蔡永傑 Wing-Kit Choi

Assistant Professor, Department of Electrical Engineering, National Taiwan University

Major Research Areas:

Liquid crystal electro-optic effects, Liquid crystal display technologies (TFT-LCDs)

Research Summary:

Prof. Choi’s current research activities at NTU focus on the development of Transflective TFT-LCDs (TR-LCDs) which have, in recent years, become a very important display technology for small to medium sized portable electronic devices such as cellular phones & digital cameras globally. The main advantage of TR-LCDs over the conventional transmissive-type TFT-LCDs is that the former is capable of displaying legible images under any illumination conditions, i.e. suitable for both indoor and outdoor usages. Due to the optical-path difference between the transmitted and reflected lights, many of  today's high-optical-efficiency TR-LCDs are based on the rather complicated “double-cell-gap” structure, which requires a more demanding fabrication process control and hence often leads to lower production yields and higher manufacturing cost. Moreover, this structure exhibits other undesirable features such as unequal response time between transmitted and reflected images, reduced aperture and very often limited viewing-angle characteristics. Prof. Choi’s research team at NTU thus focuses on developing new or novel designs of TR-LCDs which can allow a simpler structure, more cost-effective fabrication process and with good or improved optical properties. Recently, Prof. Choi has also been very interested in the development of novel Transflective displays based on the structure of OLED + LCD.