Top emission light emitting display having reflective layer

• US 7,109,652 B2
• Filed: 10/23/2003
• Issued: 09/19/2006
• Est. Priority Date: 10/23/2002
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: TPO Displays Corporation (InnoLux Corporation)
• Inventors: Chang, Shih-Chang, Tsai, Yaw-Ming
• Primary Examiner(s): Williams, Joseph
• Assistant Examiner(s): Won, Bumsuk
• Application Number:
  US10/690,636
• Publication Number:
  US 20040080476A1
• Time in Patent Office: 1,062 Days
• Field of Search: 313/506, 313/110, 313112-113, 313/512, 313/504, 315/169.3, 257/40, 428/690, 428/917
• US Class Current: 313/506
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/878 comprising reflective means

Abstract

A top emission organic light emitting display with a reflective layer therein is provided. The reflective layer, a first electrode, an organic layer, and a transparent second electrode are subsequently formed on the substrate. When a bias voltage is applied to the first electrode and the transparent second electrode, the organic layer emits radiation. The reflective layer reflects radiation from the organic layer toward the transparent second electrode, and therefore the emission efficiency of the OLED increases.

Claims

1. A top emission organic light emitting display (OLED), comprising:

a substrate;

a reflective layer disposed on the substrate;

a first electrode disposed on the reflective layer, a contact surface between the reflective layer and the first electrode being a rough surface so as to reduce color shift with a wide viewing angle;

an organic layer disposed on the first electrode; and

a transparent second electrode disposed on the organic layer;

wherein, as a bias voltage is applied to the top emission OLED via the first electrode and the transparent second electrode, the organic layer emits radiation in multiple directions, the reflective layer reflects the radiation toward the transparent second electrode.

2. The top emission OLED of claim 1, wherein the reflective layer is made of a material selected from a group consisting of aluminum, silver and alloy thereof.

3. The top emission OLED of claim 1, wherein the organic layer is composed of a plurality of compound layers, the plurality of compound layers comprise an electronic layer, a hole transport layer and a light emitting layer.

4. The top emission OLED of claim 1, further comprising a switch disposed between the substrate and the reflective layer, wherein the switch is electrically coupled to the first electrode for controlling the radiation of the top emission OLED.

5. The top emission OLED of claim 4, wherein the switch is a thin film transistor.

6. The top emission OLED of claim 1, further comprising a cap layer disposed on the transparent second electrode.

7. A top emission organic light emitting display (OLED), comprising:

a substrate having a thin film transistor;

a planarization layer disposed on the substrate covering the thin film transistor;

a reflective layer disposed on the planarization layer;

a first electrode disposed on the reflective layer and electrically coupled to the thin film transistor, a contact surface between the reflective layer and the first electrode being a rough surface so as to reduce color shift with a wide viewing angle;

an organic layer disposed on the first electrode; and

a transparent second electrode disposed on the organic layer;

wherein, as a bias voltage is applied to the first electrode and the transparent second electrode, the organic layer emits radiation in all directions, the reflective layer reflects the radiation toward the transparent second electrode for increasing brightness of the top emission OLED.

8. The top emission OLED of claim 7, wherein the reflective layer is made of a material selected from a group consisting of aluminum, silver and alloy thereof.

9. The top emission OLED of claim 7, wherein the organic layer is composed of a plurality of compound layers, the plurality of compound layers comprise an electronic layer, a hole transport layer and a light emitting layer.

10. The top emission OLED of claim 7, further comprising a cap layer disposed on the transparent second electrode.