Patent ID: 8908276

Claim:
A moiré magnification device comprising a transparent substrate carrying: i) a regular array of micro-focusing elements on a first surface, the focusing elements defining a focal plane; ii) a corresponding first array of microimage elements in a first colour and located in a plane substantially coincident with the focal plane of the focusing elements; and, a corresponding second array of microimage elements, in a second colour different from the first colour, and located in a plane substantially coincident with the focal plane of the focusing elements, wherein the pitches of the micro-focusing elements and first and second arrays of microimage elements and their relative locations are such that the array of micro-focusing elements cooperates with each of the first and second arrays of microimage elements to generate respective magnified versions of the microimage elements of each array due to the moiré effect and such that the magnified version of the first array of microimage elements is viewed against a background defined by the magnified version of the second array of microimage elements, the magnified version of the first array of microimage elements exhibiting movement relative to the background when the device is tilted, and wherein the pitch mismatch between the arrays is chosen such that the magnified version of the elements of the first array appears above or below the magnified version of the elements of the second array.