An optical lens

Abstract

The present invention discloses an optical lens. The optical lens has an object side and an image side which are oppositely arranged along the optical axis direction. The optical lens includes a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a positive optical power, a fourth lens with a negative optical power, and a fifth lens with a positive optical power, which are sequentially arranged from the object side to the image side. Among them, the optical lens satisfies the following condition: 0.32 < D / TTL < 0.39; where D is the maximum image plane diameter of the optical lens, and TTL is the overall optical length of the optical lens. Through the reasonable arrangement of five groups of lenses, the present invention enables the optical lens to have good optical performance, and the ratio of the maximum image plane diameter of the optical lens to the overall optical length of the optical lens is controlled between 0.32 and 0.39, effectively reducing the overall length of the optical lens and realizing the miniaturization of the optical lens.

Description

Technical Field

[0001] The present invention relates to the technical field of optical system design, and in particular to an optical lens. Background Art

[0002] The Advanced Driver Assistance System (ADAS) uses a variety of sensors installed on the car to sense the surrounding environment at any time while the car is driving, collect data, identify, detect and track static and dynamic objects, and combine navigation map data to perform systematic calculations and analysis, so that the driver can be aware of possible dangers in advance, effectively increasing the comfort and safety of car driving.

[0003] In recent years, with the rapid development of advanced driver assistance systems (ADAS), optical lenses have played an increasingly important role in it, and the demand for optical lenses in the automotive industry has also increased. For safety reasons, optical lenses have extremely strict requirements on certain optical parameters. For example, optical lenses have increasingly higher requirements on pixels. In order to improve the resolution capability, a 7-piece or even more lens structure is usually used to obtain high resolution, but this will seriously affect the miniaturization of the lens. Due to the limitations of the installation space and overall layout in the car, a lens size that is too large will interfere with driving and is very inconvenient to use. Summary of the invention

[0004] The main purpose of the present invention is to provide an optical lens, aiming to improve the technical problem in the prior art that the large lens size causes interference to driving.

[0005] To achieve the above object, the present invention provides an optical lens, the optical lens having an object side and an image side arranged opposite to each other along an optical axis direction, the optical lens comprising a first lens having negative optical power, a second lens having positive optical power, a third lens having positive optical power, a fourth lens having negative optical power, and a fifth lens having positive optical power, which are arranged in sequence from the object side to the image side;

[0006] Wherein, the optical lens meets the following conditions: 0.32 <D / TTL<0.39;

[0007] Wherein, D is the maximum image diameter of the optical lens, and TTL is the total optical length of the optical lens.

[0008] Optionally, the first lens, the second lens, the third lens and the fourth lens are spherical glass lenses, and the fifth lens is an aspherical glass lens.

[0009] Optionally, the first lens is a biconcave lens, the second lens is a biconvex lens, the third lens is a biconvex lens, the fourth lens is a biconcave lens, and the fifth lens is a biconvex lens.

[0010] Optionally, the third lens is a cemented lens, comprising a first lens, a second lens and a third lens stacked in sequence from the object side to the image side, the first lens is a biconvex lens with positive optical power, the second lens is a biconcave lens with negative optical power, and the third lens is a biconvex lens with positive optical power.

[0011] Optionally, the optical lens meets the following conditions: 0.7 <T1 / T2<0.9;

[0012] 0.85 <T3 / T4<0.95;

[0013] 1.2<(T5+T6+T7) / (T4+T8)<1.4;

[0014] Wherein, T1 is the distance from the image side surface of the first lens to the object side surface of the second lens on the optical axis, T2 is the distance from the object side surface of the second lens to the image side surface of the second lens on the optical axis, T3 is the distance from the image side surface of the third lens to the object side surface of the fourth lens on the optical axis, T4 is the distance from the object side surface of the fourth lens to the image side surface of the fourth lens on the optical axis, T5 is the distance from the object side surface of the first lens to the image side surface of the first lens on the optical axis, T6 is the distance from the object side surface of the second lens to the image side surface of the second lens on the optical axis, T7 is the distance from the object side surface of the third lens to the image side surface of the third lens on the optical axis, and T8 is the distance from the object side surface of the fifth lens to the image side surface of the fifth lens on the optical axis.

[0015] Optionally, the optical lens satisfies the following conditions: 5<|Vd33-Vd32|<15;

[0016] 5<|Vd5-Vd4|<15;

[0017] Among them, Vd33 is the dispersion coefficient of the third lens, Vd32 is the dispersion coefficient of the second lens, Vd5 is the dispersion coefficient of the fifth lens, and Vd4 is the dispersion coefficient of the fourth lens.

[0018] Optionally, the optical lens meets the following conditions: <f1 / f<-6;

[0019] 0.8 <f2 / f<1.2;

[0020] 1.6 <f3 / f<1.8;

[0021] -0.8 <f4 / f<-0.6;

[0022] 0.85 <f5 / f<1.05;

[0023] Among them, f is the effective focal length of the optical lens, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, and f5 is the effective focal length of the fifth lens.

[0024] Optionally, the optical lens meets the following conditions: -1.45 <R4 / R6<-1.25;

[0025] Among them, R4 is the curvature radius of the image side of the second lens, and R6 is the curvature radius of the object side of the third lens.

[0026] Optionally, the optical lens satisfies the following condition: 0<|Sag12-Sag11|<0.15;

[0027] Among them, Sag11 is the distance between the highest point of the image side light of the fourth lens and the center of the lens on the optical axis, and Sag12 is the distance between the highest point of the object side light of the fifth lens and the center of the lens on the optical axis.

[0028] Optionally, the optical lens further includes a grating and an infrared filter, the grating is located between the second lens and the third lens, and the infrared filter is located on the image side of the fifth lens.

[0029] In the technical solution provided by the present invention, the optical lens comprises a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, a fourth lens with negative optical power and a fifth lens with positive optical power, which are arranged in sequence from the object side to the image side. Through the reasonable arrangement of the five groups of lenses, the optical lens has good optical performance, and the ratio of the maximum image plane diameter of the optical lens to the total optical length of the optical lens is controlled between 0.32 and 0.39, so that the total length of the optical lens is less than 21 mm, the maximum image plane of the optical lens is greater than 7.4 mm, and a higher MTF curve effect is achieved, which not only meets the requirements of a large image plane but also effectively reduces the total lens length of the optical lens, realizes the miniaturization of the optical lens, and is conducive to later assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0031] Figure 1This is a schematic structural diagram of an optical lens according to an embodiment of the present invention.

[0032] Description of Figure Numbers:

[0033]

[0034]

[0035] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that if a directional indication is involved in the embodiment of the present invention, the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] In recent years, with the rapid development of advanced driver assistance systems (ADAS), optical lenses have played an increasingly important role in it, and the demand for optical lenses in the automotive industry has also increased. For safety reasons, optical lenses have extremely strict requirements on certain optical parameters. For example, optical lenses have increasingly higher requirements on pixels. In order to improve the resolution, 7 or more lens structures are usually used to obtain high resolution, but this will seriously affect the miniaturization of the lens. Due to the limitations of the installation space and overall layout in the car, a lens that is too large will interfere with driving and is very inconvenient to use.

[0040] In view of this, the present invention provides an optical lens. Figure 1 This is an embodiment of the optical lens, and the optical lens is described in detail below.

[0041] The optical lens has an object side and an image side which are arranged opposite to each other along the optical axis direction, and the optical lens includes a first lens 1 with negative optical focal length, a second lens 2 with positive optical focal length, a third lens 3 with positive optical focal length, a fourth lens 4 with negative optical focal length, and a fifth lens 5 with positive optical focal length, which are arranged in sequence from the object side to the image side; it can be understood that the optical focal length is equal to the difference between the convergence degree of the image-side light beam and the convergence degree of the object-side light beam, and it characterizes the ability of the optical system to deflect light. The larger the absolute value of the optical focal length is, the stronger the bending ability of the light is, and the smaller the absolute value of the optical focal length is, the weaker the bending ability of the light is. When the optical focal length is a positive number, the refraction of the light is convergent; when the optical focal length is a negative number, the refraction of the light is divergent. The optical focal length can be used to characterize a certain refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a certain lens, and can also be used to characterize a system formed by multiple lenses (i.e., a lens group).

[0042] Wherein, the optical lens meets the following conditions: 0.32 <D / TTL<0.39;

[0043] Wherein, D is the maximum image plane diameter of the optical lens, and TTL is the total optical length of the optical lens, that is, the distance from the object side of the first lens 1 to the image plane 8 on the optical axis.

[0044] In the technical solution provided by the present invention, a first lens 1 with negative optical power, a second lens 2 with positive optical power, a third lens 3 with positive optical power, a fourth lens 4 with negative optical power and a fifth lens 5 with positive optical power are arranged in sequence from the object side to the image side. Through the reasonable arrangement of the five groups of lenses, the optical lens has good optical performance, and the ratio of the maximum image plane diameter of the optical lens to the total optical length of the optical lens is controlled between 0.32 and 0.39, so that the total length of the optical lens is less than 21 mm, the maximum image plane of the optical lens is greater than 7.4 mm, and a higher MTF curve effect is achieved, which not only meets the requirement of a large image plane but also effectively reduces the total lens length of the optical lens, realizes the miniaturization of the optical lens, and is conducive to later assembly.

[0045] Specifically, in this embodiment, the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4 are spherical glass lenses, and the fifth lens 5 is an aspherical glass lens. The lenses in the optical lens are all made of glass material, so that the lens can easily meet the reliability test requirements, is not easy to deform under high temperature, low temperature or other harsh environmental conditions, and can still maintain good performance.

[0046] Specifically, in the present embodiment, since the first lens 1 has negative power, the first lens 1 is a biconcave lens, that is, the image side surface and the object side surface of the first lens 1 are both concave surfaces, the second lens 2 has positive power, the second lens 2 is a biconvex lens, that is, the image side surface and the object side surface of the second lens 2 are both convex surfaces, the third lens 3 has positive power, the third lens 3 is a biconvex lens, that is, the object side surface and the image side surface of the third lens 3 are both convex surfaces, the fourth lens 4 has negative power, the fourth lens 4 is a biconcave lens, that is, the object side surface and the image side surface of the fourth lens 4 are both concave surfaces, and the fifth lens 5 has positive power, the fifth lens 5 is a biconvex lens, that is, the object side surface and the image side surface of the fifth lens 5 are both convex surfaces.

[0047] Specifically, in this embodiment, the third lens 3 is a cemented lens. The third lens 3 includes a first lens 31, a second lens 32, and a third lens 33 stacked in sequence from the object side to the image side. The first lens 31 is a biconvex lens with a positive optical power. The second lens 32 is a biconcave lens with a negative optical power. The third lens 33 is a biconvex lens with a positive optical power. The object side surface of the first lens 31 forms the object side surface of the third lens 3. The image side surface of the third lens 33 forms the image side surface of the third lens 3. The third lens 3 adopts a cemented lens structure with three groups of lenses cemented together, which can effectively reduce the assembly difficulty, reduce the cost, and the cemented lens can well correct the chromatic aberration in the optical system, making the color restoration degree higher.

[0048] It can be understood that white light is composed of many monochromatic lights, and the refractive index of a lens for different monochromatic lights is different. The shorter the wavelength, the greater the refractive index, and the longer the wavelength, the smaller the refractive index. When a beam of white light passes through a lens and is refracted, due to the different refractive indices of light with different wavelengths, the white light is dispersed into various wavelengths of light in the ultraviolet band, visible band, and infrared band ranges, resulting in the image formed when passing through the lens having a colored edge. Specifically, at a point on the object side, a color spot may be formed on the image side, forming chromatic aberration, making the imaging unclear. Therefore, chromatic aberration has become a serious defect in lens imaging. A cemented lens is formed by cementing multiple lenses with different materials together. When light passes through one of the lenses of the cemented lens and is refracted, chromatic aberration will occur. When the refracted light continues to pass through another lens, the chromatic aberration generated is exactly the opposite and can cancel out the previously occurring chromatic aberration, thereby achieving the purpose of eliminating chromatic aberration. Therefore, the third lens 3 can eliminate chromatic aberration to the greatest extent and improve the imaging quality.

[0049] Specifically, in this embodiment, the optical lens satisfies the following conditions: 0.7 < T1 / T2 < 0.9, and 0.85 < T3 / T4 < 0.95, and 1.2 < (T5 + T6 + T7) / (T4 + T8) < 1.4;

[0050] Wherein, T1 is the distance on the optical axis from the image side of the first lens 1 to the object side of the second lens 2, T2 is the distance on the optical axis from the object side of the second lens 2 to the image side of the second lens 2, T3 is the distance on the optical axis from the image side of the third lens 3 to the object side of the fourth lens 4, T4 is the distance on the optical axis from the object side of the fourth lens 4 to the image side of the fourth lens 4, T5 is the distance on the optical axis from the object side of the first lens element 31 to the image side of the first lens element 31, T6 is the distance on the optical axis from the object side of the second lens element 32 to the image side of the second lens element 32, T7 is the distance on the optical axis from the object side of the third lens element 33 to the image side of the third lens element 33, and T8 is the distance on the optical axis from the object side of the fifth lens 5 to the image side of the fifth lens 5. When the above conditions are met, by reasonably allocating the central thicknesses of the respective lenses and the intervals between the lenses, it is conducive to mutual compensation among the lens elements to correct aberrations, achieving a higher resolving power, and at the same time being conducive to correcting field curvature and distortion.

[0051] Specifically, in this embodiment, the optical lens satisfies the following conditions: 5 < |Vd33 - Vd32| < 15, and 5 < |Vd5 - Vd4| < 15;

[0052] Wherein, Vd33 is the Abbe number of the third lens element 33, Vd32 is the Abbe number of the second lens element 32, Vd5 is the Abbe number of the fifth lens 5, and Vd4 is the Abbe number of the fourth lens 4. When the above conditions are met, by controlling the Abbe numbers of the respective lenses or lens elements and selecting appropriate lens materials, the longitudinal chromatic aberration of the lens can be corrected, improving the imaging quality.

[0053] Specifically, in this embodiment, the optical lens satisfies the following conditions: -7 < f1 / f < -6, and 0.8 < f2 / f < 1.2, and 1.6 < f3 / f < 1.8, and -0.8 < f4 / f < -0.6, and 0.85 < f5 / f < 1.05;

[0054] Wherein, f is the effective focal length of the optical lens, f1 is the effective focal length of the first lens 1, f2 is the effective focal length of the second lens 2, f3 is the effective focal length of the third lens 3, f4 is the effective focal length of the fourth lens 4, and f5 is the effective focal length of the fifth cemented lens 5. By reasonably controlling the effective focal lengths of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, and the fifth lens 5, the aberrations can be better corrected.

[0055] Specifically, in this embodiment, the optical lens satisfies the following conditions: -1.45 < R4 / R6 < -1.25;

[0056] Wherein, R4 is the curvature radius of the image side surface of the second lens 2, and R6 is the curvature radius of the object side surface of the third lens 3. When the above conditions are met, the curvature radius of the lens surface before and after the aperture 6 is controlled, which helps to correct the off-axis aberration of the optical lens and reduce the astigmatism and field curvature of the optical lens. At the same time, the incident angle of the light before and after the aperture 6 is controlled, which helps to improve the resolution of the optical lens.

[0057] Specifically, in this embodiment, the optical lens satisfies the following conditions: 0<|Sag12-Sag11|<0.15;

[0058] Wherein, Sag11 is the distance between the highest point of the image side ray of the fourth lens 4 and the center of the lens on the optical axis, and Sag12 is the distance between the highest point of the object side ray of the fifth lens 5 and the center of the lens on the optical axis. When the above conditions are met, the intervals between the fourth lens 4 and the fifth lens 5 for different fields of view can be kept relatively uniform, the shape of the lens is effectively controlled, and the processing is convenient in the later stage. At the same time, the tolerance sensitivity is reduced, so that the aberration between the fourth lens 4 and the fifth lens 5 is compensated, and the lens resolution is improved.

[0059] Specifically, in this embodiment, the optical lens further includes an aperture 6 and an infrared filter 7, wherein the aperture 6 is located between the second lens 2 and the third lens 3, and the infrared filter 7 is located on the image side of the fifth lens 5. The image side of the infrared filter 7 is also provided with an image plane 8, and the image plane 8 may be the surface of an image sensor. The infrared filter 7 may filter out infrared light to prevent infrared light from reaching the image sensor and interfering with normal visible light imaging, thereby improving imaging quality. It is understandable that light carrying information of the object being photographed may sequentially pass through the first lens 1, the second lens 2, the aperture 6, the third lens 3, the fourth lens 4, the fifth lens 5, and the infrared filter 7 and finally be imaged on the image plane 8.

[0060] Specifically, in this embodiment, each lens or lens has an object side surface and an image side surface, which are respectively the object side surface S1 of the first lens, the image side surface S2 of the first lens, the object side surface S3 of the second lens, the image side surface S4 of the second lens, the object side surface S5 of the third lens, the image side surface S8 of the third lens, the object side surface S9 of the fourth lens, the image side surface S10 of the fourth lens, the object side surface S11 of the fifth lens, and the image side surface S12 of the fifth lens. The third lens 3 is a cemented lens of three lenses cemented together, so it also includes the image side surface of the first lens (or the object side surface of the second lens) S6, the image side surface of the second lens (or the object side surface of the third lens) S7, the aperture is ST, the object side surface of the infrared filter S13, and the image side surface of the infrared filter S14.

[0061] Specifically, in this embodiment, the parameters of the optical lens are shown in the following table.

[0062] Table 1 Parameters of each lens of the optical lens

[0063]

[0064]

[0065] In this embodiment, the even-order coefficients of each aspherical surface are shown in the following table.

[0066] Table 2 Even-order coefficients of the aspherical lens of the optical lens

[0067]

[0068]

[0069] Among them, E-01 means 10 to the power of -1, and so on, EN means 10 to the power of -N.

[0070] This embodiment uses five lenses as an example. By reasonably allocating the optical focal length and surface shape of each lens, the center thickness of each lens and the air space between each lens, the optical lens can have the characteristics of high resolution, miniaturization, high resolution and small distortion.

[0071] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An optical lens, It is characterized in that The optical lens has an object side and an image side which are arranged opposite to each other along the optical axis direction, and the optical lens is composed of a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, a fourth lens with negative optical power, and a fifth lens with positive optical power which are arranged in sequence from the object side to the image side; Wherein, the optical lens meets the following conditions: 0.32 <D / TTL<0.39; Wherein, D is the maximum image diameter of the optical lens, and TTL is the total optical length of the optical lens; The optical lens satisfies the following conditions: 0<|Sag12- Sag11|<0.15; Wherein, Sag11 is the distance between the highest point of the image side light of the fourth lens and the center of the lens on the optical axis, and Sag12 is the distance between the highest point of the object side light of the fifth lens and the center of the lens on the optical axis; The first lens is a biconcave lens, the second lens is a biconvex lens, the third lens is a biconvex lens, the fourth lens is a biconcave lens, and the fifth lens is a biconvex lens.

2. The optical lens according to claim 1, It is characterized in that The first lens, the second lens, the third lens, and the fourth lens are spherical glass lenses, and the fifth lens is an aspherical glass lens.

3. The optical lens according to claim 1, It is characterized in that The third lens is a cemented lens, and is composed of a first lens, a second lens, and a third lens stacked in sequence from the object side to the image side, the first lens is a biconvex lens with positive focal power, the second lens is a biconcave lens with negative focal power, and the third lens is a biconvex lens with positive focal power.

4. The optical lens according to claim 3, It is characterized in that The optical lens meets the following conditions: 0.7< T1 / T2 <0.9; 0.85< T3 / T4<0.95; 1.2<(T5+ T6 + T7) / (T4+ T8)<1.4; Wherein, T1 is the distance from the image side surface of the first lens to the object side surface of the second lens on the optical axis, T2 is the distance from the object side surface of the second lens to the image side surface of the second lens on the optical axis, T3 is the distance from the image side surface of the third lens to the object side surface of the fourth lens on the optical axis, T4 is the distance from the object side surface of the fourth lens to the image side surface of the fourth lens on the optical axis, T5 is the distance from the object side surface of the first lens to the image side surface of the first lens on the optical axis, T6 is the distance from the object side surface of the second lens to the image side surface of the second lens on the optical axis, T7 is the distance from the object side surface of the third lens to the image side surface of the third lens on the optical axis, and T8 is the distance from the object side surface of the fifth lens to the image side surface of the fifth lens on the optical axis.

5. The optical lens according to claim 1, It is characterized in that The optical lens meets the following conditions: -1.45 <R4 / R6<-1.25; Among them, R4 is the curvature radius of the image side of the second lens, and R6 is the curvature radius of the object side of the third lens.

6. The optical lens according to claim 1, It is characterized in that The optical lens further includes an aperture and an infrared filter, wherein the aperture is located between the second lens and the third lens, and the infrared filter is located on the image side of the fifth lens.

Images