Driving circuit for use in a liquid crystal display device
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorNaohide Wakita
Life of this patent
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Abstract
In a ferroelectric liquid crystal panel, the switching current of spontaneous polarization is detected from the difference between the current supplied to a selected pixel and the constant multiplication of the current supplied to a non-selected reference pixel, and when the amount of switched spontaneous polarization reaches a desired gray scale level, the applied voltage is changed so that even if any nonuniformity is involved within the panel, a uniform analog gray scale display can be realized.
Claims7
A liquid crystal driving circuit for a liquid crystal panel in which ferroelectric liquid crystals are sandwiched between a plurality of scanning electrodes and a plurality of signal electrodes, which are opposed to each other, said driving circuit comprising:
- a switching current detecting section for detecting, from the value of a current supplied from an arbitrary signal electrode a, a switching current value due to switching of spontaneous polarization of the ferroelectric liquid crystals at a selected pixel on the arbitrary signal electrode a;
- an integrating section for integrating the switch current value to develop an integral value;
- and
- a comparator for comparing the integrated value with a gray scale indicating voltage which corresponds to gray scale data, wherein the signal voltage value applied to the arbitrary signal electrode a is changed depending on an output of said comparator, so that the gray scale indicating voltage and the integrated value are made coincident with each other.
Dependencies are inferred from the claim text.