Patent ID: 8810764

Claim:
A lateral-electric-field mode liquid crystal display device which enables display by rotating a homogeneously aligned liquid crystal by a lateral electric field that is substantially in parallel to a substrate applied between pixel electrodes and common electrodes, the liquid crystal display device comprising: a plurality of the pixel electrodes and a plurality of the common electrodes formed on a same layer and having comb-shaped parts extended alternately substantially in parallel to each other, wherein one of the plurality of the common electrodes is formed in a comb shape, the one common electrode comprising: first parts extended in parallel, a second part configured to connect the first parts, and a shielding part configured to shield a data line, one of the plurality of the pixel electrodes is provided in the comb-shaped common electrode substantially in parallel to the first parts, the first parts and the shielding part of the common electrode and a first part of the pixel electrode are tilted with respect to a liquid crystal initial alignment direction, the pixel electrode comprises: a floating electrode which has a substantially equal potential as the pixel electrode, overlaps with the first part of the pixel electrode via an insulating film, and extends toward a position close to the second part of the common electrode, and a protruded part which has a substantially equal potential as the pixel electrode and extends only toward one of the first parts of the common electrode, a reverse rotation locked region where homogeneously-aligned liquid crystals are locked is formed by being surrounded by the floating electrode, the protruded part, one of the first parts of the common electrode, and the second part of the common electrode, a rotating direction of liquid crystal molecules of the liquid crystal caused by a first electric field which works between the protruded part and the one of the first parts of the common electrode, and the lateral electric field which works between the first part of the pixel electrode and the first part of the common electrode in a region on an outside of a border of the reverse rotation locked region and the protruded part, are matched with each other, and an effective electric field which rotates the liquid crystal molecules in a forward direction is applied between the shielding part of the common electrode and the second part of the common electrode up to an edge of the second part of the common electrode.