CN218158537U

CN218158537U - Microscope objective

Info

Publication number: CN218158537U
Application number: CN202222784305.9U
Authority: CN
Inventors: 胡森虎; 李伸朋; 崔健
Original assignee: Ningbo Sunny Instruments Co Ltd
Current assignee: Ningbo Sunny Instruments Co Ltd
Priority date: 2022-10-21
Filing date: 2022-10-21
Publication date: 2022-12-27
Anticipated expiration: 2032-10-21

Abstract

The utility model relates to a microscope objective, include: a first lens group (T1), a second lens group (T2) having positive optical power, and a third lens group (T3) having negative optical power, which are arranged in this order from the image side to the object side along the optical axis, wherein the first lens group (T1) has negative optical power; the first lens group (T1) at least comprises a single lens and a cemented lens group; the second lens group (T2) at least comprises two cemented lens groups; the third lens group (T3) includes at least two single lenses having positive refractive power. The utility model discloses in, the object space numerical aperture of microscope objective can reach 1.5 at most, and the visual field number can reach 30mm the most, has 400nm ~ 1000nm wave band colour difference correction and guarantees good fluorescence performance.

Description

Microscope objective

Technical Field

The utility model relates to a microscope technical field especially relates to a microscope objective.

Background

Due to the increasing requirements of life science and industrial fields for observation resolution and imaging speed, microscope objectives tend to be developed with a larger field of view and a larger aperture (NA). When the microscope objective lens realizes the apochromatic aberration of the large numerical aperture, the good fluorescence performance of the microscope objective lens needs to be ensured, and the structure has better machinability, thereby having an important effect on the production of the microscope objective lens with the large numerical aperture. However, the correction wavelength band of the existing apochromatic objective imaging system is 436nm to 656nm, and the numerical aperture is 0.1 to 1.4. With the increasing requirements of the life science and the industrial field on observation resolution capability, imaging speed, large-field observation, observation of special samples and the like, higher requirements are put forward on the performance of the objective such as the use waveband, the numerical aperture, the observation field and the like.

SUMMERY OF THE UTILITY MODEL

Based on the problem that above-mentioned prior art exists, the utility model aims to provide a microscope objective, numerical aperture is the highest can reach 1.5, and the maximum 30mm that can of field of view number has 400nm ~ 1000nm wave band colour difference and corrects and guarantee good fluorescence performance.

To achieve the above object, the present invention provides a microscope objective comprising: a first lens group, a second lens group having positive refractive power, and a third lens group having negative refractive power, which are arranged in order in a direction from an image side to an object side along an optical axis, wherein the first lens group has negative refractive power;

the first lens group at least comprises a single lens and a cemented lens group;

the second lens group at least comprises two cemented lens groups;

the third lens group at least comprises two single lenses with positive focal power.

According to one aspect of the present invention, the first lens group comprises, in order from the image side to the object side along the optical axis, a first lens element, a second lens element, a first cemented lens group and a second cemented lens group,

the first lens and the second cemented lens group have positive focal power;

the second lens and the first cemented lens group have negative optical power.

According to an aspect of the present invention, the first cemented lens group is composed of a third lens and a fourth lens cemented together, the third lens has a negative focal power, and the fourth lens has a positive focal power;

the second cemented lens group is formed by cementing a fifth lens and a sixth lens, wherein the fifth lens has negative focal power, and the sixth lens has positive focal power.

According to an aspect of the present invention, the first lens is a convex-concave lens and the second lens is a biconcave lens in a direction from the image side to the object side along the optical axis.

According to one aspect of the present invention, the second lens group comprises a third cemented lens group and a fourth cemented lens group in this order along the optical axis from the image side to the object side,

the third cemented lens group is formed by cementing a seventh lens, an eighth lens and a ninth lens;

the fourth cemented lens group is formed by cementing a tenth lens, an eleventh lens and a twelfth lens.

According to an aspect of the present invention, the seventh lens, the ninth lens and the eleventh lens have negative optical power;

the eighth lens, the tenth lens, and the twelfth lens have positive optical power.

According to an aspect of the present invention, the eighth lens, the tenth lens, and the twelfth lens are made of a low dispersion material.

According to an aspect of the present invention, in a direction from the image side to the object side along the optical axis, the third lens group includes a thirteenth lens, a fourteenth lens, and a fifteenth lens in this order, and the thirteenth lens, the fourteenth lens, and the fifteenth lens have positive refractive power.

According to an aspect of the present invention, an object-side surface of the fourteenth lens element is a concave surface;

the object side surface of the fifteenth lens is a plane, and the image side surface of the fifteenth lens is a hyper-hemispherical surface.

According to one aspect of the present invention, the first lens group comprises, in order from the image side to the object side along the optical axis, a first cemented lens group, a third lens group, a second cemented lens group, and a sixth lens group,

the third lens and the sixth lens have negative optical power.

According to an aspect of the present invention, the first cemented lens group is composed of a first lens and a second lens cemented together, the first lens having a positive focal power, the second lens having a negative focal power;

the second cemented lens group is formed by a fourth lens and a fifth lens in a cemented mode, the fourth lens has negative focal power, and the fifth lens has positive focal power.

According to an aspect of the present invention, the image-side surface of the first lens element is a convex surface, the object-side surface of the second lens element is a concave surface, the image-side surface of the fourth lens element is a concave surface, and the object-side surface of the fifth lens element is a convex surface.

According to one aspect of the present invention, the second lens group comprises a third cemented lens group, a fourth cemented lens group and a fifth cemented lens group in this order along the optical axis from the image side to the object side,

the third cemented lens group is formed by a seventh lens and an eighth lens through cementing;

the fourth cemented lens group is formed by cementing a ninth lens, a tenth lens and an eleventh lens;

and the fifth cemented lens group is formed by cementing a twelfth lens, a thirteenth lens and a fourteenth lens.

According to an aspect of the present invention, the seventh lens, the twelfth lens and the fourteenth lens have negative optical power;

the eighth lens and the thirteenth lens have positive optical power;

two lenses of the ninth lens, the tenth lens and the eleventh lens have positive focal power, and one lens has negative focal power.

According to an aspect of the present invention, the lens having positive refractive power in the fourth cemented lens group and the thirteenth lens are both made of low dispersion material.

According to an aspect of the present invention, the eighth lens element is a biconvex lens element, and the image-side surface of the seventh lens element is a convex surface.

According to an aspect of the present invention, the third lens group includes, in order from the image side to the object side along the optical axis, a fifteenth lens, a sixteenth lens and a sixth cemented lens group,

and the sixth cemented lens group is formed by cementing a seventeenth lens and an eighteenth lens.

According to an aspect of the present invention, the fifteenth lens, the sixteenth lens, the seventeenth lens and the eighteenth lens have positive optical power.

According to an aspect of the present invention, the fifteenth lens and the sixteenth lens are biconvex lenses in a direction from the image side to the object side along an optical axis;

the seventeenth lens is a hyper-hemispherical lens;

the eighteenth lens is a plano-convex lens.

According to one aspect of the present invention, the first lens group comprises, in order from the image side to the object side along the optical axis, a first lens, a second lens and a first cemented lens group,

the first lens has positive optical power;

the second lens has a negative optical power.

According to an aspect of the present invention, the first cemented lens group is composed of a third lens and a fourth lens cemented together, the third lens has a negative focal power, and the fourth lens has a positive focal power.

According to an aspect of the present invention, the image-side surface of the third lens element is a concave surface, and the object-side surface of the fourth lens element is a convex surface.

According to one aspect of the present invention, the second lens group comprises a second cemented lens group, a third cemented lens group and a fourth cemented lens group in this order along the optical axis from the image side to the object side,

the second cemented lens group is formed by cementing a fifth lens and a sixth lens;

and the fourth cemented lens group is formed by cementing a tenth lens, an eleventh lens and a twelfth lens.

According to an aspect of the present invention, the fifth lens, the tenth lens, and the twelfth lens have negative optical power;

the sixth lens and the eleventh lens have positive optical power;

two lenses of the seventh lens, the eighth lens and the ninth lens have positive focal power, and one lens has negative focal power.

According to an aspect of the present invention, the lens having positive refractive power in the third cemented lens group and the eleventh lens are both made of low dispersion material.

According to an aspect of the present invention, the third lens group includes a thirteenth lens element, a fourteenth lens element and a fifth cemented lens element in this order from the image side to the object side along the optical axis,

the fifth cemented lens group is formed by cementing a fifteenth lens and a sixteenth lens.

According to an aspect of the present invention, the thirteenth lens, the fourteenth lens, the fifteenth lens, and the sixteenth lens have positive optical power.

According to an aspect of the present invention, the thirteenth lens and the fourteenth lens are biconvex lenses in a direction from the image side to the object side along the optical axis;

the fifteenth lens is a hyper-hemispherical lens;

the sixteenth lens is a plano-convex lens.

According to one aspect of the present invention, the first lens group comprises, in order from the image side to the object side along the optical axis, a first cemented lens group, a second cemented lens group and a third cemented lens group,

the first lens has a positive optical power.

According to an aspect of the present invention, the first lens is a meniscus lens in a direction from the image side to the object side along the optical axis.

According to an aspect of the present invention, the first cemented lens group is composed of a second lens and a third lens cemented together, the second lens having a positive focal power, the third lens having a negative focal power;

the second cemented lens group is formed by cementing a fourth lens and a fifth lens, the fourth lens has negative focal power, and the fifth lens has positive focal power;

the third cemented lens group is formed by a sixth lens and a seventh lens in a cemented mode, the sixth lens has negative focal power, and the seventh lens has positive focal power.

According to an aspect of the present invention, the image-side surface of the second lens element is a convex surface, the object-side surface of the third lens element is a concave surface, the image-side surface of the fourth lens element is a concave surface, the object-side surface of the fifth lens element is a convex surface, and the seventh lens element is a biconvex lens element.

According to one aspect of the present invention, the second lens group comprises a fourth cemented lens group and a fifth cemented lens group in this order along the optical axis from the image side to the object side,

the fourth cemented lens group is formed by cementing an eighth lens, a ninth lens and a tenth lens;

and the fifth cemented lens group is formed by cementing an eleventh lens, a twelfth lens and a thirteenth lens.

According to an aspect of the present invention, two of the eighth lens, the ninth lens and the tenth lens have positive focal power, and one of the lenses has negative focal power;

the eleventh lens and the thirteenth lens have a negative optical power, and the twelfth lens has a positive optical power.

According to an aspect of the present invention, the lens having positive refractive power in the fourth cemented lens group and the twelfth lens are both made of low dispersion material.

According to an aspect of the present invention, the third lens group includes a fourteenth lens element, a fifteenth lens element and a sixth cemented lens element in this order from the image side to the object side along the optical axis,

the sixth cemented lens group is formed by cementing a sixteenth lens and a seventeenth lens.

According to an aspect of the present invention, the fourteenth lens, the fifteenth lens, the sixteenth lens and the seventeenth lens have positive optical power.

According to an aspect of the present invention, the fourteenth lens element is a biconvex lens element in a direction from the image side to the object side along the optical axis;

the fifteenth lens is a convex-concave lens;

the sixteenth lens is a hyper-hemispherical lens;

the seventeenth lens is a plano-convex lens.

According to the utility model discloses an aspect, the object side of microscope objective to last one side distance D with microscope objective's focus fobj satisfies the conditional expression: 10< -D/fobj <40.

According to an aspect of the present invention, the focal length fobj of the microscope objective satisfies the conditional expression: fobj >1.5.

According to an aspect of the utility model, the object space numerical aperture NA of microscope objective satisfies the conditional expression: 1-NA woven fabric was constructed in 1.52.

According to the utility model discloses an aspect, central visual field edge light is in the minimum projection height H1 in lens surface of third lens crowd, central visual field edge light are in projection height H3 and the central visual field edge light on the last piece of lens surface of first lens crowd are in the lens surface of second lens crowd is the highest projection height H2 respectively satisfies following conditional expression: 0.1< | H1/H2| <1;0.5< | H2/H3| <3.

According to an aspect of the present invention, the focal length fL1 of the first lens group, the radius RL1 of the image side surface of the first lens group, and the focal length fobj of the microscope objective lens satisfy the following conditional expressions, respectively: 3< | fL1/fobj | <20; 1< | RL1/fobj | is less than 7.

According to an aspect of the present invention, the focal length fT1 of the first lens group and the focal length fobj of the microscope objective lens satisfy the conditional expression: 0< | fT1/fobj | <20.

According to an aspect of the present invention, the focal length fT2 of the second lens group and the focal length fobj of the microscope objective lens satisfy the conditional expression: 0< | fT2/fobj | is less than 15.

According to an aspect of the present invention, the focal length fT3 of the third lens group and the focal length fobj of the microscope objective lens satisfy the conditional expression: 0< | fT3/fobj | is less than 2.5.

According to the solution of the present invention, the structure of the microscope objective mainly comprises a first, a second and a third lens group having negative, positive and negative focal powers in order from the image side. The first lens group at least comprises a single lens and a cemented lens group, provides focal power, reduces the numerical aperture of other lens groups, and corrects distortion and curvature of field. The second lens group at least comprises two cemented lens groups mainly used for correcting chromatic aberration. The third lens group at least comprises two single lenses with positive focal power, provides the focal power and simultaneously provides a large numerical aperture and is used for correcting curvature of field.

The frequency spectrum range corresponding to the working wave band of chromatic aberration correction of the objective lens imaging system of the apochromatic microscope is 400 nm-1000 nm, good fluorescence performance is ensured, and the imaging effect in the wave band interval of 436-656 nm is optimal. Through the sectional control mode of the near-infrared wave band, the numerical aperture is well enlarged, the maximum numerical aperture can reach 1.5, the microscope objective lens has better resolution capability on a sample, and the potential of the microscope objective lens in the aspect of ultrahigh resolution imaging is effectively improved. In order to further improve the observable area at the same time, increase the visual field of an object, the position points needing to be observed can be more easily found under a large visual field, and the visual field number of the microscope objective can reach 30mm. Meanwhile, the design of the use of the broad spectrum enables the objective lens to have the observation capability on special samples.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a schematic diagram showing an optical structure of a microscope objective lens according to a first embodiment of the present invention;

fig. 2 schematically shows a 0-field transverse aberration diagram of a microscope objective lens according to a first embodiment of the present invention;

fig. 3 schematically shows a 1-field transverse aberration diagram of a microscope objective lens according to a first embodiment of the present invention;

fig. 4 is a field curvature distortion diagram schematically illustrating a microscope objective lens according to a first embodiment of the present invention;

fig. 5 is a graph schematically showing a chromatic aberration of a microscope objective lens according to a first embodiment of the present invention;

fig. 6 is a schematic view showing an optical structure of a microscope objective lens according to a second embodiment of the present invention;

fig. 7 schematically shows a 0-field transverse aberration diagram of a microscope objective lens according to a second embodiment of the present invention;

fig. 8 is a view schematically showing a 1-field transverse aberration diagram of a microscope objective lens according to a second embodiment of the present invention;

fig. 9 is a view schematically showing a field curvature distortion of a microscope objective lens according to a second embodiment of the present invention;

fig. 10 is a graph schematically showing a chromatic aberration of a microscope objective lens according to a second embodiment of the present invention;

fig. 11 is a schematic view showing an optical structure of a microscope objective lens according to a third embodiment of the present invention;

fig. 12 is a 0-field transverse aberration diagram schematically showing a microscope objective lens according to a third embodiment of the present invention;

fig. 13 is a view schematically showing a transverse aberration diagram of a 1 st field of view of a microscope objective lens according to a third embodiment of the present invention;

fig. 14 is a view schematically showing a field curvature distortion of a microscope objective lens according to a third embodiment of the present invention;

fig. 15 is a graph schematically showing a chromatic aberration of a microscope objective lens according to a third embodiment of the present invention;

fig. 16 is a schematic view showing an optical structure of a microscope objective lens according to a fourth embodiment of the present invention;

fig. 17 is a view schematically showing a transverse aberration diagram of 0 field of view of a microscope objective lens according to a fourth embodiment of the present invention;

fig. 18 is a schematic view showing a 1-field transverse aberration diagram of a microscope objective lens according to a fourth embodiment of the present invention;

fig. 19 is a view schematically showing a field curvature distortion of a microscope objective lens according to a fourth embodiment of the present invention;

fig. 20 is a graph schematically showing a chromatic aberration of a microscope objective lens according to a fourth embodiment of the present invention.

Detailed Description

The embodiments described in this specification are to be considered in all respects as illustrative and not restrictive, and the appended drawings are intended to be part of the entire specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and simplified for convenience. Further, the components of the structures in the drawings are described separately, and it should be noted that the components not shown or described in the drawings are well known to those skilled in the art.

Any reference to directions and orientations to the description of the embodiments herein is merely for convenience of description and should not be construed as limiting the scope of the present invention in any way. The following description of the preferred embodiments refers to combinations of features which may be present independently or in combination, and the present invention is not particularly limited to the preferred embodiments. The scope of the present invention is defined by the appended claims.

As shown in fig. 1, 6, 11, or 16, an embodiment of the present invention provides a microscope objective lens, sequentially including, along an optical axis from an image side to an object side: a first lens group T1 with negative focal power, a second lens group T2 with positive focal power and a third lens group T3 with negative focal power. The first lens group T1 includes at least one single lens and a cemented lens group, provides an optical power, reduces a numerical aperture for the other lens groups, and corrects distortion and curvature of field. The second lens group T2 at least comprises two cemented lens groups mainly used for correcting chromatic aberration. The third lens group T3 includes at least two single lenses having positive refractive power, provides optical power while providing a large numerical aperture, and is used for correcting curvature of field. The microscope objective belongs to an infinite conjugate objective. The embodiment of the utility model provides an in, it can be the air to survey the medium between object and the objective, also can be for liquid, and when the medium was the air, numerical aperture was less than 1, and when the medium was liquid, its numerical aperture can reach the maximum value.

In some embodiments of the present invention, as shown in fig. 1, the first lens group T1 includes, in order from the image side to the object side along the optical axis, a first lens element 1, a second lens element 2, a first cemented lens group G1 and a second cemented lens group G2. The first lens element 1 and the second cemented lens group G2 have positive focal power, and the second lens element 2 and the first cemented lens group G1 have negative focal power. The surface of the first lens element 1 away from the object side is convex, and the concave surface faces the object side. The second lens 2 is a biconcave lens.

The first cemented lens group G1 is composed of a third lens element 3 and a fourth lens element 4 cemented together, and is a double cemented lens group. The third lens 3 is a negative power lens, and the fourth lens 4 is a positive power lens. The second cemented lens group G2 is composed of a fifth lens element 5 and a sixth lens element 6 cemented together, i.e. a double cemented lens group. The fifth lens 5 is a negative power lens, and the sixth lens 6 is a positive power lens.

The second lens group T2 includes a third cemented lens group G3 and a fourth cemented lens group G4 in order along the optical axis from the image side to the object side. The third cemented lens group G3 is formed by a seventh lens element 7, an eighth lens element 8 and a ninth lens element 9 cemented together, i.e. a third cemented lens group. The fourth cemented lens group G4 is composed of a tenth lens element 10, an eleventh lens element 11, and a twelfth lens element 12 cemented together, i.e., a third cemented lens group. The seventh lens 7, the ninth lens 9, and the eleventh lens 11 are all negative power lenses, and the eighth lens 8, the tenth lens 10, and the twelfth lens 12 are all positive power lenses. Meanwhile, the eighth lens 8, the tenth lens 10, and the twelfth lens 12 use low dispersion materials. That is, the positive power lenses in the third and fourth cemented lens groups G3 and G4 use low dispersion materials.

The third lens group T3 includes three single lenses of a thirteenth lens 13, a fourteenth lens 14, and a fifteenth lens 15 in order along the optical axis from the image side to the object side, and the thirteenth lens 13, the fourteenth lens 14, and the fifteenth lens 15 are all positive power lenses. Wherein the concave surface of the fourteenth lens 14 faces the object side. The surface of the fifteenth lens 15 close to the object side is a plane, and the surface thereof away from the object side is a hyper-hemispherical surface.

In some embodiments of the present invention, as shown in fig. 6, the first lens group T1 includes, in order from the image side to the object side along the optical axis, a first cemented lens group G1, a third lens 3, a second cemented lens group G2 and a sixth lens 6. Wherein the third lens 3 and the sixth lens 6 are both negative power lenses. The first cemented lens group G1 is composed of a first lens element 1 and a second lens element 2 cemented together, i.e. a double cemented lens group. The first lens 1 is a positive focal power lens, and the second lens 2 is a negative focal power lens. The second cemented lens group G2 is composed of a fourth lens element 4 and a fifth lens element 5 cemented together, i.e. a double cemented lens group. The fourth lens 4 is a negative power lens, and the fifth lens 5 is a positive power lens. Meanwhile, regarding the lens shapes, the surface of the first lens 1 away from the object side is a convex surface, the surface of the second lens 2 close to the object side is a concave surface, the surface of the fourth lens 4 away from the object side is a concave surface, and the surface of the fifth lens 5 close to the object side is a convex surface.

In a direction from the image side to the object side along the optical axis, the second lens group T2 includes a third cemented lens group G3, a fourth cemented lens group G4, and a fifth cemented lens group G5 in this order. The third cemented lens group G3 is formed by cementing a seventh lens 7 and an eighth lens 8, the fourth cemented lens group G4 is formed by cementing a ninth lens 9, a tenth lens 10 and an eleventh lens 11, and the fifth cemented lens group G5 is formed by cementing a twelfth lens 12, a thirteenth lens 13 and a fourteenth lens 14. That is, the third cemented lens group G3 is a double cemented lens group, and the fourth cemented lens group G4 and the fifth cemented lens group G5 are triple cemented lens groups.

Among them, the seventh lens 7, the twelfth lens 12, and the fourteenth lens 14 are all negative power lenses, and the eighth lens 8 and the thirteenth lens 13 are all positive power lenses. Two lenses of the ninth lens 9, the tenth lens 10, and the eleventh lens 11 are positive focal power lenses, and the other lens is a negative focal power lens. Meanwhile, the two positive power lenses in the fourth cemented lens group G4 and the thirteenth lens 13 with positive power both use low dispersion materials, wherein the specific low dispersion materials of the two positive power lenses in the fourth cemented lens group G4 may be the same or different. Regarding the lens shape, the eighth lens 8 close to the object side is a biconvex lens, and the surface of the seventh lens 7 distant from the object side is also a convex surface.

The third lens group T3 includes, in order from the image side to the object side along the optical axis, a fifteenth lens 15, a sixteenth lens 16, and a sixth cemented lens group G6. The sixth cemented lens group G6 is a double cemented lens group formed by a seventeenth lens 17 and an eighteenth lens 18 cemented together. The fifteenth lens 15, the sixteenth lens 16, the seventeenth lens 17, and the eighteenth lens 18 are all positive power lenses.

The fifteenth lens 15 and the sixteenth lens 16 are each a biconvex lens in a direction from the image side to the object side along the optical axis. The seventeenth lens 17 of the sixth cemented lens group G6 located away from the object side is a hyper-hemispherical lens, and the eighteenth lens 18 located close to the object side is a plano-convex lens.

In some embodiments of the present invention, as shown in fig. 11, the first lens group T1 includes, in order from the image side to the object side along the optical axis, a first lens element 1, a second lens element 2 and a first cemented lens group G1. The first lens 1 is a positive focal power lens, and the second lens 2 is a negative focal power lens. The surface of the first lens element 1 close to the object side is a concave surface, and the surface thereof away from the object side is a convex surface. The second lens 2 is a biconcave lens. The first cemented lens group G1 is a double cemented lens group formed by a third lens element 3 and a fourth lens element 4 cemented together. The third lens 3 is a negative focal power lens, and the fourth lens 4 is a positive focal power lens. The surface of the third lens 3 away from the object side is a concave surface, and the surface of the fourth lens 4 close to the object side is a convex surface.

The second lens group T2 includes a second cemented lens group G2, a third cemented lens group G3, and a fourth cemented lens group G4 in order along the optical axis from the image side to the object side. The second cemented lens group G2 is formed by cementing a fifth lens 5 and a sixth lens 6, the third cemented lens group G3 is formed by cementing a seventh lens 7, an eighth lens 8 and a ninth lens 9, and the fourth cemented lens group G4 is formed by cementing a tenth lens 10, an eleventh lens 11 and a twelfth lens 12. That is, the second cemented lens group G2 is a double cemented lens group, and the third cemented lens group G3 and the fourth cemented lens group G4 are triple cemented lens groups.

Among them, the fifth lens 5, the tenth lens 10, and the twelfth lens 12 are all negative power lenses, and the sixth lens 6 and the eleventh lens 11 are all positive power lenses. Two lenses of the seventh lens 7, the eighth lens 8 and the ninth lens 9 of the third cemented lens group G3 are all positive focal power lenses, and the other lens is a negative focal power lens. And, the two positive power lenses in the third cemented lens group G3 and the eleventh lens 11 having positive power both use low dispersion materials. The specific low-dispersion materials of the two positive power lenses in the third cemented lens group G3 may be the same or different.

The third lens group T3 includes, in order from the image side to the object side along the optical axis, a thirteenth lens 13, a fourteenth lens 14, and a fifth cemented lens group G5. The fifth cemented lens group G5 is a double-cemented lens group formed by a fifteenth lens element 15 and a sixteenth lens element 16 cemented together. The thirteenth lens 13, the fourteenth lens 14, the fifteenth lens 15, and the sixteenth lens 16 are all positive power lenses. The thirteenth lens 13 and the fourteenth lens 14 are both double-convex lenses. The fifteenth lens element 15 of the fifth cemented lens group G5 located away from the object side is a hyper-hemispherical lens element, and the sixteenth lens element 16 located close to the object side is a plano-convex lens element.

In some embodiments of the present invention, as shown in fig. 16, the first lens group T1 includes, in order from the image side to the object side along the optical axis, a first lens element 1, a first cemented lens group G1, a second cemented lens group G2 and a third cemented lens group G3. The first lens 1 is a positive power convex-concave lens, and the surface close to the object side is a convex surface, and the surface far from the object side is a concave surface.

The first cemented lens group G1 is composed of a second lens 2 and a third lens 3 cemented together, wherein the second lens 2 is a positive power lens, and the third lens 3 is a negative power lens. In the first cemented lens group G1, the surface of the second lens element 2 away from the object side is a convex surface, and the surface of the third lens element 3 close to the object side is a concave surface. The second cemented lens group G2 is composed of a fourth lens 4 and a fifth lens 5 cemented together, wherein the fourth lens 4 is a negative power lens, and the fifth lens 5 is a positive power lens. The surface of the fourth lens element 4, away from the object side, of the second cemented lens group G2 is a concave surface, and the surface of the fifth lens element 5, close to the object side, is a convex surface. The third cemented lens group G3 is composed of a sixth lens 6 and a seventh lens 7 cemented together, wherein the sixth lens 6 is a negative power lens, and the seventh lens 7 is a positive power lens. The seventh lens element 7 of the third cemented lens group G3 on the object side is a biconvex lens. That is, the first cemented lens group G1, the second cemented lens group G2, and the third cemented lens group G3 are double cemented lens groups.

The second lens group T2 includes a fourth cemented lens group G4 and a fifth cemented lens group G5 in order along the optical axis from the image side to the object side. The fourth cemented lens group G4 is formed by cementing an eighth lens 8, a ninth lens 9 and a tenth lens 10, and the fifth cemented lens group G5 is formed by cementing an eleventh lens 11, a twelfth lens 12 and a thirteenth lens 13. The fourth cemented lens group G4 and the fifth cemented lens group G5 are triple cemented lens groups.

Two lenses among the eighth lens 8, the ninth lens 9 and the tenth lens 10 of the fourth cemented lens group G4 are positive focal power lenses, and the other lens is a negative focal power lens. The eleventh lens 11 and the thirteenth lens 13 of the fifth cemented lens group G5 are both negative power lenses, and the twelfth lens 12 is a positive power lens. Two positive power lenses in the fourth cemented lens group G4 and the twelfth lens 12 with positive power are made of low dispersion materials. The specific low-dispersion materials of the two positive power lenses in the fourth cemented lens group G4 may be the same or different.

The third lens group T3 includes, in order from the image side to the object side along the optical axis, a fourteenth lens 14, a fifteenth lens 15, and a sixth cemented lens group G6. The sixth cemented lens group G6 is a double cemented lens group formed by a sixteenth lens element 16 cemented with a seventeenth lens element 17. The fourteenth lens 14, the fifteenth lens 15, the sixteenth lens 16, and the seventeenth lens 17 are all positive power lenses. The fourteenth lens 14 is a biconvex lens. The fifteenth lens element 15 is a convex-concave lens element, and has a concave surface on a surface close to the object side and a convex surface on a surface away from the object side. In the sixth cemented lens group G6, the sixteenth lens 16 away from the object side is a hyper-hemispherical lens and the seventeenth lens 17 close to the object side is a plano-convex lens along the optical axis from the image side to the object side.

The embodiment of the utility model provides an in, the object side of microscope objective satisfies the conditional expression to the distance D of last face and the focus fobj of microscope objective: 10-sD/fobj <40. The last side here refers to the surface of the microscope objective closest to the image side, i.e. the image side of the first lens 1. The focal length fobj of the microscope objective lens satisfies the conditional expression: fobj >1.5. The objective numerical aperture NA of the microscope objective satisfies the conditional expression: 1-NA woven fabric was constructed in 1.52. The numerical aperture of the microscope objective lens is related to the focal length of the objective lens, and the smaller the focal length is, the larger the numerical aperture is in the case of the consistent entrance pupil.

The embodiment of the utility model provides an in, central visual field edge light throws height H1 at the lens surface minimum of third lens cluster T3, central visual field edge light throws height H3 and central visual field edge light at the lens surface maximum of second lens cluster T2 and throws height H2 at the last piece of lens surface of first lens cluster T1 and satisfies the following conditional expression respectively: 0.1< | H1/H2| <1;0.5< | H2/H3| <3.

The embodiment of the utility model provides an in, the following conditional expression is satisfied respectively to the radius value RL1 of the image side of the focus fL1 of the first piece of lens of first lens group T1, the first piece of lens of first lens group T1 and the focus fobj of microscope objective: 3< | fL1/fobj | <20; 1< | RL1/fobj | < 7. Here, the first lens of the first lens group T1 refers to a single lens or a cemented lens.

The embodiment of the utility model provides an in, first lens group T1's focus fT1 and microscope objective's focus fobj satisfy the conditional expression: 0< | fT1/fobj | <20. The focal length fT2 of the second lens group T2 and the focal length fobj of the microscope objective lens satisfy the conditional expression: 0< | fT2/fobj | is less than 15. The focal length fT3 of the third lens group T3 and the focal length fobj of the microscope objective lens satisfy the conditional expression: 0< | fT3/fobj | is less than 2.5.

In summary, in some embodiments of the present invention, the spectral range corresponding to the working wavelength band of the chromatic aberration correction of the objective imaging system of the apochromatic microscope is 400nm to 1000nm, and the good fluorescence performance is ensured, and the imaging effect in the wavelength band interval of 436 to 656nm is the best. Through the segmented control mode of the near-infrared wave band, the numerical aperture is well enlarged and can reach 1.5 at most, the microscope objective lens has better resolution capability on a sample, and the potential of the microscope objective lens in the aspect of ultrahigh resolution imaging is effectively improved. In order to further improve the observable area at the same time, increase the visual field of an object, the position points needing to be observed can be more easily found under a large visual field, and the visual field number of the microscope objective can reach 30mm. Meanwhile, the design of the wide spectrum makes the objective lens possess the observation capability for special samples. The working distance of the microscope objective can reach 0.17mm or more, including the working distance of 0-0.17 mm, and the working distance refers to the distance from a cover glass to the edge, close to the image side, of the first lens group T1 of the objective.

The microscope objective lens of the present invention will be specifically described below with reference to four embodiments in conjunction with the accompanying drawings and tables. In the following embodiments, the present invention is represented by S1, S2, \8230;, SN, which represents the surface of each lens, and each cemented surface of the cemented lens group is referred to as one surface.

The parameters of each example specifically satisfying the above conditional expressions are shown in table 1 below:

conditional formula (II)	Example one	Example two	EXAMPLE III	Example four
					10<D/fobj<40	27.45	26.80	26.52	27.48
fobj>1.5	1.8	1.80	1.81	1.8
					1<NA<1.52	1.45	1.50	1.44	1.44
0.5<\|H2/H3\|<3	2.08	1.70	1.50	2.22
					0.1<\|H1/H2\|<1	0.12	0.15	0.14	0.14
3<\|fL1/fobj\|<20	5.72	3.84	8.37	17.46
					1＜\|RL1/fobj\|＜7	2.5	3.1	2.90	5.64
0<\|fT1/fobj\|<20	11.27	6.4	6.34	18.42
					0<\|fT2/fobj\|＜15	8.64	9.28	9.62	11.57
0<\|fT3/fobj\|＜2.5	2.35	1.90	1.93	1.85

TABLE 1

Example one

As shown in fig. 1 and table 1, the microscope objective lens of the present embodiment has the following parameters:

the focal length is 1.8mm, the working distance is 0.13mm, the numerical aperture is 1.45, the field range is 26.5mm, and the spectral range of the working waveband is 400 nm-1000 nm.

In the present embodiment, the central field edge ray height reaches a maximum value between the fourth cemented lens group G4 of the second lens group T2 and the surface of the thirteenth lens 13 of the third lens group T3.

Table 2 lists relevant parameters of each lens in the microscope objective of the present embodiment, including: radius, thickness, refractive index of the material, and abbe number. The microscope objective lens of the present embodiment includes 15 lenses, and the object-side surface of the first lens 1 from the image side is S1, and the image-side surface of the fifteenth lens 15, which is the last lens, is S24. Radius here refers to the radius of curvature of the lens surface and thickness refers to the on-axis distance from the current surface to the next surface, e.g., the thickness of surface S1 is the distance from S1 to S2, which may be the on-axis thickness of the medium or lens, or the on-axis air gap between them.

Surface number	Radius (mm)	Thickness (mm)	Refractive index Nd	Abbe number Vd
					S24	4.174	2.867	1.81	25.4
S23	6.716	1
					S22	73.682	0.8	1.81	39.6
S21	2.472	1.394
					S20	-1.923	1.598	1.61	44.3
S19	5.494	4.249	1.62	63.3
					S18	-4.668	0.284
S17	-12.583	1	1 70	55.5
					S16	8.024	2.818	1.54	74.7
S15	-8.902	0.1
					S14	11.077	1.02	1.72	50.2
S13	6.374	5.01	1.44	94.9
					S12	-6.559	3.002	1.72	50.2
S11	-20.347	0.1
					S10	22.562	5.001	1.44	94.9
S9	-8.549	1	1.64	42.4
					S8	11.04	6.88	1.44	94.9
S7	-11.651	0.1
					S6	28.372	3.998	1.57	63.1
S5	-17.515	0.1
					S4	6.525	3	1.44	94.9
S3	16.397	0.1
					S2	2.549	3.735	1.57	71.3
S1	Infinity	0.13	1.51	41.1

TABLE 2

Fig. 2 is a transverse aberration diagram of the 0 field of view of the microscope objective lens of the present embodiment, in which the abscissa PY, PX represents the normalized entrance pupil size, the ordinate represents the transverse aberration, the scale is ± 5 μm, the Y direction is the meridional direction, and the X direction is the sagittal direction. As can be seen from the figure, the microscope objective lens has better aberration balance and better imaging performance.

Fig. 3 is a 1-field transverse aberration diagram of the microscope objective lens of the present embodiment, wherein the scale is ± 5 μm, and as can be seen from the diagram, the curve is close to the transverse axis, and the microscope objective lens has better imaging performance.

Fig. 4 is a field curvature distortion diagram of the microscope objective lens of the present embodiment. The left graph is a field curvature graph in which the ordinate represents the field of view and the abscissa represents the field curvature in μm. The axial difference between the optimal focus point of the edge view field and the optimal focus point of the central view field is less than 2 lambda/NA ² The theoretical value meets the requirement of clear full-field and flat-field objective lens. In the figure, the ordinate is the normalized field of view, the abscissa represents the field curvature, with a maximum of 2 μm and a minimum of-2 μm. The distortion diagram is shown on the right, wherein the ordinate represents the field of view and the abscissa represents the distortion (percentage), and the distortion in the full field of view is less than 0.7%. In the figure, the ordinate is the normalized field of view and the abscissa represents the distortion, with a maximum of 1% and a minimum of-1%.

FIG. 5 is a graph showing the chromatic aberration of the microscope objective of the present embodiment, which is better for the correction of chromatic aberration of the full wavelength curve, and the difference between any two curves at each field is smaller than λ/NA ² 。

The numerical aperture of the objective lens of the bioluminescent microscope in this embodiment is large (NA = 1.45), and in some preferred embodiments may be greater than 1.5.

Example two

As shown in fig. 6 and table 1, the microscope objective lens of the present embodiment has the following parameters:

the focal length is 1.8mm, the working distance is 0.17mm, the numerical aperture is 1.5, the field range is 30mm, and the spectral range of the working waveband is 436 nm-656 nm.

In the present embodiment, the central field edge ray height reaches a maximum value between the sixth lens 6 of the first lens group T1 and the fifth cemented lens group G5 of the second lens group T2.

Table 3 lists relevant parameters for each lens in the microscope objective of this example, including: radius, thickness, refractive index of the material, and abbe number. The microscope objective lens of the present embodiment includes 18 lenses, where an object-side surface of the first lens 1 is S1, and an image-side surface of the last lens, i.e., the eighteenth lens 18, is S28. Radius here refers to the radius of curvature of the lens surface and thickness refers to the on-axis distance from the current surface to the next surface, e.g., the thickness of surface S1 is the distance from S1 to S2, which may be the on-axis thickness of the medium or lens, or the on-axis air gap between them.

TABLE 3

Fig. 7 is a transverse aberration diagram of the 0 field of view of the microscope objective lens of the present embodiment, in which abscissa PY, PX represents the normalized entrance pupil size, ordinate represents the transverse aberration, scale is ± 5 μm, Y direction is the meridional direction, and X direction is the sagittal direction. As can be seen from the figure, the microscope objective has better aberration balance and better imaging performance.

Fig. 8 is a 1-field transverse aberration diagram of the microscope objective lens of the present embodiment, where the scale is ± 5 μm, and it can be seen from the diagram that the curve is close to the transverse axis, the microscope objective lens has better imaging performance.

Fig. 9 is a field curvature distortion diagram of the microscope objective lens of the present embodiment. Wherein the left image is a field curvature image in which the ordinate represents the field of view and the abscissa represents the field curvature in μm. The axial difference between the optimal focus point of the edge view field and the optimal focus point of the central view field is less than 2 lambda/NA ² The theoretical value meets the requirement of clear full-field and reaches the requirement of a flat field objective. The ordinate in the figure is the normalized field of view; the abscissa represents the field curvature with a maximum value of 2 μm and a minimum value of-2 μm. The distortion diagram is shown on the right, in which the ordinate represents the field of view and the abscissa represents the distortion (percentage), and it can be seen that the distortion in the full field is less than 1%. In the figure, the ordinate is the normalized field of view and the abscissa represents the distortion, with a maximum of 1% and a minimum of-1%.

FIG. 10 is a chromatic aberration curve chart of the microscope objective lens of this embodiment, in which the chromatic aberration of the full-wavelength curve is corrected well, and the difference between any two curves at each field is smaller than λ/NA ² 。

The object space field of the objective lens of the bioluminescent microscope in the embodiment is large (0.13 mm), the numerical aperture is large (NA = 1.5), and in some better embodiments, the field of view can be larger than 0.13mm, and the numerical aperture can be larger than 1.5.

EXAMPLE III

As shown in fig. 11 and table 1, the microscope objective lens of the present embodiment has the following parameters:

the focal length is 1.81mm, the working distance is 0.15mm, the numerical aperture is 1.44, the field range is 30mm, and the spectral range of the working waveband is 400 nm-1000 nm.

In the present embodiment, the central field edge light height reaches a maximum value between the first cemented lens group G1 of the first lens group T1 and the fourth cemented lens group G4 of the second lens group T2.

Table 4 lists relevant parameters for each lens in the microscope objective of this example, including: radius, thickness, refractive index of the material, and abbe number. The microscope objective lens of this embodiment includes 16 lenses, and the object-side surface of the first lens 1 from the image side is S1, and the image-side surface of the last lens, i.e., the sixteenth lens 16, is S25. Radius here refers to the radius of curvature of the lens surface and thickness refers to the on-axis distance from the current surface to the next surface, e.g., the thickness of surface S1 is the distance from S1 to S2, which may be the on-axis thickness of the medium or lens, or the on-axis air gap between them.

TABLE 4

Fig. 12 is a transverse aberration diagram of the 0 field of view of the microscope objective lens of the present embodiment, in which abscissa PY, PX represents the normalized entrance pupil size, ordinate represents the transverse aberration, scale is ± 5 μm, Y direction is the meridional direction, and X direction is the sagittal direction. As can be seen from the figure, the microscope objective lens has better aberration balance and better imaging performance.

Fig. 13 is a transverse aberration diagram of the microscope objective lens of the present embodiment in the 1 field of view, the scale is ± 5 μm, and it can be seen from the diagram that the curve is close to the transverse axis, and the microscope objective lens has better imaging performance.

Fig. 14 is a field curvature distortion diagram of the microscope objective lens of the present embodiment. Wherein the left graph is a field curvature graph, the ordinate of which represents the field of view and the abscissa represents the field curvature in mum. The axial difference between the optimal focus point of the edge view field and the optimal focus point of the central view field is less than 2 lambda/NA ² The theoretical value meets the requirement of clear full-field and reaches the requirement of a flat field objective. The ordinate of the plot is the normalized field of view, the abscissa represents the field curvature with a maximum of 2 μm and a minimum of-2 μm. The distortion diagram is shown on the right, in which the ordinate represents the field of view and the abscissa represents the distortion (percentage), and it can be seen that the distortion in the full field of view is less than 1%. In the figure, the ordinate is the normalized field of view, and the abscissa represents the distortion, with a maximum of 1% and a minimum of-1%.

FIG. 15 is a chromatic aberration curve chart of the microscope objective lens of this embodiment, in which the chromatic aberration of the full-wavelength curve is corrected well, and the difference between any two curves at each field is smaller than λ/NA ² 。

The object space field of the objective lens of the bioluminescent microscope in the embodiment is large (0.15 mm), and the numerical aperture is large (NA-1.44).

Example four

As shown in fig. 16 and table 1, the microscope objective lens of the present embodiment has the following parameters:

the focal length is 1.8mm, the working distance is 0.14mm, the numerical aperture is 1.44, the field range is 30mm, and the spectral range of the working waveband is 400 nm-1000 nm.

In this embodiment, the central field edge light height reaches a maximum value between the third cemented lens group G3 of the first lens group T1 and the fifth cemented lens group G5 of the second lens group T2.

Table 5 lists relevant parameters for each lens in the microscope objective of this example, including: radius, thickness, refractive index of the material, and abbe number. The microscope objective lens of the present embodiment includes 17 lenses, where an object-side surface of the first lens 1 from the image side is S1, and an image-side surface of the seventeenth lens 17, which is the last lens, is S26. Radius here refers to the radius of curvature of the lens surface and thickness refers to the on-axis distance from the current surface to the next surface, e.g., the thickness of surface S1 is the distance from S1 to S2, which may be the on-axis thickness of the medium or lens, or the on-axis air gap between them.

TABLE 5

Fig. 17 is a transverse aberration diagram of the 0 field of view of the microscope objective lens of the present embodiment, in which abscissa PY, PX represents the normalized entrance pupil size, ordinate represents the transverse aberration, scale is ± 5 μm, Y direction is the meridional direction, and X direction is the sagittal direction. As can be seen from the figure, the microscope objective lens has better aberration balance and better imaging performance.

Fig. 18 is a 1-field transverse aberration diagram of the microscope objective lens of the present embodiment, where the scale is ± 5 μm, and it can be seen from the diagram that the curve is close to the transverse axis, the microscope objective lens has better imaging performance.

Fig. 19 is a field curvature distortion diagram of the microscope objective lens of the present embodiment. Wherein the left graph is a field curvature graph, the ordinate of which represents the field of view and the abscissa represents the field curvature in μm. The axial difference between the optimal focus point of the edge view field and the optimal focus point of the central view field is less than 2 lambda/NA ² The theoretical value meets the requirement of clear full-field and reaches the requirement of a flat field objective. In the figure, the ordinate is the normalized field of view, the abscissa represents the field curvature, with a maximum of 2 μm and a minimum of-2 μm. The distortion graph is shown on the right, wherein the ordinate represents the field of view and the abscissa represents the distortion (percentage), and the distortion of the full field of view is less than 1%. In the figure, the ordinate is the normalized field of view and the abscissa represents the distortion, with a maximum of 1% and a minimum of-1%.

FIG. 20 is a graph showing the chromatic aberration of the objective lens of the microscope of the present embodiment, which is better for the correction of chromatic aberration of the full-wavelength curve, and the difference between any two curves at each field is smaller than λ/NA ² 。

The numerical aperture of the objective lens of the bioluminescent microscope in this embodiment is large (NA = 1.44), and in some preferred embodiments may be greater than 1.5.

The above description is only for the preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A microscope objective, comprising: a first lens group (T1), a second lens group (T2) having positive refractive power, and a third lens group (T3) having negative refractive power, which are arranged in this order from the image side to the object side along the optical axis, wherein the first lens group (T1) has negative refractive power;

the first lens group (T1) at least comprises a single lens and a cemented lens group;

the second lens group (T2) at least comprises two cemented lens groups;

the third lens group (T3) includes at least two single lenses having positive refractive power.

2. Microscope objective according to claim 1, characterized in that the first lens group (T1) comprises, in order in the direction of the optical axis from the image side to the object side, a first lens (1), a second lens (2), a first cemented lens group (G1) and a second cemented lens group (G2),

the first lens (1) and the second cemented lens group (G2) have positive optical power;

the second lens (2) and the first cemented lens group (G1) have negative optical power.

3. A microscope objective according to claim 2, characterized in that the first cemented lens group (G1) consists of a third lens (3) and a fourth lens (4) cemented together, the third lens (3) having a negative optical power and the fourth lens (4) having a positive optical power;

the second cemented lens group (G2) is formed by cementing a fifth lens (5) and a sixth lens (6), wherein the fifth lens (5) has negative focal power, and the sixth lens (6) has positive focal power.

4. The microscope objective according to claim 2, characterized in that, in a direction of the optical axis from the image side to the object side, the first lens (1) is a convex-concave lens and the second lens (2) is a biconcave lens.

5. A microscope objective according to claim 2, characterized in that the second lens group (T2) comprises, in order in the direction of the optical axis from image side to object side, a third cemented lens group (G3) and a fourth cemented lens group (G4),

the third cemented lens group (G3) is formed by cementing a seventh lens (7), an eighth lens (8) and a ninth lens (9);

the fourth cemented lens group (G4) is formed by cementing a tenth lens (10), an eleventh lens (11) and a twelfth lens (12).

6. The microscope objective according to claim 5, characterized in that the seventh lens (7), the ninth lens (9) and the eleventh lens (11) have a negative optical power;

the eighth lens (8), the tenth lens (10), and the twelfth lens (12) have positive optical power.

7. Microscope objective according to claim 6, characterized in that the eighth lens (8), the tenth lens (10) and the twelfth lens (12) are of low-dispersion material.

8. The microscope objective lens according to claim 5, characterized in that the third lens group (T3) comprises, in order from the image side to the object side along the optical axis, a thirteenth lens (13), a fourteenth lens (14) and a fifteenth lens (15), the thirteenth lens (13), the fourteenth lens (14) and the fifteenth lens (15) having positive optical power.

9. Microscope objective according to claim 8, characterized in that the object side of the fourteenth lens (14) is concave;

the object side surface of the fifteenth lens (15) is a plane, and the image side surface of the fifteenth lens is a hyper-hemispherical surface.

10. A microscope objective according to claim 1, characterized in that the first lens group (T1) comprises, in order in the direction of the optical axis from the image side to the object side, a first cemented lens group (G1), a third lens (3), a second cemented lens group (G2) and a sixth lens (6),

the third lens (3) and the sixth lens (6) have negative optical power.

11. A microscope objective according to claim 10, characterized in that the first cemented lens group (G1) consists of a first lens (1) and a second lens (2) cemented together, the first lens (1) having a positive optical power and the second lens (2) having a negative optical power;

the second cemented lens group (G2) is formed by a fourth lens (4) and a fifth lens (5) in a cemented mode, the fourth lens (4) has negative focal power, and the fifth lens (5) has positive focal power.

12. Microscope objective according to claim 11, characterized in that the image side of the first lens element (1) is convex, the object side of the second lens element (2) is concave, the image side of the fourth lens element (4) is concave and the object side of the fifth lens element (5) is convex.

13. Microscope objective according to claim 10, characterized in that the second lens group (T2) comprises, in order in the direction of the optical axis from the image side to the object side, a third cemented lens group (G3), a fourth cemented lens group (G4) and a fifth cemented lens group (G5),

the third cemented lens group (G3) is formed by cementing a seventh lens (7) and an eighth lens (8);

the fourth cemented lens group (G4) is formed by cementing a ninth lens (9), a tenth lens (10) and an eleventh lens (11);

the fifth cemented lens group (G5) is formed by cementing a twelfth lens (12), a thirteenth lens (13) and a fourteenth lens (14).

14. The microscope objective according to claim 13, characterized in that the seventh lens (7), the twelfth lens (12) and the fourteenth lens (14) have a negative optical power;

the eighth lens (8) and the thirteenth lens (13) have positive optical power;

two of the ninth lens (9), the tenth lens (10) and the eleventh lens (11) have positive focal power, and one has negative focal power.

15. A microscope objective according to claim 14, characterized in that the lenses of the fourth cemented lens group (G4) having positive optical power and the thirteenth lens (13) both employ low-dispersion materials.

16. Microscope objective according to claim 13, characterized in that the eighth lens (8) is a biconvex lens and the image-side face of the seventh lens (7) is convex.

17. A microscope objective according to claim 13, characterized in that the third lens group (T3) comprises, in order in the direction of the optical axis from the image side to the object side, a fifteenth lens (15), a sixteenth lens (16) and a sixth cemented lens group (G6),

the sixth cemented lens group (G6) is formed by a seventeenth lens (17) and an eighteenth lens (18) through cementing.

18. The microscope objective according to claim 17, characterized in that the fifteenth lens (15), the sixteenth lens (16), the seventeenth lens (17) and the eighteenth lens (18) have a positive optical power.

19. The microscope objective lens according to claim 17, characterized in that the fifteenth lens (15) and the sixteenth lens (16) are biconvex lenses in a direction from the image side to the object side along the optical axis;

the seventeenth lens (17) is a hyper-hemispherical lens;

the eighteenth lens (18) is a plano-convex lens.

20. Microscope objective according to claim 1, characterized in that the first lens group (T1) comprises in order in the direction of the optical axis from the image side to the object side a first lens (1), a second lens (2) and a first cemented lens group (G1),

the first lens (1) has a positive optical power;

the second lens (2) has a negative focal power.

21. Microscope objective according to claim 20, characterized in that the first lens (1) is a convex-concave lens and the second lens (2) is a biconcave lens in a direction of the optical axis from the image side to the object side.

22. A microscope objective according to claim 20, characterized in that the first cemented lens group (G1) consists of a third lens (3) and a fourth lens (4) cemented together, the third lens (3) having a negative optical power and the fourth lens (4) having a positive optical power.

23. Microscope objective according to claim 22, characterized in that the image side of the third lens (3) is concave and the object side of the fourth lens (4) is convex.

24. Microscope objective according to claim 20, characterized in that the second lens group (T2) comprises, in order in the direction of the optical axis from the image side to the object side, a second cemented lens group (G2), a third cemented lens group (G3) and a fourth cemented lens group (G4),

the second cemented lens group (G2) is formed by cementing a fifth lens (5) and a sixth lens (6);

25. The microscope objective according to claim 24, characterized in that the fifth lens (5), the tenth lens (10) and the twelfth lens (12) have a negative optical power;

the sixth lens (6) and the eleventh lens (11) have positive optical power;

two lenses of the seventh lens (7), the eighth lens (8) and the ninth lens (9) have positive focal power, and one lens has negative focal power.

26. A microscope objective according to claim 25, characterized in that the lenses of the third cemented lens group (G3) having positive optical power and the eleventh lens (11) both employ low-dispersion materials.

27. The microscope objective according to claim 24, characterized in that the third lens group (T3) comprises, in order in the direction of the optical axis from the image side to the object side, a thirteenth lens (13), a fourteenth lens (14) and a fifth cemented lens group (G5),

the fifth cemented lens group (G5) is formed by a fifteenth lens (15) and a sixteenth lens (16) through cementing.

28. Microscope objective according to claim 27, characterized in that the thirteenth lens (13), the fourteenth lens (14), the fifteenth lens (15) and the sixteenth lens (16) have a positive optical power.

29. The microscope objective according to claim 27, characterized in that the thirteenth lens (13) and the fourteenth lens (14) are biconvex lenses in a direction of the optical axis from the image side to the object side;

the fifteenth lens (15) is a hyper-hemispherical lens;

the sixteenth lens (16) is a plano-convex lens.

30. Microscope objective according to claim 1, characterized in that the first lens group (T1) comprises, in order in the direction of the optical axis from the image side to the object side, a first lens element (1), a first cemented lens group (G1), a second cemented lens group (G2) and a third cemented lens group (G3),

the first lens (1) has a positive optical power.

31. The microscope objective according to claim 30, characterized in that the first lens (1) is a meniscus lens in a direction of the optical axis from the image side to the object side.

32. A microscope objective according to claim 30, characterized in that the first cemented lens group (G1) consists of a second lens (2) and a third lens (3) cemented together, the second lens (2) having a positive optical power and the third lens (3) having a negative optical power;

the second cemented lens group (G2) is formed by a fourth lens (4) and a fifth lens (5) in a cemented mode, the fourth lens (4) has negative focal power, and the fifth lens (5) has positive focal power;

the third cemented lens group (G3) is formed by a sixth lens (6) and a seventh lens (7) in a cemented mode, the sixth lens (6) has negative focal power, and the seventh lens (7) has positive focal power.

33. The microscope objective according to claim 32, characterized in that the image-side face of the second lens element (2) is convex, the object-side face of the third lens element (3) is concave, the image-side face of the fourth lens element (4) is concave, the object-side face of the fifth lens element (5) is convex, and the seventh lens element (7) is biconvex.

34. A microscope objective according to claim 30, characterized in that the second lens group (T2) comprises, in order in the direction of the optical axis from the image side to the object side, a fourth cemented lens group (G4) and a fifth cemented lens group (G5),

the fourth cemented lens group (G4) is formed by cementing an eighth lens (8), a ninth lens (9) and a tenth lens (10);

the fifth cemented lens group (G5) is formed by cementing an eleventh lens (11), a twelfth lens (12) and a thirteenth lens (13).

35. A microscope objective according to claim 34, characterized in that two of the eighth lens (8), the ninth lens (9) and the tenth lens (10) have a positive optical power and one has a negative optical power;

the eleventh lens (11) and the thirteenth lens (13) have negative optical power, and the twelfth lens (12) has positive optical power.

36. A microscope objective according to claim 35, characterized in that the lens of the fourth cemented lens group (G4) with positive optical power and the twelfth lens (12) both employ a low-dispersion material.

37. A microscope objective lens according to claim 34, characterized in that the third lens group (T3) comprises, in order from the image side to the object side along the optical axis, a fourteenth lens (14), a fifteenth lens (15) and a sixth cemented lens group (G6),

the sixth cemented lens group (G6) is formed by cementing a sixteenth lens (16) and a seventeenth lens (17).

38. The microscope objective according to claim 37, characterized in that the fourteenth lens (14), the fifteenth lens (15), the sixteenth lens (16) and the seventeenth lens (17) have a positive optical power.

39. The microscope objective according to claim 37, characterized in that the fourteenth lens (14) is a biconvex lens in a direction from the image side to the object side along the optical axis;

the fifteenth lens (15) is a convex-concave lens;

the sixteenth lens (16) is a hyper-hemispherical lens;

the seventeenth lens (17) is a plano-convex lens.

40. The microscope objective according to one of claims 1 to 39, characterized in that the object-side to rearmost distance D of the microscope objective and the focal length fobj of the microscope objective satisfy the conditional expression: 10< -D/fobj <40.

41. Microscope objective according to one of claims 1 to 39, characterized in that the focal length fobj of the microscope objective satisfies the conditional expression: fobj >1.5.

42. The microscope objective according to one of claims 1 to 39, characterized in that the objective numerical aperture NA of the microscope objective satisfies the conditional expression: 1-NA woven fabric was constructed in 1.52.

43. The microscope objective according to one of claims 1 to 39, characterized in that the lowest projection height H1 of the central field edge rays on the lens surface of the third lens group (T3), the projection height H3 of the central field edge rays on the last lens surface of the first lens group (T1) and the highest projection height H2 of the central field edge rays on the lens surface of the second lens group (T2) satisfy the following conditions:

0.1<|H1/H2|<1；

0.5<|H2/H3|<3。

44. the microscope objective according to one of claims 1 to 39, characterized in that the focal length fL1 of the first lens group (T1), the radius value RL1 of the image side surface of the first lens group (T1) and the focal length fobj of the microscope objective each satisfy the following conditional expressions:

3<|fL1/fobj|＜20；

1＜|RL1/fobj|＜7。

45. the microscope objective according to one of claims 1 to 39, characterized in that the focal length fT1 of the first lens group (T1) and the focal length fobj of the microscope objective satisfy the conditional expression: 0< | fT1/fobj | <20.

46. The microscope objective according to one of claims 1 to 39, characterized in that the focal length fT2 of the second lens group (T2) and the focal length fobj of the microscope objective satisfy the conditional expression: 0< | fT2/fobj | is less than 15.

47. The microscope objective according to one of claims 1 to 39, characterized in that the focal length fT3 of the third lens group (T3) and the focal length fobj of the microscope objective satisfy the conditional expression: 0< | fT3/fobj | is less than 2.5.