THESIS
2001
107 leaves : ill. ; 30 cm
Abstract
Liquid Crystal Display (LCD) has been the dominant technology in electronic information display for several decades. Without static power consumption, LCD finds its applications in both high-end and low-end applications: electronic watch, information board, computer monitor and video projection system, etc. 2π-Bistable Twisted Nematic (2π-BTN) LCD is a promising technology for the electronic paper application as it consumes even less power then the usual LCD. It also has a huge viewing angle compared to the ordinary Super Twisted Nematic (STN) LCD. However, the metastability of the 2π-BTN LCD is still a problem for the realization of zero-power consumption display device....[
Read more ]
Liquid Crystal Display (LCD) has been the dominant technology in electronic information display for several decades. Without static power consumption, LCD finds its applications in both high-end and low-end applications: electronic watch, information board, computer monitor and video projection system, etc. 2π-Bistable Twisted Nematic (2π-BTN) LCD is a promising technology for the electronic paper application as it consumes even less power then the usual LCD. It also has a huge viewing angle compared to the ordinary Super Twisted Nematic (STN) LCD. However, the metastability of the 2π-BTN LCD is still a problem for the realization of zero-power consumption display device.
Recently, different researches on the π-BTN have been conducted. Comb On Plane (COP) BTN LCD cell structure is one of the candidates that has successfully realized the π-BTN display with true bistability. This is a completely new LCD cell structure with three electrodes, the driving is a combination of two electrical pulses and the response is reasonably fast for real applications. Intrinsic gray scale is also achievable by the different combinations of those driving pulses.
In this thesis, both 2π-BTN LCD and COP BTN LCD are discussed extensively in different aspects. The origin and the theories of the bistability of nematic phase liquid crystal display were investigated. The new cell structures and the fabrication process are introduced. And the optically optimized deign for both kinds of BTN LCD were discussed. Two optimized optical modes, one for each BTN, were selected for the experimental measurements. The optimal driving schemes were proposed for the both BTN devices. They are optimized for the driving speed and also the pulses amplitude. In the COP-BTN, different driving approaches to achieve permanent gray scale display were found. The switching mechanism behind this new LCD cell structure is investigated and discussed.
Post a Comment