Method of driving a liquid crystal matrix panel
First Claim
1. A method of driving a liquid crystal matrix panel where a ferroelectric liquid crystal having negative dielectric anisotropy is held between scanning electrodes and signal electrodes crossing the scanning electrodes to form a matrix of pixels at crossing positions of the scanning and signal electrodes, comprising the steps of:
- applying signal voltage pulses to a signal electrode and addressing voltage pulses to a scanning electrode in an addressed condition so as to make an addressed pixel at the crossing position of the signal electrode and the scanning electrode to be a desired molecular orientation state; and
applying to the scanning electrode, in a non-addressed condition following the addressed condition, voltage pulses whose frequency is higher than that of the addressing voltage pulses and higher than a frequency in which spontaneous polarization of the ferroelectric liquid crystal can follow and whose average voltage is zero so that the effective value of voltage pulses applied to the pixel in the non-addressed condition becomes a substantially constant value greater than an effective threshold voltage at which a molecular orientation stabilizing effect begins to be produced by the dielectric anisotropy, whereby the state of the pixel made in the addressed condition is held in the non-addressed condition until a next addressed condition.
1 Assignment
0 Petitions
Accused Products
Abstract
An improved driving method capable of achieving high-quality display even in simple matrix addressing for a ferroelectric liquid crystal matrix panel at a high multiplex ratio applies pulses of a frequency higher than that of a scanning voltage in an addressed condition to a scanning electrode in a non-addressed condition to gain either a surface stabilizing effect or an AC field stabilizing effect, hence ensuring high-contrast display. And the panel is so driven that the temporal average of the voltage applied to each pixel becomes zero, thereby averting deterioration of the liquid crystal.
53 Citations
9 Claims
-
1. A method of driving a liquid crystal matrix panel where a ferroelectric liquid crystal having negative dielectric anisotropy is held between scanning electrodes and signal electrodes crossing the scanning electrodes to form a matrix of pixels at crossing positions of the scanning and signal electrodes, comprising the steps of:
-
applying signal voltage pulses to a signal electrode and addressing voltage pulses to a scanning electrode in an addressed condition so as to make an addressed pixel at the crossing position of the signal electrode and the scanning electrode to be a desired molecular orientation state; and applying to the scanning electrode, in a non-addressed condition following the addressed condition, voltage pulses whose frequency is higher than that of the addressing voltage pulses and higher than a frequency in which spontaneous polarization of the ferroelectric liquid crystal can follow and whose average voltage is zero so that the effective value of voltage pulses applied to the pixel in the non-addressed condition becomes a substantially constant value greater than an effective threshold voltage at which a molecular orientation stabilizing effect begins to be produced by the dielectric anisotropy, whereby the state of the pixel made in the addressed condition is held in the non-addressed condition until a next addressed condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification