Abstract:
A high contrast cathode ray tube which incorporates a phosphor material responsive to electronic bombardment and generates ultraviolet radiations in response thereto and in which the ultraviolet phosphor is provided on the inner surface of a fiber optic window. Positioned on the outer surface of the fiber optic faceplate is an ultraviolet transmitting, visible absorbing filter with an organic phosphor emitting visible light in response to ultraviolet excitation and a visible transmitting, ultraviolet absorbing filter provided on the outer surface of the organic phosphor.