Survey of actual viewing conditions at home and appropriate luminance of LCD‐TV screens

Abstract

To understand actual viewing conditions at home is important for TV design. And the preferred luminance level of LCD TVs under actual viewing conditions is also important in order to obtain both good picture quality and low power consumption. The actual viewing conditions of households and the preferred luminance levels was investigated. In a field test of 83 households, the display luminance, screen illuminance, and viewing locations were measured on site. In laboratory experiments, young and elderly subjects adjusted the luminance of an LCD-TV screen to their preferred levels under different screen illuminance levels, angular screen sizes, and average luminance levels (ALL) of the images. As a result, two equations, which represent the preferred luminance level of LCD-TV screens corresponding to different viewing conditions for young and elderly subjects were obtained. When the ALL of the 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/m 2 for the young subjects and 248 cd/m 2 for the elderly subjects. By using the setting of the preferred luminance of an LCD TV under actual viewing conditions, it is possible to conserve energy consumption.

Preference survey of curvature of large-size displays

“…Each display stimulus was placed on a white table, which was 60 cm in height to position the displays at the subject's eye level, and a chair was placed 2.5 m distance from the respective display, a typical viewing distance of a television in a home environment (Fig. ) . Hence, a total of nine display stimuli and nine chairs were set in the room.…”

“…4). 17 Hence, a total of nine display stimuli and nine chairs were set in the room. At the subject's seat, the measure of the correlated color temperature was 5000 K, and the illuminance was 400 lx.…”

60.3: Investigation on Viewing Angle Requirements and Glare with Respect to Size of Flat‐panel Television Displays

“…The television viewing conditions in the living rooms of 83 households were examined in 2007-2008 [2]. From the screen, the distance to the viewer's eyes and the distance to luminaires were measured in addition to evaluating the illumination conditions.…”

“…The Japan Ergonomics Society has issued guidelines for ergonomic design of flat-panel television displays [1], and a study on the ergonomic optimization of display luminance, which constitutes part of these guidelines, was reported previously [2]. The present paper reports the results of investigating viewing angle requirements and the relation between screen tilt angle and glare as part of the same guidelines.…”

“…As the size of flat-panel television displays has increased, viewing angle requirements have become stricter. Although the distribution of viewing angles with respect to the screen center was presented in [2], the viewing angle with respect to the screen edge increases together with the screen size, and therefore the viewing angle requirements should be clarified by taking screen size into account. In addition, increasing the size of flat-panel television displays also increases the occurrence of glare, which is related to not only deterioration in image quality, but also visual fatigue in users.…”