Patent Description:
In laser processing devices, there are holders for transmissive optical elements with adjustment mechanisms that contain linear guides. Although linear guides enable precise adjustment of the optical elements, they are expensive and susceptible to wear. Other adjustment mechanisms result in non-reproducible and imprecise adjustment. Movable components of known adjustment mechanisms are also susceptible to material abrasion. <CIT> discloses an optical element mount comprising an inner member suspended within an outer member by a plurality of flexures. A tangential flexure, substantially circumferential with respect to the inner member and the optical axis, provides a tangential constraint for Z-axis rotation. <CIT> describes an optical device for shaping an electromagnetic wave, having an optical element positioned within beam propagation direction and an exciter means functionally connected to the optical element for inducing an oscillation of the focal point in at least one of an x direction and an y direction of a plane perpendicular to the beam propagation direction along a focal point oscillation path. A passive guide element can be arranged between the optical element and an attachment. According to <CIT> a laser processing machine head, a laser processing machine head monitoring system, and a method of monitoring an optical element of a laser processing machine feature a light-transmissive optical element and an optical element holder defining a cavity in which the optical element is retained against rotation.

The object is to specify a mount for a transmissive optical element that enables the optical element to be adjusted with little wear, in a reproducible and precise manner.

This object is achieved by a holder for a transmissive optical element according to claim <NUM>, a use of such holder according to claim <NUM>, a laser processing device for laser processing a workpiece according to claim <NUM>, a method for adjusting the position of a transmissive optical element according to claim <NUM>, and a computer program product according to claim <NUM>.

Further preferred embodiments of the invention are defined in the dependent claims.

One embodiment relates to a holder for a transmissive optical element of a laser processing device, having a frame for receiving in a laser beam guidance unit of the laser processing device, and having a mount for the transmissive optical element, wherein the transmissive optical element spans a plane in an X direction and a Y direction, wherein the mount is mounted within the frame with two adjusting elements offset at an angle of <NUM>° to <NUM>° to one another in or parallel to the plane and with a guide pin arranged in or parallel to the plane between, in particular centrally between, the two adjusting elements radially to the frame and is adjustable in the X direction and/or the Y-direction in each case at its distance to the frame; wherein the adjusting elements are each mounted in the frame such that they can pivot in the X and Y directions and are adjustable independently of one another in their respective length between the mount and the frame; the mount-side ends of the adjusting elements are each mounted in the mount in the X and Y directions so that they can pivot and are displaceable in the longitudinal direction of the respective adjusting element; the mount-side end of the guide pin is fixed to the mount; and the frame-side end of the guide pin is mounted in the frame such that it can pivot in the X and Y directions and is displaceable in the longitudinal direction of the guide pin.

By adjusting the length of at least one of the adjusting elements, the position of the mount can be changed within the frame in the X direction and/or Y direction. The adjusting elements can be pivoted in the frame. Furthermore, the mount-side ends of the adjusting elements and the frame-side end of the guide pin can be pivoted in the plane in the X and/or Y direction; for example, in each case on circular path segments. In addition, the mount-side ends of the adjusting elements can each be shifted in their longitudinal direction in the mount. Furthermore, the frame-side end of the guide pin can be displaced in its longitudinal direction in the frame. This provides stable mounting of the mount in the frame while a variety of positions of the mount within or parallel to the plane are achievable. The latter is promoted by the fact that the adjusting elements can be adjusted in length independently of one another. The holder thus enables a precise and reproducible adjustment of the mount in the X direction and in the Y direction. If a transmissive optical element for a laser beam is provided in the mount and the holder is arranged in a laser beam guidance unit, the transmissive optical element can be adjusted in the beam path of the laser beam at an angle, e.g., perpendicular, to the direction of propagation of the laser beam. For example, the optical element can be precisely centred in the beam path of the laser beam, wherein the optical axis of the optical element can be made substantially coincident with the central axis of the laser beam. The holder does not require linear guides to move the optical element. The adjustment mechanism implemented in the holder is low-wear, fully defined or very precisely adjustable and enables a quasi-linear change in position of the optical element. In this way, precise adjustment of the position of the transmissive optical element is possible without expensive linear guides.

The frame can have two through-openings for receiving the adjusting elements and the adjusting elements can be mounted, in particular elastically, in the respective through-opening for pivoting in the X and Y directions. The mount can have, on its outer side, a first recess and a second recess for receiving the mount-side end of the adjusting elements, wherein the first and the second recess are arranged complementary to the through-openings. In this way, a precise fit of the components of the holder is achieved. If the mount is connected to the frame via the adjusting elements, degrees of freedom of the adjusting elements and thus of the mount are made possible in the X and Y directions. This mounting of the mount within the frame also enables the mount to be highly stable during rapid movements of the laser beam guidance unit, in particular when the adjusting elements are mounted elastically.

The through-openings of the frame can be arranged offset by <NUM>° and the first recess and the second recess of the mount can be arranged offset by <NUM>°. The resulting spatial arrangement of the adjusting elements when they connect the frame and the mount enables a large number of achievable positions of the mount within the frame.

The frame may have a third recess on its inner side for receiving the frame-side end of the guide pin and the mount-side end of the guide pin may be fixed to the outer side of the mount in a position complementary to the third recess. This configuration promotes high stability of the holder when the laser beam guidance unit moves quickly.

The third recess can be arranged between the through-openings of the frame. The third recess can be arranged centrally between the through-openings of the frame. The guide pin may be secured between the first and second recesses of the mount. The guide pin may be fixed midway between the first and second recesses of the mount. These spatial arrangements promote the stability of the holder when the laser beam guidance unit moves and a large number of positions that can be reached for the mount within the frame.

At least one of the first recess and the second recess may be disc-shaped in the X and Y directions within the mount. This enables degrees of freedom for the adjusting elements and thus for the mount in the X and Y directions, while degrees of freedom perpendicular to the plane in the X and Y directions, i.e., in the Z direction, are avoided. At least one of the first recess and the second recess can have a disc-shaped first filling element that can be rotated in a circle within the respective recess in the X and Y directions. The first filling element can have a first guide for receiving the mount-side end of one of the adjusting elements. With these modifications, the accuracy of fit of the components of the holder and their stability is promoted. At the same time, wear and tear, for example, material abrasion of moving components that are in contact or coming into contact, is avoided.

The third recess can be disc-shaped within the frame in the X and Y directions. This enables degrees of freedom for the guide pin and thus for the mount in the X and Y directions, while degrees of freedom perpendicular to the plane in the X and Y directions, i.e., in the Z direction, are avoided. Furthermore, the third recess can have a disc-shaped second filling element that can be rotated in a circle within the third recess in the X and Y directions. The second filling element can have a second guide for receiving the frame-side end of the guide pin. In this way, the fitting accuracy of the components of the holder is promoted. These modifications also promote high stability of the holder when the laser beam guidance unit moves quickly. At the same time, wear and tear, for example, material abrasion of moving components that are in contact or coming into contact, is avoided.

At least one of the first recess and the second recess can have an opening to the outer side of the mount, which has a smaller diameter than a diameter of the respective recess. Furthermore, the third recess can have an opening to the inner side of the frame, which has a smaller diameter than a diameter of the third recess. This promotes the stability of the mount when the laser beam guidance unit moves quickly.

The transmissive optical element can be provided in the mount. Furthermore, the transmissive optical element can be at least one element selected from an optical element, a beam splitter, a phase plate, an optical filter, an optical grating, a lens, an aperture, and a protective glass. The transmissive optical element can be positioned in a beam path of the laser beam processing device and/or within a beam path of the laser beam processing device by means of the holder.

A passage can be provided for at least one of the adjusting elements, which passage is fastened in the frame, in particular in one of the through-openings of the frame. Furthermore, a laterally elastic spring element can be provided in at least one of the through-openings and/or the associated passage, within which the adjusting element is elastically mounted in the X and Y direction. This elastic mounting of the mount within the frame promotes high stability of the mount during rapid movements of the laser beam guidance unit. At least one of the adjusting elements can have a screw sleeve with an internal thread and a screw with an external thread complementary to the internal thread, wherein the external thread of the screw is rotatable in the internal thread of the screw sleeve to adjust the adjusting element. The length of the relevant adjusting element can be changed by turning the screw.

At least one element selected from the transmissive optical element, the mount, the adjusting elements, the guide pin, the bushing, the spring element, the screw sleeve, the screw, the first filling element, and the second filling element can be exchangeable. This promotes maintenance or repair of the holder. Furthermore, at least one of the adjusting elements, in particular its screw, can be designed to be adjustable with a controllable drive. At least one of the adjusting elements, in particular its screw, can be provided with a controllable drive for adjusting the adjusting element. By providing the controllable drive, an automatic centring mechanism can be implemented, which is controlled, for example, via a control unit of the laser processing device.

A further embodiment relates to a use of a holder according to any one of the preceding embodiments and variations for holding a transmissive optical element of a laser processing device and adjusting the position of the transmissive optical element in the X and/or Y direction, in particular for adjusting the position at an angle to the propagation direction of the laser beam to be guided of the laser processing device.

Another embodiment relates to a laser processing device for laser processing a workpiece, in particular a laser processing head, with a holder for a transmissive optical element according to any one of the above embodiments and variations. The frame of the holder can be integrated into a laser beam guidance unit of the laser processing device. Furthermore, a transmissive optical element provided in the mount of the holder can be positioned in a beam path of the laser processing device.

One embodiment relates to a method for adjusting the position of a transmissive optical element of a laser processing device, in particular a laser processing device according to the preceding embodiment, wherein the transmissive optical element is provided in a holder according to any one of the preceding embodiments and variations, and wherein the position of the transmissive optical element in the X and/or Y direction, in particular at an angle to the propagation direction of the laser beam to be guided of the laser processing device, is adjusted by adjusting at least one of the adjusting elements.

With the above embodiments of the method for adjusting the position of a transmissive optical element of a laser processing device, the same advantages and functions can be realized as with the embodiments of the holder for a transmissive optical element of a laser processing device, in particular with identical and/or analogous features.

A further embodiment relates to a computer program product comprising one or more program modules that cause the laser processing device according to the preceding embodiment to carry out steps of the method according to the preceding embodiment, in particular when the program modules are loaded into a memory of the laser processing device.

Further features and efficiencies arise from the following description of exemplary embodiments, the figures and the dependent claims. The above-mentioned features and those described below can be used without departing from the scope of the present invention not only in the respective combinations indicated, but also in other combinations or in isolation.

The invention is explained in more detail below on the basis of exemplary embodiments with reference to the accompanying drawings, which likewise disclose features that are essential to the invention. These exemplary embodiments are used for illustration purposes only and are not to be construed as limiting. For example, a description of an exemplary embodiment with a large number of elements or components should not be interpreted to the effect that all of these elements or components are necessary for implementation. Rather, other exemplary embodiments can also contain alternative elements and components, fewer elements or components, or additional elements or components. Elements or components of different exemplary embodiments can be combined with one another, unless otherwise stated. Modifications and variations which are described for one of the exemplary embodiments can also be applied to other exemplary embodiments. To avoid repetition, elements that are the same or that correspond to one another are denoted by the same reference symbols in different figures and are not explained more than once. In the figures:.

<FIG> schematically shows a holder <NUM> for a transmissive optical element <NUM>, also called an optical element, of a first example. The transmissive optical element <NUM>, for example a lens, spans a plane E in an X direction and in a Y direction.

The holder <NUM> has a frame <NUM> and a mount <NUM> for the transmissive optical element. The mount <NUM> is mounted within the frame <NUM> with two adjusting elements <NUM> and with a guide pin <NUM> arranged between the adjusting elements <NUM>. There are distances A and B between the inner side <NUM> of the frame <NUM> and the outer side <NUM> of the mount <NUM>. In the present example, the outer side of the frame <NUM> is square and the inner side of the mount <NUM>, which is used to hold the optical element <NUM>, is circular. In other examples, other shapes of frame <NUM> and mount <NUM> may be chosen.

In the present example, the adjusting elements <NUM> are in the form of adjusting screws (not shown) and the guide pin <NUM> is in the form of a cylindrical pin. Each adjusting screw consists of a screw sleeve with an internal thread and a screw with an external thread complementary to the internal thread, wherein the external thread of the screw is rotatable in the internal thread of the screw sleeve in order to adjust the adjusting element <NUM>. The adjusting elements <NUM> can be adjusted in their respective length L independently of one another. The adjusted length L can be recorded and stored to facilitate the reproducibility of the position changes.

The frame <NUM> has through-openings <NUM>, which are offset at an angle α. In the present example, a <NUM>° angle is provided as the angle α. The adjusting elements <NUM> are arranged radially to the mount <NUM> in the through-openings <NUM>. The adjusting elements <NUM> have a lateral clearance within the through-openings <NUM> and can therefore be pivoted within the through-openings <NUM>. This allows the frame-side end <NUM> of each adjusting element <NUM> to be pivoted on a circular path segment.

Furthermore, a recess <NUM> which is disc-shaped in the X and Y direction is provided in the frame <NUM> in the centre between the through-openings <NUM>. The disc-shaped recess <NUM> has an opening <NUM> to the inner side of the frame <NUM>. The frame-side end <NUM> of the guide pin <NUM> is arranged in the recess <NUM> with a precise fit and can be pivoted in the X and Y direction. In addition, the frame-side end <NUM> of the guide pin <NUM> can be displaced in the recess <NUM> in the longitudinal direction of the guide pin.

The mount <NUM> has two disc-shaped recesses <NUM> offset by <NUM>° in the X and Y directions. The recesses <NUM> are positioned complementary to the through-openings <NUM> of the frame. The disc-shaped recesses <NUM> each have an opening <NUM> to the outer side of the mount <NUM>. In the recesses <NUM>, the frame-side ends <NUM> of the adjusting elements <NUM> are arranged with a precise fit and are pivotable on circular path segments in the X and Y directions. Furthermore, the frame-side ends <NUM> of the adjusting elements <NUM> are provided in the recesses <NUM> so as to be displaceable in the longitudinal direction of the respective adjusting element. Furthermore, the guide pin <NUM> is fastened with its mount-side end <NUM> on the outer side of the mount <NUM> in the middle between the recesses <NUM>.

The openings <NUM> of the recesses <NUM> to the outer side of the mount <NUM> and the opening <NUM> of the recess <NUM> to the inner side of the frame <NUM> have a smaller diameter in comparison to the maximum diameter of the respective recess in the present example. As a result, the deflections of the adjusting elements <NUM> and the guide pin <NUM> in the X and Y directions are limited.

The respective lengths L of the adjusting elements <NUM>, the length of the guide pin <NUM> within the recess <NUM>, the respective angle that the longitudinal direction of the adjusting elements <NUM> makes with respect to a diagonal of the frame <NUM>, and the angle that the longitudinal direction of the guide pin <NUM> makes with respect to the diagonal of the frame <NUM> occupies are variable via the two adjusting elements <NUM>, the guide pin <NUM> and five pivot points. In the present example, the diagonal from the bottom right corner of the frame to the top left corner of the frame is selected as the straight reference line for the angles mentioned in the frame <NUM> shown in <FIG>. In the position of the mount shown in <FIG>, the respective angle that the longitudinal direction of the adjusting elements <NUM> occupies to the diagonal of the frame <NUM> is <NUM>°, and the angle that the longitudinal direction of the guide pin <NUM> occupies to the diagonal of the frame <NUM> is <NUM>°.

By adjusting the length L of at least one of the adjusting elements <NUM>, the position of the mount <NUM> within the frame <NUM> is changed in the X direction and/or Y direction. In other words, the distances A and B between the mount <NUM> and the frame <NUM> are changed. This can be seen in <FIG> from the adjusted position of the holder <NUM>, which is shown in dashed lines. In the position of the mount <NUM> shown in dashed lines in <FIG>, the distance A is reduced, starting from the position of the mount <NUM> shown in <FIG>, while the distance B is increased. By adjusting at least one of the lengths L of the adjusting elements <NUM>, the length of the guide pin <NUM> within the recess <NUM>, the respective angle that the longitudinal direction of the adjusting elements <NUM> makes with respect to the diagonal of the frame <NUM>, and the angle that the longitudinal direction of the guide pin <NUM> makes with respect to the diagonal of the frame <NUM>, is changed. Since the lengths L of the adjusting elements <NUM> can be adjusted independently of one another, almost any desired point in the area around the centre of the frame <NUM> can be approached with the optical axis of the optical element <NUM>. In addition, the adjusting mechanism of the holder <NUM> can be precisely adjusted.

In order to adjust the mount <NUM> from the position shown in <FIG> to the position shown in dashed lines in <FIG>, the adjusting elements <NUM> are lengthened. The mount-side ends <NUM> of the adjusting elements <NUM> are displaced in the longitudinal direction thereof in the recesses <NUM> of the mount <NUM>. The adjusting elements <NUM> are pivoted in the recesses <NUM> of the frame <NUM>. The mount-side ends <NUM> of the adjusting elements <NUM> and the frame-side end <NUM> of the guide pin <NUM> are pivoted in or parallel to the plane E in the X and/or Y direction, each on circular path segments. In addition, the frame-side end <NUM> of the guide pin <NUM> is displaced in its longitudinal direction in the recess <NUM> of the frame <NUM>. The adjusted lengths L are recorded and stored in order to keep the position changes of the mount <NUM> reproducible. In this way, the position of the mount <NUM> shown in dashed lines in <FIG> is adjusted precisely, reproducibly and essentially without material abrasion, while the mount remains stably mounted in the frame.

The holder <NUM> enables stable mounting of the mount <NUM> in the frame <NUM>, while a variety of positions of the mount <NUM> in or parallel to the plane E, i.e., in the X and/or Y direction, can be reached. The latter is promoted by the fact that the adjusting elements <NUM> can be adjusted in their length L independently of one another. The holder thus enables a precise and reproducible adjustment of the mount in the X direction and in the Y direction.

<FIG> schematically shows a laser processing device <NUM> of an example, which is embodied as a laser cutting device with a cutting head <NUM>. The device <NUM> has a laser source <NUM> for generating a laser beam <NUM> which is guided into a cutting head <NUM> by means of a transport fibre <NUM>. The laser beam <NUM> can be directed onto a workpiece <NUM> in a Z direction with the cutting head <NUM>. The device <NUM> includes a cutting head movement unit <NUM>, <NUM>, with which the cutting head <NUM> and thus the laser beam <NUM> guided therein can be moved in the cutting direction in the X and/or Y direction over the workpiece <NUM>. The cutting head moving unit contains a bridge <NUM> on which the cutting head <NUM> is arranged to be displaceable in the X direction and a carriage <NUM> on which the bridge <NUM> can be moved in the Y direction. With the cutting head moving unit, the cutting head <NUM> can also be moved perpendicular to the workpiece <NUM>, i.e., in the Z direction. In the present example, the laser processing device <NUM> has a control unit (not shown) with a memory. The cutting head moving unit <NUM>, <NUM> is connected to the control unit by wired or wireless data transmission. The holder <NUM> of <FIG> with the optical element <NUM> provided in the mount <NUM> is integrated into the cutting head <NUM>. In the present example, the adjusting elements <NUM> (not shown in <FIG>) are arranged on the outer side of the cutting head <NUM>. The holder <NUM> is positioned in such a way that the laser beam <NUM> generated during operation passes through the optical element <NUM> in the Z direction perpendicular to the plane E, i.e., perpendicular to the X and Y directions.

If the position of the optical element <NUM> in the beam path is to be changed in the X and/or Y direction outside the operation of the laser processing device <NUM>, e.g., during maintenance of the cutting head <NUM>, the adjusting elements <NUM> on the outer side of the cutting head are operated manually. In this way, the optical element <NUM> is displaced in the beam path of the laser beam perpendicular to the direction of propagation of the laser beam <NUM>. For example, the optical element is precisely centred in the optical path of the laser beam <NUM>, wherein the optical axis of the optical element <NUM> is made substantially coincident with the central axis of the laser beam.

<FIG> schematically illustrates a holder <NUM> as a second example. Compared to the holder <NUM> of <FIG>, elastic spring elements <NUM> are additionally provided in the through-openings <NUM> of the holder <NUM>, within which the adjusting elements are elastically mounted laterally in the X and Y directions. In the present example, the disc-shaped recesses <NUM> and the recess <NUM> each contain a precisely fitting rotatable disc-shaped filling element <NUM> made of a low-abrasion, temperature-resistant plastic that is mounted with a precise fit. The material of the filling element <NUM> can also contain or consist of a metal, e.g., stainless steel, aluminium or brass. The filling elements <NUM> each contain a guide <NUM> for receiving the mount-side ends <NUM> of the adjusting elements <NUM> with a precise fit or for receiving the frame-side end <NUM> of the guide pin <NUM> with a precise fit. The mount-side ends <NUM> of the adjusting elements <NUM> or the frame-side end <NUM> of the guide pin <NUM> can be displaced within the guides <NUM>. These measures increase the stability of the holder when the cutting head <NUM> moves quickly. In further examples, a passage (not shown) for receiving the adjusting elements <NUM> and/or the elastic spring elements <NUM> is fastened inside the through-openings <NUM>.

Claim 1:
A holder (<NUM>; <NUM>) for a transmissive optical element (<NUM>) of a laser processing device (<NUM>),
having
a frame (<NUM>) for receiving in a laser beam guidance unit (<NUM>) of the laser processing device, and having
a mount (<NUM>) for the transmissive optical element, wherein the transmissive optical element spans a plane (E) in an X direction and a Y direction,
wherein the mount (<NUM>) is mounted within the frame (<NUM>) with two adjusting elements (<NUM>) offset at an angle (α) of <NUM>° to <NUM>° to one another in or parallel to the plane (E) and is adjustable in the X direction and/or the Y-direction in each case at its distances (A, B) to the frame (<NUM>),
wherein
- the adjusting elements (<NUM>) are each mounted in the frame (<NUM>) such that they can pivot in the X and Y directions;
- the mount-side ends (<NUM>) of the adjusting elements (<NUM>) are each mounted in the mount (<NUM>) in the X and Y directions so that they can pivot;
characterised in that
- the adjusting elements (<NUM>) are each mounted in the frame (<NUM>) such that they are adjustable independently of one another in their respective length (L) between the mount and the frame
- the mount-side ends (<NUM>) of the adjusting elements (<NUM>) are each mounted in the mount (<NUM>) in the X and Y directions so that they are displaceable in the longitudinal direction of the respective adjusting element;
- the mount (<NUM>) is mounted with a guide pin (<NUM>) arranged in or parallel to the plane (E) between, in particular centrally between, the two adjusting elements radially to the frame;
- the mount-side end (<NUM>) of the guide pin (<NUM>) is fixed to the mount (<NUM>); and
- the frame-side end (<NUM>) of the guide pin (<NUM>) is mounted in the frame (<NUM>) such that it can pivot in the X and Y directions and is displaceable in the longitudinal direction of the guide pin.