A large field of view high resolution microscope objective

Abstract

The application discloses a large-view-field high-resolution microscopic objective lens, which is composed of a positive focal length first lens group, a positive focal length second lens group and a negative focal length third lens group arranged in sequence from an object side to an image side; the microscopic objective lens forms a total focal length distribution pattern of 'positive-positive-negative' through global focal length cooperation, realizes close cooperation in aberration correction, successfully realizes the unification of 'high numerical aperture and long working distance' and 'large view field and complex achromatism' of the medium-high magnification objective lens, and realizes high-resolution imaging.

Description

Technical Field

[0001] This invention relates to the field of microscope objectives, specifically to a large field-of-view, high-resolution microscope objective. Background Technology

[0002] As the semiconductor industry enters the post-Moore's Law era, the feature size of integrated circuits is constantly approaching physical limits, posing unprecedented challenges to defect detection and metrology technologies in chip manufacturing. In applications such as wafer macroscopic defect scanning and advanced packaging interconnect structure observation, microscopic imaging systems that combine a large field of view, high resolution, and excellent image quality have become key to improving detection efficiency and yield.

[0003] Currently, medium- and high-magnification objectives generally face the following technical bottlenecks when applied to high-end semiconductor inspection: traditional objective designs struggle to maintain a large numerical aperture while ensuring resolution and achieving a wide field of view. For medium- and high-magnification objectives, the coordinated correction of spherical aberration, coma, and chromatic aberration is extremely difficult. Therefore, medium- and high-magnification objectives that simultaneously possess a large field of view and high resolution at a large numerical aperture have become an indispensable part of the development of high-end inspection equipment. Summary of the Invention

[0004] Technical objective: To address the shortcomings of existing microscope objectives, this invention discloses a large field-of-view, high-resolution microscope objective.

[0005] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0006] A large field-of-view, high-resolution microscope objective comprises a first lens group with positive optical power, a second lens group with positive optical power, and a third lens group with negative optical power, arranged sequentially from the object side to the image side. The focal lengths of the first lens group are denoted as fG1, the second lens group as fG2, and the third lens group as fG3. The focal length of the microscope objective is fobj, where 0.6 ≥ |fG1 / fobj| ≥ 0.4, 0.3 ≥ |fG2 / fobj| ≥ 0, and 0.6 ≥ |fG3 / fobj| ≥ 0.4.

[0007] Preferably, the first lens group of the present invention includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical path direction starting from the object side. The first lens is a meniscus lens with positive optical power, the second lens is a biconvex lens with positive optical power, the third lens is a biconvex lens with positive optical power, the fourth lens is a biconvex lens with positive optical power, the fifth lens is a biconcave lens with negative optical power, and the sixth lens is a biconvex lens with positive optical power. The fourth lens, the fifth lens, and the sixth lens are cemented together sequentially to form a three-cemented lens group.

[0008] Preferably, the d-ray refractive index and Abbe number of the first lens of the present invention are n1 and v1, respectively; 2≥n1≥1.9, 25≥v1≥15;

[0009] The d-ray refractive index and Abbe number of the second lens are n2 and v2, respectively; 1.6≥n2≥1.5, 75≥v2≥65;

[0010] The d-ray refractive index and Abbe number of the third lens are n3 and v3, respectively; 1.6≥n3≥1.5, 75≥v3≥65;

[0011] The d-ray refractive index and Abbe number of the fourth lens are n4 and v4, respectively; 1.5 ≥ n4 ≥ 1.4, 100 ≥ v4 ≥ 90;

[0012] The d-ray refractive index and Abbe number of the fifth lens are n5 and v5, respectively; 1.85≥n5≥1.75, 50≥v5≥40;

[0013] The d-ray refractive index and Abbe number of the sixth lens are n6 and v6, respectively; 1.5≥n6≥1.4, 100≥v6≥90.

[0014] Preferably, the second lens group of the present invention includes a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens arranged sequentially along the optical path direction, starting from the object side.

[0015] The seventh, eighth, and ninth lenses form a triplet lens group. The seventh and ninth lenses are meniscus lenses with negative optical power, and the eighth lens is a biconvex lens with positive optical power.

[0016] The tenth and eleventh lenses form a cemented doublet lens group. The tenth lens is a meniscus lens with negative optical power, and the eleventh lens is a biconvex lens with positive optical power.

[0017] The twelfth and thirteenth lenses form a cemented doublet lens group. The twelfth lens is a meniscus lens with negative optical power, and the thirteenth lens is a biconvex lens with positive optical power.

[0018] Preferably, the d-ray refractive index and Abbe number of the seventh lens of the present invention are n7 and v7, respectively; 1.85≥n7≥1.75, 50≥v7≥40;

[0019] The d-ray refractive index and Abbe number of the eighth lens are n8 and v8, respectively; 1.5≥n8≥1.4, 100≥v8≥90;

[0020] The d-ray refractive index and Abbe number of the ninth lens are n9 and v9, respectively; 1.9≥n9≥1.8, 50≥v9≥40;

[0021] The d-ray refractive index and Abbe number of the tenth lens are n10 and v10, respectively; 1.85≥n10≥1.75, 30≥v10≥20;

[0022] The d-ray refractive index and Abbe number of the eleventh lens are n11 and v11, respectively; 1.6≥n11≥1.5, 80≥v11≥70;

[0023] The d-ray refractive index and Abbe number of the twelfth lens are n12 and v12, respectively; 1.6≥n12≥1.5, 75≥v12≥65;

[0024] The d-ray refractive index and Abbe number of the thirteenth lens are n13 and v13, respectively; 1.8≥n13≥1.7, 50≥v13≥40.

[0025] Preferably, the third lens group of the present invention includes a fourteenth lens, a fifteenth lens, a sixteenth lens, and a seventeenth lens arranged sequentially along the optical path starting from the object side, wherein the fourteenth lens is a meniscus lens with negative optical power, the fifteenth lens is a biconcave lens with negative optical power, the sixteenth lens is a plano-concave lens with negative optical power, and the seventeenth lens is a plano-convex lens with positive optical power. The planes of the sixteenth lens and the seventeenth lens are cemented together to form a cemented doublet lens group.

[0026] Preferably, the d-ray refractive index and Abbe number of the fourteenth lens of the present invention are n14 and v14, respectively; 2≥n14≥1.9, 25≥v14≥15;

[0027] The d-ray refractive index and Abbe number of the fifteenth lens are n15 and v15, respectively; 1.85≥n15≥1.75, 40≥v15≥30;

[0028] The d-ray refractive index and Abbe number of the sixteenth lens are n16 and v16, respectively; 1.5≥n16≥1.4, 100≥v16≥90;

[0029] The d-ray refractive index and Abbe number of the seventeenth lens are n17 and v17, respectively; 1.85≥n17≥1.75, 30≥v17≥20.

[0030] Beneficial effects: The present invention has the following beneficial effects:

[0031] 1. This invention is based on a "weak negative-strong positive" front-group design with a rearward-positioned optical power, achieving a coexistence of large numerical aperture and long working distance. Conventional high-magnification microscope objectives often use a strong positive optical power on the incident surface of the first lens to quickly converge light, but this directly compresses the object-side working distance. To address this contradiction, this invention uses a meniscus lens as the first lens element, designing its surface near the incident side as a weak negative incident surface with a large radius of curvature. This allows large-aperture light to enter the pupil at a gentle angle, avoiding the front group bearing excessively high positive optical power; and the main positive optical power is shifted to the subsequent biconvex lens and triplet lens group. This "front-positioned weak negative refraction + internal strong positive convergence" architecture achieves efficient collection of large-angle incident light and ensures numerical aperture while significantly extending the object-side working distance, providing the physical conditions for large-space sample observation at medium to high magnification.

[0032] 2. The second lens group of this invention utilizes a synergistic division of labor between the cemented doublet and triplet lens groups to achieve compatibility with a wide spectrum and a large field of view. The transverse chromatic aberration and image plane curvature introduced by a large field of view are the core bottlenecks limiting the breakthrough of the field of view number of conventional objectives. To address this issue, the second lens group of this invention adopts a composite correction architecture of "triplet + doublet" and introduces functional differentiation. The triplet lens group cleverly utilizes the pairing of positive and negative lenses with a large Abbe number difference and places it in the middle of the optical path with the largest incident height of off-axis rays, which can efficiently cancel chromatic aberration at the edge of the large field of view, thus removing the chromatic aberration constraint on field of view expansion. The doublet lens group of the second lens group of this invention uses heavy flint material with an extremely low Abbe number, forming a reverse dispersion compensation mechanism with the triplet lens group, specifically for correcting the second-order spectrum of axial chromatic aberration. Through the synergy of the two cemented lenses, the axial aberration of the microscope objective is compressed to the micrometer level in the 400-700nm wide wavelength range, achieving apochromatic level. In addition, while correcting chromatic aberration, the second lens group uses the strong negative curvature of its cemented surface to generate a directional field curvature, which pre-compensates the positive field curvature generated by the first lens group, significantly reducing the pressure on subsequent correction groups.

[0033] 3. The third lens group of this invention employs a "negative-positive" optical power reversal and distortion suppression structure to ensure high-resolution full-field uniformity. To achieve high-precision measurement and image stitching, the system must satisfy image-side telecenty and possess extremely low distortion. The third lens group of this invention, through a specific combination of a meniscus lens, a biconcave lens, and a cemented doublet, undertakes the core functions of global field curvature refinement and telecenty control.

[0034] 4. The microscope objective of this invention achieves a unified high resolution and large field of view under a "positive-positive-negative" architecture through global optical power coordination. From the object side to the image side, this invention sequentially configures a first lens group with positive optical power, a second lens group with positive optical power, and a third lens group with negative optical power, forming a "positive-positive-negative" overall optical power distribution pattern. This architecture achieves close coordination in aberration correction, successfully unifying "high numerical aperture and long working distance" and "large field of view and apochromatic aberration" in medium-to-high magnification objectives. While achieving a large numerical aperture, a working distance greater than 10mm, and an ultra-large field of view of 35mm, it ensures flatness across the entire field of view, good chromatic aberration correction across the entire wavelength range, and low distortion imaging. It can be widely used in high-precision industrial inspection fields such as semiconductor inspection and biochip scanning. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0036] Figure 1 This is a structural diagram of the microscope objective of the present invention;

[0037] 1-First lens, 2-Second lens, 3-Third lens, 4-Fourth lens, 5-Fifth lens, 6-Sixth lens, 7-Seventh lens, 8-Eighth lens, 9-Ninth lens, 10-Tenth lens, 11-Eleventh lens, 12-Twelfth lens, 13-Thirteenth lens, 14-Fourteenth lens, 15-Fifteenth lens, 16-Sixteenth lens, 17-Seventeenth lens, 18-First lens group, 19-Second lens group, 20-Third lens group. Detailed Implementation

[0038] Reference will now be made in detail to embodiments of the present disclosure, one or more of which are set forth herein. Each embodiment and example is provided by way of explanation of the apparatus, composition, and materials of the present disclosure, and not by way of limitation. Rather, the following description provides convenient illustrations for implementing exemplary embodiments of the present disclosure. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made to the teachings of the present disclosure without departing from the scope or spirit of the present disclosure.

[0039] like Figure 1As shown, this invention discloses a large field-of-view, high-resolution microscope objective, comprising a first lens group 18 with positive optical power, a second lens group 19 with positive optical power, and a third lens group 20 with negative optical power, arranged sequentially from the object side to the image side; the focal length of the first lens group 18 is denoted as fG1, the focal length of the second lens group 19 is denoted as fG2, the focal length of the third lens group 20 is denoted as fG3, and the focal length of the microscope objective is fobj, where 0.6≥|fG1 / fobj|≥0.4, 0.3≥|fG2 / fobj|≥0, and 0.6≥|fG3 / fobj|≥0.4.

[0040] This invention achieves a large field of view and high resolution through the rational configuration and synergy of three lens groups. The first lens group 18, the second lens group 19, and the third lens group 20 form a "positive-positive-negative" overall optical power distribution pattern. This architecture achieves close synergy in aberration correction: the first lens group 18 is responsible for receiving large-aperture light and controlling primary aberrations; the second lens group 19 serves as the core hub for aberration correction; and the third lens group 20 plays a role in aberration balancing, performing final refinement on residual higher-order aberrations, field curvature, and distortion. Through the optimal matching of the structural parameters and optical power of the above three lens groups, this invention successfully achieves the unity of "high NA and long working distance" and "large field of view and apochromatic" in medium-to-high magnification objectives.

[0041] In one specific embodiment, the lens parameters of the microscope objective of the present invention are shown in Table 1.

[0042] Table 1: Parameters of Microscope Objective Lenses

[0043] The surface number is according to Figure 1 The orientation shown is from left to right, from the seventeenth lens 17 to the first lens 1. The surfaces of each lens are numbered. For example, the surface number of the seventeenth lens 17 is R1, R2. Lenses that are cemented together share the same surface number. For example, when the seventeenth lens 17 and the sixteenth lens 16 are cemented together, R2 is the surface number shared by the two cemented surfaces. The thickness represents the distance from the current surface to the next surface. For example, the thickness of R1 represents the distance between surface R1 and surface R2, and the thickness of R2 represents the distance between surface R2 and surface R3.

[0044] The first lens group 18 of the present invention includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5 and a sixth lens 6 arranged sequentially along the optical path starting from the object side. The first lens 1 is a meniscus lens with positive optical power, the second lens 2 is a biconvex lens with positive optical power, the third lens is a biconvex lens with positive optical power, the fourth lens 4 is a biconvex lens with positive optical power, the fifth lens 5 is a biconcave lens with negative optical power, and the sixth lens 6 is a biconvex lens with positive optical power. The fourth lens 4, the fifth lens 5 and the sixth lens 6 are cemented together in sequence to form a three-cemented lens group.

[0045] The first lens 1 of the present invention has a d-ray refractive index of n1 and an Abbe number of v1, respectively; 2≥n1≥1.9, 25≥v1≥15;

[0046] The d-ray refractive index and Abbe number of the second lens 2 are n2 and v2, respectively; 1.6≥n2≥1.5, 75≥v2≥65;

[0047] The d-ray refractive index and Abbe number of the third lens 3 are n3 and v3, respectively; 1.6≥n3≥1.5, 75≥v3≥65;

[0048] The d-ray refractive index and Abbe number of the fourth lens 4 are n4 and v4, respectively; 1.5≥n4≥1.4, 100≥v4≥90;

[0049] The refractive index and Abbe number of the fifth lens 5 are n5 and v5, respectively; 1.85≥n5≥1.75, 50≥v5≥40;

[0050] The d-ray refractive index and Abbe number of the sixth lens 6 are n6 and v6, respectively; 1.5≥n6≥1.4, 100≥v6≥90.

[0051] The first lens group 18 of this invention, as a strong positive power group, is responsible for achieving a large aperture angle, efficiently collecting light and converging it towards the middle group, which is a decisive factor in achieving high resolution. At the same time, the introduction of a meniscus lens and a cemented triplicate lens provides excellent correction for spherical aberration and chromatic aberration.

[0052] The first lens 1 is a meniscus lens with positive optical power. As the lead element, its surface near the incident side is designed as a weak negative incident surface with a large radius of curvature, allowing large-aperture light to enter the pupil at a gentle angle, avoiding excessive positive optical power in the preceding group. The main positive optical power is shifted to the subsequent biconvex lens and triplet lens group. This "front-mounted weak negative refraction + internal strong positive convergence" architecture achieves efficient collection of large-angle incident light, ensures numerical aperture, and significantly extends the object-side working distance, providing the physical conditions for large-space sample observation at medium to high magnification.

[0053] Meanwhile, the triplet lens group within the first lens group 18, through the pairing of the ultra-high Abbe number materials of the fourth lens 4 and the sixth lens 6 with the medium dispersion glass of the fifth lens 5, effectively suppresses spherical aberration, coma, and primary axial chromatic aberration during the process of gathering large-aperture light, laying a low-sensitivity foundation for aberration correction of the entire system.

[0054] The second lens group 19 of the present invention includes a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, an eleventh lens 11, a twelfth lens 12, and a thirteenth lens 13 arranged sequentially from the object side along the optical path direction.

[0055] The seventh lens 7, the eighth lens 8, and the ninth lens 9 form a triplet lens group. The seventh lens 7 and the ninth lens 9 are meniscus lenses with negative optical power, and the eighth lens 8 is a biconvex lens with positive optical power.

[0056] The tenth lens 10 and the eleventh lens 11 form a cemented doublet lens group. The tenth lens 10 is a meniscus lens with negative optical power, and the eleventh lens 11 is a biconvex lens with positive optical power.

[0057] The twelfth lens 12 and the thirteenth lens 13 form a cemented doublet lens group. The twelfth lens 12 is a meniscus lens with negative optical power, and the thirteenth lens 13 is a biconvex lens with positive optical power.

[0058] Preferably, the d-ray refractive index and Abbe number of the seventh lens 7 of the present invention are n7 and v7, respectively; 1.85≥n7≥1.75, 50≥v7≥40;

[0059] The d-ray refractive index and Abbe number of the eighth lens 8 are n8 and v8, respectively; 1.5≥n8≥1.4, 100≥v8≥90;

[0060] The d-ray refractive index and Abbe number of the ninth lens 9 are n9 and v9, respectively; 1.9≥n9≥1.8, 50≥v9≥40;

[0061] The d-ray refractive index and Abbe number of the tenth lens 10 are n10 and v10, respectively; 1.85≥n10≥1.75, 30≥v10≥20;

[0062] The d-ray refractive index and Abbe number of the eleventh lens 11 are n11 and v11, respectively; 1.6≥n11≥1.5, 80≥v11≥70;

[0063] The d-ray refractive index and Abbe number of the twelfth lens 12 are n12 and v12, respectively; 1.6≥n12≥1.5, 75≥v12≥65;

[0064] The d-ray refractive index and Abbe number of the thirteenth lens 13 are n13 and v13, respectively; 1.8≥n13≥1.7, 50≥v13≥40.

[0065] The second lens group 19 of this invention utilizes a combination of cemented doublet and cemented triplet lenses to achieve compatibility with a wide spectrum and a large field of view. The cemented triplet lens group, composed of the seventh lens 7, the eighth lens 8, and the ninth lens 9, cleverly employs a pair of positive and negative lenses with a large Abbe number difference, positioned in the middle of the optical path where off-axis rays have the greatest incident height. This allows for highly efficient cancellation of chromatic aberration at the edges of the large field of view, fundamentally eliminating the chromatic aberration constraint on field of view expansion. The two cemented doublet lens groups employ heavy flint material with extremely low Abbe numbers to form a reverse dispersion compensation mechanism, specifically designed to correct the second-order spectrum of axial chromatic aberration. Through the synergy of the two cemented lenses, the axial aberration of the system is compressed to the micrometer level within a wide wavelength range of 400-700 nm, achieving apochromatic aberration levels.

[0066] Meanwhile, the second lens group 19 of the present invention, while correcting chromatic aberration, generates directional field curvature by utilizing the strong negative curvature of its cemented surface to pre-compensate the positive field curvature generated by the first lens group 18, significantly reducing the correction pressure of the subsequent third lens group 20.

[0067] The third lens group 20 of the present invention includes a fourteenth lens 14, a fifteenth lens 15, a sixteenth lens 16, and a seventeenth lens 17 arranged sequentially from the object side along the optical path direction. The fourteenth lens 14 is a meniscus lens with negative optical power, the fifteenth lens 15 is a biconcave lens with negative optical power, the sixteenth lens 16 is a plano-concave lens with negative optical power, and the seventeenth lens 17 is a plano-convex lens with positive optical power. The planes of the sixteenth lens 16 and the seventeenth lens 17 are cemented together to form a cemented doublet lens group.

[0068] Preferably, the d-ray refractive index and Abbe number of the fourteenth lens 14 of the present invention are n14 and v14, respectively; 2≥n14≥1.9, 25≥v14≥15;

[0069] The d-ray refractive index and Abbe number of the fifteenth lens 15 are n15 and v15, respectively; 1.85≥n15≥1.75, 40≥v15≥30;

[0070] The refractive index and Abbe number of the sixteenth lens 16 are n16 and v16, respectively; 1.5≥n16≥1.4, 100≥v16≥90;

[0071] The d-ray refractive index and Abbe number of the seventeenth lens 17 are n17 and v17, respectively; 1.85≥n17≥1.75, 30≥v17≥20.

[0072] The third lens group 20 of this invention adopts a "negative-positive" optical power reversal and distortion suppression structure to ensure high-resolution full-field uniformity. It undertakes the core functions of global field curvature refinement and telecentricity control of the microscope objective. It performs secondary refinement on the residual edge field curvature after compensation by the second lens group 19, and finally controls the field curvature of the entire field of view within a very small range. The cemented doublet lens composed of the sixteenth lens 16 and the seventeenth lens 17 effectively compresses the exit angle of the principal ray on the image side to near zero degrees, achieves the image side telecentricity effect, and improves the uniformity of image illumination. At the same time, the refraction angle of off-axis rays is constrained by the lens surface design, systematically suppressing the generation of negative and positive distortion, and ensuring the geometrical authenticity of the imaging across the entire field of view.

[0073] By combining the first lens group 18, the second lens group 19, and the third lens group 20, the microscope objective of the present invention has high resolution, a large field of view, and high imaging quality. The full field of view of the microscope objective is 1.65mm, the working wavelength is 400-700nm, and the working distance is greater than 10mm.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A large field-of-view, high-resolution microscope objective, characterized in that, It consists of a first lens group (18) with positive optical power, a second lens group (19) with positive optical power, and a third lens group (20) with negative optical power arranged sequentially from the object side to the image side; the focal length of the first lens group (18) is denoted as fG1, the focal length of the second lens group (19) is denoted as fG2, the focal length of the third lens group (20) is denoted as fG3, the focal length of the microscope objective is fobj, 0.6≥|fG1 / fobj|≥0.4, 0.3≥|fG2 / fobj|≥0, 0.6≥|fG3 / fobj|≥0.

4.

2. The large field-of-view, high-resolution microscope objective according to claim 1, characterized in that, The first lens group (18) includes a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5) and a sixth lens (6) arranged sequentially from the object side along the optical path direction. The first lens (1) is a meniscus lens with positive optical power, the second lens (2) is a biconvex lens with positive optical power, the third lens is a biconvex lens with positive optical power, the fourth lens (4) is a biconvex lens with positive optical power, the fifth lens (5) is a biconcave lens with negative optical power, and the sixth lens (6) is a biconvex lens with positive optical power. The fourth lens (4), the fifth lens (5) and the sixth lens (6) are cemented together in sequence to form a three-cemented lens group.

3. The large field-of-view, high-resolution microscope objective according to claim 2, characterized in that, The d-ray refractive index and Abbe number of the first lens (1) are n1 and v1, respectively; 2≥n1≥1.9, 25≥v1≥15; The d-ray refractive index and Abbe number of the second lens (2) are n2 and v2, respectively; 1.6≥n2≥1.5, 75≥v2≥65; The d-ray refractive index and Abbe number of the third lens (3) are n3 and v3, respectively; 1.6≥n3≥1.5,75≥v3≥65; The d-ray refractive index and Abbe number of the fourth lens (4) are n4 and v4, respectively; 1.5≥n4≥1.4, 100≥v4≥90; The d-ray refractive index and Abbe number of the fifth lens (5) are n5 and v5, respectively; 1.85≥n5≥1.75, 50≥v5≥40; The d-ray refractive index and Abbe number of the sixth lens (6) are n6 and v6, respectively; 1.5≥n6≥1.4, 100≥v6≥90.

4. The large field-of-view, high-resolution microscope objective according to claim 1, characterized in that, The second lens group (19) includes the seventh lens (7), the eighth lens (8), the ninth lens (9), the tenth lens (10), the eleventh lens (11), the twelfth lens (12), and the thirteenth lens (13) arranged sequentially from the object side along the optical path direction. The seventh lens (7), the eighth lens (8) and the ninth lens (9) form a triplet lens group. The seventh lens (7) and the ninth lens (9) are meniscus lenses with negative optical power, and the eighth lens (8) is a biconvex lens with positive optical power. The tenth lens (10) and the eleventh lens (11) form a cemented doublet lens group. The tenth lens (10) is a meniscus lens with negative optical power, and the eleventh lens (11) is a biconvex lens with positive optical power. The twelfth lens (12) and the thirteenth lens (13) form a cemented doublet lens group. The twelfth lens (12) is a meniscus lens with negative optical power, and the thirteenth lens (13) is a biconvex lens with positive optical power.

5. A large field-of-view, high-resolution microscope objective according to claim 4, characterized in that, The d-ray refractive index and Abbe number of the seventh lens (7) are n7 and v7, respectively; 1.85≥n7≥1.75, 50≥v7≥40; The d-ray refractive index and Abbe number of the eighth lens (8) are n8 and v8, respectively; 1.5≥n8≥1.4, 100≥v8≥90; The d-ray refractive index and Abbe number of the ninth lens (9) are n9 and v9, respectively; 1.9≥n9≥1.8, 50≥v9≥40; The d-ray refractive index and Abbe number of the tenth lens (10) are n10 and v10, respectively; 1.85≥n10≥1.75, 30≥v10≥20; The d-ray refractive index and Abbe number of the eleventh lens (11) are n11 and v11, respectively; 1.6≥n11≥1.5, 80≥v11≥70; The d-ray refractive index and Abbe number of the twelfth lens (12) are n12 and v12, respectively; 1.6≥n12≥1.5, 75≥v12≥65; The d-ray refractive index and Abbe number of the thirteenth lens (13) are n13 and v13, respectively; 1.8≥n13≥1.7, 50≥v13≥40.

6. The large field-of-view, high-resolution microscope objective according to claim 1, characterized in that, The third lens group (20) includes a fourteenth lens (14), a fifteenth lens (15), a sixteenth lens (16), and a seventeenth lens (17) arranged sequentially from the object side along the optical path direction. The fourteenth lens (14) is a meniscus lens with negative optical power, the fifteenth lens (15) is a biconcave lens with negative optical power, the sixteenth lens (16) is a plano-concave lens with negative optical power, and the seventeenth lens (17) is a plano-convex lens with positive optical power. The planes of the sixteenth lens (16) and the seventeenth lens (17) are cemented together to form a cemented doublet lens group.

7. A large field-of-view, high-resolution microscope objective according to claim 6, characterized in that, The d-ray refractive index and Abbe number of the fourteenth lens (14) are n14 and v14, respectively; 2≥n14≥1.9, 25≥v14≥15; The d-ray refractive index and Abbe number of the fifteenth lens (15) are n15 and v15, respectively; 1.85≥n15≥1.75, 40≥v15≥30; The d-ray refractive index and Abbe number of the sixteenth lens (16) are n16 and v16, respectively; 1.5≥n16≥1.4, 100≥v16≥90; The d-ray refractive index and Abbe number of the seventeenth lens (17) are n17 and v17, respectively; 1.85≥n17≥1.75, 30≥v17≥20.

Images