Display device having a plurality of pixel regions that include driving transistors each of which initialized with a voltage that depends upon the display mode, and driving method thereof

• US 10,665,175 B2
• Filed: 12/18/2017
• Issued: 05/26/2020
• Est. Priority Date: 12/19/2016
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Tae Hoon, Ka, Ji Hyun, Jang, Hwan Soo, Jeong, Jin Tae, Byun, Min Woo
• Primary Examiner(s): Lao, Lunyi
• Assistant Examiner(s): Hermann, Kirk W
• Application Number:
  US15/845,907
• Publication Number:
  US 20180174525A1
• Time in Patent Office: 890 Days
• Field of Search: None
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2310/0216 Interleaved control phases for different scan lines in the same sub-field, e.g. initialization, addressing and sustaining in plasma displays that are not simultaneous for all scan lines
• CPC Class Codes: G09G 2310/0221 with use of split matrices G09G3/3644 and G09G3/3666 take precedence
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• 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: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements

Abstract

A display device includes: a first pixel region including first pixels, each of the first pixels including a driving transistor to be initialized by a first initialization power source supplied from a first power line; a second pixel region including second pixels, each of the second pixels including a driving transistor to be initialized by a second initialization power source supplied from a second power line; and a power supplier to supply the first initialization power source and the second initialization power source, the first initialization power source and the second initialization power source having a same voltage level when the display device is driven in a first mode, and the first initialization power source and the second initialization power source having different voltage levels during at least one frame period when the display device is driven in a second mode.

Claims

1. A display device comprising:

a first pixel region comprising first pixels, each of the first pixels comprising a driving transistor configured to be initialized by a first initialization power source supplied from a first power line;

a second pixel region comprising second pixels, each of the second pixels comprising a driving transistor configured to be initialized by a second initialization power source supplied from a second power line; and

a power supplier configured to supply the first initialization power source and the second initialization power source, the first initialization power source having a same voltage level as that of the second initialization power source when the display device is driven in a first mode, and the first initialization power source having a different voltage level from that of the second initialization power source during at least one frame period when the display device is driven in a second mode,

wherein the display device is configured to be driven in the second mode when the display device is mounted on a wearable device, and the display device is configured to be driven in the first mode otherwise.

2. The display device of claim 1, wherein the power supplier is configured to supply each of the first initialization power source and the second initialization power source, each having a second voltage, when the display device is driven in the first mode.

3. The display device of claim 1, wherein the power supplier is configured to:

supply the second initialization power source having a second voltage, when the display device is driven in the second mode;

supply the first initialization power source having a first voltage that is higher than the second voltage during a first frame period, when the display device is driven in the second mode; and

supply the first initialization power source having a fourth voltage that is lower than the second voltage during a second frame period adjacent to the first frame period, when the display device is driven in the second mode.

4. The display device of claim 3, wherein the fourth voltage has a same voltage level as that of the second voltage.

5. The display device of claim 1, wherein the first power line and the second power line are at one side of the first pixel region and the second pixel region.

6. The display device of claim 1, wherein the first power line and the second power line are each at two opposite sides of the first pixel region and the second pixel region.

7. The display device of claim 1, wherein each of the first pixels and the second pixels further comprises:

an organic light emitting diode, and the driving transistor is configured to control an amount of current supplied to the organic light emitting diode, and

wherein the power supplier is configured to supply the first initialization power source and/or the second initialization power source before a data signal is supplied to a gate electrode of the driving transistor.

8. The display device of claim 7, wherein a voltage of the first initialization power source is to be supplied to an anode electrode of the organic light emitting diode of each of the first pixels before the organic light emitting diode emits light, and

wherein a voltage of the second initialization power source is to be supplied to an anode electrode of the organic light emitting diode of each of the second pixels before the organic light emitting diode emits light.

9. The display device of claim 7, wherein a voltage of a third initialization power source is to be supplied to an anode electrode of the organic light emitting diode of each of the first pixels and the second pixels via a third power line before the organic light emitting diode emits light.

10. The display device of claim 9, wherein the third initialization power source has a voltage level different from each of the first initialization power source and the second initialization power source.

11. The display device of claim 9, wherein the third initialization power source has a voltage level lower than each of the first initialization power source and the second initialization power source.

12. The display device of claim 9, wherein the power supplier is configured to supply the third initialization power source having the same voltage level when the display device is driven in the first mode and the second mode.

13. The display device of claim 9, wherein the third power line is at one side of the first pixel region and the second pixel region.

14. The display device of claim 9, wherein the third power line is at two opposite sides of each of the first pixel region and the second pixel region.

15. The display device of claim 1, further comprising:

a first scan driver configured to drive first scan lines coupled to the first pixels;

a first emission driver configured to drive first emission control lines coupled to the first pixels;

a second scan driver configured to drive second scan lines coupled to the second pixels; and

a second emission driver configured to drive second emission control lines coupled to the second pixels.

16. The display device of claim 15, wherein the first scan driver is configured to supply a scan signal to the first scan lines, and the first emission driver is configured to supply an emission control signal to the first emission control lines such that the first pixels emit light corresponding to a data signal, when the display device is driven in the first mode.

17. The display device of claim 15, wherein the first scan driver is configured to supply a gate-off voltage to the first scan lines, and the first emission driver is configured to supply a gate-off voltage to the first emission control lines, when the display device is driven in the second mode.

18. The display device of claim 15, wherein the second scan driver is configured to supply a scan signal to the second scan lines, and the second emission driver is configured to supply an emission control signal to the second emission control lines such that the second pixels emit light corresponding to a data signal, when the display device is driven in each of the first mode and the second mode.

19. The display device of claim 1, further comprising a third pixel region comprising third pixels, each of the third pixels comprising a driving transistor configured to be initialized by the first initialization power source.

20. The display device of claim 19, wherein the first initialization power source is to be supplied to the third pixels via the first power line.

21. The display device of claim 19, wherein the first initialization power source is to be supplied to the third pixels via a fourth power line different from the first power line.

22. The display device of claim 19, wherein the second pixel region is between the first pixel region and the third pixel region.

23. The display device of claim 19, wherein each of the first pixels, the second pixels, and the third pixels comprises:

an organic light emitting diode, and the driving transistor is configured to control an amount of current supplied to the organic light emitting diode, and

wherein the power supplier is configured to supply the first initialization power source and/or the second initialization power source to a gate electrode of the driving transistor before a data signal is supplied.

24. The display device of claim 23, wherein a voltage of the first initialization power source is to be supplied to an anode electrode of the organic light emitting diode of each of the first pixels and the third pixels before the organic light emitting diode emits light, and

wherein a voltage of the second initialization power source is to be supplied to an anode electrode of the organic light emitting diode of each of the second pixels before the organic light emitting diode emits light.

25. The display device of claim 23, wherein a voltage of a third initialization power source is to be supplied to an anode electrode of the organic light emitting diode of each of the first pixels, the second pixels, and the third pixels via a third power line before the organic light emitting diode emits light.

26. The display device of claim 25, wherein the third initialization power source has a voltage level different from each of the first initialization power source and the second initialization power source.

27. The display device of claim 25, wherein the power supplier is configured to supply the third initialization power source having the same voltage level when the display device is driven in each of the first mode and the second mode.

28. A method for driving a display device, the method comprising:

supplying initialization power sources having a same voltage level to first pixels included in a first pixel region and second pixels included in a second pixel region, when the display device is driven in a first mode; and

supplying the initialization power sources having different voltage levels to the first pixels and the second pixels, when the display device is driven in a second mode,

wherein the display device is driven in the second mode when the display device is mounted on a wearable device, and the display device is driven in the first mode otherwise.

29. The method of claim 28, further comprising supplying a corresponding one of the initialization power sources to an anode electrode of an organic light emitting diode of each of the first pixels and the second pixels, when the display device is driven in the first mode and the second mode.

30. The method of claim 29, wherein a voltage of the corresponding initialization power source has a voltage level different from that of each of other ones of the initialization power sources.

31. The method of claim 30, wherein the voltage level of the corresponding initialization power source is lower than that of each of the other initialization power sources.

32. The method of claim 28, wherein the first pixels are supplied with a corresponding one of the initialization power sources having a first voltage when the display device is driven in the second mode, and the first pixels are supplied with the corresponding one of the initialization power sources having a second voltage lower than the first voltage when the display device is driven in the first mode.