Liquid crystal display

Abstract

A liquid crystal display uses a layout which reduces the number of data lines relative to the number of pixel columns by providing one data line for every two pixel columns. The display is structured to prevent a passivation layer from becoming opaque due to a manufacturing haze effect by forming the pixel electrode below a gate insulating layer. It is structured to prevent a drain electrode from being damaged due to an etchant used for patterning the pixel electrode. Further, it is structured to prevent a short circuit between a common voltage line and a gate line while not substantially reducing an aperture ratio by disposing a common voltage contact hole for electrically connecting the common voltage line with a common electrode between vertically extending portions of two gate lines that generally extend horizontally.

Description

technical field [0001] The invention relates to a liquid crystal display. Background technique [0002] Liquid crystal displays (LCDs) are one of the most common types of flat panel displays in use today. An LCD is a display device in which liquid crystal molecules of a liquid crystal layer are rearranged by applying an electric field across the liquid crystal layer so that the LC molecules are reoriented and their optical properties are used to control the amount of transmitted light. An electric field across the liquid crystal layer is typically created by applying a voltage between a so-called pixel electrode and an opposing common electrode. In one type of LCD, pixel electrodes and opposing common electrodes are respectively disposed on separate substrates. In the second type of LCD, a pixel electrode and an opposite common electrode are integrally disposed on the same substrate. [0003] Liquid crystal type displays have advantages such as being easy to make thin, bu...

AI Technical Summary

Problems solved by technology

[0004] However, during the fabrication of such devices (with pixel and common electrodes on the same substrate), new problems gradually arise

The first such problem is that the optical transmittance may be reduced by the haze effect caused by chemical reduction reactions that may occur between these two electrodes

Furthermore, if a pixel electrode is formed to directly contact the drain electrode of a corresponding thin film transistor (TFT) or another such switching element, the drain electrode can be damaged by the etchant used to pattern the pixel electrode

In addition, in order to connect the common electrode to the common voltage line for transmitting the common electrode voltage thereto, it may be necessary to form a contact hole, resulting in a decrease in the aperture ratio of the liquid crystal display.

In addition, the common voltage transmission line and the gate line may become short-circuited to each other, for example, due to static electricity generated at the time of forming the drain contact hole

[0005] Also, as liquid crystal displays generally increase in size (due to market demand), the number of data lines provided on one substrate tends to increase, and the cost of data drivers for driving these data lines also tends to increase, thereby increasing the liquid crystal display. The overall manufacturing cost of the display

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