WIDEBAND COMPOUND PHASE-RETARDATION FILM AND WIDEBAND CIRCULAR POLARIZER USING THE SAME

摘要

A wideband compound phase-retardation film including a half-wave phase-retardation film and a quarter-wave phase-retardation film with different reactive rod-like liquid crystal combination is provided. The half-wave phase-retardation film uses material having a birefringence of Δn₁, and the quarter-wave phase-retardation film uses material having a birefringence of Δn₂. The birefringence Δn₁ is smaller than the birefringence Δn₂. Furthermore, the birefringence dispersion Δn₁(λ) is also smaller than Δn₂(λ).