ORGANIC LIGHT EMITTING DIODE DISPLAY

• US 20200135831A1
• Filed: 10/23/2019
• Published: 04/30/2020
• Est. Priority Date: 10/24/2018
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: BAE, Joon Woo, KANG, Mee Jae, NGUYEN, Thanh Tien, LEE, Kyoung Won, LEE, Yong Su, LEE, Jae Seob, JO, Gyoo Chul, CHA, Myoung Geun
• Granted Patent: US 11,616,108 B2
• Time in Patent Office: Days
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors
• CPC Class Codes: H10K 59/126 Shielding, e.g. light-blocking means over the TFTs
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals

Abstract

An organic light emitting diode display includes a substrate, an overlap layer on the substrate, a semiconductor layer on the overlap layer, a first gate conductor on the semiconductor layer, a second gate conductor on the first gate conductor, a data conductor on the second gate conductor, a driving transistor on the overlap layer, and an organic light emitting diode connected with the driving transistor. The driving transistor includes, in the semiconductor layer, a first electrode, a second electrode, with a channel therebetween. A gate electrode of the first gate conductor overlaps the channel. The overlap layer overlaps the channel of the driving transistor and at least a portion of the first electrode. A storage line of the second gate conductor receives a driving voltage through a driving voltage line in the data conductor. The overlap layer receives a constant voltage.

Claims

1. An organic light emitting diode display, comprising:

a substrate;

an overlap layer on the substrate;

a semiconductor layer on the overlap layer;

a first gate conductor on the semiconductor layer;

a second gate conductor on the first gate conductor;

a data conductor on the second gate conductor;

a driving transistor on the overlap layer; and

an organic light emitting diode connected with the driving transistor,

wherein the driving transistor includes a first electrode formed in the semiconductor layer, a second electrode formed in the semiconductor layer, a channel formed between the first electrode and the second electrode, and a gate electrode formed of the first gate conductor to overlap the channel,

the overlap layer overlaps the channel of the driving transistor and extends to the first electrode to overlap at least a portion of the first electrode,

the second gate conductor includes a storage line to which a driving voltage is applied through a driving voltage line formed of the data conductor, and

the overlap layer receives a constant voltage.

2. The organic light emitting diode display as claimed in claim 1, wherein

a gate insulating layer is between the gate electrode and the storage line, and

the gate electrode and the storage line constitute a storage capacitor that maintains a voltage across the gate electrode.

3. The organic light emitting diode display as claimed in claim 2,

a buffer layer is disposed between the overlap layer and the semiconductor layer, and

the overlap layer and the semiconductor layer of the driving transistor constitute an additional storage capacitor.

4. The organic light emitting diode display of claim 3, wherein

the overlap layer includes a base portion that overlaps the channel of the driving transistor, and

the base portion and the channel of the semiconductor layer constitute a first additional storage capacitor.

5. The organic light emitting diode display of claim 3, wherein

the overlap layer includes a first extension that overlaps the first electrode of the driving transistor, and

the first extension and the first electrode of the semiconductor layer constitute a second additional storage capacitor.

6. The organic light emitting diode display of claim 1, wherein

the overlap layer extends so that a left side of the overlap layer coincides with a left side of the semiconductor layer including the first electrode of the driving transistor in a plan view.

7. The organic light emitting diode display of claim 1, wherein

when a distance between a left side of the gate electrode and a left side of the overlap layer is referred to as a first distance,

the first distance is in a range of 1.0 μ

m to 4.0 μ

m.

8. The organic light emitting diode display of claim 1, wherein

when the overlap layer is formed to overlap the first electrode of the driving transistor, a reduction range of an instant afterimage is 5 times greater than that when the overlap layer is not overlapped with the first electrode of the driving transistor.

9. The organic light emitting diode display of claim 1, wherein

when the overlap layer is formed to overlap the first electrode of the driving transistor, an instant afterimage is reduced by 3 seconds or more as compared with when the overlap layer is not overlapped with the first electrode of the driving transistor.

10. The organic light emitting diode display of claim 1, wherein

a distance between overlap layers disposed at pixels adjacent to the overlap layer is in a range of 2.0 μ

m to 2.5 μ

m.

11. The organic light emitting diode display of claim 5,

further comprising a second transistor and a third transistor,

wherein the second transistor is connected to a scan line and a data line to transmit a data voltage transmitted through the data line to the first electrode of the driving transistor,

the third transistor is connected to the gate electrode and the second electrode of the driving transistor to transfer the data voltage to the storage capacitor, and

the overlap layer further includes a second extension that overlaps the semiconductor layer of the third transistor.

12. The organic light emitting diode display as claimed in claim 11, wherein the second extension of the overlap layer and the semiconductor layer of the driving transistor constitute a third additional storage capacitor.

13. The organic light emitting diode display as claimed in claim 3, wherein:

the overlap layer overlaps at least a portion of the second electrode of the driving transistor, and

the overlap layer and the second electrode constitute a fourth additional storage capacitor.

14. An organic light emitting diode display, comprising:

a substrate;

an overlap layer on the substrate;

a semiconductor layer on the overlap layer;

a gate electrode on the semiconductor layer;

a storage line on the gate electrode;

a driving voltage line on the storage line;

a driving transistor on the overlap layer;

a third transistor on the overlap layer; and

an organic light emitting diode connected with the driving transistor, wherein

the driving transistor includes a first electrode formed in the semiconductor layer, a second electrode formed in the semiconductor layer, a channel between the first electrode and the second electrode, and the gate electrode,

the third transistor is connected to the gate electrode and the second electrode of the driving transistor,

the overlap layer overlaps the channel of the driving transistor and extends to a region of the first electrode to overlap at least a portion of the first electrode,

the overlap layer overlaps the semiconductor layer of the third transistor,

a driving voltage is applied to the storage line through the driving voltage line, and

a constant voltage is applied to the overlap layer.

15. The organic light emitting diode display as claimed in claim 14, wherein

the overlap layer includes:

a base portion that overlaps the channel of the driving transistor; and

a first extension that overlaps the first electrode of the driving transistor, wherein

the base portion and the channel of the driving transistor constitute a first additional storage capacitor, and

the first extension and the first electrode of the driving transistor constitute a second additional storage capacitor.

16. The organic light emitting diode display as claimed in claim 15, further comprising:

a buffer layer between the overlap layer and the semiconductor layer,

wherein the first extension of the overlap layer and the semiconductor layer of the driving transistor constitute a third additional storage capacitor.

17. The organic light emitting diode display as claimed in claim 14, further comprising a second transistor, wherein:

the second transistor is connected to the first electrode of the driving transistor, and

the overlap layer extends so that a left side of the overlap layer coincides with a left side of the semiconductor layer including the second transistor and the first electrode of the driving transistor.

18. The organic light emitting diode display as claimed in claim 14, wherein:

when a distance between a left side of the gate electrode and a left side of the overlap layer is referred to as a first distance,

the first distance is in a range of 1.0 μ

m to 4.0 μ

m.

19. The organic light emitting diode display as claimed in claim 14, wherein a distance between overlap layers at pixels adjacent to the overlap layer is in a range of 2.0 μ

m to 2.5 μ

m.

20. The organic light emitting diode display as claimed in claim 14, wherein, when the overlap layer overlaps the first electrode of the driving transistor, a reduction range of an instant afterimage is 5 times greater than that when the overlap layer does not overlap the first electrode of the driving transistor.