Optical lens with scratch-resistant anti-reflective layer
The present invention relates to an optical lens having a lens element produced of plastic, more particularly of plastic which is transparent in a visible spectral range, and having a coating comprising a plurality of layers, the plurality of layers comprising at least one high-refractive-index layer. Furthermore, a hardcoat layer is formed adjacent to the lens element, and a superhydrophobic layer concludes the coating in opposition to the lens element. The at least one high-refractive-index layer has a thickness of less than 40 nm, and the coating overall has a thickness of more than about 380 nm.
1. An optical lens having a lens element produced of plastic and a scratch resistant anti-reflective coating comprising a plurality of layers, the plurality of layers comprising only one high-refractive-index layer, wherein a hardcoat layer is formed adjacent to the lens element, wherein a superhydrophobic layer concludes the scratch resistant anti-reflective coating, wherein the one high-refractive-index layer has a thickness of less than 40 nm, and wherein the scratch resistant anti-reflective coating excluding the hardcoat layer has a thickness of more than about 380 nm.
2. The optical lens according to claim 1 , wherein the only one high-refractive-index layer has a refractive index of n>1.65.
3. The optical lens according to claim 1 , wherein the scratch resistant anti-reflective coating excluding the hardcoat layer has a thickness of more than about 400 nm.
4. The optical lens according to claim 1 , wherein the optical lens has a Bayer value of greater than 17 and a reflectance of less than about 2.5% for visible light having a wavelength ranging from 450 nm to 650 nm.
5. An optical lens having a lens element produced of plastic, and having a scratch resistant anti-reflective coating comprising a plurality of layers, the plurality of layers comprising at least one high-refractive-index layer, wherein a hardcoat layer is formed adjacent to the lens element, wherein a superhydrophobic layer concludes the scratch resistant anti-reflective coating, wherein the scratch resistant anti-reflective coating excluding the hardcoat layer has a thickness of more than about 380 nm, wherein in the case of exactly one high-refractive-index layer, the exactly one high-refractive-index layer has a thickness of less than 40 nm, and in the case of more than one high-refractive-index layer, the high-refractive-index layers together have a thickness of less than 40 nm.
6. The optical lens according to claim 5 , wherein the superhydrophobic layer is formed of a material on which water adopts a contact angle of more than 90°.
7. The optical lens according to claim 5 , wherein the scratch resistant anti-reflective coating has precisely one high-refractive-index layer.
8. The optical lens according to claim 7 , wherein the high-refractive-index layer has a thickness of less than 15 nm.
9. The optical lens according to claim 5 , wherein the scratch resistant anti-reflective coating has two high-refractive-index layers.
10. The optical lens according to claim 9 , wherein one of the two high-refractive-index layers has a thickness of less than or equal to about 10 nm.
11. The optical lens according to claim 5 , wherein the at least one high-refractive-index layer is formed of ZrO 2 , TiO 2 or Ta 2 O 5 .
12. The optical lens according to claim 5 , wherein the scratch resistant anti-reflective coating has at least one low-refractive-index layer and/or at least one medium-refractive-index layer.
13. The optical lens according to claim 12 , wherein the at least one low-refractive-index layer is formed of SiO 2 , Al 2 O 3 or MgF 2 .
14. The optical lens according to claim 12 , wherein the at least one high-refractive-index layer is embedded between two low-refractive-index layers or two medium-refractive-index-layers or one low-refractive-index layer and one medium-refractive-index-layer.
15. The optical lens according to claim 12 , wherein the at least one medium-refractive-index layer has a refractive index of 1.5<n<=1.65 and that the at least one low-refractive-index layer has a refractive index of n<=1.5.
16. The optical lens according to claim 5 , wherein a hardness of the plurality of layers increases from the hardcoat layer in the direction of the superhydrophobic layer.
17. The optical lens according to claim 5 , wherein at least two low-refractive-index-layers and at least two medium-refractive-index layers are positioned in an alternating arrangement between the lowermost high-refractive-index layer and the hardcoat layer.
18. The optical lens according to claim 5 , wherein the at least one high-refractive-index layer has a refractive index of n>1.65.
19. The optical lens according to claim 5 , wherein the scratch resistant anti-reflective coating excluding the hardcoat layer has a thickness of more than about 400 nm.
20. The optical lens according to claim 5 , wherein the optical lens has a Bayer value of greater than 17 and a reflectance of less than about 2.5% for visible light having a wavelength ranging from 450 nm to 650 nm.