Luminous ceilings were developed in the 1940’s from a comprehensive mathematical study of the integral equations for the interflection of light in rooms. It was found that criteria for optimum vision are satisfied for most visual tasks and most shapes of rooms if the entire ceiling is the source of light and room reflectances are sufficiently high. In the 1950’s criteria for lamp spacing above the luminous panels were developed and many undecorated luminous ceilings
were installed. To make the optimum luminous environment more attractive and interesting, hand-painted luminous ceilings were developed in the 1960’s and 1970’s and applied to homes, offices and classrooms. This paper presents the criteria for creating computer generated narrative luminous ceilings and gives practical examples applied to classroom lighting.
Traditionally reflector design has been confined to the use of surfaces defined in terms of conic sections, assuming that all light sources can be considered to be point sources. In the middle of the twentieth century, it was recognized that major improvements could be made if the shape of the reflector was designed to produce a desired distribution of light form an actual light source. Cylindrical reflectors were created which illuminated airport runways using fluorescent lamps in such a way that pilots could make visual landings safely even in fog. These reflector contours were called macrofocal parabolic cylinders. Other new reflector contours introduced were macrofocal elliptic cylinders which confined the light to long rectangles. Surfaces of revolution the fourth degree were also developed which made possible uniform floodlighting of a circular region. These were called horned and peaked quartics. The optimum solution of the automotive head lighting problem has not yet been found. The paper concludes with a discussion of the possibility of developing reflectors which are neither cylindrical nor rotational but will produce the optimum field of view for the automobile driver both in clear weather and in fog.
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