Patent ID: 6822630
Filing Date: 2004-11-23
Classification: G09G

Abstract:
A liquid crystal display device having a layer of super twisted nematic liquid crystal that switches whole screen display and partial screen display as required, each of the whole screen display and the partial screen display having a number of duties, to perform time division driving, said liquid crystal display device comprising:a driving circuit executing a driving operation in a manner such that an applied voltage effective value of an OFF voltage at the partial screen display time and an applied voltage effective value of an OFF voltage at the whole screen display time should substantially coincide with each other, as well as an applied voltage effective value of an ON voltage at the partial screen display time and an applied voltage effective value of an ON voltage at the whole screen display time should substantially coincide with each other, wherein the number of duties between the full screen display and the partial screen display differs and a first bias ratio defined as a ratio of the applied voltage effective value of the ON voltage to the applied voltage effective value of the OFF voltage at the whole screen display time becomes as great as possible and a second bias ratio defined as a ratio of the applied voltage effective value of the ON voltage to the applied voltage effective value of the OFF voltage at the partial screen display time is less than or equal to the first bias ratio.