| 摘要 |
The optically variable image in optically variable imaging devices, such as holograms, kinegrams, pixelgrams and interference gratings, is enhanced by coating the image relief or interference pattern with a thin film of a synthesized high oxygen content oxide of bismuth wherein the atomic ratio of oxygen to bismuth is 1.7 or greater, i.e., BiOx (x=>1.7). A process for applying a thin film of the synthesized high oxygen content BiOx to the relief or interference pattern comprises reactive deposition of bismuth in an oxygen partial pressure atmosphere wherein the oxygen partial pressure and the dynamic deposition rate are correlated to achieve the desired degree of oxidation of the bismuth. The process also lends itself to dynamic deposition of other image enhancing materials, as well as protective coatings for the image enhancing materials. |
