ACTIVE-MATRIX ORGANIC LIGHT EMITTING DIODE DISLAY

• US 20090066617A1
• Filed: 08/25/2008
• Published: 03/12/2009
• Est. Priority Date: 09/06/2007
• Status: Abandoned Application

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: CHEN, Chi-Wen, CHANG, Meng-Hsiang
• Application Number:
  US12/197,500
• Publication Number:
  US 20090066617A1
• Time in Patent Office: Days
• US Class Current: 345/83
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

An embodiment of an active-matrix organic light emitting diode (OLED) display is disclosed. The display includes a pixel array including a plurality of pixels, wherein each pixel includes a light emitting device, a driving device and a selection device. The light emitting device includes a first organic light emitting diode, a second organic light emitting diode and a third organic light emitting diode, wherein the diodes are stacked formed in the pixel. The driving device is coupled to a voltage source and receives an enable signal and a display data to drive the light emitting device. The selection device selects and turns on a corresponding organic light emitting diode based on a control signal.

Claims

1. An active-matrix organic light emitting diode (OLED) display, comprising:

a pixel array comprising a plurality of pixels, wherein each pixel comprises;

a light emitting device, comprising a first organic light emitting diode, a second organic light emitting diode and a third organic light emitting diode, wherein the diodes are stacked formed in the pixel; and

a driving device coupled to a voltage source, to receive an enable signal and a display data to drive the light emitting device; and

a selection device to select and to turn on a corresponding organic light emitting diode based on a control signal.

2. The display as claimed in claim 1, wherein the selection device comprises a first switch, a second switch and a third switch respectively coupled to the first organic light emitting diode, the second organic light emitting diode and the third organic light emitting diode.

3. The display as claimed in claim 2, wherein the control signal comprises a first control signal, a second control signal and a third control signal respectively to control the first switch, the second switch and the third switch.

4. The display as claimed in claim 3, wherein the first control signal, the second control signal and the third control signal respectively turns on the first switch, the second switch and the third switch in a display period based on a time division multiplexing mechanism.

5. The display as claimed in claim 2, wherein the first switch is a first transistor having a first control terminal receiving the first control signal, a first input terminal coupled to a first anode of the first organic light emitting diode and a first output terminal coupled to a first cathode of the first organic light emitting diode.

6. The display as claimed in claim 2, wherein the second switch is a second transistor having a second control terminal receiving the second control signal, a second input terminal coupled to a second anode of the second organic light emitting diode and a second output terminal coupled to a second cathode of the second organic light emitting diode.

7. The display as claimed in claim 2, wherein the third switch is a third transistor having a third control terminal receiving the third control signal, a third input terminal coupled to a third anode of the third organic light emitting diode and a third output terminal coupled to a third cathode of the third organic light emitting diode.

8. The display as claimed in claim 1, wherein the first organic light emitting diode, the second organic light emitting diode and the third organic light emitting diode respectively are an red OLED, an green OLED and an blue OLED.

9. The display as claimed in claim 1, wherein the display data is a gray scale data for controlling the luminance of the light emitting device.

10. The display as claimed in claim 1, wherein the display data comprises a first display data, a second display data and a third display data.

11. The display as claimed in claim 10, wherein the driving device comprises a first driving device, a second driving device and a third driving device respectively driving the light emitting device based on the first display data, the second display data and the third display data.

12. The display as claimed in claim 11, wherein each driving device comprises:

a first transistor having a first control terminal receiving a selection signal for turning on/off the first transistor, a first input terminal receiving corresponding display data and a first output terminal;

a storage element coupled to the first output terminal; and

a second transistor having a second control terminal coupled to the first output terminal, a second input terminal coupled to the voltage source and a second output terminal coupled to the light emitting device.

13. The display as claimed in claim 12, wherein the first transistor and the second transistor are thin-film transistors.

14. The display as claimed in claim 11, wherein the first driving device, the second driving device and the third driving device respectively transmit the first display data, the second display data and the third display data to the light emitting device in a display period based on a time division multiplexing mechanism.

15. The display as claimed in claim 1, wherein the driving device is controlled by an enable signal and the driving device comprises:

a first transistor having a first control terminal receiving a selection signal for turning on/off the first transistor, a first input terminal receiving corresponding display data and a first output terminal;

a storage element coupled to the first output terminal; and

a second transistor having a second control terminal coupled to the first output terminal, a second input terminal coupled to the voltage source and a second output terminal coupled to the light emitting device.

26. The display as claimed in claim 1, wherein the driving device is controlled by the enable signal and the driving device comprises:

a first transistor having a first control terminal receiving a selection signal for turning on/off the first transistor, a first input terminal receiving corresponding display data and a first output terminal;

a storage element coupled to the first output terminal; and

a second transistor having a second control terminal coupled to the first output terminal, a second input terminal coupled to the voltage source and a second output terminal coupled to the light emitting device.

16. An active-matrix organic light emitting diode (OLED) display, comprising:

a gate driving circuit to output a control signal and an enable signal;

a data driving circuit to output a display data; and

a pixel array comprising a plurality of pixels, wherein each pixel comprise;

a light emitting device, comprising a first organic light emitting diode, a second organic light emitting diode and a third organic light emitting diode, wherein the diodes are stacked formed in the pixel; and

a driving device coupled to a voltage source, to receive the enable signal and the display data to drive the light emitting device; and

a selection device to select and to turn on the corresponding organic light emitting diode based on the control signal.

17. The display as claimed in claim 16, wherein the driving device comprises a first driving device, a second driving device and a third driving device.

18. The display as claimed in claim 17, wherein each driving device comprises:

a first transistor having a first control terminal receiving a selection signal for turning on/off the first transistor, a first input terminal receiving corresponding display data and a first output terminal;

a storage element coupled to the first output terminal; and

a second transistor having a second control terminal coupled to the first output terminal, a second input terminal coupled to the voltage source and a second output terminal coupled to the light emitting device, wherein the second transistor controls the current magnitude applied to the light emitting device based on the received display data.

19. The display as claimed in claim 16, wherein the enable signal sequentially enables the first driving device, the second driving device and the third driving device.

20. The display as claimed in claim 16, wherein the selection device comprises a first switch, a second switch and a third switch respectively parallel coupled to the first organic light emitting diode, the second organic light emitting diode and the third organic light emitting diode.

21. The display as claimed in claim 20, wherein the control signal turns on the first switch, the second switch and the third switch at different times during a display period.

22. The display as claimed in claim 16, wherein the display data comprises a first display data, a second display data and a third display data respectively transmitted to the light emitting device via a first driving device, a second driving device and a third driving device in the driving device.

23. The display as claimed in claim 16, wherein the first organic light emitting diode, the second organic light emitting diode and the third organic light emitting diode respectively are an red OLED, an green OLED and an blue OLED.

24. The display as claimed in claim 18, wherein the first transistor and the second transistor are thin-film transistors.

25. The display as claimed in claim 16, wherein the display data is a gray scale data for controlling the luminance of the light emitting device.