| 摘要 |
A method of making a security device, comprising: (a) forming an array of primary focussing elements on a first region of a focussing element support layer, by: (a)(i) applying at least one transparent curable material either to the focussing element support layer or to a casting tool carrying a surface relief over an area which includes at least the first region, the surface relief comprising portions corresponding to the primary focussing elements,; (a)(ii) forming the transparent curable material(s) with the casting tool; and (a)(iii) curing the transparent curable material(s) so as to retain the surface relief in the first region; wherein the surface relief further includes a plurality of structures of greater depth than the height of the primary focussing elements such that the cured transparent material(s) include a plurality of features protruding above the height of the primary focussing elements between primary focussing elements of the array, wherein the surface relief is configured such that more than one of the primary focussing elements of the array space each of the plurality of features from the next. |
