Organic light emitting diode display

• US 8,987,719 B2
• Filed: 05/30/2013
• Issued: 03/24/2015
• Est. Priority Date: 09/18/2012
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Moon, Sung-Hoon
• Primary Examiner(s): Schoenholtz, Joseph
• Application Number:
  US13/905,990
• Publication Number:
  US 20140077180A1
• Time in Patent Office: 663 Days
• Field of Search: None
• US Class Current: 257/40
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1229 with different crystal properties within a device or between different devices
• CPC Class Codes: H01L 27/1237 with a different composition, shape, layout or thickness of the gate insulator in different devices
• CPC Class Codes: H10K 50/30 Organic light-emitting transistors
• CPC Class Codes: H10K 50/80 Constructional details
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals

Abstract

An organic light emitting diode (OLED) display includes: a substrate; an organic light emitting element formed on the substrate; a first thin film transistor connected to the organic light emitting element and including an amorphous silicon channel region; and at least one other thin film transistor connected to the first thin film transistor and including a polysilicon channel region.

Claims

1. An organic light emitting diode (OLED) display including:

a substrate;

an organic light emitting element formed on the substrate;

a first thin film transistor providing driving power to the organic light emitting element, the first thin film transistor includes an amorphous silicon channel region; and

a plurality of other thin film transistors directly connected to the first thin film transistor, each of the plurality of other thin film transistors includes a polysilicon channel region which is directly connected to the amorphous silicon channel region, wherein

a distance between a first gate electrode and the amorphous silicon channel region of the first thin film transistor being longer than a distance between a gate electrode and the polysilicon channel region of the plurality of other thin film transistors.

2. The organic light emitting diode (OLED) display of claim 1, wherein the amorphous silicon channel region and the polysilicon channel region being positioned at the same layer.

3. The organic light emitting diode (OLED) display of claim 1, further comprising:

a first scan line extending in a first direction on the substrate;

a second scan line separated from the first scan line and extending in the first direction;

an initialization power line separated from the second scan line and extending in the first direction;

a light emission control line separated from the initialization power line and extending in the first direction;

a data line extending in a second direction crossing the first direction on the substrate; and

a driving power line separated from the data line and extending in the second direction.

4. The organic light emitting diode (OLED) display of claim 3, wherein the first scan line, the second scan line, the initialization power line, and the light emission control line being positioned at the same layer.

5. The organic light emitting diode (OLED) display of claim 3, wherein the first scan line and the light emission control line being positioned at the same layer, and the second scan line and the initialization power line being positioned on the first scan line and the light emission control line via an insulation layer.

6. The organic light emitting diode (OLED) display of claim 3, wherein the plurality of other thin film transistors including:

a second thin film transistor including a second gate electrode connected to the first scan line and connecting the data line and the first thin film transistor;

a third thin film transistor including a third gate electrode connected to the first scan line and connecting the first thin film transistor and the first gate electrode of the first thin film transistor;

a fourth thin film transistor including a fourth gate electrode connected to the second scan line and connecting the initialization power line and the first gate electrode;

a fifth thin film transistor including a fifth gate electrode connected to the light emission control line and connecting the driving power line and the first thin film transistor; and

a sixth thin film transistor including a sixth gate electrode connected to the light emission control line and connecting the first thin film transistor and the organic light emitting element.

7. The organic light emitting diode (OLED) display of claim 6, wherein the first gate electrode, the second gate electrode, the third gate electrode, the fourth gate electrode, the fifth gate electrode, and the sixth gate electrode being formed at the same layer.

8. The organic light emitting diode (OLED) display of claim 6, wherein the fourth gate electrode, the fifth gate electrode, and the sixth gate electrode being positioned at the same layer, and the first gate electrode, the second gate electrode, and the third gate electrode being positioned at different layers on the fourth gate electrode, the fifth gate electrode, and the sixth gate electrode via an insulation layer.

9. The organic light emitting diode (OLED) display of claim 8, further comprising a capacitor including a first capacitor electrode connected to the first gate electrode and positioned at the same layer as the fourth gate electrode, the fifth gate electrode, and the sixth gate electrode, and a second capacitor electrode connected to the driving power line and formed at the same layer as the first gate electrode, the second gate electrode, and the third gate electrode.

10. The organic light emitting diode (OLED) display of claim 1, wherein the organic light emitting element including:

a first electrode connected to the first thin film transistor;

an organic emission layer positioned on the first electrode; and

a second electrode positioned on the organic emission layer.