Multilayer interference filter for photochromic lenses
A multi-layer thin film is provided preferably for use with photochromic lenses, wherein the thin film comprises a plurality of layers, preferably including dielectric layers, selected and arranged so as to reflect less than about 6 percent of the UVA rays in a range of about 315 to 400 nm, more preferably about 350 to 380 nm. The thin film preferably has an activation value greater than 25%.
1. A light transmitting photochromic lens comprising photochromic dyes and having a visible colored appearance, the photochromic lens further comprising a multi-layer thin film coating applied on an outer surface thereof, the multi-layer thin film coating comprising a plurality of dielectric layers, wherein the film coating reflects an amount less than about 15% of spectral ultraviolet radiation in a range between 315 and 400 nm and reflects an amount equal to or greater than about 10% of light in the visible spectrum in a range between 410 and 800 nm so that the lens exhibits the visible colored appearance.
2. The lens of claim 1 , wherein the colored appearance comprises a mirror like appearance.
3. The lens of claim 1 , wherein the colored appearance comprises a white silver like appearance.
4. The lens of claim 1 , wherein the multi-layer thin film coating reflects less than 6% of spectral ultraviolet radiation.
5. The lens of claim 1 , wherein the plurality of dielectric layers comprises SiO 2 layers.
6. The lens of claim 1 , wherein the plurality of dielectric layers comprises TiO 2 layers.
7. The lens of claim 1 , wherein the plurality of dielectric layers are arranged to alternate low and high refractive indices.
8. The lens of claim 1 , wherein the plurality of dielectric layers comprises ZrO 2 layers.
9. The lens of claim 1 , wherein the plurality of dielectric layers comprises twelve layers.
10. The lens of claim 9 , wherein the multi-layer thin film coating comprises a twelve layer arrangement comprising alternating TiO 2 and SiO 2 layers.
11. The lens of claim 10 , wherein the dielectric layers are selected and arranged in a sequence: TiO2, SiO2, TiO2, SiO2, TiO2, SiO2, TiO2, SiO2, TiO2, SiO2, TiO2, SiO2, so as to obtain a silver mirror like appearance of the lens.
12. The lens of claim 9 , wherein the multi-layer thin film coating comprises a twelve layer arrangement comprising TiO 2 , SiO 2 and ZrO 2 layers.
13. The lens of claim 12 , wherein the dielectric layers are selected and arranged in a sequence: TiO 2 , SiO 2 , TiO 2 , SiO 2 , ZrO 2 , SiO2, TiO2, SiO2, TiO2, SiO2, ZrO2, SiO2, so as to obtain a silver mirror like appearance of the lens.
14. The lens of claim 1 , wherein the plurality of dielectric layers comprises up to 100 layers.
15. The lens of claim 1 , the lens having a photochromic range of greater than about 25%.
16. The lens of claim 1 , the lens having a photochromic range of greater than about 40%.
17. The lens of claim 1 , the lens having a photochromic range of greater than about 90%.
18. The lens of claim 1 , the lens having a photochromic range of greater than about 97%.
19. The lens of claim 1 , the lens having a photochromic range of approximately the activation value of the uncoated photochromic lens.
20. The lens of claim 1 , wherein the lens is a sunglass lens.
21. A method of creating a light transmitting colored photochromic lens comprising photochromic dyes, the method comprising forming a photochromic lens part and applying a plurality of dielectric layers onto the outer surface of the photochromic lens part wherein the plurality of dielectric layers collectively reflect an amount less than about 15% of spectral ultraviolet radiation in a range between 315 and 400 nm and reflect an amount equal to or greater than about 10% of light in the visible spectrum in a range between 410 and 800 nm so that the lens exhibits a visible colored appearance.
22. The method of claim 21 , further comprising applying a twelve layer arrangement comprising alternating TiO 2 and SiO 2 layers.
23. The method of claim 22 , further comprising applying twelve layers of TiO2 and SiO2 on the photochromic lens in a sequence: TiO2, SiO2, TiO2, SiO2, TiO2, SiO2, TiO2, SiO2, TiO2, SiO2, TiO2, SiO2, in order to obtain a silver mirror like appearance.
24. The method of claim 21 , further comprising applying a twelve layer arrangement comprising TiO 2 , SiO 2 and ZrO 2 layers.
25. The method of claim 24 , further comprising applying twelve layers of TiO2, SiO2 and ZrO2 on the photochromic lens in a sequence: TiO2, SiO2, TiO2, SiO2, ZrO2, SiO2, TiO2, SiO2, TiO2, SiO2, ZrO2, SiO2, in order to obtain a white silver like appearance.