Piezoelectric transformer and counter electrode

1. A piezoelectric transformer having a surface structure which has at least one protruding surface structure segment, wherein the piezoelectric transformer has a contour and is suitable for discharging a gas which is arranged in a gap between the piezoelectric transformer and a counter electrode in conjunction with the counter electrode for generating a plasma, wherein the surface structure is configured such that the gas discharge takes place at a multiplicity of discharge initiation points on the contour, and wherein the width of the surface structure segment of the surface structure is smaller than the width of the piezoelectric transformer.

2. The piezoelectric transformer according to claim 1 , wherein the surface structure segment defines the contour of the piezoelectric transformer.

3. The piezoelectric transformer according to claim 1 , wherein the width of the surface structure segment is greater than 10 μm.

4. The piezoelectric transformer according to claim 1 , wherein the surface structure extends between 2 mm and 4 cm over the width of the piezoelectric transformer.

5. The piezoelectric transformer according to claim 1 , wherein the surface structure has a plurality of surface structure segments, wherein a gap is arranged in each case between adjacent surface structure segments, and wherein the surface structure segments, together with the gap, form the surface structure.

6. The piezoelectric transformer according to claim 5 , wherein the surface structure has a surface profile, and wherein the profile depth (H) of the surface profile of the surface structure is greater than the width of a surface structure segment.

7. The piezoelectric transformer according to claim 5 , wherein the discharge initiation points lie in a plane, and wherein the surface structure segments in cross section are triangular, quadrangular, for example rectangular, or have more than four corners.

8. The piezoelectric transformer according to claim 1 , wherein the surface structure has a polygonal design and comprises a plurality of surface structure segments, and wherein the respective surface structure segment is determined by the straight part of a polygonal line, and wherein the discharge initiation points lie in different planes.

9. The piezoelectric transformer according to claim 1 , wherein the surface structure has just a single surface structure segment, which on the output side of the piezoelectric transformer defines an end face thereof, and wherein the discharge initiation points lie in the same plane.

10. The piezoelectric transformer according to claim 1 , which tapers toward an output side of the piezoelectric transformer.

11. The piezoelectric transformer according to claim 1 , wherein the piezoelectric transformer has a transformer body which is provided with a structural part, wherein the surface structure is formed in the structural part, and wherein the structural part is fixedly connected to the transformer body.

12. The piezoelectric transformer according to claim 1 , wherein the surface structure is electrically conductive.

13. The piezoelectric transformer according to claim 1 , wherein the surface structure is electrically insulating, and wherein the gas discharge is a dielectric barrier discharge.

14. A device having a piezoelectric transformer according to claim 1 , wherein the device comprises a counter electrode which is arranged facing toward the surface structure, and wherein the counter electrode is planar.

15. The piezoelectric transformer according to claim 1 , wherein the contour, which is defined by the surface structure segments, extends semi-circularly.

16. A counter electrode comprising a surface structure which comprises at least one protruding surface structure segment, wherein the counter electrode has a contour and is suitable for discharging a gas which is arranged in a gap between a piezoelectric transformer and the counter electrode in conjunction with the piezoelectric transformer for generating a plasma, wherein the gas discharge occurs at a multiplicity of discharge initiation points on the contour.

17. The counter electrode according to claim 16 , wherein the surface structure comprises a multiplicity of surface structure segments, wherein gaps are arranged between the surface structure segments, and wherein the gaps, together with the surface structure segments, form the surface structure.

18. A device having a counter electrode according to claim 16 and a piezoelectric transformer, wherein the device is configured to discharge the gas between the surface structure and the piezoelectric transformer.

19. The device according to claim 18 , wherein the piezoelectric transformer is arranged at least in part within a cavity formed by the counter electrode.

20. The device according to claim 18 , wherein the width of the surface structure segment of the surface structure is smaller than the width of the piezoelectric transformer.

21. A piezoelectric transformer having a surface structure which has at least one protruding surface structure segment, wherein the piezoelectric transformer has a contour and is suitable for discharging a gas in conjunction with a counter electrode for generating a plasma, wherein the surface structure is configured such that the gas discharge takes place at a multiplicity of discharge initiation points on the contour, and wherein the width of the surface structure segment of the surface structure is smaller than the width of the piezoelectric transformer, wherein the width of the surface structure segment is greater than 10 μm.

22. A piezoelectric transformer having a surface structure which has at least one protruding surface structure segment, wherein the piezoelectric transformer has a contour and is suitable for discharging a gas in conjunction with a counter electrode for generating a plasma, wherein the surface structure is configured such that the gas discharge takes place at a multiplicity of discharge initiation points on the contour, and wherein the width of the surface structure segment of the surface structure is smaller than the width of the piezoelectric transformer, wherein the surface structure extends between 2 mm and 4 cm over the width of the piezoelectric transformer.