Digital microscope and microscopy kit

Abstract

Digital microscope and microscopy kit. The invention relates to a digital microscope for capturing images of a sample with an extended depth of field. The microscope comprises a holder (01) with an opening (16) for receiving an optical unit (07). The microscope further comprises an optical unit (07) with an objective (08), an image sensor and a micro electro mechanical optical system on the optical path from the objective (08) to the image sensor. The micro electro mechanical optical system is configured for extending the depth of field on the optical path. According to the invention, the imaging unit (07) comprises a mounting unit (13) comprising a first part (14) for detachably mounting the mounting unit (13) into the opening (16) of the holder (01), a second part (18) for detachably mounting an illumination unit (17) onto the mounting unit (13) and a third part (21) for detachably mounting an additional lens (19) onto the mounting unit (13) and into the optical axis (22) of the objective (08). In addition, the invention relates to a microscopy kit.

Description

TECHNICAL FIELD

[0001] The present invention relates to a digital microscope for capturing images of a sample to be microscopically examined with an extended depth of field. In addition, the present invention relates to a microscopy kit. BACKGROUND

[0002] The paper "A method to increase the depth of focus by two step image processing" by Häusler, G, in Optics Communications, Volume 6, Issue 1, September 1972, Pages 38-42 teaches a method to obtain an increased depth of field. The method consists of two steps. The first step is to produce a modified incoherent image of the three-dimensional object which, although degraded, has the same degradation for all object planes. The second step is to filter the modified image in a coherent image processor to obtain an un-degraded image with an increased depth of field.

[0003] US 2005 / 0057812 Al shows a variable focus system including an electrically variable optic and a controller operatively configured to vary a focus configuration of the electrically variable optic. The electrically variable optic includes a plurality of moveable optical elements that can be moved substantially in unison with one another to vary either or both of a focal length of the electrically variable optic, a direction of a focal axis of the electrically variable optic. The variable focus system can be used in conjunction with an image source to construct a 3D floating image projector that projects a series of 2D images.

[0004] US 2013 / 0187669 Al shows a calibration method for a micro-mirror array device. The micro-mirror array device can be operated as a variable focal length lens. The calibration method includes determining a capacitance value for each micro-mirror element in the array device at a plurality of predetermined reference angles to provide a capacitance-reference angle relationship. From the capacitance values, an interpolation step is performed to determine an intermediate tilt angle for each micro-mirror element in the array. A voltage sweep is applied to the micro-mirror array and the capacitance value for each micro-mirror element in the array is measured. For a capacitance value that matches one of the values in the capacitance-reference angle relationship, the corresponding voltage is linked to the associated tilt angle to provide a voltage-tilt angle characteristic which is subsequently stored in a memory for subsequent use.

[0005] US 2005 / 0225884 A1 teaches a three-dimensional imaging device with a variable focus micromirror array lens, also called Micromirror Array Lens System (MALS) and Micromirror Array Lens (MMAL). The MMAL is a reflective Fresnel lens. The imaging device further comprises an optical unit on which an image of an object at a given focal length of the MMAL is formed.

[0006] US 2014 / 0368920 A1 shows a micromirror array configured for a variable focus lens. The variable focus lens comprises a micromirror array having a plurality of micromirror elements arranged in at least a first section and a second section. Each micromirror element has a tilt axis and comprises at least one actuation electrode, at least one measurement electrode and at least one stop on each of two opposite sides of the tilt axis. Additionally, each micromirror element in the first section has a first tilt axis range. Each micromirror element in the second section has a second tilt axis range. The first tilt axis range is smaller than the second tilt axis range.

[0007] DE 10 2017 101 188 A1 relates to a method for observing a sample using a microscope comprising an objective and an image sensor for converting an image formed by the objective on the image sensor. The field of view of the microscope can be changed by selecting a section of the image sensor. In one step of the method, an initial image of at least a partial section of the sample is captured by the microscope for which a first field of view is selected on the microscope. The initial image is analyzed to determine at least two different fields of view forming a partial area image. The partial area of the initial image is formed by each of the fields of view forming the partial area image. For each of the determined fields of view forming the partial area image, an image of the partial area of the sample is captured.

[0008] DE 10 2017 107 489 B3 relates to a microscope assembly for three-dimensional capturing of a sample to be microscopically examined and for displaying a three-dimensional image of the sample under a microscope. The microscope assembly comprises an image capturing unit for obtaining a photo of the sample and an image processing unit for generating a three-dimensional image of the sample from the photo. Furthermore, the microscope assembly comprises at least one display unit for three-dimensional display of the generated three-dimensional image of the sample. The microscope assembly is configured with an image refresh rate of at least 1 frame per second.

[0009] DE 10 2017 123 510 A1 relates to a method for acquiring a stack of microscopic images of a sample. The stack of microscopic images is acquired from different focal positions. Multiple microscopic images of the sample are acquired from at least some of the focal positions using different settings of an illumination unit for illuminating the sample. In each case, for at least several focal positions, the illumination settings for acquiring microscopic images of the sample through them are individually determined.

[0010] WO 2005 / 119331 A1 teaches a variable focal length lens comprising multiple micromirrors having two rotational degrees of freedom and one translational degree of freedom. Controlling the two rotational degrees of freedom and one translational degree of freedom of these micromirrors changes the focal length of the lens while satisfying the same phase condition for light. The lens is a diffractive Fresnel lens.

[0011] US 6,934,073 B1 teaches a micromirror array lens, also known as a micromirror array lens system (MALS) and a micromirror array lens (MMAL). A micromirror array lens consists of a plurality of micromirrors, each having one rotational degree of freedom and one translational degree of freedom, and an actuating component. As a reflective variable focal length lens, the micromirror array ensures that all light scattered from a point on an object has the same periodic phase and converges at a point on the image plane. As a method of operation for these lenses, the actuating component electrostatically and / or electromagnetically controls the position of the micromirrors. The optical efficiency of the micromirror array lens is increased by positioning the mechanical structure supporting the micromirrors and the actuating component below the micromirrors. These lenses can correct aberrations by independently controlling each micromirror.

[0012] WO 2007 / 134264 A2 discloses a three-dimensional imaging system with a variable focal length micromirror array lens. The micromirror array lens includes a plurality of micromirrors, wherein each of the plurality of micromirrors is controlled to change the focal length of the micromirror array lens. The imaging system further includes an optical unit and an image processing unit that uses the image captured by the optical unit and the focal length information of the micromirror array lens to generate three-dimensional image data.

[0013] EP 3 486 706 A1 teaches a functional module for a microscope. The functional module includes a mechanical interface for detachably mounting the functional module to a module support of the microscope. The functional module further includes an optical interface for establishing an optical path from the microscope objective to the functional module. Additionally, the functional module includes at least one image sensor and a first microelectromechanical optical system (MEMS-OES) and a second MEMS-OES. The first MEMS-OES is configured to enhance the depth of field on a first optical subpath pointing towards the image sensor. The second MEMS-OES is configured to enhance the depth of field on a second optical subpath pointing towards the image sensor. SUMMARY

[0014] It is an object of the present invention to provide a digital microscope and a microscopy kit that allows recording microscopic images with an extended depth of field and with an improved image quality and that maintains lateral resolution over the extended depth of field.

[0015] The microscope according to the present invention is a digital microscope, wherein the microscopic images are recorded electronically and processed digitally. The digital microscope preferably does not comprise any eyepiece.

[0016] The digital microscope is configured for capturing microscopic images of a sample to be microscopically examined, wherein the images present an extended depth of field. The depth is preferably increased by at least a factor of 5 and more preferably by at least a factor of 10 and more preferably by at least a factor of 20 and even more preferably by at least a factor of 40. The digital microscope is preferably configured to process the microscopic images with an extended depth of field into 2.5-dimensional or three-dimensional images. The digital microscope is preferably configured for processing at least 1 image per second with 2.5 or three dimensions. The digital microscope is also preferably configured for processing at least 10 images per second with 2.5 or three dimensions.

[0017] The digital microscope comprises a stand having an opening for receiving an optical unit. The stand is configured to be placed on a surface of a workspace, for example onto a table.

[0018] Further, the digital microscope comprises an optical unit for capturing microscopic images of a sample to be microscopically examined. The optical unit is mounted in a detachable manner on the stand. The optical unit is carried by the stand.

[0019] The optical unit comprises an objective for collecting light from the sample to be microscopically examined. The objective preferably comprises a plurality of optical lenses.

[0020] The optical unit comprises at least one image sensor for converting an image transmitted from the objective to the image sensor into an electrical signal. The image sensor then converts the image taken by the objective into an electrical signal. The image sensor is preferably a semiconductor, for example a CMOS. The image sensor is preferably further equipped with FPGA-based or CPU-based circuitry to further improve the speed or quality of the image processing or the processing of a stack of images.

[0021] Moreover, the optical unit comprises a micro-electro-mechanical optical system on the optical path from the objective to the image sensor. The micro-electro-mechanical optical system is configured for extending the depth of field on the optical path from the objective to the image sensor. The micro-electro-mechanical optical system is preferably a micromirror array lens system (MALS) or a micromirror array lens (MMAL).

[0022] According to the present application, the optical unit comprises a mounting unit. The mounting unit performs at least three functions. The mounting unit comprises a first portion for mounting the mounting unit in a detachable manner into a holder opening. Thereby, the optical unit is mounted into the opening of the holder. Thus, the optical unit can be mounted in a detachable manner onto the holder.

[0023] The mounting unit further comprises a second portion for mounting a lighting unit in a detachable manner onto the mounting unit. Thus, the lighting unit can be mounted in a detachable manner onto the optical unit. The lighting unit is configured to illuminate a sample to be microscopically examined. The microscope preferably comprises at least one lighting unit, wherein this one lighting unit and one of a plurality of lighting units are respectively mounted in a detachable manner onto the second portion of the mounting unit. Preferably, the lighting unit can be alternatively mounted onto the objective. The mounting of the lighting unit is preferably further supported by providing an interface for identifying the lighting unit and preferably for further integrating the lighting unit into a functional communication path between different sub-modules. This interface is preferably an electrical interface, a wireless interface, an optical interface or a contactless interface.

[0024] The mounting unit further comprises a third portion for mounting an additional lens in a detachable manner onto the mounting unit and into the optical axis of the objective. Thus, the objective can be supplemented by an exchangeable additional lens. The magnification of the microscope is changed by the additional lens. The microscope preferably comprises at least one additional lens, wherein this one additional lens and one of a plurality of additional lenses are respectively mounted in a detachable manner onto the third portion of the mounting unit.

[0025] This one and the plurality of additional lenses preferably respectively comprise a mounting interface for mounting a further lighting unit. The third portion of the mounting unit can preferably be used for mounting further components, like additional optomechanical units, a set of mirrors for tilting 360 degree observation or sample manipulation tools that can exert a magnetic or electric field on the sample.

[0026] A particular benefit of the microscope according to the present application is that by adding and / or exchanging additional lenses, images with an extended depth of field (EDoF) can be captured at different optical magnifications. A large object field on the low magnification side and a high optical resolution on the high magnification side can be provided. Since the microscope is configured for mounting additional lenses in a detachable manner, a high reproducibility of the optical configuration is guaranteed. The mounting unit ensures a robustness of the mounted additional lenses against vibrations in the operating site. Since the microscope is configured for mounting additional lenses in a detachable manner, different additional lenses can be exchanged for each other multiple times during the operating time of the microscope, preferably at least 100 times during the operating time of the microscope. The mounting unit allows an easy exchange of additional lenses and the mounting unit prevents user-induced errors. In addition, the mounting unit allows a flexible mounting of optical units to different types of holders and a flexible mounting of different types of optical units to the holder.

[0027] In a preferred embodiment of the microscope according to the present application, the opening of the holder exhibits a circular cross-section. The first part of the mounting unit exhibits a circular cross-section which fits into the circular cross-section of the opening of the holder. The circular cross-section allows an easy detachable mounting of the optical unit to the holder. The optical unit is mounted by putting the first part of the mounting unit into the opening of the holder. The holder preferably comprises a clamping element for clamping the first part of the mounting unit within the opening of the holder. In alternative embodiments, the cross-section of the first part of the mounting unit and the opening of the holder can be rectangular shaped, polygonal shaped, elliptical shaped or irregularly shaped.

[0028] Preferably, the first part of the opening unit is cylindrical shaped. This cylindrical shape can easily be put into the opening of the holder. This cylindrical shape can be reliably fixed within the opening of the holder. This cylindrical shape is preferably arranged coaxially to the optical axis which is preferably arranged vertically. A standard in the field of microscopy is that the opening unit of the holder is cylindrical shaped. Many types of holders provide such an opening.

[0029] Preferably, the second part of the opening unit has a cylindrical shape. A standard in the field of microscopy is that the illumination unit can be mounted in a detachable manner to a part which has a cylindrical shape. Many types of microscopes provide such a part. Thus, many types of illumination units can be mounted to the microscope of the present application.

[0030] In a preferred embodiment of the microscope according to the application, the first part and the second part of the mounting unit are arranged coaxially. Preferably, the first part and the second part are arranged coaxially with an optical axis, wherein the optical axis is preferably arranged vertically. The first part and the second part of the mounting unit are preferably arranged one above the other. The first part and the second part of the mounting unit are preferably arranged next to each other. The mounting unit can comprise an extension at the first part or the second part.

[0031] Preferably, the diameter of the first part of the mounting unit is larger than the diameter of the second part of the mounting unit. Thus, a circumferential step is formed between the first part and the second part.

[0032] In a preferred embodiment of the microscope according to the application, the diameter of the first part of the mounting unit is between 50 mm and 100 mm. The diameter is preferably 76 mm, as this is a general standard in the field of microscopy. Thus, the diameter of the first part of the mounting unit is preferably configured according to the 76 mm standard. The diameter of the second part of the mounting unit is preferably between 50 mm and 100 mm. The diameter is preferably 66 mm, as this is a general standard in the field of microscopy. Thus, the diameter of the second part of the mounting unit is preferably configured according to the 66 mm standard.

[0033] In a preferred embodiment of the microscope according to the application, the third part of the mounting unit is formed as part of a bayonet mount, which part is for receiving a counterpart of the bayonet mount. The counterpart is formed at the additional lens. Thus, the additional lens can be easily and reliably mounted onto the optical unit. The counterpart of the bayonet mount is preferably also formed at a further illumination, or at a set of mirrors for a 360-degree observation, or at a manipulation tool for manipulating the sample.

[0034] In a preferred embodiment of the microscope according to the application, the first part of the mounting unit, the second part of the mounting unit and the third part of the mounting unit are arranged coaxially. Preferably, the first part of the mounting unit, the second part of the mounting unit and the third part of the mounting unit are arranged coaxially with an optical axis, which is preferably arranged vertically. The first part of the mounting unit, the second part of the mounting unit and the third part of the mounting unit are preferably arranged one above the other. The second part of the mounting unit and the third part of the mounting unit are preferably arranged next to each other.

[0035] The diameter of the third part of the mounting unit is preferably between 10 mm and 50 mm.

[0036] In a preferred embodiment of the microscope according to the application, the counterpart of the bayonet mount is formed by at least two wings at the circumference of the additional lens. Preferably, there are three wings at the circumference of the additional lens. These wings and / or the spaces between these wings exhibit preferably different arcs in order to allow only one rotational position when mounting the bayonet mount. Thus, the wings are preferably not symmetrical. The part of the bayonet mount formed by the third part of the mounting unit is preferably formed by an opening in the mounting unit. This opening exhibits at least two slots for receiving the wings at the circumference of the additional lens. Each of the additional lenses comprises a counterpart of the bayonet mount, wherein all counterparts fit to the part of the bayonet mount formed by the third part of the mounting unit.

[0037] In a preferred embodiment of the microscope according to the application, the third part of the mounting unit comprises first electrical contacts for electrically contacting second electrical contacts comprised by the additional lenses. The first electrical contacts electrically contact the second electrical contacts when the additional lenses are mounted onto the third part of the mounting unit. The second electrical contacts of the additional lenses are electrically connected to an identification circuit arranged within or at the ring of the lens. Preferably, each of the additional lenses exhibits such second electrical contacts. Thus, it is possible to identify the mounted additional lenses at the microscope. The number of first electrical contacts is preferably four. The number of second electrical contacts is preferably four.

[0038] In a preferred embodiment of the microscope according to the application, at least one additional lens is optically configured for providing an additional optical magnification of a sample to be microscopically examined. Thus, the optical magnification of the microscope is changed when one of the additional lenses is mounted in a detachable manner onto the mounting unit. The optical magnification overall on the microscope depends on the optical magnification of the objective and on the optical magnification of the mounted additional lens. The optical magnification of the microscope is preferably between 0.2 and 5. In case no additional lens is mounted onto the microscope, the optical magnification of the microscope depends only on the optical magnification of the objective. The optical magnification of the objective is preferably between 1 and 1.5.

[0039] The image sensor exhibits preferably a length and / or width between 3 / 4 inch (1.905 cm) and 3 / 2 inch (3.8 cm). If the optical magnification of the microscope including the mounted additional lens is less than 0.5, the field of view related to an image sensor having a length of 1 inch (2.54 cm) exhibits preferably a length of at least 30 mm. If the optical magnification of the microscope including the mounted additional lens is more than 2, the field of view related to an image sensor having a length of 1 inch (2.54 cm) exhibits preferably a length of at most 6 mm.

[0040] If the optical magnification of the microscope including the mounted additional lens is greater than 2, the extended depth of field realized by the micro-electro-mechanical optical system is preferably at least ±0.5 mm. If the optical magnification of the microscope including the mounted additional lens is less than 0.5, the extended depth of field realized by the micro-electro-mechanical optical system is preferably at least ±30 mm.

[0041] Each of the additional lenses preferably comprises a spacer ring defining a distance between the lens element of the additional lens and the mounting element of the additional lens. In addition to or as an alternative to a spacer, a further element, like a dedicated illumination unit, is preferably mounted between the lens element of the additional lens and the mounting element of the additional lens. The mounting element of the additional lens is preferably a counterpart of the bayonet mount. The correct functioning of the additional lenses as well as of the objective is guaranteed by the defined distance. A working distance preferably extends from the detachably mounted additional lens, in particular from the lens element of the detachably mounted additional lens, to a sample holder of the microscope. The sample holder is preferably part of the stand. The working distance is preferably vertical. The working distance preferably varies between 10 mm and 150 mm. The working distance preferably varies in a range of at least 70 mm, more preferably in a range of at least 100 mm.

[0042] In a preferred embodiment of the microscope according to the application, the stand comprises a riser for lifting and lowering the optical unit. By using the riser, the working distance is variable. The working distance is preferably also changeable by adjusting the sample holder. The riser preferably comprises a vertical strut and a horizontal arm. The arm is supported by the strut.

[0043] In a preferred embodiment of the microscope according to the application, the optical unit comprises a housing covering at least the image sensor and the micro-electro-mechanical optical system. The housing is preferably permanently fixed to the mounting unit. The housing is preferably permanently fixed to the objective.

[0044] In a preferred embodiment of the microscope according to the application, the optical unit is configured for operation in at least a fixed combination of the micro-electro-mechanical optical system, the mounting unit and the objective. The fixed combination preferably also comprises the housing. A special benefit of such a fixed combination is that it guarantees a high reproducibility of the optical configuration, because the user does not have to replace anything of such a combination. The user has to replace the additional lenses.

[0045] In a preferred embodiment of the microscope according to the application, the image sensor is also exchangeable. Thus, different types of image sensors can be mounted into the optical unit.

[0046] In a preferred embodiment of the microscope according to the invention, the optical unit comprises a first beamsplitter for optically coupling the micro electro mechanical optical system into the optical path from the objective to the image sensor. The micro electro mechanical optical system is thus configured for extending the depth of field over the optical path. The optical unit preferably comprises a first mirror for guiding light from the first beamsplitter to the image sensor.

[0047] In a preferred embodiment of the microscope according to the invention, the micro electro mechanical optical system comprises an array of movable micro mirrors, also referred to as micro mirror array lens system (MALS) and micro mirror array lens (MMAL). Each of the movable micro mirrors exhibits at least one rotational degree of freedom and one translational degree of freedom. The translational degree of freedom of the movable micro mirrors of the micro electro mechanical optical system is preferably along the optical path.

[0048] The micro electro mechanical optical system is preferably a mirror array lens system. Such mirror array lens systems are also referred to as micro mirror array lens system (MALS) and micro mirror array lens (MMAL) and they are provided under the trademark MALS.

[0049] In a preferred embodiment of the microscope according to the invention, the detachably mountable illumination unit is formed as a ring light illumination. If the illumination unit is detachably mounted to the third portion of the mounting unit, the ring light illumination is coaxial with the optical axis, which is preferably vertical. The ring light illumination preferably surrounds the mounted additional lens.

[0050] The detachably mountable illumination unit preferably has a circular ring shape. The illumination unit preferably comprises a plurality of light emitting elements arranged on a circle of the circular ring shape. These light emitting elements are preferably light-emitting diodes (LEDs). Each circle comprises a plurality of LEDs. These circles are preferably concentric. These circles are preferably in a plane perpendicular to the optical axis of the microscope. This plane is preferably horizontal. Preferably, there are a plurality of illumination planes, which can have different or the same light emitting element orientation.

[0051] In a preferred embodiment of the microscope according to the invention, the circles of light emitting elements are individually powerable. Thus, each of the circles can be individually controlled to emit light.

[0052] Each of the circles of light emitting elements is preferably subdivided into at least four sectors. These sectors are preferably equal. These sectors of light emitting elements are individually powerable. Thus, each of these sectors can be individually controlled to emit light. Preferably, each sector in each of the circles is individually powerable. The number of sectors is preferably eight.

[0053] Each of the circles of light emitting elements exhibits a diameter. These diameters are different. The largest of these diameters is preferably more than twice the smallest of these diameters. The largest of these diameters is preferably between 5 cm and 15 cm. The smallest of these diameters is preferably between 2 cm and 7 cm.

[0054] The circles and / or sectors of light emitting elements of the illumination unit of the microscope allow for a uniform illumination of the sample over the entire field of view and allow for different magnifications caused by additional lenses.

[0055] In a preferred embodiment of the microscope according to the application, the optical unit comprises a coaxial illumination unit fixedly mounted to the objective. The coaxial illumination unit is preferably located in the housing. The coaxial illumination unit preferably comprises a single full-field illumination unit or a set of illumination fields. The number of illumination fields is preferably two or four or more. The optical unit preferably comprises a second beamsplitter for coupling light of the coaxial illumination unit into the optical path from the image sensor to the sample. The optical unit preferably comprises a second mirror for directing light of the illumination unit to the second beamsplitter. The second mirror is preferably movable to compensate for additional distances caused by the mounting unit. The second beamsplitter and the second mirror are preferably also located in the housing.

[0056] A preferred embodiment of the microscope according to the application further comprises control circuitry for controlling the micro electro-mechanical optical system and the image sensor. Preferably, the control circuitry is further configured for processing the images converted by the image sensor.

[0057] Preferably, the control circuitry is further configured for forming a lens surface of the micro electro-mechanical optical system, which is preferably a micro mirror array lens system (MALS) or a micro mirror array lens (MMAL).

[0058] Preferably, the control circuitry is further configured for acquiring a plurality of images with different focus values, thereby creating a stack of images. The different focus values are obtained by controlling the micro electro-mechanical optical system, in particular by moving the movable micro mirrors of the micro electro-mechanical optical system, more in particular by moving the movable micro mirrors of the micro electro-mechanical optical system to form lens surfaces of the micro electro-mechanical optical system each having a different focus value.

[0059] Preferably, the control circuitry is further configured for processing the stack of images into an image with an extended depth of field.

[0060] Preferably, the control circuitry is further configured for processing the stack of images into an image with an extended depth of field to obtain a 2.5-dimensional image or a three-dimensional image. Preferably, the control circuitry is further configured for processing a plurality of stacks of images into a plurality of images with an extended depth of field to obtain a three-dimensional image.

[0061] Preferably, the control circuitry is further configured to identify the mounted additional lens by reading out an identification circuit of the mounted additional lens. Preferably, the calibration data of each of the additional lenses is stored in the control circuitry or in the identification circuit. The control circuitry is preferably configured to use these data to fully calibrate the microscope for the mounted additional lens.

[0062] Preferably, the control circuitry is further configured to control the mounted illumination unit, in particular to control individual circles and / or individual sectors of the light emitting elements of the mounted illumination unit.

[0063] The control circuitry is preferably located in the housing.

[0064] The optical unit preferably comprises a power source to power the micro electro mechanical optical system and the image sensor. The power source is preferably further to power the coaxial illumination unit. The power source is preferably further to power the control circuitry. The power source is preferably further to power the mounted illumination unit.

[0065] The optical unit preferably comprises a first data interface. The optical unit is controllable via this first data interface, for example by a PC. This first data interface is preferably a USB interface, a GigE interface, a CamerLink interface or a CoaxExpress interface.

[0066] The optical unit preferably comprises a second data interface, which is connected to a light controller for controlling the mounted illumination unit.

[0067] The microscopy kit comprises a microscope according to the present application and at least two additional lenses, which are each mountable on the third part of the mounting unit. The additional lenses exhibit different optical magnifications. The microscopy kit preferably comprises a preferred embodiment of the microscope according to the present application.

[0068] A particular benefit of the microscopy kit according to the present application is that it provides a microscope and additional lenses for capturing images with an extended depth of field at different optical magnifications. By exchanging the additional lenses, the optical magnification can be easily changed.

[0069] The overall optical magnification of the microscope depends on the optical magnification of the objective and on the optical magnification of the mounted additional lens. This collective optical magnification of the objective and the mounted additional lens is preferably between 0.2 and 5. The collective optical magnification of the objective and the additional lens presenting the maximum optical magnification is preferably more than five times the collective optical magnification of the objective and the additional lens presenting the minimum optical magnification. The collective optical magnification of the objective and the additional lens presenting the minimum optical magnification is preferably less than 0.6. The collective optical magnification of the objective and the additional lens presenting the maximum optical magnification is preferably more than 2.

[0070] The microscopy kit preferably comprises at least two different illumination units, which are each mountable onto the second part of the mounting unit. Thus, the microscope can easily be adjusted to illuminate different samples, or to microscopically examine a sample at different optical magnifications. BRIEF DESCRIPTION OF DRAWINGS

[0071] Additional advantages, details and improvements of the present application will become apparent from the following description of preferred embodiments of the present application. There are shown:

[0072] Figure 1 : schematic representation of a preferred embodiment of a digital microscope according to the present application;

[0073] Figure 2 :: further schematic representation of a digital microscope shown in Figure 1

[0074] Figure 3 :: optical schematic representation of a digital microscope shown in Figure 2

[0075] Figure 4 :: detailed view of a ring light illumination unit shown in Figure 2 DETAILED DESCRIPTION

[0076] Figure 1 A schematic representation of a preferred embodiment of a digital microscope according to the present application is shown. The microscope comprises a stand 01 having a base plate 02, a column 03 and an arm 04. The arm 04 can be lifted by rotating a knob 06.

[0077] The microscope further comprises an optical unit 07 held by the stand 01. The optical unit 07 comprises an objective 08, an image sensor 09 (shown in Figure 3 Figure 3 a micro electro-mechanical optical system 12 (shown inThe mounting unit 13 performs three functions. The first function is to allow the optical unit 07 to be mounted in a detachable manner onto the stand 01. To this end, the mounting unit 13 comprises a first portion 14 having a cylindrical shape. This first portion 14 having a cylindrical shape fits into a circular opening 16 in the arm 04. This first portion 14 having a cylindrical shape presents an exemplary diameter of 76 mm.

[0078] The second function is to allow the ring light illumination unit 17 (as shown in Figure 2 Fig. 2) to be mounted in a detachable manner onto the optical unit 07. To this end, the mounting unit 13 comprises a second portion 18 having a cylindrical shape. This second portion 18 having a cylindrical shape presents an exemplary diameter of 66 mm. An extension tube (not shown) of the second portion 18 can be used to change the illumination working distance, or to alter the illumination working distance, or to the free space between the objective 08 and the sample 34 (as shown in Figure 3 Fig. 2). The extension tube maintains this diameter for easy adjustment of the mounting unit 13 or to provide a suitable diameter.

[0079] The third function is to allow the additional lens 19 (as shown in Figure 2 Fig. 2) to be mounted in a detachable manner onto the optical unit 07. To this end, the mounting unit 13 comprises a third portion 21. This third portion 21 forms part of a bayonet mount.

[0080] The ring light illumination unit 17 can alternatively be mounted on the additional lens 19 (as shown in Figure 2 Fig. 2) or onto the extension tube (not shown).

[0081] The mounting unit 13 is hollow and surrounds the objective 08. After the additional lens 19 (as shown in Figure 2 Fig. 2) is mounted onto the optical unit 07, the additional lens 19 (as shown in Figure 2 Fig. 2) is on the optical axis 22 of the microscope with the objective 08.

[0082] Figure 2 A further schematic representation of the digital microscope (as shown in Figure 1 Fig. 2) is shown. In this representation, the ring light illumination unit 17 and the additional lens 19 are mounted in a detachable manner onto the mounting unit 13.

[0083] Figure 3 An optical schematic representation of the digital microscope (as shown in Figure 2 Fig. 2) is shown. The image sensor 09 and the micro-electromechanical optical system 12 are co-located in the housing 11 (as shown in Figure 2 Fig. 2) with the first λ / 4 wave plate 26, the coaxial illumination unit 27, the second mirror 28, the first mirror 29, the illumination beam splitter 31 and the detection beam splitter 32.

[0084] Light 33 of the coaxial illumination unit 27 is guided via the second mirror 28 to the illumination beam splitter 31 to direct the light 33 through the objective 08, the second λ / 4 wave plate 36 and the detachably mounted additional lens 19 to the sample 34.

[0085] Light 37 reflected by the sample 34 is guided through the detachably mounted additional lens 19, the second λ / 4 wave plate 36, the objective 08, the illumination beam splitter 31, the detection beam splitter 32 and the first λ / 4 wave plate 26 to the micro electro mechanical optical system 12.

[0086] Light 38 reflected by the micro electro mechanical optical system 12 is guided through the first λ / 4 wave plate 26, the detection beam splitter 32 and the first mirror 29 to the image sensor 09.

[0087] The detachably mounted ring light illumination unit 17 also illuminates the sample 34. Thus, the sample 34 can be illuminated by the fixed coaxial illumination unit 27 and / or the detachably mounted ring light illumination unit 17.

[0088] Figure 4 A detailed view of the ring light illumination unit 17 is shown in Figure 2 The neutralization Figure 3 A detailed view of the ring light illumination unit 17 is shown in Figure 2 The view is a cross section perpendicular to the optical axis 22 (shown in

[0089] List of reference signs

[0090] 01 holder

[0091] 02 base plate

[0092] 03 post

[0093] 04 arm

[0094] 05 -

[0095] 06 knob

[0096] 07 optical unit

[0097] 08 objective

[0098] 09 image sensor

[0099] 10 -

[0100] 11 housing

[0101] 12 micro electro mechanical optical system

[0102] 13 mounting unit

[0103] 14 first part

[0104] 15 -

[0105] 16 opening

[0106] 17 annular light illumination unit

[0107] 18 second part

[0108] 19 additional lens

[0109] 20 -

[0110] 21 third part

[0111] 22 optical axis

[0112] 23 -

[0113] 24 -

[0114] 25 -

[0115] 26 first λ / 4 wave plate

[0116] 27 coaxial illumination unit

[0117] 28 second mirror

[0118] 29 first mirror

[0119] 30 -

[0120] 31 illumination beam splitter

[0121] 32 detection beam splitter

[0122] 33 light

[0123] 34 sample

[0124] 35 -

[0125] 36 second λ / 4 wave plate

[0126] 37 reflected light

[0127] 38 reflected light

[0128] 39 -

[0129] 40 -

[0130] 41 LED

[0131] 42 circle

[0132] 43 sector

Claims

1. A digital microscope for capturing images of a sample (34) to be examined under a microscope, having an extended depth of field, comprising: The bracket (01) has an opening (16) for receiving the optical unit (07). as well as Optical unit (07), the optical unit (07) comprising: Objective lens (08), which is used to collect light from the sample (34) to be examined under a microscope; An image sensor (09) is used to convert an image transmitted from the objective lens (08) to the image sensor (09) into an electrical signal; A microelectromechanical optical system (12) is configured to extend the depth of field along the optical path from the objective lens (08) to the image sensor (09); and Mounting unit (13), comprising a first part (14), a second part (18), and a third part (21), wherein the first part (14) is used to detachably mount the mounting unit (13) into the opening (16) of the bracket (01), the second part (18) is used to detachably mount the illumination unit (17) onto the mounting unit (13), and the third part (21) is used to detachably mount the additional lens (19) onto the mounting unit (13) and into the optical axis (22) of the objective lens (08). The opening (16) of the bracket (01) has a circular cross-section, and the first part (14) of the mounting unit (13) has a circular cross-section that fits into the circular cross-section of the opening (16) of the bracket (01). Wherein, the first part (14) of the mounting unit (13) is cylindrical; wherein, the second part (18) of the mounting unit (13) is cylindrical; wherein, the first part (14) and the second part (18) of the mounting unit (13) are arranged coaxially; and wherein, the diameter of the first part (14) of the mounting unit (13) is larger than the diameter of the second part (18) of the mounting unit (13), and The third part (21) of the mounting unit (13) is formed as part of the bayonet mount for receiving a mating object of the bayonet mount, wherein the mating object is formed at the additional lens (19).

2. The digital microscope according to claim 1, characterized in that, The diameter of the first part (14) of the mounting unit (13) is constructed according to the standard of 76 mm, wherein the diameter of the second part (18) of the mounting unit (13) is constructed according to the standard of 66 mm.

3. The digital microscope according to claim 1, characterized in that, The mating parts of the bayonet mount are formed by at least two wings at the circumference of the additional lens (19).

4. The digital microscope according to claim 1, characterized in that, The third part (21) of the mounting unit (13) includes a first electrical contact for contacting a second electrical contact of the additional lens (19), wherein the second electrical contact of the additional lens (19) is electrically connected to the marking circuit of the additional lens (19).

5. The digital microscope according to claim 1, characterized in that, The optical unit (07) is configured to operate in a fixed combination of the microelectro-optical system (12), the objective lens (08), and the housing (11) that at least covers the microelectro-optical system (12) and the image sensor (09).

6. The digital microscope according to claim 1, characterized in that, The microelectromechanical optical system (12) includes an array of movable micromirrors, wherein each of the movable micromirrors presents one rotational degree of freedom and one translational degree of freedom.

7. The digital microscope according to claim 1, characterized in that, The lighting unit (17) is formed as a ring-shaped lighting section; wherein the lighting unit (17) has a ring shape; wherein the lighting unit (17) includes a plurality of light-emitting elements (41), the plurality of light-emitting elements (41) being arranged on a circle (42) on the ring shape; and wherein the circle (42) of the light-emitting element (41) is individually powered.

8. The digital microscope according to claim 7, characterized in that, The circle (42) of the light-emitting element (41) is subdivided into at least four sectors (43), wherein the sectors (43) of the light-emitting element (41) are individually powered.

9. A microscope kit comprising a microscope according to any one of claims 1 to 8, and at least two additional lenses (19), each of the at least two additional lenses (19) being mountable onto the third portion (21) of the mounting unit (13), wherein, The additional lens (19) presents different optical magnification.

10. The microscope kit according to claim 9, characterized in that, The combined optical magnification of the objective lens (08) and the auxiliary lens (19) at their maximum optical magnification is greater than five times the combined optical magnification of the objective lens (08) and the auxiliary lens (19) at their minimum optical magnification.

11. The microscope kit according to claim 9 or 10, characterized in that, The common optical magnification of the objective lens (08) and the auxiliary lens (19) presenting the minimum optical magnification is less than 0.5; wherein the common optical magnification of the objective lens (08) and the auxiliary lens (19) presenting the maximum optical magnification is greater than 2.

12. The microscope kit according to claim 9 or 10, characterized in that, The microscope kit further includes at least two different illumination units (17), each of which can be mounted onto the second part (18) of the mounting unit (13).

Images