Methods Of Driving Active Display Device

• US 20120113078A1
• Filed: 08/29/2011
• Published: 05/10/2012
• Est. Priority Date: 11/09/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kwon, Dae-woong, Park, Byung-gook, Kim, Chang-jung, Park, Jae-chul
• Granted Patent: US 9,105,235 B2
• Time in Patent Office: Days
• US Class Current: 345/211
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

A method of driving an active display device. The method including recovering a threshold voltage of a switching transistor connected to a pixel. The recovering including applying a negative bias voltage to the switching transistor prior to charging each pixel during a charging period. The negative bias voltage is applied to a drain of the switching transistor.

Claims

1. A method of driving an active display device, the method comprising:

recovering a threshold voltage of a switching transistor, the switching transistor connected to a pixel, the recovering including applying a negative bias voltage to the switching transistor prior to charging the pixel during a charging period.

2. The method of claim 1, wherein the negative bias voltage is applied to a drain electrode of the switching transistor.

3. The method of claim 2, further comprising:

applying a negative gate voltage to a gate electrode of the switching transistor for a period excluding the charging period.

4. The method of claim 3, further including:

charging the switching transistor by applying a positive data voltage to the switching transistor after the applying of the negative bias voltage during the charging period

5. The method of claim 1, further comprising:

applying a negative gate voltage to a gate electrode of the switching transistor for a period excluding the charging period.

6. The method of claim 1, wherein the negative bias voltage is −

20 V.

7. The method of claim 1, further comprising:

charging the switching transistor by applying a positive data voltage to the switching transistor after the applying of the negative bias voltage during the charging period.

8. The method of claim 7, wherein the applying the negative bias voltage and the applying the positive data voltage are performed while a pulse voltage is applied to a gate electrode of the switching transistor during the charging period.

9. The method of claim 7, wherein the applying the negative bias voltage is performed if a first pulse voltage is applied to a gate electrode of the switching transistor, and the applying the positive data voltage is performed if a second pulse voltage is applied to the gate electrode of the switching transistor during the charging period.

10. The method of claim 1, wherein the active display device is an active organic light-emitting diode.

11. A method of driving an active display device, the method comprising:

recovering a threshold voltage of a switching transistor connected to a pixel, the recovering including applying a negative bias voltage to the switching transistor during a charging period; and

charging the pixel by applying a positive data voltage to the switching transistor during the charging period.

12. The method of claim 11, wherein the negative bias voltage is applied to a drain electrode of the switching transistor.

13. The method of claim 12, further comprising:

applying a negative gate voltage to a gate electrode of the switching transistor for a period excluding the charging period.

14. The method of claim 11, further comprising:

applying a negative gate voltage to a gate electrode of the switching transistor for a period excluding the charging period.

15. The method of claim 11, wherein the negative bias voltage is −

20 V.

16. The method of claim 11, wherein the applying the negative bias voltage and the applying the positive data voltage are performed while a pulse voltage is applied to a gate electrode of the switching transistor.

17. The method of claim 11, wherein the applying the negative bias voltage is performed if a first pulse voltage is applied to a gate electrode of the switching transistor, and the applying the positive data voltage is performed if a second pulse voltage is applied to the gate electrode of the switching transistor.

18. The method of claim 11, wherein the active display device is an active organic light-emitting diode.