| abstract |
A security device 10 for security documents comprise an at least partially light transmitting spacer layer 11, on one side of which are formed at least two images 12, 13. Each image comprises a plurality of repeating elements 12, 13with the elements of one image alternating with the elements of the other image. Each image is formed from a material which emits a coloured visible light when excited by a form of radiation, the colours of light radiated by the images being different from each other. On an opposing side of the spacer layer is an absorbing material 14, which absorbs the said radiation but not visible light. The absorbing material is applied in a pattern comprising a plurality of repeating elements similar to the elements of the images and having gaps 17 between the elements. |