TFT液晶ディスプレイに要求される輝度に関する検討

抄録

The purpose of this study is to investigate the required luminance for a thin film transistor liquid crystal display (TFT/LCD). This study consists of two experiments.
In Experiment 1, preferable luminance was estimated. Thirty participants were asked to adjust the brightness of both a TFT, /LCD and a CRT display as they most preferred, under four kinds of ambient illuminance conditions: 125, 250, 500 and 1000 lx at the surface of each display. The average preferable luminance adjusted for the TFT/LCD at the 250 lx was 42.1±13.0 cd/m², and it was 114.2±59.2 cd/m² for the CRT when an English text pattern was displayed.
In Experiment 2, allowable luminance, that is the lower limits of the preferable luminance, was asked. About 90 percent of the participants accepted the luminance of the TFT/LCD as low as 25 cd/m² at 250 lx.
All of participants adjusted the luminance of TFT/LCD lower than CRT as their preferable luminances in the Experiment 1. Many participants, however, felt that the luminance of the TFT/LCD was brighter than that of the CRT. This result seems to suggest that images displayed on the TFT/LCD was perceived brighter than those on the CRT, although they were displayed at the same luminance. Regarding the effects of ambient illuminance, the TFT/LCD showed the same tendency as CRT display, that is, higher luminance and lower contrast were required as the ambient illuminance was increased.