Patent ID: 6204971
Filing Date: 2001-03-20
Classification: C03C,G03B,Y10T

Abstract:
A projection screen comprising a plurality of glass microspheres in optical contact with a substrate and embedded in an opaque matrix;wherein the glass microspheres:have an index of refraction of no greater than about 1.70;comprise, on a theoretical oxide basis based on the amount of starting materials:greater than about 5 wt-% of an alkali metal oxide selected from the group consisting of Na.sub.2 O, K.sub.2 O, Li.sub.2 O, and mixtures thereof;no greater than about 40 wt-% SiO.sub.2 ; andno less than about 10 wt-% TiO.sub.2 ; andas produced have less than about 15% defects in a population.