Subjective reactions to misconvergence on a colour display

Abstract

Subjective ratings of various degrees of misconvergence were obtained from subjects viewing text and graphics pictures on a 355 mm high-resolution shadow mask colour CRT display. The pictures were displayed in four secondary colours: white, yellow, turquoise (cyan), and pink (magenta). In commercial applications, user acceptance and satisfaction often present more stringent requirements for front-of-screen quality than do objective performance criteria such as legibility. In this case, it is expected that the picture quality would become unacceptable at lower levels of misconvergence than would cause it to be considered illegible. The results show a marked degradation in apparent quality of convergence as misconvergence increases from about 0.2 mm to about 0.5 mm. To obtain subjectively acceptable picture quality, misconvergence should be no more than about 0.3 mm and should be better than 0.2 mm over the majority of the screen. (The spot size of the display used was about 0.8 mm.) Textual and graphical pictures did not produce significantly different results. © 1984.