An optical lens

Abstract

The utility model discloses an optical lens, including first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens and ninth lens that are arranged in order from object plane to image plane along the optical axis, first lens, fourth lens, fifth lens, sixth lens and seventh lens are all glass spherical surface lens, and second lens, third lens, eighth lens and ninth lens are all plastic aspherical surface lens. The optical lens provided by the utility model embodiment sets up nine lenses, adopts the structure of glass spherical surface lens and plastic aspherical surface lens mixture, and through the reasonable distribution of the focal length, surface shape and material of each lens, the lens can be used with 1 / 2.7" chip, the relative aperture can reach above F1.1, the field of view angle is greater than 120 DEG, and the total length is less than 23mm. While guaranteeing that the optical lens has wide angle and short total length characteristics, the light amount is improved, and the night imaging quality is improved.

Description

Technical Field

[0001] This utility model relates to the field of optical technology, and in particular to an optical lens. Background Technology

[0002] As the industry develops, users have increasingly higher requirements for the image quality of security monitoring images. Although day and night confocal lenses can provide visualization capabilities at night, the image quality of nighttime monitoring images deteriorates significantly compared to daytime, making it difficult to meet users' needs for nighttime monitoring image quality. Utility Model Content

[0003] This invention provides an optical lens that, while ensuring the optical lens has the characteristics of wide angle and short overall length, increases the amount of light entering the lens and improves the imaging quality at night.

[0004] This utility model provides an optical lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially along the optical axis from the object plane to the image plane;

[0005] The first lens has negative optical power; the second lens has negative optical power; the third lens has positive optical power; the fourth lens has positive optical power; the fifth lens has positive optical power; the sixth lens has negative optical power; the seventh lens has positive optical power; the eighth lens has positive optical power; and the ninth lens has negative optical power.

[0006] The first lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all glass spherical lenses; the second lens, the third lens, the eighth lens, and the ninth lens are all plastic aspherical lenses.

[0007] Optionally, the combined focal length of the first lens, the second lens, and the third lens is [missing information]. The combined focal length of the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens is [missing information]. ;

[0008] .

[0009] Optionally, the Abbe number of the first lens is , .

[0010] Optionally, the radius of curvature of the object-side surface of the second lens is The radius of curvature of the image-side surface of the second lens is ;

[0011] The radius of curvature of the object-side surface of the third lens is The radius of curvature of the image-side surface of the third lens is ;

[0012] , .

[0013] Optionally, the refractive index of the second lens is... The refractive index of the third lens is ;

[0014] , .

[0015] Optionally, the Abbe number of the fourth lens is The Abbe number of the fifth lens is ;

[0016] , .

[0017] Optionally, the combined focal length of the fourth lens and the fifth lens is... The focal length of the optical lens is ;

[0018] .

[0019] Optionally, the Abbe number of the sixth lens is The Abbe number of the seventh lens is ;

[0020] , .

[0021] Optionally, the focal length of the eighth lens is The focal length of the ninth lens is ;

[0022] , .

[0023] Optionally, the optical lens may also include an aperture stop;

[0024] The aperture is located in the optical path between the third lens and the fourth lens.

[0025] The optical lens provided in this embodiment of the invention features nine lenses, employing a hybrid structure of glass spherical lenses and plastic aspherical lenses. By rationally allocating the optical power, surface shape, and materials of each lens, the lens achieves excellent imaging performance and can be used with a 1 / 2.7” chip, resulting in a relative aperture of F1.1 or higher. This increased relative aperture enhances the lens's ability to capture light at night, improving nighttime image quality and enabling full-color imaging at night. Simultaneously, the lens has a field of view greater than 120° and a total length of less than 23mm, retaining the wide-angle characteristics of a lens while compressing its overall length, thus achieving a large-aperture lens usable both day and night with minimal difference in image quality.

[0026] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the structure of an optical lens provided in an embodiment of this utility model;

[0029] Figure 2 This is a schematic diagram of another optical lens provided in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of another optical lens provided in an embodiment of the present utility model;

[0031] Figure 4 A spherical aberration curve of an optical lens provided in Embodiment 1 of this utility model;

[0032] Figure 5 The transverse chromatic aberration diagram of the optical lens provided in Embodiment 1 of this utility model;

[0033] Figure 6 A spherical aberration curve of the optical lens provided in Embodiment 2 of this utility model;

[0034] Figure 7 The transverse chromatic aberration diagram of the optical lens provided in Embodiment 2 of this utility model;

[0035] Figure 8A spherical aberration curve of the optical lens provided in Embodiment 3 of this utility model;

[0036] Figure 9 The transverse chromatic aberration diagram of the optical lens provided in Embodiment 3 of this utility model. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] Figure 1 This is a schematic diagram of the structure of an optical lens provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of another optical lens provided in an embodiment of the present invention. Figure 3 A schematic diagram of the structure of another optical lens provided in this embodiment of the present invention is shown below. Figures 1-3 As shown, the optical lens provided in this embodiment of the present invention includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9 arranged sequentially along the optical axis from the object plane to the image plane.

[0040] The first lens L1 has negative optical power.

[0041] The second lens L2 has negative optical power.

[0042] The third lens L3 has positive optical power.

[0043] The fourth lens L4 has positive optical power.

[0044] The fifth lens L5 has positive optical power.

[0045] The sixth lens, L6, has negative optical power.

[0046] The seventh lens L7 has positive optical power.

[0047] The eighth lens L8 has positive optical power.

[0048] The ninth lens, L9, has negative optical power.

[0049] Lens L1, L4, L5, L6, and L7 are all glass spherical lenses, while lens L2, L3, L8, and L9 are all plastic aspherical lenses.

[0050] Specifically, optical power is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam; it characterizes the ability of an optical system to deflect light. The larger the absolute value of the optical power, the stronger its ability to bend light; the smaller the absolute value, the weaker its ability to bend light. When the optical power is positive, the refraction of light is converging; when the optical power is negative, the refraction of light is diverging. Optical power can be used to characterize a single refractive surface of a lens (i.e., one surface of the lens), a single lens, or a system formed by multiple lenses (i.e., a lens group).

[0051] In the lens provided in this embodiment, each lens can be fixed to a lens barrel. Figure 1 (Not shown in the text) but not limited to this.

[0052] The first lens L1, the second lens L2, and the third lens L3 can form a front lens group.

[0053] The first lens L1 has negative optical power, which diverges light at the front of the optical lens, allowing more light to enter the subsequent lenses at a larger angle, thus expanding the field of view of the optical lens.

[0054] The second lens has negative optical power and works in synergy with the first lens L1 to further enhance the negative optical power of the front lens group. This helps to avoid excessive light refraction caused by excessive concentration of optical power in the first lens L1 and reduces the difficulty of optical lens aberration correction.

[0055] The third lens L3 has positive optical power, which can be used to balance the optical power distribution, facilitate smooth light transition, and make it easier to correct aberrations.

[0056] The fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 can form the rear lens group.

[0057] The fourth lens L4 has positive optical power and can be used to converge light, allowing for a smooth transition of light.

[0058] The fifth lens L5 has positive optical power and can be used in conjunction with the fourth lens L4 to form the main converging lens of the lens, which bears most of the positive optical power and is conducive to achieving a large aperture (large relative diameter) effect.

[0059] The sixth lens L6 has negative optical power, and the seventh lens L7 has positive optical power. The sixth lens L6 and the seventh lens L7 form a "negative-positive" optical power combination. The low Abbe number of the sixth lens L6 (negative lens) can be combined with the high Abbe number of the seventh lens L7 (positive lens) to effectively correct axial chromatic aberration.

[0060] The eighth lens, L8, has positive optical power and is responsible for the final convergence of light rays.

[0061] The ninth lens, L9, has negative optical power, which, together with the positive optical power of the eighth lens, L8, forms a "positive-negative" optical power combination. This combination effectively corrects field curvature and astigmatism, resulting in a flatter image plane and improved imaging quality at the edges of the field of view. Furthermore, compared to using a thick positive lens, this design is more advantageous in reducing the back focal length and overall length of the lens.

[0062] It should be noted that the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 adopt the above-mentioned optical power combination, which can reasonably allocate the optical power of each lens so that light can propagate smoothly in the optical lens and avoid excessive bending of light on a certain lens surface, which is beneficial to improving image quality.

[0063] Furthermore, the first lens L1, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are made of glass spherical lenses. Their wide refractive index and Abbe number range effectively optimize spherical and chromatic aberration, reducing their impact on the imaging of large-aperture lenses. Simultaneously, the good transparency of glass lenses improves overall lens transmittance, resulting in brighter and clearer images. Additionally, the spherical surface shape is relatively inexpensive due to its mature manufacturing process.

[0064] Specifically, the first lens L1 is located at the very front of the lens and is directly exposed to the external environment. The use of glass can effectively resist scratches, dust, oil, etc., ensuring long-term reliability.

[0065] Lenses L4, L5, L6, and L7 are located in the central region of the optical path, where aberration correction is critical. Lenses L4 and L5 handle the primary positive optical power (converging rays), and their use of high-refractive-index materials (glass) allows for control over lens curvature and size. Lenses L6 and L7 correct axial chromatic aberration. The combination of a high Abbe number positive lens (L7) and a low Abbe number negative lens (L6) is beneficial for aberration correction. The glass material provides a stable and widely selectable Abbe number, ensuring effective chromatic aberration correction.

[0066] The second lens L2, the third lens L3, the eighth lens L8, and the ninth lens L9 are made of plastic aspherical lenses, which can effectively optimize lens aberrations. In particular, in this optical lens, it can effectively optimize the off-axis aberrations of large aperture lenses and reduce the number of lenses used, thereby reducing lens costs.

[0067] Specifically, the second lens L2 and the third lens L3 are located in the front lens group, close to the aperture stop. The correction requirements for off-axis aberrations (such as coma and astigmatism) are relatively high here. Using plastic aspherical surfaces can efficiently correct these aberrations and improve the edge image quality under a large field of view. The second lens L2 and the third lens L3 are located in the front section of the optical path, which also reduces the impact caused by the slightly poor environmental stability of plastic materials.

[0068] The eighth lens, L8, and the ninth lens, L9, are located in the rear lens group, close to the image plane. Fine correction of field curvature and astigmatism is required here to ensure a flat image plane. Aspherical surfaces play a crucial role in this area. Furthermore, the diameter of the rear lens group is typically smaller, making the cost and manufacturing advantages of using plastic aspherical surfaces more apparent.

[0069] It should be noted that this lens adopts a glass-plastic hybrid design strategy, that is, combining the use of two materials, glass and plastic, and combining spherical and aspherical surface shapes to achieve the above effect. This choice is not arbitrary, but is based on the physical properties of different materials and surface shapes, and is the optimal configuration for the function and position of each lens in the lens.

[0070] The glass lens is made of various types of glass known to those skilled in the art, and the plastic lens is made of various types of plastic known to those skilled in the art. This embodiment of the present invention will not elaborate on or limit the use of such materials.

[0071] In summary, the optical lens provided by this utility model embodiment features nine lenses and employs a hybrid structure of glass spherical lenses and plastic aspherical lenses. By rationally allocating the optical power, surface shape, and materials of each lens, the lens achieves excellent imaging performance and can be used with a 1 / 2.7” chip, resulting in a relative aperture of F1.1 or higher. This increased relative aperture enhances the lens's ability to capture light at night, improves nighttime image quality, and enables full-color imaging at night. Furthermore, the lens has a field of view greater than 120° and a total length of less than 23mm, retaining its wide-angle characteristics while compressing its overall length, thus achieving a large-aperture lens usable both day and night with minimal difference in image quality.

[0072] As one feasible implementation, the combined focal length of the first lens L1, the second lens L2, and the third lens L3 is: The combined focal length of the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 is [missing information]. , .

[0073] In this context, the first lens L1, the second lens L2, and the third lens L3 are considered as a single optical unit (front lens group), and their equivalent focal length is calculated as the combined focal length. .

[0074] Treating lenses L4 through L9 as a single optical unit (rear lens group), calculate its equivalent focal length as the combined focal length. .

[0075] In this embodiment, the ratio of the combined focal lengths is constrained. This allows for optimization of the distance between the lens groups before and after the aperture stop, and also provides excellent control over the lens's back focal length. Furthermore, by constraining the ratio of the combined focal lengths in this section, it helps reduce the overall optical length of the lens, ultimately enabling this large-aperture lens to have an overall optical length of less than 23mm.

[0076] Furthermore, the front lens group consisting of the first lens L1, the second lens L2, and the third lens L3 has a negative focal length, while the rear lens group consisting of the fourth lens L4 to the ninth lens L9 has a positive focal length. The negative-to-positive focal length ratio constitutes an anti-telephoto system, which is beneficial for the lens to achieve the characteristics of a large angle and a large aperture, enabling the lens to have a field of view of over 120° and an aperture of over F1.1.

[0077] As one feasible implementation, the Abbe number of the first lens L1 is , .

[0078] Abbe number is an index used to represent the dispersion ability of a transparent medium. The more severe the dispersion of the medium, the smaller the Abbe number; conversely, the less severe the dispersion of the medium, the larger the Abbe number.

[0079] In this embodiment, the Abbe number of the first lens L1 is set. Within the aforementioned range, chromatic aberration of the lens can be reduced. Simultaneously, by controlling the Abbe number of the first lens L1, transverse chromatic aberration of the lens at different field-of-view angles can be significantly reduced, which is beneficial for achieving the lens's wide-angle characteristics and improving the image quality of this large-aperture lens.

[0080] As one feasible implementation, the radius of curvature of the object-side surface of the second lens L2 is The radius of curvature of the image-side surface of the second lens L2 is The radius of curvature of the object-side surface of the third lens L3 is The radius of curvature of the image-side surface of the third lens L3 is ; , .

[0081] Wherein, the second lens L2 satisfies ,at this time, Less than 1, or in other words, That is, the radius of curvature of the object side of the second lens L2 is smaller than the radius of curvature of the image side. Combined with the characteristic that the second lens L2 has negative optical power, it is a meniscus negative lens with a concave object side and a relatively flat convex image side. This shape is beneficial to controlling the angle of light incident on subsequent lenses and optimizing the optical path.

[0082] The third lens L3 satisfies The wider range of this ratio, which is close to 1, means that the curvature of the object side and the image side of the third lens L3 are closer, which provides greater design freedom for the shape of the third lens L3.

[0083] By setting the ratio of the curvature radii of the second lens L2 and the third lens L3, the off-axis aberration of the system can be effectively optimized, thereby improving the image quality of the large aperture lens.

[0084] As a feasible implementation, the refractive index of the second lens L2 is... The refractive index of the third lens L3 is ; , .

[0085] The refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium. It is mainly used to describe a material's ability to refract light, and different materials have different refractive indices. The higher the refractive index, the stronger the material's ability to bend light.

[0086] In this embodiment, by setting the refractive indices of the second lens L2 and the third lens L3 within the above-mentioned range, the spherical aberration of the lens can be reduced.

[0087] Furthermore, by matching the curvature radii of the second lens L2 and the third lens L3, the monochromatic aberration of the lens is better corrected, which is beneficial to improving the image quality of the large aperture lens.

[0088] As a feasible implementation, the Abbe number of the fourth lens L4 is The Abbe number of the fifth lens L5 is ; , .

[0089] A lens with a certain Abbe number can reduce chromatic aberration. In this embodiment, by controlling the Abbe numbers of the fourth lens L4 and the fifth lens L5, the axial chromatic aberration of the lens can be effectively optimized, enabling the lens to achieve the technical effect of eliminating chromatic aberration at certain apertures.

[0090] As a feasible implementation, the combined focal length of the fourth lens L4 and the fifth lens L5 is... The focal length of the optical lens is ; .

[0091] In this embodiment, by controlling the combined focal length of the fourth lens L4 and the fifth lens L5, the relative aperture of the lens can be greatly improved. By controlling the ratio of the combined focal length of the fourth lens L4 and the fifth lens L5 to the total focal length of the lens, the lens can achieve the characteristics of a large aperture (small F number, such as a large aperture of F1.1 or higher), thereby increasing the amount of light entering the lens.

[0092] As a feasible implementation method, the Abbe number of the sixth lens L6 is The Abbe number of the seventh lens L7 is ; , .

[0093] By controlling the Abbe number of the sixth lens L6 and the seventh lens L7, the axial and transverse chromatic aberration of the lens can be effectively corrected, further improving the chromatic aberration in both the on-axis and off-axis fields of view. This ultimately enhances the image quality across the entire field of view, enabling the lens to achieve a wide angle and large aperture. The field of view of this lens can reach over 120°, and the aperture can reach over F1.1.

[0094] As a feasible implementation, the radius of curvature of the image side of the sixth lens L6 is equal to the radius of curvature of the object side of the seventh lens L7.

[0095] Among them, the image side of the sixth lens L6 and the object side of the seventh lens L7 have the same degree of curvature, which is conducive to achieving a smoother optical transition, and can more effectively balance and counteract the aberrations caused by the large aperture, thereby improving the image quality.

[0096] As a possible implementation method, such as Figure 1 As shown, the sixth lens L6 and the seventh lens L7 form a cemented lens group G1.

[0097] Among them, such as Figure 1 As shown, the sixth lens L6 and the seventh lens L7 can be glued together to form a cemented lens group G1.

[0098] In this embodiment, cementing the sixth lens L6 and the seventh lens L7 effectively reduces chromatic aberration. Simultaneously, it effectively reduces the air gap between the sixth lens L6 and the seventh lens L7, thereby helping to reduce the overall length of the lens. Furthermore, it reduces light loss caused by inter-lens reflections, improving illumination and thus enhancing image quality and the sharpness of the lens image.

[0099] As a possible implementation method, such as Figure 2 and Figure 3 As shown, the distance between the sixth lens L6 and the seventh lens L7 on the optical axis is greater than 0.

[0100] The sixth lens L6 and the seventh lens L7 can be supported by a spacer. In this case, the sixth lens L6 and the seventh lens L7 are separate independent lenses. The independent lens structure allows for more flexible allocation of optical power and adjustment of surface shape and air gap in the design, thereby achieving a better balance between controlling aberrations and compressing the total optical length. This helps to reduce the tolerance sensitivity of the lens during mass production assembly, thus significantly improving production yield and performance consistency.

[0101] As one feasible implementation method, the focal length of the eighth lens L8 is The focal length of the ninth lens L9 is ; , .

[0102] By combining the positive and negative optical powers of the eighth lens L8 and the ninth lens L9, the field curvature and astigmatism of the lens can be effectively optimized, improving the imaging quality of the entire field of view and thus increasing the field of view of the lens. At the same time, compared with the method of using thick lenses to eliminate field curvature, the method of combining positive and negative focal lengths to eliminate field curvature can reduce the total thickness of the lens, thereby reducing the total optical length and making the total length of the lens less than 23mm.

[0103] As a possible implementation, the optical lens also includes an aperture stop (not shown in the figure), which is located in the optical path between the third lens L3 and the fourth lens L4.

[0104] The aperture stop between the third lens L3 and the fourth lens L4 is used to limit the light beam. This reduces the astigmatism of the optical lens, helps to gather the light entering the optical system, and reduces the rear aperture of the optical lens, thereby improving the image quality.

[0105] As a possible implementation method, such as Figures 1-3 As shown, the optical lens provided in this embodiment of the present invention also includes a flat plate filter CG. The flat plate filter CG is located on the image side of the ninth lens L9, which can protect the imaging chip, prevent dust and contamination, and thus ensure the imaging effect of the lens.

[0106] In some cases, the flat panel filter CG can also be used to correct specific aberrations or filter out unwanted light, and this embodiment of the present invention does not specifically limit this.

[0107] Specific embodiments of the optical lens applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

[0108] Example 1

[0109] Continue to refer to Figure 1 The optical lens provided in Embodiment 1 of this utility model includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9 arranged sequentially along the optical axis from the object plane to the image plane.

[0110] The sixth lens L6 and the seventh lens L7 form a cemented lens group G1, and the flat plate filter CG is located on the image side of the ninth lens L9.

[0111] Table 1 details the surface type, radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical lens provided in Embodiment 1, according to a feasible implementation method. The optical lenses in Table 1 correspond to... Figure 1 The optical lens shown.

[0112] Table 1 Design values ​​of optical physical parameters of optical lenses

[0113]

[0114] The surface number is determined by the order of the lenses. For example, surface number "S1" represents the object side of the first lens, surface number "S2" represents the image side of the first lens, and so on. "STO" represents the aperture stop of the lens. The radius of curvature (in mm) represents the curvature of the lens surface. A positive value means that the surface bends towards the object side with the center closer to the image plane, and a negative value means that the surface bends towards the image side with the center closer to the object plane. "infinity" means that the surface is flat and the radius of curvature is infinite. The thickness (in mm) represents the axial distance between the center of the current surface and the next surface. Since the different number of digits of each parameter value can cause focusing errors, the thickness of surface 19 (S19) is not given a specific value. The value can be adjusted as needed to achieve a clear focus. nd represents the refractive index, which is the ability of the material between the current surface and the next surface to deflect light. A space indicates that the current position is air and the refractive index is 1. vd represents the Abbe number, which is the dispersion characteristic of the material between the current surface and the next surface. A space indicates that the current position is air. The semi-diameter (in mm) represents the effective diameter of the lens; the k value represents the magnitude of the conic coefficient of the aspherical surface.

[0115] In this embodiment, the aspherical conic coefficient of the aspherical lens in the optical lens can be defined using the following aspherical formula, but is not limited to the following representation:

[0116] ;

[0117] in, For the sag of an aspherical surface, Let be the fundamental curvature at the vertex. For conic section constants, The radial coordinate is perpendicular to the optical axis. For higher-order terms, For aspherical surfaces, the term is of higher order.

[0118] For example, Table 2 details the aspherical coefficients of each lens in this embodiment one of feasible implementations.

[0119] Table 2 Design values ​​of aspherical coefficients for various lenses in optical lenses

[0120]

[0121] The optical lens provided in this embodiment meets the following parameters:

[0122] Focal length: 4.380mm.

[0123] Aperture: F1.1.

[0124] Overall optical length: 22.440mm.

[0125] Figure 4 This is a spherical aberration curve of the optical lens provided in Embodiment 1 of this utility model. In the figure, the vertical direction represents the normalized 0-field pupil plane, where 0 represents the pupil center, and the vertical vertex represents the pupil vertex. The horizontal direction represents the spherical aberration at different wavelengths, in millimeters (mm). The pupil radius in the figure is 1.9911 mm. As can be seen from the figure, the axial aberrations at different wavelengths are all controlled within the range of (-0.05 mm, +0.05 mm), indicating that the optical lens achieves good control of spherical aberration at various wavelengths, which can meet application requirements.

[0126] Figure 5 This is a transverse chromatic aberration diagram of the optical lens provided in Embodiment 1 of this utility model. The vertical direction represents the field of view angle, with 0 representing the field of view angle incident parallel to the optical axis, and the vertical vertex representing the maximum half-field of view angle. The horizontal direction represents the offset within a meridional range based on 0.555 μm, in micrometers (μm). The maximum field of view in the diagram is 66.6000 Deg millimeters. The numbers corresponding to the curves in the diagram represent the wavelengths represented by those curves, in micrometers (μm). As can be seen from the diagram, the transverse chromatic aberration at different wavelengths is controlled within a good range, indicating that the transverse chromatic aberration of this optical lens is well controlled and can meet application requirements.

[0127] Example 2

[0128] Continue to refer to Figure 2 The optical lens provided in Embodiment 2 of this utility model includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9 arranged sequentially along the optical axis from the object plane to the image plane.

[0129] The distance between the sixth lens L6 and the seventh lens L7 on the optical axis is greater than 0, and the flat plate filter CG is located on the image side of the ninth lens L9.

[0130] Table 3 details the surface type, radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical lens provided in Embodiment 2, using a feasible implementation method. The optical lenses in Table 3 correspond to... Figure 2 The optical lens shown.

[0131] Table 3 Design values ​​of optical physical parameters of optical lenses

[0132]

[0133] The surface number is determined by the order of the lenses. For example, surface number "S1" represents the object side of the first lens, surface number "S2" represents the image side of the first lens, and so on. "STO" represents the aperture stop of the lens. The radius of curvature (in mm) represents the curvature of the lens surface. A positive value means that the surface bends towards the object side with the center closer to the image plane, and a negative value means that the surface bends towards the image side with the center closer to the object plane. "infinity" means that the surface is flat and the radius of curvature is infinite. The thickness (in mm) represents the axial distance between the center of the current surface and the next surface. Since the different number of digits of each parameter value can cause focusing errors, the thickness of surface 19 (S19) is not given a specific value. The value can be adjusted as needed to achieve a clear focus. nd represents the refractive index, which is the ability of the material between the current surface and the next surface to deflect light. A space indicates that the current position is air and the refractive index is 1. vd represents the Abbe number, which is the dispersion characteristic of the material between the current surface and the next surface. A space indicates that the current position is air. The semi-diameter (in mm) represents the effective diameter of the lens; the k value represents the magnitude of the conic coefficient of the aspherical surface.

[0134] In this embodiment, the aspherical conic coefficient of the aspherical lens in the optical lens can be defined using the following aspherical formula, but is not limited to the following representation:

[0135] ;

[0136] in, For the sag of an aspherical surface, Let be the fundamental curvature at the vertex. For conic section constants, The radial coordinate is perpendicular to the optical axis. For higher-order terms, For aspherical surfaces, the term is of higher order.

[0137] For example, Table 4 details the aspherical coefficients of each lens in this embodiment two according to a feasible implementation.

[0138] Table 4 Design values ​​of aspherical coefficients for various lenses in optical lenses

[0139]

[0140] The optical lens provided in this embodiment meets the following parameters:

[0141] Focal length: 4.374mm.

[0142] Aperture: F1.1.

[0143] Overall optical length: 22.425mm.

[0144] Figure 6 This is a spherical aberration curve of the optical lens provided in Embodiment 2 of this utility model. In the figure, the vertical direction represents the normalized 0-field pupil plane, where 0 represents the pupil center, and the vertical vertex represents the pupil vertex. The horizontal direction represents the spherical aberration at different wavelengths, in millimeters (mm). The pupil radius in the figure is 1.9882 mm. As can be seen from the figure, the axial aberrations at different wavelengths are all controlled within the range of (-0.05 mm, +0.05 mm), indicating that the optical lens achieves good control of spherical aberration at various wavelengths.

[0145] Figure 7 This is a transverse chromatic aberration diagram of the optical lens provided in Embodiment 2 of this utility model. The vertical direction represents the field of view angle, with 0 representing the field of view angle incident parallel to the optical axis, and the vertical vertex representing the maximum half-field of view angle. The horizontal direction represents the offset within a meridian range based on 0.555 μm, in micrometers (μm). The maximum field of view in the diagram is 66.6000 Deg millimeters. The numbers corresponding to the curves in the diagram represent the wavelengths represented by those curves, in micrometers (μm). As can be seen from the diagram, the transverse chromatic aberration of different wavelengths is controlled within a good range, indicating that the transverse chromatic aberration of this optical lens is well controlled and can meet application requirements.

[0146] Example 3

[0147] Continue to refer to Figure 3 The optical lens provided in Embodiment 3 of this utility model includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9 arranged sequentially along the optical axis from the object plane to the image plane.

[0148] The distance between the sixth lens L6 and the seventh lens L7 on the optical axis is greater than 0, and the flat plate filter CG is located on the image side of the ninth lens L9.

[0149] Table 5 details the surface type, radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical lens provided in Embodiment 3, according to a feasible implementation method. The optical lenses in Table 5 correspond to... Figure 3 The optical lens shown.

[0150] Table 5 Design values ​​of optical physical parameters of optical lenses

[0151]

[0152] The surface number is determined by the order of the lenses. For example, surface number "S1" represents the object side of the first lens, surface number "S2" represents the image side of the first lens, and so on. "STO" represents the aperture stop of the lens. The radius of curvature (in mm) represents the curvature of the lens surface. A positive value means that the surface bends towards the object side with the center closer to the image plane, and a negative value means that the surface bends towards the image side with the center closer to the object plane. "infinity" means that the surface is flat and the radius of curvature is infinite. The thickness (in mm) represents the axial distance between the center of the current surface and the next surface. Since the different number of digits of each parameter value can cause focusing errors, the thickness of surface 19 (S19) is not given a specific value. The value can be adjusted as needed to achieve a clear focus. nd represents the refractive index, which is the ability of the material between the current surface and the next surface to deflect light. A space indicates that the current position is air and the refractive index is 1. vd represents the Abbe number, which is the dispersion characteristic of the material between the current surface and the next surface. A space indicates that the current position is air. The semi-diameter (in mm) represents the effective diameter of the lens; the k value represents the magnitude of the conic coefficient of the aspherical surface.

[0153] In this embodiment, the aspherical conic coefficient of the aspherical lens in the optical lens can be defined using the following aspherical formula, but is not limited to the following representation:

[0154] ;

[0155] in, For the sag of an aspherical surface, Let be the fundamental curvature at the vertex. For conic section constants, The radial coordinate is perpendicular to the optical axis. For higher-order terms, For aspherical surfaces, the term is of higher order.

[0156] For example, Table 6 details the aspherical coefficients of each lens in this embodiment three according to a feasible implementation.

[0157] Table 6 Design values ​​of aspherical coefficients for various lenses in optical lenses

[0158]

[0159] The optical lens provided in this embodiment meets the following parameters:

[0160] Focal length: 4.380mm.

[0161] Aperture: F1.1.

[0162] Overall optical length: 22.439 mm.

[0163] Figure 8 This is a spherical aberration curve of the optical lens provided in Embodiment 3 of this utility model. In the figure, the vertical direction represents the normalized 0-field pupil plane, where 0 represents the pupil center, and the vertical vertex represents the pupil vertex. The horizontal direction represents the spherical aberration at different wavelengths, in millimeters (mm). The pupil radius in the figure is 1.9909 mm. As can be seen from the figure, the axial aberrations at different wavelengths are all controlled within the range of (-0.05 mm, +0.05 mm), indicating that the optical lens achieves good control of spherical aberration at various wavelengths.

[0164] Figure 9 This is a transverse chromatic aberration diagram of the optical lens provided in Embodiment 3 of this utility model. The vertical direction represents the field of view angle, with 0 representing the field of view angle incident parallel to the optical axis, and the vertical vertex representing the maximum half-field of view angle. The horizontal direction represents the offset within a meridional range based on 0.555 μm, in micrometers (μm). The maximum field of view in the diagram is 66.6000 Deg millimeters. The numbers corresponding to the curves in the diagram represent the wavelengths represented by those curves, in micrometers (μm). As can be seen from the diagram, the transverse chromatic aberration at different wavelengths is controlled within a good range, indicating that the transverse chromatic aberration of this optical lens is well controlled and can meet application requirements.

[0165] To provide a clearer explanation of the above embodiments, Table 7 details the specific optical physical parameters of each lens in the optical lenses provided in embodiments one to three of this utility model.

[0166] Table 7 Design values ​​of optical physical parameters of optical lenses

[0167]

[0168] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. An optical lens, characterized in that, It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially along the optical axis from the object plane to the image plane; The first lens has negative optical power; The second lens has negative optical power; The third lens has positive optical power; The fourth lens has positive optical power; The fifth lens has positive optical power; The sixth lens has negative optical power; The seventh lens has positive optical power; The eighth lens has positive optical power; The ninth lens has negative optical power; The first lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all glass spherical lenses; The second lens, the third lens, the eighth lens, and the ninth lens are all plastic aspherical lenses.

2. The optical lens according to claim 1, characterized in that, The combined focal length of the first lens, the second lens, and the third lens is The combined focal length of the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens is [missing information]. ; .

3. The optical lens according to claim 1, characterized in that, The Abbe number of the first lens is , .

4. The optical lens according to claim 1, characterized in that, The radius of curvature of the object-side surface of the second lens is The radius of curvature of the image-side surface of the second lens is ; The radius of curvature of the object-side surface of the third lens is The radius of curvature of the image-side surface of the third lens is ; , .

5. The optical lens according to claim 1, characterized in that, The refractive index of the second lens is The refractive index of the third lens is ; , .

6. The optical lens according to claim 1, characterized in that, The Abbe number of the fourth lens is The Abbe number of the fifth lens is ; , .

7. The optical lens according to claim 1, characterized in that, The combined focal length of the fourth lens and the fifth lens is The focal length of the optical lens is ; .

8. The optical lens according to claim 1, characterized in that, The Abbe number of the sixth lens is The Abbe number of the seventh lens is ; , .

9. The optical lens according to claim 1, characterized in that, The focal length of the eighth lens is The focal length of the ninth lens is ; , .

10. The optical lens according to claim 1, characterized in that, The optical lens also includes an aperture stop; The aperture is located in the optical path between the third lens and the fourth lens.

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