Patent ID: 8836684

Claim:
A liquid crystal display device, comprising: a substrate; a plurality of first electrodes arranged in a matrix of rows and columns on the substrate; scan lines extending along with the first electrodes arranged in the row direction; signal lines extending along with the first electrodes arranged in the column direction; a pixel switch arranged in an intersection portion of the scan line and the column line to switch a connection between the signal line and the first electrode by a scan signal applied to the scan line; a scan line driving circuit to sequentially scan the scan lines; a plurality of second electrodes arranged so as to counter the first electrodes with an insulating layer positioned between the first electrodes and the second electrodes, and the second electrodes extend along with the pixels in the row direction; a first voltage supply line to supply a first voltage to the second electrode; a second voltage supply line to supply a second voltage to the second electrode; a control circuit; a first switch circuit arranged between the first and second voltage supply lines and the second electrodes to switch a connection between the first voltage supply line and the second electrodes, and a connection between the second voltage supply line and the second electrodes by a control signal outputted from the control circuit; a second switch circuit arranged between the first voltage supply line and the signal line to switch a connection between the first voltage supply line and the signal line by the control signal outputted from the control circuit; and a gate open circuit to receive signals from the scan line driving circuit and the control circuit, the gate open circuit supplying a signal to switch on the pixel witch to the scan line, wherein the first switch circuit includes a first switching element to switch a connection between the first voltage supply line and the second electrode and a second switching element to switch the connection between the second voltage supply line and the second electrode under control by the control circuit; the second switch circuit includes a third switching element to switch the connection between the first voltage supply line and the signal line under control by the control circuit, the gate open circuit includes a NOT circuit to receive a signal outputted from the signal line driving circuit, and a NAND circuit to receive the output signal from the NOT circuit and the control signal from the control circuit; and the control circuit switches on the first switching element, switches off the second switching element, and switches on the third switching element by setting the control signal to a low level when the liquid crystal display device is powered off.