Active Matrix Organic Electro-Optic Devices

• US 20090201230A1
• Filed: 06/28/2007
• Published: 08/13/2009
• Est. Priority Date: 06/30/2006
• Status: Abandoned Application

• Current Assignee: Cambridge Display Technology Limited (Sumitomo Chemical Company Limited)
• Original Assignee: Cambridge Display Technology Limited (Sumitomo Chemical Company Limited)
• Inventors: Smith, Euan C.
• Application Number:
  US12/307,039
• Publication Number:
  US 20090201230A1
• Time in Patent Office: Days
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• 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 2310/0218 with collection of electrodes in groups for n-dimensional addressing
• CPC Class Codes: G09G 2310/0221 with use of split matrices G09G3/3644 and G09G3/3666 take precedence
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/3241 the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3283 in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H10K 59/121 characterised by the geometry or disposition of pixel elements
• CPC Class Codes: H10K 59/13 comprising photosensors that control luminance
• CPC Class Codes: H10K 59/60 OLEDs integrated with inorganic light-sensitive elements, e.g. with inorganic solar cells or inorganic photodiodes

Abstract

This invention generally relates to active matrix organic electro-optic devices and to related display driving methods. In embodiments the invention relates to top-emitting OLED (Organic Light Emitting Diode) displays including additional circuitry which may be employed for display driving or other functions.

An active matrix organic electro-optic device, the device having a plurality of pixels and comprising a substrate bearing pixel interface circuitry for each of said pixels and organic material over said pixel interface circuitry, wherein said device is configured such that over at least a part of an area of said device said pixel interface circuitry is staggered with respect to said pixels such that a region under at least one of said pixels is incompletely occupied by said pixel interface circuitry, and wherein additional circuitry for said device is fabricated in said region incompletely occupied by said pixel interface circuitry.

Claims

1. An active matrix organic electro-optic device, the device having a plurality of pixels and comprising a substrate bearing pixel interface circuitry for each of said pixels and organic material over said pixel interface circuitry, wherein said device is configured such that over at least a part of an area of said device said pixel interface circuitry is staggered with respect to said pixels such that a region under at least one of said pixels is incompletely occupied by said pixel interface circuitry, and wherein additional circuitry for said device is fabricated in said region incompletely occupied by said pixel interface circuitry.

2. An organic electro-optic device as claimed in claim 1 wherein said device is configured such that over at least a part of an area of said device said pixel interface circuitry is staggered with respect to said pixels such that a region under a pair of adjacent pixels is incompletely occupied by said pixel interface circuitry.

3. An organic electro-optic device as claimed in claim 1 wherein said additional circuitry includes at least one semiconductor device.

4. An organic electro-optic device as claimed in claim 1 wherein said regions are provided at regular intervals across an area of said display.

5. An organic electro-optic device as claimed in claim 1 wherein said additional circuitry comprises shared interface circuitry to provide an interface to a group of said pixels.

6. An organic electro-optic device as claimed in claim 5 wherein said shared interface circuitry comprises a signal regeneration circuit.

7. An organic electro-optic device as claimed in claim 5 wherein said shared interface circuitry includes a de-amplifying current mirror.

8. An organic electro-optic device as claimed in claim 1 wherein said additional circuitry includes a select or enable circuit to select or enable drive circuitry for a group of pixels with which said additional circuitry is associated.

9. An organic electro-optic device as claimed in claim 1 wherein said additional circuitry includes a memory element.

10. An organic electro-optic device as claimed in claim 1 wherein said additional circuitry comprises a light sensor or touch sensor.

11. An organic electro-optic device as claimed in claim 10 wherein said device comprises a touch-sensitive display.

12. An organic electro-optic device as claimed in claim 1 wherein said device comprises a top-emitting active matrix OLED structure, wherein said pixel interface circuitry comprises pixel drive circuitry, and wherein said organic material comprises OLED material over said pixel drive circuitry, whereby said structure is configured to emit light from a top surface.

13. A method of driving a pixelated display, the display having a plurality of active matrix pixels each with a data line for writing display data to the pixel, a said data line being shared for driving a plurality of pixels of said display, pixels driven by a said shared data line being allocated to groups, each group comprising multiple pixels and having a respective group data driver circuit coupled to said shared data line and to each pixel of the group for receiving pixel drive data from said shared data line and for driving a selected pixel of the group responsive to said pixel drive data, the method comprising:

driving a first pixel of each of said groups in turn; and

then driving a second pixel of each of said groups in turn.

14. A method as claimed in claim 13 further comprising repeating said driving for a third and each subsequent pixel of each of said groups in turn to drive substantially all said pixels driven by said shared data line.

15. A method as claimed in claim 13 wherein a said shared data line comprises a row or column data line of said display.

16. A method as claimed in claim 13, wherein said driving comprises storing a drive signal for a driven pixel of a said group using the respective group data driver circuit for the group.

17. A method as claimed in claim 13 wherein said driving of a pixel comprises buffering a drive signal on said shared data line using said group data driver circuit, and driving said pixel with said buffered drive signal.

18. A method as claimed in claim 17 wherein said drive signal comprises a current drive signal, wherein each said pixel has associated current drive circuitry, and wherein said buffering comprises reducing a level of said current drive signal to provide a reduced current drive signal to said pixel current drive circuitry.

19. A method as claimed in claim 18 wherein said buffering comprises using a current mirror circuit to de-amplify said level of said current drive signal.

20. A method as claimed in claim 13 further comprising locating a said group data driver circuit adjacent a pixel in a group driven by said group data driver circuit.

21. A method as claimed in claim 13 wherein a said active matrix pixel has active matrix drive circuitry, and wherein said active matrix drive circuitry for pixels of a said group is displaced to allow a said group data driver circuit to be included in said display alongside said active matrix circuitry for pixels of the group.

22. A method as claimed in claim 13 wherein said display comprise a flat panel display.

23. A method as claimed in claim 13 wherein said display comprises a top-emitting active matrix OLED display.

24. A pixelated display, the display having a plurality of active matrix pixels each with a data line for writing display data to the pixel, a said data line being shared for driving a plurality of pixels of said display, pixels driven by a said shared data line being allocated to groups, each group comprising multiple pixels and having a respective group data driver circuit coupled to said shared data line and to each pixel of the group for receiving pixel drive data from said shared data line and for driving a selected pixel of the group responsive to said pixel drive data.

25. A display as claimed in claim 24 wherein said display comprises a flat panel display.

26. A display as claimed in claim 24 wherein said display comprises a top-emitting active matrix electroluminescent display.

27. A display as claimed in claim 24 wherein a said active matrix pixel has active matrix drive circuitry, and wherein said active matrix drive circuitry for pixels of a said group is displaced to allow a said group data driver circuit to be included in said display alongside said active matrix circuitry for pixels of the group.