抄録
The preferred luminance level of LCD televisions under real viewing conditions to obtain both good picture quality and low power consumption is a rather controversial issue. The relationship between the preferable luminance and major parameters that affect it were investigated in a field test and laboratory experiments. In the field test of 83 households, the illuminance and luminance of television screens and television viewing distances were measured on site. The results indicated that the mean display luminance was 269 cd/m2 for LCD televisions. The median screen illuminance was 92 lx and the median viewing distance was 252 cm. In laboratory experiments, younger and older subjects adjusted the luminance of an LCD television screen to their preferred levels under different screen illuminance levels, angular screen sizes and average luminance levels (ALL) of images. Based on the results, the preferred luminance of LCD television screens for younger and older subjects is represented as two formulas. When the ALL of images was 25% and the screen illuminance and angular screen size were set at 100 lx and 20°, respectively, the preferred luminance was 160 cd/m2 for younger subjects and 248 cd/m2 for older subjects. By setting the preferred luminance of an LCD television under real viewing conditions, it is possible to not only reduce visual fatigue but also to conserve energy consumption.
