To analyze the kind of a light source independently of the higher harmonic analysis of flickering luminance waveform by forming a frequency distribution table using flickering luminance as a class value, and performing the analysis.

Luminance information, which enters from outside, is taken in as an A/D value by a photometalic device #002. A method for detecting flicker, which is to be generated curing the constant time, from a histogram is used. Algorithm at 80 A/D is taken in per each 128μs by an A/D timing adjusting timer, which is expressed with #004. The A/D value (digitized luminance information) from the device #002 is taken into a control device, and histogram is formed on the basis of this value. A class value of this histogram means an A/D value of the luminance. The histogram is stored in a histogram memory device, which is expressed with #005, and the kind of the light source is discriminated by the algorithm stored in the device #003, and output to an output device #007.