CN110082894B - a zoom lens - Google Patents

Abstract

The invention relates to the technical field of lenses. The invention discloses a zoom lens, which is provided with twelve lenses, wherein the first lens to the fourth lens form a compensation lens group, and the fifth lens to the twelfth lens form a zoom lens group; the diaphragm is arranged between the compensation lens group and the variable magnification lens group, the refractive index and the surface area of the first lens to the twelfth lens are correspondingly limited, the third lens and the fourth lens form a cemented lens, the sixth lens and the seventh lens form a cemented lens, the eleventh lens and the twelfth lens form a cemented lens, and the object side surfaces and the image side surfaces of the first lens to the twelfth lens are spherical surfaces. The invention has the advantages of large light transmission, minimum aperture value up to 1.5, small numerical difference from short focus to long Jiao Guangjuan, good control of transmission function, high resolution and imaging quality and low cost.

Description

A zoom lens

Technical field

The invention belongs to the technical field of lenses, and in particular relates to a zoom lens.

Background technique

With the continuous advancement of technology, optical imaging lenses have also developed rapidly in recent years and are widely used in various fields such as smartphones, tablets, video conferencing, and security monitoring.

A zoom lens is a camera lens that can change the focal length within a certain range to obtain different wide and narrow angles of view, images of different sizes and different scene ranges. A zoom lens can change the shooting range by changing the focal length without changing the shooting distance, so it is very convenient to use.

However, zoom lenses with small magnifications (generally less than 4 times) currently on the market have the following shortcomings: zoom lenses with larger light transmission use at least one aspherical lens, which is more expensive; from the shortest focal length to the longest focal length, the aperture value is different Larger, for example, the aperture value FNO is 1.6 at the shortest focal length and reaches 3.0 at the longest focal length; although some have a large amount of light, the imaging quality is relatively low.

Contents of the invention

The object of the present invention is to provide a zoom lens to solve the above-mentioned technical problems.

To achieve the above object, the technical solution adopted by the present invention is: a zoom lens, which sequentially includes first to fourth lenses, apertures, and fifth to twelfth lenses along an optical axis from the object side to the image side; The first to twelfth lenses each include an object side facing the object side and allowing imaging light to pass through, and an image side facing the image side and allowing imaging light to pass through;

The first lens has a negative refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has a negative refractive power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens has a negative refractive power, the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a concave surface; the fourth lens has a positive refractive power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the image side surface of the third lens and the object side surface of the fourth lens are glued to each other; the first lens to the fourth lens constitute a compensation lens group;

The fifth lens has a positive refractive power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; the sixth lens has a positive refractive power, the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface; the seventh lens has a negative refractive power, the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a plane; the eighth lens has a positive refractive power, the object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens is a convex surface; the ninth lens has a positive refractive power, the object side surface of the ninth lens is a convex surface, and the image side surface of the ninth lens is a convex surface; The tenth lens has a negative refractive power, the object side surface of the tenth lens is convex, and the image side surface of the tenth lens is concave; the eleventh lens has a positive refractive power, the object side surface of the eleventh lens is convex, and the image side surface of the eleventh lens is convex; the twelfth lens has a negative refractive power, the object side surface of the twelfth lens is concave, and the image side surface of the twelfth lens is convex; the image side surface of the sixth lens and the object side surface of the seventh lens are glued to each other; the image side surface of the eleventh lens and the object side surface of the twelfth lens are glued to each other; the fifth lens to the twelfth lens constitute a variable power lens group;

The object side and image side of the first to twelfth lenses are all spherical, and the zoom lens only has the above twelve lenses with refractive power.

Furthermore, the zoom lens satisfies: 1.4<nd6<1.5, 80<vd6<95, 1.8<nd7<1.9, 20<vd7<30, where nd6 and nd7 respectively represent the sixth lens and seventh lens at d The refractive index of the line, vd6 and vd7 respectively represent the dispersion coefficient of the sixth lens and the seventh lens at the d line.

Furthermore, the zoom lens satisfies: 1.45<nd11<1.6, 50<vd11<80, 1.8<nd12<2.1, 20<vd12<30, where nd11 and nd12 respectively represent the eleventh lens and the twelfth lens The refractive index at the d line, vd11 and vd12 respectively represent the dispersion coefficients of the eleventh lens and the twelfth lens at the d line.

Furthermore, the zoom lens satisfies the following requirements: 1.9<nd8<2, 16<vd8<20, 1.9<nd9<2, 16<vd9<20, where nd8 and nd9 respectively represent the eighth lens and ninth lens at d The refractive index of the line, vd8 and vd9 respectively represent the dispersion coefficient of the eighth lens and the ninth lens at the d line.

Furthermore, this zoom lens is more satisfactory: 0.3<fw/BFLw<0.5, where fw is the shortest focal length and BFLw is the back focal length at the shortest focal length.

Furthermore, this zoom lens is more satisfactory: 0.5<ft/BFLt<1, where ft is the longest focal length and BFLt is the back focal length at the longest focal length.

Furthermore, the zoom lens further satisfies: TTL<75mm, wherein TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis.

Beneficial technical effects of the present invention:

The present invention can achieve small-magnification zoom, has large light transmission, and the minimum aperture value reaches 1.5. The difference in aperture value from short focus to long focus is small (the aperture value at the shortest focal length is 1.49, and the aperture value at the longest focal length is 2.2). It also has the advantages of good control over the transfer function, high resolution and imaging quality, and low cost.

In addition, the present invention has good infrared confocal performance. In the case of visible light focusing, the imaging effect is still good when switching to infrared 850nm. Under the premise of infrared confocal, the chromatic aberration of purple wavelengths is ensured, and the blue-violet edge is better controlled.

Description of drawings

Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention at the shortest focal length;

Figure 2 is a schematic structural diagram of Embodiment 1 of the present invention at the longest focal length;

Figure 3 is an MTF diagram of 0.435-0.656um at the shortest focal length according to Embodiment 1 of the present invention;

FIG4 is an MTF diagram of infrared 850nm at the shortest focal length according to the first embodiment of the present invention;

FIG5 is an MTF diagram of 0.435-0.656 um at the longest focal length of the first embodiment of the present invention;

Figure 6 is an MTF diagram of infrared 850nm at the longest focal length according to Embodiment 1 of the present invention;

FIG. 7 is a defocus curve diagram of visible light 0.435-0.656 um at the shortest focal length according to the first embodiment of the present invention;

Figure 8 is a defocus curve of infrared 850nm at the shortest focal length according to Embodiment 1 of the present invention;

Figure 9 is a defocus curve of visible light 0.435-0.656um at the longest focal length according to Embodiment 1 of the present invention;

Figure 10 is a defocus curve of infrared 850nm at the longest focal length according to Embodiment 1 of the present invention;

FIG11 is a schematic diagram of field curvature and distortion at the shortest focal length according to the first embodiment of the present invention;

Figure 12 is a schematic diagram of field curvature and distortion at the longest focal length according to Embodiment 1 of the present invention;

Figure 13 is a schematic diagram of longitudinal chromatic aberration at the shortest focal length according to Embodiment 1 of the present invention;

Figure 14 is a schematic diagram of longitudinal chromatic aberration at the longest focal length according to Embodiment 1 of the present invention;

Figure 15 is an MTF diagram of 0.435-0.656um at the shortest focal length according to Embodiment 2 of the present invention;

FIG16 is an MTF diagram of infrared 850nm at the shortest focal length of the second embodiment of the present invention;

Figure 17 is an MTF diagram of 0.435-0.656um at the longest focal length according to Embodiment 2 of the present invention;

Figure 18 is an MTF diagram of infrared 850nm at the longest focal length according to Embodiment 2 of the present invention;

Figure 19 is a defocus curve of visible light 0.435-0.656um at the shortest focal length according to Embodiment 2 of the present invention;

Figure 20 is a defocus curve of infrared 850nm at the shortest focal length according to Embodiment 2 of the present invention;

Figure 21 is a defocus curve of visible light 0.435-0.656um at the longest focal length according to Embodiment 2 of the present invention;

Figure 22 is a defocus curve of infrared 850nm at the longest focal length according to Embodiment 2 of the present invention;

Figure 23 is a schematic diagram of field curvature and distortion at the shortest focal length according to Embodiment 2 of the present invention;

Figure 24 is a schematic diagram of field curvature and distortion at the longest focal length according to Embodiment 2 of the present invention;

Figure 25 is a schematic diagram of longitudinal chromatic aberration at the shortest focal length according to Embodiment 2 of the present invention;

Figure 26 is a schematic diagram of longitudinal chromatic aberration at the longest focal length according to Embodiment 2 of the present invention;

FIG27 is an MTF diagram of 0.435-0.656 um at the shortest focal length of the third embodiment of the present invention;

Figure 28 is an MTF diagram of infrared 850nm at the shortest focal length according to Embodiment 3 of the present invention;

Figure 29 is an MTF diagram of 0.435-0.656um at the longest focal length according to Embodiment 3 of the present invention;

FIG30 is an MTF diagram of infrared 850nm at the longest focal length of Example 3 of the present invention;

Figure 31 is a defocus curve of visible light 0.435-0.656um at the shortest focal length according to Embodiment 3 of the present invention;

FIG32 is a defocus curve diagram of infrared light of 850 nm at the shortest focal length according to Embodiment 3 of the present invention;

Figure 33 is a defocus curve of visible light 0.435-0.656um at the longest focal length according to Embodiment 3 of the present invention;

Figure 34 is a defocus curve of infrared 850nm at the longest focal length according to Embodiment 3 of the present invention;

Figure 35 is a schematic diagram of field curvature and distortion at the shortest focal length according to Embodiment 3 of the present invention;

Figure 36 is a schematic diagram of field curvature and distortion at the longest focal length according to Embodiment 3 of the present invention;

FIG37 is a schematic diagram of longitudinal chromatic aberration of Embodiment 3 of the present invention at the shortest focal length;

Figure 38 is a schematic diagram of longitudinal chromatic aberration at the longest focal length according to Embodiment 3 of the present invention;

Figure 39 is an MTF diagram of 0.435-0.656um at the shortest focal length according to Embodiment 4 of the present invention;

Figure 40 is an MTF diagram of infrared 850nm at the shortest focal length according to Embodiment 4 of the present invention;

FIG41 is an MTF diagram of 0.435-0.656 um at the longest focal length of the fourth embodiment of the present invention;

Figure 42 is an MTF diagram of infrared 850nm at the longest focal length according to Embodiment 4 of the present invention;

FIG43 is a defocus curve diagram of visible light 0.435-0.656 um at the shortest focal length according to Embodiment 4 of the present invention;

Figure 44 is a defocus curve of infrared 850nm at the shortest focal length according to Embodiment 4 of the present invention;

Figure 45 is a defocus curve of visible light 0.435-0.656um at the longest focal length according to Embodiment 4 of the present invention;

Figure 46 is a defocus curve of infrared 850nm at the longest focal length according to Embodiment 4 of the present invention;

Figure 47 is a schematic diagram of field curvature and distortion at the shortest focal length according to Embodiment 4 of the present invention;

FIG48 is a schematic diagram of field curvature and distortion at the longest focal length according to Embodiment 4 of the present invention;

Figure 49 is a schematic diagram of longitudinal chromatic aberration at the shortest focal length according to Embodiment 4 of the present invention;

Figure 50 is a schematic diagram of longitudinal chromatic aberration at the longest focal length according to Embodiment 4 of the present invention;

Figure 51 is an MTF diagram of 0.435-0.656um at the shortest focal length according to Embodiment 5 of the present invention;

Figure 52 is an MTF diagram of infrared 850nm at the shortest focal length according to Embodiment 5 of the present invention;

FIG53 is an MTF diagram of 0.435-0.656 um at the longest focal length of Example 5 of the present invention;

FIG54 is an MTF diagram of infrared 850nm at the longest focal length of Example 5 of the present invention;

Figure 55 is a defocus curve of visible light 0.435-0.656um at the shortest focal length according to Embodiment 5 of the present invention;

Figure 56 is a defocus curve of infrared 850nm at the shortest focal length according to Embodiment 5 of the present invention;

Figure 57 is a defocus curve of visible light 0.435-0.656um at the longest focal length according to Embodiment 5 of the present invention;

Figure 58 is a defocus curve of infrared 850nm at the longest focal length according to Embodiment 5 of the present invention;

Figure 59 is a schematic diagram of field curvature and distortion at the shortest focal length according to Embodiment 5 of the present invention;

Figure 60 is a schematic diagram of field curvature and distortion at the longest focal length according to Embodiment 5 of the present invention;

Figure 61 is a schematic diagram of longitudinal chromatic aberration at the shortest focal length according to Embodiment 5 of the present invention;

FIG62 is a schematic diagram of longitudinal chromatic aberration of Embodiment 5 of the present invention at the longest focal length;

Figure 63 is a numerical table of various important parameters in five embodiments of the present invention.

Detailed ways

The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

The term "a lens has positive refractive power (or negative refractive power)" means that the paraxial refractive index of the lens is positive (or negative) calculated based on Gaussian optical theory. The so-called "object side (or image side) of the lens" is defined as the specific range where imaging light passes through the lens surface. The concavity and convexity of the lens surface can be judged according to the judgment method of common knowledge in this field, that is, the concavity and convexity of the lens surface can be judged by the positive and negative sign of the radius of curvature (abbreviated as R value). R-values are commonly used in optical design software such as Zemax or CodeV. R-values are also commonly found in lens data sheets in optical design software. For the side of the object, when the R value is positive, the side of the object is judged to be convex; when the R value is negative, the side of the object is judged to be concave. On the contrary, for the image side, when the R value is positive, the image side is judged to be concave; when the R value is negative, the image side is judged to be convex.

The present invention provides a zoom lens, which sequentially includes first to fourth lenses, an aperture, and fifth to twelfth lenses along an optical axis from the object side to the image side; the first to twelfth lenses Each includes an object side facing the object side and allowing the imaging light to pass through; and an image side facing the image side and allowing the imaging light to pass;

The first lens has negative refractive power, the object side of the first lens is convex, and the image side of the first lens is concave; the second lens has negative refractive power, the object side of the second lens is convex, and the The image side of the second lens is concave; the third lens has negative refractive power, the object side of the third lens is concave, and the image side of the third lens is concave; the fourth lens has positive refractive power, and the third lens has a concave object side. The object side of the four lenses is convex, and the image side of the fourth lens is convex; the image side of the third lens and the object side of the fourth lens are glued to each other; the first to fourth lenses constitute a compensation lens group;

The fifth lens has positive refractive power, the object side of the fifth lens is convex, and the image side of the fifth lens is convex; the sixth lens has positive refractive power, and the object side of the sixth lens is convex. The image side of the sixth lens is convex; the seventh lens has negative refractive power, the object side of the seventh lens is concave, and the image side of the seventh lens is flat; the eighth lens has positive refractive power, and the eighth lens The object side of the lens is concave, the image side of the eighth lens is convex; the ninth lens has positive refractive power, the object side of the ninth lens is convex, and the image side of the ninth lens is convex; the tenth lens has Negative refractive power, the object side of the tenth lens is convex, and the image side of the tenth lens is concave; the eleventh lens has positive refractive power, the object side of the eleventh lens is convex, and the eleventh lens has a negative refractive power. The image side of the lens is convex; the twelfth lens has negative refractive power, the object side of the twelfth lens is concave, and the image side of the twelfth lens is convex; the image side of the sixth lens is consistent with the seventh lens The object side surfaces of the lenses are glued to each other; the image side surfaces of the eleventh lens and the object side surfaces of the twelfth lens are glued to each other; the fifth lens to the twelfth lens constitute a variable power lens group;

The object side and image side of the first to twelfth lenses are all spherical, which is easy to manufacture and low cost. The zoom lens only has the above twelve lenses with refractive power. The invention can achieve small-magnification zoom, has the advantages of large light transmission, a minimum aperture value of 1.5, small aperture value difference from short focal length to long focal length, good control of the transfer function, high resolution and imaging quality, and low cost.

Preferably, the zoom lens satisfies: 1.4<nd6<1.5, 80<vd6<95, 1.8<nd7<1.9, 20<vd7<30, where nd6 and nd7 respectively represent the sixth lens and seventh lens at d The refractive index of the line, vd6 and vd7 respectively represent the dispersion coefficient of the sixth lens and the seventh lens at the d line. Under the premise of confocal visible and infrared, the chromatic aberration of purple wavelengths is also corrected, and the blue-purple fringing is well controlled. The blue-purple fringing phenomenon in real shots is negligible.

Preferably, the zoom lens further satisfies: 1.45<nd11<1.6, 50<vd11<80, 1.8<nd12<2.1, 20<vd12<30, wherein nd11 and nd12 represent the refractive index of the eleventh lens and the twelfth lens at the d line, respectively, and vd11 and vd12 represent the dispersion coefficient of the eleventh lens and the twelfth lens at the d line, respectively. Under the premise of visible and infrared confocality, the chromatic aberration of the purple wavelength is also corrected, and the blue-purple edge is well controlled, and the blue-purple edge phenomenon in actual shooting can be ignored.

Preferably, the zoom lens further satisfies: 1.9<nd8<2, 16<vd8<20, 1.9<nd9<2, 16<vd9<20, wherein nd8 and nd9 respectively represent the refractive indices of the eighth lens and the ninth lens at the d-line, vd8 and vd9 respectively represent the dispersion coefficients of the eighth lens and the ninth lens at the d-line, and the eighth lens and the ninth lens are made of the same material, and can better correct chromatic aberration, so that the infrared confocal and blue-purple fringing effects are better.

Preferably, the zoom lens satisfies: 0.3<fw/BFLw<0.5, where fw is the shortest focal length and BFLw is the back focal length at the shortest focal length, so that the back focal length is longer and can better adapt to various cameras.

Preferably, the zoom lens further satisfies: 0.5<ft/BFLt<1, wherein ft is the longest focal length and BFLt is the back focal length at the longest focal length, so that the back focal length is longer and can better adapt to various cameras.

Preferably, the zoom lens further satisfies: TTL <75mm, where TTL is the distance on the optical axis from the object side of the first lens to the imaging surface, further optimizing the system length of the zoom lens and making it more compact and lightweight.

The zoom lens of the present invention will be described in detail below with specific embodiments.

Implementation

As shown in Figures 1 and 2, the present invention provides a zoom lens, which sequentially includes first to fourth lenses 11 to 14, an aperture 3, and a fifth lens 21 along an optical axis I from the object side A1 to the image side A2. to the twelfth lens 28, the flat glass 4 and the imaging surface 5; the first lens 11 to the twelfth lens 28 each includes an object side facing the object side A1 and allowing the imaging light to pass; and an object side facing the image side A2 and allowing imaging to pass through. The light passes through the side.

The first lens 11 has a negative refractive power, the object side 111 of the first lens 11 is a convex surface, and the image side 112 of the first lens 11 is a concave surface; the second lens 12 has a negative refractive power, and the second lens 12 The object side 121 of the third lens 12 is a convex surface, and the image side 122 of the second lens 12 is a concave surface; the third lens 13 has negative refractive power, the object side 131 of the third lens 13 is a concave surface, and the image side 132 of the third lens 13 is a concave surface; the fourth lens 14 has positive refractive power, the object side 141 of the fourth lens 14 is a convex surface, and the image side 142 of the fourth lens 14 is a convex surface; the image side 132 of the third lens 13 and the fourth The object side surfaces 141 of the lenses 14 are glued together; the first to fourth lenses 11 to 14 constitute the compensation lens group 1 .

The fifth lens 21 has positive refractive power, the object side 211 of the fifth lens 21 is convex, and the image side 212 of the fifth lens 21 is convex; the sixth lens 22 has positive refractive power, and the sixth lens 22 The object side 221 of the seventh lens 22 is a convex surface, and the image side 222 of the sixth lens 22 is a convex surface; the seventh lens 23 has negative refractive power, the object side 231 of the seventh lens 23 is a concave surface, and the image side 232 of the seventh lens 23 is a plane; the eighth lens 24 has positive refractive power, the object side 241 of the eighth lens 24 is a concave surface, and the image side 242 of the eighth lens 24 is a convex surface; the ninth lens 25 has positive refractive power, and the ninth lens 24 has a positive refractive power. The object side 251 of the lens 25 is convex, and the image side 252 of the ninth lens 25 is convex; the tenth lens 26 has negative refractive power, the object side 261 of the tenth lens 26 is convex, and the image of the tenth lens 26 The side surface 262 is a concave surface; the eleventh lens 27 has a positive refractive power, the object side surface 271 of the eleventh lens 27 is a convex surface, and the image side surface 272 of the eleventh lens 27 is a convex surface; the twelfth lens 28 has a negative refractive index. The refractive power, the object side 281 of the twelfth lens 28 is a concave surface, and the image side 282 of the twelfth lens 28 is a convex surface; the image side 222 of the sixth lens 22 and the object side 231 of the seventh lens 23 are glued to each other. ; The image side 272 of the eleventh lens 27 and the object side 281 of the twelfth lens 28 are glued to each other; the fifth lens 21 to the twelfth lens 28 constitute the variable power lens group 2 .

The object side and image side of the first lens 11 to the twelfth lens 28 are all spherical surfaces.

The detailed optical data of this specific embodiment at the longest focal length are shown in Table 1-1.

Table 1-1 Detailed optical data at the longest focal length of Example 1

The detailed optical data at the shortest focal length of this specific embodiment are shown in Table 1-2.

Table 1-2 Detailed optical data of Example 1 at the shortest focal length

surface Caliber(mm) Curvature radius (mm) Thickness(mm) Material refractive index dispersion coefficient Focal length(mm) - Object surface Infinity Infinity Infinity 111 first lens 26.324 178.880 1.400 H-LAF50B 1.773 49.613 -14.000 112 17.564 10.210 3.488 121 Second lens 17.376 21.417 1.200 H-ZF1 1.648 33.842 -96.481 122 16.242 15.626 4.963 131 The third lens 15.606 -29.403 0.850 H-ZK7 1.613 60.614 -14.560 132 15.510 13.033 0 141 fourth lens 15.510 13.033 3.690 H-ZF5 1.740 28.291 16.446 142 15.396 -184.810 23.055 3 aperture 8.944 Infinity 7.381 211 fifth lens 10.472 300.000 2.220 TAFD40 2.001 25.458 23.268 212 10.610 -25.403 0.100 221 sixth lens 10.124 11.047 3.920 FCD10A 1.459 90.195 11.681 222 9.438 -9.285 0 231 seventh lens 9.438 -9.285 0.710 FD225 1.808 22.764 -11.372 232 9.164 Infinity 1.302 241 eighth lens 9.066 -12.266 3.620 FDS18-W 1.946 17.984 50.960 242 10.214 -11.219 0.100 251 Ninth lens 9.828 84.802 1.780 FDS18-W 1.946 17.984 27.038 252 9.574 -36.927 0.100 261 tenth lens 9.020 22.888 0.700 H-ZF12 1.762 26.613 -13.413 262 8.394 7.013 0.186 271 Eleventh lens 8.446 7.423 3.150 FCD515 1.593 68.624 8.329 272 8.174 -12.541 0 281 twelfth lens 8.174 -12.541 1.900 TAFD40 2.001 25.458 -14.632 282 8.060 -89.181 0.091 4 plate glass 8.026 Infinity 0.500 H-K9L 1.517 64.212 Infinity - 7.968 Infinity 7.561 5 imaging surface 6.691 Infinity

Please refer to Figure 63 for the values of some conditional expressions in this specific embodiment.

For the resolution of this specific embodiment, please refer to Figures 3 to 6. From the figures, it can be seen that the transmission is well controlled, the resolution and imaging quality are high, and the visible and infrared 850nm confocal properties can be seen from Figures 7 to 10. The confocal performance of visible light and infrared is good. In the case of visible light focusing, switching to infrared 850nm, the imaging effect is still good. The field curvature and distortion diagrams are shown in (A) and (B) of Figure 11 and (A) and (A) of Figure 12 (B), the longitudinal chromatic aberration diagram is shown in Figure 13 and Figure 14 for details. It can be seen that the distortion is small, the chromatic aberration is small, and the imaging quality is high.

In this specific embodiment, the focal length of the zoom lens is f=3.1-8.6mm; the aperture value FNO=1.49-2.2.

Implementation 2

The surface irregularities and refractive power of each lens in this embodiment are the same as those in Embodiment 1, and only the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

The detailed optical data of this specific embodiment at the longest focal length are shown in Table 2-1.

Table 2-1 Detailed optical data at the longest focal length of Example 2

The detailed optical data at the shortest focal length of this specific embodiment is shown in Table 2-2.

Table 2-2 Detailed optical data at the shortest focal length of Example 2

surface Caliber(mm) Radius of curvature (mm) Thickness(mm) Material refractive index dispersion coefficient Focal length(mm) - Subject surface Infinity Infinity Infinity 111 first lens 26.746 188.013 1.400 H-LAF50B 1.773 49.613 -14.663 112 17.910 10.482 3.194 121 second lens 19.000 19.454 1.200 H-ZBAF16 1.667 48.432 -91.767 122 17.000 14.341 5.702 131 third lens 15.580 -30.671 0.850 H-ZK7 1.613 60.614 -15.158 132 15.377 13.205 0 141 fourth lens 15.377 13.205 3.690 H-ZF5 1.740 28.291 17.626 142 15.223 -291.289 22.782 3 aperture 8.900 Infinity 7.475 211 fifth lens 12.000 197.402 2.222 H-ZLAF90 2.001 25.435 24.296 212 12.000 -26.657 0.100 221 sixth lens 10.392 10.867 3.870 H-FK71 1.457 90.270 12.096 222 10.392 -9.792 0 231 seventh lens 10.392 -9.792 0.710 H-ZF71 1.808 22.691 -12.523 232 12.000 Infinity 1.219 241 eighth lens 10.000 -12.844 3.585 FDS18-W 1.946 17.984 56.399 242 13.000 -11.633 0.187 251 The ninth lens 11.507 100.742 1.691 H-ZF88 1.946 17.944 32.563 252 11.400 -41.538 0.114 261 tenth lens 8.900 22.468 0.700 H-ZF12 1.762 26.613 -14.834 262 10.271 7.279 0.264 271 Eleventh lens 11.044 7.901 3.150 FCD515 1.593 68.624 8.889 272 11.044 -13.019 0 281 twelfth lens 11.044 -13.019 1.875 H-ZLAF90 2.001 25.435 -16.908 282 11.267 -67.255 0.098 4 plate glass 13.468 Infinity 0.500 H-K9L 1.517 64.212 Infinity - 13.658 Infinity 7.587 5 imaging surface 6.602 Infinity

Please refer to Figure 63 for the values of some conditional expressions in this specific embodiment.

Please refer to Figures 15 to 18 for the resolution of this specific embodiment. It can be seen from the figures that the transmission function is well controlled, and the resolution and imaging quality are high. Please refer to Figures 19 to 22 for the confocality of visible and infrared 850nm. It can be seen that the confocality of visible light and infrared is good. When the visible light is focused, the imaging effect is still good when switching to infrared 850nm. The field curvature and distortion diagrams are detailed in (A) and (B) of Figure 23 and (A) and (B) of Figure 24. The longitudinal chromatic aberration diagrams are detailed in Figures 25 and 26. It can be seen that the distortion is small, the chromatic aberration is small, and the imaging quality is high.

In this specific embodiment, the focal length of the zoom lens is f=3.1-8.6mm; the aperture value FNO=1.49-2.2.

Implementation three

The surface irregularities and refractive power of each lens in this embodiment are the same as those in Embodiment 1, and only the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

The detailed optical data at the longest focal length of this specific embodiment is shown in Table 3-1.

Table 3-1 Detailed optical data at the longest focal length of Example 3

The detailed optical data at the shortest focal length of this specific embodiment is shown in Table 3-2.

Table 3-2 Detailed optical data at the shortest focal length of Example 3

surface Caliber(mm) Radius of curvature (mm) Thickness(mm) Material refractive index Dispersion coefficient Focal length(mm) - Object surface Infinity Infinity Infinity 111 first lens 25.960 197.709 1.400 H-LAF50B 1.770 49.610 -14.003 112 17.372 10.143 3.596 121 second lens 17.178 23.130 1.200 H-ZF1 1.650 33.840 -96.724 122 16.092 16.376 4.803 131 third lens 15.452 -30.604 0.850 H-ZK7 1.610 60.610 -14.550 132 15.346 12.779 0 141 fourth lens 15.346 12.779 3.690 H-ZF5 1.740 28.290 16.443 142 15.224 -211.625 22.782 3 Aperture 8.864 Infinity 7.490 211 fifth lens 10.416 230.673 2.270 H-ZLAF90 2.000 25.460 23.268 212 10.550 -25.723 0.100 221 sixth lens 10.054 10.693 3.870 H-FK71 1.460 90.190 11.684 222 9.356 -9.597 0 231 seventh lens 9.356 -9.597 0.710 H-ZF71 1.810 22.760 -11.375 232 9.094 Infinity 1.271 241 eighth lens 9.058 -12.930 3.570 FDS16-W 1.990 16.480 50.982 242 10.100 -11.570 0.191 251 Ninth lens 9.670 191.422 1.680 H-ZF88 1.950 17.940 27.042 252 9.430 -38.660 0.114 261 tenth lens 8.908 22.385 0.700 H-ZF12 1.760 26.610 -13.412 262 8.310 7.112 0.237 271 Eleventh lens 8.384 7.634 3.150 FCD515 1.590 68.620 8.325 272 8.134 -12.310 0 281 twelfth lens 8.134 -12.310 1.800 H-ZLAF90 2.000 25.460 -14.623 282 8.082 -57.304 0.107 4 plate glass 8.036 Infinity 0.500 H-K9L 1.520 64.210 Infinity - 7.976 Infinity 7.554 5 imaging surface 6.604 Infinity

Please refer to Figure 63 for the values of some conditional expressions in this specific embodiment.

For the resolution of this specific embodiment, please refer to Figures 27 to 30. From the figures, it can be seen that the communication is well controlled, the resolution and imaging quality are high, and the visible and infrared 850nm confocal properties can be seen from Figures 31 to 34. The confocal performance of visible light and infrared is good. In the case of visible light focusing, switching to infrared 850nm, the imaging effect is still good. For details of the field curvature and distortion diagrams, see (A) and (B) of Figure 35 and (A) and (A) of Figure 36 (B), the longitudinal chromatic aberration diagram is detailed in Figure 37 and Figure 38. It can be seen that the distortion is small, the chromatic aberration is small, and the imaging quality is high.

In this specific embodiment, the focal length of the zoom lens is f=3.1-8.6mm; the aperture value FNO=1.49-2.2.

Implementation four

The surface irregularities and refractive power of each lens in this embodiment are the same as those in Embodiment 1, and only the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

The detailed optical data at the longest focal length of this specific embodiment is shown in Table 4-1.

Table 4-1 Detailed optical data at the longest focal length of Example 4

surface Diameter(mm) Radius of curvature (mm) Thickness(mm) Material refractive index dispersion coefficient Focal length(mm) - Object surface Infinity Infinity Infinity 111 first lens 26.324 178.880 1.400 H-LAF50B 1.773 49.613 -14.000 112 17.564 10.210 3.488 121 second lens 17.376 21.417 1.200 H-ZF1 1.648 33.842 -96.482 122 16.242 15.626 4.963 131 third lens 15.606 -29.403 0.850 H-ZK7 1.613 60.614 -14.560 132 15.510 13.033 0 141 The fourth lens 15.510 13.033 3.690 H-ZF5 1.740 28.291 16.446 142 15.396 -184.810 2.634 3 aperture 8.944 Infinity 0.513 211 fifth lens 10.472 300.000 2.220 TAFD40 2.001 25.458 23.268 212 10.610 -25.403 0.100 221 sixth lens 10.124 11.047 3.920 FCD10A 1.459 90.195 11.681 222 9.438 -9.285 0 231 seventh lens 9.438 -9.285 0.710 FD225 1.808 22.764 -11.372 232 9.164 Infinity 1.302 241 Eighth lens 9.066 -12.266 3.620 FDS18-W 1.946 17.984 50.960 242 10.214 -11.219 0.100 251 Ninth lens 9.828 84.802 1.780 FDS18-W 1.946 17.984 27.038 252 9.574 -36.927 0.100 261 tenth lens 9.020 22.888 0.700 H-ZF12 1.762 26.613 -13.413 262 8.394 7.013 0.186 271 Eleventh lens 8.446 7.423 3.150 FCD515 1.593 68.624 8.329 272 8.174 -12.541 0 281 twelfth lens 8.174 -12.541 1.900 TAFD40 2.001 25.458 -14.632 282 8.060 -89.181 6.958 4 plate glass 8.026 Infinity 0.500 H-K9L 1.517 64.212 Infinity - 7.968 Infinity 7.561 5 Imaging surface 6.612 Infinity

The detailed optical data at the shortest focal length of this specific embodiment is shown in Table 4-2.

Table 4-2 Detailed optical data of Example 4 at the shortest focal length

surface Caliber(mm) Radius of curvature (mm) Thickness(mm) Material refractive index Dispersion coefficient Focal length(mm) - Object surface Infinity Infinity Infinity 111 first lens 26.324 178.880 1.400 H-LAF50B 1.773 49.613 -14.000 112 17.564 10.210 3.488 121 second lens 17.376 21.417 1.200 H-ZF1 1.648 33.842 -96.481 122 16.242 15.626 4.963 131 The third lens 15.606 -29.403 0.850 H-ZK7 1.613 60.614 -14.560 132 15.510 13.033 0 141 fourth lens 15.510 13.033 3.690 H-ZF5 1.740 28.291 16.446 142 15.396 -184.810 23.055 3 aperture 8.944 Infinity 7.381 211 fifth lens 10.472 300.000 2.220 TAFD40 2.001 25.458 23.268 212 10.610 -25.403 0.100 221 sixth lens 10.124 11.047 3.920 FCD10A 1.459 90.195 11.681 222 9.438 -9.285 0 231 seventh lens 9.438 -9.285 0.710 FD225 1.808 22.764 -11.372 232 9.164 Infinity 1.302 241 eighth lens 9.066 -12.266 3.620 FDS18-W 1.946 17.984 50.960 242 10.214 -11.219 0.100 251 Ninth lens 9.828 84.802 1.780 FDS18-W 1.946 17.984 27.038 252 9.574 -36.927 0.100 261 tenth lens 9.020 22.888 0.700 H-ZF12 1.762 26.613 -13.413 262 8.394 7.013 0.186 271 Eleventh lens 8.446 7.423 3.150 FCD515 1.593 68.624 8.329 272 8.174 -12.541 0 281 twelfth lens 8.174 -12.541 1.900 TAFD40 2.001 25.458 -14.632 282 8.060 -89.181 0.091 4 plate glass 8.026 Infinity 0.500 H-K9L 1.517 64.212 Infinity - 7.968 Infinity 7.561 5 imaging surface 6.691 Infinity

Please refer to Figure 63 for the values of some conditional expressions in this specific embodiment.

Please refer to Figures 39 to 42 for the resolution of this specific embodiment. It can be seen from the figures that the transmission function is well controlled, and the resolution and imaging quality are high. Please refer to Figures 43 to 46 for the confocality of visible and infrared 850nm. It can be seen that the confocality of visible light and infrared is good. When the visible light is focused, the imaging effect is still good when switching to infrared 850nm. The field curvature and distortion diagrams are detailed in (A) and (B) of Figure 47 and (A) and (B) of Figure 48. The longitudinal chromatic aberration diagrams are detailed in Figures 49 and 50. It can be seen that the distortion is small, the chromatic aberration is small, and the imaging quality is high.

In this specific embodiment, the focal length of the zoom lens is f=3.1-8.6mm; the aperture value FNO=1.49-2.2.

Implementation five

The surface irregularities and refractive power of each lens in this embodiment are the same as those in Embodiment 1, and only the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

The detailed optical data at the longest focal length of this specific embodiment is shown in Table 5-1.

Table 5-1 Detailed optical data at the longest focal length of Example 5

surface Caliber(mm) Radius of curvature (mm) Thickness(mm) Material refractive index dispersion coefficient Focal length(mm) - Object surface Infinity Infinity Infinity 111 first lens 26.332 178.040 1.400 H-LAF50B 1.773 49.613 -14.003 112 17.566 10.209 3.475 121 Second lens 17.382 21.317 1.200 H-ZF1 1.648 33.842 -96.724 122 16.246 15.579 4.981 131 third lens 15.604 -29.355 0.850 H-ZK7 1.613 60.614 -14.550 132 15.510 13.029 0 141 fourth lens 15.510 13.029 3.690 H-ZF5 1.740 28.291 16.444 142 15.394 -185.055 2.635 3 aperture 8.944 Infinity 0.512 211 fifth lens 10.472 300.000 2.220 TAFD40 2.001 25.458 23.268 212 10.610 -25.403 0.100 221 sixth lens 10.124 11.051 3.920 FCD10A 1.459 90.195 11.684 222 9.438 -9.288 0 231 seventh lens 9.438 -9.288 0.710 FD225 1.808 22.764 -11.376 232 9.166 Infinity 1.301 241 eighth lens 9.066 -12.271 3.620 FDS18-W 1.946 17.984 50.982 242 10.214 -11.224 0.100 251 Ninth lens 9.828 85.184 1.780 FDS18-W 1.946 17.984 27.042 252 9.574 -36.864 0.100 261 tenth lens 9.020 22.890 0.700 H-ZF12 1.762 26.613 -13.412 262 8.394 7.013 0.185 271 Eleventh lens 8.446 7.421 3.150 FCD515 1.593 68.624 8.325 272 8.176 -12.532 0 281 twelfth lens 8.176 -12.532 1.900 TAFD40 2.001 25.458 -14.623 282 8.062 -89.067 6.961 4 plate glass 8.028 Infinity 0.500 H-K9L 1.517 64.212 Infi _n it _y - 7.968 _{Infinite ​ ​} 7.561 5 imaging surface 6.612 Infinity

The detailed optical data at the shortest focal length of this specific embodiment is shown in Table 5-2.

Table 5-2 Detailed optical data at the shortest focal length of Example 5

Please refer to Figure 63 for the values of some conditional expressions in this specific embodiment.

For the resolution of this specific embodiment, please refer to Figures 51 to 54. From the figures, it can be seen that the communication is well controlled, the resolution and imaging quality are high, and the visible and infrared 850nm confocality can be seen from Figures 55 to 58. You can see The confocal performance of visible light and infrared is good. In the case of visible light focusing, switching to infrared 850nm, the imaging effect is still good. For details of field curvature and distortion diagrams, see (A) and (B) of Figure 59 and (A) and (A) of Figure 60 (B), the longitudinal chromatic aberration diagram is detailed in Figure 60 and Figure 62. It can be seen that the distortion is small, the chromatic aberration is small, and the imaging quality is high.

In this specific embodiment, the focal length of the zoom lens is f=3.1-8.6 mm; the aperture value FNO=1.49-2.2.

Although the invention has been specifically shown and described in conjunction with preferred embodiments, it will be apparent to those skilled in the art that the invention can be modified in form and detail without departing from the spirit and scope of the invention as defined by the appended claims. Various changes are made within the scope of the present invention.

Claims (5)

1. A zoom lens, characterized in that: the lens system comprises a first lens, a second lens, a third lens, a fourth lens, a diaphragm and a fifth lens, wherein the first lens, the second lens, the third lens, the fourth lens, the diaphragm and the fifth lens are sequentially arranged from an object side to an image side along an optical axis; the first lens element to the twelfth lens element each comprise an object side surface facing the object side and allowing the imaging light to pass therethrough, and an image side surface facing the image side and allowing the imaging light to pass therethrough;

the first lens has negative refractive index, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative refractive index, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens has negative refractive index, the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a concave surface; the fourth lens has positive refractive index, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the image side surface of the third lens is glued with the object side surface of the fourth lens; the first lens to the fourth lens form a compensating lens group;

the fifth lens has positive refractive index, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; the sixth lens element has positive refractive index, wherein the object-side surface of the sixth lens element is convex, and the image-side surface of the sixth lens element is convex; the seventh lens has negative refractive index, the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a plane; the eighth lens has positive refractive index, the object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens is a convex surface; the ninth lens has positive refractive index, the object side surface of the ninth lens is a convex surface, and the image side surface of the ninth lens is a convex surface; the tenth lens has negative refractive index, the object side surface of the tenth lens is a convex surface, and the image side surface of the tenth lens is a concave surface; the eleventh lens has positive refractive index, the object side surface of the eleventh lens is a convex surface, and the image side surface of the eleventh lens is a convex surface; the twelfth lens has negative refractive power, the object side surface of the twelfth lens is a concave surface, and the image side surface of the twelfth lens is a convex surface; the image side surface of the sixth lens is glued with the object side surface of the seventh lens; the image side surface of the eleventh lens is glued with the object side surface of the twelfth lens; the fifth lens to the twelfth lens form a variable magnification lens group;

the object side surface and the image side surface of the first lens to the twelfth lens are spherical, and the lens with refractive index of the zoom lens is only twelve pieces;

the zoom lens also satisfies: 1.4< nd6<1.5, 80< vd6<95,1.8< nd7<1.9, 20< vd7<30,1.45< nd11<1.6, 50< vd11<80,1.8< nd12<2.1, 20< vd12<30, where nd6 and nd7 represent refractive indices of the sixth and seventh lenses at d-line, nd11 and nd12 represent refractive indices of the eleventh and twelfth lenses at d-line, respectively, vd6 and vd7 represent dispersion coefficients of the sixth and seventh lenses at d-line, respectively, and vd11 and vd12 represent dispersion coefficients of the eleventh and twelfth lenses at d-line, respectively.

2. The zoom lens of claim 1, wherein the zoom lens further satisfies: 1.9< nd8<2, 16< vd8<20,1.9< nd9<2, 16< vd9<20, wherein nd8 and nd9 represent refractive indices of the eighth and ninth lenses, respectively, at d-line, and vd8 and vd9 represent dispersion coefficients of the eighth and ninth lenses, respectively, at d-line.

3. The zoom lens of claim 1, wherein the zoom lens further satisfies: 0.3< fw/BFLw <0.5, where fw is the shortest focal length and BFLw is the back focal length at the shortest focal length.

4. The zoom lens of claim 1, wherein the zoom lens further satisfies: 0.5< ft/BFLt <1, where ft is the longest focal length and BFLt is the back focal length at the longest focal length.

5. The zoom lens of claim 1, wherein the zoom lens further satisfies: 53.44mm < TTL <75mm, wherein TTL is the distance from the object side surface to the imaging surface of the first lens on the optical axis.