Patent ID: 7511780

Claim:
An active matrix liquid crystal display device comprising: a pixel transistor; a wiring layer that is connected to the pixel transistor; a first insulating layer that is provided on the pixel transistor and the wiring layer; a lower electrode layer that is provided on the first insulating layer and used as one of a common electrode layer and a pixel electrode layer; a second insulating layer that is provided on the lower electrode layer; and an upper electrode layer that is provided on the second insulating layer and used as the other of the common electrode layer and the pixel electrode layer, wherein where a display pixel has a substantially square shape and is composed of a plurality of sub pixels, a pitch at which the display pixels are arranged vertically and a pitch at which the display pixel are arranged horizontally are respectively P per 25.381 mm, a channel width of the pixel transistor is W, the on resistance per unit channel width of the pixel transistor is Ï ON , a period of time during which a gate line and drain line of the pixel transistor are simultaneously turned on is Ï„ON, a relative dielectric constant of the second insulating layer Îµ, a vacuum dielectric constant is Îµ 0 , and a correction parameter is k, the thickness t of the second insulating layer satisfies the following inequalities: t <[(Îµ 0 Îµ/W )Ã—{(0.025381 /P ) 2 /6}]/(100Ã—10 âˆ’9 ); and t >[(Îµ 0 Îµ/W )Ã—{(0.025381 /P ) 2 /6 }Ã—kÃ—Ï ON ]/Ï„ ON , and wherein liquid crystal molecules are driven by applying voltage between the upper electrode layer and the lower electrode layer.