PROJECTION CATHODE RAY TUBE

摘要

A projection cathode ray tube (CRT) includes a multilayered interference film interposed between a face plate pane and luminescent material layer. This multilayered interference film is composed of alternately superimposed of high refractive index material layers and low refractive index material layers, and the number of layers to be superimposed is four or five. By using a multilayered interference film of only four or five layers, the interference layer is not subject to cracks or film separation occurring during heat processing, due to the difference in thermal expansion coefficients between high and low refractive index material. Further, there still remains enough layers to produce a display highly improved in brightness in the direction of the normal of the face plate pane of the CRT.