Patent ID: 7931305

Claim:
A security document comprising a first transparent window in which a first optical element is arranged and a second transparent window in which a second optical element is arranged, wherein the first transparent window and the second transparent window are arranged on a carrier of the security document in mutually spaced relationship in such a way that the first and the second optical elements can be brought into overlapping relationship with each other, and wherein the first optical element has a first transmissive microlens field comprising an array of microlenses having a lens spacing and the second optical element has a second transmissive microlens field comprising an array of microlenses having a lens spacing, wherein the lens spacing of the microlenses of the first and second microlens fields is less than 300 μm and a first optical effect is produced upon overlap of the second microlens field with the first microlens field, and wherein the first microlens field has a region in which the optical axes of the microlenses of the first microlens field are spaced in parallel relationship in accordance with a first periodic raster at a constant lens spacing and the second microlens field has a region in which the optical axes of the microlenses of the second microlens field are spaced in parallel relationship in accordance with a second periodic raster at a constant lens spacing, and wherein the constant lens spacing of the lenses of the first microlens field differs from the constant lens spacing of the microlenses of the second microlens field.