The performance characteristics of yttrium oxysulfide—A new red phosphor for color television

A new red phosphor, europium-activated yttrium oxy-sulfide, has a luminous efficiency 40 percent greater than that of yttrium vanadate. The use of this phosphor in the P22 color screen of color television receivers results in gun-current ratios which are close to unity when balancedfor a "white" color temperature of 9300°K The white-field luminance is increased 20 percent as compared to that of vanadate P22 screens for equal power dissipation. An even greater increase in highlight brightness is obtained when the guns are driven to the limit for acceptable blooming. Because the red field requires 40 percent less beam current for the same luminance, there is a corresponding reduction in the stray electron level, and the red-field purity is noticeably improved. This paper describes the performance of the new red phosphor and the methods used in measuring the color temperature and luminance of color television picture-tube screens.