Wide-angle prime lens

Abstract

The invention provides a wide-angle prime lens, and relates to the technical field of optical lenses. The wide-angle prime lens provided by the embodiment of the invention comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens which are sequentially arranged from an object space to an image space along an optical axis, the first lens and the second lens have negative focal power; the third lens and the fourth lens have positive focal power; the wide-angle prime lens further comprises a diaphragm, and the diaphragm is located between the third lens and the fourth lens. The embodiment of the invention provides a wide-angle prime lens, so as to realize the wide-angle prime lens with small aperture and high image quality.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and in particular, to a wide-angle fixed-focus lens. Background Art

[0002] With the continuous development of technology and the increasing demand of people for technology, the application scenarios and imaging requirements of optical lenses are also constantly changing. At present, the demand for wide-angle lenses with a large imaging angle range and high imaging quality in the market is continuously increasing. However, the mainstream ultra-wide-angle lenses generally have problems such as low imaging quality, large chromatic aberration, and large distortion, which are not suitable for new application scenarios and promotion. Summary of the Invention

[0003] An embodiment of the present invention provides a wide-angle fixed-focus lens to achieve a wide-angle fixed-focus lens with a small aperture and high image quality.

[0004] An embodiment of the present invention provides a wide-angle fixed-focus lens, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens arranged in sequence along the optical axis from the object side to the image side;

[0005] The first lens and the second lens have negative optical powers;

[0006] The third lens and the fourth lens have positive optical powers; the wide-angle fixed-focus lens further includes a diaphragm, and the diaphragm is located between the third lens and the fourth lens.

[0007] Optionally, the fifth lens, the seventh lens, the ninth lens, and the tenth lens have positive optical powers;

[0008] The sixth lens and the eighth lens have negative optical powers.

[0009] Optionally, the third lens, the fourth lens, and the ninth lens are glass aspherical lenses.

[0010] Optionally, the object side surface of the third lens is recessed toward the object side, and the image side surface of the third lens is convex toward the image side;

[0011] The object side surface of the fourth lens is recessed toward the object side, and the image side surface of the fourth lens is convex toward the image side;

[0012] The object side surface of the ninth lens is recessed toward the object side, and the image side surface of the ninth lens is convex toward the image side.

[0013] Optionally, the sixth lens is a biconcave lens, and the eighth lens is a biconcave lens;

[0014] The object side of the tenth lens is recessed toward the object side, and the image side of the tenth lens is convex toward the image side.

[0015] Optionally, the overall optical length of the wide-angle fixed-focus lens is TTL, the effective focal length of the wide-angle fixed-focus lens is EFL, and the back focal length of the wide-angle fixed-focus lens is BFL, satisfying:

[0016] 6.347 ≤ TTL / EFL ≤ 7.382;

[0017] 0.046 ≤ BFL / TTL ≤ 0.077.

[0018] Optionally, the radius of curvature of the object side of the first lens is R1, and the radius of curvature of the image side of the first lens is R2, satisfying:

[0019] 1.413 ≤ (R1 + R2) / (R1 - R2) ≤ 1.501.

[0020] Optionally, the refractive index of the ninth lens is Nd9, the Abbe number of the ninth lens is Vd9, the refractive index of the tenth lens is Nd10, and the Abbe number of the tenth lens is Vd10, satisfying:

[0021] 1.32 ≤ Nd9 ≤ 1.50;

[0022] 50.00 ≤ Vd9 ≤ 95.00;

[0023] 1.60 ≤ Nd10 ≤ 1.95;

[0024] 30.00 ≤ Vd10 ≤ 50.00.

[0025] Optionally, the effective focal length of the wide-angle fixed-focus lens is EFL, and the entrance pupil diameter of the wide-angle fixed-focus lens is EPD, satisfying:

[0026] 0.323 ≤ EPD / EFL ≤ 0.380.

[0027] Optionally, the optical power of the first lens is F1, the optical power of the second lens is F2, the optical power of the third lens is F3, the optical power of the fourth lens is F4, the optical power of the fifth lens is F5, the optical power of the sixth lens is F6, the optical power of the seventh lens is F7, the optical power of the eighth lens is F8, the optical power of the ninth lens is F9, the optical power of the tenth lens is F10, and the optical power of the wide-angle fixed-focus lens is F, satisfying:

[0028] -1.779 ≤ F1 / F ≤ -1.228;

[0029] -3.788 ≤ F2 / F ≤ -2.641;

[0030] 2.879 ≤ F3 / F ≤ 3.181;

[0031] 1.722 ≤ F4 / F ≤ 1.947;

[0032] 2.737 ≤ F5 / F ≤ 3.028;

[0033] -1.700 ≤ F6 / F ≤ -1.427;

[0034] 1.222 ≤ F7 / F ≤ 1.331;

[0035] -1.810 ≤ F8 / F ≤ -0.556;

[0036] 1.170 ≤ F9 / F ≤ 8.286;

[0037] 5.003 ≤ F10 / F ≤ 43.405.

[0038] In the wide-angle fixed-focus lens provided by the embodiment of the present invention, the optical powers of the first lens and the second lens are both negative, ensuring a larger aperture before the light enters the diaphragm and reducing the aperture of the wide-angle fixed-focus lens. The diaphragm is placed between the third lens with positive optical power and the fourth lens with positive optical power, so that the high-order aberrations of the wide-angle fixed-focus lens are controlled at the front end of the wide-angle fixed-focus lens, improving the light transmission of the wide-angle fixed-focus lens, ensuring good image quality while increasing the image height and expanding the imaging range at the rear end of the wide-angle fixed-focus lens, and meeting the usage requirements in more situations. Thus, a wide-angle fixed-focus lens with a small aperture and high image quality is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of the wide-angle fixed-focus lens provided by Embodiment 1 of the present invention;

[0040] Figure 2 It is the field curvature diagram of the wide-angle fixed-focus lens provided by Embodiment 1 of the present invention;

[0041] Figure 3 It is the distortion diagram of the wide-angle fixed-focus lens provided by Embodiment 1 of the present invention;

[0042] Figures 4 - 9 It is the light fan diagram of the wide-angle fixed-focus lens provided by Embodiment 1 of the present invention;

[0043] Figure 10 It is the lateral chromatic aberration diagram of the wide-angle fixed-focus lens provided by Embodiment 1 of the present invention;

[0044] Figure 11 It is a schematic structural diagram of the wide-angle fixed-focus lens provided by Embodiment 2 of the present invention;

[0045] Figure 12Field curvature diagram of the wide-angle fixed-focus lens provided in the second embodiment of the present invention;

[0046] Figure 13 Distortion diagram of the wide-angle fixed-focus lens provided in the second embodiment of the present invention;

[0047] Figures 14 - 19 Fan diagram of the wide-angle fixed-focus lens provided in the second embodiment of the present invention;

[0048] Figure 20 Axial chromatic aberration diagram of the wide-angle fixed-focus lens provided in the second embodiment of the present invention;

[0049] Figure 21 Schematic structural diagram of the wide-angle fixed-focus lens provided in the third embodiment of the present invention;

[0050] Figure 22 Field curvature diagram of the wide-angle fixed-focus lens provided in the third embodiment of the present invention;

[0051] Figure 23 Distortion diagram of the wide-angle fixed-focus lens provided in the third embodiment of the present invention;

[0052] Figures 24 - 29 Fan diagram of the wide-angle fixed-focus lens provided in the third embodiment of the present invention;

[0053] Figure 30 Axial chromatic aberration diagram of the wide-angle fixed-focus lens provided in the third embodiment of the present invention. Detailed implementation manners

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention are shown in the accompanying drawings rather than all the structures.

[0055] Embodiment 1

[0056] Figure 1 Schematic structural diagram of the wide-angle fixed-focus lens provided in the first embodiment of the present invention. Refer to Figure 1 , the wide-angle fixed-focus lens 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, a ninth lens L9, and a tenth lens L10 arranged in sequence from the object side to the image side along the optical axis. The first lens L1 and the second lens L2 have negative optical powers; the third lens L3 and the fourth lens L4 have positive optical powers. The wide-angle fixed-focus lens further includes a diaphragm STO, and the diaphragm STO is located between the third lens L3 and the fourth lens L4.

[0057] In the wide-angle fixed-focus lens provided by the embodiment of the present invention, the optical powers of the first lens L1 and the second lens L2 are both negative, ensuring that the light has a larger aperture before entering the aperture STO, and reducing the aperture of the wide-angle fixed-focus lens. The aperture STO is placed between the third lens L3 with positive optical power and the fourth lens L4 with positive optical power, so that the high-order aberrations of the wide-angle fixed-focus lens are controlled at the front end of the wide-angle fixed-focus lens, improving the light transmission of the wide-angle fixed-focus lens, and ensuring good image quality while increasing the image height and expanding the imaging range at the rear end of the wide-angle fixed-focus lens, meeting the usage requirements in more cases. Thus, a wide-angle fixed-focus lens with a small aperture and high image quality is realized.

[0058] The wide-angle fixed-focus lens provided by the embodiment of the present invention realizes clear imaging in the wavelength range of 436nm - 870nm under a 1" target surface, with a small aperture, higher image quality, and an imaging range of 150° - 180°, which is suitable for the usage requirements in more cases.

[0059] Optionally, referring to Figure 1 , the fifth lens L5, the seventh lens L7, the ninth lens L9, and the tenth lens L10 have positive optical powers; the sixth lens L6 and the eighth lens L8 have negative optical powers. The lenses in the wide-angle fixed-focus lens adopt a combination of negative-negative-positive-positive-positive-negative-positive-negative-positive-positive to reasonably distribute the optical powers of each lens, enabling the light to propagate more smoothly within the wide-angle fixed-focus lens, preventing the light from being excessively refracted on the surface of a certain lens, thereby avoiding the introduction of larger aberrations. While ensuring a small aperture and low chromatic aberration, it further corrects high-order aberrations and controls distortion, achieving higher imaging quality.

[0060] Optionally, referring to Figure 1 , the third lens L3, the fourth lens L4, and the ninth lens L9 are glass aspherical lenses.

[0061] Furthermore, the fifth lens L5 and the tenth lens L10 can also be set as glass aspherical lenses. The third lens L3, the fourth lens L4, the fifth lens L5, the ninth lens L9, and the tenth lens L10 all use glass aspherical lenses. The use of aspherical surfaces can more easily correct high-order aberrations. When the light passes through the third lens L3 and then enters the fourth lens L4, the fifth lens L5, the ninth lens L9, and the tenth lens L10 through the aperture STO, the light can be converged, avoiding excessive pressure on the first lens L1, the second lens, the sixth lens L6, the seventh lens L7, and the eighth lens L8 during the correction of chromatic aberration, aberration, and CRA, and preventing the appearance of difficult-to-machine shapes. Here, CRA refers to the angle at which the chief rays of different fields of view enter the image plane.

[0062] Exemplarily, the first lens L1, the second lens L2, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are glass spherical lenses. In the embodiment of the present invention, a combination of 5 glass spherical lenses and 5 glass aspherical lenses is used to realize a wide-angle fixed-focus lens with a small aperture and high image quality.

[0063] Optionally, referring to Figure 1 , the object side of the third lens L3 is recessed towards the object side, the image side of the third lens L3 is convex towards the image side, and the third lens L3 is a concave-convex lens. The object side of the fourth lens L4 is recessed towards the object side, the image side of the fourth lens L4 is convex towards the image side, and the fourth lens L4 is a concave-convex lens. The object side of the ninth lens L9 is recessed towards the object side, and the image side of the ninth lens L9 is convex towards the image side. The ninth lens L9 is a concave-convex lens.

[0064] Optionally, referring to Figure 1 , the sixth lens L6 is a biconcave lens, the object side of the sixth lens L6 is recessed towards the object side, the image side of the sixth lens L6 is recessed towards the image side, and the sixth lens L6 is a concave-concave lens. The eighth lens L8 is a biconcave lens, the object side of the eighth lens L8 is recessed towards the object side, and the image side of the eighth lens L8 is recessed towards the image side. The eighth lens L8 is a concave-concave lens. The object side of the tenth lens L10 is recessed towards the object side, and the image side of the tenth lens L10 is convex towards the image side. The tenth lens L10 is a concave-convex lens.

[0065] Exemplarily, the first lens L1 is a convex-concave glass spherical lens; the second lens L2 is a convex-concave glass spherical lens; the third lens L3 is a concave-convex glass aspherical lens; the fourth lens L4 is a concave-convex glass aspherical lens; the fifth lens L5 is a concave-convex glass aspherical lens; the sixth lens L6 is a concave-concave glass spherical lens; the object side of the seventh lens L7 is convex towards the object side, and the seventh lens L7 is a glass spherical lens; the eighth lens L8 is a concave-concave glass spherical lens; the ninth lens L9 is a concave-convex glass aspherical lens; the tenth lens L10 is a concave-convex glass aspherical lens.

[0066] Optionally, referring to Figure 1 , the overall optical length of the wide-angle fixed-focus lens is TTL, the effective focal length of the wide-angle fixed-focus lens is EFL, and the back focal length of the wide-angle fixed-focus lens is BFL, satisfying: 6.347 ≤ TTL / EFL ≤ 7.382;

[0067] 0.046 ≤ BFL / TTL ≤ 0.077. While meeting the optical performance requirements, the wide-angle fixed-focus lens can greatly reduce the volume of the wide-angle fixed-focus lens and improve the compatibility of the wide-angle fixed-focus lens in use.

[0068] Optionally, referring to Figure 1, the radius of curvature of the object side surface of the first lens L1 is R1, and the radius of curvature of the image side surface of the first lens L1 is R2, satisfying: 1.413 ≤ (R1 + R2) / (R1 - R2) ≤ 1.501. Light can smoothly pass through the first lens L1 without sudden changes and enter the subsequent structure, which is beneficial to increasing the image height and expanding the field of view angle, meeting the usage requirements in more cases.

[0069] Optionally, referring to Figure 1 , the refractive index of the ninth lens L9 is Nd9, and the Abbe number of the ninth lens L9 is Vd9. The refractive index of the tenth lens L10 is Nd10, and the Abbe number of the tenth lens L10 is Vd10, satisfying: 1.32 ≤ Nd9 ≤ 1.50; 50.00 ≤ Vd9 ≤ 95.00; 1.60 ≤ Nd10 ≤ 1.95; 30.00 ≤ Vd10 ≤ 50.00. The ninth lens L9 and the tenth lens L10 are located at the outermost end position of the wide-angle fixed-focus lens. The ninth lens L9 uses a material with a low refractive index and a high Abbe number, which can bend light more effectively, thereby effectively controlling the incident angle of light entering the imaging chip and avoiding too large a divergence angle of the incident light passing through the ninth lens L9 resulting in too large an incident angle of light, which is beneficial to adapting to more imaging chips. The tenth lens L10 uses a material with a high refractive index and a low Abbe number, which is beneficial to offsetting the dispersion effect, thereby effectively correcting the high-order chromatic aberration and improving the color accuracy of imaging. Further, by carefully matching the refractive indices and Abbe numbers of the ninth lens L9 and the tenth lens L10, it is also beneficial to the correction of high-order aberrations and the improvement of imaging quality.

[0070] Optionally, referring to Figure 1 , the effective focal length of the wide-angle fixed-focus lens is EFL, and the entrance pupil diameter of the wide-angle fixed-focus lens is EPD, satisfying: 0.323 ≤ EPD / EFL ≤ 0.380. The wide-angle fixed-focus lens realizes a small aperture, enabling the wide-angle fixed-focus lens to ensure a large light transmission amount and achieve clear imaging even when working at night. When the focal length is fixed, it is possible to control the entrance pupil diameter of the wide-angle fixed-focus lens while meeting the requirements of a large image plane and high-quality imaging, ensuring sufficient field of view angle at the edge of the large image plane imaging system and increasing the image plane brightness.

[0071] Optionally, referring to Figure 1, the optical power of the first lens L1 is F1, the optical power of the second lens L2 is F2, the optical power of the third lens L3 is F3, the optical power of the fourth lens L4 is F4, the optical power of the fifth lens L5 is F5, the optical power of the sixth lens L6 is F6, the optical power of the seventh lens L7 is F7, the optical power of the eighth lens L8 is F8, the optical power of the ninth lens L9 is F9, the optical power of the tenth lens L10 is F10, and the optical power of the wide-angle fixed-focus lens is F, satisfying: -1.779 ≤ F1 / F ≤ -1.228; -3.788 ≤ F2 / F ≤ -2.641; 2.879 ≤ F3 / F ≤ 3.181; 1.722 ≤ F4 / F ≤ 1.947; 2.737 ≤ F5 / F ≤ 3.028;

[0072] -1.700 ≤ F6 / F ≤ -1.427; 1.222 ≤ F7 / F ≤ 1.331; -1.810 ≤ F8 / F ≤ -0.556; 1.170 ≤ F9 / F ≤ 8.286; 5.003 ≤ F10 / F ≤ 43.405.

[0073] Exemplarily, referring to Figure 1 , the wide-angle fixed-focus lens further includes a flat glass CG, and the flat glass CG is located on the side of the tenth lens L10 away from the first lens L1. The flat glass CG is located on the image-side surface of the tenth lens L10. Behind the flat glass CG, the image plane is schematically shown.

[0074] Table 1 shows a set of design values of the wide-angle fixed-focus lens in the first embodiment

[0075]

[0076] Table 1 shows a set of design values of the wide-angle fixed-focus lens in the first embodiment, and the specific numerical values can be adjusted according to product requirements, which is not a limitation to the embodiments of the present invention. The wide-angle fixed-focus lens shown in Table 1 can be Figure 1As shown in the figure. A lens generally includes two surfaces, and each surface is a refracting surface. The surface numbers in Table 1 are numbered according to the surfaces of each lens. Among them, surface number 1 represents the front surface (i.e., the object side surface) of the first lens L1, surface number 2 represents the rear surface (i.e., the image side surface) of the first lens L1, and so on, which will not be elaborated here. STO in the surface type column represents the diaphragm. IMX in the surface type column represents the image plane. The radius of curvature represents the degree of curvature of the lens surface. A positive radius of curvature value indicates that the center of curvature is on the image side near the surface, that is, a positive value represents that the surface bends towards the image side; a negative radius of curvature value represents that the center of curvature is on the side far from the image side of the surface, that is, a negative value represents that the surface bends towards the object side. INF in the radius of curvature column represents that the surface is a plane and the radius of curvature is infinite. The value in the thickness column represents the central axial distance from the current surface to the next surface. The refractive index column represents the refractive index of the medium between the current surface and the next surface, representing the ability of the material between the current surface and the next surface to deflect light. The space in the refractive index column is the refractive index of air, and the refractive index of air is 1. The Abbe number represents the dispersion characteristic of the material between the current surface and the next surface to light, and the space represents that the current position is air.

[0077] Table 2 shows a set of design values of the aspheric coefficients of the lenses in the wide-angle fixed-focus lens in the first embodiment

[0078] Table 2 shows a set of design values of the aspheric coefficients of the lenses in the wide-angle fixed-focus lens in the first embodiment, and the specific numerical values can be adjusted according to product requirements, which is not a limitation to the embodiments of the present invention. The wide-angle fixed-focus lens shown in Table 2 can be Figure 1 As shown in the figure. The meaning of the surface number column in Table 2 is consistent with that of the surface numbers in Table 1. "E" in each embodiment of the present invention represents the exponent with base 10.

[0079] Optionally, the surface of the aspheric lens satisfies the formula:

[0080] .

[0081] Where z is the axial sagittal height in the Z direction of the aspheric surface; r is the height of the aspheric surface; c is the curvature of the fitted spherical surface, numerically the reciprocal of the radius of curvature; k is the fitted conic coefficient; to are the 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, 20th order coefficients of the aspheric polynomial.

[0082] Exemplarily, in the first embodiment, the maximum diameter that the image plane size can reach is 15.0 mm, the field of view angle is 166°, the EFL is 4.749, the aperture number (i.e., F / #) is 2.81. The TTL is 31.794 mm, and the applicable wavelength band includes 436 nm to 870 nm.

[0083] Exemplarily, in the first embodiment, TTL / EFL = 6.695, BFL / TTL = 0.066, (R1 + R2) / (R1 - R2) = 1.442, EPD / EFL = 0.357, F1 / F = -1.764, F2 / F = -3.406, F3 / F = 3.004, F4 / F = 1.811, F5 / F = 2.873, F6 / F = -1.596, F7 / F = 1.269, F8 / F = -0.974, F9 / F = 3.542, F10 / F = 6.454.

[0084] Figure 2 This is the field curvature diagram of the wide-angle fixed-focus lens provided in the first embodiment of the present invention. Refer to Figure 2 , the horizontal coordinate represents the magnitude of the field curvature, with the unit of mm; the vertical coordinate represents the normalized image height, without a unit; where T represents the meridian and S represents the sagittal. It can be Figure 2 seen that the field curvature of the wide-angle fixed-focus lens provided in this embodiment is effectively controlled, that is, when imaging, the image quality difference between the center and the periphery is small.

[0085] Figure 3 This is the distortion diagram of the wide-angle fixed-focus lens provided in the first embodiment of the present invention. Refer to Figure 3 , the horizontal coordinate represents the magnitude of the distortion, with the unit of %; the vertical coordinate represents the normalized image height, without a unit.

[0086] Figures 4 - 9 This is the fan diagram of the wide-angle fixed-focus lens provided in the first embodiment of the present invention. Refer to Figures 4 - 9 , the fan diagram is one of the most commonly used evaluation methods in modern optical design. The abscissa is the beam aperture, and the ordinate is the lateral aberration. The most ideal curve is a straight line that coincides with the abscissa, indicating that all rays converge at the same point on the image plane. The corresponding interval on the ordinate of the curve is the maximum dispersion range of the beam on the ideal image plane. The fan diagram can not only reflect the monochromatic aberration of different wavelengths but also represent the magnitude of the lateral chromatic aberration. It can be Figures 4 - 9 seen that the wide-angle fixed-focus lens is well approximated to the abscissa at each field of view and each wavelength, indicating that the lateral aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion among each wavelength, indicating that the chromatic aberration of the wide-angle fixed-focus lens is also well corrected, thus ensuring that the wide-angle fixed-focus lens can meet the high-resolution imaging requirements.

[0087] Figure 10This is the lateral chromatic aberration diagram of the wide-angle fixed-focus lens provided in the first embodiment of the present invention. Refer to Figure 10 , the vertical direction represents the normalization of the field of view, and 0 represents on the optical axis; the main wavelength is 546 nm, and the horizontal direction represents the offset relative to the main wavelength, with the unit of micrometer (um). It can be seen from Figure 10 that the lateral chromatic aberrations of different wavelengths are all controlled within a good range, indicating that the lateral chromatic aberration of this wide-angle fixed-focus lens is well controlled and can meet the requirements of wide-spectrum applications.

[0088] Embodiment 2

[0089] Similarities with the above embodiments will not be elaborated here.

[0090] Table 3 shows a set of design values of the wide-angle fixed-focus lens in Embodiment 2

[0091]

[0092] Table 3 shows a set of design values of the wide-angle fixed-focus lens in Embodiment 2, and the specific numerical values can be adjusted according to product requirements, which is not a limitation to the embodiments of the present invention. The wide-angle fixed-focus lens shown in Table 3 can be as shown in Figure 11 .

[0093] Table 4 shows a set of design values of the aspherical coefficients of the lenses in the wide-angle fixed-focus lens in Embodiment 2

[0094]

[0095] Table 4 shows a set of design values of the aspherical coefficients of the lenses in the wide-angle fixed-focus lens in Embodiment 2, and the specific numerical values can be adjusted according to product requirements, which is not a limitation to the embodiments of the present invention. The fixed-focus lens shown in Table 4 can be as shown in Figure 11 .

[0096] Exemplarily, in Embodiment 2, the maximum diameter that the image plane size can reach is 16.0 mm, the field of view angle is 164°, the EFL is 4.800, the f-number (i.e., F / #) is 2.804, the TTL is 32.122 mm, and the applicable wavelength band includes 436 nm to 870 nm.

[0097] Exemplarily, in Embodiment 2, TTL / EFL = 6.692, BFL / TTL = 0.056, (R1 + R2) / (R1 - R2) = 1.472, EPD / EFL = 0.361, F1 / F = -1.769, F2 / F = -3.235, F3 / F = 2.980, F4 / F = 1.797, F5 / F = 2.834, F6 / F = -1.609, F7 / F = 1.259, F8 / F = -0.976, F9 / F = 4.082, F10 / F = 6.007.

[0098] Figure 12 This is the field curvature diagram of the wide-angle fixed-focus lens provided in the second embodiment of the present invention. Refer to Figure 12 . The horizontal coordinate represents the magnitude of the field curvature, with the unit of mm; the vertical coordinate represents the normalized image height, without a unit; where T represents the meridian and S represents the sagittal. It can be Figure 12 seen that the field curvature of the wide-angle fixed-focus lens provided in this embodiment is effectively controlled, that is, when imaging, the image quality difference between the center and the periphery is small.

[0099] Figure 13 This is the distortion diagram of the wide-angle fixed-focus lens provided in the second embodiment of the present invention. Refer to Figure 13 . The horizontal coordinate represents the magnitude of the distortion, with the unit of %; the vertical coordinate represents the normalized image height, without a unit.

[0100] Figures 14 - 19 This is the fan diagram of the wide-angle fixed-focus lens provided in the second embodiment of the present invention. Refer to Figures 14 - 19 . The fan diagram is one of the most commonly used evaluation methods in modern optical design. The abscissa is the beam aperture, and the ordinate is the lateral aberration. The most ideal curve is a straight line that coincides with the abscissa, indicating that all rays converge at the same point on the image plane. The corresponding interval on the ordinate of the curve is the maximum dispersion range of the beam on the ideal image plane. The fan diagram can not only reflect the monochromatic aberration of different wavelengths but also represent the magnitude of the lateral chromatic aberration. It can be Figures 14 - 19 seen that the wide-angle fixed-focus lens is well approximated to the abscissa at each wavelength in each field of view, indicating that the lateral aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion among the wavelengths, indicating that the chromatic aberration of the wide-angle fixed-focus lens is also well corrected, thus ensuring that the wide-angle fixed-focus lens can meet the high-resolution imaging requirements.

[0101] Figure 20 This is the lateral chromatic aberration diagram of the wide-angle fixed-focus lens provided in the second embodiment of the present invention. Refer to Figure 20 . The vertical direction represents the normalization of the field of view, with 0 indicating on the optical axis; the main wavelength is 546 nm, and the horizontal direction represents the offset relative to the main wavelength, with the unit of micrometer (um). It can be Figure 20 seen that the lateral chromatic aberration of different wavelengths is controlled within a good range, indicating that the lateral chromatic aberration of the wide-angle fixed-focus lens is well controlled and can meet the requirements of wide-spectrum applications.

[0102] Embodiment 3

[0103] Similarities with the above embodiments will not be elaborated here.

[0104] Table 5 A design value of the wide-angle fixed-focus lens in Embodiment 3

[0105]

[0106] Table 5 shows a set of design values for the wide-angle fixed-focus lens in Embodiment 3. The specific numerical values can be adjusted according to product requirements and do not limit the embodiments of the present invention. The wide-angle fixed-focus lens shown in Table 5 can be Figure 21 as shown in

[0107] Table 6 shows a set of design values for the aspherical coefficients of the lenses in the wide-angle fixed-focus lens in Embodiment 3

[0108]

[0109] Table 6 shows a set of design values for the aspherical coefficients of the lenses in the wide-angle fixed-focus lens in Embodiment 3. The specific numerical values can be adjusted according to product requirements and do not limit the embodiments of the present invention. The fixed-focus lens shown in Table 6 can be Figure 21 as shown in

[0110] Exemplarily, in Embodiment 3, the maximum diameter that the image plane size can reach is 14.6 mm, the field of view angle is 160°, the EFL is 4.55, the aperture number (i.e., F / #) is 2.808. The TTL is 32.019 mm, and the applicable wavelength band includes 436 nm to 870 nm.

[0111] Exemplarily, in Embodiment 3, TTL / EFL = 7.037, BFL / TTL = 0.057, (R1 + R2) / (R1 - R2) = 1.458, EPD / EFL = 0.342, F1 / F = -1.772, F2 / F = -3.024, F3 / F = 3.080, F4 / F = 1.872, F5 / F = 2.931, F6 / F = -1.518, F7 / F = 1.295, F8 / F = -1.392, F9 / F = 5.914, F10 / F = 24.706.

[0112] Figure 22 This is the field curvature diagram of the wide-angle fixed-focus lens provided in Embodiment 3 of the present invention. Refer to Figure 22 , where the horizontal coordinate represents the magnitude of the field curvature in mm; the vertical coordinate represents the normalized image height without unit; where T represents meridional and S represents sagittal. It can be Figure 22 seen that the field curvature of the wide-angle fixed-focus lens provided in this embodiment is effectively controlled, that is, when imaging, the image quality difference between the center and the periphery is small.

[0113] Figure 23 This is the distortion diagram of the wide-angle fixed-focus lens provided in Embodiment 3 of the present invention. Refer to Figure 23 , where the horizontal coordinate represents the magnitude of the distortion in %; the vertical coordinate represents the normalized image height without unit.

[0114] Figures 24 - 29 This is the fan diagram of the wide-angle fixed-focus lens provided in the third embodiment of the present invention. Refer to Figures 24 - 29 . The fan diagram is one of the most commonly used evaluation methods in modern optical design. The abscissa is the beam aperture, and the ordinate is the lateral aberration. The most ideal curve is a straight line that coincides with the abscissa, indicating that all rays converge at the same point on the image plane. The corresponding interval on the ordinate of the curve is the maximum dispersion range of the beam on the ideal image plane. The fan diagram can not only reflect the monochromatic aberration of different wavelengths but also represent the magnitude of the lateral chromatic aberration. From Figures 24 - 29 , it can be seen that the wide-angle fixed-focus lens closely approaches the abscissa at each wavelength in each field of view, indicating that the lateral aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion among the wavelengths, indicating that the chromatic aberration of the wide-angle fixed-focus lens is also well corrected, thus ensuring that the wide-angle fixed-focus lens can meet the high-resolution imaging requirements.

[0115] Figure 30 This is the lateral chromatic aberration diagram of the wide-angle fixed-focus lens provided in the third embodiment of the present invention. Refer to Figure 30 . The vertical direction represents the normalization of the field of view, where 0 indicates on the optical axis; the principal wavelength is 546 nm, and the horizontal direction represents the offset relative to the principal wavelength, with the unit of micrometer (um). From Figure 30 , it can be seen that the lateral chromatic aberration of different wavelengths is controlled within a good range, indicating that the lateral chromatic aberration of the wide-angle fixed-focus lens is well controlled and can meet the requirements of wide-spectrum applications.

[0116] Note that the above is only the preferred embodiment of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here. Various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A wide-angle fixed-focus 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, a ninth lens, and a tenth lens arranged in sequence from the object side to the image side along the optical axis; The first lens and the second lens have negative optical powers; The third lens and the fourth lens have positive optical powers; the wide-angle fixed-focus lens further includes a diaphragm, and the diaphragm is located between the third lens and the fourth lens.

2. The wide-angle fixed-focus lens according to claim 1, wherein The fifth lens, the seventh lens, the ninth lens, and the tenth lens have positive optical powers; The sixth lens and the eighth lens have negative optical powers.

3. The wide-angle fixed-focus lens according to claim 1, wherein, The third lens, the fourth lens, and the ninth lens are glass aspherical lenses.

4. The wide-angle fixed-focus lens according to claim 3, characterized in that, The object side surface of the third lens is concave towards the object side, and the image side surface of the third lens is convex towards the image side; The object side surface of the fourth lens is concave towards the object side, and the image side surface of the fourth lens is convex towards the image side; The object side surface of the ninth lens is concave towards the object side, and the image side surface of the ninth lens is convex towards the image side.

5. The wide-angle fixed-focus lens according to claim 4, wherein The sixth lens is a biconcave lens, and the eighth lens is a biconcave lens; The object side surface of the tenth lens is concave towards the object side, and the image side surface of the tenth lens is convex towards the image side.

6. The wide-angle fixed-focus lens according to claim 1, wherein The overall optical length of the wide-angle fixed-focus lens is TTL, the effective focal length of the wide-angle fixed-focus lens is EFL, and the back focal length of the wide-angle fixed-focus lens is BFL, satisfying: ； 。 7. The wide-angle fixed-focus lens according to claim 1, wherein, The radius of curvature of the object side surface of the first lens is R1, and the radius of curvature of the image side surface of the first lens is R2, satisfying: 。 8. The wide-angle fixed-focus lens according to claim 1, wherein The refractive index of the ninth lens is Nd9, the Abbe number of the ninth lens is Vd9, the refractive index of the tenth lens is Nd10, and the Abbe number of the tenth lens is Vd10, satisfying: ； ； ； 。 9. The wide-angle fixed-focus lens according to claim 1, wherein The effective focal length of the wide-angle fixed-focus lens is EFL, and the entrance pupil diameter of the wide-angle fixed-focus lens is EPD, satisfying: 。 10. The wide-angle fixed-focus lens according to claim 2, characterized in that, The optical power of the first lens is F1, the optical power of the second lens is F2, the optical power of the third lens is F3, the optical power of the fourth lens is F4, the optical power of the fifth lens is F5, the optical power of the sixth lens is F6, the optical power of the seventh lens is F7, the optical power of the eighth lens is F8, the optical power of the ninth lens is F9, the optical power of the tenth lens is F10, and the optical power of the wide-angle fixed-focus lens is F, satisfying: ； ； ； ； ； ； ； ； ； 。

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