Device and arrangement for aligning an optical element in an optical beam path

Abstract

The invention relates to a device (1) for aligning an optical element (12) in an optical beam path (16). This device comprises a base body (2) with a free beam passage (3) along a beam axis (4), wherein the base body (2) can be rotated about the beam axis (4); and a holder (7) for holding the optical element (12) on the beam axis (4), wherein the holder (7) can be tilted relative to the beam axis (4) in a controlled manner by an angle selected from a predetermined angular range, in that a current inclination of the holder (7) can be adjusted by means of a cam control (9) that partially or completely revolves around the base body (2) and is decoupled from a rotational position of the base body (2). The invention also relates to an arrangement (13) with a device (1) according to the invention and to a microscope (23) with an arrangement (13) according to the invention.

Description

[0001] The invention relates to a device and an arrangement for aligning an optical element in an optical beam path.

[0002] If at least one optical element in an optical beam path is to be adjusted not just once, but repeatedly controlled in terms of its position and / or alignment, i.e., two-dimensionally or three-dimensionally, within the beam path, multiple drives are required. However, accommodating and controlling multiple drives (manual mechanical drives, motors) requires a correspondingly large amount of space.

[0003] Examples of space-saving technical solutions can be found in EP 1 643 283 A1, in which an optically active element can be held on an optical axis and deflected there about two perpendicular axes of rotation. However, the need for two drives still exists. An optical element can be adjusted about three axes using three drives according to the solution disclosed in US 2018 / 0217349 A1. A rather space-consuming option for aligning an optical element is described in WO 2007 / 038827 A1.

[0004] The invention is based on the object of proposing a further possibility for aligning an optical element in an optical beam path, by means of which the disadvantages occurring in the prior art are reduced.

[0005] The problem is solved by the subject matter of the independent claim. Advantageous embodiments can be found in the dependent claims.

[0006] The device according to the invention for aligning an optical element in an optical beam path comprises a base body with a free beam passage along a beam axis. This virtual beam axis can coincide with an optical axis of an optical beam path when the invention is used as intended. The base body is rotatable about the beam axis or can be rotated about it. The beam passage can advantageously have a symmetrical, in particular a rotationally symmetrical, cross-section. A holder is provided for holding the optical element on the beam axis. This holder can be tilted relative to the beam axis in a controlled manner by an angle that is selected or is selected from a predetermined angular range. A respective (current) inclination can be adjusted using a curve control.The cam control is designed and arranged in such a way that it partially or completely revolves around the base body. It is decoupled from the rotational position of the base body, so that the current inclination of the mount is set or adjustable using the cam control, regardless of the current rotational position of the base body.

[0007] For the purposes of this description, an optical element is understood to be a component that exerts an optical effect on radiation of a selected wavelength range (optically active element). An optical effect includes, in particular, (bi)refraction, filtering, beam shaping, and / or deflection of the radiation.

[0008] In an advantageous embodiment of the invention, the optical element can be a plane plate that is transmissive for a selected wavelength range. This plate can be birefringent. Slight absorption does not contradict the concept of transmissivity. Using a plane plate, for example, made of glass, beam alignment can be achieved in a simple and cost-effective manner, as described in more detail below.

[0009] The cam control is advantageously implemented as a cam disk, which is designed, for example, as a half ring, but preferably ring-shaped and has a varying width parallel to the beam axis. The design of the cam disk determines which angle of inclination the holder assumes or can assume. If the holder is mounted accordingly, the holder can be tilted both clockwise and counterclockwise with respect to an orientation running orthogonally to the beam axis (zero angle of inclination). In other designs, tilting is only possible in one of the two directions. The latter option is sufficient and easier to implement. If, in addition, the cam disk is designed as a closed ring, i.e. the holder can be adjusted in its inclination over an angular range of 360°, tilting on one side allows the same adjustment options as tilting on both sides.

[0010] In further embodiments of the invention, the cam disc can be interchangeable, so that the device can be equipped with differently designed cam discs either at the factory or by a user.

[0011] The core of the invention is to be able to tilt the mount with the optical element independently of the current rotational position of the base body, and also to design the cam control used for this purpose to partially or completely surround the base body. This allows for the greatest possible combination of rotational positions of the base body and inclinations of the optical element while simultaneously requiring minimal installation space.

[0012] The bracket is in mechanical contact with the cam control, in particular with a control cam of the cam control. To ensure continuous contact with the cam control by the bracket, for example, via an adjusting lever, a compression or tension spring or a component made of an elastic material may be present.

[0013] In order to efficiently transmit a force, for example that of a drive, to the base body in order to rotate it in a controlled manner around the beam axis, an advantageous embodiment of the invention provides a first drive track that partially or completely encircles the base body. The first drive track is either firmly connected to the base body, fastened thereto in such a way that the two are mechanically coupled, or it is formed on the surface of the base body. Such a drive track can, for example, be a gear ring for engaging a gear wheel or a toothed belt, or a track designed to suit a friction wheel drive. In particular, a positive-locking drive prevents slippage between the input and output, which in turn has a positive effect on the positionability and resolution of the assembly.In addition, a positive fit easily prevents accidental misalignment of the base body and the mounting bracket. Accidental misalignment can also be prevented by a suitable design of a friction drive and / or the use of a braking device. Adjusting the required braking torque by adjusting the friction forces between the gear partners and their bearings is advantageous. Furthermore, additional components such as rotary brakes or locking devices can be provided and used.

[0014] In this sense, in a further embodiment of the device according to the invention, a second drive track for transmitting a force to the cam control and for its rotation around the base body can be formed on a side surface of the cam control, in particular one facing away from the base body. The cam control can then, for example, be in contact with the holder or the actuating lever via one of its end faces.

[0015] The device according to the invention can be part of an assembly. Part of the assembly is a frame or a housing in which the base body is mounted so as to be rotatable about the beam axis. The beam axis advantageously coincides with an optical axis of an optical beam path. Furthermore, at least one drive is provided for applying an (actuating) force to the first drive track and / or the second drive track.

[0016] In an advantageous embodiment of the invention, a common drive is provided for both drive tracks. This allows one drive to be omitted and saves installation space. The common drive transmits a force for rotating the base body or cam control to the corresponding components via two gears with opposing drive and freewheel directions, selectively and depending on the direction of rotation.

[0017] The existing drives are connected to a controller, for example in the form of a computer, a microcontroller or an FPGA, in a connection suitable for exchanging data. The controller can optionally receive data from a sensor located in the beam path, by means of which the current effect of the optical element on the radiation, for example its beam position, can be recorded and evaluated. Alternatively or additionally, the current rotational position of the base body and / or the holder or the cam control can be recorded and evaluated. Depending on the result of the evaluation, control commands can be sent to the drives or to the shared drive via the controller. When executed, the current rotational position of the base body and / or the current inclination of the holder and, accordingly, the optical element can be set.Such a setup can enable beam tracking and / or manipulation in ongoing scientific experiments, which has a positive effect on necessary repetitions and processing times.

[0018] The device according to the invention or the arrangement according to the invention can be present and used in an optical system, for example in an illumination detection device, for optical positioning tasks (scanning) or zoom systems, e.g. in microscopes or other opto-mechanical systems.

[0019] The invention is explained in more detail below with reference to illustrations and exemplary embodiments. They show: Fig. 1 a schematic representation of an embodiment of a device according to the invention in a lateral sectional view (longitudinal section); Fig. 2 a schematic representation of the embodiment of the device according to the invention in a perspective view; and Fig. 3 a schematic representation of an embodiment of an arrangement according to the invention in a lateral sectional view (longitudinal section).

[0020] In a representation of a device 1 according to the invention, the essential parts shown are a base body 2 with a beam passage 3 along a beam axis 4 and a holder 7 for holding an optical element 12 ( Fig. 1).

[0021] The base body 2 can be rotated about the beam axis 4 by applying a force, in particular to a drive ring 5 arranged circumferentially around the base body 2. The drive ring 5 is connected to the base body 2 or formed on its surface. A first drive track 6 in the form of a gear ring is formed on an outwardly facing end face of the drive ring 5.

[0022] The holder 7 is supported by an adjusting lever 8 against the end face of a control cam (cam disk) of a cam control 9. To ensure that this contact is maintained constantly, a spring element 11 is provided, which is connected to the base body 2 and the holder 7 and exerts a pressing force of the adjusting lever 8 against the cam control 9.

[0023] The cam control 9 is designed to rotate freely around the base body 2, meaning it is freely rotatable around the base body 2. The cam control 9 has a second drive track 10 in the form of a toothed ring on its outer circumferential surface. The width of the cam control 9 increases continuously from a minimum width B1 to a maximum width B2, and further along the circumference, this decreases again to the minimum width B1. Fig. 1 shows a simplified current position of the cam control 9, in which the maximum width B2 of the cam control 9 pushes the adjusting lever 8 outwards as far as possible and thus a maximum achievable inclination of the holder 7 and the optical element 12 relative to the beam axis 4 with the selected cam control 9 is effected.

[0024] The mode of operation of the device 1 according to the invention is illustrated using a virtual beam (optical beam path 16) directed along the beam axis 4 into the beam passage 3. The optical element 12 is a flat plate made of glass with two mutually plane-parallel side surfaces. When the beam strikes the optical element 12, it is refracted towards the normal according to the law of refraction and passes through the optical element 12 at an angle. As a result of this oblique path through the optical element 12, the beam leaves the beam axis 4. Upon reaching the second side surface of the optical element 12, the beam is refracted again, this time away from the normal, and leaves the optical element 12 offset from the beam axis 4. This radial offset of the beam in a y-direction is illustrated by way of example using the coordinate system on the right in the image.

[0025] If the current inclination of the mount 7 is maintained and the base body 2 is rotated around the beam axis 4, the point of impact of the beam is guided along a circular path (inner circle, dashed solid line). The outer circle, also depicted with a dashed solid line, exemplifies the maximum area onto which the beam can be directed with the possible combinations of the rotational position of the base body 2 and the inclination of the mount 7.

[0026] An embodiment of the first and second drive tracks 6, 10 as respective gear rings is shown in Fig. 2. The compact design of the device 1 according to the invention can be clearly seen. In addition to the technical elements already described, a carrier 14 is provided which holds the base body 2 and serves for connection to a frame or housing 22 in order to be able to mount the device 1 in an optical system, for example in a microscope 23, and to operate it there (see also Fig. 3).

[0027] An embodiment of the invention as a component of an arrangement 13 in a microscope 23 has a common drive 19, by means of which both the base body 2 can be moved about the beam axis 4 and the cam control 9 can be moved about the base body 2.

[0028] In order that both movements can be realized independently of one another with only one common drive 19, a first gear 17 and a second gear 18 are provided between the common drive 19 and the respective elements 2, 9 to be driven.

[0029] The gears 17, 18 can be driven by the action of the drive 19. Shown as an example is a drive shaft 20 for transmitting power from the drive 19 to the gears 17, 18. The first gear 17 is in contact with the first drive track 6 of the drive ring 5, which enables power transmission from the first gear 17 to the drive ring 5 and thus to the base body 2. The same applies to the second gear 18, which is connected to the cam control 9. The drive 19 is advantageously a motor that can be controlled by a controller 21 with regard to its respective direction of rotation and the angular range covered in each case.

[0030] Both gears 17 and 18 are provided with a freewheel in one direction of their mechanical power flow (freewheel direction FR), while in the opposite direction a power line from the common drive 19 to the respective drive track 6, 10 (see Fig. 1, Fig. 2) (drive direction AR). Both directions are symbolized by arrows of different line types next to the reference symbol.

[0031] In Fig. Figure 3 shows a view of the respective circumferential end faces of the gears 17, 18, both of which are designed as gears corresponding to the respective drive tracks 6, 10. Depending on the control commands of the controller 21, the common drive 19 rotates through a specific rotation angle in one direction. The gear 17, 18 whose drive direction AR corresponds to the current direction of rotation of the drive 19 transmits the force to the respective drive track 6, 10 and rotates the base body 2 or the cam control 9 through an angle determined by the gear ratio of the gear 17, 18.

[0032] If the drive 19 stops or its direction of rotation is reversed, the previously driven gear 17, 18 operates in the freewheel direction FR and no power is transmitted. When the direction of rotation changes, the other gear 17, 18 is moved in the drive direction AR. In this way, both the rotational position of the base body 2 and the inclination of the holder 7 can be adjusted consecutively with just one drive 19.

[0033] If separate drives (not shown) are used for the movement of the base body 2 and the adjustment of the inclination of the holder 7 instead of a common drive 19, the adjustment movements can also be superimposed and thus carried out simultaneously.

[0034] The device 1 according to the invention is rotatably mounted and held in a carrier 14 by means of bearings 15, for example, roller bearings. The carrier 14 can in turn be arranged in a frame or a housing 22 (shown only in outline), wherein the beam axis 4 advantageously coincides with an optical beam path 16. Reference symbol 1 device 2 basic bodies 3 Beam passage 4 beam axis 5 drive ring 6 first drive track 7 Bracket 8 adjusting levers 9 Cam control, cam disc 10 second drive track 11 Spring element 12 optical element 13 Arrangement 14 carriers 15 warehouses 16 optical beam path 17 first gearbox 18 second gearbox 19 common drive 20 drive shaft 21 Control 22 housings 23 Microscope AR drive direction B1 minimum width B2 maximum width FR freewheel direction QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

[0000] EP 1 643 283 A1

[0003] US 2018 / 0217349 A1

[0003] WO 2007 / 038827 A1

[0003]

Claims

[1] Device (1) for aligning an optical element (12) in an optical beam path, comprising - a base body (2) with a free beam passage (3) along a beam axis (4), wherein the base body (2) can be rotated about the beam axis (4); - a holder (7) for holding the optical element (12) on the beam axis (4), wherein o the support (7) can be tilted relative to the beam axis (4) by an angle selected from a predetermined angular range by means of a cam control (9) which is partially or completely rotating around the base body (2) and decoupled from a rotational position of the base body (2) to adjust the current tilt of the support (7). [2] Device (1) according to claim 1, characterized by, that a first drive path (6) is formed which is partially or completely circumferential around the base body (2) for the transmission of a force to the base body (2) and for its rotation around the beam axis (4). [3] Device (1) according to claim 1 or 2, characterized by , that a second drive track (10) is formed on a side surface of the curve control (9) for transmitting a force to the curve control (9) and for its circulation around the base body (2). [4] Device (1) according to any one of the preceding claims, characterized by , that a planar plate transparent for a selected wavelength range is present as an optical element (12). [5] Arrangement (13) encompassing - a device (1) according to one of the preceding claims and a housing (22) in which the base body (2) is rotatably mounted about the beam axis (4), - and at least one drive (19) to apply a force to the first drive track (6) and / or to the second drive track (10). [6] Arrangement (13) according to claim 5, characterized by , that for both drive tracks (6, 10) there is a common drive (19) which, by means of two gears (17, 18) with opposite drive directions (AR) and freewheel directions (FR), selectively and depending on the direction of rotation, introduces a force to rotate the base body (2) or the cam control (9). [7] Microscope (23) with an arrangement (13) according to any one of claims 1 to 6.

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