DE202015105900U1 - Lens holder for a microscope and microscope with such a lens holder - Google Patents

Abstract

Lens holder for a microscope (1), with a first lens (10, 11) arranged in the lens holder (9) and a first piezo linear drive (13, 14) arranged in the lens holder (9), which holds the first lens (10, 11) along its optical axis relative to the lens holder (9) can move.

Description

The present invention relates to a lens holder for a microscope and a microscope with such a lens holder.

In the case of microscopes, there is often a requirement that as much space as possible should be present between the objective and the sample, which is positioned on a sample stage. This is the case, for example, in electrophysiological applications. The existing space may then be e.g. used for positioning of micropipettes. Only for the applicative examination of the sample should the lens then move to the required working position.

On the other hand, the distance between a lens and the sample should be as small as possible in order to take good pictures with high magnification. Furthermore, there are the requirements to change this distance for various microscopic applications quickly (within ms).

Proceeding from this, it is an object of the invention to provide a lens holder that can meet these requirements as possible. Furthermore, a microscope is to be provided with such a lens holder.

According to the invention the object is achieved by a lens holder for a microscope, wherein the lens holder has a first lens and a first piezo linear actuator, both of which are arranged in the lens holder, wherein the first piezo linear actuator move the first lens along its optical axis relative to the lens holder can.

With such a piezo linear drive, it is possible to provide longer travel paths (for example at least 15 mm, 20 mm or 25 mm) so that, on the one hand, the desired large distance between the objective holder and the sample stage in the intended use of the objective holder in a microscope e.g. can be provided for positioning of micropipettes. On the other hand, a good imaging is possible because the piezo linear actuator can position the first lens for recording with high accuracy and high speed close to the sample.

The lens holder may include a second lens and a second piezo linear actuator, both of which are provided in the lens holder, wherein the second piezo linear actuator can move the second lens along its optical axis relative to the lens holder. The second

Piezo linear drive can also provide a travel of at least 15 mm, 20 mm or 25 mm.

The lens holder can be designed, in particular, as an objective changer or objective revolver. Furthermore, the lens holder can be made exchangeable, so that it can be arranged on different microscopes.

The lens holder may further be formed so that the first lens has a parking position and a working position, wherein in the parking position, the lens is completely or at least partially disposed within the lens holder and in the working position facing away from the lens holder end of the lens from the lens holder a greater distance as in the parking position. In particular, the difference between parking position and working position may be 10 mm, 15 mm or 20 mm. The same applies to the second lens and the second piezo linear drive.

The lens holder may also contain more than two lenses. It is also possible that the lens holder contains exactly two lenses with exactly two piezo linear drives. Furthermore, the lens holder can contain exactly one lens with exactly one piezo linear drive. Depending on the space available in the lens holder, the system can be designed with any number of combinations of lenses and piezo linear actuators.

Each of the piezo linear actuators can have at least two spaced-apart legs, which can be controlled electrically by a drive device. The legs are designed so that by suitable control on the one hand, the length of the legs (ie, the extension in the longitudinal direction) is changeable and on the other hand, a bending or bending of the legs in a direction transverse to the longitudinal direction of the legs is possible.

The piezo linear drive comprises at least two legs. To move the lens, a leg that is in mechanical contact with a part of the lens and a corresponding guide plate or rail is curved so that an advancing movement takes place. The other leg is not in mechanical contact with the lens, but can preferably be bent against the feed direction. Once the advancing movement is completed by means of the first leg, the second leg can be brought into contact with the lens and then perform the desired advancing movement, while the first leg is disengaged and again preferably moved counter to the advancing movement. By repeatedly performing these steps, a high-precision moving or positioning of the lens can be performed. The piezo linear drive preferably has more than two legs. For example, the piezo linear drive can have a drive element with four legs. In particular, can the piezo linear drive comprise a plurality of drive elements.

The piezo linear drive can in particular be designed as it in the DE 101 48 267 A1 is described. The content of this document is hereby incorporated with respect to the piezo linear actuator.

The piezo linear drive can also be referred to as a piezo stepping drive.

There is also provided a microscope with a tripod and a tripod-mounted lens holder according to the invention (including its development according to the invention).

The microscope may include a sample table and a mechanical guide over which the lens holder is mounted on the tripod, the mechanical guide moving the objective holder along a first direction that is parallel to or coincident with the optical axis of the objective, if this is positioned in the imaging beam path of the microscope, allows to change the distance between the sample table and the lens holder.

The movement by means of the mechanical guide and the piezo linear drive can be carried out simultaneously. These can be either in the same direction or in opposite directions.

The mechanical guide can be motor-driven. It can e.g. be driven by an electric motor or have a stepper motor.

In the microscope according to the invention, after a lens change by means of the objective holder, a focus offset correction (or a parfocality adjustment) can be carried out. This advantageously achieves that after a lens change, the same point in the sample is displayed sharply.

The microscope according to the invention can automatically perform several recordings in different focal planes, the focal planes being set by means of the piezo linear drive. The advantage lies in the fact that the positions can be approached quickly and precisely in wide travel ranges.

Furthermore, it is possible that the focusing is performed by means of the piezo linear drive. Again, precision and speed are seen as outstanding features.

The microscope according to the invention can be designed in particular as a microscope with a sample table which is not movable in the first direction. This is particularly advantageous for electrophysiological applications, since in this case, for example, micropipettes are positioned in the sample.

The microscope can be designed in particular as an upright microscope. Furthermore, the microscope according to the invention may be formed as a transmitted light and / or incident light microscope. Furthermore, it is possible that the microscope according to the invention is designed as a laser scanning microscope.

The objective holder can be interchangeably arranged in the microscope according to the invention.

Furthermore, it is possible for the microscope to have an exchangeable module which only permits a change of objective by means of the objective holder if all the objectives contained in the objective holder are in their parking position. The change module can mechanically and / or block the lens change electromechanically by means of a software control.

In particular, a further objective can be arranged in the objective holder, which can be brought from its parked position into its working position (and vice versa) by means of a mechanical actuating device (such as eg a mechanical lever, a lifting or lowering device). Under the parking position, in particular, such a position is understood in which a lens change is feasible.

In particular, the mechanical actuating device can be designed such that an actuation only leads to a movement of the further objective from its parking position into its working position, when all the other objectives of the objective holder are in their parking position and the objective is positioned in the microscope axis. This can be realized so that the operation of the actuator blocked and thus is not possible. Alternatively, it is possible that, although the actuating device can be actuated mechanically (ie that the lever can be moved, for example), this does not lead to a change in the position of the further objective since, for example, a mechanical engagement with other mechanical elements for a such movement is not present.

The microscope according to the invention can have further elements known to the person skilled in the art, which are necessary for the operation of the microscope.

It is understood that the features mentioned above and those yet to be explained not only in the specified combinations, but also in other combinations or in Stand alone, without departing from the scope of the present invention.

The invention will be explained in more detail for example with reference to the accompanying drawings, which also disclose characteristics essential to the invention. Show it:

1 a schematic view of an embodiment of the microscope according to the invention;

2 an enlarged view of the lens holder 9 with an extended lens;

3 an enlarged view of the lens holder 9 , both lenses retracted;

4 an enlarged view of the first piezo linear actuator 13 ;

5 an enlarged view of the first piezo linear actuator 13 ;

6 - 9 Views of the piezoactuator 20 together with the friction rail 19 to explain the operation of the first piezo linear actuator 13 , and

10 a view of the second track 25 of the glass scale 21 of the first piezo linear actuator 13 ,

At the in 1 The embodiment according to the invention comprises the microscope according to the invention 1 a tripod 2 at which a lighting device 3 , a sample table 4 , a manipulation device 5 , an imaging device 6 and a recording device 7 ,

The microscope according to the invention 1 is here designed as a transmitted-light microscope, so that one on the sample table 4 arranged sample 8th from below by means of the lighting device 3 is illuminated and from above by means of the imaging device 6 shown enlarged and then by means of the receiving device 7 can be included. The recording device 7 can eg have a digital camera or a digital video camera. Alternatively or additionally, an eyepiece (not shown) may be provided for viewing the enlarged image.

The imaging device 6 has a lens holder 9 on, the first lens 10 and a second lens 11 contains, by means of the lens holder 9 can be selectively positioned in the imaging beam path. The lens holder 9 can therefore be referred to as a lens changer or nosepiece.

The lens holder 9 is about a mechanical guide 12 with the tripod 2 connected. The mechanical guidance 12 is designed so that movement of the lens holder 9 in the imaging direction (z-direction) is possible. The movement can be performed either manually or by means of a motor (for example a stepper motor).

For the first and second lens 10 . 11 is in the lens holder 9 one piezo linear drive each 13 . 14 provided, which serves the corresponding lens 10 . 11 along its optical axis (ie in the z-direction) to move. This movement can, as will be described in detail below, be used to that appropriate lens 10 . 11 from its parking position, where it is completely inside the lens holder, for example 9 is positioned to move to its working position to perform the desired imaging. When displayed in 1 is the first lens 10 Being used for the picture just in its working position and is the second lens 11 in its parking position within the lens holder 9 , The parts of the lenses 10 . 11 and the linear drives 13 . 14 inside the lens holder 9 are and therefore in the representation of 1 are not visible, are shown by dashed lines for clarity.

Furthermore, the piezo linear drives 13 . 14 for focusing the corresponding objective 10 . 11 be used and the appropriate lens 10 . 11 high-precision and fast positioning in the imaging direction.

Through the piezo linear drives 13 . 14 is it possible, therefore, the lenses 10 . 11 to hold in their park position until the corresponding lens 10 . 11 in the imaging beam path by means of the objective holder 9 is positioned. Only then will the appropriate lens 10 . 11 by means of the piezo linear drive 13 respectively. 14 moved to the working position. This is advantageously achieved that a lot of space between the lens holder 9 and the sample table 4 exists, so that this place for the arrangement of the manipulation device 5 , which may be a micropipette, for example, can be used. This is advantageous, for example, for electrophysiological applications.

In 2 is the lens holder 9 from 1 shown enlarged. After the two piezo linear drives 13 . 14 are formed the same, hereinafter only the first piezo linear actuator 13 described. The first piezo linear actuator 13 comprises a rotor unit 15 that mechanically with the first lens 10 is connected, and a drive unit 16 that mechanically with the lens holder 9 connected is. The drive unit 16 can be the runner unit 15 in the direction of the optical axis of the first objective 10 move and so for example the first lens 10 move to the park position as they are in 3 is shown schematically.

In 4 is in a side view of the first piezo linear actuator 13 shown. The runner unit 15 includes a runner plate 17 in a linear guide 18 is guided and can be moved only in the z-direction. The runner plate 17 is mechanical with the first lens 10 connected.

On the runner plate 17 is a friction rail 19 , which extends in the z-direction, attached. A piezoactuator 20 , the part of the drive unit 16 is due to the friction rail 19 and can move them in the z-direction, as will be described in more detail below.

Further, on the runner plate 17 a glass scale 21 mounted for optical position determination. The glass scale 21 has a first track 22 with a high-precision division, by an incremental sensor 23 is scanned, the sensor 23 with the lens holder 9 connected and thus not in the z-direction is displaced. Based on the data of the sensor 23 Can in conjunction with the piezo actuator 20 a positioning accuracy of eg 2 nm can be achieved.

Furthermore, the glass scale includes 21 a second track 24 holding a bright first section 25 and a dark second section 26 (hatched shown). The second track 24 can be used for referencing. If the sensor 23 the dark second section 26 captured, is the first lens 10 in his parking position. This is in the presentation of 4 the case.

In 5 is the first piezo linear drive 13 shown in the case that the first lens 10 is in his working position.

The first piezo linear actuator 13 is formed to have a travel in the z-direction of at least 15 . 20 or 25 mm. This makes it possible, the above-mentioned large sample space or distance between lens holder 9 and sample table 4 provide.

In 6 is the piezoactuator 20 is together with the friction rail 19 in a same view as in 2 shown enlarged. As the view is correct 6 can be seen, includes the piezoelectric actuator 20 a substrate 27 , on which, for example, four identical piezoceramic stacks 28 are formed spaced apart. Every piezoceramic stack 28 is formed in two parts, wherein it has a first stack part 29 and a second stack part 30 having. The first batch part 29 serves here for a shear or propulsion movement and the second stack part 30 serves here for a pressure movement. As in 7 to 9 is shown schematically, the piezoceramic stacks 28 be driven so that they carry out mutual antiphase Andruck- feed movements, resulting in a step-like displacement of the friction rail 19 and thus the runner plate 17 in the z-direction. The first piezo linear actuator 13 can therefore also be referred to as a piezo stepping drive.

Of course it is also possible that the first batch part 29 for the pressure movement and the second stack part 30 are designed and used for the shear or propulsion movement.

In the embodiment described here, the two lenses are 10 . 11 positioned so that the lens change over a manual or driven by a motor rotation of the lens holder 9 by 90 °. The rotational positions of the lens holder 9 in which the first or second lens 10 . 11 are positioned in the imaging beam path are encoded. This coding can eg by means of the tripod 2 recorded and evaluated. Thus, the microscope according to the invention 1 be formed so that a process of the lens 10 . 11 from its parking position to the working position is only possible if the lens 10 . 11 is positioned in the imaging beam path. The lowering can thereby by means of a software for controlling the microscope 1 and / or by pressing a corresponding switch, button or other input unit of the microscope 1 respectively. The lowering of the lens 10 . 11 from the parking position to the working position, for example, be 22 mm. At a maximum displacement speed of 10 mm / s, this procedure can be carried out in the working position in only about 3 seconds.

In particular, the lens holder 9 designed so that twisting of the lens holder 9 is blocked when a lens 10 . 11 is positioned in its working position or if not both lenses 10 . 11 are in their parking position. This will unintentional damage of eg the manipulation device 5 avoided.

In operation, the piezo linear drive 13 . 14 can also be used to perform the desired focusing for the image. In particular, a so-called Z-stack can be recorded. Different shots are taken at different z-coordinates, for which a movement of the lens 10 in the z-direction is necessary. The travel path for receiving such a Z-stack can be, for example, a total 5 mm.

According to the invention by means of the first piezo linear actuator 13 thus a method of the first lens 10 from the parking position to the working position and the focusing and / or the inclusion of a Z-stack carried out.

Furthermore, in the microscope according to the invention, a referencing can be performed when in the microscope 1 still no exact indication of the position of the rotor plate 17 relative to the linear guide 18 is present. This is the case, for example, when the microscope 1 just turned on.

In such a case, you should first make a homing run. In 10 is the second track 24 with the two sections 25 and 26 shown enlarged, the limit 31 between both sections 25 and 26 is used as a reference mark. The parking position is slightly below the limit 31 , Here is the distance to the border 31 about 0.2 mm, as indicated by the arrow 32 indicated is the position of the sensor 23 indicates if the lens 10 . 11 is in his parking position.

If the first lens 10 is in its parking position and not in the optical axis of the microscope 1 is positioned, the Referenzierungsfahrt example, take place immediately after switching. For such a referencing drive, for example, the lens 10 0.5 mm downwards (ie towards the sample table 4 ) and then upwards by 1 mm. In this case, the limit would have to 27 lie within this travel, so that the desired referencing can take place.

If the first lens 10 in the optical axis of the microscope 1 is still positioned in its parking position, the referencing can be performed in the same way.

If the first lens 10 In his working position, a homing drive should only be feasible after a safety inquiry.

After the performed referencing can then, if the lens 10 in the imaging beam path of the microscope 1 is, the lens 10 in his working position (arrow 33 ). There is a predetermined work area 34 in front of this working position, which can be eg +/- 1.5 mm or even +/- 2.5 mm.

Of course, in addition to the procedure by means of the piezo linear drive 13 a method of the lens holder 9 through the mechanical guidance 12 respectively.

Furthermore, in the microscope according to the invention 1 the illumination have a condenser which is positioned, for example, as a function of the z position of the first objective. In particular, the condenser can be adjusted when taking a Z-stack, for example, to the center position of the Z-stack.

Furthermore, it is possible that after a change of the lens (eg, when changing from the first lens 10 to the second lens 11 ) the microscope according to the invention 1 Perform a parfocality comparison. In addition, in a motorized condenser, the field and aperture stops can be adjusted according to the optical requirements of the lens used.

In the microscope according to the invention, the lens holder 9 another lens (not shown) that can be moved via a mechanical actuator from its parking position to the working position. The mechanical actuating device can be designed, for example, as a lever, as a lifting, turning and / or lowering device.

The mechanical actuator is designed so that moving the lens from the parking position to the working position can only be done when the other two lenses 10 . 11 via the piezo linear drives 13 . 14 can be brought from the park to the working position in their parking position and the lens is in the microscope axis. In this case, z. B., when the mechanical actuator is designed as a lever, the lever for the mechanically operated lens to be freely rotatable or operable. Is one of the other two lenses 10 . 11 not in its parking position (for example, in its working position), the mechanical actuator is either locked or disengaged with other mechanical elements such that no lowering of the lens is possible. If the mechanical actuator is designed as a lever, this can either be blocked or z. B. by turning the lens holder 9 be in a position where the lever mechanism does not interact with the mechanism for lowering or operating the lens. There is no mechanical intervention. If the mechanically operated objective is in its working position and thus also in the microscope axis, the z-focusing can be carried out via a classical z-drive.

Of course, each of the first or second lens may 10 . 11 only be moved from its parking position when the mechanically adjustable lens is in its parking position and the object to be moved from the parking position is located in the microscope axis. Appropriate software-side attempts the lens 10 or 11 are therefore not performed if this condition is not met. It can be a case in this case corresponding error message or request to be issued to the user to transfer the mechanically operable lens or the lens positioned in the microscope axis in the parking position and to change the desired lens in the microscope axis.

Of course, one of the two lenses 10 . 11 be designed as a lens that can be moved with a mechanical actuator from its Park- to its working position, provided it is located in the Mikrsokopachse. Furthermore, it is possible that several mechanically movable lenses in the lens holder 9 are provided. In any case, the lens holder always has a lens that with a piezo linear actuator 13 . 14 can be moved.

Basically, it is the case that a lens change (positioning of the desired objective in the microscope axis) is mechanically possible only when all the lenses located in the objective turret are in parking position. In addition, the transfer of the lens position from parking position to the working position is possible only in the microscope axis.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10148267 A1 [0014]

Claims (16)

Lens holder for a microscope ( 1 ), with one in the lens holder ( 9 ) arranged first lens ( 10 . 11 ) and one in the lens holder ( 9 ) arranged first piezo linear actuator ( 13 . 14 ), which is the first lens ( 10 . 11 ) along its optical axis relative to the lens holder ( 9 ) can move. Lens holder according to claim 1, wherein the first piezo linear drive ( 13 . 14 ) provides a travel of at least 20 mm. A lens holder according to claim 1 or 2, wherein a second objective ( 11 . 10 ) and a second piezo linear drive ( 14 . 13 ) in the lens holder ( 19 ) are provided, wherein the second piezo linear drive ( 14 . 13 ) the second lens ( 11 . 10 ) along its optical axis relative to the lens holder ( 9 ) can move. Lens holder according to claim 3, wherein the second piezo linear drive ( 14 . 13 ) provides a travel of at least 20 mm. Microscope with a tripod ( 2 ) and one on the tripod ( 2 ) attached lens holder ( 9 ) according to one of the above claims. Microscope according to claim 5, having a sample table ( 4 ) and a mechanical guide ( 12 ), over which the lens holder ( 9 ) on the tripod ( 2 ), wherein the mechanical guide ( 12 ) a movement of the lens holder ( 9 ) along a first direction to increase the distance between the sample stage ( 4 ) and the lens holder ( 9 ) to change. Microscope according to claim 6, wherein the movement by means of the mechanical guidance ( 12 ) and the piezo linear drive ( 13 . 14 ) can be performed simultaneously.  Microscope according to one of claims 5 to 7, wherein after a lens change by means of the lens holder, a Fokusablagenkorrektur is performed. Microscope according to one of claims 5 to 8, in which automatically several shots in different focal planes can be performed, wherein by means of the piezo linear drive ( 13 . 14 ) the focal planes are adjusted. Microscope according to one of claims 5 to 9, wherein the focusing by means of the piezo linear actuators ( 13 . 14 ) is carried out. Microscope according to one of Claims 5 to 10, in which the piezo linear drive ( 13 . 14 ) a scale ( 21 ) and a sensor ( 23 ) for optical scanning of the scale ( 21 ) for determining the position of the objective ( 10 . 11 ) having. Microscope according to Claim 11, in which, on the basis of the scale ( 21 ) is determined whether the lens ( 10 . 11 ) is in a parking position or a working position, and a referencing run is performed to the lens ( 10 . 11 ) in his parking position. Microscope according to Claim 11, in which, on the basis of the scale ( 21 ) is determined whether the lens ( 10 . 11 ) is in a parking position or a working position, and a lens change is only allowed if the lens ( 10 . 11 ) is in the parking position. Microscope according to one of claims 5 to 13, in which a lens change is only allowed if all lenses ( 10 . 11 ) of the lens holder ( 9 ) in their parking position. Microscope according to claims 5 to 14, wherein in the objective holder ( 9 ) A further lens is arranged, which can be brought by means of a mechanical actuator from its parking position to its working position. Microscope according to claim 15, in which an actuation of the mechanical actuating device only leads to a movement of the further objective from its parking position into its working position, when all other objectives ( 10 . 11 ) of the lens holder ( 9 ) are in their parking position and the lens has been positioned in the optical axis of the microscope.

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