T - Vmin addressing mode and an improved equivalent circuit model for ferroelectric liquid crystal displays

The authors describe an improved model for modelling the electro-optical response of a ferroelectric liquid crystal display and discuss its applicability. The model includes the direct coupling of applied electric fields to dielectric permittivity, an effect not accounted for in previous equivalent circuits. Compared with previous models, the new model has more capability in optical response prediction and device setup optimisation when the dielectric biaxiality of ferroelectric liquid crystals is of a relatively high value. In the improved model, different trends of switching time are observed as drive voltage rises in cases of positive anisotropy and negative anisotropy. The bend in tau-V min mode, that is, the minimum pulse area for switching directors, is measured and the mechanism of optical contrast enhancement and switching process complemented by high-frequency ac pulses is clearly explained. Results obtained from the improved model compare favourably with that obtained from numerical models and from testing of a real cell

[1]  Sven T. Lagerwall,et al.  Ferroelectric and Antiferroelectric Liquid Crystals , 1999 .

[2]  J. Gourlay,et al.  Modelling of binary phase modulation in surface stabilized ferroelectric liquid crystal spatial light modulators , 2004, Microelectron. J..

[3]  Akio Takimoto,et al.  Analysis of Charge-Controlled Gray Scale in Ferroelectric Liquid Crystal Optically Addressed Spatial Light Modulator , 1994 .

[4]  M. Handschy,et al.  Electrooptic response during switching of a ferroelectric liquid crystal cell with uniform director orientation , 1987 .

[5]  S. Lagerwall,et al.  Dielectric anisotropy and dielectric torque in ferroelectric liquid crystals and their importance for electro‐optic device performance , 1990 .

[6]  Martin Schadt,et al.  Physics and Electronic Model of Deformed Helix Ferroelectric Liquid Crystal Displays , 1994 .

[7]  Li Nuohan.  Circuit-Level Analysis on the VCSOA Typical Parameter Properties , 2004 .

[8]  E. P. Raynes,et al.  Measurement of the biaxial permittivities for several smectic C host materials used in ferroelectric liquid crystal devices , 1992 .

[9]  Craig Tombling,et al.  A diffraction based polarisation independent lightvalve , 2000 .

[10]  J. R. Sambles,et al.  The mechanism of ac stabilization in ferroelectric liquid‐crystal‐filled cells , 1990 .

[11]  M. J. O'Callaghan,et al.  Switching dynamics and surface forces in thresholdless "V-shaped" switching ferroelectric liquid crystals. , 2003, Physical review. E, Statistical, nonlinear, and soft matter physics.

[12]  Computer simulation of the electro-optical switching process in ferroelectric liquid crystal cells with bookshelf geometry , 1993 .

[13]  Kiat Seng Yeo,et al.  Equivalent circuit model of on-wafer CMOS interconnects for RFICs , 2005, IEEE Trans. Very Large Scale Integr. Syst..

[14]  Clark,et al.  Smectic-C "chevron," a planar liquid-crystal defect: Implications for the surface-stabilized ferroelectric liquid-crystal geometry. , 1988, Physical review. A, General physics.

[15]  Jan G. Korvink,et al.  Equivalent circuit model of resistive IC sensors derived with the box integration method , 1999, IEEE Trans. Comput. Aided Des. Integr. Circuits Syst..

[16]  N. Clark,et al.  Submicrosecond bistable electro‐optic switching in liquid crystals , 1980 .

[17]  Akira Sakaigawa,et al.  Switching behavior of surface stabilized ferroelectric liquid crystals induced by pulse voltages , 1997 .

[18]  J. R. Hughes,et al.  Fast, high-contrast ferroelectric liquid crystal displays and the role of dielectric biaxiality , 1993 .

[19]  Anthony J. Walton,et al.  An improved SPICE model for ferroelectric liquid crystal microdisplays , 2003, International Conference on Microelectronic Test Structures, 2003..

[20]  Arl Travis,et al.  PSpice electronic model of a ferroelectric liquid crystal cell , 1999 .

[21]  Shinya Kondoh.  Ultra high-resolution FLC display for PDA , 2004 .

[22]  Haruhiko Okumura,et al.  Equivalent Circuit Model for Thresholdless Antiferroelectric Liquid Crystal Displays , 1999 .

[23]  José Manuel Otón,et al.  Modelling and characterization of ferroelectric liquid crystal displays , 1994 .

[24]  Munehiro Kimura,et al.  Dynamic Response of Surface-Stabilized Ferroelectric Liquid Crystals: Effect of Alignment Films , 1994 .