Blue luminescent cathode ray tube device with improved color filtering system

摘要

The invention relates to a cathode ray tube device for generating a bright blue light of the type that is particularly useful for projection color television and information display. To filter out undesired radiation emitted by a silver-activated zinc sulfide phosphor, there is located in the path of blue radiation a concentrated solution of a soluble erbium salt and Methyl Violet 2B.