Photochromic security system.

摘要

The present invention is directed to a security document which includes a photochromic security system. The photochromic security system comprises a photochrome and a sensitizer which causes the photochrome to colorize at a wavelength of electromagnetic radiation emitted by an image processing device. Desirably, the photochromic system of the present invention will undergo a color change and/or a change in optical density from about 300 nm to about 500 nm.