Conductive coating for reduced reflectivity on electronic displays
View Patent ↗In an optical thin-film arrangement on a transparent optical substrate, such as a display screen, two or more conductive layers are stacked in an alternating fashion with one or more dielectric layers. The conductive layer can include, for example, indium-tin oxide (ITO), and the dielectric layer can include an index-matching material. The conductive layers can be in electrical contact with one another at their peripheries to provide EMI/RFI shielding. A structure having more than one conductive layer can be made to have the same net sheet resistance and thus provide the same degree of shielding as a conventional single-layer conductive coating but with lower reflectivity.
1. An optical structure, comprising:
a substrate transparent to one or more selected wavelengths of electromagnetic energy; and
a plurality of thin-film layers essentially transparent to the one or more selected wavelengths, at least one of the layers in contact with the substrate, the thin-film layers comprising:
a plurality of thin-film conductive layers; and
a thin-film dielectric layer sandwiched between and around the thin-film conductive layers, wherein at least one thin-film dielectric layer comprises magnesium fluoride.
2. The optical structure claimed in claim 1 , wherein the substrate comprises an element of a display screen.
3. The optical structure claimed in claim 1 , wherein the thin-film layers comprise coatings by vacuum deposition.
4. The optical structure claimed in claim 1 , wherein the thin-film conductive layers comprise indium-tin oxide (ITO).
5. The optical structure claimed in claim 1 , wherein the at least one thin-film dielectric layer that comprises magnesium fluoride is an index-matching layer for matching air.
6. The optical structure claimed in claim 1 , wherein the thin-film layers comprise a plurality of thin-film dielectric layers, each sandwiched between thin-film conductive layers in an alternating arrangement.
7. The optical structure claimed in claim 6 , wherein the thin-film conductive layers comprise indium-tin oxide (ITO).
8. The optical structure claimed in claim 6 , wherein at least one thin-film dielectric layer is an index-matching layer to at least one thin-film conductive layer.
9. The optical structure claimed in claim 8 , wherein the thin-film conductive layers comprise indium-tin oxide (ITO).
10. The optical structure claimed in claim 6 , wherein each of the plurality of thin-film layers has a periphery, and at least a portion of the periphery of each of the thin-film conductive layers is in contact with at least a portion of the periphery of another of the thin-film conductive layers.
11. The optical structure claimed in claim 10 , wherein the periphery of each of the thin-film conductive layers is rectangular, and at least one edge of the periphery of each of the thin-film conductive layers is in contact with at least a corresponding edge of the periphery of another of the thin-film conductive layers.
12. The optical structure claimed in claim 11 , wherein each of four edges of the periphery of each of the thin-film conductive layers is in contact with one of four corresponding edges of the periphery of another of the thin-film conductive layers.
13. The optical structure claimed in claim 12 , wherein the thin-film conductive layers comprise indium-tin oxide (ITO).
14. The optical structure claimed in claim 1 , wherein the at least one thin-film dielectric layer is an index-matching layer for matching the substrate.
15. An optical structure, comprising:
a substrate transparent to one or more selected wavelengths of electromagnetic energy; and
a plurality of thin-film layers essentially transparent to the one or more selected wavelengths, at least one of the layers in contact with the substrate, the thin-film layers comprising:
a plurality of thin-film dielectric layers, wherein at least one thin-film dielectric layer comprises magnesium fluoride;
a plurality of thin-film conductive layers sandwiched between the thin-film dielectric layers, wherein the plurality of thin-film conductive layers comprises indium-tin oxide (ITO); and
wherein each of the thin-film conductive layers is in contact with at least one corresponding edge of the periphery of another of the thin-film conductive layers.
16. The optical structure claimed in claim 15 , wherein the at least one thin-film dielectric layer index-matching layer comprises magnesium fluoride is an index-matching layer for air.
17. The optical structure claimed in claim 15 , wherein at least one thin-film dielectric layer is an index-matching layer for matching the substrate.
18. The optical structure claimed in claim 15 , wherein the thin-film layers comprise a plurality of thin-film dielectric layers, each sandwiched between thin-film conductive layers in an alternating arrangement.
19. The optical structure claimed in claim 18 , wherein at least one thin-film dielectric layer is an index-matching layer to at least one thin-film conductive layer.