Security device having optically variable device portion and method of making the same
A security device includes a liquid crystal layer having one of a cholesteric phase, a nematic phase, and a cholesteric phase and having molecules therein aligned volumetrically in a predetermined manner to form a predetermined diffractive optical pattern or image. The molecules of the liquid crystal layer are volumetrically aligned in the predetermined manner through at least a portion of the thickness of the liquid crystal layer.
1. A security device comprising:
a liquid crystal layer having one of a smectic phase, a nematic phase, and a cholesteric phase and having molecules therein aligned volumetrically in a predetermined manner to form a predetermined diffractive optical pattern or image,
wherein the molecules of the liquid crystal layer are volumetrically aligned in the predetermined manner through at least a portion of the thickness of the liquid crystal layer.
2. The security device of claim 1 , wherein the liquid crystal has a cholesteric phase.
3. The security device of claim 1 , further comprising:
a substrate layer disposed on the liquid crystal layer.
4. The security device of claim 3 , wherein the substrate layer is disposed directly on the liquid crystal layer and comprises a material that causes spontaneous alignment of the liquid crystal layer.
5. The security device of claim 3 , further comprising:
a primer layer disposed directly on the liquid crystal layer and between the liquid crystal layer and the substrate layer,
wherein the primer layer comprises a material that causes spontaneous alignment of the liquid crystal layer.
6. The security device of claim 1 , further comprising:
an adhesive layer configured to attached the optically variable device to an article.
7. The security device of claim 6 , further comprising:
an opaque layer disposed between the liquid crystal layer and the adhesive layer.
8. The security device of claim 1 , wherein the molecules of the liquid crystal layer are volumetrically aligned in the predetermined manner through the full thickness of the liquid crystal layer.