Liquid crystal display device

Abstract

Provided is a liquid crystal display device having a pixel comprising a liquid crystal layer 42, a pixel electrode 12 and a counter electrode 22 confronting each other through the liquid crystal layer, a pair of vertically-oriented films 32a and 32b, and orientation maintaining layers 34a and 34b formed on the surfaces of the liquid crystal layer sides of the oriented films and made of a photochemically polymerized material. The pixel electrode includes cross-shaped trunks 12h and 12v arranged over the polarizing axes of a pair of polarizing plates, and a plurality of branches 12a, 12b, 12c and 12d extending in directions of about 45 degrees from the cross-shaped trunks. The counter electrode has a cross-shaped opening 22a arranged to confront the cross-shaped trunks. When a predetermined voltage is applied to the liquid crystal layer, four liquid crystal domains are formed, and the liquid crystal molecules of the regions corresponding individually to the four liquid crystal domains are specified in a pre-tilt azimuth by the orientation maintaining layers.

Description

technical field [0001] The present invention relates to a liquid crystal display device, and particularly relates to an alignment control structure suitably applied to a liquid crystal display device having a relatively small pixel pitch. Background technique [0002] Currently, as liquid crystal display devices having wide viewing angle characteristics, transverse electric field modes (including IPS mode and FFS mode) and vertical alignment (VA) modes are being used. Since the VA mode is superior to the transverse electric field mode in terms of mass productivity, it is widely used for TV applications and mobile applications. [0003] VA mode liquid crystal display devices are further broadly classified into MVA mode (see Patent Document 1) and CPA mode (see Patent Document 2). [0004] In the MVA mode, linear orientation-regulating units (slits or ribs) are arranged along two directions orthogonal to each other, and between the orientation-regulating units, the azimuth an...

AI Technical Summary

Problems solved by technology

[0005] However, the above-mentioned MVA mode is not suitable for small pixels (for example, less than 100 μm on the short side, especially less than 60 μm)

Since the part where the slit (or rib) is installed does not contribute to the display, if it is applied to a pixel whose short side is less than 100 μm, the transmittance (brightness) will be extremely reduced

[0014] However, in the liquid crystal display device 90B, unlike the rivet 92 of the liquid crystal display device 90A, which exerts an alignment restricting force regardless of the presence of an electric field, since the alignment restricting force is only found when a voltage is applied, when the applied voltage is low, Orientation restriction force cannot be obtained sufficiently

Therefore, especially at a grayscale lower than the intermediate grayscale, there is a problem that the alignment of liquid crystal molecules is unstable, so it cannot be used practically.

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