Browsing by Author "Hsu, Jy-Shan"

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Dynamic behaviors of dual frequency liquid crystals in bistable chiral tilted-homeotropic nematic liquid crystal cell
(2006-07-31)
Hsu, Jy-Shan
;
Liang, Bau-Jy
;
Chen, Shu-Hsia
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光電工程學系
;
Department of Photonics
The switching behaviors of dual frequency liquid crystals (DFLC) in a bistable chiral tilted-homeotropic nematic (BHN) LC cell are simulated and compared with the observed results. This cell can be switched between tilted-homeotropic state and twisted state under the applied voltage as low as 5 V. The reason for the low switching voltage is attributed to the dielectric anisotropy character of DFLC. The analysis also shows that the switching wave form accelerates the switching behaviors of the directors which results in faster response in BHN LC cell. (c) 2006 American Institute of Physics.
Improved Electric Properties of Degraded Liquid Crystal Using Metal-Organic Frameworks
(2013-12-01)
Huang, Cheng-Ting
;
Liao, Kun-Ting
;
Lin, Chia-Her
;
Hsu, Jy-Shan
;
Lee, Wei
A series of experiments are conducted to examine the purification effect on degraded liquid crystal (LC) by soaking porous metal-organic frameworks in the LC material. The results indicate that the electric properties of the degraded LC are dramatically improved due to the adsorption and removal of moisture and impurity ions, most likely originating from the atmosphere. This investigation leads to the advancement in the feasible recycling of deteriorated LC materials, including LC leftovers from flat-panel production lines, with a simple and cost-effective treatment method. (C) 2013 The Japan Society of Applied Physics
Metal-Organic Frameworks for Regeneration of Degraded Liquid Crystals
(2014-09-22)
Lee, Wei
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Huang, Cheng-Ting
;
Liao, Kun-Ting
;
Hsu, Jy-Shan
;
Lin, Chia-Her
This paper is concerned with the dramatic purification effect of porous metal-organic frameworks (MOFs) and regeneration of a degraded liquid crystal (LC) as leftover from a flat-panel production line. By soaking MOFs in the LC, the correlation between the recovery of electrical properties and the water-sorption capacity of MOFs is unambiguously revealed. Experimental evidence from the data of voltage-dependent capacitance, dielectric spectroscopy and voltage holding ratio strongly suggests that the primary contaminant in a LC leftover is moisture. This investigation paves the way for feasible recycling of deteriorated LC materials. The approach reported in this study can be applied to many fluids for purification and regeneration.
Purification of deteriorated liquid crystals by employing porous metal-organic-framework/polymer composites
(2015-03-01)
Tasi, Tsung-Yu
;
Wu, Po-Chang
;
Liao, Kun-Ting
;
Huang, Hsi-Ya
;
Lin, Chia-Her
This study demonstrates the effectual purification of degraded nematic liquid crystals (LCs) by introducing metal-organic framework (MOF) into the copolymer with either negatively charged 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or positively charged (vinylbenzyl) trimethylammonium chloride (VBTA). Experimental results show that the ion elimination is primarily achieved by the nanoporous MOF itself while AMPS or VBTA plays an important role in functionalizing MOF with hydrophilicity. It was found that the overall ion-removal efficacy of either MOF/polymer-AMPS or MOF/polymer-VBTA composite is higher than that of the pristine MOF counterpart. (C) 2014 Optical Society of America
Thermally induced light leakage in in-plane-switching liquid crystal displays
(2009-02-01)
Hsu, Jy-Shan
;
Lin, Yi-Hsin
;
Lin, Hung-Chun
;
Yang, Kei-Hsiung
;
光電工程學系
In this paper, we report the thermally induced light leakage in in-plane-switching liquid crystal displays (IPS LCDs) that have a built-in small-angle deviation (< 4 deg) between the polarization axis of a polarizer and the rubbing directions for liquid crystal (LC) alignment. We have found that the thermally induced light leakage depends strongly on the phase retardation which is a function of cell gap, wavelength, and birefringence of LCs used in the IPS LC cells. In addition, we have measured the light leakage of vertically aligned LC cells, which is independent of temperature and the deviation angle. A temperature-scanning method is proposed to reduce the light leakage of the IPS LCDs.