Finite-cell-gap corrections to the capacitance analysis of liquid crystal displays with periodic interdigital electrodes

Abstract

Corrections to the capacitance analysis of liquid crystal displays with periodic interdigital electrodes are presented, accounting for the finite thickness of the liquid crystal (LC) cell gap. Conformal mapping calculations of the corrected equivalent dielectric constant for the LC material and glass substrate are carried out in terms of the aperture ratio, cell gap and LC effective dielectric constant. Departure from the infinite-cell-gap approximation occurs as the gap thickness approaches the electrode width, or the aperture ratio approaches unity. The capacitance–voltage characteristic curve obtained from the conformal mapping calculations is very close to that obtained from the two-dimensional simulations with less than 5% deviation.