Optical article comprising an antireflective coating with a low reflection both in the ultraviolet region and in the visible region

Patent metadata

Field	Value
Publication number	US-10317577-B2
Application number	US-201515504481-A
Country	US
Kind code	B2
Filing date	Aug 17, 2015
Priority date	Aug 18, 2014
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

An ophthalmic lens with a low reflection in both the ultraviolet region and the visible region is disclosed. The ophthalmic lens comprises a substrate with a front main face and a rear main face. The rear main face is coated with a multilayered antireflective coating. The antireflective coating comprises a stack of at least one layer having a refractive index higher than 1.6 and of at least one layer having a refractive index lower than 1.55. The mean reflection factor Ruv on the rear face between 280 nm and 380 nm, weighted by the function W(λ), is lower than or equal to 5%, preferably is lower than or equal to 4%, for an angle of incidence of 35°. The Chroma C* of reflected light is equal to or lower than 4, preferably lower or equal to 3, for an angle of incidence (θ) of 15°.

First claim

The invention claimed is:

1. An ophthalmic lens comprising a transparent substrate with a front main face and a rear main face, said rear main face being coated with a multilayered antireflective coating comprising a stack of at least one layer having a refractive index higher than 1.6 and of at least one layer having a refractive index lower than 1.55, wherein:
a mean reflection factor R UV on said rear face between 280 nm and 380 nm, weighted by a function W(λ), is lower than or equal to 5%, for an angle of incidence of 35°; and
a Chroma C* of reflected light for an angle of incidence (θ) of 15° is equal or lower than 4, and
wherein said antireflective coating is substantially achromatic.

2. The lens according to claim 1 , wherein the mean reflection factor R UV on said rear face between 280 nm and 380 nm, weighted by the function W(λ), is lower than or equal to 4%, for an angle of incidence of 35°.

3. The lens according to claim 1 , wherein the Chroma C* of reflected light for an angle of incidence (θ) of 15° is lower or equal to 3.

4. The lens according to claim 1 , wherein the Chroma C* of reflected light for an angle of incidence (θ) of 15° is located in the area of a L*a*b* space defined by:
−3<=a*<=1 and −4<=b*<=1 and (a*+b*)>=−5.

5. The lens according to claim 1 , wherein the Chroma C* of reflected light measured on two separated points of the same lens differs by less than 2.

6. The lens according to claim 1 , wherein the multilayered antireflective coating comprises a number of layers higher than or equal to 3 and lower than or equal to 7.

7. The lens according to claim 6 , wherein the multilayered antireflective coating comprises a number of layers higher than or equal to 4 and lower than or equal to 6.

8. The lens according to claim 1 , wherein the mean reflection factor on said rear face in a visible region R m is lower than or equal to 3%, for an angle of incidence lower than or equal to 35°.

9. The lens according to claim 8 , wherein the mean reflection factor on said rear face in the visible region R m is lower than or equal to 2.5%, for an angle of incidence lower than or equal to 35°.

10. The lens according to claim 1 , wherein the mean light reflection factor on said rear face in a visible region R v is lower than or equal to 2%, for an angle of incidence lower than or equal to 35°.

11. The lens according to claim 10 , wherein the mean light reflection factor on said rear face in the visible region R v is lower than or equal to 1.5%, for an angle of incidence lower than or equal to 35°.

12. The lens according to claim 1 , wherein the antireflective coating is deposited on a silica-based sub-layer layer having a thickness of from 100 to 300 nm.

13. The lens according to claim 1 , wherein the antireflective coating comprises at least two layers having a refractive index higher than 1.6 and at least two layers having a refractive index lower than 1.55.

14. The lens according to claim 1 , wherein the antireflective coating comprises at least one electrically conductive layer.

15. The lens according to claim 1 , wherein the antireflective coating comprises, in the direction moving away from the substrate, a layer having a refractive index higher than 1.6 with a thickness of from 8 to 25 nm, a layer having a refractive index lower than 1.55 with a thickness of from 15 to 40 nm, a layer having a refractive index higher than 1.6 with a thickness of from 80 to 115 nm, optionally an electrically conductive layer with a thickness of from 3 to 10 nm, and a layer having a refractive index lower than 1.55, with a thickness of from 65 to 95 nm.

16. The lens according to claim 15 , wherein the antireflective coating comprises, in the direction moving away from the substrate, a layer having a refractive index higher than 1.6 with a thickness of from 8 to 25 nm, a layer having a refractive index lower than 1.55 with a thickness of from 15 to 40 nm, a layer having a refractive index higher than 1.6 with a thickness of from 85 to 110 nm, optionally an electrically conductive layer with a thickness of from 3 to 10 nm, and a layer having a refractive index lower than 1.55, with a thickness of from 65 to 95 nm.

17. The lens according to claim 15 , wherein the antireflective coating comprises, in the direction moving away from the substrate, a layer having a refractive index higher than 1.6 with a thickness of from 10 to 18 nm, a layer having a refractive index lower than 1.55 with a thickness of from 25 to 35 nm, a layer having a refractive index higher than 1.6 with a thickness of from 95 to 110 nm, optionally an electrically conductive layer with a thickness of from 3 to 10 nm, and a layer having a refractive index lower than 1.55, with a thickness of from 75 to 85 nm.

18. The lens according to claim 15 , wherein the antireflective coating comprises, in the direction moving away from the substrate, a layer having a refractive index higher than 1.6 with a thickness of from 18 to 25 nm, a layer having a refractive index lower than 1.55 with a thickness of from 15 to 25 nm, a layer having a refractive index higher than 1.6 with a thickness of from 85 to 95 nm, optionally an electrically conductive layer with a thickness of from 3 to 10 nm, and a layer having a refractive index lower than 1.55, with a thickness of from 70 to 90 nm.

19. The lens according to claim 1 , wherein said ophthalmic lens is substantially achromatic.

Assignees

• Essilor Int
• Essilor Int

Inventors

• Bolshakov Ilya

Classifications

• G02C7/107

  Interference colour filters · CPC title

• G02B5/283

  designed for the ultraviolet · CPC title

• G02B1/115 Primary

  Multilayers · CPC title

• G02C2202/16

  Laminated or compound lenses · CPC title

• G02C7/022

  Ophthalmic lenses having special refractive features achieved by special materials or material structures (G02C7/049 takes precedence) · CPC title