DE102019127979A1 - Device for deflecting a laser beam - Google Patents

Abstract

The invention relates to a device (1) for deflecting a supplied laser beam (2). For this purpose, the device (1) has a laser head (3) with at least one optical element (5) for radial deflection of the laser beam (2) in order to be able to cyclically distribute the supplied laser radiation to several coupling surfaces (9). In this way, for example, different laser processing heads can be supplied with the laser radiation from the same beam source, which are only connected to one of the connections I to V for this purpose.

Description

The invention relates to a device for deflecting a laser beam with a laser head for the selective or cyclical deflection of the laser beam onto different coupling surfaces.

Electro-optical deflection units are already known from the prior art, which have, for example, a light guide in which the light beams are guided by total reflection at interfaces.

In addition, elements are provided with which an entry angle at which the light beam is coupled into the light guide or an exit angle at which the light beam emerges from the light guide can be influenced.

These elements can include, for example, liquid crystals, the refractive index of which can be changed under the influence of an electric field. Such a deflection unit is for example in the US 8,995,038 B1 described.

In addition, the WO 2014/200 581 A2 a lidar system in which a laser beam is deflected in different spatial directions by means of an electro-optical deflection unit. The electro-optical deflection unit is designed in particular as a so-called Steerable Electro-Evanesent Optical Reflector (SEEOR).

From the DE 196 22 413 A1 a cable drive is known as an adjustment drive for positioning optics in a laser processing head.

From the DE 43 17 384 A1 a laser head is known whose beam-shaping optics can be displaced in the longitudinal direction of the laser beam by a worm drive.

The invention is based on the object of creating a device for deflecting a laser beam onto different coupling surfaces for supplying laser radiation as required.

This object is achieved according to the invention with a device according to the features of claim 1. The further embodiment of the invention can be found in the subclaims.

According to the invention, a device for deflecting a laser beam is equipped with a laser head for the optional or cyclical deflection of the laser beam onto different coupling surfaces of a distributor head and with at least one optical element for deflecting the beam onto the coupling surfaces, the optical element and the distributor head for cyclical deflection of the laser beam at least one of the coupling surfaces can be driven in a rotationally movable manner relative to one another.

As a result, the laser radiation that is continuously supplied, for example, is split up and supplied cyclically to individual coupling-in surfaces. These could, for example, be coupled to a device for laser machining a workpiece in order to use the supplied laser energy. Furthermore, the laser energy can also be fed through the coupling surface of a device for modifying the laser radiation or a distributor or line system, so that a supply network comparable to other energy carriers is created. For this purpose, the coupling surface can also be part of a plug connection in order to create a standardized connection option.

As a result, a quasi-pulsed laser radiation is generated by the cyclic coupling of the laser radiation into different coupling surfaces, whereby variable overlapping areas with areas of the distributor head adjoining the respective coupling surface are created by the continuous circular movement of the optical element.

According to the invention, several applications can be supplied from a single beam source at the same time. For this purpose, the optical element can be driven in a revolving manner at constant or variable speed, so that the laser beam cyclically strikes a plurality of coupling surfaces in each case, which are, in particular, evenly distributed.

By means of the device according to the invention, the laser radiation is divided into several quasi-simultaneous processing points and, at the same time, short pulses of very high frequency are generated from the continuous light of the laser. The high pulse repetition rate results in correspondingly high processing speeds.

In practice, the coupling surfaces are preferably arranged in a stationary or stationary manner, while the optical element for deflecting the beam can be rotated.

Particularly preferably, the optical element is driven to be rotationally movable about the optical axis of the supplied laser beam as the axis of rotation, the speed of rotation being adjustable depending on the application. In this way, the pulse duration of the injected laser radiation is determined at the same time.

A particularly simple variant of the device is also achieved when the deflection for coupling into the respective coupling surface takes place in the radial direction with respect to the axis of rotation. Here, the distributor head encloses the optical element on the circumferential side, so that the laser radiation enters the coupling surfaces radially.

In another, likewise particularly advantageous embodiment of the invention, the laser beam can be deflected several times with respect to the optical axis of the incident laser beam by means of the optical element and can be deflected along a beam axis onto the coupling surface, the beam axis being oriented parallel to the optical axis. In this way, the device for beam distribution can also be retrofitted, for example, in existing systems without any problems, with the orientation of the beam guidance of the supplied laser beam relative to the beam guidance being retained after coupling into the respective coupling surface. In addition, all coupling surfaces can be arranged in parallel planes or in a common plane, which reduces the design effort. Furthermore, a particularly compact design is realized in this way.

According to a particularly advantageous embodiment of the invention, the optical element has at least two reflector surfaces, for example to initially deflect the laser beam in the radial direction and then to offset the beam axis parallel to the optical axis through a further deflection with an orientation parallel to the optical axis to reach. For this purpose, the reflector surfaces can be connected in one piece by the optical element.

According to a further, particularly promising modification, the optical element has at least two reflectors movable relative to one another, each with a reflector surface, in order to be able to adjust the parallel offset, i.e. the radial distance between the beam axis and the optical axis of the supplied laser beam, as required. The distance can thereby be adapted in order to be able to adapt in particular to differently sized distributor heads or different coupling surfaces.

In addition, a sensor-based monitoring of the coupling surfaces can also be provided in order to be able to adjust the distance by means of a control unit. This could possibly also be varied cyclically during a full revolution of the machining head around the optical axis if, for example, several coupling surfaces are arranged on different concentric circular paths.

By means of an additional, also double beam deflection, the laser beam, after its lateral deflection, is first deflected radially inward and then as a beam axis parallel to the optical axis of the supplied laser beam. In this way, if necessary, very small distances between the beam axis and the optical axis can also be set, so that a particularly small design of the distributor head can be implemented. In particular, the minimum radial distance between the beam axis is not restricted by the size or design of the reflectors.

• 1 eine perspektivische Darstellung einer erfindungsgemäßen Vorrichtung zur Verteilung des Laserstrahls;
• 2 einen Querschnitt durch die in 1 gezeigte Vorrichtung.

The invention allows various embodiments. To further clarify its basic principle, one of them is shown in the drawing and is described below. This shows in

• 1 a perspective view of a device according to the invention for distributing the laser beam;
• 2 a cross section through the in 1 shown device.

A first variant of a device according to the invention 1 for radial deflection and distribution of a supplied laser beam 2 is explained below using the 1 and 2 explained in more detail. The device 1 has a laser head 3 with a coolant inlet 4th and with an optical element 5 for radial deflection of the laser beam 2 . The laser beam is used for this 2 opposite the optical axis 6th of the supplied laser beam 2 by means of the relative to several coupling surfaces 9 rotating optical element 5 deflected radially at a reflector designed as a prism. This radially deflected beam axis 8th thus encounters the coupling surfaces arranged along a concentric circular ring all around 9 . An external deflection element is only hinted at 7th shown, which of the beam deflection in one to the optical axis 6th axially parallel direction is used and which with the device 1 can be connected. Alternatively, the coupling into the deflecting element 7th also take place by means of a light guide (not shown) or a free beam path.

By means of the device 1 For example, different laser processing heads can be supplied with the laser radiation from the same central beam source as required, which for this purpose, for example, is connected to one of the connections by means of a plug connection I. to V be connected. The duration of the interruption can be determined by the speed of rotation of the optical element 5 can be set.

List of reference symbols

1

contraption

2

laser beam

3

Laser head

4th

Coolant inlet

5

optical element

6th

optical axis

7th

Deflection element

8th

Beam axis

9

Coupling surface

I - V

connection

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• US 8995038 B1 [0004]
• WO 2014/200581 A2 [0005]
• DE 19622413 A1 [0006]
• DE 4317384 A1 [0007]

Claims (10)

Device (1) for deflecting a laser beam (2) with a laser head (3) for optional or cyclical deflection of the laser beam (2) onto different coupling surfaces (9) of a distributor head with at least one optical element (5) for deflecting the beam onto the coupling surfaces (9) ), wherein the optical element (5) and the distributor head for the cyclical deflection of the laser beam (2) onto at least one of the coupling surfaces (9) can be rotated relative to one another. Device (1) according to Claim 1 , characterized in that the optical element (5) is driven to be rotationally movable about the optical axis (6) of the supplied laser beam (2) as the axis of rotation. Device (1) according to Claim 1 or 2 , characterized in that the deflection for coupling into the respective coupling surface (9) takes place in the radial direction with respect to the axis of rotation. Device (1) according to at least one of the preceding claims, characterized in that the laser beam (2) is incident on the coupling surface (2) with respect to the optical axis (6) of the incident laser beam (2) by means of the optical element (5) along a beam axis (8). 9) is deflectable, the beam axis (8) having a parallel orientation with respect to the optical axis (6) with a spacing. Device (1) according to at least one of the preceding claims, characterized in that the optical element (5) has at least two reflector surfaces. Device (1) according to at least one of the preceding claims, characterized in that the optical element (5) has at least two reflectors movable relative to one another, each with a reflector surface. Device (1) according to at least one of the preceding claims, characterized in that at least one reflector can be positioned at different radial distances in relation to the optical axis (6). Device (1) according to at least one of the preceding claims, characterized in that the device (1) has at least one in particular external deflecting element (7) for deflecting the beam along a predetermined beam axis. Device (1) according to Claim 8 , characterized in that the deflecting element (7) is connected to the respective coupling surface (9) by means of a light guide and / or a free jet path. Device (1) according to at least one of the preceding claims, characterized in that the coupling-in surfaces (9) enclose the optical element (5) on the circumferential side and that adjacent coupling-in surfaces (9) abut one another without gaps or at least approximately without gaps.

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