Patent ID: 7862880

Claim:
A film comprising: at least one anisotropic polymer layer of an at least partially oriented liquid crystal material, wherein the at least one anisotropic polymer layer includes at least one first region which forms a first security feature responsive to linearly polarized light, the at least one anisotropic polymer layer further includes at least one second region which forms a second security feature responsive to elliptically polarized light, wherein the first security feature is visualised when viewed through a first polariser and the second security feature is visualised when viewed through a second polarizer, wherein the first polarizer is responsive to a different polarisation state of an incident light than the second polarizer, wherein the film includes at least one replication layer to which the anisotropic polymer layer is applied and in which a diffractive structure for orientation of the anisotropic polymer layer is introduced into the surface of the replication layer, wherein the diffractive structure is formed from a superimposition of a first structure for orientation of the liquid crystal material and a second structure for adjusting at least one of the polarized light responses, wherein the first structure is a line grating with a spatial frequency of 1500 lines/mm to 3500 lines/mm and a depth of 50 nm to 500 nm.