Prime lens

Abstract

The utility model discloses a prime lens. The prime lens comprises a first lens to a ninth lens which are sequentially arranged from the object space to the image space along the optical axis. The first lens is a glass lens with negative focal power, the second lens is a plastic lens with negative focal power, the third lens is a plastic lens with positive focal power, the fourth lens is a glass lens with positive focal power, the fifth lens is a glass lens with positive focal power, the sixth lens is a glass lens with negative focal power, and the seventh lens is a glass lens with positive focal power. The eighth lens is a plastic lens with negative focal power, and the ninth lens is a plastic lens with positive focal power. The prime lens provided by the utility model adopts a 5G4P optical system structure, and by optimizing the shape and focal power of each lens and the relative position of each lens, the aperture number is 0.96-1.091, the total optical length is less than or equal to 22.5 mm, the maximum field angle is 161.28 degrees, and the requirements of large aperture, ultra-wide angle and infrared confocal are met.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of lens especially relates to a fixed focus lens. BACKGROUND

[0002] With the progress of science and technology and the development of 5G (the fifth generation mobile communication), all walks of life have put forward higher requirements on the performance of lenses in all aspects, and since small aperture cannot meet the demand of low-illumination shooting environment, large aperture has become the trend of photographic lens products. At present, a series of large aperture products have appeared on the market, but there are few large aperture super wide-angle lenses, and even fewer lenses that can meet the requirements of large aperture and infrared focal coincidence at the same time. SUMMARY

[0003] The utility model provides a fixed focus lens, this fixed focus lens adopts 5 piece glass lens and 4 piece plastic lens (5G4P) optical system structure, and through optimizing the shape of each lens, the focal power and the relative position of each lens, finally realizes the lens design of large aperture, super wide angle, infrared focal coincidence, the aperture number of this fixed focus lens is 0.96~1.091, the total length of optics is less than or equal to 22.5mm, the maximum field of view angle is 161.28 °, meets the requirements of large aperture, super wide angle, infrared focal coincidence.

[0004] According to an aspect of the utility model, provide a fixed focus lens, including first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens and ninth lens arranged in order along the optical axis from the object side to the image side;

[0005] Among them, the first lens is the glass lens with negative focal power, the second lens is the plastic lens with negative focal power, the third lens is the plastic lens with positive focal power, the fourth lens is the glass lens with positive focal power, the fifth lens is the glass lens with positive focal power, the sixth lens is the glass lens with negative focal power, the seventh lens is the glass lens with positive focal power, the eighth lens is the plastic lens with negative focal power, and the ninth lens is the plastic lens with positive focal power.

[0006] Optionally, the first lens and the second lens satisfy:

[0007] -0.533≤Φ1 / Φ≤-0.493;

[0008] -0.279≤Φ2 / Φ≤-0.152;

[0009] 1.866≤Nd1≤1.914;

[0010] 38.982≤Vd1≤50.238;

[0011] Wherein, Φ1 represents the optical power of the first lens, Φ2 represents the optical power of the second lens, Φ represents the optical power of the entire fixed focus lens, Nd1 and Vd1 represent the refractive index and Abbe number of the first lens respectively.

[0012] Optionally, the first lens is a convex-concave glass spherical lens, and the second lens is a concave-convex plastic aspherical lens.

[0013] Optionally, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy:

[0014] 0.185≤Φ3 / Φ≤0.307;

[0015] 0.234≤Φ4 / Φ≤0.421;

[0016] 0.134≤Φ5 / Φ≤0.313;

[0017] -0.767≤Φ6 / Φ≤-0.499;

[0018] 0.539≤Φ7 / Φ≤0.643;

[0019] 1.792≤Nd4≤1.972;

[0020] 26.936≤Vd4≤40.903;

[0021] 1.585≤Nd5≤1.660;

[0022] 51.485≤Vd5≤71.028;

[0023] 1.800≤Nd6≤1.841;

[0024] 24.956≤Vd6≤25.364;

[0025] 1.547≤Nd7≤1.598;

[0026] 67.250≤Vd7≤94.010;

[0027] Φ3, Φ4, Φ5, Φ6 and Φ7 represent the optical power of the third lens, the optical power of the fourth lens, the optical power of the fifth lens, the optical power of the sixth lens and the optical power of the seventh lens respectively, Φ represents the optical power of the entire fixed focus lens, Nd4, Vd4, Nd5, Vd5, Nd6, Vd6, Nd7 and Vd7 represent the refractive index of the fourth lens, the Abbe number of the fourth lens, the refractive index of the fifth lens, the Abbe number of the fifth lens, the refractive index of the sixth lens, the Abbe number of the sixth lens, the refractive index of the seventh lens and the Abbe number of the seventh lens respectively.

[0028] Optionally, the third lens is a double-convex plastic aspheric lens, the fourth lens is a double-convex glass spherical lens or a double-convex glass aspheric lens, the fifth lens is a glass spherical lens, the sixth lens is a convex-concave or double-concave glass spherical lens, and the seventh lens is a double-convex glass spherical lens.

[0029] Optionally, the eighth lens and the ninth lens satisfy:

[0030] -0.777≤Φ8 / Φ≤-0.394;

[0031] 0.422≤Φ9 / Φ≤0.808;

[0032] Φ8 represents the optical power of the eighth lens, Φ9 represents the optical power of the ninth lens, and Φ represents the optical power of the entire fixed focus lens.

[0033] Optionally, the eighth lens is a plastic aspheric lens with a concave object side, and the ninth lens is a plastic aspheric lens with a convex object side.

[0034] Optionally, the fixed focus lens has an aperture number ranging from 0.96 to 1.091, and the total optical length of the fixed focus lens is less than or equal to 22.5 mm.

[0035] Optionally, it further comprises a diaphragm, and the diaphragm is located between the second lens and the third lens.

[0036] Optionally, it further comprises a filter, and the filter is located between the ninth lens and the image plane.

[0037] The fixed focus lens provided by the embodiment of the utility model, adopts the optical system structure of 5G4P, and through optimizing the shape, focal length of each lens and the relative position of each lens, finally realizes the lens design of large aperture, super wide angle and infrared confocal; the fixed focus lens aperture number is 0.96~1.091, the optical total length is less than or equal to 22.5mm, the maximum field of view angle is 161.28°, satisfies the requirements of large aperture, super wide angle and infrared confocal.

[0038] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the utility model, and is not used to limit the scope of the utility model. Other features of the utility model will become easy to understand through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical scheme in the embodiments of the utility model, the drawings needed to be used in the embodiment description will be briefly introduced, obviously, the drawings in the following description are only some embodiments of the utility model, and for the ordinary skilled in the art, other drawings can be obtained according to these drawings without creating creative labor.

[0040] Figure 1 The structure schematic diagram of a fixed focus lens provided by the embodiment of the utility model is provided;

[0041] Figure 2 The axial aberration curve schematic diagram of embodiment 1 is provided;

[0042] Figure 3 The structure schematic diagram of another fixed focus lens provided by the embodiment of the utility model is provided;

[0043] Figure 4 The axial aberration curve schematic diagram of embodiment 2 is provided;

[0044] Figure 5 The structure schematic diagram of still another fixed focus lens provided by the embodiment of the utility model is provided;

[0045] Figure 6 Axial aberration curve schematic diagram for example 3;

[0046] Figure 7 Structure schematic diagram of another fixed focus lens provided by the utility model embodiment;

[0047] Figure 8 Axial aberration curve schematic diagram for example 4. DETAILED DESCRIPTION

[0048] In order to enable personnel in the technical field to better understand the utility model scheme, the technical scheme in the utility model embodiment will be clearly and completely described below in combination with the drawings in the utility model embodiment. Obviously, the described embodiment is only a part of the embodiment of the utility model, rather than all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor should belong to the protection scope of the utility model.

[0049] It should be noted that the terms "first", "second" and the like in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be exchanged under appropriate circumstances, so that the embodiments of the utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to the clearly listed steps or units, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] Figure 1 Structure schematic diagram of a fixed focus lens provided by the utility model embodiment, refer to Figure 1The fixed-focus lens comprises, in sequence along the optical axis from the object side to the image side, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70, an eighth lens 80 and a ninth lens 90; wherein the first lens 10 is a glass lens with negative refractive power, the second lens 20 is a plastic lens with negative refractive power, the third lens 30 is a plastic lens with positive refractive power, the fourth lens 40 is a glass lens with positive refractive power, the fifth lens 50 is a glass lens with positive refractive power, the sixth lens 60 is a glass lens with negative refractive power, the seventh lens 70 is a glass lens with positive refractive power, the eighth lens 80 is a plastic lens with negative refractive power, and the ninth lens 90 is a plastic lens with positive refractive power.

[0051] It can be understood that the refractive power is the reciprocal of the focal length, and represents the ability of the optical system to deflect light rays. The greater the absolute value of the refractive power, the stronger the bending ability of the light rays, and the smaller the absolute value of the refractive power, the weaker the bending ability of the light rays. When the refractive power is positive, the refraction of the light rays is convergent; when the refractive power is negative, the refraction of the light rays is divergent. The glass lens is easy to process and has better thermal stability, the plastic lens has low cost, the plastic aspheric lens has better aberration correction effect, and the design of the glass-plastic hybrid structure can play a mutual compensation effect. The use of glass and plastic lenses in combination in the fixed-focus lens can better balance the resolution of the lens and improve the imaging effect. By setting the refractive power of the first lens 10 and the second lens 20 to be negative, more light rays are ensured to enter the fixed-focus lens, which is conducive to the realization of the super-wide-angle system; by setting the refractive power combination of the third lens 30, the fourth lens 40, the fifth lens 50, the sixth lens 60 and the seventh lens 70, the realization of large aperture and infrared confocal is facilitated; by setting the eighth lens 80 and the ninth lens 90, aberration correction is facilitated to ensure the resolution; by reasonably designing the shape, refractive power and relative position of each lens, the aperture number is 0.96-1.091, the total optical length is less than or equal to 22.5mm, the maximum field of view is 161.28°, and the requirements of large aperture, super-wide-angle and infrared confocal are met.

[0052] Optionally, with reference back to Figure 1 , the fixed-focus lens further comprises a diaphragm 100, and the diaphragm 100 is located between the second lens 20 and the third lens 30. The diaphragm 100 is arranged between the second lens 20 with negative refractive power and the third lens 30 with positive refractive power, and can be used to block off-axis light rays, better correct high-order aberrations and improve imaging quality.

[0053] Optionally, with reference back to Figure 1 , the fixed-focus lens further comprises a filter 110, and the filter 110 is located between the ninth lens 90 and the image plane.

[0054] The filter 110 is configured to filter light outside the wavelength range of the imaging light, thereby improving the imaging quality.

[0055] Optionally, the first lens 10 and the second lens 20 satisfy:

[0056] -0.533≤Φ1 / Φ≤-0.493;

[0057] -0.279≤Φ2 / Φ≤-0.152;

[0058] 1.866≤Nd1≤1.914;

[0059] 38.982≤Vd1≤50.238;

[0060] wherein Φ1 represents the optical power of the first lens 10, Φ2 represents the optical power of the second lens 20, Φ represents the optical power of the entire fixed focus lens, and Nd1 and Vd1 represent the refractive index and Abbe number of the first lens 10, respectively.

[0061] Optionally, the first lens 10 is a convex-concave glass spherical lens, and the second lens 20 is a concave-convex plastic aspherical lens.

[0062] By configuring the first lens 10 and the second lens 20 to satisfy the above conditions, the system is conducive to the realization of ultra-wide angle.

[0063] Optionally, the third lens 30, the fourth lens 40, the fifth lens 50, the sixth lens 60 and the seventh lens 70 satisfy:

[0064] 0.185≤Φ3 / Φ≤0.307;

[0065] 0.234≤Φ4 / Φ≤0.421;

[0066] 0.134≤Φ5 / Φ≤0.313;

[0067] -0.767≤Φ6 / Φ≤-0.499;

[0068] 0.539≤Φ7 / Φ≤0.643;

[0069] 1.792≤Nd4≤1.972;

[0070] 26.936≤Vd4≤40.903;

[0071] 1.585≤Nd5≤1.660;

[0072] 51.485≤Vd5≤71.028;

[0073] 1.800≤Nd6≤1.841;

[0074] 24.956≤Vd6≤25.364;

[0075] 1.547≤Nd7≤1.598;

[0076] 67.250≤Vd7≤94.010;

[0077] wherein, Φ3, Φ4, Φ5, Φ6 and Φ7 represent the optical power of the third lens 30, the optical power of the fourth lens 40, the optical power of the fifth lens 50, the optical power of the sixth lens 60 and the optical power of the seventh lens 70 respectively, Φ represents the optical power of the whole fixed focus lens, Nd4, Vd4, Nd5, Vd5, Nd6, Vd6, Nd7 and Vd7 represent the refractive index of the fourth lens 40, the Abbe number of the fourth lens 40, the refractive index of the fifth lens 50, the Abbe number of the fifth lens 50, the refractive index of the sixth lens 60, the Abbe number of the sixth lens 60, the refractive index of the seventh lens 70 and the Abbe number of the seventh lens 70 respectively.

[0078] Optionally, the third lens 30 is a double-convex plastic aspheric lens, the fourth lens 40 is a double-convex glass spherical lens or a double-convex glass aspheric lens, the fifth lens 50 is a glass spherical lens, the sixth lens 60 is a convex-concave or double-concave glass spherical lens, and the seventh lens 70 is a double-convex glass spherical lens.

[0079] When the optical power, the refractive index and the Abbe number of the third lens 30, the fourth lens 40, the fifth lens 50, the sixth lens 60 and the seventh lens 70 satisfy the above ranges, the high-order spherical aberration introduction amount can be reduced, the chromatic aberration can be corrected, and the realization of large aperture and infrared confocal is facilitated.

[0080] Optionally, the eighth lens 80 and the ninth lens 90 satisfy:

[0081] -0.777≤Φ8 / Φ≤-0.394;

[0082] 0.422≤Φ9 / Φ≤0.808;

[0083] wherein, Φ8 represents the optical power of the eighth lens 80, Φ9 represents the optical power of the ninth lens 90, and Φ represents the optical power of the whole fixed focus lens.

[0084] Optionally, the eighth lens 80 is a plastic aspheric lens with a concave object side, and the ninth lens 90 is a plastic aspheric lens with a convex object side.

[0085] When the optical power of the eighth lens 80 and the ninth lens 90 satisfies the above range, the light ray angle reaching the image plane can be reduced, the relative luminance of the imaging picture is ensured to be high, and the aberration correction is beneficial to ensure the resolving power. By reasonably allocating the material, optical power, central thickness of each lens, and the on-axis distance between each lens and other parameters, the aberration of the lens in the wavelength range of 436nm-850nm is reasonably corrected and balanced, so that the above fixed focus lens system can realize at least one of the beneficial effects of large aperture, super wide angle, infrared confocal, etc.

[0086] In the embodiment, the surface of the aspheric lens satisfies the following formula:

[0087]

[0088] Wherein, z is the axial height of the aspheric Z direction; r is the height of the aspheric surface; c is the curvature of the fitting sphere, which is the reciprocal of the radius of curvature in numerical value; k is the fitting conical coefficient; A, B, C, D, E, F, G are respectively the 4th, 6th, 8th, 10th, 12th, 14th, 16th order coefficients of the aspheric polynomial.

[0089] For example, Table 1 is the specific parameters of the corresponding fixed focus lens: Figure 1

[0090] Table 1 Specific parameters of fixed focus lens

[0091] Scope of protection Example 1 Lower limit Upper limit Φ1 / Φ -0.530 -0.533 -0.493 Φ2 / Φ -0.162 -0.279 -0.152 Φ3 / Φ 0.195 0.185 0.307 Φ4 / Φ 0.406 0.234 0.421 Φ5 / Φ 0.230 0.134 0.313 Φ6 / Φ -0.743 -0.767 -0.499 Φ7 / Φ 0.603 0.539 0.643 Φ8 / Φ -0.746 -0.777 -0.394 Φ9 / Φ 0.776 0.422 0.808 Nd1 1.910 1.866 1.914 Nd4 1.957 1.792 1.972 Nd5 1.654 1.585 1.660 Nd6 1.838 1.800 1.841 Nd7 1.552 1.547 1.598 Vd1 49.300 38.982 50.238 Vd4 28.100 26.936 40.903 Vd5 53.114 51.485 71.028 Vd6 24.990 24.956 25.364 Vd7 91.780 67.250 94.010

[0092] Table 2 is the parameter data of each lens in Example 1, and Example 1 can realize a fixed focus lens with focal length f=3.14mm, aperture number F#=1.08, image plane Field of view FOV=161.28°.

[0093] Table 2 Design values of optical and physical parameters of fixed focus lens of Example 1

[0094]

[0095]

[0096] ​The surface number is numbered according to the surface sequence of each lens, S11 and S12 are cemented surfaces, OBJ represents an object plane of the fixed-focus lens, STO represents a stop of the fixed-focus lens, IMA represents an image plane of the fixed-focus lens, the radius of curvature represents the bending degree of the surface of the lens, a positive value represents that the surface is bent to the image plane side, and a negative value represents that the surface is bent to the object plane side, Infinity represents that the surface is a plane, the radius of curvature is infinite, and the distance is infinite, the thickness represents the central axis distance from the current surface to the next surface, the refractive index represents the light deflection ability of the material between the current surface and the next surface, the space represents that the current position is air, and the refractive index is 1, the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface, the space represents that the current position is air, the half aperture represents the effective diameter of the light of the lens, and the k value represents the numerical size of the conic coefficient of the aspheric surface.

[0097] Table 3 is the design value of the aspheric surface parameter in Example 1:

[0098]

[0099]

[0100] Continuation of Table 3

[0101] Surface number E F G S3 1.8961E-07 -9.1044E-09 0.0000E+00 S4 2.9431E-07 -6.3171E-09 0.0000E+00 S6 2.2721E-07 -1.8338E-09 -1.8710E-10 S7 2.6877E-08 -2.7649E-12 8.6423E-11 S8 -2.8356E-10 -2.0179E-11 0.0000E+00 S9 1.7862E-09 -4.8194E-10 0.0000E+00 S14 -1.2378E-08 1.5904E-08 -1.1349E-09 S15 -8.8862E-08 -1.3160E-09 1.1095E-10 S16 1.6319E-07 -1.0998E-08 0.0000E+00 S17 -7.5687E-08 -4.5862E-09 0.0000E+00

[0102] -3.7372E-03 represents that the A coefficient of the surface number S3 is -3.7372*10 -3 .

[0103] Figure 2 FIG. 1 is an axial aberration curve schematic diagram of Example 1, the vertical direction represents the normalized aperture, 0 represents on the optical axis, and the vertical direction vertex represents the maximum pupil radius; the horizontal direction represents the offset amount relative to the ideal focus point, and the unit is millimeter (mm). Different color curves in the figure represent different wavelengths of system imaging, and the color curve of the leftmost side represents the wavelength of 450nm, the color curve of the middle represents the wavelength of 550nm, and the color curve of the rightmost side represents the wavelength of 650nm. Figure 2 It can be seen that the axial aberration of different wavelengths is controlled in the range of (-0.05mm, +0.05mm), which indicates that the aberration of the fixed-focus lens at each wavelength is well controlled, and the wide-spectrum application requirement can be met.

[0104] Figure 3 FIG. 2 is a structure schematic diagram of another fixed-focus lens provided by the embodiment of the utility model, and Table 4 is the specific parameters of the corresponding fixed-focus lens: Figure 3

[0105] Table 4 is the specific parameters of the fixed-focus lens

[0106]

[0107] ​

[0108] Table 5 is the parameter data of each lens in Example 2, which can realize a focal length f = 2.975 mm, an aperture number F# = 0.956, an image surface of a field of view FOV = 151.62° of a fixed focus lens.

[0109] Table 5 is the design value of the optical physical parameters of the fixed focus lens of Example 2

[0110]

[0111]

[0112] The surface number of each lens is numbered according to the surface order, S13 is the cemented surface, "OBJ" represents the object surface of the fixed focus lens, "STO" represents the stop of the fixed focus lens, "IMA" represents the image surface of the fixed focus lens, the radius of curvature represents the bending degree of the lens surface, the positive value represents that the surface is bent to the image side, and the negative value represents that the surface is bent to the object side, wherein "Infinity" represents that the surface is a plane, the radius of curvature is infinite, and the distance is infinite; the thickness represents the center axis distance from the current surface to the next surface, the refractive index represents the light deflection ability of the material between the current surface and the next surface, and the space represents that the current position is air, the refractive index is 1; the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface, and the space represents that the current position is air; the half aperture represents the effective diameter of the lens; the k value represents the numerical size of the conic coefficient of the aspheric surface.

[0113] Table 6 is the design value of the aspheric surface parameters in Example 2:

[0114] Surface number A B C D S3 3.1686E-04 2.5740E-05 -2.2829E-05 2.6783E-06 S4 6.2579E-03 -3.9845E-04 3.2043E-05 -5.1406E-06 S6 -1.4851E-03 1.4518E-04 6.5103E-06 -2.6398E-06 S7 -1.9030E-05 1.8002E-04 -5.8199E-06 -2.7262E-07 S8 1.1130E-03 -3.9749E-05 3.1146E-07 3.9306E-09 S9 3.5017E-04 -2.5045E-06 4.0849E-07 4.9887E-08 S15 2.9053E-03 -3.5501E-04 1.2811E-05 4.7865E-07 S16 1.0744E-04 -9.9284E-05 -6.8762E-06 1.0805E-06 S17 -1.0577E-03 4.9607E-05 -2.1659E-05 -9.4782E-07 S18 -2.0563E-03 9.3489E-05 -2.5554E-05 1.3157E-06

[0115] Table 6 (continued)

[0116]

[0117]

[0118] wherein 3.1686E-04 represents that the A coefficient of the surface number S3 is 3.1686 x 10 -4 .

[0119] Figure 4 Figure 2 is an axial aberration curve diagram of Example 2, the vertical direction represents the normalized aperture, 0 represents on the optical axis, and the vertical direction vertex represents the maximum pupil radius; the horizontal direction represents the relative ideal focus offset, and the unit is millimeter (mm). Different color curves in the figure represent different wavelengths of system imaging, and the Figure 4It can be seen that the axial aberration of different wavelengths is controlled in the range of (-0.05mm, +0.05mm), which shows that the aberration of the fixed focus lens at each wavelength is well controlled, and the wide spectrum application requirement can be met.

[0120] Figure 5 Table 7 is a structure schematic diagram of another fixed focus lens provided by the embodiment of the utility model, and table 7 is the specific parameters of the corresponding fixed focus lens. Figure 5 The specific parameters of the corresponding fixed focus lens are shown in table 7.

[0121] Table 7 is the specific parameters of the fixed focus lens

[0122]

[0123]

[0124] Table 8 is the parameter data of each lens in the embodiment 3, and the embodiment 3 can realize the fixed focus lens with focal length f=2.985mm, aperture number F#=1.08, image surface and field of view angle FOV=151.64°.

[0125] Table 8 is the design value of the optical physical parameters of the fixed focus lens of the embodiment 3

[0126]

[0127]

[0128] The surface number in the table is numbered according to the surface order of each lens, S13 is a cemented surface, "OBJ" represents the object surface of the fixed focus lens, "STO" represents the diaphragm of the fixed focus lens, and "IMA" represents the image surface of the fixed focus lens; the radius of curvature represents the bending degree of the lens surface, the positive value represents that the surface is bent to the image surface side, and the negative value represents that the surface is bent to the object surface side, wherein "Infinity" represents that the surface is a plane, the radius of curvature is infinite, and the distance is infinite; the thickness represents the central axial distance from the current surface to the next surface, the refractive index represents the deflection ability of the material between the current surface and the next surface, and the space represents that the current position is air, and the refractive index is 1; the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface, and the space represents that the current position is air; the half radius represents the effective diameter of the light of the lens; the k value represents the numerical size of the conic coefficient of the aspheric surface.

[0129] Table 9 is the design value of the aspheric surface parameters in the embodiment 3:

[0130] Surface number A B C D S3 5.5111E-05 6.1058E-05 -1.8640E-05 2.7846E-06 S4 6.0198E-03 -2.9272E-04 3.1653E-05 -5.5666E-06 S6 -1.5133E-03 1.2316E-04 3.2529E-06 -2.9224E-06 S7 3.6992E-04 1.6130E-04 -8.6776E-06 -3.8888E-07 S8 1.0121E-03 -4.5843E-05 5.0755E-07 5.0618E-09 S9 2.7964E-04 -6.7811E-06 1.5092E-06 9.7784E-08 S15 1.9344E-03 -2.5318E-04 1.4389E-05 2.4726E-07 S16 1.6991E-03 -1.4046E-04 -6.3397E-06 1.2568E-06 S17 -1.2354E-03 1.2119E-04 -2.0821E-05 -1.0230E-06 S18 -2.3535E-03 2.0398E-04 -3.0698E-05 1.1943E-06

[0131] Table 9 is continued

[0132]

[0133]

[0134] where 5.5111E-05 means that the A coefficient of the surface sequence number S3 is 5.5111×10 -5 .

[0135] Figure 6 Figure 3 is a schematic diagram of the axial aberration curve of Example 3, the vertical direction represents the normalized aperture, 0 represents on the optical axis, and the vertical direction vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focal point, with the unit of millimeter (mm). Different color curves in the figure represent different wavelengths of system imaging, and the specific parameters are shown in Table 10. Figure 6 It can be seen that the axial aberration of different wavelengths is controlled within the range of (-0.05mm, +0.05mm), which shows that the aberration of the fixed focus lens at each wavelength is well controlled, and the wide spectrum application requirement can be met.

[0136] Figure 7 Figure 4 is a schematic diagram of another structure of a fixed focus lens provided by the embodiment of the present application, and Table 11 is the specific parameters of the fixed focus lens corresponding to Figure 4. Figure 7

[0137] Table 10 Specific parameters of the fixed focus lens

[0138] Scope of protection Example 4 Lower limit Upper limit Φ1 / Φ -0.529 -0.533 -0.493 Φ2 / Φ -0.268 -0.279 -0.152 Φ3 / Φ 0.268 0.185 0.307 Φ4 / Φ 0.300 0.234 0.421 Φ5 / Φ 0.298 0.134 0.313 Φ6 / Φ -0.745 -0.767 -0.499 Φ7 / Φ 0.590 0.539 0.643 Φ8 / Φ -0.449 -0.777 -0.394 Φ9 / Φ 0.517 0.422 0.808 Nd1 1.870 1.866 1.914 Nd4 1.810 1.792 1.972 Nd5 1.590 1.585 1.660 Nd6 1.810 1.800 1.841 Nd7 1.590 1.547 1.598 Vd1 40.700 38.982 50.238 Vd4 40.900 26.936 40.903 Vd5 68.600 51.485 71.028 Vd6 25.500 24.956 25.364 Vd7 68.600 67.250 94.010

[0139] Table 11 is the parameter data of each lens in Example 4, and Example 4 can realize a fixed focus lens with a focal length f = 2.969mm, an aperture number F# = 1.091, an image surface field angle FOV = 151.65°.

[0140] Table 11 Design values of optical physical parameters of the fixed focus lens of Example 4

[0141]

[0142] ​The surface number is numbered according to the surface sequence of each lens, S11 and S12 are cemented surfaces, "OBJ" represents an object surface of the fixed-focus lens, "STO" represents a stop surface of the fixed-focus lens, "IMA" represents an image surface of the fixed-focus lens, the radius of curvature represents the bending degree of the lens surface, a positive value represents that the surface is bent to the image surface side, and a negative value represents that the surface is bent to the object surface side, wherein "Infinity" represents that the surface is a plane, the radius of curvature is infinite, and the distance is infinite, the thickness represents the central axis distance from the current surface to the next surface, the refractive index represents the light deflection ability of the material between the current surface and the next surface, the space represents that the current position is air, and the refractive index is 1, the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface, and the space represents that the current position is air, the half aperture represents the effective diameter of the lens, and the k value represents the numerical size of the conic coefficient of the aspheric surface.

[0143] Table 12 is the design value of the aspheric surface parameter in Example 4:

[0144] Surface number A B C D S3 1.776E-04 2.686E-05 -1.913E-05 2.298E-06 S4 5.795E-03 -3.538E-04 3.663E-05 -5.197E-06 S6 -1.924E-03 1.064E-04 6.449E-06 -2.483E-06 S7 -9.778E-04 1.207E-04 -4.503E-06 -9.110E-08 S14 2.111E-03 -3.172E-04 1.531E-05 3.728E-07 S15 3.500E-04 -8.271E-05 -6.952E-06 1.055E-06 S16 -1.051E-03 7.102E-05 -1.955E-05 -1.153E-06 S17 -1.607E-03 9.878E-05 -2.697E-05 1.309E-06

[0145] Table 12 (continued)

[0146] Surface number E F G S3 -1.570E-07 5.588E-09 0.000E+00 S4 4.575E-07 -1.508E-08 0.000E+00 S6 2.222E-07 -4.992E-09 -6.152E-11 S7 1.645E-08 4.332E-10 8.383E-13 S14 -7.410E-08 1.274E-09 6.087E-11 S15 -5.087E-08 -1.029E-09 1.065E-10 S16 1.603E-07 -3.256E-09 0.000E+00 S17 -8.882E-09 2.926E-10 0.000E+00

[0147] wherein 1.776E-04 represents that the A coefficient of the surface number S3 is 1.776*10 -4 .

[0148] Figure 8 Fig. 6 is an axial aberration curve schematic diagram of Example 4, the vertical direction represents the normalized aperture, 0 represents on the optical axis, and the vertical direction vertex represents the maximum pupil radius; the horizontal direction represents the relative ideal focus offset, and the unit is millimeter (mm). Different color curves in the figure represent different wavelengths of system imaging, and the color of the curve represents the wavelength of the curve. Figure 8 It can be seen that the axial aberrations of different wavelengths are controlled within the range of (-0.05 mm, +0.05 mm), which indicates that the aberrations of the fixed-focus lens at different wavelengths are well controlled, and the wide-spectrum application requirement can be met.

[0149] The above specific embodiments do not constitute a limitation on the protection scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A 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, and a ninth lens arranged sequentially along the optical axis from the object side to the image side; Wherein, the first lens is a glass lens with negative optical power, the second lens is a plastic lens with negative optical power, the third lens is a plastic lens with positive optical power, the fourth lens is a glass lens with positive optical power, the fifth lens is a glass lens with positive optical power, the sixth lens is a glass lens with negative optical power, the seventh lens is a glass lens with positive optical power, the eighth lens is a plastic lens with negative optical power, and the ninth lens is a plastic lens with positive optical power.

2. The fixed-focus lens according to claim 1, characterized in that, The first lens and the second lens satisfy the following: -0.533≤Φ1 / Φ≤-0.493; -0.279≤Φ2 / Φ≤-0.152; 1.866≤Nd1≤1.914; 38.982≤Vd1≤50.238; Wherein, Φ1 represents the optical power of the first lens, Φ2 represents the optical power of the second lens, Φ represents the overall optical power of the fixed-focus lens, and Nd1 and Vd1 represent the refractive index and Abbe number of the first lens, respectively.

3. The fixed-focus lens according to claim 2, characterized in that, The first lens is a convex-concave glass spherical lens, and the second lens is a concave-convex plastic aspherical lens.

4. The fixed-focus lens according to claim 1, characterized in that, The third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy the following: 0.185≤Φ3 / Φ≤0.307; 0.234≤Φ4 / Φ≤0.421; 0.134≤Φ5 / Φ≤0.313; -0.767≤Φ6 / Φ≤-0.499; 0.539≤Φ7 / Φ≤0.643; 1.792≤Nd4≤1.972; 26.936≤Vd4≤40.903; 1.585≤Nd5≤1.660; 51.485≤Vd5≤71.028; 1.800≤Nd6≤1.841; 24.956≤Vd6≤25.364; 1.547≤Nd7≤1.598; 67.250≤Vd7≤94.010; Wherein, Φ3, Φ4, Φ5, Φ6 and Φ7 represent the optical power of the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens, respectively; Φ represents the overall optical power of the fixed-focus lens; and Nd4, Vd4, Nd5, Vd5, Nd6, Vd6, Nd7 and Vd7 represent the refractive index of the fourth lens, the Abbe number of the fourth lens, the refractive index of the fifth lens, the Abbe number of the fifth lens, the refractive index of the sixth lens, the Abbe number of the sixth lens, the refractive index of the seventh lens and the Abbe number of the seventh lens, respectively.

5. The fixed-focus lens according to claim 4, characterized in that, The third lens is a biconvex plastic aspherical lens, the fourth lens is a biconvex glass spherical lens or a biconvex glass aspherical lens, the fifth lens is a glass spherical lens, the sixth lens is a convex-concave or biconcave glass spherical lens, and the seventh lens is a biconvex glass spherical lens.

6. The fixed-focus lens according to claim 1, characterized in that, The eighth lens and the ninth lens satisfy the following: -0.777≤Φ8 / Φ≤-0.394; 0.422≤Φ9 / Φ≤0.808; Wherein, Φ8 represents the optical power of the eighth lens, Φ9 represents the optical power of the ninth lens, and Φ represents the overall optical power of the fixed-focus lens.

7. The fixed-focus lens according to claim 6, characterized in that, The eighth lens is a plastic aspherical lens with a concave object side, and the ninth lens is a plastic aspherical lens with a convex object side.

8. The fixed-focus lens according to claim 1, characterized in that, The aperture number of the fixed-focus lens ranges from 0.96 to 1.091, and the total optical length of the fixed-focus lens is less than or equal to 22.5 mm.

9. The fixed-focus lens according to claim 1, characterized in that, It also includes an aperture stop, which is located between the second lens and the third lens.

10. The fixed-focus lens according to claim 1, characterized in that, It also includes a filter, which is located between the ninth lens and the image plane.

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