Optical device and method for manufacturing same
A method for manufacturing a structured optical device ( 1 ) starts with a substrate ( 2 ), on which is coated an alignment layer ( 3 ) and a liquid crystal polymer network layer ( 4 ). One of these layers can be created as a coating using a conventional technique. The other layer, either in a first step the alignment layer or in a second step the liquid crystal polymer network layer, is jet printed. The invention advantageously enables the making of a patterned liquid crystal polymer network which can be personalized upon manufacturing.
1. A method for manufacturing a liquid crystal polymer network having a pattern structure, comprising:
providing a substrate;
jet printing a first alignment layer, which comprises a material to which an aligning property can be imparted by exposure to polarized light, in a first pattern onto the substrate;
exposing the first alignment layer to a first polarized light;
coating the substrate bearing the alignment layer with a first layer comprising a cross-linkable liquid crystal material;
allowing the liquid crystal material to align; and
cross-linking the liquid crystal material.
2. A method according to claim 1 , further comprising:
jet printing a second alignment layer, which comprises a material to which an aligning property can be imparted by exposure to polarized light, in a second pattern on or adjacent to the first alignment layer; and
exposing the second alignment layer to a second polarized light having a polarization different from the first polarized light.
3. A method according to claim 1 , wherein the first alignment layer covers a first area creating an image element and wherein the first layer comprising a cross-linkable liquid crystal material covers a second area including at least said image element.
4. A method according to claim 2 , further comprising:
jet printing at least one further alignment layer in at least one further pattern adjacent the first and the second alignment layers; and
exposing the at least one further alignment layer to a further polarized light.
5. A method according claim 4 , wherein data representing the first, second, and further patterns are stored in a memory of a computer system and wherein the computer system controls jet printing of the alignment layer and wherein the computer system further controls coating of the cross-linkable liquid crystal onto the substrate.
6. A method according to claim 4 , wherein at least one of the first, second, and further alignment layers comprises a layer containing a linearly photopolymerisable material.
7. A method according to claim 4 , wherein the first, second, and further polarized lights to which the first, second, and further alignment layers are exposed is selected from one of linearly and elliptically polarized.
8. A method according to claim 1 , wherein the jet printing is selected from one of a piezo jet printing method and a bubble jet printing method.
9. An optical device comprising a liquid crystal polymer network having a pattern structure manufactured according to claim 1 .
10. An optical device according to claim 9 , which is an optical security device.
11. A method according to claim 1 , wherein at least one layer comprising a cross-linkable liquid crystal material further comprises at least one dichroic dye.
12. A method for manufacturing a liquid crystal polymer network having a pattern structure, comprising:
providing a substrate comprising a first alignment layer;
jet printing a first layer comprising a cross-linkable liquid crystal material in a first pattern;
allowing the liquid crystal material to align; and
cross-linking the liquid crystal material.
13. A method according to claim 12 , wherein the first alignment layer comprises at least a second pattern.
14. A method according to claim 12 , further comprising:
producing the first alignment layer by one of embossing, etching, and scratching.
15. A method according to claim 12 , further comprising:
jet printing a second alignment layer, which comprises a material to which an aligning property can be imparted by exposure to polarized light, in a second pattern on or adjacent to the first alignment layer; and
exposing the second alignment layer to a polarized light such that the second alignment layer is oriented in a direction different to the orientation of the first alignment layer.
16. A method according to claim 12 , wherein at least two additional layers comprising a cross-linkable liquid crystal material are jet printed adjacent to each other.
17. A method according to claim 12 , further comprising:
jet printing at least one further alignment layer, which comprise a material to which an aligning property can be imparted by exposure to polarized light, on at least one of the already existing layers comprising a cross-linkable liquid crystal material;
exposing the at least one further alignment layer to polarized light;
jet printing at least one further layer comprising a cross-linkable liquid crystal material; and
cross-linking the at least one further layer comprising a cross-linkable liquid crystal material.
18. A method according to claim 12 , wherein the first alignment layer covers an area creating an image element and wherein the first layer comprising a cross-linkable liquid crystal material covers a second area encompassing at least said image element.
19. A method according to claim 12 , wherein the first layer comprising a cross-linkable liquid crystal material covers an area creating an image element on the first alignment layer covering a bigger area encompassing at least said image element.
20. A method according to claim 13 , wherein data representing the first and at least second patterns are stored in a memory of a computer system and wherein the computer system controls the jet printing of the cross-linkable liquid crystal material.
21. A method according to claim 15 , wherein at least one alignment layer comprises a layer containing a linearly photopolymerisable material.
22. A method according to claim 15 , wherein the first and the second polarized light are selected from one of linearly and elliptically polarized light.
23. A method according to claim 12 , wherein at least one layer comprising a cross-linkable liquid crystal material further comprises at least one dichroic dye.
24. A method according to claim 12 , wherein the jet printing is selected from a piezo jet printing method and a bubble jet printing method.
25. An optical device comprising a liquid crystal polymer network having a pattern structure manufactured according to claim 12 .
26. An optical device according to claim 25 , which is an optical security device.