Industrial lens

Abstract

The invention discloses an industrial lens. The industrial lens comprises a first lens group, a second lens group and a third lens group, the positions of the first lens group and the third lens group are fixed, and the position of the second lens group is floatable; the first lens group comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens; the second lens group comprises a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens; the third lens group comprises a thirteenth lens and a fourteenth lens. The second lens group moves along the optical axis to realize focusing of different object distances, and the first lens group and the third lens group are fixed, so that the influence of focusing to different object distances on resolution can be reduced, and the balance of image quality of each working distance is ensured. And the number of the lenses in each lens group is reasonably set, so that the industrial lens with high image quality imaging performance can be realized.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of optical devices, and in particular to an industrial lens. Background Art

[0002] With the demand for automated equipment, the application of optical lenses is becoming more and more advanced, especially in the field of precision detection, such as: dimension measurement, PCB board defect detection, wafer defect detection, etc., but high-resolution optical lenses are very scarce in the market today. With the gradual improvement of the detection accuracy requirements of modern automated equipment, the performance requirements for the field of view, resolution, optical distortion and other aspects of optical lenses are becoming more and more stringent. Summary of the invention

[0003] The present invention provides an industrial lens, which realizes an industrial lens with high image quality imaging performance.

[0004] An embodiment of the present invention provides an industrial lens, comprising a first lens group, a second lens group, and a third lens group arranged in sequence from an object plane to an image plane along an optical axis; the positions of the first lens group and the third lens group are fixed, and the position of the second lens group can float along the optical axis;

[0005] The first lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens; the second lens group includes a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens; and the third lens group includes a thirteenth lens and a fourteenth lens.

[0006] Optionally, the optical power of the first lens group is The optical power of the second lens group is The optical power of the industrial lens is

[0007] in,

[0008] Optionally, the first lens and the second lens are glued together, the third lens and the fourth lens are glued together, and the fifth lens and the sixth lens are glued together;

[0009] The eighth lens and the ninth lens are cemented together, and the tenth lens, the eleventh lens and the twelfth lens are cemented together.

[0010] Optionally, the optical power of the first lens is The Abbe number is vd11; the focal power of the second lens is The Abbe number is vd12; the focal length of the third lens is The Abbe number is vd13; the focal power of the fourth lens is The Abbe number is vd14; the optical power of the fifth lens is The Abbe number is vd15; the focal length of the sixth lens is The Abbe number is vd16;

[0011] in,

[0012]

[0013] Optionally, the tenth lens is a positive power lens and its focal length is The eleventh lens is a negative power lens and its focal length is The twelfth lens is a positive power lens and its focal length is The optical power of the industrial lens is

[0014] The refractive index of the tenth lens is nd24, and the Abbe number is vd24; the refractive index of the eleventh lens is nd25, and the Abbe number is vd25; the refractive index of the twelfth lens is nd26, and the Abbe number is vd26;

[0015] in,

[0016] nd24<nd25, nd26<nd25, vd24<vd25, vd26<vd25.

[0017] Optionally, the optical power of the seventh lens is The optical power of the eighth lens is The optical power of the industrial lens is

[0018] in,

[0019] Optionally, the moving distance of the second lens group is ZOL, and the distance between the image side surface of the fourteenth lens and the image plane is BFL;

[0020] Among them, 0.3390≤ZOL / BFL≤0.8787.

[0021] Optionally, the first lens includes a first object-side surface close to the object plane and a first image-side surface close to the image plane, the first object-side surface is a convex surface, and the first image-side surface is a concave surface or a convex surface;

[0022] The second lens comprises a second object-side surface close to the object plane and a second image-side surface close to the image plane, the second object-side surface is a convex surface or a concave surface, and the second image-side surface is a concave surface;

[0023] The third lens comprises a third object-side surface close to the object plane and a third image-side surface close to the image plane, the third object-side surface is a convex surface or a concave surface, and the third image-side surface is a convex surface or a concave surface;

[0024] The fourth lens comprises a fourth object-side surface close to the object plane and a fourth image-side surface close to the image plane, the fourth object-side surface is a concave surface or a convex surface, and the fourth image-side surface is a concave surface, a flat surface or a convex surface;

[0025] The fifth lens comprises a fifth object-side surface close to the object plane and a fifth image-side surface close to the image plane, the fifth object-side surface is a convex surface or a concave surface, and the fifth image-side surface is a concave surface;

[0026] The sixth lens comprises a sixth object-side surface close to the object plane and a sixth image-side surface close to the image plane, the sixth object-side surface is a convex surface, and the sixth image-side surface is a convex surface;

[0027] The seventh lens comprises a seventh object-side surface close to the object plane and a seventh image-side surface close to the image plane, the seventh object-side surface is a convex surface, and the seventh image-side surface is a concave surface or a convex surface;

[0028] The eighth lens comprises an eighth object-side surface close to the object plane and an eighth image-side surface close to the image plane, the eighth object-side surface is a convex surface, and the eighth image-side surface is a convex surface or a concave surface;

[0029] The ninth lens comprises a ninth object-side surface close to the object plane and a ninth image-side surface close to the image plane, the ninth object-side surface is a concave surface or a convex surface, and the ninth image-side surface is a concave surface;

[0030] The tenth lens comprises a tenth object-side surface close to the object plane and a tenth image-side surface close to the image plane, the tenth object-side surface is a convex surface, and the tenth image-side surface is a convex surface;

[0031] The eleventh lens comprises an eleventh object-side surface close to the object plane and an eleventh image-side surface close to the image plane, the eleventh object-side surface is a concave surface, and the eleventh image-side surface is a concave surface;

[0032] The twelfth lens comprises a twelfth object-side surface close to the object plane and a twelfth image-side surface close to the image plane, the twelfth object-side surface is a convex surface, and the twelfth image-side surface is a convex surface;

[0033] The thirteenth lens comprises a thirteenth object-side surface close to the object plane and a thirteenth image-side surface close to the image plane, the thirteenth object-side surface is a concave surface, and the thirteenth image-side surface is a concave surface;

[0034] The fourteenth lens includes a fourteenth object-side surface close to the object plane and a fourteenth image-side surface close to the image plane. The fourteenth object-side surface is a convex surface, and the fourteenth image-side surface is a convex surface or a concave surface.

[0035] 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, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens and the fourteenth lens are all glass spherical lenses;

[0036] The thirteenth lens is a glass aspherical lens.

[0037] Optionally, the industrial lens further includes an aperture, and the aperture is arranged in the light path between the ninth lens and the tenth lens.

[0038] The industrial lens provided by the embodiment of the present invention is provided with a second lens group that can float along the optical axis, so as to ensure that focusing can be achieved at different working distances and clear imaging can be achieved at different working object distances. Furthermore, the first lens group and the third lens group are fixed, so as to reduce the influence of focusing at different object distances on the resolution, ensure that the image quality at each working distance is balanced, and realize an industrial lens with high image quality imaging performance.

[0039] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 This is a schematic structural diagram of an industrial lens provided by Embodiment 1 of the present invention at an optimal object distance;

[0042] Figure 2 1 is a schematic diagram of an MTF curve of an industrial lens at an optimal object distance provided by the first embodiment of the present invention;

[0043] Figure 3 1 is a schematic diagram of a field curvature distortion curve of an industrial lens at an optimal object distance provided by the first embodiment of the present invention;

[0044] Figure 4This is a schematic diagram of the structure of an industrial lens at an optimal object distance provided by the second embodiment of the present invention;

[0045] Figure 5 Schematic diagram of an MTF curve of an industrial lens at an optimal object distance provided by Embodiment 2 of the present invention;

[0046] Figure 6 1 is a schematic diagram of a field curvature distortion curve of an industrial lens at an optimal object distance provided by the second embodiment of the present invention;

[0047] Figure 7 This is a schematic structural diagram of an industrial lens at an optimal object distance provided by Embodiment 3 of the present invention;

[0048] Figure 8 Schematic diagram of an MTF curve of an industrial lens at an optimal object distance provided by Embodiment 3 of the present invention;

[0049] Fig. 9 It is a schematic diagram of a field curvature distortion curve of an industrial lens at an optimal object distance provided by Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0051] Embodiment 1

[0052] Figure 1 Schematic diagram of the structure of an industrial lens at an optimal object distance provided by the first embodiment of the present invention. Figure 1 As shown, the industrial lens provided by the embodiment of the present invention includes a first lens group S1, a second lens group S2 and a third lens group S3 which are arranged in sequence from the object plane to the image plane along the optical axis; the positions of the first lens group S1 and the third lens group S3 are fixed, and the position of the second lens group S2 can float along the optical axis; the first lens group S1 includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105 and a sixth lens 106; the second lens group S2 includes a seventh lens 107, an eighth lens 108, a ninth lens 109, a tenth lens 110, an eleventh lens 111 and a twelfth lens 112; the third lens group S3 includes a thirteenth lens 113 and a fourteenth lens 114.

[0053] Specifically, the industrial lens provided in the embodiment of the present invention includes a first lens group S1, a third lens group S3, and a second lens group S2 located between the first lens group S1 and the third lens group S3 along the optical axis. The first lens group S1 and the third lens group S3 can be understood as lenses whose lens positions are fixed and do not change, and the second lens group S2 can be understood as a lens group whose lens group position changes. The second lens group S2 specifically moves between the first lens group S1 and the third lens group S3. The focal length of the industrial lens is adjusted by the position change of the second lens group S2 to ensure that the industrial lens can achieve focus at different object distances and ensure clear imaging at different object distances. Specifically, in the case of close object distance focusing, the second lens group S2 is close to the first lens group S1; in the case of infinity focusing, the second lens group S2 is close to the third lens group S3. Furthermore, since the positions of the first lens group S1 and the third lens group S3 remain stationary, under different working distances, the aberration changes caused by the forward and backward movement of the second lens group S2 will be weakened due to the fact that the first lens group S1 and the third lens group S3 are fixed and symmetry is maintained, thereby ensuring that the image quality at each working distance is balanced and the imaging quality is guaranteed.

[0054] Further, the first lens group S1 includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105 and a sixth lens 106; the second lens group S2 includes a seventh lens 107, an eighth lens 108, a ninth lens 109, a tenth lens 110, an eleventh lens 111 and a twelfth lens 112; and the third lens group S3 includes a thirteenth lens 113 and a fourteenth lens 114. That is, the first lens group S1 includes six lenses, the second lens group S2 includes six lenses, and the third lens group S3 includes two lenses. That is, the industrial lens includes eight lenses that remain fixed and six lenses that move for focusing, so that focusing can be achieved by moving multiple lenses, and the moving focus of multiple lenses can ensure a good focusing effect; and multiple lenses can be fixed to reduce the influence of the movement process of the second lens group S2 on aberrations, ensuring that the image quality of each working distance is balanced and the imaging quality is guaranteed.

[0055] In summary, the industrial lens provided by the embodiment of the present invention is provided with a second lens group that can float along the optical axis, so as to ensure that focusing can be achieved at different working distances and clear imaging can be achieved at different working object distances; multiple lenses can be moved for focusing to ensure a good focusing effect. Furthermore, the first lens group and the third lens group are fixed, so as to reduce the impact of focusing on different object distances on the resolution, ensure that the image quality at each working distance is balanced, and achieve an industrial lens with high image quality imaging performance. In addition, the arrangement of fourteen lenses ensures that the number of lenses in the optical system is reasonably set, and the lens volume will not be larger due to too many lenses, nor will the aberration of a single lens due to a larger optical focal length be larger due to too few lenses. While miniaturizing the optical system, the imaging aberration is small and the imaging quality is high.

[0056] Based on the above embodiments, continue to refer to Figure 1 As shown, the industrial lens provided by the embodiment of the present invention further includes a stop STO, and the stop STO is arranged in the optical path between the ninth lens 109 and the tenth lens 110.

[0057] Specifically, setting the aperture STO can adjust the propagation direction of the light beam, which is beneficial to improving the imaging quality. In addition, in the industrial lens, the aperture STO is set in the optical path between the ninth lens 109 and the tenth lens 110, that is, the aperture STO is set in the optical system, which is beneficial to reduce the aperture value and achieve a large aperture. In addition, the aperture STO is set between the two lenses in the second lens group S2, and the aperture STO moves with the second lens group S2 during the focusing process to ensure the imaging quality during the focusing process.

[0058] Furthermore, the industrial lens provided in the embodiment of the present invention may also include a filter 115. The filter 115 is arranged in the light path between the fourteenth lens 114 and the image plane, and can filter out stray light and improve the imaging effect.

[0059] Furthermore, the industrial lens provided in the embodiment of the present invention may also include a protective glass and an image acquisition element. The protective glass may be arranged on the image side of the filter, and the image acquisition element may be arranged on the image side of the protective glass. The protective glass is used to protect the optical system, and the image is acquired by the image acquisition element to realize the normal imaging function of the optical system.

[0060] Based on the above embodiment, the optical power of the first lens group S1 is The optical power of the second lens group S2 is The optical power of industrial lenses is in,

[0061] Specifically, the focal length is equal to the difference between the convergence of the image-side beam and the convergence of the object-side 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.

[0062] Because when the off-axis light deflection angle of the front lens group is too large, it has a greater impact on aberrations. The above solution constrains the focal length of the front lens group of the industrial lens, and sets the focal length of the first lens group S1 and the second lens group S2 within this range, which can make the light transition smoothly inside the lens and reduce the impact on imaging aberrations.

[0063] On the basis of the above embodiment, the first lens 101 and the second lens 102 are cemented together, the third lens 103 and the fourth lens 104 are cemented together, the fifth lens 105 and the sixth lens 106 are cemented together; the eighth lens 108 and the ninth lens 109 are cemented together, and the tenth lens 110, the eleventh lens 111 and the twelfth lens 112 are cemented together.

[0064] Specifically, the bonding of different lenses can be understood as the image side surface of the front lens and the object side surface of the rear lens in the optical path being bonded to each other and having the same surface shape. Figure 1 As shown, the first lens 101 and the second lens 102 are glued together, which can be understood as the image side surface of the first lens 101 is glued to the object side surface of the second lens 102. The third lens 103 and the fourth lens 104 are glued together, which can be understood as the image side surface of the third lens 103 is glued to the object side surface of the fourth lens 104. The fifth lens 105 and the sixth lens 106 are glued together, which can be understood as the image side surface of the fifth lens 105 is glued to the object side surface of the sixth lens 106. That is, the first lens group S1 can include three lens groups glued together in pairs.

[0065] The eighth lens 108 and the ninth lens 109 are cemented together, which can be understood as the image side surface of the eighth lens 108 is attached to the object side surface of the ninth lens 109. The tenth lens 110, the eleventh lens 111 and the twelfth lens 112 are cemented together, which can be understood as the image side surface of the tenth lens 110 is attached to the object side surface of the eleventh lens 111, and the image side surface of the eleventh lens 111 is attached to the object side surface of the twelfth lens 112. That is, the second lens group S2 can include a group of lens groups cemented in pairs and a group of lens groups cemented in pairs.

[0066] Cemented lenses can be used to minimize or eliminate chromatic aberration. Using cemented lenses in industrial lenses can improve image quality and reduce reflection loss of light energy, thereby improving the clarity of lens imaging. In addition, the bonding of lenses omits the air gap between the two lenses, making the overall optical system compact and meeting the needs of system miniaturization. In addition, the bonding of lenses will reduce the tolerance sensitivity problems such as tilt / eccentricity generated by the lens unit during the assembly process.

[0067] Further, the first lens 101 and the second lens 102 may be supported by a gasket or may be bonded by glue; the third lens 103 and the fourth lens 104 may be supported by a gasket or may be bonded by glue; the fifth lens 105 and the sixth lens 106 may be supported by a gasket or may be bonded by glue; the eighth lens 108 and the ninth lens 109 may be supported by a gasket or may be bonded by glue; the tenth lens 110, the eleventh lens 111 and the twelfth lens 112 may be supported by a gasket or may be bonded by glue.

[0068] Based on the above embodiment, the optical power of the first lens 101 is The Abbe number is vd11; the optical power of the second lens 102 is The Abbe number is vd12; the focal length of the third lens 103 is The Abbe number is vd13; the optical power of the fourth lens 104 is The Abbe number is vd14; the optical power of the fifth lens 105 is The Abbe number is vd15; the optical power of the sixth lens 106 is The Abbe number is vd16; where

[0069]

[0070] This condition can constrain the optical power and chromatic aberration of the doublet lens composed of the first lens 101 and the second lens 102, the doublet lens composed of the third lens 103 and the fourth lens 104, and the doublet lens composed of the fifth lens 105 and the sixth lens 106, thereby improving image quality.

[0071] Based on the above embodiment, the tenth lens is a positive power lens and its focal length is The eleventh lens is a negative power lens and its focal length is The twelfth lens is a positive power lens and its power is The optical power of industrial lenses is The refractive index of the tenth lens 110 is nd24, and the Abbe number is vd24; the refractive index of the eleventh lens 111 is nd25, and the Abbe number is vd25; the refractive index of the twelfth lens 112 is nd26, and the Abbe number is vd26; wherein,

[0072]

[0073] Specifically, the tenth lens 110, the eleventh lens 111 and the twelfth lens 112 form a triplet lens, and the structure adopted by the tenth lens 110, the eleventh lens 111 and the twelfth lens 112 is a positive-negative positive lens combination, and the negative power lens in the triplet lens has a high refractive index and high dispersion, and the positive power lens has a low refractive index and low dispersion, that is, nd24<nd25, nd26<nd25, vd24<vd25, vd26<vd25. By further limiting the optical power of the tenth lens 110, the eleventh lens 111 and the twelfth lens 112, it is ensured that the triplet lens has good correction capabilities for astigmatism and coma, thereby improving the imaging quality.

[0074] Based on the above embodiment, the optical power of the seventh lens 107 is The optical power of the eighth lens 108 is The optical power of industrial lenses is in, By limiting the optical power of the seventh lens 107 and the eighth lens 108 to within this range, the lens distortion can be balanced and the imaging quality can be guaranteed. In the embodiment of the present invention, the |optical distortion|≤0.1%.

[0075] Based on the above embodiment, the moving distance of the second lens group S2 is ZOL, and the distance between the image side surface of the fourteenth lens 114 and the image plane is BFL; wherein 0.3390≤ZOL / BFL≤0.8787.

[0076] Specifically, the distance between the image side surface of the fourteenth lens 114 and the image plane can be understood as the distance from the last optical surface vertex of the optical system to the image plane, or as the back focus of the optical system. By limiting 0.3390≤ZOL / BFL≤0.8787, it is beneficial to compress the total length of industrial lenses.

[0077] On the basis of the above embodiments, the first lens 101 includes a first object-side surface close to the object plane and a first image-side surface close to the image plane, the first object-side surface is a convex surface, and the first image-side surface is a concave surface or a convex surface; the second lens 102 includes a second object-side surface close to the object plane and a second image-side surface close to the image plane, the second object-side surface is a convex surface or a concave surface, and the second image-side surface is a concave surface; the third lens 103 includes a third object-side surface close to the object plane and a third image-side surface close to the image plane, the third object-side surface is a convex surface or a concave surface, and the third image-side surface is a convex surface or a concave surface; the fourth lens 104 includes a fourth object-side surface close to the object plane The fifth lens 105 includes a fifth object side surface close to the object plane and a fifth image side surface close to the image plane, the fifth object side surface is convex or concave, and the fifth image side surface is concave; the sixth lens 106 includes a sixth object side surface close to the object plane and a sixth image side surface close to the image plane, the sixth object side surface is convex, and the sixth image side surface is convex; the seventh lens 107 includes a seventh object side surface close to the object plane and a seventh image side surface close to the image plane, the seventh object side surface is convex, and the seventh image side surface is flat. The eighth lens 108 includes an eighth object-side surface close to the object plane and an eighth image-side surface close to the image plane, the eighth object-side surface is a convex surface, and the eighth image-side surface is a convex surface or a concave surface; the ninth lens 109 includes a ninth object-side surface close to the object plane and a ninth image-side surface close to the image plane, the ninth object-side surface is a concave surface or a convex surface, and the ninth image-side surface is a concave surface; the tenth lens 110 includes a tenth object-side surface close to the object plane and a tenth image-side surface close to the image plane, the tenth object-side surface is a convex surface, and the tenth image-side surface is a convex surface; the eleventh lens 111 includes an eleventh object-side surface close to the object plane and an eleventh image-side surface close to the image plane The eleventh image side surface is concave, and the eleventh image side surface is concave; the twelfth lens 112 includes the twelfth object side surface close to the object plane and the twelfth image side surface close to the image plane, the twelfth object side surface is convex, and the twelfth image side surface is convex; the thirteenth lens 113 includes the thirteenth object side surface close to the object plane and the thirteenth image side surface close to the image plane, the thirteenth object side surface is concave, and the thirteenth image side surface is concave; the fourteenth lens 114 includes the fourteenth object side surface close to the object plane and the fourteenth image side surface close to the image plane, the fourteenth object side surface is convex, and the fourteenth image side surface is convex or concave.

[0078] Specifically, the object-side surface of the lens can be understood as the surface of the lens close to the object plane, and the image-side surface of the lens can be understood as the surface of the lens close to the image plane.

[0079] The object side surface of the first lens 101 is convex, and the image side surface is concave or convex. It can be understood that the object side surface of the first lens 101 is convex toward the object plane at the near optical axis position, and the image side surface is concave or convex toward the image plane at the near optical axis position, that is, the first lens 101 is a lens with a convex-concave structure or a double convex structure. Figure 1 In the structure shown, the first lens 101 is taken as an example of a convex-concave structure lens.

[0080] The object side surface of the second lens 102 is convex or concave, and the image side surface is concave. It can be understood that the object side surface of the second lens 102 is convex or concave toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the second lens 102 is a lens with a convex-concave structure or a double-concave structure. Figure 1 In the structure shown, the second lens 102 is taken as an example of a convex-concave structure lens.

[0081] The object side surface of the third lens 103 is convex or concave, and the image side surface is convex or concave. It can be understood that the object side surface of the third lens 103 is convex or concave toward the object plane at the near optical axis position, and the image side surface is convex or concave toward the image plane at the near optical axis position, that is, the third lens 103 can be a lens with a double convex structure, a convex-concave structure, or a double concave structure. Figure 1 In the structure shown, the third lens 103 is a biconvex lens as an example for explanation.

[0082] The object side surface of the fourth lens 104 is concave or convex, and the image side surface is concave, flat or convex. It can be understood that the object side surface of the fourth lens 104 is concave or convex toward the object plane at the near optical axis position, and the image side surface is concave, flat or convex toward the image plane at the near optical axis position, that is, the fourth lens 104 can be a lens with a double concave structure, a convex-flat structure or a double convex structure. Figure 1 In the structure shown, the fourth lens 104 is described as a biconcave lens as an example.

[0083] The object side surface of the fifth lens 105 is convex or concave, and the image side surface is concave. It can be understood that the object side surface of the fifth lens 105 is convex or concave toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the fifth lens 105 can be a lens with a convex-concave structure or a double-concave structure. Figure 1 In the structure shown, the fifth lens 105 is a biconcave lens as an example for explanation.

[0084] The object side surface of the sixth lens 106 is convex, and the image side surface is convex. It can be understood that the object side surface of the sixth lens 106 is convex toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the sixth lens 106 can be a lens with a double convex structure. Figure 1In the structure shown, the sixth lens 106 is taken as a biconvex lens as an example for explanation.

[0085] The object-side surface of the seventh lens 107 is a convex surface, and the image-side surface is a concave surface or a convex surface. It can be understood that the object-side surface of the seventh lens 107 is convex toward the object plane at the near optical axis position, and the image-side surface is concave or convex toward the image plane at the near optical axis position, that is, the seventh lens 107 can be a lens with a convex-concave structure or a double-convex structure. Figure 1 In the structure shown, the seventh lens 107 is taken as an example of a convex-concave structure lens.

[0086] The object-side surface of the eighth lens 108 is convex, and the image-side surface is convex or concave. It can be understood that the object-side surface of the eighth lens 108 is convex toward the object plane at the near optical axis position, and the image-side surface is convex or concave toward the image plane at the near optical axis position, that is, the eighth lens 108 can be a lens with a double convex structure or a convex-concave structure. Figure 1 In the structure shown, the eighth lens 108 is a biconvex lens as an example for explanation.

[0087] The object side surface of the ninth lens 109 is a concave surface or a convex surface, and the image side surface is a concave surface. It can be understood that the object side surface of the ninth lens 109 is concave or convex toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the ninth lens 109 can be a lens with a double concave or convex-concave structure. Figure 1 In the structure shown, the ninth lens 109 is taken as an example of a double concave lens.

[0088] The object side surface of the tenth lens 110 is convex, and the image side surface is convex. It can be understood that the object side surface of the tenth lens 110 is convex toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the tenth lens 110 can be a lens with a double convex structure.

[0089] The object side surface of the eleventh lens 111 is a concave surface, and the image side surface is a concave surface. It can be understood that the object side surface of the eleventh lens 111 is concave toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the eleventh lens 111 can be a lens with a double concave structure.

[0090] The object side surface of the twelfth lens 112 is convex, and the image side surface is convex. It can be understood that the object side surface of the twelfth lens 112 is convex toward the object plane at the near optical axis position, and the image side surface is convex toward the image plane at the near optical axis position, that is, the twelfth lens 112 can be a lens with a double convex structure.

[0091] The object side surface of the thirteenth lens 113 is a concave surface, and the image side surface is a concave surface. It can be understood that the object side surface of the thirteenth lens 113 is concave toward the object plane at the near optical axis position, and the image side surface is concave toward the image plane at the near optical axis position, that is, the thirteenth lens 113 can be a lens with a double concave structure.

[0092] The object side surface of the fourteenth lens 114 is convex, and the image side surface is convex or concave. It can be understood that the object side surface of the fourteenth lens 114 is convex toward the object plane at the near optical axis position, and the image side surface is convex or concave toward the image plane at the near optical axis position, that is, the fourteenth lens 114 can be a lens with a double convex structure or a convex-concave structure. Figure 1 In the structure shown, the fourteenth lens 114 is a double convex structure lens as an example for explanation.

[0093] By reasonably setting the concave and convex surface types of each lens, it is possible to ensure that each lens modulates the light emission angle, and for a glued lens, the glued setting of at least two adjacent lenses can be achieved. On the other hand, the distance between adjacent lenses can be reduced, which is conducive to the realization of a small-volume industrial lens design.

[0094] On the basis of the above embodiments, the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, the seventh lens 107, the eighth lens 108, the ninth lens 109, the tenth lens 110, the eleventh lens 111, the twelfth lens 112 and the fourteenth lens 114 are all glass spherical lenses; and the thirteenth lens 113 is a glass aspherical lens.

[0095] Specifically, by setting the thirteenth lens 113 as an aspherical lens, the field aberration can be optimized, the field curvature and distortion can be corrected, and the imaging effect can be improved. Further, the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, the seventh lens 107, the eighth lens 108, the ninth lens 109, the tenth lens 110, the eleventh lens 111, the twelfth lens 112 and the fourteenth lens 14 are all glass spherical lenses, and an optical structure of 13 glass spherical lenses and 1 glass aspherical lens is used to better correct chromatic aberration and aberration, improve image quality, and reduce processing costs to achieve higher cost performance. The material of the glass spherical lens and the glass aspherical lens is various types of glass known to those skilled in the art, and the embodiment of the present invention does not repeat or limit this.

[0096] As a feasible implementation method, the parameters of each lens in the industrial lens are described below.

[0097] Table 1 Optical design values ​​of industrial lens in Example 1

[0098]

[0099] Table 2 Design values ​​of optical physical parameters of industrial lenses

[0100]

[0101]

[0102] The surface numbers in Table 2 are numbered according to the order of the surfaces of each lens. "0" represents the object surface, "1" represents the object side surface of the first lens, "2" represents the image side surface of the first lens, and so on. The radius of curvature represents the degree of curvature of the corresponding 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. "INF" represents that the surface is a plane and the radius of curvature is infinite. The thickness represents the central axial distance from the current surface to the next surface, and the refractive index represents the ability of the material between the current surface and the next surface to deflect light. 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.

[0103] Table 3 Design value of aspheric coefficient of industrial lens

[0104]

[0105] Among them, 1.255784E-03 means 1.255784*10 -3 , the remaining parameters can be expressed in this way.

[0106] Furthermore, the aspheric cone coefficient can be defined by the following aspheric formula, but is not limited to the following representation method:

[0107]

[0108] Among them, 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 radius of curvature; k is the cone coefficient; AG is the coefficient of the 4th, 6th, 8th, 10th, 12th, 14th and 16th order terms of the aspheric polynomial.

[0109] Table 4 A design value of focus interval

[0110] Object distance Object distance 150mm Object distance 10000mm Focus interval 1 1.684mm 5.177mm Focus interval 2 4.019mm 0.526mm

[0111] Figure 2It is a schematic diagram of the MTF curve of an industrial lens at the optimal object distance provided by Example 1 of the present invention. The MTF curve diagram indicates the resolution of the optical system for objects at different frequencies in different fields of view, meridian and sagittal directions, and reflects the degree of imaging of the image quality of the object after passing through the optical system. The most ideal curve is the highest diffraction limit, which indicates the physical limit of the lens under this parameter. The vertical coordinate of the curve corresponds to the black and white line boundary contrast (M' / M), where M refers to the grating modulation before imaging, and M' refers to the grating modulation after imaging, so 0≤M' / M≤1. The horizontal coordinate corresponds to the number of black and white lines within 1mm. S and T correspond to the sagittal and meridian of each field of view. From Figure 2 It can be seen that the system is close to the diffraction limit at each wavelength in each field of view, indicating that the aberration of the system at each wavelength is well corrected. At the same time, there is no obvious dispersion in the sagittal and meridian of each field of view, indicating that the system astigmatism is also well corrected, thereby ensuring that the optical system can achieve high-resolution imaging requirements.

[0112] Figure 3 : is a schematic diagram of a field curvature distortion curve of an industrial lens at an optimal object distance provided by the first embodiment of the present invention, wherein 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; wherein the solid line represents the meridian, and the dotted line represents the sagittal; Figure 3 It can be seen that the field curvature of the lens provided in this embodiment is effectively controlled, 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 units of %; the vertical coordinate represents the normalized image height, in units of %. Figure 3 It can be seen that the distortion of the lens provided in this embodiment is well corrected, and the imaging distortion is small.

[0113] In summary, the industrial lens provided in the embodiment of the present invention adopts an all-glass 14G structure, and through the matching of lens materials and the reasonable distribution of the optical focal length of each component, an intermediate group focusing method is adopted to achieve an industrial lens design that can take into account both high resolution and low optical distortion, with |optical distortion|≤0.1% and full field MTF 230lp / mm>0.3.

[0114] Embodiment 2

[0115] Figure 4 Schematic diagram of the structure of an industrial lens at an optimal object distance provided by the second embodiment of the present invention. Figure 4As shown, the industrial lens provided by Embodiment 2 of the present invention comprises a first lens group S1, a second lens group S2 and a third lens group S3, whose optical axes are arranged in sequence from the object plane to the image plane; the positions of the first lens group S1 and the third lens group S3 are fixed, and the position of the second lens group S2 can float along the optical axis; the first lens group S1 comprises a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105 and a sixth lens 106; the second lens group S2 comprises a seventh lens 107, an eighth lens 108, a ninth lens 109, a tenth lens 110, an eleventh lens 111 and a twelfth lens 112; the third lens group S3 comprises a thirteenth lens 113 and a fourteenth lens 114.

[0116] Among them, the difference between Example 2 and Example 1 is that the image side surface of the first lens is convex; the object side surface of the second lens is concave; the image side surface of the third lens is concave; the object side surface of the fourth lens is convex, and the image side surface is flat; the image side surface of the seventh lens is convex, the object side surface of the eighth lens is concave, and the image side surface of the ninth lens is convex.

[0117] Other parameters are the same as those in the first embodiment and will not be described again here.

[0118] As another feasible implementation, specific parameters in the industrial lens are described below.

[0119] Table 5 Optical design values ​​of the industrial lens in Example 2

[0120]

[0121] Table 6 Design values ​​of optical physical parameters of industrial lenses

[0122]

[0123]

[0124] The surface numbers in Table 6 are numbered according to the order of the surfaces of each lens. "0" represents the object surface, "1" represents the object side surface of the first lens, "2" represents the image side surface of the first lens, and so on. The radius of curvature represents the degree of curvature of the corresponding 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. "INF" represents that the surface is a plane and the radius of curvature is infinite. The thickness represents the central axial distance from the current surface to the next surface, and the refractive index represents the ability of the material between the current surface and the next surface to deflect light. 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.

[0125] Table 7 Design value of aspheric coefficient of industrial lens

[0126]

[0127] Among them, 1.290913E-03 means 1.290913*10 -3 , the remaining parameters can be expressed in this way.

[0128] Furthermore, the aspheric cone coefficient can be defined by the following aspheric formula, but is not limited to the following representation method:

[0129]

[0130] Among them, 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 radius of curvature; k is the cone coefficient; AG is the coefficient of the 4th, 6th, 8th, 10th, 12th, 14th and 16th order terms of the aspheric polynomial.

[0131] Table 8 A design value of focus interval

[0132] Object distance Object distance 150mm Object distance 10000mm Focus interval 1 0.136mm 7.072mm Focus interval 2 7.933mm 0.997mm

[0133] Figure 5 It is a schematic diagram of the MTF curve of an industrial lens at the optimal object distance provided by Example 2 of the present invention. The MTF curve represents the resolution of the optical system for objects at different frequencies in different fields of view, meridian and sagittal directions, and reflects the degree of imaging of the image quality of the object after passing through the optical system. The most ideal curve is the diffraction limit at the highest altitude, which indicates the physical limit of the lens under this parameter. The vertical coordinate of the curve corresponds to the black and white line boundary contrast (M' / M), where M refers to the grating modulation degree before imaging, and M' refers to the grating modulation degree after imaging, so 0≤M' / M≤1. The horizontal coordinate corresponds to the number of black and white lines within 1mm. S and T correspond to the sagittal and meridian of each field of view. From Figure 5 It can be seen that the system is close to the diffraction limit at each wavelength in each field of view, indicating that the aberration of the system at each wavelength is well corrected. At the same time, there is no obvious dispersion in the sagittal and meridian of each field of view, indicating that the system astigmatism is also well corrected, thereby ensuring that the optical system can achieve high-resolution imaging requirements.

[0134] Figure 6 : is a schematic diagram of a field curvature distortion curve of an industrial lens at an optimal object distance provided by the second embodiment of the present invention, wherein 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; wherein the solid line represents the meridian, and the dotted line represents the sagittal; Figure 6It can be seen that the field curvature of the lens provided in this embodiment is effectively controlled, 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 units of %; the vertical coordinate represents the normalized image height, in units of %. Figure 6 It can be seen that the distortion of the lens provided in this embodiment is well corrected, and the imaging distortion is small.

[0135] In summary, the industrial lens provided in the embodiment of the present invention adopts an all-glass 14G structure, and through the matching of lens materials and the reasonable distribution of the optical focal length of each component, an intermediate group focusing method is adopted to achieve an industrial lens design that can take into account both high resolution and low optical distortion, with |optical distortion|≤0.1% and full field MTF 230lp / mm>0.3.

[0136] Embodiment 3

[0137] Figure 7 Schematic diagram of the structure of an industrial lens at an optimal object distance provided by the third embodiment of the present invention. Figure 7 As shown, the industrial lens provided by the third embodiment of the present invention comprises a first lens group S1, a second lens group S2 and a third lens group S3, whose optical axes are arranged in sequence from the object plane to the image plane; the positions of the first lens group S1 and the third lens group S3 are fixed, and the position of the second lens group S2 can float along the optical axis; the first lens group S1 comprises a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105 and a sixth lens 106; the second lens group S2 comprises a seventh lens 107, an eighth lens 108, a ninth lens 109, a tenth lens 110, an eleventh lens 111 and a twelfth lens 112; and the third lens group S3 comprises a thirteenth lens 113 and a fourteenth lens 114. .

[0138] Among them, the difference between Example 3 and Example 1 is that the object side surface of the third lens is concave, and the image side surface is concave; the object side surface of the fourth lens is convex, and the image side surface is convex; the object side surface of the fifth lens is convex; the image side surface of the eighth lens is concave; the object side surface of the ninth lens is convex, and the image side surface of the fourteenth lens is concave.

[0139] Other parameters are the same as those in the first embodiment and will not be described again here.

[0140] As another feasible implementation, specific parameters in the industrial lens are described below.

[0141] Table 9 Optical design values ​​of the fixed focus lens in Example 3

[0142]

[0143] Table 10 Optical design values ​​of each lens in industrial lens

[0144]

[0145]

[0146] The surface numbers in Table 10 are numbered according to the order of the surfaces of each lens. "0" represents the object surface, "1" represents the object side surface of the first lens, "2" represents the image side surface of the first lens, and so on. The radius of curvature represents the degree of curvature of the corresponding 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. "INF" represents that the surface is a plane and the radius of curvature is infinite. The thickness represents the central axial distance from the current surface to the next surface, and the refractive index represents the ability of the material between the current surface and the next surface to deflect light. 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.

[0147] Table 11 Design value of aspheric coefficient of industrial lens

[0148]

[0149] Among them, 1.192787E-03 means 1.192787*10 -3 , the remaining parameters can be expressed in this way.

[0150] Furthermore, the aspheric cone coefficient can be defined by the following aspheric formula, but is not limited to the following representation method:

[0151]

[0152] Among them, 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 radius of curvature; k is the cone coefficient; AG is the coefficient of the 4th, 6th, 8th, 10th, 12th, 14th and 16th order terms of the aspheric polynomial.

[0153] Table 12 A design value of focus interval

[0154] Object distance Object distance 150mm Object distance 10000mm Focus interval 1 3.24mm 6.9mm Focus interval 2 4.343mm 0.68mm

[0155] Figure 8It is a schematic diagram of the MTF curve of an industrial lens at the optimal object distance provided by Example 3 of the present invention. The MTF curve represents the resolution of the optical system for objects at different frequencies in different fields of view, meridian and sagittal directions, and reflects the degree of imaging of the image quality of the object after passing through the optical system. The most ideal curve is the diffraction limit at the highest altitude, which indicates the physical limit of the lens under this parameter. The vertical coordinate of the curve corresponds to the black and white line boundary contrast (M' / M), where M refers to the grating modulation before imaging, and M' refers to the grating modulation after imaging, so 0≤M' / M≤1. The horizontal coordinate corresponds to the number of black and white lines within 1mm. S and T correspond to the sagittal and meridian of each field of view. From Figure 8 It can be seen that the system is close to the diffraction limit at each wavelength in each field of view, indicating that the aberration of the system at each wavelength is well corrected. At the same time, there is no obvious dispersion in the sagittal and meridian of each field of view, indicating that the system astigmatism is also well corrected, thereby ensuring that the optical system can achieve high-resolution imaging requirements.

[0156] Fig. 9 : is a schematic diagram of a field curvature distortion curve of an industrial lens at an optimal object distance provided by Embodiment 3 of the present invention, wherein 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; wherein the solid line represents the meridian, and the dotted line represents the sagittal; Fig. 9 It can be seen that the field curvature of the lens provided in this embodiment is effectively controlled, 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 units of %; the vertical coordinate represents the normalized image height, in units of %. Fig. 9 It can be seen that the distortion of the lens provided in this embodiment is well corrected, and the imaging distortion is small.

[0157] In summary, the industrial lens provided in the embodiment of the present invention adopts an all-glass 14G structure, and through the matching of lens materials and the reasonable distribution of the optical focal length of each component, an intermediate group focusing method is adopted to achieve an industrial lens design that can take into account both high resolution and low optical distortion, with |optical distortion|≤0.1% and full field MTF 230lp / mm>0.3.

[0158] The above specific implementations do not constitute a limitation on the protection scope of the present invention. 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 invention should be included in the protection scope of the present invention.

Claims

1. An industrial lens, characterized in that: It comprises a first lens group, a second lens group and a third lens group which are arranged in sequence from the object plane to the image plane along the optical axis; the positions of the first lens group and the third lens group are fixed, and the position of the second lens group can float along the optical axis; The first lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens; the second lens group includes a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens; and the third lens group includes a thirteenth lens and a fourteenth lens.

2. The industrial lens according to claim 1, characterized in that: The focal power of the first lens group is φ1, the focal power of the second lens group is φ2, and the focal power of the industrial lens is φ; Among them, -0.0919<φ1 / φ<-0.0242, 1.0767<φ2 / φ<1.4985.

3. The industrial lens according to claim 1, characterized in that: The first lens and the second lens are glued together, the third lens and the fourth lens are glued together, and the fifth lens and the sixth lens are glued together; The eighth lens and the ninth lens are cemented together, and the tenth lens, the eleventh lens and the twelfth lens are cemented together.

4. The industrial lens according to claim 3, characterized in that: The focal power of the first lens is φ11, and the Abbe number is vd11; the focal power of the second lens is φ12, and the Abbe number is vd12; the focal power of the third lens is φ13, and the Abbe number is vd13; the focal power of the fourth lens is φ14, and the Abbe number is vd14; the focal power of the fifth lens is φ15, and the Abbe number is vd15; the focal power of the sixth lens is φ16, and the Abbe number is vd16; Among them, 0.2661<1000*(φ11 / vd11+φ12 / vd12)<0.7723; -1.2859<1000*(φ13 / vd13+φ14 / vd14)<0.7207; -2.6274<1000*(φ15 / vd15+φ16 / vd16)<-0.7042.

5. The industrial lens according to claim 3, characterized in that: The tenth lens is a positive power lens and its focal power is φ24, the eleventh lens is a negative power lens and its focal power is φ25, the twelfth lens is a positive power lens and its focal power is φ26, and the focal power of the industrial lens is φ; The refractive index of the tenth lens is nd24, and the Abbe number is vd24; the refractive index of the eleventh lens is nd25, and the Abbe number is vd25; the refractive index of the twelfth lens is nd26, and the Abbe number is vd26; Among them, 0.6514<(φ24 / φ+φ25 / φ+φ26 / φ)<1.0607; nd24<nd25, nd26<nd25, vd24<vd25, vd26<vd25.

6. The industrial lens according to claim 1, characterized in that: The focal power of the seventh lens is φ21, the focal power of the eighth lens is φ22, and the focal power of the industrial lens is φ; Among them, -3.1435<φ21 / φ<-2.5719, 2.0825<φ22 / φ<2.6761.

7. The industrial lens according to claim 1, characterized in that: The moving distance of the second lens group is ZOL, and the distance between the image side surface of the fourteenth lens and the image plane is BFL; Among them, 0.3390≤ZOL / BFL≤0.8787.

8. The industrial lens according to claim 1, characterized in that: The first lens comprises a first object-side surface close to the object plane and a first image-side surface close to the image plane, the first object-side surface is a convex surface, and the first image-side surface is a concave surface or a convex surface; The second lens comprises a second object-side surface close to the object plane and a second image-side surface close to the image plane, the second object-side surface is a convex surface or a concave surface, and the second image-side surface is a concave surface; The third lens comprises a third object-side surface close to the object plane and a third image-side surface close to the image plane, the third object-side surface is a convex surface or a concave surface, and the third image-side surface is a convex surface or a concave surface; The fourth lens comprises a fourth object-side surface close to the object plane and a fourth image-side surface close to the image plane, the fourth object-side surface is a concave surface or a convex surface, and the fourth image-side surface is a concave surface, a flat surface or a convex surface; The fifth lens comprises a fifth object-side surface close to the object plane and a fifth image-side surface close to the image plane, the fifth object-side surface is a convex surface or a concave surface, and the fifth image-side surface is a concave surface; The sixth lens comprises a sixth object-side surface close to the object plane and a sixth image-side surface close to the image plane, the sixth object-side surface is a convex surface, and the sixth image-side surface is a convex surface; The seventh lens comprises a seventh object-side surface close to the object plane and a seventh image-side surface close to the image plane, the seventh object-side surface is a convex surface, and the seventh image-side surface is a concave surface or a convex surface; The eighth lens comprises an eighth object-side surface close to the object plane and an eighth image-side surface close to the image plane, the eighth object-side surface is a convex surface, and the eighth image-side surface is a convex surface or a concave surface; The ninth lens comprises a ninth object-side surface close to the object plane and a ninth image-side surface close to the image plane, the ninth object-side surface is a concave surface or a convex surface, and the ninth image-side surface is a concave surface; The tenth lens comprises a tenth object-side surface close to the object plane and a tenth image-side surface close to the image plane, the tenth object-side surface is a convex surface, and the tenth image-side surface is a convex surface; The eleventh lens comprises an eleventh object-side surface close to the object plane and an eleventh image-side surface close to the image plane, the eleventh object-side surface is a concave surface, and the eleventh image-side surface is a concave surface; The twelfth lens comprises a twelfth object-side surface close to the object plane and a twelfth image-side surface close to the image plane, the twelfth object-side surface is a convex surface, and the twelfth image-side surface is a convex surface; The thirteenth lens comprises a thirteenth object-side surface close to the object plane and a thirteenth image-side surface close to the image plane, the thirteenth object-side surface is a concave surface, and the thirteenth image-side surface is a concave surface; The fourteenth lens includes a fourteenth object-side surface close to the object plane and a fourteenth image-side surface close to the image plane. The fourteenth object-side surface is a convex surface, and the fourteenth image-side surface is a convex surface or a concave surface.

9. 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, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens and the fourteenth lens are all glass spherical lenses; The thirteenth lens is a glass aspherical lens.

10. The industrial lens according to claim 1, characterized in that: The industrial lens further includes an aperture, which is arranged in the optical path between the ninth lens and the tenth lens.

Images