Browsing by Author "Chen, Szu-Fen Fenny"

Now showing 1 - 4 of 4

Improvement of fast response LC materials by bent-core dopants in optical compensated bend (OCB) mode liquid crystal displays
(2008)
Wang, Ling-Yung
;
Tsai, Shin-Yi
;
Lin, Hong-Cheu
;
Chen, Szu-Fen Fenny
;
Lyu, Robert
The stabilization of bend configuration in optical compensated bend (OCB) mode cells by doping bent-core molecules was developed in this study. The values of response time (tau) and threshold voltage (V-th) in OCB cells were dependent on not only the concentration but also the shape, dipole direction, and flexible chain length of the doping molecules. Experimental results showed that the total response time (tau(total)) and threshold voltage (V-th) of OCB cells could be reduced by doping bent-core molecules, and smaller tau values by reducing flexible chain lengths as well as smaller V-th values by reducing polarization of bent-core molecules were normally obtained. In general, higher concentrations of dopants normally induced shorter field-on response time (tau(on)) and a minimum field-off response time (tau(off)) occurred at 0.5% of doping concentration, where the fastest total response time (tau(total)) values were achieved.
Improvement of fast responsive LC materials by bent-core dopants in optical compensated bend mode liquid crystal displays
(2011-03-01)
Lin, Hong-Cheu
;
Wang, Ling-Yung
;
Jiang, Meng-Dan
;
Tsai, Shin-Yi
;
Chen, Szu-Fen Fenny
Stabilization of bend configuration in optical compensated bend (OCB) mode cells by doping bent-core molecules was developed in this study. The values of response time (t) and threshold voltage (V(th)) in OCB cells were dependent not only on the concentration but also on the shape, dipole direction, and flexible chain length of the doping molecules. Experimental results showed that the total response time (t(total)) and threshold voltage (V(th)) of OCB cells could be reduced by doping bent-core molecules, and smaller t values produced by reducing flexible chain lengths. In addition, attaining smaller V(th) values could be achieved by reducing polarization of bent-core molecules. In general, higher concentrations of dopants normally induced shorter field-on response time (t(on)) and a minimum field-off response time (t(off)) occurred at 0.5% of doping concentration, where the fastest total response time (t(total)) values were achieved.
Improvement of Optical Compensated Bend (OCB) and Vertical Alignment (VA) Mode Liquid Crystal Displays by Nano-alignment Technique
(2009)
Chen, Wei-Hong
;
Wang, Shia-Fan
;
Lin, Hong-Cheu
;
Mo, Yung-Lung
;
Chuang, Yun-Ching
Surface-modified silicon oxide (SiO(2)) nanoparticles containing surfactants with amino end-groups were synthesized. The amounts of surfactants anchoring on SiO(2) nanoparticles were characterized to research 8 wt% by thermogravimetric analysis (TGA). The characteristic amino peak of surfactants on SiO(2) nanoparticles can also be confirmed by nuclear magnetic resonance (NMR) spectroscopy. By spin-coating reactive surface-modified SiO(2) nanoparticles on the pre-cured polyimide (PI), amino end-groups of the surfactants can be further reacted with pre-cured PI layer over the ITO surface by thermo-curing. Moreover, the distribution of post-cured nanoparticles in the optical compensated bend (OCB) and vertical alignment (VA) cells have been investigated by scanning electron microscope (SEM). As a result, the newly developed nano-alignment technique with different process conditions, such as various particle sizes and concentrations, can be applied to improve the threshold voltage, response time, and pre-tilt angle in the OCB and VA mode liquid crystal display (LCD) cells.
Wide band reflective cholesteric liquid crystal displays for e-book application
(2005)
Chan, Meng-Xi
;
Chen, Szu-Fen Fenny
;
Shieh, Han-Ping D.
;
光電工程學系
;
Department of Photonics
A wide band reflective cholesteric liquid crystal display (Ch-LCD) has been demonstrated by utilizing full spectrum reflective method. The white state is realized by a narrow band of invisible light reflection in Ch-LC's planar texture, combined with full band reflector. The black state is created by Ch-LC's scattering type depolarization effect and polarizer's filtration effect in focal conic texture. The wide band reflective display has advantages of low power consumption and high display quality. With conventional color filter process, a full color Ch-LCD for E-book application can be realized.