Low reflectance removable lens stack
A removable lens stack includes a base layer, a first removable lens layer, and a second removable lens layer. The base layer may include a substrate and a moth eye coating. The first removable lens layer may include a substrate, a single or multi-layer interference antireflective coating on a first side of the substrate, and a fluoropolymer coating on a second side of the substrate. The first removable lens layer may be stacked on top of the base layer with the fluoropolymer coating being molded to fit the moth eye coating. The second and any subsequent removable lens layer may include a substrate, a single or multi-layer interference antireflective coating on a first side of the substrate, and an acrylic or polyurethane adhesive on a second side of the substrate. The second removable lens layer may be stacked on top of the first removable lens layer and so on.
1. A removable lens stack comprising:
a base layer including a substrate and a moth eye coating on a first side of the substrate;
a first removable lens layer including a substrate, a single or multi-layer interference antireflective coating on a first side of the substrate, and a fluoropolymer coating on a second side of the substrate opposite the first side, the first removable lens layer being stacked on top of the base layer such that the second side of the substrate of the first removable lens layer faces the first side of the substrate of the base layer, the fluoropolymer coating being molded to fit the moth eye coating; and
a second removable lens layer including a substrate, a single or multi-layer interference antireflective coating on a first side of the substrate, and an acrylic or polyurethane adhesive on a second side of the substrate opposite the first side, the second removable lens layer being stacked on top of the first removable lens layer such that the second side of the substrate of the second removable lens layer faces the first side of the substrate of the first removable lens layer.
2. The removable lens stack of claim 1 , wherein the moth eye coating comprises a polymer.
3. The removable lens stack of claim 1 , wherein the moth eye coating defines a pattern of bumps with half-wave pitch.
4. The removable lens stack of claim 1 , wherein the moth eye coating defines a pattern of bumps with half-wave height.
5. The removable lens stack of claim 1 , wherein the moth eye coating defines a pattern of cones.
6. The removable lens stack of claim 1 , wherein the base layer further includes a moth eye coating on a second side of the substrate opposite the first side.
7. The removable lens stack of claim 1 , wherein, in each of the base layer, the first removable lens layer, and the second removable lens layer, the substrate comprises polyethylene terephthalate (PET).
8. The removable lens stack of claim 1 , further comprising a third removable lens layer including a substrate, a single or multi-layer interference antireflective coating on a first side of the substrate, and an acrylic or polyurethane adhesive on a second side of the substrate opposite the first side, the third removable lens layer being stacked on top of the second removable lens layer such that the second side of the substrate of the third removable lens layer faces the first side of the substrate of the second removable lens layer.
9. The removable lens stack of claim 8 , further comprising a fourth removable lens layer including a substrate, a single or multi-layer interference antireflective coating on a first side of the substrate, and an acrylic or polyurethane adhesive on a second side of the substrate opposite the first side, the fourth layer being stacked on top of the third removable lens layer such that the second side of the substrate of the fourth removable lens layer faces the first side of the substrate of the third removable lens layer.
10. The removable lens stack of claim 1 , wherein a peel strength of the first removable lens layer is less than 100 grams per inch.
11. The removable lens stack of claim 10 , wherein the peel strength of the first removable lens layer is between 15 and 50 grams per inch.
12. The removable lens stack of claim 11 , wherein the peel strength of the first removable lens layer is between 15 and 30 grams per inch.
13. The removable lens stack of claim 1 , wherein a visible light transmission (VLT) of the removable lens stack is greater than 95%.
14. The removable lens stack of claim 13 , wherein the VLT of the removable lens stack is greater than 98%.
15. A method of manufacturing a removable lens stack, the method comprising:
providing a base layer including a substrate and a moth eye coating on a first side of the substrate;
stacking a first removable lens layer on top of the base layer, the first removable lens layer including a substrate, a single or multi-layer interference antireflective coating on a first side of the substrate, and a fluoropolymer coating on a second side of the substrate opposite the first side, the first removable lens layer being stacked on top of the base layer such that the second side of the substrate of the first removable lens layer faces the first side of the substrate of the base layer;
laminating the stacked first removable lens layer to the base layer, the fluoropolymer coating being molded to fit the moth eye coating; and
stacking a second removable lens layer on top of the first removable lens layer, the second removable lens layer including a substrate, a single or multi-layer interference antireflective coating on a first side of the substrate, and an acrylic or polyurethane adhesive on a second side of the substrate opposite the first side, the second removable lens layer being stacked on top of the first removable lens layer such that the second side of the substrate of the second removable lens layer faces the first side of the substrate of the first removable lens layer.
16. The method of claim 15 , wherein said laminating comprises laminating the stacked first removable lens layer to the base layer under pressure at a temperature less than 40° C.
17. The method of claim 15 , wherein said laminating is performed prior to said stacking the second removable lens layer on top of the first removable lens layer.
18. The method of claim 15 , further comprising applying a corona treatment between the substrate and the moth eye coating of the base layer.
19. The method of claim 15 , further comprising applying a corona treatment between the substrate and the fluoropolymer coating of the first removable lens layer.
20. The method of claim 15 , further comprising stacking a third removable lens layer on top of the second removable lens layer, the third removable lens layer including a substrate, a single or multi-layer interference antireflective coating on a first side of the substrate, and an acrylic or polyurethane adhesive on a second side of the substrate opposite the first side, the third removable lens layer being stacked on top of the second removable lens layer such that the second side of the substrate of the third removable lens layer faces the first side of the substrate of the second removable lens layer.