CN114879343A

CN114879343A - Panoramic lens and imaging device

Info

Publication number: CN114879343A
Application number: CN202210493773.2A
Authority: CN
Inventors: 李伟娜; 高博; 赖晗; 何晓源
Original assignee: Zhongshan Liantuo Optical Co ltd
Current assignee: Zhongshan Liantuo Optical Co ltd
Priority date: 2022-05-08
Filing date: 2022-05-08
Publication date: 2022-08-09
Anticipated expiration: 2042-05-08
Also published as: CN114879343B

Abstract

The invention discloses a panoramic lens and imaging equipment, the panoramic lens comprises the following components in sequence from an object side to an imaging surface along an optical axis: the first lens with negative focal power has a convex object-side surface and a concave image-side surface; a second lens with negative focal power, wherein the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; a third lens element having a positive optical power, the object-side surface of the third lens element being convex at a paraxial region and the image-side surface of the third lens element being convex; a diaphragm; a fourth lens having a positive refractive power, both the object-side surface and the image-side surface of the fourth lens being convex; a fifth lens element having a negative refractive power, both the object-side surface and the image-side surface of the fifth lens element being concave; a sixth lens element with positive optical power having a convex object-side surface and a concave image-side surface at a paraxial region; the seventh lens with positive focal power has a convex object-side surface and a concave image-side surface. The panoramic lens has the advantages of small volume, low cost, high image quality and the like.

Description

Panoramic lens and imaging device

Technical Field

The invention relates to the technical field of imaging lenses, in particular to a panoramic lens and imaging equipment.

Background

Along with the development of the mobile internet and the popularity of social, video and live broadcast software, people are more and more popular in photography, pursuits for imaging effects are more diversified, high-definition image quality is required, an ultra-large visual field is required to shoot pictures with strong large-range visual impact, and the unmanned aerial vehicle wins favor of consumers through unique high-altitude visual angles and wide shooting pictures. At present, unmanned aerial vehicles develop rapidly, and corresponding requirements for panoramic lenses matched with the unmanned aerial vehicles are higher and higher.

Because the unmanned aerial vehicle is mostly used in complex environments such as severe vibration, high pressure, extreme temperature and the like, the performance requirement on the collocated panoramic lens is extremely high, the unmanned aerial vehicle has good thermal stability to adapt to outdoor severe environment, and light appearance and smaller weight are required to increase the endurance time of the unmanned aerial vehicle during high-altitude flight shooting; simultaneously, still require the camera lens to have big light ring in order to satisfy unmanned aerial vehicle can both shoot clear and vivid picture in changeable environment such as day night. At present, the diversified use demands of the unmanned aerial vehicle can be hardly met by the conventional panoramic lens in the market.

Disclosure of Invention

Therefore, the invention aims to provide a panoramic lens and imaging equipment, which at least have the advantages of small volume and high image quality and can meet diversified use requirements in the fields of unmanned aerial vehicles, motion cameras and the like.

The invention achieves the above objects by the following technical scheme.

In a first aspect, the present invention provides a panoramic lens, sequentially including, from an object side to an image plane along an optical axis: the lens comprises a first lens with negative focal power, a second lens and a third lens, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens with negative focal power is provided, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; a third lens having a positive optical power, an object-side surface of the third lens being convex at a paraxial region, an image-side surface of the third lens being convex; a diaphragm; the fourth lens is provided with positive focal power, and the object side surface and the image side surface of the fourth lens are convex surfaces; a fifth lens element having a negative optical power, the fifth lens element having a concave object-side surface and a concave image-side surface; a sixth lens having a positive optical power, an object-side surface of the sixth lens being convex and an image-side surface of the sixth lens being concave at a paraxial region; the lens comprises a seventh lens with positive focal power, wherein the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface; wherein, the panoramic lens satisfies the following conditional expression: 10.0< TTL/f < 10.5; wherein, TTL represents the optical total length of the panoramic lens, and f represents the effective focal length of the panoramic lens.

In a second aspect, the present invention provides an imaging apparatus comprising an imaging element for converting an optical image formed by the panoramic lens into an electrical signal, and the panoramic lens provided in the first aspect.

Compared with the prior art, the panoramic lens and the imaging equipment provided by the invention have the advantages that the arrangement among the lenses is compact, and the length of the lens is effectively reduced; the structure setting of the diaphragm and each lens of the lens is reasonable, so that light quantity in a wider range can enter the machine body, and the imaging requirement of a light and dark environment is met.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of a panoramic lens according to a first embodiment of the present invention;

FIG. 2 is a MTF graph of a panoramic lens according to a first embodiment of the present invention;

FIG. 3 is a graph showing F-Theta distortion of a panoramic lens according to a first embodiment of the present invention;

FIG. 4 is a graph of the spherical aberration on axis of the panoramic lens according to the first embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a panoramic lens according to a second embodiment of the present invention;

FIG. 6 is an MTF graph of a panoramic lens according to a second embodiment of the present invention;

FIG. 7 is a graph showing F-Theta distortion of a panoramic lens according to a second embodiment of the present invention;

FIG. 8 is a graph of spherical aberration on axis of a panoramic lens according to a second embodiment of the present invention;

fig. 9 is a schematic structural diagram of a panoramic lens according to a third embodiment of the present invention;

fig. 10 is an MTF graph of a panoramic lens according to a third embodiment of the present invention;

FIG. 11 is a graph showing F-Theta distortion of a panoramic lens according to a third embodiment of the present invention;

FIG. 12 is a graph showing an on-axis spherical aberration and chromatic aberration of a panoramic lens according to a third embodiment of the present invention;

fig. 13 is a schematic configuration diagram of an image forming apparatus according to a fourth embodiment of the present invention.

Detailed Description

In order to make the objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. Several embodiments of the invention are presented in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Like reference numerals refer to like elements throughout the specification.

The invention provides a panoramic lens, which sequentially comprises the following components from an object side to an imaging surface along an optical axis: the optical lens comprises a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an optical filter, wherein the optical centers of the lenses are positioned on the same straight line.

The first lens has negative focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface;

the second lens has negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface;

the third lens has positive focal power, the object side surface of the third lens is convex at a paraxial region, and the image side surface of the third lens is convex;

the fourth lens has positive focal power, and both the object side surface and the image side surface of the fourth lens are convex surfaces;

the fifth lens has negative focal power, and the object side surface and the image side surface of the fifth lens are both concave surfaces;

the sixth lens has positive focal power, the object-side surface of the sixth lens is convex, and the image-side surface of the sixth lens is concave at a paraxial region;

the seventh lens has positive focal power, the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface.

The diaphragm can be made of shading paper with a light through hole in the center, and the light through aperture of the diaphragm is smaller than that of the space ring, so that the light through amount of the panoramic lens is determined by the light through aperture of the diaphragm. The diaphragm is arranged between the third lens and the fourth lens, so that the field angle of the panoramic lens can be improved, and the incident angle of the chip can be better matched; meanwhile, the shading paper with the light through hole in the center is used as the diaphragm, so that the requirement of the light through hole of the lens cone can be reduced, the forming difficulty of the light through hole of the lens cone is reduced, the production efficiency is improved, and the production cost is reduced.

In some embodiments, to reduce the weight and the unit price of the lens, the panoramic lens includes at least one lens made of plastic; meanwhile, in order to enable the lens to have good thermal stability, the panoramic lens further comprises at least one lens made of glass. Specifically, the panoramic lens comprises five plastic lenses and two glass lenses, adopts such glass to mould mixed structure, can make the volume and the weight of camera lens obtain reducing by a wide margin, is fit for mass production, and the stability of camera lens imaging performance in high low temperature environment has still furthest been guaranteed simultaneously.

In some embodiments, in order to improve the resolution of the lens and effectively reduce the vertical axis chromatic aberration of the lens, the panoramic lens adopts a plurality of aspheric lenses, and the use of the aspheric lenses can better correct the aberration of the lens, improve the resolution of the lens and enable the image to be clearer. Specifically, the first lens in the panoramic lens is a glass spherical lens, the fourth lens is a glass aspheric lens, and the second lens, the third lens, the fifth lens, the sixth lens and the seventh lens are plastic aspheric lenses.

In some embodiments, the panoramic lens satisfies the following conditional expression:

10.0<TTL/f<10.5； (1)

wherein, TTL represents the optical total length of the panoramic lens, and f represents the effective focal length of the panoramic lens. The relation between the total optical length and the effective focal length is limited when the conditional expression (1) is satisfied, so that the total optical length of the system can be effectively controlled while the ultra-large field angle range is satisfied, and the miniaturization of the lens is realized. When TTL/f is more than 10.5, the total optical length of the system is too long, which is not beneficial to miniaturization; when TTL/f is less than 10.0, the effective focal length of the system is too long, which is not beneficial to meeting the ultra-large field angle range of the system, and enough object space information cannot be obtained.

In some embodiments, the panoramic lens satisfies the conditional expression:

1<SD14/IH<1.1； (2)

where SD14 denotes a maximum effective radius of an image side surface of the seventh lens, and IH denotes an image height corresponding to a maximum field angle of the panoramic lens. The condition formula (2) is satisfied, so that the light passing through the lens group can be smoothly received into the chip, and the requirement of the optimal light incidence angle of the chip is satisfied.

In some embodiments, the panoramic lens satisfies the conditional expression:

0.3<RS2/SD2<0.4； (3)

wherein RS2 represents the rise of the image side of the first lens and SD2 represents the maximum effective diameter of the image side of the first lens. Satisfying the above conditional expression (3), the first lens can have a sufficient field angle to satisfy the light entrance requirement of the ultra-large field of view.

In some embodiments, the panoramic lens satisfies the conditional expression:

-3.5<f2/f<-3.0； (4)

0.1<AT12/AT23<0.3； (5)

wherein f2 represents an effective focal length of the second lens, f represents an effective focal length of the panoramic lens, AT12 represents an air space between the first lens and the second lens on an optical axis, and AT23 represents an air space between the second lens and the third lens on the optical axis. Satisfying the above conditional expressions (4) and (5), the effective focal length of the second lens and the positions of the second lens and the front and rear lenses can be adjusted to reduce the light deflection angle, so as to reduce the aberration of the subsequent lens.

0.6<SD7/SD5<0.7； (6)

wherein SD5 represents the maximum effective diameter of the object side surface of the third lens, and SD7 represents the maximum effective diameter of the object side surface of the fourth lens. Satisfying the above conditional expression (6), by controlling the aperture of the lens before and after the diaphragm, it can play a good role of light collection, and ensure the maximum light flux while making the lens have enough field angle.

0.15<CT3/TTL<0.25； (7)

wherein CT3 represents the center thickness of the third lens, and TTL represents the total optical length of the panoramic lens. The ratio of the third lens to the total optical length of the lens can be controlled by satisfying the conditional expression (7), so that the total volume of the lens is controlled, and the manufacturing cost of the lens is further reduced.

11<(CT5+CT6)/AT56<13； (8)

wherein CT5 denotes a center thickness of the fifth lens, CT6 denotes a center thickness of the sixth lens, and AT56 denotes an air space between the fifth lens and the sixth lens on an optical axis. Satisfying the above conditional expression (8), by controlling the thickness and the interval of the fifth lens element and the sixth lens element, the lens element can be made more compact, which is advantageous for maintaining the miniaturization.

0.15<RS13/SD13<0.25； (9)

wherein RS13 denotes a rise of an object side surface of the seventh lens, and SD13 denotes a maximum effective diameter of the object side surface of the seventh lens. The conditional expression (9) is satisfied, the incident angle of the peripheral field on the seventh lens can be effectively reduced, and excessive high-order aberration is avoided, so that the imaging performance is improved.

0.42<Φ4/Φ<0.45； (10)

wherein Φ 4 represents an optical power of the fourth lens, and Φ represents an optical power of the panoramic lens. The condition (10) is satisfied, and the lens can be ensured to have better imaging performance at different temperatures.

0.7<f/SD _ST <0.8； (11)

wherein f denotes an effective focal length of the panorama lens, SD _ST Representing the maximum aperture of the diaphragm. And the condition formula (11) is met, so that the light flux of the lens is enough under the condition of ensuring the imaging quality, and the imaging requirement of a light and dark environment is met.

20＜|Vd5-Vd6|＜40； (12)

wherein Vd5 denotes an abbe number of the fifth lens, and Vd6 denotes an abbe number of the sixth lens. The abbe number is an index indicating the dispersive power of the transparent medium. Generally, the smaller the abbe number of the lens, the more severe the dispersion; conversely, the larger the abbe number of the lens, the more slight the dispersion. In general, the chromatic aberration generated by the positive and negative lenses can compensate each other, but the abbe number difference is selected to be appropriate. When the value of Vd5-Vd6 exceeds the lower limit, the chromatic aberration of the system is insufficiently corrected; when the value of | Vd5-Vd6| exceeds the upper limit, the local chromatic aberration correction is too large, and material selection difficulty may occur.

8°<CRA<18°； (13)

wherein the CRA represents an incident angle of a chief ray of the panoramic lens on an imaging plane. The condition formula (13) is met, the chief ray incident angle of the chip can be well matched, the light effect received by the photosensitive area of the chip is effectively improved, and the optimal imaging effect is achieved.

The invention is further illustrated below in the following examples. In each embodiment, the thickness, the curvature radius and the material selection part of each lens in the panoramic lens are different, and the specific difference can be referred to the parameter table of each embodiment. The following examples are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following examples, and any other changes, substitutions, combinations or simplifications which do not depart from the innovative points of the present invention should be construed as being equivalent substitutions and shall be included within the scope of the present invention.

In the embodiments of the present invention, when the lenses in the panoramic lens are aspheric lenses, each aspheric surface type satisfies the following equation:

wherein z is the distance rise from the aspheric surface vertex when the aspheric surface is at the position with the height h along the optical axis direction, c is the paraxial curvature of the surface, A _2i Is aspheric surface type coefficient of 2i order, k is conic coefficient, when k is less than-1, the curve is hyperbolic curve, when k is equal to-1, it is parabolic curve, when k is between-1 and 0, it is elliptic curve, when k is equal to 0, it is circular curve, when k is greater than 0, it is oblate curve. The surface shape and size of the front and back aspheric surfaces of the lens can be accurately set through the parameters. The aspheric surface shape meets an even-order aspheric surface equation, and different aspheric surface coefficients are utilized, so that the aspheric surface plays the most role in the system, and more perfect resolving power is obtained.

First embodiment

Referring to fig. 1, a schematic structural diagram of a panoramic lens 100 according to a first embodiment of the present invention is shown, where the panoramic lens 100 sequentially includes, from an object side to an image plane along an optical axis: the lens comprises a first lens L1, a second lens L2, a third lens L3, a diaphragm ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and a filter L8, wherein the optical centers of the lenses are positioned on the same straight line.

The first lens L1 has negative focal power, the object-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave;

the second lens L2 has negative focal power, the object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is concave;

the third lens element L3 has positive optical power, the object-side surface S5 of the third lens element is convex at the paraxial region, and the image-side surface S6 of the third lens element is convex;

the fourth lens L4 has positive optical power, and both the object-side surface S7 and the image-side surface S8 of the fourth lens are convex;

the fifth lens L5 has negative power, and both the object-side surface S9 and the image-side surface S10 of the fifth lens are concave;

the sixth lens element L6 has positive power, the object-side surface S11 of the sixth lens element is convex, and the image-side surface S12 of the sixth lens element is concave at the paraxial region;

the seventh lens L7 has positive refractive power, and the object-side surface S13 of the seventh lens is convex, and the image-side surface S14 of the seventh lens is concave;

the object-side surface of the filter L8 is S15, and the image-side surface is S16.

The first lens element L1 is a glass spherical lens element, the fourth lens element L4 is a glass aspherical lens element, and the second lens element L2, the third lens element L3, the fifth lens element L5, the sixth lens element L6 and the seventh lens element L7 are all plastic aspherical lens elements.

The parameters related to each lens of the panoramic lens 100 provided in this embodiment are shown in table 1.

TABLE 1

The relevant parameters of the aspherical lens of the panoramic lens 100 in the present embodiment are shown in table 2.

TABLE 2

Flour mark

k

A ₄

A ₆

A ₈

A ₁₀

A ₁₂

S3

-1.75

-3.64E-02

5.17E-03

7.27E-05

-6.01E-05

3.32E-06

S4

-1.30

-2.48E-02

1.91E-02

-1.20E-02

5.03E-03

-7.05E-04

S5

68.89

-1.47E-02

-1.37E-03

4.74E-05

-1.81E-04

3.80E-05

S6

0.16

-1.51E-02

1.00E-03

2.13E-05

-3.46E-05

2.28E-09

S7

-8.69

-2.32E-02

-2.58E-03

-2.23E-03

-1.01E-03

-8.85E-11

S8

0.31

-2.67E-03

8.90E-03

-6.68E-03

9.66E-04

4.39E-10

S9

78.42

-5.55E-02

3.39E-02

-1.60E-02

3.89E-03

-2.00E-04

S10

-5.19

-6.78E-03

6.01E-03

-2.93E-03

7.14E-04

-8.36E-05

S11

-5.43

-1.8E-03

8.33E-04

-4.65E-04

2.13E-04

-2.58E-05

S12

-28.91

-5.5E-02

9.68E-03

-5.59E-04

-3.25E-04

6.64E-05

S13

-3.61

6.06E-03

-3.64E-04

-1.05E-04

2.75E-05

-5.52E-06

S14

189.31

5.44E-02

-2.05E-02

4.64E-03

-5.82E-04

2.61E-05

Referring to fig. 2, an MTF graph of the panoramic lens 100 of the present embodiment is shown, and it can be seen from the graph that the MTF value of the lens within 0.7 field of view is above 0.42 at a spatial frequency of 200lp/mm, which indicates that the panoramic lens 100 has a higher resolution.

Referring to fig. 3, an F-Theta distortion diagram of the panoramic lens 100 in the present embodiment is shown, and it can be seen from the diagram that the F-Theta distortion of the lens is smaller and less than 6.5%, which indicates that the distortion of the panoramic lens 100 is well corrected.

Referring to fig. 4, a graph of on-axis chromatic aberration of the panoramic lens 100 of the present embodiment is shown, and it can be seen from the graph that the offset of the on-axis chromatic aberration is controlled within ± 0.02 mm, which shows that the panoramic lens 100 can effectively correct the on-axis chromatic aberration.

Second embodiment

Referring to fig. 5, a schematic structural diagram of a panoramic lens 200 according to the present embodiment is shown, in which the surface shape of the panoramic lens 200 in the present embodiment is substantially the same as that of the lens 100 in the first embodiment, but the difference is that: the radius of curvature, thickness of each lens and air space between each lens are different. The parameters related to each lens of the panoramic lens 200 in this embodiment are shown in table 3.

TABLE 3

The relevant parameters of the aspherical lens of the panoramic lens 200 in the present embodiment are shown in table 4.

TABLE 4

Flour mark

k

A ₄

A ₆

A ₈

A ₁₀

A ₁₂

S3

-1.64

-3.55E-02

5.13E-03

6.78E-05

-6.05E-05

3.31E-06

S4

-1.24

-2.21E-02

1.86E-02

-1.21E-02

5.03E-03

-7.03E-04

S5

32.11

-1.49E-02

-1.38E-03

4.69E-05

-1.80E-04

3.79E-05

S6

0.46

-1.55E-02

2.60E-03

3.44E-05

-2.97E-05

-5.31E-07

S7

-7.69

-2.25E-02

-2.51E-03

-1.87E-03

-5.85E-04

3.41E-04

S8

0.27

-1.66E-03

9.39E-03

-6.55E-03

1.03E-03

3.62E-05

S9

80.26

-5.59E-02

3.37E-02

-1.61E-02

3.85E-03

-2.28E-04

S10

-5.23

-6.79E-03

6.00E-03

-2.94E-03

7.12E-04

-8.41E-05

S11

-5.41

-1.42E-03

7.91E-04

-4.80E-04

2.11E-04

-2.50E-05

S12

-33.84

-5.50E-02

9.68E-03

-5.58E-04

-3.25E-04

6.65E-05

S13

-3.62

5.32E-03

-4.27E-04

-9.99E-05

3.01E-05

-4.87E-06

S14

-1.64

5.39E-02

-2.05E-02

4.65E-03

-5.82E-04

2.64E-05

Referring to fig. 6, which shows an MTF graph of the panoramic lens 200 of the present embodiment, the MTF value of the lens within 0.7 field of view is above 0.48 at a spatial frequency of 200lp/mm, which indicates that the panoramic lens 200 has a higher resolution.

Referring to fig. 7, an F-Theta distortion diagram of the panoramic lens 200 of the present embodiment is shown, and it can be seen from the diagram that the F-Theta distortion of the lens is smaller and less than 6%, which indicates that the distortion of the panoramic lens 200 is well corrected.

Referring to fig. 8, a graph of on-axis chromatic aberration of the panoramic lens 200 of the present embodiment is shown, and it can be seen from the graph that the offset of the on-axis chromatic aberration is controlled within ± 0.02 mm, which shows that the panoramic lens 200 can effectively correct the on-axis chromatic aberration.

Third embodiment

Referring to fig. 9, a schematic structural diagram of the panoramic lens 300 according to the present embodiment is shown, in which the surface shape of the panoramic lens 300 of the present embodiment is substantially the same as the surface shape of the lens of the panoramic lens 100 of the first embodiment, but the difference is that: the radius of curvature, thickness of each lens and air space between each lens are different. The parameters related to the respective lenses of the panoramic lens 300 in this embodiment are shown in table 5.

TABLE 5

Table 6 shows relevant parameters of the aspherical lens of the panoramic lens 300 in the present embodiment.

TABLE 6

Flour mark

k

A ₄

A ₆

A ₈

A ₁₀

A ₁₂

S3

-1.76

-3.65E-02

5.15E-03

7.12E-05

-6.04E-05

3.30E-06

S4

-1.30

-2.47E-02

1.90E-02

-1.20E-02

5.02E-03

-7.06E-04

S5

77.60

-1.47E-02

-1.37E-03

4.38E-05

-1.83E-04

3.72E-05

S6

0.25

-1.00E-02

2.65E-03

6.55E-06

-3.82E-05

3.12E-06

S7

-7.68

-2.24E-02

-2.49E-03

-2.35E-03

-8.20E-04

2.64E-04

S8

0.29

-2.12E-03

8.93E-03

-6.73E-03

9.50E-04

2.74E-05

S9

78.91

-5.60E-02

3.37E-02

-1.61E-02

3.86E-03

-2.22E-04

S10

-5.18

-6.70E-03

6.02E-03

-2.93E-03

7.13E-04

-8.45E-05

S11

-5.48

-1.40E-03

8.23E-04

-4.69E-04

2.11E-04

-2.67E-05

S12

-30.01

-5.69E-02

9.65E-03

-5.62E-04

-3.26E-04

6.62E-05

S13

-3.64

5.98E-03

-3.70E-04

-1.04E-04

2.79E-05

-5.38E-06

S14

-299.83

5.23E-02

-2.05E-02

4.64E-03

-5.82E-04

2.62E-05

Referring to fig. 10, which shows an MTF graph of the panoramic lens 300 of the present embodiment, the MTF value of the lens within 0.7 field of view is above 0.46 at a spatial frequency of 200lp/mm, which indicates that the panoramic lens 300 has a higher resolution.

Referring to fig. 11, an F-Theta distortion diagram of the panoramic lens 300 of the present embodiment is shown, and it can be seen from the diagram that the F-Theta distortion of the lens is smaller and less than 6.5%, which shows that the distortion of the panoramic lens 300 is well corrected.

Referring to fig. 12, a graph of on-axis chromatic aberration of the panoramic lens 300 of the present embodiment is shown, and it can be seen from the graph that the offset of the on-axis chromatic aberration is controlled within ± 0.02 mm, which shows that the panoramic lens 300 can effectively correct the on-axis chromatic aberration.

Please refer to table 7, which shows the optical characteristics of the panoramic lens provided in the three embodiments, including the total optical length TTL, the F # of the panoramic lens, the effective focal length F, the field angle FOV and the image height IH, and further includes the corresponding values of each of the above conditional expressions.

TABLE 7

	First embodiment	Second embodiment	Third embodiment
				IH(mm)	4.6	4.6	4.6
FOV(°)	200	200	200
				TTL(mm)	14	14	14
f(mm)	1.35	1.36	1.34
				F#	2.0	2.0	2.0
TTL/f	10.40	10.28	10.46
				SD14/IH	1.06	1.06	1.03
RS2/SD2	0.34	0.35	0.34
				f2/f	-3.26	-3.24	-3.28
AT12/AT23	0.21	0.23	0.24
				SD7/SD5	0.62	0.62	0.63
CT3/TTL	0.17	0.17	0.17
				(CT5+CT6)/AT56	11.43	12.69	12.12
RS13/SD13	0.20	0.20	0.21
				Φ4/Φ	0.43	0.44	0.43
f/SD _ST	0.74	0.74	0.73
				\|Vd5-Vd6\|	34.50	34.50	34.50
CRA(°)	11.3	11.7	11.5

In conclusion, the panoramic lens and the imaging equipment provided by the invention adopt a glass-plastic mixed matching structure, and particularly adopt two glass lenses and five plastic lenses in a specified bit sequence, so that the lens has good imaging quality in high and low temperature environments, the weight and the volume of the lens are effectively reduced, and the processing cost is reduced; meanwhile, the lenses are compactly arranged, so that the length of the lens is effectively reduced, and the head of the lens is smaller, so that the lens has smaller volume; moreover, the arrangement of the structure of the diaphragm and each lens of the lens is reasonable, so that light quantity in a wider range can enter the camera body, and the imaging requirement of a bright and dark environment is met.

Fourth embodiment

Referring to fig. 13, an imaging apparatus 400 according to a fourth embodiment of the present invention is shown, where the imaging apparatus 400 may include an imaging element 410 and a panoramic lens (e.g., the panoramic lens 100) in any of the embodiments described above. The imaging element 410 may be a CMOS (Complementary Metal Oxide Semiconductor) image sensor, and may also be a CCD (Charge Coupled Device) image sensor.

This imaging device 400 can be an unmanned aerial vehicle, a motion camera, security equipment, a smart phone, and any other electronic device equipped with the above-mentioned panoramic lens.

The imaging apparatus 400 provided in the present embodiment includes the panoramic lens 100, and since the panoramic lens 100 has the advantages of a large aperture, a high resolution, and a super-large wide angle, the imaging apparatus 400 having the panoramic lens 100 also has the advantages of a large aperture, a high resolution, and a super-large wide angle.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A panoramic lens, comprising, in order from an object side to an image plane along an optical axis:

the lens comprises a first lens with negative focal power, a second lens and a third lens, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface;

the second lens with negative focal power is provided, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface;

a third lens having a positive optical power, an object-side surface of the third lens being convex at a paraxial region, an image-side surface of the third lens being convex;

a diaphragm;

the fourth lens is provided with positive focal power, and the object side surface and the image side surface of the fourth lens are convex surfaces;

a fifth lens element having a negative optical power, the fifth lens element having a concave object-side surface and a concave image-side surface;

a sixth lens element having a positive optical power, said sixth lens element having a convex object-side surface and a concave image-side surface at a paraxial region;

the lens comprises a seventh lens with positive focal power, wherein the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface;

wherein, the panoramic lens satisfies the following conditional expression:

10.0<TTL/f<10.5；

wherein, TTL represents the optical total length of the panoramic lens, and f represents the effective focal length of the panoramic lens.

2. The panoramic lens of claim 1, wherein the panoramic lens satisfies the following conditional expression:

1<SD14/IH<1.1；

wherein SD14 denotes a maximum effective diameter of an image side surface of the seventh lens, and IH denotes an image height corresponding to a maximum field angle of the panoramic lens.

3. The panoramic lens of claim 1, wherein the panoramic lens satisfies the following conditional expression:

0.3<RS2/SD2<0.4；

wherein RS2 represents the rise of the image side of the first lens and SD2 represents the maximum effective diameter of the image side of the first lens.

4. The panoramic lens of claim 1, wherein the panoramic lens satisfies the following conditional expression:

-3.5<f2/f<-3.0；

0.1<AT12/AT23<0.3；

wherein f2 represents an effective focal length of the second lens, f represents an effective focal length of the panoramic lens, AT12 represents an air space between the first lens and the second lens on an optical axis, and AT23 represents an air space between the second lens and the third lens on the optical axis.

5. The panoramic lens of claim 1, wherein the panoramic lens satisfies the following conditional expression:

0.6<SD7/SD5<0.7；

wherein SD5 represents the maximum effective diameter of the object side surface of the third lens, and SD7 represents the maximum effective diameter of the object side surface of the fourth lens.

6. The panoramic lens of claim 1, wherein the panoramic lens satisfies the following conditional expression:

0.15<CT3/TTL<0.25；

wherein CT3 represents the center thickness of the third lens, and TTL represents the total optical length of the panoramic lens.

7. The panoramic lens of claim 1, wherein the panoramic lens satisfies the following conditional expression:

11<(CT5+CT6)/AT56<13；

wherein CT5 denotes a center thickness of the fifth lens, CT6 denotes a center thickness of the sixth lens, and AT56 denotes an air space between the fifth lens and the sixth lens on an optical axis.

8. The panoramic lens of claim 1, wherein the panoramic lens satisfies the following conditional expression:

0.15<RS13/SD13<0.25；

wherein RS13 denotes the sagittal height of the object side face of the seventh lens, and SD13 denotes the maximum effective diameter of the object side face of the seventh lens.

9. The panoramic lens of claim 1, wherein the panoramic lens satisfies the following conditional expression:

0.42<Φ4/Φ<0.45；

wherein Φ 4 represents an optical power of the fourth lens, and Φ represents an optical power of the panoramic lens.

10. An imaging apparatus comprising the panoramic lens of any one of claims 1 to 9 and an imaging element for converting an optical image formed by the panoramic lens into an electrical signal.