画像の平均輝度レベル，観視者の年齢，照明環境を考慮した液晶ディスプレイの輝度制御

We investigated what influences the average luminance level (ALL) of displayed images, screen illuminance, and viewers ages had on the preferred luminance of LCDs. Twenty young subjects (mean age: 21.8) and 24 seniors (mean age: 68.9) adjusted the luminance of a 17-inch 1000: 1 LCD monitor to their preferred levels under different experimental conditions. The results indicate that the preferred luminance of LCDs corresponded to the following formula: Lp=k×ALLα. This is where Lp is the peak white luminance of the LCDs, k is a constant, and ALL is the average luminance level of the displayed images. Here, α is a constant from −0.19 to −0.20 for the seniors and from −0.14 to −0.17 for the young subjects. The influences of age-related changes in vision and ambient lighting on the luminance requirements for LCDs are also discussed. These results can be applied to the design of luminance-control systems for LCDs.