Organic light emitting diode display

• US 7,649,513 B2
• Filed: 06/23/2006
• Issued: 01/19/2010
• Est. Priority Date: 06/25/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Park, Kwon Shik, Yoon, Soo Young, Chun, Min Doo
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): Alemu; Ephrem
• Application Number:
  US11/473,320
• Publication Number:
  US 20070008268A1
• Time in Patent Office: 1,306 Days
• Field of Search: 315/169.3, 345/76, 345/77, 345/92, 345/204, 345/205, 345/690, 345/78
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0417 Special arrangements specific to the use of low carrier mobility technology
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2310/0254 Control of polarity reversal in general, other than for liquid crystal displays
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G11C 19/28 using semiconductor elements G11C19/14, G11C19/36 take precedence

Abstract

An Organic light emitting diode display device includes: a pixel array having a plurality of scan lines and a plurality of data lines that cross each other, a plurality of power voltage supply lines to which a high level power supply voltage is supplied and that are substantially parallel to the data lines, a plurality of reset lines substantially parallel to the scan lines, a plurality of organic light emitting diodes that emit light due to the high level power supply voltage from the power voltage supply line, and a plurality of organic light emitting diode drive circuits that drive the organic light emitting diode with data from the data line in response to a scan signal from the scan line and that is initialized in response to a reset signal from the reset line; a scan drive circuit that supplies the scan signal to the scan lines; a reset drive circuit that supplies the reset signal to the reset lines that initializes the organic light emitting diode drive circuit; and a data drive circuit that supplies the data to the data lines respectively, wherein the scan drive circuit and the reset drive circuit are on a substrate including the pixel array.

Claims

1. An organic light emitting diode display device, comprising:

a pixel array having a plurality of scan lines and a plurality of data lines that cross each other, a plurality of power voltage supply lines to which a high level power supply voltage is supplied and that are substantially parallel to the data lines, a plurality of reset lines substantially parallel to the scan lines, a plurality of organic light emitting diodes that emit light due to the high level power supply voltage from the power voltage supply line, and a plurality of organic light emitting diode drive circuits that drive the organic light emitting diode with data from the data line in response to a scan signal from the scan line and that is initialized in response to a reset signal from the reset line;

a scan drive circuit that supplies the scan signals to the scan lines by plurality of stages that each have a first Q node, a first QB node, a first pull-up transistor that supplies the scan signal to the scan line in response to a voltage of the first Q node and a first pull-down transistor that discharges the scan line in response to a voltage of the first QB node;

a reset drive circuit that supplies the reset signals to the reset lines by a plurality of stages that each have a second Q node, a second QB node, a second pull-up transistor that supplies the reset signal to the reset line in response to a voltage of the second Q node and a second pull-down transistor that discharges the reset line in response to the voltage of a second QB node;

a first transistor that discharges the first Q node of the scan drive circuit in response to the reset signal, wherein the first transistor has a source electrode connected to the first Q node connected to each of the stages of the scan drive circuit, a gate electrode connected to the reset line and a drain electrode connected to a low level power supply voltage source; and

a second transistor that discharges the second Q node of the reset drive circuit in response to the scan signal, wherein the second transistor has a source electrode connected to the second Q node connected to each of the stages of the reset drive circuit, a gate electrode connected to the scan line and a drain electrode connected to the low level power supply voltage source.

2. The organic light emitting diode display device according to claim 1, wherein the pixel array is disposed between the scan drive circuit and the reset drive circuit.

5. The organic light emitting diode display device according to claim 1, comprising:

a third transistor that discharges the scan line in response to the reset signal; and

a fourth transistor that discharges the reset line in response to the scan signal.

6. The organic light emitting diode display device according to claim 5, wherein the third transistor has a source electrode connected to the scan line, a gate electrode connected to the reset line and a drain electrode connected to a low level power supply voltage source, and the fourth transistor has a source electrode connected to the reset line, a gate electrode connected to the scan line and a drain electrode connected to the low level power supply voltage source.

7. The organic light emitting diode display device according to claim 6 wherein:

pairs of adjacent reset lines are connected to each other and the reset signal is supplied thereto at the same time;

the connected reset lines are commonly connected to the gate electrodes that are formed in the third transistors respectively; and

the scan line is connected to the gate electrode of the fourth transistor in a one-to-one relationship.

8. The organic light emitting diode display device according to claim 7, wherein the number of stages of the reset drive circuit is less than the number of stages of the scan drive circuit.

9. The organic light emitting diode display device according to claim 1, wherein the organic light emitting diode drive circuit includes:

a switching transistor that supplies the data to a first node in response to the scan signal;

a drive transistor that controls a current, that flows in the organic light emitting diode, by a voltage of the first node; and

a reset transistor that discharges the first node in response to the reset signal.

10. The organic light emitting diode display device according to claim 9, wherein transistors within the pixel array and transistors within the scan drive circuit and reset drive circuit are amorphous silicon transistors.

11. The organic light emitting diode display device according to claim 9, wherein transistors within the pixel array and transistors within the scan drive circuit and reset drive circuit are poly silicon transistors.

12. The organic light emitting diode display device according to claim 9, wherein the reset signal is delayed versus the scan signal.

13. The organic light emitting diode display device according to claim 12, wherein the reset signal is generated approximately in ½

a frame period after the scan signal.

14. The organic light emitting diode display device according to claim 9, wherein the stages of the scan drive signal include:

a (n−

1)^th stage that outputs a (n−

1)^th scan signal in response to one of a scan start signal and a (n−

2)^th scan signal; and

an n^th stage that outputs an n^th scan signal in response to the (n−

1)^th scan signal,

wherein the (n−

1)^th stage discharges the first Q node and charges the first QB node in response to the n^th scan signal.

15. The organic light emitting diode display device according to claim 14, wherein the stages of the reset drive signal include:

a (n−

1)^th stage that outputs a (n−

1)^th reset signal in response to one of a reset start signal and a (n−

2)^th reset signal; and

an n^th stage that outputs an n^th reset signal in response to the (n−

1)^th reset signal,

wherein the (n−

1)^th stage discharges the second Q node and charges the second QB node in response to the n^th reset signal.

3. The organic light emitting diode display device according to claim l, wherein:

pairs of adjacent reset lines are connected to each other and the reset signal is supplied thereto at the same time;

the connected reset lines are commonly connected to the gate electrodes that are formed in the first transistors respectively; and

the scan line is connected to the gate electrode of the second transistor in a one-to-one relationship.

4. The organic light emitting diode display device according to claim 3, wherein the number of stages of the reset drive circuit is less than the number of stages of the scan drive circuit.

16. An organic light emitting diode display device, comprising:

a pixel array having a plurality of scan lines and a plurality of data lines that cross each other, a plurality of power voltage supply lines to which a high level power supply voltage is supplied and that are substantially parallel to the data lines, a plurality of reset lines substantially parallel to the scan lines, a plurality of organic light emitting diodes that emit light due to the high level power supply voltage from the power voltage supply line, and a plurality of organic light emitting diode drive circuits that drive the organic light emitting diode with data from the data line in response to a scan signal from the scan line and that is initialized in response to a reset signal from the reset line;

a scan drive circuit that supplies the scan signals to the scan lines by a plurality of stages that each have a first Q node, a first QB node, a first pull-up transistor that supplies the scan signal to the scan line in response to a voltage of the first Q node and a first pull-down transistor that discharges the scan line in response to a voltage of the first QB node;

a reset drive circuit that supplies the reset signals to the reset lines by a plurality of stages that each have a second Q node, a second QB node, a second pull-up transistor that supplies the reset signal to the reset line in response to a voltage of the second Q node and a second pull-down transistor that discharges the reset line in response to a voltage of the second QB node;

a first transistor that discharges the scan line in response to the reset signal, wherein the first transistor has a source electrode connected to the scan line, a gate electrode connected to the reset line and a drain electrode connected to a low level power supply voltage source; and

a second transistor that discharges the reset line in response to the scan signal, wherein the second transistor has a source electrode connected to the reset line, a gate electrode connected to the scan line and a drain electrode connected to the low level power supply voltage source.

17. The organic light emitting diode display device according to claim 16, wherein the pixel array is disposed between the scan drive circuit and the reset drive circuit.

18. The organic light emitting diode display device according to claim 16, wherein the reset signal is delayed versus the scan signal.

19. The organic light emitting diode display device according to claim 18, wherein the reset signal is generated approximately in ½

a frame period after the scan signal.

20. The organic light emitting diode display device according to claim 16, wherein the stages of the scan drive signal include:

a (n−

1)^th stage that outputs a (n−

1)^th scan signal in response to one of a scan start signal and a (n−

2)^th scan signal; and

an n^th stage that outputs an n^th scan signal in response to the (n−

1)^th scan signal,

wherein the (n−

1)^th stage discharges the first Q node and charges the first QB node in response to the n^th scan signal.

21. The organic light emitting diode display device according to claim 20, wherein the stages of the reset drive signal include:

a (n−

1)^th stage that outputs a (n−

1)^th reset signal in response to one of a reset start signal and a (n−

2)^th reset signal; and

an n^th stage that outputs an n^th reset signal in response to the (n−

1)^th reset signal,

wherein the (n−

1)^th stage discharges the second Q node and charges the second QB node in response to the n^th reset signal.

22. The organic light emitting diode display device according to claim 16, wherein pairs of adjacent reset lines are connected to each other and the reset signal is supplied thereto at the same time;

the connected reset lines are commonly connected to the gate electrodes that are formed in the first transistors respectively; and

the scan line is connected to the gate electrode of the second transistor in a one-to-one relationship.

23. The organic light emitting diode display device according to claim 22, wherein the number of stages of the reset drive circuit is less than the number of stages of the scan drive circuit.

24. The organic light emitting diode display device according to claim 16, wherein the organic light emitting diode drive circuit includes:

a switching transistor that supplies the data to a first node in response to the scan signal;

a drive transistor that controls a current, that flows in the organic light emitting diode, by a voltage of the first node; and

a reset transistor that discharges the first node in response to the reset signal.

25. The organic light emitting diode display device according to claim 24, wherein transistors within the pixel array and transistors within the scan drive circuit and reset drive circuit are amorphous silicon transistors.

26. The organic light emitting diode display device according to claim 25, wherein transistors within the pixel array and transistors within the scan drive circuit and reset drive circuit are poly silicon transistors.