A visible light wide-band long-focus lens, a camera module and a terminal device

Abstract

The application discloses a visible light wide-band long-focus lens, a camera module and a terminal device. The visible light wide-band long-focus lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along an optical axis from an object plane to an image plane; one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens is an ultra-surface lens, and the rest lenses are all spherical surface lenses; the application combines the five spherical surface lenses with the one ultra-surface lens, and cooperates the lens materials and optical powers, so that the total optical length of the lens is effectively compressed, and the miniaturization and light weight design is realized. Meanwhile, the relationship among the relative illumination RI , the effective area size of the ultra-surface lens D M and the optical distortion value D 0 is optimized, so that the long-focus lens has the ability of high resolution and low aberration, and especially realizes the advantages of high-resolution imaging in the visible light wide-band range.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of visible light photography, in particular to a visible light wide-band long-focus lens, a camera module and a terminal device. BACKGROUND

[0002] Unmanned aerial vehicles (UAVs) were initially developed to meet the needs of special environment operations, and have now been widely applied in civilian fields, such as agricultural monitoring, logistics distribution and aerial photography for films and television. An unmanned aerial vehicle system mainly includes a power system, a flight control system, a communication system, a task load system and a power supply system. As a core task component, a camera directly affects the image acquisition and perception ability of the unmanned aerial vehicle, and high-precision real-time imaging plays a key role in scenarios such as surveying and mapping and security protection. At present, the unmanned aerial vehicle camera faces the challenge of being difficult to balance miniaturization, lightweight and high performance; traditional long-focus lenses are large in size and high in manufacturing cost, and it is difficult to meet the high-quality imaging demand in a limited space, which restricts the development of unmanned aerial vehicles in high-end applications.

[0003] As a kind of ultra-thin planar optical element composed of sub-wavelength microstructures, metasurface has strong wavefront control ability and can accurately manipulate the phase of light on a nanometer scale, providing a new way to realize compact cameras.

[0004] However, a single metasurface lens is prone to dispersion in wide-band imaging, and while unmanned aerial vehicle cameras are pursuing miniaturization and lightweight, they still need to cope with the challenge of high-performance imaging, especially in the visible light wide-band range, there is still room for optimization to achieve high-resolution imaging. SUMMARY

[0005] The purpose of the present application is to provide a visible light wide-band long-focus lens, a camera module and a terminal device, which aims to solve the problem that the existing long-focus lens is difficult to cope with high-resolution imaging in the visible light wide-band range while pursuing miniaturization and lightweight.

[0006] To solve the above technical problems, the purpose of the present application is achieved by the following technical scheme: a visible light wide-band long-focus lens is provided, which includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in order along the optical axis from the object plane to the image plane; one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens is a metasurface lens, and the remaining lenses are all spherical lenses;

[0007] The long-focus lens satisfies: ;

[0008] wherein, RI represents the relative luminance of the long-focus lens, D M is the effective area size of the metasurface lens,D 0 an optical distortion value of the long-focus lens.

[0009] Further, the fourth lens is a super surface lens, and the first lens, the second lens, the third lens, the fifth lens and the sixth lens are all spherical lenses.

[0010] Further, the refractive index relationship of each spherical lens in the long-focus lens satisfies:

[0011] wherein, n 1, n 2, n 3, n 4, n 5 and n 6 respectively represent the refractive index of the first lens, the second lens, the third lens, the fifth lens and the sixth lens.

[0012] Further, the first lens has a positive focal power, and the object side and the image side of the first lens are both convex surfaces;

[0013] the second lens has a positive focal power or a negative focal power, the object side of the second lens is a convex surface or a concave surface, and the image side of the second lens is a concave surface;

[0014] the third lens has a positive focal power or a negative focal power, the object side of the third lens is a convex surface, and the image side of the third lens is a concave surface;

[0015] the base of the fourth lens is glass, and the object side or the image side of the fourth lens is arranged with a microstructure;

[0016] the fifth lens has a negative focal power, the object side of the fifth lens is a convex surface or a concave surface, and the image side of the fifth lens is a concave surface;

[0017] the sixth lens has a positive focal power, and the object side and the image side of the sixth lens are both convex surfaces.

[0018] Further, the total optical length of the long-focus lens TTL and the effective focal length of the long-focus lens f satisfy: ; wherein the total optical length TTL is the distance from the optical axis center of the object side of the first lens to the image surface.

[0019] Further, the materials of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all glass.

[0020] Further, the visible light wide-band long-focus lens further comprises a diaphragm and a protective window.​

[0021] The aperture stop is located on the object side of the first lens, or in front of the object side of the first lens, or in the optical path between the fourth lens and the fifth lens;

[0022] The protective window is located behind the sixth lens.

[0023] Furthermore, the aperture value of the telephoto lens F satisfy: F ≤3.0; The relative illuminance of the telephoto lens satisfies: RI ≥55%.

[0024] This invention also provides a camera module, including the above-mentioned wide-band telephoto lens for visible light.

[0025] This invention also provides a terminal device, including the camera module described above.

[0026] The beneficial effects of this invention are as follows: by combining five spherical lenses with one metasurface lens, and through the coordination of lens materials and optical power, the overall optical length of the lens is effectively compressed, achieving a miniaturized and lightweight design. Simultaneously, by optimizing relative illumination... RI Effective area size of metasurface lenses D M and optical distortion value D 0 The relationship between these factors enables telephoto lenses to achieve high resolution and low aberrations, especially in the wide visible light spectrum, where they achieve the advantage of high-resolution imaging. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the visible light wide-band telephoto lens provided in Embodiment 1 of the present invention;

[0029] Figure 2 The visible light wide-band telephoto lens provided in Embodiment 1 of the present invention MTF Schematic diagram;

[0030] Figure 3 This is a schematic diagram of the blur spot of a wide-band telephoto lens for visible light provided in Embodiment 1 of the present invention.

[0031] Figure 4This is a schematic diagram of the relative illumination of a wide-band telephoto lens for visible light provided in Embodiment 1 of the present invention;

[0032] Figure 5 This is a schematic diagram of distortion in a wide-band telephoto lens for visible light provided in Embodiment 1 of the present invention;

[0033] Figure 6 This is a schematic diagram of the visible light wide-band telephoto lens provided in Embodiment 2 of the present invention;

[0034] Figure 7 The visible light wide-band telephoto lens provided in Embodiment 2 of the present invention MTF Schematic diagram;

[0035] Figure 8 This is a schematic diagram of the blur pattern of a wide-band telephoto lens for visible light provided in Embodiment 2 of the present invention;

[0036] Figure 9 This is a schematic diagram of the relative illumination of a wide-band telephoto lens for visible light provided in Embodiment 2 of the present invention;

[0037] Figure 10 This is a distortion diagram of a visible light wide-band telephoto lens provided in Embodiment 2 of the present invention;

[0038] Explanation of the markings in the image:

[0039] 110. Aperture stop; 120. First lens; 130. Second lens; 140. Third lens; 150. Fourth lens; 160. Fifth lens; 170. Sixth lens; 180. Protective window; 190. Imaging plane. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0042] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0043] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0044] Please see Figure 1 and Figure 6 This invention provides a visible light wide-band telephoto lens, comprising a first lens 120, a second lens 130, a third lens 140, a fourth lens 150, a fifth lens 160, and a sixth lens 170 arranged sequentially along the optical axis from the object plane to the image plane; one of the first lens 120, the second lens 130, the third lens 140, the fourth lens 150, the fifth lens 160, and the sixth lens 170 is a metasurface lens, and the remaining lenses are spherical lenses;

[0045] The telephoto lens satisfies: ;

[0046] in, RI This indicates the relative illumination of the telephoto lens. D M The effective area size of the metasurface lens is given. D 0 The optical distortion value is the value of the telephoto lens.

[0047] In this embodiment, a hybrid refractive-metasurface lens scheme combining five spherical lenses and one metasurface lens is employed, effectively compressing the overall optical length of the lens and achieving a miniaturized and lightweight design. Simultaneously, by optimizing relative illumination... RI Effective area size of metasurface lenses D M and optical distortion value D 0 The relationship between them makes telephoto lenses... It has the ability to achieve high resolution and low aberrations within a wide range, especially in the wide visible light band, where it achieves the advantage of high-resolution imaging.

[0048] In one embodiment, the fourth lens 150 is a metasurface lens, and the first lens 120, the second lens 130, the third lens 140, the fifth lens 160, and the sixth lens 170 are all spherical lenses.

[0049] In this embodiment, the metasurface lens consists of a substrate and microstructures disposed on the substrate. These microstructures are composed of a subwavelength-scale micro / nano unit array, possessing specific shapes, sizes, and arrangements to achieve precise control over the phase, amplitude, or polarization state of incident light waves. Specifically, the period of the microstructures ranges from 250 to 400. nm The preferred value is 380. nm The height range is 600-1000. nm The preferred value is 600. nm The diameter coverage range is 100-280. nm The microstructure is made of silicon dioxide and arranged in shapes such as squares and regular hexagons. Based on this microstructure design, the metasurface lens has an achromatic function, which can effectively correct chromatic aberration in telephoto lenses, thereby improving the image quality of telephoto lenses.

[0050] In one embodiment, the refractive index relationship of the spherical lenses in the telephoto lens satisfies: ;in, n 1. n 2. n 3. n 4. n 5 and n 6. These represent the refractive indices of the first lens 120, the second lens 130, the third lens 140, the fifth lens 160, and the sixth lens 170, respectively.

[0051] In this embodiment, based on the above refractive index relationship formula, the materials of the first lens 120, the second lens 130, the third lens 140, the fifth lens 160 and the sixth lens 170 are all glass, which can effectively control the aberration of the telephoto lens, so that the visible light wide-band telephoto lens has the function of achromatic aberration, thereby enabling the imaging quality of the panoramic lens to remain unchanged within a certain range.

[0052] Please continue reading. Figure 1 and Figure 6 In one embodiment, the first lens 120 has positive optical power, and both the object side and the image side of the first lens 120 are convex.

[0053] The second lens 130 has positive or negative optical power, the object side of the second lens 130 is convex or concave, and the image side of the second lens 130 is concave.

[0054] The third lens 140 has a positive or negative optical power lens, the object side of the third lens 140 is convex, and the image side of the third lens 140 is concave.

[0055] The substrate of the fourth lens 150 is glass, and the object side or image side of the fourth lens 150 has microstructures arranged thereon.

[0056] The fifth lens 160 has negative optical power, the object side of the fifth lens 160 is convex or concave, and the image side of the fifth lens 160 is concave.

[0057] The sixth lens 170 has positive optical power, and both the object side and the image side of the sixth lens 170 are convex.

[0058] In this embodiment, by combining different lenses and designing the optical power and surface shape of each lens, aberrations can be effectively corrected and image quality improved. Specifically, lenses with positive optical power help converge light, while lenses with negative optical power help diverge light; the combination of the two can better balance the aberrations of the system. It should be emphasized that the first lens 120 and the sixth lens 170 both adopt a biconvex surface design, which can further reduce spherical aberration and chromatic aberration, and improve image sharpness; the second lens 130, the third lens 140, and the fifth lens 160, through different combinations of optical power and surface shape, can specifically correct other aberrations of the system, such as coma, astigmatism, and field curvature; the fourth lens 150, by arranging microstructures on its object side or image side, can modulate light, further optimize the imaging effect, and reduce the impact of various interference factors generated during light propagation on image quality.

[0059] In this embodiment, with the arrangement of the six lenses as described above, the total optical length of the telephoto lens is... TTL With the effective focal length of a telephoto lens f 'satisfy: Among them, the total optical length TTL This is the distance from the center of the optical axis on the object side of the first lens 120 to the image plane. Telephoto lenses within this range can achieve a more compact and lightweight design while ensuring sufficient image quality and field of view.

[0060] In this embodiment, with the six lenses arranged as described above, the aperture value of the telephoto lens... F satisfy: F ≤3.0; The relative illuminance of the telephoto lens satisfies: RI ≥55%; Under these aperture values ​​and relative illumination conditions, telephoto lenses can capture clear and bright images in low-light environments, with minimal brightness attenuation at the image edges, ensuring a relatively uniform brightness distribution across the entire image.

[0061] In one embodiment, the visible light wide-band telephoto lens further includes an aperture stop 110 and a protective window 180; the aperture stop 110 is located on the object side of the first lens 120 (e.g., Figure 1 (as shown), or located in front of the object side of the first lens 120, or in the optical path between the fourth lens 150 and the fifth lens 160 (as shown).Figure 6 (As shown); the protective window 180 is located behind the sixth lens 170.

[0062] In this embodiment, the design of the aperture 110 helps control the path of light through the lens, reducing stray light interference and thus improving image quality. The position of the aperture 110 can be adjusted according to actual needs to achieve the best imaging effect. The protective window 180 is used to protect the internal optical components of the lens, preventing damage to the lens from external factors such as dust and moisture. In practical applications, the combined use of the aperture 110 and the protective window 180 enables the wide-band visible light telephoto lens to work stably in various complex environments, providing a strong guarantee for obtaining high-quality images.

[0063] In summary, the visible light wide-band telephoto lens provided by this invention employs six glass lenses, is small in size, and can operate within a temperature range of -40℃ to 105℃. Furthermore, by setting the first lens 120, second lens 130, third lens 140, fifth lens 160, and sixth lens 170 as spherical lenses, and by rationally allocating the phase of the metasurface lenses, the visible light wide-band telephoto lens meets the requirements... The conditions are met simultaneously, and the total optical length and effective focal length of the visible light wide-band telephoto lens satisfy... This ensures high imaging resolution. At 125 lp / mm At that time, the central field of view MTF ≥0.7; in 250 lp / mm At that time, the central field of view MTF With a wavelength of ≥0.4, this addresses the challenge of achieving high-resolution imaging across a wide visible light spectrum in the pursuit of miniaturization and lightweight design for existing drone cameras. Furthermore, the metasurface's manufacturing process is relatively simple, employing conventional methods such as photolithography, etching, sputtering, and spraying, resulting in lower costs.

[0064] The lens parameters of the present invention are described below with reference to two specific embodiments.

[0065] In Embodiment 1, as an example, Table 1 details the specific optical data parameters of each lens in the visible light wide-band telephoto lens provided in Embodiment 1 of the present invention, illustrating a feasible implementation method. The optical data parameters in Table 1 correspond to... Figure 1 The image shows a wide-band telephoto lens for visible light.

[0066] The first lens 120 is a spherical lens with positive optical power, and both its object-side and image-side surfaces are convex. The second lens 130 is a spherical lens with positive optical power, and its object-side surface is convex and its image-side surface is concave. The third lens 140 is a spherical lens with negative optical power, and its object-side surface is convex and its image-side surface is concave. The fourth lens 150 is a metasurface lens with a glass substrate and microstructures arranged on its object-side surface. The fifth lens 160 is a spherical lens with negative optical power, and its object-side surface is convex and its image-side surface is concave. The sixth lens 170 is a spherical lens with positive optical power, and both its object-side and image-side surfaces are convex. The aperture stop 110 is located on the object-side surface of the first lens 120.

[0067] The optical parameter data of the visible light wide-band telephoto lens in this embodiment are shown in Table 1:

[0068] Table 1

[0069]

[0070] In Table 1, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object-side surface of the first lens 120, surface number 2 represents the image-side surface of the first lens 120, and so on, with the final surface number 15 being the imaging surface 190. "Standard" represents the standard surface, "Binary2" represents the binary surface, and "Infinity" represents a plane. The radius of curvature represents the degree of curvature of the lens surface; a positive value indicates that the surface bends towards the image surface, and a negative value indicates that the surface bends towards the object surface. The spacing represents the central axial distance from the current surface to the next surface. The units for both the radius of curvature and the spacing are millimeters (mm).

[0071] For example, Table 2 details the phase of the metasurface in Embodiment 1 with a feasible implementation method;

[0072] Table 2

[0073]

[0074] Where R1 is the normalized radius of the binary surface; A1 to A5 represent the coefficients of the metasurface phase.

[0075] Based on the specific optical data parameters exemplified in Example 1 of this embodiment; relative illuminance RI Effective area size of metasurface lenses D M and optical distortion value D 0 The following conditions must be met: The refractive indices of the materials of the first lens 120, the second lens 130, the third lens 140, the fifth lens 160, and the sixth lens 170 satisfy the following: Overall optical lengthTTL and effective focal length f 'satisfy: .

[0076] The telephoto lens provided in this embodiment operates in the wavelength range of 436-656. nm , F =2.80 meets the usage requirements of drone camera modules.

[0077] Figure 2 This is a schematic diagram of the MTF (modulation transfer function) of the telephoto lens provided in Embodiment 1 of the present invention. The telephoto lens provided in Embodiment 1 of the present invention has high resolution characteristics, at 125... lp / mm Under these conditions, the central field of view MTF ≥0.7; in 250 lp / mm Under these conditions, the central field of view MTF A value ≥0.4 is sufficient to meet the high-quality imaging requirements of drone cameras. Here, Tangential represents the meridian direction; Sagittal represents the sagittal direction.

[0078] Figure 3 This is a schematic diagram of the blur pattern of a telephoto lens provided in Embodiment 1 of the present invention. The visible light wide-band telephoto lens provided in this embodiment exhibits a relatively concentrated and uniform distribution of blur patterns throughout the entire long-band range, thereby effectively meeting the requirements of high-resolution imaging.

[0079] Figure 4 This is a schematic diagram of the relative illumination of a telephoto lens provided in Embodiment 1 of the present invention, clearly showing the relative illumination values ​​corresponding to different fields of view. Within its operating wavelength range, the telephoto lens exhibits a relative illumination value exceeding 88%, and the brightness distribution is uniform.

[0080] Figure 5 This is a schematic diagram of the distortion of a telephoto lens provided in Embodiment 1 of the present invention. The telephoto lens provided in this embodiment has small distortion and minimal image deformation, which can meet the requirements of high-quality imaging.

[0081] In Embodiment 2, Table 3, exemplarily, details the specific optical data parameters of each lens in the visible light wide-band telephoto lens provided in Embodiment 2 of the present invention, illustrating a feasible implementation method. The optical data parameters in Table 3 correspond to... Figure 6 The image shows a wide-band telephoto lens for visible light.

[0082] The first lens 120 is a spherical lens with positive optical power, and both its object-side and image-side surfaces are convex. The second lens 130 is a spherical lens with negative optical power, and both its object-side and image-side surfaces are concave. The third lens 140 is a spherical lens with both positive and negative optical power, and both its object-side and image-side surfaces are convex. The fourth lens 150 is a metasurface lens with a glass substrate and microstructures arranged on its image-side surface. The fifth lens 160 is a spherical lens with negative optical power, and both its object-side and image-side surfaces are concave. The sixth lens 170 is a spherical lens with positive optical power, and both its object-side and image-side surfaces are convex. The aperture stop 110 is located in the optical path between the fourth lens 150 and the fifth lens 160.

[0083] The optical parameter data of the visible light wide-band telephoto lens in this embodiment are shown in Table 3:

[0084] Table 3

[0085]

[0086] In Table 3, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens 120, surface number 2 represents the image side of the first lens 120, and so on. Surface number 9 represents the aperture stop 110, and the last surface number 16 is the imaging plane 190. "Standard" represents the standard surface, "Binary2" represents the binary surface, and "Infinity" represents a plane. The radius of curvature represents the degree of curvature of the lens surface; a positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. The spacing represents the central axial distance from the current surface to the next surface. The units for both the radius of curvature and the spacing are millimeters (mm).

[0087] For example, Table 4 details the phase of the metasurface in Embodiment 2 with a feasible implementation method;

[0088] Table 4

[0089]

[0090] Where R1 is the normalized radius of the binary surface; A1 to A5 represent the coefficients of the metasurface phase.

[0091] Based on the specific optical data parameters exemplified in this second embodiment; relative illuminance RI Effective area size of metasurface lenses D M and optical distortion value D 0 The following conditions must be met: The refractive indices of the materials of the first lens 120, the second lens 130, the third lens 140, the fifth lens 160, and the sixth lens 170 satisfy the following: Overall optical length TTL and effective focal length f 'satisfy: .

[0092] The telephoto lens provided in this embodiment operates in the wavelength range of 436-656. nm , F =2.94 meets the usage requirements of drone camera modules.

[0093] Figure 7 This is a schematic diagram of the MTF (modulation transfer function) of the telephoto lens provided in Embodiment 2 of the present invention. The telephoto lens provided in Embodiment 2 of the present invention has high resolution characteristics, at 125... lp / mm Under these conditions, the central field of view MTF ≥0.7; in 250 lp / mm Under these conditions, the central field of view MTF A value of ≥0.45 is sufficient to meet the high-quality imaging requirements of drone cameras.

[0094] Figure 8 This is a schematic diagram of the blur pattern of a telephoto lens provided in Embodiment 2 of the present invention. The visible light wide-band telephoto lens provided in this embodiment exhibits a relatively concentrated and uniform distribution of blur patterns throughout the entire long-band range, thereby effectively meeting the requirements of high-resolution imaging.

[0095] Figure 9 This is a schematic diagram of the relative illumination of the telephoto lens provided in Embodiment 2 of the present invention, clearly showing the relative illumination values ​​corresponding to different fields of view. Within its operating wavelength range, the telephoto lens exhibits a relative illumination value exceeding 58%, and the brightness distribution is uniform.

[0096] Figure 10 This is a distortion diagram of a telephoto lens provided in Embodiment 2 of the present invention. The telephoto lens provided in this embodiment has small distortion and minimal image deformation, which can meet the requirements of high-quality imaging.

[0097] In summary, the specific solutions of both Embodiment 1 and Embodiment 2 can satisfy the relationships shown in Table 5 below:

[0098] Table 5

[0099]

[0100] The visible light wide-band telephoto lens provided in this invention adopts a hybrid refractive-supersurface lens technology, combining five spherical lenses with one metasurface lens to effectively compress the overall optical length of the lens, achieving a miniaturized and lightweight design. Simultaneously, by optimizing relative illumination... RI Effective area size of metasurface lensesD M and optical distortion value D 0 The relationship between these factors enables telephoto lenses to achieve high resolution and low aberrations, especially in the wide visible light spectrum, where they achieve the advantage of high-resolution imaging.

[0101] This invention also provides a camera module, including the visible light wide-band telephoto lens as described above.

[0102] This invention also provides a terminal device, including the camera module described above.

[0103] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A visible light wide-band telephoto lens, characterized in that, It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical axis from the object plane to the image plane; the fourth lens is a metasurface lens, and the first, second, third, fifth, and sixth lenses are all spherical lenses; The telephoto lens satisfies: ; in, RI This indicates the relative illumination of the telephoto lens. D M The effective area size of the metasurface lens is given. D 0 The optical distortion value of the telephoto lens; The first lens has positive optical power, the second lens has positive or negative optical power, the third lens has positive or negative optical power, the fifth lens has negative optical power, and the sixth lens has positive optical power.

2. The visible light wide-band telephoto lens according to claim 1, characterized in that, The refractive index relationship of the spherical lenses in the telephoto lens satisfies: ; in, n 1. n 2. n 3. n 5 and n 6 represents the refractive index of the first lens, second lens, third lens, fifth lens, and sixth lens, respectively.

3. The visible light wide-band telephoto lens according to claim 1, characterized in that, Both the object-side and image-side surfaces of the first lens are convex. The object-side surface of the second lens is either convex or concave, and the image-side surface of the second lens is concave. The object-side surface of the third lens is convex, and the image-side surface of the third lens is concave. The substrate of the fourth lens is glass, and the object side or image side of the fourth lens has microstructures arranged thereon. The object-side surface of the fifth lens is either convex or concave, and the image-side surface of the fifth lens is concave. The object-side and image-side surfaces of the sixth lens are both convex.

4. The visible light broadband telephoto lens according to any one of claims 1-3, characterized in that, The total optical length of the telephoto lens TTL With the effective focal length of the telephoto lens f 'satisfy: The total optical length TTL The distance is the distance from the center of the optical axis on the object side of the first lens to the image plane.

5. The visible light wide-band telephoto lens according to any one of claims 1-3, characterized in that, The first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are all made of glass.

6. The visible light broadband telephoto lens according to any one of claims 1-3, characterized in that, It also includes apertures and protective windows; The aperture stop is located on the object side of the first lens, or in front of the object side of the first lens, or in the optical path between the fourth lens and the fifth lens; The protective window is located behind the sixth lens.

7. The visible light broadband telephoto lens according to any one of claims 1-3, characterized in that, The aperture value of the telephoto lens F satisfy: F ≤3.0; The relative illuminance of the telephoto lens satisfies: RI ≥55%.

8. A camera module, characterized in that, Including the visible light wide-band telephoto lens as described in any one of claims 1-7.

9. A terminal device, characterized in that, Includes the camera module as described in claim 8.

Images