Spherical ultra-wide-angle lens

Abstract

The spherical ultra-wide-angle lens sequentially comprises a first single lens, a second single lens, a third single lens, a fourth single lens, a first gluing group, a fifth single lens, a sixth single lens, a seventh single lens, a second gluing group and an eighth single lens along a light incidence direction, the object side surface and the image side surface of the first single lens are respectively a convex surface and a concave surface; the object side surface and the image side surface of the second single lens are respectively a convex surface and a concave surface; the object side surface and the image side surface of the third single lens are convex surfaces; the object side surface and the image side surface of the fourth single lens are respectively a convex surface and a concave surface; the object side surface and the image side surface of the first gluing group are concave surfaces; the object side surface and the image side surface of the fifth single lens are convex surfaces; the object side surface and the image side surface of the sixth single lens are convex surfaces; the object side surface and the image side surface of the seventh single lens are concave surfaces; the object side surface and the image side surface of the second gluing group are convex surfaces; and the object side surface and the image side surface of the eighth single lens are concave and convex respectively. The invention has the advantages of low cost, ultra-wide angle, compact structure and optical passive athermalization design.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to a spherical ultra-wide-angle lens. Background Art

[0002] Optical imaging systems play an increasingly important role in the process of information collection. In the field of airborne photography, optical systems collect optical information of the external environment or target through optical lenses, and then display images through back-end devices to provide information. Therefore, the performance indicators and imaging quality of optical lenses are key evaluation indicators of optical imaging systems. The field of view of the optical lens determines the range of scenes that can capture images. In order to obtain a wider range of information, ultra-wide-angle optical lenses are usually used, but ultra-wide-angle lenses will bring about greater image distortion. Image distortion will cause the optical imaging screen to deform, which is very different from the actual screen. In order to obtain better imaging effects, the luminous flux of the optical system should be as large as possible and the aberration should be as small as possible. It can be seen from the illumination formula of the imaging surface that the luminous flux of the optical system is proportional to the square of the relative aperture. In order to improve the luminous flux of the optical system, the relative aperture should be as large as possible and the corresponding F number should be as small as possible. However, the smaller the F number, the more difficult it is to correct the corresponding optical system aberration. Aspherical lenses have a good effect on correcting aberrations, but they are expensive. Considering cost factors and structural limitations, optical lenses should be compact and spherical lenses should be used as much as possible. In order to better adapt to the field of airborne photography, the optical lens should be able to achieve athermal design simply by adjusting the lens material and structure, so that the optical lens can adapt to a wider temperature range.

[0003] Patent application number CN11723398.B discloses an ultra-wide-angle, small-distortion optical lens, which effectively controls distortion and aberration by optimizing and changing the surface parameters of the lens. However, the extensive use of aspherical lenses makes the optical system expensive, which is not conducive to large-scale promotion.

[0004] Patent application number CN117518402.A discloses a spherical ultra-wide-angle optical imaging system with a field of view of 102°, and all spherical lenses are low in cost, but the F number is 3.5, the luminous flux is small, and it is difficult to ensure the imaging quality under insufficient light illumination. Summary of the invention

[0005] The present invention provides a spherical ultra-wide-angle lens to solve the technical problems mentioned in the background technology.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] The present invention provides a spherical ultra-wide-angle lens, which includes, in sequence from the object side to the imaging surface along the optical axis:

[0008] a first single lens having negative optical power, wherein the object side surface of the first single lens is a convex surface, and the image side surface of the first single lens is a concave surface;

[0009] a second single lens having negative optical power, wherein the object side surface of the second single lens is convex, and the image side surface of the second single lens is concave;

[0010] a third single lens having positive refractive power, wherein the object side surface of the third single lens is a convex surface, and the image side surface of the third single lens is a convex surface;

[0011] a fourth single lens having positive refractive power, wherein the object side surface of the fourth single lens is convex, and the image side surface of the fourth single lens is concave;

[0012] A first cemented group having negative optical power, wherein the object side surface of the first cemented group is a concave surface, and the image side surface of the first cemented group is a concave surface;

[0013] a fifth single lens having positive refractive power, wherein the object side surface of the fifth single lens is a convex surface, and the image side surface of the fifth single lens is a convex surface;

[0014] a sixth single lens having positive refractive power, wherein the object side surface of the sixth single lens is a convex surface, and the image side surface of the sixth single lens is a convex surface;

[0015] a seventh single lens having negative optical power, wherein the object side surface of the seventh single lens is a concave surface, and the image side surface of the seventh single lens is a concave surface;

[0016] A second cemented group having negative optical power, wherein the object side surface of the second cemented group is a convex surface, and the image side surface of the second cemented group is a convex surface;

[0017] An eighth single lens having negative optical power, wherein the object side surface of the eighth single lens is a concave surface, and the image side surface of the eighth single lens is a convex surface.

[0018] Furthermore, the spherical ultra-wide-angle lens further includes an aperture, and the aperture is arranged between the fifth single lens and the sixth single lens;

[0019] Or, the aperture is arranged on the surface of one of the optical elements in the first single lens, the second single lens, the third single lens, the fourth single lens, the first cemented group, the fifth single lens, the sixth single lens, the seventh single lens, the second cemented group, and the eighth single lens.

[0020] Furthermore, the distance between the fifth single lens and the aperture is between 0.3 and 0.8 mm, and the distance between the aperture and the sixth single lens is between 0.1 and 0.3 mm.

[0021] Furthermore, the spherical ultra-wide-angle lens further includes a filter, a sensor protection window and an imaging surface arranged in sequence along the optical axis direction;

[0022] The filter is disposed on one side of the image side of the eighth singlet lens for filtering light; the sensor protection window is used to protect the chip inside the optical system; the imaging surface is used for imaging.

[0023] Further, the refractive index Nd of the materials of the filter and the sensor protection window satisfies 1.5 < Nd < 1.6, and the Abbe number Vd satisfies 62 < Vd < 64;

[0024] The distance between the filter and the eighth singlet lens is between 0.2 and 0.6 mm, the distance between the filter and the sensor protection window is between 0.5 and 2 mm, and the distance between the sensor protection window and the imaging surface is between 0.3 and 0.8 mm.

[0025] Further, the first cemented group includes a meniscus negative lens and a meniscus positive lens;

[0026] The object side of the meniscus negative lens is concave, and the image side of the meniscus negative lens is concave; the refractive index Nd of the material of the meniscus negative lens satisfies 1.7 < Nd < 1.8, and the Abbe number Vd satisfies 33 < Vd < 35;

[0027] The object side of the meniscus positive lens is convex, and the image side of the meniscus positive lens is concave; the object side of the meniscus positive lens is adhered to the image side of the meniscus negative lens; the refractive index Nd of the material of the meniscus positive lens satisfies 1.4 < Nd < 1.5, and the Abbe number Vd satisfies 33 < Vd < 67.

[0028] Further, the second cemented group includes a biconvex positive lens and a meniscus concave lens;

[0029] The object side of the biconvex positive lens is convex, and the image side of the biconvex positive lens is convex; the refractive index Nd of the material of the biconvex positive lens satisfies 1.6 < Nd < 1.7, and the Abbe number Vd satisfies 57 < Vd < 59;

[0030] The object side of the meniscus concave lens is concave, and the image side of the meniscus concave lens is convex; the object side of the meniscus concave lens is adhered to the image side of the biconvex positive lens, and the refractive index Nd of the material of the meniscus concave lens satisfies 1.9 < Nd < 2.0, and the Abbe number Vd satisfies 30 < Vd < 32.

[0031] Further, the optical power of the first singlet lens is between -0.02 and -0.06;

[0032] And / or, the optical power of the second singlet lens is between -0.02 and -0.06;

[0033] And / or, the optical power of the third single lens is between 0.02 and 0.04;

[0034] And / or, the optical power of the fourth single lens is between 0.02 and 0.04;

[0035] And / or, the optical focal length of the first bonding group is between -0.02 and -0.04;

[0036] And / or, the optical power of the fifth single lens is between 0.07 and 0.09;

[0037] And / or, the optical power of the sixth single lens is between 0.06 and 0.08;

[0038] And / or, the optical power of the seventh single lens is between -0.04 and -0.06;

[0039] And / or, the optical focal length of the second cementing group is between -0.02 and -0.04;

[0040] And / or, the optical power of the eighth single lens is between -0.04 and 0.06.

[0041] Furthermore, the optical elements in the spherical ultra-wide-angle lens satisfy at least one or more of the following inequalities:

[0042] The effective focal length f11 of the first single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4 < f11 / f < -2; the effective focal length f12 of the second single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4 < f12 / f < -1; the effective focal length f13 of the third single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 1 < f13 / f < 4; the effective focal length f14 of the fourth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 1 < f14 / f < 4; the object-side lens effective focal length f151 of the first cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -0.2 < f151 / f < -2; the image-side lens effective focal length f152 of the first cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 1 < f152 / f < 4; the effective focal length f16 of the fifth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 1 < f16 / f < 4; the effective focal length f31 of the sixth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 1 < f31 / f < 4; the effective focal length f32 of the seventh single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4 < f32 / f < -1; the object-side lens effective focal length f331 of the second cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 0.1 < f331 / f < 2; the image-side lens effective focal length f332 of the second cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -2 < f331 / f < -0.1; the effective focal length f34 of the eighth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4 < f34 / f < -1.

[0043] Furthermore, the distance intervals between the various optical elements within the spherical ultra-wide-angle lens satisfy at least one or more of the following distance intervals;

[0044] The distance between the first single lens and the second single lens is between 6 and 8 mm, the distance between the second single lens and the third single lens is between 3 and 5 mm, the distance between the third single lens and the fourth single lens is between 0.1 and 0.2 mm, the distance between the fourth single lens and the first cemented group is between 1 and 3 mm, and the distance between the first cemented group and the fifth single lens is between 0.05 and 0.2 mm;

[0045] The distance between the sixth single lens and the seventh single lens is between 0.1 and 0.2 mm, the distance between the seventh single lens and the second cemented group is between 0.7 and 0.9 mm, and the distance between the second cemented group and the eighth single lens is between 3 and 5 mm.

[0046] Furthermore, the refractive index and Abbe number of the materials used for each optical element in the spherical ultra-wide-angle lens satisfy at least one or more of the following inequalities;

[0047] The refractive index Nd of the material of the first singlet lens satisfies 1.7 < Nd < 1.8, and the Abbe number Vd satisfies 49 < Vd < 51; the refractive index Nd of the material of the second singlet lens satisfies 1.6 < Nd < 1.7, and the Abbe number Vd satisfies 55 < Vd < 57; the refractive index Nd of the material of the third singlet lens satisfies 1.8 < Nd < 1.9, and the Abbe number Vd satisfies 39 < Vd < 41; the refractive index Nd of the material of the fourth singlet lens satisfies 1.8 < Nd < 1.9, and the Abbe number Vd satisfies 38 < Vd < 40; the refractive index Nd of the material of the fifth singlet lens satisfies 1.6 < Nd < 1.7, and the Abbe number Vd satisfies 54 < Vd < 56; the refractive index Nd of the material of the sixth singlet lens satisfies 1.7 < Nd < 1.8, and the Abbe number Vd satisfies 53 < Vd < 55; the refractive index Nd of the material of the seventh singlet lens satisfies 1.5 < Nd < 1.6, and the Abbe number Vd satisfies 63 < Vd < 65; the refractive index Nd of the material of the eighth singlet lens satisfies 1.6 < Nd < 1.7, and the Abbe number Vd satisfies 57 < Vd < 59.

[0048] Advantages of the present invention:

[0049] 1. The first lens (i.e., the first singlet lens) of the present invention uses a straw hat structure to collect wide-angle light, and the second lens (i.e., the second singlet lens) uses a similar straw hat structure for distortion correction. The symmetric structure has a good effect on aberration correction, and at the same time ensures the compactness of the optical system structure, so that the observation aperture of the optical system after installing the present invention will not be too large.

[0050] 2. All lenses in the present invention use glass spherical lenses, which are inexpensive, easy to process, and have high stability, greatly reducing the processing cost of the spherical ultra-wide-angle lens.

[0051] 3. The structure of the present invention is compact, and the assembly and debugging are simple. By adopting the form of all-glass spherical optical elements, material combination and reasonable distribution of optical power, an optical athermalization design is achieved, so that the optical system maintains clear imaging in the temperature range of -55°C to +70°C, greatly expanding the applicable range of the spherical ultra-wide-angle lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic structural diagram of the present invention;

[0053] Figure 2 is a schematic diagram of the distribution of each mirror surface of the spherical ultra-wide-angle lens in the present invention;

[0054] Figure 3This is a graph showing the MTF evaluation results of the spherical ultra-wide-angle lens at room temperature (20° C.) in a specific embodiment of the present invention;

[0055] Figure 4 This is a diagram showing the low temperature (-55°C) MTF evaluation result of the spherical ultra-wide angle lens in a specific embodiment of the present invention;

[0056] Figure 5 This is a diagram showing the high temperature (70°C) MTF evaluation result of the spherical ultra-wide-angle lens in a specific embodiment of the present invention;

[0057] Figure 6 This is a distortion evaluation result diagram of a spherical ultra-wide-angle lens in a specific embodiment of the present invention;

[0058] Figure 7 This is a diagram showing the relative illumination evaluation results of a spherical ultra-wide-angle lens in a specific embodiment of the present invention.

[0059] Description of reference numerals:

[0060] 1. Front group; 2. Aperture; 3. Rear group; 4. Filter; 5. Sensor protection window; 6. Imaging surface, 11. First single lens; 12. Second single lens; 13. Third single lens; 14. Fourth single lens; 15. First cemented group; 16. Fifth single lens; 31. Sixth single lens; 32. Seventh single lens; 33. Second cemented group; 34. Eighth single lens; 151. Meniscus negative lens; 152. Meniscus positive lens; 331. Double convex positive lens; 332. Meniscus concave lens;

[0061] S1, the object side surface of the first single lens; S2, the image side surface of the first single lens; S3, the object side surface of the second single lens; S4, the image side surface of the second single lens; S5, the object side surface of the third single lens; S6, the image side surface of the third single lens; S7, the object side surface of the fourth single lens; S8, the image side surface of the fourth single lens; S9, the object side surface of the negative meniscus lens; S10, the image side surface of the negative meniscus lens; S11, the object side surface of the positive meniscus lens; S12, the image side surface of the positive meniscus lens; S13, the object side surface of the fifth single lens; S14, the image side surface of the fifth single lens; S15, the object side surface of the sixth single lens; S16, the image side surface of the sixth single lens; S17, the object side surface of the seventh single lens; S18, the image side surface of the seventh single lens; S19, the object side surface of the biconvex positive lens; S20, the image side surface of the biconvex positive lens; S21, the object side surface of the concave meniscus lens; S22, the image side surface of the concave meniscus lens; S23, the object side surface of the eighth single lens; S24, the image side surface of the eighth single lens. DETAILED DESCRIPTION

[0062] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present invention are provided in the drawings. However, the present invention can be implemented in many other different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0063] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0065] It should also be noted that, in the embodiments of the present application, the same figure mark is used to represent the same component or the same part. For the same parts in the embodiments of the present application, the figure may only mark one of the parts or components as an example. It should be understood that the figure mark also applies to other identical parts or components.

[0066] Reference Figure 1 and Figure 2 , the embodiment of the present application provides a spherical ultra-wide-angle lens, which includes a front group 1 and a rear group 3 in sequence from the object side to the imaging surface along the optical axis;

[0067] The front group 1 includes the following components from the object side to the imaging surface along the optical axis:

[0068] A first single lens 11 having negative optical power, wherein the object side surface S1 of the first single lens is a convex surface, and the image side surface S2 of the first single lens is a concave surface;

[0069] A second single lens 12 having negative optical power, wherein the object side surface S3 of the second single lens is convex, and the image side surface S4 of the second single lens is concave;

[0070] A third single lens 13 having positive refractive power, wherein the object side surface S5 of the third single lens is a convex surface, and the image side surface S6 of the third single lens is a convex surface;

[0071] A fourth single lens 14 having positive refractive power, wherein the object side surface S7 of the fourth single lens is a convex surface, and the image side surface S8 of the fourth single lens is a concave surface;

[0072] A first cemented group 15 having negative optical power, wherein the object side surface of the first cemented group 15 is a concave surface, and the image side surface of the first cemented group 15 is a concave surface;

[0073] A fifth single lens 16 having positive refractive power, wherein the object side surface S13 of the fifth single lens is a convex surface, and the image side surface S14 of the fifth single lens is a convex surface;

[0074] The rear group 3 includes the following components along the optical axis from the object side to the imaging surface:

[0075] A sixth single lens 31 having positive refractive power, wherein the object side surface S15 of the sixth single lens is a convex surface, and the image side surface S16 of the sixth single lens is a convex surface;

[0076] A seventh single lens 32 having negative optical power, wherein the object side surface S17 of the seventh single lens is a concave surface, and the image side surface S18 of the seventh single lens is a concave surface;

[0077] A second cemented group 33 with negative optical power, wherein the object side surface of the second cemented group 33 is a convex surface, and the image side surface of the second cemented group 33 is a convex surface;

[0078] The eighth single lens 34 has a negative optical power, wherein the object side surface S23 of the eighth single lens is a concave surface, and the image side surface S24 of the eighth single lens is a convex surface.

[0079] Reference Figure 6 and Figure 7 In this embodiment, the spherical ultra-wide-angle lens is a fixed-focus imaging lens with a focal length of 10.3, an F number (aperture number) of 2.1, a field of view of 103.8°, an operating band of 400nm to 700nm, and a total optical length of 47.5mm. The distortion is 15.09%, such as Figure 6 As shown; the relative illumination of the edge field of view is 31%, as shown Figure 7 shown.

[0080] The first lens (i.e., the first single lens 11) of the present invention adopts a straw hat structure to collect wide-angle light, and the second lens (i.e., the second single lens 12) uses a similar straw hat structure to correct distortion. The symmetrical structure has a good aberration correction effect, while ensuring the compactness of the optical system structure, so that the observation aperture of the optical system after installing the present invention will not be too large.

[0081] In some embodiments, the spherical ultra-wide-angle lens further includes a stop 2, and the stop 2 is disposed between the fifth single lens 16 and the sixth single lens 31;

[0082] Or, the aperture 2 is arranged on the surface of one of the optical elements in the first single lens 11, the second single lens 12, the third single lens 13, the fourth single lens 14, the first cemented group 15, the fifth single lens 16, the sixth single lens 31, the seventh single lens 32, the second cemented group 33, and the eighth single lens 34.

[0083] In some embodiments, the distance between the fifth single lens 16 and the aperture 2 is between 0.3 and 0.8 mm. Preferably, the distance between the fifth single lens 16 and the aperture 2 is 0.557 mm.

[0084] The distance between the aperture 2 and the sixth single lens 31 is between 0.1 and 0.3 mm. Preferably, the distance between the aperture 2 and the sixth single lens 31 is 0.2 mm.

[0085] In some embodiments, the spherical ultra-wide-angle lens further includes a filter 4, a sensor protection window 5 and an imaging surface 6 arranged in sequence along the optical axis direction;

[0086] The filter 4 is arranged on the side of the image side S24 of the eighth single lens for filtering light; the sensor protection window 5 is used to protect the chip inside the optical system; and the imaging surface 6 is used for imaging.

[0087] In some embodiments, the filter 4 and the sensor protection window 5 are made of optical glass HK9L;

[0088] In some embodiments, the distance between the filter 4 and the eighth single lens 34 is between 0.2 and 0.6 mm. Preferably, the distance between the filter 4 and the eighth single lens 34 is 0.429 mm.

[0089] In some embodiments, the distance between the filter 4 and the sensor protection window 5 is between 0.5 and 2 mm. Preferably, the distance between the filter 4 and the sensor protection window 5 is 1.029 mm.

[0090] In some embodiments, the distance between the sensor protection window 5 and the imaging surface 6 is between 0.3 and 0.8 mm. Preferably, the distance between the sensor protection window 5 and the imaging surface 6 is 0.505 mm.

[0091] In some embodiments, the first cemented group 15 includes a negative meniscus lens 151 and a positive meniscus lens 152;

[0092] The object side S9 of the meniscus negative lens is a concave surface, and the image side S10 of the meniscus negative lens is a concave surface; the material of the meniscus negative lens 151 is optical glass HTF8;

[0093] The object side S11 of the meniscus positive lens is convex, and the image side S12 of the meniscus positive lens is concave; the object side S11 of the meniscus positive lens is bonded to the image side S10 of the meniscus negative lens; the material of the meniscus positive lens 152 is optical glass HQK1.

[0094] In some embodiments, the second cemented group 33 includes a biconvex positive lens 331 and a meniscus concave lens 332;

[0095] The object side S19 of the biconvex positive lens is a convex surface, and the image side S20 of the biconvex positive lens is a convex surface; the material of the biconvex positive lens 331 is optical glass HLAK50A;

[0096] The object side S21 of the meniscus concave lens is a concave surface, and the image side S22 of the meniscus concave lens is a convex surface; the object side S21 of the meniscus concave lens is bonded to the image side S20 of the double convex positive lens, and the material of the meniscus concave lens 332 is optical glass HZLAF75B.

[0097] In some embodiments, the optical power of the first single lens 11 is between -0.02 and -0.06; preferably, the optical power of the first single lens 11 is -0.032;

[0098] In some embodiments, the optical power of the second single lens 12 is between -0.02 and -0.06. Preferably, the optical power of the second single lens 12 is -0.047.

[0099] In some embodiments, the optical power of the third single lens 13 is between 0.02 and 0.04. Preferably, the optical power of the third single lens 13 is 0.034.

[0100] In some embodiments, the optical power of the fourth single lens 14 is between 0.02 and 0.04. Preferably, the optical power of the fourth single lens 14 is 0.034.

[0101] In some embodiments, the optical focal length of the first adhesive group 15 is between -0.02 and -0.04. Preferably, the optical focal length of the first adhesive group 15 is -0.037.

[0102] In some embodiments, the optical power of the fifth single lens 16 is between 0.07 and 0.09. Preferably, the optical power of the fifth single lens 16 is 0.082.

[0103] In some embodiments, the optical power of the sixth single lens 31 is between 0.06 and 0.08. Preferably, the optical power of the sixth single lens 31 is 0.072.

[0104] In some embodiments, the optical power of the seventh single lens 32 is between -0.04 and -0.06. Preferably, the optical power of the seventh single lens 32 is -0.055.

[0105] In some embodiments, the optical focal length of the second adhesive group 33 is between -0.02 and -0.04. Preferably, the optical focal length of the second adhesive group 33 is -0.034.

[0106] In some embodiments, the optical focal length of the eighth single lens 34 is between -0.04 and 0.06. Preferably, the optical focal length of the eighth single lens 34 is -0.05.

[0107] The preferred optical focal lengths of the above lenses are obtained through a large number of comparative experiments. This set of data, combined with the selection of materials and shapes of each lens (i.e., the materials and shapes of each lens hereinafter), enables the present invention to achieve an optical athermal design, allowing the optical system to maintain clear imaging within a temperature range of -55°C to +70°C, greatly expanding the scope of application of spherical ultra-wide-angle lenses.

[0108] In some embodiments, the distance between the first single lens 11 and the second single lens 12 is between 6 and 8 mm. Preferably, the distance between the first single lens 11 and the second single lens 12 is 7.5 mm.

[0109] In some embodiments, the distance between the second single lens 12 and the third single lens 13 is between 3 and 5 mm. Preferably, the distance between the second single lens 12 and the third single lens 13 is 3.986 mm.

[0110] In some embodiments, the distance between the third single lens 13 and the fourth single lens 14 is between 0.1 and 0.2 mm. Preferably, the distance between the third single lens 13 and the fourth single lens 14 is 0.122 mm.

[0111] In some embodiments, the distance between the fourth single lens 14 and the first glued group 15 is between 1 and 3 mm. Preferably, the distance between the fourth single lens 14 and the first glued group 15 is 2.672 mm.

[0112] In some embodiments, the distance between the first glued group 15 and the fifth single lens 16 is between 0.05 and 0.2 mm. Preferably, the distance between the first glued group 15 and the fifth single lens 16 is 0.1 mm.

[0113] In some embodiments, the distance between the sixth single lens 31 and the seventh single lens 32 is between 0.1 and 0.2 mm. Preferably, the distance between the sixth single lens 31 and the seventh single lens 32 is 0.11 mm.

[0114] In some embodiments, the distance between the seventh single lens 32 and the second glued group 33 is between 0.7 and 0.9 mm. Preferably, the distance between the seventh single lens 32 and the second glued group 33 is 0.827 mm.

[0115] In some embodiments, the distance between the second cementing group 33 and the eighth single lens 34 is between 3 and 5 mm. Preferably, the distance between the second cementing group 33 and the eighth single lens 34 is 4.373 mm.

[0116] The preferred distances between the above lenses are obtained through a large number of experiments. By comparing multiple groups of data, it is found that this group of data (i.e., the preferred distances between the above lenses) can make the structure of the present invention more compact while ensuring that the optical system after installing the present invention has the best clear imaging effect, and also reduces the observation aperture of the optical system after installing the present invention.

[0117] In some embodiments, the optical elements in the spherical ultra-wide-angle lens satisfy at least one or more of the following inequalities:

[0118] The effective focal length f11 of the first single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: <f11 / f<-2;

[0119] The effective focal length f12 of the second single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: <f12 / f<-1;

[0120] The effective focal length f13 of the third single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 1 <f13 / f<4;

[0121] The effective focal length f14 of the fourth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 1 <f14 / f<4;

[0122] The effective focal length f151 of the object lens of the first cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -0.2 <f151 / f<-2;

[0123] The effective focal length f152 of the image side lens of the first cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy the following: 1<f152 / f<4;

[0124] The effective focal length f16 of the fifth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 1 <f16 / f<4;

[0125] The effective focal length f31 of the sixth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 1 <f31 / f<4;

[0126] The effective focal length f32 of the seventh single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4 < f32 / f < -1;

[0127] The effective focal length f331 of the object-side lens of the second cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy: 0.1 < f331 / f < 2;

[0128] The effective focal length f332 of the image-side lens of the second cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -2 < f331 / f < -0.1;

[0129] The effective focal length f34 of the eighth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4 < f34 / f < -1.

[0130] In some embodiments, the refractive index and Abbe number of the materials used for each optical element in the spherical ultra-wide-angle lens satisfy at least one or more of the following inequalities;

[0131] The refractive index Nd of the material of the first single lens satisfies 1.7 < Nd < 1.8, and the Abbe number Vd satisfies 49 < Vd < 51;

[0132] The refractive index Nd of the material of the second single lens satisfies 1.6 < Nd < 1.7, and the Abbe number Vd satisfies 55 < Vd < 57;

[0133] The refractive index Nd of the material of the third single lens satisfies 1.8 < Nd < 1.9, and the Abbe number Vd satisfies 39 < Vd < 41;

[0134] The refractive index Nd of the material of the fourth single lens satisfies 1.8 < Nd < 1.9, and the Abbe number Vd satisfies 38 < Vd < 40;

[0135] The refractive index Nd of the material of the fifth single lens satisfies 1.6 < Nd < 1.7, and the Abbe number Vd satisfies 54 < Vd < 56;

[0136] The refractive index Nd of the material of the sixth single lens satisfies 1.7 < Nd < 1.8, and the Abbe number Vd satisfies 53 < Vd < 55;

[0137] The refractive index Nd of the material of the seventh single lens satisfies 1.5 < Nd < 1.6, and the Abbe number Vd satisfies 63 < Vd < 65;

[0138] The refractive index Nd of the material of the eighth single lens satisfies 1.6 < Nd < 1.7, and the Abbe number Vd satisfies 57 < Vd < 59.

[0139] In some embodiments, the material of the first single lens 11 is optical glass HLAK3; the material of the second single lens 12 is optical glass HZK10L; the material of the third single lens 13 is optical glass HZLAF73; the material of the fourth single lens 14 is optical glass HZLAF68N; the material of the fifth single lens 16 is optical glass HLAK10; the sixth single lens 31 is optical glass HLAK52; the material of the seventh single lens 32 is optical glass HK9LA; the material of the eighth single lens 34 is optical glass HLAK50A.

[0140] The data of each optical element in the spherical ultra-wide-angle lens provided in this embodiment are shown in Table 1. The data shown in Table 1 are only examples of data in the embodiments of the present invention and cannot be used to limit the protection scope of the present invention;

[0141] Table 1: Data table of each optical element in the spherical ultra-wide-angle lens

[0142]

[0143] The spherical ultra-wide-angle lens provided by the present invention can achieve clear imaging in an ultra-wide temperature range of -55°C to +70°C. Figure 3 , Figure 4 , Figure 5 It should be noted that the MTF (Modulation Transfer Function) evaluation curve represents the relative change of modulation with spatial frequency (line pairs per millimeter, unit: lp / mm) during the imaging process, and is often used to evaluate the resolution of imaging lenses. Figures 3 to 5 It is the MTF evaluation result diagram at different temperatures; the abscissa in the figure represents the spatial frequency, and the ordinate in the figure represents the modulation degree (optical transfer function modulus).

[0144] The present invention has a compact structure and is easy to assemble and debug. By adopting the form of a full-spherical glass optical element, a material combination, and a reasonable distribution of optical focal length, an optical athermal design is realized, so that the optical system maintains clear imaging within a temperature range of -55°C to +70°C, greatly expanding the scope of application of the spherical ultra-wide-angle lens.

[0145] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered within the protection scope of the present invention. In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A spherical ultra-wide-angle lens, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: a first single lens having negative optical power, wherein the object side surface of the first single lens is a convex surface, and the image side surface of the first single lens is a concave surface; a second single lens having negative optical power, wherein the object side surface of the second single lens is convex, and the image side surface of the second single lens is concave; a third single lens having positive refractive power, wherein the object side surface of the third single lens is a convex surface, and the image side surface of the third single lens is a convex surface; a fourth single lens having positive refractive power, wherein the object side surface of the fourth single lens is convex, and the image side surface of the fourth single lens is concave; A first cemented group having negative optical power, wherein the object side surface of the first cemented group is a concave surface, and the image side surface of the first cemented group is a concave surface; a fifth single lens having positive refractive power, wherein the object side surface of the fifth single lens is a convex surface, and the image side surface of the fifth single lens is a convex surface; a sixth single lens having positive refractive power, wherein the object side surface of the sixth single lens is a convex surface, and the image side surface of the sixth single lens is a convex surface; a seventh single lens having negative optical power, wherein the object side surface of the seventh single lens is a concave surface, and the image side surface of the seventh single lens is a concave surface; A second cemented group having negative optical power, wherein the object side surface of the second cemented group is a convex surface, and the image side surface of the second cemented group is a convex surface; An eighth single lens having negative optical power, wherein the object side surface of the eighth single lens is a concave surface, and the image side surface of the eighth single lens is a convex surface.

2. The spherical ultra-wide-angle lens according to claim 1, characterized in that: It also includes an aperture, which is arranged between the fifth single lens and the sixth single lens; the distance between the fifth single lens and the aperture is between 0.3 and 0.8 mm, and the distance between the aperture and the sixth single lens is between 0.1 and 0.3 mm; Or, the aperture is arranged on the surface of one of the optical elements in the first single lens, the second single lens, the third single lens, the fourth single lens, the first cemented group, the fifth single lens, the sixth single lens, the seventh single lens, the second cemented group, and the eighth single lens.

3. The spherical ultra-wide-angle lens according to claim 1, characterized in that: It also includes filters, sensor protection windows and imaging surfaces arranged in sequence along the optical axis; The filter is arranged on the image side of the eighth single lens for filtering light; the sensor protection window is used to protect the chip inside the optical system; and the imaging surface is used for imaging.

4. The spherical ultra-wide-angle lens according to claim 3, characterized in that: The refractive index Nd of the material of the filter and the sensor protection window satisfies 1.5<Nd<1.6, and the Abbe number 62<Vd<64; The distance between the filter and the eighth single lens is between 0.2 and 0.6 mm, the distance between the filter and the sensor protection window is between 0.5 and 2 mm, and the distance between the sensor protection window and the imaging surface is between 0.3 and 0.8 mm.

5. The spherical ultra-wide-angle lens according to claim 1, characterized in that: The first cemented group includes a negative meniscus lens and a positive meniscus lens; The object side surface of the meniscus negative lens is a concave surface, and the image side surface of the meniscus negative lens is a concave surface; the refractive index Nd of the material of the meniscus negative lens satisfies 1.7<Nd<1.8, and the Abbe number Vd satisfies 33<Vd<35; The object side surface of the meniscus positive lens is convex, and the image side surface of the meniscus positive lens is concave; the object side surface of the meniscus positive lens is bonded to the image side surface of the meniscus negative lens; the refractive index Nd of the material of the meniscus positive lens satisfies 1.4<Nd<1.5, and the Abbe number Vd satisfies 33<Vd<67.

6. The spherical ultra-wide-angle lens according to claim 1, characterized in that: The second cemented group includes a biconvex positive lens and a meniscus concave lens; The object side surface of the biconvex positive lens is a convex surface, and the image side surface of the biconvex positive lens is a convex surface; the refractive index Nd of the material of the biconvex positive lens satisfies 1.6<Nd<1.7, and the Abbe number Vd satisfies 57<Vd<59; The object side surface of the meniscus concave lens is a concave surface, and the image side surface of the meniscus concave lens is a convex surface; the object side surface of the meniscus concave lens is a concave surface and is bonded to the image side surface of the double convex positive lens. The refractive index Nd of the material of the meniscus concave lens satisfies 1.9<Nd<2.0, and the Abbe number Vd satisfies 30<Vd<32.

7. The spherical ultra-wide-angle lens according to claim 1, characterized in that: The optical power of the first single lens is between -0.02 and -0.06; And / or, the optical power of the second single lens is between -0.02 and -0.06; And / or, the optical power of the third single lens is between 0.02 and 0.04; And / or, the optical power of the fourth single lens is between 0.02 and 0.04; And / or, the optical focal length of the first bonding group is between -0.02 and -0.04; And / or, the optical power of the fifth single lens is between 0.07 and 0.09; And / or, the optical power of the sixth single lens is between 0.06 and 0.08; And / or, the optical power of the seventh single lens is between -0.04 and -0.06; And / or, the optical focal length of the second cementing group is between -0.02 and -0.04; And / or, the optical power of the eighth single lens is between -0.04 and 0.

06.

8. The spherical ultra-wide-angle lens according to claim 1, characterized in that: The optical elements in the spherical ultra-wide-angle lens satisfy at least one or more of the following inequalities: The effective focal length f11 of the first single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4<f11 / f<-2; The effective focal length f12 of the second single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4<f12 / f<-1; The effective focal length f13 of the third single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy the following conditions: 1<f13 / f<4; The effective focal length f14 of the fourth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy the following: 1<f14 / f<4; The effective focal length f151 of the object lens of the first cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -0.2<f151 / f<-2; The effective focal length f152 of the image side lens of the first cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy the following conditions: 1<f152 / f<4; The effective focal length f16 of the fifth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy the following: l<f16 / f<4; The effective focal length f31 of the sixth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: l<f31 / f<4; The effective focal length f32 of the seventh single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4<f32 / f<-1; The effective focal length f331 of the object lens of the second cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy the following conditions: 0.1<f331 / f<2; The effective focal length f332 of the image side lens of the second cemented group and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -2<f331 / f<-0.1; The effective focal length f34 of the eighth single lens and the effective focal length f of the spherical ultra-wide-angle lens satisfy: -4<f34 / f<-1.

9. The spherical ultra-wide-angle lens according to claim 1, characterized in that: The spacing intervals between the optical elements in the spherical ultra-wide-angle lens at least satisfy one or more of the following spacing intervals; The distance between the first single lens and the second single lens is between 6 and 8 mm, the distance between the second single lens and the third single lens is between 3 and 5 mm, the distance between the third single lens and the fourth single lens is between 0.1 and 0.2 mm, the distance between the fourth single lens and the first cemented group is between 1 and 3 mm, and the distance between the first cemented group and the fifth single lens is between 0.05 and 0.2 mm; The distance between the sixth single lens and the seventh single lens is between 0.1 and 0.2 mm, the distance between the seventh single lens and the second cemented group is between 0.7 and 0.9 mm, and the distance between the second cemented group and the eighth single lens is between 3 and 5 mm.

10. The spherical ultra-wide-angle lens according to claim 1, characterized in that: The refractive index and Abbe number of the materials used for each optical element in the spherical ultra-wide-angle lens at least satisfy one or more of the following inequalities; The refractive index Nd of the material of the first single lens satisfies 1.7<Nd<1.8, and the Abbe number Vd satisfies 49<Vd<51; The refractive index Nd of the material of the second single lens satisfies 1.6<Nd<1.7, and the Abbe number Vd satisfies 55<Vd<57; The refractive index Nd of the material of the third single lens satisfies 1.8<Nd<1.9, and the Abbe number Vd satisfies 39<Vd<41; The refractive index Nd of the material of the fourth single lens satisfies 1.8<Nd<1.9, and the Abbe number Vd satisfies 38<Vd<40; The refractive index Nd of the material of the fifth single lens satisfies 1.6<Nd<1.7, and the Abbe number Vd satisfies 54<Vd<56; The refractive index Nd of the material of the sixth single lens satisfies 1.7<Nd<1.8, and the Abbe number Vd satisfies 53<Vd<55; The refractive index Nd of the material of the seventh single lens satisfies 1.5<Nd<1.6, and the Abbe number Vd satisfies 63<Vd<65; The refractive index Nd of the material of the eighth single lens satisfies 1.6<Nd<1.7, and the Abbe number Vd satisfies 57<Vd<59.

Images