EP3452859A1

EP3452859A1 - Digital microscope having an objective and having an image sensor

Info

Publication number: EP3452859A1
Application number: EP17728084.9A
Authority: EP
Inventors: Alexander Gaiduk; Ralf Wolleschensky
Original assignee: Carl Zeiss Microscopy GmbH
Current assignee: Carl Zeiss Microscopy GmbH
Priority date: 2016-06-06
Filing date: 2017-05-23
Publication date: 2019-03-13
Also published as: WO2017211584A1; CN109313332A; DE102016110407A1; US20190302441A1; US10732398B2

Abstract

The invention relates to a digital microscope (16; 17), which comprises an objective (11) for the magnified optical imaging of a sample (10) in an image plane. An image can be provided in the image plane with an optical resolution by means of the objective (11). The microscope (16; 17) also comprises an image sensor (12) for converting the image imaged onto the image sensor (12) by the objective (11) into an electrical signal. The image sensor (12) comprises a matrix of pixels, by which a maximum image resolution of the image sensor is determined, which maximum image resolution is finer than the optical resolution of the objective (11). The objective (11) has a maximum magnification factor of at most 40. The optical resolution of the objective (11) is defined as a minimum distance of two structures that can be distinguished in the image. The maximum image resolution of the image sensor (12) is defined by a pixel distance. A quotient of the minimum distance of two structures that can be distinguished in the image and the pixel distance defines a scanning factor, which is at least five.

Description

Digital microscope with a lens and with one

image sensor

The present invention relates to a digital microscope with an objective for enlarged optical imaging of a sample in an image plane and with an image sensor for converting the image imaged by the objective onto the image sensor into an electrical signal.

GB 2 384 379 A shows a display system with a camera and a display for the front area of a train. The digital camera is high resolution. A zoom in the displayed image is realized by the fact that the digital image

is enlarged, whereby only a small part of the image is visible.

US 2006/0171038 A1 shows a system for zooming digital images. The system includes an image sensor, a

A / D converter, an image processing unit and a display.

The sensitivity of the image converter is greater than that

Resolution of the ad. For example, the imager is formed by a CMOS converter with a resolution of 4096 by 3072 pixels, while the display has a resolution of 1024 by 768 pixels.

The digital camera SC100 from the manufacturer Olympus has a picture sensor with 10.6 million pixels with one

Pixel pitch of 1.67 ym. The camera has a maximum

Image refresh rate of 42 frames per second at one

Resolution of 968 times 686 pixels. The refresh rate drops to 3 frames per second when the highest resolution is used. In the scientific article by EJ Botcherby, R.

Juskaitis, M.J. Booth, T. Wilson: "An optical technique for remote focusing in microscopy" in Optics Communications 281 (2008) 880-887 introduces the method of refocusing, which avoids a spherical one

Aberration and allows a large axial scan area and a large scan speed without mechanical interference between the lens and the sample.

The object of the present invention, starting from the prior art, is to avoid the disadvantages of undersampling in a digital microscope. The above object is achieved by a digital microscope according to the appended claim 1.

The digital microscope according to the invention serves for

Microscopy of a sample. In the digital microscope is an electronic image conversion, wherein the recorded image processed in the form of digital data and brought to display on an electronic image display device. The digital microscope initially comprises a lens for enlarged optical imaging of the sample in an image plane. Through the lens, an image with an optical resolution in the image plane can be displayed. The optical resolution is due to the physical processes and properties of the

Objectively determined. The objective comprises optical components for enlarged optical imaging of the sample in the

Image plane. The optical components are in particular by optical lenses and possibly by one or more apertures and Filter formed. The imaged image is preferably formed by a light image.

The digital microscope further comprises an image sensor for converting the image of the lens on the image sensor

Picture in an electrical signal. The image sensor comprises a matrix of pixels, i. H. a matrix of individual

Image sensor elements. The matrix of pixels determines a maximum image resolution of the image sensor. By converting the image with the image sensor is a local

two-dimensional scanning of the image. The image sensor is an image sensor and is preferably formed by a CMOS image sensor. The matrix is not just a single or a few lines of pixels, such as those used for scanning methods. The

The number of pixels in each row of the matrix and the number of pixels in each column of the matrix belong to the same order of magnitude. According to the invention, the maximum image resolution of the image sensor is finer than the optical resolution of the objective, so that the pixels of the image sensor are smaller than the smallest structures in the image imaged by the objective. Thus, the image sensor has a higher resolution than the lens. In this respect, a resolution of smaller structures than a higher one

Resolution, the maximum image resolution of the image sensor is higher than the optical resolution of the image sensor

Lens. Insofar as the resolution is given by a distance between two structures which can still be represented or differentiated, the maximum image resolution of the

Image sensor smaller than the optical resolution of the lens. Insofar as the objective has changeable properties which influence the optical resolution of the objective, the maximum image resolution of the image sensor is finer than any optical resolution achievable with the objective. In particular, a magnification factor of the lens can be changed by a user, whereby the optical resolution of the lens changes. According to the invention, the maximum image resolution of the image sensor is finer than the resulting optical resolution of the objective for each magnification factor that can be selected on the lens. In particular, for the largest magnification factor selectable on the lens, the maximum image resolution of the image sensor is finer than the resulting optical resolution of the lens. According to the invention, the lens has a maximum

Magnification factor of 40 or less. Insofar that

Objectively has a fixed magnification factor, so this also represents the maximum magnification factor. A particular advantage of the digital invention

Microscope is that the image conversion by the image sensor is basically done with a local oversampling of the image. For this purpose, according to the invention, a lens with a low magnification factor of at most 40 is used, which is available at low cost. Accordingly, an electronic image sensor having an image resolution sufficient for oversampling is used. electronic

Image sensors with very high image resolutions are already available at low cost.

The maximum image resolution of the image sensor is preferably at least 2 times as fine as the optical resolution of the

Lens. The maximum image resolution of the image sensor is more preferably at least 3 times as fine as the optical resolution of the objective. This will be a multiple

Oversampling, resulting in, for example, a higher

Contrast is ensured in the converted image. Also, noise reduction in terms of diffraction-limited

Areas of the lens are made possible, which can be done in temporal and spatial correlation.

In preferred embodiments, the maximum

Image resolution of the image sensor at least 5 times as fine as the optical resolution of the lens. In further preferred embodiments, the maximum image resolution of

Image sensor at least 10 times as fine as the optical

Resolution of the lens. This leads to a

Oversampling of a higher order, which ensures a high quality of the converted image. For example, a fast and aberration-free 3D microscopy can be realized thereby. Also, fast autofocusing, fast phase detection, high spectral resolution, high temporal resolution and / or improved

Dynamic range can be achieved.

In preferred embodiments of the digital microscope, the maximum magnification factor is at most 30. In further preferred embodiments of the digital microscope, the maximum magnification factor is at most 20. In further preferred embodiments of the digital microscope, the maximum magnification factor is at most 10. In further preferred embodiments of the digital microscope is the maximum magnification factor 5 or less.

The optical resolution of the lens is just a minimum distance between two in the image defined distinguishable structures. Thus, the optical resolution is the distance that two structures must at least have to be perceived as separate structures. The structures are preferably formed by punctiform objects or by lines. Accordingly, the optical resolution is preferably defined by the distance between these two lines.

The maximum image resolution of the image sensor is defined by a pixel pitch. The pixel pitch is the distance between two immediately adjacent pixels. The pixel pitch is the quotient of the extension of the image sensor in one of its directions of extent by the number of pixels in this span direction. The pixel pitch is

for example, the quotient of the width of the image sensor by the number of pixels in a row of the matrix. The pixel pitch is, for example, the quotient of the height of the image sensor by the number of pixels in a column of the matrix.

A quotient of the minimum distance between two in the picture

distinguishable structures by the pixel pitch represents a local sampling factor. The sampling factor is thus the quotient of the optical resolution of the lens by the maximum image resolution of the image sensor. The sampling factor is at least five according to the invention. The sampling factor is preferably at least six.

In preferred embodiments of the digital microscope, the pixel pitch of the image sensor is at most 2 ym. In further preferred embodiments of the digital

Microscope, the pixel pitch of the image sensor is at most 1.85 ym. The pixel pitch of the image sensor is especially preferably 2.0 ym, 1.8 ym, 1.6 ym, 1.4 ym, 1.2 ym, 1.0 ym, 0.8 ym or 0.6 ym.

The number of pixels in a column of the matrix-shaped

Image sensor is preferably at least 1,000, while at the same time the number of pixels in a row of

matrix-shaped image sensor is also at least 1,000.

In preferred embodiments of the digital microscope, the number of pixels of the image sensor is at least 5

Millions. In further preferred embodiments of the digital microscope, the number of pixels of the

Image sensor at least 8 million. In other preferred embodiments of the digital microscope, the number of pixels of the image sensor is at least 20 million. at

further preferred embodiments of the digital

Microscope, the number of pixels of the image sensor is at least 50 million. For further preferred

Embodiments of the digital microscope, the number of pixels of the image sensor is at least 100 million.

In preferred embodiments of the digital microscope, the ratio between the height of the image sensor to a height of the individual pixels is at least 3,000. In further preferred embodiments of the digital microscope, the ratio between the height of the image sensor and the height of the individual pixels is at least 3,900. The ratio between the height of the image sensor and the height of the individual pixels is more preferably 3,900, 4,000, 5,000, 6,000, 7,000 or 10,000.

In preferred embodiments of the digital microscope, the ratio between the width of the image sensor is too a width of each pixel at least 2,000. In further preferred embodiments of the digital

Microscope is the ratio between the width of the image sensor to the width of the individual pixels at least 2,800. The ratio between the width of the image sensor and the width of the individual pixels is more preferably 2,800, 3,000, 4,000, 5,000, 7,000 or 10,000.

The width of the image sensor is preferably between 6 mm and 25 mm; more preferably between 7 mm and 10 mm. The height of the image sensor is preferably between 4 mm and 25 mm; more preferably between 7 mm and 10 mm.

The objective has a numerical aperture, which is preferably at most 1.4. The numerical aperture is more preferably at most 1. The numerical aperture is

more preferably 0.25; 0.5; 0.8; 1.0 or 1.4.

At least one filter is preferably arranged in front of the image sensor. For example, in front of each pixel of the

Image sensor a filter with one of three colors can be arranged. The filter or filters can be tuned.

In front of the image sensor, an optical element is preferably arranged, which leads to wavelength-dependent delays for the passing light, so that a spectral

Resolution by a Fourier spectroscopy is possible.

At least one polarizer is preferably arranged in front of the image sensor. Preferably, a plurality of the polarizers is arranged in front of the image sensor, so that a spatially resolved polarized image of the sample can be recorded. The image processing unit of the digital microscope is preferably configured to process the signals from a plurality of the pixels of the image sensor with different delays in order to achieve temporal resolution, whereby, for example, spatially unresolvable regions of the sample can be resolved. Thus, a spatial resolution and a temporal resolution can be achieved.

The image processing unit of the digital microscope is preferably configured to receive the signals from a plurality of the

Process pixels of the image sensor with different sensitivities and / or different gains, whereby, for example, spatially unresolvable areas of the sample can be resolved.

In preferred embodiments of the digital microscope, the magnification factor of the objective can be changed from a minimum magnification factor to the maximum magnification factor, such that the objective is embodied, for example, as a zoom objective. The maximum image resolution of the

Image sensor according to the invention is independent of the selected

Magnification factor is generally finer than the optical resolution of the lens. The achievable with the digital microscope resolution is constant and determined only by the maximum image resolution of the image sensor.

The digital microscope is preferably designed for automated recording of portions of the sample. These

Subareas are also called tiles. It is therefore a so-called scanning microscope for large

Rehearse. Accordingly, the digital microscope preferably includes an automatically movable sample carrier with the aid of which the individual tiles can be accommodated. The digital microscope also includes a

Image processing unit designed to

to combine recorded images of the partial regions to form an image of the sample.

The digital microscope preferably comprises an electronic mobile device, which is preferably formed by a smartphone or by a tablet computer. The electronic

Mobile device includes a camera with the image sensor and

preferably at least a part of the objective. The

electronic mobile device preferably comprises the lens, which in the reverse direction also for macroscopic

Photographs, d. H. can be used for ordinary photographs with the mobile device. The lens can also be separated from the mobile device, so that the camera includes the image sensor, but not the lens.

A first exemplary embodiment of the digital microscope according to the invention has a digital zoom, but no optical zoom, so that the magnification factor of the

Lens is fixed. The microscope includes an image sensor that has 41 million pixels in a matrix of 7,152 by 5,360 active pixels. The image sensor is 8 mm by 6 mm in size. The digital zoom factor is 3.4 in a case where the converted image has a resolution of 1,600 by 1,600 pixels without interpolation or extrapolation. The digital zoom factor is 6 in a case where the converted image has a resolution of 1,000 by 1,000 pixels without interpolation or extrapolation.

A second exemplary embodiment of the

Digital microscope according to the invention is a

High-speed scanning microscope for large samples. The Microscope includes an image sensor that has 41 million pixels in a matrix of 7,152 by 5,360 active pixels. The image sensor is 8 mm by 6 mm in size. The microscope includes a lens with a numerical aperture of 0.25 and a magnification factor of 5. This lens performs in this

Embodiment of the microscope according to the invention to a 16 times faster digitization of the sample than in a microscope according to the prior art with a lens with a numerical aperture of 0.25 and a

Magnification factor of 20. The microscope comprises alternatively a lens with a numerical aperture of 0.5 and a magnification factor of 10. In this embodiment of the microscope according to the invention, this objective leads to a 16 times faster digitization of the sample than in the case of a microscope according to the prior art Technique with a lens with a numerical aperture of 0.5 and one

Magnification factor of 40. The microscope comprises alternatively a lens with a numerical aperture of 0.8 and a magnification factor of 20. In this embodiment of the microscope according to the invention this lens leads to a

20 times faster digitization of the sample than in a prior art microscope with a lens with a numerical aperture of 0.8 and one

Magnification factor of 100. The microscope alternatively includes a lens with a numerical aperture of 1.0 and one

Magnification factor of 20. In this embodiment of the microscope according to the invention, this objective leads to a 56 times faster digitization of the sample than in the case of a microscope according to the prior art with a lens with a numerical aperture of 1.0 and one

Magnification factor of 150. The microscope alternatively includes a lens with a numerical aperture of 1.4 and a magnification factor of 40. This lens performs in this Embodiment of the microscope according to the invention for a 14 times faster digitization of the sample than in a microscope according to the prior art with a lens with a numerical aperture of 1.4 and a

Magnification factor of 150.

A third exemplary embodiment of the

Digital microscope according to the invention is a

High-speed scanning microscope for large samples. To illustrate the invention, it is assumed by way of example that a sample is microscoped at a suitable resolution, resulting in an image of 15,000 by 7,000 pixels. The digital microscope includes in this

Embodiment an image sensor having 18 million pixels in a matrix of about 5,000 by 3,500 active pixels and a refresh rate of 10 frames per second

allows. Accordingly, a breakdown in

(15,000 / 5,000) · (7,000 / 3,500) = 3 -2 = 6 tiles required. The positioning of the sample takes about every tile

2 seconds. Accordingly, the recording of the entire takes

Sample: 6 · 1 / (10 1 / s) + 6 · 2 s ~ 13 s. Alternatively, the frame rate is 1 frame per second, resulting in a total sample time of 6 x 1 / (1 1 / s) + 6 - 2 s = 18 seconds. In comparison, a digital microscope according to the prior art, for example, an image sensor, the

Has 2 million pixels in a matrix of about 2,000 by 1,000 active pixels and a frame rate of 25

Images per second possible. Accordingly, one is

Division into (15,000 / 2,000) · (7,000 / 1,000) * 7 -7 = 49

Tiles required. The positioning of the sample takes about 1 second for each tile. Accordingly, the total sample takes up to 49 · 1 / (25 1 / s) + 49 · 1 s ~ 51 s. This comparison clarifies that the inventive digital Microscope in this embodiment allows multiple times faster recording of the entire sample.

A fourth exemplary embodiment of the

A digital microscope according to the invention comprises

electronic mobile device in the form of a smartphone,

Tablet computers or the like. The electronic mobile device comprises a camera with an image sensor, which the

Image sensor of the microscope forms. The image sensor has a small pixel pitch of less than 2.0 ym and a large one

Pixel count of 8, 13, 20, 40, 50 or 100 million pixels.

In the following Table 1, parameters are seven

various embodiments of the invention

Microscopes listed. In each case the magnification factor M of the objective is indicated in the first column. In the second column, the numerical aperture NA of the objective is indicated in each case. In all seven embodiments, light having a central wavelength λ = 500 nm is used. In all seven embodiments, the resolution factor is

RF = 1.22. In the third column in each case the optical resolution Δχ of the lens is indicated. The optical resolution Δχ results according to the Rayleigh criterion as

Δχ = RF · λ / (2 · NA). To indicate the representable

Line pairs assume that each of the line pairs is as wide as the optical resolution Δχ, so that the number of line pairs LP per mm is 1 / Ax in the fourth column. Furthermore, a factor of 4 based on the Nyquist condition is assumed. In the fifth

Column is the resulting from this invention

Pixel distance PP of the image sensor specified. Preferably, the pixel pitch is smaller than the specified value. M NA Δχ in nm LP per mm PP in ym

2.50 0.075 4076 246 2.542

10 0.45 678 1475 1, 694

20 0.8381 2623 1, 906

40 0, 95 321 3115 3,211

63 1.4 218 4590 3.431

25 0.3 1017 984 6, 354

Table 1.

Further details and developments of the invention will become apparent from the following description

Embodiments of the invention, with reference to the drawing. 1 is a diagram showing the dependence of the resolution on the magnification factor in a microscope according to the invention and in a microscope according to the prior art; a comparative representation of embodiments of the microscope according to the invention and microscopes according to the prior art; and a further illustration of two embodiments of the microscope according to the invention.

1 shows a diagram for depicting the dependence of the resolution of a microscope on the magnification factor of the microscope in a preferred embodiment of a microscope

microscope according to the invention and in a microscope according to the prior art. On the x-axis of the diagram is the Magnification factor applied. On the y-axis of the diagram, the resolution is plotted in ym. A first graph Ol of several points shows the dependence of the resolution on the magnification factor for a microscope according to the prior art. The resolution is not constant and comes with

increasing magnification factor, approaching a minimum value. A second graph 02 shows the

Dependence of the resolution on the magnification factor for a preferred embodiment of the invention

digital microscope. The resolution is not of that

Magnification factor dependent and always has the minimum value compared to the prior art.

Fig. 2 shows a comparative illustration of

Embodiments of the microscope according to the invention and

Microscopes according to the prior art. They are a first embodiment 04, a second embodiment 05 and a third embodiment 06 according to the prior art

shown. It is still a first preferred

Embodiment 07 and a second preferred embodiment

Represented 08 of the microscope according to the invention. In each case, a sample 10, an objective 11 and an image sensor 12 are shown. The objective 11 of the first embodiment 04 according to the prior art has a fixed

Magnification factor on. The image sensor 12 of the first

Prior art embodiment 04 has a large pixel pitch, so it is local

Sub-sampling comes. The image sensor 12 of the second

Embodiment 05 according to the prior art and the

Image sensors 12 of the third embodiment 06 according to the prior art are each in a smartphone (not

shown) and have a smaller one

Pixel pitch on. In the smartphone is one each Lens 13, which forms a part of the lens 11 at the same time. The lens 11 of the third embodiment 06 also has an eyepiece 14. Since the distance of the smartphone is changeable, the magnification factor also changes. However, the achievable figure is not the respective

Image sensor 12 adapted. The first embodiment 07 and the second embodiment 08 of the microscope according to the invention differ from the embodiments 04, 05, 06 according to the prior art in particular in that they have a small magnification factor of at most 40.

This also results in a larger field of view. The image of the objective 11 is in the two embodiments 07, 08 according to the invention on the image sensor 12 with a small pixel pitch of at most 2.0 ym

adjusted so that a local oversampling is ensured.

FIG. 3 shows a further illustration of two embodiments of the microscope according to the invention. It's a third one

preferred embodiment 16 and a fourth preferred

Embodiment 17 of the microscope according to the invention

shown, which in turn each include the lens 11 and the image sensor 12. The lens 11 of the third

Embodiment 16 includes two equal partial lenses 20, each of which may comprise a group of lenses or a single lens. The fourth embodiment 17 comprises an automatic focusing device 21 with a further objective 22 and a further image sensor 23. The fourth embodiment 17 comprises a beam splitter 24, which passes through a 50/50 beam splitter through a beam splitter

Polarization beam splitter can be formed by a mirror or by an interference beam splitter. Of the

Beam splitter 24 is optionally removable. The pixel pitch of the image sensor 12 of the third

Embodiment 16 is 1 ym while the pixel pitch of the image sensor 12 of the fourth embodiment 17 is 2 ym. The number of pixels of the image sensor 12 is 15.2 million by way of example. The magnification factor of the objective 11 of the third and fourth embodiments 16, 17 is 4 and alternatively 10 or 20. The third

Embodiment 16 is designed as a scanning microscope, for which the image sensor 12 is displaceable.

The small value of the pixel pitch of at most 2 ym leads to an improvement of the image quality, in particular to an aberration-free image. In addition, the small value of the pixel pitch of at most 2 ym allows fast

Autofocusing by multi-spot measurement using a lens with a small magnification factor of 40 or less, e.g. 4, 10 or 20. Inasmuch as the objective has a magnification factor of 4, the image sensor must have at least 15.2 million pixels. Insofar that

Objectively has a magnification factor of 10, the image sensor must have at least 2.5 million pixels.

Insofar as the objective has a magnification factor of 20, the image sensor must have at least 630,000 pixels. Will a lens with a higher

Magnification factor is used, then an image sensor with a smaller number of pixels to achieve the same

Function needed. Insofar the lens one

Magnification factor of 60, the image sensor must have at least 68,000 pixels. Insofar the lens one

Magnification factor of 100, the image sensor must have at least 33,000 pixels. LIST OF REFERENCE NUMBERS

01 first graph

02 second graph

03

04 first embodiment according to the prior art

05 second embodiment according to the prior art

06 third embodiment according to the prior art

07 first embodiment of the microscope according to the invention

08 second embodiment of the microscope 09 according to the invention

10 samples

11 lens

12 image sensor

13 lens

14 eyepiece

15

16 third embodiment of the microscope according to the invention

17 fourth embodiment of the microscope 18 according to the invention

19

20 partial lens

21 Automatic focusing device

22 more lens

23 more image sensor

24 beam splitters

Claims

Patent claims

1. Digital microscope (07; 08; 16; 17); full:

an objective (11) for enlarged optical imaging of a sample (10) in an image plane, an image with an optical resolution in the image plane being able to be displayed by the objective (11); and

an image sensor (12) for converting the image imaged by the lens (11) onto the image sensor (12) into an electrical signal, the image sensor (12) comprising a matrix of pixels by which a maximum image resolution of the image sensor is determined;

characterized in that the maximum image resolution of the image sensor (12) is finer than the optical resolution of the lens (11), and that the lens (11) has a maximum magnification factor of at most 40, the optical resolution of the lens (11) being a minimum distance between two distinguishable in the image

Structures is defined, the maximum image resolution of the image sensor (12) being defined by a pixel distance, and a quotient of the minimum distance between two structures that can be distinguished in the image and the

Pixel pitch defines a sampling factor that is at least five.

2. Microscope (07; 08; 16; 17) according to claim 1, thereby

characterized in that the maximum magnification factor of the lens (11) is at most 20.

3. Microscope (07; 08; 16; 17) according to claim 2, thereby

characterized in that the maximum magnification factor of the lens (11) is at most 10.

4. Microscope (07; 08; 16; 17) according to one of claims 1 to 3, characterized in that a pixel spacing of the

Image sensor (12) is at most 2 ym.

5. Microscope (07; 08; 16; 17) according to claim 4, thereby

characterized in that the pixel spacing of the image sensor (12) is at most 1.85 ym.

6. Microscope (07; 08; 16; 17) according to one of claims 1 to 5, characterized in that the number of pixels of the image sensor (12) is at least 8 million.

7. Microscope (07; 08; 16; 17) according to claim 6, thereby

characterized in that the number of pixels of the image sensor (12) is at least 20 million.

8. Microscope (07; 08; 16; 17) according to claim 7, thereby

characterized in that the number of pixels of the image sensor (12) is at least 50 million.

9. Microscope (07; 08; 16; 17) according to one of claims 1 to

8, characterized in that the ratio of a height of the image sensor (12) to a height of the individual pixels of the image sensor (12) is at least 3,900.

10. Microscope (07; 08; 16; 17) according to one of claims 1 to

9, characterized in that the ratio of a width of the image sensor (12) to a width of the individual pixels of the image sensor (12) is at least 2,800.

11. Microscope (07; 08; 16; 17) according to one of claims 1 to 10, characterized in that the objective (11) has a numerical aperture which is at most 1.4.

12. Microscope (07; 08; 16; 17) according to claim 11, characterized

characterized in that the numerical aperture of the lens is at most 1.

13. Microscope (07; 08; 16; 17) according to one of claims 1 to 12, characterized in that the magnification factor of the objective (11) can be changed from a minimum magnification factor to the maximum magnification factor, the maximum image resolution of the image sensor ( 12) is greater than the optical resolution of the objective (11), regardless of the selected magnification factor.

14. Microscope (16) according to one of claims 1 to 13, characterized in that it is designed for automated recording of partial areas of the sample (10), an image processing unit of the microscope (16) being designed to record images of the partial areas to combine an image of the sample (10).

15. Microscope (16) according to one of claims 1 to 14, characterized in that it comprises an electronic mobile device which is formed by a smartphone or by a tablet computer and which comprises a camera with the image sensor.