平面光源による空間照度の計算式および概算法についての考察

抄録

By means of a newly developed analytical method applying the via-perspective method, equations to calculate various spacial illuminances by means of flat surface sources with an arbitrary shape and at arbitrary location have been able to develop.
When calculations are achieved by using the equations, it has been clarified that the error in the rough calculating method to obtain a spherical illuminance by average of six-directions-illuminances becomes very large when an angle subtending a flat surface source is small.
However, assuming a twenty-six minute face pieces interpolated at 45 degrees, it has been clarified that the degree of error may be significantly improved by adopting a method to average the values obtained by multiplying respectively the illuminance of each face by area ratio of each face.