CIRCULARLY POLARIZING PLATE FOR ORGANIC EL DISPLAY DEVICE, AND ORGANIC EL DISPLAY DEVICE

• Main Authors: MURAKAMI NAO, KOJIMA TADASHI, UWADA KAZUTAKA, YAGINUMA HIRONORI, TAKEDA KENTARO
• Format: Patent
• Language: English; Japanese
• Published: 17.01.2019
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; SEMICONDUCTOR DEVICES

To provide a circularly polarizing plate for an organic EL display device, which can be manufactured with superior productivity, is free from warping, and can achieve a superior color tone.SOLUTION: A circularly polarizing plate of the present invention is an elongate circularly polarizing plate used for organic EL display devices. The circularly polarizing plate includes in this order an elongate polarizer having an absorption axis in a longitudinal direction, an elongate first retardation layer acting as a λ/2 plate, and an elongate second retardation layer acting as a λ/4 plate. An angle formed by the absorption axis of the polarizer and a slow axis of the first retardation layer is 20° to 25°, and the absorption axis of the polarizer and the slow axis of the second retardation layer is substantially perpendicular to each other. Re(450)/Re(550) in a laminate of the first retardation layer and the second retardation layer is 0.86 to 0.96, and Re(650)/Re(550) is 1.03 to 1.10.SELECTED DRAWING: Figure 1 【課題】生産性に優れ、反りが防止され、かつ、優れた色味を実現し得る有機ＥＬ表示装置用円偏光板を提供すること。【解決手段】本発明の円偏光板は、有機ＥＬ表示装置に用いられる長尺状の円偏光板である。この円偏光板は、長尺方向に吸収軸を有する長尺状の偏光子と、λ／２板として機能する長尺状の第１の位相差層と、λ／４板として機能する長尺状の第２の位相差層と、をこの順に備える。偏光子の吸収軸と第１の位相差層の遅相軸とがなす角度は２０°〜２５°であり、偏光子の吸収軸と第２の位相差層の遅相軸とは実質的に直交している。第１の位相差層と第２の位相差層との積層体のＲｅ（４５０）／Ｒｅ（５５０）は０．８６〜０．９６であり、Ｒｅ（６５０）／Ｒｅ（５５０）は１．０３〜１．１０である。【選択図】図１