Method of forming a bistable watermark
View Patent ↗A watermark formed of a bistable material, and a method of forming the watermark, are described.
1. A method of forming a material comprising a watermark area, wherein the method comprises:
forming the watermark area comprising
a substrate and
a layer of bistable material on the substrate;
wherein the layer of bistable material comprises an imagewise pattern, the imagewise pattern comprising areas of the bistable material and areas of a filling material between the areas of bistable material, the filling material comprises the bistable material and a second bistable material, the second bistable material is different from the bistable material, and
the filling material does not react or interact with the areas of bistable material; and
joining the watermark area with the material.
2. The method of claim 1 , further comprising applying energy to the bistable material of the watermark area to form an imagewise pattern in the layer of bistable material.
3. The method of claim 2 , wherein the imagewise pattern is permanent.
4. The method of claim 2 , wherein the imagewise pattern is permanent and hideable.
5. The method of claim 2 , wherein the watermark area is incorporated into the material before forming the imagewise pattern.
6. The method of claim 1 , wherein the bistable material comprises one or more of an electrochemical material, an electrophoretic material, an electrochromic material, a magnetic material, a ferroelectric material, a nematic liquid crystal material, or a chiral nematic liquid crystal material.
7. The method of claim 1 , wherein the bistable material is a polymer dispersed chiral nematic liquid crystal material.
8. The method of claim 1 , wherein the filling material is gelatin.
9. The method of claim 1 , wherein the filling material is a different thickness than the bistable material.
10. The method of claim 1 , wherein the material is paper, synthetic paper, cloth, packaging material, a tag, an electronic display, or an electronic document.
11. The method of claim 1 , wherein joining the watermark area with the material comprises adhering the watermark area onto the material.
12. The method of claim 1 , wherein joining the watermark area with the material comprises incorporating the watermark area into the material.
13. A method of forming a material comprising a watermark area, wherein the method comprises:
forming the watermark area comprising
a substrate and
a layer of bistable material on the substrate;
wherein the layer of bistable material comprises an imagewise pattern, the imagewise pattern comprising areas of the bistable material and areas of a filling material between the areas of bistable material, and
the filling material comprises the bistable material and a second bistable material, the second bistable material is different from the bistable material; and
joining the watermark area with the bistable material.
14. A method of forming a material comprising a watermark area, wherein the method comprises:
forming the watermark area comprising
a substrate and
a layer of bistable material on the substrate;
wherein the layer of bistable material comprises an imagewise pattern, the imagewise pattern comprising areas of the bistable material and areas of a filling material between the areas of bistable material, and
the filling material is gelatin; and
joining the watermark area with the bistable material.