end and telephoto end.

[0106] In summary, the zoom lens adopts a five-group structure of "positive-negative-positive-positive", wherein two variable groups, one focusing group and two fixed groups are provided. With the movement of the second lens group 2 and the third lens group 3, the focal length changes. The fourth lens group 4 is used for focusing. For example, when a 1 / 1.8" 16:9 CCD is used, the focal length can be changed from <7.09mm at the wide-angle end to >175mm at the telephoto end. The horizontal shooting angle at the wide-angle end is >59°, and the optical distortion at the wide-angle end and the telephoto end is within -4.4%. The zoom lens has the effects of wide angle, small distortion and large zoom. Moreover, the zoom lens contains three glass aspherical surfaces, which fully guarantees good optical performance.

[0107] The zoom lens uses an adjustable diaphragm. With the aperture number reaching 1.6 at the wide-angle end and 5.19 at the telephoto end, the zoom lens has extremely high light sensitivity, and can still shoot a clear picture in a relatively dark environment.

[0108] The distance between the first lens group 1 and the photosensitive chip 8 is fixed. The distance between the first lens group 1 and the photosensitive chip 8 is less than 110mm (for example, when a 1 / 1.8" CCD is used, the distance is appropriately scaled when other size CCDs are used).

[0109] The zoom lens can achieve a resolution higher than 4K (80 million pixels). For example, when a 1 / 1.8" sensor is used, the center resolution of the zoom lens is higher than 300lp / mm, and the peripheral 0.7H (70% diagonal position) resolution is higher than 1400TVline.

[0110] In addition, the present application also provides a monitoring camera device, which comprises the zoom lens according to the above technical solutions. Since the monitoring camera device comprises the zoom lens, the specific structure of the zoom lens is referred to the above embodiments. Since the zoom lens of the monitoring camera device adopts all the technical solutions of the above embodiments, at least all the beneficial effects brought by the technical solutions of the above embodiments are achieved, which will not be described here.

[0111] The above description is only optional embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields within the inventive concept of the present application and the contents of the specification and drawings are included in the patent protection scope of the present application.

Claims

1. A zoom lens, characterized in that, The zoom lens has an object side and an image side arranged oppositely along the optical axis direction, and comprises: a housing; and a plurality of lens groups arranged in the housing, including, from the object side to the image side, a first lens group with positive refractive power, a second lens group with negative refractive power, a diaphragm, a third lens group with positive refractive power, a fourth lens group with positive refractive power, a fifth lens group with negative refractive power, and a photosensitive chip, wherein the first lens group and the fifth lens group are fixedly installed on the housing, the second lens group, the third lens group, and the fourth lens group are movably arranged along the extension direction of the optical axis, the second lens group and the third lens group move cooperatively along the optical axis direction to adjust the focal length of the zoom lens, and the fourth lens group is movably arranged along the optical axis direction to focus the zoom lens; wherein the focal length of the zoom lens at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the focal length of the fifth lens group is f5, and the zoom lens satisfies the following conditions: 0.128<fw / f1<0.173, and -0.825<fw / f2<-0.61, and 0.195<fw / f3<0.264, and 0.272<fw / f4≤0.313, and -0.126< fw / f5<-0.093; The first lens group comprises, from the object side to the image side, a first lens with negative refractive power, a second lens with positive refractive power, a third lens with positive refractive power, and a fourth lens with positive refractive power; The second lens group comprises, from the object side to the image side, a fifth lens with negative refractive power, a sixth lens with negative refractive power, and a seventh lens with positive refractive power; The third lens group comprises, from the object side to the image side, an eighth lens with positive refractive power, a ninth lens with positive refractive power, a tenth lens with negative refractive power, and an eleventh lens with positive refractive power, The fourth lens group comprises, from the object side to the image side, a twelfth lens with positive refractive power, a thirteenth lens with positive refractive power, and a fourteenth lens with negative refractive power; The fifth lens group comprises, from the object side to the image side, a fifteenth lens with positive refractive power and a sixteenth lens with negative refractive power.

2. The zoom lens according to claim 1, wherein The focal length of the first lens is f11, the focal length of the second lens is f12, the focal length of the third lens is f13, the focal length of the fourth lens is f14, and the first lens group and the first lens, the second lens, the third lens, and the fourth lens satisfy the following conditions: -0.529<f1 / f11<-0.391, and 0.468<f1 / f12<0.633, and 0.378<f1 / f13<0.511, and 0.438<f1 / f14<0.

593.

3. The zoom lens according to claim 1, wherein The sixth lens is a glass aspheric lens. A focal length of the fifth lens is f21, a focal length of the sixth lens is f22, a focal length of the seventh lens is f23, the second lens group and the fifth lens, the sixth lens, the seventh lens satisfy the following conditions: 0.764 < f2 / f21 < 1.033, and 0.393 < f2 / f22 < 0.531, and -0.424 < f2 / f23 < -0.

313.

4. The zoom lens according to claim 1, wherein The eleventh lens is a glass aspheric lens. A focal length of the eighth lens is f31, a focal length of the ninth lens is f32, a focal length of the tenth lens is f33, a focal length of the eleventh lens is f34, the third lens group and the eighth lens, the ninth lens, the tenth lens, the eleventh lens satisfy the following conditions: 0.737 < f3 / f31 < 0.997, and 0.863 < f3 / f32 < 1.167, and -2.809 < f3 / f33 < -2.077, and 1.111 < f3 / f34 < 1.

503.

5. The zoom lens according to claim 1, wherein A focal length of the twelfth lens is f41, a focal length of the thirteenth lens is f42, a focal length of the fourteenth lens is f43, the fourth lens group and the twelfth lens, the thirteenth lens, the fourteenth lens satisfy the following conditions: 0.353 < f4 / f41 < 0.477, and 0.698 < f4 / f42 < 0.944, and -0.218 < f4 / f43 < -0.

161.

6. The zoom lens according to claim 1, wherein The sixteenth lens is a glass aspheric lens.

7. The zoom lens according to claim 1, wherein The zoom lens satisfies the following condition: 0.317 < øL11 / TTL < 0.447; Wherein, øL11 is an effective light aperture of the first lens, TTL is an optical total length of the zoom lens.

8. The zoom lens according to claim 1, wherein The zoom lens satisfies the following condition: 0.233 < ΔZ1W-T / TTL < 0.329; wherein ΔZ1 W-T is the relative displacement of the second lens group when the zoom lens is in the wide-angle end position and when the zoom lens is in the telephoto end position, and TTL is the total track length of the zoom lens.

9. The zoom lens according to claim 1, wherein The zoom lens satisfies the following condition: 0.099 < ΔZ2W-T / TTL < 0.14; Wherein, ΔZ2W-T is a relative displacement of the third lens group when the zoom lens is at a wide-angle end position and when the zoom lens is at a telephoto end position, TTL is an optical total length of the zoom lens.

10. A surveillance camera, characterized by The monitoring camera device comprises the zoom lens as claimed in any one of claims 1 to 9.

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