Objective lens imaging system and optical detection equipment

Abstract

The invention discloses an objective lens imaging system and optical detection equipment. The objective lens imaging system comprises a first concave-convex lens, a first lens group, a second lens group, a fourth concave-convex lens and a plano-convex lens which are sequentially arranged on the same optical axis from an object side to an image side. The convex surface of the first concave-convex lens faces the object side, the plane of the plano-convex lens faces the image side, and the convex surface faces the concave surface of the fourth concave-convex lens; the first lens group comprises a first biconcave lens and a first biconvex lens, the second concave surface of the first biconcave lens is attached to the first convex surface of the first biconvex lens, and the first concave surface of the first biconcave lens faces the concave surface of the first concave-convex lens; the second lens group comprises a second biconvex lens, a second concave-convex lens and a third concave-convex lens, the second concave-convex lens and the third concave-convex lens are attached to the two convex faces of the second biconvex lens, the convex face of the second concave-convex lens faces the second convex face of the first biconvex lens, and the convex face of the third concave-convex lens faces the convex face of the fourth concave-convex lens. The invention has the advantages of small volume, small field loss and excellent resolution.

Description

Technical Field

[0001] The present invention belongs to the field of optical technology, and in particular relates to an objective lens imaging system and optical detection equipment. Background Art

[0002] Existing microscope objective lenses typically have an outer diameter greater than 20 mm, making them standard products. These large lenses make it difficult to insert into tissue for real-time imaging, particularly for fluorescence imaging of living organisms. To achieve real-time imaging of tissue while maintaining resolution, some field of view must be sacrificed, but this fails to meet the demands of microscope miniaturization.

[0003] Therefore, in order to solve the above technical problems, it is necessary to provide an objective lens imaging system and an optical detection device. Summary of the Invention

[0004] The object of the present invention is to provide an objective lens imaging system and an optical detection device, which can solve the problem that a microscope objective lens cannot achieve both miniaturization and resolution.

[0005] In order to achieve the above object, a specific embodiment of the present invention provides an objective lens imaging system, and the technical solution is as follows:

[0006] An objective lens imaging system comprises a first concave-convex lens, a first lens group, a second lens group, a fourth concave-convex lens and a plano-convex lens, which are arranged in sequence from the object side to the image side on the same optical axis;

[0007] The convex surface of the first meniscus lens faces the object side, the plane of the plano-convex lens faces the image side, and the convex surface faces the concave surface of the fourth meniscus lens;

[0008] The first lens group includes a first biconcave lens and a first biconvex lens, the second concave surface of the first biconcave lens is bonded to the first convex surface of the first biconvex lens, and the first concave surface of the first biconcave lens faces the concave surface of the first meniscus lens;

[0009] The second lens group includes a second biconvex lens and a second meniscus lens and a third meniscus lens attached to the two convex surfaces of the second biconvex lens, the convex surface of the second meniscus lens faces the second convex surface of the first biconvex lens, and the convex surface of the third meniscus lens faces the convex surface of the fourth meniscus lens.

[0010] In one or more embodiments of the present invention, the first meniscus lens, the first biconcave lens, the second meniscus lens, and the third meniscus lens have negative focal lengths, and the second meniscus lens and the third meniscus lens have the same focal length; the first biconvex lens, the second biconvex lens, the fourth meniscus lens, and the plano-convex lens have positive focal lengths.

[0011] In one or more embodiments of the present invention, the focal length of the first biconcave lens is -3.376 mm, the refractive index is 1.617722, and the center thickness is 2.096 mm; the curvature radius of the first concave surface of the first biconcave lens is -3.424 mm, and the curvature radius of the second concave surface is 6.732 mm; and / or,

[0012] The Abbe number of the first biconcave lens is 49.815; and / or,

[0013] The focal length of the first biconvex lens is 6.75 mm, the refractive index is 1.595220, and the center thickness is 6.006 mm; the curvature radius of the first convex surface of the first biconvex lens is 6.732 mm, and the curvature radius of the second convex surface is -6.732 mm; and / or,

[0014] The Abbe number of the first biconvex lens is 67.736.

[0015] In one or more embodiments of the present invention, the focal length of the second meniscus lens and the third meniscus lens are both -17.041 mm, the refractive index is both 1.854779, the center thickness is both 0.900 mm, the curvature radius of the convex surface of the second meniscus lens is 16.433 mm, and the curvature radius of the concave surface is 7.592 mm, the curvature radius of the concave surface of the third meniscus lens is -7.592 mm, and the curvature radius of the convex surface is -16.433 mm; and / or,

[0016] The Abbe numbers of the second meniscus lens and the third meniscus lens are both 24.799; and / or,

[0017] The second biconvex lens has a focal length of 7.006 mm, a refractive index of 1.595220, a center thickness of 3.865 mm, and curvature radii of the two convex surfaces of 7.592 mm and -7.592 mm respectively; and / or,

[0018] The Abbe number of the second biconvex lens is 67.736.

[0019] In one or more embodiments of the present invention, the focal length of the first meniscus lens is -134.135 mm, the refractive index is 1.959060, and the center thickness is 5.678 mm; the curvature radius of the convex surface of the first meniscus lens is 7.244 mm, and the curvature radius of the concave surface is 4.200 mm; and / or,

[0020] The Abbe number of the first meniscus lens is 17.471.

[0021] In one or more embodiments of the present invention, the fourth meniscus lens has a focal length of 23.626 mm, a refractive index of 1.816000, and a center thickness of 4.994 mm; the radius of curvature of the convex surface of the fourth meniscus lens is 7.178 mm, and the radius of curvature of the concave surface thereof is 7.802 mm; and / or,

[0022] The Abbe number of the fourth meniscus lens is 46.556.

[0023] In one or more embodiments of the present invention, the focal length of the plano-convex lens is 5.858 mm, the refractive index is 1.959060, and the center thickness is 5.906 mm; the curvature radius of the concave surface of the plano-convex lens is 5.754 mm; and / or,

[0024] The Abbe number of the plano-convex lens is 17.471.

[0025] In one or more embodiments of the present invention, the center distance between the concave surface of the first meniscus lens and the first concave surface of the first biconcave lens is 3.908 mm; the center distance between the second convex surface of the first biconvex lens and the convex surface of the second meniscus lens is 0.1 mm; the center distance between the convex surface of the third meniscus lens and the convex surface of the fourth meniscus lens is 0.078 mm; the center distance between the concave surface of the fourth meniscus lens and the convex surface of the plano-convex lens is 0.111 mm; and / or,

[0026] The center distance between the convex surface of the first meniscus lens and the plane of the plano-convex lens is 34.54 mm, and the minimum distance between the first meniscus lens and the first lens group is 1.998 mm.

[0027] In one or more embodiments of the present invention, the spacing tolerance of the objective lens imaging system is ±0.005 mm, and the eccentricity tolerance is ±0.005 mm; and / or,

[0028] The first concave-convex lens and the plano-convex lens are made of the same material; and / or,

[0029] The second meniscus lens and the third meniscus lens in the second lens group are made of the same material; and / or,

[0030] The working medium of the objective lens imaging system includes water.

[0031] A specific embodiment of the present invention provides an optical detection device, and the technical solution is as follows:

[0032] An optical detection device comprises a lens barrel and the above-mentioned objective lens imaging system installed in the lens barrel.

[0033] Compared with the prior art, in the objective lens imaging system of the present invention, through the combination and position design of the first concave-convex lens, the first lens group, the second lens group, the fourth concave-convex lens and the plano-convex lens, and based on the characteristics and spacing design of each lens or lens group, not only can the volume of the objective lens imaging system be reduced and the resolution be maintained unchanged, but the loss of field of view can also be reduced to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 Schematic diagram of the structure of an objective lens imaging system in one embodiment of the present invention;

[0036] Figure 2 Schematic diagram of the optical path of the objective lens imaging system in one embodiment of the present invention;

[0037] Figure 3 A schematic structural diagram of an optical detection device according to an embodiment of the present invention;

[0038] Figure 4 FIG. 1 is a schematic cross-sectional view of an optical detection device according to an embodiment of the present invention.

[0039] Description of main reference numerals:

[0040] 10. First meniscus lens; 21. First biconcave lens; 22. First biconvex lens; 31. Second meniscus lens; 32. Second biconvex lens; 33. Third meniscus lens; 40. Fourth meniscus lens; 50. Plano-convex lens; 1. Lens barrel. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present disclosure.

[0042] Reference Figure 1, optical detection equipment such as microscopes are difficult to enter tissues for real-time imaging due to their large size. Therefore, in order to achieve real-time imaging of tissues, it is necessary to sacrifice part of the field of view while maintaining the resolution of the microscope objective lens. The objective lens imaging system and optical detection equipment of the present application have the beneficial effects of being small in size and maintaining the resolution unchanged, and can also minimize the loss of field of view. Therefore, the objective lens imaging system and optical detection equipment of the present application can be applied to real-time fluorescence imaging in living bodies, such as being able to directly enter living tissues (such as monkeys) for imaging, which has important application value for brain science research and living pathological diagnosis. The objective lens imaging system and optical detection equipment of the present application are specifically introduced below.

[0043] Reference Figure 1 In one embodiment of the present invention, an objective lens imaging system is disclosed, comprising a first meniscus lens 10, a first lens group, a second lens group, a fourth meniscus lens 40, and a plano-convex lens 50, arranged coaxially from the object side to the image side. The first lens group comprises a first biconcave lens 21 and a first biconvex lens 22, and the second lens group comprises a second biconvex lens 32, and a second meniscus lens 31 and a third meniscus lens 33 attached to the two convex surfaces of the second biconvex lens 32.

[0044] Therefore, the objective lens imaging system in this embodiment is arranged in sequence along the same optical axis from the object side to the image side, namely, the first concave-convex lens 10, the first biconcave lens 21, the first biconvex lens 22, the second concave-convex lens 31, the second biconvex lens 32, the third concave-convex lens 33, the fourth concave-convex lens 40 and the plano-convex lens 50.

[0045] Reference Figure 1 Specifically, the convex surface of the first meniscus lens 10 faces the object side, the plano-convex lens 50 faces the image side, and its convex surface faces the concave surface of the fourth meniscus lens 40. The second concave surface of the first biconcave lens 21 is aligned with the first convex surface of the first biconvex lens 22, and the first concave surface of the first biconcave lens 21 faces the concave surface of the first meniscus lens 10. The convex surface of the second meniscus lens 31 faces the second convex surface of the first biconvex lens 22, and the convex surface of the third meniscus lens 33 faces the convex surface of the fourth meniscus lens 40.

[0046] In this embodiment, the combination of the first meniscus lens 10, the first lens group, the second lens group, the fourth meniscus lens 40 and the plano-convex lens 50 not only reduces the volume of the microscope objective lens and maintains the resolution unchanged, but also reduces the loss of field of view to a certain extent.

[0047] In this embodiment, the first meniscus lens, the first biconcave lens, the second meniscus lens, and the third meniscus lens have negative focal lengths, and the second meniscus lens and the third meniscus lens have the same focal length; the first biconvex lens, the second biconvex lens, the fourth meniscus lens, and the plano-convex lens have positive focal lengths.

[0048] Specifically, the focal length of the first meniscus lens is -134.135 mm, the refractive index is 1.959060, and the center thickness is 5.678 mm; the curvature radius of the convex surface of the first meniscus lens is 7.244 mm, and the curvature radius of the concave surface is 4.200 mm; further, in this embodiment, the Abbe number of the first meniscus lens is 17.471.

[0049] The first concave-convex lens is used to converge the incident light. Its convex surface faces the object side (the light source side), minimizing spherical aberration and achieving a clearer focus. Compared to a plano-convex lens, it also achieves a smaller focus and fewer aberrations, ensuring the imaging resolution of the objective imaging system, thereby improving image quality and reducing the size of the objective imaging system.

[0050] Reference Figure 1 , the first lens group includes a first biconcave lens and a first biconvex lens. The focal length of the first biconcave lens is -3.376mm, the refractive index is 1.617722, and the center thickness is 2.096mm; the radius of curvature of the first concave surface of the first biconcave lens is -3.424mm, and the radius of curvature of the second concave surface is 6.732mm. Further, in this embodiment, the Abbe number of the first biconcave lens is 49.815. The focal length of the first biconvex lens is 6.75mm, the refractive index is 1.595220, and the center thickness is 6.006mm; the radius of curvature of the first convex surface of the first biconvex lens is 6.732mm, and the radius of curvature of the second convex surface is -6.732mm. Further, in this embodiment, the Abbe number of the first biconvex lens is 67.736.

[0051] The first biconcave lens is used to diverge light. Leveraging its divergent properties, the direction of light propagation can be corrected, collimating the light beam and ensuring that the incident light more closely follows the intended path. In this embodiment, the position of the first biconcave lens can be adjusted to adjust the focal length of the light source and image size, thereby ensuring the clarity of the final image.

[0052] The primary function of a first biconvex lens is to converge light, or to bring it to a specific point. When used as a positive lens, the first biconvex lens's primary functions include relaying images (the process of converting a physical object into a real image), focusing diverging beams, and converging them. It can magnify small objects for easier observation.

[0053] In this embodiment, the first biconcave lens and the first biconvex lens in the first lens group are formed into a double-cemented lens by gluing as an example for illustrative explanation, which does not limit the bonding method. Among them, the double-cemented lens can reduce the reflection and scattering between the lenses due to the lack of air gap, and has excellent light transmittance, thereby improving the transmittance of light. Since the double-cemented lens has no air gap, the environmental changes such as temperature and humidity have little effect on its characteristics, and it has good environmental adaptability. The first lens group can not only combine the advantages of the two lenses to form a wider field of view, but also prevent dust and moisture from entering the optical device, thereby extending the service life of the optical device and maintaining its performance. By adjusting the various parameters of the first biconcave lens and the first biconvex lens in the first lens group, not only can the magnified imaging and refractive error correction effects of the double-cemented lens itself be achieved, but the resolution of the objective lens imaging system can also be further maintained.

[0054] Reference Figure 1 The second lens group includes a second meniscus lens, a second biconvex lens, and a third meniscus lens. In this embodiment, the focal length of the second meniscus lens and the third meniscus lens are both -17.041 mm, the refractive index is both 1.854779, and the center thickness is both 0.900 mm. The radius of curvature of the convex surface of the second meniscus lens is 16.433 mm, and the radius of curvature of the concave surface is 7.592 mm. The radius of curvature of the concave surface of the third meniscus lens is -7.592 mm, and the radius of curvature of the convex surface is -16.433 mm. Furthermore, in this embodiment, the Abbe number of the second meniscus lens and the third meniscus lens is both 24.799. The focal length of the second biconvex lens is 7.006 mm, the refractive index is 1.595220, the center thickness is 3.865 mm, and the curvature radii of the two convex surfaces are 7.592 mm and -7.592 mm respectively. Furthermore, in this embodiment, the Abbe number of the second biconvex lens is 67.736.

[0055] The second lens group can reduce the chromatic aberration caused by light, ensuring the imaging quality of the objective lens imaging system. In this embodiment, the second concave-convex lens, the second biconvex lens, and the third concave-convex lens of the second lens group are exemplified by bonding to form a triplet lens, which does not limit the bonding method. Specifically, the second biconvex lens can be made of low-refractive index glass, and the second concave-convex lens and the third concave-convex lens can be made of high-refractive index glass. Compared with a single lens or a concave-convex lens, the second lens group can produce clear and realistic images. In an optical projection system, neither a single lens nor a biconvex lens can form the high-quality image that a triplet lens can. Therefore, by limiting the various parameters of the second concave-convex lens, the second biconvex lens, and the third concave-convex lens, the resolution of the objective lens imaging system can be further ensured and the volume of the objective lens imaging system can be reduced.

[0056] In one specific embodiment, the second and third meniscus lenses in the second lens group are made of the same material. By using the same optical glass material, the second and third meniscus lenses are symmetrical, minimizing the impact on light passing through the second lens group. Specifically, both the second and third meniscus lenses in the second lens group can be made of S-NBH56.

[0057] The fourth meniscus lens has a focal length of 23.626 mm, a refractive index of 1.816000, and a center thickness of 4.994 mm. The radius of curvature of the convex surface of the fourth meniscus lens is 7.178 mm, and the radius of curvature of the concave surface thereof is 7.802 mm. Furthermore, in this embodiment, the Abbe number of the fourth meniscus lens is 46.556.

[0058] The convex surface of the fourth concave-convex lens faces the second lens group and is used to converge parallel light emitted from the second lens group. Its main function is to reduce spherical aberration and simultaneously make the focus clearer, thereby improving the imaging quality. The fourth concave-convex lens can also shorten the focal length, increasing the numerical aperture of the system without introducing significant spherical aberration. At the same time, the fourth concave-convex lens can not only correct aberrations, but also serve as a condenser for the illumination system. By selecting the fourth concave-convex lens of an appropriate thickness, chromatic aberration can also be eliminated. In this embodiment, the various parameters of the fourth concave-convex lens are limited to further ensure the imaging resolution of the objective lens imaging system and reduce the volume of the objective lens imaging system.

[0059] The focal length of the plano-convex lens is 5.858 mm, the refractive index is 1.95906, and the center thickness is 5.906 mm; the curvature radius of the concave surface of the plano-convex lens is 5.754 mm; further, in this embodiment, the Abbe number of the plano-convex lens is 17.471.

[0060] Plano-convex lenses focus light toward the center of the lens, magnifying images of living tissue and improving the imaging quality of objective imaging systems. Because a plano-convex lens is an optical element with a positive focal length, consisting of a convex surface and a flat surface, it primarily scales light by changing its path length, effectively directing a beam in a specific direction. In optical systems, plano-convex lenses can be used to produce sharp images. Adjusting and correcting plano-convex lenses can also reduce spherical aberration in imaging.

[0061] Specifically, based on the curvature radius, center thickness, focal length, and refractive index of the above-mentioned first concave-convex lens, first biconcave lens, first biconvex lens, second concave-convex lens, second biconvex lens, third concave-convex lens, fourth concave-convex lens, and plano-convex lens, the spacing between the first concave-convex lens, the first lens group, the second lens group, the fourth concave-convex lens, and the plano-convex lens can be determined to achieve the purpose of reducing the volume of the objective imaging system and ensuring the resolution of the objective imaging system.

[0062] In this embodiment, the center-to-center distance between the concave surface of the first meniscus lens and the first concave surface of the first biconcave lens is 3.908 mm; the center-to-center distance between the second convex surface of the first biconvex lens and the convex surface of the second meniscus lens is 0.1 mm; the center-to-center distance between the convex surface of the third meniscus lens and the convex surface of the fourth meniscus lens is 0.078 mm; and the center-to-center distance between the concave surface of the fourth meniscus lens and the convex surface of the plano-convex lens is 0.111 mm. The above center-to-center distances are the distances between the intersections of the lens surfaces and the optical axis.

[0063] Furthermore, the center-to-center distance between the convex surface of the first meniscus lens and the flat surface of the plano-convex lens is 34.54 mm, and the minimum distance between the first meniscus lens and the first lens group is 1.998 mm. This spacing arrangement can further reduce the volume of the objective imaging system while maintaining the resolution of the objective imaging system.

[0064] In this embodiment, the spacing tolerance of the objective lens imaging system is ±0.005 mm, and the decentering tolerance is ±0.005 mm. Considering the possible errors of the objective lens imaging system in actual industrial production, corresponding regulations are made for the spacing tolerance and decentering tolerance of the objective lens imaging system, which can avoid imaging errors of the objective lens imaging system to a certain extent.

[0065] In one specific embodiment, the first meniscus lens and the plano-convex lens are made of the same material. This avoids optical distortion caused by the interface between the different materials, maintaining imaging quality and accuracy. It also reduces the effects of refractive index mismatch and reduces chromatic aberration.

[0066] Among them, suitable materials can be selected according to the function and position of each lens to ensure the imaging quality of the objective lens imaging system. The following is an exemplary description of the preparation materials of each lens in the objective lens imaging system of this application, which is not a limitation on the materials.

[0067] Specifically, the first meniscus lens can be made of S-NPH3; the first biconcave lens in the first lens group can be made of S-BSM28, and the first biconvex lens in the first lens group can be made of S-FPM2; the second meniscus lens in the second lens group can be made of S-NBH56, the second biconvex lens can be made of S-FPM2, and the third meniscus lens can be made of S-NBH56; the fourth meniscus lens can be made of H-ZLAF69A; and the plano-convex lens can be made of S-NPH3. Both the first meniscus lens and the plano-convex lens can be made of S-NPH3.

[0068] The working medium of the objective lens imaging system of the present application includes water. In one optional embodiment, the central thickness of the water is 0.548 mm. In this embodiment, using water as the working medium of the objective lens imaging system not only reduces the refraction and reflection of light on living tissue, improving the objective lens's ability to capture this stray light, but also matches the refractive index of the lens, thereby increasing the amount of light in the final image. It also facilitates cleaning, reducing the cost of the objective lens imaging system of the present application.

[0069] The following describes the parameters of the first concave-convex lens, the first biconcave lens, the first biconvex lens, the second concave-convex lens, the second biconvex lens, the third concave-convex lens, the fourth concave-convex lens, and the plano-convex lens of the objective imaging system of the present application, taking a specific embodiment as an example, as shown in Table 1 below.

[0070]

[0071] The curvature radius of the convex surface of the first meniscus lens is 7.244 mm, and the curvature radius of the concave surface is 4.200 mm; the curvature radius of the first concave surface of the first biconcave lens is -3.424 mm, and the curvature radius of the second concave surface is 6.732 mm; the curvature radius of the first convex surface of the first biconvex lens is 6.732 mm, and the curvature radius of the second convex surface is -6.732 mm; the curvature radius of the convex surface of the second meniscus lens is 16.433 mm. The curvature radius of the concave surface is 7.592mm; the curvature radii of the two convex surfaces of the second biconvex lens are 7.592mm and -7.592mm respectively; the curvature radius of the concave surface of the third meniscus lens is -7.592mm, and the curvature radius of the convex surface is -16.433mm; the curvature radius of the convex surface of the fourth meniscus lens is 7.178mm, and the curvature radius of its concave surface is 7.802mm; the curvature radius of the concave surface of the plano-convex lens is 5.754mm.

[0072] The center-to-center distance between the concave surface of the first meniscus lens and the first concave surface of the first biconcave lens is 3.908mm; the center-to-center distance between the second convex surface of the first biconvex lens and the convex surface of the second meniscus lens is 0.1mm; the center-to-center distance between the convex surface of the third meniscus lens and the convex surface of the fourth meniscus lens is 0.078mm; the center-to-center distance between the concave surface of the fourth meniscus lens and the convex surface of the plano-convex lens is 0.111mm. The center-to-center distance between the convex surface of the first meniscus lens and the flat surface of the plano-convex lens is 34.54mm. The minimum distance between the first meniscus lens and the first lens group is 1.998mm.

[0073] Based on the above data, compared to the 0.6mm field of view of a conventional microscope objective lens with a 40x magnification, the objective imaging system of the present application, based on the combination of the first concave-convex lens, the first lens group, the second lens group, the fourth concave-convex lens, and the plano-convex lens, also has a 40x magnification, and can still maintain a 0.5mm field of view even when the outer diameter is reduced by more than half. Therefore, the objective imaging system of the present application is compact and has good resolution, and can also minimize the loss of field of view.

[0074] Reference Figure 2 The parallel incident light is refracted by the convex surface of the first concave-convex lens 10, and the refracted light is refracted again by the concave surface of the first concave-convex lens 10 to become parallel light; the parallel light is refracted by the first biconcave lens 21 in the second lens group and then diverges and is emitted as parallel light; the parallel light is converged by the convex surface of the second concave-convex lens 31 in the third lens group, and then becomes parallel light after passing through the concave surface of the second concave-convex lens 31. The parallel light passes through the second biconvex lens 32, diverges after passing through the bonding surface of the second biconvex lens 32 and the third concave-convex lens 33, and then becomes parallel outgoing light after passing through the convex surface of the third concave-convex lens 33; the parallel outgoing light is refracted and converged at the focal point by the fourth concave-convex lens 40 and the plano-convex lens 50, thereby forming an image.

[0075] Reference Figure 3 and Figure 4 In one embodiment of the present invention, an optical inspection device is disclosed, comprising a lens barrel 1 and an objective lens imaging system such as the above-described one, mounted within the lens barrel. It will be appreciated that, by incorporating the above-described objective lens imaging system, the optical inspection device of the present invention also achieves the effective effects of being compact and having high resolution, while also minimizing loss of field of view.

[0076] It will be apparent to those skilled in the art that the present disclosure is not limited to the details of the exemplary embodiments described above and that the present disclosure can be implemented in other specific forms without departing from the spirit or essential characteristics of the present disclosure. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present disclosure is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present disclosure. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0077] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An objective lens imaging system, characterized in that: The lens comprises a first meniscus lens, a first lens group, a second lens group, a fourth meniscus lens and a plano-convex lens, which are arranged in sequence from the object side to the image side on the same optical axis. The convex surface of the first meniscus lens faces the object side, the plane of the plano-convex lens faces the image side, and the convex surface faces the concave surface of the fourth meniscus lens; The first lens group includes a first biconcave lens and a first biconvex lens, the second concave surface of the first biconcave lens is bonded to the first convex surface of the first biconvex lens, and the first concave surface of the first biconcave lens faces the concave surface of the first meniscus lens; The second lens group includes a second biconvex lens and a second meniscus lens and a third meniscus lens attached to the two convex surfaces of the second biconvex lens, the convex surface of the second meniscus lens faces the second convex surface of the first biconvex lens, and the convex surface of the third meniscus lens faces the convex surface of the fourth meniscus lens.

2. The objective lens imaging system according to claim 1, characterized in that: The first meniscus lens, the first biconcave lens, the second meniscus lens, and the third meniscus lens have negative focal lengths, and the focal lengths of the second meniscus lens and the third meniscus lens are equal; the first biconvex lens, the second biconvex lens, the fourth meniscus lens, and the plano-convex lens have positive focal lengths.

3. The objective lens imaging system according to claim 1, characterized in that: The focal length of the first biconcave lens is -3.376 mm, the refractive index is 1.617722, and the center thickness is 2.096 mm; the curvature radius of the first concave surface of the first biconcave lens is -3.424 mm, and the curvature radius of the second concave surface is 6.732 mm; and / or, The Abbe number of the first biconcave lens is 49.815; and / or, The focal length of the first biconvex lens is 6.75 mm, the refractive index is 1.595220, and the center thickness is 6.006 mm; the curvature radius of the first convex surface of the first biconvex lens is 6.732 mm, and the curvature radius of the second convex surface is -6.732 mm; and / or, The Abbe number of the first biconvex lens is 67.

736.

4. The objective lens imaging system according to claim 1, wherein: The focal lengths of the second meniscus lens and the third meniscus lens are both -17.041 mm, the refractive indices are both 1.854779, the center thicknesses are both 0.900 mm, the convex surface of the second meniscus lens has a curvature radius of 16.433 mm, and the concave surface has a curvature radius of 7.592 mm, and the concave surface of the third meniscus lens has a curvature radius of -7.592 mm, and the convex surface has a curvature radius of -16.433 mm; and / or, The Abbe numbers of the second meniscus lens and the third meniscus lens are both 24.799; and / or, The second biconvex lens has a focal length of 7.006 mm, a refractive index of 1.595220, a center thickness of 3.865 mm, and curvature radii of the two convex surfaces of 7.592 mm and -7.592 mm respectively; and / or, The Abbe number of the second biconvex lens is 67.

736.

5. The objective lens imaging system according to claim 1, characterized in that: The focal length of the first meniscus lens is -134.135 mm, the refractive index is 1.959060, and the center thickness is 5.678 mm; the curvature radius of the convex surface of the first meniscus lens is 7.244 mm, and the curvature radius of the concave surface is 4.200 mm; and / or, The Abbe number of the first meniscus lens is 17.

471.

6. The objective lens imaging system according to claim 1, characterized in that: The fourth meniscus lens has a focal length of 23.626 mm, a refractive index of 1.816000, and a center thickness of 4.994 mm; the convex surface of the fourth meniscus lens has a curvature radius of 7.178 mm, and the concave surface thereof has a curvature radius of 7.802 mm; and / or, The Abbe number of the fourth meniscus lens is 46.

556.

7. The objective lens imaging system according to claim 1, characterized in that: The focal length of the plano-convex lens is 5.858 mm, the refractive index is 1.959060, and the center thickness is 5.906 mm; the curvature radius of the concave surface of the plano-convex lens is 5.754 mm; and / or, The Abbe number of the plano-convex lens is 17.

471.

8. The objective lens imaging system according to claim 1, characterized in that: The center distance between the concave surface of the first meniscus lens and the first concave surface of the first biconcave lens is 3.908 mm; the center distance between the second convex surface of the first biconvex lens and the convex surface of the second meniscus lens is 0.1 mm; the center distance between the convex surface of the third meniscus lens and the convex surface of the fourth meniscus lens is 0.078 mm; the center distance between the concave surface of the fourth meniscus lens and the convex surface of the plano-convex lens is 0.111 mm; and / or, The center distance between the convex surface of the first meniscus lens and the plane of the plano-convex lens is 34.54 mm, and the minimum distance between the first meniscus lens and the first lens group is 1.998 mm.

9. The objective lens imaging system according to claim 1, characterized in that: The spacing tolerance of the objective lens imaging system is ±0.005mm, and the eccentricity tolerance is ±0.005mm; and / or, The first concave-convex lens and the plano-convex lens are made of the same material; and / or, The second meniscus lens and the third meniscus lens in the second lens group are made of the same material; and / or, The working medium of the objective lens imaging system includes water.

10. An optical detection device, characterized in that: The invention comprises a lens barrel and an objective lens imaging system according to any one of claims 1 to 9 installed in the lens barrel.

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