1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device for displaying an image using light transmittance of liquid crystal molecules.
2. Discussion of the Background
An LCD device includes an LCD panel that displays an image using the light transmittance of liquid crystal molecules, and a backlight assembly disposed under the LCD panel to provide the LCD panel with light.
The LCD panel includes a first substrate, a second substrate facing the first substrate, and a liquid crystal layer interposed between the first and second substrates. The first substrate includes a thin-film transistor (TFT) and a pixel electrode. The second substrate includes a common electrode.
The liquid crystal molecules of the liquid crystal layer may be operated in a vertical alignment mode by an electric field formed between the pixel electrode and the common electrode. For example, when an electric field is not formed between the pixel electrode and the common electrode, the LCD panel may display a white image. Alternatively, when an electric field is formed between the pixel electrode and the common electrode, the LCD panel may display a black image.
When an electric field is formed between the pixel electrode and the common electrode, the liquid crystal molecules of the liquid crystal layer are aligned in a direction substantially perpendicular to the pixel electrode or the common electrode. When the liquid crystal molecules are aligned in a vertical direction, the contrast ratio of an image viewed from the front of the LCD panel may be high, but the contrast ratio of an image viewed from the side of the LCD panel may be low, because the phase of light proceeding toward the side of the LCD panel may be delayed in a thickness direction of the LCD panel by the liquid crystal molecules.
That is, the LCD panel operated in the vertical alignment mode may have a problem in that the contrast ratio of an image viewed from the side of the LCD panel is low, because of the phase retardation in the thickness direction of the LCD panel caused by the liquid crystal molecules.