Patent ID: 7259817

Claim:
A liquid crystal display device having a first substrate, a second substrate, a liquid crystal layer pinched between said first substrate and said second substrate, and a driving unit, wherein a characteristic of a reflectivity versus an applied voltage is a normally closed type and a characteristic of a transmissivity versus an applied voltage is the normally closed type: wherein said first substrate has a common electrode, and an upside polarization plate and an upside phase plate on an upper surface; wherein said second substrate has a reflective electrode and a transparent electrode connected with an active element, and a downside polarization plate and a downside phase plate on a lower surface; wherein said liquid crystal layer has a twist angle not less than 40 degrees and not more than 65 degrees; wherein a retardation of the liquid crystal layer in a reflective display unit is within a range of not less than 230 nm and not more than 300 nm; and wherein a retardation of the liquid crystal layer in a transmissive display unit is larger than the retardation of the liquid crystal layer in the reflective display unit, wherein the twist angle and Δnd of said liquid crystal layer are included within a polygon of which apexes, in a graph of which lateral axis is the twist angle of the liquid crystal layer and of which longitudinal axis is the Δnd, consist of six points: (twist angle of the liquid crystal layer, retardation Δnd of the liquid crystal layer)=(47 degrees, 216 nm), (60 degrees, 216 nm), (60 degrees, 259 nm), (42 degrees, 324 nm), (39 degrees, 324 nm), and (47 degrees, 252 nm).