Panoramic lens

Abstract

The invention provides a panoramic lens. The panoramic lens is sequentially composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and plate glass from the object side face to the image face. The first lens has negative focal power, the second lens has negative focal power, the third lens has positive focal power, the fourth lens has positive focal power, the fifth lens has negative focal power, the sixth lens has positive focal power, the seventh lens has negative focal power, and the eighth lens has negative focal power. The method satisfies the following conditional expression: 190 degree lt; a FOVlt; 205 DEG, wherein FOV represents a full field angle of the panoramic lens; iMA is greater than or equal to 6 mm and less than or equal to 7 mm, 0.38 lt; iMA / TTLlt; 0.46, 0.95 lt, 0.46, 0.95 lt; cA1 / TTLlt; 1, VP is greater than or equal to 2, 2.97 lt; iMA / FNOlt; and 3.57, can be matched with a 1 / 1.8 inch large-target surface sensor to realize high-resolution imaging, has a field angle of about 200 degrees, meets the requirements of users on large-view panoramic imaging, has the characteristics of short total length, small caliber and small volume, and is convenient for realizing miniaturization and portability of photographic equipment.

Description

Technical Field

[0001] The invention relates to the technical field of optical imaging, and in particular to a panoramic lens. Background Art

[0002] With the rise of various social platforms, life sharing methods such as pictures, short videos, and live broadcasts have gradually become popular, and portable cameras have become a very popular imaging device after smartphones. The main users of portable cameras are young people, and their pursuit of imaging effects is more diversified. They require not only extremely high image quality, but also a large field of view to shoot wide-format panoramic images with strong visual impact. In order to adapt to the diversified application scenarios, portable panoramic cameras came into being.

[0003] For example, the Chinese invention patent application publication number CN108535847A, the application publication date is September 14, 2018, which discloses an ultra-wide-angle high-pixel fisheye optical system, such as Figure 1 As shown, along the optical axis from the object plane to the image plane, it includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. On the other hand, an embodiment of the present invention also provides a camera module. The embodiment of the present invention is mainly composed of 8 lenses, with a small number of lenses and a simple structure; different lenses are combined with each other and the focal length is reasonably distributed, and it has good optical performance such as 200° ultra-wide angle and more than 20 million high pixels, which is suitable for professional-grade panoramic VR cameras and micro-single cameras. Due to the high requirements of users for imaging resolution, portable panoramic cameras are upgraded to use 1 / 1.3-inch large-size photosensitive elements, but this will also lead to an increase in the front diameter and total length of the camera, which is contrary to the compact and portable characteristics expected by users. Therefore, how to improve the imaging resolution and field of view while maintaining a compact volume has become a technical problem that needs to be solved urgently. At present, the performance of conventional panoramic lenses on the market is often not enough to adapt to diversified application scenarios, and it is difficult to meet the needs of users. In view of this situation, it is urgent to improve. Summary of the invention

[0004] In view of the above problems, the present invention provides a panoramic lens, which can be used with a 1 / 1.3-inch large-target sensor to achieve high-resolution imaging, with a field of view of approximately 200°, meeting the user's needs for panoramic imaging with a large field of view; it has the characteristics of short total length, small aperture, and small volume, which facilitates the miniaturization and portability of photographic equipment, and enables the panoramic camera to have a smaller visual blind spot, which is beneficial to the subsequent stitching and improvement of the panoramic imaging effect.

[0005] To achieve the above object, the present invention solves the problem through the following technical solutions:

[0006] A panoramic lens is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a flat glass in sequence from the object side to the image side;

[0007] The first lens has a negative focal power, the second lens has a negative focal power, the third lens has a positive focal power, the fourth lens has a positive focal power, the fifth lens has a negative focal power, the sixth lens has a positive focal power, the seventh lens has a negative focal power, and the eighth lens has a negative focal power;

[0008] It satisfies the conditional formula:

[0009] 190° < FOV < 205°, where FOV represents the full field of view angle of the panoramic lens;

[0010] 6mm ≤ IMA ≤ 7mm, where IMA represents the image circle diameter of the panoramic lens;

[0011] 0.38 < IMA / TTL < 0.46, where TTL represents the total length of the panoramic lens;

[0012] 0.95 < CA 1 / TTL < 1, where CA 1 represents the effective light passing aperture of the object side of the first lens;

[0013] VP ≥ 2, where VP represents the number of plastic lenses with a refractive index greater than 1.6 in the panoramic lens;

[0014] 2.97 < IMA / FNO < 3.57, where FNO represents the aperture number of the panoramic lens.

[0015] Preferably, the first lens is set as a glass spherical lens; the third lens is set as a molded aspherical lens;

[0016] The second lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are all set as plastic aspherical lenses;

[0017] The refractive index temperature coefficients of the materials of the first lens and the third lens are both greater than 0, and the refractive index temperature coefficients of the second lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are all less than 0;

[0018] The flat glass is set as an infrared cut-off filter;

[0019] The object side of the first lens is convex and the image side is concave;

[0020] The object side of the second lens is convex and the image side is concave, and the object side of the second lens has an inflection point;

[0021] The object side of the third lens is convex, and the image side is convex;

[0022] The object side of the fourth lens is convex, and the image side is convex;

[0023] The object side of the fifth lens is concave, and the image side is concave;

[0024] The object side of the sixth lens is convex, and the image side is convex;

[0025] The object side of the seventh lens is concave, and the image side is concave; the image side of the seventh lens has an inflection point;

[0026] The object side of the eighth lens is convex, and the image side is concave; the object side and the image side of the eighth lens have inflection points.

[0027] Preferably, it satisfies the conditional formula Nd 3 > 1.8, where Nd 3 represents the refractive index of the third lens.

[0028] Preferably, it satisfies the conditional formula Hk>700, where Hk represents the material hardness of the first lens;

[0029] (AT 9 + AT 10 ) / TTL> 0.045, where AT 9 represents the minimum thickness of the air layer between the eighth lens and the flat glass, and AT 10 represents the minimum thickness of the air layer between the flat glass and the image side.

[0030] Preferably, at 0.92 FOV, it satisfies the conditional formula VD ≤ 2 mm, where VD represents the viewpoint depth of the panoramic lens.

[0031] Preferably, it satisfies the conditional formula 30° < CRA < 35°, where CRA represents the principal ray angle of the panoramic camera.

[0032] Preferably, it satisfies the conditional formula 0.4 < GT / TTL < 0.6, where GT represents the sum of the central thicknesses of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the flat glass.

[0033] Preferably, it satisfies the conditional formula L / TTL ≈ 0.66, where L represents the length of the front end of the aperture in the panoramic lens.

[0034] Preferably, it satisfies the conditional formula RI>55%, where RI represents the relative illuminance.

[0035] Preferably, it satisfies the condition

[0036] 3.8<|f 1 / f|<4.7,

[0037] 5.0<|(f 1 +f 2 +f 3 ) / f|<6.0,

[0038] 1.2<|(f 3 +f 4 ) / f|<1.6,

[0039] 5.3<|(f 4 +f 5 ) / f|<5.8,

[0040] 2.5<|(f 4 +f 5 +f 6 +f 7 +f 8 ) / f|<3.0,

[0041] 2.0<|(f 1 +f 2 +f 3 ) / (f 4 +f 5 +f 6 +f 7 +f 8 )|<2.5,

[0042] 12.0<|f 8 / f|<14.5,

[0043] Among them, f 1 represents the focal length of the first lens, f 2 represents the focal length of the second lens, f 3 represents the focal length of the third lens, f 4 represents the focal length of the fourth lens, f 5 represents the focal length of the fifth lens, f 6 represents the focal length of the sixth lens, f 7 represents the focal length of the seventh lens, f 8 represents the focal length of the eighth lens, and f represents the focal length of the panoramic lens.

[0044] Preferably, it satisfies the condition

[0045] ET 2 / CT 2 <2.8, among which, CT 2 represents the center thickness of the second lens, ET2 represents the edge thickness of the second lens;

[0046] CT 4 / ET 4 <2.5, among which, CT 4 represents the central thickness of the fourth lens, ET 4 represents the edge thickness of the fourth lens;

[0047] ET 5 / CT 5 <3, among which, CT 5 Denotes the central thickness of the fifth lens, ET 5 represents the edge thickness of the fifth lens;

[0048] CT 6 / ET 6 <2.8, among which, CT 6 represents the central thickness of the sixth lens, ET 6 represents the edge thickness of the sixth lens;

[0049] ET 7 / CT 7 <2, among which, CT 7 Denotes the center thickness of the seventh lens, ET 7 represents the edge thickness of the seventh lens;

[0050] ET 8 / CT 8 <0.97, CT 8 represents the central thickness of the eighth lens, ET 8 represents the edge thickness of the eighth lens;

[0051] EA<51°, where EA represents the edge cutting angles of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens.

[0052] The beneficial effects of the present invention are:

[0053] 1. The present invention satisfies 0.38 <IMA / TTL<0.46,6mm≤IMA≤7mm,2.97<IMA / FNO<3.57,0.95<CA 1 / TTL<1, so it can be used with a 1 / 1.3-inch large-surface sensor, with a field of view of up to 200°, meeting the user's needs for wide-view panoramic imaging. At the same time, it has the characteristics of short total length, small aperture, and small size, which is convenient for miniaturization and portability of photographic equipment, ensuring that the panoramic camera has a small visual blind spot, which is conducive to the subsequent stitching and improvement of panoramic imaging effects;

[0054] 2. The present invention uses multiple plastic lenses, which have the advantage of being lightweight, and at the same time, the thickness ratio of each lens is reasonably limited, and the edge cutting angle of each lens is less than 51°, which ensures the processability of the lens;

[0055] 3. The present invention provides inflection points on the object side of the second lens, the image plane of the seventh lens, and the object side and image plane of the eighth lens, which can correct aberrations at a larger field of view, especially lateral chromatic aberration, avoid the generation of purple fringing, improve the imaging quality, and obtain a high-resolution panoramic image with a large field of view;

[0056] 4. The present invention ensures the imaging quality in an environment of -20°C to 70°C by rationally distributing the optical focal length and coordinating the refractive index temperature coefficient of the lens material, allowing the photographic equipment to adapt to diversified application scenarios and better meet the user's usage needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic cross-sectional structure diagram of a first embodiment of the present invention;

[0058] Figure 2 is an optical transfer function curve diagram of the first embodiment of the present invention;

[0059] Figure 3 is a spot diagram of a first embodiment of the present invention;

[0060] Figure 4 is a graph of F-Theta distortion curve in the first embodiment of the present invention;

[0061] Figure 5 is an on-axis defocus curve diagram at -20°C in the first embodiment of the present invention;

[0062] Figure 6 is an on-axis defocus curve diagram at 70° C. in the first embodiment of the present invention;

[0063] Figure 7 is a schematic cross-sectional structural diagram of a second embodiment of the present invention;

[0064] Figure 8 is an optical transfer function curve diagram of the second embodiment of the present invention;

[0065] Fig. 9 is a spot diagram of a second embodiment of the present invention;

[0066] Fig.10 is a graph of F-Theta distortion curve in the second embodiment of the present invention;

[0067] Fig.11 is an on-axis defocus curve diagram at -20°C in the second embodiment of the present invention;

[0068] Fig.12 This is the off-axis defocus curve graph at 70 ° C in the second embodiment of the present invention.

[0069] The reference numerals are: first lens 10, second lens 11, third lens 12, aperture stop 20, fourth lens 13, fifth lens 14, sixth lens 15, seventh lens 16, eighth lens 17, flat glass 18, image plane 19. Detailed implementation manners

[0070] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present invention is thorough and comprehensive.

[0071] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein 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 of the related listed items.

[0072] A panoramic lens of the present invention is composed of a first lens 10, a second lens 11, a third lens 12, an aperture stop 20, a fourth lens 13, a fifth lens 14, a sixth lens 15, a seventh lens 16, an eighth lens 17, and a flat glass 18 in sequence from the object side to the image plane 19;

[0073] The first lens 10 has a negative optical power, the second lens 11 has a negative optical power, the third lens 12 has a positive optical power, the fourth lens 13 has a positive optical power, the fifth lens 14 has a negative optical power, the sixth lens 15 has a positive optical power, the seventh lens 16 has a negative optical power, and the eighth lens 17 has a negative optical power;

[0074] It satisfies the conditional formula:

[0075] 190° < FOV < 205°, where FOV represents the full field of view angle of the panoramic lens; this limitation enables the present invention to have a sufficiently large field of view angle, facilitating subsequent stitching and improving the panoramic imaging effect;

[0076] 6mm ≤ IMA ≤ 7mm, where IMA represents the image circle diameter of the panoramic lens; this limitation enables the present invention to be paired with a large target surface sensor of 1 / 1.3 inches to obtain high-resolution imaging results;

[0077] 0.38 < IMA / TTL < 0.46, where TTL represents the total length of the panoramic lens; this limitation gives the present invention the characteristics of a short total length and a small volume, facilitating the miniaturization and portability of the photographic device, ensuring that the panoramic camera has a small visual blind area, and being beneficial to subsequent stitching and the improvement of the panoramic imaging effect;

[0078] 0.95 < CA 1 / TTL < 1, where CA 1 represents the effective light - passing aperture of the object side of the first lens 10; this limitation gives the present invention the characteristics of a small aperture and a small volume, facilitating the miniaturization and portability of the photographic device;

[0079] VP ≥ 2, where VP represents the number of plastic lenses with a refractive index greater than 1.6 in the panoramic lens; this limitation enables the present invention to ensure a short total length and a small volume while improving the image resolution, facilitating the miniaturization and portability of the photographic device;

[0080] 2.97 < IMA / FNO < 3.57, where FNO represents the aperture number of the panoramic lens; Nd 3 >1.8, where Nd 3 represents the refractive index of the third lens 12; this limitation enables the present invention to match a higher - pixel chip, improve the image resolution on the basis of a large field of view, and at the same time have a light - passing amount matching the size of the imaging surface, improving the imaging clarity;

[0081] As a preferred embodiment, the first lens 10 is set as a glass spherical lens; the third lens 12 is set as a molded aspherical lens;

[0082] The second lens 11, the fourth lens 13, the fifth lens 14, the sixth lens 15, the seventh lens 16, and the eighth lens 17 are all set as plastic aspherical lenses;

[0083] The refractive index temperature coefficients of the materials of the first lens 10 and the third lens 12 are both greater than 0, and the refractive index temperature coefficients of the second lens 11, the fourth lens 13, the fifth lens 14, the sixth lens 15, the seventh lens 16, and the eighth lens 17 are all less than 0; through the cooperation of the refractive index temperature coefficients of the lens materials, ultra - high - definition resolution of the panoramic lens at high and low temperatures can be achieved, improving the imaging quality.

[0084] The flat glass 18 is set as an infrared - cut - off filter;

[0085] The object side of the first lens 10 is convex, and the image side 19 is concave;

[0086] The object side of the second lens 11 is convex, and the image side 19 is concave, and the object side of the second lens 11 has an inflection point;

[0087] The object side surface of the third lens 12 is a convex surface, and the image surface 19 is a convex surface;

[0088] The object side surface of the fourth lens 13 is a convex surface, and the image surface 19 is a convex surface;

[0089] The object side surface of the fifth lens 14 is a concave surface, and the image surface 19 is a concave surface;

[0090] The object side surface of the sixth lens 15 is a convex surface, and the image surface 19 is a convex surface;

[0091] The object side surface of the seventh lens 16 is a concave surface, and the image surface 19 is a concave surface; the image surface 19 of the seventh lens 16 has an inflection point;

[0092] The object-side surface of the eighth lens 17 is convex, and the image surface 19 is concave; the object-side surface and the image surface 19 of the eighth lens 17 have inflection points.

[0093] In the present invention, the setting of the inflection point can correct the aberration of the edge field of view, especially the lateral chromatic aberration, avoid the generation of purple fringing and the like, improve the imaging quality, and obtain a high-resolution panoramic image with a large field of view.

[0094] As a preferred embodiment, it satisfies the conditional formula Hk>700, wherein Hk represents the material hardness of the first lens 10; this restriction condition enables the side surface of the object of the present invention to be scratch-resistant and impact-resistant, thereby ensuring the stability of the photographic equipment during operation and extending its service life.

[0095] (AT 9 +AT 10 ) / TTL>0.045, where AT 9 represents the minimum thickness of the air layer between the eighth lens 17 and the flat glass 18, AT 10 It indicates the minimum thickness of the air layer between the flat glass 18 and the image plane 19. This limit can prevent scratches, ensure the stability of the photographic equipment during operation, and extend its service life.

[0096] As a preferred embodiment, at 0.92 FOV, the condition VD≤2mm is satisfied, where VD represents the viewpoint depth of the panoramic lens. This restriction prevents the present invention from being blocked by the camera body when shooting a panoramic image with a large field of view, thus ensuring the continuity of the field of view and facilitating subsequent stitching.

[0097] As a preferred embodiment, it satisfies the condition 30°<CRA<35°, where CRA represents the chief ray angle of the panoramic camera. This restriction enables the present invention to cooperate well with the imaging chip, ensuring the efficiency of the chip in receiving light energy.

[0098] As a preferred embodiment, it satisfies the conditional expression 0.4 < GT / TTL < 0.6, where GT represents the sum of the central thicknesses of the first lens 10, the second lens 11, the third lens 12, the fourth lens 13, the fifth lens 14, the sixth lens 15, the seventh lens 16, the eighth lens 17, and the flat glass 18. This limitation enables the optimal image plane of the present invention not to shift excessively at high and low temperatures and allows the lens to be bent better, correct aberration, and ensure imaging quality.

[0099] As a preferred embodiment, it satisfies the conditional expression L / TTL ≈ 0.66, where L represents the length in front of the aperture 20 in the panoramic lens. By reasonably allocating the lengths of each part, it can be ensured that the lens has the characteristics of a short total length, a large target surface, and a high-resolution imaging effect.

[0100] As a preferred embodiment, it satisfies the conditional expression RI > 55%, where RI represents the relative illuminance. This limiting condition can ensure that the illuminance of the edge field of view of the present invention is high enough, avoid excessive noise points in the subsequent algorithm adjustment process, and ensure the quality of the wide-angle panoramic image.

[0101] As a preferred embodiment, it satisfies the conditional expression

[0102] 3.8 < |f 1 / f| < 4.7,

[0103] 5.0 < |(f 1 +f 2 +f 3 ) / f| < 6.0,

[0104] 1.2 < |(f 3 +f 4 ) / f| < 1.6,

[0105] 5.3 < |(f 4 +f 5 ) / f| < 5.8,

[0106] 2.5 < |(f 4 +f 5 +f 6 +f 7 +f 8 ) / f| < 3.0,

[0107] 2.0 < |(f 1 +f 2 +f 3 ) / (f 4 +f 5 +f 6 +f 7 +f 8 )| < 2.5,

[0108] 12.0<|f 8 / f|<14.5,

[0109] Among them, f 1 represents the focal length of the first lens 10, f 2 represents the focal length of the second lens 11, f 3 represents the focal length of the third lens 12, f 4 represents the focal length of the fourth lens 13, f 5 represents the focal length of the fifth lens 14, f 6 represents the focal length of the sixth lens 15, f 7 represents the focal length of the seventh lens 16, f 8 represents the focal length of the eighth lens 17, and f represents the focal length of the panoramic lens. By reasonably setting the focal length, the ultra-clear resolution of the high and low temperature panoramic lens can be achieved and the imaging quality can be improved.

[0110] As a preferred embodiment, it satisfies the conditional formula

[0111] ET 2 / CT 2 <2.8, among which, CT 2 represents the center thickness of the second lens 11, ET 2 represents the edge thickness of the second lens 11;

[0112] CT 4 / ET 4 <2.5, among which, CT 4 represents the center thickness of the fourth lens 13, ET 4 represents the edge thickness of the fourth lens 13;

[0113] ET 5 / CT 5 <3, among which, CT 5 represents the central thickness of the fifth lens 14, ET 5 represents the edge thickness of the fifth lens 14;

[0114] CT 6 / ET 6 <2.8, among which, CT 6 represents the central thickness of the sixth lens 15, ET 6 represents the edge thickness of the sixth lens 15;

[0115] ET 7 / CT 7 <2, among which, CT 7 represents the center thickness of the seventh lens 16, ET 7 represents the edge thickness of the seventh lens 16;

[0116] ET 8 / CT 8 <0.97, CT 8 represents the central thickness of the eighth lens 17, ET 8 represents the edge thickness of the eighth lens 17;

[0117] EA<51°, where EA represents the edge cutting angles of the first lens 10, the second lens 11, the third lens 12, the fourth lens 13, the fifth lens 14, the sixth lens 15, the seventh lens 16, and the eighth lens 17. The above restrictions can ensure the processability of each lens.

[0118] The present invention provides a panoramic lens, which can be matched with a 1 / 1.3-inch large-target sensor to achieve high-resolution imaging, and the field of view angle is about 200°, meeting the user's demand for large-field panoramic imaging; it has the characteristics of short total length, small aperture, and small volume, which is convenient for miniaturization and portability of photographic equipment, so that the panoramic camera has a smaller visual blind spot, which is conducive to subsequent stitching and improvement of panoramic imaging effects; it uses multiple aspherical plastic lenses, which can meet the requirements of lightweight while correcting aberrations as much as possible, especially lateral chromatic aberration, avoiding the occurrence of purple fringing and other phenomena, and improving imaging quality; it can ensure imaging quality in an environment of -20°C to 70°C, so that photographic equipment can adapt to diversified application scenarios and better meet the user's usage needs.

[0119] For the first embodiment, please refer to Figure 1-6 A panoramic lens is provided in the first embodiment of the present invention. The relevant parameters of each lens in the panoramic lens are shown in Table 1-1, and the parameters of the aspherical surfaces of each lens in this embodiment are shown in Table 1-2.

[0120] Table 1-1

[0121]

[0122] Table 1-2

[0123]

[0124] The aspheric surfaces all satisfy the following equation:

[0125]

[0126] Among them: z represents the distance vector height from the vertex of the aspherical surface along the optical axis when the distance from the optical axis to the curved surface is h, c represents the curvature of the vertex of the curved surface, K represents the quadratic surface coefficient, B, C, D, E, F, G, H represent the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively. All aspherical surface shapes satisfy this formula.

[0127] In the first embodiment, when the ambient temperature is 20° C., the system focal length f=1.791 mm, FNO=2.11, the system total length TOTR=16.11 mm, and the field of view angle is 200°. Table 1-3 shows the conditional calculation results.

[0128] Table 1-3

[0129] Conditional expression actual result 190°<FOV<205° 200° conform to 6mm≤IMA≤7mm 6.278mm conform to 0.38<IMA / TTL<0.46 0.39 conform to <![CDATA[0.95<CA 1 / TTL<1]]> 0.99 conform to VP≥2 2 conform to <![CDATA[Nd 3 >1.8]]> 1.85 conform to 2.97<IMA / FNO<3.57 2.98 conform to Hk>700 >700 conform to VD≤2mm 1.8mm conform to 30°<CRA<35° 30.334° conform to 0.4<GT / TTL<0.6 0.48 conform to L / TTL≈0.66 0.66 conform to RI>55% >64％ conform to <![CDATA[(AT 9 +AT 10 ) / TTL>0.045]]> 0.053 conform to <![CDATA[3.8<|f 1 / f|<4.7]]> 4.6 conform to <![CDATA[5.0<|f 1 +f 2 +f 3 / f|<6.0]]> 5.96 conform to <![CDATA[1.2<|(f 3 +f 4 ) / f|<1.6]]> 1.50 conform to <![CDATA[5.3<|(f 4 +f 5 ) / f|<5.8]]> 5.66 conform to <![CDATA[2.5<|(f 4 +f 5 +f 6 +f 7 +f 8 ) / f|<3.0]]> 2.69 conform to <![CDATA[2.0<|(f 1 +f 2 +f 3 ) / (f 4 +f 5 +f 6 +f 7 +f 8 )|<2.5]]> 2.21 conform to <![CDATA[12.0<|f 8 / f|<14.5]]> 14.36 conform to <![CDATA[ET 2 / CT 2 <2.8]]> 2.75 conform to <![CDATA[CT 4 / AND 4 2.5]]> 1.84 conform to <![CDATA[ET 5 / CT 5 <3]]> 2.19 conform to <![CDATA[CT 6 / AND 6 2.8]]> 2.64 conform to <![CDATA[ET 7 / CT 7 <2]]> 1.88 conform to <![CDATA[ET 8 / CT 8 <0.97]]> 0.96 conform to EA<51° <50.6° conform to

[0130] For the second embodiment, please refer to Figures 7 to 12 A panoramic lens is provided in the second embodiment of the present invention, and the parameters of each lens in the panoramic lens are shown in Table 2-1, and the parameters of the aspherical surfaces of each lens in this embodiment are shown in Table 2-2.

[0131] Table 2-1

[0132]

[0133]

[0134] Table 2-2

[0135]

[0136]

[0137] The aspheric surfaces all satisfy the following equation:

[0138]

[0139] Among them: z represents the distance vector height from the vertex of the aspherical surface along the optical axis when the distance from the optical axis to the curved surface is h, c represents the curvature of the vertex of the curved surface, K represents the quadratic surface coefficient, B, C, D, E, F, G, H represent the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively. All aspherical surface shapes satisfy this formula.

[0140] In the second embodiment, when the ambient temperature is 20°C, the system focal length f=1.986 mm, FNO=1.93, the system total length TOTR=16.65 mm, and the field of view angle is 200°. Table 2-3 shows the conditional calculation results.

[0141] Table 2-3

[0142]

[0143]

[0144] The above-mentioned embodiments only express two implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A panoramic lens, which is composed of a first lens (10), a second lens (11), a third lens (12), a diaphragm (20), a fourth lens (13), a fifth lens (14), a sixth lens (15), a seventh lens (16), an eighth lens (17) and a flat glass (18) in sequence from the object side to the image plane (19); Characterized in that: The first lens (10) has a negative focal power, the second lens (11) has a negative focal power, the third lens (12) has a positive focal power, the fourth lens (13) has a positive focal power, the fifth lens (14) has a negative focal power, the sixth lens (15) has a positive focal power, the seventh lens (16) has a negative focal power, and the eighth lens (17) has a negative focal power; It satisfies the conditional formula: 190° < FOV < 205°, where FOV represents the full field of view angle of the panoramic lens; 6mm ≤ IMA ≤ 7mm, where IMA represents the image circle diameter of the panoramic lens; 0.38 < IMA / TTL < 0.46, where TTL represents the total length of the panoramic lens; 0.95 < CA1 / TTL < 1, where CA1 represents the effective clear aperture of the object side of the first lens (10); VP ≥ 2, where VP represents the number of plastic lenses with a refractive index greater than 1.6 in the panoramic lens; 2.97 < IMA / FNO < 3.57, where FNO represents the aperture number of the panoramic lens.

2. A panoramic lens according to claim 1, characterized in that: The first lens (10) is set as a glass spherical lens; the third lens (12) is set as a molded aspherical lens; The second lens (11), the fourth lens (13), the fifth lens (14), the sixth lens (15), the seventh lens (16), and the eighth lens (17) are all set as plastic aspherical lenses; The refractive index temperature coefficients of the materials of the first lens (10) and the third lens (12) are both greater than 0, and the refractive index temperature coefficients of the second lens (11), the fourth lens (13), the fifth lens (14), the sixth lens (15), the seventh lens (16), and the eighth lens (17) are all less than 0; The flat glass (18) is set as an infrared cut-off filter; The object side of the first lens (10) is convex, and the image plane (19) is concave; The object side of the second lens (11) is convex, and the image plane (19) is concave. The object side of the second lens (11) has an inflection point; The object side of the third lens (12) is convex, and the image plane (19) is convex; The object side of the fourth lens (13) is convex, and the image plane (19) is convex; The object side of the fifth lens (14) is concave, and the image plane (19) is concave; The object side of the sixth lens (15) is convex, and the image plane (19) is convex; The object side of the seventh lens (16) is concave, and the image plane (19) is concave. The image plane (19) of the seventh lens (16) has an inflection point; The object side of the eighth lens (17) is convex, and the image plane (19) is concave. The object side and the image plane (19) of the eighth lens (17) have inflection points.

3. The panoramic lens according to claim 1, characterized in that: It satisfies the conditional expression Nd3 > 1.8, where Nd3 represents the refractive index of the third lens (12).

4. The panoramic lens according to claim 1, characterized in that: It satisfies the conditional expression Hk > 700, where Hk represents the material hardness of the first lens (10); (AT9+AT 10 ) / TTL>0.045, wherein AT9 represents the minimum thickness of the air layer between the eighth lens (17) and the flat glass (18), AT 10 Indicates the minimum thickness of the air layer between the flat glass (18) and the image plane (19).

5. The panoramic lens according to claim 1, characterized in that: At 0.92 FOV, it satisfies the conditional expression VD ≤ 2 mm, where VD represents the viewpoint depth of the panoramic lens.

6. The panoramic lens according to claim 1, characterized in that: It satisfies the conditional expression 30° < CRA < 35°, where CRA represents the chief ray angle of the panoramic camera.

7. The panoramic lens according to claim 1, characterized in that: It satisfies the conditional expression 0.4 < GT / TTL < 0.6, where GT represents the sum of the central thicknesses of the first lens (10), the second lens (11), the third lens (12), the fourth lens (13), the fifth lens (14), the sixth lens (15), the seventh lens (16), the eighth lens (17), and the flat glass (18).

8. The panoramic lens according to claim 1, characterized in that: It satisfies the conditional expression L / TTL ≈ 0.66, where L represents the length of the front end of the aperture (20) in the panoramic lens.

9. The panoramic lens according to claim 1, characterized in that: It satisfies the conditional expression RI > 55%, where RI represents the relative illuminance.

10. The panoramic lens according to claim 1, characterized in that: It satisfies the conditional expression 3.8 < |f1 / f| < 4.7, 5.0 < |(f1 + f2 + f3) / f| < 6.0, 1.2 < |(f3 + f4) / f| < 1.6, 5.3 < |(f4 + f5) / f| < 5.8, 2.5 < |(f4 + f5 + f6 + f7 + f8) / f| < 3.0, 2.0 < |(f1 + f2 + f3) / (f4 + f5 + f6 + f7 + f8)| < 2.5, 12.0 < |f8 / f| < 14.5, where f1 represents the focal length of the first lens (10), f2 represents the focal length of the second lens (11), f3 represents the focal length of the third lens (12), f4 represents the focal length of the fourth lens (13), f5 represents the focal length of the fifth lens (14), f6 represents the focal length of the sixth lens (15), f7 represents the focal length of the seventh lens (16), f8 represents the focal length of the eighth lens (17), and f represents the focal length of the panoramic lens.

11. The panoramic lens according to claim 1, characterized in that: It satisfies the conditional expression ET2 / CT2 < 2.8, where CT2 represents the central thickness of the second lens (11), and ET2 represents the edge thickness of the second lens (11); CT4 / ET4 < 2.5, where CT4 represents the central thickness of the fourth lens (13), and ET4 represents the edge thickness of the fourth lens (13); ET5 / CT5 < 3, where CT5 represents the central thickness of the fifth lens (14), and ET5 represents the edge thickness of the fifth lens (14); CT6 / ET6 < 2.8, where CT6 represents the central thickness of the sixth lens (15), and ET6 represents the edge thickness of the sixth lens (15); ET7 / CT7 < 2, where CT7 represents the central thickness of the seventh lens (16), and ET7 represents the edge thickness of the seventh lens (16); ET8 / CT8 < 0.97, CT8 represents the central thickness of the eighth lens (17), and ET8 represents the edge thickness of the eighth lens (17); EA<51°, where EA represents the edge cutting angles of the first lens (10), the second lens (11), the third lens (12), the fourth lens (13), the fifth lens (14), the sixth lens (15), the seventh lens (16), and the eighth lens (17).

Images