A technique for aging the phosphor of high-resolution cathode-ray tubes with particular application to P-16

An accelerated aging technique--restricted to P-16 phosphor--that measures a cathode-ray tube screen degradation with use is described. A small area of the screen is aged at high excitation densities and the light output from this area is plotted as a function of deposited charge per unit area. A pre-aged part of the screen is used as a reference level for measuring these light output levels. Measurements made to determine phosphor aging with cathode-ray tube operating modes are described. Aging is found invariant with spot focus, beam voltage, beam current, power density per unit area, and sweep speed over normal operating ranges. Deposited charge per unit area is confirmed as the dominant stress factor. Under restricted operating conditions, the data is reproducible within ±4 percent at the 95 percent confidence level. Aging rates accelerated by a factor of more than a thousand as compared to normal usage have been obtained.