Infinity correction microscope objective for scanning applications

Abstract

The invention relates to an infinity correction microscope objective (2) for scanning applications, having a small number of lenses dependent on the light collection rate (G), such that it has a first light collection rate (G1) in the range of 0.8 mm2 to 1.8 mm2 and a maximum of nine lenses (Li; 1 < = i < = 9) or it has a second light collecting rate (G2) in the range of greater than 1.8 mm2 and does not exceed 15 lenses (Li; 1 < = i < = 15).

Description

[0001] This application claims the priority of German patent application DE 10 2023 206 338.7, the content of which is incorporated herein by reference. Technical Field

[0002] The invention relates to an infinity-corrected microscope objective for scanning applications. The invention also relates to an optical assembly and a microscope having such an objective. Finally, the invention relates to the use of a corresponding objective and to a method for automatically scanning a sample. Background Art

[0003] Depending on the area of ​​application, microscope objectives have to meet various requirements.

[0004] Microscope objectives with high etendue are known from the prior art.

[0005] US2019-0324246, US 9746658 and US 8350904 relate to dry objectives with high etendue. US9939622, US 8988780, JP 2011075982 and DE 102011109783 relate to immersion objectives with high etendue.

[0006] On the one hand, these objectives are very complex, and on the other hand, the image quality decreases sharply towards the periphery. Summary of the invention

[0007] It is an object of the present invention to improve a microscope objective. In particular, a particular object is to provide an infinity-corrected microscope objective having a simplified setup and improved optical properties.

[0008] This object is achieved by the microscope objective according to the invention.

[0009] According to the first aspect, the objective lens may have a width of 0.8 mm. 2 Up to 1.8mm 2 The objective lens can also have a range of etendue and up to 9 lenses. 2 In this case, the etendue can be in particular less than 5.1 mm 2 .

[0010] In particular, the objective may have a vignetting of less than 5%.

[0011] In particular, the objective lens may be apochromatically corrected over a spectral bandwidth of at least 200 nm, in particular in a range of 400 nm to 800 nm. In particular, the objective lens may be apochromatically corrected over a spectral bandwidth of at least 200 nm, in particular in a range of 400 nm to 700 nm. In particular, the objective lens may be apochromatically corrected over a spectral bandwidth of at least 200 nm, in particular in a range of 400 nm to 660 nm.

[0012] The objective may preferably have a numerical aperture of at least 0.9.

[0013] The objectives according to the invention can be produced particularly cost-effectively. However, they result in a high robustness of the optical system.

[0014] According to a further aspect, objectives according to the invention can have a Strehl ratio of at least 0.8, in particular at least 0.9, despite their reduced complexity.

[0015] In particular, the objective can have such a high Strehl ratio over at least 50%, in particular over at least 70%, in particular over at least 90%, in particular over the entire field of view.

[0016] In particular, the objective can have such a high Strehl ratio over a partial field of view region having an area of ​​at least 1 square millimeter.

[0017] This ensures high resolution over a large field of view area, especially over the entire field of view. This makes it easier to combine multiple partially overlapping images into a mosaic image.

[0018] The field of view is also called the object field.

[0019] According to the invention, it has been recognized that, in particular for scanning applications in which large, in particular large-area samples are examined, it is advantageous if the microscope objective used for this purpose has a large field of view and at the same time provides a high resolution over the entire field of view. The Strehl ratio can be used to characterize the resolution. For the objective according to the invention, in particular over the entire field of view, the Strehl ratio is at least 0.8, in particular at least 0.83, in particular at least 0.89, in particular at least 0.9.

[0020] Particularly for scanning applications, it may be necessary to take a large number of images and then assemble them into a mosaic image. Preferably, this is done automatically.

[0021] For high throughput, the total time required to capture the individual images is a key factor. This time depends firstly on the recording time of a single image and secondly on the number of images to be captured. It is always desirable to reduce the total time required to capture the individual images. This leads to faster results and increased throughput. Typically, this leads to lower costs.

[0022] In addition to the time to record a single image, an important factor affecting the total time required to record a single image is the field of view size of the optical system. A larger field of view size allows a larger area to be recorded in each image. Therefore, fewer frames are required to image a large number of samples. This results in reduced scanning time and reduced effort required to assemble the images into a mosaic.

[0023] However, when the field size is enlarged, it is crucial that the objective has high resolution for all relevant wavelength ranges throughout the field of view. This requirement for high resolution with a large field of view corresponds to an increase in etendue, in particular, a maximization of etendue. Etendue is proportional to the square of the linear size (in particular the diameter) of the field of view. It is also proportional to the square of the numerical aperture (NA).

[0024] At the same time, in particular for conventional applications, it may be desirable to reduce the complexity of the microscope objective. In particular, this can lead to cost savings. Reduced complexity is particularly understood to mean a reduction in the number of required optical elements (in particular lenses). In particular, the number of aspherical lenses is preferably reduced. It has been shown that this leads to significant cost savings.

[0025] Finally, for many applications it may be advantageous if objectives with different properties, in particular with different magnifications, can be used interchangeably. This makes it possible, for example, to first record an overview image with a relatively low resolution. The overview image can be used to record regions of interest (ROI). These regions can then be examined in detail with a high-resolution objective.

[0026] To simplify the interchange of objectives and achieve compatibility with standard microscope stands, it is advantageous if the objective is infinity-corrected. This means that it is designed for use in infinity optical units. In this case, the imaging light leaves the objective as a parallel beam. This allows the use of tubes of any length.

[0027] According to the invention, it is also recognized that the complexity of an objective generally increases with increasing etendue.Thus, the objective may have a number of lenses depending on the etendue (G).

[0028] The objectives according to the invention have a significantly reduced complexity, in particular a lower number of lenses for a given etendue. Due to their high Strehl ratio, they still ensure a high resolution over the entire field of view.

[0029] Objectives with a maximum of nine lenses can have an object field height of more than 0.3 mm, ie half the object field diameter.

[0030] Objectives with a maximum of 15 lenses can have an object field height of more than 0.6 mm, ie half the object field diameter.

[0031] Vignetting may be at most 5%, in particular at most 3%.

[0032] For example, in the case of an objective with 9 lenses, the lenses may be arranged in 6 subgroups. For example, the lenses may be 3 singlets and 3 cemented doublets.

[0033] In the case of an objective with a maximum of 15 lenses, the lenses may be arranged in 8 or 9 subgroups. A subgroup may include 2 cemented triplets, 3 cemented doublets and 3 single lenses or 2 cemented triplets, 2 cemented doublets and 5 single lenses.

[0034] With such an arrangement of lenses, particularly advantageous optical properties can be achieved.

[0035] According to one aspect, the objective lens can be designed as a dry objective lens. It can have a numerical aperture (NA) in the range of 0.9-1.0. This results in a particularly high resolution.

[0036] According to another aspect, the objective can be designed as an immersion objective. It can have a numerical aperture (NA) of at least 1.0, in particular at least 1.1. This results in a particularly high resolution of the objective.

[0037] According to another aspect, the objective can be designed without aspherical lenses at all. This further reduces the complexity of the objective. This leads in particular to a reduction in costs.

[0038] In the case of 9 lenses, they can be made of at least 5, in particular at least 6, in particular at least 7, in particular at least 8 different types of glass.

[0039] In the case of an objective having a maximum of 15 lenses, the lenses can be made from at least 8, in particular at least 10, in particular at least 12 different types of glass.

[0040] It has been shown that particularly good optical properties of the objective can be achieved by suitable selection of different types of glass.

[0041] According to another aspect, the second lens group of the objective can have two cemented elements.

[0042] In the case of less than 1.8mm 2 In the objectives of the etendue, they can be cemented doublets.

[0043] In the case of a size greater than 1.8 mm 2 The etendue of the objective lenses is such that they can be cemented triplets.

[0044] According to another aspect, the objective can be apochromatically corrected over a bandwidth of at least 200 nm, in particular in a wavelength range between 400 nm and 800 nm, in particular in a range from 400 nm to 700 nm, in particular in a range from 460 nm to 660 nm. It has been shown that by reducing the bandwidth over which the objective is apochromatically corrected, the number of required lenses can be reduced.

[0045] Apochromatic correction means that the maximum deviation of the focus position within the spectrum relative to the reference wavelength is within the depth of field.

[0046] According to another aspect, the third lens group may have three subgroups (G31, G32, and G33). Here, the first subgroup (G31) may have positive refractive power. The second subgroup (G32) may have negative refractive power. The third subgroup (G33) may have negative refractive power.

[0047] Here and below, the order of the optical elements of the objective is indicated in the direction from the object field to the field of view.With respect to the objective, "front" refers to the side facing the object field and "rear" refers to the side facing away from the object field.

[0048] Further possible details of the objective lens are described below.

[0049] The objective lens may have a relatively short working distance. In particular, the following may apply:

[0050] d:L<4.9×10 -3 ,

[0051] where d indicates the distance from the cover glass to the periphery of the foremost lens surface of the objective, and L indicates the total distance between the object field and the vertex of the rearmost lens surface of the objective (in the direction of the light beam).

[0052] The working distance of the objective lens can also meet the following conditions:

[0053] d0:L<9×10 -3 ,

[0054] where d0 indicates the distance from the object field to the vertex of the foremost lens surface of the objective.

[0055] If the maximum distance of a light ray emitted from an object on the optical axis to the optical axis is defined as h1, h2, and h3 in the three sub-groups G31, G32, and G33 of the third lens group G3, these parameters may specifically satisfy the following inequality:

[0056] 1.1

[0057] 1.2 <h2:h3<1.6。

[0058] ​For an objective lens having a maximum of 9 lenses, the third lens group G3 may have a first lens having positive refractive power and a second lens having negative refractive power.

[0059] Together with a tube lens unit, in particular together with a tube lens with a focal length of 200 mm or with a focal length of 164.5 mm, a microscope objective according to the above description can form an optical assembly.

[0060] Another object of the invention is to improve microscopes, in particular for scanning applications, in particular for optical mapping.

[0061] This object is achieved by a microscope having an objective according to the preceding description.The advantages are apparent from the preceding description.

[0062] The microscope may include an automatic scanning device. The scanning device may enable a one-dimensional (linear) displacement of the sample, a two-dimensional displacement of the sample or a three-dimensional displacement of the sample. In addition to the linear displacement, the scanning device may also have one, two or three rotational degrees of freedom. This allows for a very flexible arrangement of the samples, in particular for their displacement.

[0063] The scanning device may comprise an image acquisition device, in particular a digital image acquisition device, in particular a digital camera.

[0064] The scanning device may include image processing means. In particular, the latter may enable automated processing. In particular, this simplifies the splicing of frames into a mosaic image.

[0065] The above-mentioned microscope objectives are particularly advantageous for use in scanning applications, in particular for optical mapping. In particular, they simplify the automated scanning of large (in particular large-area) samples.

[0066] Another object of the present invention is to improve a method for automatically scanning a sample. This object is achieved by a method comprising the following steps:

[0067] - providing a microscope according to the preceding description,

[0068] - provide samples to be inspected,

[0069] - acquiring at least two images of different parts of the sample, wherein the parts have overlapping areas, and

[0070] - Assembling said images into a mosaic image.

[0071] In particular, the method may be an optical mapping method.

[0072] Before assembling the images, they may be analyzed and / or processed using image processing algorithms. This may simplify and / or improve the assembly of the images.

[0073] The assembled mosaic image may also be analyzed and / or processed after the images have been assembled using an image processing algorithm. This may further improve the quality.

[0074] In order to record images of different parts of the sample, the sample can be displaced linearly, two-dimensionally or three-dimensionally. It can in particular be displaced stepwise.

[0075] In particular, the displacement of the sample and the recording of successive images of different parts of the sample can be automated. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Further details of the present invention will become apparent from the description of exemplary embodiments with reference to the accompanying drawings, in which:

[0077] Figure 1 Schematic showing the microscope setup,

[0078] Figure 2 shows a schematic longitudinal section through the optical components of a microscope objective according to a first variant (E1),

[0079] Figure 3 shows a schematic longitudinal section through the optical components of a microscope objective according to a second variant (E2),

[0080] Figure 4 shows a schematic longitudinal section through the optical components of a microscope objective according to a third variant (E3),

[0081] Figure 5 The object field heights (h obj ) and numerical aperture,

[0082] Figures 6 to 8 schematically shows the distribution of the Strehl ratio over the field of view at different wavelengths of light, and

[0083] Figures 9 to 11 The distribution of the intensity of the incident light illumination on the field of view of three objectives according to variants E1 , E2 and E3 is schematically shown. DETAILED DESCRIPTION

[0084] Figure 1 By way of example, a basic setup of a microscope 1 is schematically shown. The illustration is to be understood as an example and not as a limitation.

[0085] The microscope 1 comprises an infinity optical unit. This means that the beam path 3 downstream of the objective 2 runs parallel. The area between the objective 2 and the tube lens 5 of the tube lens unit 6 is also referred to as the infinity space 4. With the aid of the tube lens unit 6, an intermediate image is generated in the intermediate image plane 7. The intermediate image can be observed using an eyepiece 8. It can also be guided to an image acquisition device, in particular in the form of a camera 9. The camera 9 can in particular be a digital camera.

[0086] Figure 1 Also shown is an illumination device 10 as an example. The illumination device 10 has a radiation source unit 11. In particular, a laser can be used as the radiation source unit 11.

[0087] The illumination device 10 can also have a beam splitter 12. By means of the beam splitter 12, the illumination radiation 3 can be guided through the objective 2 to a sample 13 to be observed. Figure 1 The beam path schematically shown in FIG. 1 is particularly suitable for epi-fluorescence systems. The illumination may be in the form of Köhler illumination. Critical illumination is also possible. Instead of the beam splitter 12, a prism, in particular a cubic prism, may also be provided. Alternative variants for coupling the illuminating radiation are known from the prior art.

[0088] Figure 1 Schematically shown is also a scanning device 14. The scanning device 14 comprises one or more displacement devices 15. By means of the displacement device 15, the sample 13 can be displaced in the microscope 1 relative to the beam path 3, in particular relative to the objective 2.

[0089] To illustrate the working distance of the objective lens 2, as an example, Figure 1 The distance d from the cover glass 16 to the periphery of the frontmost lens surface 17 of the objective lens 2 is shown in FIG.

[0090] The distance from the object plane 18 to the vertex 19 of the frontmost lens surface 17 is shown as d0.

[0091] L represents the total distance between the object plane 18 and the vertex 19 of the rearmost lens surface of the objective 2 (in the direction of the beam). Figure 1 Clearly shown in.

[0092] The microscope 1 can have a footprint with a width b of not more than 250 mm, in particular not more than 205 mm.

[0093] Figure 2 A longitudinal section through the arrangement of the optical components of objective 2 is shown.

[0094] All variants (E1, E2 and E3) are suitable for use with a cover glass 16 having a thickness of 0.17 mm, a refractive index nd=1.523 and an Abbe number vd=54.52 (based on the d-line of 587.562 nm).

[0095] Figures 2 to 4 By way of example, the contours of a central chief ray HS and two marginal rays RS1 , RS2 are shown.

[0096] For the sake of clarity, the mechanical components of the objective 2 are not shown in the figure.

[0097] Figure 2 , Figure 3 and Figure 4 A cover glass (DG) 16 is also shown.

[0098] The objective 2 is in particular an apochromatic objective 2 .

[0099] Figure 2 The variant (E1) shown in FIG. 1 is in particular a dry objective.

[0100] according to Figure 2 The objective lens 2 has 9 lenses L1 to L9.

[0101] according to Figure 2 The optical design data of the objective lens 2 is shown in Table 1.

[0102] Table 1: According to Figure 2 Optical design data of objective lens 2:

[0103] Surface number r(mm) d(mm) nd vd 1 -16.730 15.067 1.804 46.50 2 9.846 4.663 1.717 29.62 3 -59.780 4.416 4 Infinity 0.154 5 13.962 9.317 1.439 94.95 6 -13.757 2.902 1.691 54.71 7 -22.985 1.525 8 18.606 5.402 1.569 71.34 9 -13.522 1.000 2.003 28.27 10 45.162 0.673 11 15.918 3.165 1.569 71.34 12 66.860 0.354 13 9.509 4.089 1.592 68.37 14 12.624 0.130 15 5.477 6.684 1.883 40.76 16 4.311 0.288

[0104] The refractive index (nd) and Abbe number (vd) refer to the d-line (587.562 nm).

[0105] Additional data for objective 2:

[0106] Magnification: 40 times

[0107] NA: 0.95

[0108] L: 60.00mm

[0109] d: 0.150mm

[0110] d0: 0.288mm

[0111] d:L=2.5×10 -3

[0112] d0:L=4.8×10 -3

[0113] h obj: 0.3125mm

[0114] G=0.8699mm 2

[0115] The objective lens 2 is suitable for use with a tube lens 5 having a focal length of 200 mm.

[0116] The objective lens 2 has three lens groups G1, G2 and G3. The first lens group G1 has positive refractive power and includes lenses L1, L2 and L3.

[0117] The second lens group G2 has positive refractive power. The second lens group G2 includes lenses L4, L5, L6 and L7.

[0118] Lenses L4 and L5 form a cemented doublet.

[0119] Lenses L6 and L7 form a cemented doublet.

[0120] The third lens group G3 has negative refractive power.

[0121] The third lens group G3 includes lenses L8 and L9.

[0122] Lenses L8 and L9 form a cemented doublet. Lens L8 is also known as optical element OE31. It has positive refractive power.

[0123] Lens L9 is also called optical element OE32. It has negative refractive power.

[0124] Figure 2 The objective lens 2 shown in FIG. has a G=0.8699 mm 2 of light etendue.

[0125] Figure 3 A second variant ( E2 ) of objective 2 is shown.

[0126] according to Figure 3 The objective lens 2 has 15 lenses L1 to L15.

[0127] The first lens group G1 includes lenses L1 to L4 .

[0128] The second lens group G2 includes lenses L5 to L10.

[0129] Lenses L5 to L7 form a cemented triplet.

[0130] Lenses L8 to L10 form a cemented triplet.

[0131] The third lens group G3 includes lenses L11 to L15 .

[0132] Lenses L11 form a subgroup G31.

[0133] Lenses L12 and L13 of subgroup G32 form a cemented doublet lens.

[0134] Lenses L14 and L15 of subgroup G33 form a cemented doublet lens.

[0135] according to Figure 3 The objective lens 2 has G = 3.4799 mm 2 of light etendue.

[0136] according to Figure 3 Objective 2 is a dry objective.

[0137] according to Figure 2 The optical design data of the objective lens 2 is shown in Table 1.

[0138] Table 2: According to Figure 3 Optical design data of objective lens 2:

[0139]

[0140]

[0141] The refractive index (nd) and the Abbe number (vd) refer to the d-line (587.562 nm). Figure 3 Other data of objective 2:

[0142] Magnification: 20 times

[0143] NA: 0.95

[0144] L: 107.99mm

[0145] d: 0.411mm

[0146] d0: 0.894mm

[0147] d:L=3.8×10 -3

[0148] d0:L=8.3×10 -3

[0149] h obj : 0.625mm

[0150] G=3.4799mm 2

[0151] The objective lens 2 is suitable for use with a tube lens 5 having a focal length of 164.5 mm.

[0152] If the maximum distance of a light ray emitted from an object on the optical axis to the optical axis is defined as h1, h2, and h3 in the three sub-groups G31, G32, and G33 of the third lens group G3, then:

[0153] h1=14.36mm,

[0154] h2=11.00mm,

[0155] h3=7.71mm

[0156] And therefore

[0157] h1:h2=1.305 and

[0158] h2:h3=1.427.

[0159] Figure 4 Another variant (E3) of the objective 2 is shown.

[0160] according to Figure 4 Objective lens 2 is a water immersion objective lens.

[0161] according to Figure 4 The optical design data of objective lens 2 is shown in Table 3.

[0162] Table 3: According to Figure 4 Optical design data of objective lens 2:

[0163]

[0164]

[0165] The refractive index (nd) and Abbe number (vd) refer to the d-line (587.562 nm).

[0166] according to Figure 4 Other data of objective 2:

[0167] Magnification: 20 times

[0168] NA: 1.0 (water immersion)

[0169] L: 169.78mm

[0170] d: 0.302mm

[0171] d0: 0.302mm

[0172] d:L=1.8×10 -3

[0173] d0:L=1.8×10 -3

[0174] h obj : 0.625mm

[0175] G=4.6649mm 2

[0176] The objective lens 2 is suitable for use with a tube lens 5 having a focal length of 164.5 mm.

[0177] according to Figure 4 The objective lens 2 (E3) has a light collection efficiency G = 4.6649 mm 2 .

[0178] If the maximum distance of a light ray emitted from an object on the optical axis to the optical axis is defined as h1, h2, and h3 in the three sub-groups G31, G32, and G33 of the third lens group G3, then:

[0179] h1=16.55mm,

[0180] h2=13.78mm,

[0181] h3=9.79mm

[0182] And therefore

[0183] h1:h2=1.301 and

[0184] h2:h3=1.408.

[0185] Figure 5 Schematic diagram showing the field height (h) relative to the numerical aperture (NA) of the objective lenses (E1, E2 and E3). obj ), which is half the diameter of the field of view. In addition, Figure 5 The etendue G = 0.8 mm is shown 2 , G=1.8mm 2 , and G = 5.1 mm 2 The curve of . Objectives 2 with a numerical aperture of at least 1 form immersion objectives. Objectives with a numerical aperture NA<1 can be designed as dry objectives. The diagram thus distinguishes three different regions of etendue. As an example, these are referred to as "level 1", "level 2" and "level 3".

[0186] Figures 6 to 8 They are shown according to Figure 2 , 3 Strehl ratios of the three objective lenses 2 and 4 for light with wavelengths λ1 = 460 nm, λ2 = 546 nm and λ3 = 660 nm.

[0187] As can be seen from the figure, the Strehl ratio over the entire field of view is greater than 0.8. For a single wavelength or a limited wavelength range, the Strehl ratio over the entire field of view is even greater, particularly greater than 0.83, and particularly greater than 0.9.

[0188] exist Figures 9 to 11, the relative illumination intensity over the field of view at a wavelength of 546.074 nm is shown in order to illustrate the peripheral light falloff.

[0189] As can be seen from the figure, objective 2 results in uniform illumination of the field of view with slight vignetting under incident light illumination.

Claims

1. An infinity-corrected microscope objective (2) for scanning applications, comprising: 1.

1. A first lens group (G1) having positive refractive power, 1.

2. A second lens group (G2) having positive refractive power, and 1.

3. The third lens group (G3) has negative refractive power, 1.

4. Wherein, the microscope objective lens (2) has 1.4.

1. A numerical aperture (NA) of at least 0.9, 1.4.

2. Less than 5% vignetting, 1.4.

3. Apochromatically corrected over a spectral bandwidth of at least 200 nm, and 1.4.

4. With a small number of lenses depending on etendue (G), e.g. 1.4.4.

1. The microscope objective lens (2) has a diameter of 0.8 mm. 2 Up to 1.8mm 2 and having no more than nine lenses (Li; 1≤i≤9), or Those 1.4.4.

2. The microscope objective (2) has a diameter greater than 1.8 mm. 2 A second etendue (G2) within a range and having no more than 15 lenses (Li; 1≤i≤15).

2. The microscope objective (2) according to claim 1, characterized in that The microscope objective is designed as a dry objective and has a numerical aperture (NA) in the range of 0.9 to 1.

0.

3. The microscope objective (2) according to claim 1, characterized in that: The microscope objective is designed as an immersion objective and has a numerical aperture (NA) of at least 1.

0.

4. Microscope objective (2) according to any one of the preceding claims, characterized in that The microscope objective (2) has a Strehl ratio of at least 0.8 over at least 70% of the field of view.

5. Microscope objective (2) according to any one of the preceding claims, characterized in that The microscope objective has no aspherical lenses.

6. Microscope objective (2) according to any one of the preceding claims, characterized in that The second lens group (G2) has two cemented elements (G21, G22).

7. Microscope objective (2) according to any one of the preceding claims, characterized in that The microscope objective is apochromatically corrected over a bandwidth of at least 200 nm in the wavelength range between 400 nm and 800 nm.

8. Microscope objective (2) according to any one of the preceding claims, wherein: The third lens group (G3) has three sub-groups (G31, G32 and G33), wherein the first sub-group (G31) has positive refractive power, the second sub-group (G32) has negative refractive power, and the third sub-group (G33) has negative refractive power.

9. Microscope objective (2) according to any one of the preceding claims, characterized in that The following optical design data:

10. The microscope objective (2) according to any one of claims 1 to 8, characterized in that The following optical design data:

11. The microscope objective (2) according to any one of claims 1 to 8, characterized in that The following optical design data:

12. An optical component comprising 12.

1. Microscope objective (2) according to any one of the preceding claims, and 12.

2. A tube lens unit (6) having a tube lens (5) with a focal length of 200 mm or 164.5 mm.

13. A microscope (1) having a microscope objective (2) according to any one of claims 1 to 11.

14. The microscope (1) according to claim 13, characterized in that Automatic scanning device (14).

15. A method for automatically scanning a sample, comprising the steps of: 15.

1. Provide a microscope (1) according to any one of claims 13 to 14, 15.

2. Provide samples for inspection, 15.

3. Acquire at least two images of different parts of the sample, wherein the parts have overlapping areas, 15.

4. Assemble the images into a mosaic image.

Images