Luminescent display device and method that drives the same

• US 20070075954A1
• Filed: 06/22/2006
• Published: 04/05/2007
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Chung, Hoon, Park, Young, Oh, Du
• Granted Patent: US 7,907,104 B2
• Time in Patent Office: Days
• US Class Current: 345/92
• CPC Class Codes: G09G 2300/0465 Improved aperture ratio, e.g. by size reduction of the pixel circuit, e.g. for improving the pixel density or the maximum displayable luminance or brightness
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G11C 19/184 with field-effect transistors, e.g. MOS-FET

Abstract

A luminescent display device and a method for driving the same are disclosed which are capable of increasing the aspect ratio of pixel regions. The luminescent display device includes a display including gate lines, and data lines extending orthogonally to the gate lines, a first shift register connected to one end of each of the gate lines, to sequentially supply first scan pulses to the gate lines, respectively, a second shift register connected to the other end of each of the gate lines, to sequentially supply second scan pulses to the gate lines, respectively, switching elements each adapted to switch an ON voltage or an OFF voltage from the associated data line in accordance with the first scan pulse from the associated gate line, and to switch an OFF voltage from the associated data line in accordance with the second scan pulse from the associated gate line, drive switching elements each adapted to generate current in accordance with the ON voltage from the associated switching element, each drive switching element being turned off in accordance with the OFF voltage from the associated switching element, capacitors each connected between gate and source terminals of an associated one of the drive switching elements, and light emitting elements each adapted to emit light in accordance with the current from the associated drive switching element.

Claims

1. A luminescent display device that comprises:

a display that includes a plurality of gate lines and a plurality of data lines that extend orthogonally to the gate lines;

a first shift register connected to one end of each of the gate lines, and adapted to sequentially supply first scan pulses to the gate lines;

a second shift register connected to the other end of each of the gate lines, and adapted to sequentially supply second scan pulses to the gate lines;

switching elements adapted to switch an ON voltage or an OFF voltage from one of the data lines in accordance with the first scan pulse from one of the gate lines, and to switch an OFF voltage from the associated data line in accordance with the second scan pulse from the associated gate line;

drive switching elements adapted to generate current in accordance with the ON voltage from an associated one of the switching elements, wherein the drive switching elements are turned off in accordance with the OFF voltage from the associated switching element;

capacitors connected between gate and source terminals of one of the drive switching elements; and

light emitting elements adapted to emit light in accordance with the current from an associated one of the drive switching elements.

2. The luminescent display device according to claim 1, wherein the first shift register includes a plurality of stages that supply a first scan pulse to an end of one of the gate lines.

3. The luminescent display device according to claim 2, wherein the second shift register includes a plurality of stages that supply a second scan pulse to an end of one of the gate lines.

4. The luminescent display device according to claim 3, wherein a first one of the stages included in the first shift register includes:

first, third, fifth, and seventh clock transfer lines that transfer the first, third, fifth, and seventh pulses, wherein the outputs are output in a sequential manner;

first and second power lines that transfer first and second voltages that have different polarities;

a first switching element that responds to a first start pulse synchronous with the seventh clock pulse, the first switching element that outputs the first start pulse in response to the first start pulse;

a second switching element that supplies the first start pulse output from the first switching element in response to the seventh clock pulse from the seventh clock transfer line;

a third switching element that outputs the first clock pulse from the first clock transfer line as a first scan pulse in response to the first start pulse supplied to the first node, and supplies the first scan pulse to one end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a fourth switching element that connects the other end of the capacitor and one end of the associated gate line in response to the first start pulse supplied to the first node;

a fifth switching element that supplies the first voltage to a second node in response to the third clock pulse from the third clock transfer line;

a sixth switching element that supplies the second voltage to the first node in response to the first voltage supplied to the second node, to turn off the third and fourth switching elements;

a seventh switching element that supplies the second voltage to one end of the associated gate line and to the downstream stage in response to the first voltage supplied to the second node;

an eighth switching element that supplies the second voltage to the second node in response to the first start pulse, to turn off the sixth and seventh switching elements; and

a ninth switching element that supplies the second voltage to the second node in response to a second start pulse synchronous with the eighth clock pulse, to turn off the sixth and seventh switching elements.

5. The luminescent display device according to claim 4, wherein the second, fourth, fifth, sixth, eighth, and ninth switching elements are dual switching elements that include two switching elements connected in series.

6. The luminescent display device according to claim 4, wherein each of the remaining stages of the first shift register, except for the first stage, includes:

first, third, fifth, and seventh clock transfer lines that transfer first, third, fifth, and seventh pulses;

first and second power lines that transfer the first and second voltages;

a first switching element that supplies a first scan pulse from the upstream stage to a first node in response to the first clock pulse synchronous with the first scan pulse from the upstream stage;

a second switching element that outputs the third clock pulse from the third clock transfer line as a first scan pulse in response to the first scan pulse supplied to the first node, and supplies the first scan pulse to one end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a third switching element that connects the other end of the capacitor and one end of the associated gate line in response to the first scan pulse supplied to the first node;

a fourth switching element that supplies the first voltage to a second node in response to the fifth clock pulse from the fifth clock transfer line;

a fifth switching element that supplies the second voltage to the first node in response to the first voltage supplied to the second node, to turn off the second and third switching elements;

a sixth switching element that supplies the second voltage to one end of the associated gate line and to the downstream stage in response to the first voltage supplied to the second node; and

a seventh switching element that supplies the second voltage to the second node in response to the first scan pulse from the upstream stage, to turn off the fifth and sixth switching elements.

7. The luminescent display device according to claim 6, wherein the first, third, fourth, fifth, and seventh switching elements are dual switching elements that include two switching elements connected in series.

8. The luminescent display device according to claim 4, wherein a first one of the stages included in the second shift register includes:

second, fourth, sixth, and eighth clock transfer lines that transfer second, fourth, sixth, and eighth pulses;

first and second power lines that transfer the first and second voltages;

a first switching element that responds to the second start pulse synchronous with the eighth clock pulse, the first switching element that outputs the second start pulse in response to the second start pulse;

a second switching element that supplies the second start pulse output from the first switching element in response to the eighth clock pulse from the eighth clock transfer line;

a third switching element that outputs the second clock pulse from the second clock transfer line as a second scan pulse in response to the second start pulse supplied to the first node, and supplies the second scan pulse to the other end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a fourth switching element that connects the other end of the capacitor and the other end of the associated gate line in response to the second start pulse supplied to the first node;

a fifth switching element that supplies the first voltage to a second node in response to the fourth clock pulse from the fourth clock transfer line;

a sixth switching element that supplies the second voltage to the first node in response to the first voltage supplied to the second node, to turn off the third and fourth switching elements;

a seventh switching element that supplies the second voltage to the other end of the associated gate line and to the downstream stage in response to the first voltage supplied to the second node;

an eighth switching element that supplies the second voltage to the second node in response to the second start pulse, to turn off the sixth and seventh switching elements; and

a ninth switching element that supplies the second voltage to the second node in response to the first start pulse synchronous with the seventh clock pulse, to turn off the sixth and seventh switching elements.

9. The luminescent display device according to claim 8, wherein the second, fourth, fifth, sixth, eighth, and ninth switching elements are dual switching elements that include two switching elements connected in series.

10. The luminescent display device according to claim 8, wherein each of the remaining stages of the second shift register, except for the first stage, includes:

second, fourth, sixth, and eighth clock transfer lines that transfer the second, fourth, sixth, and eighth clock pulses;

first and second power lines that transfer the first and second voltages;

a first switching element that supplies a second scan pulse from the upstream stage to a first node in response to the second clock pulse that is synchronous with the second scan pulse from the upstream stage;

a second switching element that outputs the fourth clock pulse from the fourth clock transfer line as a second scan pulse in response to the second scan pulse supplied to the first node, and supplies the second scan pulse to the other end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a third switching element that connects the other end of the capacitor and the other end of the associated gate line in response to the second scan pulse supplied to the first node;

a fourth switching element that supplies the first voltage to a second node in response to the sixth clock pulse from the sixth clock transfer line;

a fifth switching element that supplies the second voltage to the first node in response to the first voltage supplied to the second node, to turn off the second and third switching elements;

a sixth switching element that supplies the second voltage to the other end of the associated gate line and to the downstream stage in response to the first voltage supplied to the second node; and

a seventh switching element that supplies the second voltage to the second node in response to the second scan pulse from the upstream stage, to turn off the fifth and sixth switching elements.

11. The luminescent display device according to claim 10, wherein the first, third, fourth, fifth, and seventh switching elements are dual switching elements that include two switching elements connected in series.

12. The luminescent display device according to claim 3, wherein a first one of the stages included in the first shift register includes:

first, third, and fifth clock transfer lines that transfer first, third, and fifth ones of first through sixth clock pulses output in a sequential manner;

first and second power lines that transfer first and second voltages that have different polarities;

a first switching element that responds to a first start pulse that is synchronous with the fifth clock pulse, the first switching element outputs the first start pulse in response to the first start pulse;

a second switching element that supplies the first start pulse output from the first switching element in response to the fifth clock pulse from the fifth clock transfer line;

a third switching element that outputs the first clock pulse from the first clock transfer line as a first scan pulse in response to the first start pulse supplied to the first node, and supplies the first scan pulse to one end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a fourth switching element that connects the other end of the capacitor and one end of the associated gate line in response to the first start pulse supplied to the first node;

a fifth switching element that supplies the first voltage to a second node in response to the third clock pulse from the third clock transfer line;

a sixth switching element that supplies the second voltage to the first node in response to the first voltage supplied to the second node, to turn off the third and fourth switching elements;

a seventh switching element that supplies the second voltage to one end of the associated gate line and to the downstream stage in response to the first voltage supplied to the second node;

an eighth switching element that supplies the second voltage to the second node in response to the first start pulse, to turn off the sixth and seventh switching elements; and

a ninth switching element that supplies the second voltage to the second node in response to a second start pulse synchronous with the sixth clock pulse, to turn off the sixth and seventh switching elements.

13. The luminescent display device according to claim 12, wherein the second, fourth, fifth, sixth, eighth, and ninth switching elements are dual switching elements including two switching elements connected in series.

14. The luminescent display device according to claim 12, wherein each of the remaining stages of the first shift register, except for the first stage, includes:

first, third, and fifth clock transfer lines that transfer first, third, and fifth pulses;

first and second power lines that transfer the first and second voltages;

a first switching element that supplies a first scan pulse from the upstream stage to a first node in response to the first clock pulse synchronous with the first scan pulse from the upstream stage;

a second switching element that outputs the third clock pulse from the third clock transfer line as a first scan pulse in response to the first scan pulse supplied to the first node, and supplies the first scan pulse to one end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a third switching element that connects the other end of the capacitor and one end of the associated gate line in response to the first scan pulse supplied to the first node;

a fourth switching element that supplies the first voltage to a second node in response to the fifth clock pulse from the fifth clock transfer line;

a fifth switching element that supplies the second voltage to the first node in response to the first voltage supplied to the second node, to turn off the second and third switching elements;

a sixth switching element that supplies the second voltage to one end of the associated gate line and to the downstream stage in response to the first voltage supplied to the second node; and

a seventh switching element that supplies the second voltage to the second node in response to the first scan pulse from the upstream stage, to turn off the fifth and sixth switching elements.

15. The luminescent display device according to claim 14, wherein the first, third, fourth, fifth, and seventh switching elements are dual switching elements that include two switching elements connected in series.

16. The luminescent display device according to claim 12, wherein a first one of the stages included in the second shift register includes:

second, fourth, and sixth clock transfer lines that transfer second, fourth, and sixth ones of the first through sixth clock pulses;

first and second power lines that transfer the first and second voltages;

first and second power lines that transfer first and second voltages that have different polarities;

a first switching element that responds to the second start pulse synchronous with the sixth clock pulse, the first switching element that outputs the second start pulse in response to the second start pulse;

a second switching element that supplies the second start pulse output from the first switching element in response to the sixth clock pulse from the sixth clock transfer line;

a third switching element that outputs the second clock pulse from the second clock transfer line as a second scan pulse in response to the second start pulse supplied to the first node, and supplies the second scan pulse to the other end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a fourth switching element that connects the other end of the capacitor and the other end of the associated gate line in response to the second start pulse supplied to the first node;

a fifth switching element that supplies the first voltage to a second node in response to the fourth clock pulse from the fourth clock transfer line;

a sixth switching element that supplies the second voltage to the first node in response to the first voltage supplied to the second node, to turn off the third and fourth switching elements;

a seventh switching element that supplies the second voltage to the other end of the associated gate line and to the downstream stage in response to the first voltage supplied to the second node;

an eighth switching element that supplies the second voltage to the second node in response to the second start pulse, to turn off the sixth and seventh switching elements; and

a ninth switching element that supplies the second voltage to the second node in response to the first start pulse synchronous with the fifth clock pulse, to turn off the sixth and seventh switching elements.

17. The luminescent display device according to claim 16, wherein each of the second, fourth, fifth, sixth, eighth, and ninth switching elements are dual switching elements that include two switching elements connected in series.

18. The luminescent display device according to claim 16, wherein the remaining stages of the second shift register, except for the first stage, includes:

second, fourth, and sixth clock transfer lines that transfer the second, fourth, and sixth clock pulses;

first and second power lines that transfer the first and second voltages;

a first switching element that supplies a second scan pulse from the upstream stage to a first node in response to the second clock pulse synchronous with the second scan pulse from the upstream stage;

a second switching element that outputs the fourth clock pulse from the fourth clock transfer line as a second scan pulse in response to the second scan pulse supplied to the first node, and supplies the second scan pulse to the other end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a third switching element that connects the other end of the capacitor and the other end of the associated gate line in response to the second scan pulse supplied to the first node;

a fourth switching element that supplies the first voltage to a second node in response to the sixth clock pulse from the sixth clock transfer line;

a fifth switching element that supplies the second voltage to the first node in response to the first voltage supplied to the second node, to turn off the second and third switching elements;

a sixth switching element that supplies the second voltage to the other end of the associated gate line and to the downstream stage in response to the first voltage supplied to the second node; and

a seventh switching element that supplies the second voltage to the second node in response to the second scan pulse from the upstream stage, to turn off the fifth and sixth switching elements.

19. The luminescent display device according to claim 18, wherein the first, third, fourth, fifth, and seventh switching elements are dual switching elements that include two switching elements connected in series.

20. The luminescent display device according to claim 3, wherein a first one of the stages included in the first shift register includes:

first and third clock transfer lines that transfer first and third pulses output in a sequential manner;

first and second power lines that transfer first and second voltages that have different polarities;

a first switching element that responds to a first start pulse synchronous with the third clock pulse, the first switching element that outputs the first start pulse in response to the first start pulse;

a second switching element that supplies, to a first node, the first start pulse output from the first switching element in response to the third clock pulse from the third clock transfer line;

a third switching element that outputs the first clock pulse from the first clock transfer line as a first scan pulse in response to the first start pulse supplied to the first node, and supplies the first scan pulse to one end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a fourth switching element that connects the other end of the capacitor and one end of the associated gate line in response to the first start pulse supplied to the first node;

a fifth switching element that supplies the first scan pulse to a second node in response to the first clock pulse from the downstream stage;

a sixth switching element that supplies the second voltage to the first node in response to the first voltage supplied to the second node, to turn off the third and fourth switching elements;

a seventh switching element that supplies the second voltage to one end of the associated gate line and to the downstream stage in response to the first voltage supplied to the second node;

an eighth switching element that supplies the second voltage to the second node in response to the first start pulse, to turn off the sixth and seventh switching elements; and

a ninth switching element that supplies the second voltage to the second node in response to a second start pulse synchronous with the fourth clock pulse, to turn off the sixth and seventh switching elements.

21. The luminescent display device according to claim 20, wherein the second, fourth, fifth, sixth, eighth, and ninth switching elements are dual switching elements that include two switching elements connected in series.

22. The luminescent display device according to claim 20, wherein each of the remaining stages of the first shift register, except for the first stage, includes:

first and third clock transfer lines that transfer first and third ones of the first through fourth clock pulses;

first and second power lines that transfer the first and second voltages;

a first switching element that supply a first scan pulse from the upstream stage to a first node in response to the first clock pulse synchronous with the first scan pulse from the upstream stage;

a second switching element that outputs the third clock pulse from the third clock transfer line as a first scan pulse in response to the first scan pulse that is supplied to the first node, and supplies the first scan pulse to one end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a third switching element that connects the other end of the capacitor and one end of the associated gate line in response to the first scan pulse that is supplied to the first node;

a fourth switching element that supplies the first scan pulse to a second node in response to the first scan pulse from the downstream stage;

a fifth switching element that supplies the second voltage to the first node in response to the first scan pulse supplied to the second node, to turn off the second and third switching elements;

a sixth switching element that supplies the second voltage to one end of the associated gate line and to the downstream stage in response to the first scan pulse supplied to the second node; and

a seventh switching element that supplies the second voltage to the second node in response to the first scan pulse from the upstream stage, to turn off the fifth and sixth switching elements.

23. The luminescent display device according to claim 22, wherein the first, third, fourth, fifth, and seventh switching elements are dual switching elements that include two switching elements connected in series.

24. The luminescent display device according to claim 20, wherein a first one of the stages included in the second shift register includes:

second and fourth clock transfer lines that transfer second and fourth pulses;

first and second power lines that transfer the first and second voltages;

a first switching element that responds to the second start pulse synchronous with the fourth clock pulse, the first switching element that outputs the second start pulse in response to the second start pulse;

a second switching element that supplies the second start pulse output from the first switching element in response to the fourth clock pulse from the fourth clock transfer line;

a third switching element that outputs the second clock pulse from the second clock transfer line as a second scan pulse in response to the second start pulse supplied to the first node, and supplies the second scan pulse to the other end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a fourth switching element that connects the other end of the capacitor and the other end of the associated gate line in response to the second start pulse supplied to the first node;

a fifth switching element that supplies the second scan pulse to a second node in response to the first scan pulse from the downstream stage;

a sixth switching element that supplies the second voltage to the first node in response to the second scan pulse supplied to the second node, to turn off the third and fourth switching elements;

a seventh switching element that supplies the second voltage to the other end of the associated gate line and to the downstream stage in response to the second scan pulse supplied to the second node;

an eighth switching element that supplies the second voltage to the second node in response to the second start pulse, to turn off the sixth and seventh switching elements; and

a ninth switching element that supplies the second voltage to the second node in response to the first start pulse synchronous with the third clock pulse, to turn off the sixth and seventh switching elements.

25. The luminescent display device according to claim 24, wherein the second, fourth, fifth, sixth, eighth, and ninth switching elements are dual switching elements that include two switching elements connected in series.

26. The luminescent display device according to claim 24, wherein each of the remaining stages of the second shift register, except for the first stage, includes:

second and fourth clock transfer lines that transfer the second and fourth clock pulses;

first and second power lines that transfer the first and second voltages;

a first switching element that supplies a second scan pulse from the upstream stage to a first node in response to the second clock pulse synchronous with the second scan pulse from the upstream stage;

a second switching element that outputs the fourth clock pulse from the fourth clock transfer line as a second scan pulse in response to the second scan pulse supplied to the first node, and supplies the second scan pulse to the other end of the associated gate line and to the downstream stage;

a capacitor connected to the first node at one terminal of the capacitor;

a third switching element that connects the other end of the capacitor and the other end of the associated gate line in response to the second scan pulse supplied to the first node;

a fourth switching element that supplies the second scan pulse to a second node in response to the second scan pulse from the downstream stage;

a fifth switching element that supplies the second voltage to the first node in response to the second scan pulse supplied to the second node, to turn off the second and third switching elements;

a sixth switching element that supplies the second voltage to the other end of the associated gate line and to the downstream stage in response to the second scan pulse supplied to the second node; and

a seventh switching element that supplies the second voltage to the second node in response to the second scan pulse from the upstream stage, to turn off the fifth and sixth switching elements.

27. The luminescent display device according to claim 26, wherein the first, third, fourth, fifth, and seventh switching elements are dual switching elements that include two switching elements connected in series.

28. A method that drives a luminescent display device including a plurality of gate lines and a plurality of data lines that extend orthogonally to the gate lines, switching elements adapted to switch an ON voltage or an OFF voltage from an associated one of the data lines in accordance with a scan pulse from an associated one of the gate lines, and to switch an OFF voltage from the associated data line in accordance with the second scan pulse from the associated gate line, drive switching elements that supply current in accordance with the ON voltage from an associated one of the switching elements, and cutt off the supply of current in accordance with the OFF voltage from the associated switching element, and light emitting elements adapted to emit light in accordance with the current from an associated one of the drive switching elements, the method comprises the acts of:

supplying a first scan pulse to the gate lines,;

supplying the ON voltage to the data line associated with the gate line;

supplying a second scan pulse to the gate line; and

supplying the OFF voltage to the associated data line.

29. The method according to claim 28, wherein the act of supplying the first scan pulse to the gate lines primarily turns on the switching element associated with the gate line.

30. The method according to claim 28, wherein the act of supplying a second scan pulse to the gate line turns on the associated switching element.