光源显色性对视觉辨认的影响

THE EFFECT OF COLOUR-RENDERING PROPERTIES OF LIGHT SOURCES ON VISUAL ACUITY

本实验采用四种不同显色特性的光源分别作为两种类型视标的照明。在同一照度上对各照明条件下的视觉敏度予以测定和计算。结果表明:增加光源显色指数对于颜色背景上黑色视标的辨认能力有所提高;而对于中灰色背景上颜色视标的辨认能力则有所下降。这种效果主要是由于在不同光源照明下,视标与背景的亮度对比变化所致。结果还表明:使用中灰背景颜色视标在辨认效果上优于颜色背景黑视标。对前一类型视标采用高压钠灯照明有助于提高视觉辨别力。这对推广应用这种显色指数较低,但光效率较高的新光源有实际意义。

In this experiment four types of lighting sources with differentcolour rendering properties are used in turn to illuminate two kindsof visual task separately. The visual acuity under each condition has been measured andcalculated. It is found that raising the colour rendering index of thelighting source could increase the visual discrimination effect in reco-gnizing the black signs against coloured background; while decreasingit in recognizing the coloured signs against grey background. These eff-ects are mainly the results of the function of luminance contrast betweenthe details and the corresponding backgrounds under different lightingsources. The results agree with the relationship of V=f(c) which isbased on the visual performance of human observers. Besides, it showsthat the coloured details against grey background are better definedthan the black detail against coloured background in visual discrimin-ation, and the colour contrast plays an important role in advancingvisual acuity. It is proved that the high pressure sodium lamp (HPSL)is one of the best lighting sources for the former sign pattern in raisingvisual acuity and saving electric energy in spite of. its lower colourrendering property.