Patent ID: 7688394

Claim:
An active matrix liquid crystal display device comprising a plurality of gate lines, a plurality of source busses extending orthogonal to the gate lines, a plurality of liquid crystal elements provided in intersections of the gate lines with the source busses and, as a whole, disposed in matrix form, the liquid crystal elements being connected between a pixel electrode and an opposite electrode connected to a first bus line in a floating condition, a plurality of control circuits provided in relation with the liquid crystal elements, the control circuits having: first and second transistors, of which gates are connected to the gate lines respectively, arranged in series between the source busses and the pixel electrode, a third transistor provided between a midpoint node of the first and second transistors and a second bus line to serve as a switch, the second bus line being identical in potential to the first bus line and being electrically isolated from the first bus line, and a fourth transistor between a midpoint node of the first and second transistors and the pixel electrode to constitute a high resistance element, and wherein resistance of the third transistor is greater than ON resistance of the first or second transistor, the fourth transistor is greater in resistance than the third transistor, the OFF resistance of the first or second transistor is greater than the resistance of the fourth transistor.