A wide-angle fixed-focus lens

Abstract

The present invention provides a wide-angle fixed-focus lens, which relates to the technical field of optical lenses. The wide-angle fixed-focus lens provided in an embodiment of the present invention 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 along the optical axis from the object side to the image side; the first lens and the second lens have negative optical power; the third lens and the fourth lens have positive optical power; the wide-angle fixed-focus lens also includes an aperture, which is located between the third lens and the fourth lens. The embodiment of the present invention provides a wide-angle fixed-focus lens to achieve a small aperture and high image quality wide-angle fixed-focus lens.

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 advancement of technology and increasing consumer demand for it, the application scenarios and imaging requirements of optical lenses are constantly evolving. Currently, market demand for wide-angle lenses with a wide viewing angle and high image quality is increasing. However, mainstream ultra-wide-angle lenses generally suffer from low image quality, large chromatic aberration, and high distortion, making them unsuitable 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 realize 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, 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, a ninth lens, and a tenth lens, arranged in sequence along an optical axis from the object side to the image side;

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

[0006] The third lens and the fourth lens have positive refractive power; the wide-angle fixed-focus lens further includes a stop, which 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 refractive power;

[0008] The sixth lens and the eighth lens have negative refractive power.

[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 concave 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 concave 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 concave 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 surface of the tenth lens is concave toward the object side, and the image-side surface of the tenth lens is convex toward the image side.

[0015] Optionally, the total 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 optical back focus 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 curvature radius of the object-side surface of the first lens is R1, and the curvature radius of the image-side surface 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 focal power of the first lens is F1, the focal power of the second lens is F2, the focal power of the third lens is F3, the focal power of the fourth lens is F4, the focal power of the fifth lens is F5, the focal power of the sixth lens is F6, the focal power of the seventh lens is F7, the focal power of the eighth lens is F8, the focal power of the ninth lens is F9, the focal power of the tenth lens is F10, and the focal 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 an embodiment of the present invention, the focal powers of both the first and second lenses are negative, ensuring that light has a larger diameter before entering the aperture, thereby reducing the aperture of the wide-angle fixed-focus lens. The aperture is placed between the third lens (with positive focal power) and the fourth lens (with positive focal power). This allows the high-order aberrations of the wide-angle fixed-focus lens to be controlled at the front end of the wide-angle fixed-focus lens, increasing the light throughput of the wide-angle fixed-focus lens and ensuring that the image height and imaging range are increased at the rear end of the wide-angle fixed-focus lens while maintaining good image quality, meeting the requirements of a wider range of use cases. This results in a wide-angle fixed-focus lens with a small aperture and high image quality. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0040] Figure 2 A field curvature diagram of the wide-angle fixed-focus lens provided in Example 1 of the present invention;

[0041] Figure 3 This is a distortion diagram of the wide-angle fixed-focus lens provided in Example 1 of the present invention;

[0042] Figure 4-Figure 9 A ray fan diagram of the wide-angle fixed-focus lens provided in Example 1 of the present invention;

[0043] Figure 10 A diagram of vertical axial chromatic aberration of the wide-angle fixed-focus lens provided in Example 1 of the present invention;

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

[0045] Figure 12A field curvature diagram of the wide-angle fixed-focus lens provided in Example 2 of the present invention;

[0046] Figure 13 This is a distortion diagram of the wide-angle fixed-focus lens provided in Example 2 of the present invention;

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

[0048] Figure 20 A diagram of vertical chromatic aberration of the wide-angle fixed-focus lens provided in Example 2 of the present invention;

[0049] Figure 21 This is a schematic structural diagram of a wide-angle fixed-focus lens provided in Embodiment 3 of the present invention;

[0050] Figure 22 A field curvature diagram of the wide-angle fixed-focus lens provided in Example 3 of the present invention;

[0051] Figure 23 This is a distortion diagram of the wide-angle fixed-focus lens provided in Example 3 of the present invention;

[0052] Figure 24-29 A ray fan diagram of the wide-angle fixed-focus lens provided in Example 3 of the present invention;

[0053] Figure 30 This is a diagram of vertical axial chromatic aberration of the wide-angle fixed-focus lens provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0055] Example 1

[0056] Figure 1 This is a schematic diagram of the structure of the wide-angle fixed-focus lens provided in Example 1 of the present invention, with reference 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 order along the optical axis from the object side to the image side. The first lens L1 and the second lens L2 have negative optical power; the third lens L3 and the fourth lens L4 have positive optical power. The wide-angle fixed-focus lens also includes an aperture stop STO located between the third lens L3 and the fourth lens L4.

[0057] In the wide-angle fixed-focus lens provided by an embodiment of the present invention, the optical power of the first lens L1 and the second lens L2 are both negative, ensuring that light has a larger diameter before entering the aperture STO, thereby 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. This allows the high-order aberrations of the wide-angle fixed-focus lens to be controlled at the front end of the wide-angle fixed-focus lens, increasing the light throughput of the wide-angle fixed-focus lens and ensuring that the image height and imaging range are increased at the rear end of the wide-angle fixed-focus lens while maintaining good image quality, meeting the requirements of a wider range of use cases. This results in a wide-angle fixed-focus lens with a small aperture and high image quality.

[0058] The wide-angle fixed-focus lens provided in the embodiment of the present invention achieves clear imaging in the 436nm to 870nm band under a 1" target surface, has a small aperture, and has higher image quality. The imaging range is 150° to 180°, which is suitable for use in a wide range of situations.

[0059] Optionally, refer to Figure 1 , the fifth lens L5, the seventh lens L7, the ninth lens L9, and the tenth lens L10 have positive focal power; the sixth lens L6 and the eighth lens L8 have negative focal power. The lenses in the wide-angle fixed-focus lens adopt a negative-negative-positive-positive-positive-positive-negative-positive-negative-positive arrangement to rationally distribute the focal power of each lens. This allows light to propagate more smoothly within the wide-angle fixed-focus lens, preventing excessive deflection of light on the surface of any 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 image quality.

[0060] Optionally, refer 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 aspheric 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 aspheric lenses. The use of aspheric surfaces can more easily correct high-order aberrations. When the light passes through the third lens L3 and enters the fourth lens L4, the fifth lens L5, the ninth lens L9, and the tenth lens L10 from the aperture STO, the light can be converged to avoid 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 process of correcting chromatic aberration, aberration, and CRA, resulting in a shape that is difficult to process. Among them, CRA refers to the angle at which the main light of different fields of view is incident on 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. This embodiment of the present invention utilizes a combination of five glass spherical lenses and five glass aspherical lenses to achieve a wide-angle, fixed-focus lens with a small aperture and high image quality.

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

[0064] Optionally, refer to Figure 1 The sixth lens element L6 is a biconcave lens. Its object-side surface is concave toward the object side, and its image-side surface is concave toward the image side. Therefore, the sixth lens element L6 is a concave-concave lens. The eighth lens element L8 is a biconcave lens. Its object-side surface is concave toward the object side, and its image-side surface is concave toward the image side. The eighth lens element L8 is a concave-concave lens. The object-side surface of the tenth lens element L10 is concave toward the object side, and its image-side surface is convex toward the image side. The tenth lens element L10 is a concave-convex lens.

[0065] Illustratively, 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 surface of the seventh lens L7 is convex toward 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; and the tenth lens L10 is a concave-convex glass aspherical lens.

[0066] Optionally, refer to Figure 1 , the total 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 optical back focus 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 size of the wide-angle fixed-focus lens and improve its compatibility.

[0068] Optionally, refer to Figure 1The radius of curvature of the object-side surface of first lens L1 is R1, and the radius of curvature of the image-side surface of first lens L1 is R2, satisfying the following: 1.413 ≤ (R1 + R2) / (R1 - R2) ≤ 1.501. This allows light to smoothly pass through first lens L1 and into subsequent components without abrupt changes, which helps increase image height and expand the field of view, meeting the requirements of more situations.

[0069] Optionally, refer to Figure 1 The refractive index of the ninth lens element, L9, is Nd9, and the Abbe number of the ninth lens element, L9, is Vd9. The refractive index of the tenth lens element, L10, is Nd10, and the Abbe number of the tenth lens element, L10, is Vd10, satisfying the following: 1.32≤Nd9≤1.50; 50.00≤Vd9≤95.00; 1.60≤Nd10≤1.95; and 30.00≤Vd10≤50.00. The ninth and tenth lenses, L9 and L10, are located at the very end of the wide-angle fixed-focus lens. The ninth lens element, L9, is made of a low-refractive-index, high-Abbe-number material, which effectively bends light and thus effectively controls the angle of incidence of light entering the imaging chip. This prevents the incident light from diverging too much after passing through the ninth lens element, resulting in excessively large angles of incidence. This facilitates compatibility with a wider range of imaging chips. The tenth lens element, L10, is made of a high-refractive-index, low-Abbe-number material, which helps offset chromatic aberration, effectively correcting high-order chromatic aberrations and improving color accuracy. Furthermore, by carefully matching the refractive index and Abbe number of the ninth lens element L9 and the tenth lens element L10, it is also beneficial to correct high-order aberrations and improve image quality.

[0070] Optionally, refer to Figure 1 The effective focal length of a wide-angle fixed-focus lens is EFL, and the entrance pupil diameter is EPD, satisfying the following: 0.323 ≤ EPD / EFL ≤ 0.380. The small aperture of a wide-angle fixed-focus lens allows for a large light throughput and clear imaging even at night. While maintaining a fixed focal length, the entrance pupil diameter can be controlled while maintaining a large image area and high-quality imaging, ensuring a sufficient field of view at the edges of the large-image imaging system and improving image brightness.

[0071] Optionally, refer to Figure 1The focal power of the first lens L1 is F1, the focal power of the second lens L2 is F2, the focal power of the third lens L3 is F3, the focal power of the fourth lens L4 is F4, the focal power of the fifth lens L5 is F5, the focal power of the sixth lens L6 is F6, the focal power of the seventh lens L7 is F7, the focal power of the eighth lens L8 is F8, the focal power of the ninth lens L9 is F9, and the focal power of the tenth lens L10 is F10. The focal power of the wide-angle fixed-focus lens is F, and satisfies the following: -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] For example, refer to Figure 1 The wide-angle fixed-focus lens also includes a flat glass CG, which is located on the side of the tenth lens element L10 away from the first lens element L1. The flat glass CG is located on the image side of the tenth lens element L10. Behind the flat glass CG is the image plane.

[0074] Table 1: Design values of the wide-angle fixed-focus lens in Example 1

[0075]

[0076] Table 1 shows a design value of the wide-angle fixed-focus lens in Example 1. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The wide-angle fixed-focus lens shown in Table 1 can be Figure 1As shown in . A lens generally consists of two surfaces, each of which is a refractive surface. The surface numbers in Table 1 are numbered according to the surface of each lens. Surface number 1 represents the front surface (i.e., object side) of the first lens L1, surface number 2 represents the back surface (i.e., image side) of the first lens L1, and so on. The STO in the Surface Type column represents the aperture. The 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 indicates that the center of curvature is on the image side of the surface, meaning that the surface is curved toward the image; a negative radius of curvature indicates that the center of curvature is on the image side of the surface, meaning that the surface is curved toward the object. The INF in the Radius of Curvature column indicates that the surface is flat and has an infinite radius of curvature. The value in the Thickness column represents the axial distance from the center of the current surface to the next surface. The Refractive Index column represents the refractive index of the medium between the current and next surfaces, indicating the light-bending ability of the material between the current and next surfaces. The blank space in the Refractive Index column represents the refractive index of air, which is 1. The Abbe number represents the dispersion characteristics of light from the material between the current surface and the next surface, and the blank space indicates that the current position is air.

[0077] Table 2 A design value of the aspheric coefficient of the lens in the wide-angle fixed-focus lens in Example 1

[0078] Table 2 shows a design value of the aspheric coefficient of the lens in the wide-angle fixed-focus lens of Example 1. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The wide-angle fixed-focus lens shown in Table 2 can be Figure 1 The meaning of the face number column in Table 2 is consistent with that in Table 1. "E" in each embodiment of the present invention represents an exponent with base 10.

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

[0080] .

[0081] Wherein, z is the axial sagittal height of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitted sphere, which is the inverse of the curvature radius; k is the fitting cone coefficient; to These are the 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, and 20th order coefficients of the aspheric polynomial.

[0082] For example, in Example 1, the maximum diameter of the image plane is 15.0 mm, the field of view 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 range is 436 nm to 870 nm.

[0083] For example, in Example 1, 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, and F10 / F=6.454.

[0084] Figure 2 This is a field curvature diagram of the wide-angle fixed-focus lens provided in Example 1 of the present invention, referring to Figure 2 , the horizontal coordinate represents the magnitude of field curvature, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, S represents arc loss. Figure 2 It can be seen that the wide-angle fixed-focus lens provided in this embodiment has effectively controlled field curvature, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is relatively small.

[0085] Figure 3 This is a distortion diagram of the wide-angle fixed-focus lens provided in Example 1 of the present invention, referring to Figure 3 The horizontal coordinate represents the size of the distortion, and the unit is %. The vertical coordinate represents the normalized image height, and there is no unit.

[0086] Figure 4-Figure 9 This is a ray fan diagram of the wide-angle fixed-focus lens provided in Example 1 of the present invention, referring to Figure 4-Figure 9 The ray fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane. The corresponding interval on the vertical axis of the curve is the maximum diffusion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 4-Figure 9 It can be seen that the wide-angle fixed-focus lens is close to the horizontal axis at all wavelengths in all fields of view, indicating that the vertical axis aberration of the system at each wavelength is well corrected. At the same time, there is no obvious dispersion at 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 achieve high-resolution imaging requirements.

[0087] Figure 10This is a vertical axis chromatic aberration diagram of the wide-angle fixed-focus lens provided in Example 1 of the present invention, with reference to Figure 10 , the vertical direction represents the normalization of the field of view, 0 represents the optical axis; the main wavelength is 546nm, the horizontal direction represents the offset relative to the main wavelength, the unit is micron (um), Figure 10 It can be seen that the vertical chromatic aberration of different wavelengths is well controlled, indicating that the vertical chromatic aberration of this wide-angle fixed-focus lens is well controlled and can meet the needs of wide-spectrum applications.

[0088] Example 2

[0089] Similarities with the above embodiment are not repeated here.

[0090] Table 3: Design values of the wide-angle fixed-focus lens in Example 2

[0091]

[0092] Table 3 shows a design value of the wide-angle fixed-focus lens in Example 2. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The wide-angle fixed-focus lens shown in Table 3 can be Figure 11 As shown in .

[0093] Table 4: Design values of the aspheric coefficients of the lens in the wide-angle fixed-focus lens in Example 2

[0094]

[0095] Table 4 shows a design value of the aspheric coefficient of the lens in the wide-angle fixed-focus lens of Example 2. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The fixed-focus lens shown in Table 4 can be Figure 11 As shown in .

[0096] For example, in Example 2, the maximum diameter of the image plane is 16.0 mm, the field of view is 164°, the EFL is 4.800, the aperture number (i.e., F / #) is 2.804, the TTL is 32.122 mm, and the applicable wavelength range is 436 nm to 870 nm.

[0097] For example, in Example 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, and F10 / F=6.007.

[0098] Figure 12 This is a field curvature diagram of the wide-angle fixed-focus lens provided in Example 2 of the present invention, referring to Figure 12 , the horizontal coordinate represents the magnitude of field curvature, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, S represents arc loss. Figure 12 It can be seen that the wide-angle fixed-focus lens provided in this embodiment has effectively controlled field curvature, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is relatively small.

[0099] Figure 13 This is a distortion diagram of the wide-angle fixed-focus lens provided in Example 2 of the present invention, referring to Figure 13 The horizontal coordinate represents the size of the distortion, and the unit is %. The vertical coordinate represents the normalized image height, and there is no unit.

[0100] Figures 14-19 This is a ray fan diagram of the wide-angle fixed-focus lens provided in Example 2 of the present invention, referring to Figures 14-19 The ray fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane. The corresponding interval on the vertical axis of the curve is the maximum diffusion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figures 14-19 It can be seen that the wide-angle fixed-focus lens is close to the horizontal axis at all wavelengths in all fields of view, indicating that the vertical axis aberration of the system at each wavelength is well corrected. At the same time, there is no obvious dispersion at 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 achieve high-resolution imaging requirements.

[0101] Figure 20 This is a vertical axis chromatic aberration diagram of the wide-angle fixed-focus lens provided in Example 2 of the present invention, referring to Figure 20 , the vertical direction represents the normalization of the field of view, 0 represents the optical axis; the main wavelength is 546nm, the horizontal direction represents the offset relative to the main wavelength, the unit is micron (um), Figure 20 It can be seen that the vertical chromatic aberration of different wavelengths is well controlled, indicating that the vertical chromatic aberration of this wide-angle fixed-focus lens is well controlled and can meet the needs of wide-spectrum applications.

[0102] Example 3

[0103] Similarities with the above embodiment are not repeated here.

[0104] Table 5: Design values of the wide-angle fixed-focus lens in Example 3

[0105]

[0106] Table 5 shows a design value of the wide-angle fixed-focus lens in Example 3. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The wide-angle fixed-focus lens shown in Table 5 can be Figure 21 As shown in .

[0107] Table 6: Design values of the aspheric coefficients of the lens in the wide-angle fixed-focus lens in Example 3

[0108]

[0109] Table 6 shows a design value of the aspheric coefficient of the lens in the wide-angle fixed-focus lens of Example 3. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The fixed-focus lens shown in Table 6 can be Figure 21 As shown in .

[0110] For example, in Example 3, the maximum diameter of the image plane is 14.6 mm, the field of view 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 range is 436 nm to 870 nm.

[0111] For example, in Example 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, and F10 / F=24.706.

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

[0113] Figure 23 This is a distortion diagram of the wide-angle fixed-focus lens provided in Example 3 of the present invention, referring to Figure 23 The horizontal coordinate represents the size of the distortion, and the unit is %. The vertical coordinate represents the normalized image height, and there is no unit.

[0114] Figure 24-29 This is a ray fan diagram of the wide-angle fixed-focus lens provided in Example 3 of the present invention, referring to Figure 24-29 The ray fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane. The corresponding interval on the vertical axis of the curve is the maximum diffusion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 24-29 It can be seen that the wide-angle fixed-focus lens is close to the horizontal axis at all wavelengths in all fields of view, indicating that the vertical axis aberration of the system at each wavelength is well corrected. At the same time, there is no obvious dispersion at 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 achieve high-resolution imaging requirements.

[0115] Figure 30 This is a vertical axis chromatic aberration diagram of the wide-angle fixed-focus lens provided in Example 3 of the present invention, referring to Figure 30 , the vertical direction represents the normalization of the field of view, 0 represents the optical axis; the main wavelength is 546nm, the horizontal direction represents the offset relative to the main wavelength, the unit is micron (um), Figure 30 It can be seen that the vertical chromatic aberration of different wavelengths is well controlled, indicating that the vertical chromatic aberration of this wide-angle fixed-focus lens is well controlled and can meet the needs of wide-spectrum applications.

[0116] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations, and substitutions are possible for those skilled in the art without departing from the 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 and may include many other equivalent embodiments without departing from the scope of the present invention. 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 consists of 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 power; The third lens and the fourth lens have positive refractive power; the wide-angle fixed-focus lens further includes an aperture stop, which is located between the third lens and the fourth lens; The fifth lens, the seventh lens, the ninth lens and the tenth lens have positive refractive power; The sixth lens and the eighth lens have negative optical power; The total 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 optical back focus of the wide-angle fixed-focus lens is BFL, which satisfies: ； 。 2. 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.

3. The wide-angle fixed-focus lens according to claim 2, wherein: The object-side surface of the third lens is concave toward the object side, and the image-side surface of the third lens is convex toward the image side; The object-side surface of the fourth lens is concave toward the object side, and the image-side surface of the fourth lens is convex toward the image side; The object-side surface of the ninth lens is concave toward the object side, and the image-side surface of the ninth lens is convex toward the image side.

4. The wide-angle fixed-focus lens according to claim 3, 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 toward the object side, and the image-side surface of the tenth lens is convex toward the image side.

5. The wide-angle fixed-focus lens according to claim 1, wherein: The curvature radius of the object-side surface of the first lens is R1, and the curvature radius of the image-side surface of the first lens is R2, satisfying: 。 6. 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: ； ； ； 。 7. The wide-angle fixed-focus lens according to claim 1, wherein: The entrance pupil diameter of the wide-angle fixed-focus lens is EPD, which satisfies: 。 8. The wide-angle fixed-focus lens according to claim 1, wherein: The focal power of the first lens is F1, the focal power of the second lens is F2, the focal power of the third lens is F3, the focal power of the fourth lens is F4, the focal power of the fifth lens is F5, the focal power of the sixth lens is F6, the focal power of the seventh lens is F7, the focal power of the eighth lens is F8, the focal power of the ninth lens is F9, the focal power of the tenth lens is F10, and the focal power of the wide-angle fixed-focus lens is F, which satisfies: ； ； ； ； ； ； ； ； ； 。

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