wide-angle lens

Abstract

The application discloses a wide-angle lens which is composed of nine lenses and sequentially comprises, along an optical axis from an object side to an imaging surface, a first lens with negative focal power, the object side of which is a convex surface and the image side of which is a concave surface; a second lens with negative focal power, the object side of which is a convex surface and the image side of which is a concave surface; a third lens with positive focal power; a fourth lens with negative focal power; a fifth lens with positive focal power; a sixth lens with positive focal power, the image side of which is a convex surface; a seventh lens with negative focal power, the object side of which is a concave surface; an eighth lens with positive focal power; and a ninth lens with negative focal power; wherein the wide-angle lens satisfies a condition formula: 2 < TTL / IH < 3, TTL represents the total optical length of the wide-angle lens, and IH represents the image height corresponding to the full field of view angle of the wide-angle lens. The wide-angle lens provided by the application has the advantages of super wide angle, small distortion, large aperture, high image quality and the like by reasonably matching the focal power and surface type of the nine lenses.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and particularly to a wide-angle lens. Background Art

[0002] With the continuous development of optical technology, optical lenses have been widely used in various fields. For example, optical lenses play an irreplaceable role in various fields such as mobile phone cameras, security monitoring, UAV photography, action cameras, and automotive assisted driving. At the same time, in order to improve the competitiveness of their own products and better meet the diverse needs of users, lens manufacturers in various fields have a more diverse pursuit of imaging effects. They not only require high-definition image quality, but also require a super-large field of view to capture large-range images with strong visual impact, and also require sufficient light input to ensure that the lens can capture high-definition images in darker or strong light environments. However, a large shooting angle, a large light input, and high-definition image quality are often the difficulties in the development of lenses.

[0003] Currently, the field of view angle of optical lenses on the market is relatively small, making it difficult to capture large-range images. Moreover, the edge distortion of most wide-angle lenses cannot be well corrected, resulting in poor imaging effects at the edges and insufficiently high image quality. Therefore, it is difficult for optical lenses on the market to simultaneously achieve the balance of ultra-wide angle, large aperture, and high image quality, and it is difficult to meet the diverse market demands. Summary of the Invention

[0004] For this reason, the purpose of the present invention is to provide a wide-angle lens, which at least has the advantages of ultra-wide angle, small distortion, large aperture, and high image quality.

[0005] The embodiments of the present invention implement the above purpose through the following technical solutions.

[0006] The present invention provides a wide-angle lens composed of nine lenses. The wide-angle lens sequentially includes, along the optical axis from the object side to the imaging surface: a first lens with negative optical power, whose object side is convex and whose image side is concave; a second lens with negative optical power, whose object side is convex and whose image side is concave; a third lens with positive optical power; a fourth lens with negative optical power; a fifth lens with positive optical power; a sixth lens with positive optical power, whose image side is convex; a seventh lens with negative optical power, whose object side is concave; an eighth lens with positive optical power; a ninth lens with negative optical power; wherein, the wide-angle lens satisfies the conditional formula: 2 < TTL / IH < 3, where TTL represents the overall optical length of the wide-angle lens, and IH represents the image height corresponding to the full field of view angle of the wide-angle lens.

[0007] Compared to existing technologies, the wide-angle lens provided by this invention, through the reasonable combination of the surface shape and optical power of the nine lenses, not only gives the lens an ultra-wide shooting range, but also effectively reduces the distortion at the edge of the field of view, so that the lens has high image fidelity throughout the entire field of view. At the same time, it also gives the lens the characteristics of a large aperture and a large image plane, allowing more light to enter the lens system, so that the lens can also produce clear images in low-light environments. It can achieve a reasonable balance of ultra-wide angle, low distortion, large aperture and high pixel count in optical lenses. Attached Figure Description

[0008] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0009] Figure 1 This is a schematic diagram of the structure of a wide-angle lens according to the first embodiment of the present invention.

[0010] Figure 2 This is a distortion curve diagram of the wide-angle lens according to the first embodiment of the present invention.

[0011] Figure 3 This is a chromatic aberration curve of the wide-angle lens according to the first embodiment of the present invention.

[0012] Figure 4 This is an MTF curve diagram of the wide-angle lens according to the first embodiment of the present invention.

[0013] Figure 5 This is a schematic diagram of the structure of a wide-angle lens according to the second embodiment of the present invention.

[0014] Figure 6 This is a distortion curve diagram of a wide-angle lens according to the second embodiment of the present invention.

[0015] Figure 7 This is a chromatic aberration curve of the wide-angle lens according to the second embodiment of the present invention.

[0016] Figure 8 This is an MTF curve diagram of the wide-angle lens according to the second embodiment of the present invention.

[0017] Figure 9 This is a schematic diagram of the structure of a wide-angle lens according to the third embodiment of the present invention.

[0018] Figure 10 This is a distortion curve diagram of the wide-angle lens according to the third embodiment of the present invention.

[0019] Figure 11 This is a chromatic aberration curve of the wide-angle lens according to the third embodiment of the present invention.

[0020] Figure 12 This is an MTF curve diagram of the wide-angle lens according to the third embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying 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. Rather, these embodiments are provided so that the disclosure of the present invention will be thorough and complete.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Throughout this specification, the same reference numerals refer to the same elements.

[0023] In this article, "near the optical axis" refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the near-optical axis region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the near-optical axis region.

[0024] This invention proposes a wide-angle lens composed of nine lenses, which, along the optical axis from the object side to the imaging plane, include: a first lens, a second lens, a third lens, a fourth lens, an aperture stop, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a filter.

[0025] The first lens has negative optical power, with a convex object side and a concave image side. The first lens adopts a meniscus shape, which can collect light from a wide field of view into the rear optical system, effectively increasing light transmission and facilitating the achievement of wide-angle and large-aperture performance.

[0026] The second lens has negative optical power, with a convex object-side surface and a concave image-side surface. This convex-concave surface design of the second lens is beneficial for collecting light rays entering through the first lens. Simultaneously setting both the first and second lenses as meniscus lenses with negative optical power allows for smoother outgoing light, which is beneficial for minimizing distortion. Since the large field-of-view light rays exiting the first lens incident at a relatively small angle on the object-side surface of the second lens, setting the object-side surface of the second lens as convex ensures a large field of view while better converging the light rays, preventing excessive divergence on the object side, which would be detrimental to distortion and aberration correction. Furthermore, setting the image-side surface of the second lens as concave makes the outgoing light rays even smoother, which is beneficial for controlling the aperture of the rear lenses.

[0027] The third lens has positive optical power, and both its object-side and image-side surfaces are convex. Setting the third lens as a biconvex positive lens can effectively converge light rays. At the same time, in conjunction with the two negative optical power lenses in front, it helps light rays enter the rear lens smoothly, thereby improving the resolving power.

[0028] The fourth lens has negative optical power, with a concave object side and an image side that can be either concave or convex. The use of a concave object side negative lens in the fourth lens allows light rays at the edge of a large field of view to rise, which helps the image point on the image plane to move away from the optical axis, thus obtaining a larger image plane and achieving better compatibility with large-size chips.

[0029] The fifth lens has positive optical power, and both its object-side and image-side surfaces can be convex. Setting the fifth lens as a biconvex positive lens facilitates light convergence, ensures a smooth transition of light paths, reduces the difficulty of aberration correction, and improves image quality.

[0030] The sixth lens has positive optical power and its image-side surface is convex.

[0031] The seventh lens has negative optical power and its object-side surface is concave. The sixth and seventh lenses are designed with a positive-negative pairing, which can better eliminate system chromatic aberration and improve image quality.

[0032] The eighth lens has positive optical power, and both its object-side and image-side surfaces can be convex. The eighth lens is a biconvex positive lens, which helps to better converge the light entering the system and effectively reduces ghost image energy reflected from the imaging surface, thus minimizing interference with image quality.

[0033] The ninth lens has negative optical power, and its image side is concave near the optical axis. The use of a negative lens in the ninth lens allows for proper control of light trajectory, increasing the angle of incidence of light entering the image plane. This achieves a large image plane while avoiding excessive lens sensitivity caused by excessive light deflection.

[0034] The wide-angle lens also includes an aperture stop, which is positioned between the fourth and fifth lenses. This aperture stop effectively limits the aperture of the light beam, further improving the lens's image quality. Positioning the aperture stop between the fourth and fifth lenses helps to effectively gather the light entering the lens, reducing the aperture of the rear lens element and lowering the system's assembly sensitivity. In this application, the aperture stop is positioned between the fourth and fifth lenses; however, in other embodiments, the aperture stop can be positioned at other locations as needed.

[0035] In some embodiments, the wide-angle lens satisfies the conditional formula: 2 < TTL / IH < 3, where TTL represents the total optical length of the wide-angle lens, and IH represents the image height corresponding to the full field angle of the wide-angle lens. Meeting the above conditions is conducive to the miniaturization of the lens, while enabling the lens to have a larger image plane, capable of matching a larger-sized chip, and achieving high-definition imaging within a large wide-angle range of the system.

[0036] In some embodiments, the wide-angle lens satisfies the conditional formula: 8 < TTL / f < 11, where TTL represents the total optical length of the wide-angle lens, and f represents the effective focal length of the wide-angle lens. Meeting the above conditions can effectively limit the length of the lens and achieve the miniaturization of the wide-angle lens.

[0037] In some embodiments, the wide-angle lens satisfies the conditional formula: where, represents the optical power of the first lens, represents the optical power of the second lens, represents the optical power of the wide-angle lens. Meeting the above conditions can enable the first and second lenses to have appropriate negative optical powers, slow down the degree of refraction of incident light, help more light enter the optical system within a larger range, be conducive to expanding the field angle of the lens while achieving the large aperture characteristic of the lens. The realization of the wide-angle characteristic is conducive to the optical lens obtaining more scene information and meeting the requirements of large-range shooting. The realization of the large aperture characteristic is conducive to improving the problem that the relative brightness of the edge field of view decreases rapidly due to the wide angle, and thus is also conducive to obtaining more scene information.

[0038] In some embodiments, the wide-angle lens satisfies the conditional formulas: 2 < R11 / R12 < 5, 1 < R21 / R22 < 5, where R11 represents the curvature radius of the object side surface of the first lens, R12 represents the curvature radius of the image side surface of the first lens, R21 represents the curvature radius of the object side surface of the second lens, and R22 represents the curvature radius of the image side surface of the second lens. Meeting the above conditions, by reasonably setting the surface profiles of the first and second lenses, is conducive to light entering the system more smoothly, reducing the difficulty of distortion and aberration correction, and improving the resolution of the optical lens.

[0039] In some embodiments, the wide-angle lens satisfies the conditional formula: where, represents the optical power of the third lens, R31 represents the object-side radius of curvature of the third lens, and R32 represents the image-side radius of curvature of the third lens. Meeting these conditions allows the third lens to have appropriate positive optical power and surface shape. This better corrects aberrations caused by the two negative lenses and facilitates a smooth transition of light rays, thus improving the image quality of the wide-angle lens.

[0040] In some implementations, the wide-angle lens satisfies the following condition: in, This indicates the optical power of the fourth lens. This indicates the optical power of the wide-angle lens. By appropriately setting the optical power of the fourth lens, the distortion of the lens at a large field of view can be effectively corrected, resulting in less distortion and improved image quality.

[0041] In some implementations, the wide-angle lens satisfies the following condition: in, This indicates the optical power of the fifth lens. R51 represents the optical power of the wide-angle lens, R52 represents the radius of curvature of the object-side surface of the fifth lens, and R53 represents the radius of curvature of the image-side surface of the fifth lens. Meeting these conditions allows the fifth lens to have appropriate positive optical power and surface shape, effectively mitigating the deflection angle of light passing through the fifth lens, reducing tolerance sensitivity and the difficulty of distortion correction.

[0042] In some embodiments, the sixth lens and the seventh lens form a cemented lens group, and the wide-angle lens satisfies the following condition: in, This indicates the combined optical power of the sixth lens and the seventh lens. This indicates the optical power of the wide-angle lens. This indicates the optical power of the sixth lens. This indicates the optical power of the seventh lens. The sixth and seventh lenses form a cemented lens, which can minimize or eliminate chromatic aberration. The optical power of this cemented lens group meets the above conditions, allowing for better correction of system aberrations, and is particularly beneficial for chromatic aberration correction. It also facilitates large image plane imaging. Furthermore, by appropriately setting the optical power ratio of the sixth and seventh lenses, their optical power values ​​can be made relatively close, contributing to a smoother light transition and thus improving image quality.

[0043] In some implementations, the wide-angle lens satisfies the following condition: in, This indicates the optical power of the eighth lens. represents the optical power of the wide-angle lens, R81 represents the curvature radius of the object side surface of the eighth lens, and R82 represents the curvature radius of the image side surface of the eighth lens. Meeting the above conditions can endow the eighth lens with appropriate positive optical power and surface shape, which is beneficial to better converge the marginal rays, enable the converged rays to smoothly enter the rear optical system, and further make the light trend transition smoothly, reduce the correction difficulty of distortion and aberration, and further improve the imaging quality of the optical lens.

[0044] In some embodiments, the wide-angle lens satisfies the conditional formula: -1 < f / f9 < -0.2, -2 < R92 / f9 < -0.2, where f9 represents the focal length of the ninth lens, f represents the effective focal length of the wide-angle lens, and R92 represents the curvature radius of the image side surface of the ninth lens. Meeting the above conditions, by reasonably setting the optical power and surface shape of the ninth lens, the shape change of the ninth lens can be slowed down, the generation of stray light can be reduced, and at the same time, the light trend can be reasonably controlled, the incident angle of the light entering the image plane can be increased, and while achieving a large image plane, the problem of excessive lens sensitivity caused by excessive light deflection can be avoided.

[0045] In some embodiments, the wide-angle lens satisfies the conditional formula: 50° < (FOV × f) / IH < 65°, 3 < IH / f < 4, where FOV represents the maximum field angle of the wide-angle lens, f represents the effective focal length of the wide-angle lens, and IH represents the image height corresponding to the full field angle of the wide-angle lens. Meeting the above conditions can not only achieve the ultra-wide-angle characteristic of the lens to meet the large-range shooting requirements, but also achieve the large-image-plane characteristic to improve the imaging quality of the optical lens, and can effectively balance the requirements of large-range detection and high-quality imaging.

[0046] In some embodiments, the wide-angle lens satisfies the conditional formula: where, represents the optical power of the second lens, represents the optical power of the third lens. Meeting the above conditions, by reasonably setting the optical power distribution of the second lens and the third lens, it is beneficial to converge the marginal field rays, enable the converged rays to smoothly enter the rear optical system, and further make the light trend transition smoothly, reduce the distortion correction difficulty of the marginal field, make the lens have less distortion, and improve the imaging quality of the lens.

[0047] In some embodiments, the wide-angle lens satisfies the conditional formula: where, 2]represents the optical power of the third lens, represents the optical power of the fourth lens. Meeting the above conditions can effectively balance the aberration and distortion of the marginal field, ensure that the system still has good image quality while having a large field angle, and reduce the image deformation degree at the marginal field.

[0048] In some embodiments, the wide-angle lens satisfies the conditional formula: the optical lens satisfies the conditional formula: 2 < DM1 / IH < 3, where DM1 represents the maximum effective aperture of the first lens, and IH represents the image height corresponding to the full field angle of the wide-angle lens. Meeting the above conditions can make the first lens have a larger aperture, receive as much light as possible into the system, achieve an ultra-wide angle of the lens while reducing the rear aperture of the lens, and better achieve the balance between the ultra-wide angle and miniaturization of the lens volume.

[0049] In the present application, the wide-angle lens can adopt a combination of glass lenses and plastic lenses, or can adopt a full plastic lens or a full glass lens structure; in order to achieve wide-angle and small distortion of the lens while ensuring good imaging effects of the lens, the first lens, the third lens, the fourth lens, the sixth lens and the seventh lens in the wide-angle lens adopt glass spherical lenses, and the second lens, the fifth lens, the eighth lens and the ninth lens can adopt glass aspherical lenses or plastic aspherical lenses. Adopting aspherical lenses can effectively reduce costs, correct aberrations, and provide optical performance products with higher cost performance.

[0050] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, curvature radius, and material selection of each lens in the wide-angle lens are partially different. For specific differences, refer to the parameter tables of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations or simplifications made without departing from the innovative points of the present invention shall be regarded as equivalent replacement methods and shall be included in the protection scope of the present invention.

[0051] In each embodiment of the present invention, the aspherical surface types of each lens all satisfy the following equation:

[0052]

[0053] where z is the sagitta distance from the vertex of the aspherical surface when the aspherical surface is at a position with a height of h along the optical axis direction, c is the paraxial curvature of the surface, k is the conic coefficient, and A 2i is the aspherical surface type coefficient of the 2i-th order.

[0054] First Embodiment

[0055] Please refer to Figure 1The diagram shown is a schematic diagram of the structure of a wide-angle lens 100 provided in the first embodiment of the present invention. The wide-angle lens 100 includes, along the optical axis from the object side to the imaging plane S20, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, and a filter G1.

[0056] The first lens L1 has negative optical power, the object side S1 of the first lens is convex, and the image side S2 of the first lens is concave.

[0057] The second lens L2 has negative optical power, the object side S3 of the second lens is convex, and the image side S4 of the second lens is concave.

[0058] The third lens L3 has positive optical power. The object side S5 of the third lens is convex, and the image side S6 of the third lens is convex.

[0059] The fourth lens L4 has negative optical power. The object side S7 of the fourth lens is concave, and the image side S8 of the fourth lens is convex.

[0060] The fifth lens L5 has positive optical power. The object side S9 of the fifth lens is convex, and the image side S10 of the fifth lens is convex.

[0061] The sixth lens L6 has positive optical power. The object side S11 of the sixth lens is convex, and the image side of the sixth lens is also convex.

[0062] The seventh lens L7 has negative optical power. The object side of the seventh lens is concave, and the image side S13 of the seventh lens is convex. The sixth lens L6 and the seventh lens L7 form a cemented lens. The image side of the sixth lens and the object side of the seventh lens form the cemented surface S12.

[0063] The eighth lens L8 has positive optical power. The object side S14 of the eighth lens is convex, and the image side S15 of the eighth lens is convex.

[0064] The ninth lens L9 has negative optical power. The object side S16 of the ninth lens is convex near the optical axis, and the image side S17 of the ninth lens is concave near the optical axis.

[0065] The object side of filter G1 is S18, and the image side is S19.

[0066] Lens L1, L3, L4, L6, and L7 are all spherical glass lenses, while lens L2, L5, L8, and L9 are all aspherical glass lenses.

[0067] The relevant parameters of each lens element in the wide-angle lens 100 provided in this embodiment are shown in Table 1.

[0068] Table 1

[0069]

[0070] The surface coefficients of each aspherical surface of the wide-angle lens 100 in this embodiment are shown in Table 2.

[0071] Table 2

[0072]

[0073]

[0074] Please refer to Figures 2 to 4 The figures shown are the f-θ distortion curve, lateral chromatic aberration curve, and MTF curve of the 100 wide-angle lens, respectively.

[0075] Figure 2 The distortion curves represent the f-θ distortion at different image heights on the imaging plane. The horizontal axis in the figure represents the percentage of distortion, and the vertical axis represents the field of view (unit: degrees). As can be seen from the figure, the f-θ distortion of the lens is less than 12% and is positive distortion, indicating that the distortion of the 100 wide-angle lens is well corrected.

[0076] Figure 3 The chromatic aberration curve represents the chromatic aberration between the longest and shortest wavelengths at different image heights on the imaging plane. The horizontal axis represents the chromatic aberration value of each wavelength relative to the center wavelength (unit: micrometers), and the vertical axis represents the normalized field of view. As can be seen from the figure, the chromatic aberration of each wavelength relative to the center wavelength within different fields of view is controlled within ±2 micrometers, indicating that the chromatic aberration of the 100mm wide-angle lens is well corrected.

[0077] Figure 4 The MTF curve represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis in the figure represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of the wide-angle lens 100 in this embodiment is above 0.55 within a 0.85 field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating that the wide-angle lens 100 has good imaging quality and good detail resolution in both low and high frequency conditions.

[0078] Second Embodiment

[0079] Please see Figure 5The diagram shows a schematic diagram of the structure of the wide-angle lens 200 provided in the second embodiment of the present invention. The wide-angle lens 200 in this embodiment is generally the same as that in the first embodiment, except that: the image side surface S8 of the fourth lens is concave, the image side surface S13 of the seventh lens is concave, the object side surface S16 of the ninth lens is concave, and the curvature radius, aspherical coefficient, thickness, material selection, etc. of each lens surface are different.

[0080] The relevant parameters of each lens element in the wide-angle lens 200 provided in this embodiment are shown in Table 3.

[0081] Table 3

[0082]

[0083]

[0084] The surface coefficients of each aspherical surface of the wide-angle lens 200 in this embodiment are shown in Table 4.

[0085] Table 4

[0086] Face number k <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> S3 3.15E+00 3.32E-04 -2.64E-04 2.37E-05 -1.03E-06 1.74E-08 S4 -6.23E-01 4.38E-03 -1.27E-04 -1.55E-05 9.35E-06 -6.79E-07 S9 3.15E+00 -8.91E-03 -2.70E-03 5.77E-04 -3.57E-04 -8.05E-08 S10 -6.23E-01 -3.73E-03 -9.41E-04 4.78E-05 -2.06E-05 -8.09E-06 S14 2.45E+00 -8.24E-03 -5.46E-04 -2.41E-05 -3.37E-05 4.49E-06 S15 -4.42E+00 1.02E-02 -3.45E-03 1.37E-04 2.54E-05 -2.92E-06 S16 2.31E+01 9.88E-03 -4.45E-03 4.30E-04 2.56E-05 -3.75E-06 S17 2.75E-01 -9.71E-03 -5.11E-04 7.22E-05 9.71E-06 -1.05E-06

[0087] Please refer to Figures 6 to 8 The figures shown are the f-θ distortion curve, lateral chromatic aberration curve, and MTF curve of the 200mm wide-angle lens, respectively.

[0088] from Figure 6 As can be seen, the f-θ distortion of the lens is within -3%, indicating that the distortion of the 200 wide-angle lens has been well corrected.

[0089] from Figure 7 As can be seen, the chromatic aberration of each wavelength relative to the center wavelength in different fields of view is controlled within ±2 micrometers, indicating that the chromatic aberration of the wide-angle lens 200 is well corrected.

[0090] from Figure 8 As can be seen, in this embodiment, the MTF value of the wide-angle lens 200 is above 0.55 within a field of view of 0.85. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating that the wide-angle lens 200 has good imaging quality and good detail resolution in both low and high frequency conditions.

[0091] Third Embodiment

[0092] Please see Figure 9The figure shows a schematic diagram of the structure of the wide-angle lens 300 provided in the third embodiment of the present invention. The wide-angle lens 300 in this embodiment is roughly the same as that in the first embodiment above. The main differences are: the object side surface S11 of the sixth lens is concave, the object side surface S16 of the ninth lens is concave, and the curvature radius, aspherical coefficient, thickness, material selection, etc. of each lens surface are different.

[0093] The relevant parameters of each lens element in the wide-angle lens 300 provided in this embodiment are shown in Table 5.

[0094] Table 5

[0095]

[0096]

[0097] The surface coefficients of each aspherical surface of the wide-angle lens in this embodiment are shown in Table 6.

[0098] Table 6

[0099] Face number k <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> S3 -1.29E+00 -8.64E-03 3.05E-04 -5.39E-06 4.00E-08 -4.64E-10 S4 -8.65E-01 -1.65E-02 2.67E-04 -8.61E-05 1.20E-05 0.00E+00 S9 -1.19E+02 -1.79E-02 -5.74E-03 1.45E-03 -1.33E-03 1.22E-07 S10 1.91E+00 -1.46E-02 -1.11E-03 -5.91E-04 -3.29E-04 7.77E-05 S14 -1.96E+02 -5.13E-03 -8.84E-04 -6.52E-05 1.19E-05 2.89E-06 S15 -1.57E+01 -8.52E-03 -2.31E-03 1.07E-04 -1.02E-05 2.90E-06 S16 -2.75E+00 -2.36E-02 -2.18E-03 2.91E-04 2.19E-05 -2.74E-06 S17 6.87E-01 -2.41E-02 1.74E-03 -9.87E-05 -3.11E-07 2.71E-07

[0100] Please refer to Figures 10 to 12 The figures shown are the f-θ distortion curve, lateral chromatic aberration curve, and MTF curve of the 300mm wide-angle lens, respectively.

[0101] from Figure 10 As can be seen, the f-θ distortion of the lens is less than 10% and is positive distortion, indicating that the distortion of the 300 wide-angle lens has been well corrected.

[0102] from Figure 11 As can be seen, the chromatic aberration of each wavelength relative to the center wavelength in different fields of view is controlled within ±2 micrometers, indicating that the chromatic aberration of the 300 wide-angle lens is well corrected.

[0103] from Figure 12 As can be seen, in this embodiment, the MTF value of the wide-angle lens 300 is above 0.6 within a field of view of 0.85. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating that the wide-angle lens 300 has good imaging quality and good detail resolution in both low and high frequency conditions.

[0104] Table 9 shows the optical characteristics corresponding to the three embodiments above, mainly including the effective focal length f, total optical length TTL, aperture value F#, field of view FOV, image height IH corresponding to the full field of view, and the values ​​corresponding to each of the above conditions.

[0105] Table 9

[0106]

[0107] In summary, the wide-angle lens provided in the embodiments of the present invention has at least the following advantages:

[0108] (1) The wide-angle lens provided by the present invention has an ultra-wide field of view (up to 200°) and small distortion due to the reasonable setting of the lens surface shape and optical power of each lens. It can better meet the needs of ultra-wide angle, small distortion and high pixel.

[0109] (2) The wide-angle lens provided by the present invention has reasonable lens shape and aperture position setting, which is conducive to expanding the field of view of the lens while realizing the large aperture characteristic of the lens. The realization of the wide-angle characteristic is conducive to the wide-angle lens to obtain more scene information and meet the needs of large-scale shooting. The realization of the large aperture characteristic is conducive to improving the problem of rapid decrease in relative brightness at the edge of the field of view caused by the wide-angle lens, and thus also conducive to obtaining more scene information.

[0110] (3) The wide-angle lens provided by the present invention has an ultra-large field of view through the combination of spherical and aspherical lenses, which can capture a large range of images. It can be better matched with large-size sensor chips, improve the light-sensitive area of ​​the wide-angle lens, and can well meet the diverse usage needs.

[0111] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0112] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A wide-angle lens, composed of nine lenses, characterized in that, The wide-angle lens sequentially includes, along the optical axis from the object side to the imaging surface: A first lens with a negative optical power, whose object side is convex and whose image side is concave; A second lens with a negative optical power, whose object side is convex and whose image side is concave; A third lens with a positive optical power; A fourth lens with a negative optical power; A fifth lens with a positive optical power; A sixth lens with a positive optical power, whose image side is convex; A seventh lens with a negative optical power, whose object side is concave; An eighth lens with a positive optical power; A ninth lens with a negative optical power; Wherein, the wide-angle lens satisfies the conditional formula: 2 < TTL / IH < 3, TTL represents the overall optical length of the wide-angle lens, and IH represents the image height corresponding to the full field angle of the wide-angle lens; The sixth lens and the seventh lens form a cemented lens group, and the wide-angle lens satisfies the conditional formula: -0.1 < φ67 / φ < 0.1, where φ67 represents the combined optical power of the sixth lens and the seventh lens, and φ represents the optical power of the wide-angle lens.

2. The wide-angle lens according to claim 1, characterized in that, The object side and the image side of the third lens are both convex; the object side of the fourth lens is concave; the object side and the image side of the fifth lens are both convex; the object side and the image side of the eighth lens are both convex; the image side of the ninth lens is concave near the optical axis.

3. The wide-angle lens according to claim 1, characterized in that, The wide-angle lens satisfies the conditional formulas: -0.35 < φ1 / φ < -0.2, -0.5 < φ2 / φ < -0.2, where φ1 represents the optical power of the first lens, φ2 represents the optical power of the second lens, and φ represents the optical power of the wide-angle lens.

4. The wide-angle lens according to claim 1, characterized in that, The wide-angle lens satisfies the conditional formula: 0.2 < φ3 / φ < 0.5, where φ3 represents the optical power of the third lens, and φ represents the optical power of the wide-angle lens.

5. The wide-angle lens according to claim 1, characterized in that, The wide-angle lens satisfies the conditional formula: -0.25 < φ4 / φ < 0, where φ4 represents the optical power of the fourth lens, and φ represents the optical power of the wide-angle lens.

6. The wide-angle lens according to claim 1, characterized in that, The wide-angle lens satisfies the conditional formula: 0.2 < φ5 / φ < 0.5, where φ5 represents the optical power of the fifth lens, and φ represents the optical power of the wide-angle lens.

7. The wide-angle lens according to claim 1, characterized in that, The sixth lens and the seventh lens form a cemented lens group, and the wide-angle lens satisfies the conditional formula: -0.089 ≤ φ67 / φ ≤ 0.011, where φ67 represents the combined optical power of the sixth lens and the seventh lens, and φ represents the optical power of the wide-angle lens.

8. The wide-angle lens according to claim 1, characterized in that, The wide-angle lens satisfies the conditional formula: 0.15 < φ8 / φ < 0.8, where φ8 represents the optical power of the eighth lens, and φ represents the optical power of the wide-angle lens.

9. The wide-angle lens according to claim 1, characterized in that, The wide-angle lens satisfies the conditional formula: -1 < φ9 / φ < -0.2, where φ9 represents the optical power of the ninth lens, and φ represents the optical power of the wide-angle lens.

10. The wide-angle lens according to claim 1, characterized in that, The wide-angle lens satisfies the conditional formula: 50° < (FOV × f) / IH < 65°, where FOV represents the maximum field angle of the wide-angle lens, and f represents the effective focal length of the wide-angle lens; The wide-angle lens satisfies the conditional formula: 2.555 ≤ TTL / IH ≤ 2.570, where TTL represents the total optical length of the wide-angle lens, and IH represents the image height corresponding to the full field angle of the wide-angle lens; The wide-angle lens satisfies the conditional formula: 3 < IH / f < 4, where f represents the effective focal length of the wide-angle lens, and IH represents the image height corresponding to the full field angle of the wide-angle lens.

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