DEVICE FOR MEASURING LUMINANCE ADAPTING TO FOVEA

摘要

PURPOSE:To measure luminance adapting to the fovea of a video apparatus or the like by using luminance values obtained by measuring the luminance of a substance observed by an abserver at a fixed time interval, time at the measurement and the time constant of the photochemical reaction of the observed substance at the fovea. CONSTITUTION:An eye's motion tracing part 6 traces the eye's motion of an observer 5 and outputs a signal corresponding to the eye's direction. An observed substance luminance measuring part 7 obtains the positional information of the substance observed by the observer 5 from the output signal of the tracing part 6 and measures the luminance of the observed object at the fixed time interval. Output signals from the luminance measuring part 7 are successively stored in a memory part 8 together with the measuring time. An observed substance density operating part 9 calculates the density S of the observed substance from the luminance values and time stored in the memory 8 and the time constant of the photochemical reaction of the observed substance at the fovea. A fovea adapting luminance operating part 10 calculates the fovea adapting luminance Lf from the density S found by the density operating part 9 on the basis of a calculating formula. Thus, the fovea adapting luminance can be measured from the plural luminance values, the measuring time and the time constant of the photochemical reaction of the observed substance at the fovea.