Cathode ray tube having a fluorescent layer with varying amounts of silica

摘要

A cathode ray tube having a face plate including a fluorescent screen formed on the inner surface of the face plate. A conventional metal backing layer backs up the fluorescent screen. The improvements of the present invention are involved with the composition of the fluorescent material composition which includes fluorescent particles and not less than 0.6 parts by weight of SiO2 per 100 parts by weight of fluorescent particles in that portion of the material which contacts the face plate, the amount of SiO2 being insufficient to cause the brightness of the fluorescent particles to deteriorate, and not more than 0.3 parts by weight of SiO2 per 100 parts by weight of fluorescent particles in that portion of the fluorescent material which faces the metal backing layer.