Bent Core Liquid Crystals for Fast Switching Field-Induced-Biaxial (FIB) Displays

KSU.293

Abstract:This invention is directed to an electro-optical liquid crystal device made with banana-shaped or bent core liquid crystal molecules.  These devices, which may be used for fast switching electric field-induced-biaxial (EFIB) displays, electro-optical switching and electro-optical storage, utilize an orthogonal dielectric phase of the banana-shaped molecules.  This invention is directed to liquid crystal display and electro-optical devices having faster switching times, a wider viewing angle, continuous gray level, improved transmittance of the clear state, approximately no threshold voltage and low power consumption.  The aspects of the invention are achieved by a liquid crystal device comprising an orthogonal nematic, smectic or columnar LC phase, which is uniaxial in absence of electric field, but becomes biaxial when electric field is applied normal to the director (in between electrodes for planar alignment or in-plane electric field in case of homeotropic alignment).

 Applications:

• Liquid crystal television
• Beam steering
• Spatial light modulators and a variety of others

 Advantages: The nature of the switching is dielectric (not piezoelectric) and does not involve variation of layer spacing variation, so as to be mechanically much more stable than prior systems.  The high switching speed combined with a large change in the effective birefringence and constant optical axis of the LC materials provide useful features. 

 Inventors: Dr. Antal (Tony) Jakli