TWI801326B - Optical lens - Google Patents

Abstract

An optical lens includes a first lens group, a second lens group and an aperture stop between the first lens group and the second lens group. The first lens group has negative refractive power and a number of lenses with refractive power of less than three. The second lens group has positive refractive power and a number of lenses with refractive power of less than five, and the second lens group has at least one aspheric lens with a diffraction surface. The optical lens satisfies the condition: 2 < (Φd*V)/Φr < 5, where Φd denotes refractive power of the diffraction surface, Φr denotes refractive power of the lens with the diffraction surface, and V denotes the Abbe number of the lens with the diffraction surface.

Description

optical lens

The present invention relates to an optical lens with diffractive elements and day and night confocal performance.

In recent years, smart home surveillance cameras have become more and more vigorous, and people's requirements for thinner and optical performance are also getting higher and higher. To meet such requirements, the lens generally needs to have the characteristics of low cost, large aperture, wide viewing angle, light weight, and day and night confocal. Especially for the day and night confocal part, the traditional method must use low dispersion material (fluorite), but the weight of fluorite material is heavy (about 1.5 times that of ordinary glass), and the cost is high (about 18 times that of ordinary glass) ), thus conflicting with the trend of low cost and light weight. Therefore, there is an urgent need for an imaging lens design that can take into account both light weight and day and night confocal, and can provide lower manufacturing costs and better imaging quality.

Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the embodiments of the present invention.

An embodiment of the present invention provides an optical lens, including a first lens group and a second lens group arranged in sequence from one direction, and an aperture disposed between the first lens group and the second lens group. The first lens group has negative diopter and the number of lenses with diopter is less than 3. The second lens group has positive diopter and contains The number of lenses with a diopter is less than 5 and an aspheric lens with a diffraction surface; and an optical lens that meets the following conditions: 2<(Φd*V)/Φr<5 where Φd is the diopter of the diffraction surface, and Φr is the lens with a diffraction surface The refractive power of the lens, V is the Abbe number of the lens with diffractive surface.

Through the design of the embodiments of the present invention, an optical lens design that can take into account light weight and day and night confocal, and can provide lower manufacturing cost and better imaging quality can be provided.

Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention. In order to make the above and other objects, features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

10a-10d: Optical lens

12: optical axis

14: Aperture

16: Glass cover

18: Imaging plane

20: The first lens group

30: Second lens group

L1-L7: lens

S1-S15: Surface

FIG. 1 is a schematic diagram of an optical lens 10a according to an embodiment of the present invention.

Figures 2 to 5 are the imaging optical simulation data diagrams of the optical lens in Figure 1, wherein Figures 2-3 are the light fan diagrams of visible light and 850 nm infrared light respectively, and Figures 4-5 are respectively 587 nm green light and 850 nm infrared light Diffraction optical transfer function curve of nano-infrared light.

FIG. 6 is a schematic diagram of an optical lens 10b according to another embodiment of the present invention.

Figures 7 to 10 are the imaging optical simulation data diagrams of the optical lens in Figure 6, wherein Figures 7-8 are the light fan diagrams of visible light and 850 nm infrared light respectively, and Figures 9-10 are 587 nm green light and 850 nm infrared light respectively Diffraction optical transfer function curve of nano-infrared light.

FIG. 11 is a schematic diagram of an optical lens 10c according to another embodiment of the present invention.

Figures 12 to 15 are the imaging optical simulation data diagrams of the optical lens in Figure 11, wherein Figures 12-13 are the light fan diagrams of visible light and 850 nm infrared light respectively, and Figures 14-15 are 587 nm green light and 850 nm infrared light respectively Diffraction optical transfer function curve of nano-infrared light.

FIG. 16 is a schematic diagram of an optical lens 10d according to another embodiment of the present invention.

Figures 17 to 20 are the imaging optical simulation data diagrams of the optical lens in Figure 16, wherein Figures 17-18 are the light fan diagrams of visible light and 850 nm infrared light respectively, and Figures 19-20 are 587 nm green light and 850 nm infrared light respectively Diffraction optical transfer function curve of nano-infrared light.

The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of the embodiments with reference to the drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only directions referring to the attached drawings. Accordingly, the directional terms used are for the purpose of illustration and not for the purpose of limiting the invention.

上述的公式(1)中，Z為光軸方向之偏移量(sag)，c是密切球面(osculating sphere)的半徑之倒數，也就是接近光軸處的曲率半徑的倒數，k是二次曲面係數(conic)，r是非球面高度，即為從透鏡中心往透鏡邊緣的高度。表二的A-D分別代表非球面多項式的4階項、6階項、8階項、10階項係數值。 FIG. 1 is a schematic diagram showing an optical lens 10a according to an embodiment of the present invention. The optical lens 10 a is disposed between an enlargement side (the left side of FIG. 1 ; for example, the object side) and a reduction side (the right side of FIG. 1 ; for example, the image side). As shown in FIG. 1 , the optical lens 10a includes a first lens group (for example, a front group) 20 with negative diopter and positioned between the zoom side and the zoom side, and a positive refractive power positioned between the first lens group 20 and the zoom side. The second lens group (for example, the rear group) 30 and an aperture 14 located in the second lens group 30 . Moreover, a glass cover 16 and an image sensor can be provided on the zooming out side, the imaging plane of which is marked as 18 , and the glass cover 16 is located between the second lens group 30 and the imaging plane 18 . The first lens group 20 may include a first lens L1 and a second lens L2 arranged in sequence along the optical axis 12 of the optical lens 10a from the enlarging side to the reducing side, and the second lens group 30 may include along the optical axis 10a of the optical lens 10a. A third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 are arranged in order from the magnification side to the reduction side of the optical axis 12. The diopters of the first lens L1 to the sixth lens L6 are respectively Negative, negative, positive, positive, negative, positive. In this embodiment, the sixth lens L6 can be an aspheric lens including a diffractive surface, the first lens L1, the second lens L2 and the fifth lens L5 are crescent lenses, and the third lens L3 and the fourth lens Lens L4 is a biconvex lens. In addition, the fourth lens L4 and the fifth lens L5 form a cemented lens with positive diopter. It is worth noting that the two adjacent surfaces of the fourth lens L4 and the fifth lens L5 have the same radius of curvature, and the adjacent two surfaces of the cemented lens can be bonded in different ways, for example, optical glue is coated between the two adjacent surfaces. Gluing, pressing the adjacent two sides with mechanical components, etc. The lens design parameters, profile, aspheric coefficient and diffraction surface of the optical lens 10a are shown in Table 1, Table 2 and Table 3 respectively. In each of the following design examples of the present invention, the aspheric polynomial can be represented by the following formula:

In the above formula (1), Z is the offset in the direction of the optical axis (sag), c is the reciprocal of the radius of the osculating sphere, that is, the reciprocal of the radius of curvature near the optical axis, and k is the quadratic Surface coefficient (conic), r is the height of the aspheric surface, that is, the height from the center of the lens to the edge of the lens. AD in Table 2 represents the coefficient values of the 4th order item, 6th order item, 8th order item, and 10th order item of the aspheric polynomial respectively.

上述的公式(2)中，

(r)為繞射元件(diffractice optical element)的相位函數(phase)，r是與光學鏡頭光軸的徑向距離(radial distance)，λ ₀是參考波長(reference wavelength)，也就是說繞射面(diffractice optical surface)為透鏡表面加上相位函數(phase)。表三的C1-C4分別代表繞射面多項式的2階項、4階項、6階項、8階項係數值。 In each of the following design examples of the present invention, the diffraction surface polynomial can be expressed by the following formula:

In the above formula (2),

(r) is the phase function (phase) of the diffractice optical element, r is the radial distance (radial distance) from the optical axis of the optical lens, and λ ₀ is the reference wavelength (reference wavelength), that is to say the diffraction The diffractice optical surface is the lens surface plus the phase function (phase). C1-C4 in Table 3 respectively represent the coefficient values of the 2nd order item, 4th order item, 6th order item, and 8th order item of the diffraction surface polynomial.

S1的間距為表面S1到S2在光軸12的距離，S2的間距為表面S2到S3在光軸12的距離，S13間距和下一個間距的和為玻璃蓋S13表面到成像平面18在光軸12的距離

The distance of S1 is the distance from the surface S1 to S2 on the optical axis 12, the distance of S2 is the distance from the surface S2 to S3 on the optical axis 12, the sum of the S13 distance and the next distance is the surface of the glass cover S13 to the imaging plane 18 on the optical axis 12 distance

Effective focal length of visible light (EFL of visible light)=3.976mm

Effective focal length of infrared light (EFL of NIR 850nm light)=3.984mm

Aperture value (F-Number)=1.8

Maximum field of view (Max.field of view, FOV) = 163.8 degrees

The maximum imaging height of the imaging plane (Max.Image Height)=8.914mm

Lens total length (total track length, TTL, distance from S1 to imaging plane) = 28.83mm

Figure 2-3 is the ray fan plot of visible light and 850nm infrared light respectively, where the X-axis is the position where the light passes through the entrance pupil, and the Y-axis is the main ray projection Relative value to the position of the image plane (eg imaging plane 18). Fig. 4 to Fig. 5 are the imaging optical simulation data diagrams of the optical lens 10a of the present embodiment, wherein Fig. 4-5 are the diffraction optical transfer function curves (modulation transfer function, MTF), the focal plane offset of the two is about 1 micron. Note that 555 nm green light can also be used instead of 587 nm green light to plot imaging optics simulation data. The graphs shown in the simulated data graphs in FIGS. 2-5 are all within the standard range, so it can be verified that the optical lens 10 a of this embodiment can indeed have both good optical imaging quality and day and night confocal characteristics.

The optical lens of this embodiment may include two lens groups and the aperture value may be 1.8. The optical lens may include an aspheric lens with a diffraction surface to correct aberrations and chromatic aberrations. Furthermore, the following conditions can be met: 2<(Φd*V)/Φr<5---(3)

20<V<60---(4)

Among them, Φd is the diopter of the diffraction surface, which is C1/(-0.5) in Table 3, Φr is the refraction diopter of the aspheric lens, and V is the Abbe number of the aspheric lens. Specifically, assuming that the optical lens is designed to meet (Φd*V)/Φr>5, at this time, the chromatic aberration of both visible light and infrared light is over-corrected, and the focal plane of infrared light is shortened. On the other hand, assuming that the optical lens is designed to meet (Φd*V)/Φr<2, at this time, the chromatic aberration correction of both visible light and infrared light is insufficient, and the focal plane of infrared light becomes longer. Therefore, the optical lens of this embodiment is designed to meet the condition of 2<(Φd*V)/Φr<5, so that the optical lens can have both good optical imaging quality and day and night confocal characteristics.

FIG. 6 is a schematic diagram showing an optical lens 10b according to another embodiment of the present invention. The optical lens 10b is disposed between an enlargement side (the left side of FIG. 6; for example, the object side) and a reduction side (the right side of FIG. 6; for example, the image side). As shown in FIG. 6, the optical lens 10b includes a first lens group having a negative diopter and located between the enlargement side and the reduction side. (for example, the front group) 20 , a second lens group (for example, the rear group) 30 with positive diopter and located between the first lens group 20 and the reduction side, and an aperture 14 located in the second lens group 30 . Moreover, a glass cover 16 and an image sensor can be provided on the zooming out side, the imaging plane of which is marked as 18 , and the glass cover 16 is located between the second lens group 30 and the imaging plane 18 . The first lens group 20 may include a first lens L1 and a second lens L2 arranged in sequence along the optical axis 12 of the optical lens 10b from the enlarging side to the reducing side, and the second lens group 30 may include along the optical axis 10b of the optical lens 10b. A third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 are arranged in order from the magnification side to the reduction side of the optical axis 12. The diopters of the first lens L1 to the sixth lens L6 are respectively Negative, negative, positive, positive, positive, negative. In this embodiment, the fourth lens L4 can be an aspheric lens including a diffractive surface, the first lens L1, the second lens L2, the third lens L3 and the sixth lens L6 are crescent lenses, and the fifth Lens L5 double convex lens. In addition, the fifth lens L5 and the sixth lens L6 form a cemented lens with positive diopter. It is worth noting that the two adjacent surfaces of the fifth lens L5 and the sixth lens L6 have the same radius of curvature, and the adjacent two surfaces of the cemented lens can be bonded in different ways, for example, optical glue is coated between the two adjacent surfaces. Gluing, pressing the adjacent two sides with mechanical components, etc. The lens design parameters, shape, aspheric coefficient and diffraction surface of the optical lens 10b are shown in Table 4, Table 5 and Table 6 respectively, wherein A-D in Table 5 represent the 4th order of the aspheric polynomial (as shown in Formula 1) respectively Term, 6th-order term, 8th-order term, and 10th-order term coefficient value. C1-C4 in Table 6 respectively represent the coefficient values of the 2nd-order item, 4th-order item, 6th-order item, and 8-order item of the diffraction surface polynomial (as shown in Formula 2).

S1的間距為表面S1到S2在光軸12的距離，S2的間距為表面S2到S3在光軸12的距離，S13間距和下一個間距的和為玻璃蓋S13表面到成像平面18在光軸12的距離

The distance of S1 is the distance from the surface S1 to S2 on the optical axis 12, the distance of S2 is the distance from the surface S2 to S3 on the optical axis 12, the sum of the S13 distance and the next distance is the surface of the glass cover S13 to the imaging plane 18 on the optical axis 12 distance

Effective focal length of visible light (EFL of visible light)=4.04mm

Effective focal length of infrared light (EFL of NIR 850nm light)=4.054mm

Aperture value (F-Number)=1.8

Maximum field of view (Max.field of view, FOV) = 138.5 degrees

The maximum imaging height of the imaging plane (Max.Image Height)=8.914mm

Lens total length (total track length, TTL, distance from S1 to imaging plane) = 30mm

7-8 are ray fan plots of visible light and 850nm infrared light respectively, wherein the X-axis is the position where the light passes through the entrance pupil, and the Y-axis is the position where the main ray is projected to the image plane (such as imaging plane 18). The relative value of the position. Fig. 9 to Fig. 10 are the imaging optical simulation data graphs of the optical lens 10b of the present embodiment, wherein Fig. 9-10 are respectively the diffraction optical transfer function curves (modulation transfer function, 587 nm green light and 850 nm infrared light MTF), the focal plane offset of the two is about 4 microns. Note that 555 nm green light can also be used instead of 587 nm green light to plot imaging optics simulation data. The graphs shown in the simulated data graphs in FIGS. 7-10 are all within the standard range, so it can be verified that the optical lens 10 b of this embodiment can indeed have both good optical imaging quality and day and night confocal characteristics.

The optical lens of this embodiment may include two lens groups and the aperture value may be 1.8. The optical lens may include an aspheric lens with a diffraction surface to correct aberrations and chromatic aberrations. Furthermore, the following conditions can be met: 2<(Φd*V)/Φr<5---(3)

20<V<60---(4)

Among them, Φd is the diopter of the diffraction surface, which is C1/(-0.5) in Table 6, and Φr is aspheric The refractive power of the surface lens, V is the Abbe number of the aspheric lens. Specifically, assuming that the optical lens is designed to meet (Φd*V)/Φr>5, at this time, the chromatic aberration of both visible light and infrared light is over-corrected, and the focal plane of infrared light is shortened. On the other hand, assuming that the optical lens is designed to meet (Φd*V)/Φr<2, at this time, the chromatic aberration correction of both visible light and infrared light is insufficient, and the focal plane of infrared light becomes longer. Therefore, the optical lens of this embodiment is designed to meet the condition of 2<(Φd*V)/Φr<5, so that the optical lens can have both good optical imaging quality and day and night confocal characteristics.

FIG. 11 is a schematic diagram showing an optical lens 10c according to an embodiment of the present invention. The optical lens 10c is disposed between an enlargement side (the left side of FIG. 11; for example, the object side) and a reduction side (the right side of FIG. 11; for example, the image side). As shown in FIG. 11 , the optical lens 10c includes a first lens group 20 located between the enlargement side and the reduction side, a second lens group 30 having positive diopter and located between the first lens group 20 and the reduction side, and a lens group 30 located between the first lens group 20 and the reduction side. An aperture 14 is formed between the lens group 20 and the second lens group 30 . Moreover, a glass cover 16 and an image sensor can be provided on the zooming out side, the imaging plane of which is marked as 18 , and the glass cover is located between the second lens group 30 and the imaging plane 18 . The first lens group 20 may include a first lens L1, a second lens L2, and a third lens L3 arranged in sequence along the optical axis 12 of the optical lens 10c from the enlargement side to the reduction side, and the second lens group 30 may be It includes a fourth lens L4, a fifth lens L5 and a sixth lens L6 arranged in sequence along the optical axis 12 of the optical lens 10c from the enlargement side to the reduction side. The diopters of the first lens L1 to the sixth lens L6 are respectively Negative, negative, positive, positive, negative, positive. In this embodiment, the sixth lens L6 can be an aspheric lens including a diffractive surface, the first lens L1, the second lens L2 and the fifth lens L5 are crescent lenses, and the third lens L3 and the fourth lens Lens L4 is a biconvex lens. In addition, the fourth lens L4 and the fifth lens L5 forms a doublet lens with positive diopters. It is worth noting that the two adjacent surfaces of the fourth lens L4 and the fifth lens L5 have the same radius of curvature, and the adjacent two surfaces of the cemented lens can be pasted in different ways, for example, optical glue is coated between the two adjacent surfaces. Gluing, pressing the adjacent two sides with mechanical components, etc. The lens design parameters, shape, aspheric coefficient and diffraction surface of the optical lens 10c are shown in Table 7, Table 8 and Table 9 respectively, wherein A-D in Table 7 represent the 4th order term, 6th order term, 8th order term and 8th order term of the aspheric polynomial respectively. Coefficient value of order item and 10th order item. The lens design parameters, shape, aspheric coefficient and diffraction surface of the optical lens 10c are shown in Table 7, Table 8 and Table 9 respectively, wherein A-D in Table 8 represent the 4th order of the aspheric polynomial (as shown in formula 1) respectively Term, 6th-order term, 8th-order term, and 10th-order term coefficient value. C1-C4 in Table 9 respectively represent the coefficient values of the 2nd-order item, 4th-order item, 6th-order item, and 8-order item of the diffraction surface polynomial (as shown in Formula 2).

S1的間距為表面S1到S2在光軸12的距離，S2的間距為表面S2到S3在光軸12的距離，S13間距和下一個間距的和為玻璃蓋S13表面到成像平面18在光軸12的距離

The distance of S1 is the distance from the surface S1 to S2 on the optical axis 12, the distance of S2 is the distance from the surface S2 to S3 on the optical axis 12, the sum of the S13 distance and the next distance is the surface of the glass cover S13 to the imaging plane 18 on the optical axis 12 distance

Effective focal length of visible light (EFL of visible light)=3.964mm

Effective focal length of infrared light (EFL of NIR 850nm light)=3.959mm

Aperture value (F-Number)=1.8

Maximum field of view (Max.field of view, FOV) = 154.8 degrees

The maximum imaging height of the imaging plane (Max.Image Height)=8.914mm

Lens total length (total track length, TTL, distance from S1 to imaging plane) = 29.6mm

12-13 are ray fan plots of visible light and 850nm infrared light, respectively, where the X-axis is the position where the light passes through the entrance pupil, and the Y-axis is the position where the main ray is projected to the image plane (such as imaging plane 18). The relative value of the position. Fig. 14 to Fig. 15 are the imaging optical simulation data graphs of the optical lens 10c of the present embodiment, wherein Fig. 14-15 are respectively the diffraction optical transfer function curves (modulation transfer function, 587 nm green light and 850 nm infrared light MTF), the focal plane offset of the two is about 4 microns. Note that 555 nm green light can also be used instead of 587 nm green light to plot imaging optics simulation data. The graphs shown in the simulated data graphs in FIGS. 12-15 are all within the standard range, so it can be verified that the optical lens 10c of this embodiment can indeed have both good optical imaging quality and day and night confocal characteristics.

The optical lens of this embodiment may include two lens groups and the aperture value may be 1.8. The optical lens may include an aspheric lens with a diffraction surface to correct aberrations and chromatic aberrations. Furthermore, the following conditions can be met: 2<(Φd*V)/Φr<5---(3)

20<V<60---(4)

Among them, Φd is the diopter of the diffraction surface, which is C1/(-0.5) in Table 9, Φr is the refraction diopter of the aspheric lens, and V is the Abbe number of the aspheric lens. Specifically, assuming that the optical lens is designed to meet (Φd*V)/Φr>5, at this time, the chromatic aberration of both visible light and infrared light is over-corrected, and the focal plane of infrared light is shortened. On the other hand, assuming that the optical lens is designed to meet (Φd*V)/Φr<2, at this time, the chromatic aberration correction of both visible light and infrared light is insufficient, and the focal plane of infrared light becomes longer. Therefore, the optical lens of this embodiment is designed to meet the condition of 2<(Φd*V)/Φr<5, so that the optical lens can have both good optical imaging quality and day and night confocal characteristics.

FIG. 16 is a schematic diagram showing an optical lens 10d according to an embodiment of the present invention. The optical lens 10d is disposed between an enlargement side (the left side of FIG. 16; for example, the object side) and a reduction side (the right side of FIG. 16; for example, the image side). As shown in FIG. 16, the optical lens 10d is located at the first lens group 20 between the enlargement side and the reduction side, the second lens group 30 having positive diopter and located between the first lens group 20 and the reduction side, and the first lens group 30 located between the first lens group 20 and the reduction side. An aperture 14 between the group 20 and the second lens group 30 . Moreover, a glass cover 16 and an image sensor can be provided on the zooming out side, the imaging plane of which is marked as 18 , and the glass cover is located between the second lens group 30 and the imaging plane 18 . The first lens group 20 may include a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged in sequence along the optical axis 12 of the optical lens 10d from the enlargement side to the reduction side, and The second lens group 30 may include a fifth lens L5, a sixth lens L6, and a seventh lens L7 arranged in sequence from the enlargement side to the reduction side along the optical axis 12 of the optical lens 10a, the first lenses L1 to the sixth The diopters of the lens L7 are respectively negative, negative, positive, positive, positive, negative, and positive. In this embodiment, the fourth lens L4 can be an aspheric lens including a diffraction surface, the first lens L1 and the sixth lens L6 are crescent lenses, the second lens L2 is a biconcave lens and the third lens L3, The fifth lens L5 and the seventh lens L7 are biconvex lenses. In addition, the fifth lens L5 and the sixth lens L6 form a cemented lens with positive diopter. It is worth noting that the two adjacent surfaces of the fifth lens L5 and the sixth lens L6 have the same radius of curvature, and the adjacent two surfaces of the cemented lens can be bonded in different ways, for example, optical glue is coated between the two adjacent surfaces. Gluing, pressing the adjacent two sides with mechanical components, etc. The lens design parameters, shape, aspheric coefficient and diffraction surface of the optical lens 10d are shown in Table 10, Table 11 and Table 12 respectively, wherein A-D in Table 11 represent aspheric surface polynomials (as shown in formula 1) respectively. The 4th-order term, 6th-order term, 8th-order term, 10th order term coefficient value. C1-C4 in Table 12 respectively represent the coefficient values of the 2nd-order item, 4th-order item, 6th-order item, and 8-order item of the diffraction surface polynomial (as shown in Formula 2).

S1的間距為表面S1到S2在光軸12的距離，S2的間距為表面S2到S3在光軸12的距離，S15間距和下一個間距的和為玻璃蓋S15表面到 成像平面18在光軸12的距離

The spacing of S1 is the distance from the surface S1 to S2 on the optical axis 12, the spacing of S2 is the distance from the surface S2 to S3 on the optical axis 12, the sum of the S15 spacing and the next spacing is the surface of the glass cover S15 to the imaging plane 18 on the optical axis 12 distance

Effective focal length of visible light (EFL of visible light)=4.02mm

Effective focal length of infrared light (EFL of NIR 850nm light)=4.03mm

Aperture value (F-Number)=1.8

Maximum field of view (Max.field of view, FOV) = 163.6 degrees

The maximum imaging height of the imaging plane (Max.Image Height)=8.914mm

Lens total length (total track length, TTL, distance from S1 to imaging plane) = 29.1mm

Figures 17-18 are ray fan plots of visible light and 850nm infrared light, respectively, where the X-axis is the position where the light passes through the entrance pupil, and the Y-axis is the position where the main ray is projected to the image plane (such as imaging plane 18) The relative value of the position. Fig. 19 to Fig. 20 are the imaging optical simulation data graphs of the optical lens 10d of the present embodiment, wherein Fig. 19-20 are the diffraction optical transfer function curves (modulation transfer function, respectively) of 587 nm green light and 850 nm infrared light MTF), the focal plane offset of the two is about 53 microns. Note that it is also possible to use 555 nm green light instead of 587 nm green light to Plot the imaging optics simulation data.

Through the designs of embodiments 10a, 10b and 10c, a design of an imaging lens that can take into account light weight and day and night confocal characteristics, and can provide lower manufacturing costs and better imaging quality can be provided.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in this art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application. In addition, any embodiment or scope of claims of the present invention does not necessarily achieve all the objectives or advantages or features disclosed in the present invention. In addition, the abstract and the title are only used to assist the search of patent documents, and are not used to limit the scope of rights of the present invention.

10a: Optical lens

12: optical axis

14: Aperture

16: Glass cover

18: Imaging plane

20: The first lens group

30: Second lens group

L1-L6: Lens

S1-S13: Surface

Claims (10)

An optical lens, comprising: a first lens group and a second lens group, the first lens group and the second lens group are arranged sequentially from one direction; an aperture is arranged between the first lens group and the second lens group Between two lens groups, wherein the second lens group has a positive diopter and includes a lens with a diffraction surface; and the optical lens meets the following conditions: 2<(Φd*V)/Φr<5 where Φd is the circumference The refractive power of the incident surface, Φr is the refractive power of the lens, and V is the Abbe number of the lens. An optical lens, comprising: a first lens group with negative diopter and a second lens group with positive diopter, wherein the first lens group and the second lens group are arranged in sequence from one direction, and the second lens group The diopter of a lens group is separated from the diopter of the second lens group, the second lens group includes a lens with a diffractive surface; and the optical lens meets the following conditions: 2<(Φd*V)/Φr<5 wherein Φd is the diopter of the diffraction surface, Φr is the refraction diopter of the lens, and V is the Abbe number of the lens. The optical lens as described in any one of items 1-2 of the scope of the patent application, wherein the number of lenses with diopters included in the first lens group is less than 3. The optical lens as described in any one of items 1-2 of the scope of the patent application, wherein the second lens group includes less than 5 lenses with diopters. An optical lens comprising: A first lens group; a second lens group with positive diopter, the first lens group and the second lens group are arranged sequentially from one direction; an aperture is arranged between the first lens group and the second lens Between groups, wherein the first lens group includes lenses with a diopter number less than 3, the second lens group includes a lens with a diopter number less than 5 and includes a lens with a diffractive surface; and the optical lens meets the following conditions : If the 555 nm or 587 nm green light passes through a focal plane of the optical lens as the measurement reference, the optical lens can meet the displacement of 850 nm infrared light on the focal plane, and the distance from the measurement reference is less than 5 microns . The optical lens as described in any one of item 1, 2 or 5 of the scope of application, wherein the lens with the diffractive surface satisfies the following condition: 20<V<60. The optical lens as described in any one of item 1, 2 or 5 of the scope of application, wherein the first lens group includes a first lens with negative diopter and a second lens with negative diopter. The optical lens as described in any one of the claims 1, 2 or 5, wherein the lens is an aspherical lens. The optical lens as described in any one of item 1, 2 or 5 of the scope of application, wherein the diopter of the lens is positive and the second lens group further includes a cemented lens with positive diopter and another lens with positive diopter lens. The optical lens as described in claim 9, wherein the lens is farther away from the first lens group than the other lens.

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