Optical article comprising an interference coating with high reflectivity in the ultraviolet region
View Patent ↗The present invention relates to a transparent ophthalmic lens comprising a substrate having a main front face and a main rear face, said main front face being coated with a multilayer interference coating, preferably an anti-reflection coating, comprising a stack of at least one layer have a refractive index greater than 1.6 and at least one layer having a refractive index less than 1.55, characterized in that: the mean reflection factor on said main front face coated with said interference coating, between 350 nm and a wavelength between 380 and 400 nm, preferably between 350 and 380 nm, weighted by the function W(I), is greater than or equal to 35% for at least one angle of incidence between 0° and 17°; the light reflection factor at 400 nm on said main front face coated with said interference coating is less than or equal to 35% for at least one angle of incidence between 0° and 17°.
1. A transparent ophthalmic lens comprising a substrate having a front main face and a back main face, said front main face being coated with a multilayer interference coating comprising a stack of at least one layer having a refractive index higher than 1.6, called the high-refractive-index layer, and of at least one layer having a refractive index lower than 1.55, called the low-refractive-index layer, and which does not contain titanium, wherein:
the average reflectance of said coated front main face of said interference coating, between 350 nm and a wavelength comprised between 380 and 400 nm, weighted by the function W(λ), is higher than or equal to 50% at at least one angle of incidence comprised between 0° and 17°; and
the light reflectance at 400 nm of said coated front main face of said interference coating is lower than or equal to 35% at at least one angle of incidence comprised between 0° and 17°.
2. The ophthalmic lens of claim 1 , wherein said multilayer interference coating is an antireflection coating.
3. The ophthalmic lens of claim 1 , wherein the average reflectance of said coated front main face of said interference coating, between 350 nm and a wavelength comprised between 350 and 380 nm, weighted by the function W(λ), is higher than or equal to 50% at at least one angle of incidence comprised between 0° and 17°.
4. The ophthalmic lens of claim 1 , wherein said average reflectance of said front main face between 350 nm and a wavelength comprised between 380 and 400 nm is higher than or equal to 65% at at least one angle of incidence comprised between 0° and 17°.
5. The ophthalmic lens of claim 1 , wherein the light reflectance at 400 nm of said coated front main face of said interference coating is lower than or equal to 25% at at least one angle of incidence comprised between 0° and 17°.
6. The ophthalmic lens of claim 5 , wherein the light reflectance at 400 nm of said coated front main face of said interference coating is lower than or equal to 15% at at least one angle of incidence comprised between 0° and 17°.
7. The ophthalmic lens of claim 1 , wherein said multilayer interference coating comprises a number of layers higher than or equal to 3 and a number of layers lower than or equal to 10.
8. The ophthalmic lens of claim 7 , wherein said multilayer interference coating comprises a number of layers higher than or equal to 4 and a number of layers lower than or equal to 8.
9. The ophthalmic lens of claim 8 , wherein said multilayer interference coating comprises a number of layers higher than or equal to 6 and a number of layers lower than or equal to 8.
10. The ophthalmic lens of claim 1 , wherein the one or more high-refractive-index layers of the multilayer interference coating have a refractive index higher than or equal to 1.8.
11. The ophthalmic lens of claim 10 , wherein the one or more high-refractive-index layers of the multilayer interference coating have a refractive index higher than or equal to 1.9.
12. The ophthalmic lens of claim 1 , wherein the light reflected from said coated front main face of said interference coating has a chroma C* lower than or equal to 15 at at least one angle of incidence comprised between 0° and 17°.
13. The ophthalmic lens of claim 12 , wherein the light reflected from said coated front main face of said interference coating has a chroma C* lower than or equal to 10 at at least one angle of incidence comprised between 0° and 17°.
14. The ophthalmic lens of claim 1 , wherein the substrate has a transmittance T higher than or equal to 1% at a wavelength located between 350 nm and 400 nm.
15. The ophthalmic lens of claim 1 , wherein the reflectance in the visible Rv between 380 nm and 780 nm of said coated front main face of said interference coating is lower than or equal to 3%.
16. The ophthalmic lens of claim 15 , wherein the reflectance in the visible Rv between 380 nm and 780 nm of said coated front main face of said interference coating is lower than or equal to 1.5%.
17. The ophthalmic lens of claim 1 , wherein the interference coating comprises, in order starting from the substrate:
a high-refractive-index layer having a refractive index higher than 1.6 of 15 to 39 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 26 to 62 nm thickness;
a high-refractive-index layer having a refractive index higher than 1.6 of 24 to 63 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 52 to 81 nm thickness;
a high-refractive-index layer having a refractive index higher than 1.6 of 24 to 45 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 27 to 64 nm thickness;
a high-refractive-index layer having a refractive index higher than 1.6 of 28 to 58 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 84 to 116 nm thickness.
18. The ophthalmic lens of claim 17 , wherein the interference coating comprises, in order starting from the substrate:
a high-refractive-index layer having a refractive index higher than 1.6 of 15 to 35 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 42 to 62 nm thickness;
a high-refractive-index layer having a refractive index higher than 1.6 of 24 to 44 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 61 to 81 nm thickness;
a high-refractive-index layer having a refractive index higher than 1.6 of 25 to 45 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 27 to 57 nm thickness;
a high-refractive-index layer having a refractive index higher than 1.6 of 30 to 58 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 84 to 114 nm thickness.
19. The ophthalmic lens of claim 18 , wherein the interference coating further comprises an electrically conductive layer of 3 to 10 nm thickness between the a high-refractive-index layer having a refractive index higher than 1.6 of 30 to 58 nm thickness and the low-refractive-index layer having a refractive index lower than 1.55 of 84 to 114 nm thickness.
20. The ophthalmic lens of claim 17 , wherein the interference coating comprises, in order starting from the substrate:
a high-refractive-index layer having a refractive index higher than 1.6 of 19 to 39 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 26 to 46 nm thickness;
a high-refractive-index layer having a refractive index higher than 1.6 of 43 to 63 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 52 to 72 nm thickness;
a high-refractive-index layer having a refractive index higher than 1.6 of 24 to 44 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 44 to 64 nm thickness;
a high-refractive-index layer having a refractive index higher than 1.6 of 28 to 48 nm thickness;
a low-refractive-index layer having a refractive index lower than 1.55 of 95 to 116 nm thickness.
21. The ophthalmic lens of claim 20 , wherein the interference coating further comprises an electrically conductive layer of 3 to 10 nm thickness between the high-refractive-index layer having a refractive index higher than 1.6 of 28 to 48 nm thickness and the low-refractive-index layer having a refractive index lower than 1.55 of 95 to 116 nm thickness.
22. The ophthalmic lens of claim 17 , wherein the interference coating further comprises an electrically conductive layer of 3 to 10 nm thickness between the high-refractive-index layer having a refractive index higher than 1.6 of 28 to 58 nm thickness and the low-refractive-index layer having a refractive index lower than 1.55 of 84 to 116 nm thickness.
23. The ophthalmic lens of claim 1 , wherein the reflectance in the UV R uv , of said back main face between 280 nm and 380 nm, weighted by the function W(λ), is lower than or equal to 10% at an angle of incidence of 35°.
24. The ophthalmic lens of claim 23 , wherein the reflectance in the UV R uv , of said back main face between 280 nm and 380 nm, weighted by the function W(λ), is lower than or equal to 5% at an angle of incidence of 35°.
25. The ophthalmic lens of claim 1 , wherein the ESPF coefficient of the lens is higher than 10.
26. A process for manufacturing an ophthalmic lens of claim 1 , wherein the multilayer interference coating is vacuum deposited.