Hot plate and hob comprising a corresponding hot plate
View Patent ↗A hot plate includes a base plate having an underside. A coating has at least two metallic layers and at least two dielectric layers and is formed on the underside of the base plate in such a way that a reflectivity of the hot plate is lower than 15% in a wavelength range between 380 nm and 780 nm.
1. A hot plate, comprising:
a base plate having an underside and a topside; and
a coating having at least two metallic layers and at least two dielectric layers and formed on the underside of the base plate in such a way that a reflectivity of the hot plate, of a light source located above the hot plate, is lower than 15%,
wherein the reflectivity is in a wavelength range between 380 nm and 780 nm,
the reflectivity is measured at the topside, and
the coating is uniform on the entire underside of the base plate.
2. The hot plate of claim 1 , wherein
the reflectivity of the hot plate, in a wavelength range of between 380 nm and less than 400 nm, is less than 10%, and
the reflectivity of the hot plate, in a wavelength range of between greater than 530 nm and less than 780 nm, is less than 10%.
3. The hot plate of claim 1 , wherein the coating is formed in such a way that a transmittance of the hot plate in the wavelength range between 380 nm and 780 nm is smaller than 12%.
4. The hot plate of claim 1 , wherein the coating is formed in such a way that a transmittance of the hot plate in the wavelength range between 380 nm and 780 nm is between 0.5% and 10%.
5. The hot plate of claim 1 , wherein the coating has a number of metallic layers which is 2 or 3.
6. The hot plate of claim 1 , wherein the coating has a number of dielectric layers which is between 2 and 4.
7. The hot plate of claim 1 , wherein the coating is embodied as a bottom finish with a protective layer.
8. The hot plate of claim 7 , wherein the protective layer is a protective anti-oxidation layer.
9. The hot plate of claim 1 , wherein the metallic layers and the dielectric layers respectively have layer thicknesses of less than 100 nm.
10. The hot plate of claim 1 , wherein the at least two metal layers of the coating have different layer thicknesses or the at least two dielectric layers of the coating have different layer thicknesses.
11. The hot plate of claim 1 , wherein the metal layers and the dielectric layers of the coating are formed by sputtering on the underside.
12. The hot plate of claim 11 , wherein the sputtering includes magnetron sputtering.
13. The hot plate of claim 1 , wherein one of the metal layers is made of a material selected from the group consisting of stainless steel, the elements Mo, Ni, Cr, Nb, V, Ti, Ta, W, Cu and a compound of at least two of stainless steel and the said elements.
14. The hot plate of claim 1 , wherein a first one of the dielectric layers includes SnO x with a layer thickness of 46 nm, with the first dielectric layer being followed by at least a first one of the metal layers which includes SSt with a layer thickness of of 8 nm, followed by a second one of the dielectric layers includes SnO x with a layer thickness of 56 nm, followed by at least a second one of the metallic layers which includes SSt with a layer thickness of 33 nm, said coating having a third dielectric layer which includes SnO x with a layer thickness of 50 nm.
15. The hot plate of claim 1 , wherein the coating has a layer thickness of between 10 nm and 500 nm.
16. The hot plate of claim 1 , further comprising an imprint or an internal marking on the underside or the topside of the base plate.
17. The hot plate of claim 16 , wherein the marking is created using laser light.
18. A cooktop, comprising a hot plate including a base plate having an underside and a topside, and a coating having at least two metallic layers and at least two dielectric layers and formed on the underside of the base plate in such a way that a reflectivity of the hot plate, of a light source located above the hot plate, is lower than 15%,
wherein the reflectivity is in a wavelength range between 380 nm and 780 nm,
the reflectivity is measured at the topside, and
the coating is uniform on the entire underside of the base plate.
19. The cooktop of claim 18 , wherein
the reflectivity of the hot plate, in a wavelength range of between 380 nm and less than 400 nm, is less than 10%, and
the reflectivity of the hot plate, in a wavelength range of between greater than 530 nm and less than 780 nm, is less than 10%.
20. The cooktop of claim 18 , wherein the coating is formed in such a way that a transmittance of the hot plate in the wavelength range between 380 nm and 780 nm is smaller than 12%.
21. The cooktop of claim 18 , wherein the coating is formed in such a way that a transmittance of the hot plate in the wavelength range between 380 nm and 780 nm is between 0.5% and 10%.
22. The cooktop of claim 18 , wherein the coating has a number of metallic layers which is 2 or 3.
23. The cooktop of claim 18 , wherein the coating has a number of dielectric layers which is between 2 and 4.
24. The cooktop of claim 18 , wherein the coating is embodied as a bottom finish with a protective layer.
25. The cooktop of claim 24 , wherein the protective layer is a protective anti-oxidation layer.
26. The cooktop of claim 18 , wherein the metallic layers and the dielectric layers respectively have layer thicknesses of less than 100 nm.
27. The cooktop of claim 18 , wherein the at least two metal layers of the coating have different layer thicknesses or the at least two dielectric layers of the coating have different layer thicknesses.
28. The cooktop of claim 18 , wherein the metal layers and the dielectric layers of the coating are formed by sputtering on the underside.
29. The cooktop of claim 11 , wherein the sputtering includes magnetron sputtering.
30. The cooktop of claim 18 , wherein one of the metal layers is made of a material selected from the group consisting of stainless steel, the elements Mo, Ni, Cr, Nb, V, Ti, Ta, W, Cu and a compound of at least two of stainless steel and the said elements.
31. The cooktop of claim 18 , wherein a first one of the dielectric layers includes SnO x with a layer thickness of 46 nm, with the first dielectric layer being followed by at least a first one of the metal layers which includes SSt with a layer thickness of of 8 nm, followed by a second one of the dielectric layers which includes SnO x with a layer thickness of 56 nm, followed by at least a second one of the metallic layers which includes SSt with a layer thickness of 33 nm, said coating having a third dielectric layer which includes SnO x with a layer thickness of 50 nm.
32. The cooktop of claim 18 , wherein the coating has a layer thickness of between 10 nm and 500 nm.
33. The cooktop of claim 18 , wherein the hot plate has an imprint or an internal marking on the underside or the topside of the base plate.
34. The cooktop of claim 33 , wherein the marking is created using laser light.
35. The hot plate of claim 1 , wherein the at least two metallic layers and at least two dielectric layers are alternating such that one of the dielectric layers is located between two of the metallic layers and one of the metallic layers is located between two of the dielectric layers.
36. The cooktop of claim 18 , wherein the at least two metallic layers and at least two dielectric layers are alternating such that one of the dielectric layers is located between two of the metallic layers and one of the metallic layers is located between two of the dielectric layers.