A 4mm large aperture athermal high-definition all-glass lens

Abstract

The present invention discloses a 4mm large-aperture athermal, high-definition, all-glass lens. The lens comprises, in order from the object side to the image side along the lens optical axis: a first lens, a spherical glass lens with negative optical power; a second lens, a spherical glass lens with negative optical power; a third lens, a spherical glass lens with positive optical power; a fourth lens, a spherical glass lens with positive optical power; a fifth lens, a spherical glass lens with positive optical power; a sixth lens, a glass lens with positive optical power; a seventh lens, a glass lens with negative optical power; the sixth and seventh lenses cemented together; an eighth lens, a glass lens with positive optical power; and a ninth lens, a glass lens with positive optical power. This 4mm large-aperture, high-definition, all-glass lens utilizes nine glass lenses, achieving an F# of 1.6. It can be used with a 5MP, 2 / 3-inch chip, achieving athermalization, lightweight, large image area, and low illumination, offering a high cost-effectiveness.

Description

Technical Field

[0001] The present invention relates to the field of optical lenses, and in particular to a 4mm large aperture athermal high-definition all-glass lens. Background Art

[0002] As drone technology matures, its low cost, ease of operation, and high flexibility make it possible to carry critical equipment from the air and perform specialized missions such as aerial surveillance, aerial communication, broadcasting, and emergency rescue. These drones demonstrate strong survivability, excellent maneuverability, and ease of use when performing these missions, playing a vital role in responding to natural disasters, accidents, and social security incidents. In recent years, with the improvement of people's living standards, consumer drones have become increasingly commonplace, enriching people's leisure and leisure activities. However, both professional and consumer drones rely on onboard cameras. Summary of the Invention

[0003] Based on this, the purpose of the present invention is to provide a 4mm large aperture athermal high-definition all-glass lens, which uses 9 pieces of glass and can be used with a 5MP, 2 / 3-inch chip. It can take clear pictures in the temperature range of -40℃ to +80℃ and has excellent low-light photography effects.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A 4mm large aperture athermal high-definition all-glass lens. The surface of the lens adjacent to the object plane is defined as the object side, and the surface of the lens adjacent to the image plane is defined as the image side. The following are arranged in order from the object side to the image side along the lens optical axis:

[0006] a first lens, wherein the first lens is a glass lens with negative optical power, the object-side surface of the first lens being convex, and the image-side surface of the first lens being concave;

[0007] a second lens, wherein the second lens is a glass lens having negative optical power, and the object-side surface and the image-side surface of the second lens are concave;

[0008] a third lens, the third lens being a glass lens with positive optical power, the object-side surface of the third lens being concave, and the image-side surface being convex;

[0009] a fourth lens, the fourth lens being a spherical glass lens with positive refractive power, the object-side surface of the fourth lens being convex, and the image-side surface of the fourth lens being convex;

[0010] a fifth lens element, the fifth lens element being a spherical glass lens with positive optical power, the object-side surface of the fifth lens element being convex, and the image-side surface of the fifth lens element being concave;

[0011] a sixth lens, the sixth lens being a glass lens with positive optical power, the object-side surface of the sixth lens being convex, and the image-side surface of the sixth lens being convex;

[0012] a seventh lens element, the seventh lens element being a glass lens with negative optical power, the object-side surface of the seventh lens element being concave, and the image-side surface of the seventh lens element being concave;

[0013] an eighth lens element, the eighth lens element being a glass lens with positive optical power, the object-side surface of the eighth lens element being convex, and the image-side surface of the eighth lens element being convex;

[0014] a ninth lens element, the ninth lens element being a glass lens with positive optical power, the object-side surface of the ninth lens element being convex, and the image-side surface of the ninth lens element being concave;

[0015] The sixth lens and the seventh lens are cemented lenses;

[0016] a filter, the filter being arranged on the image side surface of the ninth lens, and the filter being made of H-K9L;

[0017] A protective glass, wherein the protective glass is integrated on the image sensor and is arranged on the image side of the filter;

[0018] The lens further includes an aperture stop, and the aperture stop is located between the fifth lens and the sixth lens.

[0019] Furthermore, the lens meets the following conditions:

[0020] -6.5≤f1 / f≤-3.5,

[0021] -4≤f2 / f≤-2,

[0022] 10≤f3 / f≤45,

[0023] 5≤f4 / f≤8.5,

[0024] 6.5≤f5 / f≤10,

[0025] 2.0≤f6 / f≤3.0,

[0026] -2.2≤f7 / f≤-1.2,

[0027] 3.5≤f8 / f≤6.5,

[0028] 4.0≤f9 / f≤7.0;

[0029] In the relationship, f is the total focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, f8 is the focal length of the eighth lens, and f9 is the focal length of the ninth lens.

[0030] Furthermore, the focal length, refractive index and curvature radius of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens respectively meet the following conditions:

[0031]

[0032] Wherein, f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the radius of curvature of the object side surface of the first lens, and R12 is the radius of curvature of the image side surface of the first lens; f2 is the focal length of the second lens, ND2 is the refractive index of the second lens 2, R21 is the radius of curvature of the object side surface of the second lens, and R22 is the radius of curvature of the image side surface of the second lens; f is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the radius of curvature of the object side surface of the third lens, and R32 is the radius of curvature of the image side surface of the third lens; f4 is the focal length of the fourth lens, ND4 is the refractive index of the fourth lens, R41 is the radius of curvature of the object side surface of the fourth lens, and R42 is the radius of curvature of the image side surface of the fourth lens; f5 is the focal length of the fifth lens, ND5 is the refractive index of the fifth lens, R51 is the radius of curvature of the object side surface of the fifth lens, and R52 is The image side surface curvature radius of the fifth lens; f6 is the focal length of the sixth lens, ND6 is the refractive index of the sixth lens, R61 is the object side surface curvature radius of the sixth lens, and R62 is the image side surface curvature radius of the sixth lens; f7 is the focal length of the seventh lens, ND7 is the refractive index of the seventh lens, R71 is the object side surface curvature radius of the seventh lens, and R72 is the image side surface curvature radius of the seventh lens; f8 is the focal length of the eighth lens, ND8 is the refractive index of the eighth lens, R81 is the object side surface curvature radius of the eighth lens, and R82 is the image side surface curvature radius of the eighth lens; f9 is the focal length of the ninth lens, ND9 is the refractive index of the ninth lens, R91 is the object side surface curvature radius of the ninth lens, and R92 is the image side surface curvature radius of the ninth lens; the “-” sign indicates that the surface is curved toward the object plane. The unit of focal length is mm, and the unit of curvature radius is mm.

[0033] Furthermore, the lens satisfies the following relationship:

[0034] IC / TTL≥0.12,

[0035] TTL / f≤19,

[0036] OBFL / TTL ≥ 0.06;

[0037] In this equation, f is the total focal length of the lens, TTL is the total optical length of the lens, OBFL is the optical back focus distance of the lens, and IC is the full image height of the 2 / 3" sensor used with the lens system.

[0038] Furthermore, the aperture of the lens is F#, which satisfies F#≤1.6, the total focal length of the lens is f, which satisfies f=4mm, and the total optical length of the lens is TTL, which satisfies TTL≤80mm.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows: the 4mm large aperture athermal high-definition all-glass lens adopts a 9-piece all-glass structure, the total focal length of the optical lens is f=4mm, and the aperture F# satisfies F#≤1.6. Under the large aperture and large focal length, the light aperture is relatively large, which can ensure the high relative illumination of the system, and there is no dark corner in the picture during shooting. At the same time, the system aberration is well corrected, and the optical performance is good. In terms of manufacturability, each lens is insensitive, the lens surface is simple and easy to manufacture, the structure between the lenses is compact, and its processing cost is relatively low compared to the market, with a very high cost performance, and can achieve the characteristics of small size, light weight, good performance and low cost. Moreover, after reasonable lens material selection, optical power distribution and optical design optimization, the present invention can be matched with 5MP and 2 / 3 chips to achieve 24-hour all-weather high-definition photography, excellent low-illumination effect, and clear actual pictures at high temperatures of +80°C and low temperatures of -40°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the optical structure of embodiment 1 of the present invention;

[0041] Figure 2 This is a schematic diagram of the optical path structure of Example 1 of the present invention;

[0042] Figure 3 This is a defocus curve of visible light 0.435-0.656 μm (100 lp / mm) at room temperature +20°C in Example 1 of the present invention;

[0043] Figure 4 This is a low-temperature -40°C defocus curve diagram of visible light 0.435-0.656 μm (100 lp / mm) in Example 1 of the present invention;

[0044] Figure 5 This is a high temperature +80°C defocus curve diagram of visible light 0.435-0.656 μm (100 lp / mm) in Example 1 of the present invention;

[0045] Figure 6 This is the relative illumination diagram of visible light 0.546 μm in Example 1 of the present invention;

[0046] Figure 7This is the FFT MTF curve of visible light 0.435-0.656μm in Example 1 of the present invention;

[0047] Figure 8 This is a graph showing the F-Theta distortion curve of visible light at 0.546 μm in Example 1 of the present invention;

[0048] Figure 9 This is an on-axis chromatic aberration curve for visible light 0.435-0.656 μm in Example 1 of the present invention;

[0049] Figure 10 Schematic diagram of the optical structure of embodiment 2 of the present invention;

[0050] Figure 11 This is a schematic diagram of the optical path structure of Example 2 of the present invention;

[0051] Figure 12 This is a defocus curve of visible light 0.435-0.656 μm (100 lp / mm) at room temperature +20°C in Example 2 of the present invention;

[0052] Figure 13 This is a low-temperature -40°C defocus curve for visible light 0.435-0.656 μm (100 lp / mm) in Example 2 of the present invention;

[0053] Figure 14 This is a high-temperature +80°C defocus curve for visible light 0.435-0.656 μm (100 lp / mm) in Example 2 of the present invention;

[0054] Figure 15 This is the relative illumination diagram of visible light 0.546 μm in Example 2 of the present invention;

[0055] Figure 16 This is the FFT MTF curve of visible light 0.435-0.656μm in Example 2 of the present invention;

[0056] Figure 17 This is a graph showing the F-Theta distortion curve of visible light at 0.546 μm in Example 2 of the present invention;

[0057] Figure 18 This is an on-axis chromatic aberration curve for visible light 0.435-0.656 μm in Example 2 of the present invention;

[0058] Figure 19 Schematic diagram of the optical structure of embodiment 3 of the present invention;

[0059] Figure 20 This is a schematic diagram of the optical path structure of Example 3 of the present invention;

[0060] Reference numerals: 1 - first lens; 2 - second lens; 3 - third lens; 4 - fourth lens; 5 - fifth lens; 6 - sixth lens; 7 - seventh lens; 8 - eighth lens; 9 - ninth lens; 10 - filter; 11 - protective glass; 12 - aperture stop. DETAILED DESCRIPTION

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. In this specification, the expressions first, second, third, etc. are only used to distinguish one feature from another and do not represent any limitation on the features. The shape of the spherical or aspherical surface is not limited to the spherical or aspherical shape shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0062] In the present invention, the paraxial region refers to the region near the optical axis. If a lens surface is convex and the position of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region; if a lens surface is concave and the position of the concave surface is undefined, it means that the lens surface is concave at least in the paraxial region; if a lens surface is not defined as convex, concave, or flat, it means that the lens surface can be convex, concave, or flat. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0063] Unless otherwise defined, all terms (including technical and scientific terms) used in the present invention have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this invention.

[0064] It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of this application may be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention. For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings.

[0065] The present invention provides a 4mm large aperture athermal high-definition all-glass lens. The surface of the lens adjacent to the object plane is the object side surface, and the surface of the lens adjacent to the image plane is the image side surface. The lens comprises the following components in order from the object side to the image side along the optical axis of the lens:

[0066] A first lens 1 is a glass lens with negative optical power, wherein the object-side surface of the first lens 1 is convex and the image-side surface is concave;

[0067] A second lens 2, which is a glass lens with negative optical power, has a concave object-side surface and a concave image-side surface;

[0068] The third lens 3 is a glass lens with positive refractive power, the object-side surface of the third lens 3 is concave, and the image-side surface is convex;

[0069] The fourth lens 4 is a spherical glass lens with positive refractive power, and the object-side surface and image-side surface of the fourth lens 4 are convex;

[0070] a fifth lens element 5, which is a spherical glass lens with positive refractive power, wherein the object-side surface of the fifth lens element 5 is convex and the image-side surface is concave;

[0071] a sixth lens element 6, which is a glass lens with positive refractive power, and has a convex object-side surface and a convex image-side surface;

[0072] a seventh lens element 7, which is a glass lens with negative optical power, having a concave object-side surface and a concave image-side surface;

[0073] an eighth lens element 8, which is a glass lens having positive refractive power, and has a convex object-side surface and a convex image-side surface;

[0074] A ninth lens element 9 is a glass lens having positive refractive power, wherein the object-side surface of the ninth lens element 9 is convex and the image-side surface is concave;

[0075] A filter 10 is provided on the image side of the ninth lens element 9 and is made of H-K9L;

[0076] Protective glass 11, which is integrated on the image sensor and disposed on the image side of the filter 10;

[0077] The lens further includes an aperture 12 , which is located between the fifth lens 5 and the sixth lens 6 .

[0078] The sixth lens and the seventh lens are cemented lenses.

[0079] In the present invention, in order to make the optical system present better performance, we must reasonably select lens materials, reasonably allocate the focal lengths of each lens, and reasonably optimize the optical system during the design process to correct the aberrations of the system, and ultimately optimize the performance of the optical system. In the present invention, the focal length of the first lens 1 is f1, the focal length of the second lens 2 is f2, the focal length of the third lens 3 is f3, the focal length of the fourth lens 4 is f4, the focal length of the fifth lens 5 is f5, the focal length of the sixth lens 6 is f6, the focal length of the seventh lens 7 is f7, the focal length of the eighth lens 8 is f8, the focal length of the ninth lens 9 is f9, the total focal length of the lens is f, and the ratio of the focal length of each lens to the total focal length of the system meets the following conditions:

[0080] -6.5≤f1 / f≤-3.5,

[0081] -4≤f2 / f≤-2,

[0082] 10≤f3 / f≤45,

[0083] 5≤f4 / f≤8.5,

[0084] 6.5≤f5 / f≤10,

[0085] 2.0≤f6 / f≤3.0,

[0086] -2.2≤f7 / f≤-1.2,

[0087] 3.5≤f8 / f≤6.5,

[0088] 4.0≤f9 / f≤7.0.

[0089] In the present invention, taking into account the aberrations and temperature drift of the optical system, the focal lengths, refractive indices, and curvature radii of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, and the ninth lens 9 respectively meet the following conditions:

[0090]

[0091] Wherein, f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the radius of curvature of the object side surface of the first lens, and R12 is the radius of curvature of the image side surface of the first lens; f2 is the focal length of the second lens, ND2 is the refractive index of the second lens 2, R21 is the radius of curvature of the object side surface of the second lens, and R22 is the radius of curvature of the image side surface of the second lens; f is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the radius of curvature of the object side surface of the third lens, and R32 is the radius of curvature of the image side surface of the third lens; f4 is the focal length of the fourth lens, ND4 is the refractive index of the fourth lens, R41 is the radius of curvature of the object side surface of the fourth lens, and R42 is the radius of curvature of the image side surface of the fourth lens; f5 is the focal length of the fifth lens, ND5 is the refractive index of the fifth lens, and R51 is the radius of curvature of the object side surface of the fifth lens Surface curvature radius, R52 is the image side surface curvature radius of the fifth lens; f6 is the focal length of the sixth lens, ND6 is the refractive index of the sixth lens, R61 is the object side surface curvature radius of the sixth lens, R62 is the image side surface curvature radius of the sixth lens; f7 is the focal length of the seventh lens, ND7 is the refractive index of the seventh lens, R71 is the object side surface curvature radius of the seventh lens, R72 is the image side surface curvature radius of the seventh lens; f8 is the focal length of the eighth lens, ND8 is the refractive index of the eighth lens, R81 is the object side surface curvature radius of the eighth lens, R82 is the image side surface curvature radius of the eighth lens; f9 is the focal length of the ninth lens, ND9 is the refractive index of the ninth lens, R91 is the object side surface curvature radius of the ninth lens, R92 is the image side surface curvature radius of the ninth lens; the “-” sign indicates that the surface is curved toward the object side.

[0092] In the present invention, f is the total focal length of the lens, TTL is the total optical length of the lens, OBFL is the optical back focus of the lens, and the optical back focus of the lens is the distance from the point closest to the image plane on the image side of the ninth lens element to the image plane; IC is the total image height of the 2 / 3" chip used in the lens system; they satisfy the following relationship:

[0093] IC / TTL≥0.12,

[0094] TTL / f≤19,

[0095] OBFL / TTL≥0.06.

[0096] In the present invention, the aperture of the lens is F#, which satisfies F#≤1.6, the focal length of the lens is f, which satisfies f=4mm, and the total optical length of the lens is TTL, which satisfies TTL≤80mm.

[0097] The following describes a specific embodiment of the 4mm large aperture athermal high-definition all-glass lens according to the present invention. The symbols for the main elements are shown in Table 1:

[0098] Table 1

[0099]

[0100] The specific implementation data are summarized in Table 2 below:

[0101] Table 2

[0102]

[0103] Example 1

[0104] Reference Figure 1 、 Figure 2 As shown in the figure, they are respectively a schematic diagram of the optical structure and a schematic diagram of the optical path structure. In this embodiment, the total focal length of the lens is f = 4.2mm, the aperture value F# = 1.6, the full image height IC = 10.18mm, the field of view angle DFOV = 155°, the total optical length TTL of the lens is 65.41mm, and the optical back focus distance of the lens system is OBFL = 4.22mm.

[0105] In this embodiment, the curvature radius (unit: mm), center thickness d (unit: mm), refractive index (ND), and Abbe constant (VD) of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, and the ninth lens 9 are shown in Table 3.

[0106] Table 3

[0107]

[0108] In Table 3, the radius of curvature represents the degree of curvature of the lens surface. A positive value indicates that the surface is curved toward the image plane, and a negative value indicates that the surface is curved toward the object plane. "Infinity" indicates that the surface is flat. The thickness represents the central axial distance from the current surface to the next surface. The refractive index represents the light deflection ability of the current lens material. The Abbe number represents the dispersion characteristics of the current lens material to light.

[0109] In this embodiment, reference Figure 3-5 As shown in the figure, the defocus of the lens is less than 8μm at high temperature of +80℃ and low temperature of -40℃. Such a small defocus ensures that the lens can shoot high-definition images at high temperature of +80℃ and low temperature of -40℃.

[0110] refer to Figure 6 As shown in the figure, the relative illumination of the lens at the maximum field of view is greater than 52%, and the amount of light entering is sufficient, ensuring that there will be no dark corners in the actual shooting picture even when the lens is used in a dim environment.

[0111] See also Figure 7The following figure shows the MTF curve of the lens used in this embodiment. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, at a spatial frequency of 220 lp / mm, the MTF value within a 75-degree field of view (FOV) of the lens is above 0.3, indicating that the lens has high resolution.

[0112] See also Figure 8 , shows the F-Theta distortion diagram of the lens used in this embodiment. The horizontal axis represents F-Theta distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the lens is small, less than 10%, indicating that the fisheye lens distortion is well corrected.

[0113] See also Figure 9 Figure 2 shows the on-axis chromatic aberration of the lens used in this embodiment. The horizontal axis represents the intersection of the light rays and the optical axis (unit: mm), and the vertical axis represents different lens apertures. As can be seen from the figure, the on-axis chromatic aberration is approximately 0.05 mm, which is well corrected.

[0114] Example 2

[0115] In this embodiment, the total focal length of the lens is f=4mm, the aperture value F#=1.6, the full image height IC=8.5mm, the field of view angle DFOV=160°, the total optical length TTL of the lens is 52.66mm, and the optical back focus distance of the lens system is OBFL=3.62mm.

[0116] In this embodiment, the curvature radius (unit: mm), center thickness d (unit: mm), refractive index (ND), and Abbe constant (VD) of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, and the ninth lens 9 are shown in Table 4.

[0117] Table 4

[0118]

[0119] In this embodiment, reference Figure 12-14 As shown in the figure, the defocus of the lens is less than 8μm at high temperature of +80℃ and low temperature of -40℃. Such a small defocus ensures that the lens can shoot high-definition images at high temperature of +80℃ and low temperature of -40℃.

[0120] refer to Figure 15 As shown in the figure, the relative illumination of the lens at the maximum field of view is greater than 65%, and the amount of light entering is sufficient, ensuring that there will be no dark corners in the actual shooting picture even when the lens is used in a dim environment.

[0121] See also Figure 16The following figure shows the MTF curve of the lens used in this embodiment. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, at a spatial frequency of 220 lp / mm, the MTF value within the 75-degree field of view (FOV) of the lens is above 0.2, indicating that the lens has high resolution.

[0122] See also Figure 17 , shows the F-Theta distortion diagram of the lens used in this embodiment. The horizontal axis represents F-Theta distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the lens is small, less than 10%, indicating that the fisheye lens distortion is well corrected.

[0123] See also Figure 18 Figure 2 shows the on-axis chromatic aberration of the lens used in this embodiment. The horizontal axis represents the intersection of the light rays and the optical axis (unit: mm), and the vertical axis represents different lens apertures. As can be seen from the figure, the on-axis chromatic aberration is approximately 0.05 mm, which is well corrected.

[0124] Example 3

[0125] In this embodiment, the total focal length of the lens is f=4mm, the aperture value F#=1.6, the full image height IC=9.7mm, the field of view angle DFOV=150°, the total optical length TTL of the lens is 75.49mm, and the optical back focus distance of the lens system is OBFL=4.62mm.

[0126] In this embodiment, the curvature radius (unit: mm), center thickness d (unit: mm), refractive index (ND), and Abbe constant (VD) of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, and the ninth lens 9 are shown in Table 5.

[0127] Table 5

[0128]

[0129] To sum up, the 4mm large aperture athermal high-definition all-glass lens adopts a 9-piece all-glass structure. The total focal length of the optical lens is f=4mm, and the aperture F# satisfies F#≤1.6. Under the large aperture and large focal length, the light aperture is relatively large, which can ensure the high relative illumination of the system, and there is no dark corner in the picture during shooting. At the same time, the system aberration is well corrected, and the optical performance is good. In terms of manufacturability, each lens is insensitive, the lens surface is simple and easy to manufacture, and the structure between the lenses is compact. Its processing cost is also relatively low compared to the market, with a very high cost performance, and can achieve the characteristics of small size, light weight, good performance and low cost. Moreover, after reasonable lens material selection, optical power distribution and optical design optimization, the present invention can be matched with 5MP and 2 / 3 chips to achieve 24-hour all-weather high-definition photography, excellent low-illumination effect, and clear actual pictures at high temperatures of +80℃ and low temperatures of -40℃.

[0130] The above description only represents several embodiments of the present invention, and the description is relatively specific and detailed, but it should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, and the present invention is intended to include such modifications and variations.

Claims

1. A 4mm large aperture athermal high-definition all-glass lens, characterized by: Set along the lens optical axis from the object side to the image side in order: a first lens, wherein the first lens is a glass lens with negative optical power, the object-side surface of the first lens being convex, and the image-side surface of the first lens being concave; a second lens, wherein the second lens is a glass lens having negative optical power, and the object-side surface and the image-side surface of the second lens are concave; a third lens, the third lens being a glass lens with positive optical power, the object-side surface of the third lens being concave, and the image-side surface being convex; a fourth lens, the fourth lens being a spherical glass lens with positive refractive power, the object-side surface of the fourth lens being convex, and the image-side surface of the fourth lens being convex; a fifth lens element, the fifth lens element being a spherical glass lens with positive optical power, the object-side surface of the fifth lens element being convex, and the image-side surface of the fifth lens element being concave; a sixth lens, the sixth lens being a glass lens with positive optical power, the object-side surface of the sixth lens being convex, and the image-side surface of the sixth lens being convex; a seventh lens element, the seventh lens element being a glass lens with negative optical power, the object-side surface of the seventh lens element being concave, and the image-side surface of the seventh lens element being concave; an eighth lens element, the eighth lens element being a glass lens with positive optical power, the object-side surface of the eighth lens element being convex, and the image-side surface of the eighth lens element being convex; a ninth lens element, the ninth lens element being a glass lens with positive optical power, the object-side surface of the ninth lens element being convex, and the image-side surface of the ninth lens element being concave; The sixth lens and the seventh lens are cemented lenses; The lens further includes an aperture, and the aperture is located between the fifth lens and the sixth lens; The lens satisfies the following relationship: -6.5≤f1 / f≤-3.5, -4≤f2 / f≤-2, 10≤f3 / f≤45, 5≤f4 / f≤8.5, 6.5≤f5 / f≤10, 2.0≤f6 / f≤3.0, -2.2≤f7 / f≤-1.2, 3.5≤f8 / f≤6.5, 4.0≤f9 / f≤7.0, IC / TTL≥0.12, TTL / f≤19, OBFL / TTL ≥ 0.06; In the relationship, f is the total focal length of the lens, f1 is the focal length of the first lens element, f2 is the focal length of the second lens element, f3 is the focal length of the third lens element, f4 is the focal length of the fourth lens element, f5 is the focal length of the fifth lens element, f6 is the focal length of the sixth lens element, f7 is the focal length of the seventh lens element, f8 is the focal length of the eighth lens element, f9 is the focal length of the ninth lens element, TTL is the total optical length of the lens, OBFL is the optical back focus distance of the lens, and IC is the total image height of the 2 / 3" sensor used with the lens system.

2. The 4mm large aperture athermal high-definition all-glass lens according to claim 1, characterized in that: The refractive index ranges corresponding to the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens are 1.61-1.76, 1.62-1.90, 1.74-1.85, 1.60-1.76, 1.72-1.80, 1.58-1.79, 1.88-1.94, 1.56-1.75 and 1.78-1.97 respectively.

3. The 4mm large aperture athermal high-definition all-glass lens according to claim 1, characterized in that: The object-side surface curvature radii corresponding to the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens are in the ranges of 35.9 to 76.5, -37.5 to -12.5, -135 to -36, 40.2 to 86.34, 12.44 to 23.1, 8.96 to 65.2, -11.3 to -9.94, 8.45 to 26.0, and 10.54 to 13.18, respectively; wherein the "-" sign indicates that the surface is curved toward the object plane, and the unit of the curvature radius is mm.

4. The 4mm large aperture athermal high-definition all-glass lens according to claim 1, characterized in that: The image-side surface curvature radii corresponding to the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens are in the ranges of 8.19 to 11.8, 13.5 to 17.0, -53.2 to -20.62, -28.48 to -15.7, 26.55 to 79.2, -11.3 to -9.94, 7.63 to 48.5, -200 to -25, and 20.19 to 32.0, respectively; wherein the "-" sign indicates that the surface is curved toward the object plane, and the unit of the curvature radius is mm.

5. The 4mm large aperture athermal high-definition all-glass lens according to claim 1, characterized in that: The aperture of the lens is F#, which satisfies F#≤1.

6.

6. The 4mm large aperture athermal high-definition all-glass lens according to claim 1, characterized in that: The total focal length of the lens is f, which satisfies f=4mm.

7. The 4mm large aperture athermal high-definition all-glass lens according to claim 1, characterized in that: The total optical length of the lens is TTL, satisfying TTL≤80mm.

8. The 4mm large aperture athermal high-definition all-glass lens according to claim 1, characterized in that: The lens further includes a filter and a protective glass. The filter is arranged on the image side of the ninth lens. The protective glass is integrated on the image sensor and is arranged on the image side of the filter.

9. The 4mm large aperture athermal high-definition all-glass lens according to claim 8, characterized in that: The filter is made of H-K9L.

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