Conventional high-brightness projectors employ normally white mode, which is advantageous for increasing brightness. This mode uses the optimum LCD array for white display, so when displaying black the LCD must be controlled by applying an electric field^*1 to the inside of the LCD cell.
In this case the LCD molecules on the alignment film interface cannot be perfectly aligned as shown in the figure below, so the light scatters which results in light leakage and lower contrast.
Conversely, the normally black mode employed by “BrightEra” devices uses the optimum LCD array for black display. As a result there is little light scattering, so light leakage can be reduced and high contrast can be obtained.
In addition, the inorganic alignment film and new LCD device designs have been optimized to efficiently control the LCD array even during white display when an electric field is applied. This also makes it possible to simultaneously increase brightness.

*1: The condition with voltage applied to the upper electrode and the lower electrode to create a potential difference