Positioning device and method for imaging device
By using a positioning device composed of eccentric rotating circular elements, the vibration, gap non-sealing and integration problems of the plate-based microscope stage is solved, and stable sample positioning and compact design are achieved, which is suitable for microscope cultivation applications.
Patent Information
- Application Number
- CN202380039936.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-05-18
- Filing Date
- 2023-03-21
- Publication Date
- 2024-12-20
AI Technical Summary
The existing plate-based microscope stage is susceptible to vibration, the gap is not sealed, the sample stage is susceptible to being stuck and extruded, and it is difficult to integrate into the microscope shell.
A positioning device consisting of three eccentric rotating circular elements provides three degrees of freedom to move the sample, and improves stiffness and vibration characteristics through the support elements, reducing gaps for an airtight seal and compact design.
The stable positioning and observation of the sample within the microscope is achieved, the risk of collision between the objective lens and the positioning device is reduced, suitable for cultivation applications, and the integration of the device is simplified.
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Figure CN119173799A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a positioning device for an imaging device. The invention also relates to an imaging device, in particular a microscope. In addition, the invention also relates to a method for positioning a sample and a computer program product. Background Art
[0002] A microscope typically includes a microscope stage for positioning a sample in the field of view of the microscope optical system. A typical microscope stage includes two or more stacked rectangular plates. The first plate is configured to move in the X direction and the second plate is configured to move in the Y direction. Thus, known microscope stages provide two degrees of freedom in which the sample can be moved. For this reason, microscope stages with two degrees of freedom are also referred to as xy stages. Linear guides are typically provided on both sides of the plate and the plate can be moved by a motor. The plate can have an opening for accommodating a sample stage with a sample mounted therein and through which the sample can be observed or illuminated.
[0003] However, known plate-based microscope stages have a number of disadvantages: The rectangular plates are not supported on at least two sides and are therefore susceptible to vibrations. Typically, there are considerable gaps between the plates. This is not conducive to culture applications, as these gaps must be hermetically sealed before the device can be used for culture applications. In addition, there is a risk that the sample carrier will get stuck in the gaps between the plates and be squeezed out of shape. Since the plates are arranged one on top of the other, the arrangement of the plates is also very thick. Therefore, the microscope objective may need to be moved deep into the opening to observe the sample. Therefore, the microscope objective may also collide with the plates when the plates are moved. Finally, the microscope stage cannot be easily integrated into the microscope housing, as space must be reserved at the stage periphery for the plates to extend. Summary of the invention
[0004] Therefore, an object of the present invention is to provide a positioning device for an imaging device and a method for positioning a sample to overcome the disadvantages of the above-mentioned plate-based microscope stage.
[0005] The above objects are achieved by the subject-matter of the independent claims. The dependent claims and the following description define advantageous embodiments.
[0006] The proposed positioning device for an imaging device comprises: a base element having a first opening, a first circular element rotatably arranged in the first opening and having a second opening, and a second circular element rotatably arranged in the second opening and having a third opening. The rotation center of the second circular element is eccentrically arranged relative to the rotation center of the first circular element. The positioning device also includes a third circular element rotatably arranged in the third opening. The rotation center of the third circular element is eccentrically arranged relative to the rotation center of the second circular element, and the third circular element has a fourth opening for accommodating a sample carrier.
[0007] Due to the eccentric arrangement of the rotation centers of the second circular element and the third circular element, the fourth opening can be freely moved in the first opening by simply rotating the first circular element and the second circular element. The orientation of the fourth opening can also be controlled by rotating the third circular element. Therefore, the sample mounted on the sample carrier accommodated in the fourth opening can be freely moved in the first opening. Therefore, the positioning device of the present invention has three degrees of freedom. Not only can the sample be moved in the x and y directions, but the sample can also be rotated.
[0008] The circular elements are nested in each other and are all arranged in one plane. Therefore, compared with the positioning device including plates stacked on each other, the positioning device of the present invention is very flat. Due to this flatness, the objective lens of the imaging device can be moved to a position very close to the sample in the fourth opening without the risk of the microscope objective lens colliding with the positioning device. The circular elements are supported along the circumference by respective support elements. This leads to a higher rigidity of the circular element device, and therefore, because there is no dominant vibration direction, its vibration characteristics are also better. In addition, since the circular elements are supported along their circumference, there is no obvious gap between two adjacent elements. This greatly reduces the risk of objects, such as sample carriers, cloth pieces or user's fingers getting stuck between the two elements. This makes the operation of the positioning device safer. In addition, the gap between two adjacent elements can be very easily sealed with airtightness, so that the proposed positioning device is suitable for cultivation applications. The circular elements only move in the region of the first opening of the substrate element. Therefore, the coverage area of the positioning device depends entirely on the substrate element. Any moving element will not exceed the substrate element. This simple geometry makes it easy for the positioning device to be integrated into the housing of the imaging device. Therefore, the proposed positioning device overcomes all the disadvantages of the above-mentioned plate-based positioning devices.
[0009] In a preferred embodiment, the positioning device comprises: a controller configured to receive a user input, determine a second position of the fourth opening within the first opening according to the user input, and move the fourth opening from an initial position to the second position by rotating at least the first circular element and the second circular element relative to each other. The user input defines the second position. Then, at least the first circular element and the second circular element are rotated to position the fourth opening, and thereby position the sample carrier and the sample in the second position. The rotation of the first circular element and the second circular element is controlled by the controller, so that the positioning device can be used to automatically move the sample carrier installed in the fourth opening.
[0010] In another preferred embodiment, the controller is configured to convert the user input into a rotation of at least the first circular element and the second circular element. Each position of the fourth opening within the first opening corresponds to a unique rotational position of the first circular element and the second circular element. In this embodiment, the controller is used to convert the user input (which may be an input in the form of Cartesian coordinates, i.e., an xy position) into a rotation of the first and second circular elements. Therefore, the user only needs to input the xy position to position the sample, thereby making the positioning device easy to use.
[0011] In another preferred embodiment, the controller is configured to determine a first relative rotation between the base element and the first circular element and a second relative rotation between the first circular element and the second circular element according to the user input. The controller is also configured to rotate the first circular element according to the first relative rotation and rotate the second circular element according to the second relative rotation so as to move the fourth opening to the second position. In this embodiment, by determining the first relative rotation and the second relative rotation, the user input is converted into the rotation of the first and second circular elements. Specifically, the controller can convert the user input (which can be in the form of Cartesian coordinates) into the first relative rotation and the second relative rotation (which can be in the form of polar coordinates).
[0012] In another preferred embodiment, the controller is configured to determine a third relative rotation between the second circular element and the third circular element based on user input. The controller is also used to rotate the third circular element based on the third relative rotation so as to move the fourth opening to the second position. The orientation of the fourth opening is adjusted by rotating the third circular element, thereby adjusting the orientation of the sample carrier accommodated in the fourth opening. In this embodiment, the user input includes information about the desired orientation of the sample carrier. The controller is used to convert the desired orientation into the third relative rotation. Since the orientation of the fourth opening also depends on the rotational position of the first circular element and the second circular element, the controller preferably also takes these factors into account when determining the third relative rotation. The positioning device according to this embodiment can be used to automatically adjust the orientation of the sample carrier installed in the fourth opening, thereby realizing automation of all three degrees of freedom, making the positioning device easier to use.
[0013] In another preferred embodiment, the controller is used to determine the third relative rotation so that the relative rotation of the third circular element with respect to the base element is the same in the initial position and in the second position. Rotating the first circular element and the second circular element necessarily causes a rotation of the fourth opening, thereby rotating the sample carrier accommodated in the fourth opening. In order to simulate the linear movement of the known plate-based positioning device, the controller in this embodiment maintains the orientation of the fourth opening unchanged. In particular, the controller is also used to promote the linear movement of the fourth opening between the initial position and the second position. Therefore, users who are already familiar with known microscope stages can easily adapt to the use of the positioning device in this embodiment.
[0014] In another preferred embodiment, the positioning unit comprises a first drive unit configured to rotate the first circular element, a second drive unit configured to rotate the second circular element, and a third drive unit configured to rotate the third circular element. In particular, the drive unit can be a motor unit or a magnetic drive. In particular, the drive unit is controlled by a controller. In this embodiment, the movement of the circular element is driven by the drive unit. Therefore, the positioning of the fourth opening and thus the positioning of the sample carrier are fully automated.
[0015] In another preferred embodiment, the first drive unit is arranged on the base element, the second drive unit is arranged on the first circular element, and the third drive element is arranged on the second circular element. In this arrangement, the drive units and the circular element moved by the drive units are mounted on the same element. This configuration is mechanically very stable and facilitates the movement of the circular element with very low vibrations.
[0016] In another preferred embodiment, the first drive unit, the second drive unit and the third drive unit all include stepper motors. Alternatively, the first drive unit, the second drive unit and the third drive unit all include linear motors. Linear motors and stepper motors can be used to accurately control the movement. Therefore, in this embodiment, the rotation of the circular element can be very accurately controlled, thereby very accurately controlling the position of the fourth opening.
[0017] In another preferred embodiment, the positioning device includes: a first position determination unit configured to determine the position of the first circular element relative to the base element, a second position determination unit configured to determine the position of the second circular element relative to the first circle, and a third position determination unit configured to determine the position of the third circular element relative to the second circular element. The position and orientation of the fourth opening are uniquely determined by the relative positions between the circular elements, that is, the angles between them. Therefore, the position determination unit can be used to accurately determine the position and orientation of the fourth opening, thereby determining the sample carrier accommodated in the fourth opening. The control unit can use this information to more accurately control the positioning device.
[0018] In another preferred embodiment, the first opening, the second opening and the third opening are all circular; wherein the second opening is arranged eccentrically with respect to the first circular element; and wherein the third opening is arranged eccentrically with respect to the second circular element. In this embodiment, the entire circumference of the circular element is supported by the respective support element. This makes the arrangement of the circular elements very rigid and thus rotates more smoothly.
[0019] In another preferred embodiment, the fourth opening is rectangular. The rectangular opening can easily accommodate most sample carriers, especially microscope slides and microplates. Therefore, this embodiment is compatible with most sample carriers.
[0020] In another preferred embodiment, the first circular element, the second circular element and the third circular element are mounted by rolling bearings, because the rolling bearings produce very little vibration when the circular elements rotate. Therefore, the rolling bearings make the circular elements run very smoothly.
[0021] The present invention also relates to an imaging device comprising the above positioning device. The imaging device is preferably a microscope, especially an inverted microscope. The imaging device has the same advantages as the above positioning device.
[0022] The present invention also relates to a method for positioning a sample by means of the positioning device described above. The method comprises the following steps: arranging a sample carrier carrying the sample in the fourth opening. Determining a second position of the fourth opening within the first opening according to a user input. Moving the fourth opening from an initial position to a second position by rotating at least the first circular element and the second circular element relative to each other.
[0023] The method has the same advantages as the positioning device described above and can be supplemented by the features of the positioning device described in the dependent claims.
[0024] The invention also relates to a computer program product, comprising a program code for executing the above method when the computer program product runs on a processor.
[0025] The computer program product has the same advantages as the above-described locating device and method and can in particular be supplemented by the features of the dependent claims directed to the locating device. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The specific embodiments will be described below with reference to the accompanying drawings, wherein:
[0027] Figure 1 is a schematic diagram of an imaging device according to an embodiment;
[0028] Figure 2 for Figure 1A schematic top view of a positioning device of the imaging device shown;
[0029] Figure 3 for Figure 2 A schematic cross-sectional view of the positioning device shown; and
[0030] Figure 4 To pass Figure 2 and Figure 3 A flow chart of a method for positioning a sample using a positioning device is shown. DETAILED DESCRIPTION
[0031] Figure 1 is a schematic diagram of an imaging device 100 according to an embodiment.
[0032] In this embodiment, the imaging device 100 is exemplarily formed as an inverted microscope. However, the imaging device 100 may also be any other type of microscope, for example, an upright microscope or a box microscope. In particular, the imaging device 100 is not limited to a microscope. The imaging device 100 may be, for example, a device for inspecting semiconductor workpieces.
[0033] The imaging device 100 is configured to image a sample 102 disposed on a sample carrier 104 (e.g., a microscope slide, a microplate, or a culture dish). In order to capture an image of the sample 102, the imaging device 100 includes an optical imaging system 106. The optical imaging system 106 includes an objective lens 108 that is aligned with the sample 102 from below, and a detector element 110. The objective lens 108 receives detection light emitted by the sample 102 and directs the received detection light to the detector element 110. Exemplarily, an illumination unit 112 for illuminating the sample 102 is disposed above the sample 102. Therefore, the imaging device 100 according to the present embodiment is configured as a transmission microscope. The sample carrier 104 and the sample 102 are disposed on a positioning device 114 for positioning the sample 102 within the field of view of the objective lens 108. Reference will be made to Figure 2 and Figure 3 The positioning device 114 is described in more detail.
[0034] The imaging device 100 further includes a control unit 116. The control unit 116 is connected to the optical imaging device 100, the illumination unit 112, and the positioning device 114, and is configured to control the imaging device 100. In particular, the control unit 116 includes a controller 118 for controlling the positioning device 114. The controller 118 of the positioning device 114 is configured to execute the method for positioning the sample 102. Figure 4 Describe the method.
[0035] Figure 2 for Figure 1 A schematic top view of a positioning device 200 of an imaging device 100 is shown.
[0036] In contrast to known plate-based positioning devices that position the sample carrier 104 by linear motion of the plate, Figure 2 The positioning device 200 shown in the figure positions the sample carrier 104 by the rotational movement of three circular elements 202, 204 and 206. The three circular elements 202, 204 and 206 are nested in each other and can rotate eccentrically relative to each other. The relative eccentric rotation allows the smallest third circular element 206 among the three mutually nested circular elements 202, 204, 206 to be freely positioned within the diameter range of the largest first circular element 202 among the three mutually nested circular elements 202, 204, 206. Therefore, the sample carrier 104 set on the third circular element 206 can also be freely positioned within the diameter range of the first circular element 202.
[0037] The positioning device 200 includes a base member 208, which illustratively has a square footprint. The base member 208 can be fixed to the imaging device 100 via bolt holes 210. Fixing the positioning device 200 can prevent the positioning device 200 from moving relative to the imaging device 100. The first opening 212 of the base member 208 is circular, and its diameter is slightly smaller than the side length of the base member 208.
[0038] The three circular elements 202, 204 and 206 are all received in the first opening 212 of the base element 208. The diameter of the first circular element 202 is selected so that the first circular element 202 matches the first opening 212. Therefore, the first circular element 202 is mounted on the base element 208 along its entire circumference. The first circular element 202 can rotate freely in the first opening 212, and its rotation axis is perpendicular to Figure 2 The first circular element 202 has a circular second opening 214 that is eccentrically disposed relative to the first circular element 202. The diameter of the second opening 214 is approximately three quarters of the diameter of the first circular element 202.
[0039] The second circular element 204 is received in the second opening 214. The diameter of the second circular element 204 is smaller than the diameter of the first circular element 202. The diameter of the second circular element 204 is selected so that the second circular element 204 matches the second opening 214. Therefore, the second circular element 204 is mounted on the first circular element 202 along its entire circumference. The second circular element 204 can rotate freely in the second opening 214, and its rotation axis is also perpendicular to the first circular element 202. Figure 2The rotation axis of the second circular element 204 is eccentrically disposed relative to the first circular element 202. The second circular element 204 has a circular third opening 216 eccentrically disposed relative to the second circular element 204. The diameter of the third opening 216 is about three quarters of the diameter of the second circular element 204 or about half of the diameter of the first circular element 202.
[0040] The third circular element 206 is received in the third opening 216. The diameter of the third circular element 206 is smaller than the diameter of the second circular element 204. The diameter of the third circular element 206 is selected so that the third circular element 206 matches the third opening 216. Accordingly, the third circular element 206 is mounted on the second circular element 204 along its entire circumference. The third circular element 206 can rotate freely in the third opening 216, and its rotation axis is also perpendicular to the Figure 2 The rotation axis of the third circular element 206 is eccentrically arranged relative to the second circular element 204. The third circular element 206 has a rectangular fourth opening 218 for accommodating the sample carrier 104. Because the fourth opening 218 runs through the entire positioning device 200 from top to bottom, the sample 102 mounted on the sample carrier 104 can be observed from below.
[0041] In order to make the three circular elements 202, 204, 206 rotate automatically, the positioning device includes three drive units 220, 222, 224, which are exemplarily formed as motor units. The first drive unit 220 is mounted on the base element 208 and is configured to rotate the first circular element 202. The second drive unit 222 is mounted on the first circular element 202 and is configured to rotate the second circular element 204. The third drive unit 224 is mounted on the second circular element 204 and is configured to rotate the third circular element 206. According to this embodiment, each circular element 202, 204, 206 is moved by the drive unit 220, 222, 224 mounted on the same element 204, 206, 208 as the corresponding circular element 202, 204, 206. Other configurations are also possible. For example, each circular element 202, 204, 206 can be installed with a drive unit that rotates it. Alternatively, the drive units 220, 222, 224 can also be all mounted on the base element 208.
[0042] Reference will now be made to a cross-sectional view of the positioning device 200. Figure 3 The positioning device 200 is described in more detail. Figure 2 The dotted line A in the Figure 3 The section axis of the sectional view.
[0043] Figure 3 yes Figure 2A schematic cross-sectional view of a positioning device 200 is shown.
[0044] from Figure 3 It can be seen that the nested circular elements 202, 204, 206 are arranged in a single plane represented by the dashed line B. This arrangement makes it possible to Figure 2 and Figure 3 The positioning device 200 shown has a flat profile. Due to the flatness of the positioning device 200, when the sample carrier 104 is accommodated at the top of the fourth opening 218, the objective lens 108 of the imaging device 100 can be moved very close to the sample 102 on the sample carrier 104 without actually moving into the fourth opening 218. This greatly reduces the risk of the objective lens 108 colliding with the positioning device 200.
[0045] from Figure 3 It can also be seen that there is no obvious gap between two adjacent circular elements 202, 204, 206 and between the first circular element 202 and the base element 208. In addition, these small gaps are covered from the top by the cover parts 300, 302, 304 of the corresponding circular elements 202, 204, 206, respectively. The cover parts 300, 302 and 304 can prevent foreign objects from getting stuck in the small gaps. By providing components such as rubber lips on the cover parts 300, 302 and 304, an airtight seal for culture applications can be provided.
[0046] Figure 3 A cross-sectional view of a second drive unit 222 mounted on the first circular element 202 and configured to rotate the second circular element 204 is exemplarily shown. Exemplarily, the drive units 220, 222, 224 are disposed on top of the circular elements 202, 204, 206. Each drive unit 220, 222, 224 includes a motor 306 for driving a cogwheel 308 meshing with a pinion of one of the cover parts 300, 302, 304. Rotating the cogwheel 308 moves the corresponding cover part 300, 302, 304 to move one of the circular elements 202, 204, 206 relative to the element 304, 306, 308 on which the corresponding drive unit 220, 222, 224 is mounted. Figure 3 Other arrangements than those shown are possible. For example, one or more of the drive units 220 , 222 , 224 may include a linear motor disposed over the entire circumference of one of the circular elements 202 , 204 , 206 .
[0047] The circular elements 202, 204, 206 are mounted by rolling bearings 310, 312, 314, respectively. The rolling bearings 310, 312, 314 ensure that the circular elements 202, 204, 206 run smoothly. The entire circumference of all circular elements 202, 204, 206 is mounted by rolling bearings 310, 312, 314, making the arrangement of the circular elements 202, 204, 206 very strong, thereby further reducing vibrations. The rolling bearing 312 for mounting the second circular element 204 and the rolling bearing 314 for mounting the third circular element 206 are arranged on the same plane as the corresponding circular elements 204 and 206. The rolling bearing 310 for mounting the first circular element 202 is arranged below the first circular element 202. This arrangement makes the diameter of the first circular element 202 as large as possible compared to the footprint of the base element 208. Since the diameter of the first circular element 202 determines the area in which the sample carrier 104 can move, it is particularly important to increase the diameter of the first circular element 202 .
[0048] Figure 4 To pass Figure 2 and Figure 3 The flowchart of the method of positioning the sample 102 by the positioning device 200 is shown.
[0049] In the process defined by the method, the third circular element 206 is moved from the initial position to the second position. Thus, the sample carrier 104 accommodated in the fourth opening 218 of the third circular element 206 is also moved from the initial position to the second position. Both the initial position and the second position are located within the diameter of the first circular element 202.
[0050] The process starts at step S400. In step S402, the controller 118 of the positioning device 200 receives (for example, through a user input device such as a keyboard and / or a mouse) user input. The user input includes at least position information and may also include orientation information. The position information may be an absolute position (i.e., a position relative to the positioning device 200) or a relative position (i.e., a position relative to the current position). The absolute position may be represented by a set of Cartesian coordinates. The relative position may be represented in the form of a vector. The orientation information may include an absolute orientation (i.e., a rotation relative to the positioning device 200) or a relative orientation (i.e., a rotation relative to the current rotation). Specifically, the orientation information may include that the absolute orientation must be the same at the initial position and the second position, and / or that the orientation must not change during the movement between the initial position and the second position.
[0051] In step S404, the controller 118 determines the relative rotations of the three circular elements 202, 204, and 206 relative to each other so as to position and orient the sample carrier 104 received in the fourth opening 218 according to the user input. Each position of the third circular element 206 is uniquely determined by the first relative rotation between the base element 208 and the first circular element 202 and the second relative rotation between the first circular element 202 and the second circular element 204. Each orientation of the third circular element 206 is uniquely determined by the first relative rotation, the second relative rotation, and the third relative rotation between the second circular element 204 and the third circular element 206. Therefore, the controller 118 determines the first relative rotation, the second relative rotation, and the third relative rotation according to the user input.
[0052] In step S406, the circular elements 202, 204, 206 are moved by the drive units 220, 222, 224 according to the first relative rotation, the second relative rotation, and the third relative rotation. Although the position and orientation of the third circular element 206 are uniquely determined by the first relative rotation, the second relative rotation, and the third relative rotation, there is no unique path between the initial position and the second position. Other restrictions may also be imposed on the path. For example, the third circular element 206 moves linearly or in a straight line. After the third circular element 206 reaches the second position, the process is stopped in step S408.
[0053] The same reference symbols are used in all figures to represent the same or similar elements. The term "and / or" used herein includes any one and all combinations of one or more related listed items, which can be abbreviated as " / ". The various features of the embodiments and all combinations between the various features of the embodiments, as well as the combination with the various features or feature groups in the above description and / or claims, are all considered to be disclosed.
[0054] Although some aspects are described in the context of an apparatus, it is apparent that these aspects also represent descriptions of corresponding methods, where a block or apparatus corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method step also represent descriptions of corresponding blocks or items or features of corresponding apparatus.
[0055] List of reference numerals:
[0056] 100 Imaging Devices
[0057] 102 samples
[0058] 104 sample stage
[0059] 106 Optical Imaging System
[0060] 108 objective lens
[0061] 110 detector elements
[0062] 112 lighting units
[0063] 114 Positioning device
[0064] 116 Control Unit
[0065] 118 Controller
[0066] 200 positioning device
[0067] 202, 204, 206 round components
[0068] 208 base element
[0069] 210 bolt holes
[0070] 212, 214, 216, 218 opening
[0071] 220, 222, 224 drive units
[0072] 300, 302, 304 cover
[0073] 306 motor
[0074] 308 Gear
[0075] 310, 312, 314 rolling bearings
[0076] A, B dotted line
Claims
1. A positioning device (114, 200) for an imaging device (100), comprising: a base member (208) having a first opening (212); a first circular element (202) rotatably arranged in the first opening (212), the first circular element (202) having a second opening (214); a second circular element (204) rotatably arranged in the second opening (214) and having a third opening (216), wherein a rotation center of the second circular element (204) is eccentrically arranged relative to a rotation center of the first circular element (202); and A third circular element (206) is rotatably arranged in the third opening (216), wherein the rotation center of the third circular element (206) is eccentrically arranged relative to the rotation center of the second circular element (204), and wherein the third circular element (206) has a fourth opening (218) for accommodating a sample carrier (104).
2. The positioning device (114, 200) according to claim 1 comprises a controller (118) configured to receive user input, thereby determining a second position of the fourth opening (218) within the first opening (212) based on the user input, and moving the fourth opening (218) from an initial position to the second position by rotating at least the first circular element (202) and the second circular element (204) relative to each other.
3. The positioning device (114, 200) according to claim 2, wherein: The controller (118) is configured to convert the user input into a rotation of at least the first circular element (202) and the second circular element (204).
4. The positioning device (114, 200) according to claim 2 or 3, wherein: The controller (118) is configured to determine a first relative rotation between the base element (208) and the first circular element (202) and a second relative rotation between the first circular element (202) and the second circular element (204) according to the user input; the controller (118) is also configured to rotate the first circular element (202) according to the first relative rotation and rotate the second circular element (204) according to the second relative rotation, thereby moving the fourth opening (218) to the second position.
5. The positioning device (114, 200) according to claim 4, wherein: The controller (118) is configured to determine a third relative rotation between the second circular element (204) and the third circular element (206) based on the user input; the controller (118) is also configured to rotate the third circular element (206) based on the third relative rotation, thereby moving the fourth opening (218) to the second position.
6. The positioning device (114, 200) according to claim 5, wherein: The controller (118) is configured to determine the third relative rotation such that the relative rotation of the third circular element (206) with respect to the base element (208) is the same in the initial position and the second position.
7. The positioning device (114, 200) according to any one of the preceding claims, comprises a first drive unit (220) configured to rotate the first circular element (202), a second drive unit (222) configured to rotate the second circular element (204), and a third drive unit (224) configured to rotate the third circular element (206).
8. The positioning device (114, 200) according to claim 7, wherein: The first drive unit (220) is arranged on the base element (208), the second drive unit (222) is arranged on the first circular element (202), and the third drive element is arranged on the second circular element (204).
9. The positioning device (114, 200) according to claim 7 or 8, wherein: The first drive unit (220), the second drive unit (222), and the third drive unit (224) each include a stepping motor.
10. The positioning device (114, 200) according to claim 7 or 8, wherein: The first drive unit (220), the second drive unit (222) and the third drive unit (224) each include a linear motor.
11. The positioning device (114, 200) according to any one of the preceding claims, comprising: A first position determination unit configured to determine the position of the first circular element (202) relative to the base element (208), a second position determination unit configured to determine the position of the second circular element (204) relative to the first circle, and a third position determination unit configured to determine the position of the third circular element (206) relative to the second circular element (204).
12. The positioning device (114, 200) according to any one of the preceding claims, wherein: The first opening (212), the second opening (214) and the third opening (216) are all circular; wherein the second opening (214) is eccentrically disposed relative to the first circular element (202); and wherein the third opening (216) is eccentrically disposed relative to the second circular element (204).
13. An imaging device (100) comprising a positioning device (114, 200) according to any one of the preceding claims.
14. A method for positioning a sample (102) by means of a positioning device, wherein: The positioning device (114, 200) is a positioning device (114, 200) according to any one of claims 1 to 13, and the method comprises: placing a sample carrier (104) carrying a sample (102) into the fourth opening (218); determining a second position of the fourth opening (218) within the first opening (212) based on user input; The fourth opening (218) is moved from an initial position to the second position by rotating at least the first circular element (202) and the second circular element (204) relative to each other.
15. A computer program product comprising a program code, wherein the program code is configured to perform the method according to claim 14 when the computer program product is run on a processor.