Patent ID: 7973784

Claim:
A drive circuit of an electro-optical device including: plural rows of scanning lines; plural columns of data lines; a plurality of common electrodes provided in correspondence with the plural rows of scanning lines; pixel switching elements provided in correspondence with intersections of the plural rows of scanning lines and the plural columns of data lines, each of which has one end connected to the data line corresponding thereto and is put into a conductive state when a scanning line corresponding thereto is selected; pixel capacitors, each of which has one end connected to the other end of the pixel switching element corresponding thereto and the other end of which is connected to the common electrode corresponding thereto; and pixels each having a gray scale level according to a hold voltage of the pixel capacitor corresponding thereto, the drive circuit comprises: a scanning line drive circuit for sequentially selecting one of the scanning lines in a predetermined order; a plurality of common electrode drive circuits for connecting the common electrodes to a power supply line, to which a predetermined voltage is applied, when the scanning line corresponding to the common electrode is selected, each common electrode drive circuit including a first transistor and a second transistor connected to each of the plurality of common electrodes; a common signal output circuit for supplying a common signal having a voltage for allowing a detection voltage of the common electrode corresponding to a scanning line to become a reference voltage when the scanning line is selected; and a data line drive circuit for supplying a data signal having a voltage according to the gray scale level of the pixel to the pixel corresponding to the selected scanning line via the data line, each of the first transistors connected to each common electrode has a gate electrode connected to the scanning line corresponding to the common electrode, a source electrode connected to the power supply line, and a drain electrode connected to the common electrode, each of the second transistors connected to each common electrode has a gate electrode connected to the scanning line corresponding to the common electrode, a source electrode connected to the common electrode, and a drain electrode connected to a detection line, and the common signal output circuit outputs the common signal to the power supply line such that the voltage of the detection line becomes the reference voltage.