Microscopy imaging system

Abstract

The present application relates to a kind of microscope imaging systems, including first lens group (C1) and second lens group (C2) sequentially arranged from object side to image side along optical axis, the first lens group (C1) at least includes a double cemented lens group, the second lens group (C2) only includes a double cemented lens group.The low power large field wide spectrum macroscopic observation of the present application has the characteristics of large numerical aperture, small distortion and the variety of observable sample, wide category.

Description

TECHNICAL FIELD

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

[0002] With the increasing requirements of life science and industrial field in observation resolution, imaging speed, large field of view observation and observation of special samples, the use wavelength and observation field of view of the microscope system are also required to be higher. However, the use wavelength of the microscope imaging system in the prior art is usually between 436nm-656nm, and there are few microscope imaging systems with a use wavelength of 400nm-1700nm. Moreover, the magnification is generally between 2X and 100X, and there are few objectives with a magnification below 2X. It can be seen that the prior art is difficult to meet the development needs of the microscope. SUMMARY

[0003] The present application relates to the field of microscopy, in particular to a microscope imaging system.

[0004] To achieve the above-mentioned purpose of the application, the present application provides a microscope imaging system, comprising a first lens group and a second lens group arranged in order along an optical axis from an object side to an image side, wherein the first lens group comprises at least one doublet lens group, and the second lens group comprises only one doublet lens group.

[0005] According to an aspect of the present application, the first lens group comprises a first optical element, which is a lens or a doublet lens group, and has a positive focal power or a negative focal power.

[0006] According to an aspect of the present application, when the first optical element is a doublet lens group, it is composed of a negative lens on the object side and a positive lens on the image side.

[0007] According to an aspect of the present application, the first lens group further comprises a second doublet lens group with a positive focal power.

[0008] According to an aspect of the present application, the second doublet lens group is composed of a negative lens and a positive lens.

[0009] According to an aspect of the present application, the first lens group has a positive focal power or a negative focal power.

[0010] According to an aspect of the present application, the first optical element and the second doublet lens group are concave-convex opposite.

[0011] According to an aspect of the present application, the second lens group comprises a third doublet lens group with a positive focal power.

[0012] The third doublet lens group is composed of a negative lens and a positive lens.

[0013] According to an aspect of the present application, the second cemented lens group and the third cemented lens group are convex to each other.

[0014] According to an aspect of the present application, the distance M from the object plane to the last surface of the microscope imaging system and the focal length fsys of the microscope imaging system satisfy the following relationship: 1 < M / fsys < 3.

[0015] The focal length fsys of the microscope imaging system satisfies the following condition: 100 < fsys < 200.

[0016] The object-side numerical aperture NA of the microscope imaging system satisfies the following condition: 0.01 < NA < 0.1.

[0017] According to an aspect of the present application, the projection height H2 of the central field edge ray on the lowest surface of the lens, the projection height H1 of the central field edge ray on the highest surface of the lens, and the projection height H3 of the central field edge ray on the last surface of the lens satisfy the following relationship: 0.15 < |H2 / H1| < 1; 0.1 < |H2 / H3| < 1.5.

[0018] According to an aspect of the present application, the focal length fsys of the microscope imaging system, the combined focal length fC1 of the first lens group, and the radius value RC1 of the surface facing the object side satisfy the following relationship: 0.1 < |fC1 / fsys| < 2; 0 < |RC1 / fsys| < 2.

[0019] According to an aspect of the present application, the combined focal length fC2 of the second lens group and the focal length fsys of the microscope imaging system satisfy the following relationship: 0.5 < |fC2 / fsys| < 2.

[0020] According to the scheme of the present application, a wide-spectrum wide-field microscope imaging system is provided, mainly applied to the fields of industrial lens vehicle-mounted, etc., especially as an imaging system of a microscope with wide spectrum and large field of view, comprising two lens groups, the first lens group being used for acquiring parallel light.

[0021] According to the scheme of the present application, by reasonably setting the composition of the two lens groups, the field curvature, chromatic aberration and distortion can be better corrected, the image plane is more flat, the background color is more perfect, and the image plane is complete.

[0022] According to the scheme of the present application, in order to further expand the observable area at the same time, further reduce the imaging magnification (≤1.5X), and generally make the relative 2X objective lens visual range increase more than one time, so that it is easier to find the required observation site under a large field of view, and the wide-spectrum design also enables the objective lens to have the observation ability for special samples.

[0023] According to the scheme of the present application, since low magnification imaging is easy to cause larger distortion, the distortion can be corrected by using special design, so that the distortion is less than or equal to 0.2%, and image distortion under large field of view is avoided.

[0024] According to the scheme of the present application, since the numerical aperture of low magnification imaging is small, the segmented control mode for near-infrared band well expands the numerical aperture (≥0.02), and has better resolution capability for the sample. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A structural diagram of a microscope imaging system according to a first embodiment of the present application is schematically shown;

[0026] Figure 2 A 0 field of view visible light lateral aberration diagram of the microscope imaging system according to the first embodiment of the present application is schematically shown;

[0027] Figure 3 A 0 field of view infrared light lateral aberration diagram of the microscope imaging system according to the first embodiment of the present application is schematically shown;

[0028] Figure 4 A 1 field of view visible light lateral aberration diagram of the microscope imaging system according to the first embodiment of the present application is schematically shown;

[0029] Figure 5 A 1 field of view infrared light lateral aberration diagram of the microscope imaging system according to the first embodiment of the present application is schematically shown;

[0030] Figure 6 A visible light field curvature distortion diagram of the microscope imaging system according to the first embodiment of the present application is schematically shown;

[0031] Figure 7 An infrared light field curvature distortion diagram of the microscope imaging system according to the first embodiment of the present application is schematically shown;

[0032] Figure 8 A structural diagram of a microscope imaging system according to a second embodiment of the present application is schematically shown;

[0033] Figure 9 A 0 field of view visible light lateral aberration diagram of the microscope imaging system according to the second embodiment of the present application is schematically shown;

[0034] Figure 10 A 0 field of view infrared light lateral aberration diagram of the microscope imaging system according to the second embodiment of the present application is schematically shown;

[0035] Figure 11 A 1 field of view visible light lateral aberration diagram of the microscope imaging system according to the second embodiment of the present application is schematically shown;

[0036] Figure 12 A 1 -field infrared lateral aberration map for a microscope imaging system according to a second embodiment of the application;

[0037] Figure 13 A visible field curvature distortion map for a microscope imaging system according to a second embodiment of the application;

[0038] Figure 14 An infrared field curvature distortion map for a microscope imaging system according to a second embodiment of the application;

[0039] Figure 15 A schematic diagram of a microscope imaging system according to a third embodiment of the application;

[0040] Figure 16 A 0 -field visible lateral aberration map for a microscope imaging system according to a third embodiment of the application;

[0041] Figure 17 A 0 -field infrared lateral aberration map for a microscope imaging system according to a third embodiment of the application;

[0042] Figure 18 A 1 -field visible lateral aberration map for a microscope imaging system according to a third embodiment of the application;

[0043] Figure 19 A 1 -field infrared lateral aberration map for a microscope imaging system according to a third embodiment of the application;

[0044] Figure 20 A visible field curvature distortion map for a microscope imaging system according to a third embodiment of the application;

[0045] Figure 21 An infrared field curvature distortion map for a microscope imaging system according to a third embodiment of the application;

[0046] Figure 22 A schematic diagram of a microscope imaging system according to a fourth embodiment of the application;

[0047] Figure 23 A 0 -field visible lateral aberration map for a microscope imaging system according to a fourth embodiment of the application;

[0048] Figure 24 A 0 -field infrared lateral aberration map for a microscope imaging system according to a fourth embodiment of the application;

[0049] Figure 25A 1 field visible light lateral aberration map of a microscope imaging system according to a fourth embodiment of the present application;

[0050] Figure 26 An infrared light lateral aberration map of a microscope imaging system according to a fourth embodiment of the present application;

[0051] Figure 27 A visible light field curvature distortion map of a microscope imaging system according to a fourth embodiment of the present application;

[0052] Figure 28 An infrared light field curvature distortion map of a microscope imaging system according to a fourth embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0054] In the description of the embodiments of the present application, the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" expressed by the orientation or positional relationship shown in the relevant drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the above terms cannot be understood as a limitation of the present application.

[0055] The present application will be described in detail below with reference to the drawings and specific embodiments, which cannot be exhaustively described here, but the embodiments of the present application are not limited to the following embodiments.

[0056] Referring to Figure 1 The microscope imaging system of the present application belongs to an infinite conjugate system, which comprises a first lens group C1 and a second lens group C2 arranged in order along the optical axis from the object side to the image side. In this way, the two lens groups jointly bear the optical power of the whole system and play a role in increasing the field of view and correcting the field curvature. In the present application, the first lens group C1 comprises at least one doublet lens group, and the second lens group C2 comprises only one doublet lens group.

[0057] In the present application, the first lens group C1 has positive or negative focal power, according to the embodiments of the present application, the first lens group C1 comprises a first optical element G1 which is a single lens or a doublet, and has positive or negative focal power. The object side surface of the first optical element G1 is concave, flat or convex. When the first optical element G1 is a doublet, it is composed of a negative lens on the object side and a positive lens on the image side. In some embodiments, the first lens group C1 further comprises a second doublet G2 which has positive focal power. The second doublet G2 is composed of a negative lens and a positive lens.

[0058] In the present application, the second lens group C2 only comprises a third doublet G3 which has positive focal power. The third doublet G3 is composed of a negative lens and a positive lens.

[0059] Therefore, the first lens group C1 and the second lens group C2 meet the above settings, which can better correct field curvature, chromatic aberration and distortion, make the image plane more flat, the background color more perfect and the image plane complete.

[0060] In the present application, the distance M from the object plane to the last surface of the microscope imaging system and the focal length fsys of the microscope imaging system satisfy the following relationship: 1 < M / fsys < 3. The focal length fsys of the microscope imaging system satisfies the following condition: 100 < fsys < 200. The object side numerical aperture NA of the microscope imaging system satisfies the following condition: 0.01 < NA < 0.1.

[0061] In the present application, the lowest projection height H2 of the central field edge light on the lens surface, the highest projection height H1 of the central field edge light on the lens surface and the projection height H3 of the central field edge light on the last lens surface satisfy the following relationship: 0.15 < |H2 / H1| < 1; 0.1 < |H2 / H3| < 1.5.

[0062] In the present application, the focal length fsys of the microscope imaging system, the combined focal length fC1 of the first lens group C1 and the radius value RC1 of the surface towards the object side satisfy the following relationship: 0.1 < |fC1 / fsys| < 2; 0 < |RC1 / fsys| < 2. The combined focal length fC2 of the second lens group C2 and the focal length fsys of the microscope imaging system satisfy the following relationship: 0.5 < |fC2 / fsys| < 2.

[0063] In summary, the low magnification large field of view wide spectrum macroscopic observation microscope imaging system of the present application has a relatively large numerical aperture of 0.02, a magnification range of 0.8X-1.5X, and a maximum image field of view of 50mm. Moreover, it has a very small distortion of ≤0.2%, thereby restoring a more true appearance of the sample. The system can not only observe an increased variety of samples, but also has a wider use range (environment). The working distance of the microscope objective can reach more than 150mm, and the achromatic effect in any interval of the 400-1700nm wavelength band can be achieved. In addition, by modifying the combination mode, curvature, thickness and spacing of the double cemented lens group in the first lens group C1, a smaller distortion and a smaller field curvature under a large field of view can be obtained to adapt to different uses.

[0064] The microscope imaging system of the present application is described in detail below in four groups of embodiments. In the following embodiments, S1, S2, …, SN represent the surfaces of each lens, and the cemented surface of the cemented lens group is denoted as a surface.

[0065] First embodiment

[0066] Reference is made to Figure 1 In this embodiment, the first lens group C1 has a positive focal power, and the second lens group C2 has a positive focal power. The first lens group C1 includes a first optical element G1 and a second cemented lens group G2. The first optical element G1 is a double cemented lens group and has a negative focal power, and the object side surface is a concave surface. The second cemented lens group G2 has a positive focal power, and the object side surface is a convex surface. The third cemented lens group G3 has a positive focal power. That is, the microscope imaging system of this embodiment includes three double cemented lens groups and six lenses in total, and the three groups of lens groups form a relatively symmetrical arrangement to correct the distortion and field curvature of the overall imaging system.

[0067] The first optical element G1 is composed of a negative lens on the object side and a positive lens on the image side. The second cemented lens group G2 is composed of a negative lens on the object side and a positive lens on the image side. The third cemented lens group G3 is composed of a positive lens on the object side and a negative lens on the image side.

[0068] The first optical element G1 and the second cemented lens group G2 have opposite concave and convex surfaces, and they form the objective part of the microscope imaging system. The second cemented lens group G2 and the third cemented lens group G3 have opposite convex surfaces, forming an infinite conjugate system. The third cemented lens group G3 forms the tube lens part of the microscope imaging system. In this way, there is enough space in the microscope imaging system to arrange the intervention of various optical modules, realizing various observation modes of the combination of the first lens group C1 and the second lens group C2.

[0069] The working distance of the microscope objective in the embodiment is ≥ 150 mm (the working distance is the distance from the cover glass to the edge of the first group of lenses of the objective), the focal length is 119.47 mm, and the objective cover glass thickness is adjustable in the range of 0-1.2 mm. The axial difference between the best focus point of the edge field of view of the objective and the best focus point of the central field of view is less than λ / NA 2 F' light and C' light are achromatic. Wherein, λ is the central wavelength, NA is the numerical aperture of the objective, F' represents light with a wavelength of 0.479 μm, e represents light with a wavelength of 0.546 μm, and C' represents light with a wavelength of 0.656 μm.

[0070] The parameters in the microscope imaging system of the embodiment are as follows: fsys=119.47 mm; M=290 mm; NA=0.05; H1=3.82 mm; H2=3.12 mm; H3=3.58 mm; fC1=172 mm; fC2=198.94 mm; RC1=-34.46 mm.

[0071] The parameters such as the thickness and radius of each lens of the microscope objective in the embodiment are shown in Table 1 below:

[0072]

[0073]

[0074] Table 1

[0075] In the embodiment, the refractive index n and Abbe number v of the two lenses in the first optical element G1 are respectively: n1=1.58, v1=40.7; n2=1.72, v2=29.5. The refractive index n and Abbe number v of the two lenses in the second cemented lens group G2 are respectively: n3=1.72, v3=47.9; n4=1.60, v4=65.5. The refractive index n and Abbe number v of the two lenses in the third cemented lens group G3 are respectively: n5=1.65, v5=55.9; n6=1.81, v6=25.4.

[0076] The spectral range of the low-power large-field-of-view achromatic microscope imaging system of the embodiment is 400 nm-1700 nm, the field of view range is ≥ 40 mm, and the numerical aperture is 0.05.

[0077] Figure 2 is the 0 field of view visible light lateral aberration diagram of the microscope imaging system of the first embodiment, wherein the abscissa PY, PX represents the normalized entrance pupil size, the ordinate represents the lateral aberration, the Y direction is the meridional direction, and the X direction is the sagittal direction. As can be seen from the figure, the aberration balance is good, and the imaging performance is good.

[0078] Figure 3is a 0 field of view infrared light lateral aberration graph of the microscope imaging system of the first embodiment, wherein the abscissa PY, PX represents a normalized entrance pupil size, the ordinate represents a lateral aberration, the Y direction is a meridional direction, and the X direction is a sagittal direction. As shown in the graph, the aberration is well balanced, and the imaging performance is good.

[0079] Figure 4 is a 1 field of view visible light lateral aberration graph of the microscope imaging system of the first embodiment. As shown in the graph, the curve is close to the abscissa, and the imaging performance is good.

[0080] Figure 5 is a 1 field of view infrared light lateral aberration graph of the microscope imaging system of the first embodiment. As shown in the graph, the curve is close to the abscissa, and the imaging performance is good.

[0081] Figure 6 is a field curvature distortion graph of the visible light of the microscope imaging system of the first embodiment. The left graph is a field curvature graph, in which the ordinate represents a field of view, and the abscissa represents a field curvature, and the unit is μm. The axial difference between the best focus point of the edge field of view and the best focus point of the central field of view is less than 2λ / NA 2 , and the theoretical value meets the requirement of clear full field of view, and achieves the requirement of flat field objective lens. The right graph is a distortion graph, in which the ordinate represents a field of view, and the abscissa represents a distortion (percentage). As shown in the graph, the full field of view distortion is less than 0.2%. In the graph, the ordinate is a normalized field of view, and the abscissa represents a distortion. The maximum is 0.2%, and the minimum is -0.2%.

[0082] Figure 7 is a field curvature distortion graph of the infrared light of the microscope imaging system of the first embodiment. The left graph is a field curvature graph, in which the ordinate represents a field of view, and the abscissa represents a field curvature, and the unit is μm. The theoretical value meets the requirement of clear full field of view, and achieves the requirement of flat field objective lens. The right graph is a distortion graph, in which the ordinate represents a field of view, and the abscissa represents a distortion (percentage). As shown in the graph, the full field of view distortion is less than 0.2%. In the graph, the ordinate is a normalized field of view, and the abscissa represents a distortion. The maximum is 0.2%, and the minimum is -0.2%.

[0083] Second embodiment

[0084] Reference Figure 8 In the present embodiment, the first lens group C1 includes a first optical element G1 and a second cemented lens group G2. The first optical element G1 is a single lens, and the object side surface is a concave surface with a small curvature. The optical power of the two lenses in the second cemented lens group G2 is negative-positive from left to right. The optical power of the two lenses in the third cemented lens group G3 is positive-negative from left to right. That is, the microscope imaging system of the present embodiment includes a single lens and two double cemented lens groups. The first optical element G1 and the second cemented lens group G2 are oppositely arranged with concave and convex surfaces. The second cemented lens group G2 and the third cemented lens group G3 are oppositely arranged with convex surfaces.

[0085] The parameters in the microscope imaging system of the present embodiment are as follows: fsys = 119.739 mm; M = 290 mm; NA = 0.04; H1 = 7.84 mm; H2 = 6.4 mm; H3 = 7.3 mm; fC1 = 180 mm; fC2 = 200 mm; RC1 = -36.83 mm.

[0086] The parameters of each lens thickness and radius of the microscope objective in the present embodiment are shown in Table 2 below:

[0087] Surface Radius (mm) Thickness (mm) Nd Vd S1 Inf 160 S2 -36.83 5 1.58 40.7 S3 45.28 1.54 S4 56.29 3 1.72 47.9 S5 -173.90 5 1.60 65.5 S6 -34.90 105 S7 235.87 8 1.65 55.9 S8 -84.33 3 1.81 25.4 S9 -195.14 180

[0088] Table 2

[0089] In the present embodiment, the refractive index n and Abbe number v of the first optical element G1 (i.e. a single lens) are: n1 = 1.58, v1 = 40.7. The refractive index n and Abbe number v of the two lenses in the second cemented lens group G2 are: n2 = 1.72, v2 = 47.9; n3 = 1.60, v3 = 65.5, respectively. The refractive index n and Abbe number v of the two lenses in the third cemented lens group G3 are: n4 = 1.65, v4 = 55.9; n5 = 1.81, v5 = 25.4, respectively.

[0090] The spectral range of the low-power large-field achromatic microscope imaging system of the present embodiment is 400 nm-1700 nm, the field range is ≥ 44 mm, and the numerical aperture is 0.04.

[0091] Figure 9 is a visible light 0 field lateral aberration diagram of the microscope imaging system of the second embodiment, wherein the abscissa PY, PX represents the normalized entrance pupil size, the ordinate represents the lateral aberration, the Y direction is the meridional direction, and the X direction is the sagittal direction. As can be seen from the diagram, the aberration is well balanced, and has good imaging performance.

[0092] Figure 10 is an infrared light 0 field lateral aberration diagram of the microscope imaging system of the second embodiment, wherein the abscissa PY, PX represents the normalized entrance pupil size, the ordinate represents the lateral aberration, the Y direction is the meridional direction, and the X direction is the sagittal direction. As can be seen from the diagram, the aberration is well balanced, and has good imaging performance.

[0093] Figure 11 is a visible light 1 field lateral aberration diagram of the microscope imaging system of the second embodiment. As can be seen from the diagram, the curve is close to the horizontal axis, and has good imaging performance.

[0094] Figure 12 is an infrared light 1 field lateral aberration diagram of the microscope imaging system of the second embodiment. As can be seen from the diagram, the curve is close to the horizontal axis, and has good imaging performance.

[0095] Figure 13 is the field curvature distortion figure of the microscope imaging system of the second embodiment, the left figure is the field curvature figure, the vertical coordinate represents the field of view, and the horizontal coordinate represents the field curvature, with the unit of μm. The axial difference between the best focus point of the edge field of view and the best focus point of the central field of view is less than 2λ / NA 2 , and the theoretical value meets the requirement of clear full field of view and achieves the flat field objective requirement. The right figure is the distortion figure, the vertical coordinate represents the field of view, and the horizontal coordinate represents the distortion (percentage). As can be seen from the figure, the full field of view distortion is less than 0.25%. The vertical coordinate in the figure is the normalized field of view, and the horizontal coordinate represents the distortion, with the maximum of 0.25% and the minimum of -0.25%.

[0096] Figure 14 is the field curvature distortion figure of the microscope imaging system of the second embodiment, the left figure is the field curvature figure, the vertical coordinate represents the field of view, and the horizontal coordinate represents the field curvature, with the unit of μm. The axial difference between the best focus point of the edge field of view and the best focus point of the central field of view is less than 2λ / NA 2 , and the theoretical value meets the requirement of clear full field of view and achieves the flat field objective requirement. The right figure is the distortion figure, the vertical coordinate represents the field of view, and the horizontal coordinate represents the distortion (percentage). As can be seen from the figure, the full field of view distortion is less than 0.25%. The vertical coordinate in the figure is the normalized field of view, and the horizontal coordinate represents the distortion, with the maximum of 0.25% and the minimum of -0.25%.

[0097] Third embodiment

[0098] Reference Figure 15 In the present embodiment, the first lens group C1 has a negative optical power, the second lens group C2 has a positive optical power, and the first lens group C1 and the second lens group C2 satisfy the symmetry. The first lens group C1 only includes the first optical element G1, the first optical element G1 is a doublet, has a negative optical power, and the object side surface is a convex surface with a smaller curvature. That is, the microscope imaging system of the present embodiment includes two doublets and four lenses in total. The optical powers of the two lenses of the first optical element G1 are positive and negative from left to right in order, and the optical powers of the two lenses in the second doublet G3 are negative and positive from left to right in order.

[0099] The parameters in the microscope imaging system of the present embodiment are as follows: fsys=128.03 mm; M=317.85 mm; NA=0.03; H1=5.97 mm; H2=5.42 mm; H3=10.35 mm; fC1=200 mm; fC2=200 mm; RC1=-234.27 mm.

[0100] The parameters of the thickness and radius of each lens of the microscope objective in the present embodiment are shown in Table 3 as follows:

[0101] Surface Radius (mm) Thickness (mm) Nd Vd S1 Inf 153.47 S2 93.28 3 1.81 25.4 S3 -95.22 4 1.69 49.7 S4 242.84 100 S5 -242.84 4 1.53 77.0 S6 95.22 3 1.74 44.7 S7 -93.28 181.2

[0102] Table 3

[0103] In the present embodiment, the refractive index n and Abbe number v of the two lenses in the first optical element G1 (i.e. the doublet lens group) are respectively: n1 = 1.81, v1 = 25.4, n2 = 1.69, v2 = 49.7. The refractive index n and Abbe number v of the two lenses in the third cemented lens group G3 are respectively: n3 = 1.53, v3 = 77.0; n4 = 1.74, v4 = 44.7.

[0104] The spectral range of the low magnification large field chromatic aberration corrected microscope imaging system of the present embodiment is 400nm-1700nm, the field of view range is ≥46mm, and the numerical aperture is 0.03.

[0105] Figure 16 is the lateral aberration chart of the visible light 0 field of view of the microscope imaging system of the third embodiment, wherein the abscissa PY, PX represents the normalized entrance pupil size, the ordinate represents the lateral aberration, 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.

[0106] Figure 17 is the lateral aberration chart of the infrared light 0 field of view of the microscope imaging system of the third embodiment, wherein the abscissa PY, PX represents the normalized entrance pupil size, the ordinate represents the lateral aberration, 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] Figure 18 is the lateral aberration chart of the visible light 1 field of view of the microscope imaging system of the third embodiment. It can be seen from the figure that the curve is close to the horizontal axis, and has good imaging performance.

[0108] Figure 19 is the lateral aberration chart of the infrared light 1 field of view of the microscope imaging system of the third embodiment. It can be seen from the figure that the curve is close to the horizontal axis, and has good imaging performance.

[0109] Figure 20 is the field curvature distortion chart of the visible light of the microscope imaging system of the third embodiment. The left figure is the field curvature chart, wherein the ordinate represents the field of view, and the abscissa represents the field curvature, with the unit of μm. 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 , and the theoretical value meets the clear full field of view, meeting the requirements of the flat field objective lens. The right figure is the distortion chart, wherein 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 0.02%. In the figure, the ordinate is the normalized field of view, and the abscissa represents the distortion. The maximum is 0.02%, and the minimum is -0.02%.

[0110] Figure 21 is the field curvature distortion graph of the microscope imaging system of the third embodiment, the left graph is the field curvature graph, the vertical coordinate represents the field of view, and the horizontal coordinate represents the field curvature in units of μm. The axial difference between the best focus point of the edge field of view and the best focus point of the central field of view is less than 2λ / NA 2 , the theoretical value meets the requirement of clear full field of view, and reaches the requirement of flat field objective. The right graph is the distortion graph, the vertical coordinate represents the field of view, and the horizontal coordinate represents the distortion (percentage). As can be seen from the graph, the distortion of the full field of view is less than 0.02%. The vertical coordinate in the graph is the normalized field of view, and the horizontal coordinate represents the distortion. The maximum is 0.02%, and the minimum is -0.02%.

[0111] The fourth embodiment

[0112] Referring to Figure 22 In the embodiment, the first lens group C1 only includes the first optical element G1, and the first optical element G1 is a doublet lens group, and the object side is a plane. That is, the microscope imaging system of the embodiment includes two doublet lens groups, and a total of four lenses. The refractive powers of the two lenses in the third cemented lens group G3 are positive and negative from left to right.

[0113] The parameters in the microscope imaging system of the embodiment are as follows: fsys=120.68 mm; M=305 mm; NA=0.02; H1=3.13 mm; H2=3.01 mm; H3=3.0 mm; fC1=157.7 mm; fC2=188 mm; RC1=Inf.

[0114] The parameters such as lens thickness and radius of the microscope objective lens in the embodiment are shown in Table 4 as follows:

[0115] Surface Radius (mm) Thickness (mm) Nd Vd S1 Inf 150 S2 Inf 5 1.76 27 S3 -92.57 4 1.61 56.4 S4 -123.15 100 S5 114.07 6 1.69 53.3 S6 -55.85 5 1.74 27.6 S7 Inf 185

[0116] Table 4

[0117] In the embodiment, the refractive index n and Abbe number v of the two lenses in the first optical element G1 (i.e. the doublet lens group) are as follows: n1=1.76, v1=27, n2=1.61, v2=56.4. The refractive index n and Abbe number v of the two lenses in the third cemented lens group G3 are as follows: n3=1.69, v3=53.3, n4=1.74, v4=27.6.

[0118] The spectral range of the low-power large-field chromatic aberration-free microscope imaging system of the embodiment is 400 nm-1700 nm, the field of view is ≥46 mm, and the numerical aperture is 0.02.

[0119] Figure 23The figure is a lateral aberration graph of the microscope imaging system of the fourth embodiment under visible light 0 field of view, wherein the horizontal coordinates PY, PX represent normalized entrance pupil size, the vertical coordinates represent lateral aberration, 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 the imaging performance is good.

[0120] Figure 24 The figure is a lateral aberration graph of the microscope imaging system of the fourth embodiment under infrared light 0 field of view, wherein the horizontal coordinates PY, PX represent normalized entrance pupil size, the vertical coordinates represent lateral aberration, 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 the imaging performance is good.

[0121] Figure 25 The figure is a lateral aberration graph of the microscope imaging system of the fourth embodiment under visible light 1 field of view. It can be seen from the figure that the curve is close to the horizontal axis, and the imaging performance is good.

[0122] Figure 26 The figure is a lateral aberration graph of the microscope imaging system of the fourth embodiment under infrared light 1 field of view. It can be seen from the figure that the curve is close to the horizontal axis, and the imaging performance is good.

[0123] Figure 27 The figure is a field curvature and distortion graph of the microscope imaging system of the fourth embodiment under visible light. The left figure is a field curvature graph, wherein the vertical coordinates represent field of view, and the horizontal coordinates represent field curvature with the unit of μm. 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, and the theoretical value meets the requirement of clear full field of view and achieves the requirement of flat field objective lens. The right figure is a distortion graph, wherein the vertical coordinates represent field of view, and the horizontal coordinates represent distortion (percentage). It can be known from the figure that the distortion of the full field of view is less than 0.02%. The vertical coordinates in the figure are normalized field of view, and the horizontal coordinates represent distortion. The maximum is 0.02%, and the minimum is -0.02%. 2

[0124] Figure 28 The figure is a field curvature and distortion graph of the microscope imaging system of the fourth embodiment under infrared light. The left figure is a field curvature graph, wherein the vertical coordinates represent field of view, and the horizontal coordinates represent field curvature with the unit of μm. 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, and the theoretical value meets the requirement of clear full field of view and achieves the requirement of flat field objective lens. The right figure is a distortion graph, wherein the vertical coordinates represent field of view, and the horizontal coordinates represent distortion (percentage). It can be known from the figure that the distortion of the full field of view is less than 0.02%. The vertical coordinates in the figure are normalized field of view, and the horizontal coordinates represent distortion. The maximum is 0.02%, and the minimum is -0.02%. 2

[0125] ​​The above merely describes one embodiment of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A microscope imaging system comprising two lens groups (Cl) and (C2) arranged in order from an object side to an image side along an optical axis, the first lens group (Cl) comprising at least one doublet lens group, characterized in that, The second lens group (C2) is a doublet lens group; the first lens group (C1) and the second lens group (C2) both have positive refractive power; The combined focal length fC2 of the second lens group (C2) and the focal length fsys of the microscope imaging system satisfy the following relationship: 0.5<|fC2 / fsys|<2. The distance M from the object plane to the last surface of the microscope imaging system and the focal length fsys of the microscope imaging system satisfy the following relationship: 1<M / fsys<3. The focal length fsys of the microscope imaging system satisfies the following condition: 100<fsys<200. The object-side numerical aperture NA of the microscope imaging system satisfies the following condition: 0.01<NA<0.

1.

2. The microscope imaging system of claim 1, wherein, The first lens group (C1) comprises a first optical element (G1), which is a lens or a doublet lens group, having positive refractive power or negative refractive power.

3. The microscope imaging system of claim 2, wherein, When the first optical element (G1) is a doublet lens group, it is composed of a negative lens on the object side and a positive lens on the image side.

4. The microscope imaging system of claim 2, wherein, The first lens group (C1) further comprises a second cemented lens group (G2) having positive refractive power.

5. The microscope imaging system of claim 4, wherein, The second cemented lens group (G2) is composed of a negative lens and a positive lens.

6. The microscope imaging system of claim 4, wherein, The first optical element (G1) and the second cemented lens group (G2) are concave-convex opposite.

7. The microscope imaging system of claim 4, wherein, The second lens group (C2) comprises a third cemented lens group (G3) having positive refractive power; The third cemented lens group (G3) is composed of a negative lens and a positive lens.

8. The microscope imaging system of claim 7, wherein, The second cemented lens group (G2) and the third cemented lens group (G3) are convex opposite.

9. The microscope imaging system of claim 1, wherein, The focal length fsys of the microscope imaging system and the combined focal length fC1 of the first lens group (C1), the radius value RC1 of the surface towards the object side satisfy the following relationship: 0.1<|fC1 / fsys|<2; 0<|RC1 / fsys|<2.

Images