Microscope objective

Abstract

The present application relates to a kind of microscope objective, which includes sequentially arranged from image side to object side: the first lens group with negative focal power;Second lens group with positive focal power and third lens group with positive focal power;The microscope objective satisfies the relationship formula: 1.5<|H2 / H3|<5;0.05<|H1 / H2|<1;Wherein, wherein, H1 represents the lowest projection height of central field edge light in the third lens group in the lens surface;H2 represents the highest projection height of central field edge light in the lens surface of the second lens group;H3 represents the projection height of central field edge light in the lens surface closest to image side in first lens group.The numerical aperture of the microscope objective can reach 1.25 at most, the field number can reach 32, the range of waveband chromatic aberration correction can reach 380nm-1700nm, and good fluorescence performance can be guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microscopy, in particular to a microscope objective. BACKGROUND

[0002] With the increasing demand for detail resolution and scanning imaging speed in the field of life science, microscope objectives tend to have wider field of view and larger numerical aperture (NA). Since living cells and tissues are generally cultured in liquid and need to be observed in real time, the microscope objective is required to be capable of realizing water immersion observation.

[0003] The existing microscope objectives capable of realizing water immersion observation are generally difficult to realize large numerical aperture apochromatism while ensuring good fluorescence performance of the microscope objective, and the machinability of the structure of the microscope objective is also difficult to guarantee. SUMMARY

[0004] Therefore, it is necessary to provide a microscope objective which can realize large numerical aperture apochromatism and good fluorescence performance at the same time.

[0005] A microscope objective, comprising, in order from the image side to the object side:

[0006] a first lens group with negative focal power, the first lens group comprising at least one single lens or cemented lens group with negative focal power, the object side surface of the lens closest to the object side in the first lens group and the image side surface of the lens closest to the image side being convex and convex respectively;

[0007] a second lens group with positive focal power, the second lens group comprising a single lens and a cemented lens group; and

[0008] a third lens group with positive focal power, the third lens group comprising at least one single lens with positive focal power and a combination of cemented lens groups with positive focal power, and the lens closest to the object side in the third lens group being a single lens with positive focal power or a cemented lens group with positive focal power;

[0009] The microscope objective satisfies the following relationship:

[0010] 1.5<|H2 / H3|<5;

[0011] 0.05<|H1 / H2|<1;

[0012] Among them, H1 represents the lowest projection height of the central field edge light on the lens surface in the third lens group; H2 represents the highest projection height of the central field edge light on the lens surface in the second lens group; H3 represents the projection height of the central field edge light on the lens surface closest to the image side in the first lens group.

[0013] In one embodiment, the microscope objective lens satisfies the relationship:

[0014] 10 <D / fobj<40;

[0015] fobj>4;

[0016] 1.00 <NA<1.30;

[0017] Wherein, D represents the distance from the object plane to the surface of the microscope objective lens closest to the object side; fobj represents the focal length of the microscope objective lens; NA represents the numerical aperture of the microscope objective lens on the object side.

[0018] In one embodiment, the lens closest to the image side in the first lens group is a single lens or a cemented lens group, and the object side surface and the image side surface of the lens closest to the image side in the first lens group are concave and convex respectively;

[0019] The microscope objective lens satisfies the relationship:

[0020] 40<|fL1 / fobj|<60;

[0021] 1<|RL1 / fobj|<3;

[0022] Wherein, fL1 represents the focal length of the lens closest to the image side in the first lens group; RL1 represents the radius of the image side surface of the lens closest to the image side in the first lens group; and fobj represents the focal length of the microscope objective lens.

[0023] In one embodiment, the microscope objective lens satisfies the relationship:

[0024] 5<|fT1 / fobj|<20;

[0025] Wherein, fT1 is the focal length of the first lens group, and fobj is the focal length of the microscope objective lens.

[0026] In one embodiment, the first lens group includes a first cemented lens group with positive optical focal length and a second cemented lens group with negative optical focal length, which are arranged in sequence from the image side to the object side. The first cemented lens group includes a first lens and a second lens, which are arranged in sequence from the image side to the object side, and the second cemented lens group includes a third lens and a fourth lens, which are arranged in sequence from the image side to the object side. The first lens has positive optical focal length, and the image side surface and the object side surface of the first lens are convex and concave respectively. The second lens has negative optical focal length, and the object side surface of the second lens is concave. The third lens has negative optical focal length, and the image side surface and the object side surface of the third lens are convex and concave respectively. The fourth lens has positive optical focal length, and the image side surface and the object side surface of the fourth lens are convex and convex respectively.

[0027] In one embodiment, the first lens group includes a first lens, a second lens and a second cemented lens group with negative optical power, which are arranged in sequence from the image side to the object side, and the second cemented lens group includes a third lens and a fourth lens; the first lens has positive optical power, and the image side surface and the object side surface of the first lens are convex and concave respectively; the second lens has negative optical power, and the object side surface of the second lens is concave; the third lens has negative optical power, and the image side surface and the object side surface of the third lens are convex and concave respectively; the fourth lens has positive optical power, and the image side surface and the object side surface of the fourth lens are convex and convex respectively.

[0028] In one embodiment, the microscope objective lens satisfies the relationship:

[0029] 20<|fT2 / fobj|<500;

[0030] Wherein, fT2 is the focal length of the second lens group, and fobj is the focal length of the microscope objective lens.

[0031] In one of the embodiments, the second lens group comprises, sequentially from the image side to the object side, a third cemented lens group with negative refractive power, a fourth cemented lens group with positive refractive power, and a fifth cemented lens group with positive refractive power, the third cemented lens group comprises, sequentially from the image side to the object side, a fifth lens and a sixth lens, the fourth cemented lens group comprises, sequentially from the image side to the object side, a seventh lens, an eighth lens, and a ninth lens, the fifth cemented lens group comprises, sequentially from the image side to the object side, a tenth lens and an eleventh lens, the fifth lens has positive refractive power, and the object side surface of the fifth lens is a convex surface; the sixth lens has negative refractive power, and the image side surface and the object side surface of the sixth lens are respectively a concave surface and a convex surface; the seventh lens has positive refractive power, and the image side surface and the object side surface of the seventh lens are respectively a convex surface and a convex surface; the eighth lens has negative refractive power, and the image side surface and the object side surface of the eighth lens are respectively a concave surface and a concave surface; the ninth lens has positive refractive power, and the image side surface and the object side surface of the ninth lens are respectively a convex surface and a convex surface; the tenth lens has negative refractive power, and the image side surface and the object side surface of the tenth lens are respectively a convex surface and a concave surface; and the eleventh lens has positive refractive power, and the image side surface of the eleventh lens is a convex surface.

[0032] In one of the embodiments, the microscope objective satisfies the relationship:

[0033] 1 < |fT3 / fobj| < 5;

[0034] wherein fT3 is the focal length of the third lens group, and fobj is the focal length of the microscope objective.

[0035] In one of the embodiments, the third lens group comprises, sequentially from the image side to the object side, a twelfth lens, a thirteenth lens, and a sixth cemented lens group with negative refractive power, the sixth cemented lens group comprises, sequentially from the image side to the object side, a fourteenth lens and a fifteenth lens, the twelfth lens has positive refractive power, and the image side surface and the object side surface of the twelfth lens are respectively a convex surface and a concave surface; the thirteenth lens has positive refractive power, and the image side surface and the object side surface of the thirteenth lens are respectively a convex surface and a concave surface; the fourteenth lens has negative refractive power, and the image side surface and the object side surface of the fourteenth lens are respectively a convex surface and a concave surface; and the fifteenth lens has positive refractive power, and the image side surface and the object side surface of the fifteenth lens are respectively a convex surface and a plane.

[0036] The above-mentioned microscope objective has a wide chromatic aberration correction band, which can cover the spectral range of 380nm to 800nm ​​and 800nm ​​to 1700nm, achieve better chromatic aberration correction, and meet a richer application environment; the microscope objective has a field of view greater than or equal to 32mm, which can obtain more effective information at the same time and reduce the scanning imaging time; the microscope objective has a numerical aperture greater than or equal to 1.25, and can complete 40X high-resolution scanning in a smaller space. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic plan view of a microscope objective lens provided for the first example of the present application;

[0038] Figure 2 shows a lateral aberration diagram of the zero field of view of the microscope objective lens according to the first example of the present application;

[0039] Figure 3 shows a lateral aberration diagram of one field of view of a microscope objective lens according to a first example of the present application;

[0040] Figure 4 shows a field curvature distortion diagram of a microscope objective lens according to a first example of the present application;

[0041] Figure 5 shows a chromatic aberration curve diagram of a microscope objective lens according to a first example of the present application;

[0042] Figure 6 A schematic plan view of a microscope objective lens provided for a second example of the present application;

[0043] Figure 7 shows a 0-field lateral aberration diagram of a microscope objective lens according to a second example of the present application;

[0044] Figure 8 shows a lateral aberration diagram of one field of view of a microscope objective lens according to a second example of the present application;

[0045] Figure 9 shows a field curvature distortion diagram of a microscope objective lens according to a second example of the present application;

[0046] Figure 10 shows a chromatic aberration curve diagram of a microscope objective lens according to a second example of the present application;

[0047] Figure 11 A schematic plan view of a microscope objective lens provided for a third example of the present application;

[0048] Figure 12 shows a lateral aberration diagram of zero field of view of a microscope objective lens according to a third example of the present application;

[0049] Figure 13 A 1 field lateral aberration map of the microscope objective according to the third example of the present application is shown;

[0050] Figure 14 A field curvature distortion map of the microscope objective according to the third example of the present application is shown;

[0051] Figure 15 A chromatic aberration curve of the microscope objective according to the third example of the present application is shown.

[0052] Reference signs: G1, first lens group; G2, second lens group; G3, third lens group; T1, first cemented lens group; T2, second cemented lens group; T3, third cemented lens group; T4, fourth cemented lens group; T5, fifth cemented lens group; T6, sixth cemented lens group; 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, fifth lens; 6, sixth lens; 7, seventh lens; 8, eighth lens; 9, ninth lens; 10, tenth lens; 11, eleventh lens; 12, twelfth lens; 13, thirteenth lens; 14, fourteenth lens; 15, fifteenth lens. DETAILED DESCRIPTION

[0053] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, to one skilled in the art that the present application can be practiced without using some or all of these specific details, and that the present application is not limited to the specific embodiments disclosed below.

[0054] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0056] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0057] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0058] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0059] Given that existing microscope objectives capable of water immersion observation struggle to achieve both high numerical aperture apochromatism and good fluorescence performance, a microscope objective is provided. This microscope objective boasts a maximum numerical aperture of 1.25, a field of view of 32, and a wavelength range of chromatic aberration correction from 380nm to 1700nm, ensuring excellent fluorescence performance.

[0060] For details, please refer to Figure 1 、 Figure 6 and Figure 11The microscope objective lens includes a first lens group, a second lens group, and a third lens group, which are arranged in sequence from the image side to the object side. The first lens group has negative optical power and includes at least one single lens or a cemented lens group with negative optical power. The object side surface of the lens closest to the object side and the image side surface of the lens closest to the image side in the first lens group are convex and convex, respectively. The second lens group has positive optical power and includes a single lens and a cemented lens group. The third lens group has positive optical power and includes a combination of at least one single lens with positive optical power and a cemented lens group with positive optical power. The lens closest to the object side in the third lens group is a single lens with positive optical power or a cemented lens group with positive optical power. The microscope objective lens satisfies the relationships: 1.5<|H2 / H3|<5 and 0.05<|H1 / H2|<1. Among them, H1 represents the lowest projection height of the central field edge light on the lens surface in the third lens group; H2 represents the highest projection height of the central field edge light on the lens surface in the second lens group; H3 represents the projection height of the central field edge light on the lens surface closest to the image side in the first lens group.

[0061] It is understood that this microscope objective lens is an infinite conjugate objective lens. The second lens group of this microscope objective lens can be used to correct chromatic aberration, and the third lens group of this microscope objective lens can provide a large numerical aperture and correct for field curvature. By controlling the projection heights of the first lens group, the second lens group, and the third lens group within the above-mentioned values, the numerical aperture of the microscope objective lens can be increased.

[0062] The projection height of the light from the microscope objective lens reaches its maximum between the lens closest to the object side in the second lens group and the lens closest to the image side in the third lens group. In other words, the projection height of the light from the microscope objective lens reaches its maximum between the second lens group and the third lens group.

[0063] The medium between the microscope objective and the observed object can be gas or liquid. When the medium is air, the numerical aperture of the microscope objective is less than 1. When the medium is liquid, the numerical aperture of the microscope objective can reach a maximum value.

[0064] In one embodiment, the microscope objective lens satisfies the relationship: 10 <D / fobj<40,fobj> 4 and 1.00 <NA<1.30。其中,D表示物面至该显微镜物镜最靠近物方的表面的距离;fobj表示该显微镜物镜的焦距;NA表示该显微镜物镜的物方的数值孔径。

[0065] When the numerical aperture of the microscope objective lens is greater than or equal to 1.25, 40X high-resolution scanning can be completed in a smaller space.

[0066] In one of the embodiments, the lens closest to the image side in the first lens group is a single lens or a cemented lens group, and the object side surface and the image side surface of the lens closest to the image side in the first lens group are concave and convex respectively; the microscope objective satisfies the relationship: 40<|fL1 / fobj|<60 and 1<|RL1 / fobj|<3; wherein, fL1 represents the focal length of the lens closest to the image side in the first lens group; RL1 represents the radius value of the image side surface of the lens closest to the image side in the first lens group; fobj represents the focal length of the microscope objective.

[0067] In this way, the curvature radius of the first lens close to the image side in the first lens group is controlled, so that the first lens is easier to process, and the situation that special processing features lead to difficult processing can be avoided. In addition, the processing yield can be improved, and the sensitivity of the microscope objective can be reduced.

[0068] In one of the embodiments, the microscope objective satisfies the relationship: 5<|fT1 / fobj|<20; wherein, fT1 is the focal length of the first lens group, and fobj is the focal length of the microscope objective.

[0069] In this way, by controlling the focal length of the first lens group, the overall negative focal length and the stretched light height of the microscope objective are controlled.

[0070] Optionally, as shown in Figure 1 In one of the embodiments, the first lens group comprises a first cemented lens group with positive focal length and a second cemented lens group with negative focal length arranged in order from the image side to the object side, the first cemented lens group comprises a first lens and a second lens arranged in order from the image side to the object side, and the second cemented lens group comprises a third lens and a fourth lens arranged in order from the image side to the object side; the first lens has positive focal length, and the image side surface and the object side surface of the first lens are convex and concave respectively; the second lens has negative focal length, and the object side surface of the second lens is concave; the third lens has negative focal length, and the image side surface and the object side surface of the third lens are convex and concave respectively; and the fourth lens has positive focal length, and the image side surface and the object side surface of the fourth lens are convex and convex respectively.

[0071] Optionally, as shown in Figure 6 and Figure 11As shown, in one embodiment, the first lens group includes a first lens, a second lens and a second cemented lens group with negative optical power which are arranged in sequence from the image side to the object side, and the second cemented lens group includes a third lens and a fourth lens; the first lens has positive optical power, and the image side surface and the object side surface of the first lens are convex and concave respectively; the second lens has negative optical power, and the object side surface of the second lens is concave; the third lens has negative optical power, and the image side surface and the object side surface of the third lens are convex and concave respectively; the fourth lens has positive optical power, and the image side surface and the object side surface of the fourth lens are convex and convex respectively.

[0072] In one embodiment, the microscope objective lens satisfies the relationship: 20<|fT2 / fobj|<500; wherein fT2 is the focal length of the second lens group, and fobj is the focal length of the microscope objective lens.

[0073] In this configuration, by controlling the second lens group to have a large focal length, the optical power borne by the second lens group is reduced, so that the second lens group is focused on correcting chromatic aberration, thereby reducing the sensitivity of the microscope objective lens to chromatic aberration.

[0074] Alternatively, as Figure 1 、 Figure 6 and Figure 11 As shown, in one embodiment, the second lens group includes a third cemented lens group with negative focal power, a fourth cemented lens group with positive focal power, and a fifth cemented lens group with positive focal power, which are sequentially arranged from the image side to the object side. The third cemented lens group includes a fifth lens and a sixth lens sequentially arranged from the image side to the object side. The fourth cemented lens group includes a seventh lens, an eighth lens, and a ninth lens sequentially arranged from the image side to the object side. The fifth cemented lens group includes a tenth lens and an eleventh lens sequentially arranged from the image side to the object side. The fifth lens has positive focal power, and the object side surface of the fifth lens is a convex surface. The sixth lens has negative focal power, and the image side surface and the object side surface of the sixth lens are concave and convex respectively; the seventh lens has positive focal power, and the image side surface and the object side surface of the seventh lens are convex and convex respectively; the eighth lens has negative focal power, and the image side surface and the object side surface of the eighth lens are concave and concave respectively; the ninth lens has positive focal power, and the image side surface and the object side surface of the ninth lens are convex and convex respectively; the tenth lens has negative focal power, and the image side surface and the object side surface of the tenth lens are convex and concave respectively; the eleventh lens has positive focal power, and the image side surface of the eleventh lens is convex.

[0075] In one embodiment, the microscope objective lens satisfies the relationship: 1<|fT3 / fobj|<5; wherein fT3 is the focal length of the third lens group, and fobj is the focal length of the microscope objective lens.

[0076] With such an arrangement, the focal length of the third lens group is controlled to control the overall positive focal power of the microscope objective lens, thereby controlling the numerical aperture and working distance of the microscope objective lens.

[0077] Alternatively, as Figure 1 、 Figure 6 and Figure 11 As shown, in one embodiment, the third lens group includes a twelfth lens, a thirteenth lens and a sixth cemented lens group with negative optical power, which are arranged in sequence from the image side to the object side. The sixth cemented lens group includes a fourteenth lens and a fifteenth lens, which are arranged in sequence from the image side to the object side. The twelfth lens has positive optical power, and the image side surface and the object side surface of the twelfth lens are convex and concave respectively; the thirteenth lens has positive optical power, and the image side surface and the object side surface of the thirteenth lens are convex and concave respectively; the fourteenth lens has negative optical power, and the image side surface and the object side surface of the fourteenth lens are convex and concave respectively; the fifteenth lens has positive optical power, and the image side surface and the object side surface of the fifteenth lens are convex and flat respectively.

[0078] Specific embodiments of microscope objective lenses applicable to the above-mentioned embodiments are further described below with reference to the accompanying drawings.

[0079] like Figure 1 As shown, the first example of the present application provides a microscope eyepiece. When the microscope objective is a fluorescence biological microscope objective, the spectral range of the microscope objective is 380nm to 1000nm, the field of view range is ≥30mm, and the maximum numerical aperture is 1.25.

[0080] This microscope objective has the following features:

[0081] D / fobj=10.91;

[0082] fobj=4.52;

[0083] NA=1.20;

[0084] Where D is the distance from the object plane to the surface of the microscope objective lens closest to the object side; fobj is the focal length of the microscope objective lens; and NA is the numerical aperture of the microscope objective lens on the object side.

[0085] The microscope objective lens satisfies the relationship:

[0086] |H2 / H3|=1.39;

[0087] |H1 / H2|=0.07;

[0088] Among them, H1 represents the lowest projection height of the central field edge light on the lens surface in the third lens group G3; H2 represents the highest projection height of the central field edge light on the lens surface in the second lens group G2; H3 represents the projection height of the central field edge light on the lens surface closest to the image side in the first lens group G1.

[0089] The microscope objective lens satisfies the relationship:

[0090] |fL1 / fobj|=17.7;

[0091] |RL1 / fobj|=1.97;

[0092] Wherein, fL1 represents the focal length of the first cemented lens group T1; RL1 represents the radius of the image side surface of the first cemented lens group T1; and fobj represents the focal length of the microscope objective lens.

[0093] |fT1 / fobj|=5.29;

[0094] Wherein, fT1 is the focal length of the first lens group G1, and fobj is the focal length of the microscope objective lens.

[0095] |fT2 / fobj|=5.77;

[0096] Wherein, fT2 is the focal length of the second lens group G2, and fobj is the focal length of the microscope objective lens.

[0097] |fT3 / fobj|=1.93;

[0098] Wherein, fT3 is the focal length of the third lens group G3, and fobj is the focal length of the microscope objective lens.

[0099] The microscope objective lens includes a first lens group G1, a second lens group G2, and a third lens group G3. The first lens group G1 includes a first cemented lens group T1 and a second cemented lens group T2. The first cemented lens group T1 is a doublet having positive focal power and includes a first lens 1 and a second lens 2. The second cemented lens group T2 is a doublet having negative focal power and includes a third lens 3 and a fourth lens 4. The second lens group G2 includes a third cemented lens group T3, a fourth cemented lens group T4, and a fifth cemented lens group T5. The third cemented lens group T3 is a doublet having negative focal power and includes a fifth lens 5 and a sixth lens 6. The fourth cemented lens group T4 is a triplet having positive focal power and includes a seventh lens 7, an eighth lens 8, and a ninth lens 9. The fifth cemented lens group T5 is a doublet having positive focal power and includes a tenth lens 10 and an eleventh lens 11. The third lens group G3 includes a twelfth lens 12 , a thirteenth lens 13 and a sixth cemented lens group T6 . The sixth cemented lens group T6 is a doublet-cemented lens group with negative optical power, and includes a fourteenth lens 14 and a fifteenth lens 15 .

[0100] The first lens 1 has positive focal power, and the image side surface and object side surface of the first lens 1 are convex and concave respectively; the second lens 2 has negative focal power, and the image side surface and object side surface of the second lens 2 are convex and concave respectively; the third lens 3 has negative focal power, and the image side surface and object side surface of the third lens 3 are convex and concave respectively; the fourth lens 4 has positive focal power, and the image side surface and object side surface of the fourth lens 4 are convex and convex respectively; the fifth lens 5 has positive focal power, and the image side surface and object side surface of the fifth lens 5 are flat and convex respectively; the sixth lens 6 has negative focal power, and the image side surface and object side surface of the sixth lens 6 are concave and convex respectively; the seventh lens 7 has positive focal power, and the image side surface and object side surface of the seventh lens 7 are convex and convex respectively; the eighth lens 8 has negative focal power, and the image side surface and object side surface of the eighth lens 8 are flat and convex respectively. concave and concave surfaces; the ninth lens 9 has positive focal power, and the image side surface and the object side surface of the ninth lens 9 are convex and convex surfaces respectively; the tenth lens 10 has negative focal power, and the image side surface and the object side surface of the tenth lens 10 are convex and concave surfaces respectively; the eleventh lens 11 has positive focal power, and the image side surface and the object side surface of the eleventh lens 11 are convex and convex surfaces respectively; the twelfth lens 12 has positive focal power, and the image side surface and the object side surface of the twelfth lens 12 are convex and concave surfaces respectively; the thirteenth lens 13 has positive focal power, and the image side surface and the object side surface of the thirteenth lens 13 are convex and concave surfaces respectively; the fourteenth lens 14 has negative focal power, and the image side surface and the object side surface of the fourteenth lens 14 are convex and concave surfaces respectively; the fifteenth lens 15 has positive focal power, and the image side surface and the object side surface of the fifteenth lens 15 are convex and flat respectively.

[0101] This microscope objective has a system focal length of 4.52 mm, a working distance of 0.3 mm, and a numerical aperture of 1.20. The first surface of the microscope objective, starting from the first lens group G1, is designated S23, and the last surface of the third lens group G3 is designated S1. The parameters of each lens of this first example microscope eyepiece, including surface, radius, refractive index Nd, and Abbe number Vd, are shown in Table 1 below.

[0102] Table 1: Lens parameter table of the microscope objective lens of the first example

[0103]

[0104]

[0105] Here, the radius refers to the radius of curvature of the surface, and the thickness refers to the on-axis distance from the current surface to the next surface. For example, the thickness of surface S23 is the distance from S23 to S22, which may be the on-axis thickness of the medium or lens, or the on-axis air gap between them.

[0106] like Figure 2 As shown, Figure 2 This is the lateral aberration diagram of the zero field of view of the microscope objective lens of the first example, where the horizontal coordinates PY and PX represent the normalized entrance pupil size, the vertical coordinate represents the lateral aberration, the scale is ±20μm, the Y direction is the meridional direction, and the X direction is the sagittal direction. It can be seen from the figure that the aberration is well balanced and has good imaging performance.

[0107] like Figure 3 As shown, Figure 3 This is the lateral aberration diagram of the microscope objective lens in the first example for one field of view. The scale is ±20 μm. It can be seen from the figure that the curve is close to the horizontal axis, which has good imaging performance.

[0108] like Figure 4 As shown, Figure 4 This is the field curvature distortion diagram of the microscope objective lens in the first example. The left figure is the field curvature diagram. The vertical axis represents the field of view and the horizontal axis represents the field curvature. The unit is mm. The axial difference between the best focus point at the edge of the field of view and the best focus point at the center of the field of view is less than 2λ / NA 2 The theoretical value satisfies the full field of view clarity and meets the requirements of a flat-field objective. The ordinate in the figure represents the normalized field of view; the abscissa represents the field curvature, with a maximum value of 50μm and a minimum of -50μm. The figure on the right is a distortion diagram, with the ordinate representing the field of view and the abscissa representing the distortion (percentage). As can be seen from the figure, the full field of view distortion is less than 1.5%. The ordinate in the figure represents the normalized field of view, and the abscissa represents the distortion, with a maximum of 2% and a minimum of -2%.

[0109] like Figure 5 As shown, Figure 5 This is the chromatic aberration curve of the microscope objective lens in the first example. The full wavelength curve chromatic aberration correction is good, and the difference between any two curves in each field of view is less than 2λ / NA 2 .

[0110] When the microscope objective lens of the first example is a semiconductor detection microscope objective lens, the microscope objective lens has a large numerical aperture of 1.25, a sufficient working distance of 0.3 mm and a field of view of 30 mm. At 45 mm parfocality, in some embodiments, the microscope objective lens can achieve a working distance of 0.4 mm and a field of view of 32 mm.

[0111] like Figure 6 As shown, the second example of the present application provides a microscope eyepiece. When the microscope objective is a fluorescence biological microscope objective, the spectral range of the microscope objective is 380nm to 800nm, the field of view is 30mm, and the numerical aperture is 1.12.

[0112] This microscope objective has the following features:

[0113] D / fobj=10.41;

[0114] fobj=4.5;

[0115] NA=1.12;

[0116] Where D is the distance from the object plane to the surface of the microscope objective lens closest to the object side; fobj is the focal length of the microscope objective lens; and NA is the numerical aperture of the microscope objective lens on the object side.

[0117] The microscope objective lens satisfies the relationship:

[0118] |H2 / H3|=1.43;

[0119] |H1 / H2|=13.57;

[0120] Among them, H1 represents the lowest projection height of the central field edge light on the lens surface in the third lens group G3; H2 represents the highest projection height of the central field edge light on the lens surface in the second lens group G2; H3 represents the projection height of the central field edge light on the lens surface closest to the image side in the first lens group G1.

[0121] The microscope objective lens satisfies the relationship:

[0122] |fL1 / fobj|=2.76;

[0123] |RL1 / fobj|=1.61;

[0124] Wherein, fL1 represents the focal length of the first lens 1; RL1 represents the radius value of the image side surface of the first lens 1; and fobj represents the focal length of the microscope objective lens.

[0125] |fT1 / fobj|=13.15;

[0126] Wherein, fT1 is the focal length of the first lens group G1, and fobj is the focal length of the microscope objective lens.

[0127] |fT2 / fobj|=9.87;

[0128] Wherein, fT2 is the focal length of the second lens group G2, and fobj is the focal length of the microscope objective lens.

[0129] |fT3 / fobj|=1.33;

[0130] Wherein, fT3 is the focal length of the third lens group G3, and fobj is the focal length of the microscope objective lens.

[0131] The microscope objective lens includes a first lens group G1, a second lens group G2, and a third lens group G3. The first lens group G1 includes a first cemented lens group T1 and a second cemented lens group T2. The first cemented lens group T1 is a doublet having positive focal power and includes a first lens 1 and a second lens 2. The second cemented lens group T2 is a doublet having negative focal power and includes a third lens 3 and a fourth lens 4. The second lens group G2 includes a third cemented lens group T3, a fourth cemented lens group T4, and a fifth cemented lens group T5. The third cemented lens group T3 is a doublet having negative focal power and includes a fifth lens 5 and a sixth lens 6. The fourth cemented lens group T4 is a triplet having positive focal power and includes a seventh lens 7, an eighth lens 8, and a ninth lens 9. The fifth cemented lens group T5 is a doublet having positive focal power and includes a tenth lens 10 and an eleventh lens 11. The third lens group G3 includes a twelfth lens 12 , a thirteenth lens 13 and a sixth cemented lens group T6 . The sixth cemented lens group T6 is a doublet-cemented lens group with negative optical power, and includes a fourteenth lens 14 and a fifteenth lens 15 .

[0132] The first lens 1 has positive focal power, and the image side surface and object side surface of the first lens 1 are convex and concave respectively; the second lens 2 has negative focal power, and the image side surface and object side surface of the second lens 2 are concave and concave respectively; the third lens 3 has negative focal power, and the image side surface and object side surface of the third lens 3 are convex and concave respectively; the fourth lens 4 has positive focal power, and the image side surface and object side surface of the fourth lens 4 are convex and convex respectively; the fifth lens 5 has positive focal power, and the image side surface and object side surface of the fifth lens 5 are convex and convex respectively; the sixth lens 6 has negative focal power, and the image side surface and object side surface of the sixth lens 6 are concave and convex respectively; the seventh lens 7 has positive focal power, and the image side surface and object side surface of the seventh lens 7 are convex and convex respectively; the eighth lens 8 has negative focal power, and the image side surface and object side surface of the eighth lens 8 are concave and concave surfaces; the ninth lens 9 has positive focal power, and the image side surface and the object side surface of the ninth lens 9 are convex and convex surfaces respectively; the tenth lens 10 has negative focal power, and the image side surface and the object side surface of the tenth lens 10 are convex and concave surfaces respectively; the eleventh lens 11 has positive focal power, and the image side surface and the object side surface of the eleventh lens 11 are convex and concave surfaces respectively; the twelfth lens 12 has positive focal power, and the image side surface and the object side surface of the twelfth lens 12 are convex and concave surfaces respectively; the thirteenth lens 13 has positive focal power, and the image side surface and the object side surface of the thirteenth lens 13 are convex and concave surfaces respectively; the fourteenth lens 14 has negative focal power, and the image side surface and the object side surface of the fourteenth lens 14 are convex and concave surfaces respectively; the fifteenth lens 15 has positive focal power, and the image side surface and the object side surface of the fifteenth lens 15 are convex and flat respectively.

[0133] This microscope objective has a system focal length of 4.50 mm, a working distance of 0.35 mm, a numerical aperture of 1.12, and a field of view of 26 mm. The first surface of the microscope objective, starting from the first lens group G1, is S24, and the last surface of the third lens group G3 is S1. The parameters of each lens of the microscope eyepiece of this second example, including surface, radius, refractive index Nd, and Abbe number Vd, are shown in Table 2 below.

[0134] Table 2: Lens parameter table of the microscope objective lens of the second example

[0135]

[0136]

[0137] Here, the radius refers to the radius of curvature of the surface, and the thickness refers to the on-axis distance from the current surface to the next surface. For example, the thickness of surface S24 is the distance from S24 to S23, which may be the on-axis thickness of the medium or lens, or the on-axis air gap between them.

[0138] like Figure 7 As shown, Figure 7 This is the lateral aberration diagram of the zero field of view of the microscope objective lens of the second example, where the horizontal coordinates PY and PX represent the normalized entrance pupil size, the vertical coordinate represents the lateral aberration, the scale is ±20μm, the Y direction is the meridional direction, and the X direction is the sagittal direction. It can be seen from the figure that the aberration is well balanced and has good imaging performance.

[0139] like Figure 8 As shown, Figure 8 This is the lateral aberration diagram of the microscope objective lens of the second example for one field of view. The scale is ±20 μm. It can be seen from the figure that the curve is close to the horizontal axis, which has good imaging performance.

[0140] like Figure 9 As shown, Figure 9 This is the field curvature distortion diagram of the microscope objective lens in the second example. The left figure is the field curvature diagram. The vertical axis represents the field of view, and the horizontal axis represents the field curvature, and the unit is mm. The axial difference between the best focus point at the edge of the field of view and the best focus point at the center of the field of view is less than 2λ / NA 2 The theoretical value satisfies the full field of view clarity and meets the requirements of a flat-field objective. The ordinate in the figure represents the normalized field of view; the abscissa represents the field curvature, with a maximum value of 10μm and a minimum of -10μm. The figure on the right is a distortion diagram, with the ordinate representing the field of view and the abscissa representing the distortion (percentage). As can be seen from the figure, the full field of view distortion is less than 0.7%. The ordinate in the figure represents the normalized field of view, and the abscissa represents the distortion, with a maximum of 1% and a minimum of -1%.

[0141] like Figure 10 As shown, Figure 10This is the chromatic aberration curve of the microscope objective lens in the second example. The full wavelength curve chromatic aberration correction is good, and the difference between any two curves in each field of view is less than 2λ / NA 2 .

[0142] When the microscope objective lens of the second example is a semiconductor detection microscope objective lens, the microscope objective lens has a long working distance of 0.35 mm and a wide working spectrum of 380 nm to 800 nm. In some embodiments, when the coating is adapted, the applicable working spectrum band of the microscope objective lens can be extended to 900 nm to 1700 nm.

[0143] like Figure 11 As shown, the third example of the present application provides a microscope eyepiece. When the microscope objective lens is a fluorescence biological microscope objective lens, the microscope objective lens has the following features:

[0144] D / fobj=10.83;

[0145] Fobj=4.51;

[0146] NA=1.20;

[0147] Where D is the distance from the object plane to the surface of the microscope objective lens closest to the object side; fobj is the focal length of the microscope objective lens; and NA is the numerical aperture of the microscope objective lens on the object side.

[0148] The microscope objective lens satisfies the relationship:

[0149] |H2 / H3|=1.58;

[0150] |H1 / H2|=0.075;

[0151] Among them, H1 represents the lowest projection height of the central field edge light on the lens surface in the third lens group G3; H2 represents the highest projection height of the central field edge light on the lens surface in the second lens group G2; H3 represents the projection height of the central field edge light on the lens surface closest to the image side in the first lens group G1.

[0152] The microscope objective lens satisfies the relationship:

[0153] |fL1 / fobj|=4.28;

[0154] |RL1 / fobj|=2.04;

[0155] Wherein, fL1 represents the focal length of the first lens 1; RL1 represents the radius value of the image side surface of the first lens 1; and fobj represents the focal length of the microscope objective lens.

[0156] |fT1 / fobj|=8.62;

[0157] Wherein, fT1 is the focal length of the first lens group G1, and fobj is the focal length of the microscope objective lens.

[0158] |fT2 / fobj|=5.16;

[0159] Wherein, fT2 is the focal length of the second lens group G2, and fobj is the focal length of the microscope objective lens.

[0160] |fT3 / fobj|=1.75;

[0161] Wherein, fT3 is the focal length of the third lens group G3, and fobj is the focal length of the microscope objective lens.

[0162] The microscope objective lens includes a first lens group G1, a second lens group G2, and a third lens group G3. The first lens group G1 includes a first cemented lens group T1 and a second cemented lens group T2. The first cemented lens group T1 is a doublet having positive focal power and includes a first lens 1 and a second lens 2. The second cemented lens group T2 is a doublet having negative focal power and includes a third lens 3 and a fourth lens 4. The second lens group G2 includes a third cemented lens group T3, a fourth cemented lens group T4, and a fifth cemented lens group T5. The third cemented lens group T3 is a doublet having negative focal power and includes a fifth lens 5 and a sixth lens 6. The fourth cemented lens group T4 is a triplet having positive focal power and includes a seventh lens 7, an eighth lens 8, and a ninth lens 9. The fifth cemented lens group T5 is a doublet having positive focal power and includes a tenth lens 10 and an eleventh lens 11. The third lens group G3 includes a twelfth lens 12 , a thirteenth lens 13 and a sixth cemented lens group T6 . The sixth cemented lens group T6 is a doublet-cemented lens group with negative optical power, and includes a fourteenth lens 14 and a fifteenth lens 15 .

[0163] The first lens 1 has positive focal power, and the image side surface and object side surface of the first lens 1 are convex and concave respectively; the second lens 2 has negative focal power, and the image side surface and object side surface of the second lens 2 are convex and concave respectively; the third lens 3 has negative focal power, and the image side surface and object side surface of the third lens 3 are convex and concave respectively; the fourth lens 4 has positive focal power, and the image side surface and object side surface of the fourth lens 4 are convex and convex respectively; the fifth lens 5 has positive focal power, and the image side surface and object side surface of the fifth lens 5 are convex and convex respectively; the sixth lens 6 has negative focal power, and the image side surface and object side surface of the sixth lens 6 are concave and convex respectively; the seventh lens 7 has positive focal power, and the image side surface and object side surface of the seventh lens 7 are convex and convex respectively; the eighth lens 8 has negative focal power, and the image side surface and object side surface of the eighth lens 8 are concave and concave surfaces; the ninth lens 9 has positive focal power, and the image side surface and the object side surface of the ninth lens 9 are convex and convex surfaces respectively; the tenth lens 10 has negative focal power, and the image side surface and the object side surface of the tenth lens 10 are convex and concave surfaces respectively; the eleventh lens 11 has positive focal power, and the image side surface and the object side surface of the eleventh lens 11 are convex and convex surfaces respectively; the twelfth lens 12 has positive focal power, and the image side surface and the object side surface of the twelfth lens 12 are convex and concave surfaces respectively; the thirteenth lens 13 has positive focal power, and the image side surface and the object side surface of the thirteenth lens 13 are convex and concave surfaces respectively; the fourteenth lens 14 has negative focal power, and the image side surface and the object side surface of the fourteenth lens 14 are convex and concave surfaces respectively; the fifteenth lens 15 has positive focal power, and the image side surface and the object side surface of the fifteenth lens 15 are convex and flat respectively.

[0164] This microscope objective has a system focal length of 4.51 mm, a working distance of 0.22 mm, a numerical aperture of 1.21, and a field of view of 32 mm. The first surface of the microscope objective, starting from the first lens group G1, is S24, and the last surface of the third lens group G3 is S1. The parameters of each lens of this third example microscope eyepiece, including surface, radius, refractive index Nd, and Abbe number Vd, are shown in Table 3 below.

[0165] Table 3: Lens parameter table of the microscope objective lens of the third example

[0166] surface Radius (mm) Thickness (mm) Refractive index Nd Abbe number Vd S24 9.220 2.401 1.75 35.3 S23 23.567 3.547 S22 59.441 0.09 1.62 63.3 S21 5.233 2.813 S20 -5.542 0.800 1.57 56.4 S19 30.1586 4.278 1.44 94.9 S18 -6.563 0.08 S17 24.320 4.11 1.44 94.9 S16 -7.823 0.800 1.72 50.2 S15 -119.959 0.102 S14 15.963 4.501 1.44 94.9 S13 -10.971 0.826 1.64 42.4 S12 21.436 3.60 1.44 94.9 S11 -20.139 3.126 S10 17.179 1.14 1.64 42.4 S9 10.449 5.351 1.44 94.9 S8 -23.403 0.101 S7 11.140 3.285 1.57 71.3 S6 34.685 0.1 S5 5.347 2.912 1.57 71.3 S4 7.531 0.111 S3 3.244 2.811 1.91 35 S2 0.752 0.79 1.52 64.1 S1 INF 0.22

[0167] Here, the radius refers to the radius of curvature of the surface, and the thickness refers to the on-axis distance from the current surface to the next surface. For example, the thickness of surface S24 is the distance from S24 to S23, which may be the on-axis thickness of the medium or lens, or the on-axis air gap between them.

[0168] like Figure 12 As shown, Figure 12This is the lateral aberration diagram of the zero field of view of the microscope objective lens of the third example, where the horizontal coordinates PY and PX represent the normalized entrance pupil size, the vertical coordinate represents the lateral aberration, the scale is ±20μm, the Y direction is the meridional direction, and the X direction is the sagittal direction. It can be seen from the figure that the aberration is well balanced and has good imaging performance.

[0169] like Figure 13 As shown, Figure 13 This is the lateral aberration diagram of the microscope objective lens of the third example for one field of view. The scale is ±20μm. It can be seen from the figure that the curve is close to the horizontal axis, which has good imaging performance.

[0170] like Figure 14 As shown, Figure 14 This is the field curvature distortion diagram of the microscope objective lens in the third example. The left figure is the field curvature diagram. The vertical axis represents the field of view, and the horizontal axis represents the field curvature, with the unit being μm. The axial difference between the best focus point at the edge of the field of view and the best focus point at the center of the field of view is less than 2λ / NA 2 The theoretical value satisfies the full field of view clarity and meets the requirements of a flat-field objective. The ordinate in the figure represents the normalized field of view; the abscissa represents the field curvature, with a maximum value of 50μm and a minimum of -50μm. The figure on the right is a distortion diagram, with the ordinate representing the field of view and the abscissa representing the distortion (percentage). As can be seen from the figure, the full field of view distortion is less than 0.3%. The ordinate in the figure represents the normalized field of view, and the abscissa represents the distortion, with a maximum of 0.5% and a minimum of -0.5%.

[0171] like Figure 15 As shown, Figure 15 This is the chromatic aberration curve of the microscope objective lens in the third example. The full wavelength curve chromatic aberration correction is good, and the difference between any two curves in each field of view is less than 2λ / NA 2 .

[0172] When the microscope objective lens of the third example is a semiconductor detection microscope objective lens, the microscope objective lens has a long working distance of 0.22mm, which can ensure the safety of the detection sample, a wide working spectrum of 900nm to 1700nm, which can be suitable for different detection scenarios, and an ultra-large field of view of 32mm, which can simultaneously observe a wider range and has near-infrared detection capabilities.

[0173] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0174] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A microscope objective lens, characterized in that: The microscope objective lens includes the following components arranged in sequence from the image side to the object side: a first lens group having negative optical power, the first lens group comprising at least one single lens or cemented lens group having negative optical power, wherein the object-side surface of the lens closest to the object side and the image-side surface of the lens closest to the image side in the first lens group are convex and convex, respectively; a second lens group having positive optical power, the second lens group comprising a single lens and a cemented lens group; as well as a third lens group having positive power, the third lens group comprising at least one combination of a single lens having positive power and a cemented lens group having positive power, wherein the lens element of the third lens group closest to the object side is a single lens having positive power or a cemented lens group having positive power; The microscope objective lens satisfies the relationship: 1.5<|H2 / H3|<5; 0.05<|H1 / H2|<1; Among them, H1 represents the lowest projection height of the central field edge light on the lens surface in the third lens group; H2 represents the highest projection height of the central field edge light on the lens surface in the second lens group; H3 represents the projection height of the central field edge light on the lens surface closest to the image side in the first lens group.

2. The microscope objective lens according to claim 1, characterized in that The microscope objective lens satisfies the relationship: 10 <D / fobj<40; fobj>4; 1.00 <NA<1.30; Wherein, D represents the distance from the object plane to the surface of the microscope objective lens closest to the object side; fobj represents the focal length of the microscope objective lens; NA represents the numerical aperture of the microscope objective lens on the object side.

3. The microscope objective lens according to claim 1, characterized in that The lens closest to the image side in the first lens group is a single lens or a cemented lens group, and the object-side surface and the image-side surface of the lens closest to the image side in the first lens group are concave and convex, respectively; The microscope objective lens satisfies the relationship: 40<|fL1 / fobj|<60; 1<|RL1 / fobj|<3; Wherein, fL1 represents the focal length of the lens closest to the image side in the first lens group; RL1 represents the radius of the image side surface of the lens closest to the image side in the first lens group; and fobj represents the focal length of the microscope objective lens.

4. The microscope objective according to any one of claims 1 to 3, characterized in that The microscope objective lens satisfies the relationship: 5<|fT1 / fobj|<20; Wherein, fT1 is the focal length of the first lens group, and fobj is the focal length of the microscope objective lens.

5. The microscope objective lens according to claim 4, characterized in that The first lens group includes a first cemented lens group with positive optical power and a second cemented lens group with negative optical power, which are arranged in sequence from the image side to the object side. The first cemented lens group includes a first lens and a second lens, which are arranged in sequence from the image side to the object side. The second cemented lens group includes a third lens and a fourth lens, which are arranged in sequence from the image side to the object side. The first lens has positive optical power, and the image side surface and the object side surface of the first lens are convex and concave respectively. The second lens has negative optical power, and the object side surface of the second lens is concave. The third lens has negative optical power, and the image side surface and the object side surface of the third lens are convex and concave respectively. The fourth lens has positive optical power, and the image side surface and the object side surface of the fourth lens are convex and convex respectively.

6. The microscope objective lens according to claim 4, characterized in that The first lens group includes a first lens, a second lens and a second cemented lens group with negative optical power, which are arranged in sequence from the image side to the object side, and the second cemented lens group includes a third lens and a fourth lens; the first lens has positive optical power, and the image side surface and the object side surface of the first lens are convex and concave respectively; the second lens has negative optical power, and the object side surface of the second lens is concave; the third lens has negative optical power, and the image side surface and the object side surface of the third lens are convex and concave respectively; the fourth lens has positive optical power, and the image side surface and the object side surface of the fourth lens are convex and convex respectively.

7. The microscope objective according to any one of claims 1 to 3, characterized in that The microscope objective lens satisfies the relationship: 20<|fT2 / fobj|<500; Wherein, fT2 is the focal length of the second lens group, and fobj is the focal length of the microscope objective lens.

8. The microscope objective lens according to claim 7, characterized in that The second lens group includes a third cemented lens group with negative focal power, a fourth cemented lens group with positive focal power, and a fifth cemented lens group with positive focal power, which are sequentially arranged from the image side to the object side. The third cemented lens group includes a fifth lens and a sixth lens sequentially arranged from the image side to the object side. The fourth cemented lens group includes a seventh lens, an eighth lens, and a ninth lens sequentially arranged from the image side to the object side. The fifth cemented lens group includes a tenth lens and an eleventh lens sequentially arranged from the image side to the object side. The fifth lens has positive focal power, and the object side surface of the fifth lens is convex. The sixth lens has negative focal power. The sixth lens has a concave surface and a convex surface on the image side and the object side surface of the sixth lens; the seventh lens has a positive focal power, and the image side surface and the object side surface of the seventh lens are convex and convex respectively; the eighth lens has a negative focal power, and the image side surface and the object side surface of the eighth lens are concave and concave respectively; the ninth lens has a positive focal power, and the image side surface and the object side surface of the ninth lens are convex and convex respectively; the tenth lens has a negative focal power, and the image side surface and the object side surface of the tenth lens are convex and concave respectively; the eleventh lens has a positive focal power, and the image side surface of the eleventh lens is convex.

9. The microscope objective according to any one of claims 1 to 3, characterized in that The microscope objective lens satisfies the relationship: 1<|fT3 / fobj|<5; Wherein, fT3 is the focal length of the third lens group, and fobj is the focal length of the microscope objective lens.

10. The microscope objective lens according to claim 9, characterized in that The third lens group includes a twelfth lens, a thirteenth lens and a sixth cemented lens group with negative optical power, which are arranged in sequence from the image side to the object side. The sixth cemented lens group includes a fourteenth lens and a fifteenth lens, which are arranged in sequence from the image side to the object side. The twelfth lens has positive optical power, and the image side surface and the object side surface of the twelfth lens are convex and concave respectively; the thirteenth lens has positive optical power, and the image side surface and the object side surface of the thirteenth lens are convex and concave respectively; the fourteenth lens has negative optical power, and the image side surface and the object side surface of the fourteenth lens are convex and concave respectively; the fifteenth lens has positive optical power, and the image side surface and the object side surface of the fifteenth lens are convex and flat respectively.

Images