Computer-aided design for an asymmetrical reflector with HID lamp

This paper describes computer-aided design procedurers for predicting the luminous intensity distribution for the HID lamp luminaire having an asymmetrical reflector for tunnel lighting and the like. The proposed procedures first divide a light source and a reflector into minor parts, then trace three-dimensional optical paths from each direction oriented by every minor part combination of the source and the reflector, and finally total both reflected and direct rays from the light source to predict the luminous intensity distribution of the luminaire. The arithmetical weight of the minor light source intensity is given prior to the calculation by means of measuring luminance, and the differences among reflected light distributions made by the glossiness of the reflector surface is also considered.