Device and method for supplying an impregnation medium

Abstract

A device for supplying an immersion medium for use with an objective lens, with which a specimen can be microscopically imaged, is described. The device comprises: a cap that is releasably or fixedly attached to the objective lens, the cap defining a receptacle for the immersion medium, the cap having an outlet opening facing an optical element of the objective lens facing the specimen, through which the immersion medium held in the receptacle can be supplied to a target space located between the optical element of the objective lens and the specimen; and a sensor integrated in the cap having an electrode structure for detecting the amount of immersion medium supplied. The electrode structure at least partially surrounds the outlet opening and has a three-dimensional detection region extending radially away from the outlet opening.

Description

Technical Field

[0001] The present invention relates to an input device for an immersion medium for use with an objective lens with which a specimen can be imaged microscopically. The invention also relates to a method for inputting an immersion medium using the input device. Background Art

[0002] To increase the numerical aperture, in optical microscopy, an immersion medium with a significantly higher refractive index than air is often introduced between the objective and the specimen to be examined. This immersion medium has the function of preventing or at least reducing undesired light refraction that occurs at the transition from the coverslip, which is part of the specimen to be examined, to air and that is directed away from the optical axis of the objective.

[0003] In order to introduce immersion medium into the area between the specimen and the front lens of the objective, hereinafter referred to as the target space, supply devices are known from the prior art that utilize so-called immersion caps. Such immersion caps can be attached to the objective releasably or fixedly and define a receiving space into which the immersion medium is supplied, for example, by means of a pump. The immersion cap has an outlet opening facing the front lens of the objective, through which the immersion medium located in the receiving space is supplied to the target space between the front lens of the objective and the specimen.

[0004] An example of an input device of the aforementioned type is described in DE 10 2006 042 499 A1. This input device comprises an immersion cap with a sensor that is intended to measure the amount of immersion medium on the objective lens. The sensor is designed as a photocell, conductivity sensor, or capacitive sensor. A disadvantage of such sensors is that, due to their design as point sensors, they cannot accurately measure the amount of immersion medium in the target area.

[0005] Document DE 10 2006 042 088 B4 discloses a device for supplying an immersion medium. The device comprises a plate that can be placed onto an objective lens and has an outlet opening oriented toward the center of the objective lens front lens. A channel extending to the outlet opening runs within the plate, through which the immersion medium is supplied. The outlet opening is surrounded by two electrodes, which form a sensor for detecting the amount of immersion medium supplied. The sensor's three-dimensional detection area is limited to the outlet opening. Consequently, immersion medium located radially outside the outlet opening cannot be detected.

[0006] For the prior art, reference is also made to document EP 1 777 572 A1, which discloses an impregnation hood with a heating device. Summary of the Invention

[0007] The object of the present invention is to provide a device for supplying an immersion medium, an objective equipped with the device, and a method which enable precise detection of the immersion medium level in a target space between the objective and the specimen.

[0008] The invention achieves this object by the subject matter of the independent claims. Advantageous developments are given in the dependent claims.

[0009] The present invention provides an input device for an immersion medium for use with an objective lens, which is used to microscopically image specimens. The input device includes a cover that is releasably or fixedly attached to the objective lens, defining a storage space for the immersion medium. The cover has an outlet opening that faces the specimen-facing optical components of the objective lens, through which the immersion medium held in the storage space can be supplied to a target space located between the objective lens's optical components and the specimen. The input device also includes a sensor integrated in the cover, having an electrode structure for detecting the amount of immersion medium supplied. The electrode structure at least partially surrounds the outlet opening and has a three-dimensional detection region that extends radially away from the outlet opening.

[0010] By extending the stereoscopic detection area at least into the space radially outside the output opening when viewed from above, the sensor significantly increases the target area between the specimen and the objective lens that can be detected by the sensor compared to the known solutions mentioned above, in which the immersion medium is detected only in the area of ​​the output opening. Because the liquid film formed by the immersion medium extends beyond the output opening, for example, in the event of lateral relative movement between the objective lens and the specimen, it is significantly more robust than in measurement configurations in which the target area is limited to the area of ​​the output opening, within which the liquid film is detected. The aforementioned stereoscopic detection area of ​​the sensor is the space between the specimen and the objective lens, within which the sensor is sensitive to the immersion medium located.

[0011] The proposed radial enlargement of the sensor's three-dimensional detection area also has the advantage that the amount of immersion medium detected by the sensor can be used as a stable control parameter to adjust the desired target amount of immersion medium in a control loop. The radially expanded detection area within the target space thus provides a tolerance range that prevents air from entering the optical path between the objective lens and the specimen. The input device, with its electrode structure integrated into the cover, thus offers the possibility of precise control of the immersion medium amount.

[0012] In particular, the three-dimensional detection area of ​​the sensor can be designed to detect the level of the immersion medium both in the receiving space inside the cover, i.e., in the area between the cover and the objective lens, and in the target space between the objective lens and the specimen. The detection signal generated by the sensor can be used as a measurement parameter to ensure that the immersion medium is initially pumped into the cover and then into the target space through the outlet opening in an optimal amount. Furthermore, the aforementioned measurement parameter allows this optimal adjustment to be maintained through continuous or discrete readjustment. This allows for compensation of changes in the immersion medium level, such as those caused by evaporation or relative movement between the specimen and the objective lens.

[0013] The immersion medium can be, for example, water, oil, glycerol or other common media which ensure the desired increase in the refractive index in the target space between the objective and the specimen.

[0014] In a preferred embodiment, the sensor is a capacitive or resistive sensor. If the sensor is designed as a capacitive sensor, the electrode structure that determines the shape of the sensor is electrically insulated, for example, by being cast into the material forming the cover. In this case, the electrode structure comprises at least two electrically insulated electrodes that collectively function as a capacitor, and the capacitance of these electrodes changes when an immersion medium is introduced into the vicinity of the intermediate space separating the two electrodes. In this embodiment, the two electrodes are connected to a suitable electronic measuring unit via contacts. In contrast, if the sensor is designed as a resistive sensor, the electrode structure forming the sensor is exposed to the outside in the cover so that it can come into contact with the immersion medium. In this resistive measurement, the electrode structure comprises at least two electrodes that are separated from each other and arranged on the cover, so that when the immersion medium reaches a predetermined liquid level, electrical contact is established between the two electrodes, thereby generating a detection signal. In both embodiments, these electrode structures are connected to a suitable measuring unit via two contacts, respectively.

[0015] Compared to resistive measurement, capacitive measurement has the advantage that it provides a continuous detection signal as the liquid level changes, thus allowing quantitative quantity or position determination, which is particularly well suited for level control. Furthermore, capacitive measurement is independent of the possibly varying conductivity of the immersion medium.

[0016] In the case of capacitive measurements, the electrode structure forming the sensor can also be used as a distance sensor, which detects the distance to the specimen. In the case of resistive measurements, the electrode structure can be used as a contact sensor.

[0017] Preferably, the cover has an end wall facing the specimen, in which an output opening is provided, wherein the end wall separates the receiving space from the target space, and the electrode structure is integrated into the end wall. In this embodiment, the electrode structure is located in the region of the three-dimensional separation between the receiving space and the target space, which is achieved by the end wall, and which in particular also provides for a measurement-related separation of the two spaces.

[0018] Preferably, the electrode structure of the capacitive sensor is electrically insulated by end walls on the one hand from the receiving space and on the other hand from the target space, so that the three-dimensional detection area of ​​the electrode structure covers at least the entire target space.

[0019] In addition, the electrode structure can also be designed so that its three-dimensional detection area also covers the receiving space.

[0020] In a preferred embodiment, the end wall comprises a first material layer that electrically insulates the electrode structure of the capacitive sensor from the receiving space, and a second material layer that electrically insulates the electrode structure of the capacitive sensor from the target space. The electrode structure's sensitivity to the amount of immersion medium supplied to the receiving space is determined by the thickness of the first material layer, while the electrode structure's sensitivity to the amount of immersion medium supplied to the target space is determined by the thickness of the second material layer.

[0021] In a special embodiment, the sensor's electrode structure is insensitive to the amount of immersion medium located in the outlet opening. This insensitivity of the electrode structure in the area of ​​the outlet opening can be used to achieve a measurement-technical separation between the receiving space and the target space, which are interconnected via the outlet opening of the cover. Thus, before the liquid level rises further as the immersion medium enters the target space, the sensor's detection signal does not change when the immersion medium, after completely filling the receiving space, enters the area of ​​the outlet opening and gradually fills the latter. Thus, during the phase in which the immersion medium gradually fills the outlet opening, the sensor's detection signal remains at a constant value, which allows for measurement-technical separation between the receiving space and the target space.

[0022] However, in an alternative embodiment, the sensor's electrode structure can also be designed to be sensitive to the amount of immersion medium located in the outlet opening. This can be achieved, for example, by including, in addition to the electrode that causes the sensor's three-dimensional detection area to expand radially outward from the outlet opening, at least two further electrodes located radially innermost within the electrode structure and directly surrounding the outlet opening. Since the outlet opening of the cover is located in the space between the aforementioned electrodes, and these electrodes, like the other electrodes, also serve as capacitor plates, the sensor's detection signal changes when the amount of immersion medium in the area of ​​the receiving opening changes.

[0023] In a particularly preferred embodiment, the electrode structure is designed as an intercalated structure. This intercalated structure is designed, for example, so that in a defined plane—which lies within the cover material in the case of capacitive measurement and on the surface of the cover in the case of resistive measurement—the finger-shaped electrode structures of the two relevant electrodes fit tightly into one another without touching. This intercalated structure makes it particularly easy to provide a three-dimensional detection area of ​​the sensor that extends radially away from the output opening in the desired manner.

[0024] The output opening is preferably circular. In this case, the electrode structure, preferably implemented as an intervening structure, is designed rotationally symmetrically with respect to the output opening in a top view of the cover. If the electrode structure surrounds the output opening and thus the optical axis of the objective lens, the amount of immersion medium can be averaged concentrically. This requires only a single measured value, which is advantageous if the immersion medium is assumed to be distributed radially symmetrically about the optical axis of the objective lens.

[0025] In another embodiment, the electrode structure can also include multiple independently controllable electrode pairs distributed around the output opening. For example, it is possible to arrange multiple electrode pairs in a transverse plane perpendicular to the optical axis of the objective lens, with these electrode pairs spaced equidistantly from one another. Thus, for example, three such electrode pairs could be arranged at 120° intervals. By providing multiple, individually analyzable electrode structures, it is possible not only to detect the amount of immersion medium but also, if necessary, to detect asymmetrical distribution of the immersion medium in the aforementioned transverse plane. This means that, in this embodiment, the immersion medium can be detected based on position.

[0026] In a particularly preferred embodiment, a measuring unit provided for the sensor is integrated into the cover. This integration of the measuring unit in the cover largely avoids electromagnetic interference signals that could affect the connection between the electrode and the measuring unit and distort the detection signal. However, it is also possible to arrange the measuring unit outside the cover if this offers advantages in the specific application.

[0027] Preferably, the input device includes a conductor track structure integrated into the cover, electrically insulated from the receiving space and the target space, and designed to resistively heat the immersion medium held in the receiving space and / or the target space. For example, to heat the immersion medium, the conductor track structure can be arranged within the end wall of the cover. The conductor track structure, for example, consists of at least one fully conductive conductor track that is insulated from the exterior, with its two ends extending from the cover as connection contacts. The conductor track is designed to form a resistor. When current flows through the conductor track, it heats up due to this resistance, and the generated heat is dissipated to the immersion medium through the cover material, preferably the end wall. This provides resistive heating of the immersion medium. This embodiment offers significant advantages over conventional solutions that primarily heat the objective lens rather than directly heating the immersion medium in the critical target space between the objective lens and the specimen. While the objective lens, due to its relatively large mass, creates a significant temperature well, in this embodiment, the cover, particularly its relatively thin end wall, creates only a minimal temperature well.

[0028] The conductor track structure for heating the immersion medium comprises, for example, at least one fully electrically conductive conductor track that is insulated from the outside, with both ends extending from the cover as connecting contacts. The conductor track is designed so that it forms a resistor. If current flows through the conductor track, it heats up due to this resistance and dissipates the heat through the cover material to the immersion medium.

[0029] The input device preferably has a temperature sensor for detecting the temperature of the immersion medium. The temperature sensor can be integrated in the cover, for example.

[0030] In a particularly preferred embodiment, the temperature sensor is formed by the aforementioned conductor track structure, which has a predetermined, temperature-dependent resistance and is designed to alternately resistively heat the immersion medium held in the receiving space and resistively detect its temperature over time. If the temperature-dependent resistance of the electrode structure is known, temperature measurement can be achieved using appropriate electronics. For this purpose, a platinum measuring resistor can be used as the conductor track structure, for example. It is particularly feasible to design the electrode structure for heating the immersion medium in the form of a single electrode, which then alternately heats the immersion medium and detects its temperature over time. To achieve sufficiently high resistance over the smallest possible area and good temperature distribution, the electrode structure is preferably designed in a meandering manner. In particular, to heat the immersion medium, the electrode structure can be designed rotationally symmetrically with respect to the outlet opening. It is also feasible to provide a plurality of independently controllable electrode pairs for heating the immersion medium, which are preferably spaced at equal angular intervals around the outlet opening.

[0031] Of the two conductor structures, one is used to detect the liquid level of the immersion medium, and the other is used for heating and, if necessary, temperature measurement. These conductor structures are spatially separated within the cover. For example, the two aforementioned structures may be stacked one above the other in a top view of the cover, but arranged in different planes with respect to the thickness direction of the cover. Alternatively or additionally, it is possible to arrange the two structures offset from one another in a top view of the cover.

[0032] Preferably, the edge of the end wall defining the output opening forms a gap with the specimen-facing optics of the objective, via which the immersion medium is output into the target space. The preferably annular gap formed in this way enables particularly simple covering of the optics with the immersion medium.

[0033] The end wall preferably extends substantially conically toward the output opening. However, it is equally feasible that the end wall has a horizontal orientation, ie, a orientation perpendicular to the objective optical axis.

[0034] The cover particularly has a substantially cylindrical wall connected to the end wall, which defines, together with the end wall, a receiving space for the immersion medium. In this way, the cover can be particularly simply and releasably arranged on the objective lens.

[0035] The supply device preferably comprises a pump system, which is connected to the receptacle of the cover via at least one hose and is designed to pump the immersion medium into the receptacle. The pump system is, for example, part of a supply system having a reservoir, from which the pump system conveys the immersion medium into the receptacle. The pump system is, for example, designed as a reversible pump. However, the pump system may also consist of two separate pump units for forward and reverse rotation, or be configured as a double-head pump. The immersion medium to be disposed of can be returned to the reservoir for reuse, or it can also be introduced into another container for disposal.

[0036] The aforementioned supply system can be arranged, for example, on the objective lens revolving head. However, it is also possible to provide the supply system separately from the microscope or to integrate it into the microscope housing. It is also possible to spatially separate the components of the supply system from one another, that is, for example, to arrange the pump on the objective lens revolving head and the storage container separately from the microscope.

[0037] Preferably, a control / regulating unit is provided, which is responsible for pumping the immersion medium into the receiving space in accordance with the detection signal provided by the sensor. If there is also resistance heating in the immersion cover, the control / regulating unit can also take over its temperature regulation.

[0038] According to another aspect of the present invention, a method for supplying an immersion medium using the aforementioned supply device is described. In this method, the immersion medium is pumped into a receiving space by means of a pump system, and simultaneously a sensor generates a detection signal corresponding to the amount of immersion medium supplied. The pump system is controlled by means of this detection signal to adjust a target amount of immersion medium.

[0039] When using this method, the sensor is preferably designed as a capacitive sensor. It is capable of continuously detecting the level of the immersion medium. This allows, on the one hand, automatic initial adjustment of the optimal target amount of immersion medium in the target space. On the other hand, the continuous level detection can subsequently be used to maintain this optimal target amount constant by means of a control circuit.

[0040] Preferably, the immersion medium is pumped into the receiving space at a constant pump speed. This facilitates, in particular, the initial adjustment of the target amount of immersion medium.

[0041] To determine the target quantity, for example, the quantity of immersion medium when it reaches the outlet opening of the cover is first detected as a reference quantity, and the target quantity is then determined based on this reference quantity.

[0042] In a preferred embodiment, the amount of immersion medium supplied is controlled within a predetermined tolerance range around a target amount and / or when a predetermined operating state exists. Such an operating state may occur, for example, when the contact surface of the cover or the specimen covered by the immersion medium changes during the experiment, for example due to focus adjustment. It is therefore advantageous to interrupt the control of the amount of immersion medium for a period of time until the focus adjustment is at rest. Based on the sensor detection signal then present, the control can then be resumed to achieve the desired amount of immersion medium.

[0043] In another aspect, the invention provides an objective with an input device of the aforementioned type. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein:

[0045] Figure 1 is a schematic diagram of an input device for an immersion medium for use with an objective lens;

[0046] Figure 2 is a perspective view of an immersion cover that can be placed on an objective lens;

[0047] Figure 3 Based on Figure 2 A cross-sectional view of the impregnated cover;

[0048] Figure 4A schematic diagram of an electrode structure integrated in a cover in a special embodiment for detecting the amount of immersion medium supplied;

[0049] Figure 5 is a schematic diagram of an individually controllable electrode pair, which according to another embodiment is part of an electrode structure;

[0050] Figure 6 For multiple bases Figure 5 Schematic diagram of the electrode structure of the electrode pair;

[0051] Figure 7 is a schematic diagram of an additional electrode pair, which is sensitive to the amount of immersion medium located in the output opening;

[0052] Figure 8 1 is a schematic diagram of a conductor track structure integrated in a cover in a special embodiment, which serves to resistively heat the immersion medium;

[0053] Figure 9 is a schematic diagram of an individually controllable conductor track, which, according to another embodiment, is part of a conductor track structure intended for heating an immersion medium;

[0054] Figure 10 A conductor track structure is shown, which has a plurality of Figure 9 Individually controllable printed conductors;

[0055] Figure 11 is a schematic diagram showing the three-dimensional arrangement of an electrode structure forming a sensor and a conductor track structure intended for heating the immersion medium in a special embodiment;

[0056] Figure 12 is a schematic diagram of a microscope in which an input device for an immersion medium can be used;

[0057] Figure 13 is a schematic diagram of the microscope in a modified embodiment;

[0058] Figure 14 is a graph showing an exemplary time profile of a detection signal detected by the sensor when the cap is filled with immersion medium. DETAILED DESCRIPTION

[0059] Figure 1 An input device 100 is shown schematically, which is one embodiment of the present invention.

[0060] The input device 100 is intended for use with an objective lens 102, which is part of a microscope. The input device 100 comprises an immersion cap 104 which is releasably or fixedly mounted on the objective lens 102. In this case, the immersion cap 104 is located at the front end of the objective lens 102 facing the specimen 106. The specimen 106 is located in the microscope. Figure 1 The sample, not explicitly shown, and the sample carrier, which can be designed, for example, as a cover glass or a glass slide, or also as a microtiter plate.

[0061] like Figure 2 and 3 As shown in detail in the figure, the immersion cap 104 has an end wall 108 facing the specimen 106 and a cylindrical wall 110 connected to the end wall 108, which has a conically extending end section 109. Both the end wall 108 and the wall 110 connected thereto are adapted in their shape to the outer contour of the objective lens 102. It can be seen from this that the immersion cap 104 is not limited to the shape shown in the figures.

[0062] In the exemplary embodiment shown, the end wall 108 has a central outlet opening 112 in its conically tapering end section 109, which is preferably circular in plan view of the immersion cap 104. The outlet opening 112 faces a front lens 114 facing the specimen 106, which is also circular and is part of a lens system 116 contained in the objective 102.

[0063] The input device 100 further includes a supply system 118 having a reservoir 120 for containing an immersion medium 122, such as water, oil, or glycerin, and a pump system 124 connected to the reservoir 120 via a hose 126. The pump system 124 is further coupled to the immersion cap 104 via another hose 127. The pump system is used to pump the immersion medium 122 from the reservoir 120 into a receiving space 128, which is defined within the immersion cap 104, which is placed on the objective lens 102.

[0064] If the immersion medium 122 is conveyed into the interior of the immersion cap 104 by means of a pump system 124, the immersion medium gradually fills the receiving space 128 until it reaches the region of a circular edge 130 of the end wall 108, which delimits the outlet opening 112. This edge 130 of the end wall 108, together with the front lens 114 of the objective 102, forms an annularly encircling gap 132, through which the immersion medium 122 first completely wets the surface of the front lens 114 facing the specimen 106 and is subsequently discharged through the outlet opening 112 into a target space 134 located between the front lens 114 and the specimen 106. In this process, a sufficient amount of immersion medium 122 is pumped into the immersion cap 104 until it completely covers not only the front lens 114 but also portions of an outer surface 136 of the end wall 108 that extend radially away from the outlet opening 112. Thus, in a top view of the objective 102, the target volume 134 filled with the immersion medium 122 has a radial extension relative to the optical axis O of the objective 102 that is significantly greater than the radial extension of the output opening 112. This ensures that the beam path along the optical axis O to the specimen 106 always lies completely within the immersion medium 122, so that no air can enter the beam path and prevent the desired adjustment of the refractive index there.

[0065] As is apparent from the above, the end wall 108 separates the receiving space 128 located inside the impregnation cover 104 from the target space 134 located outside the impregnation cover 104. Figure 1 In the view shown in FIG, the target space 134 is limited in the radial direction by two curved lines marked with K1 or K2, while the target space 134 is limited in the vertical direction, i.e. along the optical axis O of the objective lens 102, on the one hand by the bottom surface of the specimen 106 and on the other hand by the plane where the output opening 112 is located.

[0066] As in the case of the impregnation cover 104 according to Figure 3 As shown in the cross-sectional view of FIG, the input device 100 has a capacitive sensor 300 integrated into the immersion cap 104, which in the present embodiment is formed by an electrode structure 302 cast into the end wall 108. The sensor 300 has the function of detecting the amount of immersion medium 122, which the pump system 124 pumps into the interior of the immersion cap 104 via an input opening 306 provided in the wall 110. In this case, the electrode structure 302 forming the sensor 300 is arranged within the end wall 108 of the immersion cap 104, so that the three-dimensional detection area of ​​the sensor 300 corresponds to Figure 1The target volume 134 shown in FIG extends outward from the output opening 112 in a radial direction, i.e., transversely to the optical axis O of the objective lens 102. This means that the electrode structure 302 can always detect immersion medium 122 located radially outside the output opening 112 in the target volume 134. However, this should not exclude that the three-dimensional detection range of the electrode structure 302 also covers areas of the target volume 134 radially within the output opening 112, i.e., the electrode structure 302 is also sensitive to the immersion medium 122 located there.

[0067] like Figure 3 Combined with the basis Figure 4 As shown in the top view of FIG302 (which is a purely schematic cross-sectional view), in the present embodiment, electrode structure 302 is composed of a pair of electrodes 410 and 412, which together form an interdigitated structure. Each electrode 410 and 412 has a plurality of concentrically extending electrode segments 410a and 412a, which are closely adjacent and concentrically surround output opening 112 at varying radial intervals. The electrode segments 410a of electrode 410 and the electrode segments 412a of electrode 412 form a finger-like structure that alternately intersects without contacting each other.

[0068] In accordance with Figure 4 In the example shown, the alternating interlocking of the two electrodes 410 and 412 divides the three-dimensional detection area of ​​the sensor 300 into four radial sub-areas R1, R2, R3, and R4. The innermost sub-area R1 has the smallest radial distance from the output opening 112, and the outermost sub-area R4 has the largest radial distance from the output opening 112. Each of these sub-areas R1-R4 is located between one of the electrode segments 410a of the electrode 410 and an adjacent electrode segment 412a of the second electrode 412, with the two electrode segments 410a and 412b acting as capacitor plates. If the amount of immersion medium 122 changes in the vicinity of a respective sub-area R1-R4, this change is detected by a corresponding change in the detection signal provided by the electrode structure 302.

[0069] If according to Figure 3As can be seen from the cross-sectional view of FIG, end wall 108 includes a first material layer 312 below electrode structure 302 and a second material layer 310 above electrode structure 302. The first material layer 312 electrically insulates electrode structure 302 from receiving space 128 within impregnation cover 104. In contrast, the second material layer 310 electrically insulates electrode structure 302 from target space 134 outside impregnation cover 104. The sensitivity of electrode structure 302 to the amount of impregnation medium 122 supplied to receiving space 128 is determined by the thickness of first material layer 312. Correspondingly, the sensitivity of electrode structure 302 to the amount of impregnation medium 122 supplied to target space 134 is determined by the thickness of second material layer 310.

[0070] Since the end wall 108 itself is only a few tenths of a millimeter thick in order to fit into the space between the objective lens 102 and the specimen 106, the two material layers are correspondingly thin. These material layers thus form a thinly designed insulating cover for the electrode structure 302, so that the electrode structure 302, whether facing the receiving space 128 or the target space 134, is sensitive to the amount of immersion medium 122 located there. By concentrically surrounding the output opening 112 and thus the optical axis O of the objective lens 102, the amount of immersion medium 122 in the receiving space 128 and / or the target space 134 can be detected concentrically and averaged. Figure 3 and 4 When the electrode structure 302 shown in FIG is used, only one unique measurement value needs to be determined.

[0071] like Figure 3 It is also shown that the immersion cap 104 has an integrated electronic measuring unit 314. The measuring unit is connected to the two electrodes 410, 412 in Figure 4 The connection contacts 410b and 412b shown in FIG are connected, and the detected detection signal is transmitted to the detection pin 316 through the connection pin 316. Figure 3 and 4 The control / regulation unit is not shown.

[0072] Although according to Figure 3 and 4 The capacitively measuring electrode structure 302 has only one pair of electrodes 410, 412 and accordingly detects only one single measurement value, but in a variant embodiment, the electrode structure can have a plurality of individually controllable electrode pairs, which in their entirety provide a number of measurement values ​​equal to the number of electrode pairs. A related example is Figure 5 and 6 Shown in.

[0073] In accordance with Figure 5The schematic diagram of FIG shows a pair of electrodes 510 and 512, each of which has a connection contact 510b or 512b and a plurality of finger-shaped electrode segments 510a or 512a. Here, the finger-shaped electrode segments 510a and 512a of the two electrodes 510 and 512 are also embedded in each other in an interleaved structure without contacting each other. Figure 5 The electrode pair 510 , 512 shown in FIG. 5 forms an individually controllable substructure which provides a single measured value which is related to the detected amount of immersion medium 122 .

[0074] Figure 6 A capacitively measuring electrode structure 602 is shown, which may be composed of a plurality of Figure 5 The partial structure of the type shown in Figure 6 In the example shown, three electrode pairs 510, 512 are arranged at angular intervals of 120° around the output opening 112 and thus around the optical axis O of the objective 102, wherein each electrode pair 510, 512 extends radially away from the output opening 112. The three electrode pairs 510, 512, which are electrically isolated from one another, provide three detection signals, with which it is possible to detect not only the amount of immersion medium 122 but also its distribution in a transverse direction, i.e., in a plane transverse to the optical axis O of the objective 102, which may be asymmetrical.

[0075] The electrode structure is shown in the previous reference. Figures 3 to 6 The embodiments described are designed so that they are insensitive to the amount of immersion medium 122 located in the outlet opening 112. This is because they do not have a capacitively measured substructure that surrounds the outlet opening 112 and is therefore sensitive to the immersion medium 122 located there. However, it is also possible to design the capacitive sensor so that its three-dimensional detection area also covers the outlet opening 112 in the radial direction, that is, the sensor is also sensitive to the amount of immersion medium 122 inside the outlet opening 112. For this purpose, Figures 3 to 6 The structure shown in for example complements a pair of Figure 7 Electrodes 710, 712 are shown in FIG.

[0076] In accordance with Figure 7 In the example of FIG, the two electrodes 710, 712 each have a semicircular electrode section 710a, 712a surrounding the outlet opening 112. The two electrode sections 710a, 712b thus circularly surround the outlet opening 112 in their entirety, thus enabling capacitive measurement of the amount of immersion medium 122 located therebetween.

[0077] In addition to the electrode structure forming the capacitive sensor for detecting the fill level of the immersion medium 122, the immersion cap 104 can also have an integrated conductor track structure which is electrically insulated from the receiving space 128 and the target space 134 and is designed to heat the immersion medium 122 resistively, i.e., by means of resistance heating. Examples of such conductor tracks are described in accordance with Figure 8 is shown in the schematic diagram.

[0078] In accordance with Figure 8 In the embodiment of FIG, the conductor track structure intended for heating the immersion medium 122 consists of a single, fully electrically conductive conductor track 820, whose two ends protrude from the immersion cap 104 as connecting contacts 820b, 820c. Conductor track 820 is designed so that it forms a resistor, and the current flowing through conductor track 820 heats it. The heated conductor track 820 transfers its heat to the cap material in which it is embedded, and further to the immersion medium 122 adjacent thereto.

[0079] In accordance with Figure 8 In an embodiment, the conductor track has a plurality of conductor track sections 820a, which concentrically surround the outlet opening 112 in different radial sections. Taking into account the thickness of the material layers of the impregnation cap 104, which electrically insulate the conductor track 820 from the receiving space 128 or the target space 134, the conductor track 820 can be designed so that it heats the immersion medium 122 only in the receiving space 128 and only in the target space 134, but also in both spaces.

[0080] according to Figure 8 The conductor track 820 can also be designed so that it has a predetermined temperature-dependent resistance, the knowledge of which allows temperature measurement. For this purpose, the conductor track 820 forms a platinum measuring resistor, for example. This temperature measurement is carried out according to Figure 8 In an embodiment of , which provides only a single conductor track as resistance heating, the temperature of conductor track 820 is preferably measured in a temporally alternating manner with the resistive heating of immersion medium 122. Heating cycles and temperature measurement cycles thus alternate.

[0081] Figure 8 The concentric conductor track structure shown in FIG, due to its conductor track segments 820a that are staggered in a meandering manner, can provide a sufficiently large resistance on a minimal surface, thereby achieving a good temperature distribution. However, this preferred meandering design can also be achieved in other ways, for example, by using Figure 9 and 10 This is achieved using the structure shown in .

[0082] Figure 9 1 shows first an individually controllable conductor track 920 with a meandering structure, which covers an approximately rectangular area and whose two ends protrude from the impregnation cap 104 as connecting contacts 920b, 920c. Figure 10 As shown in FIG, the printed conductor structure in this embodiment has a plurality of Figure 9 The printed conductor 920 of the type shown in FIG. Figure 10 In the example shown, three conductor tracks 920 are provided, spaced 120 degrees apart around the outlet opening 112. This resistance heating formed by individually controllable conductor tracks 920 allows the immersion cap 104 to be heated to varying degrees at different locations. This can be advantageous, for example, if the thermal load is less effective at one of the aforementioned locations than at another, for example due to the design of the immersion cap 104. Even under these conditions, uniform heating of the immersion medium 122 is thus achieved.

[0083] In accordance with Figure 11 The schematic diagram of FIG shows purely by way of example how an electrode structure intended for detecting the fill level of the immersion medium 122 and a conductor track structure serving as a resistance heater and, if appropriate, also as a temperature sensor can be integrated together in the immersion cap 104. Figure 11 In the embodiment of the present invention, the aforementioned structure is based on Figure 5 The electrode pair 510, 512 is formed, and on the other hand, Figure 9 The conductor tracks 920 are formed and are distributed offset from one another around the output opening 112. Alternatively or additionally, it is also possible, for example, to arrange the two structures within the immersion cap 104 in two planes that are offset from one another along the optical axis O of the objective 102.

[0084] Figure 12 An embodiment of a microscope 1200 is shown in which an input device 100 of the type described above is employed. Figure 12 The microscope 1200 is formed as an inverted microscope, wherein the objective lens 102 is located below the specimen 106. Figure 1 In addition to the components shown in FIG. 1 , the microscope 1200 also has a control / regulator unit 1202, for example, designed as a microcontroller, and an electronic measuring unit 1204, which is coupled to the connecting contacts of the electrode structure 302 forming the capacitive sensor 300 via a first connecting cable 1206 on the one hand, and to the control / regulator unit 1202 via a second connecting cable 1208 on the other hand. Figure 12 The illustration is purely schematic. In particular, the electronic measuring unit 1204 can also be arranged directly on the dipping cover 104, as described above with reference to Figure 3In any case, it is advantageous if the electronic measuring unit 1204 is located as close as possible to the electrode structure 302 , since the detection signal provided by the electrode structure 302 is then largely insensitive to electromagnetic interference signals.

[0085] exist Figure 13 In the illustrated embodiment variant, the electronic measuring unit 1204 is integrated into the control / regulatory unit 1202. However, it goes without saying that this embodiment is also to be understood as purely exemplary.

[0086] Both the electronic measuring unit 1204 and the control / regulation unit 1202 can be arranged on the objective lens 102 or the objective lens revolving mount. Figure 12 As shown in the embodiment of the present invention, it is arranged offset from the microscope 1200, or as ... Figure 13 As shown in the view of , it is integrated into the microscope housing 1210.

[0087] The connection between the control / regulation unit 1202 and the electronic measuring unit 1204 can be as follows Figure 12 and 13 As provided in the embodiment of , it is designed to be wired, preferably low-ohmic. In this case, digital signal transmission is particularly preferred. However, it is also possible to transmit the detection signal wirelessly or optically from the electronic measuring unit 1204 to the control / regulation unit 1202.

[0088] Figure 12 and 13The control / regulator unit 1202 shown in FIG. 1 allows the user to operate the microscope 1200, for example, as follows. First, the user transmits a command via a suitable user interface, which causes the pump system 124 to pump the immersion medium 122 from the reservoir 120 into the immersion cap 104. The user can thereby adjust the optimal amount of immersion medium 122 for the respective experiment within the target space 134 between the immersion cap 104 and the specimen 106. At this point, the control / regulator unit 1202 receives the detection signal of the capacitive sensor 300 from the measuring unit 1204 and stores it. The control / regulator unit 1202 then controls the pump system 124 for a predetermined period of time so that the desired amount of immersion medium 122 in the target space 134 remains as constant as possible. To avoid causing continuous small movements in the immersion medium 122, it is advantageous if the control / regulator unit 1202 specifies a tolerance range within which the detection signal is allowed to vary before the next corrective pumping operation is performed. Furthermore, it is advantageous if the control / regulation unit 1202 allows the pumping process only when the microscope 1200 is not currently recording the specimen 106. If, for example, a long experiment is to be carried out in which evaporation of the immersion medium 122 is crucial, the control / regulation unit 1202 can also define a time window in order to plan the pumping process during the experiment.

[0089] If the distance between the immersion cap 104 and the specimen 106 changes during an experiment, for example due to a focusing process, this inevitably results in a change in the contact surface of the immersion cap 104 with the specimen 106, which is covered by the immersion medium 122. During this distance change—which is achieved, for example, by correspondingly controlling a z-drive acting along the optical axis O of the objective 102—it is therefore advantageous to interrupt the control of the amount of immersion medium 122 for a period of time, until the z-drive is at a standstill for a minimum period of time. Based on the detection signal of the sensor 300 that is then present, the control can then be resumed in order to achieve the desired amount of immersion medium 122.

[0090] The following reference Figure 14 The graph of FIG. 1 shows a preferred method that enables automatic initial adjustment of the optimal amount of impregnation medium 122. Figure 14 The graph of φ 120 shows the time curve of a detection signal, designated by C, which capacitive sensor 300 outputs to control / regulation unit 1202 during a continuous measurement.

[0091] Figure 14The method shown in FIG. 1 is based on a situation in which no immersion medium 122 is present in the three-dimensional detection range of the capacitive sensor 300. For the exemplary embodiment discussed here, this means that no immersion medium 122 is present near the end wall 108 of the immersion cap 104. From this state, the pump system 124 now begins to pump the immersion medium 122 into the immersion cap 104, preferably at a constant speed. If the immersion medium 122 then enters the three-dimensional detection range of the sensor 300, the detection signal C output by the sensor 300 begins to increase according to Figure 14 The detection signal C then rises for a while until the immersion medium 122 enters the area of ​​the outlet opening 112 of the immersion cover 104. For the present embodiment, it is assumed that the sensor 300 is designed so that it is not sensitive to the amount of immersion medium 122 located in the outlet opening 112. For this purpose, the sensor 300 has, for example, Figures 3 to 6 Since the sensor 300 is insensitive to the output opening 112, the detection signal C no longer rises in the phase where the output opening 112 is gradually filled with the immersion medium 122. Figure 14 During this phase, which is defined by two points b and c in the graph of FIG, the detection signal C is thus kept constant at the value C ref When the immersion medium 122 begins to fill the target space 134 between the immersion cover 104 and the specimen 106 in a planar manner, the detection signal C starts to rise continuously from point c. Figure 14 Indicated by segment d.

[0092] The control / regulation unit 1202 is designed so that it recognizes the above-mentioned trends abcd on the curve of the detection signal C and determines the measured value C in the region where the detection signal C is constant. ref The method thus allows to make the prescribed state of the amount of impregnation medium 122 comparable to the absolute measured value C as a reference value. ref In particular, in the reference value C determined in this way ref All interfering parameters that would otherwise make capacitive level measurement difficult are already taken into account. Such interfering parameters result, for example, from the particular design of the objective lens 102 used or from the proximity of the capacitive sensor 300 to the specimen 106. Based on this, it is possible to determine an absolute target value C for the optimal amount of immersion medium 122. 目标 , the target value is not related to the aforementioned interference parameters. Target value C 目标 For example, it can be determined as follows:

[0093] C 目标 =C ref +const.; or,

[0094] C 目标 =C ref ×const.,

[0095] Here, const. represents an empirical constant.

[0096] If the detection signal C reaches the determined target value C 目标 , the pump system stops, thereby stopping the continuous flow of the impregnation medium 122 into the impregnation cover 104.

[0097] The above-described method also allows, for example, that after the immersion medium has been pumped out, for example when the specimen or the objective lens is changed, the immersion medium 122 can be pumped back into the target space 134 via the immersion cover 104 until the front lens 114 of the objective lens 102 is optimally covered, without changes in the electromagnetic field caused by the specimen or objective lens change having an adverse effect on the input immersion medium 122.

[0098] The above embodiments are to be understood purely as examples. Therefore, when describing these embodiments, it is primarily assumed that the sensor for detecting the fill level of the immersion medium 122 is designed as a capacitive sensor. However, it is also possible to use a resistive sensor. Figures 4 to 7 The electrode structure shown in is also applicable to resistive sensors. It should only be noted here that, unlike capacitive sensors embedded in the impregnated cover material, resistive sensors are exposed on the surface of the impregnated cover in order to contact the immersion medium 122.

[0099] Although some aspects have been described in the context of apparatus, it is clear that these aspects are also descriptions of corresponding methods, where a block or apparatus corresponds to a method step or a function of a method step. Similarly, aspects described in the context of method steps are also descriptions of corresponding blocks, components, or features of corresponding apparatus. Some or all method steps can be performed by (or using) hardware devices, such as processors, microprocessors, programmable computers, or electronic circuits. In some embodiments, one or more of the most important method steps can be performed by such devices.

[0100] Depending on the implementation requirements, embodiments of the present invention may be implemented using hardware or software. They may be implemented using non-volatile storage media, such as digital storage media such as hard disks, DVDs, Blu-ray discs, CDs, ROMs, PROMs, EPROMs, EEPROMs, or flash memory, storing electronically readable control signals that interact (or can interact) with a programmable computer system to implement the corresponding method. The digital storage medium may thus be computer-readable.

[0101] Some exemplary embodiments according to the invention comprise a data carrier with electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0102] Generally speaking, the embodiments of the present invention can be implemented as a computer program product with a program code, wherein when the computer program product runs on a computer, the program code is effective for implementing one of the methods. The program code can be stored on a machine-readable carrier, for example.

[0103] Further exemplary embodiments comprise the computer program for performing one of the methods described herein, stored on a machine-readable carrier.

[0104] In other words, one exemplary embodiment of the present invention is, therefore, a computer program with a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0105] A further embodiment of the inventive method is, therefore, a storage medium (or a data carrier or a computer-readable medium) comprising, stored thereon, the computer program for performing one of the methods described herein, when the computer program is executed by a processor.

[0106] The data carrier, digital storage medium or presentation medium is typically tangible and / or not seamless.Another embodiment of the present invention is an apparatus, as described herein, comprising a processor and a storage medium.

[0107] A further embodiment of the invention is therefore a data stream or a signal sequence representing the computer program for performing one of the methods described herein. The data stream or the signal sequence can be configured, for example, so that they are transmitted via a data communication connection, for example the Internet.

[0108] A further exemplary embodiment comprises a processing means, for example a computer or a programmable logic device, which is configured or adapted to perform one of the methods described herein. A further exemplary embodiment comprises a computer on which a computer program for performing one of the methods described herein is installed.

[0109] Another embodiment of the present invention includes an apparatus or system configured to transmit (e.g., electronically or optically) a computer program for performing one of the methods described herein to a recipient. The recipient may be, for example, a computer, a mobile device, a storage device, etc. The apparatus or system may include, for example, a file server for transmitting the computer program to the recipient.

[0110] In some embodiments, a programmable logic device (e.g., a field programmable gate array (FPGA)) may be used to perform some or all of the functions of the methods described herein. In some embodiments, the FPGA may be coupled with a microprocessor to perform one of the methods described herein. Typically, these methods are preferably implemented by each hardware device.

[0111] List of Reference Numerals

[0112] 100 Input device

[0113] 102 objective lens

[0114] 104 Impregnation Cover

[0115] 106 specimens

[0116] 108 end wall

[0117] 110 cylindrical wall

[0118] 112 output opening

[0119] 114 front lens

[0120] 116 lens system

[0121] 118 Supply System

[0122] 120 Storage Containers

[0123] 122 impregnation medium

[0124] 124 Pump System

[0125] 126 hose

[0126] 127 hose

[0127] 128 Accommodation Space

[0128] 130 Edge of end wall

[0129] 132 Gap

[0130] 134 Target Space

[0131] 136 Outside of end wall

[0132] 300 Capacitive Sensor

[0133] 302 electrode structure

[0134] 306 Input Opening

[0135] 410 electrode

[0136] 410a Electrode segment

[0137] 410b connection contacts

[0138] 412 electrodes

[0139] 412a Electrode segment

[0140] 412b connection contacts

[0141] 510 electrode

[0142] 510a Electrode segment

[0143] 510b connection contacts

[0144] 512 electrodes

[0145] 512a Electrode segment

[0146] 512b connection contacts

[0147] 602 electrode structure

[0148] 710 electrode

[0149] 710a Electrode segment

[0150] 712 electrodes

[0151] 712a Electrode segment

[0152] 820 printed conductors

[0153] 820a Printed conductor section

[0154] 820b connection contacts

[0155] 820c connection contacts

[0156] 920 printed conductors

[0157] 920a Printed conductor section

[0158] 920b connection contacts

[0159] 920c connection contacts

[0160] 1200 Microscope

[0161] 1202 Control / regulation unit

[0162] 1204 Electronic measuring unit

[0163] 1206 Connection Cable

[0164] 1208 connection cable

[0165] 1210 Microscope Housing

[0166] K1, K2 target space limit lines

[0167] Parts of R1, R2, R3, and R4

[0168] C detection signal

[0169] C ref Reference value

[0170] C 目标 Target value

[0171] t time

Claims

1. An input device (100) for an immersion medium (122) for use with an objective lens (102) with which a specimen (106) can be microscopically imaged, the input device comprising: a cover (104) which is detachably or fixedly mounted on the objective (102) and defines a receiving space (128) for the immersion medium (122), wherein the cover (104) has an output opening (112) facing the optical device of the objective lens (102) facing the specimen (106), and the immersion medium (122) held in the accommodation space (128) can be input into a target space (134) located between the optical device of the objective lens (102) and the specimen (106) via the output opening; and a sensor (300) integrated in the cover (104) with an electrode structure (302) for detecting the input amount of immersion medium (122), The electrode structure (302) at least partially surrounds the output opening (112) and has a three-dimensional detection area extending away from the output opening (112) in a radial direction.

2. The input device (100) according to claim 1, wherein The sensor (300) is a capacitive or resistive sensor.

3. The input device (100) according to claim 1, wherein The cover (104) has an end wall (108) facing the specimen (106), in which the output opening (112) is provided, wherein the end wall (108) separates the receiving space (128) from the target space (134), and the electrode structure (302) is integrated into the end wall (108).

4. The input device (100) according to claim 3, wherein: The end wall (108) electrically insulates the electrode structure (302) of the capacitive sensor (300) from the receiving space (128) on the one hand and from the target space (134) on the other hand, so that the three-dimensional detection area of ​​the electrode structure (302) covers at least the entire target space (134).

5. The input device (100) according to claim 4, wherein: The three-dimensional detection area of ​​the electrode structure (302) also covers the accommodation space (128).

6. The input device (100) according to any one of claims 3 to 5, wherein: The end wall (108) has a first material layer (312) that electrically insulates the electrode structure (302) of the capacitive sensor (300) relative to the receiving space (128) and a second material layer (310) that electrically insulates the electrode structure (302) of the capacitive sensor (300) relative to the target space (134).

7. The input device (100) according to any one of claims 1 to 5, wherein: The electrode structure (302) of the sensor (300) is insensitive to the amount of immersion medium (122) located in the output opening (112).

8. The input device (100) according to any one of claims 1 to 5, wherein: The electrode structure (302) of the sensor (300) is sensitive to the amount of immersion medium (122) located in the output opening (112).

9. The input device (100) according to any one of claims 1 to 5, wherein: The electrode structure (302) is designed as an intercalated structure.

10. The input device (100) according to any one of claims 1 to 5, wherein: The output opening (112) is circular, and the electrode structure (302) is designed to be rotationally symmetrical with respect to the output opening (112).

11. The input device (100) according to any one of claims 1 to 5, wherein: The electrode structure comprises a plurality of electrode pairs (510, 512) which are independently controllable and distributed around the output opening (112).

12. The input device (100) according to any one of claims 1 to 5, comprising a measuring unit (314) provided for the sensor (300) and integrated into the cover (104).

13. The input device (100) as claimed in any one of claims 1 to 5, comprising a conductor track structure integrated into the cover (104), which conductor track structure is electrically insulated relative to the receiving space (128) and the target space (134) and is designed to resistively heat the immersion medium (122).

14. The input device (100) according to claim 13, comprising a temperature sensor for detecting the temperature of the immersion medium (122).

15. The input device (100) according to claim 14, wherein: The temperature sensor is formed by the conductor track structure, which has a predetermined temperature-dependent resistance and is designed to alternately resistively heat an immersion medium (122) held in the receiving space (128) and resistively detect its temperature over time.

16. The input device (100) according to any one of claims 14 to 15, wherein: The conductor track structure is designed in a meandering manner.

17. The input device (100) according to any one of claims 3 to 5, wherein: An edge (130) of the end wall (108) defining the output opening (112) forms a gap (132) with the optical component of the objective (102), through which the immersion medium (122) is output into the target space (134).

18. The input device (100) according to any one of claims 3 to 5, wherein: The end wall (108) extends substantially conically toward the outlet opening (112).

19. The input device (100) according to claim 18, wherein The cover (104) has a substantially cylindrical wall (110) connected to the end wall (108) and which, together with the end wall (108), defines a receiving space (128) for the immersion medium (122).

20. The input device (100) according to any one of claims 1 to 5, comprising a pump system (124), which is connected to the receiving space (128) of the cover (104) via at least one hose (126, 127) and is designed to pump the immersion medium (122) into the receiving space (128).

21. The input device (100) according to claim 20, comprising a control / regulation unit (1202) which is designed to pump the immersion medium (122) into the receiving space (128) as a function of the detection signal provided by the sensor (300).

22. A method for supplying an immersion medium (122) using the supply device (100) according to claim 21, wherein: The immersion medium (122) is pumped into the receiving space (128) by means of a pump system (124), and at the same time a detection signal corresponding to the input amount of the immersion medium (122) is generated by means of a sensor (300), and the pump system (124) is controlled by means of the detection signal to adjust the target amount (C) of the immersion medium (122) 目标 ).

23. The method of claim 22, wherein: The immersion medium (122) is pumped into the receiving space (128) at a constant pump speed.

24. The method of claim 22, wherein: In order to determine the target amount (C 目标 ), firstly detecting the amount of the impregnation medium (122) when it reaches the output opening (112) of the cover (104) as a reference amount (C ref ), then based on the reference amount (C ref ) to obtain the target quantity (C 目标 ).

25. The method according to any one of claims 22 to 24, wherein According to the control circuit, the target value (C 目标 ) remains constant.

26. The method of claim 25, wherein: The input amount of the impregnation medium (122) is regulated within a predetermined error range around the target amount and / or when predetermined operating conditions exist.

27. An objective lens (102) having an input device (100) according to any one of claims 1 to 21.

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