Optical laminate film and organic electroluminescent display device
An object of the present invention is to provide is an optical laminate film exhibiting excellent uniformity in reflection tint and an organic EL display device using this optical laminate film and exhibiting excellent uniformity in reflection tint when turned off. The object is achieved by providing an optical laminate film including a polarizer, a phase difference layer, and a circularly polarized light separating layer in this order, in which an in-plane retardation Re(550) of the phase difference layer is 120 to 160 nm, the polarizer and the phase difference layer are arranged to form an angle of 45°±10°, the circularly polarized light separating layer is a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystalline phase, in a case where an average refractive index of the liquid crystal compound forming the circularly polarized light separating layer is n, a birefringence thereof is Δn, and a selective reflection center wavelength thereof is λ, it is “ReMAX [nm]=k×Δn×λ/n (where k=0.213)”, and an in-plane retardation Re(550) of the circularly polarized light separating layer satisfies “0.5×ReMax≤Re(550)≤R.
1. An organic electroluminescent display device comprising:
an optical laminate film comprising, at least:
a polarizer;
a phase difference layer; and
a circularly polarized light separating layer,
wherein the polarizer, the phase difference layer, and the circularly polarized light separating layer are arranged in this order,
an in-plane retardation Re(550) of the phase difference layer is 120 to 160 nm,
the polarizer and the phase difference layer are arranged such that an angle formed between a transmission axis of the polarizer and a slow axis of the phase difference layer is 45°±10°,
the circularly polarized light separating layer is a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystalline phase and having a liquid crystal compound as a main component,
in a case where an average refractive index of the liquid crystal compound forming the circularly polarized light separating layer is n, a birefringence of the liquid crystal compound forming the circularly polarized light separating layer is Δn, and a selective reflection center wavelength of the circularly polarized light separating layer is λ,
ReMAX [nm]=k×Δn×λ/n (where k=0.213), and
an in-plane retardation Re(550) of the circularly polarized light separating layer satisfies
0.5×ReMax≤Re(550)≤ReMax; and
an organic electroluminescent light emitting element,
wherein the optical laminate film and the organic electroluminescent light emitting element are arranged so as to sandwich the circularly polarized light separating layer between the phase difference layer and the organic electroluminescent light emitting element,
wherein film thickness of the circularly polarized light separating layer is 0.8 to 1.3 μm.
2. The organic electroluminescent display device according to claim 1 ,
wherein a total of retardations Rth(550) in a thickness direction of members arranged between the polarizer and the organic electroluminescent light emitting element is −50 to 50 nm.
3. The organic electroluminescent display device according to claim 1 , further comprising:
a C-plate between the polarizer and the organic electroluminescent light emitting element.