DEVICE FOR MACHINING MATERIAL BY MEANS OF LASER RADIATION

• US 20170371166A1
• Filed: 01/27/2016
• Published: 12/28/2017
• Est. Priority Date: 01/28/2015
• Status: Active Grant

• Current Assignee: Precitec GmbH & Co. KG
• Original Assignee: Precitec GmbH & Co. KG
• Inventors: RUDOLF, Andreas, SCHNLEBER, Martin
• Granted Patent: US 10,444,521 B2
• Time in Patent Office: Days
• CPC Class Codes: B23K 26/0652 comprising prisms
• CPC Class Codes: B23K 26/067 Dividing the beam into multiple beams, e.g. multifocusing
• CPC Class Codes: B23K 26/21 by welding
• CPC Class Codes: B23K 26/38 by boring or cutting
• CPC Class Codes: B29C 65/1635 at least passing through one of the parts to be joined, i.e. laser transmission welding
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 5/02 of prismatic shape F21V5/04 takes precedence
• CPC Class Codes: F21V 7/05 plane
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0938 Using specific optical elements
• CPC Class Codes: G02B 27/0972 Prisms prisms per se G02B5/04
• CPC Class Codes: G02B 27/4255 for alignment or positioning purposes optical displacement encoding scales G01D5/347
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A device for machining material by means of laser radiation, including a focusing optics for focusing a laser beam onto a workpiece and an adjusting optics for adjusting the intensity distribution comprising at least two plate-shaped optical elements which are arranged one behind the other in the beam path of the laser beam, which are rotatable relative to one another in the circumferential direction, and which each have a surface with a circular pattern of sector-shaped facets which, in the circumferential direction, are alternately inclined with respect to the respective plate plane.

Claims

1. A device for machining material by means of laser radiation, comprising a focusing optics for focusing a laser beam onto a workpiece and an adjusting optics for adjusting the intensity distribution including at least one plate-shaped optical element having a circular pattern of sector-shaped facets which, in the circumferential direction, are alternately inclined with respect to the respective plate plane.

2. The device according to claim 1, wherein said plate-shaped optical element of said adjusting optics can be moved into and out of the beam path of said laser beam.

3. The device according to claim 1, wherein said adjusting optics includes at least two plate-shaped optical elements, each having a circular pattern of sector-shaped facets which, in the circumferential direction, are alternately inclined with respect to the respective plate plane, wherein said at least two plate-shaped optical elements are arranged one behind the other in the beam path of said laser beam and are rotatable relative to one another in the circumferential direction.

4. The device according to claim 1, wherein all sector-shaped facets of a plate-shaped optical element have the same azimuthal width.

5. The device according to claim 1, wherein the surfaces of the sector-shaped facets of said plate-shaped optical elements are planar or curved or have two or more differently inclined portions.

6. The device according to claim 3, wherein said two plate-shaped optical elements of said adjusting optics face each other with their sector-shaped facet patterns.

7. The device according to claim 3, wherein said two plate-shaped optical elements of said adjusting optics are rotatable about an axis which is coaxial with a central axis of a laser beam bundle.

8. The device according to claim 3, wherein the sector-shaped facet patterns of said two plate-shaped optical elements of

9. The device according to claim 3, wherein said adjusting optics comprises a further plate-shaped optical element having a sector-shaped facet pattern.

10. The device according to claim 9, wherein said further plate-shaped optical element has a sector-shaped facet pattern on both sides and is arranged between the two first plate-shaped optical elements.

11. The device according to claim 9, wherein said further plate-shaped optical element has a sector-shaped facet pattern which is different from the sector-shaped facet pattern of said two first plate-shaped optical elements.

12. The device according to claim 11, wherein the facet surfaces of said further plate-shaped optical element are inclined by an angle with respect to the plate plane which differs from the inclination angle of said two first plate-shaped optical elements and, in particular, is as large as the sum of the inclination angles of said two first plate-shaped optical elements.

13. The device according to claim 11, wherein the facets of said further plate-shaped optical element have an azimuthal width which is different from the azimuthal width of the facets of said two first plate-shaped optical elements.

14. The device according to claim 1, wherein the inclination angle of the facet surfaces with respect to the plate plane is between ±

0.1° and

±

0.6°

.

15. The device according to claim 1, wherein the number of facets is 18 to 72, preferably 24 to 40, in particular 36.

16. The device according to claim 1, wherein a collimator optics is provided for widening said laser beam, and that said adjusting optics is arranged between said collimator optics and said focusing optics.

17. The device according to claim 1, wherein a rotary drive is assigned to at least one of said plate-shaped optical elements so that the plate-shaped optical element can be driven during a laser machining process so as to rotate at a constant or variable speed.

18. The device according to claim 16, wherein a rotary drive is assigned to each of said plate-shaped optical elements.

19. The device according to claim 17, wherein said rotary drives can be driven independently of one another, so that the rotational speed and the direction of rotation of each of said plate-shaped optical elements can be selected.

20. A method for machining material by means of laser radiation using a focusing optics for focusing a laser beam onto a workpiece and an adjusting optics for adjusting the intensity distribution, comprising at least two plate-shaped optical elements, each having a circular pattern of sector-shaped facets which, in the circumferential direction, are alternately inclined with respect to the respective plate plane, wherein said at least two plate-shaped optical elements are disposed one behind the other in the beam path of said laser beam and are rotatable in the circumferential direction, wherein, during laser machining, at least one of said plate-shaped optical elements is rotated at a constant or variable speed in order to vary a power density distribution at a desired modulation frequency.

21. The method according to claim 20, wherein both of said at least two plate-shaped optical elements are rotated in opposite directions at the same or different speeds.

22. The method according to claim 20, wherein the output power of the laser is modulated during laser machining while one or more of said plate-shaped optical elements are rotated, wherein a modulation frequency of the laser is coupled to the modulation frequency of the power density distribution.