Advanced IPS technology for mobile applications

Abstract— In-plane-switching LCD (IPS-LCD) technologies originally developed for LCD monitors and TV applications are applied to mobile applications. Advantages of the IPS mode over other optical modes for mobile applications are quantitatively clarified. The panel achieves stable color reproduction and chromaticity in the viewing-angle range for mobile displays. Superiority of the IPS mode over other optical modes is discussed also from the viewpoints of stability in chromaticity during the brightness change and the driving power consumption. A transflective IPS mode with good performance is accomplished by the use of a proper optical design. A new structure, IPS-Pro, which enables sunlight readability by increasing the transmittance, i.e., the brightness of the panel, without additional cost and power consumption in contrast to additional fabrication processes required to fabricate the transflective mode is realized. Furthermore, to improve the users' convenience, an automatic luminance control system and a controllable viewing-angle device are developed. The panels developed fulfill the market requirements of increasing the function and performance variations and will be the most appropriate ones to be applied to mobile appliances, such as cellular phones, digital still cameras, music players, GPS, mobile TV sets, etc.