Visible light broadband telephoto lens, camera module and terminal equipment

Abstract

The invention discloses a visible light broadband telephoto lens, a camera module and terminal equipment. The visible light broadband telephoto 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 from an object plane to an image plane along an optical axis. 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 other lenses are spherical lenses; according to the invention, the five spherical lenses are combined with the metasurface lens, and all lens materials and focal power are matched, so that the total optical length of the lens is effectively compressed, and the design of miniaturization and light weight is realized. Meanwhile, by optimizing the relation among the relative illumination RI, the effective area size DM of the metasurface lens and the optical distortion value D0, the telephoto lens has the capabilities of high resolution and low aberration, and particularly, the advantage of high-resolution imaging is realized in a visible light broadband 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; The long-focus lens satisfies: ; wherein, RI represents the relative luminance of the long-focus lens, D M is the effective area size of the metasurface lens, D 0an optical distortion value of the long-focus lens.

[0007] Further, the fourth lens is a metasurface lens, and the first lens, the second lens, the third lens, the fifth lens and the sixth lens are all spherical lenses.

[0008] Further, the refractive index relationship of each spherical lens in the long-focus lens satisfies: ; 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.

[0009] Further, the first lens has a positive focal power, and the object side and the image side of the first lens are both convex; The second lens has a positive focal power or a negative focal power, the object side of the second lens is convex or concave, and the image side of the second lens is concave; The third lens has a positive focal power or a negative focal power, the object side of the third lens is convex, and the image side of the third lens is concave; The base of the fourth lens is glass, and the object side or the image side of the fourth lens is arranged with microstructures; The fifth lens has a negative focal power, the object side of the fifth lens is convex or concave, and the image side of the fifth lens is concave; The sixth lens has a positive focal power, and the object side and the image side of the sixth lens are both convex.

[0010] 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.

[0011] 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.

[0012] Further, the visible light wide-band long-focus lens further comprises a diaphragm and a protective window; The diaphragm is located on the object side of the first lens, or before 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 after the sixth lens.

[0013] Further, the aperture value of the long-focus lens satisfies: F F ≤3.0; the relative luminance of the long-focus lens satisfies: RI ≥55%.

[0014] The embodiment of the present application also provides a camera module comprising the visible light wide-band long-focus lens.

[0015] The embodiment of the present application also provides a terminal device comprising the camera module.

[0016] The beneficial effects of the embodiment of the present application are: by combining five spherical lenses and one super-surface lens, and by matching the materials and optical powers of the lenses, the total optical length of the lens is effectively compressed, and the design of miniaturization and light weight is realized. At the same time, by optimizing the relationship among the relative luminance RI , the effective area size of the super-surface lens D M and the optical distortion value D 0 , 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. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0018] Figure 1 A structural schematic diagram of the visible light wide-band long-focus lens provided by the first embodiment of the present application is shown in the figure. Figure 2 A structural schematic diagram of the visible light wide-band long-focus lens provided by the first embodiment of the present application is shown in the figure. MTF Figure 3 A diffraction spot schematic diagram of the visible light wide-band long-focus lens provided by the first embodiment of the present application is shown in the figure. Figure 4 A relative luminance schematic diagram of the visible light wide-band long-focus lens provided by the first embodiment of the present application is shown in the figure. Figure 5 A distortion schematic diagram of the visible light wide-band long-focus lens provided by the first embodiment of the present application is shown in the figure. Figure 6 A structural schematic diagram of the visible light wide-band long-focus lens provided by the second embodiment of the present application is shown in the figure. Figure 7 ​​The dispersion spot diagram of the visible light wide-band long-focus lens provided in the second embodiment of the present application MTF schematic diagram Figure 8 The dispersion spot diagram of the visible light wide-band long-focus lens provided in the second embodiment of the present application Figure 9 The relative luminance diagram of the visible light wide-band long-focus lens provided in the second embodiment of the present application Figure 10 The distortion diagram of the visible light wide-band long-focus lens provided in the second embodiment of the present application Identification in the figure: 110, diaphragm; 120, first lens; 130, second lens; 140, third lens; 150, fourth lens; 160, fifth lens; 170, sixth lens; 180, protective window; 190, imaging surface. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0020] It should be understood that, when used in the specification and the appended claims, the terms “comprise” and “include” indicate the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0021] It should also be understood that the terms used in the present application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the present application 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.

[0022] It should be further understood that the term “and / or” used in the present application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0023] Please refer to Figure 1 and Figure 6The embodiment of the present application provides a visible light wide-band long-focus lens, which comprises 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 in sequence along an optical axis from an object plane to an 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 super surface lens, and the remaining lenses are all spherical surface lenses. The long-focus lens satisfies: ; Wherein, RI represents the relative luminance of the long-focus lens, D M is an effective area size of the super surface lens, D 0 is an optical distortion value of the long-focus lens.

[0024] In the embodiment, a hyper-hybrid scheme combining five spherical surface lenses and one super surface lens is adopted, so that the total optical length of the lens is effectively compressed, and the design of miniaturization and light weight is realized. Meanwhile, by optimizing the relationship among the relative luminance RI , the effective area size of the super surface lens D M and the optical distortion value D 0 , the long-focus lens has the ability of high resolution and low aberration in the range of , and especially realizes the advantages of high resolution imaging in the visible light wide-band range.

[0025] In an embodiment, the fourth lens 150 is a super surface 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 surface lenses.

[0026] In the embodiment, the super surface lens is composed of a substrate and a microstructure arranged on the substrate, the microstructure is composed of an array of subwavelength scale micro-nano units, the microstructure has a specific shape, size and arrangement mode to realize accurate regulation of phase, amplitude or polarization state of incident light waves. Specifically, the period of the microstructure ranges from 250 to 400 nm , and the preferred value is 380 nm ; the height ranges from 600 to 1000 nm , and the preferred value is 600 nm ; the diameter covers a range of 100-280 nm ; the material of the microstructure is silicon dioxide, and the microstructure is arranged in the shape of a square or a regular hexagon. Based on the microstructure design, the super surface lens has achromatic function and can effectively correct the chromatic aberration of the long-focus lens, thereby improving the imaging quality of the long-focus lens.

[0027] In an embodiment, the refractive index relationship of each spherical lens in the long-focus lens satisfies: ; wherein, n 1、 n 2、 n 3、 n 4、 n 5 and n 6, respectively, represent the refractive index of the first lens 120, the second lens 130, the third lens 140, the fifth lens 160, and the sixth lens 170.

[0028] In the embodiment, on the basis of the 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 long-focus lens, so that the visible wide-band long-focus lens has an achromatic function, thereby realizing the imaging quality of the surround-view lens unchanged within a certain range.

[0029] Please continue to refer to Figure 1 and Figure 6 In an embodiment, the first lens 120 has a positive focal power, and the object side and the image side of the first lens 120 are both convex. The second lens 130 has a positive focal power or a negative focal power, the object side of the second lens 130 is convex or concave, and the image side of the second lens 130 is concave. The third lens 140 has a positive focal power or a negative focal power, the object side of the third lens 140 is convex, and the image side of the third lens 140 is concave. The base of the fourth lens 150 is glass, and the object side or the image side of the fourth lens 150 is arranged with a microstructure. The fifth lens 160 has a negative focal power, the object side of the fifth lens 160 is convex or concave, and the image side of the fifth lens 160 is concave. The sixth lens 170 has a positive focal power, and the object side and the image side of the sixth lens 170 are both convex.

[0030] In this embodiment, by matching different lenses and designing the optical power and surface shape of each lens, the aberration can be effectively corrected and the imaging quality can be improved. Specifically, the lens with positive optical power helps to converge light, and the lens with negative optical power helps to diverge light, and the combination of the two can better balance the aberration of the system. It should be emphasized that the first lens 120 and the sixth lens 170 are designed as double convex surfaces, which can further reduce the spherical aberration and chromatic aberration and improve the clarity of imaging; the second lens 130, the third lens 140 and the fifth lens 160 can be combined by different optical power and surface shape to correct other aberrations of the system, such as coma, astigmatism and field curvature, etc.; the fourth lens 150 can modulate light by arranging microstructures on its object side or image side, further optimizing the imaging effect and reducing the influence of various interference factors on the imaging quality during the light propagation process.

[0031] In this embodiment, under the arrangement design of the above six lenses, the total optical length of the long focal lens TTL satisfies: f ; wherein the total optical length TTL is the distance from the optical axis center of the object side of the first lens 120 to the image surface. The long focal lens in this range can realize more compact and lightweight design while ensuring sufficient imaging quality and field of view.

[0032] In this embodiment, under the arrangement design of the above six lenses, the aperture value of the long focal lens F satisfies: F ≤3.0; the relative luminance of the long focal lens satisfies: RI ≥55%; under the conditions of the aperture value and the relative luminance, the long focal lens can capture clear and bright images in low light environment, and the brightness attenuation of the image edge is small, which can ensure that the entire image has a relatively uniform brightness distribution.

[0033] In an embodiment, the visible light wide-band long focal lens further comprises a diaphragm 110 and a protective window 180; the diaphragm 110 is located on the object side of the first lens 120 (as shown in Figure 1 ), or before the object side of the first lens 120, or in the light path between the fourth lens 150 and the fifth lens 160 (as shown in Figure 6 ); the protective window 180 is located after the sixth lens 170.

[0034] ​In this embodiment, the design of the diaphragm 110 helps to control the path of light through the lens, reduce the interference of stray light, and improve the imaging quality. The position of the diaphragm 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 elements of the lens and prevent dust, water vapor and other external factors from damaging the lens. In actual application, the cooperation of the diaphragm 110 and the protective window 180 can make the visible light wide-band long-focus lens work stably in various complex environments, and provide strong guarantee for obtaining high-quality images.

[0035] In summary, the visible light wide-band long-focus lens provided by the present application adopts six glass lenses, has small volume, and can work in a temperature range of-40℃ to 105℃. Moreover, by setting the first lens 120, the second lens 130, the third lens 140, the fifth lens 160 and the sixth lens 170 as spherical lenses and reasonably distributing the phase of the super surface lens, the visible light wide-band long-focus lens meets the condition of , while the total optical length and the effective focal length of the visible light wide-band long-focus lens meet , ensuring a high imaging resolution. In 125 lp / mm , the central field of view MTF is greater than or equal to 0.7; in 250 lp / mm , the central field of view MTF is greater than or equal to 0.4, solving the problem that the existing unmanned aerial vehicle camera is difficult to realize high-resolution imaging in the visible light wide-band range while pursuing miniaturization and light weight. In addition, the manufacturing process of the super surface is relatively simple, and can be made by conventional photolithography, etching, sputtering, spraying and other methods, with low cost.

[0036] The lens parameters of the present application will be introduced in two specific embodiments.

[0037] In the first embodiment, the visible light wide-band long-focus lens provided by the present application is exemplified. Table 1 details the specific optical data parameters of each lens in the visible light wide-band long-focus lens of the first embodiment of the present application in a feasible implementation manner. The optical data parameters in Table 1 correspond to the visible light wide-band long-focus lens shown in Figure 1 .

[0038] The first lens 120 is a spherical lens with positive focal power, and both the object side and the image side are convex. The second lens 130 is a spherical lens with positive focal power, the object side is convex, and the image side is concave. The third lens 140 is a spherical lens with negative focal power, the object side is convex, and the image side is concave. The fourth lens 150 is a super surface lens, the base is glass, and the object side is arranged with microstructures. The fifth lens 160 is a spherical lens with negative focal power, the object side is convex, and the image side is concave. The sixth lens 170 is a spherical lens with positive focal power, and both the object side and the image side are convex. The stop 110 is located on the object side of the first lens 120.

[0039] The optical parameter data of the visible light wide-band long-focus lens of this embodiment is shown in Table 1: Table 1

[0040] In Table 1, the surface number is numbered according to the surface order 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. The last surface number 15 is the imaging surface 190. Among them, “Standard” represents the standard surface, “Binary2” represents the binary surface, and “Infinity” represents the plane; the curvature radius represents the bending degree of the lens surface, the positive value represents that the surface bends to the image side, and the negative value represents that the surface bends to the object side; the interval represents the center axis distance from the current surface to the next surface. The units of curvature radius and interval are millimeters (mm).

[0041] For example, Table 2 details the phase of the super surface in embodiment one in a possible implementation manner; Table 2

[0042] Among them, R1 is the normalized radius of the binary surface; A1 to A5 represent the coefficients of the phase of the super surface.

[0043] Based on the specific optical data parameters shown in this embodiment one; relative luminance RI , effective area size of super surface lens D M and optical distortion value D 0 satisfy: ; the material refractive index of the first lens 120, the second lens 130, the third lens 140, the fifth lens 160 and the sixth lens 170 satisfies: ; the total optical length TTL and the effective focal length f satisfy: . The working waveband range of the long-focus lens provided by the embodiment is 436-656

[0044] nm. nm F =2.80, which meets the use requirements of the unmanned aerial vehicle camera module.

[0045] Figure 2 The MTF (modulation transfer function) diagram of the long-focus lens provided by the embodiment one of the application is shown in the figure, and the long-focus lens provided by the embodiment one of the application has the high-resolution characteristic. lp mm Under the condition of 125 MTF lp Under the condition of 250 mm MTF , the central field of view is greater than or equal to 0.4, which can meet the high-quality imaging requirements of the unmanned aerial vehicle camera. Wherein, Tangential represents the meridional direction; Sagittal represents the sagittal direction.

[0046] Figure 3 The diffraction spot diagram of the long-focus lens provided by the embodiment one of the application is shown in the figure, and the visible light wide-band long-focus lens provided by the embodiment has the relatively concentrated and uniform distribution of the diffraction pattern in the whole long-waveband range, thereby effectively meeting the high-resolution imaging requirements.

[0047] Figure 4 The relative luminance diagram of the long-focus lens provided by the embodiment one of the application is shown in the figure, and the relative luminance values corresponding to different fields of view are clearly presented. The relative luminance value of the long-focus lens in the working waveband range is greater than 88%, and the brightness distribution is uniform.

[0048] Figure 5 The distortion diagram of the long-focus lens provided by the embodiment one of the application is shown in the figure, and the long-focus lens provided by the embodiment has the small distortion and the small image deformation degree, thereby meeting the high-quality imaging requirements.

[0049] In the embodiment two, the specific optical data parameters of each lens in the visible light wide-band long-focus lens provided by the embodiment two of the application are illustrated in detail in a feasible implementation manner in Table 3. Figure 6

[0050] ​​​​​The first lens 120 is a spherical lens with positive focal power, both the object side and the image side are convex; the second lens 130 is a spherical lens with negative focal power, the object side is concave, and the image side is concave; the third lens 140 is a spherical lens with positive focal power, the object side is convex, and the image side is concave; the fourth lens 150 is a super surface lens, the base is glass, and the image side is arranged with microstructures; the fifth lens 160 is a spherical lens with negative focal power, the object side is concave, and the image side is concave; the sixth lens 170 is a spherical lens with positive focal power, both the object side and the image side are convex; the diaphragm 110 is located in the optical path between the fourth lens 150 and the fifth lens 160.

[0051] The optical parameter data of the visible light wide-band long-focus lens of this embodiment two is shown in Table 3: Table 3

[0052] In Table 3, the surface number is numbered according to the surface order of each lens, for example, the surface number 1 represents the object side of the first lens 120, the surface number 2 represents the image side of the first lens 120, and so on, the surface number 9 represents the diaphragm 110, and the last surface number 16 is the imaging surface 190. Among them, "Standard" represents the standard surface, "Binary2" represents the binary surface, and "Infinity" represents the plane; the curvature radius represents the bending degree of the lens surface, the positive value represents that the surface bends to the image side, and the negative value represents that the surface bends to the object side; the interval represents the center axis distance from the current surface to the next surface, and the units of the curvature radius and the interval are millimeters (mm).

[0053] For example, Table 4 details the phase of the super surface in embodiment two in a possible implementation manner; Table 4

[0054] Among them, R1 is the normalized radius of the binary surface; A1 to A5 represent the coefficients of the phase of the super surface.

[0055] Based on the specific optical data parameters exemplified in this embodiment two; relative luminance RI , effective area size of the super surface lens D M and optical distortion value D 0 satisfy: ; the material refractive index of the first lens 120, the second lens 130, the third lens 140, the fifth lens 160 and the sixth lens 170 satisfies: ; the total optical length TTL and the effective focal length f satisfy: .

[0056] The working waveband range of the long-focus lens provided by the embodiment is 436-656 nm , F =2.94, which meets the use requirements of the unmanned aerial vehicle camera module.

[0057] Figure 7 The MTF (modulation transfer function) diagram of the long-focus lens provided by the embodiment two is shown, and the long-focus lens provided by the embodiment two has high resolution characteristics, and the central field of view lp / 125 mm , the central field of view MTF ≥0.7; under the condition of 250 lp / 250 mm , the central field of view MTF ≥0.45, which can meet the high-quality imaging requirements of the unmanned aerial vehicle camera.

[0058] Figure 8 The long-focus lens provided by the embodiment two is a long-focus lens for visible light wide waveband, and the dispersion pattern is concentrated and uniform in the whole long waveband range, so that the high-resolution imaging requirements can be effectively met.

[0059] Figure 9 The relative luminance diagram of the long-focus lens provided by the embodiment two is shown, which clearly shows the relative luminance values corresponding to different fields of view. The relative luminance value of the long-focus lens in the working waveband range is more than 58%, and the brightness distribution is uniform.

[0060] Figure 10 The distortion diagram of the long-focus lens provided by the embodiment two is shown, and the long-focus lens provided by the embodiment has small distortion and small image deformation degree, which can meet the high-quality imaging requirements.

[0061] In summary, the specific schemes of the embodiment one and the embodiment two can meet the following relationship shown in Table 5: Table 5

[0062] The visible light wide waveband long-focus lens provided by the embodiment adopts a fold super hybrid technical scheme, and five spherical lenses and one super surface lens are combined, so that the total optical length of the lens is effectively compressed, and the design of miniaturization and light weight is realized. At the same time, by optimizing the relative luminance RI , the effective area size of the super surface lens D M and the optical distortion value D 0The relationship between the focal length and the resolution is made, 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 a wide range of visible light.

[0063] The embodiment of the present application also provides a camera module, which comprises the visible light wide-band long-focus lens.

[0064] The embodiment of the present application also provides a terminal device, which comprises the camera module.

[0065] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A visible light wide-band long-focus lens, characterized in that, The first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are sequentially arranged from the object plane to the image plane along the optical axis; one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens is a super surface lens, and the rest are spherical surface lenses; The long-focus lens satisfies: ; wherein, RI represents a relative illumination of the tele lens, D M is an effective area size of the metasurface lens, D 0 is an optical distortion value of the tele lens.

2. The visible wide-band long-focus lens according to claim 1, characterized in that, 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 spherical surface lenses.

3. The visible wide-band long-focus lens according to claim 2, characterized in that, The refractive index relationship of each spherical lens in the long-focus lens satisfies: ; wherein n 1、 n 2、 n 3、 n 4、 n 5 and n 6, respectively, denote the refractive indices of the first lens, the second lens, the third lens, the fifth lens and the sixth lens.

4. The visible wide-band long-focus lens according to claim 2, wherein, The first lens has positive focal power, and the object side surface and the image side surface of the first lens are both convex surfaces; The second lens has positive focal power or negative focal power, the object side surface of the second lens is a convex surface or a concave surface, and the image side surface of the second lens is a concave surface; The third lens has positive focal power or negative focal power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; The base of the fourth lens is glass, and the object side surface or the image side surface of the fourth lens is arranged with a microstructure; The fifth lens has negative focal power, the object side surface of the fifth lens is a convex surface or a concave surface, and the image side surface of the fifth lens is a concave surface; The sixth lens has positive focal power, and the object side surface and the image side surface of the sixth lens are both convex surfaces.

5. The wide-band long-focus lens for visible light according to any one of claims 1 to 4, characterized in that, The total optical length of the long-focus lens TTL The effective focal length of the long-focus lens f Satisfies: ; wherein the total optical length TTL The distance from the optical axis center of the object side of the first lens to the image plane.

6. The wide-band long-focus lens for visible light according to any one of claims 1 to 4, characterized in that, 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.

7. The wide-band long-focus lens for visible light according to any one of claims 1 to 4, characterized in that, Further comprising a diaphragm and a protective window; The diaphragm is located on the object side surface of the first lens, or before the object side surface of the first lens, or in the optical path between the fourth lens and the fifth lens; The protective window is located after the sixth lens.

8. The wide-band long-focus lens for visible light according to any one of claims 1 to 4, characterized in that, An aperture value of the long-focus lens F satisfies: F ≤ 3.0; a relative luminance of the long-focus lens satisfies: RI ≥ 55%.

9. An image capture module, comprising: The visible light wide-band long-focus lens comprises the visible light wide-band long-focus lens according to any one of claims 1-8.

10. A terminal device, comprising: The camera module comprises the camera module according to claim 9.

Images