When viewing LCD monitors from an oblique angle, it is not uncommon to witness a dramatic color shift. Occasionally, this can appear as a total color inversion. This is primarily caused by a polarization asymmetry, where light rays passing through the pixel matrix at oblique angles are influenced by the relative orientation of the liquid crystal (see paper for more details).
Engineers and designers have sought to reduce these effects for more than two decades. This effort has been further driven by the popularity of LCD televisions, which have viewers located at wider angles than seen in typical computing setups. This has led to the emergence of more advanced LCD technologies, such as In-Plane Switching (IPS) and Vertical Alignment (VA) screens, which have superior field of view. However, this benefit comes with a higher price tag, slower refresh rate, and increased power consumption.
We take an opposite stance, embracing these optical peculiarities, and consider how they can be used in productive ways. Our paper discusses how a special palette of colors can yield visual elements that are invisible when viewed straight-on, but visible at oblique angles. In essence, this allows conventional, unmodified LCD screens to output two images simultaneously – a feature normally only available in far more complex setups. We enumerate several applications that could take advantage of this ability.