40x infinite conjugate microscope objective

Abstract

The present invention provides a 40x infinite conjugate microscope objective lens, which relates to the field of objective lenses. The 40x infinite conjugate microscope objective lens includes a first lens group, a second lens group, and a third lens group, which are arranged in sequence along the optical axis from the object side to the image side. The first lens group includes a first lens and a second lens, which are arranged in sequence along the optical axis from the object side to the image side. The second lens group includes a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens, which are arranged in sequence along the optical axis from the object side to the image side. The third lens group includes a tenth lens and an eleventh lens, which are arranged in sequence along the optical axis from the object side to the image side. The 40x infinite conjugate microscope objective lens can achieve high resolution, a flat image plane, and an achromatic objective lens. At a shorter parfocal distance, the numerical aperture is larger, the illumination at the image plane is increased, and the image is clearer. The on-axis field of view and the off-axis field of view are both close to the diffraction limit, and the point array radius is also close to within the Airy disk.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging equipment, and in particular to a 40x infinite conjugate microscope objective lens. Background Art

[0002] Infinite conjugate microscope objectives are an optical design widely used in modern microscope systems. Compared to traditional finite conjugate objectives, they offer greater flexibility, improved imaging quality, and expanded functionality. Infinite conjugate microscope objectives are frequently used in fluorescence microscopy, enabling high-resolution imaging of fluorescent markers in biological samples.

[0003] For traditional high-magnification microscope objectives, as the numerical aperture increases, the incident height of marginal light increases, which will introduce greater spherical aberration, chromatic aberration and field curvature, causing the modulation transfer function to fail to meet high-resolution requirements, the image plane to be not flat enough, and the achromatic effect to be general, which reduces the imaging quality of the microscope objective. Summary of the Invention

[0004] The purpose of the present invention includes providing a 40x infinite conjugate microscope objective lens, which can improve the imaging effect.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] The present application provides a 40x infinite conjugate microscope objective lens, comprising a first lens group, a second lens group, and a third lens group arranged in sequence along the optical axis from the object side to the image side;

[0007] The first lens group includes a first lens and a second lens arranged in sequence from the object side to the image side along the optical axis, the first lens being a meniscus lens with positive optical power, with its concave surface facing the object side and its convex surface facing the image side; the second lens being a meniscus lens with positive optical power, with its concave surface facing the object side and its convex surface facing the image side;

[0008] The second lens group includes a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens, which are arranged in sequence along the optical axis from the object side to the image side; the third lens is a biconvex lens with positive optical power; the fourth lens is a meniscus lens with negative optical power, with the concave surface of the fourth lens facing the object side and the convex surface facing the image side; the fifth lens is a biconvex lens with positive optical power, the sixth lens is a biconcave lens with negative optical power, the seventh lens is a biconvex lens with positive optical power, the eighth lens is a biconvex lens with positive optical power, and the ninth lens is a biconcave lens with negative optical power; the third lens and the fourth lens are cemented to form a first doublet lens group, and the first doublet lens group has positive optical power; the fifth lens, the sixth lens, and the seventh lens are cemented to form a triplet lens group, and the triplet lens group has positive optical power; the eighth lens and the ninth lens are cemented to form a second doublet lens group, and the second doublet lens group has positive optical power;

[0009] The third lens group includes a tenth lens and an eleventh lens arranged in sequence from the object side to the image side along the optical axis, the tenth lens is a biconvex lens with positive optical power, and the eleventh lens is a biconcave lens with negative optical power; the tenth lens and the eleventh lens are cemented to form a third doublet lens group, and the third doublet lens group has negative optical power.

[0010] In an optional embodiment, the combined focal length of the first lens group is f G1 ,f G1 The values ​​satisfy the following relationship:

[0011]

[0012] The combined focal length of the second lens group is f G2 ,f G2 The values ​​satisfy the following relationship:

[0013]

[0014] The combined focal length of the third lens group is f G3 ,f G3 The values ​​satisfy the following relationship:

[0015]

[0016] Where f is the focal length of the 40x infinite conjugate microscope objective.

[0017] In an optional embodiment, the second lens group further includes a stop, and the stop is disposed between the seventh lens and the eighth lens.

[0018] In an optional embodiment, the difference between the Abbe numbers of the third lens and the fourth lens satisfies the following relationship:

[0019] v d3 -v d4 >60;

[0020] The difference in refractive index between the third lens and the fourth lens satisfies the following relationship:

[0021] |n d3 -n d4 |>0.3;

[0022] Among them, v d3 is the Abbe number of the third lens, v d4 is the Abbe number of the fourth lens, n d3 is the refractive index of the third lens, n d4 is the refractive index of the fourth lens.

[0023] In an optional embodiment, the difference between the Abbe numbers of the eighth lens and the ninth lens satisfies the following relationship:

[0024] v d8 -v d9 >40;

[0025] The difference in refractive index between the eighth lens and the ninth lens satisfies the following relationship:

[0026] |n d8 -n d9 |>0.2; where v d8 is the Abbe number of the eighth lens, v d9 is the Abbe number of the ninth lens, n d8 is the refractive index of the eighth lens, n d9 is the refractive index of the ninth lens;

[0027] The difference in Abbe numbers between the tenth lens and the eleventh lens satisfies the following relationship:

[0028] v d10 -v d11 >20

[0029] The difference in refractive index between the tenth lens and the eleventh lens satisfies the following relationship:

[0030] |n d10 -n d11 |>0.1;

[0031] Among them, v d10 is the Abbe number of the tenth lens, v d11 is the Abbe number of the eleventh lens, n d10 is the refractive index of the tenth lens, n d11 is the refractive index of the eleventh lens.

[0032] In an optional embodiment, the Abbe number v of the fifth lens is d5 The value is greater than 70.

[0033] In an optional embodiment, the Abbe number v of the second lens is d2 and the Abbe number v of the third lens d3 The values ​​of are all greater than 90.

[0034] In an optional embodiment, the focal length of the first lens is represented by f1, and the value of f1 satisfies the following relationship:

[0035]

[0036] The thickness of the first lens is represented by d1, and the value of d1 satisfies the following relationship:

[0037]

[0038] Where f is the focal length of the 40x infinite conjugate microscope objective.

[0039] In an optional embodiment, the curvature radius of the concave surface of the eleventh lens on the image side is represented by R1, and the value of R1 satisfies the following relationship:

[0040]

[0041] Where f is the focal length of the 40x infinite conjugate microscope objective.

[0042] In an optional embodiment, the numerical aperture of the 40x infinite conjugate microscope objective lens set is represented by NA, and the value of NA satisfies the following relationship:

[0043] 0.5<NA<0.7.

[0044] The beneficial effects of the 40x infinite conjugate microscope objective lens provided by the embodiment of the present invention include:

[0045] This application achieves a high-resolution, flat image plane, and apochromatic objective lens by providing a combination of a first lens group, a second lens group, and a third lens group, and by designing each lens. This objective lens has a large numerical aperture at a short parfocal distance, increasing the illumination at the image plane and facilitating clearer imaging with the microscope objective lens. The microscope objective lens's MTF value is within the visible light band, approaching the diffraction limit for both on-axis and off-axis fields of view, and the point array radius is also close to within the Airy disk. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 A schematic structural diagram of a 40x infinite conjugate microscope objective lens provided in an embodiment of the present invention;

[0048] Figure 2 A modulation transfer function diagram of a 40x infinite conjugate microscope objective lens provided in an embodiment of the present invention;

[0049] Figure 3 A point diagram of a 40x infinite conjugate microscope objective lens provided by an embodiment of the present invention;

[0050] Figure 4 Field curvature and distortion diagram of the 40x infinite conjugate microscope objective lens provided by an embodiment of the present invention;

[0051] Figure 5This is a wavefront aberration diagram of the 40x infinite conjugate microscope objective lens provided by an embodiment of the present invention.

[0052] Icon: G1-first lens group; G2-second lens group; G3-third lens group; L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; L5-fifth lens; L6-sixth lens; L7-seventh lens; L8-eighth lens; L9-ninth lens; L10-tenth lens; L11-eleventh lens; C1-first doublet group; C2-triplet group; C3-second doublet group; C4-third doublet group; ST-aperture stop; S-slide. DETAILED DESCRIPTION

[0053] For traditional high-magnification microscope objectives, as the numerical aperture increases, the incident height of marginal light increases, which will introduce greater spherical aberration, chromatic aberration and field curvature, causing the modulation transfer function to fail to meet high-resolution requirements, the image plane to be not flat enough, and the achromatic effect to be general, which reduces the imaging quality of the microscope objective.

[0054] In response to the above problems, the present invention provides a 40x infinite conjugate microscope objective lens, which can improve the imaging effect, thereby improving the above problem of poor imaging effect.

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0056] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0057] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0058] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0059] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0060] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0061] The overall structure, working principle and technical effects of the 40x infinite conjugate microscope objective lens provided by the present invention are described in detail below through embodiments and in conjunction with the accompanying drawings.

[0062] Please refer to Figures 1 to 5In this embodiment, the 40x infinite conjugate microscope objective lens includes a first lens group G1, a second lens group G2, and a third lens group G3, arranged sequentially along the optical axis from the object side to the image side. The first lens group G1 includes a first lens L1 and a second lens L2, arranged sequentially along the optical axis from the object side to the image side. The first lens L1 is a positive meniscus lens with a concave surface facing the object side and a convex surface facing the image side. The second lens L2 is a positive meniscus lens with a concave surface facing the object side and a convex surface facing the image side. The second lens group G2 includes a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9, arranged sequentially along the optical axis from the object side to the image side. The third lens L3 is a biconvex lens with positive optical power. The fourth lens L4 is a negative meniscus lens with a concave surface facing the object side and a convex surface facing the image side. The fifth lens L5 is a biconvex lens with positive optical power, the sixth lens L6 is a biconcave lens with negative optical power, the seventh lens L7 is a biconvex lens with positive optical power, the eighth lens L8 is a biconvex lens with positive optical power, and the ninth lens L9 is a biconcave lens with negative optical power. The third lens L3 and the fourth lens L4 are cemented together to form a first doublet lens group C1, which has positive optical power. The fifth lens L5, the sixth lens L6, and the seventh lens L7 are cemented together to form a triplet lens group C2, which has positive optical power. The eighth lens L8 and the ninth lens L9 are cemented together to form a second doublet lens group C3, which has positive optical power. The third lens group G3 includes the tenth lens L10 and the eleventh lens L11, arranged in order from the object side to the image side along the optical axis. The tenth lens L10 is a biconvex lens with positive optical power, and the eleventh lens L11 is a biconcave lens with negative optical power. The tenth lens L10 and the eleventh lens L11 are cemented together to form a third doublet lens group C4. The third doublet lens group C4 has negative power.

[0063] The 40x infinite conjugate microscope objective lens provided in this embodiment achieves high resolution, a flat image plane, and an achromatic objective lens through the combination of the first lens group G1, the second lens group G2, and the third lens group G3, as well as the design of each lens. The 40x infinite conjugate microscope objective lens has a large numerical aperture at a short parfocal distance, which increases the illumination of the objective lens at the image plane, facilitating clearer imaging with the 40x infinite conjugate microscope objective lens. The MTF value of the 40x infinite conjugate microscope objective lens is within the visible light band, and is close to the diffraction limit for both the on-axis and off-axis fields of view, and the point array radius is also close to within the Airy disk.

[0064] Furthermore, the combined focal length of the first lens group G1 is f G1 ,f G1 The values ​​satisfy the following relationship:

[0065]

[0066] The combined focal length of the second lens group G2 is f G2 ,f G2 The values ​​satisfy the following relationship:

[0067]

[0068] The combined focal length of the third lens group G3 is f G3 ,f G3 The values ​​satisfy the following relationship:

[0069]

[0070] Where f is the focal length of the 40x infinite conjugate microscope objective.

[0071] The above parameter settings can effectively correct the spherical aberration, chromatic aberration and field curvature of the 40x infinite conjugate microscope objective lens, achieving a high-resolution, flat image plane and apochromatic objective lens. The 40x infinite conjugate microscope objective lens has a large numerical aperture at a short parfocal distance, which increases the illumination of the objective lens at the image plane, which is conducive to clearer imaging of the microscope objective lens. The MTF value of the 40x infinite conjugate microscope objective lens is within the visible light band, and is close to the diffraction limit for both the on-axis field of view and the off-axis field of view. The modulation transfer function MTF value at a spatial frequency of 600 line pairs / mm is higher than 0.5. The point array radius is also close to within the Airy disk.

[0072] In this embodiment, the second lens group G2 further includes a stop ST, which is disposed between the seventh lens L7 and the eighth lens L8.

[0073] In this embodiment, an aperture ST is positioned between the seventh lens element L7 and the eighth lens element L8 to control the angle of incident light and adjust the luminous flux. A properly positioned aperture ST effectively corrects off-axis aberrations. The aperture ST also reduces stray light and improves image contrast.

[0074] Please refer to Figures 1 to 5 Furthermore, the difference between the Abbe numbers of the third lens L3 and the fourth lens L4 satisfies the following relationship:

[0075] v d3 -v d4 >60;

[0076] The difference in refractive index between the third lens L3 and the fourth lens L4 satisfies the following relationship:

[0077] |n d3 -n d4 |>0.3;

[0078] Among them, v d3is the Abbe number of the third lens L3, v d4 is the Abbe number of the fourth lens L4, n d3 is the refractive index of the third lens L3, n d4 is the refractive index of the fourth lens L4.

[0079] In this embodiment, setting the difference in Abbe number and refractive index between the third lens L3 and the fourth lens L4 in the first doublet lens group C1 to the above range is beneficial for correcting axial chromatic aberration and reducing spherical aberration.

[0080] Furthermore, the difference between the Abbe numbers of the eighth lens L8 and the ninth lens L9 satisfies the following relationship:

[0081] v d8 -v d9 >40;

[0082] The difference in refractive index between the eighth lens L8 and the ninth lens L9 satisfies the following relationship:

[0083] |n d8 -n d9 |>0.2;

[0084] Among them, v d8 is the Abbe number of the eighth lens L8, v d9 is the Abbe number of the ninth lens L9, n d8 is the refractive index of the eighth lens L8, n d9 is the refractive index of the ninth lens L9.

[0085] In this embodiment, setting the difference in Abbe number and the difference in refractive index between the eighth lens L8 and the ninth lens L9 in the second doublet lens group C3 to the above range is beneficial for correcting axial chromatic aberration and reducing spherical aberration.

[0086] Furthermore, the difference between the Abbe numbers of the tenth lens L10 and the eleventh lens L11 satisfies the following relationship:

[0087] v d10 -v d11 >20;

[0088] The difference in refractive index between the tenth lens L10 and the eleventh lens L11 satisfies the following relationship:

[0089] |n d10 -n d11 |>0.1;

[0090] Among them, v d10 is the Abbe number of the tenth lens L10, v d11 is the Abbe number of the eleventh lens L11, n d10 is the refractive index of the tenth lens L10, n d11is the refractive index of the eleventh lens L11.

[0091] In this embodiment, setting the difference in Abbe number and refractive index between the tenth lens L10 and the eleventh lens L11 in the third doublet lens group C4 to the above range is beneficial for correcting axial chromatic aberration and reducing spherical aberration.

[0092] Please refer to Figures 1 to 5 In this embodiment, the Abbe number v of the fifth lens L5 is d5 The value is greater than 70.

[0093] In this embodiment, the Abbe number of the fifth lens L5 in the triplet lens group C2 is set to v d5 The angle is greater than 70, and the triplet lens group C2 is a positive-negative-positive structure, which is beneficial for correcting the secondary spectrum and achieving apochromatism.

[0094] Furthermore, the Abbe number v of the second lens L2 is d2 and the Abbe number v of the third lens L3 d3 The values ​​of are all greater than 90. This is beneficial for correcting the secondary spectrum.

[0095] Of course, in some other embodiments of the present application, other positive lenses may also use special dispersion materials with an Abbe number higher than 90, and the relative dispersion coefficient is similar, which is conducive to correcting the secondary spectrum.

[0096] Furthermore, the focal length of the first lens L1 is represented by f1, and the value of f1 satisfies the following relationship:

[0097]

[0098] The thickness of the first lens L1 is denoted by d1, and the value of d1 satisfies the following relationship:

[0099]

[0100] In this embodiment, the first lens element L1 is a thick meniscus lens with a negative object-side power surface and a positive image-side power surface. The incident height of light on the positive power surface of the first lens element L1 is greater than that on the negative power surface. Furthermore, the large thickness d1 of the first lens element L1 facilitates correction of image curvature and achieves a relatively flat image plane. Furthermore, by rationally setting the range of focal length f1, the optical power of the first lens element L1 is maintained at a positive level.

[0101] Furthermore, the curvature radius of the concave surface of the eleventh lens L11 on the image side is denoted by R1, and the value of R1 satisfies the following relationship:

[0102]

[0103] The eleventh lens L11 is arranged in this way so that the concave surface on the image side has a negative optical focal length, which diverges the light, is conducive to realizing an infinitely conjugated microscope objective lens, and can compensate for the high-order spherical aberration generated by the other surfaces.

[0104] Furthermore, the numerical aperture of the 40x infinite conjugate microscope objective is represented by NA, and the value of NA satisfies the following relationship:

[0105] 0.55 <NA<0.7。

[0106] In this embodiment, the numerical aperture value set within the above range can capture sufficient light and is more suitable for fluorescence imaging. Because fluorescence signals are generally weak, a higher light flux is required to improve the signal-to-noise ratio. Compared with objectives with lower numerical apertures, objectives with a numerical aperture of 0.5 to 0.7 can capture more fluorescence signal, provide brighter images, reduce noise, and improve imaging quality. It also does not cause excessive light intensity to be concentrated on the sample, reducing photobleaching of fluorescent molecules and extending the duration of the fluorescence signal.

[0107] Please refer to Figures 1 to 5 Specifically, the value of f is 4.125mm. The magnification of the 40x infinite conjugate microscope objective is 40. The numerical aperture is 0.6, the parfocal distance is 45mm, the working distance is 2.2mm, the field of view is 22.8mm, the object field of view is 0.57mm, the objective resolution is 0.59μm, the operating wavelength range is 480nm to 680nm, and the distortion is within 1%.

[0108] The structural parameters of each lens of the 40x infinite conjugate microscope objective are shown in the following table:

[0109]

[0110]

[0111] Please refer to Figure 2 . Figure 2 This is the modulation transfer function diagram or MTF diagram of the 40x infinite conjugate microscope objective lens provided by the embodiment of the present invention. The MTF diagram uses spatial frequency as the horizontal axis and OTF modulus as the vertical axis. The MTF curve shows the contrast transmission capability of the objective lens of this embodiment at different spatial frequencies. Figure 2 It can be seen that the 40x infinite conjugate microscope objective lens provided in this embodiment has been improved and enhanced in terms of resolution, imaging quality, etc.

[0112] Please refer to Figure 3 . Figure 3 This is the point diagram of the 40x infinite conjugate microscope objective lens provided in this embodiment. Figure 3The spot diagram shows that the 40x infinite conjugate microscope objective provided by this embodiment has significantly improved the correction of aberrations such as spherical aberration, chromatic aberration, and field curvature. The speckle size in the spot diagram reflects a resolution close to the diffraction limit and good imaging capability.

[0113] Please refer to Figure 4 . Figure 4 This is the field curvature and distortion diagram of the 40x infinite conjugate microscope objective lens provided in this embodiment. Figure 4 It can be seen that the field curvature and distortion of the 40x infinite conjugate microscope objective lens provided in this embodiment are greatly improved.

[0114] Please refer to Figure 5 . Figure 5 : is the wavefront error diagram of the 40x infinite conjugate microscope objective lens provided in the embodiment. Figure 5 It can be seen that the root mean square value of the wavefront difference of most fields of view of the 40x infinite conjugate microscope objective provided by this embodiment is within the diffraction limit.

[0115] In summary, the 40x infinite conjugate microscope objective provided in this embodiment can achieve high resolution, a flat image plane, and an apochromatic objective. This 40x infinite conjugate microscope objective has a large numerical aperture at a short parfocal distance, which increases the illumination of the objective at the image plane, facilitating clearer imaging. The MTF value of this microscope objective is within the visible light band, and is close to the diffraction limit for both on-axis and off-axis fields of view, with a point array radius close to within the Airy disk.

[0116] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with this technical field within the technical scope disclosed in the present invention should be covered by the scope of protection of the present invention.

Claims

1. A 40x infinite conjugate microscope objective lens, characterized in that: The 40x infinite conjugate microscope objective lens consists of the first lens group (G1), the second lens group (G2), and the third lens group (G3) arranged in sequence along the optical axis from the object side to the image side; The first lens group (G1) comprises a first lens (L1) and a second lens (L2) arranged in sequence from the object side to the image side along the optical axis, the first lens (L1) being a meniscus lens with positive optical power, the concave surface of the first lens (L1) facing the object side, and the convex surface facing the image side; the second lens (L2) is a meniscus lens with positive optical power, the concave surface of the second lens (L2) facing the object side, and the convex surface facing the image side; The second lens group (G2) includes a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7), an eighth lens (L8) and a ninth lens (L9) arranged in sequence along the optical axis from the object side to the image side; the third lens (L3) is a biconvex lens with positive focal length; the fourth lens (L4) is a meniscus lens with negative focal length, the concave surface of the fourth lens (L4) faces the object side and the convex surface faces the image side; the fifth lens (L5) is a biconvex lens with positive focal length, the sixth lens (L6) is a biconcave lens with negative focal length, the seventh lens (L7) is a biconvex lens with positive focal length, and the The eighth lens (L8) is a biconvex lens with positive focal power, and the ninth lens (L9) is a biconcave lens with negative focal power; the third lens (L3) and the fourth lens (L4) are cemented to form a first doublet lens group (C1), and the first doublet lens group (C1) has positive focal power; the fifth lens (L5), the sixth lens (L6) and the seventh lens (L7) are cemented to form a triplet lens group (C2), and the triplet lens group (C2) has positive focal power; the eighth lens (L8) and the ninth lens (L9) are cemented to form a second doublet lens group (C3), and the second doublet lens group (C3) has positive focal power; The third lens group (G3) includes a tenth lens (L10) and an eleventh lens (L11) arranged in sequence from the object side to the image side along the optical axis, the tenth lens (L10) is a biconvex lens with positive focal length, and the eleventh lens (L11) is a biconcave lens with negative focal length; the tenth lens (L10) and the eleventh lens (L11) are cemented together to form a third doublet lens group (C4), and the third doublet lens group (C4) has negative focal length; The combined focal length of the first lens group (G1) is , The values ​​satisfy the following relationship: The combined focal length of the second lens group (G2) is , The values ​​satisfy the following relationship: The combined focal length of the third lens group (G3) is , The values ​​satisfy the following relationship: in, is the focal length of the 40x infinite conjugate microscope objective lens.

2. The 40x infinite conjugate microscope objective lens according to claim 1, characterized in that: The second lens group (G2) further includes a stop (ST), and the stop (ST) is arranged between the seventh lens (L7) and the eighth lens (L8).

3. The 40x infinite conjugate microscope objective lens according to claim 1, characterized in that: The difference between the Abbe numbers of the third lens (L3) and the fourth lens (L4) satisfies the following relationship: The difference in refractive index between the third lens (L3) and the fourth lens (L4) satisfies the following relationship: in, is the Abbe number of the third lens (L3), is the Abbe number of the fourth lens (L4), is the refractive index of the third lens (L3), is the refractive index of the fourth lens (L4); The difference between the Abbe numbers of the eighth lens (L8) and the ninth lens (L9) satisfies the following relationship: The difference in refractive index between the eighth lens (L8) and the ninth lens (L9) satisfies the following relationship: in, is the Abbe number of the eighth lens (L8), is the Abbe number of the ninth lens (L9), is the refractive index of the eighth lens (L8), is the refractive index of the ninth lens (L9); The difference between the Abbe numbers of the tenth lens (L10) and the eleventh lens (L11) satisfies the following relationship: The difference in refractive index between the tenth lens (L10) and the eleventh lens (L11) satisfies the following relationship: in, is the Abbe number of the tenth lens (L10), is the Abbe number of the eleventh lens (L11), is the refractive index of the tenth lens (L10), is the refractive index of the eleventh lens (L11).

4. The 40x infinite conjugate microscope objective lens according to claim 1, characterized in that: Abbe number of the fifth lens (L5) The value is greater than 70.

5. The 40x infinite conjugate microscope objective lens according to claim 1, characterized in that: Abbe number of the second lens (L2) and the Abbe number of the third lens (L3) The value is greater than 90.

6. The 40x infinite conjugate microscope objective lens according to claim 1, characterized in that , the focal length of the first lens (L1) is express, The values ​​satisfy the following relationship: The thickness of the first lens (L1) is express, The values ​​satisfy the following relationship: in, is the focal length of the 40x infinite conjugate microscope objective lens.

7. The 40x infinite conjugate microscope objective lens according to claim 1, characterized in that The curvature radius of the concave surface of the eleventh lens (L11) located on the image side is express, The value of satisfies the following relationship: in, is the focal length of the 40x infinite conjugate microscope objective lens.

8. The 40x infinite conjugate microscope objective lens according to claim 1, characterized in that: The numerical aperture of the 40x infinite conjugate microscope objective is express, The value of satisfies the following relationship: 。

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