| 摘要 |
PROBLEM TO BE SOLVED: To obtain good sharpens, a high contrast ratio and high transmittance in a bright state by providing a liquid crystal layer with a spiral structure which gradually changes the major axis direction of liquid crystal molecules between substrates when voltage is impressed on this layer. SOLUTION: Nematic liquid crystals 10 which are negative in dielectric constant anisotropy and are added with a chiral agent are injected between a pair of substrates 20 and 21 of a perpendicular orientation type ECB mode liquid crystal display element. At the time of not impressing the voltage, double refraction does not exist in the intra-surface direction of the substrates 20, 21 and since the liquid crystal molecules 10 are perpendicularly oriented, the good black display is obtd. When the voltage is impressed on this cell, the liquid crystal molecules 10 fall and retardation increases, thus attaining the state of allowing the transmission of light (bright state). At this time, the liquid crystal molecules 10 attain the twisted structure (spiral arrangement) to gradually change the major axis direction as shown by dotted lines between the upper and lower substrates 20 and 21 on account of the chiral agent. The sharpness which is the ratio of the change in the transmittance to the change in the voltage is made to have a high value by such chirality. |
