Method of driving an organic electroluminescent display device and display device suitable for said method

• US 6,927,542 B2
• Filed: 05/15/2002
• Issued: 08/09/2005
• Est. Priority Date: 05/15/2001
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Sempel, Adrianus, Los, Remco, Liedenbaum, Coen Theodorus Hubertus Fransiscus
• Primary Examiner(s): Tran, Thuy V.
• Application Number:
  US10/477,490
• Publication Number:
  US 20040164937A1
• Time in Patent Office: 1,182 Days
• Field of Search: 315/169.1, 315/169.3, 345/45, 345 76- 77, 345/55, 345/60, 313/505, 313306-307
• US Class Current: 315/169.3
• CPC Class Codes: G09G 2310/065 Waveforms comprising zero voltage phase or pause
• CPC Class Codes: G09G 2320/0214 with crosstalk due to leakage current of pixel switch in active matrix panels
• CPC Class Codes: G09G 3/3216 using a passive matrix
• CPC Class Codes: G09G 3/3225 using an active matrix

Abstract

A display has a light-emitting layer, such as a light-emitting polymer or a small molecule compound layer, sandwiched between two electrodes structures including an anode structure having a plurality of subgroups of separated anode segments. Each mode segment in each anode subgroup is surrounded by anode segments that are not members of the same anode subgroup. Essentially each anode segment is a member of the anode subgroups. A signal selector assembly is connected to each anode segment, and is arranged to provide the anode segments of a single anode subgroup with image information signals, while holding the remaining anode segments at equal potentials.

Claims

1. A method of driving a display device having a layer of organic electroluminescent material, such as a light-emitting polymer or a small molecule compound, said layer being sandwiched between an anode and a cathode, said anode comprising a plurality of separated anode segments, the method comprising:

dividing the anode segments of said display device into a plurality of anode subgroups, each anode segment in each anode subgroup being surrounded by anode segments that are not members of the same anode subgroup, essentially each anode segment of the display device being a member of one of said anode subgroups;

dividing an image signal, comprising all information necessary to display a full and complete picture on said display, into a plurality of image signal subgroups corresponding in number to the plurality of anode subgroups, such that each image signal subgroup of the plurality of image signal subgroups comprises the information intended to be fed to the anode segments of a respective anode subgroup; and

during a first time period, feeding a first image signal subgroup of said image signal subgroups to a corresponding first anode subgroup of the plurality of anode subgroups while holding all anode segments, not belonging to said first anode subgroup and surrounding any anode segment belonging to said first anode subgroup at essentially equal potentials.

2. The method of claim 1, including:

sequentially feeding, during subsequent time periods, successive ones of the image signal subgroups to respective ones of the anode subgroups, while holding all anode segments surrounding any anode segment belonging to the anode subgroup being fed at essentially equal potentials, until each anode subgroup has been activated, and

repeating said sequential feedings for a subsequent image signal frame.

3. The method of claim 1, wherein the step of holding all anode segments not belonging to said first anode subgroup and surrounding any anode segment belonging to said first anode subgroup at essentially equal potentials comprises the step of connecting all anode segments not belonging to said first anode subgroup to ground.

4. The method of claim 1, wherein said display device is a passive matrix display device comprising column anodes and row cathodes, wherein said column anodes comprise said anode segments.

5. The method of claim 4, wherein there are exactly two anode subgroups and two image signal subgroups.

6. The method of claim 1, wherein said display device is an active matrix display device having a separated anode segment for each pixel, essentially each pixel being totally surrounded by a plurality of neighbouring pixels.

7. A display device comprising a light-emitting layer, such as a light-emitting polymer or a small molecule compound layer, sandwiched between a first and a second electrode structure, wherein said first electrode structure, constituting an anode structure, comprises a plurality of separated anode segments that are divided into a plurality of anode subgroups, said anode subgroups being such that each anode segment in each anode subgroup is surrounded by anode segments that are not members of the same anode subgroup, essentially each anode segment of the display device being a member of one of said anode subgroups, wherein said display device further comprises a signal selector assembly connected to each anode segment, said signal selector assembly being arranged to provide the anode segments of a single anode subgroup with image information signals, while holding the remaining anode segments at equal potentials.

8. The device of claim 7, wherein an image signal frame, comprising all information necessary to display a full picture on said display, is arranged to be fed to said signal selector assembly and divided into a plurality of image signal subgroups, corresponding to said anode subgroups, wherein, during each of a number of subsequent time periods a respective signal subgroup of said image signal subgroups is arranged to be fed to a respective anode segment subgroup, until each anode subgroup has been activated, whereafter the above is repeated for a subsequent image signal frame.

9. The device of claim 7, wherein said signal selector assembly is arranged to provide the anode segments of a single anode subgroup with image information signals, while connecting the remaining anode segments to ground.

10. The device of claim 7, wherein said display is a passive matrix display device comprising column anodes and row cathodes, wherein said column anodes comprise said anode segments.

11. The device of claim 10, wherein there are exactly two anode subgroups and two image signal.

12. The device of claim 7, wherein said display device is an active matrix display device having a separated anode segment for each pixel, essentially each pixel being totally surrounded by a plurality of neighbouring pixels.