Patent ID: 7728804

Claim:
A liquid crystal display device, comprising: a first substrate; a plurality of gate lines on the first substrate; a plurality of data lines on the first substrate, crossing the plurality of gate lines; thin film transistors arranged at crossings of the plurality of gate and data lines; pixel electrodes connected to the thin film transistors; a second substrate; a common electrode on the second substrate; a layer of liquid crystal material between the first and second substrates; a protrusion on the common electrode for controlling an orientation direction of the liquid crystal layer so as to form different orientation directions in the liquid crystal layer; a common voltage generator applying a common voltage to the common electrode, wherein the common voltage is an AC voltage having a predetermined period; a data driver that applies a pixel voltage signal to the plurality of data lines; a gate driver for driving the plurality of gate lines; and a timing controller for controlling the gate and data drivers and for applying a pixel data signal to the data driver; wherein a potential difference between the common voltage and the pixel voltage signal is set to a predetermined value to control the orientation of liquid crystal molecules arranged proximately to a projected area of the common electrode, wherein a polarity of the pixel voltage signal is inverted every horizontal period and frame period, and a polarity of the common voltage is inverted every horizontal period and frame period, wherein the layer of liquid crystal material is driven according to a two-domain twist nematic mode, and wherein a potential difference between the common voltage and a positive pixel voltage signal is about 10 V and a potential difference between the common voltage and a negative pixel voltage signal is about 10 V, wherein a left/right viewing angle of the liquid crystal display device is 80°/80° while a top/bottom viewing angle is 80°/80°, wherein the thin film transistors (TFTs) is formed of polycrystalline silicon.