A zoom lens

Abstract

The embodiment of the present application discloses a zoom lens, comprising a negative focal length focusing lens group and a positive focal length zoom lens group arranged in sequence along the optical axis from the object plane to the image plane; the focusing lens group comprises a first lens with negative focal length, a second lens with negative focal length and a third lens with positive focal length; the zoom lens group comprises a fourth lens with positive focal length, a fifth lens with positive focal length, a sixth lens with positive focal length, a seventh lens with negative focal length, an eighth lens with positive focal length and a ninth lens with negative focal length, and the focal length FT of the long focal end of the zoom lens and the focal length FW of the wide angle end satisfy 4.2 <= FT / FW <= 5.2. By reasonably setting the focal length of each lens group, the number of lenses included in each lens group, the focal length of each lens and the ratio between the focal length of the long focal end and the focal length of the wide angle end, it is ensured that a zoom lens with larger aperture, higher image quality and more suitable for more situations can be realized.

Description

Technical Field

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

[0002] In the security field, zoom lenses have been widely used due to their advantages such as long shooting distance and wide shooting angle. With the development of technology, cameras are gradually moving towards miniaturization and refinement, which also puts forward more stringent requirements for mainstream zoom lenses.

[0003] Currently, the mainstream zoom lens on the market is still 1 / 2.7". However, as camera sizes gradually decrease, the size of traditional zoom lenses can no longer meet the requirements of cameras, and traditional zoom lenses also suffer from problems such as small apertures. Therefore, developing a lens with a large aperture is essential. Summary of the Invention

[0004] This invention provides a zoom lens that achieves a zoom lens design that balances small size and large aperture.

[0005] This invention provides a zoom lens, including a focusing lens group and a zoom lens group arranged sequentially along the optical axis from the object plane to the image plane; the focusing lens group has a negative optical power, and the zoom lens group has a positive optical power.

[0006] The focusing lens group includes a first lens with negative optical power, a second lens with negative optical power, and a third lens with positive optical power.

[0007] The zoom lens group includes a fourth lens with positive optical power, a fifth lens with positive optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power, and a ninth lens with negative optical power.

[0008] Furthermore, 4.2 ≤ FT / FW ≤ 5.2; where FT represents the focal length at the telephoto end of the zoom lens, and FW represents the focal length at the wide-angle end of the zoom lens.

[0009] Optionally, -2.65≤F1 / FW≤-1.76; 2.30≤F2 / FW≤2.85;

[0010] Wherein, F1 represents the focal length of the focusing lens group, F2 represents the focal length of the zoom lens group, and FW represents the focal length of the wide-angle end of the zoom lens.

[0011] Optionally, 0.49 ≤ S1 / S2 ≤ 0.71;

[0012] Wherein, S1 represents the distance between the closest position and the farthest position of the focusing lens group in the zoom lens to the image plane during the movement, and S2 represents the distance between the closest position and the farthest position of the zoom lens group in the zoom lens to the image plane during the movement.

[0013] Optionally, 1.63≤nd1≤1.90; 30.0≤vd1≤60.0; 1.50≤nd4≤1.56, 74.0≤vd4≤81.6;

[0014] 1.43≤nd6≤1.50; 80.0≤vd6≤96.0; 1.52≤nd7≤1.84; 24.0≤vd7≤40.0;

[0015] Wherein, nd1 represents the refractive index of the first lens, and vd1 represents the Abbe number of the first lens; nd4 represents the refractive index of the fourth lens, and vd4 represents the Abbe number of the fourth lens; nd6 represents the refractive index of the sixth lens, and vd6 represents the Abbe number of the sixth lens; nd7 represents the refractive index of the seventh lens, and vd7 represents the Abbe number of the seventh lens.

[0016] Optionally, 0.160 < ΦG1 / TTLW < 0.175;

[0017] Wherein, ΦG1 represents the maximum lens diameter in the focusing lens group, and TTLW represents the total optical length of the zoom lens at the wide-angle end.

[0018] Optionally, the first lens, the fourth lens, the sixth lens, and the seventh lens are all glass spherical lenses, and the second lens, the third lens, the fifth lens, the eighth lens, and the ninth lens are all plastic aspherical lenses.

[0019] Optionally, the first lens includes a first object-side surface near the object surface and a first image-side surface near the image surface, wherein the first object-side surface is convex and the first image-side surface is concave.

[0020] The second lens includes a second object-side surface near the object plane and a second image-side surface near the image plane, wherein the second object-side surface is concave and the second image-side surface is concave.

[0021] The third lens includes a third object-side surface near the object surface, and the third object-side surface is convex.

[0022] The fourth lens includes a fourth object-side surface near the object surface, and the fourth object-side surface is a convex surface;

[0023] The fifth lens includes a fifth object-side surface near the object plane and a fifth image-side surface near the image plane. The fifth object-side surface is convex, and the fifth image-side surface is concave.

[0024] The sixth lens includes a sixth object-side surface near the object plane and a sixth image-side surface near the image plane. The sixth object-side surface is convex, and the sixth image-side surface is convex.

[0025] The seventh lens includes a seventh object-side surface near the object surface, and the seventh object-side surface is concave.

[0026] The eighth lens includes an eighth object-side surface near the object plane and an eighth image-side surface near the image plane. The eighth object-side surface is convex, and the eighth image-side surface is concave.

[0027] The ninth lens includes a ninth object-side surface near the object plane and a ninth image-side surface near the image plane. The ninth object-side surface is convex, and the ninth image-side surface is concave.

[0028] Optionally, the sixth lens is cemented together with the seventh lens.

[0029] Optionally, the zoom lens further includes an aperture stop, which is disposed in the optical path between the fourth lens and the fifth lens.

[0030] Optionally, the zoom lens further includes a filter, which is disposed in the optical path between the ninth lens and the image plane.

[0031] The zoom lens provided in this embodiment of the invention comprises a focusing lens group with negative optical power and a zoom lens group with positive optical power. The focusing lens group includes a first lens, a second lens with negative optical power, and a third lens with positive optical power. The zoom lens group includes a fourth lens, a fifth lens, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power, and a ninth lens with negative optical power. Furthermore, the focal length FT at the telephoto end and the focal length FW at the wide-angle end of the zoom lens satisfy 4.2 ≤ FT / FW ≤ 5.2. By reasonably setting the optical power of each lens group, the number of lenses in each lens group, the optical power of each lens, and the ratio between the focal length at the telephoto end and the focal length at the wide-angle end, a zoom lens with a larger aperture, higher image quality, and suitability for a wider range of situations can be achieved.

[0032] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

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

[0034] Figure 1 This is a schematic diagram of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention;

[0035] Figure 2 This is a schematic diagram of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention;

[0036] Figure 3 This is a schematic diagram of the axial aberration curve of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention;

[0037] Figure 4 This is a ray fan diagram of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention;

[0038] Figure 5 This is a transverse chromatic aberration diagram of a zoom lens at the wide-angle end provided in Embodiment 1 of the present invention;

[0039] Figure 6 This is a schematic diagram of the axial aberration curve of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention.

[0040] Figure 7 This is a ray fan diagram of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention;

[0041] Figure 8 This is a transverse chromatic aberration diagram of a zoom lens at the telephoto end provided in Embodiment 1 of the present invention;

[0042] Figure 9 This is a schematic diagram of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention;

[0043] Figure 10 This is a schematic diagram of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention;

[0044] Figure 11 This is a schematic diagram of the axial aberration curve of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention;

[0045] Figure 12 This is a ray fan diagram of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention;

[0046] Figure 13This is a transverse chromatic aberration diagram of a zoom lens at the wide-angle end provided in Embodiment 2 of the present invention;

[0047] Figure 14 This is a schematic diagram of the axial aberration curve of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention;

[0048] Figure 15 This is a ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention;

[0049] Figure 16 This is a transverse chromatic aberration diagram of a zoom lens at the telephoto end provided in Embodiment 2 of the present invention;

[0050] Figure 17 This is a schematic diagram of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

[0051] Figure 18 This is a schematic diagram of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention;

[0052] Figure 19 This is a schematic diagram of the axial aberration curve of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

[0053] Figure 20 This is a ray fan diagram of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

[0054] Figure 21 This is a transverse chromatic aberration diagram of a zoom lens at the wide-angle end provided in Embodiment 3 of the present invention;

[0055] Figure 22 This is a schematic diagram of the axial aberration curve of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention;

[0056] Figure 23 This is a ray fan diagram of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention;

[0057] Figure 24 This is a transverse chromatic aberration diagram of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention. Detailed Implementation

[0058] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0059] Example 1

[0060] Figure 1 This is a schematic diagram of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention, as shown below. Figure 1 and Figure 2 As shown, the zoom lens provided in Embodiment 1 of the present invention includes a focusing lens group G1 and a zoom lens group G2 arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the focusing lens group G1 is negative, and the optical power of the zoom lens group G2 is positive; the focusing lens group G1 includes a first lens 101 with negative optical power, a second lens 102 with negative optical power, and a third lens 103 with positive optical power; the zoom lens group G2 includes a fourth lens 104 with positive optical power, a fifth lens 105 with positive optical power, a sixth lens 106 with positive optical power, a seventh lens 107 with negative optical power, an eighth lens 108 with positive optical power, and a ninth lens 109 with negative optical power; and 4.2≤FT / FW≤5.2; where FT represents the focal length at the telephoto end of the zoom lens, and FW represents the focal length at the wide-angle end of the zoom lens.

[0061] Specifically, in the zoom lens provided in this embodiment, the focusing lens group G1 and the zoom lens group G2 can be arranged in one lens barrel ( Figure 1 (Not shown in the image). The focusing lens group G1 and the zoom lens group G2 can reciprocate along the optical axis within the lens barrel. Through the joint movement of the focusing lens group G1 and the zoom lens group G2, the focal length of the zoom lens can be continuously changed from wide-angle to telephoto, ensuring high image quality at all focal points.

[0062] Understandably, during the zoom process achieved by moving the focusing lens group G1 and the zoom lens group G2, the zoom lens is at its shortest focal length, i.e., at the wide-angle end, and at its longest focal length, i.e., at the telephoto end. At the wide-angle end and the telephoto end, the zoom lens has different focal lengths and optical powers, as well as different lengths or shapes.

[0063] Furthermore, optical power is equal to the difference between the convergence of the beam at the image plane and the convergence of the beam at the object plane, characterizing the ability of an optical system to deflect light. The larger the absolute value of the optical power, the stronger the bending ability of light; the smaller the absolute value, the weaker the bending ability. When the optical power is positive, the refraction of light is converging; when the optical power is negative, the refraction of light is diverging. Optical power can be used to characterize a single refractive surface of a lens (i.e., a surface of the lens), a single lens, or a system formed by multiple lenses (i.e., a lens group). A negative optical power in the focusing lens group G1 ensures that light has a larger aperture before entering the aperture stop, increasing the aperture of the fixed-focus lens. Simultaneously, the focusing lens group G1, in conjunction with the fourth lens 104 in the zoom lens group G2, ensures that light passes smoothly through the aperture stop 110, avoiding stray light such as reflections at the aperture stop 110, while also adjusting the aberrations of the zoom lens to a certain extent, ensuring aberration balance and stable high and low temperature performance of the zoom lens.

[0064] Furthermore, the first lens 101 and the second lens 102 are negative power lenses, which can effectively deflect large-angle incident light rays, ensuring that more light enters the optical system. This effectively increases the field of view of the zoom lens, ensuring that the optical system has wide-angle characteristics. The third lens 103 is a positive power lens. Thus, the third lens 103 can promptly correct the large aberrations produced by the first lens 101 and the second lens 102, especially effectively correcting the edge aberrations of the zoom lens, thereby improving the imaging resolution of the optical system.

[0065] Furthermore, the focal length FT at the telephoto end of the zoom lens and the focal length FW at the wide-angle end of the zoom lens satisfy 4.2 ≤ / FW ≤ 5.2. This allows control over the zoom range and focal length range of the lens, meeting the usage needs under more conditions.

[0066] In summary, the zoom lens provided in this embodiment of the invention, by setting the zoom lens to include a focusing lens group with negative optical power and a zoom lens group with positive optical power, and simultaneously setting the focusing lens group to include a first lens with negative optical power, a second lens with negative optical power, and a third lens with positive optical power, and setting the zoom lens group to include a fourth lens with positive optical power, a fifth lens with positive optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power, and a ninth lens with negative optical power, and by reasonably setting the optical power of each lens group, the number of lenses included in each lens group, the optical power of each lens, and the ratio between the focal length at the telephoto end and the focal length at the wide-angle end, ensures that a zoom lens with a larger aperture, higher image quality, and suitability for more situations can be achieved.

[0067] Based on the above embodiments, continue to refer to Figure 1 and Figure 2 As shown, the zoom lens also includes an aperture stop 110, which is disposed in the optical path between the fourth lens 104 and the fifth lens 105.

[0068] Specifically, by setting the aperture stop 110, the propagation direction of the light beam can be adjusted, which is beneficial to improving image quality. Furthermore, in this zoom lens, the aperture stop 110 can be located in the optical path between the fourth lens 104 and the fifth lens 105. The fact that the aperture stop 110 is located in the middle of the zoom lens can ensure that the front and rear apertures of the zoom lens are minimized.

[0069] Based on the above embodiments, continue to refer to Figure 1 and Figure 2 As shown, the zoom lens provided in this embodiment of the invention may further include a filter 111. The filter 111 is disposed in the optical path between the ninth lens 109 and the image plane. The filter 111 can filter out interference light and improve the imaging effect of the zoom lens.

[0070] Based on the above embodiments, continue to refer to Figure 1 and Figure 2 As shown, the zoom lens provided in this embodiment of the invention may further include a flat glass plate, which is disposed in the optical path between the filter 111 and the image plane. The flat glass plate can protect the photosensitive chip in the imaging sensor. The imaging chip is used to convert the light signal collected by the zoom lens into an electrical signal, thereby ensuring the imaging effect of the zoom lens.

[0071] Based on the above embodiment, -2.65≤F1 / FW≤-1.76; 2.30≤F2 / FW≤2.85; where F1 represents the focal length of the focusing lens group, F2 represents the focal length of the zoom lens group, and FW represents the focal length at the wide-angle end of the zoom lens. Using this lens configuration achieves a reasonable balance of optical power, allowing light to pass through the lens more smoothly and significantly correcting the impact of advanced lens aberrations on image quality.

[0072] Based on the above embodiment, 0.49 ≤ S1 / S2 ≤ 0.71; where S1 represents the distance between the closest and farthest positions of the focusing lens group to the image plane during the movement of the zoom lens group, and S2 represents the distance between the closest and farthest positions of the zoom lens group to the image plane during the movement of the zoom lens group. By controlling the movement distance of the focusing lens group G1 and the zoom lens group G2, the movement range of the focusing lens group G1 is minimized to the greatest extent, thereby significantly reducing the lens size.

[0073] Based on the above embodiment, 0.160 < ΦG1 / TTLW < 0.175; where ΦG1 represents the maximum lens diameter in the focusing lens group, and TTLW represents the total optical length of the zoom lens at the wide-angle end. This range limits and controls the lens size, allowing for smaller lenses while maximizing the field of view and light intake to meet the needs of use under more demanding conditions.

[0074] Based on the above embodiments, the first lens 101, the fourth lens 104, the sixth lens 106 and the seventh lens 107 are all glass spherical lenses, and the second lens 102, the third lens 103, the fifth lens 105, the eighth lens 108 and the ninth lens 109 are all plastic aspherical lenses.

[0075] Specifically, aspherical lenses are characterized by a continuous change in curvature from the center to the periphery, unlike spherical lenses which have a constant curvature. Aspherical lenses offer superior curvature radius characteristics, improving distortion and astigmatism. Using aspherical lenses can minimize aberrations during image formation, thus enhancing image quality. Furthermore, plastic lenses are significantly cheaper and lighter than glass lenses. Using multiple plastic aspherical lenses in zoom lenses reduces both cost and weight, allowing for a wider range of applications. Spherical lenses, on the other hand, have a constant curvature from the center to the periphery, simplifying lens design. Glass lenses have a low coefficient of thermal expansion and good stability. Therefore, including glass spherical lenses in zoom lenses helps balance high and low temperatures. When the ambient temperature varies significantly, this helps maintain focal length stability, ensuring stable optical performance within a range of -40℃ to 85℃.

[0076] The zoom lens in this embodiment of the invention comprises at least four glass spherical lenses, and both the focusing lens group G1 and the zoom lens group G2 of the zoom lens contain at least two plastic aspherical lenses. The glass and plastic materials can compensate for each other. Using a combination of glass and plastic lenses in the zoom lens can effectively balance the lens's resolution under high and low temperature conditions. Furthermore, a suitable combination of glass lenses also provides good aberration correction. Using these materials ensures good resolution within the range of -40 to 80°C. In addition, using glass lenses can significantly correct chromatic aberration. The aforementioned combination of glass lenses can achieve good resolution across the entire wavelength range of 430nm-850nm, expanding the lens's usability.

[0077] Furthermore, the use of glass in the first lens 101 of the focusing lens group G1 serves two purposes: firstly, it protects the lens to a certain extent and extends its lifespan; secondly, it helps to reduce chromatic aberration, preventing excessive chromatic aberration at the rear of the lens that is difficult to correct. Additionally, the first lens 101, second lens 102, and third lens 103 constitute the focusing lens group G1, which requires controlled high and low temperature conditions. Using glass in the first lens 101 significantly controls the high and low temperature conditions of the focusing lens group G1, preventing serious impact on the entire lens. Similarly, the use of glass in the fourth lens 104 of the zoom lens group G2 helps to correct chromatic aberration before light enters the aperture stop, preventing greater impact on the rear. Furthermore, the glass material of the fourth lens 104 helps to maintain the high and low temperature conditions of the zoom lens group G2. The sixth lens 106 and seventh lens 107 of the zoom lens group G2 are also made of glass, working in conjunction with the fourth lens 104 to control the high and low temperature conditions of the zoom group. The ninth lens 109 uses a plastic aspherical lens to control advanced aberrations at the rear of the lens, further improving image quality. In addition, the use of an aspherical lens at the rear of the lens allows for more precise control of the exit angle of light, improving the matching degree between the lens and the signal receiving device.

[0078] Based on the above embodiments, the sixth lens 106 and the seventh lens 107 are cemented together. This cementing effectively eliminates chromatic aberration in light that has just passed through the aperture 110, preventing the formation of difficult-to-eliminate high-order aberrations at the rear of the lens. This improves the lens's image quality to a certain extent and further ensures clear images across the entire spectral range. Furthermore, after light passes through the aperture, the cemented lens group effectively corrects chromatic aberration, avoiding the need for a large amount of high Abbe number material to pull back chromatic aberration at the rear of the lens, thus saving costs while improving image quality.

[0079] Based on the above embodiments, 1.63≤nd1≤1.90; 30.0≤vd1≤60.0; 1.50≤nd4≤1.56, 74.0≤vd4≤81.6; 1.43≤nd6≤1.50; 80.0≤vd6≤96.0; 1.52≤nd7≤1.84; 24.0≤vd7≤40.0; where nd1 represents the refractive index of the first lens, vd1 represents the Abbe number of the first lens; nd4 represents the refractive index of the fourth lens, vd4 represents the Abbe number of the fourth lens; nd6 represents the refractive index of the sixth lens, vd6 represents the Abbe number of the sixth lens; nd7 represents the refractive index of the seventh lens, vd7 represents the Abbe number of the seventh lens.

[0080] Specifically, refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium. It is mainly used to describe a material's ability to refract light, and different materials have different refractive indices. Therefore, by matching the refractive indices of the various glass lenses in a zoom lens, a better correction effect on lens aberrations can be achieved. The Abbe number is an index used to represent the dispersion ability of a transparent medium. The more severe the dispersion of the medium, the smaller the Abbe number; conversely, the less severe the dispersion, the larger the Abbe number. Using a glass material with a high Abbe number for the fourth lens 104 in zoom lens group G2 can minimize chromatic aberration before the light enters the aperture stop 110, avoiding a greater impact on the back end.

[0081] Based on the above embodiments, the first lens 101 includes a first object-side surface near the object plane and a first image-side surface near the image plane, wherein the first object-side surface is convex and the first image-side surface is concave; the second lens 102 includes a second object-side surface near the object plane and a second image-side surface near the image plane, wherein the second object-side surface is concave and the second image-side surface is concave; the third lens 103 includes a third object-side surface near the object plane, wherein the third object-side surface is convex; the fourth lens 104 includes a fourth object-side surface near the object plane, wherein the fourth object-side surface is convex; and the fifth lens 105 includes a fifth object-side surface near the object plane and a fifth image-side surface near the image plane. The fifth object side is convex, and the fifth image side is concave; the sixth lens 106 includes a sixth object side near the object plane and a sixth image side near the image plane, the sixth object side and the sixth image side are both convex; the seventh lens 107 includes a seventh object side near the object plane, the seventh object side is concave; the eighth lens 108 includes an eighth object side near the object plane and an eighth image side near the image plane, the eighth object side is convex, and the eighth image side is concave; the ninth lens 109 includes a ninth object side near the object plane and a ninth image side near the image plane, the ninth object side is convex, and the ninth image side is concave.

[0082] Specifically, the first object-side surface of the first lens 101 is convex, and the first image-side surface is concave. That is, the object-side surface of the first lens 101 convexes towards the object plane, and the image-side surface is concave towards the image plane; thus, the first lens 101 is a lens with a convex-concave structure. The second object-side surface of the second lens 102 is concave, and the second image-side surface is concave. That is, the object-side surface of the second lens 102 is concave towards the object plane, and the image-side surface is concave towards the image plane; thus, the second lens 102 is a lens with a double-concave structure. The third object-side surface of the third lens 103 is convex, and the third object-side surface of the fourth lens 104 is convex. The fifth object-side surface of the fifth lens 105 is convex, and the fifth image-side surface is concave. That is, the object-side surface of the fifth lens 105 convexes towards the object plane, and the image-side surface is concave towards the image plane; thus, the fifth lens 105 is a lens with a convex-concave structure. The sixth object-side surface of the sixth lens 106 is convex, and the sixth image-side surface is convex. That is, the object-side surface of the sixth lens 106 convexes towards the object plane, and the image-side surface is concave towards the image plane; thus, the sixth lens 106 is a lens with a double-convex structure. The seventh object-side surface is concave, meaning the object-side surface of the seventh lens 107 is recessed towards the object plane. The eighth object-side surface is convex, and the eighth image-side surface is concave, meaning the object-side surface of the eighth lens 108 is convex towards the object plane, and the image-side surface is concave towards the image plane; therefore, the eighth lens 108 is a lens with a convex-concave structure. The ninth object-side surface is convex, and the ninth image-side surface is concave, meaning the object-side surface of the ninth lens 109 is convex towards the object plane, and the image-side surface is concave towards the image plane; therefore, the ninth lens 109 is a lens with a convex-concave structure. Through the surface design of each lens and combined with the optical power of each lens, the imaging effect of the zoom lens can be further adjusted.

[0083] Furthermore, the convex-concave structure of the first lens 101 facilitates light collection, ensuring a wider field of view for the zoom lens. The concave image-side surface of the second lens 102, in conjunction with the convex side surface of the third lens 103, shortens the overall optical length of the focusing lens group G1, thereby reducing the overall length of the zoom lens. Similarly, the combination of the concave image-side surface of the fifth lens 105 with the convex side surface of the sixth lens 106, and the combination of the concave image-side surface of the eighth lens 108 with the convex side surface of the ninth lens 109, further shortens the overall optical length of the zoom lens group G2, and consequently, the overall length of the zoom lens.

[0084] As a feasible implementation method, the parameters of each lens in the zoom lens will be explained next.

[0085] Table 1. Optical design values ​​for the zoom lens in Example 1

[0086]

[0087] Table 2 Design values ​​of optical physical parameters for a zoom lens

[0088]

[0089] Table 3. Zoom intervals at the wide-angle and telephoto ends of a zoom lens.

[0090]

[0091] In Table 2 above, the surface numbers are assigned according to the surface sequence of each lens. "S1" represents the object surface of the first lens, "S2" represents the image surface of the first lens, and so on. "STO" represents the aperture stop of the lens. The radius of curvature represents the curvature of the lens surface; a positive value indicates that the surface bends towards the object surface, and a negative value indicates that the surface bends towards the image surface. "INF" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the central axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current location is air with a refractive index of 1. The Abbe constant represents the dispersion characteristics of the material between the current surface and the next surface; a blank space indicates that the current location is air.

[0092] The zoom intervals in Table 3 above represent different interval values ​​for the lens at the wide-angle and telephoto ends.

[0093] Table 4 Design values ​​of aspherical conic coefficient in a zoom lens

[0094]

[0095] express All other coefficients are represented in this way.

[0096] The aspherical conic coefficients can be defined using the following aspherical formulas, but are not limited to the following representations:

[0097]

[0098] Where z is the axial sagitta in the Z direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature R; and k is the fitted conic coefficient. These are the higher-order aspheric coefficients corresponding to the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders of aspheric surfaces. These can be combined to form higher-order terms for the corresponding aspherical surfaces.

[0099] The optical parameters of the optical system in this embodiment are shown in Table 5 below.

[0100] Table 5 Specific parameters for this embodiment

[0101]

[0102] Figure 3 This is a schematic diagram of the axial aberration curve of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention, as shown below. Figure 3 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 3 It can be seen that the axial aberrations of different wavelengths (0.3~1.0 normalized aperture) are all controlled within a reasonable range, indicating that the zoom lens achieves good control over transverse chromatic aberration at the wide-angle end. Furthermore, at pupil positions of 0.5-0.9, there is no significant chromatic aberration between visible and infrared light, meeting the basic requirement for clear nighttime imaging and achieving a clear image across the entire wavelength range.

[0103] Figure 4 The ray fan pattern of the zoom lens at the wide-angle end provided in Embodiment 1 of the present invention is as follows: Figure 4 As shown, in a single image, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should perfectly coincide with the horizontal axis, in which case all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 4 It can be seen that this zoom lens closely approximates the horizontal axis at various wavelengths (specifically 436nm, 486nm, 546nm, 588nm, 656nm, and 850nm) across all fields of view, indicating that its transverse aberrations at each wavelength are well corrected. Furthermore, the curves for each color do not show significant dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0104] Figure 5 This is a transverse chromatic aberration diagram of a zoom lens at the wide-angle end provided in Embodiment 1 of the present invention, such as... Figure 5 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 5 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the wide-angle end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0105] Figure 6 This is a schematic diagram of the axial aberration curve of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention, as shown below. Figure 6 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 6 It can be seen that the axial aberrations of different wavelengths (0.3~1.0 normalized aperture) are all controlled within a reasonable range, indicating that the zoom lens achieves good control over transverse chromatic aberration at the wide-angle end. Furthermore, at pupil positions of 0.5-0.9, there is no significant chromatic aberration between visible and infrared light, meeting the basic requirement for clear nighttime imaging and achieving a clear image across the entire wavelength range.

[0106] Figure 7 The ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 1 of the present invention is as follows: Figure 7 As shown, in a single image, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should perfectly coincide with the horizontal axis, in which case all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 7 It can be seen that this zoom lens closely approximates the horizontal axis at various wavelengths (specifically 436nm, 486nm, 546nm, 588nm, 656nm, and 850nm) across all fields of view, indicating that its transverse aberrations at each wavelength are well corrected. Furthermore, the curves for each color do not show significant dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0107] Figure 8 This is a transverse chromatic aberration diagram of a zoom lens at the telephoto end provided in Embodiment 1 of the present invention, as shown below. Figure 8 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 8 It can be seen that the transverse chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the telephoto end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0108] In summary, the zoom lens provided in Embodiment 1 of this invention achieves full-band confocal focusing in the 436nm-850nm wavelength range under a 1 / 2.7″ target surface by reasonably setting the optical power of different lens groups, the number of lenses included in different lens groups, and the optical power of each lens. At the same time, by setting optical parameters such as the glass-plastic form and surface shape of each lens, the ratio between the focal length of each lens group and the focal length at the wide-angle end of the zoom lens, the refractive index of the lens, the Abbe number, and the cementation condition, it also achieves a larger aperture, higher image quality, and suitability for a wider range of usage needs.

[0109] Example 2

[0110] Figure 9 This is a schematic diagram of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention. Figure 10 This is a schematic diagram of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention, as shown below. Figure 9 and Figure 10 As shown, the zoom lens provided in Embodiment 2 of the present invention includes a focusing lens group G1 and a zoom lens group G2 arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the focusing lens group G1 is negative, and the optical power of the zoom lens group G2 is positive; the focusing lens group G1 includes a first lens 101 with negative optical power, a second lens 102 with negative optical power, and a third lens 103 with positive optical power; the zoom lens group G2 includes a fourth lens 104 with positive optical power, a fifth lens 105 with positive optical power, a sixth lens 106 with positive optical power, a seventh lens 107 with negative optical power, an eighth lens 108 with positive optical power, and a ninth lens 109 with negative optical power; and 4.2≤FT / FW≤5.2; where FT represents the focal length at the telephoto end of the zoom lens, and FW represents the focal length at the wide-angle end of the zoom lens.

[0111] The lens setup is the same as in Embodiment 1, and will not be repeated here.

[0112] As another feasible implementation method, the specific parameters of the zoom lens are described below. Table 6: Optical design values ​​of the zoom lens in Example 2.

[0113]

[0114] Table 7 Design values ​​of optical physical parameters for a zoom lens

[0115]

[0116] Table 8. Zoom intervals at the wide-angle and telephoto ends of a zoom lens.

[0117]

[0118] In Table 7 above, the surface numbers are assigned according to the surface sequence of each lens. "S1" represents the object surface of the first lens, "S2" represents the image surface of the first lens, and so on. "STO" represents the aperture stop of the lens. The radius of curvature represents the degree of curvature of the lens surface; a positive value indicates that the surface bends towards the object surface, and a negative value indicates that the surface bends towards the image surface. "INF" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the central axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current location is air with a refractive index of 1. The Abbe constant represents the dispersion characteristics of the material between the current surface and the next surface; a blank space indicates that the current location is air.

[0119] The zoom intervals in Table 8 above are the different interval values ​​for the lens at the wide-angle end and the telephoto end.

[0120] Table 9 Design values ​​of aspherical conic coefficient in a zoom lens

[0121]

[0122] express All other coefficients are represented in this way.

[0123] The aspherical conic coefficients can be defined using the following aspherical formulas, but are not limited to the following representations:

[0124]

[0125] Where z is the axial sagitta in the Z-direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, numerically the reciprocal of the radius of curvature R; k is the fitted conic coefficient; a4, a6, a8, a10, a12, a14, and a16 are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order higher-order aspherical coefficients corresponding to the aspherical surface. These can be combined to form higher-order terms for the corresponding aspherical surfaces.

[0126] The optical parameters of the optical system in this embodiment are shown in Table 10 below.

[0127] Table 10 Specific parameters for this embodiment

[0128]

[0129] Figure 11 This is a schematic diagram of the axial aberration curve of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention, as shown below. Figure 11 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 11 It can be seen that the axial aberrations of different wavelengths (0.3~1.0 normalized aperture) are all controlled within a reasonable range, indicating that the zoom lens achieves good control over transverse chromatic aberration at the wide-angle end. Furthermore, at pupil positions of 0.5-0.9, there is no significant chromatic aberration between visible and infrared light, meeting the basic requirement for clear nighttime imaging and achieving a clear image across the entire wavelength range.

[0130] Figure 12 The ray fan pattern of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention is as follows: Figure 12As shown, in a single image, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should perfectly coincide with the horizontal axis, in which case all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 12 It can be seen that this zoom lens closely approximates the horizontal axis at various wavelengths (specifically 436nm, 486nm, 546nm, 588nm, 656nm, and 850nm) across all fields of view, indicating that its transverse aberrations at each wavelength are well corrected. Furthermore, the curves for each color do not show significant dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0131] Figure 13 This is a transverse chromatic aberration diagram of the zoom lens at the wide-angle end provided in Embodiment 2 of the present invention, such as... Figure 13 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 13 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the wide-angle end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0132] Figure 14 This is a schematic diagram of the axial aberration curve of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention, as shown below. Figure 14 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 14 It can be seen that the axial aberrations of different wavelengths (0.3~1.0 normalized aperture) are all controlled within a reasonable range, indicating that the zoom lens achieves good control over transverse chromatic aberration at the wide-angle end. Furthermore, at pupil positions of 0.5-0.9, there is no significant chromatic aberration between visible and infrared light, meeting the basic requirement for clear nighttime imaging and achieving a clear image across the entire wavelength range.

[0133] Figure 15 The ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention is as follows: Figure 15As shown, in a single image, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should perfectly coincide with the horizontal axis, in which case all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 15 It can be seen that this zoom lens closely approximates the horizontal axis at various wavelengths (specifically 436nm, 486nm, 546nm, 588nm, 656nm, and 850nm) across all fields of view, indicating that its transverse aberrations at each wavelength are well corrected. Furthermore, the curves for each color do not show significant dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0134] Figure 16 This is a transverse chromatic aberration diagram of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention, as shown below. Figure 16 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 16 It can be seen that the transverse chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the telephoto end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0135] In summary, the zoom lens provided in Embodiment 2 of this invention achieves full-band confocal focusing in the 436nm-850nm wavelength range under a 1 / 2.7″ target surface by reasonably setting the optical power of different lens groups, the number of lenses included in different lens groups, and the optical power of each lens. At the same time, it achieves full-band confocal focusing in the 436nm-850nm wavelength range under a 1 / 2.7″ target surface with a larger aperture and higher image quality, making it suitable for a wider range of usage needs.

[0136] Example 3

[0137] Figure 17 This is a schematic diagram of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention. Figure 18 This is a schematic diagram of the zoom lens at the telephoto end provided in Embodiment 3 of the present invention, as shown below. Figure 17 and Figure 18As shown, the zoom lens provided in Embodiment 3 of the present invention includes a focusing lens group G1 and a zoom lens group G2 arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the focusing lens group G1 is negative, and the optical power of the zoom lens group G2 is positive; the focusing lens group G1 includes a first lens 101 with negative optical power, a second lens 102 with negative optical power, and a third lens 103 with positive optical power; the zoom lens group G2 includes a fourth lens 104 with positive optical power, a fifth lens 105 with positive optical power, a sixth lens 106 with positive optical power, a seventh lens 107 with negative optical power, an eighth lens 108 with negative optical power, and a ninth lens 109 with negative optical power; and 4.2≤FT / FW≤5.2; where FT represents the focal length at the telephoto end of the zoom lens, and FW represents the focal length at the wide-angle end of the zoom lens.

[0138] The lens setup is the same as in Embodiment 1, and will not be repeated here.

[0139] As another feasible implementation method, the specific parameters of the zoom lens are explained below.

[0140] Table 11. Optical design values ​​for the zoom lens in Example 3.

[0141]

[0142] Table 12 Design values ​​of optical physical parameters for a zoom lens

[0143]

[0144] Table 13 Zoom interval at the wide-angle and telephoto ends of a zoom lens

[0145]

[0146] In Table 12 above, the surface numbers are assigned according to the surface sequence of each lens. "S1" represents the object surface of the first lens, "S2" represents the image surface of the first lens, and so on. "STO" represents the aperture stop of the lens. The radius of curvature represents the curvature of the lens surface; a positive value indicates that the surface bends towards the object surface, and a negative value indicates that the surface bends towards the image surface. "INF" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the central axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current location is air with a refractive index of 1. The Abbe constant represents the dispersion characteristics of the material between the current surface and the next surface; a blank space indicates that the current location is air.

[0147] The zoom intervals in Table 13 above are the different interval values ​​for the lens at the wide-angle end and the telephoto end.

[0148] Table 14 Design values ​​of aspherical conic coefficient in a zoom lens

[0149]

[0150] express All other coefficients are represented in this way.

[0151] The aspherical conic coefficients can be defined using the following aspherical formulas, but are not limited to the following representations:

[0152]

[0153] Where z is the axial sagitta in the Z-direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, numerically the reciprocal of the radius of curvature R; k is the fitted conic coefficient; a4, a6, a8, a10, a12, a14, and a16 are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order higher-order aspherical coefficients corresponding to the aspherical surface. These can be combined to form higher-order terms for the corresponding aspherical surfaces.

[0154] The optical parameters of the optical system in this embodiment are shown in Table 15 below.

[0155] Table 15 Specific parameters for this embodiment

[0156]

[0157] Figure 19 This is a schematic diagram of the axial aberration curve of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention, as shown below. Figure 19 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 19 It can be seen that the axial aberrations of different wavelengths (0.3~1.0 normalized aperture) are all controlled within a reasonable range, indicating that the zoom lens achieves good control over transverse chromatic aberration at the wide-angle end. Furthermore, at pupil positions of 0.5-0.9, there is no significant chromatic aberration between visible and infrared light, meeting the basic requirement for clear nighttime imaging and achieving a clear image across the entire wavelength range.

[0158] Figure 20 The ray fan pattern of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention is as follows: Figure 20As shown, in a single image, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should perfectly coincide with the horizontal axis, in which case all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 20 It can be seen that this zoom lens closely approximates the horizontal axis at various wavelengths (specifically 436nm, 486nm, 546nm, 588nm, 656nm, and 850nm) across all fields of view, indicating that its transverse aberrations at each wavelength are well corrected. Furthermore, the curves for each color do not show significant dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0159] Figure 21 This is a transverse chromatic aberration diagram of the zoom lens at the wide-angle end provided in Embodiment 3 of the present invention, such as... Figure 21 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 21 It can be seen that the transverse chromatic aberration of different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the wide-angle end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0160] Figure 22 This is a schematic diagram of the axial aberration curve of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention, as shown below. Figure 22 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 22 It can be seen that the axial aberrations of different wavelengths (0.3~1.0 normalized aperture) are all controlled within a reasonable range, indicating that the zoom lens achieves good control over transverse chromatic aberration at the wide-angle end. Furthermore, at pupil positions of 0.5-0.9, there is no significant chromatic aberration between visible and infrared light, meeting the basic requirement for clear nighttime imaging and achieving a clear image across the entire wavelength range.

[0161] Figure 23 The ray fan pattern of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention is as follows: Figure 23As shown, in a single image, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. Ideally, each curve should perfectly coincide with the horizontal axis, in which case all rays in that field of view focus at the same point on the image plane; the vertical axis in a single image can also represent the maximum dispersion range of the beam on the ideal image plane. The fan plot can not only reflect monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figure 23 It can be seen that this zoom lens closely approximates the horizontal axis at various wavelengths (specifically 436nm, 486nm, 546nm, 588nm, 656nm, and 850nm) across all fields of view, indicating that its transverse aberrations at each wavelength are well corrected. Furthermore, the curves for each color do not show significant dispersion, indicating that this zoom lens also effectively corrects chromatic aberration, ensuring the imaging requirement of sharp images across the entire wavelength range.

[0162] Figure 24 This is a transverse chromatic aberration diagram of the zoom lens at the telephoto end provided in Embodiment 2 of the present invention, as shown below. Figure 24 As shown, the vertical direction represents the normalized aperture, 0 indicates it is on the optical axis, and the vertex in the perpendicular direction represents the maximum pupil radius; the dominant wavelength is 546.074 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 24 It can be seen that the transverse chromatic aberration at different wavelengths is controlled within a reasonable range, indicating that the transverse chromatic aberration of the zoom lens is well controlled at the telephoto end, which can meet the requirements of wide spectrum application across the entire wavelength range.

[0163] In summary, the zoom lens provided in Embodiment 2 of this invention achieves full-band confocal focusing in the 436nm-850nm wavelength range under a 1 / 2.7″ target surface by reasonably setting the optical power of different lens groups, the number of lenses included in different lens groups, and the optical power of each lens. At the same time, it achieves full-band confocal focusing in the 436nm-850nm wavelength range under a 1 / 2.7″ target surface with a larger aperture and higher image quality, making it suitable for a wider range of usage needs.

[0164] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A zoom lens, characterized in that, It includes a focusing lens group and a zoom lens group arranged sequentially along the optical axis from the object plane to the image plane; the optical power of the focusing lens group is negative, and the optical power of the zoom lens group is positive. The focusing lens group includes a first lens with negative optical power, a second lens with negative optical power, and a third lens with positive optical power, arranged sequentially from the object plane to the image plane. The zoom lens group includes a fourth lens with positive optical power, a fifth lens with positive optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power, and a ninth lens with negative optical power, arranged sequentially from the object plane to the image plane. Furthermore, 4.8972≤FT / FW≤5.2; where FT represents the focal length at the telephoto end of the zoom lens, and FW represents the focal length at the wide-angle end of the zoom lens; The zoom lens also includes a filter, which is disposed in the optical path between the ninth lens and the image plane; The zoom lens has nine lenses with optical power. The focusing lens group and the zoom lens group are disposed in a lens barrel; the focusing lens group and the zoom lens group reciprocate along the optical axis in the lens barrel, and through the joint movement of the focusing lens group and the zoom lens group, the focal length of the zoom lens can be continuously changed from the wide-angle end to the telephoto end. -2.65≤F1 / FW≤-2.56; 2.7695≤F2 / FW≤2.85; Wherein, F1 represents the focal length of the focusing lens group, and F2 represents the focal length of the zoom lens group.

2. The zoom lens according to claim 1, characterized in that, 1.77≤nd1≤1.90; 30.0≤vd1≤49.6; 1.50≤nd4≤1.56、74.0≤vd4≤81.6; 1.44≤nd6≤1.50; 80.0≤vd6≤95.1; 1.72≤nd7≤1.84; 24.0≤vd7≤29.5; Wherein, nd1 represents the refractive index of the first lens, and vd1 represents the Abbe number of the first lens; nd4 represents the refractive index of the fourth lens, and vd4 represents the Abbe number of the fourth lens; nd6 represents the refractive index of the sixth lens, and vd6 represents the Abbe number of the sixth lens; nd7 represents the refractive index of the seventh lens, and vd7 represents the Abbe number of the seventh lens.

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

4. The zoom lens according to claim 1, characterized in that, The sixth lens and the seventh lens are cemented together.

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

Images