Industrial lens

Abstract

The utility model discloses an industrial lens comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens which are sequentially arranged from an object plane to an image plane along an optical axis. The industrial lens further comprises a focusing lens group and a fixed lens group, the focusing lens group at least comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, and the fixed lens group at least comprises an eighth lens and a ninth lens; the industrial lens further comprises a diaphragm, the combined focal power of the multiple lenses located between the object plane and the diaphragm is phi a, the combined focal power of the multiple lenses located between the diaphragm and the image plane is phi b, and phi a / phi b is larger than or equal to 0.8 and smaller than or equal to 1.42. In conclusion, by reasonably setting the number of the lenses in the industrial lens and the corresponding relation between the focal power of the diaphragm front lens group and the focal power of the diaphragm rear lens group, the large target surface requirement of the industrial lens can be met, the size of an imaging chip is matched, and the imaging quality of the industrial lens is ensured.

Description

Technical Field

[0001] The utility model embodiment relates to the technical field of optical devices, and in particular to an industrial lens. Background Art

[0002] With the continuous development of modern industrial technology, industrial lenses are being used more and more widely, and their specifications are becoming more diverse. The size of camera chips is also becoming larger to adapt to more large-viewing field inspections.

[0003] The target surface of existing industrial lenses is generally small (usually less than 1"), and the size of one of the mainstream imaging chips for industrial lenses has increased to 1.2", but the number of optical lenses with this chip on the market is still relatively small. Utility Model Content

[0004] The utility model provides an industrial lens to meet the demand of the industrial lens for a large target surface.

[0005] The embodiment of the utility model provides an industrial lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens arranged in sequence from an object plane to an image plane along an optical axis;

[0006] The industrial lens further includes a focusing lens group and a fixed lens group, the focusing lens group includes at least the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens, and the fixed lens group includes at least the eighth lens and the ninth lens;

[0007] The industrial lens also includes an aperture, the combined focal length of the multiple lenses between the object plane and the aperture is Φa, the combined focal length of the multiple lenses between the aperture and the image plane is Φb, and 0.8≤Φa / Φb≤1.42.

[0008] Optionally, the focusing lens group includes the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens, and the fixed lens group includes the eighth lens and the ninth lens;

[0009] Alternatively, the focusing lens group includes the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens, and the fixed lens group includes the seventh lens, the eighth lens and the ninth lens;

[0010] Optionally, the aperture is disposed in the optical path between the third lens and the fourth lens, or the aperture is disposed in the optical path between the fourth lens and the fifth lens.

[0011] Optionally, the focal length of the second lens is Φ2, and the focal length of the industrial lens is Φ;

[0012] Among them, 0.403≤Φ2 / Φ≤0.794.

[0013] Optionally, the eighth lens and the ninth lens are bonded together;

[0014] The focal power of the eighth lens is Φ8, the focal power of the ninth lens is Φ9, the Abbe constant of the eighth lens is vd8, and the Abbe constant of the ninth lens is vd9;

[0015] Among them, 0.21≤1000*(Φ8 / vd8+Φ9 / vd9)≤0.34.

[0016] Optionally, the combined focal length of the sixth lens and the seventh lens is Φ6_7, the focal length of the industrial lens is Φ, and the refractive index of the seventh lens is nd7;

[0017] Among them, 1.122≤Φ6_7 / Φ≤2.553, and nd7>1.9.

[0018] Optionally, the focal power of the first lens is Φ1, the focal power of the fifth lens is Φ5, and the focal power of the industrial lens is Φ;

[0019] Among them, -0.83≤Φ1 / Φ≤-0.78, -3.067≤Φ5 / Φ≤1.391.

[0020] Optionally, the moving distance of the focusing lens group from the near object distance to the far object distance is ZOL, the focal length of the industrial lens is f, the clear aperture of the first lens is D1, and the distance from the vertex of the object side surface of the first lens to the image plane is TTL;

[0021] Among them, 0.300≤ZOL / f≤0.385, and 0.258≤D1 / TTL≤0.315.

[0022] Optionally, the focal length of the focusing lens group is EFL1, and the focal length of the fixed lens group is EFL2;

[0023] Among them, 0.319≤EFL1 / EFL2≤0.51.

[0024] Optionally, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens are all spherical lenses.

[0025] The industrial lens provided by the embodiment of the utility model 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 in sequence from the object plane to the image plane along the optical axis; further, the focusing lens group includes at least the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens, and the fixed lens group includes at least the eighth lens and the ninth lens; and the combined focal power Φa of the multiple lenses located between the object plane and the aperture and the combined focal power Φb of the multiple lenses located between the aperture and the image plane satisfy 0.8≤Φa / Φb≤1.42. By reasonably setting the number of lenses in the industrial lens, the setting method of the lenses in the focusing lens group and the fixed lens group, and the corresponding relationship between the focal powers of the lens group before the aperture and the lens group after the aperture, the requirements of the large target surface of the industrial lens can be met to match the size of the imaging chip and ensure the imaging quality of the industrial lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of an industrial lens provided by the first embodiment of the utility model;

[0027] Figure 2 This is a schematic diagram of a light fan of an industrial lens provided in the first embodiment of the utility model;

[0028] Figure 3 This is a schematic diagram of field curvature distortion of an industrial lens provided in the first embodiment of the utility model;

[0029] Figure 4 This is a structural schematic diagram of an industrial lens provided by Embodiment 2 of the present utility model;

[0030] Figure 5 This is a schematic diagram of a light fan of an industrial lens provided in the second embodiment of the utility model;

[0031] Figure 6 This is a schematic diagram of field curvature distortion of an industrial lens provided by the second embodiment of the utility model;

[0032] Figure 7 This is a schematic diagram of the structure of an industrial lens provided by Embodiment 3 of the present utility model;

[0033] Figure 8 This is a schematic diagram of a light fan of an industrial lens provided in Embodiment 3 of the present utility model;

[0034] Fig. 9 This is a schematic diagram of field curvature distortion of an industrial lens provided in Embodiment 3 of the present utility model. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0036] Embodiment 1

[0037] Figure 1 Schematic diagram of the structure of an industrial lens provided by the first embodiment of the utility model. Figure 1 As shown, the industrial lens provided in the first embodiment of the utility model includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, an eighth lens 180 and a ninth lens 190 arranged in sequence along the optical axis from the object plane to the image plane; the industrial lens also includes a focusing lens group G1 and a fixed lens group G2, the focusing lens group G1 at least includes the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160, and the fixed lens group G2 at least includes the eighth lens 180 and the ninth lens 190; the industrial lens also includes a diaphragm 200, the combined optical power of the multiple lenses located between the object plane and the diaphragm 200 is Φa, the combined optical power of the multiple lenses located between the diaphragm 200 and the image plane is Φb, and 0.8≤Φa / Φb≤1.42.

[0038] Specifically, in the industrial lens provided in this embodiment, the focusing lens group G1 and the fixed lens group G2 can be arranged in a lens barrel ( Figure 1 The fixed lens group G2 is fixed in the lens barrel, and the focusing lens group G1 can move back and forth along the optical axis in the lens barrel. Through the movement of the focusing lens group G1, the object distance of the industrial lens can be continuously changed, ensuring that the industrial lens has high image quality at different object distances.

[0039] It is understandable that the industrial lens realizes the focusing process at different object distances by moving the focusing lens group G1, and also has different lengths or shapes.

[0040] Furthermore, the focusing lens group G1 includes at least a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150 and a sixth lens 160, and the fixed lens group G2 includes at least an eighth lens 180 and a ninth lens 190. Figure 1In the industrial lens shown, the focus lens group G1 includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160 and a seventh lens 170, and the fixed lens group G2 includes an eighth lens 180 and a ninth lens 190. In other embodiments, the focus lens group G1 and the fixed lens group G2 may also have other configurations, which will be described in subsequent embodiments.

[0041] Furthermore, the focal length is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam, and it characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal length, the stronger the ability to bend light, and the smaller the absolute value of the focal length, the weaker the ability to bend light. When the focal length is a positive number, the refraction of light is convergent; when the focal length is a negative number, the refraction of light is divergent. The focal length can be used to characterize a certain refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a certain lens, and can also be used to characterize a system formed by multiple lenses (i.e., a lens group). The industrial lens provided in this embodiment includes nine lenses and an aperture 200. By setting the aperture 200, the part of the light beam emitted by the off-axis object point that participates in the imaging can be adjusted, which is beneficial to improving the imaging quality. The combined focal length of the multiple lenses located between the object plane and the aperture 200 can be understood as the combined focal length of all lenses before the aperture 200, and the combined focal length of the multiple lenses located between the aperture 200 and the image plane can be understood as the focal length of all lenses after the aperture. By constraining 0.8≤Φa / Φb≤1.42, the lens can meet the requirements of a large target surface; and the structure of the industrial lens in the embodiment of the utility model is evolved from a double Gaussian structure. The symmetry of the double Gaussian structure can well improve distortion and balance aberrations, thereby further enabling the lens to meet the requirements of a large target surface.

[0042] Based on the above embodiments, the first lens 110 , the second lens 120 , the third lens 130 , the fourth lens 140 , the fifth lens 150 , the sixth lens 160 , the seventh lens 170 , the eighth lens 180 and the ninth lens 190 are all spherical lenses.

[0043] Specifically, the spherical lens is characterized by having a constant curvature from the center of the lens to the periphery of the lens, ensuring that the lens is set in a simple manner. Furthermore, the spherical lens provided in the embodiment of the utility model can be a glass spherical lens. Since the thermal expansion coefficient of a lens made of glass material is small and has good stability, the first lens 110 to the ninth lens 190 can be set to be glass spherical lenses, which can balance high and low temperatures. When the ambient temperature used by the industrial lens changes greatly, it is beneficial to maintain the focal length of the industrial lens stable. At the same time, setting the first lens 110 to the ninth lens 190 to be spherical lenses can also reduce the total length of the lens, which is conducive to realizing a miniaturized lens design.

[0044] On the basis of the above embodiments, the focusing lens group G1 may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160 and a seventh lens 170, and the fixed lens group G2 may include an eighth lens 180 and a ninth lens 190; or, the focusing lens group G1 may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150 and a sixth lens 160, and the fixed lens group G2 may include a seventh lens 170, an eighth lens 180 and a ninth lens 190.

[0045] Specifically, Figure 1 Taking the example that the focusing lens group G1 may include the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160 and the seventh lens 170, and the fixed lens group G2 may include the eighth lens 180 and the ninth lens 190, the following embodiments illustrate the case where the focusing lens group G1 includes the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160, and the fixed lens group G2 includes the seventh lens 170, the eighth lens 180 and the ninth lens 190. In different embodiments, the seventh lens 170 may be flexibly arranged in the focusing lens group G1 or the fixed lens group G2 to meet a variety of different usage requirements.

[0046] Furthermore, the aperture 200 may be disposed in the optical path between the third lens 130 and the fourth lens 140 (eg, Figure 1 Alternatively, the aperture 200 can be disposed in the optical path between the fourth lens 140 and the fifth lens 150. By arranging the aperture 200 in the middle of the industrial lens, the front and rear apertures of the industrial lens can be minimized.

[0047] On the basis of the above embodiment, the focal power of the second lens 120 is Φ2, and the focal power of the industrial lens is Φ; wherein 0.403≤Φ2 / Φ≤0.794. Since the off-axis light height of the second lens 120 is relatively high, the influence on the aberration is relatively obvious. By constraining the focal power of the front lens in the focusing lens group G1, the focal power Φ2 of the second lens 120 and the focal power Φ of the industrial lens are constrained to satisfy 0.403≤Φ2 / Φ≤0.794, which can reduce the influence of the movement of the focusing lens group G1 on the image quality at different working object distances.

[0048] On the basis of the above embodiment, the eighth lens 180 and the ninth lens 190 are glued together; the optical power of the eighth lens 180 is Φ8, the optical power of the ninth lens 190 is Φ9, the Abbe constant of the eighth lens 180 is vd8, and the Abbe constant of the ninth lens 190 is vd9; wherein, 0.21≤1000*(Φ8 / vd8+Φ9 / vd9)≤0.34.

[0049] Specifically, the eighth lens 180 and the ninth lens 190 are bonded together, which can be understood as the surface of the eighth lens 180 close to the image side is bonded to the surface of the ninth lens 190 close to the object side, that is, the image side surface of the eighth lens 180 is bonded to the object side surface of the ninth lens 190. By setting the eighth lens 180 and the ninth lens 190 to be bonded together, the air gap between the eighth lens 180 and the ninth lens 190 can be reduced, which helps to reduce the total optical length of the lens, and can also reduce the tolerance sensitivity problems such as tilt / eccentricity generated by the lens unit during the assembly process, simplify the assembly procedure during the lens manufacturing process, and improve equipment efficiency. At the same time, the eighth lens 180 and the ninth lens 190 are bonded together, which can also reduce the light loss caused by reflection between lenses, improve illumination, and reduce the risk of ghosting; and the bonded lens can be used to minimize or eliminate chromatic aberration. The use of bonded lenses in industrial lenses can improve image quality, reduce the reflection loss of light energy, thereby improving image quality and enhancing the clarity of lens imaging. Furthermore, the eighth lens 180 and the ninth lens 190 may be bonded together by glue, and the present invention does not limit the specific bonding method.

[0050] Furthermore, the optical power Φ8 and the Abbe constant vd8 of the eighth lens 180, and the optical power Φ9 and the Abbe constant vd9 of the ninth lens 190 satisfy 0.21≤1000*(Φ8 / vd8+Φ9 / vd9)≤0.34, so that the chromatic aberration of the cemented lens formed by the eighth lens 180 and the ninth lens 190 can be constrained, the system chromatic aberration can be effectively corrected, and the image quality can be improved.

[0051] On the basis of the above embodiment, the combined focal length of the sixth lens 160 and the seventh lens 170 is Φ6_7, the focal length of the industrial lens is Φ, and the refractive index of the seventh lens 170 is nd7; wherein, 1.122≤Φ6_7 / Φ≤2.553, and nd7>1.9. The focal lengths of the sixth lens 160 and the seventh lens 170 are constrained within this range, and the seventh lens 170 is made of a high refractive index material, which can effectively converge the light height at the tail end of the entire industrial lens and reduce the off-axis aberration caused by the large target surface, thereby achieving the purpose of high resolution.

[0052] Based on the above embodiment, the focal length of the first lens 110 is Φ1, the focal length of the fifth lens 150 is Φ5, and the focal length of the industrial lens is Φ; wherein, -0.83≤Φ1 / Φ≤-0.78, -3.067≤Φ5 / Φ≤1.391. Since the distortion of the optical system is the sum of the distortions of all lenses, by constraining the focal lengths of the front first lens 110 and the middle fifth lens 150 to be within this range, the lens distortion can be balanced by limiting the focal length of the lens, thereby improving the imaging effect.

[0053] On the basis of the above embodiment, the moving distance of the focus lens group G1 from the near object distance to the far object distance is ZOL, the focal length of the industrial lens is f, the clear aperture of the first lens 110 is D1, and the distance from the vertex of the object side of the first lens 110 to the image plane is TTL; wherein, 0.300≤ZOL / f≤0.385, and 0.258≤D1 / TTL≤0.315. By setting the corresponding relationship between the moving range of the focus lens group G1 and the focal length of the industrial lens within the above range, and the corresponding relationship between the clear aperture of the first lens 110 and the total optical length of the industrial lens within the above range, it is possible to avoid the moving range of the focus lens group G1 being too large, resulting in the clear aperture of the first lens 110 being too large, which is further conducive to the control and compression of the total length of the industrial lens.

[0054] Based on the above embodiment, the focal length of the focusing lens group G1 is EFL1, and the focal length of the fixed lens group G2 is EFL2; wherein 0.319≤EFL1 / EFL2≤0.51. By rationally allocating the focal length of the focusing lens group G1 and the focal length of the fixed lens group G2, it is helpful to ensure the focal length and image quality during the focusing process.

[0055] Based on the above embodiments, continue to refer to Figure 1 As shown, the industrial lens provided by the embodiment of the utility model further includes a filter 210, which is arranged in the optical path between the ninth lens 190 and the image plane. The arrangement of the filter 210 can filter out stray spectra to ensure the imaging quality. Furthermore, the industrial lens can also include flat glass to protect the lens and the image sensor.

[0056] Table 1 illustrates the parameters in Example 1 in a feasible implementation manner.

[0057] Table 1 Optical design values ​​of industrial lens in Example 1

[0058]

[0059]

[0060] Table 2 shows the design of an industrial lens provided in Example 1 of the utility model, and the focal length f of the lens is 24.928 mm.

[0061] Table 2 Surface type, curvature radius, thickness, refractive index, Abbe number and aperture of industrial lenses

[0062]

[0063] Among them, the surface number is numbered according to the order of the surfaces of each lens, "1" represents the object surface, "2" represents the object surface of the first lens 110, "3" represents the image surface of the first lens 110, and so on; the radius of curvature represents the curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; the thickness represents the central axial distance from the current surface to the next surface, the refractive index represents the ability of the material between the current surface and the next surface to deflect light, 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 to light; the semi-aperture represents half of the aperture size of the current surface.

[0064] Table 3 shows the focus interval values ​​in Table 2 (this focus interval limit can ensure clear imaging at different object distances):

[0065] Table 3 A design value of zoom interval

[0066] Object distance Object distance 100mm Object distance 1500mm Focus interval 9.500mm 2.004mm

[0067] Furthermore, Figure 2 This is a schematic diagram of a light fan of an industrial lens provided in the first embodiment of the utility model. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. Figure 2 The horizontal axis represents the beam aperture, and the vertical axis represents 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 dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 2 It can be seen that each wavelength of the system in each field of view is well close to the horizontal axis, indicating that the vertical axis aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the system is also well corrected, thereby ensuring that the optical system can achieve high-resolution imaging requirements.

[0068] Figure 3 This is a schematic diagram of field curvature distortion of an industrial lens provided by the first embodiment of the utility model. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, in units of mm. Figure 3It can be seen that the lens provided in this embodiment is effectively controlled in terms of field curvature from light with a wavelength of 0.449 μm to light with a wavelength of 0.680 μm (specifically, meridional rays and sagittal rays of 0.449 μm, 0.510 μm, 0.540 μm, 0.570 μm, 0.600 μm, 0.640 μm and 0.680 μm), that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; in the coordinate system on the right, the horizontal coordinate represents the size of the distortion, in %, and the vertical coordinate represents the normalized image height, without a unit; Figure 3 It can be seen that the imaging distortion of the lens provided in this embodiment is well corrected and the imaging distortion is small.

[0069] In summary, the industrial lens provided by the embodiment of the utility model, by reasonably setting the combination mode of the focusing lens group and the fixed lens group and the correspondence between the focal lengths, and at the same time reasonably setting the aperture position, the correspondence between the focal power of the lens group before the aperture and the focal power of the lens group after the aperture, the focal power of different lenses, the Abbe number, the refractive index, the moving distance of the focusing lens group, the aperture of the first lens, the total optical length, the focal length of the lens, and the lens type, finally realizes an industrial lens design that can take into account a large target surface, low distortion, and high resolution. The target surface of the industrial lens provided by the embodiment of the utility model can be 1.2″, |optical distortion|≤0.6%, and the resolution standard can reach 25MP.

[0070] Embodiment 2

[0071] Figure 4 Schematic diagram of the structure of an industrial lens provided by the second embodiment of the utility model. Figure 4 As shown, the industrial lens provided by Embodiment 2 of the present utility model includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, an eighth lens 180 and a ninth lens 190 arranged in sequence along the optical axis from the object plane to the image plane; the industrial lens also includes a focusing lens group G1 and a fixed lens group G2, the focusing lens group G1 at least includes the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160, and the fixed lens group G2 at least includes the eighth lens 180 and the ninth lens 190; the industrial lens also includes a diaphragm 200, the combined optical power of the multiple lenses located between the object plane and the diaphragm 200 is Φa, the combined optical power of the multiple lenses located between the diaphragm 200 and the image plane is Φb, and 0.8≤Φa / Φb≤1.42.

[0072] The second embodiment and the first embodiment differ in the division of different lens groups in the industrial lens. In this embodiment, the focusing lens group G1 includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, and a sixth lens 160, and the fixed lens group G2 includes a seventh lens 170, an eighth lens 180, and a ninth lens 190.

[0073] Other optical parameters are the same as those in the first embodiment and will not be described again here.

[0074] Table 4 illustrates the parameters in Example 2 in a feasible implementation manner.

[0075] Table 4 Optical design values ​​of industrial lens in Example 2

[0076] Scope of protection Example 2 Lower limit Upper limit Φ2 / Φ 0.404 0.403 0.794 1000*(Φ8 / vd8+Φ9 / vd9) 0.274 0.210 0.340 Φ6_7 / Φ 1.124 1.122 2.553 nd7 1.986 1.9 Φ1 / Φ -0.823 -0.83 -0.78 Φ5 / Φ 1.390 -3.067 1.391 ZOL / f 0.385 0.300 0.385 D1 / TTL 0.259 0.258 0.315 Φa / Φb 1.240 0.8 1.42 EFL1 / EFL2 0.485 0.319 0.51

[0077] Table 5 shows the design of an industrial lens provided in Example 2 of the present utility model, and the focal length f of the lens is 25.072 mm.

[0078] Table 5 Surface type, curvature radius, thickness, refractive index, Abbe number and aperture of industrial lenses

[0079]

[0080] Among them, the surface number is numbered according to the order of the surfaces of each lens, "1" represents the object surface, "2" represents the object surface of the first lens 110, "3" represents the image surface of the first lens 110, and so on; the radius of curvature represents the curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; the thickness represents the central axial distance from the current surface to the next surface, the refractive index represents the ability of the material between the current surface and the next surface to deflect light, 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 to light; the semi-aperture represents half of the aperture size of the current surface.

[0081] Table 6 shows the focus interval values ​​in Table 5 (this focus interval limit can ensure clear imaging at different object distances):

[0082] Table 6 A design value of zoom interval

[0083] Object distance Object distance 100mm Object distance 1500mm Focus interval 10.640mm 1.000mm

[0084] Furthermore, Figure 5 This is a schematic diagram of a light fan of an industrial lens provided in the second embodiment of the utility model. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. Figure 5The horizontal axis represents the beam aperture, and the vertical axis represents 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 dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 5 It can be seen that each wavelength of the system in each field of view is well close to the horizontal axis, indicating that the vertical axis aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the system is also well corrected, thereby ensuring that the optical system can achieve high-resolution imaging requirements.

[0085] Figure 6 This is a schematic diagram of field curvature distortion of an industrial lens provided by the second embodiment of the utility model. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, in units of mm. Figure 6 It can be seen that the lens provided in this embodiment is effectively controlled in terms of field curvature from light with a wavelength of 0.449 μm to light with a wavelength of 0.680 μm (specifically, meridional rays and sagittal rays of 0.449 μm, 0.510 μm, 0.540 μm, 0.570 μm, 0.600 μm, 0.640 μm and 0.680 μm), that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; in the coordinate system on the right, the horizontal coordinate represents the size of the distortion, in %, and the vertical coordinate represents the normalized image height, without a unit; Figure 6 It can be seen that the imaging distortion of the lens provided in this embodiment is well corrected and the imaging distortion is small.

[0086] In summary, the industrial lens provided by the embodiment of the utility model, by reasonably setting the combination mode of the focusing lens group and the fixed lens group and the correspondence between the focal lengths, and at the same time reasonably setting the aperture position, the correspondence between the focal power of the lens group before the aperture and the focal power of the lens group after the aperture, the focal power of different lenses, the Abbe number, the refractive index, the moving distance of the focusing lens group, the aperture of the first lens, the total optical length, the focal length of the lens, and the lens type, finally realizes an industrial lens design that can take into account a large target surface, low distortion, and high resolution. The target surface of the industrial lens provided by the embodiment of the utility model can be 1.2″, |optical distortion|≤0.6%, and the resolution standard can reach 25MP.

[0087] Embodiment 3

[0088] Figure 7 Schematic diagram of the structure of an industrial lens provided by the third embodiment of the utility model. Figure 7As shown, the industrial lens provided in Embodiment 3 of the present utility model includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, an eighth lens 180 and a ninth lens 190 arranged in sequence along the optical axis from the object plane to the image plane; the industrial lens also includes a focusing lens group G1 and a fixed lens group G2, the focusing lens group G1 at least includes the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160, and the fixed lens group G2 at least includes the eighth lens 180 and the ninth lens 190; the industrial lens also includes a diaphragm 200, the combined optical power of the multiple lenses located between the object plane and the diaphragm 200 is Φa, the combined optical power of the multiple lenses located between the diaphragm 200 and the image plane is Φb, and 0.8≤Φa / Φb≤1.42.

[0089] The solution of the third embodiment is different from the solution of the first embodiment in the location of the aperture. In this embodiment, the aperture 200 is disposed in the optical path between the fourth lens 140 and the fifth lens 150 .

[0090] Other optical parameters are the same as those in the first embodiment and will not be described again here.

[0091] Table 7 illustrates the parameters in Example 3 in a feasible implementation manner.

[0092] Table 7 Optical design values ​​of industrial lens in Example 3

[0093] Scope of protection Example 3 Lower limit Upper limit Φ2 / Φ 0.794 0.403 0.794 1000*(Φ8 / vd8+Φ9 / vd9) 0.336 0.210 0.340 Φ6_7 / Φ 2.553 1.122 2.553 nd7 1.911 1.9 Φ1 / Φ -0.781 -0.83 -0.78 Φ5 / Φ -3.066 -3.067 1.391 ZOL / f 0.342 0.300 0.385 D1 / TTL 0.314 0.258 0.315 Φa / Φb 0.803 0.8 1.42 EFL1 / EFL2 0.510 0.319 0.51

[0094] Table 8 shows the design of an industrial lens provided in Example 3 of the present utility model, and the focal length f of the lens is 25.029 mm.

[0095] Table 8 Surface type, curvature radius, thickness, refractive index, Abbe number and aperture of industrial lenses

[0096]

[0097]

[0098] Among them, the surface number is numbered according to the order of the surfaces of each lens, "1" represents the object surface, "2" represents the object surface of the first lens 110, "3" represents the image surface of the first lens 110, and so on; the radius of curvature represents the curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; the thickness represents the central axial distance from the current surface to the next surface, the refractive index represents the ability of the material between the current surface and the next surface to deflect light, 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 to light; the semi-aperture represents half of the aperture size of the current surface.

[0099] Table 9 shows the focus interval values ​​in Table 8 (this focus interval limit can ensure clear imaging at different object distances):

[0100] Table 9 A design value of zoom interval

[0101] Object distance Object distance 100mm Object distance 1500mm Focus interval 16.100mm 7.530mm

[0102] Furthermore, Figure 8 This is a schematic diagram of a light fan of an industrial lens provided in the third embodiment of the utility model. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. Figure 8 The horizontal axis represents the beam aperture, and the vertical axis represents 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 dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 8 It can be seen that each wavelength of the system in each field of view is well close to the horizontal axis, indicating that the vertical axis aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the system is also well corrected, thereby ensuring that the optical system can achieve high-resolution imaging requirements.

[0103] Fig. 9 This is a schematic diagram of field curvature distortion of an industrial lens provided by the third embodiment of the utility model. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, in units of mm. Fig. 9It can be seen that the lens provided in this embodiment is effectively controlled in terms of field curvature from light with a wavelength of 0.449 μm to light with a wavelength of 0.680 μm (specifically, meridional rays and sagittal rays of 0.449 μm, 0.510 μm, 0.540 μm, 0.570 μm, 0.600 μm, 0.640 μm and 0.680 μm), that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; in the coordinate system on the right, the horizontal coordinate represents the size of the distortion, in %, and the vertical coordinate represents the normalized image height, without a unit; Fig. 9 It can be seen that the imaging distortion of the lens provided in this embodiment is well corrected and the imaging distortion is small.

[0104] In summary, the industrial lens provided by the embodiment of the utility model, by reasonably setting the combination mode of the focusing lens group and the fixed lens group and the correspondence between the focal lengths, and at the same time reasonably setting the aperture position, the correspondence between the focal power of the lens group before the aperture and the focal power of the lens group after the aperture, the focal power of different lenses, the Abbe number, the refractive index, the moving distance of the focusing lens group, the aperture of the first lens, the total optical length, the focal length of the lens, and the lens type, finally realizes an industrial lens design that can take into account a large target surface, low distortion, and high resolution. The target surface of the industrial lens provided by the embodiment of the utility model can be 1.2″, |optical distortion|≤0.6%, and the resolution standard can reach 25MP.

[0105] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An industrial 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 which are arranged in sequence from the object plane to the image plane along the optical axis; The industrial lens further includes a focusing lens group and a fixed lens group, the focusing lens group includes at least the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens, and the fixed lens group includes at least the eighth lens and the ninth lens; The industrial lens also includes an aperture, the combined focal length of the multiple lenses between the object plane and the aperture is Φa, the combined focal length of the multiple lenses between the aperture and the image plane is Φb, and 0.8≤Φa / Φb≤1.

42.

2. The industrial lens according to claim 1, characterized in that: The focusing lens group includes the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens, and the fixed lens group includes the eighth lens and the ninth lens; Alternatively, the focusing lens group includes the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens, and the fixed lens group includes the seventh lens, the eighth lens and the ninth lens.

3. The industrial lens according to claim 2, characterized in that: The aperture stop is disposed in the optical path between the third lens and the fourth lens, or the aperture stop is disposed in the optical path between the fourth lens and the fifth lens.

4. The industrial lens according to claim 1, characterized in that: The focal power of the second lens is Φ2, and the focal power of the industrial lens is Φ; Among them, 0.403≤Φ2 / Φ≤0.

794.

5. The industrial lens according to claim 1, characterized in that: The eighth lens and the ninth lens are glued together; The focal power of the eighth lens is Φ8, the focal power of the ninth lens is Φ9, the Abbe constant of the eighth lens is vd8, and the Abbe constant of the ninth lens is vd9; Among them, 0.21≤1000*(Φ8 / vd8+Φ9 / vd9)≤0.

34.

6. The industrial lens according to claim 1, characterized in that: The combined focal length of the sixth lens and the seventh lens is Φ6_7, the focal length of the industrial lens is Φ, and the refractive index of the seventh lens is nd7; Among them, 1.122≤Φ6_7 / Φ≤2.553, and nd7>1.

9.

7. The industrial lens according to claim 1, characterized in that: The focal power of the first lens is Φ1, the focal power of the fifth lens is Φ5, and the focal power of the industrial lens is Φ; Among them, -0.83≤Φ1 / Φ≤-0.78, -3.067≤Φ5 / Φ≤1.

391.

8. The industrial lens according to claim 1, characterized in that: The moving distance of the focusing lens group from the near object distance to the far object distance is ZOL, the focal length of the industrial lens is f, the clear aperture of the first lens is D1, and the distance from the vertex of the object side surface of the first lens to the image plane is TTL; Among them, 0.300≤ZOL / f≤0.385, and 0.258≤D1 / TTL≤0.

315.

9. The industrial lens according to claim 1, characterized in that: The focal length of the focusing lens group is EFL1, and the focal length of the fixed lens group is EFL2; Among them, 0.319≤EFL1 / EFL2≤0.

51.

10. The industrial lens according to claim 1, characterized in that: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens are all spherical lenses.

Images