Pixel and method of aging the pixel

Patent metadata

Field	Value
Publication number	US-12424171-B2
Application number	US-202318488754-A
Country	US
Kind code	B2
Filing date	Oct 17, 2023
Priority date	Mar 14, 2023
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

The disclosure provides a pixel and a method of aging the pixel for reducing or preventing damage to a display element during aging of a driving transistor, the pixel including a display element including an anode and a cathode, a first transistor configured to control a magnitude of a driving current flowing to the display element in response to a gate-source voltage, the first transistor including a first gate electrode configured to function as a gate of the first transistor, a semiconductor layer, and a second gate electrode in a floating state between the first gate electrode and the semiconductor layer, and a second transistor configured to deliver a first voltage to the first transistor in response to a first scan signal.

First claim

What is claimed is:

1. A method of aging a pixel comprising: a display element having an anode and a cathode; a first transistor having a semiconductor layer, a first gate electrode configured to function as a gate of the first transistor, a second gate electrode in a floating state between the first gate electrode and the semiconductor layer, a first electrode, and a second electrode connected to the anode of the display element; a storage capacitor having a first storage electrode, and a second storage electrode connected to the first gate electrode of the first transistor; and a second transistor comprising a third gate electrode, a third electrode connected to a data line, and a fourth electrode connected to the first gate electrode of the first transistor, the method comprising:
applying a first driving voltage to the first electrode of the first transistor;
applying a second driving voltage to the cathode of the display element, wherein a level of the first driving voltage is higher than a level of the second driving voltage;
applying a first aging voltage to the first gate electrode of the first transistor such that carriers in the semiconductor layer tunnel through the second gate electrode to adjust a threshold voltage of the first transistor; and
applying a third driving voltage, which is the same as the first aging voltage, from a voltage source directly connected to the first storage electrode of the storage capacitor to reduce a voltage across the storage capacitor to reduce damage to the storage capacitor during application of the first aging voltage for aging the first transistor to the second storage electrode of the storage capacitor, wherein a level of the third driving voltage is lower than the level of the first driving voltage,
wherein the applying of the first driving voltage to the first electrode of the first transistor, the applying of the second driving voltage to the cathode of the display element, the applying of the first aging voltage to the first gate electrode of the first transistor, and the applying of the third driving voltage to the first storage electrode of the storage capacitor are performed concurrently.

2. The method of claim 1 , wherein the applying of the first aging voltage to the first gate electrode of the first transistor comprises:
applying a turn-on level voltage to the third gate electrode of the second transistor; and
applying the first aging voltage to the data line.

3. The method of claim 1 , wherein the first transistor is configured to control a magnitude of a driving current flowing to the display element in response to a gate-source voltage.

4. The method of claim 1 , wherein the first gate electrode is above the semiconductor layer, and at least partially overlaps a channel area of the semiconductor layer, and
wherein the second gate electrode is between the first gate electrode and the channel area of the semiconductor layer, and at least partially overlaps channel area of the semiconductor layer.

5. A method of aging a pixel comprising: a display element having an anode and a cathode; a first transistor having a semiconductor layer, a first gate electrode configured to function as a gate of the first transistor, a second gate electrode in a floating state between the first gate electrode and the semiconductor layer, a first electrode, and a second electrode connected to the anode of the display element; a storage capacitor having a first storage electrode, and a second storage electrode connected to the first gate electrode of the first transistor; a second transistor comprising a third gate electrode, a third electrode connected to a data line, and a fourth electrode connected to the first gate electrode of the first transistor; and a third transistor comprising a fourth gate electrode, a fifth electrode connected to the anode of the display element, and a sixth electrode, the method comprising:
applying a first driving voltage to the first electrode of the first transistor;
applying a second driving voltage to the cathode of the display element, wherein a level of the first driving voltage is higher than a level of the second driving voltage;
applying a first aging voltage to the first gate electrode of the first transistor to generate an aging current through the first transistor such that carriers in the semiconductor layer tunnel through the second gate electrode to adjust a threshold voltage of the first transistor;
applying a second aging voltage to the anode of the display element through the third transistor which is turned on, not to flow the aging current through the display element, wherein a level of the second aging voltage is lower than the level of the second driving voltage; and
applying a third driving voltage, which is the same as the first aging voltage, from a voltage source directly connected to the first storage electrode of the storage capacitor to reduce a voltage across the storage capacitor to reduce damage to the storage capacitor during application of the first aging voltage for aging of the first transistor to the second storage electrode of the storage capacitor, wherein a level of the third driving voltage is lower than the level of the first driving voltage,
wherein the applying of the first driving voltage to the first electrode of the first transistor, the applying of the second driving voltage to the cathode of the display element, the applying of the first aging voltage to the first gate electrode of the first transistor, the applying of the second aging voltage to the anode of the display element, and the applying of the third driving voltage to the first storage electrode of the storage capacitor are performed concurrently.

6. The method of claim 5 , wherein the applying of the first aging voltage to the first gate electrode of the first transistor comprises:
applying a turn-on level voltage to the third gate electrode of the second transistor; and
applying the first aging voltage to the data line.

7. The method of claim 5 , wherein the applying of the second aging voltage to the anode of the display element comprises:
applying a turn-on level voltage to the fourth gate electrode of the third transistor; and
applying the second aging voltage to the sixth electrode of the third transistor.

8. The method of claim 5 , wherein the first transistor is configured to control a magnitude of a driving current flowing to the display element in response to a gate-source voltage.

9. The method of claim 5 , wherein the first gate electrode is above the semiconductor layer, and at least partially overlaps a channel area of the semiconductor layer, and
wherein the second gate electrode is between the first gate electrode and the channel area of the semiconductor layer, and at least partially overlaps channel area of the semiconductor layer.

Assignees

• Samsung Display Co Ltd

Inventors

• Yoon Juwon
• Jin Guanghai
• NOH Junghun

Classifications

• G09G3/3291

  in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements · CPC title

• G09G2300/0842

  forming a memory circuit, e.g. a dynamic memory with one capacitor · CPC title

• G09G2300/0819

  used for counteracting undesired variations, e.g. feedback or autozeroing · CPC title

• G09G2320/043

  Preventing or counteracting the effects of ageing · CPC title

• G09G3/3233 Primary

  with pixel circuitry controlling the current through the light-emitting element · CPC title