Abstract
Flat-panel displays, especially liquid crystal displays (LCDs), are now firmly established as important devices for information displays. But do LCDs assure better readability than cathode-ray tubes (CRTs)? We carried out an experiment using four types of displays: negative and positive CRTs, and LCDs with and without backlighting. A syllable-checking task using the Japanese katakana alphabet was conducted among fifteen healthy workers. They were divided into three groups; Group 1 had five young males aged 25 to 29, Group 2 was made up of five young females aged 18 to 24, and Group 3 consisted of five middle-aged workers who were 40 to 50 years old. We used four ambient light levels: 200lx, 500lx, 1250lx without reflected glare, and 500lx with reflected glare, on the display screens from behind. The illuminance of the glare was approximately 200cd/m2. Multiple regression analysis showed that non-backlit LCDs reduced reading performance in middle-aged subjects significantly. Since middle-aged workers have more difficulties than young workers, they need more appropriate displays and a more comfortable illuminance environment than younger workers.
