Λ/4 PHASE DIFFERENCE FILM, CIRCULARLY POLARIZING PLATE, AND ORGANIC ELECTROLUMINESCENT DISPLAY DEVICE

摘要

The purpose of the present invention is to provide: a lambda/4 phase difference film having high phase difference-generating ability and good reverse wavelength dispersion properties; and a circularly polarizing plate and an organic electroluminescent display device each equipped with the lambda/4 phase difference film. The lambda/4 phase difference film according to the present invention has such wavelength dispersion properties that Ro(450)/Ro(550) falls within the range from 0.72 to 0.96 and Ro(550)/Ro(650) falls within the range from 0.83 to 0.98 when the in-plane phase difference value measured at a measurement wavelength (lambda (nm)) under an environment having a temperature of 23°C and a relative humidity of 55% is defined as Ro(lambda), said lambda/4 phase difference film being characterized by containing a specific compound, wherein the half width (Deltalambdaxmax) of an absorption band of a maximum absorption wavelength assigned to the main chain (x) of the compound and the half width (Deltalambdaymax) of an absorption band of a maximum absorption wavelength assigned to a side chain (y) of the compound fulfill the formula: Deltalambdaymax/Deltalambdaxmax >= 2.