Electro-optic characteristics of a twisted nematic (TN) liquid crystal display (LCD) fabricated by doping Ag nanoparticles protected with NLC, 5CB (K-15, Merck) molecules has been investigated and it is shown that the device exhibits a unique electrooptic response characteristics that is sensitive to the high frequency component of the operating voltage together with the conventional root-mean-square response to the operating voltage. We call this device frequency modulation (FM) TN-LCD. The FM TN-LCD is switched by switching the frequency of the operating voltage while its amplitude is kept unchanged. As an example, by switching the frequency from 20Hz to 500Hz or 50Hz to 2kHz, and the switching is done with the time constant of several ms. This device shows a peculiar response to a burst AC square voltage waveforms, where the device exhibits bipolar response with the time constant of 500 ms and the envelope with the time constants shorter than those of an undoped TN-LCD by from 30% to 80%. The mechanism of the FM-TN-LCD is investigated through the study of its dielectric properties.

Date Published: 28 May 2004
PDF: 8 pages
Proc. SPIE 5289, Liquid Crystal Materials, Devices, and Applications X and Projection Displays X, (28 May 2004); doi: 10.1117/12.532169

Published in SPIE Proceedings Vol. 5289:
Liquid Crystal Materials, Devices, and Applications X and Projection Displays X
Ming Hsien Wu; Liang-Chy Chien, Editor(s)