Random depolarization film design for real-color displays

Liquid crystal displays and organic light-emitting diode displays emit polarized light through polarizers and quarter-wave plates, which cause blackout and color change problems when the displays are viewed through polarizers, such as polarized sunglasses. Random depolarization films (RDFs) are polymer films doped with calcite particles, which randomize the polarization of light emitted from displays to resolve polarization problems. To realize displays without any color change, we investigate the retardation values and fabrication conditions required for RDFs. Analysis of the transmittance spectra and interference colors of different RDFs suggested that retardation values of approximately 600-1200 nm are sufficient to realize real-color displays. In addition, the color change measurements of displays with the RDFs revealed that an optimal dopant particle size exists and that the RDFs doped with 3.6 and 7.3 µm calcite particles achieved chromaticity changes of less than 0.02 for all 24 colors in the Macbeth chart.