Photochromic compound, photochromic composition and photochromic display element using the same

摘要

A photochromic display element comprising a photochromic layer 12 containing a 4,4'-bipyridine derivative as a photochromic compound intervined between a transparent substrate 11 placed at a front surface side and a substrate 13 placed at a rear surface side. When a light containing an infrared light having a wavelength of 830 nm is irradiated, the photochromic display element exhibits the absorbance spectrum within a visible light region is reversibly changed whereby the photochromic layer 12 is colored and bleached.