| 摘要 |
PROBLEM TO BE SOLVED: To obtain a liquid crystal display element having a high visual field angle and high contrast by setting the pretilt angles formed by the major axis direction of liquid crystal molecules with substrates within a specific range. SOLUTION: The orientation directions (arrows 19, 20) of the liquid crystal molecules in the off-state of the liquid crystal display element of an IPS system are set perpendicular to the longitudinal direction of the teeth of comb tooth electrodes 15, 16 and nearly parallel with the substrates 11, 12 and are parallel orientation facing the same direction. The angles formed by the major axis of the liquid crystal molecules with the substrates 11, 12, i.e., the pretilt anglesΨare so set as to be kept within the range of 0 to 1.5 deg.. The equal contrast curve of the liquid crystal display element of the IPS system is such that the contrast in the major axis direction of the liquid crystal molecules is high but the contrast is poor and there is the relatively strong dependency on visual angles in the minor axis direction and other specific directions. The probable reason thereof lies in that the liquid crystal molecules have the relatively high pretilt angles and the incident light receives the double refraction effect of the liquid crystal molecules. The double refraction effect is, thereupon, suppressed in all directions by setting the pretilt angles low.
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