(a) Field of the Invention
The present invention relates to a liquid crystal display apparatus. More particularly, the present invention relates to a liquid crystal display apparatus capable of achieving high resolution by enhancing a space utilizing efficiency.
(b) Description of the Related Art
A liquid crystal display apparatus, which is prominently used in flat panel display apparatuses, includes two panels having electric field generating electrodes such as pixel electrodes and a common electrode and a liquid crystal layer interposed therebetween. The liquid crystal display apparatus displays an image by applying a voltage to the electric field generating electrodes to generate an electric field in the liquid crystal layer. A magnitude off the electric field determines an alignment of liquid crystal molecules in the liquid crystal layer to control polarization of incident light.
A liquid crystal display apparatus with a vertical alignment mode has liquid crystal molecules arranged such that major axes of the liquid crystal molecules are perpendicular to the upper and lower panels when no electric field is generated. Such liquid crystal display apparatuses with a vertical alignment mode have attracted recent attention, since they provide a high contrast ratio and a wide reference viewing angle. Here, the reference viewing angle denotes a viewing angle corresponding to a contrast ratio of 1:10 or a limited angle for brightness inversion between gray voltages.
Forming cut portions in and/or forming protrusions on the electric field generating electrodes are current means for implementing the wide viewing angle in the liquid crystal display apparatus with a vertical alignment mode. Since the cut portions and the protrusions can determine tilt directions of liquid crystal molecules, the tilt directions of the liquid crystal molecules can be variously distributed by using the cut portions and the protrusions, so that the wide viewing angle can be secured.
However, there is a problem in that side visibility deteriorates in comparison to front visibility of the liquid crystal display apparatus with a vertical alignment mode. For example, images of side portions of a liquid crystal display apparatus with a vertically aligned pattern provided with cut portions become brighter. In more severe cases, the brightness difference between high gray voltages disappears and a distorted image may be displayed.
Methods proposed to solve these problems include providing different transmittances by dividing one pixel into two sub-pixels, coupling the two sub-pixels in a capacitive manner, and providing different voltages to the two sub-pixels by directly applying a first voltage to one sub-pixel and a reduced second voltage relative to the first voltage to the other sub-pixel due to capacitive coupling.
However, use of the above proposed methods results in the generation of parasite capacitance between the pixel electrodes and the data lines, resulting in various defects, such as vertical specks and stitch defects. In particular, the defects in a normally black type of liquid crystal display apparatus are more dominant than those in a normally white type.
In order to solve the above noted problems, a method for providing storage electrodes between the data lines and the pixel electrodes has been proposed.
However, in cases where such storage electrodes are employed in a liquid crystal display apparatus having the aforementioned two sub-pixels, which are divided as left and right sub-pixels, the storage capacitances of the two sub-pixels are not uniform and are different from each other due to alignment variation. Therefore, kick-back voltages and charging ratios become different, that may result in defects such as flicker, latent images and specks to occur.
USPTO Backgrounds
USPTO Backgrounds