40-time infinite conjugate microscope objective

Abstract

The invention provides a 40-time infinite conjugate microscope objective, and relates to the field of objective lenses. The 40-time infinite conjugate microscope objective comprises a first lens group, a second lens group and a third lens group which are sequentially arranged along an optical axis from an object space to an image space. The first lens group comprises a first lens and a second lens which are sequentially arranged from the object side to the image side in the optical axis direction. The second lens group comprises a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens which are sequentially arranged from the object space to the image space in the optical axis direction. The third lens group comprises a tenth lens and an eleventh lens which are sequentially arranged from the object space to the image space in the optical axis direction. The 40-time infinite conjugate microscope objective can realize a high-resolution flat image plane and apochromatic objective, under a short parfocal distance, the numerical aperture is larger, the illumination at the image plane is increased, the imaging is clearer, the on-axis field of view and the off-axis field of view are close to diffraction limits, and the point array radius is close to be within the Airy spot.

Description

Technical Field

[0001] The 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 with traditional finite conjugate objectives, they have higher flexibility, better imaging quality and more functional expandability. Infinite conjugate microscope objectives are often used in fluorescence microscopy and can achieve high-resolution imaging of fluorescent markers in biological samples.

[0003] For traditional high-power microscope objectives, as the numerical aperture increases, the incident height of the marginal light increases, which will introduce greater spherical aberration, chromatic aberration and field curvature, causing the modulation transfer function to fail to meet the 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 40-fold 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 an 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 is a meniscus lens with positive optical power, the concave surface of the first lens faces the object side, and the convex surface faces the image side; the second lens is a meniscus lens with positive optical power, the concave surface of the second lens faces the object side, and the convex surface faces 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 arranged in sequence from the object side to the image side along the optical axis; the third lens is a biconvex lens with positive focal power; the fourth lens is a meniscus lens with negative focal power, the concave surface of the fourth lens faces the object side, and the convex surface faces the image side; the fifth lens is a biconvex lens with positive focal power, the sixth lens is a biconcave lens with negative focal power, the seventh lens is a biconvex lens with positive focal power, the eighth lens is a biconvex lens with positive focal power, and the ninth lens is a biconcave lens with negative focal power; the third lens and the fourth lens are cemented to form a first double cemented lens group, and the first double cemented lens group has positive focal power; the fifth lens, the sixth lens and the seventh lens are cemented to form a triple cemented lens group, and the triple cemented lens group has positive focal power; the eighth lens and the ninth lens are cemented to form a second double cemented lens group, and the second double cemented lens group has positive focal 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 double convex lens with positive optical power, and the eleventh lens is a double concave lens with negative optical power; the tenth lens and the eleventh lens are cemented to form a third double cemented lens group, and the third double cemented 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 an aperture stop, and the aperture 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 implementation, 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 between the Abbe numbers of 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 implementation, 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] The present application can realize a high-resolution, flat image plane and achromatic objective lens by setting a combination of the first lens group, the second lens group and the third lens group and the design of each lens. The 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 microscope objective lens is within the visible light band, and the on-axis field of view and the off-axis field of view are close to the diffraction limit, 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 drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A schematic diagram of the structure 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 provided by an embodiment of the present invention;

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

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

[0051] Figure 5A wavefront error diagram of a 40x infinite conjugate microscope objective provided in 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 double-cemented lens group; C2-triplet-cemented lens group; C3-second double-cemented lens group; C4-third double-cemented lens group; ST-aperture; S-slide. DETAILED DESCRIPTION

[0053] For traditional high-power microscope objectives, as the numerical aperture increases, the incident height of the marginal light increases, which will introduce greater spherical aberration, chromatic aberration and field curvature, causing the modulation transfer function to fail to meet the 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 view of the above problems, the present invention provides a 40x infinite conjugate microscope objective lens, which can improve the imaging effect, thereby improving the above-mentioned problem of poor imaging effect.

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 here 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 claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are 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, further definition and explanation thereof is not required 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 drawings, or is the orientation or position relationship commonly placed when the product of the invention is used. 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, and therefore cannot be understood as a limitation on the present invention.

[0059] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions 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 in sequence from the object side to the image side along the optical axis. The first lens group G1 includes 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 is a meniscus lens with positive focal power, with 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 focal power, with 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 from the object side to the image side along the optical axis. The third lens L3 is a biconvex lens with positive focal power. The fourth lens L4 is a meniscus lens with negative focal power, with the concave surface of the fourth lens L4 facing the object side and the convex surface facing the image side. The fifth lens L5 is a biconvex lens with positive power, the sixth lens L6 is a biconcave lens with negative power, the seventh lens L7 is a biconvex lens with positive power, the eighth lens L8 is a biconvex lens with positive power, and the ninth lens L9 is a biconcave lens with negative power. The third lens L3 and the fourth lens L4 are cemented to form a first double cemented lens group C1, and the first double cemented lens group C1 has positive power. The fifth lens L5, the sixth lens L6 and the seventh lens L7 are cemented to form a triple cemented lens group C2, and the triple cemented lens group C2 has positive power. The eighth lens L8 and the ninth lens L9 are cemented to form a second double cemented lens group C3, and the second double cemented lens group C3 has positive 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 direction, the tenth lens L10 is a biconvex lens with positive power, and the eleventh lens L11 is a biconcave lens with negative 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 can realize a high-resolution, flat image plane and achromatic objective lens by setting the combination of the first lens group G1, the second lens group G2 and the third lens group G3 and 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, which is conducive to clearer imaging of 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 the on-axis field of view and the off-axis field of view are close to the diffraction limit, 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 better correct the spherical aberration, chromatic aberration and field curvature of the 40x infinite conjugate microscope objective, and realize a high-resolution, flat image plane and apochromatic objective. The 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, which is conducive to clearer imaging of the microscope objective. The MTF value of the 40x infinite conjugate microscope objective 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, and the stop ST is disposed between the seventh lens L7 and the eighth lens L8.

[0073] In this embodiment, a stop ST is arranged between the seventh lens L7 and the eighth lens L8, which can control the angle of the incident light and adjust the light flux. A suitable stop ST position can better correct off-axis aberrations. The stop ST can also reduce stray light and improve image contrast.

[0074] Please refer to Figures 1 to 5 , further, 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 the difference in 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 to 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 the difference in 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 to 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 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 L1 is a meniscus thick lens, and the object side surface is a negative focal surface, and the image side surface is a positive focal surface. The incident height of the light on the positive focal surface of the first lens L1 is greater than the incident height on the negative focal surface, and the thickness d1 of the first lens L1 is large, which is conducive to correcting the image curvature and achieving a flatter image surface. And by reasonably setting the range of the focal length f1, the focal power of the first lens L1 is kept positive.

[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 is a negative optical focal length surface, which has a divergent effect on the light, is conducive to realizing an infinitely conjugated microscope objective lens, and can compensate for the high-order spherical aberrations produced 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 is set to the above range to capture enough light, which is more suitable for fluorescence imaging. Since the fluorescence signal is usually weak, a higher light flux is required to improve the signal-to-noise ratio. Compared with an objective lens with a low numerical aperture, an objective lens with a numerical aperture of 0.5 to 0.7 can capture more fluorescence signals, provide brighter images, reduce noise, improve imaging quality, and will not cause excessive light intensity to be concentrated on the sample, thereby reducing the photobleaching phenomenon 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 0.59um, the working band 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 provided by the embodiment of the present invention. The MTF diagram uses the spatial frequency as the horizontal coordinate and the OTF modulus as the vertical coordinate. The MTF curve shows the contrast transmission capability of the objective of this embodiment at different spatial frequencies. Figure 2 It can be seen that the 40x infinite conjugate microscope objective provided in this embodiment has been improved and enhanced in terms of resolution, imaging quality, etc.

[0112] Please refer to Figure 3 . Figure 3 is the spot diagram of the 40x infinite conjugate microscope objective provided in this embodiment. Figure 3The spot diagram shows that the 40x infinite conjugate microscope objective provided in this embodiment has a certain improvement in the correction effect of the spherical aberration, chromatic aberration, field curvature and other aberrations of the objective lens. The speckle size in the spot diagram reflects that the resolution is close to the diffraction limit and has 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 provided in this embodiment. Figure 4 It can be seen that the field curvature and distortion of the 40x infinite conjugate microscope objective provided in this embodiment are greatly improved.

[0114] Please refer to Figure 5 . Figure 5 4 is a wavefront error diagram of the 40x infinite conjugate microscope objective provided in the embodiment. Figure 5 It can be seen that the root mean square value of the wavefront difference of most of the fields of view of the 40x infinite conjugate microscope objective provided in this embodiment is within the diffraction limit.

[0115] In summary, the 40x infinite conjugate microscope objective provided in this embodiment can achieve high resolution, flat image plane and achromatic objective. The 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, which is conducive to clearer imaging of the microscope objective. The MTF value of the microscope objective is within the visible light band, and the on-axis field of view and the off-axis field of view are close to the diffraction limit, and the point array radius is also close to within the Airy disk.

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

Claims

1. A 40x infinite conjugate microscope objective lens, characterized in that: It comprises a first lens group (G1), a second lens group (G2) and a third lens group (G3) which are 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) which are 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) comprises 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) which are arranged in sequence from the object side to the image side along the optical axis; the third lens (L3) is a biconvex lens with positive focal power; the fourth lens (L4) is a meniscus lens with negative focal power, 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 power, the sixth lens (L6) is a biconcave lens with negative focal power, the seventh lens (L7) is a biconvex lens with positive focal power, 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 glued to form a first double-cemented lens group (C1), and the first double-cemented lens group (C1) has positive focal power; the fifth lens (L5), the sixth lens (L6) and the seventh lens (L7) are glued to form a triple-cemented lens group (C2), and the triple-cemented lens group (C2) has positive focal power; the eighth lens (L8) and the ninth lens (L9) are glued to form a second double-cemented lens group (C3), and the second double-cemented lens group (C3) has positive focal power; The third lens group (G3) comprises a tenth lens (L10) and an eleventh lens (L11) which are sequentially arranged from the object side to the image side along the optical axis, the tenth lens (L10) is a biconvex lens with positive focal power, and the eleventh lens (L11) is a biconcave lens with negative focal power; the tenth lens (L10) and the eleventh lens (L11) are cemented to form a third double cemented lens group (C4), and the third double cemented lens group (C4) has negative focal power.

2. The 40x infinite conjugate microscope objective lens according to claim 1, characterized in that: The combined focal length of the first lens group (G1) is f G1 ,f G1 The values ​​satisfy the following relationship: The combined focal length of the second lens group (G2) is f G2 ,f G2 The values ​​satisfy the following relationship: The combined focal length of the third lens group (G3) is f G3 ,f G3 The values ​​satisfy the following relationship: Wherein, f is the focal length of the 40x infinite conjugate microscope objective lens.

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

4. The 40x infinite conjugate microscope objective lens according to claim 1 or 2, characterized in that: The difference between the Abbe numbers of the third lens (L3) and the fourth lens (L4) satisfies the following relationship: v d3 -v d4 >60; The difference in refractive index between the third lens (L3) and the fourth lens (L4) satisfies the following relationship: |n d3 -n d4 |>0.3; Among them, v d3 is 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); The difference between the Abbe numbers of the eighth lens (L8) and the ninth lens (L9) satisfies the following relationship: v d8 -v d9 >40; The difference in refractive index between the eighth lens (L8) and the ninth lens (L9) satisfies the following relationship: |n d8 -n d9 |>0.2; 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); The difference between the Abbe numbers of the tenth lens (L10) and the eleventh lens (L11) satisfies the following relationship: v d10 -v d11 >20; The difference in refractive index between the tenth lens (L10) and the eleventh lens (L11) satisfies the following relationship: |n d10 -n d11 |>0.1; 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 d11 is the refractive index of the eleventh lens (L11).

5. The 40x infinite conjugate microscope objective lens according to claim 1 or 2, characterized in that: The Abbe number v of the fifth lens (L5) is d5 The value is greater than 70.

6. The 40x infinite conjugate microscope objective lens according to claim 1 or 2, characterized in that: The Abbe number v of the second lens (L2) d2 and the Abbe number v of the third lens (L3) d3 The value is greater than 90.

7. The 40x infinite conjugate microscope objective lens according to claim 1 or 2, characterized in that , the focal length of the first lens (L1) is represented by f1, and the value of f1 satisfies the following relationship: The thickness of the first lens (L1) is denoted by d1, and the value of d1 satisfies the following relationship: Wherein, f is the focal length of the 40x infinite conjugate microscope objective lens.

8. The 40x infinite conjugate microscope objective lens according to claim 1 or 2, characterized in that The curvature radius of the concave surface of the eleventh lens (L11) located on the image side is represented by R1, and the value of R1 satisfies the following relationship: Wherein, f is the focal length of the 40x infinite conjugate microscope objective lens.

9. The 40x infinite conjugate microscope objective lens according to claim 1 or 2, characterized in that: 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: 0.5 <NA<0.7

Images