Process and apparatus for manufacturing auto-collimating phosphors

A process for forming an anisotropic, auto-collimating imaging screen using vapor deposition techniques, which comprises:

• a) positioning an imaging screen substrate on a substrate fixture;
• b) positioning said substrate fixture in a vapor deposition chamber having a vapor generator, said substrate fixture being positioned at an oblique angle to said vapor generator;
• c) introducing phosphor constituents into said vapor generator capable of forming a vapor of said phosphor constituents;
• d) placing said chamber under an inert atmosphere;
• e) activating said vapor generator to form an ingot pool of said -phosphor constituents and, thereby generate said vapor of said phosphor constituents;
• f) directing said vapor of said phosphor constituents towards said substrate fixture;
• g) maintaining a constant height of said ingot pool of said phosphor constituents in said vapor generator;
• and
• h) rotating said substrate fixture for a time sufficient to effect deposition of a phosphor complex on said imaging screen substrate to thereby form said anisotropic, auto-collimating imaging screen.