1993 年 77 巻 10 号 p. 649-657
Reduction of reflected glare on visual tasks such as printed papers in an office, is one of the most important factors of office lighting designs.
In this paper, experimental studies have been carried out to apply the latest lighting technology to office lighting designs for reduction of reflected glare.
The authors studied the permissible luminance limits of the reflected light source by subjective appraisal, and developed rules for the relationship among various lighting factors. The factors are: permissible luminance of the light source, illuminance on paper, luminance contrast between a character and its background.
The results are as follows:
(1) Luminance contrast between a character and its background without reflected glare gives a large influence on the necessary value of luminance contrast with reflected glare. A higher luminance contrast without reflected glare needs a larger amount of luminance contrast with reflected glare under the same condition of the background luminance.
(2) Accordingly, if the luminance contrast without reflected glare is different, each character with reflected glare on paper does not have the same visibility, even though both background luminance and luminance contrast are the same.