Microscope objective lens

Abstract

The microscope objective lens comprises a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group and a sixth lens group which are sequentially arranged from an image side to an object side, the second lens group has positive focal power; the third lens group has positive focal power; the microscope objective lens satisfies the following relational expression: 1.5 lt; h2 / H3lt; 5; 0.05 lt; 0.05 lt; h1 / H2lt; 1; wherein H1 represents the lowest projection height of the edge light of the central field of view on the surface of the lens in the third lens group; h2 represents the highest projection height of the edge light of the central field of view on the lens surface of the second lens group; and H3 represents the projection height of the central field-of-view edge light on the lens surface closest to the image space in the first lens group. The numerical aperture of the microscope objective lens can be up to 1.25, the number of fields of view can be up to 32, the band chromatic aberration correction range can be up to 380 nm to 1700 nm, and good fluorescence performance can be ensured.

Description

Technical Field

[0001] The present invention relates to the field of microscope technology, in particular to a microscope objective lens. Background Art

[0002] As the requirements for detail resolution and scanning imaging speed in the field of life sciences increase, microscope objectives tend to have wider fields of view and larger numerical apertures (NA). However, since living cells and living tissues are generally cultured in liquids and need to be observed in real time, microscope objectives are required to be able to achieve water immersion observation.

[0003] Currently available microscope objectives capable of water immersion observation usually have difficulty in achieving 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 ensure. Summary of the invention

[0004] Based on this, it is necessary to provide a microscope objective lens to address the problem that existing microscope objectives capable of water immersion observation have difficulty in achieving large numerical aperture apochromatism and ensuring good fluorescence performance.

[0005] A microscope objective lens, comprising:

[0006] A first lens group with negative optical power, the first lens group includes at least one single lens or 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;

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

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

[0009] The microscope objective lens satisfies the relationship:

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

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

[0012] Among them, H1 represents the lowest projection height of the edge light of the central field of view on the lens surface in the third lens group; H2 represents the highest projection height of the edge light of the central field of view on the lens surface of the second lens group; H3 represents the projection height of the edge light of the central field of view 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; and 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 value 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 embodiment, the second lens group includes a third cemented lens group with negative power, a fourth cemented lens group with positive power, and a fifth cemented lens group with positive 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 power, and the object side surface of the fifth lens is a convex surface; the sixth lens The 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.

[0032] In one embodiment, the microscope objective lens satisfies the relationship:

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

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

[0035] 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.

[0036] The above-mentioned microscope objective has a wide chromatic aberration correction band, which can cover the light in 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, 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 provided for a first example of the present application;

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

[0039] Figure 3 shows a lateral aberration diagram of 1 field of view of a microscope objective according to a first example of the present application;

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

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

[0042] Figure 6 A schematic plan view of a microscope objective 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 a field of view of a microscope objective according to a second example of the present application;

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

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

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

[0048] Fig.12 shows a 0-field lateral aberration diagram of a microscope objective lens according to a third example of the present application;

[0049] Fig.13 shows a lateral aberration diagram of a field of view of a microscope objective lens according to a third example of the present application;

[0050] Fig.14 shows a field curvature distortion diagram of a microscope objective according to a third example of the present application;

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

[0052] Figure numerals: 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-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0054] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0056] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in 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 a central 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 a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0059] Based on the problem that the existing microscope objective lens capable of water immersion observation is difficult to achieve large numerical aperture apochromatism and ensure good fluorescence performance, a microscope objective lens is provided. The numerical aperture of the microscope objective lens can reach up to 1.25, the field of view number can reach 32, the band chromatic aberration correction range can reach 380nm to 1700nm, and good fluorescence performance can be ensured.

[0060] For details, please refer to Figure 1 , Figure 6 and Fig.11, the microscope objective lens includes a first lens group, a second lens group, and a third lens group arranged in sequence from the image side to the object side. The first lens group has a negative optical power and includes at least one single lens or 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 both convex surfaces. The second lens group has a positive optical power and includes a single lens and a cemented lens group. The third lens group has a 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, and 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 relational expressions: 1.5 < |H2 / H3| < 5 and 0.05 < |H1 / H2| < 1. Wherein, H1 represents the lowest projection height of the marginal ray of the central field of view on the lens surface in the third lens group; H2 represents the highest projection height of the marginal ray of the central field of view on the lens surface in the second lens group; H3 represents the projection height of the marginal ray of the central field of view on the lens surface closest to the image side in the first lens group.

[0061] It can be understood that this microscope objective lens belongs to an infinity 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 is used to correct field curvature. By controlling the projection heights of the first lens group, the second lens group, and the third lens group within the above numerical values, the numerical aperture of this microscope objective lens can be increased.

[0062] The projection height of the light rays of this microscope objective lens reaches the maximum value 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 rays of this microscope objective lens reaches the maximum value between the second lens group and the third lens group.

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

[0064] In one of the embodiments, this microscope objective lens satisfies the relational expressions: 10 < D / fobj < 40, fobj > 4, and 1.00 < NA < 1.30. Wherein, D represents the distance from the object plane to the surface closest to the object side of this microscope objective lens; fobj represents the focal length of this microscope objective lens; NA represents the numerical aperture of the object side of this microscope objective lens.

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

[0066] 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; the microscope objective lens 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; and fobj represents the focal length of the microscope objective lens.

[0067] By setting it in this way, the curvature radius of the first lens near the image side in the first lens group is controlled, so that the first lens can be easier to process and the situation that special processing morphology causes difficulty in processing can be avoided. In addition, the processing yield can be improved and the sensitivity of the microscope objective lens can be reduced.

[0068] In one embodiment, 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.

[0069] With such arrangement, the overall negative focal length of the microscope objective and the height of the stretched light can be controlled by controlling the focal length of the first lens group.

[0070] Alternatively, if Figure 1 As shown, 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.

[0071] Alternatively, if Figure 6 and Fig.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, the second lens group is controlled to have a large focal length to reduce the optical focal length of the second lens group, so that the second lens group can focus on correcting chromatic aberration, thereby reducing the sensitivity of the microscope objective to chromatic aberration.

[0074] Alternatively, if Figure 1 , Figure 6 and Fig.11 As shown, in one embodiment, the second lens group includes a third cemented lens group with negative power, a fourth cemented lens group with positive power, and a fifth cemented lens group with positive 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 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] In this arrangement, by controlling the focal length of the third lens group, the overall positive focal power of the microscope objective lens can be controlled, thereby controlling the numerical aperture and working distance of the microscope objective lens.

[0077] Alternatively, if Figure 1 , Figure 6 and Fig.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 the microscope objective lens 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 fluorescent 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] 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.

[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 edge light of the central field of view on the lens surface in the third lens group G3; H2 represents the highest projection height of the edge light of the central field of view on the lens surface of the second lens group G2; H3 represents the projection height of the edge light of the central field of view 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 value of the image side surface of the first cemented lens group T1; and fobj represents the focal length of the microscope objective.

[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.

[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.

[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.

[0099] The microscope objective lens comprises a first lens group G1, a second lens group G2 and a third lens group G3. The first lens group G1 comprises a first cemented lens group T1 and a second cemented lens group T2. The first cemented lens group T1 is a double cemented lens group with positive focal power, comprising a first lens 1 and a second lens 2; the second cemented lens group T2 is a double cemented lens group with negative focal power, comprising a third lens 3 and a fourth lens 4. The second lens group G2 comprises 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 double cemented lens group with negative focal power, comprising a fifth lens 5 and a sixth lens 6; the fourth cemented lens group T4 is a triple cemented lens group with positive focal power, comprising a seventh lens 7, an eighth lens 8 and a ninth lens 9; the fifth cemented lens group T5 is a double cemented lens group with positive focal power, comprising 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 double 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 respectively concave and concave; 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 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 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 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 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 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 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] The system focal length of the microscope objective lens is 4.52 mm, the working distance is 0.3 mm, and the numerical aperture is 1.20. The first surface of the microscope objective lens from the first lens group G1 is S23, and the last surface of the third lens group G3 is S1. The parameters of each lens of the microscope eyepiece of the first example include surface, radius, refractive index Nd, and Abbe number Vd, as shown in Table 1 below.

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

[0103]

[0104]

[0105] Among them, the radius refers to the radius of curvature of the surface, and the thickness refers to the axial 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 axial thickness of the medium or lens, or the axial 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 of the first example, wherein the abscissas PY and PX represent the normalized entrance pupil size, the ordinate represents the lateral aberration, the scale is ±20μm, the Y direction is the meridian 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 1 field of view of the microscope objective lens of the first example. The scale is ±20μm. It can be seen from the figure that the curve is close to the horizontal axis and has good imaging performance.

[0108] like Figure 4 As shown, Figure 4 This is the field curvature distortion diagram of the microscope objective lens of the first example. The left figure is the field curvature diagram. The ordinate represents the field of view, and the abscissa 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 meets the requirements of full field of view clarity and flat field objective lens. The ordinate in the figure is the normalized field of view; the abscissa represents the field curvature, the maximum value is 50μm, and the minimum value is -50μm. The right figure is a distortion diagram, in which the ordinate represents the field of view, and the abscissa represents the distortion (percentage). It can be seen from the figure that the full field of view distortion is less than 1.5%. The ordinate in the figure is the normalized field of view, and the abscissa represents the distortion, the maximum is 2%, and the minimum is -2%.

[0109] like Figure 5 As shown, Figure 5 This is the chromatic aberration curve of the microscope objective lens of 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 of the first example is a semiconductor inspection microscope objective, the microscope objective 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 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 fluorescent 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] 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.

[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 edge light of the central field of view on the lens surface in the third lens group G3; H2 represents the highest projection height of the edge light of the central field of view on the lens surface of the second lens group G2; H3 represents the projection height of the edge light of the central field of view 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.

[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.

[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.

[0131] The microscope objective lens comprises a first lens group G1, a second lens group G2 and a third lens group G3. The first lens group G1 comprises a first cemented lens group T1 and a second cemented lens group T2. The first cemented lens group T1 is a double cemented lens group with positive focal power, comprising a first lens 1 and a second lens 2; the second cemented lens group T2 is a double cemented lens group with negative focal power, comprising a third lens 3 and a fourth lens 4. The second lens group G2 comprises 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 double cemented lens group with negative focal power, comprising a fifth lens 5 and a sixth lens 6; the fourth cemented lens group T4 is a triple cemented lens group with positive focal power, comprising a seventh lens 7, an eighth lens 8 and a ninth lens 9; the fifth cemented lens group T5 is a double cemented lens group with positive focal power, comprising 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 double 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 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 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 surfaces respectively.

[0133] The system focal length of the microscope objective lens is 4.50 mm, the working distance is 0.35 mm, the numerical aperture is 1.12, and the field of view is 26 mm. The first surface of the microscope objective lens 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 the second example include surface, radius, refractive index Nd, and Abbe number Vd, as shown in Table 2 below.

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

[0135]

[0136]

[0137] Among them, the radius refers to the radius of curvature of the surface, and the thickness refers to the axial 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 axial thickness of the medium or lens, or the axial 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 of the second example, wherein the abscissas PY and PX represent the normalized entrance pupil size, the ordinate represents the lateral aberration, the scale is ±20μm, the Y direction is the meridian direction, and the X direction is the sagittal direction. It can be seen from the figure that the aberration balance is good and has good imaging performance.

[0139] like Figure 8 As shown, Figure 8 This is the lateral aberration diagram of the 1 field of view of the microscope objective of the second example. The scale is ±20μm. It can be seen from the figure that the curve is close to the horizontal axis and has good imaging performance.

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

[0141] like Fig.10 As shown, Fig.10This is the chromatic aberration curve of the microscope objective lens of 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 of the second example is a semiconductor detection microscope objective, the microscope objective 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 can be extended to 900 nm to 1700 nm.

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

[0144] D / fobj=10.83;

[0145] Fobj=4.51;

[0146] NA=1.20;

[0147] 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.

[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 edge light of the central field of view on the lens surface in the third lens group G3; H2 represents the highest projection height of the edge light of the central field of view on the lens surface of the second lens group G2; H3 represents the projection height of the edge light of the central field of view 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.

[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.

[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.

[0162] The microscope objective lens comprises a first lens group G1, a second lens group G2 and a third lens group G3. The first lens group G1 comprises a first cemented lens group T1 and a second cemented lens group T2. The first cemented lens group T1 is a double cemented lens group with positive focal power, comprising a first lens 1 and a second lens 2; the second cemented lens group T2 is a double cemented lens group with negative focal power, comprising a third lens 3 and a fourth lens 4. The second lens group G2 comprises 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 double cemented lens group with negative focal power, comprising a fifth lens 5 and a sixth lens 6; the fourth cemented lens group T4 is a triple cemented lens group with positive focal power, comprising a seventh lens 7, an eighth lens 8 and a ninth lens 9; the fifth cemented lens group T5 is a double cemented lens group with positive focal power, comprising 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 double 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 respectively concave and concave; 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 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 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 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 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 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 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] The system focal length of the microscope objective lens is 4.51 mm, the working distance is 0.22 mm, the numerical aperture is 1.21, and the field of view is 32 mm. The first surface of the microscope objective lens 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 the third example include surface, radius, refractive index Nd, and Abbe number Vd, as 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] Among them, the radius refers to the radius of curvature of the surface, and the thickness refers to the axial 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 axial thickness of the medium or lens, or the axial air gap between them.

[0168] like Fig.12 As shown, Fig.12This is the lateral aberration diagram of the zero field of view of the microscope objective of the third example, wherein 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 meridian 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 Fig.13 As shown, Fig.13 This is the lateral aberration diagram of the 1 field of view of the microscope objective of the third example. The scale is ±20μm. It can be seen from the figure that the curve is close to the horizontal axis and has good imaging performance.

[0170] like Fig.14 As shown, Fig.14 This is the field curvature distortion diagram of the microscope objective lens of the third example. The left figure is the field curvature diagram. The ordinate represents the field of view, and the abscissa represents the field curvature, in 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 meets the requirements of full field of view clarity and flat field objective lens. The ordinate in the figure is the normalized field of view; the abscissa represents the field curvature, the maximum value is 50μm, and the minimum value is -50μm. The right figure is a distortion diagram, in which the ordinate represents the field of view, and the abscissa represents the distortion (percentage). It can be seen from the figure that the full field of view distortion is less than 0.3%. The ordinate in the figure is the normalized field of view, and the abscissa represents the distortion, the maximum is 0.5%, and the minimum is -0.5%.

[0171] like Fig.15 As shown, Fig.15 This is the chromatic aberration curve of the microscope objective 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 0.22 mm, 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-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A microscope objective lens, It is characterized in that The microscope objective lens includes: A first lens group with negative optical power, the first lens group includes at least one single lens or 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; a second lens group having positive optical power, wherein the second lens group comprises a single lens and a cemented lens group; as well as a third lens group with positive power, the third lens group comprising at least one combination of a single lens with positive power and a cemented lens group with positive power, and the lens of the third lens group closest to the object side is a single lens with positive power or a cemented lens group with 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 edge light of the central field of view on the lens surface in the third lens group; H2 represents the highest projection height of the edge light of the central field of view on the lens surface of the second lens group; H3 represents the projection height of the edge light of the central field of view on the lens surface closest to the image side in the first lens group.

2. The microscope objective lens according to claim 1, It is 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; and NA represents the numerical aperture of the microscope objective lens on the object side.

3. The microscope objective lens according to claim 1, It is 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 value 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, It is 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, It is 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, 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 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, It is 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, It is 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, It is characterized in that The second lens group includes a third cemented lens group with negative optical power, a fourth cemented lens group with positive optical power and a fifth cemented lens group with positive optical 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 optical power, and the object side surface of the fifth lens is a convex surface. The sixth lens has negative optical 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 respectively; 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 a convex surface.

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

10. The microscope objective according to claim 9, It is 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