REFERENCE TO RELATED APPLICATIONS

The current application claims the benefit of German Patent Application No. 10 2020 111 715.9, filed on 29 Apr. 2020, which is hereby incorporated by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates to an immersion objective and an immersion microscopy method.

BACKGROUND OF THE DISCLOSURE

Immersion objectives are used in numerous light microscopy applications. An immersion objective is an objective whose front side is immersed in an immersion medium (immersion fluid) during operation. The immersion fluid is applied, for example, on a cover slip under which a sample to be analysed is located.

Immersion fluids should generally be applied in a controlled and targeted manner. This is frequently carried out manually, which requires practice by the user. With electronically controlled immersion devices, it should be possible to apply, in particular to a precisely defined location, an amount of immersion fluid that can be set or replicated with precision. In the case of long-term analyses, a precise addition of immersion fluid should be possible. At the same time, a simple operability for a user is desired without manual imprecisions effected by a user potentially leading to an imprecise application of immersion fluid. Moreover, for a simple operability, a compact design of the overall immersion system is desired. It should be avoided that the different components used for immersion fluids get in the way and impede the handling of the microscope. In particular, the function of other microscope components should ideally not be adversely affected by an immersion device.

Numerous immersion systems for the automated feeding of the immersion fluid are known in the prior art, which, however, do not completely satisfy the aforementioned objects.

EP 1 717 628 B1 describes an immersion objective to which immersion fluid tubes for a feeding and removal immersion fluid are fixed. Immersion fluid tanks with corresponding pumps are provided separately from the immersion objective. The overall system is relatively large and the guiding of the tubes to the objective could be a hindrance, for example in the event of a changing of the objective via an objective revolver or when other microscope components such as an overview camera are used at the same time.

Similarly, WO 2019/016048 A1 describes an objective to which a channel from a separate immersion fluid tank leads. The necessary pump and the immersion fluid tank limit a flexible handling of the microscope. Moreover, a special elastically mounted attachment is required, which must be designed for a specific objective.

In DE 10 333 326 B4, the immersion fluid is brought via a feed tube from an immersion fluid reservoir positioned at a distance to the front area of the objective. An attachment comprising a capillary channel, to which a suction device for the removal of immersion medium is attached, is connected to the objective.

In DE 10123027 B4, the immersion medium is fed directly into the immersion area between the slide and the front of the objective via a feed tube (capillary) by means of an immersion device positioned outside the objective. The immersion medium which is subsequently to be removed is led off via a tube and a corresponding collection device located outside the objective.

DE 10 2005 040 828 A1 describes a fully automated microscope system which, in addition to an automated immersion operation, also enables an automatic cleaning of the front lens of the microscope objective at the end of an immersion operation. The components necessary for the application and removal of the immersion fluid are arranged next to the microscope stand. Tubes for the immersion fluid must be arranged accordingly for the feeding and removal of immersion fluid.

WO 2019/063782 A2 describes an immersion objective and an immersion device that is provided separately from the immersion objective. Formed in a front lens of the immersion objective are channels to which the immersion device is connected for the conveyance of immersion fluid via the same to the area between the slide and the front lens.

DE 10 2017 217 380 A1 discloses a feed component for immersion media. The feed component is arranged at a distance from the objective and comprises a medium conduit through which a pump conveys the immersion fluid to the front area of the objective.

In DE 10 2013 011 544 A1, a protective device for preventing a leakage of fluid from the immersion film area and a device for the automatic feeding of the immersion fluid into the immersion film area are used on an inverted microscope. The protective device is arranged statically in the main body of the microscope stand. The device for feeding the immersion fluid into the immersion film area includes an aquastop system which communicates with the protective apparatus.

DE 10 2006 042 088 B4 and U.S. Pat. No. 3,837,731 A respectively describe an objective to which a kind of cap is fixed. The cap supports a tube or comprises a channel for the feeding and removal of immersion fluid. Similarly, JP 2005 234 458 A describes an immersion device positioned at a distance from the objective, from which tubes lead to the objective.

DE 10 2015 200 927 A1 describes an immersion device formed separately from the objective. The objective and parts of the immersion device can be supported so as to be adjacent to one another on the objective revolver. Due to the size of the immersion device, an immersion fluid tank is once more located at a distance and is connected to the parts on the objective revolver via a tube. No mechanical modification of the objective used is necessary here, which enables an improved handling and a continuous working with different objectives. To this end, the injection device must be arranged far enough away from the objective that a changing of the objective by means of the objective revolver and the moving of the microscope stage can take place unhindered. For this purpose, the injection device can be arranged in particular on the axis of the objective revolver or directly on the microscope stand outside the installation space of the objective revolver. An unhindered injection of the immersion medium to the slide is thus possible. As a result of this arrangement of the injection device on the microscope stand, the stream of immersion fluid must be injected over a distance of approx. 20-30 mm. Due to this relatively large distance, the stream of immersion fluid must be configured with regard to its parameters (e.g. flow speed, stream diameter, stream characteristics) in such a manner that the immersion fluid volume required for the objective in question reaches the desired site of impingement on the slide entirely and reliably. One problem here is the tendency, resulting from the flow energy of the stream of immersion fluid, for air bubbles to form both in the stream itself as well as at the site of impingement in the emerging immersion fluid meniscus (initial immersion) or in the already existing immersion fluid meniscus (supplemental immersion) between the objective and the slide. For microscopic applications, air bubbles visible in the object field are undesirable. Moreover, air bubbles in the immersion area can lead to microscope malfunctions, e.g. of the autofocus system. As a result, due to this injection technology's issue with air bubbles, extensive measures for avoiding and reducing bubbles have been proposed, e.g., an optimization of the pump parameters, a degassing of the immersion medium or “bubble removal exercises” by varying the microscope stage.

DE 20 2017 000 475 U1 describes an immersion fluid component which is arranged separately from the objective and which injects immersion fluid from a certain distance to the front area of the objective via an injection device.

In terms of flow characteristics and with regard to an immersion with as few bubbles as possible, the introduction of the immersion medium in proximity to the sample is advantageous. The necessary equipment for this purpose, at least a tube or channel, must thus be positioned or fixed on the objective itself or in direct proximity to the objective. This is technically challenging due to the limited space for the installation of components between the objective and the sample and could increase the risk of collisions during use. The feeding and removal of the immersion medium via tubes must also be ensured. This complicates or limits the use of the microscope, e.g., with regard to changing the objective, focussing, manipulation or incubation. Due to the considerable space requirements of the immersion device (cannulas, immersion caps, tubes, immersion fluid containers, external pumps, etc.) and the concomitant risk of collision, a combination with other microscope components can also be problematic, e.g., with overview cameras, sensors or aquastop/accident-prevention devices. These are protective devices for the prevention of the penetration of immersion or sample fluids into the microscope, in particular in the case of inverted microscopes. Functional limitations may result in some cases, e.g. an objective change that is limited with respect to its direction of rotation. It can also be necessary to move the immersion device into a parked position when not in use in order to avoid further limiting other microscope functions.

A relatively compact design is obtained with a generic immersion objective. This comprises an objective body in which optical components are accommodated, at least one immersion fluid tank and at least one objective-body coupling connection on the objective body. The immersion fluid tank is supportable in a detachable manner via the objective-body coupling connection. The immersion fluid tank can be supported on the objective-body coupling connection directly or indirectly via intermediate components on the objective-body coupling connection.

Accordingly, a generic immersion microscopy method comprises an immersion objective with an objective body in which optical components are accommodated and at least one immersion fluid tank which is supported in a detachable manner via at least one objective-body coupling connection on the objective body.

Generic immersion objectives are known, e.g., from JP 2010 026 218 A and WO 2008/028475 A2.

JP 2010026218 A describes an immersion device in which an immersion fluid container is attached separately to the outside of the objective. The other necessary functional and control elements of the immersion device are located at a distance from the objective. In WO 2008/028475 A2, an immersion fluid tank can be supported on the objective in a similar fashion. To this end, a cap with immersion fluid channels is located on the objective and the immersion fluid tank is plugged into the cap. Other components of the immersion device (in particular a functional component that can comprise a pump and control electronics) are fixed to the objective revolver separately from the objective.

In order to increase the functionality of an objective, an objective socket with an electrical interface is described in DE 10 2013 006 997 A1.

Known immersion systems are limited with respect to their flexibility and handling. In part, specific and precise arrangements of the components must be carried out. In other cases, if used carelessly, there is the risk of collisions with components of the immersion system.

SUMMARY OF THE DISCLOSURE

The indication of an immersion objective and an immersion microscopy method which allow an automated, precise feeding of immersion fluid, with easy handling and without undue obstruction of other microscope functions, can be considered an object of the invention.

This object is achieved by means of the immersion objective and by means of the method described below.

An immersion objective according to an embodiment of the invention comprises:an objective body in which optical components are accommodated;at least one immersion fluid tank; andat least one objective-body coupling connection on the objective body, wherein the objective-body coupling connection is configured to support the immersion fluid tank in a detachable manner;at least one pump, which is supported via the objective body, wherein the pump is arranged for the conveyance of immersion fluid from the immersion fluid tank to an objective front side; anda control electronics component, which is supported via the objective body, wherein the control electronics component is configured to control the pump.

An immersion microscopy method according to an embodiment of the invention uses an immersion objective comprising an objective body, in which optical components are accommodated, and at least one immersion fluid tank, wherein the at least one immersion fluid tank is supported in a detachable manner on the objective body via at least one objective-body coupling connection. The method comprises conveying immersion fluid from the immersion fluid tank to an objective front side by means of at least one pump which is supported via the objective body; and controlling the at least one pump by means of the control electronics component which is supported via the objective body.

All components necessary for immersions may be arranged on the objective and be supported by the same. These components comprise at least the immersion fluid tank, the pump for immersion fluid and the corresponding control electronics component. The components in question can be supported on the objective body directly or via intermediate components on the objective body. In contrast to the known prior art, this obviates the need for discrete immersion devices that are spatially separate from the objective being used. The risk of collisions with components of a separate immersion device during the changing of an objective is thereby avoided. Other microscope functions are not or hardly hindered on account of the small size of the immersion device integrated on the objective. The user is spared a precise positioning of parts of the immersion device, as the correct position of the immersion fluid components is already determined by the position of the objective. Furthermore, the immersion objective according to the invention can be readily used with a variety of different light microscopes, as modifications of the light microscope or special arrangements of immersion fluid components on the microscope stand or on the objective revolver are not necessarily required. Herein lies a significant difference from the prior art discussed above, in which parts of the immersion device (for example the pump) invariably have to be arranged separately on the objective revolver or on the stand.

For example, the invention can enable an automated feeding of immersion fluid, in particular in the form of a supplemental immersion, in long-term experiments, some of which last several days. This advantage is particularly relevant when compared to cases where a supplemental immersion would have to be carried out manually, e.g. every 30 min., by a user.

Optional Embodiments

Advantageous variants of the immersion objective according to the invention and of the method according to the invention are the object of the dependent claims and are explained in greater detail in the following description.

Objective-Body Coupling Connection

The objective-body coupling connection can be understood as a connection for mechanical support and optionally for electrical connection. The mechanical support and electrical connection functions can be performed by spatially separate parts of the connection. For example, the mechanical support may be provided by a clamping connection, a plug/socket connection, a tensioned connection or a threaded connection. An electrical contact may be provided at a distance therefrom, e.g. by electrical contact pins or surfaces that are elastic or spring-mounted. For a compact structure, however, it is also possible for the same connection part to effect both the electrical contacting as well as the mechanical support of the connected components. The objective-body coupling connection can comprise an electrical plug/socket connector (hereinafter: objective-body plug/socket connector) or be constituted by such, wherein the plug/socket connector, depending on its design, reinforces the mechanical support or is solely responsible for said support.

The objective-body coupling connection can also comprise a magnetic coupling point instead of or in addition to a mechanical connection.

At least one immersion fluid tank is supported via the at least one objective-body coupling connection. Optionally, the at least one pump can also be supported via the same connection. In principle, the objective-body coupling connection here can comprise separate connection parts (e.g. plug/socket connectors) for the immersion fluid tank and the pump. A compacter design, however, is one in which the objective-body coupling connection comprises merely a sole connection part or a sole electrical connection via which both an immersion fluid tank and a pump can be supported or electrically contacted. For example, the immersion fluid tank can be designed to be connected directly to the objective-body coupling connection and the pump can be supported in or on the immersion fluid tank. Alternatively, a pump adapter, which will be described in greater detail later on, can be connected directly to the objective-body coupling connection and the immersion fluid tank is connected to the pump adapter. In principle, other intermediate components (for example, sleeves, mounting brackets, the control electronics component or parts of the same) can also be connected directly to the objective-body coupling connection, wherein the immersion fluid tank and the pump are connected to the objective-body coupling connection via this/these intermediate component(s).

The immersion objective can comprise an electrical interface together with a mechanical mounting connection for the attachment of the immersion objective, for example a bayonet mount or a thread for attachment to the objective revolver or stand, wherein an electrical contact is also provided. The control electronics component, which is supported via the objective body, can now be electrically connected both to the electrical interface as well as to the objective-body coupling connection. The control electronics component can thereby receive control commands and/or electrical energy via the electrical interface and can control the pump via the objective-body coupling connection and, depending on its configuration, also communicate with optional electrical parts of the immersion fluid tank, in particular with a fill-level sensor.

In other words, the objective-body coupling connection may be configured to establish an electrical connection also with components of the immersion fluid tank, in particular with a fill-level sensor of the immersion fluid tank.

In some variants, the immersion objective is suitable for inverted as well as upright microscopy. The immersion objective is rotated 180° in the event of such a transition. An immersion fluid tank, however, depending on its design, cannot be operated correctly in an inverted position (upside down), as the pump, in the event that the immersion fluid tank is only partially filled, could draw air and not immersion fluid. To solve this problem, it is advantageous if the immersion fluid tank can also be supported on the objective-body coupling connection in a position rotated 180° relative to the objective body. In particular, the objective-body coupling connection or its electrical connection can be designed to be symmetrically contactable so that the immersion fluid tank is supportable in different orientations for inverted and upright microscopy. For example, a symmetrically structured electrical plug/socket connector can be used. Designs are also possible in which the objective-body coupling connection comprises two separate mechanical mounts (and/or two separate electrical connection means), of which one is used for inverted microscopy while the other is used for upright microscopy. It is also possible with such designs to couple an immersion fluid tank with the objective body in two orientations which are rotated 180° in relation to one another.

The objective-body coupling connection can in particular be located at mid-height on the objective body, i.e. symmetrically in relation to the height of the latter. This is advantageous in order to avoid, in the cases of both inverted and upright microscopy (i.e. regardless of the orientation in which it is supported via the objective-body coupling connection), that the immersion fluid tank protrudes beyond the objective front side or the mounting connection of the objective.

In order for the immersion objective to be usable in both an inverted as well as an upright arrangement, a fluid connection to the immersion fluid tank can also be pivotable. The fluid connection can in particular lock in two specific pivot positions. The two pivot positions differ from each other in the height between the objective front side and the mounting connection of the objective. For the inverted and upright arrangements, the pivot position is used which is respectively lower. The pump thereby suctions immersion fluid from the lower area of a connected immersion fluid tank via the fluid connection. In some cases, it may be necessary to use differently designed immersion fluid tanks for the upright and inverted arrangements.

Immersion Fluid Tank

An immersion fluid tank can generally be understood to be a fluid container.

Depending on its design, each immersion fluid tank is connected to the objective-body coupling connection directly or via intermediate components. For a direct connection, each immersion fluid tank can comprise a mating plug or socket, which is formed so as to be apt for connection to the objective-body coupling connection. Depending on its design, the mating plug/socket can provide mechanical support only or also an electrical connection. To this end, the mating plug/socket can be configured, e.g., as an electrical plug/socket connector.

In particular if the immersion fluid tank is connected directly to the objective-body coupling connection, the corresponding pump can be accommodated in said immersion fluid tank. Compact pumps, often referred to as micropumps, can thus be accommodated in a space-saving manner and with a small number of mechanical plug-in connections.

Each immersion fluid tank can comprise an air vent valve. This can be arranged on the immersion fluid tank at an end opposite the pump. The pump can thus be located in the lower area of the immersion fluid tank during operation, while the air vent valve is at the upper end. By means of the air vent valve, a negative pressure, which would hamper a precisely dosed conveyance of immersion fluid by the pump, is avoided in the immersion fluid tank when in a partially filled state.

Each immersion fluid tank can also comprise a fill-level sensor that can be electrically connected to the objective-body coupling connection, in particular by means of the mating plug/socket of the immersion fluid tank.

Each immersion fluid tank can comprise a refill opening for the refilling of immersion fluid. A valve or cap on the refill opening can prevent contaminants from entering while immersion fluid can be refilled via, e.g., a syringe. The refill opening is advantageously located in a position opposite the site of the pump, i.e. on the upper end of the immersion fluid tank. Refilling can occur while the immersion objective is mounted on a light microscope and in operation. This can be a significant advantage in long-term experiments.

The aforementioned features are particularly suitable when the immersion fluid tank has rigid outer walls. Alternatively, however, an immersion fluid tank can also be designed as a flexible tank whose walls contract as the volume of the immersion fluid it contains decreases. A flexible bag (collapsing bag) is also possible as the immersion fluid tank or in the described immersion fluid tank, wherein the immersion fluid is accommodated in the bag. In these designs with flexible walls, the volume of the bag decreases when the amount of contained immersion fluid is reduced. The pump can thus empty the bag regardless of the location of a pump connection on the bag. As a result, the structure consisting of a pump and an immersion fluid bag can advantageously be used with both inverted and upright microscopes without having to effect different orientations of the pump and bag in relation to the objective body. The bag can be emptied in both cases largely completely without the pump drawing air. User friendliness is thus enhanced.

Pump Adapter

It can also be provided that an immersion fluid tank is not connected directly to the objective-body coupling connection, but rather via an intermediate component, which can in particular be a pump adapter. A pump adapter comprises a mating plug/socket for connecting to the objective-body coupling connection, the pump, which is electrically connected to the mating plug/socket, and a support bracket for supporting the immersion fluid tank in a detachable manner. The mating plug/socket of the pump adapter can in particular be designed as an electrical plug/socket connector or comprise one. This design is particularly well-suited to a use of an immersion fluid tank as a disposable immersion fluid tank: more costly parts like the pump are detached from the immersion fluid tank so that the tank can be designed particularly simply and cost-effectively as a disposable component.

The support bracket of the pump adapter for the immersion fluid tank can either be purely mechanical or also provide an electrical connection. To this end, the support bracket can be designed, for example, as an electrical plug/socket connector and the immersion fluid tank comprises a matching plug/socket connector. The electrical connection can be used for, e.g., a fill-level sensor.

Optionally, each immersion fluid tank can have a respective receiving recess for receiving the respective pump in its lower area. In particular, the part of the pump adapter in which the pump is located can thus be inserted in the receiving recess. This arrangement can be particularly space-saving. Moreover, the receiving recess can also be formed for mechanical support on the pump or pump adapter, in particular for an interlocking support. The receiving recess can thus also contribute to the mechanical support of the immersion fluid tank on the pump adapter in addition to the plug/socket connector (mating plug/socket).

A pump adapter can be L-shaped in cross section, wherein a long side of the L shape fits against the objective body. A part protruding from the long side, in which part the pump is located, protrudes into the receiving recess of the immersion fluid tank.

Each immersion fluid tank can comprise a pump coupling in its lower area. This is designed for the fluid connection of the pump and prevents a leakage of immersion fluid through the pump coupling when the pump is not connected. The lower quarter of the immersion fluid tank, for example, can be understood to be the lower area of an immersion fluid tank. Accordingly, the upper quarter of the immersion fluid tank can designate the upper area.

Control Electronics Component

The control electronics component is configured to control the pump(s) and can optionally also communicate with all other electrical or electronic components of the immersion objective. For example, the control electronics component can retrieve the current fill level of an immersion fluid tank from a fill-level sensor. If immersion fluid tanks respectively comprise a chip on which identification data as well as information regarding the contained immersion fluid are saved, the control electronics component can also read such data of the chip.

The control electronics component can optionally further be configured to selectively control the pump or one of the pumps either to pump immersion fluid from the immersion fluid tank to the objective front side or conversely to pump immersion fluid away from the objective front side to the immersion fluid tank.

The control electronics component can be accommodated in a control electronics housing, which can be designed so as to be detachable from the objective body. To this end, the control electronics housing can in particular comprise a plug/socket connector via which the control electronics housing is electrically connected to and optionally mechanically supported on the objective body. This facilitates its flexible use. For example, the same control electronics component can be used successively with different objectives or a control electronics component can be replaced by a newer one without other components of the immersion objective having to be discarded.

Alternatively, the control electronics housing can also be solidly connected to the objective body or be formed by common sleeves or housing parts.

If the objective body comprises a plug/socket connector to which the control electronics housing is connected, then the plug/socket connector can be located closer to the mounting connection of the objective than to the objective front side. In contrast to the objective-body coupling connection, the plug/socket connector for connecting the control electronics housing to the objective body can have a keyed shape. This allows a connection in a sole orientation so that the control electronics housing can only be fixed in the desired position in relation to the objective body.

A control electronics housing or the above-described control electronics housing can have a ring segment shape in cross section (perpendicularly to the longitudinal axis of the immersion objective). In particular, an inner side with a circle segment shape can fit against the objective body. An outer side of the control electronics housing can also have a circle segment shape, which yields an overall space-saving system while undesired collisions with other microscope components become less likely. The ring segment shape of the control electronics housing can form a closed ring shape in conjunction with one or more immersion fluid tanks respectively having a ring segment shape. This ring surrounds the objective body, which is generally circular in cross section.

In order for the control electronics component to be able to use the room in the housing with the ring-segment shape efficiently, the control electronics component can comprise circuit boards in rigid-flex technology. A plurality of circuit boards can be connected by flexible broadband wires so that the circuit boards extend in the shape of a ring segment when viewed together.

Arrangement of the Immersion Fluid Tank(S)

The at least one immersion fluid tank, like the control electronics housing, can be arranged around the objective body in the shape of a ring segment. Each immersion fluid tank can respectively have an inner side with a circle segment shape, which fits against the objective body. The outer side, viewed radially from the objective axis, of each immersion fluid tank can optionally also have the shape of a circle segment.

There can also be at least two immersion fluid tanks arranged on the objective body for different immersion fluids. The objective body can accordingly have respective coupling connections for the plurality of immersion fluid tanks.

A Y-channel (Y-shunt) can optionally be connected to the two immersion fluid tanks or to two of the immersion fluid tanks directly or via two tubes. By means of the Y-channel, the contained immersion fluids, for example glycerine and water, can be mixed. A sole tube subsequently guides the mixture to the objective front side. The control electronics component can set a mixing ratio of the two immersion fluids by means of a corresponding control of the respective pumps.

In principle, variations of different-sized immersion fluid tanks forming, for example, a quarter ring or a half ring in cross section can also be used. Two smaller immersion fluid tanks (respectively with, e.g., the shape of a quarter ring) are thus attached to adjacent objective-body coupling connections; in contrast, a larger immersion fluid tank (e.g. with the shape of a half ring) would contact only one of the objective-body coupling connections electrically and would comprise a recess or solely a mechanical support bracket or electrical contact for the adjacent objective-body coupling connections.

In addition, a residual immersion fluid tank can also be arranged on the objective body, in particular via an additional objective-body coupling connection. A residual immersion fluid pump is supported via the objective body and arranged to suction immersion fluid from an objective front side to a residual immersion fluid tank. In principle, the residual immersion fluid tank and the residual immersion fluid pump can be designed in the same manner as the described immersion fluid tank and its pump.

Tube for Immersion Fluid

The immersion fluid can be transported from an immersion fluid tank to the objective front side with the aid of the pump via, for example, channels in the objective body, channels in optical components in the objective body and/or via a tube.

Each pump or each immersion fluid tank can comprise a tube connector fitting for connecting a tube. At least one replaceable tube is attached to the tube connector fitting in a detachable manner and leads to the objective front side. In particular, one tube can be provided per pump. If a Y-channel is connected to two tube connector fittings of two pumps, a single tube is accordingly used for two pumps (i.e. for two immersion fluid tanks).

If a tube leads all the way from the tube connector fitting to the objective front side, no other components are contaminated by immersion fluid residues or the potential formation of germs besides the tube. If the tube is replaced, an otherwise laborious cleaning, as required in systems of the prior art, is no longer necessary. The tube can in particular be used once and then replaced or be replaced after a predetermined number of immersion operations. The control electronics component can optionally be configured to provide an indication to a user (e.g. via the electrical interface of the immersion objective) that the tube should be changed. The tube connector fitting is advantageous for the simple connection of the tube, although a mechanical interlocking or clamping connection and/or a tube guide channel or a guide groove can additionally be provided in the area of the objective front side. The tube guide channel accommodates the tube and does not itself come into contact, or negligibly, with immersion fluid, whereby a laborious cleaning of the tube guide channel is no longer necessary or is necessary less frequently. The tube or a channel can optionally also lead to a perforation in the front lens.

A filter can be provided at the end of the tube or channel, i.e. in the area of the objective front side. The filter can be fixed on the tube itself or on the objective front side. In an embodiment on the tube, the filter can easily be replaced together with the tube. By means of a filter, the formation of air bubbles in the outgoing immersion fluid is avoided. Air bubbles would interfere, for example, with an autofocusing system or the viewing of the sample.

The described tube can be configured either as one piece or as a plurality of tube sections placed end to end, in particular as described in greater detail in the description of the figures.

Pump

The pump can be understood to designate every device suitable for conveying the immersion fluid from an immersion fluid tank or for conveying immersion fluid to a residual immersion fluid tank. Compact dimensions of the pump in the form of a micropump are advantageous. The pump can be designed, for example, as a piezoelectric pump, as an electroosmotic pump or as a tube pump. In the case of a tube or peristaltic pump, the pump effects an outer mechanical deformation (pillowing) of the tube so that a medium is conveyed in the same. In the process, the tube pump does not itself come into contact with the conveyed medium, i.e. the immersion fluid, so that contaminations of the tube pump do not occur. If an immersion fluid tank is designed as a flexible bag, then the pump can also be a device which exerts a pressure on the bag.

In particular when the pump does not come into direct contact with immersion fluid, it is not absolutely necessary to render the pump replaceable. The different described embodiments can thus be modified so that the at least one pump is permanently installed in or on the objective body. The pump can also be arranged next to the control electronics component, in particular in the control electronics housing.

A separate pump can be provided for each immersion fluid tank. In principle, a plurality of pumps or immersion fluid tanks can be connected via the same objective-body coupling connection, although it can be provided for simple handling that each immersion fluid tank is to be connected to a respective objective-body coupling connection.

General Features

Immersion objective: An immersion objective denotes an objective that is designed to be connected to a light microscope and used with an immersion fluid.

Objective front side: The objective front side denotes the end of the immersion objective that faces a sample. During operation, a part of the objective front side should be immersed in immersion fluid.

Objective body: Objective body denotes an encasing or a housing in which optical components, in particular lenses or mirrors, are accommodated. The objective body can consist of more than one part. For example, the objective body can comprise one or more sleeves for supporting the optical components and a distinct outer encasing or support on which the at least one objective-body coupling connection is formed. The specific structure of the objective body is not of decisive importance provided that the components supported by the objective body or via the at least one objective-body coupling connection are ultimately supported by the mechanical mounting connection of the objective (e.g. a bayonet or threaded connection).

An adapter that enables, e.g., a connection to an objective revolver can be considered part of the objective body. A bayonet connection or a bayonet connection configured as an adapter can also be considered part of the objective body in the context of the invention. The objective-body coupling connection can also be formed on the bayonet connection and the immersion fluid tank can be supported via the same. In particular, an orientation of the immersion fluid tank here can be such that it extends in the direction of or on the axis of rotation of the objective revolver. The bayonet connection can comprise a coupling for fluid media with an integrated check valve, whereby there is no leakage of fluids into the bayonet interface when the objective is removed. In order to simplify the use of the objective revolver, a decoupling of the tube can also be provided in the rotation axis of the objective revolver with a rotatable tube coupling.

Support via the objective body denotes that the weight of the corresponding components is borne by the objective body or in conjunction with the objective body via its mounting connection (i.e., for example, via the same e-bayonet connection). These components, in particular the control electronics component, the immersion fluid tank and the pump, are thus not supported on the stand or detached from the objective.

The detachable support via the objective-body coupling connection is intended to denote that a non-destructive demounting is possible, optionally without tools. This can be the case, for example, with plug/socket, magnetic or bayonet connections. For an efficient use of installation space, it can be advantageous for a pump and an immersion fluid tank to be supported via the same electrical and mechanical coupling means on the objective body. In principle, however, it is also possible to provide separate electrical and/or mechanical coupling means on the objective body for the pump and the immersion fluid tank.

Descriptions in the singular are employed for the sake of an easier comprehension and do not necessarily mean that a single component is provided. If, for example, “the pump” is described, further pumps optionally formed in the manner of the described pump may also be provided.

Plug/socket connector: In the context of the present invention, electrical plug/socket connectors may be understood to designate connections which establish an electrical connection by being plugged together. A plug/socket connector here can comprise contact pins pointing outwards and/or contact openings directed inwards. The plug/socket connector can optionally also provide, besides an electrical connection, the mechanical support of a connected component and can in particular be designed as a plug, socket or coupling.

The characteristics described as additional features of the immersion objective, if implemented as intended, also yield variants of the method according to the invention. Conversely, the immersion objective can also be configured to carry out the described method variants.

