Device for radiating light onto a skin surface during a medical or cosmetic skin treatment

1. A device for radiating laser light onto a skin surface during a medical or cosmetic treatment comprising:

a laser light source emitting the laser light;

a hand piece including an optical coupling element having a light entrance surface facing toward the laser light source and a light exit surface configured to contact the skin surface during the treatment, wherein the laser light has an intensity distribution with a flat top shape at the light entrance surface and is guided by the optical coupling element from the light entrance surface to the light exit surface so that the intensity distribution of the laser light at the light exit surface has the flat top shape;

the coupling element including a bundle of light guides having end sections ending at the light entrance surface on one side and at the light exit surface on an other side, the light guides being fused together, at least at the end sections, so as to avoid optically inactive intermediate spaces;

wherein the coupling element has a longitudinal axis and a frustum-shaped section disposed between the light entrance surface and the light exit surface centrically to the longitudinal axis, wherein a circumference of the coupling element in a region between the light entrance surface and a smaller diameter of the frustum-shaped section has a diameter that is larger than the diameter of the light entrance surface and also larger than the smaller diameter of the frustum-shaped section,

wherein each light guide in the bundle has a smaller cross-sectional area at the light entrance surface than at the light exit surface so that the light exit surface is different from the light entrance surface in geometrical profile and/or circumference, and

wherein an angle of emergence of a laser light component from each light guide is smaller than an angle of entrance of the laser light component into the respective light guide.

2. The device as recited in claim 1 wherein the light exit surface is larger than the light entrance surface.

3. A device for radiating laser light onto a skin surface during a medical or cosmetic treatment comprising:

a laser light source emitting the laser light;

a hand piece including an optical coupling element having a center axis and a light entrance surface facing toward the laser light source and a light exit surface configured to contact the skin surface during the treatment, wherein the laser light has an intensity distribution with a flat top shape at the light entrance surface and is guided by the optical coupling element from the light entrance surface to the light exit surface so that the intensity distribution of the laser light at the light exit surface has the flat top shape;

the coupling element including a truncated cone-shaped section disposed between the light entrance surface and the light exit surface, and having a peripheral surface tapering toward the light entrance surface and coaxially aligned with the center axis, wherein the coupling element includes a bundle of light guides each having end sections ending at the light entrance surface on one side and at the light exit surface on the other side, the light guides being fused together, at least at the end sections, so as to avoid optically inactive intermediate spaces, wherein a cross-sectional area of each light guide is larger at the light exit surface than at the light entrance surface, and wherein an angle of emergence of a laser light component from each light guide is smaller than an angle of entrance of the laser light component into the respective light guide, wherein a circumference of the coupling element in a region between the light entrance surface and a smaller diameter of the truncated cone-shaped section has a diameter that is larger than the diameter of light entrance surface and also larger than the smaller diameter of the truncated cone-shaped section.

4. The device as recited in claim 3 wherein the light exit surface has a geometrical outline and/or an extent different from a geometrical outline and/or an extent of the light entrance surface.

5. The device as recited in claim 3 wherein the peripheral surface of the coupling element in the area of the truncated-cone-shaped section is transparent to light directed from an inside of the coupling element toward an outside.

6. The device as recited in claim 3 wherein the light entrance surface has a circular outline and the light exit surface has a square outline.

7. The device as recited in claim 3 further comprising a light guide device having an emission-side end facing toward the light entrance surface inside the handpiece, the light guide device being connected to a laser light source.

8. The device as recited in claim 3 further comprising a laser light source having at least one laser diode integrated into the hand piece.

9. The device as recited in claim 3 wherein the truncated-cone-shaped section is provided at half the distance between the light entrance surface and the light exit surface and has a smaller diameter at one end and a larger diameter at another end, the peripheral surface including another section cylindrical and concentric relative to the center axis in a region between the light entrance surface and the smaller diameter of the truncated-cone-shaped section, a diameter of the light entrance surface corresponding to the smaller diameter of the truncated-cone-shaped section and a diameter of the light exit surface corresponding to the larger diameter of the truncated-cone-shaped section.

10. The device as recited in claim 9 wherein in a region between the light entrance surface and the smaller diameter of the truncated-cone-shaped section, the circumference of the coupling element has a further diameter larger than the diameter of the light entrance surface and larger than the smaller diameter of the truncated-cone-shaped section, the further diameter tapering toward the light entrance surface and toward the smaller diameter of the truncated-cone-shaped section.