Active retarder panel used in the twisted nematic mode

Abstract

The twisted nematic (TN) mode is often employed when using three-dimensional active retarder (3DAR) technology, owing to its many merits such as low operating voltage, high aperture ratio and large cell-gap tolerance. However, an unexpected problem with the TN mode is that it leads to an asymmetric contrast ratio (CR) between the normally white TN (NW-TN) mode and normally black TN (NB-TN) mode due to the dispersion characteristics caused by the 90° twist angle. To overcome this problem, we designed a film compensation method using numerical calculations and validated it through experiments. Using our optical configuration, asymmetric CRs can be drastically improved.

Keywords:

• three-dimensional active retarder
• twisted nematic mode
• compensation film

Acknowledgements

This work was supported by the Fundamental R&D Program for Core Technology of materials (10037191, Structuring Technologies for Multi-functionally Converged Nanofibers) funded by Ministry of Knowledge Economy (MKE, Korea).