CN116755217B - Optical lens and laser radar - Google Patents

Abstract

The application relates to an optical lens and a laser radar, which consists of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged from an object space to an image space; the fourth lens and the fifth lens form a double-cemented lens, and the other lenses are all single lenses. The application overcomes the defects of small angle of view, insufficient target surface, large distortion and the like existing in the long optical lens used in the laser radar at present, and has the advantages of large angle of view, large target surface and low distortion simultaneously by optimizing and limiting parameters such as focal power, concave-convex shape of each surface, air gap, curvature radius, half diameter, center thickness, material, refractive index, abbe coefficient and the like and limiting the first lens and the sixth lens to be aspheric lenses.

Description

Optical lenses and lidar

Technical field

The invention relates to an optical lens and a laser radar, and is used in the production fields of laser radar lenses and laser radar.

Background technique

The application of lidar is to first transmit a detection signal to the target, and then focus the reflected light back onto the detector through the receiving lens set in front of the lidar detector, and then convert the reflected light into a reflected signal, and combine the reflected signal with After the transmitted signals are compared and processed appropriately, relevant information about the target, such as target distance, height, speed and other parameters, can be obtained, so that the target can be detected, tracked and identified. The optical lenses currently used on lidar generally have shortcomings such as small field of view, insufficient target surface, and large distortion. For example, the high-definition optical lens and high-performance lidar disclosed in CN202211167735.4 have a field of view of 77.3°, a distortion of -19.3%, and a target surface of φ8mm; the optical lens and lidar disclosed in CN202222121872.6, The field of view distortion is -60%, and the target surface is φ7.55mm.

Therefore, it has become an urgent task to provide an optical lens and lidar that have a large field of view, a large target surface, and low distortion.

Contents of the invention

In order to overcome the common shortcomings of long optical lenses currently used in lidar such as small field of view angle, insufficient target surface, large distortion, etc., the present invention provides an optical lens and lidar. By optimally limiting the optical power, each surface Concave and convex shape, air gap, radius of curvature, semi-diameter, center thickness, material, refractive index, Abbe coefficient and other parameters, together with the limitation that both the first lens and the sixth lens are aspherical lenses, with the ability to have both field of view angle It has the advantages of large target area and low distortion.

The technical solution of the present invention is as follows:

An optical lens, which includes a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens arranged in sequence from the object side to the image side; wherein, the fourth lens and the fifth lens The lens consists of a double cemented lens, and the remaining lenses are single lenses;

The first lens is a negative power lens, the first surface of the first lens is a convex surface, and the second surface is a concave surface,

The second lens is a lens with positive optical power. The first surface of the second lens is a convex surface and the second surface is a concave surface.

The third lens is a negative power lens. The first surface of the third lens is a convex surface and the second surface is a concave surface.

The fourth lens is a negative power lens. The first surface of the fourth lens is a convex surface and the second surface is a concave surface.

The fifth lens is a positive power lens, the first surface of the fifth lens is convex, and the second surface is convex.

The sixth lens is a positive power lens, the first surface of the sixth lens is convex, and the second surface is convex;

The air gap between the first lens and the second lens is 0.891~4.898mm.

The air gap between the second lens and the third lens is 0.1~0.231mm.

The air gap between the third lens and the diaphragm is 3.17~4.381mm.

The air gap between the diaphragm and the fourth lens is 1.141~1.659mm.

The air gap between the fifth lens and the sixth lens is 4.369~5.687mm;

The first surface curvature radius of the first lens is 37.373~40.004mm, and the second surface curvature radius is 10.339~11.195mm.

The first surface curvature radius of the second lens is 11.725~15.743mm, and the second surface curvature radius is 31.455~58.73mm.

The first surface curvature radius of the third lens is 10.825~19.682mm, and the second surface curvature radius is 3.709~3.95mm.

The first surface curvature radius of the fourth lens is 28.137~48.907mm, and the second surface curvature radius is 12.586~12.794mm.

The first surface curvature radius of the fifth lens is 12.568~12.794mm, and the second surface curvature radius is -7.116~-8.235mm.

The first surface curvature radius of the sixth lens is 30.325~31.654mm, and the second surface curvature radius is -19.185~-21.740mm;

The first surface semi-diameter of the first lens is 10.505~17.04mm, and the second surface semi-diameter is 7.540~9.453mm.

The first surface semi-diameter of the second lens is 7.354~9.188mm, and the second surface semi-diameter is 8mm.

The first surface semi-diameter of the third lens is 5.030~5.432mm, and the second surface semi-diameter is 3.044~3.4mm.

The first surface semi-diameter of the fourth lens is 4.9mm, and the second surface semi-diameter is 6.8mm.

The first surface semi-diameter of the fifth lens is 6.8mm, and the second surface semi-diameter is 6.822~7.111mm.

The first surface semi-diameter of the sixth lens is 8.398~9.225mm, and the second surface semi-diameter is 8.257~9.070mm;

The center thickness of the first lens is 1.652~2.103mm.

The center thickness of the second lens is 2.312~4.22mm,

The center thickness of the third lens is 1~1.634mm,

The center thickness of the fourth lens is 1~1.794mm,

The center thickness of the fifth lens is 4.787~7.8mm.

The center thickness of the sixth lens is 4.114~4.5mm;

The first lens and the sixth lens are both aspherical lenses.

The optical lens of this application preferably defines parameters such as optical power, concave and convex shape of each surface, air gap, radius of curvature, semi-diameter, center thickness, material, refractive index, Abbe coefficient, etc., and cooperates to define the first lens and the sixth lens. They are all aspherical lenses, which have the advantages of large field of view, large target surface, and low distortion. The focal length of this optical lens is 6.28mm±10%mm, the maximum field of view FOV can reach 105°, and it has a large target surface of 1 inch (the corresponding image surface size is φ16mm), and the aperture F number is 2.0± 5%, the half-image height can reach 8.1mm, and the optical system uses double-piece molded aspherics, allowing the system to achieve ultra-low optical distortion of <|1.2|% under 40mm short TTL, greatly reducing the overall size of the lens And obtain high-precision cloud images. The optical lens is arranged in front of the detector during use.

The first lens is made of glass material: 1.55<n<1.75, 45<Vd<55,

The second lens is made of glass material: 1.80<n<2.10, 15<Vd<25,

The third lens is made of glass material: 1.55<n<1.75, 55<Vd<65,

The fourth lens is made of glass material: 1.80<n<2.10, 15<Vd<25,

The fifth lens is made of glass material: 1.55<n<1.75, 60<Vd<70,

The sixth lens is made of glass material: 1.70<n<1.95, 35<Vd<45,

Among them, n is the refractive index and Vd is the Abbe coefficient.

The optical lens is arranged in front of the detector, and a plane lens is provided on the detector. The plane lens is located between the detector and the sixth lens. The air gap between the sixth lens and the plane lens is 1 to 3 mm.

This plane lens is a protective lens and can protect the detector.

The plane lens is made of glass material: 1.50<n<1.70, 55<Vd<65, where n is the refractive index and Vd is the Abbe coefficient.

The optimized plane lens material, refractive index and Abbe coefficient can further ensure the large angle, large target surface and low distortion imaging of the optical lens.

A lidar includes the above-mentioned optical lens.

Lidar with the specially designed optical lens of this application can have the advantages of large angle, large target area, and low distortion imaging. The lidar can receive laser reflection points with a wavelength of 0.850um-0.950um returned from the target, and construct 4D point cloud imaging to obtain surrounding environment information.

Compared with the existing technology, the application of the present invention has the following advantages:

1) The optical lens of this application optimizes the parameters such as optical power, concave and convex shape of each surface, air gap, radius of curvature, semi-diameter, center thickness, material, refractive index, Abbe coefficient, etc., and cooperates to define the first lens and the third lens. The six lenses are all aspherical lenses, which have the advantages of large field of view, large target surface, and low distortion;

2) The lidar in this application can have the advantages of large angle, large target surface, and low distortion imaging. The lidar can receive laser reflection points with a wavelength of 0.850um-0.950um returned from the target and construct 4D point cloud imaging. , thereby obtaining the surrounding environment information.

Description of the drawings

Figure 1 is an optical system diagram of the optical lens and lidar according to the present invention;

Figure 2 is an MTF diagram of the optical lens and lidar Embodiment 1 of the present invention;

Figure 3 is a point diagram of the optical lens and lidar Embodiment 1 of the present invention;

Figure 4 is a field curvature/distortion diagram of the optical lens and lidar Embodiment 1 of the present invention;

Figure 5 is an illumination diagram of the optical lens and lidar Embodiment 1 of the present invention;

Figure 6 is an MTF diagram of the optical lens and lidar Embodiment 2 of the present invention;

Figure 7 is a point diagram of the optical lens and lidar Embodiment 2 of the present invention;

Figure 8 is a field curvature/distortion diagram of the optical lens and lidar Embodiment 2 of the present invention;

Figure 9 is an illumination diagram of the optical lens and lidar Embodiment 2 of the present invention;

Figure 10 is an MTF diagram of the optical lens and lidar embodiment 3 of the present invention;

Figure 11 is a point diagram of the optical lens and lidar Embodiment 3 of the present invention;

Figure 12 is a field curvature/distortion diagram of the optical lens and lidar Embodiment 3 of the present invention;

Figure 13 is an illumination diagram of the optical lens and laser radar according to Embodiment 3 of the present invention.

Label description:

1. First lens, 2. Second lens, 3. Third lens, 4. Fourth lens, 5. Fifth lens, 6. Sixth lens, 7. Plane lens, 8. Diaphragm, 9. Detector .

Detailed ways

The technical solution of the present invention will be described in detail below with reference to Figures 1-13 of the description.

Example 1 (focal length is 6.28mm)

As shown in Figures 1-5, an optical lens according to the present invention has a first lens 1, a second lens 2, a third lens 3, an aperture 8, and a fourth lens arranged in sequence from the object side to the image side. 4. Composed of the fifth lens 5 and the sixth lens 6; among them, the fourth lens 4 and the fifth lens 5 form a double cemented lens, and the remaining lenses are single lenses;

The first lens 1 is a negative power lens, the first surface of the first lens 1 is a convex surface, and the second surface is a concave surface.

The second lens 2 is a positive power lens, the first surface of the second lens 2 is a convex surface, and the second surface is a concave surface.

The third lens 3 is a negative power lens. The first surface of the third lens 3 is a convex surface and the second surface is a concave surface.

The fourth lens 4 is a negative power lens. The first surface of the fourth lens 4 is a convex surface and the second surface is a concave surface.

The fifth lens 5 is a positive power lens. The first surface of the fifth lens 5 is a convex surface and the second surface is a convex surface.

The sixth lens 6 is a positive power lens, the first surface of the sixth lens 6 is a convex surface, and the second surface is a convex surface;

The air gap between the first lens 1 and the second lens 2 is 2.873mm.

The air gap between the second lens 2 and the third lens 3 is 0.231mm.

The air gap between the third lens 3 and the diaphragm 8 is 3.17mm.

The air gap between the diaphragm 8 and the fourth lens 4 is 1.468mm.

The air gap between the fifth lens 5 and the sixth lens 6 is 4.369mm;

The first surface curvature radius of the first lens 1 is 37.84mm, and the second surface curvature radius is 10.6mm.

The first surface curvature radius of the second lens 2 is 15.52mm, and the second surface curvature radius is 58.73mm.

The first surface curvature radius of the third lens 3 is 11.51mm, and the second surface curvature radius is 3.95mm.

The first surface curvature radius of the fourth lens 4 is 39.3mm, and the second surface curvature radius is 12.645mm.

The first surface curvature radius of the fifth lens 5 is 12.645mm, and the second surface curvature radius is -8.235mm.

The first surface curvature radius of the sixth lens 6 is 31.41mm, and the second surface curvature radius is -21.22mm;

The first surface semi-diameter of the first lens 1 is 17.04mm, and the second surface semi-diameter is 9.289mm.

The first surface semi-diameter of the second lens 2 is 9.188mm, and the second surface semi-diameter is 8mm.

The first surface semi-diameter of the third lens 3 is 5.432mm, and the second surface semi-diameter is 3.4mm.

The first surface semi-diameter of the fourth lens 4 is 4.9mm, and the second surface semi-diameter is 6.8mm.

The first surface semi-diameter of the fifth lens 5 is 6.8mm, and the second surface semi-diameter is 6.926mm.

The first surface semi-diameter of the sixth lens 6 is 8.846mm, and the second surface semi-diameter is 8.846mm;

The center thickness of the first lens 1 is 2mm,

The center thickness of the second lens 2 is 4.22mm,

The center thickness of the third lens 3 is 1mm.

The center thickness of the fourth lens 4 is 1 mm.

The center thickness of the fifth lens 5 is 7.8mm.

The center thickness of the sixth lens 6 is 4.5mm;

The first lens 1 is made of glass material: 1.55<n<1.75, 45<Vd<55,

The second lens 2 is made of glass material: 1.80<n<2.10, 15<Vd<25,

The third lens 3 is made of glass material: 1.55<n<1.75, 55<Vd<65,

The fourth lens 4 is made of glass material: 1.80<n<2.10, 15<Vd<25,

The fifth lens 5 is made of glass material: 1.55<n<1.75, 60<Vd<70,

The sixth lens 6 is made of glass material: 1.70<n<1.95, 35<Vd<45,

Among them, n is the refractive index, Vd is the Abbe coefficient;

The first lens 1 and the sixth lens 6 are both aspherical lenses.

Among them, each aspheric surface conforms to the following even-order aspheric surface formula:

In the formula, r is the aperture in the direction perpendicular to the optical axis, z is the distance sag from the aspheric vertex when the aspheric surface is at a height r along the optical axis, c represents the vertex curvature of the surface (that is, the reciprocal of the radius of curvature), k is the cone coefficient, ɑ is the higher-order aspherical coefficient, and its value refers to the aspherical coefficient table, i is the aspherical order, α _i is the coefficient of each higher-order term, and 2i is the higher-order power of the aspherical surface.

Conic coefficient of the first surface of the first lens: 1.383,

Conic coefficient of the second surface of the first lens: -0.696,

Conic coefficient of the first surface of the sixth lens: 10.127,

Conic coefficient of the second surface of the sixth lens: -63.155.

The aspheric coefficients are as follows:

Table 1 Aspheric coefficient

surface α4 α6 α8 α10 α12 α14 first lens first surface 1.362E-004 7.855E-007 -2.741E-008 2.406E-0010 -1.050E-012 1.860E-015 first lens second surface 6.598E-005 1.296E-005 -3.256E-007 4.668E-009 -4.201E-011 1.582E-013 Sixth lens first surface 6.986E-007 -5.628E-007 6.300E-008 -1.458E-009 1.482E-011 -7.856E-014 Sixth lens second surface -4.580E-004 2.231E-005 -5.471E-007 9.406E-009 -9.154E-011 3.490E-013

The optical lens is arranged in front of the detector 9. The detector 9 is provided with a plane lens 7. The plane lens 7 is located between the detector 9 and the sixth lens 6. The air gap between the sixth lens 6 and the plane lens 7 is 1 mm. .

The plane lens 7 is made of glass material: 1.50<n<1.70, 55<Vd<65, where n is the refractive index and Vd is the Abbe coefficient.

A lidar includes the above-mentioned optical lens.

Example 2 (focal length is 7mm)

As shown in Figures 1 and 6-9, an optical lens according to the present invention has a first lens 1, a second lens 2, a third lens 3, an aperture 8, and a third lens arranged in sequence from the object side to the image side. It consists of four lenses 4, a fifth lens 5 and a sixth lens 6; among them, the fourth lens 4 and the fifth lens 5 form a double cemented lens, and the remaining lenses are single lenses;

The first lens 1 is a negative power lens, the first surface of the first lens 1 is a convex surface, and the second surface is a concave surface.

The second lens 2 is a positive power lens, the first surface of the second lens 2 is a convex surface, and the second surface is a concave surface.

The third lens 3 is a negative power lens. The first surface of the third lens 3 is a convex surface and the second surface is a concave surface.

The fourth lens 4 is a negative power lens. The first surface of the fourth lens 4 is a convex surface and the second surface is a concave surface.

The fifth lens 5 is a positive power lens. The first surface of the fifth lens 5 is a convex surface and the second surface is a convex surface.

The sixth lens 6 is a positive power lens, the first surface of the sixth lens 6 is a convex surface, and the second surface is a convex surface;

The air gap between the first lens 1 and the second lens 2 is 0.891mm.

The air gap between the second lens 2 and the third lens 3 is 0.117mm.

The air gap between the third lens 3 and the diaphragm 8 is 4.381mm.

The air gap between the diaphragm 8 and the fourth lens 4 is 1.141mm.

The air gap between the fifth lens 5 and the sixth lens 6 is 5.687mm;

The first surface curvature radius of the first lens 1 is 40.004mm, and the second surface curvature radius is 11.195mm.

The first surface curvature radius of the second lens 2 is 11.725mm, and the second surface curvature radius is 31.455mm.

The first surface curvature radius of the third lens 3 is 19.682mm, and the second surface curvature radius is 3.896mm.

The first surface curvature radius of the fourth lens 4 is 28.137mm, and the second surface curvature radius is 12.794mm.

The first surface curvature radius of the fifth lens 5 is 12.794mm, and the second surface curvature radius is -8.194mm.

The first surface curvature radius of the sixth lens 6 is 31.654mm, and the second surface curvature radius is -21.740mm;

The first surface semi-diameter of the first lens 1 is 10.505mm, and the second surface semi-diameter is 7.540mm.

The first surface semi-diameter of the second lens 2 is 7.354mm, and the second surface semi-diameter is 8mm.

The first surface semi-diameter of the third lens 3 is 5.030mm, and the second surface semi-diameter is 3.044mm.

The first surface semi-diameter of the fourth lens 4 is 4.9mm, and the second surface semi-diameter is 6.8mm.

The first surface semi-diameter of the fifth lens 5 is 6.8mm, and the second surface semi-diameter is 7.111mm.

The first surface semi-diameter of the sixth lens 6 is 9.225mm, and the second surface semi-diameter is 9.070mm;

The center thickness of the first lens 1 is 1.652mm,

The center thickness of the second lens 2 is 2.312mm,

The center thickness of the third lens 3 is 1.634mm.

The center thickness of the fourth lens 4 is 1.505mm.

The center thickness of the fifth lens 5 is 4.787mm.

The center thickness of the sixth lens 6 is 4.114mm;

The first lens 1 is made of glass material: 1.55<n<1.75, 45<Vd<55,

The second lens 2 is made of glass material: 1.80<n<2.10, 15<Vd<25,

The third lens 3 is made of glass material: 1.55<n<1.75, 55<Vd<65,

The fourth lens 4 is made of glass material: 1.80<n<2.10, 15<Vd<25,

The fifth lens 5 is made of glass material: 1.55<n<1.75, 60<Vd<70,

The sixth lens 6 is made of glass material: 1.70<n<1.95, 35<Vd<45,

Among them, n is the refractive index, Vd is the Abbe coefficient;

The first lens 1 and the sixth lens 6 are both aspherical lenses.

Among them, each aspheric surface conforms to the following even-order aspheric surface formula:

In the formula, r is the aperture in the direction perpendicular to the optical axis, z is the distance sag from the aspheric vertex when the aspheric surface is at a height r along the optical axis, c represents the vertex curvature of the surface (that is, the reciprocal of the radius of curvature), k is the cone coefficient, ɑ is the higher-order aspherical coefficient, and its value refers to the aspherical coefficient table, i is the aspherical order, α _i is the coefficient of each higher-order term, and 2i is the higher-order power of the aspherical surface.

Conic coefficient of the first surface of the first lens: 1.383

Conic coefficient of the second surface of the first lens: -0.696

Conic coefficient of the first surface of the sixth lens: 10.127

Conic coefficient of the second surface of the sixth lens: -63.155

The aspheric coefficients are as follows:

Table 2 Aspheric coefficient

surface α4 α6 α8 α10 α12 α14 first lens first surface 1.362E-004 7.855E-007 -2.741E-008 2.406E-0010 -1.050E-012 1.860E-015 first lens second surface 6.598E-005 1.296E-005 -3.256E-007 4.668E-009 -4.201E-011 1.582E-013 Sixth lens first surface 6.986E-007 -5.628E-007 6.300E-008 -1.458E-009 1.482E-011 -7.856E-014 Sixth lens second surface -4.580E-004 2.231E-005 -5.471E-007 9.406E-009 -9.154E-011 3.490E-013

The optical lens is arranged in front of the detector 9. The detector 9 is provided with a plane lens 7. The plane lens 7 is located between the detector 9 and the sixth lens 6. The air gap between the sixth lens 6 and the plane lens 7 is 2mm. .

The plane lens 7 is made of glass material: 1.50<n<1.70, 55<Vd<65, where n is the refractive index and Vd is the Abbe coefficient.

A lidar includes the above-mentioned optical lens.

Example 3 (focal length is 5.65mm)

As shown in Figures 1 and 10-13, an optical lens according to the present invention has a first lens 1, a second lens 2, a third lens 3, an aperture 8, and a third lens arranged in sequence from the object side to the image side. It consists of four lenses 4, a fifth lens 5 and a sixth lens 6; among them, the fourth lens 4 and the fifth lens 5 form a double cemented lens, and the remaining lenses are single lenses;

The first lens 1 is a negative power lens, the first surface of the first lens 1 is a convex surface, and the second surface is a concave surface.

The second lens 2 is a positive power lens, the first surface of the second lens 2 is a convex surface, and the second surface is a concave surface.

The third lens 3 is a negative power lens. The first surface of the third lens 3 is a convex surface and the second surface is a concave surface.

The fourth lens 4 is a negative power lens. The first surface of the fourth lens 4 is a convex surface and the second surface is a concave surface.

The fifth lens 5 is a positive power lens. The first surface of the fifth lens 5 is a convex surface and the second surface is a convex surface.

The sixth lens 6 is a positive power lens, the first surface of the sixth lens 6 is a convex surface, and the second surface is a convex surface;

The air gap between the first lens 1 and the second lens 2 is 4.898mm.

The air gap between the second lens 2 and the third lens 3 is 0.1mm.

The air gap between the third lens 3 and the diaphragm 8 is 4.052mm.

The air gap between the diaphragm 8 and the fourth lens 4 is 1.659mm.

The air gap between the fifth lens 5 and the sixth lens 6 is 4.81mm;

The first surface curvature radius of the first lens 1 is 37.373mm, and the second surface curvature radius is 10.339mm.

The first surface curvature radius of the second lens 2 is 15.743mm, and the second surface curvature radius is 54.234mm.

The first surface curvature radius of the third lens 3 is 10.825mm, and the second surface curvature radius is 3.709mm.

The first surface curvature radius of the fourth lens 4 is 48.907mm, and the second surface curvature radius is 12.586mm.

The first surface curvature radius of the fifth lens 5 is 12.586mm, and the second surface curvature radius is -7.116mm.

The first surface curvature radius of the sixth lens 6 is 30.325mm, and the second surface curvature radius is -19.185mm;

The first surface semi-diameter of the first lens 1 is 12.974mm, and the second surface semi-diameter is 9.453mm.

The first surface semi-diameter of the second lens 2 is 8.704mm, and the second surface semi-diameter is 8mm.

The first surface semi-diameter of the third lens 3 is 5.274mm, and the second surface semi-diameter is 3.329mm.

The first surface semi-diameter of the fourth lens 4 is 4.9mm, and the second surface semi-diameter is 6.8mm.

The first surface semi-diameter of the fifth lens 5 is 6.8mm, and the second surface semi-diameter is 6.822mm.

The first surface semi-diameter of the sixth lens 6 is 8.398mm, and the second surface semi-diameter is 8.257mm;

The center thickness of the first lens 1 is 2.103mm,

The center thickness of the second lens 2 is 3.344mm,

The center thickness of the third lens 3 is 1.088mm.

The center thickness of the fourth lens 4 is 1.794mm.

The center thickness of the fifth lens 5 is 5mm.

The center thickness of the sixth lens 6 is 4.381mm;

The first lens 1 is made of glass material: 1.55<n<1.75, 45<Vd<55,

The second lens 2 is made of glass material: 1.80<n<2.10, 15<Vd<25,

The third lens 3 is made of glass material: 1.55<n<1.75, 55<Vd<65,

The fourth lens 4 is made of glass material: 1.80<n<2.10, 15<Vd<25,

The fifth lens 5 is made of glass material: 1.55<n<1.75, 60<Vd<70,

The sixth lens 6 is made of glass material: 1.70<n<1.95, 35<Vd<45,

Among them, n is the refractive index, Vd is the Abbe coefficient;

The first lens 1 and the sixth lens 6 are both aspherical lenses.

Among them, each aspheric surface conforms to the following even-order aspheric surface formula:

In the formula, r is the aperture in the direction perpendicular to the optical axis, z is the distance sag from the aspheric vertex when the aspheric surface is at a height r along the optical axis, c represents the vertex curvature of the surface (that is, the reciprocal of the radius of curvature), k is the cone coefficient, ɑ is the higher-order aspherical coefficient, and its value refers to the aspherical coefficient table, i is the aspherical order, α _i is the coefficient of each higher-order term, and 2i is the higher-order power of the aspherical surface.

Conic coefficient of the first surface of the first lens: 1.383

Conic coefficient of the second surface of the first lens: -0.696

Conic coefficient of the first surface of the sixth lens: 10.127

Conic coefficient of the second surface of the sixth lens: -63.155

The aspheric coefficients are as follows:

Table 3 Aspheric coefficient

surface α4 α6 α8 α10 α12 α14 first lens first surface 1.362E-004 7.855E-007 -2.741E-008 2.406E-0010 -1.050E-012 1.860E-015 first lens second surface 6.598E-005 1.296E-005 -3.256E-007 4.668E-009 -4.201E-011 1.582E-013 Sixth lens first surface 6.986E-007 -5.628E-007 6.300E-008 -1.458E-009 1.482E-011 -7.856E-014 Sixth lens second surface -4.580E-004 2.231E-005 -5.471E-007 9.406E-009 -9.154E-011 3.490E-013

The optical lens is arranged in front of the detector 9. The detector 9 is provided with a plane lens 7. The plane lens 7 is located between the detector 9 and the sixth lens 6. The air gap between the sixth lens 6 and the plane lens 7 is 3mm. .

The plane lens 7 is made of glass material: 1.50<n<1.70, 55<Vd<65, where n is the refractive index and Vd is the Abbe coefficient.

A lidar includes the above-mentioned optical lens.

It can be seen from Figures 1-13 of the description that the full field of view MTF of Example 1 satisfies 30lp/mm>0.49, RMS radius <10.819um, distortion <|1.2|%, and relative illumination>47%; the full field of view of Example 2 MTF satisfies 30lp/mm>0.5, RMS radius <7.843um, distortion <|1.2|%, relative illumination>53%; the full field of view MTF of Example 3 satisfies 30lp/mm>0.5, RMS radius <11.356um, distortion < |1.2|%, relative illumination>72%. That is, the optical lens of the present application has the advantages of large angle, large target surface, and low distortion.

The optical lens and laser radar described in the present invention are not limited to the above-mentioned embodiments. Any improvements or replacements based on the principles of the present invention should be within the protection scope of the present invention.

Claims (5)

1. An optical lens, characterized in that: the lens comprises a first lens (1), a second lens (2), a third lens (3), a diaphragm (8), a fourth lens (4), a fifth lens (5) and a sixth lens (6) which are sequentially arranged from an object side to an image side; wherein the fourth lens (4) and the fifth lens (5) form a double-cemented lens, and the other lenses are all single lenses;

the first lens (1) is a negative focal power lens, the first surface of the first lens (1) is a convex surface, the second surface is a concave surface,

the second lens (2) is a positive focal power lens, the first surface of the second lens (2) is a convex surface, the second surface is a concave surface,

the third lens (3) is a negative focal power lens, the first surface of the third lens (3) is a convex surface, the second surface is a concave surface,

the fourth lens (4) is a negative focal power lens, the first surface of the fourth lens (4) is a convex surface, the second surface is a concave surface,

the fifth lens (5) is a positive focal power lens, the first surface of the fifth lens (5) is a convex surface, the second surface is a convex surface,

the sixth lens (6) is a positive focal power lens, the first surface of the sixth lens (6) is a convex surface, and the second surface is a convex surface;

the air gap between the first lens (1) and the second lens (2) is 0.891-4.898 mm,

the air gap between the second lens (2) and the third lens (3) is 0.1-0.231 mm,

the air gap between the third lens (3) and the diaphragm (8) is 3.17-4.381 mm,

the air gap between the diaphragm (8) and the fourth lens (4) is 1.141-1.659 mm,

the air gap between the fifth lens (5) and the sixth lens (6) is 4.369-5.687 mm;

the first surface of the first lens (1) has a curvature radius of 37.373-40.004 mm and the second surface has a curvature radius of 10.339-11.195 mm,

the curvature radius of the first surface of the second lens (2) is 11.725-15.743 mm, the curvature radius of the second surface is 31.455-58.73 mm,

the radius of curvature of the first surface of the third lens (3) is 10.825-19.682 mm, the radius of curvature of the second surface is 3.709-3.95 mm,

the curvature radius of the first surface of the fourth lens (4) is 28.137-48.907 mm, the curvature radius of the second surface is 12.586-12.794 mm,

the curvature radius of the first surface of the fifth lens (5) is 12.586-12.794 mm, the curvature radius of the second surface is-7.116-8.235 mm,

the curvature radius of the first surface of the sixth lens (6) is 30.325-31.654 mm, and the curvature radius of the second surface is-19.185-21.740 mm;

the half diameter of the first surface of the first lens is 10.505-17.04 mm, the half diameter of the second surface is 7.540-9.453 mm,

the half diameter of the first surface of the second lens is 7.354-9.188 mm, the half diameter of the second surface is 8mm,

the half diameter of the first surface of the third lens is 5.030-5.432 mm, the half diameter of the second surface is 3.044-3.4 mm,

the first surface half diameter of the fourth lens is 4.9mm, the second surface half diameter is 6.8mm,

the half diameter of the first surface of the fifth lens is 6.8mm, the half diameter of the second surface is 6.822-7.111 mm,

the half diameter of the first surface of the sixth lens is 8.398-9.225 mm, and the half diameter of the second surface is 8.257-9.070 mm;

the center thickness of the first lens (1) is 1.652-2.103 mm,

the center thickness of the second lens (2) is 2.312-4.22 mm,

the center thickness of the third lens (3) is 1-1.634 mm,

the center thickness of the fourth lens (4) is 1-1.794 mm,

the center thickness of the fifth lens (5) is 4.787-7.8 mm,

the center thickness of the sixth lens (6) is 4.114-4.5 mm;

the first lens (1) and the sixth lens (6) are both aspherical lenses.

2. The optical lens of claim 1, wherein:

the first lens (1) is made of a glass material: 1.55< n <1.75, 45< Vd <55,

the second lens (2) is made of glass material: 1.80< n <2.10, 15< Vd <25,

the third lens (3) is made of glass material: 1.55< n <1.75, 55< Vd <65,

the fourth lens (4) is made of glass material: 1.80< n <2.10, 15< Vd <25,

the fifth lens (5) is made of glass material: 1.55< n <1.75, 60< Vd <70,

the sixth lens (6) is made of glass material: 1.70< n <1.95, 35< Vd <45,

where n is the refractive index and Vd is the Abbe's number.

3. The optical lens of claim 1, wherein: the optical lens is arranged in front of the detector (9), the detector (9) is provided with a plane lens (7), the plane lens (7) is positioned between the detector (9) and the sixth lens (6), and the air gap between the sixth lens (6) and the plane lens (7) is 1-3 mm.

4. An optical lens as claimed in claim 3, wherein: the planar lens (7) is made of glass material: 1.50< n <1.70, 55< Vd <65, where n is the refractive index and Vd is the Abbe's coefficient.

5. A lidar, characterized in that: comprising an optical lens as claimed in any one of claims 1 to 4.