Viewing angle controller based on dual hybrid alignment nematic cells for automotive co-driver displays

We proposed a viewing angle controller (VAC) for automotive co-driver displays (CDDs). This VAC, integrated with the CDD, provides essential information to the co-driver while minimizing distractions for the driver. It consists of two hybrid alignment nematic (HAN) liquid crystal cells, two -C films, and two polarizers. The simulation and experimental results demonstrate that the VAC enables a narrow 35° viewing angle under low voltage, effectively blocking light directed toward the driver while allowing for a wider viewing angle under high-voltage conditions. This VAC ensures excellent light transmission at normal viewing angles and symmetrical viewing angle characteristics in both privacy and shared modes. Compared to previous studies, the device has reduced light leakage at large polar angles while obtaining a narrow viewing angle, lower drive voltage, and good compatibility with LCD and OLED displays. This VAC can deliver entertainment content for the co-driver while ensuring the driver's safety.