Image display device, and display panel and driving method thereof, and pixel circuit

A display panel for image display, said display panel comprising a plurality of data lines for transferring a data voltage representing an image signal, a plurality of scan lines, and a plurality of pixel circuits, each pixel circuit being coupled to a corresponding said data line, a current scan line among the scan lines for transferring a current selection signal and a previos scan line among the scan lines for transferring a previous selection signal, each pixel circuit comprising:

• a display element for displaying a portion of an image, the image portion corresponding to a quantity of applied current;
• a first transistor having a main electrode and a control electrode;
• a capacitor coupled between the main electrode and the control electrode of the first transistor, wherein the first transistor is for generating the applied current in response to voltage between the main electrode and the control electrode;
• a second transistor having a control electrode coupled to the control electrode of the first transistor, the second transistor being configured to operate as a diode;
• a first switching element coupled to a main electrode of the second transistor, wherein the first switching element transfers the data voltage from the data lines to the second transistor in response to the current selection signal;
• a second switching element for transferring a precharge voltage to the control electrode of the first transistor in response to the previous selection signal before the data voltage is supplied;
• and
• a third switching element configured to be turned off in response to the previous selection signal for electrically isolating the first transistor from the display element, wherein
• the second switching element comprises a transistor of a first conductive type, the third switching element comprises a transistor of a second conductive type, the second conductive type being an opposite of the first conductive type.

A display panel for image display, said display panel comprising a plurality of data lines for transferring a data voltage representing an image signal, a plurality of scan lines for transferring a selection signal, and a plurality of pixel circuits, each pixel circuit being coupled to a corresponding said data line and two adjacent said scan lines, each pixel circuit comprising:

• a display element for displaying a portion of an image, the image portion corresponding to a quantity of applied current;
• a first transistor having a main electrode and a control electrode;
• a capacitor coupled between the main electrode and the control electrode of the first transistor, wherein the first transistor is for generating the applied current in response to voltage between the main electrode and the control electrode;
• a second transistor having a control electrode coupled to the control electrode of the first transistor, the second transistor being configured to operate as a diode;
• a first switching element coupled to a main electrode of the second transistor, wherein the first switching element transfers the data voltage from the data lines to the second transistor in response to the selection signal from one of the two adjacent scan lines;
• a second switching element for transferring a precharge voltage to the control electrode of the first transistor in response to a first control signal before the data voltage is supplied;
• and
• a third switching element configured to be turned off in response to a second control signal for electrically isolating the first transistor from the display element,
• wherein the two adjacent scan lines comprise a current scan line and a previous scan line, and said one of the two adjacent scan lines is the current scan line,
• wherein the third switching element is turned off during a time period of transferring the precharge voltage using the first control signal and another time period of transferring the data voltage using the selection signal from the current scan line, and
• wherein the third switching element comprises third and fourth transistors coupled in series,
• the second control signal comprising a third control signal for turning the third transistor off during the time period of transferring the precharge voltage, and a fourth control signal for turning the fourth transistor off during said another time period of transferring the data voltage.

A method for driving an image display device coupled to a current scan line and a previous scan line among a plurality of scan lines, the image display device comprising a first transistor having a main electrode and a control electrode;

• a capacitor coupled between the main electrode and the control electrode of the first transistor, the first transistor being for generating a current corresponding to a voltage charged in the capacitor, a second transistor having a control electrode coupled to the control electrode of the first transistor and being configured to operate as a diode, and a display element for displaying a portion of an image corresponding to a quantity of the current generated by the first transistor, the method comprising:
• transferring a precharge voltage to the control electrode of the first transistor in response to a previous selection signal from the previous scan line during a first time period;
• transferring a data voltage to the control electrode of the first transistor through the second transistor in response to a current selection signal from the current scan line during a second time period;
• and
• interrupting the transfer of the data voltage,
• wherein the first transistor is electrically isolated fromthe display element in response to the previous selection signal during the first time period.

A method for driving a voltage programming type image display device coupled to two adjacent scan lines, the image display device comprising a first transistor having a main electrode and a control electrode;

• a capacitor coupled between the main electrode and the control electrode of the first transistor, the first transistor being for generating a current corresponding to a voltage charged in the capacitor, a second transistor having a control electrode coupled to the control electrode of the first transistor and being configured to operate as a diode, and a display element for displaying a portion of an image corresponding to a quantity of the current generated by the first transistor, the method comprising:
• transferring a precharge voltage to the control electrode of the first transistor in response to a first control signal during a first time period;
• transferring a data voltage to the control electrode of the first transistor through the second transistor in response to a selection signal from one of the two adjacent scan lines during a second time period;
• and
• interrupting the transfer of the data voltage,
• wherein the first transistor is electrically isolated from the display element during at least one of the first time period in which a capacitor coupled to the first transistor is charged with the precharge voltage or the second time period in which the capacitor is charged with the data voltage,
• wherein the first transistor is electrically isolated from the display element in response to a second control signal during the second time period,
• wherein the second control signal is the selection signal from said one of the two adjacent scan lines, and
• wherein the first transistor is electrically isolated from the display element in response to the first control signal during the first time period.

A method for driving a voltage programming type image display device coupled to two adjacent scan lines, the image display device comprising a first transistor having a main electrode and a control electrode;

• a capacitor coupled between the main electrode and the control electrode of the first transistor, the first transistor being for generating a current corresponding to a voltage charged in the capacitor, a second transistor having a control electrode coupled to the control electrode of the first transistor and being configured to operate as a diode, and a display element for displaying a portion of an image corresponding to a quantity of the current generated by the first transistor, the method comprising:
• transferring a precharge voltage to the control electrode of the first transistor in response to a first control signal during a first time period;
• transferring a data voltage to the control electrode of the first transistor through the second transistor in response to a selection signal from one of the two adjacent scan lines during a second time period;
• interrupting the transfer of the data voltage;
• and
• preventing the precharge voltage and the data voltage from being transferred to the control electrode of the first transistor between the first and second time periods,
• wherein the first transistor is electrically isolated from the display element during at least one of the first time period in which a capacitor coupled to the first transistor is charged with the precharge voltage or the second time period in which the capacitor is charged with the data voltage,
• wherein the first transistor is electrically isolated from the display element in response to a second control signal during the second time period,
• wherein the second control signal is the selection signal from said one of the two adjacent scan lines, and
• wherein the two adjacent scan lines comprise a current scan line and a previous scan line, wherein said one of the two adjacent scan lines is the current scan line.

A method for driving an image display device coupled to two adjacent scan lines the image display device comprising a first transistor having a main electrode and a control electrode;

• a capacitor coupled between the main electrode and the control electrode of the first transistor, the first transistor being for generating a current corresponding to a voltage charged in the capacitor, a second transistor having a control electrode coupled to the control electrode of the first transistor and being configured to operate as a diode, and a display element for displaying a portion of an image corresponding to a quantity of the current generated by the first transistor, the method comprising:
• transferring a precharge voltage to the control electrode of the first transistor in response to a first control signal during a first time period;
• transferring a data voltage to the control electrode of the first transistor through the second transistor in response to a selection signal from one of the two adjacent scan lines during a second time period;
• interrupting the transfer of the data voltage;
• and
• preventing the precharge voltage and the data voltage from being transferred to the control electrode of the first transistor between the first and second time periods,
• wherein the first transistor is electrically isolated from the display element during at least one of the first time period or the second time period,
• wherein the two adjacent scan lines comprise a current scan line and a previous scan line, wherein said one of the two adjacent scan lines is the current scan line,
• wherein the first control signal is a selection signal from the previous scan line, the first transistor is electrically isolated from the display element in response to the selection signal from the previous scan line during the first time period, and
• the first transistor is electrically isolated from the display element in response to the selection signal from the current scan line during the second time period.

A voltage programming type pixel circuit, which responds to a precharge voltage from a first signal line and a data voltage representing an image signal from a second signal line, the pixel circuit coupled to a current scan line and a previous scan line, the pixel circuit comprising:

• a first transistor having a main electrode and a control electrode;
• a capacitor coupled between the main electrode and the control electrode, wherein the first transistor is for generating a current in response to a voltage charged in the capacitor;
• a second transistor having a control electrode coupled to the control electrode of the first transistor, the second transistor being configured to operate as a diode;
• a display element for displaying a portion of an image, said image portion corresponding to the current generated by the first transistor;
• and
• switching means coupled between the first transistor and the display element,
• wherein the precharge voltage is applied to the control electrode of the first transistor in response to a previous selection signal from the previous scan line for a first time period, and the data voltage is applied to the control electrode of the first transistor in response to a current select signal from the current scan line for a second time period, and the first transistor is electrically isolated from the display element by the switching means during at least one of the first time period in which the capacitor is charged with the precharge voltage, or the second time period in which the capacitor is charged with the data voltage, and
• wherein the switching means is controlled by the previos select signal.

A display device comprising:

• a display element for displaying a portion of an image in response to a current being applied;
• a first transistor having a main electrode and a control electrode, and coupled between a voltage source and the display element;
• a capacitor coupled between the main electrode and the control electrode, wherein the first transistor is for generating the current in response to a charge in the capacitor;
• a first switching element coupled between the first transistor and the display element to interrupt the current to the display element while charging the capacitor using at least one of a precharge voltage or a data voltage representative of the image portion;
• and
• a second switching element coupled to a selection signal, wherein, when the selection signal is activated, the second switching element allows the data voltage to be applied to the capacitor for charging and the first switching element is turned off to prevent the current from flowing to the display element.

A display device comprising:

• a display element for displaying a portion of an image in response to a current being applied;
• a first transistor having a main electrode and a control electrode, and coupled between a voltage source and the display element;
• a capacitor coupled between the main electrode and the control electrode, wherein the first transistor is for generating the current in response to a charge in the capacitor;
• a first switching element coupled between the first transistor and the display element to interrupt the current to the display element while charging the capacitor using at least one of a precharge voltage or a data voltage representative of the image portion;
• a second switching element coupled to a first selection signal, wherein, when the first selection signal is activated, the second switching element allows the precharge voltage to be applied to the capacitor for charging and the first switching element is turned off to prevent the current from flowing to the display element;
• and
• a third switching element coupled to a second selection signal, wherein, when the second selection signal is activated, the third switching element allows the data voltage to be applied to the capacitor for charging and the first switching element is turned off to prevent the current from flowing to the display element.

A display device comprising:

• a display element for displaying a portion of an image in response to a current being applied;
• a first transistor having a main electrode and a control electrode, and coupled between a voltage source and the display element;
• a capacitor coupled between the main electrode and the control electrode of the first transistor, wherein the first transistor is for generating the current in response to a charge in the capacitor;
• a first switching element coupled between the first transistor and the display element to interrupt the current to the display element while charging the capacitor using at least one of a precharge voltage or a data voltage representative of the image portion;
• a second switching element coupled to a selection signal, wherein, when the selection signal is activated, the second switching element allows the data voltage to be applied to the capacitor for charging and the first switching element is turned off to prevent the current from flowing to the display element;
• and
• a second transistor having a control electrode and a main electrode, wherein the control electrode of the second transistor is coupled to the control electrode of the first transistor, the main electrode of the second transistor is coupled to the data voltage via the second switching element, and the second transistor is configured to operate as a diode.