Liquid crystal display device

Abstract

A liquid crystal display device having a second substrate and a first substrate that is placed so as to face the above-described second substrate with pixel regions aligned in a matrix is provided with: protrusions that are formed on pixel boarders and protrude from the second substrate on the liquid crystal side; first electrodes made of sidewall electrodes formed on sidewalls of protrusions and a lower end side electrode extending from the sidewall electrodes on the bottom side; and second electrodes made of a first linear electrode formed within a pixel region and a second linear electrode that is formed on the second substrate and faces the first linear electrode.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]The present application claims priority over Japanese Patent Application JP2011-154440 filed on Jul. 13, 2011, the contents of which are hereby incorporated into this application by reference.BACKGROUND OF THE INVENTION[0002](1) Field of the Invention[0003]The present invention relates to a liquid crystal display device, and in particular, to an in-plane switching mode liquid crystal display device where an electrical field is applied parallel to the surface of the substrates.[0004](2) Description of the Related Art[0005]In in-plane switching (IPS) mode liquid crystal display devices, liquid crystal molecules are aligned parallel to the surface of the panel and an electrical field (lateral electrical field) is applied parallel to the surface of the panel so that the liquid crystal molecules rotate by 90° in the plane. In such IPS mode liquid crystal display devices, a common electrode is formed on the first substrate where video signal lin...

AI Technical Summary

Benefits of technology

The present invention solves the problem of decreased efficiency in display mode and decreased contrast ratio in liquid crystal display devices that have pixel electrodes that are proximate to the end portions of adjacent pixels. It provides a liquid crystal display device that can increase efficiency in display mode even if electrodes are formed so as to stand in the liquid crystal layer.

Problems solved by technology

However, the alignment of liquid crystal cannot be controlled in the places of the pixel electrodes, the common electrodes and the vicinity thereof, and thus, it is known that the aperture ratio is low.

In the liquid crystal display devices having this structure, however, the pixel electrodes in the adjacent pixels are proximate to the end portions of a pixel, and therefore, there is an electrical field distribution in and around the pixel electrode due to the difference in the potential between a pixel and its adjacent pixels.

This difference in the potential becomes maximum when white is displayed through the driving for inverting the display pixel by pixel, and in this case, there is a concern that the efficiency in the display mode for white display may lower due to the lack of balance in the distribution of the lateral electrical field.

Likewise, during the driving for inverting the display pixel by pixel when a pixel displays black and its adjacent pixels display white, the brightness for displaying black increases, that is to say, the transmittance increases at the time when black is displayed, and therefore, there is a concern that the contrast ratio may lower.

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