CIRCULARLY POLARIZING ELEMENT, AND ELECTROLUMINESCENCE ELEMENT

摘要

Intended is to provide an organic EL element having no color taste change, even viewed in an oblique direction, and a circular polarization element to be used in the organic EL element. The intention is achieved by the circular polarization element, which includes an absorption type linear polarizer to be used in an electroluminescence element and one to five phase difference plates and which is characterized in that at least one of the phase difference plates is an optical film satisfying the following relations (1) and (2): Relation (1) 0 = Ro = 5; and Relation (2) -70 = Rt = 10. (Here, Ro = (nx - ny) x d and Rt = ((nx + ny)/2 - nz) x d, wherein nx indicates the refractive index in the delay-phase axial direction in the plane of the optical film, ny indicates the refractive index in a direction perpendicular to the delay-phase axis in the plane, nz indicates the refractive index in a thickness direction, and d indicates the thickness (mm) of the optical film.)