Claims
- 1. A lens element comprising
a lens substrate; and a coating carried by said lens substrate, wherein the coating includes a first dielectric layer closest to the lens substrate and a second dielectric layer formed on said first dielectric layer, wherein said first dielectric layer is formed of CrxOy, and wherein the ratio of y to x is less than 3 to 2 and wherein the first dielectric layer is between 3 and 80 nm in thickness.
- 2. The lens element of claim 1, wherein the first dielectric layer is formed by evaporating Cr at a controlled rate in the presence of a controlled amount of oxygen insufficient to completely oxidize the deposited chromium.
- 3. The lens element of claim 1, wherein at least three dielectric interfaces produce significant reflection from the lens element, the three interfaces being defined by the first and second dielectric layers and dielectric material immediately adjacent to the first and second dielectric layers.
- 4. The lens element of claim 3, wherein the second dielectric layer is an oxide of silicon which forms the outermost layer of the coating and wherein one of said dielectric interfaces lies at a boundary between the second dielectric layer and air.
- 5. The lens element of claim 3, further comprising a polymer hardcoat layer on the substrate, and wherein one of said dielectric interfaces lies at a boundary between the hardcoat layer and first dielectric layer, wherein the second dielectric interface lies at a boundary between the first dielectric layer and the second dielectric layer, and wherein the third dielectric interface lies at a boundary between the second dielectric layer and air.
- 6. The lens effect of claim 5, wherein the index of refraction of the polymer hardcoat layer is about 1.50, the index of refraction of the first dielectric layer is greater than about 2 and the index of refraction of the second dielectric layer is about 1.5
- 7. The lens element of claim 1, wherein the index of refraction of the first dielectric layer is greater than about 2.
- 8. The lens element of claim 1, wherein the index of refraction of the first dielectric layer is about 2.15.
- 9. The lens element of claim 1, wherein the index of refraction of the second dielectric layer is about 1.5.
- 10. The lens element of claim 1, wherein the coating further comprises:
a third dielectric layer located on the second dielectric layer, said third dielectric layer being formed of CrxOy, wherein the ratio of y to x is less than 3 to 2; and a fourth dielectric layer located on the third dielectric layer, said fourth dielectric layer being formed of an oxide of silicon.
- 11. A coating for a spectacle lens element comprising:
a relatively thin adhesion layer including a first material deposited on a surface of the lens element; a first dielectric layer including a second material having a refraction index substantially greater than the refraction index of lens element at said surface, wherein the second material is selected from the group of CrxOy, TiO2, ZnSe, ZnS and mixtures thereof and wherein x is a number between 1 and 2 and y is a number between 1 and 3; and a second dielectric layer including a third material having a refraction index substantially lower than the refraction index of said second material.
- 12. The coating of claim 11, further comprising:
a third dielectric layer including said second material; and a fourth dielectric layer of a material having a refraction index lower than the refraction index of the material of the third dielectric layer.
- 13. The coating of claim 11, wherein the first material is Cr, the second material is CrxOy and the third material is an oxide of Silicon.
- 14. The coating of claim 11, wherein the lens element includes a lens substrate made of a glass or a plastic having a refraction index a 500 nm between 1.38 and 1.75.
- 15. The coating of claim 14, wherein the coating further comprises:
a primer coating; and a polymer hardcoat layer which forms the surface on which the thin adhesion layer is deposited.
- 16. The coating of claim 14, characterized in that said plastic is selected from the group comprising: acrylic-based polymers and copolymers, polymethylmethacrylate, polycarbonate, polyol-allyl-carbonates, cellulose esters, polyacrylates, polystyrene, polyurethanes.
- 17. The coating of claim 11, characterized in that the layer including said first material has a thickness between 0.5 and 5 nm.
- 18. The claim 11, characterized in that the layer including said second material has a thickness between 3 and 80 nm.
- 19. The coating of claim 11, characterized in that the layer including said third material has a thickness between 5 and 400 nm.
- 20. The coating of claim 11, characterized in that said first material is selected from the group of Cr, Ti, SiO, SiO2, In2O3, SnO2 and mixtures thereof.
- 21. The coating of claim 11, characterized in that said second material has a refraction index between 1.7 and 2.7.
- 22. The coating of claim 11, characterized in that said third material has a refraction index between 1.32 and 1.8.
- 23. The coating of claim 11, characterized in that said third material is selected from the group of SiO, Sio2, MgF2, Na5Al3F14, and mixtures thereof.
- 24. The coating of claim 11, wherein the coated lens element is in the form of lens or visor for glasses.
- 25. The coating of claim 11, wherein the coated lens element is in the form of a lens blank or protective shield.
- 26. A method for forming, on a lens element, the coating of claim 11, comprising the steps of:
a) placing said lens element in a sealed chamber; b) bringing said chamber to a predetermined vacuum degree; c) activating the surface of said lens element by means of ion discharge in an oxygen-containing environment for a predetermined period of time; d) depositing in substantial absence of oxygen the first material on the lens element so as to form an adhesion layer having a predetermined thickness; e) depositing, at a controlled rate, the first dielectric layer on said adhesion layer by evaporating a metal in the presence of oxygen; and f) depositing, on said first dielectric layer the third material having a refraction index lower than the refraction index of said second material, so as to form a layer having a predetermined thickness.
- 27. The method of claim 26, wherein the adhesion layer is evaporated Cr deposited sufficiently thinly so as to have no appreciable effect on the optical properties of the coated lens element, wherein the first dielectric layer is incompletely oxidized CrxOy and wherein the second dielectric layer is an oxide of silicon.
- 28. The method of claim 26, wherein said steps d), e), f) are carried out by evaporating said first, second and third material by means of the Joule effect.
- 29. Method according to claim 26, wherein each of said steps d), e), f) is preceded by a step of pre-heating the materials to be evaporated at a predetermined temperature.
- 30. Method according to claim 26, wherein said step e) is carried out so as to have a deposition rate of said second material onto the lens element of between 0.05 and 0.15 nm/s.
Priority Claims (1)
Number |
Date |
Country |
Kind |
00114611.7 |
Jul 2000 |
EP |
|
Parent Case Info
[0001] This application is a continuation-in-part of PCT/EP01/07170 filed on Jun. 25, 2001 in English which designates the United States.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
PCT/EP01/07170 |
Jun 2001 |
US |
Child |
10122353 |
Apr 2002 |
US |