A long working distance 10x large NA telecentric microscope objective and optical system thereof

Abstract

The application relates to the technical field of imaging optical systems and device design, and discloses a long-working-distance 10-fold-NA telecentric microscope lens and an optical system thereof. The optical system comprises, arranged in sequence from an object side to an image side, a front group S1 with positive refractive power, an aperture stop T and a rear group S2 with negative refractive power, the aperture stop T is placed at the focal point of the front group S1, and an object-side telecentric architecture is formed; the maximum outer diameters of all the lenses in the front group S1 are the same, and the maximum outer diameters of all the lenses in the rear group S2 are the same; the working distance of the optical system is WD, and the numerical aperture is NA, and the relationship is: NA x WD <= 17. The optical system provided by the application has a magnification of 10 times, can realize a 1.5-micron resolution of a microscope level, and has the same lens outer diameter size of the front group and the rear group, which is beneficial to guarantee coaxiality after assembly and molding, and improves the imaging quality of the lens.

Description

Technical Field

[0001] This invention relates to the field of imaging optical system and device design technology, and in particular to a long working distance 10x large NA telecentric microscope lens and its optical system. Background Technology

[0002] With the rapid development of machine vision technology, the requirements for lenses in visual inspection systems are becoming increasingly stringent. Microscopic visual inspection applications, such as semiconductor and ITO micro-area inspection, are seeing a growing demand for telecentric lenses with long working distances and higher numerical apertures (NA). Currently, in high-magnification, high-NA applications, a configuration of microscope objectives paired with a telescope is commonly chosen. However, most microscope objectives face challenges in use due to their short working distances and large telescope lengths. Furthermore, their non-telecentric design leads to variations in magnification and parallax caused by changes in object distance.

[0003] Currently, there are very few telecentric lenses with long working distances and large numerical apertures (NA) on the domestic market. Increasing both the working distance and the NA will increase the design difficulty and the difficulties in production and assembly. For example, Chinese patent number "CN201910523470.9" provides a telecentric lens with a magnification of 4x. Another example is Chinese patent number "CN202210789365.1", which provides a high-magnification long working distance coaxial illumination telecentric optical system and lens. However, both of these lack corresponding object-side numerical apertures (NA).

[0004] In summary, there is an urgent need in this field for a telecentric microscope lens with a long working distance and a large numerical aperture (NA) to meet the precision inspection requirements of machine vision microscopic systems.

[0005] The above information is provided as background information only to aid in understanding this disclosure and does not constitute an assertion or admission that any of the above content can be used as prior art relative to this disclosure. Summary of the Invention

[0006] The purpose of this invention is to provide a long working distance, 10x large NA telecentric microscope lens and its optical system, so as to solve or at least partially solve the technical problems existing in the prior art.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an optical system for a long working distance 10x large NA telecentric microscope lens, comprising a front group S1 with positive optical power, an aperture T, and a rear group S2 with negative optical power arranged sequentially from the object side to the image side. The aperture T is placed at the focal point of the front group S1 to form an object-side telecentric structure. In this system, all lenses in the front group S1 have the same maximum outer diameter, and all lenses in the rear group S2 have the same maximum outer diameter.

[0009] The combined focal length of the front group S1 is f S1 The combined focal length of the rear group S2 is f. S2 f S1 and f S2 Satisfies the relation: 4<|f S1 / f S2 |<6;

[0010] The working distance of the optical system is WD, and the numerical aperture is NA. WD and NA satisfy the relationship: NA×WD≤17.

[0011] Optionally, the front group S1 includes a first lens G1 with positive optical power, a second lens G2 with positive optical power, a third lens G3 with negative optical power, a fourth lens G4 with positive optical power, a fifth lens G5 with negative optical power, a sixth lens G6 with positive optical power, a seventh lens G7 with positive optical power, and an eighth lens G8 with positive optical power; wherein the third lens G3 and the fourth lens G4 form a first cemented lens U1, and the fifth lens G5 and the sixth lens G6 form a second cemented lens U2.

[0012] The focal length of the first lens G1 is f1, and f1 and f S1 The relation 1.5 < |f1 / f is satisfied. S1 |<2.5;

[0013] The focal length of the second lens G2 is f2, and f2 and f1 satisfy the relationship: 0.75 < |f1 / f2| < 1.25;

[0014] The focal length of the first cemented lens U1 is f U1 f U1 with f S1 Satisfy the relation: |f S1 / f U1 |<0.1;

[0015] The focal length of the second cemented lens U2 is f U2 f U2 with f S1 Satisfies the relation: 1.4 < |f U2 / f S1 |<2.1;

[0016] The focal length of the seventh lens G7 is f7, and f7 is the same as f... S1 The relation is satisfied: 2.5 < |f7 / f S1 |<3.2;

[0017] The focal length of the eighth lens G8 is f8, and f8 is different from f... S1 The relation 1.6 < |f8 / f is satisfied. S1 |<2.4.

[0018] Optionally, the rear group S2 includes a ninth lens G9 with negative optical power, a tenth lens G10 with negative optical power, and an eleventh lens G11 with positive optical power; wherein the tenth lens G10 and the eleventh lens G11 form a third cemented lens U3.

[0019] The focal length of the ninth lens G9 is f9, and f9 is the same as the focal length of the second lens G9. S2 Satisfies the relation: 1 < |f9 / f S2 |<1.6;

[0020] The focal length of the third cemented lens U3 is f U3 f U3 with f S2 Satisfies the relation: 4.9 < |f U3 / f S2 |<5.7.

[0021] Optionally, the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, and the eleventh lens G11 are all spherical lenses, and the optical axes of all spherical lenses are on a predetermined optical axis.

[0022] Optionally, the first lens G1 and the third lens G3 are both meniscus lenses, the second lens G2, the fourth lens G4, the sixth lens G6, the seventh lens G7 and the eleventh lens G11 are all biconvex lenses, the fifth lens G5 and the tenth lens G10 are both biconcave lenses, and the ninth lens G9 is a meniscus lens or a plano-concave lens.

[0023] Optionally, the second lens G2, the fourth lens G4, and the sixth lens G6 are all made of low-dispersion crown glass, and the eighth lens G8 is made of high-dispersion flint glass.

[0024] Optionally, the maximum outer diameter of all lenses in the front group S1 is set to Φ36mm, and the maximum outer diameter of all lenses in the rear group S2 is set to Φ8mm.

[0025] Optionally, a beam splitter P is also provided between the front group S1 and the aperture T. The beam splitter P is a semi-transparent and semi-reflective prism, and the rear group S2 is located on the refraction path of the beam splitter P.

[0026] The reflection path of the beam splitter P is also equipped with a coaxial illumination source or imaging component.

[0027] Optionally, the aperture of the stop T is a circular hole, and the center of the circular hole is on the predetermined optical axis.

[0028] Secondly, the present invention provides a long working distance 10x large NA telecentric microscope lens, including the optical system of the long working distance 10x large NA telecentric microscope lens as described above.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The optical system of the long working distance 10x large NA telecentric microscope lens provided by this invention is designed with object-side telecentricity. With a working distance of 58mm, the numerical aperture (NA) can reach 0.25, and the magnification is 10x, thereby achieving a microscope-level resolution of 1.5 micrometers. The outer diameter of the front and rear lens groups is the same, which is beneficial to ensure coaxiality after assembly and improve the imaging quality of the lens.

[0031] The present invention has other features and advantages, which will be apparent from or will be set forth in detail in the accompanying drawings and the following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the optical system of a long working distance, 10x large NA telecentric microscope lens provided in an embodiment of the present invention.

[0034] Figure 2 This is an optical path diagram of an optical system for a long working distance, 10x large NA telecentric microscope lens provided in an embodiment of the present invention.

[0035] Figure 3 Object-space MTF diagram of an optical system with a long working distance and 10x large NA telecentric microscope lens provided in an embodiment of the present invention.

[0036] Figure 4The distortion diagram is provided for an optical system of a long working distance, 10x large NA telecentric microscope lens according to an embodiment of the present invention. Detailed Implementation

[0037] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0038] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0039] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0040] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0041] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0042] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0043] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0044] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0045] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0046] Example 1:

[0047] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the optical system of a long working distance, 10x large NA telecentric microscope lens provided in an embodiment of the present invention. Figure 2 Optical path diagram of an optical system for a long working distance, 10x large NA telecentric microscope lens provided in an embodiment of the present invention.

[0048] like Figure 1 As shown, the optical system includes:

[0049] The front group S1 with positive optical power, the aperture T, and the rear group S2 with negative optical power are arranged sequentially from the object side to the image side. The aperture T is placed at the focal point of the front group S1, forming a telecentric structure on the object side. All lenses in the front group S1 have the same maximum outer diameter, and all lenses in the rear group S2 have the same maximum outer diameter.

[0050] The combined focal length of the front group S1 is f S1 The combined focal length of the rear group S2 is f. S2 f S1 and f S2 Satisfies the relation: 4<|f S1 / f S2 |<6;

[0051] The working distance of the optical system is WD, and the numerical aperture is NA. WD and NA satisfy the relationship: NA×WD≤17.

[0052] In this embodiment, the front group S1 has positive optical power and the rear group S2 has negative optical power. The two are separated by a certain distance, which is beneficial for correcting the field curvature of the system and improving the consistency of imaging quality.

[0053] Preferably, in this embodiment, the maximum outer diameter of the lenses in the front group S1 is set to Φ36mm, and the maximum outer diameter of the lenses in the rear group S2 is set to Φ8mm. Using the same outer diameter for the front and rear groups is beneficial to the design and processing of the mechanical structure, as well as to the assembly and adjustment of the lenses, ensuring coaxiality and improving the imaging quality of the lens.

[0054] Specifically, the front group S1 includes a first lens G1 with positive optical power, a second lens G2 with positive optical power, a third lens G3 with negative optical power, a fourth lens G4 with positive optical power, a fifth lens G5 with negative optical power, a sixth lens G6 with positive optical power, a seventh lens G7 with positive optical power, and an eighth lens G8 with positive optical power; wherein, the third lens G3 and the fourth lens G4 form a first cemented lens U1, and the fifth lens G5 and the sixth lens G6 form a second cemented lens U2.

[0055] The focal length of the first lens G1 is f1, and f1 and f S1 The relation 1.5 < |f1 / f is satisfied. S1 |<2.5; The first lens G1 has a structure that tends to bend towards the object surface in order to reduce spherical aberration;

[0056] The focal length of the second lens G2 is f2, and f2 and f1 satisfy the relationship: 0.75 < |f1 / f2| < 1.25. The second lens G2 shares the light-reflecting capability of the first lens G1, and softens the incident angle of light passing through the lens, which helps to reduce tolerance sensitivity and assembly difficulty.

[0057] The focal length of the first cemented lens U1 is f U1 f U1 with f S1 Satisfy the relation: |f S1 / f U1 |<0.1;

[0058] The focal length of the second cemented lens U2 is f U2 f U2 with f S1 Satisfies the relation: 1.4 < |f U2 / f S1 |<2.1;

[0059] The focal length of the seventh lens G7 is f7, and f7 is the same as f... S1 The relation is satisfied: 2.5 < |f7 / f S1 |<3.2;

[0060] The focal length of the eighth lens G8 is f8, and f8 is different from f... S1 The relation 1.6 < |f8 / f is satisfied. S1 |<2.4.

[0061] Preferably, the second lens G2, the fourth lens G4 and the sixth lens G6 are all made of low-dispersion crown glass, and the eighth lens G8 is made of high-dispersion flint glass.

[0062] In this embodiment, by placing two adjacent cemented doublet achromatic lenses in the front group S1 and by rationally matching and combining the optical power and materials of each lens, the chromatic aberration and spherical aberration of the system can be effectively corrected; the two groups of cemented doublet lenses are arranged in the form of negative and positive lenses, which is beneficial for correcting spherical aberration and field curvature; the light rays pass through the first cemented lens U1 in near parallel order, and its cemented surface can correct the astigmatism and higher-order aberrations of the optical system; the sixth lens G6 to the eighth lens G8 all have positive optical power, which can reduce the curvature of the lens surface and form a smaller spherical aberration.

[0063] Furthermore, the rear group S2 includes a ninth lens G9 with negative optical power, a tenth lens G10 with negative optical power, and an eleventh lens G11 with positive optical power; wherein, the tenth lens G10 and the eleventh lens G11 form a third cemented lens U3.

[0064] The focal length of the ninth lens G9 is f9, and f9 is the same as the focal length of the second lens G9. S2 Satisfies the relation: 1 < |f9 / f S2 |<1.6;

[0065] The focal length of the third cemented lens U3 is f U3 f U3 with f S2 Satisfies the relation: 4.9 < |fU3 / f S2 |<5.7; The third cemented lens U3 can compensate for the chromatic aberration of the front group S1 and also help correct distortion.

[0066] In a preferred embodiment, the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, and the eleventh lens G11 are all spherical lenses. Preferably, the first lens G1 to the eleventh lens G11 are all spherical lenses, which have good manufacturability; in this embodiment, the optical axes of all spherical lenses are on a predetermined optical axis (…). Figure 1 (as shown by the dashed line).

[0067] In this embodiment, the aperture of the stop T is a circular aperture, and the center of the circular aperture is on the predetermined optical axis. It is understood that the aperture value of the stop T needs to be adjusted according to the specific application scenario.

[0068] Specifically, the first lens G1 and the third lens G3 are both meniscus lenses, the second lens G2, the fourth lens G4, the sixth lens G6, the seventh lens G7 and the eleventh lens G11 are all biconvex lenses, the fifth lens G5 and the tenth lens G10 are both biconcave lenses, and the ninth lens G9 is either a meniscus lens or a plano-concave lens.

[0069] As an optional implementation, a beam splitter P is also provided between the front group S1 and the aperture T. The beam splitter P is a semi-transparent and semi-reflective prism, and the rear group S2 is located on the refraction path of the beam splitter P.

[0070] The reflection path of the beam splitter P is also equipped with a coaxial illumination source or imaging component.

[0071] To verify whether the optical system described above meets the design objectives, the following are specific application examples based on the above settings in this embodiment:

[0072] In this application example, the lens data for the optical system are shown in Table 1 below:

[0073] Table 1

[0074]

[0075]

[0076] It should be noted that in Table 1, "front surface" corresponds to... Figure 1 The left surface of the lens or lens group corresponds to the middle surface, while the rear surface corresponds to the left surface. Figure 1 The right side surface of the corresponding lens or lens group; or it can be understood as: the object surface in Figure 1 On the left, the image plane (or image surface) is... Figure 1 On the right side, the surface closer to the object is called the "front surface", and the surface closer to the image is called the "back surface".

[0077] In this application example, the combined focal length of the front group S1 is f. S1 =46mm; the combined focal length of the rear group S2 is f S2＝ -9mm; the focal length of the first lens G1 is f1 = 94mm; the focal length of the second lens G2 is f2 = 93mm; the focal length of the first cemented lens U1 is f U1 = -1536mm; Focal length f of the second cemented lens U2 U2 = -80mm; the focal length of the seventh lens G7 is f7 = 130mm; the focal length of the eighth lens G8 is f8 = 91mm; the focal length of the ninth lens G9 is f9 = -13mm; the focal length of the third cemented lens U3 is f U3 = -50mm;

[0078] The optical path diagram of the optical system is as follows: Figure 2 As shown.

[0079] Please refer to Figure 3 and Figure 4 , Figure 3 This is an object-side MTF (Modulation Transfer Function) curve of an optical system for a long working distance, 10x large NA telecentric microscope lens provided in Embodiment 1 of the present invention. Figure 4 The distortion diagram is provided for an optical system of a long working distance 10x large NA telecentric microscope lens according to Embodiment 1 of the present invention.

[0080] like Figure 3 and Figure 4 As shown, the optical parameters of this optical system are as follows:

[0081] Table 2

[0082] Working distance WD >58mm Numerical Aperture (NA) 0.25 Object-image distance 263mm resolution 1.5 micrometers Magnification 10 times Maximum field of view Φ1.1mm Telecentricity <0.1° distortion 0.02％

[0083] In Table 2, the formula for calculating the resolution is 0.65*λ / NA, where λ is the wavelength.

[0084] In summary, compared with the prior art, the optical system of the long working distance 10x large NA telecentric microscope lens provided in this embodiment has the following beneficial effects:

[0085] It adopts a telecentric object design, and with a working distance of 58mm, the numerical aperture (NA) can reach 0.25, the magnification is 10x, thus achieving a microscope-level resolution of 1.5 micrometers.

[0086] All lenses are spherical lenses, thus possessing excellent manufacturability;

[0087] The outer diameters of the front group S1 and the rear group S2 lenses are made uniform, which is beneficial for assembly and forming, ensures coaxiality, and improves the image quality of the lens.

[0088] Example 2:

[0089] This embodiment provides a long working distance 10x large NA telecentric microscope lens, including the optical system of a long working distance 10x large NA telecentric microscope lens as described in Embodiment 1.

[0090] Since the optical system has been described in detail in the above embodiments, it will not be repeated in this embodiment.

[0091] This embodiment addresses the shortcomings of existing technologies by providing a 10x telecentric microscope lens with a long working distance and a large numerical aperture (NA), which can meet the precision detection requirements of machine vision microsystems.

[0092] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical system of a long working distance 10x large NA telecentric microscope objective, characterized in that, The front group S1 with positive focal length, the diaphragm T and the rear group S2 with negative focal length are sequentially arranged from the object side to the image side, the diaphragm T is placed at the focal point of the front group S1, and a far object side is formed; wherein the maximum outer diameters of all lenses in the front group S1 are the same, and the maximum outer diameters of all lenses in the rear group S2 are the same; The front group S1 is composed of a first lens G1 with positive focal length, a second lens G2 with positive focal length, a third lens G3 with negative focal length, a fourth lens G4 with positive focal length, a fifth lens G5 with negative focal length, a sixth lens G6 with positive focal length, a seventh lens G7 with positive focal length and an eighth lens G8 with positive focal length; The rear group S2 is composed of a ninth lens G9 with negative focal length, a tenth lens G10 with negative focal length and an eleventh lens G11 with positive focal length; The combined focal length of the front group S1 is f S1 The combined focal length of the rear group S2 is f S2 f S1 and f S2 satisfy the relationship: 4 < |f S1 / f S2 | < 6; The working distance of the optical system is WD, and the numerical aperture is NA, and the WD and the NA satisfy the relationship: NA×WD≤17.

2. The optical system of a long working distance 10x large-NA telecentric microscope objective of claim 1, wherein, The third lens G3 and the fourth lens G4 form a first cemented lens U1, and the fifth lens G5 and the sixth lens G6 form a second cemented lens U2; The focal length of the first lens G1 is f1, and f1 and f S1 satisfies the relationship: 1.5 < |f1 / f S1 | < 2.5; The focal length of the second lens G2 is f2, and f2 and f1 satisfy the relationship: 0.75<|f1 / f2|<1.25; The focal length of the first cemented lens U1 is f U1 , f U1 and f S1 satisfy the relationship: |f S1 / f U1 | < 0.1; The focal length of the second cemented lens U2 is f U2 , f U2 and f S1 satisfy the relationship: 1.4 < |f U2 / f S1 | < 2.1; The focal length of the seventh lens G7 is f7, and f7 and f S1 satisfies the relationship: 2.5 < |f7 / f S1 | < 3.2; The focal length of the eighth lens G8 is f8, and f8 and f S1 satisfies the relationship: 1.6 < |f8 / f S1 | < 2.

4.

3. The optical system of a long working distance 10x large-NA telecentric microscope objective of claim 2, wherein, The tenth lens G10 and the eleventh lens G11 form a third cemented lens U3; The focal length of the ninth lens G9 is f9, which is greater than the focal length f8 of the eighth lens G8, and smaller than the focal length f10 of the tenth lens G10. S2 The relationship 1<|f9 / f S2 |<1.6; The focal length of the third cemented lens U3 is f U3 , f U3 and f S2 satisfy the relationship: 4.9 < |f U3 / f S2 | < 5.

7.

4. The optical system of a long working distance 10x large-NA telecentric microscope objective of claim 3, wherein, The first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10 and the eleventh lens G11 are all spherical lenses, and the optical axes of all the spherical lenses are on the predetermined optical axis.

5. The optical system of a long working distance 10x large-NA telecentric microscope objective of claim 4, wherein, The first lens G1 and the third lens G3 are both meniscus lenses, the second lens G2, the fourth lens G4, the sixth lens G6, the seventh lens G7 and the eleventh lens G11 are all double convex lenses, the fifth lens G5 and the tenth lens G10 are both double concave lenses, and the ninth lens G9 is a meniscus lens or a flat concave lens.

6. The optical system of a long working distance 10x large-NA telecentric microscope objective of claim 3, wherein, The materials of the second lens G2, the fourth lens G4 and the sixth lens G6 are all low-dispersion crown glass, and the material of the eighth lens G8 is high-dispersion flint glass.

7. The optical system of a long working distance 10x large-NA telecentric microscope objective of claim 1, wherein, The maximum outer diameters of all lenses in the front group S1 are all set to Φ36mm, and the maximum outer diameters of all lenses in the rear group S2 are all set to Φ8mm.

8. The optical system of a long working distance 10x large-NA telecentric microscope objective of claim 1, wherein, A light splitting prism P is further arranged between the front group S1 and the diaphragm T, the light splitting prism P is a half-transmission half-reflection prism, and the rear group S2 is arranged on the refractive path of the light splitting prism P; A coaxial illumination light source or an imaging assembly is further arranged on the reflection path of the light splitting prism P.

9. The optical system of a long working distance 10x large-NA telecentric microscope objective of claim 4, wherein, The aperture of the diaphragm T is a circular hole, and the center of the circular hole is on the predetermined optical axis.

10. A long working distance 10x NA telecentric microscope objective lens characterized by, An optical system comprising a long working distance 10 times large NA far-infrared microscope lens according to any one of claims 1-9. An optical system comprising a long working distance 10 times large NA far-infrared microscope lens according to any one of claims 1-9.

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