CN215813537U - Microscope objective - Google Patents

Abstract

The utility model relates to a microscope objective lens, which comprises a first lens group (T1) with positive focal power, a second lens group (T2) with positive focal power and a third lens group (T3) with negative focal power, which are arranged in sequence from an object side to an image side along an optical axis, wherein the third lens group (T3) comprises a double-Gaussian structure consisting of two optical elements. The microscope objective lens has the advantages of large field of view number and large numerical aperture.

Description

Microscope objective

Technical Field

The utility model relates to the field of microscopes, in particular to a microscope objective.

Background

Due to the increasing requirements of life sciences and industrial fields for observation resolution and imaging speed, the trend of microscope objectives is also moving towards larger field of view and larger aperture (NA). However, while achieving apochromatic performance with a large numerical aperture, it is necessary to ensure that the fluorescence performance of the microscope objective is good and the structure has good processability, which plays an important role in the production of the microscope objective with a large numerical aperture.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a microscope objective.

In order to achieve the above object, the present invention provides a microscope objective lens, which comprises a first lens group having positive refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power, arranged in order from an object side to an image side along an optical axis, wherein the third lens group comprises a double-gauss structure composed of two optical elements.

According to an aspect of the present invention, the first lens group includes a first optical element, a second optical element, and a third optical element, and the second lens group includes a fourth optical element, a fifth optical element, and a sixth optical element, from an object side to an image side along an optical axis.

According to one aspect of the present invention, the first optical element is a cemented lens group having positive optical power;

the object side surface of the first optical element is a plane, and the image side surface of the first optical element is a hemispherical surface.

According to an aspect of the present invention, the first optical element is composed of a plano-convex lens on an object side and a hyper-hemispherical lens on an image side.

According to an aspect of the present invention, each of the second optical element and the third optical element is a lens having positive optical power.

According to an aspect of the utility model, the fourth optical element is a triplet;

the fifth optical element and the sixth optical element are double combined lenses, and focal powers are symmetrical;

the fourth, fifth, and sixth optical elements have shapes comprising a biconvex type.

According to one aspect of the present invention, the fourth optical element is composed of two positive power lenses and one negative power lens, and the materials of the two positive power lenses are both materials with abbe numbers larger than 70;

the fifth optical element is composed of a negative power lens positioned on the object side and a positive power lens positioned on the image side;

the sixth optical element is composed of a positive power lens on the object side and a negative power lens on the image side.

According to an aspect of the present invention, the third lens group includes a seventh cemented lens group and an eighth cemented lens group having positive and negative symmetry of optical power arranged in order from the object side along the optical axis;

the concave surfaces of the seventh cemented lens group and the eighth cemented lens group are opposite to each other to form a double-Gaussian structure;

the seventh cemented lens group and the eighth cemented lens group are double cemented lens groups respectively.

According to one aspect of the present invention, the seventh cemented lens group is composed of a positive power lens on the object side and a negative power lens on the image side;

the eighth cemented lens group consists of a negative power lens at the object side and a positive power lens at the image side.

According to an aspect of the utility model, the third lens group further includes a ninth optical element with positive refractive power located on the image side of the eighth cemented lens, and the ninth optical element is a single lens or a double cemented lens.

According to an aspect of the present invention, the third lens group further includes a tenth optical element of positive power or negative power on the seventh cemented lens group side;

the tenth optical element is a lens with a meniscus shape and a concave image side surface.

According to one aspect of the utility model, the distance D of the object plane to the rearmost side of the microscope objective and the focal length fobj of the microscope objective satisfy the following relationship: 10< D/fobj < 36.2;

the focal length fobj of the microscope objective satisfies the following condition: fobj > 1.7;

the objective numerical aperture NA of the microscope objective meets the following conditions: 1< NA < 1.5.

According to an aspect of the present invention, the projection height H2 of the central field edge ray on the last lens surface of the second lens group, the minimum projection height H1 of the central field edge ray on the lens surface of the third lens group, and the projection height H3 of the central field edge ray on the last lens surface of the first lens group satisfy the following relations: 0.1< | H2/H3| < 1.5; 0.1< | H1/H2| < 0.8.

According to an aspect of the present invention, a focal length fL1, a radius value RL1 of a surface of a side facing an object of the first lens group and a focal length fobj of the microscope objective lens satisfy the following relationship 1< | fL1/fobj |, respectively; l RL1/fobj | ═ infinity.

According to an aspect of the utility model, the combined focal length fT1 of the first lens group and the focal length fobj of the microscope objective lens satisfy the following relationship: 1< | fT1/fobj | < 30.

According to an aspect of the utility model, the combined focal length fT2 of the second lens group and the focal length fobj of the microscope objective lens satisfy the following relationship: 1< | fT2/fobj |;

according to an aspect of the utility model, the combined focal length fT3 of the third lens group and the focal length fobj of the microscope objective lens satisfy the following relationship: 0.1< | fT3/fobj |.

According to one aspect of the utility model, applied to bioluminescence observation, the number of fields of view is at most 30, and the applied band is 436-.

According to the scheme of the utility model, the first lens group consists of one double-lens combination and at least one single lens and is mainly used for improving the numerical aperture of an object space. The second lens group is composed of at least one cemented lens group and a single lens and is mainly used for eliminating chromatic aberration. The third lens group consists of a double-gauss structure and a single lens or a cemented lens group, so that the maximum field of view can reach 30, the maximum numerical aperture can reach 1.5, and the fluorescence performance of the wave band of 405nm to 1000nm is good.

Drawings

FIG. 1 schematically shows a configuration 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 utility model;

FIG. 3 schematically shows a 1-field transverse aberration diagram of a microscope objective lens according to a first embodiment of the utility model;

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

FIG. 5 schematically shows a chromatic aberration diagram of a microscope objective according to a first embodiment of the utility model;

FIG. 6 is a schematic diagram showing the 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 utility model;

FIG. 8 schematically shows a 1-field transverse aberration diagram of a microscope objective lens according to a second embodiment of the utility model;

FIG. 9 is a field curvature distortion plot schematically illustrating a microscope objective lens according to a second embodiment of the present invention;

FIG. 10 schematically shows a chromatic aberration diagram of a microscope objective according to a second embodiment of the utility model;

FIG. 11 is a schematic representation of the construction of a microscope objective lens according to a third embodiment of the utility model;

FIG. 12 schematically shows a 0-field transverse aberration diagram of a microscope objective lens according to a third embodiment of the utility model;

FIG. 13 schematically shows a 1-field transverse aberration diagram of a microscope objective lens according to a third embodiment of the utility model;

FIG. 14 schematically shows a field curvature distortion diagram of a microscope objective lens according to a third embodiment of the present invention;

FIG. 15 shows schematically a chromatic aberration diagram of a microscope objective according to a third embodiment of the utility model;

FIG. 16 is a schematic diagram showing the construction of a microscope objective lens according to a fourth embodiment of the present invention;

FIG. 17 schematically shows a 0-field transverse aberration diagram of a microscope objective lens according to a fourth embodiment of the utility model;

FIG. 18 schematically shows a 1-field transverse aberration diagram of a microscope objective lens according to a fourth embodiment of the utility model;

FIG. 19 schematically shows a field curvature distortion diagram of a microscope objective lens according to a fourth embodiment of the present invention;

FIG. 20 shows schematically a chromatic aberration diagram of a microscope objective according to a fourth embodiment of the utility model;

FIG. 21 is a schematic diagram showing the configuration of a microscope objective lens according to a fifth embodiment of the present invention;

FIG. 22 is a diagram schematically illustrating the transverse aberration of the 0 field of view of a microscope objective lens according to a fifth embodiment of the present invention;

FIG. 23 schematically shows a 1-field transverse aberration diagram of a microscope objective lens according to a fifth embodiment of the utility model;

FIG. 24 is a field curvature distortion plot schematically illustrating a microscope objective lens according to a fifth embodiment of the present invention;

FIG. 25 schematically shows a chromatic aberration plot of a microscope objective according to a fifth embodiment of the utility model;

FIG. 26 is a schematic diagram showing the configuration of a microscope objective lens according to a sixth embodiment of the present invention;

FIG. 27 is a schematic illustration of a transverse aberration diagram of the 0 field of view of a microscope objective lens according to a sixth embodiment of the present invention;

FIG. 28 is a schematic illustration of a 1-field transverse aberration diagram of a microscope objective lens according to a sixth embodiment of the present invention;

FIG. 29 is a field curvature distortion plot schematically illustrating a microscope objective lens according to a sixth embodiment of the present invention;

fig. 30 schematically shows a chromatic aberration diagram of a microscope objective lens according to a sixth embodiment of the present invention.

Detailed Description

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 utility model, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

In describing embodiments of the present invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship that is based on the orientation or positional relationship shown in the associated drawings, which is for convenience and simplicity of description only, and does not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus, the above-described terms should not be construed as limiting the present invention.

The present invention is described in detail below with reference to the drawings and the specific embodiments, which are not repeated herein, but the embodiments of the present invention are not limited to the following embodiments.

Referring to fig. 1, the microscope objective of the present invention belongs to an infinite conjugate objective, and during observation, a medium between an observation object and the objective may be air or liquid, and when the medium is air, the numerical aperture is less than 1, and when the medium is liquid, the numerical aperture may reach a maximum value. The microscope objective lens comprises a first lens group T1 with positive focal power, which is arranged in sequence from the object side to the image side along the optical axis and comprises at least one lens with positive focal power; a second lens group T2 with positive focal power, which includes at least one lens or a cemented lens group, wherein the cemented lens group is a double-cemented lens group or a multi-lens cemented lens group, and the shape of the cemented lens group can be a meniscus shape or a biconvex shape; and a third lens group T3 having a negative optical power.

From the object side to the image side along the optical axis, the first lens group T1 includes a first optical element G1, a second optical element G2, and a third optical element G3, and the second lens group T2 includes a fourth optical element G4, a fifth optical element G5, and a sixth optical element G6. In the present invention, the third lens group T3 includes a double-gauss structure composed of two optical elements.

In the present invention, the first optical element G1 is a cemented lens group having positive optical power. The object side surface of the first optical element G1 is a plane, and the image side surface is a hemisphere (or nearly a hemisphere). Specifically, the first optical element G1 is composed of a plano-convex lens on the object side and a hyper-hemispherical lens on the image side. The second optical element G2 and the third optical element G3 are each a lens or a cemented lens group, and both have positive optical power. That is, in the first lens group T1, the first optical element G1 is followed by at least one single lens or cemented lens group.

In the present invention, the fourth optical element G4 is a triple cemented lens set, and the fifth optical element G5 and the sixth optical element G6 are double cemented lens sets, and the focal powers of the two are symmetrical. The shapes of the fourth optical element G4, the fifth optical element G5, and the sixth optical element G6 include a biconvex type. The fourth optical element G4 is composed of two positive power lenses and one negative power lens, and the materials of the two positive power lenses are both materials with abbe numbers greater than 70. The fifth optical element G5 is composed of a negative power lens on the object side and a positive power lens on the image side. The sixth optical element G6 is composed of a positive power lens on the object side and a negative power lens on the image side.

In the present invention, the third lens group T3 includes at least two lens elements. Specifically, the third lens group T3 includes a seventh cemented lens group G7 and an eighth cemented lens group G8 with positive and negative power symmetry arranged in sequence from the object side along the optical axis, that is, the power of the two cemented lens groups is positive and negative, and the concave surfaces of the two cemented lens groups are opposite to each other, thereby forming a double gauss structure. The seventh cemented lens group G7 and the eighth cemented lens group G8 are each a double cemented lens group or a multiple cemented lens group. The seventh cemented lens group G7 may be composed of a positive power lens on the object side and a negative power lens on the image side. The eighth cemented lens group G8 may be composed of a negative power lens on the object side and a positive power lens on the image side.

In the present invention, the third lens group T3 further includes at least one optical element located on the image side of the eighth cemented lens group G8. In some embodiments, the optical element is a ninth optical element G9 with positive optical power, and the ninth optical element G9 is a lens or a double cemented lens.

In the present invention, the third lens group T3 further includes at least one optical element on the object side of the seventh cemented lens group G7, in some embodiments, the optical element is a tenth optical element G10 with positive or negative power, the tenth optical element G10 is a lens with a meniscus shape and a concave image-side surface, and in some embodiments, the optical power thereof may be negative.

In the utility model, the distance D from the object plane to the last surface of the microscope objective lens and the focal length fobj of the microscope objective lens satisfy the following relation: 10< D/fobj < 36.2. The focal length fobj of the microscope objective satisfies the following condition: fobj > 1.7. The numerical aperture NA of the object space of the microscope objective lens meets the following conditions: 1< NA < 1.5.

In the utility model, the projection height H2 of the central field edge light on the last lens surface of the second lens group T2, the minimum projection height H1 of the central field edge light on the lens surface of the third lens group T3, and the projection height H3 of the central field edge light on the last lens surface of the first lens group T1 respectively satisfy the following relations: 0.1< | H2/H3| < 1.5; 0.1< | H1/H2| < 0.8. The height of the light reaches a maximum between the last lens group of the first lens group T1 and the last lens group of the second lens group T2.

In the utility model, the focal length fL1 and the radius value RL1 of the surface facing the object side of the first lens group T1 respectively satisfy the following relation 1< | fL1/fobj |; l RL1/fobj | ═ infinity.

In the present invention, the combined focal length fT1 of the first lens group T1 and the focal length fobj of the microscope objective lens satisfy the following relationship: 1< | fT1/fobj | < 30. The combined focal length fT2 of the second lens group T2 and the focal length fobj of the microscope objective lens satisfy the following relationship: 1< | fT2/fobj |. The combined focal length fT3 of the third lens group T3 and the focal length fobj of the microscope objective lens satisfy the following relationship: 0.1< | fT3/fobj |.

In summary, the objective lens of the microscope of the present invention includes three lens groups, and the first lens group T1 is composed of a double cemented lens group and at least one single lens, and is used to increase the object numerical aperture. The second lens group T2 is composed of at least one cemented lens group and a single lens for eliminating chromatic aberration. The third lens group T3 is composed of a double gauss structure and a single lens or a cemented lens group. The microscope objective lens has the maximum field of view number of 30, the maximum numerical aperture of 1.5 and good fluorescence performance in a wave band of 405nm to 1000 nm. In addition, the working distance of the microscope objective can reach more than 0.17mm, of course, the working distance also comprises 0mm-0.17mm, and the working distance is the distance from the cover glass to the edge of the first group of lenses of the objective. The lens materials of the utility model require low near ultraviolet transmittance and good fluorescence performance. The number of the lenses is 16-18, which is the highest cost performance, and can be applied to biological fluorescence observation, the maximum field number can reach 30, the maximum numerical aperture can reach 1.5, apochromatism can be realized in an application wave band (436-. Of course, to further improve performance, lenses may also be added.

Hereinafter, the microscope objective lens of the present invention will be described in more detail by six embodiments, where the surfaces of the respective lenses are denoted by S1, S2, … and SN, and the cemented surface of the cemented lens group is referred to as one surface. In the following embodiments, the first lens group T1 is mainly used to provide optical power and reduce the numerical aperture for the rear portion; the second lens group T2 is mainly used for correcting chromatic aberration, and the third lens group T3 is mainly used for correcting curvature of field. The working distance of the fluorescence biomicroscope objective lens is 0.17 mm. The microscope objective has a working band (spectral range) of 400nm-1000nm, and in some embodiments, 436nm-1000nm, and has the best imaging effect in the 436-656nm band region, a field range of 26.5, and a numerical aperture of 1.3.

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

TABLE 1

First embodiment

Referring to fig. 1, in the present embodiment, the microscope objective lens is composed of 18 lenses, where the first lens surface is S1 from the object side, and the last lens surface is S28.

The first optical element G1 is a cemented lens group having positive refractive power and a plano-convex shape, and is composed of a first lens L1 whose lens on the object side is a plano-convex type and a second lens L2 whose lens on the image side is a super-hemispherical type. The second optical element G2 and the third optical element G3 are each a single lens having positive optical power, i.e., a third lens L3 and a fourth lens L4. The fourth optical element G4 is a triple cemented lens group, which is composed of two positive power lenses and one negative power lens, and is a fifth lens L5, a sixth lens L6 and a seventh lens L7, wherein the two positive power lenses may be made of the same or different materials, and are both low dispersion materials. The fifth optical element G5 is a double cemented lens assembly including an eighth lens L8 with negative power on the object side and a ninth lens L9 with positive power on the image side. The sixth optical element G6 is a double cemented lens assembly including a tenth lens element L10 with positive power at the object side and an eleventh lens element L11 with negative power at the image side, and the sixth optical element G6 and the fifth optical element G5 form two symmetrical double cemented lens assemblies. The tenth optical element G10 is a meniscus-shaped twelfth lens element L12, and has a concave image-side surface. The seventh cemented lens group G7 is a double cemented lens group including a thirteenth lens element L13 with positive power located on the object side and a fourteenth lens element L14 with negative power located on the image side. The eighth cemented lens group G8 is a double cemented lens group including a fifteenth lens element L15 with negative power at the object side and a sixteenth lens element L16 with positive power at the image side, and the eighth cemented lens group G8 and the seventh cemented lens group G7 form two symmetrical double cemented lens groups. The ninth optical element G9 is a double compound lens with positive optical power.

In this embodiment, the focal length of the system is 3mm, the working distance is 0.17mm, the numerical aperture is 1.3, and the parameters of the microscope objective lens, such as the lens thickness and the radius, are as shown in table 2 below:

TABLE 2

Where radius refers to the radius of curvature of a 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.

Fig. 2 is a transverse aberration diagram of the 0 field of view of the microscope objective lens according to the first embodiment, in which abscissa PY and PX represent normalized entrance pupil size, ordinate represents transverse aberration, scale is ± 5 μm, Y direction is a meridional direction, and X direction is a sagittal direction.

FIG. 3 is a 1-field transverse aberration diagram of the microscope objective lens of the first embodiment, wherein the scale is + -5 μm, and the curve is close to the horizontal axis, so that the microscope objective lens has better imaging performance.

Fig. 4 is a field curvature distortion diagram of the microscope objective lens of the first embodiment, the left diagram being a field curvature diagram 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/NA²The theoretical value meets the requirement of clear full-field and flat-field objective lens. The ordinate in the figure is the normalized field of view; the abscissa represents the field curvature with a maximum value of 10 μm and a minimum value of-10 μm. The distortion graph is shown on the right, wherein the ordinate represents the visual field, and the abscissa represents the distortion (percentage), and the distortion of the full visual field is less than 0.5%. In the figure, the ordinate is the normalized field of view and the abscissa represents the distortion, with a maximum of 0.5% and a minimum of-0.5%.

FIG. 5 shows a first embodimentThe chromatic aberration curve chart of the microscope objective has good chromatic aberration correction of full-wavelength curve, and the difference value of any two curves at each view field is less than lambda/NA²。

The bioluminescent microscope objective of the present embodiment has a large numerical aperture (NA ═ 1.3), which in some preferred embodiments can be greater than 1.5.

Second embodiment

Referring to fig. 6, in the present embodiment, the microscope objective lens is composed of 17 lenses, where the first lens surface from the object side is S1, and the last lens surface is S27.

The first optical element G1 is a cemented lens group having positive refractive power and a plano-convex shape, and is composed of a plano-convex first lens L1 on the object side and a super-hemispherical second lens L2 on the image side. The second optical element G2 and the third optical element G3 are both lenses of positive optical power, i.e., a third lens L3 and a fourth lens L4. The fourth optical element G4 is a triple cemented lens group, which is composed of two positive power lenses and one negative power lens, and is a fifth lens L5, a sixth lens L6 and a seventh lens L7, wherein the two positive power lenses may be made of the same or different materials, and are both low dispersion materials. The fifth optical element G5 is a double cemented lens assembly including an eighth lens L8 with negative power on the object side and a ninth lens L9 with positive power on the image side. The sixth optical element G6 is a double cemented lens assembly including a tenth lens element L10 with positive power at the object side and an eleventh lens element L11 with negative power at the image side, and the sixth optical element G6 and the fifth optical element G5 form two symmetrical double cemented lens assemblies. The tenth optical element G10 is a meniscus-shaped twelfth lens element L12, and has a concave image-side surface. The seventh cemented lens group G7 is a double-cemented lens group with negative refractive power, and is composed of a thirteenth lens element L13 with positive refractive power located on the object side and a fourteenth lens element L14 with negative refractive power located on the image side. The eighth cemented lens group G8 is a double-cemented lens group with positive refractive power, and is composed of a fifteenth lens element L15 with negative refractive power at the object side and a sixteenth lens element L16 with positive refractive power at the image side, and the eighth cemented lens group G8 and the seventh cemented lens group G7 constitute two symmetrical double-cemented lens groups. The ninth optical element G9 is a single lens of positive power, i.e., a seventeenth lens L17. In the present embodiment, the working distance of the microscope objective lens is 0.17mm, the spectral range is 436nm to 656nm, and the field range is 25.

In this embodiment, the focal length of the system is 3mm, the working distance is 0.17mm, the numerical aperture is 1.3, and the parameters of the microscope objective lens, such as the lens thickness and the radius, are as shown in table 3 below:

surface of	Radius (mm)	Thickness (mm)	Nd	Vd
					S27	-300	1.4	1.43	95
S26	-16.189	0.15
					S25	4.568	3.3	1.74	32.3
S24	35.125	1	1.60	65.4
					S23	2.125	2.7
S22	-2.894	1	1.74	32.3
					S21	45.369	3.8	1.43	95
S20	-4.985	0.15
					S19	-20.698	2.5	1.43	95
S18	-9.325	0.15
					S17	-29.254	1	1.43	95
S16	18.693	3.9	1.74	32.3
					S15	-17.742	0.15
S14	50.365	3.9	1.43	95
					S13	-10.351	1.2	1.52	64.1
S12	-76.328	0.15
					S11	13.475	5	1.43	95
S10	-10.954	1.2	1.61	44.3
					S9	12.581	6	1.43	95
S8	-29.343	0.15
					S7	105.984	2.3	1.43	95
S6	-29.656	0.15
					S5	15.147	2.6	1.43	95
S4	198.469	0.15
					S3	4.633	5.23	1.88	40.8
S2	2.067	0.7	1.52	64.1
					S1	Infinity	0.17

TABLE 3

Where radius refers to the radius of curvature of a 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.

Fig. 7 is a transverse aberration diagram of the 0 field of view of the microscope objective lens according to the second embodiment, in which abscissa PY and PX represent normalized entrance pupil size, ordinate represents transverse aberration, scale is ± 5 μm, Y direction is a meridional direction, and X direction is a sagittal direction.

FIG. 8 is a transverse aberration diagram of the field of view 1 of the microscope objective lens according to the second embodiment, wherein the scale is + -5 μm, and the horizontal axis is close to the curve visible from the diagram, so that the microscope objective lens has better imaging performance.

Fig. 9 is a field curvature distortion diagram of the microscope objective lens of the second embodiment, the left diagram being a field curvature diagram 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/NA²The theoretical value meets the requirement of clear full-field and flat-field objective lens. The ordinate in the figure is the normalized field of view; the abscissa represents the field curvature with a maximum value of 5 μm and a minimum value of-5 μm. The distortion graph is shown on the right, wherein the ordinate represents the visual field, and the abscissa represents the distortion (percentage), and the distortion of the full visual field is less than 0.2 percent. In the figure, the ordinate is the normalized field of view, and the abscissa represents the distortion, with a maximum of 0.2% and a minimum of-0.2%.

FIG. 10 is a chromatic aberration curve diagram of the microscope objective lens according to the second embodiment, in which the chromatic aberration is corrected well for the full wavelength curve, and any two objective lenses are arranged at each fieldCurve difference smaller than lambda/NA²。

The bioluminescent microscope objective lens of the embodiment has a large object space field (0.21mm) and a large numerical aperture (NA ═ 1.3), and in some preferred embodiments, the field of view can be larger than 0.5mm and the numerical aperture can be larger than 1.45.

Third embodiment

Referring to fig. 11, in the present embodiment, the microscope objective lens is composed of 16 lenses, and the first lens surface from the object side is S1, and the last lens surface is S25.

The first optical element G1 is a cemented lens group having positive refractive power and a plano-convex shape, and is composed of a plano-convex first lens L1 on the object side and a super-hemispherical second lens L2 on the image side. The second optical element G2 and the third optical element G3 are both lenses of positive optical power, i.e., a third lens L3 and a fourth lens L4. The fourth optical element G4 is a triple cemented lens group, which is composed of two positive power lenses and one negative power lens, and is a fifth lens L5, a sixth lens L6 and a seventh lens L7, wherein the two positive power lenses may be made of the same or different materials, and are both low dispersion materials. The fifth optical element G5 is a double cemented lens assembly including an eighth lens L8 with negative power on the object side and a ninth lens L9 with positive power on the image side. The sixth optical element G6 is a double cemented lens assembly including a tenth lens element L10 with positive power at the object side and an eleventh lens element L11 with negative power at the image side, and the sixth optical element G6 and the fifth optical element G5 form two symmetrical double cemented lens assemblies. The seventh cemented lens group G7 is a double cemented lens group including a twelfth lens element L12 with positive power located on the object side and a thirteenth lens element L13 with negative power located on the image side. The eighth cemented lens group G8 is a double cemented lens group including a fourteenth lens element L14 with negative power at the object side and a fifteenth lens element L15 with positive power at the image side, and the eighth cemented lens group G8 and the seventh cemented lens group G7 form two symmetrical double cemented lens groups. The ninth optical element G9 is a single lens of positive optical power, i.e., a sixteenth lens L16.

In this embodiment, the system focal length f is 3mm, the working distance is 0.17mm, the numerical aperture is 1.3, and the parameters of the microscope objective lens, such as the lens thickness and radius, are shown in table 4 below:

TABLE 4

Where radius refers to the radius of curvature of a 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.

Fig. 12 is a transverse aberration diagram of the 0 field of view of the microscope objective lens according to the third embodiment, in which abscissa PY and PX represent normalized entrance pupil size, ordinate represents transverse aberration, scale is ± 5 μm, Y direction is a meridional direction, and X direction is a sagittal direction.

FIG. 13 is a 1-field transverse aberration diagram of a microscope objective lens according to a third embodiment, wherein a scale is + -5 μm, and a graph with a visible curve close to a transverse axis has a good imaging performance.

Fig. 14 is a field curvature distortion diagram of a microscope objective lens of the third embodiment, the left diagram being a field curvature diagram 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/NA²The theoretical value meets the requirement of clear full-field and flat-field objective lens. The ordinate in the figure is the normalized field of view; the abscissa represents the field curvature with a maximum value of 10 μm and a minimum value of-10 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. 15 is a chromatic aberration curve of a microscope objective lens of a third embodimentThe chromatic aberration of the full-wavelength curve is better corrected, and the difference value of any two curves at each view field is smaller than lambda/NA²。

The bioluminescent microscope objective lens of the embodiment has a large object space field (0.42mm) and a large numerical aperture (NA ═ 1.3), and in some preferred embodiments, the field of view can be larger than 0.5mm and the numerical aperture can be larger than 1.45.

Fourth embodiment

Referring to fig. 16, in the present embodiment, the microscope objective lens is composed of 17 lenses, and the first lens surface from the object side is S1, and the last lens surface is S27.

The first optical element G1 is a cemented lens group having positive refractive power and a plano-convex shape, and is composed of a plano-convex first lens L1 on the object side and a super-hemispherical second lens L2 on the image side. The second optical element G2 and the third optical element G3 are both lenses of positive optical power, i.e., a third lens L3 and a fourth lens L4. The fourth optical element G4 is a triple cemented lens group, which is composed of two positive power lenses and one negative power lens, and is a fifth lens L5, a sixth lens L6 and a seventh lens L7, wherein the two positive power lenses may be made of the same or different materials, and are both low dispersion materials. The fifth optical element G5 is a double cemented lens assembly including an eighth lens L8 with negative power on the object side and a ninth lens L9 with positive power on the image side. The sixth optical element G6 is a double cemented lens assembly including a tenth lens element L10 with positive power at the object side and an eleventh lens element L11 with negative power at the image side, and the sixth optical element G6 and the fifth optical element G5 form two symmetrical double cemented lens assemblies. The tenth optical element G10 is a meniscus-shaped twelfth lens element L12, and has a concave image-side surface. The seventh cemented lens group G7 is a double cemented lens group including a thirteenth lens element L13 with positive power located on the object side and a fourteenth lens element L14 with negative power located on the image side. The eighth cemented lens group G8 is a double cemented lens group including a fifteenth lens element L15 with negative power at the object side and a sixteenth lens element L16 with positive power at the image side, and the eighth cemented lens group G8 and the seventh cemented lens group G7 form two symmetrical double cemented lens groups. The ninth optical element G9 is a seventeenth lens L17.

In this embodiment, the focal length of the system is 1.8mm, the working distance is 0.17mm, the numerical aperture is 1.45, and the parameters of the microscope objective lens, such as the lens thickness and the radius, are as shown in table 5 below:

surface of	Radius (mm)	Thickness (mm)	Nd	Vd
					S27	25.367	1.6	1.43	95
S26	-17.365	0.15
					S25	3.889	3	1.74	32.3
S24	-28.361	1	1.60	65.4
					S23	2.451	2.1
S22	-2.566	1.5	1.74	32.3
					S21	500	5.5	1.57	71.3
S20	-7.823	0.15
					S19	-16.121	2	1.43	95
S18	-7.254	0.15
					S17	-18.326	1	1.43	95
S16	6.187	5.7	1.74	32.3
					S15	-17.689	0.15
S14	33.521	1.2	1.43	95
					S13	-9.851	4.6	1.61	44.3
S12	-27.698	0.15
					S11	17.863	4	1.43	95
S10	-12.336	1.2	1.61	44.3
					S9	10.525	5.7	1.43	95
S8	-19.855	0.15
					S7	33.696	2	1.43	95
S6	-189.336	0.15
					S5	15.413	2.1	1.43	95
S4	-22.989	0.15
					S3	3.378	4.667	1.88	40.8
S2	2.055	0.588	1.52	64.1
					S1	Infinity	0.17

TABLE 5

Where radius refers to the radius of curvature of a 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.

Fig. 17 is a transverse aberration diagram of the 0 field of view of the microscope objective lens according to the fourth embodiment, in which abscissa PY and PX represent normalized entrance pupil size, ordinate represents transverse aberration, scale is ± 5 μm, Y direction is a meridional direction, and X direction is a sagittal direction.

FIG. 18 is a 1-field transverse aberration diagram of a microscope objective lens according to a fourth embodiment, wherein a scale is + -5 μm, and a graph showing a curve close to a transverse axis has a good imaging performance.

Fig. 19 is a field curvature distortion diagram of a microscope objective lens of the fourth embodiment, the left diagram being a field curvature diagram 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/NA²The theoretical value meets the requirement of clear full-field and flat-field objective lens. 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 graph is shown on the right, wherein the ordinate represents the visual field, and the abscissa represents the distortion (percentage), and the distortion of the full visual field is less than 0.5%. In the figure, the ordinate is the normalized field of view and the abscissa represents the distortion, with a maximum of 0.5% and a minimum of-0.5%.

FIG. 20 is a graph showing the chromatic aberration of the objective lens of the microscope according to the fourth 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/NA²。

The bioluminescent microscope objective of the present embodiment has a large numerical aperture (NA ═ 1.45), which in some preferred embodiments can be greater than 1.5.

Fifth embodiment

Referring to fig. 21, in the present embodiment, the microscope objective lens is composed of 16 lenses, and the first lens surface from the object side is S1, and the last lens surface is S25.

The first optical element G1 is a cemented lens group having positive refractive power and a plano-convex shape, and is composed of a plano-convex first lens L1 on the object side and a super-hemispherical second lens L2 on the image side. The second optical element G2 and the third optical element G3 are both lenses of positive optical power, i.e., a third lens L3 and a fourth lens L4. The fourth optical element G4 is a triple cemented lens group, which is composed of two positive power lenses and one negative power lens, and is a fifth lens L5, a sixth lens L6 and a seventh lens L7, wherein the two positive power lenses may be made of the same or different materials, and are both low dispersion materials. The fifth optical element G5 is a double cemented lens assembly including an eighth lens L8 with negative power on the object side and a ninth lens L9 with positive power on the image side. The sixth optical element G6 is a double cemented lens assembly including a tenth lens element L10 with positive power at the object side and an eleventh lens element L11 with negative power at the image side, and the sixth optical element G6 and the fifth optical element G5 form two symmetrical double cemented lens assemblies. The seventh cemented lens group G7 is a double cemented lens group including a twelfth lens element L12 with positive power located on the object side and a thirteenth lens element L13 with negative power located on the image side. The eighth cemented lens group G8 is a double cemented lens group including a fourteenth lens element L14 with negative power at the object side and a fifteenth lens element L15 with positive power at the image side, and the eighth cemented lens group G8 and the seventh cemented lens group G7 form two symmetrical double cemented lens groups. The ninth optical element is a sixteenth lens L16.

In this embodiment, the focal length of the system is 1.8mm, the working distance is 0.17mm, the numerical aperture is 1.47, and the parameters of the microscope objective lens, such as the lens thickness and the radius, are as shown in table 6 below:

TABLE 6

Where radius refers to the radius of curvature of a 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.

Fig. 22 is a transverse aberration diagram of the 0 field of view of the microscope objective lens according to the fifth embodiment, in which abscissa PY and PX represent normalized entrance pupil size, ordinate represents transverse aberration, scale is ± 5 μm, Y direction is a meridional direction, and X direction is a sagittal direction.

FIG. 23 is a transverse aberration diagram of the field of view 1 of the microscope objective lens according to the fifth embodiment, wherein the scale is + -5 μm, and the horizontal axis is close to the curve visible from the diagram, so that the microscope objective lens has better imaging performance.

Fig. 24 is a field curvature distortion diagram of a microscope objective lens of the fifth embodiment, the left diagram being a field curvature diagram 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/NA²The theoretical value meets the requirement of clear full-field and flat-field objective lens. 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 graph is shown on the right, wherein the ordinate represents the visual field, and the abscissa represents the distortion (percentage), and the distortion of the full visual field is less than 0.2 percent. In the figure, the ordinate is the normalized field of view, and the abscissa represents the distortion, with a maximum of 0.2% and a minimum of-0.2%.

FIG. 25 is a chromatic aberration diagram of a microscope objective lens according to a fifth embodiment, in which the chromatic aberration of the full-wavelength curve is better corrected, and the difference between any two curves at each field is smaller than λ/NA²。

The bioluminescent microscope objective of the present embodiment has a large numerical aperture (NA ═ 1.47), which in some preferred embodiments can be greater than 1.5.

Sixth embodiment

Referring to fig. 26, in the present embodiment, the microscope objective lens is composed of 18 lenses, where the first lens surface from the object side is S1, and the last lens surface is S28.

The first optical element G1 is a cemented lens group having positive refractive power and a plano-convex shape, and is composed of a plano-convex first lens L1 on the object side and a super-hemispherical second lens L2 on the image side. The second optical element G2 and the third optical element G3 are both lenses of positive optical power, i.e., a third lens L3 and a fourth lens L4. The fourth optical element G4 is a triple cemented lens group, which is composed of two positive power lenses and one negative power lens, and is a fifth lens L5, a sixth lens L6 and a seventh lens L7, wherein the two positive power lenses may be made of the same or different materials, and are both low dispersion materials. The fifth optical element G5 is a double cemented lens assembly including an eighth lens L8 with negative power on the object side and a ninth lens L9 with positive power on the image side. The sixth optical element G6 is a double cemented lens assembly including a tenth lens element L10 with positive power at the object side and an eleventh lens element L11 with negative power at the image side, and the sixth optical element G6 and the fifth optical element G5 form two symmetrical double cemented lens assemblies. The tenth optical element G10 is a meniscus-shaped twelfth lens element L12, and has a concave image-side surface. The seventh cemented lens group G7 is a double cemented lens group including a thirteenth lens element L13 with positive power located on the object side and a fourteenth lens element L14 with negative power located on the image side. The eighth cemented lens group G8 is a double cemented lens group including a fifteenth lens element L15 with negative power at the object side and a sixteenth lens element L16 with positive power at the image side, and the eighth cemented lens group G8 and the seventh cemented lens group G7 form two symmetrical double cemented lens groups. The ninth optical element G9 is a double-cemented lens with positive refractive power, and is composed of a seventeenth lens L17 on the object side and an eighteenth lens L18 on the image side.

In this embodiment, the focal length of the system is 4.5mm, the working distance is 0.17mm, the numerical aperture is 1.21, and the parameters of the microscope objective lens, such as the lens thickness and the radius, are as shown in table 7 below:

TABLE 7

Where radius refers to the radius of curvature of a 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.

Fig. 27 is a transverse aberration diagram of the 0 field of view of the microscope objective lens according to the sixth embodiment, in which abscissa PY and PX represent normalized entrance pupil size, ordinate represents transverse aberration, scale is ± 5 μm, Y direction is a meridional direction, and X direction is a sagittal direction.

FIG. 28 is a transverse aberration diagram of the field of view 1 of the microscope objective lens according to the sixth embodiment, wherein the scale is + -5 μm, and the horizontal axis is followed by a graph showing good imaging performance.

Fig. 29 is a field curvature distortion diagram of a microscope objective lens of the sixth embodiment, the left diagram being a field curvature diagram 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/NA²The theoretical value meets the requirement of clear full-field and flat-field objective lens. The ordinate in the figure is the normalized field of view; the abscissa represents the field curvature with a maximum value of 10 μm and a minimum value of-10 μm. The distortion graph is shown on the right, wherein the ordinate represents the visual field, and the abscissa represents the distortion (percentage), and the distortion of the full visual field is less than 0.5%. In the figure, the ordinate is the normalized field of view and the abscissa represents the distortion, with a maximum of 0.5% and a minimum of-0.5%.

FIG. 30 is a chromatic aberration diagram of a microscope objective lens according to a sixth embodiment, in which the chromatic aberration of the full-wavelength curve is corrected well and two arbitrary fields are observed at each fieldThe difference value of the strip curve is less than lambda/NA²。

The bioluminescent microscope objective of the present embodiment has a large object field (object field 0.625mm), which may be greater than 0.65mm in some preferred embodiments.

The above description is only one embodiment of the present invention, and is not intended to limit the present invention, and it is apparent to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (18)

1. A microscope objective lens comprising, in order from an object side to an image side along an optical axis, a first lens group (T1) having a positive optical power, a second lens group (T2) having a positive optical power, and a third lens group (T3) having a negative optical power, characterized in that the third lens group (T3) comprises a double-gauss structure consisting of two optical elements.

2. The microscope objective according to claim 1, characterized in that the first lens group (T1) comprises a first optical element (G1), a second optical element (G2) and a third optical element (G3) along the optical axis from the object side to the image side, the second lens group (T2) comprising a fourth optical element (G4), a fifth optical element (G5) and a sixth optical element (G6).

3. A microscope objective according to claim 2, characterized in that the first optical element (G1) is a set of cemented lenses having positive optical power;

the object side surface of the first optical element (G1) is a plane, and the image side surface of the first optical element is a hemispherical surface.

4. The microscope objective according to claim 3, characterized in that the first optical element (G1) consists of a plano-convex lens on the object side and a hyper-hemispherical lens on the image side.

5. The microscope objective according to claim 2, characterized in that the second optical element (G2) and the third optical element (G3) are each a lens, each having a positive optical power.

6. A microscope objective according to claim 2, characterized in that the fourth optical element (G4) is a triplex cemented lens group;

the fifth optical element (G5) and the sixth optical element (G6) are double combined lenses, and the optical power is symmetrical;

the shapes of the fourth optical element (G4), the fifth optical element (G5), and the sixth optical element (G6) include a biconvex type.

7. The microscope objective according to claim 6, characterized in that the fourth optical element (G4) consists of two lenses of positive power and one lens of negative power, the materials of the two lenses of positive power both being materials with an Abbe number greater than 70;

the fifth optical element (G5) is composed of a negative power lens on the object side and a positive power lens on the image side;

the sixth optical element (G6) is composed of a positive power lens on the object side and a negative power lens on the image side.

8. The microscope objective according to claim 1, characterized in that the third lens group (T3) comprises a seventh and an eighth cemented lens group (G7, G8) of positive-negative symmetry of optical power, arranged in order from the object side along the optical axis;

the concave surfaces of the seventh cemented lens group (G7) and the eighth cemented lens group (G8) are opposite to each other to form a double Gaussian structure;

the seventh cemented lens group (G7) and the eighth cemented lens group (G8) are each double cemented lens groups.

9. The microscope objective according to claim 8, characterized in that the seventh cemented lens group (G7) consists of a positive-power lens on the object side and a negative-power lens on the image side;

the eighth cemented lens group (G8) is composed of a negative power lens on the object side and a positive power lens on the image side.

10. The microscope objective according to claim 8, characterized in that the third lens group (T3) further comprises a ninth optical element (G9) of positive optical power located on the image side of the eighth cemented lens group (G8), the ninth optical element (G9) being a lens or a double cemented lens.

11. The microscope objective according to claim 8, characterized in that the third lens group (T3) further comprises a tenth optical element (G10) of positive or negative power on the object side of the seventh cemented lens group (G7);

the tenth optical element (G10) is a lens with a meniscus shape and a concave image side surface.

12. Microscope objective according to claim 1, characterized in that the distance D of the object plane to the rearmost side of the microscope objective and the focal length fobj of the microscope objective satisfy the following relationship: 10< D/fobj < 36.2;

the focal length fobj of the microscope objective satisfies the following condition: fobj > 1.7;

the objective numerical aperture NA of the microscope objective meets the following conditions: 1< NA < 1.5.

13. The microscope objective according to claim 1, wherein the projection height H2 of the central field edge ray on the last lens surface of the second lens group (T2) and the minimum projection height H1 of the central field edge ray on the lens surface of the third lens group (T3) and the projection height H3 of the central field edge ray on the last lens surface of the first lens group (T1) satisfy the following relationships: 0.1< | H2/H3| < 1.5; 0.1< | H1/H2| < 0.8.

14. The microscope objective according to claim 1, characterized in that the focal length fL1, the value of the radius RL1 of the object-facing side surface of the first lens group (T1) and the focal length fobj of the microscope objective satisfy the following relationship 1< | fL1/fobj |; l RL1/fobj | ═ infinity.

15. The microscope objective according to claim 1, characterized in that the combined focal length fT1 of the first lens group (T1) and the focal length fobj of the microscope objective satisfy the following relationship: 1< | fT1/fobj | < 30.

16. The microscope objective according to claim 1, characterized in that the combined focal length fT2 of the second lens group (T2) and the focal length fobj of the microscope objective satisfy the following relationship: 1< | fT2/fobj |.

17. The microscope objective according to claim 1, characterized in that the combined focal length fT3 of the third lens group (T3) and the focal length fobj of the microscope objective satisfy the following relationship: 0.1< | fT3/fobj |.

18. Microscope objective according to claim 1, characterized in that for the bioluminescence observation the number of fields of view is at most 30 and the wavelength band is 436- "656 nm.

Images