Patent ID: 8896499

Claim:
A stereoscopic image display comprising: a liquid crystal display panel including data lines, gate lines crossing the data lines, a common electrode to which a common voltage is applied, a 3D control line to which a 3D control voltage is applied, and a plurality of pixels, each of the pixels being divided into a main pixel portion and an active black stripe; a data driving circuit that supplies a data voltage of a 2D image to the data lines in 2D mode, and supplies a data voltage of a 3D image to the data lines in 3D mode; a gate driving circuit that sequentially supplies gate pulses swinging between a gate low voltage and a gate high voltage to the gate lines in the 2D mode and the 3D mode; and a 3D control voltage generation circuit that supplies the 3D control voltage to the 3D control line and discharges a voltage of the active black stripe down to a black gray voltage, wherein the 3D control voltage generation circuit supplies an alternating voltage swinging between the 3D control voltage and the gate low voltage to the 3D control line in the 3D mode, and supplies the gate low voltage to the 3D control line in the 2D mode, wherein the 3D control voltage is higher than the common voltage and lower than the gate high voltage, wherein a voltage of the 3D control line is lowered to the gate low voltage during a vertical blank period between an N-th (where N is a natural number) frame period and an (N+1)-th frame period.