The feature of color comparator with double Si p-n junction

The current ratio of color comparator is presented to characterize the color difference which results from variation in spectral power of color source. For actual application, spectral power distribution of color source is fitted by one or more Lorentzian function. The relation between the variation in color source and current ratio of color comparator is analyzed numerically. The results show that the variation in the peak wavelength of spectral power distribution of color source will result in the considerable color difference and can be effectively discriminated by color comparator. An experiment to confirm resolution of color comparator is designed. The experimental observation confirms the theoretical analysis.