Patent ID: 9293094
Filing Date: 2016-03-22
CPC Classification: G09G

Claim Text:
1. A liquid crystal display device comprising: a substrate configuring a display panel; and a plurality of switching elements formed on the substrate, in which an oxide semiconductor is used as a semiconductor layer configuring the plurality of switching elements, the liquid crystal display device comprising: a plurality of video signal lines for transmitting a video signal; a plurality of scanning signal lines that intersect with the plurality of video signal lines; a plurality of pixel formation portions arranged in a matrix shape corresponding to the plurality of video signal lines and the plurality of scanning signal lines; a scanning signal line drive circuit that includes a shift register formed of a plurality of bistable circuits that sequentially output pulses based on a clock signal, and selectively drives the plurality of scanning signal lines based on the pulses output from the shift register, the plurality of bistable circuits being provided in one-to-one correspondence with the plurality of scanning signal lines; a power supply state detector that detects ON/OFF states of power supply provided from outside; and a drive controller that outputs the clock signal, a reference potential as a potential which becomes a reference of operations of the plurality of bistable circuits, and a clear signal for initializing states of the plurality of bistable circuits, and controls an operation of the scanning signal line drive circuit, wherein the plurality of video signal lines, the plurality of scanning signal lines, the plurality of pixel formation portions, and the scanning signal line drive circuit are formed on the substrate, each of the plurality of bistable circuits has the power supply state detector applies a predetermined power supply off signal to the drive controller when the power supply state detector detects an OFF state of the power supply, and when the drive controller receives the power supply off signal, the drive controller controls an operation of the scanning signal line drive circuit so that a first discharge process of discharging a charge in the pixel formation portion is performed and thereafter controls an operation of the scanning signal line drive circuit so that a second discharge process of discharging a charge on the scanning signal line, a charge of the second-node, and a charge of the first-node is performed.