Active-matrix display device and method for driving the same

An active-matrix display device comprising:

• a display portion including a plurality of data signal lines, a plurality of scanning signal lines crossing the data signal lines, and a plurality of pixel forming portions arranged in a matrix along the data signal lines and the scanning signal lines, at least two of the scanning signal lines being different in time constant from each other;
• a scanning signal line driver circuit configured to generate a plurality of scanning signals respectively provided to the scanning signal lines;
• a scanning clock generation circuit configured to generate a scanning clock signal to be provided to the scanning signal line driver circuit;
• and
• a waveform control circuit configured to control a waveform of the scanning clock signal, the waveform control circuit being provided inside or outside the scanning clock generation circuit, wherein,
• each of the pixel forming portions includes:
• a capacitive electrode serving as one of electrodes that form predetermined capacitance;
• and
• a field-effect transistor serving as a pixel switching element and having a first conduction terminal connected to one of the data signal lines, a second conduction terminal connected to the capacitive electrode, and a control terminal connected to one of the scanning signal lines,
• the scanning signal line driver circuit includes:
• a shift register configured to sequentially transfer an inputted start pulse and having stages corresponding in number to the scanning signal lines;
• and
• a plurality of analog switches respectively connected to the scanning signal lines and being respectively turned on or off by output signals from the stages of the shift register that correspond to the scanning signal lines to which the analog switches are connected,
• the scanning signal line driver circuit applies a plurality of signals respectively to the scanning signal lines as the scanning signals, the plurality of signals being obtained by sampling the scanning clock signal by the analog switches, and
• the waveform control circuit controls the waveform of the scanning clock signal such that a time period taken for a voltage of the scanning clock signal to change from an on-voltage for rendering the pixel switching element in ON-state to an off-voltage for rendering the pixel switching element in OFF-state, at a fall or rise of a pulse included in the scanning clock signal, increases as the scanning signal line to which a scanning signal including the pulse is to be applied decreases in time constant.