Optical lens with scratch-resistant anti-reflective layer

Patent metadata

Field	Value
Publication number	US-9817155-B2
Application number	US-201514617257-A
Country	US
Kind code	B2
Filing date	Feb 9, 2015
Priority date	Oct 1, 2010
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

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.

First claim

What is claimed is:

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 precisely two high-refractive-index layers, wherein a hardcoat layer is formed adjacent to the lens element, wherein a superhydrophobic layer concludes the scratch resistant anti-reflective coating, wherein the two high-refractive-index layers have an overall thickness of less than 40 nm, and wherein the scratch resistant anti-reflective coating excluding the hardcoat layer has an overall thickness of more than about 380 nm, wherein the optical lens has a Bayer value of greater than 17.

2. The optical lens according to claim 1 , wherein the superhydrophobic layer is formed of a material on which water adopts a contact angle of more than 90°.

3. The optical lens according to claim 1 , wherein at least one of the two high-refractive-index layers has a thickness of less than 15 nm.

4. The optical lens according to claim 1 , wherein one of the two high-refractive-index layers has a thickness of less than or equal to about 10 nm.

5. The optical lens according to claim 1 , wherein the two high-refractive-index layers are formed of ZrO 2 , TiO 2 or Ta 2 O 5 .

6. The optical lens according to claim 1 , wherein the scratch resistant anti-reflective coating has at least one low-refractive-index layer and/or at least one medium-refractive-index layer.

7. The optical lens according to claim 6 , wherein the at least one low-refractive-index layer is formed of SiO 2 , Al 2 O 3 or MgF 2 .

8. The optical lens according to claim 6 , wherein each of the two high-refractive-index layers 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.

9. The optical lens according to claim 6 , 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.

10. The optical lens according to claim 1 , wherein a hardness of the plurality of layers increases from the hardcoat layer in the direction of the superhydrophobic layer.

11. The optical lens according to claim 1 , 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.

12. The optical lens according to claim 1 , wherein the two high-refractive-index layers have a refractive index of n>1.65.

13. The optical lens according to claim 1 , wherein the optical lens has a reflectance of less than about 2.5% for visible light having a wavelength ranging from 450 nm to 650 nm.

14. The optical lens according to claim 1 , wherein the optical lens has a Bayer value of greater than 20.

15. 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 at least two high-refractive-index layers, wherein a hardcoat layer is formed adjacent to the lens element, wherein a superhydrophobic layer concludes the scratch resistant anti-reflective coating, wherein the at least two high-refractive-index layers have an overall thickness of less than 40 nm, and wherein the scratch resistant anti-reflective coating excluding the hardcoat layer has an overall thickness of more than about 380 nm, wherein the optical lens has a Bayer value of greater than 17, wherein the at least two high-refractive index layers are formed of ZrO 2 or TiO 2 , and wherein the scratch resistant anti-reflective coating has at least one low-refractive-index layer, wherein the at least one low-refractive-index layer comprises one or more materials selected from YbF 3 , YF 3 , a mixture of YbF 3 —CaF 2 , or a mixture YF 3 —BaF 2 .

16. 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 at least two high-refractive-index layers, at least one medium-refractive index layer, and at least one low-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 at least two high-refractive-index layers have an overall thickness of less than 40 nm, the at least two high-refractive index layers are formed of ZrO 2 or TiO 2 and the at least one low-refractive-index layer comprises one or more materials selected from YbF 3 , YF 3 , a mixture of YbF 3 —CaF 2 , or a mixture YF 3 —BaF 2 wherein the scratch resistant anti-reflective coating excluding the hardcoat layer has an overall thickness of more than about 380 nm, and wherein the optical lens has a Bayer value of greater than 17.

17. 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 at least two high-refractive-index layers, wherein a hardcoat layer is formed adjacent to the lens element, wherein a superhydrophobic layer concludes the scratch resistant anti-reflective coating, wherein the at least two high-refractive-index layers have an overall thickness of less than 40 nm, and wherein the scratch resistant anti-reflective coating excluding the hardcoat layer has an overall thickness of more than about 380 nm, wherein the optical lens has a Bayer value of greater than 17, 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 17 , 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.

Assignees

• Zeiss Carl Vision Int Gmbh

Inventors

• Neuffer Andreas

Classifications

• G02B1/115 Primary

  Multilayers · CPC title

• G02B27/0006

  with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation (G02B1/18 takes precedence; cleaning in general B08B) · CPC title

• G02C7/02

  Lenses; Lens systems {; Methods of designing lenses} · CPC title

• G02B1/14 Primary

  Protective coatings, e.g. hard coatings · CPC title

• G02B1/18

  Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films (G02B1/16 takes precedence) · CPC title