Continuously variable zoom microscope objective

Abstract

The application belongs to the technical field of optical design, and particularly relates to a continuous zooming microscopic imaging objective lens. The continuous zooming microscopic imaging objective lens comprises a front fixed group one, a variable aperture diaphragm, a front fixed group two, a variable magnification group and a rear fixed group arranged in sequence along the optical axis direction between an object plane and an image plane, and the front fixed group one is close to the object plane and the rear fixed group is close to the image plane; the continuous zooming of the microscopic imaging objective lens is realized by moving the variable magnification group along the optical axis direction, and the object side numerical aperture and the image side numerical aperture of the microscopic imaging objective lens are adjusted by adjusting the light passing aperture of the variable aperture diaphragm. The application can realize the continuous change of the object side imaging field between 10mm*10mm and 200mm*200mm, and meet the requirement of the change range of the large imaging field.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of optical design, and particularly relates to a continuous zooming microscopic imaging objective. BACKGROUND

[0002] With the increasing development of biological or medical research, especially the research on diseases and related treatments, the research has been increasingly transferred from in vitro molecular and cell research to live animal research. Therefore, constructing a new research platform based on live animals is an important foundation for carrying out translational medical research and conducting preclinical research of new drugs. The optical imaging technology of small animals in vivo has the advantages of simple operation, intuitive results, fast measurement, high sensitivity, no toxic side effects and low cost, and is increasingly widely used in various fields of preclinical disease research, including cancer research, infectious disease research, cardiovascular disease research, neurological disease research, inflammatory disease research, immunology and stem cell research, metabolic disease research, biomedical material research, new drug research, etc. The optical imaging technology of small animals in vivo is to label the research object by using bioluminescence and fluorescence probes, and directly monitor the development and changes of diseases on live animals by using sensitive optical detection instruments, and carry out preclinical research and development of related drugs.

[0003] The in vivo fluorescence imaging equipment of live small animals needs a microscopic objective with high light collection ability, high magnification, large imaging field of view and continuously variable magnification. The existing microscopic objective for live small animals is in a step switching mode, which cannot realize continuous magnification change, and the change range of the switching magnification is also small, which cannot meet the imaging requirements of large magnification ratio and high performance. SUMMARY

[0004] Therefore, the present application aims to provide a continuous zooming microscopic imaging objective to solve the problem that the microscopic imaging objective designed by the prior art cannot meet the design requirements of large numerical aperture, large field of view, high magnification and large magnification ratio, and the present application can realize the continuous change of the object imaging field of view between 10mm*10mm and 200mm*200mm, and meet the requirement of the change range of the large imaging field of view.

[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] The application discloses a continuous zooming microscope imaging objective, which comprises a front fixed group, a variable aperture diaphragm, a front fixed group II, a zooming group and a rear fixed group arranged in sequence along the optical axis direction from an object plane to an image plane, wherein the front fixed group is close to the object plane, and the rear fixed group is close to the image plane; the continuous zooming of the microscope imaging objective is realized by moving the zooming group along the optical axis direction; the image plane position of the microscope imaging objective is compensated by moving a loading platform of a microscope on which the microscope imaging objective is arranged along the optical axis of the microscope imaging objective; and the object side numerical aperture and the image side numerical aperture of the microscope imaging objective are adjusted by adjusting the light passing aperture of the variable aperture diaphragm.

[0007] Further, the front fixed group and the front fixed group II have positive refractive powers, the zooming group has a negative refractive power, and the rear fixed group has a positive refractive power; the interval between the object plane and the front fixed group ranges from 22 mm to 496 mm, the interval between the front fixed group II and the zooming group ranges from 2 mm to 152 mm, the interval between the zooming group and the rear fixed group ranges from 2 mm to 152 mm, and the interval between the rear fixed group and the image plane is 230 mm.

[0008] The light passing aperture of the variable aperture diaphragm ranges from 20 mm to 42.8 mm; when the light passing aperture of the variable aperture diaphragm is 20 mm, the microscope imaging objective is a large field of view and a low magnification; and when the light passing aperture of the variable aperture diaphragm is 42.8 mm, the microscope imaging objective is a small field of view and a high magnification.

[0009] Further, when the microscope imaging objective is at the lowest magnification, the object side numerical aperture is 0.0145, and the image side numerical aperture is 0.05; and when the microscope imaging objective is at the highest magnification, the object side numerical aperture is 0.243, and the image side numerical aperture is 0.04.

[0010] Further, the front fixed group comprises a first cemented lens, a plug-in filter, a plane compensation glass and a second cemented lens arranged in sequence along the optical axis direction; the first cemented lens comprises a first meniscus lens and a first biconcave lens arranged in sequence along the optical axis direction, and the convex surface of the first meniscus lens faces the plane compensation glass; the second cemented lens comprises a second meniscus lens and a first biconvex lens arranged in sequence along the optical axis direction, and the convex surface of the second meniscus lens faces the plane compensation glass; and the spectral selection during the imaging of the microscope imaging objective is realized by setting the plug-in state of the plug-in filter.

[0011] The front fixed group II comprises a third cemented lens, a second biconvex lens and a first plano-convex lens arranged in sequence along the optical axis direction, the convex surface of the first plano-convex lens faces away from the second biconvex lens, and the third cemented lens is composed of a third biconvex lens and a second biconcave lens arranged in sequence along the optical axis direction.

[0012] Further, the radius of curvature of the lens close to the object plane in the first meniscus lens is -220 mm, the radius of curvature of the lens far from the object plane in the first meniscus lens is -83 mm, the thickness of the first meniscus lens is 5 mm, the refractive index is 1.954, and the Abbe number is 33.3;

[0013] The radius of curvature of the lens close to the object plane in the first biconcave lens is -83 mm, the radius of curvature of the lens far from the object plane in the first biconcave lens is 35 mm, the thickness of the first biconcave lens is 3 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0014] The radius of curvature of the plug-in filter is ∞, and the thickness is 2 mm;

[0015] The radius of curvature of the plane compensation glass is ∞, and the thickness is 30 mm;

[0016] The radius of curvature of the lens close to the object plane in the second meniscus lens is 70 mm, the radius of curvature of the lens far from the object plane in the second meniscus lens is 70 mm, the thickness of the second meniscus lens is 28 mm, the refractive index is 1.805, and the Abbe number is 25.5;

[0017] The radius of curvature of the lens close to the object plane in the first biconvex lens is 70 mm, the radius of curvature of the lens far from the object plane in the first biconvex lens is -55 mm, the thickness of the first biconvex lens is 12 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0018] The radius of curvature of the lens close to the object plane in the third biconvex lens is 231 mm, the radius of curvature of the lens far from the object plane in the third biconvex lens is -35 mm, the thickness of the third biconvex lens is 15 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0019] The radius of curvature of the lens close to the object plane in the second biconcave lens is -35 mm, the radius of curvature of the lens far from the object plane in the second biconcave lens is 170.8 mm, the thickness of the second biconcave lens is 4 mm, the refractive index is 1.806, and the Abbe number is 33.3;

[0020] The radius of curvature of the lens close to the object plane in the second biconvex lens is 255.5 mm, the radius of curvature of the lens far from the object plane in the second biconvex lens is -91 mm, the thickness of the second biconvex lens is 9 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0021] The radius of curvature of the lens close to the object plane in the first plano-convex lens is -2582 mm, the radius of curvature of the lens far from the object plane in the first plano-convex lens is -93.9 mm, the thickness of the first plano-convex lens is 8 mm, the refractive index is 1.847, and the Abbe number is 23.8.

[0022] Further,

[0023] When the minimum magnification is presented, the distance between the object plane and the center of the first meniscus lens is 496.4mm, and when the maximum magnification is presented, the distance between the object plane and the center of the first meniscus lens is 22mm.

[0024] Further, the zoom group comprises a third double-concave lens, a first double-concave lens and a fourth cemented lens arranged in sequence along the optical axis, the concave surface of the first double-concave lens faces away from the fourth cemented lens, and the fourth cemented lens comprises a fourth double-concave lens and a fourth double-convex lens arranged in sequence along the optical axis.

[0025] The curvature radius of the lens close to the object plane in the third double-concave lens is -187.7mm, the curvature radius of the lens away from the object plane in the third double-concave lens is 110mm, the thickness of the third double-concave lens is 4mm, the refractive index is 1.901, and the Abbe number is 37.1.

[0026] The curvature radius of the lens close to the object plane in the first double-concave lens is -93mm, the curvature radius of the lens away from the object plane in the first double-concave lens is -1067mm, the thickness of the third double-concave lens is 4.4mm, the refractive index is 1.901, and the Abbe number is 37.1.

[0027] The curvature radius of the lens close to the object plane in the fourth double-concave lens is -145mm, the curvature radius of the lens away from the object plane in the fourth double-concave lens is 182mm, the thickness of the fourth double-concave lens is 18.5mm, the refractive index is 1.606, and the Abbe number is 43.9.

[0028] The curvature radius of the lens close to the object plane in the fourth double-convex lens is 182mm, the curvature radius of the lens away from the object plane in the fourth double-convex lens is -85mm, the thickness of the fourth double-convex lens is 14mm, the refractive index is 1.762, and the Abbe number is 26.6.

[0029] Further, the rear fixed group comprises a fifth double-convex lens, a fifth cemented lens and a third meniscus lens arranged in sequence along the optical axis, the convex surface of the third meniscus lens faces the fifth cemented lens, the fifth cemented lens comprises a sixth double-convex lens and a second double-concave lens arranged in sequence along the optical axis, and the concave surface of the second double-concave lens faces the fifth double-convex lens.

[0030] The curvature radius of the lens close to the object plane in the fifth double-convex lens is 590mm, the curvature radius of the lens away from the object plane in the fifth double-convex lens is -138mm, the thickness of the fifth double-convex lens is 24mm, the refractive index is 1.487, and the Abbe number is 70.4.

[0031] The curvature radius of the lens close to the object plane in the sixth lenticular lens is 377 mm, the curvature radius of the lens far from the object plane in the sixth lenticular lens is -177 mm, the thickness of the sixth lenticular lens is 30 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0032] The curvature radius of the lens close to the object plane in the second plano-concave lens is -177 mm, the curvature radius of the lens far from the object plane in the second plano-concave lens is 443 mm, the thickness of the second plano-concave lens is 10 mm, the refractive index is 1.806, and the Abbe number is 33.3;

[0033] The curvature radius of the lens close to the object plane in the third meniscus lens is 168 mm, the curvature radius of the lens far from the object plane in the third meniscus lens is 495 mm, the thickness of the third meniscus lens is 14.5 mm, the refractive index is 1.741, and the Abbe number is 27.7.

[0034] Further, the maximum clear aperture of the variable magnification group is 67.6 mm, and the maximum clear aperture of the rear fixed group is 122.5 mm.

[0035] Further,

[0036] The air gap between the object plane and the first cemented lens is 22-496 mm;

[0037] The air gap between the first cemented lens and the plug-in filter is 7.4 mm;

[0038] The air gap between the plug-in filter and the plane compensation glass is 3 mm;

[0039] The air gap between the plane compensation glass and the second cemented lens is 0.4 mm;

[0040] The air gap between the second cemented lens and the variable aperture diaphragm is 3.2 mm;

[0041] The air gap between the variable aperture diaphragm and the third cemented lens is 4.2 mm;

[0042] The air gap between the third cemented lens and the second lenticular lens is 2 mm;

[0043] The air gap between the second lenticular lens and the first plano-convex lens is 4 mm;

[0044] The air gap between the first plano-convex lens and the third biconcave lens is 2-152 mm;

[0045] The air gap between the third biconcave lens and the first plano-concave lens is 6.5 mm;

[0046] The air gap between the first plano-concave lens and the fourth cemented lens is 3.6 mm;

[0047] The air interval of the fourth cemented lens and the fifth double convex lens is 2-152mm;

[0048] The air interval of the fifth double convex lens and the fifth cemented lens is 6mm;

[0049] The air interval of the fifth cemented lens and the third meniscus lens is 19mm;

[0050] The air interval of the third meniscus lens and the image surface is 233mm.

[0051] Compared with the prior art, the application can achieve the following beneficial effects:

[0052] (1) The continuous zooming microscopic imaging objective lens can realize 21 times change of imaging magnification from 0.29 to 6.3 through axial movement of the zooming group, and realize compensation of the image surface position through object distance change, so as to ensure clear imaging of the microscopic imaging objective lens during zooming, and finally the magnification of the microscopic imaging objective lens is 0.29-6.3.

[0053] (2) The microscopic imaging objective lens can realize continuous change of the object side imaging field between 10mm*10mm and 200mm*200mm under the condition that the target surface size is 61.44mm*61.44mm, so as to meet the requirement of large imaging field change range.

[0054] (3) The microscopic imaging objective lens can realize spectral measurement range of 500nm-850nm. DETAILED DESCRIPTION

[0055] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. The present application is not limited by the improper limitation of the accompanying drawings. In the drawings:

[0056] Figure 1 The structure schematic view of the microscopic objective lens described in the embodiments of the present application;

[0057] Figure 2 The structure schematic view of the front fixed group one and the front fixed group two described in the embodiments of the present application;

[0058] Figure 3 The structure schematic view of the zooming group described in the embodiments of the present application;

[0059] Figure 4 The structure schematic view of the rear fixed group described in the embodiments of the present application;

[0060] Figure 5 The structure schematic view of the zooming process described in the embodiments of the present application;

[0061] Fig. 6(a)-Fig. 6(d) are MTF curves of the embodiment of the present application at magnification M of M=0.29, M=1.2, M=4, M=6.3, respectively;

[0062] Fig. 7(a)-Fig. 7(d) are point array diagrams of the embodiment of the present application at magnification M of M=0.29, M=1.2, M=4, M=6.3, respectively;

[0063] Fig. 8(a)-Fig. 8(d) are distortion diagrams of the embodiment of the present application at magnification M of M=0.3, M=1.2, M=4, M=6.3, respectively;

[0064] Fig. 9(a)-Fig. 9(d) are relative luminance curves of the embodiment of the present application at magnification M of M=0.3, M=1.2, M=4, M=6.3, respectively;

[0065] Figure 10 Fig. 10 is a diagram showing the changes of magnification, object distance, distance between the front fixed group and the variable magnification group, distance between the variable magnification group and the rear fixed group, and diaphragm size corresponding to the 12 different sampling points of the embodiment of the present application.

[0066] BRIEF DESCRIPTION OF DRAWINGS

[0067] 1, front fixed group; 2, variable aperture diaphragm; 3, front fixed group 2; 4, variable magnification group; 5, rear fixed group; 1-1, first cemented lens; 1-2, plug-in filter; 1-3, plane compensation glass; 1-4, second cemented lens; 1-1-1, first meniscus lens; 1-1-2, first double concave lens; 1-4-1, second meniscus lens; 1-4-2, first double convex lens; 3-1, third cemented lens; 3-2, second double convex lens; 3-3, first plano-convex lens; 3-1-1, third double convex lens; 3-1-2, second double concave lens; 4-1, third double concave lens; 4-2, first plano-concave lens; 4-3, fourth cemented lens; 4-3-1, fourth double concave lens; 4-3-2, fourth double convex lens; 5-1, fifth double convex lens; 5-2, fifth cemented lens; 5-3, third meniscus lens; 5-2-1, sixth double convex lens; 5-2-2, second plano-concave lens. DETAILED DESCRIPTION

[0068] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and do not constitute a limitation on the present application.

[0069] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other in the case of no conflict.

[0070] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0071] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0072] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0073] As Figure 1 shown, a continuous zooming microscope imaging objective includes a front fixed group 1, a variable aperture diaphragm 2, a front fixed group 2 3, a zoom group 4 and a rear fixed group 5 arranged in sequence along the optical axis direction from the object plane to the image plane, and the front fixed group 1 is close to the object plane, and the rear fixed group 5 is close to the image plane; the continuous zooming of the microscope imaging objective is realized by moving the zoom group 4 along the optical axis direction, the image plane position of the microscope imaging objective is compensated by moving the object platform of the microscope on which the microscope imaging objective is located along the optical axis of the microscope imaging objective, and the object side numerical aperture and the image side numerical aperture of the microscope imaging objective are adjusted by adjusting the light aperture of the variable aperture diaphragm 2.

[0074] The front fixed group 1 and the front fixed group 2 3 are positive optical powers, the zoom group 4 is negative optical powers, and the rear fixed group 5 is positive optical powers; the distance between the object plane and the front fixed group 1 varies from 22mm to 496mm, the distance between the front fixed group 2 3 and the zoom group 4 varies from 2mm to 152mm, the distance between the zoom group 4 and the rear fixed group 5 varies from 2mm to 152mm, and the distance between the rear fixed group 5 and the image plane is 230mm;

[0075] The aperture of the variable aperture stop 2 varies from 20mm to 42.8mm. When the aperture of the variable aperture stop 2 is 20mm, the microscope imaging objective is a large field of view with low magnification. When the aperture of the variable aperture stop 2 is 42.8mm, the microscope imaging objective is a small field of view with high magnification.

[0076] When the microscope imaging objective is at its lowest magnification, the object-side numerical aperture is 0.0145 and the image-side numerical aperture is 0.05; when the microscope imaging objective is at its highest magnification, the object-side numerical aperture is 0.243 and the image-side numerical aperture is 0.04.

[0077] like Figure 2 As shown, the front fixed group 1 includes a first cemented lens 1-1 (negative optical power), a pluggable filter 1-2, a planar compensation glass 1-3, and a second cemented lens 1-4 (positive optical power) arranged sequentially along the optical axis. The first cemented lens 1-1 includes a first meniscus lens 1-1-1 and a first biconcave lens 1-1-2 arranged sequentially along the optical axis, with the convex surface of the first meniscus lens 1-1-1 facing the planar compensation glass 1-3. The second cemented lens 1-4 includes a second meniscus lens 1-4-1 and a first biconvex lens 1-4-2 arranged sequentially along the optical axis, with the convex surface of the second meniscus lens 1-4-1 facing the planar compensation glass 1-3. By setting the pluggable state of the pluggable filter 1-2, spectral selection can be achieved when imaging with the microscope imaging objective.

[0078] The front fixed second group 3 includes a third cemented lens 3-1 (negative optical power), a second biconvex lens 3-2 and a first plano-convex lens 3-3 arranged sequentially along the optical axis. The convex surface of the first plano-convex lens 3-3 faces away from the second biconvex lens 3-2. The third cemented lens 3-1 is composed of a third biconvex lens 3-1-1 and a second biconcave lens 3-1-2 arranged sequentially along the optical axis.

[0079] The lens parameters for front fixed group 1 and front fixed group 3 are as follows:

[0080] The radius of curvature of the lens closest to the object surface in the first meniscus lens 1-1-1 is -220mm, the radius of curvature of the lens furthest from the object surface in the first meniscus lens 1-1-1 is -83mm, the thickness of the first meniscus lens 1-1-1 is 5mm, the refractive index is 1.954, and the Abbe value is 33.3.

[0081] The radius of curvature of the lens close to the object plane in the first double-concave lens 1-1-2 is -83 mm, the radius of curvature of the lens far from the object plane in the first double-concave lens 1-1-2 is 35 mm, the thickness of the first double-concave lens 1-1-2 is 3 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0082] The radius of curvature of the plug-in filter 1-2 is ∞, and the thickness is 2 mm;

[0083] The radius of curvature of the plane compensation glass 1-3 is ∞, and the thickness is 30 mm;

[0084] The radius of curvature of the lens close to the object plane in the second meniscus lens 1-4-1 is 70 mm, the radius of curvature of the lens far from the object plane in the second meniscus lens 1-4-1 is 70 mm, the thickness of the second meniscus lens 1-4-1 is 28 mm, the refractive index is 1.805, and the Abbe number is 25.5;

[0085] The radius of curvature of the lens close to the object plane in the first double-convex lens 1-4-2 is 70 mm, the radius of curvature of the lens far from the object plane in the first double-convex lens 1-4-2 is -55 mm, the thickness of the first double-convex lens 1-4-2 is 12 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0086] The radius of curvature of the lens close to the object plane in the third double-convex lens 3-1-1 is 231 mm, the radius of curvature of the lens far from the object plane in the third double-convex lens 3-1-1 is -35 mm, the thickness of the third double-convex lens 3-1-1 is 15 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0087] The radius of curvature of the lens close to the object plane in the second double-concave lens 3-1-2 is -35 mm, the radius of curvature of the lens far from the object plane in the second double-concave lens 3-1-2 is 170.8 mm, the thickness of the second double-concave lens 3-1-2 is 4 mm, the refractive index is 1.806, and the Abbe number is 33.3;

[0088] The radius of curvature of the lens close to the object plane in the second double-convex lens 3-2 is 255.5 mm; the radius of curvature of the lens far from the object plane in the second double-convex lens 3-2 is -91 mm; the thickness of the second double-convex lens 3-2 is 9 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0089] The radius of curvature of the lens close to the object plane in the first plano-convex lens 3-3 is -2582 mm; the radius of curvature of the lens far from the object plane in the first plano-convex lens 3-3 is -93.9 mm; the thickness of the first plano-convex lens 3-3 is 8 mm, the refractive index is 1.847, and the Abbe number is 23.8.

[0090] The distance between the object plane and the center of the first meniscus lens 1-1-1 is 496.4 mm when the minimum magnification of the microscopic imaging objective is reached, and the distance between the object plane and the center of the first meniscus lens 1-1-1 is 22 mm when the maximum magnification of the microscopic imaging objective is reached.

[0091] As shown in Figure 3 The zoom group 4 includes, in order along the optical axis, a third double-concave lens 4-1, a first flat-concave lens 4-2, and a fourth cemented lens 4-3 (positive focal power), the concave surface of the first flat-concave lens 4-2 faces away from the fourth cemented lens 4-3, and the fourth cemented lens 4-3 includes, in order along the optical axis, a fourth double-concave lens 4-3-1 and a fourth double-convex lens 4-3-2;

[0092] The lens parameters of the zoom group 4 are as follows:

[0093] The curvature radius of the lens close to the object in the third double-concave lens 4-1 is -187.7 mm, the curvature radius of the lens away from the object in the third double-concave lens 4-1 is 110 mm, the thickness of the third double-concave lens 4-1 is 4 mm, the refractive index is 1.901, and the Abbe number is 37.1;

[0094] The curvature radius of the lens close to the object in the first flat-concave lens 4-2 is -93 mm, the curvature radius of the lens away from the object in the first flat-concave lens 4-2 is -1067 mm, the thickness of the third double-concave lens 4-1 is 4.4 mm, the refractive index is 1.901, and the Abbe number is 37.1;

[0095] The curvature radius of the lens close to the object in the fourth double-concave lens 4-3-1 is -145 mm, the curvature radius of the lens away from the object in the fourth double-concave lens 4-3-1 is 182 mm, the thickness of the fourth double-concave lens 4-3-1 is 18.5 mm, the refractive index is 1.606, and the Abbe number is 43.9;

[0096] The curvature radius of the lens close to the object in the fourth double-convex lens 4-3-2 is 182 mm, the curvature radius of the lens away from the object in the fourth double-convex lens 4-3-2 is -85 mm, the thickness of the fourth double-convex lens 4-3-2 is 14 mm, the refractive index is 1.762, and the Abbe number is 26.6.

[0097] As shown in Figure 4 The rear fixed group 5 includes, in order along the optical axis, a fifth double-convex lens 5-1, a fifth cemented lens 5-2, and a third meniscus lens 5-3, the convex surface of the third meniscus lens 5-3 faces the fifth cemented lens 5-2 (negative focal power), the fifth cemented lens 5-2 includes, in order along the optical axis, a sixth double-convex lens 5-2-1 and a second flat-concave lens 5-2-2, and the concave surface of the second flat-concave lens 5-2-2 faces the fifth double-convex lens 5-1;

[0098] The lens parameters of the rear fixed group 5 are as follows:

[0099] The radius of curvature of the lens close to the object plane in the fifth double convex lens 5-1 is 590 mm; the radius of curvature of the lens away from the object plane in the fifth double convex lens 5-1 is -138 mm; the thickness of the fifth double convex lens 5-1 is 24 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0100] The radius of curvature of the lens close to the object plane in the sixth double convex lens 5-2-1 is 377 mm, the radius of curvature of the lens away from the object plane in the sixth double convex lens 5-2-1 is -177 mm, the thickness of the sixth double convex lens 5-2-1 is 30 mm, the refractive index is 1.487, and the Abbe number is 70.4;

[0101] The radius of curvature of the lens close to the object plane in the second plano-concave lens 5-2-2 is -177 mm, the radius of curvature of the lens away from the object plane in the second plano-concave lens 5-2-2 is 443 mm, the thickness of the second plano-concave lens 5-2-2 is 10 mm, the refractive index is 1.806, and the Abbe number is 33.3;

[0102] The radius of curvature of the lens close to the object plane in the third meniscus lens 5-3 is 168 mm; the radius of curvature of the lens away from the object plane in the third meniscus lens 5-3 is 495 mm; the thickness of the third meniscus lens 5-3 is 14.5 mm, the refractive index is 1.741, and the Abbe number is 27.7.

[0103] The maximum clear aperture of the variable magnification group 4 is 67.6 mm, and the maximum clear aperture of the rear fixed group 5 is 122.5 mm.

[0104] The air gap between each lens and optical element is: the air gap between the object plane and the first cemented lens 1-1 is 22-496mm; the air gap between the first cemented lens 1-1 and the plug-in filter 1-2 is 7.4mm; the air gap between the plug-in filter 1-2 and the plane compensation glass 1-3 is 3mm; the air gap between the plane compensation glass 1-3 and the second cemented lens 1-4 is 0.4mm; the air gap between the second cemented lens 1-4 and the variable aperture diaphragm 2 is 3.2mm; the air gap between the variable aperture diaphragm 2 and the third cemented lens 3-1 is 4.2mm; the air gap between the third cemented lens 3-1 and the second double convex lens 3-2 is 2mm; the air gap between the second double convex lens 3-2 and the first plano-convex lens 3-3 is 4mm; the air gap between the first plano-convex lens 3-3 and the third double concave lens 4-1 is 2-152mm; the air gap between the third double concave lens 4-1 and the first plano-concave lens 4-2 is 6.5mm; the air gap between the first plano-concave lens 4-2 and the fourth cemented lens 4-3 is 3.6mm; the air gap between the fourth cemented lens 4-3 and the fifth double convex lens 5-1 is 2-152mm; the air gap between the fifth double convex lens 5-1 and the fifth cemented lens 5-2 is 6mm; the air gap between the fifth cemented lens 5-2 and the third meniscus lens 5-3 is 19mm; and the air gap between the third meniscus lens 5-3 and the image plane is 233mm.

[0105] The microscopic imaging objective designed by the present application is used for imaging a live small animal, and the design indexes of the microscopic objective are shown in Table 1.

[0106] Table 1

[0107]

[0108] According to the motion state of the live small animal, the variable power group 4 is moved between the front fixed two groups 3 and the rear fixed group 5 along the optical axis direction to realize continuous zooming of the microscopic imaging objective, and meanwhile, the object platform of the microscope where the microscopic imaging objective is located is adjusted to move along the optical axis of the microscopic imaging objective, so as to realize compensation of the image plane position of the microscopic imaging objective. Through cooperation and change of the variable power group 4 and the object distance, the magnification of the microscopic imaging objective is continuously changed between 0.29 and 6.3.

[0109] As shown in Figure 5 When the variable power group 4 is close to the front fixed two groups 3, the size of the variable aperture diaphragm 2 is adjusted to be small, so that the corresponding object distance is increased and the magnification is reduced; when the variable power group 4 is close to the rear fixed group 5, the size of the variable aperture diaphragm 2 is adjusted to be large, so that the corresponding object distance is reduced and the magnification is increased. In the zooming process, the distance between the front fixed two groups 3 and the camera where the image plane is located is 682.9mm, and the distance between the rear fixed group 5 and the camera is 233mm.

[0110] During zooming, as the object distance and the zoom group 4 and the cooperating group move, the exiting angle of the light rays after passing through the zoom group 4 is always close to parallel light, i.e. the light rays between the zoom group 4 and the rear fixed group 5 are parallel, from the perspective of Gaussian optics, the front fixed group (including the front fixed group 1 and the front fixed group 3) and the zoom group 4 can be regarded as an optical group M1, the focal length of M1 is f1', the rear fixed group 5 is set as M2, the focal length of M2 is f2', the magnification of the whole system can be expressed as f2' / f1', f2' is constant, the distance between the front fixed group and the zoom group 4 is changed by moving the zoom group 4 horizontally along the optical axis, thereby the focal length f1' of M1 is changed, then the object plane is adjusted to be at the front focal plane of M1, so that the magnification of the whole microscopic imaging objective is changed.

[0111] As shown in FIGS. 6(a)-6(d), the horizontal coordinate is spatial frequency, and the vertical coordinate is transfer function, the resolution of the microscopic imaging objective at each position is better than 50 lp / mm in the range of 0.7 field of view, and the edge field of view resolution is 20 lp / mm.

[0112] As shown in FIGS. 7(a)-7(d), the horizontal coordinate represents points in the object side, and the vertical coordinate represents the imaging of these points on the IMA plane after passing through the microscopic imaging objective, RMS RADIUS represents the root mean square radius value, GEO RADIUS represents the geometric radius (maximum radius), and SCALE BAR is the scale. The spot diagrams of the microscopic imaging objective in FIGS. 7(a)-7(d) are uniform, the energy is concentrated, and there is no obvious aberration.

[0113] As shown in FIGS. 8(a)-8(d), the horizontal and vertical coordinates are image coordinates and distortion values, respectively, and MAXIMUM DISTORTION is the maximum distortion value. The maximum distortion of the microscopic imaging objective is less than 3.1% at the low magnification position, and the maximum distortion is less than 0.5% at the high magnification position.

[0114] As shown in FIGS. 9(a)-9(d), the horizontal coordinate is the angle in the field of view, and the vertical coordinate is the relative luminance, WAVELENGTH is the wavelength. When the microscopic imaging objective is at the low magnification position, the relative luminance of the edge field of view is about 80%, and when the microscopic imaging objective is at the magnification positions other than the low magnification position, the relative luminance of the edge field of view is better than 90%, the luminance is uniform in the whole field of view, and there is no obvious black edge.

[0115] As shown in FIG. 9(a)-9(d), the horizontal coordinate is the angle in the field of view, and the vertical coordinate is the relative luminance, WAVELENGTH is the wavelength. When the microscopic imaging objective is at the low magnification position, the relative luminance of the edge field of view is about 80%, and when the microscopic imaging objective is at the magnification positions other than the low magnification position, the relative luminance of the edge field of view is better than 90%, the luminance is uniform in the whole field of view, and there is no obvious black edge. Figure 10 As shown in FIG. 9(a)-9(d), the horizontal coordinate is the angle in the field of view, and the vertical coordinate is the relative luminance, WAVELENGTH is the wavelength. When the microscopic imaging objective is at the low magnification position, the relative luminance of the edge field of view is about 80%, and when the microscopic imaging objective is at the magnification positions other than the low magnification position, the relative luminance of the edge field of view is better than 90%, the luminance is uniform in the whole field of view, and there is no obvious black edge.

[0116] Table 2

[0117] Table 2

[0118] In combination Figure 10 The moving track of the object distance, the distance between the front fixed group and the variable group 4, and the distance between the variable group 4 and the rear fixed group 5 has no inflection point during the change of the lens magnification, which is convenient for the realization of the structural design.

[0119] It should be understood that the various forms of flow shown above can be used to reorder, add or delete steps. For example, the steps described in the present disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions of the present disclosure can be achieved, which is not limited herein.

[0120] The above specific embodiments do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent replacement and improvement made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A continuously variable focal length microscope imaging objective, characterized in that: It comprises a front fixed group, a variable aperture stop, a front fixed group, a zoom group, and a rear fixed group arranged sequentially from the object plane to the image plane along the optical axis. The front fixed group is closer to the object plane, and the rear fixed group is closer to the image plane. Continuous zooming of the microscope imaging objective is achieved by moving the zoom group along the optical axis. The image plane position of the microscope imaging objective is compensated by adjusting the platform of the microscope on which the microscope imaging objective is located, so that the platform moves along the optical axis of the microscope imaging objective. The object-side numerical aperture and image-side numerical aperture of the microscope imaging objective are adjusted by adjusting the aperture of the variable aperture stop. The front fixed group includes a first cemented lens, a pluggable filter, a planar compensation glass, and a second cemented lens arranged sequentially along the optical axis. The first cemented lens includes a first meniscus lens and a first biconcave lens arranged sequentially along the optical axis, with the convex surface of the first meniscus lens facing the planar compensation glass. The second cemented lens includes a second meniscus lens and a first biconvex lens arranged sequentially along the optical axis, with the convex surface of the second meniscus lens facing the planar compensation glass. By setting the pluggable filter's pluggable state, spectral selection can be achieved when the microscope imaging objective is used for imaging. The front fixed two groups include a third cemented lens, a second biconvex lens and a first plano-convex lens arranged sequentially along the optical axis. The convex surface of the first plano-convex lens faces away from the second biconvex lens. The third cemented lens is composed of a third biconvex lens and a second biconcave lens arranged sequentially along the optical axis. The zoom group includes a third biconcave lens, a first plano-concave lens, and a fourth cemented lens arranged sequentially along the optical axis. The concave surface of the first plano-concave lens faces away from the fourth cemented lens. The fourth cemented lens includes a fourth biconcave lens and a fourth biconvex lens arranged sequentially along the optical axis. The rear fixing assembly includes a fifth biconvex lens, a fifth cemented lens, and a third meniscus lens arranged sequentially along the optical axis. The convex surface of the third meniscus lens faces the fifth cemented lens. The fifth cemented lens includes a sixth biconvex lens and a second plano-concave lens arranged sequentially along the optical axis. The concave surface of the second plano-concave lens faces the fifth biconvex lens.

2. The continuously variable focal length microscope imaging objective according to claim 1, characterized in that: The first and second front fixed groups are positive optical power, the zoom group is negative optical power, and the rear fixed group is positive optical power; the distance between the object plane and the first front fixed group varies from 22mm to 496mm, the distance between the second front fixed group and the zoom group varies from 2mm to 152mm, the distance between the zoom group and the rear fixed group varies from 2mm to 152mm, and the distance between the rear fixed group and the image plane is 230mm. The variable aperture stop has a light transmission diameter ranging from 20mm to 42.8mm. When the light transmission diameter of the variable aperture stop is 20mm, the microscope imaging objective is a large field of view with low magnification. When the light transmission diameter of the variable aperture stop is 42.8mm, the microscope imaging objective is a small field of view with high magnification.

3. The continuously zoom microscope imaging objective according to claim 1, characterized in that: When the microscope imaging objective is at its lowest magnification, the object-side numerical aperture is 0.0145 and the image-side numerical aperture is 0.05; when the microscope imaging objective is at its highest magnification, the object-side numerical aperture is 0.243 and the image-side numerical aperture is 0.

04.

4. The continuously variable focal length microscope imaging objective according to claim 1, characterized in that: The radius of curvature of the lens closest to the object surface in the first meniscus lens is -220mm, the radius of curvature of the lens furthest from the object surface in the first meniscus lens is -83mm, the thickness of the first meniscus lens is 5mm, the refractive index is 1.954, and the Abbe value is 33.

3. The first biconcave lens has a radius of curvature of -83 mm for the lens closest to the object surface and a radius of curvature of 35 mm for the lens furthest from the object surface. The first biconcave lens has a thickness of 3 mm, a refractive index of 1.487, and an Abbe value of 70.

4. The pluggable filter has a radius of curvature of ∞ and a thickness of 2 mm. The radius of curvature of the planar compensating glass is ∞, and its thickness is 30mm; The second meniscus lens has a radius of curvature of 70 mm for the lens closest to the object surface and a radius of curvature of 70 mm for the lens furthest from the object surface. The second meniscus lens has a thickness of 28 mm, a refractive index of 1.805, and an Abbe value of 25.

5. The first biconvex lens has a radius of curvature of 70 mm for the lens closest to the object surface and a radius of curvature of -55 mm for the lens furthest from the object surface. The first biconvex lens has a thickness of 12 mm, a refractive index of 1.487, and an Abbe value of 70.

4. The radius of curvature of the lens closest to the object surface in the third biconvex lens is 231 mm, the radius of curvature of the lens furthest from the object surface in the third biconvex lens is -35 mm, the thickness of the third biconvex lens is 15 mm, the refractive index is 1.487, and the Abbe value is 70.

4. The second biconcave lens has a radius of curvature of -35 mm for the lens closest to the object surface and a radius of curvature of 170.8 mm for the lens furthest from the object surface. The second biconcave lens has a thickness of 4 mm, a refractive index of 1.806, and an Abbe value of 33.

3. The radius of curvature of the lens closest to the object surface in the second biconvex lens is 255.5 mm; the radius of curvature of the lens furthest from the object surface in the second biconvex lens is -91 mm; the thickness of the second biconvex lens is 9 mm, the refractive index is 1.487, and the Abbe value is 70.

4. The first plano-convex lens has a radius of curvature of -2582 mm for the lens closest to the object surface; a radius of curvature of -93.9 mm for the lens furthest from the object surface; and a thickness of 8 mm, a refractive index of 1.847, and an Abbe value of 23.

8.

5. The continuously zoom microscope imaging objective according to claim 4, characterized in that: When the microscope imaging objective is at its minimum magnification, the distance between the object surface and the center of the first meniscus lens is 496.4 mm; when the microscope imaging objective is at its maximum magnification, the distance between the object surface and the center of the first meniscus lens is 22 mm.

6. The continuously zoom microscope imaging objective according to claim 5, characterized in that: The radius of curvature of the lens closest to the object surface in the third biconcave lens is -187.7 mm; the radius of curvature of the lens furthest from the object surface in the third biconcave lens is 110 mm; the thickness of the third biconcave lens is 4 mm, the refractive index is 1.901, and the Abbe value is 37.

1. The radius of curvature of the lens closest to the object surface in the first plano-concave lens is -93 mm; the radius of curvature of the lens furthest from the object surface in the first plano-concave lens is -1067 mm; the thickness of the third biconcave lens is 4.4 mm, the refractive index is 1.901, and the Abbe value is 37.

1. The radius of curvature of the lens closest to the object surface in the fourth biconcave lens is -145mm, the radius of curvature of the lens furthest from the object surface in the fourth biconcave lens is 182mm, the thickness of the fourth biconcave lens is 18.5mm, the refractive index is 1.606, and the Abbe value is 43.

9. The radius of curvature of the lens closest to the object surface in the fourth biconvex lens is 182 mm, the radius of curvature of the lens furthest from the object surface in the fourth biconvex lens is -85 mm, the thickness of the fourth biconvex lens is 14 mm, the refractive index is 1.762, and the Abbe value is 26.

6.

7. The continuously zoom microscope imaging objective according to claim 6, characterized in that: The radius of curvature of the lens closest to the object surface in the fifth biconvex lens is 590 mm; the radius of curvature of the lens furthest from the object surface in the fifth biconvex lens is -138 mm; the thickness of the fifth biconvex lens is 24 mm, the refractive index is 1.487, and the Abbe value is 70.

4. The radius of curvature of the lens closest to the object surface in the sixth biconvex lens is 377 mm, the radius of curvature of the lens furthest from the object surface in the sixth biconvex lens is -177 mm, the thickness of the sixth biconvex lens is 30 mm, the refractive index is 1.487, and the Abbe value is 70.

4. The second plano-concave lens has a radius of curvature of -177 mm for the lens closest to the object surface and a radius of curvature of 443 mm for the lens furthest from the object surface. The second plano-concave lens has a thickness of 10 mm, a refractive index of 1.806, and an Abbe value of 33.

3. The radius of curvature of the third meniscus lens closest to the object surface is 168 mm; the radius of curvature of the third meniscus lens furthest from the object surface is 495 mm; the thickness of the third meniscus lens is 14.5 mm, the refractive index is 1.741, and the Abbe value is 27.

7.

8. The continuously zoom microscope imaging objective according to claim 7, characterized in that: The maximum aperture of the zoom group is 67.6 mm, and the maximum aperture of the rear fixed group is 122.5 mm.

9. The continuously zoom microscope imaging objective according to claim 8, characterized in that: The air gap between the object surface and the first cemented lens is 22~496mm; The air gap between the first cemented lens and the pluggable filter is 7.4 mm; The air gap between the pluggable filter and the planar compensation glass is 3mm; The air gap between the planar compensating glass and the second cemented lens is 0.4 mm; The air gap between the second cemented lens and the variable aperture stop is 3.2 mm; The air gap between the variable aperture stop and the third cemented lens is 4.2 mm; The air gap between the third cemented lens and the second biconvex lens is 2mm; The air gap between the second biconvex lens and the first plano-convex lens is 4 mm; The air gap between the first plano-convex lens and the third biconcave lens is 2~152mm; The air gap between the third biconcave lens and the first plano-concave lens is 6.5 mm; The air gap between the first plano-concave lens and the fourth cemented lens is 3.6 mm; The air gap between the fourth cemented lens and the fifth biconvex lens is 2~152mm; The air gap between the fifth biconvex lens and the fifth cemented lens is 6 mm; The air gap between the fifth cemented lens and the third meniscus lens is 19 mm; The air gap between the third meniscus lens and the image plane is 233 mm.

Images