Pixel circuit and display device including the same

A pixel circuit comprising:

• a driving element comprising a first electrode electrically connected to a first node to which a pixel driving voltage is configured to be applied, a gate electrode electrically connected to a second node, and a second electrode electrically connected to a third node;
• a light-emitting element comprising an anode electrode electrically connected to a fourth node and a cathode electrode configured to receive a low-potential power supply voltage;
• a first switch element comprising a first electrode to which an initialization voltage is configured to be applied, a gate electrode to which an initialization pulse is configured to be applied, and a second electrode electrically connected to the second node, the first switch element is configured to supply the initialization voltage to the second node in response to the initialization pulse;
• a second switch element comprising a first electrode electrically connected to the third node or the fourth node, a gate electrode to which a sensing pulse is configured to be applied, and a second electrode to which a reference voltage configured to be applied, the second switch element is configured to supply the reference voltage to the third node or the fourth node in response to the sensing pulse;
• a third switch element comprising a first electrode to which a data voltage is configured to be applied, a gate electrode to which a scan pulse is configured to be applied, and a second electrode electrically connected to the second node, the third switch element is configured to supply the data voltage to the second node in response to the scan pulse;
• and
• a fourth switch element comprising a first electrode electrically connected to the third node, a gate electrode to which a first emission control pulse is configured to be applied, and a second electrode electrically connected to the fourth node, the fourth switch element is configured to connect the third node to the fourth node in response to the first emission control pulse;
• a first capacitor electrically connected between the second node and the third node;
• and
• a second capacitor electrically connected between the third node and a node to which a constant voltage is configured to be applied, wherein the constant voltage is one of the pixel driving voltage, the initialization voltage, or the reference voltage.

A display device comprising:

• a display panel on which a plurality of data lines, a plurality of gate lines overlapping the data lines, a plurality of power lines to which different constant voltages are applied, and a plurality of subpixels are disposed;
• a data driver configured to supply a data voltage of pixel data to the data lines;
• and
• a gate driver configured to supply an initialization pulse, a sensing pulse, a scan pulse, and an emission control pulse to the gate lines,
• wherein each of the subpixels comprises:
• a driving element comprising a first electrode electrically connected to a first node to which a pixel driving voltage is applied, a gate electrode electrically connected to a second node, and a second electrode electrically connected to a third node;
• a light-emitting element comprising an anode electrode electrically connected to a fourth node and a cathode electrode to which a low-potential power supply voltage is applied;
• a first switch element comprising a first electrode to which an initialization voltage is applied, a gate electrode to which the initialization pulse is applied, and a second electrode electrically connected to the second node, and configured to supply the initialization voltage to the second node in response to the initialization pulse;
• a second switch element comprising a first electrode electrically connected to the third node or the fourth node, a gate electrode to which the sensing pulse is applied, and a second electrode to which a reference voltage is applied, and configured to supply the reference voltage to the third node or the fourth node in response to the sensing pulse;
• a third switch element comprising a first electrode to which the data voltage is applied, a gate electrode to which the scan pulse is applied, and a second electrode electrically connected to the second node, and configured to supply the data voltage to the second node in response to the scan pulse;
• and
• a fourth switch element comprising a first electrode electrically connected to the third node, a gate electrode to which the emission control pulse is applied, and a second electrode electrically connected to the fourth node, and configured to connect the third node to the fourth node in response to the emission control pulse,
• wherein the fourth switch is disabled during a time period in which at least one of the first or second switch is enabled and is enabled during a time period when both of the first and second switches are disabled.

A method of driving a light emitting element comprising:

• providing a high voltage to a first terminal of a drive transistor at the same time that an initialization voltage is provided to a gate of the drive transistor during a first time period;
• electrically isolating a first terminal of the light emitting element from a second terminal of the drive transistor during the first time period;
• providing a data signal that contains light emission data to a gate of the drive transistor during a second time period;
• maintaining the first terminal of the light emitting element being electrically isolated from the second terminal of the drive transistor during the second time period;
• providing a sense signal to a gate of a sense switching transistor during both the first and the second time periods, the sense switching transistor having a first terminal electrically connected to the first terminal of the light emitting element;
• boosting the voltage on the gate of the drive transistor during a third time period;
• electrically connecting the first terminal of the light emitting element to the second terminal of the drive transistor during the third time period;
• and
• emitting light from the light emitting element during a fourth time period.