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Chemical Physics Publications

1996

Articles 1 - 3 of 3

Full-Text Articles in Physics

Model Of Liquid Crystal Alignment By Exposure To Linearly Polarized Ultraviolet Light, J. Chen, D. L. Johnson, Philip J. Bos, Xinghua Wang, John L. West Aug 1996

Model Of Liquid Crystal Alignment By Exposure To Linearly Polarized Ultraviolet Light, J. Chen, D. L. Johnson, Philip J. Bos, Xinghua Wang, John L. West

Chemical Physics Publications

A simple theoretical model of liquid crystal (LC) alignment by exposure to linearly polarized ultraviolet (UV) light is proposed. The model predicts a universal relationship describing the change of the LC anchoring direction with exposure times, and the changes of polarization direction for the case of a double linearly polarized UV exposure process. This relationship is quantitatively confirmed by our experimental results on polyimide systems. The model also suggests that the LC anchoring strength can be controlled by UV exposure dosage. Pretransitional birefringent measurements show that the order parameter of a linearly polarized UV exposed polyimide surface is much lower ...


Four-Domain Twisted Nematic Liquid Crystal Display Fabricated By Reverse Rubbed Polyimide Process, J. Chen, Philip J. Bos, D. L. Johnson, Douglas R. Bryant, J. Li, S. H. Jamal, J. R. Kelly May 1996

Four-Domain Twisted Nematic Liquid Crystal Display Fabricated By Reverse Rubbed Polyimide Process, J. Chen, Philip J. Bos, D. L. Johnson, Douglas R. Bryant, J. Li, S. H. Jamal, J. R. Kelly

Chemical Physics Publications

In Appl. Phys. Lett. 67, 1990 (1995), we proposed a particularly simple four‐domain (4‐D) twisted nematic(TN) liquid crystal display(LCD) device, which is composed of two left‐handed and two right‐handed TN subpixels. The two members of each pair of same handedness subpixels are rotated 180° with respect to each other, resulting in four domains that spatially average one another optically to provide a wide angle of viewing with no gray scale inversion. The optical performance of the 4‐D TN LCD was confirmed by studies of a test cell fabricated by a two‐step SiO ...


Radially And Azimuthally Oriented Liquid Crystal Alignment Patterns Fabricated By Linearly Polarized Ultraviolet Exposure Process, J. Chen, D. L. Johnson, Philip J. Bos, S. Sprunt, J. Lando, J. A. Mann Jr. Feb 1996

Radially And Azimuthally Oriented Liquid Crystal Alignment Patterns Fabricated By Linearly Polarized Ultraviolet Exposure Process, J. Chen, D. L. Johnson, Philip J. Bos, S. Sprunt, J. Lando, J. A. Mann Jr.

Chemical Physics Publications

A structure for an electro-optically controlled liquid crystal diffraction grating is proposed, which can dramatically simplify the fabrication process of liquid crystal optical gratings. The structure consists of two alternating stripes. Each stripe is a hybrid liquid crystal cell with adjacent stripes oriented perpendicularly. This kind of electro-optically controlled diffraction grating in principle gives 100% diffraction efficiency and no polarization direction dependence. The detailed fabrication process is presented. (C) 1995 American Institute of Physics.