円環光源の測光に関する研究 (その3)

円環型けい光灯の近似配光について

抄録

The effects of the thickness of toroidal light source and interflection in its cavity have already been written in a treatise in this Journal.
To discuss the light distribution of the toroidal fluorescent lamps in the market, the following three factors must be still more considered ; i. e. the deviation from the perfect diffusion characteristics of light emittion from the surface element of the source, the incomplete toroidal form of the lamps and the finite photometric distance.
In this report, these factors are discussed separately. And the method to obtain the approximate theoretical equation of light distribution of the toroidal fluorescent lamp is discussed, and the equation is obtained by synthesizing the five effects mentioned above. The calculated results of approximate light distribution and the results of experiments have coincided as far as 20 Watt and 40 Watt lamps are concerned.
From the above facts, the parameter b representing the deviation from the perfect diffusion characteristics and the parameter φ representing the effective defect angle can be well estimated.