Light emitting display device

• US 10,482,823 B2
• Filed: 12/22/2017
• Issued: 11/19/2019
• Est. Priority Date: 12/27/2016
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Wonjun, Lee, Gichang, Kim, Cholho, Yang, Gunwoo
• Primary Examiner(s): Boddie, William
• Assistant Examiner(s): Gyawali, Bipin
• Application Number:
  US15/852,773
• Publication Number:
  US 20180182301A1
• Time in Patent Office: 697 Days
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0866 by means of changes in the pixel supply voltage
• CPC Class Codes: G09G 2310/0245 Clearing or presetting the whole screen independently of waveforms, e.g. on power-on G09G2310/063 takes precedence
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/063 Waveforms for resetting the whole screen at once
• CPC Class Codes: G09G 2320/0219 Reducing feedthrough effects in active matrix panels, i.e. voltage changes on the scan electrode influencing the pixel voltage due to capacitive coupling
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• 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: 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 light emitting display device includes: a first switch connected between a data line and a first node and including a gate connected to a first scan line; a second switch connected between a first driving power line and a second node and including a gate electrode connected to the first node; a first capacitor connected between the first node and the second node; a light emitting element connected between the second node and a second driving power line; a scan driver applying a first A-scan signal and a first B-scan signal during different times to the first scan line; a data driver applying a first initialization signal and a data signal to the data line at different times; and a power supply portion applying a first driving voltage, a second driving voltage, and a third driving voltage to the first driving power line at different times.

Claims

1. A light emitting display device comprising:

a first switch comprising a gate electrode connected to a first scan line, the first switch connected between a data line and a first node;

a second switch comprising a gate electrode connected to the first node, the second switch connected between a first driving power line and a second node;

a first capacitor connected between the first node and the second node;

a light emitting element connected between the second node and a second driving power line;

a scan driver configured to apply a first A-scan signal to the first scan line in at least a part of first, second and third periods among a consecutive first period, the second period, the third period, a fourth period, a fifth period, a sixth period and a seventh period, and to apply a first B-scan signal to the first scan line in a part of the fifth period;

a data driver configured to apply a first initialization signal to the data line in at least a part of the first, second and third periods, and to apply a data signal to the data line in a part of the fifth period; and

a power supply portion configured to apply a first driving voltage to the first driving power line in at least a part of the second period, applying a second driving voltage, which is greater than the first driving voltage, to the first driving power line in at least a part of the third, fourth, fifth and sixth periods, and applying a third driving voltage, which is greater than the second driving voltage, to the first driving power line in at least a part of the first period and at least a part of the seventh period.

2. The light emitting display device of claim 1, wherein the first A-scan signal has an active voltage in the first, second and third periods, and

the first B-scan signal has an active voltage in one horizontal period of the fifth period.

3. The light emitting display device of claim 1, further comprising a second scan line adjacent to the first scan line,

wherein the scan driver is further configured to apply a second A-scan signal and a second B-scan signal to the second scan line, and

the scan driver is configured to apply the second A-scan signal to the second scan line in at least a part of the first, second and third periods and to apply the second B-scan signal to the second scan line in at least a part of the fifth period.

4. The light emitting display device of claim 3, wherein the first A-scan signal and the second A-scan signal have an active voltage in the first, second and third periods,

the first B-scan signal has an active voltage in a first horizontal period of the fifth period, and

the second B-scan signal has an active voltage in a second horizontal period of the fifth period.

5. The light emitting display device of claim 4, wherein a positive edge time point of the first A-scan signal is substantially equal to a positive edge time point of the second A-scan signal, and

a negative edge time point of the first A-scan signal is substantially equal to a negative edge time point of the second A-scan signal.

6. The light emitting display device of claim 4, wherein the first A-scan signal and the second A-scan signal have a substantially equal pulse width.

7. The light emitting display device of claim 4, wherein a positive edge time point of the first B-scan signal is ahead of a positive edge time point of the second B-scan signal, and

a negative edge time point of the first B-scan signal is ahead of a negative edge time point of the second B-scan signal.

8. The light emitting display device of claim 4, wherein the first B-scan signal and the second B-scan signal have a substantially equal pulse width.

9. The light emitting display device of claim 1, wherein the first switch comprises at least two switches connected in series between the data line and the first node.

10. The light emitting display device of claim 1, further comprising a second capacitor connected between the second node and the second driving power line.

11. The light emitting display device of claim 1, further comprising a third switch comprising a gate electrode to which configured to receive a control signal, the third switch connected between the second node and an initialization line configured to receive a second initialization signal.

12. The light emitting display device of claim 11, wherein the power supply portion is configured to apply the second initialization signal.

13. The light emitting display device of claim 11, wherein the control signal has an active voltage in at least a part of the first period.

14. The light emitting display device of claim 11, wherein the second initialization signal and the first initialization signal have a substantially equal voltage.

15. The light emitting display device of claim 1, wherein the power supply portion is configured to apply a fourth driving voltage to the second driving power line.

16. The light emitting display device of claim 15, wherein the fourth driving voltage is less than or equal to the first driving voltage.

17. The light emitting display device of claim 1, wherein the data driver is further configured to apply a first initialization signal to the data line in at least a part of the seventh period.