Extraordinarily wide-view and wide spectral bandwidth transflective liquid-crystal displays

Abstract

This work presents a simple compensation method for widening the viewing angle of transflective liquid-crystal displays (TR-LCDs). For an off-axis light, the slow axis of a biaxial film shifts linearly as the Nz factor is varied. By using this optical characteristic of a biaxial film, the broadband condition of broadband circular polarizers exactly holds over a full 80 degrees viewing cone, thus eliminating the off-axis light leakage to widen the viewing angle of TR-LCDs. Based on the proposed compensation method, the TR-LCDs theoretically have a wide spectral bandwidth and a viewing angle of 80 degrees for contrast-ratio (CR) >100:1 and >30:1 in transmissive and reflective modes, respectively. Experiments also show that the proposed TR-LCD has a viewing angle of over the entire 80 degrees and 65 degrees viewing cone in T-mode and R-mode, respectively, for CR>10:1. The proposed TR-LCD is highly promising for mobile display applications.