A panoramic lens

Abstract

The present invention provides a panoramic lens, which is composed of a first lens, a second lens, a third lens, an aperture stop, 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; 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; it satisfies the conditional formula: 190° < FOV < 205°, where FOV represents the full field angle of the panoramic lens; 6mm ≤ IMA ≤ 7mm, 0.38 < IMA / TTL < 0.46, 0.95 < CA1 / TTL < 1, VP ≥ 2, 2.97 < IMA / FNO < 3.57, and it can be paired with a large format sensor of 1 / 1.3 inches to achieve high-resolution imaging, with a field angle of about 200°, meeting the user's demand for large-field panoramic imaging, and having the characteristics of short overall length, small aperture, and small volume, which is convenient for realizing the miniaturization and portability of photographic equipment.

Description

Technical Field

[0001] The present 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 media platforms, sharing life through photos, short videos, and livestreams has become increasingly popular. Portable cameras have become a highly popular imaging device, following the smartphone. Young people are primarily users of portable cameras, and their imaging requirements are becoming more diverse, demanding both high-quality images and a wide field of view for wide, visually impactful panoramic shots. To accommodate these diverse applications, portable panoramic cameras have emerged.

[0003] For example, the Chinese invention patent application publication number CN108535847A, published on September 14, 2018, discloses an ultra-wide-angle high-pixel fisheye optical system. Figure 1 As shown, along the optical axis, from the object plane to the image plane, the lens includes, in order: 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. Another embodiment of the present invention provides a camera module. This embodiment of the present invention primarily comprises eight lenses, resulting in a simple structure with a small number of lenses. By combining different lenses and rationally distributing optical power, it achieves excellent optical performance, including a 200° ultra-wide angle and over 20 million pixels, making it suitable for professional-grade panoramic VR cameras and micro-single cameras. Due to users' high demands for imaging resolution, portable panoramic cameras are being upgraded to use larger 1 / 1.3-inch sensors. However, this also increases the camera's front port diameter and overall length, contradicting the user's desired compactness and portability. Therefore, improving imaging resolution and field of view while maintaining a compact size has become a pressing technical challenge. Currently, conventional panoramic lenses on the market often lack the performance to adapt to diverse application scenarios and struggle to meet user needs. Given this situation, improvement is urgently needed. Summary of the Invention

[0004] To address the above problems, the present invention provides a panoramic lens that 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 users' needs for wide-field panoramic imaging. It has the characteristics of short total length, small aperture, and small size, which facilitates the miniaturization and portability of photographic equipment, and enables panoramic cameras to have smaller visual blind spots, which is beneficial to subsequent stitching and improvement of panoramic imaging effects.

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

[0006] A panoramic lens consists of a first lens, a second lens, a third lens, an aperture stop, 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 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 < CA1 / TTL < 1, where CA1 represents the effective clear 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 f-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 Nd3>1.8, where Nd3 represents the refractive index of the third lens. <00000​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0037] 5.0<|(f1+f2+f3) / f|<6.0,

[0038] 1.2<|(f3+f4) / f|<1.6,

[0039] 5.3<|(f4+f5) / f|<5.8,

[0040] 2.5<|(f4+f5+f6+f7+f8) / f|<3.0,

[0041] 2.0<|(f1+f2+f3) / (f4+f5+f6+f7+f8)|<2.5,

[0042] 12.0<|f8 / f|<14.5,

[0043] Among them, f1 represents the focal length of the first lens, f2 represents the focal length of the second lens, f3 represents the focal length of the third lens, f4 represents the focal length of the fourth lens, f5 represents the focal length of the fifth lens, f6 represents the focal length of the sixth lens, f7 represents the focal length of the seventh lens, f8 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] ET2 / CT2<2.8, where CT2 represents the center thickness of the second lens, and ET2 represents the edge thickness of the second lens;

[0046] CT4 / ET4<2.5, where CT4 represents the center thickness of the fourth lens, and ET4 represents the edge thickness of the fourth lens;

[0047] ET5 / CT5<3, where CT5 represents the center thickness of the fifth lens, and ET5 represents the edge thickness of the fifth lens;

[0048] CT6 / ET6<2.8, where CT6 represents the center thickness of the sixth lens, and ET6 represents the edge thickness of the sixth lens;

[0049] ET7 / CT7<2, where CT7 represents the center thickness of the seventh lens, and ET7 represents the edge thickness of the seventh lens;

[0050] ET8 / CT8<0.97, CT8 represents the center thickness of the eighth lens, and ET8 represents the edge thickness of the eighth lens;

[0051] EA < 51°, where EA represents the edge chamfer 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 as follows:

[0053] 1. By satisfying the conditional equations of 0.38 < IMA / TTL < 0.46, 6 mm ≤ IMA ≤ 7 mm, 2.97 < IMA / FNO < 3.57, and 0.95 < CA1 / TTL < 1, the present invention can be paired with a large-format sensor of 1 / 1.3 inches, and the field of view angle can reach 200°, meeting the user's demand for large-field panoramic imaging. At the same time, it has the characteristics of short overall length, small aperture, and small volume, facilitating the miniaturization and portability of photographic equipment, ensuring that the panoramic camera has a small visual blind area, and being beneficial to subsequent stitching and the improvement of panoramic imaging effects;

[0054] 2. The present invention uses multiple plastic lenses, having the advantage of light weight. At the same time, the thickness ratios of each lens are reasonably restricted, and the edge chamfer angles of each lens are less than 51°, ensuring the processability of the lens;

[0055] 3. Inflection points are provided on the object side of the second lens, the image side of the seventh lens, the object side and the image side of the eighth lens, which can correct the aberration at a large field of view, especially the lateral chromatic aberration, avoiding the generation of purple edges and other situations, improving the imaging quality, and obtaining a large-field panoramic image with high resolution;

[0056] 4. Through the reasonable distribution of optical power and the cooperation of the refractive index temperature coefficients of lens materials, the present invention ensures the imaging quality in an environment of -20°C to 70°C, enabling photographic equipment to adapt to diversified application scenarios and better meeting the user's usage requirements. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0058] Figure 2 is a graph of the optical transfer function of the first embodiment of the present invention;

[0059] [[ID=​​​​​​​​​​​​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] Figure 9 is a spot diagram of a second embodiment of the present invention;

[0066] Figure 10 is an F-Theta distortion curve diagram in the second embodiment of the present invention;

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

[0068] Figure 12 FIG. 1 is an on-axis defocus curve at 70° C. in the second embodiment of the present invention.

[0069] Reference numerals are: first lens 10 , second lens 11 , third lens 12 , aperture 20 , fourth lens 13 , fifth lens 14 , sixth lens 15 , seventh lens 16 , eighth lens 17 , flat glass 18 , image plane 19 . DETAILED DESCRIPTION

[0070] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0071] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0072] A panoramic lens of the present invention is composed of, from the object side to the image plane 19, a first lens 10, a second lens 11, a third lens 12, an aperture 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;

[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 angle of the panoramic lens; this limitation enables the present invention to have a sufficiently large field 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 enables the present invention to have the characteristics of a short total length and a small volume, facilitating the miniaturization and portability of photographic equipment, 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 < CA1 / TTL < 1, where CA1 represents the effective clear aperture of the object side surface of the first lens 10; this limitation enables the present invention to have the characteristics of a small aperture and a small volume, facilitating the miniaturization and portability of photographic equipment;

[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 photographic equipment;

[0080] 2.97 < IMA / FNO < 3.57, where FNO represents the aperture number of the panoramic lens; Nd3 > 1.8, where Nd3 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 imaging surface size to improve 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. By coordinating the refractive index temperature coefficients of the lens materials, ultra-high resolution of high and low temperature panoramic lenses can be achieved, thereby improving imaging quality.

[0084] The flat glass 18 is configured as an infrared cutoff filter;

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

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

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

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

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

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

[0091] The object-side surface of the seventh lens element 16 is concave, and the image surface 19 is concave; the image surface 19 of the seventh lens element 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 occurrence 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 expression Hk>700, where Hk represents the material hardness of the first lens 10; this restriction condition makes the side surface of the object of the present invention scratch-resistant and impact-resistant, thereby ensuring the stability of the photographic equipment during operation and extending its service life.

[0095] (AT9+AT 10 ) / TTL>0.045, where AT9 represents the minimum thickness of the air layer between the eighth lens 17 and the flat glass 18, and AT 10 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, it satisfies the conditional formula VD ≤ 2 mm, where VD represents the viewing depth of the panoramic lens. This limitation ensures that the present invention is not blocked by the body of the photographic equipment when taking panoramic images with a large viewing angle, guarantees the continuity of the viewing field, and is beneficial for subsequent stitching.

[0097] As a preferred embodiment, it satisfies the conditional formula 30° < CRA < 35°, where CRA represents the principal ray angle of the panoramic camera. This limitation enables the present invention to cooperate well with the imaging chip and ensures the efficiency of the chip receiving light energy.

[0098] As a preferred embodiment, it satisfies the conditional formula 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 ensures that the best image plane of the present invention does not shift excessively at high and low temperatures and enables the lens to bend better, correct aberration, and guarantee the imaging quality.

[0099] As a preferred embodiment, it satisfies the conditional formula 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 formula RI > 55%, where RI represents the relative illuminance. This limiting condition can ensure that the illuminance of the edge viewing field of the present invention is high enough, avoid excessive noise points in the subsequent algorithm adjustment process, and guarantee the quality of the wide-angle panoramic image.

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

[0102] 3.8 < |f1 / f| < 4.7, <000022>

[0103] 5.0 < |(f1 + f2 + f3) / f| < 6.0,

[0104] 1.2 < |(f3 + f4) / f| < 1.6,

[0105] 5.3 < |(f4 + f5) / f| < 5.8,

[0106] 2.5 < |(f4 + f5 + f6 + f7 + f8) / f| < 3.0,

[0107] 2.0 < |(f1 + f2 + f3) / (f4 + f5 + f6 + f7 + f8)| < 2.5,

[0108] 12.0<|f8 / f|<14.5,

[0109] Wherein, 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. By properly setting the focal length, ultra-high resolution can be achieved for high and low temperature panoramic lenses, improving imaging quality.

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

[0111] ET2 / CT2<2.8, where CT2 represents the center thickness of the second lens 11, and ET2 represents the edge thickness of the second lens 11;

[0112] CT4 / ET4<2.5, where CT4 represents the center thickness of the fourth lens 13 and ET4 represents the edge thickness of the fourth lens 13;

[0113] ET5 / CT5<3, where CT5 represents the center thickness of the fifth lens 14 and ET5 represents the edge thickness of the fifth lens 14;

[0114] CT6 / ET6<2.8, where CT6 represents the center thickness of the sixth lens 15 and ET6 represents the edge thickness of the sixth lens 15;

[0115] ET7 / CT7<2, where CT7 represents the center thickness of the seventh lens element 16 and ET7 represents the edge thickness of the seventh lens element 16;

[0116] ET8 / CT8<0.97, CT8 represents the center thickness of the eighth lens 17, and ET8 represents the edge thickness of the eighth lens 17;

[0117] EA<51°, where EA represents the edge cutting angle 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 that 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 users' needs for wide-field panoramic imaging. It has the characteristics of short total length, small aperture, and small size, which facilitates the miniaturization and portability of photographic equipment, and enables panoramic cameras to have a smaller visual blind spot, which is beneficial for subsequent stitching and improvement of panoramic imaging effects. It uses multiple aspherical plastic lenses to achieve lightweight while correcting aberrations as much as possible, especially lateral chromatic aberration, avoiding the occurrence of phenomena such as purple fringing and improving imaging quality. It can ensure imaging quality in an environment of -20°C to 70°C, allowing photographic equipment to adapt to diverse application scenarios and better meet users' 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 aspheric 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] Where: z represents the distance vector from the aspheric surface vertex along the optical axis when the distance from the optical axis to the surface is h, c represents the curvature of the surface vertex, K represents the quadratic surface coefficient, and B, C, D, E, F, G, and H represent the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients, respectively. All aspheric surface shapes meet 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 calculation results under these conditions.

[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<CA1 / TTL<1]]> 0.99 conform to VP≥2 2 conform to <![CDATA[Nd3>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[(AT9+AT 10 ) / TTL>0.045]]> 0.053 conform to <![CDATA[3.8<|f1 / f|<4.7]]> 4.6 conform to <![CDATA[5.0<|f1+f2+f3 / f|<6.0]]> 5.96 conform to <![CDATA[1.2<|(f3+f4) / f|<1.6]]> 1.50 conform to <![CDATA[5.3<|(f4+f5) / f|<5.8]]> 5.66 conform to <![CDATA[2.5<|(f4+f5+f6+f7+f8) / f|<3.0]]> 2.69 conform to <![CDATA[2.0<|(f1+f2+f3) / (f4+f5+f6+f7+f8)|<2.5]]> 2.21 conform to <![CDATA[12.0<|f8 / f|<14.5]]> 14.36 conform to <![CDATA[ET2 / CT2<2.8]]> 2.75 conform to <![CDATA[CT4 / ET4<2.5]]> 1.84 conform to <![CDATA[ET5 / CT5<3]]> 2.19 conform to <![CDATA[CT6 / ET6<2.8]]> 2.64 conform to <![CDATA[ET7 / CT7<2]]> 1.88 conform to <![CDATA[ET8 / CT8<0.97]]> 0.96 conform to EA<51° <50.6° conform to

[0130] For the second embodiment, please refer to Figures 7-12The second embodiment of the present invention provides a panoramic lens, and the parameters of each lens in the panoramic lens are shown in Table 2-1. 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] Where: z represents the distance vector from the aspheric surface vertex along the optical axis when the distance from the optical axis to the surface is h, c represents the curvature of the surface vertex, K represents the quadratic surface coefficient, and B, C, D, E, F, G, and H represent the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients, respectively. All aspheric surface shapes meet 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 calculation results under these conditions.

[0141] Table 2-3

[0142]

[0143]

[0144] The above-described embodiments merely represent two implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A panoramic lens, which consists 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); It is 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 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; 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 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 object side of the eighth lens (17) is convex, and the image plane (19) is concave.

2. The 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 second lens (11) has an inflection point; the image plane (19) of the seventh lens (16) has an inflection point; the object side and the image plane (19) of the eighth lens (17) have inflection points.

3. The panoramic lens according to claim 1, wherein: 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, wherein: 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., CT8 represents the central thickness of the eighth lens (17), and ET8 represents the edge thickness of the eighth lens (17); EA<51°, wherein 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).

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