Legibility of Light Signals Composed of Multiple Point Sources

Abstract

A visual experiment was carried out to clarify the optimum intensity for legibility of light signals composed of multiple point light sources. In this experiment, 3 to 7 sources were placed in a row, 3 ×3 to 7 × 7 sources were placed in a matrix, and other multiple-source signals were also employed as test stimuli on a screen panel. The separation of neighbouring points was 2 to 32 minutes of arc. The results show that the optimum average luminance of E-shaped lights and arrow-shaped lights agrees well with that of the row lights and the matrix lights. It was clarified that using the average luminance of the light is an effective method of obtaining the optimum intensity for legibility of light signals composed of multiple point light sources.