WO2022208223A1

WO2022208223A1 - Optical microscope

Info

Publication number: WO2022208223A1
Application number: PCT/IB2022/052479
Authority: WO
Inventors: Piotr WASYLCZYK
Original assignee: Uniwersytet Warszawski
Current assignee: Uniwersytet Warszawski
Priority date: 2021-03-31
Filing date: 2022-03-18
Publication date: 2022-10-06
Anticipated expiration: 2023-09-30
Also published as: PL437476A1; PL245406B1

Abstract

The invention relates to an optical microscope, preferably configurable one, comprising at least one objective and a detection optical system. In the microscope according to the invention, directly behind the microscope objective on the side of the detection optical system, there is a mirror set at an angle of 30-60°, preferably 45°, with respect to the optical axis of the microscope objective, for bending light beams passing through the objective in the direction from and towards the detection optical system, the optical elements of which are arranged in one or more horizontal planes. The microscope according to the invention is applicable for visual evaluation and image recording of samples in laboratory research in the fields of medicine, biology, chemistry, physics, geology, etc.

Description

OPTICAL MICROSCOPE

Field of the invention

The invention relates to an optical microscope, preferably a configurable one, wherein the optical elements of the detection optical system are arranged in one or more horizontal planes. The microscope according to the invention is applicable to the visual evaluation and image recording of samples in laboratory research in the fields of medicine, biology, chemistry, physics, geology, etc.

State of the art

Various designs of optical microscopes, both analogue and digital, are known. A typical optical microscope in its basic configuration comprises an objective or a turret head with several (usually two, three, four or six) objectives with magnifications usually between lx and lOOx. The rotation of the head allows the objective to be changed quickly on the optical path. The objective is directed towards a table with sample holders (in the case of plate samples) and a central through-hole, below which a light source or a mirror transmitting light from another external light source is installed. Other optical elements, such as a condenser, may be installed between the light source/mirror and the hole in the table. Typically, the microscope also has an eyepiece (or a pair of eyepieces) providing magnification usually in the order of lOx or 15x, or a camera for viewing and recording images. The eyepiece or camera is connected - physically and optically - to the objective via a tube or other body mounted on a stand attached to a base.

For example, US 2017/108688 discloses an optical system for use with a microscope, comprising a turret head provided with several objectives and configured to switch them on the optical path, the first objective being configured to transmit an image of the sample to a detector in the imaging position of the first objective, and the second objective comprising a directional optical element configured to form an optical path with an auxiliary detector and transmit an image of the sample to that detector in the imaging position of the second objective.

US 2018/284412, in turn, discloses an optical microscope comprisinga lightsource, a turret head provided with several objectives and configured to switch them on the optical path, a sensor detecting the objective positioned on the optical path, and an illumination adjustment system comprising a table of illumination levels for each of the objectives, a table of illumination level values indicated by the observer, a unit for adjusting the illumination level depending on the correlation of the values from the two tables, and a controller for adjusting the illumination level with respect to the aforementioned values.

Furthermore, US 2018/329174 discloses an optical microscope in an upright configuration, having a stand, a sample table, a turret head provided with several objectives and configured to switch them on the optical path, a tube comprising an optical system together with a pair of eyepieces, and elements such as a rotating ring and a hitch part for manually repositioning the objectives by rotating the head.

PL 179625 B1 discloses a coaxial illumination microscope, wherein the optical axis of the illuminator lying between the front plane of the optical fibre or other light source and the refracting element coincides with the axis of rotation of the magnification changer, and the optical axis of the illuminator behind the refracting element lies close to or coincides with the optical axis of the objective, wherein the light beam coming from the drum region of the changer is optically isolated, between the changer drum and the objective, from the vision path by an opaque cover.

WO 2014/210536A2 describes a microscope with a dual configuration: normal upright and inverted. The microscope comprises a base, a body and an objective. The base has an upper and a lower part, the latter being the support element of the microscope. The body has three parts, with the second, intermediate part, positioned between the first and third parts of the body, being rotatably connected to the upper part of the base. The axis of rotation extends in the longitudinal direction relative to the microscope. The objective is located closer to the first part of the body, and the light source is located closer to the second part of the body. Changing from the upright vertical configuration (with the objective directed downwards - for examining samples on glass plates) to the inverted configuration (with the objective directed upwards - e.g. for examining samples in vessels) requires the whole microscope body to be rotated 180° relative to the base.

On the market of optical microscopes, there is a niche of open designs where the user can configure the optical system of the microscope himself: light beam path, light sources, detectors, etc. In this way, the possibility of creating new optical systems in microscopy, later adapted by other users, is ensured. These types of designs are sometimes referred to as configurable microscopes. Example sets are disclosed in David G. Rosenegger et al. "A High Performance, Cost-Effective, Open-Source Microscope for Scanning Two-Photon Microscopy that Is Modular and Readily Adaptable” PLOS ONE, 1 October 2014, Vol. 9, Issue 10, el 10475. Optical system manufacturers offer such open platforms (e.g. the Cerna® system from Thorlabs), but all of them are based on a design in an upright arrangement, where, most often, successive microscope elements are placed (suspended) on a vertical column (acting as a stand). Such a design is inconvenient because it can reach considerable heights e.g. with a larger number of optical elements. It does not provide the possibility of using standard optical elements, and guiding the beams upright is dangerous due to the possibility of accidentally directing the laser beam into the eye. If an optical component is not mounted accurately, it can fall from a great height, damaging other components and damaging itself. A rather significant disadvantage of many such systems is also insufficient mechanical stability, which directly affects the result of observations made with such a configurable microscope, where the positions of the elements often have to be stable with an accuracy in the order of micrometres or more.

Among the known solutions, there are not any optical microscopes in an open configuration (adaptable by the user according to his specific needs) with easy access to all elements and light beams, using standard optical elements and ensuring the mechanical stability of the system.

Summary of the invention

The inventor of the present invention has found that bending the optical path just behind the microscope objective with a mirror so that the entire optical system is built horizontally, on one or more standard optical plates, avoids a number of disadvantages associated with the aforementioned solutions from the state of the art

The object of the invention is an optical microscope comprising at least one objective and a detection optical system, characterised in that directly behind the microscope objective on the side of the detection optical system, there is a mirror set at an angle of 30-60°, preferably 45°, with respect to the optical axis of the microscope objective, for bending light beams passing through the objective in the direction from and towards the detection optical system, the optical elements of which are arranged in one or more horizontal planes.

Preferably, the microscope according to the invention comprises a support structure on which the following are successively mounted, preferably removably:

- a sample holder,

- at least one microscope objective,

- a mirror positioned directly behind the microscope objective and set at an angle of 30- 60°, preferably 45° with respect to the optical axis of the microscope objective,

- a detection optical system, wherein the microscope also has a system for adjustingthe relative position of the components, and the optical elements of the optical system are mounted on the support structure in one or more horizontal planes.

Preferably, at least one microscope objective is mounted directly on the head that in turn is mounted on the support structure.

Preferably, in the microscope according to the invention, the head is a turret head having two parts rotatably connected to each other, wherein one, fixed part of the head is mounted on the support structure and the other, rotatable part of the head is provided with at least two microscope objectives arranged on its surface, the number of objectives corresponding to the number of positions of the rotatable part of the head, where each position of the rotatable part of the head indicates a setting of one of the objectives between the sample holder and the mirror.

In one preferred embodiment of the microscope according to the invention, the fixed part of the head is in the form of a cylinder having an axis of symmetry lying in the horizontal plane, and the rotatable part of the head in the form of a cylinder having an inner diameter larger than the outer diameter of the fixed part of the head is rotatably and coaxially mounted on the fixed part of the head, and at least two microscope objectives mounted to the rotatable part of the head are arranged on the lateral surface of the cylinder so that their optical axes lie in a plane perpendicular to the axis of symmetry of the rotatable part of the head, and a mirror is mounted inside the cylinder forming the fixed part of the head in a position unchanged with respect to the detection optical system and the sample holder, irrespective of changes in position of the rotatable part of the head. In a particularly preferred embodiment, the axis of rotation of the rotatable part of the head coincides with the axis of the light beam passing between the mirror and the first element of the detection optical system. In an alternative embodiment, the value of distance between the axis of rotation of the rotatable part of the head and the axis, parallel to it, of the light beam passing between the mirror and the first element of the detection optical system is greater than zero.

In another preferred embodiment of the microscope according to the invention, the rotatable part of the head is in the form of a truncated cone with the axis of rotation forming an angle a, preferably 45°, with the light beam passing between the mirror and the first element of the detection optical system, and at least two objectives are arranged on the lateral surface of the conical part of the rotatable head on the side opposite to the mirror so that the optical axis of the objective situated at a given position of the rotatable part of the head in a setting between the sample holder and the mirror forms an angle b = 90° - a with the axis of rotation of the rotatable part of the head. In one preferred embodiment, the fixed part of the head is in the form of a cylinder with a truncated end entering inside the rotatable part of the head, the truncated end being terminated with a mirror, and a hole is made in the wall of the cylinder near the truncated end for passing light beams passing between the mirror and the objective. In another preferred embodiment, mirrors are mounted on the inner side of the circular base of the rotatable part of the head, the number and arrangement of which correspond to the number and arrangement of the objectives.

Preferably, in the microscope according to the invention, the fixed part of the head is mounted on the support structure with the possibility of changing its position by rotation in the vertical plane.

Preferably, the detection optical system comprises a digital camera. Preferably, the detection optical system comprises a dichroic mirror and is additionally provided with a source of radiation to excite fluorescence of the sample, preferably a source of laser radiation or a light emitting diode (LED).

Preferably, the system for adjusting the relative position of the optical elements comprises at least one micrometric screw for precise movement and at least one macrometric screw for coarse movement.

Preferably, on the side of the sample holder opposite to the objective, there is a light source, preferably selected from a lamp, a source of laser radiation or an LED. In a particularly preferred embodiment, a condenser is placed between the light source and the sample holder.

Preferably, the detection optical system also comprises a light source, preferably selected from a lamp, a source of laser radiation or an LED.

Preferably, between the objective and the detection optical system, the microscope according to the invention has a diaphragm with a small aperture.

Preferably, the microscope according to the invention is a configurable microscope.

The solution used in the microscope according to the invention, i.e. mounting the optical system on a horizontal standard optical plate (or several such plates), allows the use of standard optical and opto-mechanical elements (e.g. for mounting mirrors, filters, prisms, lenses), provides excellent optical stability, even with a small mass of the plate(s), and ensures that laser beams (if used) are guided safely horizontally. The horizontal arrangement also means that all system elements and light beams in the microscope are easily accessible, which not only makes it easier to observe the sample with a given configuration, but also allows this configuration to be easily modified to meet the user's current needs.

In the context of the present invention, the term "detection optical system" means a system comprising optical elements for directly recording and/or processing an image of a sample. However, such a system may also comprise other elements that perform functions not directly related to image detection, including, in particular, light sources (illuminating or exciting the sample) such as a lamp, a source of laser radiation or an LED.

In addition, such a solution allows the design of a simple turret head with several objectives to quickly change the objective being used at the moment to observe the sample and, even more importantly, it allows the microscope to be very easily changed from an upright (i.e. with the objective directed downwards) to an inverted configuration (i.e. with the objective directed upwards), or even an intermediate configuration (where the optical axis of the objective currently used to observe the sample forms an arbitrary angle with the horizontal plane) by rotating the head itself, rather than the entire microscope body, as in previously known solutions, such as the rotating microscope disclosed in WO 2014/210536A2 https: //discover- echo.com/revolvel. Preferably, the head is rotated about a rotation axis coinciding with the axis of the horizontal light beam between the mirror and the first element of the detection optical system. The configuration with the objective being used at the moment set to observe the sample at an unusual angle can be particularly useful for the analysis of special types of samples/objects (including animals, e.g. mice).

An additional advantage of the embodiment, where the head comprises a cylindrical fixed part and a cylindrical rotatable part mounted thereon rotatably, and where the axis of rotation of the rotatable part of the head does not coincide with the axis of the light beam passing between the mirror and the first element of the detection optical system, is that the mirror can be very easily replaced.

An additional advantage of the embodiment with the head having a rotatable part in the form of a truncated cone is the compact arrangement Furthermore, when mirrors, the number and arrangement of which correspond to the number and arrangement of the objectives, are mounted on the circular base of the rotatable part of the head, a better match between a particular type of mirror and a particular objective can be ensured, e.g. depending on the source of radiation exciting the sample tested. For example, although mirrors with a silver reflective coating are typically used, mirrors with a gold reflective coating may be preferably used for infrared radiation.

When the detection optical system comprises a dichroic mirror and, in addition, the microscope is provided with a source of radiation to excite fluorescence of the sample, such as a source of laser radiation or an LED, the microscope according to the invention can be used for fluorescence microscopy techniques having particular importance in medical and biological research.

In turn, when a diaphragm with a small aperture is placed between the objective and the detection optical system, the microscope according to the invention can function as a confocal microscope.

Brief description of the drawing figures

The invention in embodiments is illustrated in the drawing, wherein:

Fig. 1 shows a schematic side view of a microscope according to the invention in a normal upright configuration;

Fig. 2 shows a schematic side view of the microscope from Fig. 1 in an inverted configuration;

Fig. 3 shows a schematic side view of the microscope according to one preferred embodiment;

Fig. 4 shows a schematic side view of the microscope according to a second preferred embodiment; Fig. 5A shows a perspective view of a turret head of the microscope according to the invention in a preferred embodiment;

Fig. 5B shows a view of the head from Fig. 5A in cross-section;

Fig. 6A shows a perspective view of the turret head of the microscope according to the invention in an alternative preferred embodiment;

Fig. 6B shows a view of the head from Fig. 6A in cross-section;

Fig. 7A shows a perspective view of the turret head of the microscope according to the invention in a third preferred embodiment;

Fig. 7B shows a view of the head from Fig. 7A in cross-section;

Fig. 8A shows a perspective view of the turret head of the microscope according to the invention in a fourth preferred embodiment;

Fig. 8B shows a view of the head from Fig. 8A in cross-section;

Fig. 9 shows a perspective view of an example configuration of the microscope according to the invention.

Detailed discussion of the invention

Fig. 1 shows a schematic side view of a microscope according to the invention in a normal upright configuration, where a microscope objective 1 is positioned upright above a sample S. Directly behind the microscope objective on the side of a detection optical system 2, there is a mirror 3 set at an angle of 45° with respect to an optical axis A of the microscope objective 1. The mirror 3 bends light beams passing through the objective 1 towards the detection optical system 2.

Fig. 2 shows a schematic side view of the microscope according to the invention comprising the same elements as in Fig. 1 but in an inverted configuration, where the objective 1 is positioned upright under the sample, and below the objective, there is the mirror 3 positioned at an angle of 45° with respect to the optical axis A of the objective 1, bending the light beams passing through the objective 1 towards the detection optical system 2.

Example 1

The microscope shown schematically in a side view in Fig. 3 has a support structure on which mechanical and optical components are mounted. The microscope has a turret head comprising two parts that are rotatably connected to each other. One, fixed part 4 of the head, mounted on an element 6 of the support structure, is in the form of a cylinder with an axis of symmetry lying in a horizontal plane. A second, rotatable part 5 of the head in the form of a cylinder having an inner diameter larger than the outer diameter of the fixed part 4 of the head is rotatably and coaxially mounted on the fixed part 4 of the head. At least two microscope objectives 1 are mounted to the rotatable part 4 of the head (this is seen in the side view in fig. 3] The objectives 1 are arranged on the lateral surface of the cylinder so that their optical axes lie in a plane perpendicular to the axis of symmetry of the rotatable part 5 of the head, that is also its axis of rotation A2. The mirror 3, set at an angle of 45° with respect to the optical axis of the objective 1 directed at the sample S, is mounted inside the cylinder constituting the fixed part 4 of the head in a position unchanged with respect to the detection optical system 2 and a holder 7 for the sample S, irrespective of changes in the position of the rotatable part 5 of the head. In the embodiment shown in Fig. 3, the axis of rotation of the rotatable part 5 of the head coincides with the axis of light beams A1 bent by the mirror 3 towards the detection optical system 2. The number of the objectives 1 corresponds to the number of positions of the rotatable part 5 of the head, where each position of the rotatable part 5 of the head indicates the setting of one of the objectives 1 between the holder 7 for the sample S and the mirror 3.

The detection optical system comprises a plurality of optical elements 201, 202, 203, 204, 205 and 206 arranged on two optical plates 207, 208. Each of the optical elements 201-206 is seated on a holder mounted on a pin 210 that in turn is seated in a sleeve 209 mounted on a respective optical plate 207, 208. The mounting of the pin (together with the holder with the optical element 201-206 mounted thereon] in the sleeve 209 is detachable, and is typically implemented by means of a mounting screw entering a threaded opening in the hole made in the sleeve 209 perpendicularly to the direction of insertion of the pin 210.

In Fig. 3, the axis of the light beams passing between the optical elements 205 and 206 is denoted as A3. This axis is parallel to the plane of the optical plate 208.

The sample S rests on the holder 7 that in Fig. 3 is in the form of a table provided with elements allowing to change its relative position (and thus also the position of the sample S] with respect to the objective 1 directed at the sample S in the x and y directions (in the plane of the optical plate 208). Optionally, the holder 7 for the sample S in the form of a table can also be provided with elements allowing it to be moved precisely together with the sample S also in the Z direction (to and from the objective 1] The holder 7 for the sample S is mounted on a stand 8 that in turn is movably mounted to a base 9 provided with an adjustment knob 10 for adjusting the position of the stand 8 in the z direction, thus for bringing the holder 7 with the sample S closer or further from the objective 1, respectively.

To change the objective 1 used to observe the sample, the movable part 5 of the head is rotated with respect to the fixed part 4 of the head. Preferably, the rotational connection between the two parts comprises known elements such as springs and bolts to ensure that the movable part 5 of the head is latched when the rotation required to change the objective 1 to the nearest adjacent objective 1 is performed. Rotating the movable part 5 of the head in order to change the objective 1 to another objective not directly adjacent to it requires passing through a sufficient number of such latching positions. This is a typical and well-known mechanism of operation of a turret head. Example 2

The microscope shown schematically in a side view in Fig. 4, like the embodiment of Example 1, has a support structure on which mechanical and optical components are mounted, but in this case has an inverted configuration, i.e. one where the sample S is above the objective used to observe it. The microscope in this embodiment also has a turret head comprising two parts rotatably connected to each other, wherein the rotatable part 5 of the head is in the form of a truncated cone with a rotation axis forming an angle a with the light beam passing between the mirror 3 and the first optical element 201 of the detection optical system 2. At least two microscope objectives 1 (this is seen in the side view in fig. 4] are arranged on the lateral conical surface of the rotatable part 5 of the head on the side opposite to the mirror 3 in such a way that the optical axis A of the objective 1 situated at a given position of the rotatable part 5 of the head in the setting between the sample holder 7 and the mirror 3 forms an angle b = 90° - a with the axis of rotation of the rotatable part 5 of the head. The fixed part 4 of the head is mounted on a mounting element 12 that in this embodiment is mounted on a base 9 provided with an adjustment knob 10 for changing the position of the mounting element 12 (and together with it, the entire head) in the z direction.

As opposed to Example 1 (Fig. 3), in the microscope embodiment of Example 2 (Fig. 4) the detection optical system comprises a plurality of optical elements 201, 202, 203 and 204 arranged on a single optical plate 207. These elements are mounted on the plate 207 analogously to the optical elements on the upper optical plate 207 in Example 1.

Another important difference of the microscope embodiment shown in Fig. 4 with respect to Example 1 (and Fig. 3) is the fact that the mirror 3 is not mounted inside the head, but below, in the optical axis A of the microscope objective 1 used for observing the sample S mounted in the holder 7, the mirror being inclined with respect to this optical axis A at an angle of 45° so as to bend the light beams passing through the objective 1 towards the detection optical system. The holder 7 itself is mounted from above on the stand 8 and has elements for changing its position relative to the objective 1 directed at the sample S in the x and y directions, and optionally also in the z direction. In turn, the inclined mirror 3 is mounted immovably on the base 9.

The change of objectives 1 in this embodiment of the microscope is performed analogously to that described in Example 1.

Example 3

A turret head of the microscope according to the invention of the type generally shown in Example 1, provided with four microscope objectives 1 arranged symmetrically on the lateral surface of the rotatable part 5 of the head is shown in Fig. 5 a in perspective view, and in fig. 5B in cross-section. In this embodiment, the fixed part 4 of the head is rotatably seated in a hole made in the vertical part of the mounting element 6 that in turn is designed to be mounted immovably on the microscope support structure, for example on the optical plate 207, as shown in Fig. 3. In order to change the position of the entire head, e.g. from normal uprightto inverted, or by any other angle, the head change position adjustment screw in a hole 15 is loosened and the entire head is rotated about the axis of rotation constituting the axis of symmetry of the fixed part 4 of the head by a desired angle, and then, by tightening the adjustment screw in the hole 15, the head is fixed in the new position.

In the embodiment shown in Fig. 5 A and 5B, the axis of rotation of the rotatable part 5 of the head coincides with the axis of the light beam passing between the mirror 3 seated on a mounting element 13 and the first element of the detection optical system (not shown]. On the side opposite to the mounting element, the rotatable part 5 of the head is closed by a front cover 11 detachably mounted thereto. In the wall of the cylinder constituting the fixed part 4 of the head, there is a hole 14 for passing light beams passing between the mirror 3 and the objective 1 that, in a given position, is used to observe the sample. The change of objectives 1 in this embodiment of the microscope is performed analogously to that described in Example 1

Example 4

Figs. 6A and 6B show - in perspective view and in cross-section, respectively - a head of the microscope according to the invention, having a design similar to that of Example 3 and Figs. 5A and 5B, but with the difference that the value of distance between the axis of rotation of the rotatable part 5 of the head and the axis, parallel to it, of the light beam lying between the mirror 3 and the first element of the detection optical system (not shown], is greater than zero. In other words, the axis of rotation of the rotatable part 5 of the head does not coincide with the axis of the light beam passing between the mirror 3 and the first element of the detection optical system. In this embodiment, when the front cover 11 is detached from the rotatable part 5 of the head, easy access is provided to the mounting/pressing element 13 under which the mirror 3 is seated. The mounting element 13 can be made in the form of a threaded nut that can be easily removed to replace the mirror 3.

Example 5

Figs. 7A and 7B show - in perspective view and in cross-section, respectively - a head of the microscope according to the invention, wherein the rotatable part 5 of the head is in the form of a truncated cone having an axis of rotation forming an angle a with the light beam passing between the mirror 3 and the first optical element of the detection optical system (not shown]. In the illustrated embodiment, the angle a = 45° and the number of the microscope objectives 1 symmetrically arranged on the lateral conical surface of the rotatable part 5 on the side opposite to the mirror 3 is six (Fig. 7 A and 7B show five and four of them, respectively]. The head is shown in the normal upright configuration, i.e. one in which the objective 1 used in a given position of the rotatable part 5 of the head for observing the sample is situated vertically above the sample. As opposed to Example 2, the fixed part 4 of the head is in the form of a cylinder with a truncated end entering inside the rotatable part 5 of the head, the truncated end being terminated with the mirror 3, and a hole 1 is made in the wall of the cylinder near the truncated end for passing light beams passing between the mirror 3 and the objective 1. The fixed part 4 of the head is mounted on the mounting element 12 that in turn may be mounted to the support structure of the microscope, either immovably or with the possibility of moving the entire head together with the mounting element 12 vertically - analogously to Example 2. The change of objectives 1 in this embodiment of the microscope is performed analogously to that described in Example 1.

Example 6

Figs. 8A and 8B show - in perspective view and in cross-section, respectively - a head of the microscope according to the invention, having a design similar to that of Example 5 and Figs. 7 A and 7B, but with the difference that, on the inner side, on the circular base of the rotatable part 5 of the head, mirrors are mounted, the number and arrangement of which correspond to the number and arrangement of the objectives - so in this embodiment there are six of them. In this embodiment, the fixed part 4 of the head has the form of a ring located concentrically with the axis of rotation of the rotatable part 5 of the head and provided with centrally arranged connecting elements that together with the corresponding connecting elements of the rotatable part 5 of the head form a rotatable connection. In particular, these connecting elements may take the form of a bearing. The fixed part 4 of the head in this embodiment is provided with a central hole to provide a path for light beams passing between the mirror 3 and the optical system.

Example 7

Fig. 9 shows a perspective view of an example configuration of the Raman microscope according to the invention. The microscope has the turret head described in detail in Example 3. On the upper optical plate 207, the optical element 201 is a tube lens, the optical element 202 is a dichroic mirror and the element 203 is a source of laser radiation. On the lower optical plate 208, an edge spectral filter, a flat mirror, a photodiode and a light detector 206 are mounted successively. In such a configuration, the laser beam runs horizontally (and therefore safely], and only the [weak] light scattered on or emitted from the sample placed on the holder 7 passes to the lower level.

List of designations in the drawing:

1 microscope objective

2 detection optical system 3 mirror

5 sample

A optical axis of the microscope objective 1

4 fixed part of the head 5 rotatable part of the head

6 support structure element

A1 axis of light beams bent by the mirror 3 towards the detection optical system 2 A2 axis of rotation of the rotatable part 5 of the head A3 axis of light beams between optical elements 205 and 206 7 holder for sample S

8 stand

9 base

10 adjustment knob

201-206 optical elements ofthe detection optical system 2 207, 208 optical plates

209 mounting sleeve

210 mounting pin

211, 212 upright elements of the support structure

11 front cover of the rotatable part 5 of the head 12 mounting element for the fixed part 4 of the head

13 mounting element for the mirror 3

14 hole in lateral surface of the fixed part 4 of the head

15 hole for the head position change adjustment screw

Claims

1. An optical microscope comprising at least one objective and a detection optical system, characterised in that directly behind the microscope objective on the side of the detection optical system, there is a mirror set at an angle of 30-60°, preferably 45°, with respect to the optical axis of the microscope objective, for bending light beams passing through the objective in the direction from and towards the detection optical system, the optical elements of which are arranged in one or more horizontal planes.

2. The microscope according to claim 1, characterised in that it comprises a support structure on which the following are successively mounted, preferably removably: a sample holder,

- at least one microscope objective,

3. The microscope according to claim 2, characterised in that at least one microscope objective is mounted directly on the head that in turn is mounted on the support structure.

4. The microscope according to claim 3, characterised in that the head is a turret head having two parts rotatably connected to each other, wherein one, fixed part of the head is mounted on the support structure and the other, rotatable part of the head is provided with at least two microscope objectives arranged on its surface, the number of objectives corresponding to the number of positions of the rotatable part of the head, where each position of the rotatable part of the head indicates a setting of one of the objectives between the sample holder and the mirror.

5. The microscope according to claim 4, characterised in that the fixed part of the head is in the form of a cylinder having an axis of symmetry lying in the horizontal plane, and the rotatable part of the head in the form of a cylinder having an inner diameter larger than the outer diameter of the fixed part of the head is rotatably and coaxially mounted on the fixed part of the head, and at least two microscope objectives mounted to the rotatable part of the head are arranged on the lateral surface of the cylinder so that their optical axes lie in a plane perpendicular to the axis of symmetry ofthe rotatable part ofthe head, and a mirror is mounted inside the cylinder forming the fixed part of the head in a position unchanged with respect to the detection optical system and the sample holder, irrespective of changes in position of the rotatable part of the head.

6. The microscope according to claim 5, characterised in that the axis of rotation of the rotatable part of the head coincides with the axis of the light beam passing between the mirror and the first element of the detection optical system.

7. The microscope according to claim 5, characterised in that the value of distance between the axis of rotation of the rotatable part of the head and the axis, parallel to it, of the light beam passing between the mirror and the first element of the detection optical system is greater than zero.

8. The microscope according to claim 4, characterised in that the rotatable part of the head is in the form of a truncated cone with the axis of rotation forming an angle a, preferably 45°, with the light beam passing between the mirror and the first element of the detection optical system, and at least two objectives are arranged on the lateral surface of the conical part of the rotatable head on the side opposite to the mirror so that the optical axis of the objective situated at a given position of the rotatable part of the head in a setting between the sample holder and the mirror forms an angle b = 90° - a with the axis of rotation of the rotatable part of the head.

9. The microscope according to claim 8, characterised in that the fixed part of the head is in the form of a cylinder with a truncated end entering inside the rotatable part of the head, the truncated end being terminated with a mirror, and a hole is made in the wall of the cylinder near the truncated end for passing light beams passing between the mirror and the objective.

10. The microscope according to claim 8, characterised in that mirrors are mounted on the inner side of the circular base of the rotatable part of the head, the number and arrangement of which correspond to the number and arrangement of the objectives.

11. The microscope according to any one of claims 4 to 10, characterised in that the fixed part of the head is mounted on the support structure with the possibility of changing its position by rotation in the vertical plane.

12. The microscope according to any one of claims 1 to 11, characterised in that the detection optical system comprises a digital camera.

13. The microscope according to any one of claims 1 to 12, characterised in that the detection optical system comprises a dichroic mirror and is additionally provided with a source of radiation to excite fluorescence of the sample, preferably a source of laser radiation or a light emitting diode (LED).

14. The microscope according to any one of claims 2 to 13, characterised in that the system for adjusting the relative position of the optical elements comprises at least one micrometric screw for precise movement and at least one macrometric screw for coarse movement.

15. The microscope according to any one of claims 2 to 14, characterised in that on the side of the sample holder opposite to the objective, there is a light source, preferably selected from a lamp, a source of laser radiation or an LED.

16. The microscope according to claim 15, characterised in thata condenser is placed between the light source and the sample holder.

17. The microscope according to any one of claims 1 to 16, characterised in that the detection optical system also comprises a light source, preferably selected from a lamp, a source of laser radiation or an LED.

18. The microscope according to any one of claims 1 to 17, characterised in that between the objective and the detection optical system, it has a diaphragm with a small aperture.

19. The microscope according to any one of claims 1 to 18, characterised in that it is a configurable microscope.