Pixel circuits and display device using the same

A pixel circuit comprising:

• a light-emitting element;
• a driving transistor electrically connected to the light-emitting element through a second electrode thereof to supply a current to the light-emitting element, and controlled by a voltage applied to a gate electrode thereof;
• a capacitor having a first terminal connected to the gate electrode of the driving transistor;
• and
• an internal compensation unit including a plurality of switch elements to sense a threshold voltage of the driving transistor during a sampling period, and supply a current, in which the threshold voltage is compensated for, to the light-emitting element,
• wherein data lines, through which an analog data voltage converted from a digital data signal is supplied, are connected to the internal compensation unit, the digital data signal being configured to adjust a light emission grayscale of the light-emitting element based on a number of bits thereof,
• wherein the data lines include a first data line and a second data line, the first data line being electrically connected to a first electrode of the driving transistor, and the second data line being electrically connected to a second terminal of the capacitor,
• wherein the light-emitting element emits light with a grayscale corresponding to a first voltage by charging a difference between a voltage of the second data line and a voltage of the first data line as the first voltage in the capacitor during the sampling period,
• wherein the first data line is electrically connected to the first electrode of the driving transistor through a first switch element,
• wherein the second data line is electrically connected to the second terminal of the capacitor through a second switch element,
• wherein the first switch element and the second switch element are controlled by a same scan signal and are turned on during the sampling period, and
• wherein the second terminal of the capacitor is electrically connected to a pixel driving voltage line through one or more switch elements that are turned off during the sampling period.

A display device comprising:

• a display panel in which data lines and gate lines crossing each other are disposed, the display panel including pixels;
• a data driver configured to convert a digital data signal into an analog data voltage and supply the analog data voltage to the data lines;
• a gate driver configured to supply a gate signal to the gate lines;
• a timing controller configured to transmit the digital data signal to the data driver and generate a signal for controlling operation timings of the data driver and the gate driver;
• and
• a power supply unit configured to generate voltages for driving the pixels, the data driver, the gate driver, and the timing controller,
• wherein each of the pixels includes sub-pixels each having a pixel circuit,
• wherein the pixel circuit includes:
• a light-emitting element;
• a driving transistor electrically connected to the light-emitting element through a second electrode thereof to supply a current to the light-emitting element, and controlled by a voltage applied to a gate electrode thereof;
• a capacitor having a first terminal connected to the gate electrode of the driving transistor;
• and
• an internal compensation unit including a plurality of switch elements to sense a threshold voltage of the driving transistor during a sampling period and supply a current,
• in which the threshold voltage is compensated for, to the light-emitting element,
• wherein the data lines are connected to the internal compensation unit and adjust a light emission grayscale of the light-emitting element based on a number of bits of the digital data signal,
• wherein the data lines connected to the internal compensation unit include a first data line and a second data line, the first data line being electrically connected to a first electrode of the driving transistor, and the second data line being electrically connected to a second terminal of the capacitor,
• wherein the light-emitting element emits light with a grayscale corresponding to a first voltage by charging a difference between a voltage of the second data line and a voltage of the first data line as the first voltage in the capacitor during the sampling period,
• wherein the voltage of the first data line supplied to the pixel circuit is a data voltage for lower bits of the digital data signal,
• wherein the voltage of the second data line supplied to the pixel circuit is a data voltage for upper bits of the digital data signal,
• wherein the number of bits of the digital data signal is an even natural number, and
• wherein each of a number of the upper bits and a number of the lower bits is half of the number of bits of the digital data signal.

A display device comprising:

• a display panel in which data lines and gate lines crossing each other are disposed, the display panel including pixels;
• a data driver configured to convert a digital data signal into an analog data voltage and supply the analog data voltage to the data lines;
• a gate driver configured to supply a gate signal to the gate lines;
• a timing controller configured to transmit the digital data signal to the data driver and generate a signal for controlling operation timings of the data driver and the gate driver;
• and
• a power supply unit configured to generate voltages for driving the pixels, the data driver, the gate driver, and the timing controller,
• wherein each of the pixels includes sub-pixels each having a pixel circuit,
• wherein the pixel circuit includes;
• a light-emitting element;
• a driving transistor electrically connected to the light-emitting element through a second electrode thereof to supply a current to the light-emitting element, and controlled by a voltage applied to a gate electrode thereof;
• a capacitor having a first terminal connected to the gate electrode of the driving transistor;
• and
• an internal compensation unit including a plurality of switch elements to sense a threshold voltage of the driving transistor during a sampling period and supply a current, in which the threshold voltage is compensated for, to the light-emitting element,
• wherein the data lines are connected to the internal compensation unit and adjust a light emission grayscale of the light-emitting element based on a number of bits of the digital data signal,
• wherein the data lines connected to the internal compensation unit include a first data line and a second data line, the first data line being electrically connected to a first electrode of the driving transistor, and the second data line being electrically connected to a second terminal of the capacitor,
• wherein the light-emitting element emits light with a grayscale corresponding to a first voltage by charging a difference between a voltage of the second data line and a voltage of the first data line as the first voltage in the capacitor during the sampling period,
• wherein the first data line is electrically connected to the first electrode of the driving transistor through a first switch element,
• wherein the second data line is electrically connected to the second terminal of the capacitor through a second switch element,
• wherein the first switch element and the second switch element are controlled by a same scan signal and are turned on during the sampling period,
• wherein the power supply unit supplies voltages for driving the pixels to a pixel driving voltage line, and
• wherein the second terminal of the capacitor is electrically connected to the pixel driving voltage line through one or more switch elements that are turned off during the sampling period.

A display device comprising:

• a display panel in which a plurality of data lines and a plurality of gate lines crossing each other are disposed, the display panel including pixels;
• a data driver configured to convert a digital data signal into an analog data voltage and supply the analog data voltage to the data lines;
• and
• a demultiplexing unit configured to distribute the data voltage converted from the digital data signal by the data driver to the data lines,
• wherein each of the pixels includes sub-pixels each having a pixel circuit,
• wherein one of the gate lines and two of the data lines are connected to each of the sub-pixels,
• wherein the two data lines connected to each of the sub-pixels include:
• a first data line to which one of voltages, obtained by dividing the digital data signal into two parts and converting each, is supplied through one channel of the data driver, and
• a second data line, to which the other one of the voltages is supplied by being provided through another channel of the data driver and being distributed by the demultiplexing unit,
• wherein the pixel circuit includes:
• a light-emitting element;
• a driving transistor electrically connected to the light-emitting element through a second electrode thereof to supply a current to the light-emitting element, and controlled by a voltage applied to a gate electrode thereof;
• a capacitor having a first terminal connected to the gate electrode of the driving transistor;
• and
• an internal compensation unit including a plurality of switch elements to sense a threshold voltage of the driving transistor during a sampling period and supply a current, in which the threshold voltage is compensated for, to the light-emitting element,
• wherein the first data line and the second data line, which are data lines connected to each of the sub-pixels, are connected to the internal compensation unit and adjust a light emission grayscale of the light-emitting element based on a number of bits of the digital data signal, the first data line being electrically connected to a first electrode of the driving transistor, and the second data line being electrically connected to a second terminal of the capacitor,
• wherein the light-emitting element emits light with a grayscale corresponding to a first voltage by charging a difference between a voltage of the second data line and a voltage of the first data line as the first voltage in the capacitor during the sampling period,
• wherein the first data line is electrically connected to the first electrode of the driving transistor through a first switch element,
• wherein the second data line is electrically connected to the second terminal of the capacitor through a second switch element,
• wherein the first switch element and the second switch element are controlled by a same scan signal and are turned on during the sampling period,
• wherein a power supply unit supplies voltages for driving the pixels to a pixel driving voltage line, and
• wherein the second terminal of the capacitor is electrically connected to the pixel driving voltage line through one or more switch elements that are turned off during the sampling period.