Optimization of the display viewing angle for automotive application

We studied the optimization of viewing angle properties of the in-plane switching (IPS) liquid crystal display (LCD) for automotive applications. We studied the optical properties inside the automotive viewing zone (AVZ) with narrow vertical and wide horizontal viewing angle range defined in German OEM specifications. The average dark state transmittance (TRd) and contrast ratio (CR) of the IPS-LCD compensated with a + A and a + C plate could be enhanced by 2.5% and 0.8%, respectively, in the AVZ by inserting an additional -C plate. The uniformity of TRd and CR in the AVZ zone also improved by 39.3% and 24.9%, respectively. Enhancement of optical properties by the additional -C plate was also observed in the IPS-LCD compensated with a Z plate. On the other hand, the optical properties of the IPS-LCD compensated with a -B and a + C plate were optimal when Rth of the existing + C plate is optimized for automotive displays.