MEASUREMENT OF OPTICAL REFLECTION CHARACTERISTIC

摘要

PURPOSE:To facilitate measurement of a mirror reflectivity and a diffusion reflection coefficient of an object, by employing a coefficient for calculating intensity of illumination of an surface to be measured as generated by a light source and a brightness value of an image reflected when the light source is placed at two positions, a brightness value of an image reflected when the light source placed at one of the two positions is varied in the brightness of the light source and the like. CONSTITUTION:A light source 3 is placed at two different positions A and A' so arranged that the light source 3 and a luminance meter 2 are on straight lines respectively set in surface symmetry with a plane containing normal of a surface 1 to be measured while dimensions of view angle made by an image as obtained when a light emitting section uniform in the brightness of the light source 3 is reflected on a surface 1 to be measured is within a measuring angle of the luminance meter 2. The brightness of an image reflected when the light source 3 is placed at positions A and A' is measured. The brightness of an image reflected is measured varying the brightness of the light source 3 which is placed at one of the positions A and A'. Then, a coefficient is used for calculating brightness values of the three images reflected, the brightness of the light source 3 and intensity of lumination of the surface 1 being measured generated by the light source 3 thereby enabling the determination of a mirror reflectivity and a diffusion reflection factor of the surface 1 being measured without using a lumination meter.