OLED Display Black Matrix Using Compound Semiconductor

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Solution Overview

Problem

Conventional OLED display devices suffer from decreased contrast due to external light reflection, which is addressed by using a polarizer, increasing production costs and reducing brightness.

Innovation Solution

A method of forming a black matrix using a compound semiconductor to improve internal optical efficiency and reduce external light reflection, involving a substrate with emission and non-emission regions, a buffer layer, semiconductor layer, gate insulating layer, and electrodes, including a transparent conductive oxide layer to minimize light reflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a polarizer is adhered to the entire surface of the display device to prevent external light reflection, then contrast is improved, but production cost increases and brightness decreases

Engineering Contradiction:

Improveexternal light reflectionVSAvoidproduction cost

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent extracts the polarizer from the display structure and replaces it with a black matrix layer that selectively blocks external light in non-emission regions while allowing emitted light to pass through. This eliminates the need for the expensive polarizer while maintaining contrast improvement benefits.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The black matrix is applied only to non-emission regions rather than the entire display surface. This localized approach selectively blocks external light where needed (in non-emission regions) while allowing emitted light from the emission regions to pass through unobstructed, thereby maintaining brightness while improving contrast.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If a polarizer is adhered to the entire surface of the display device to prevent external light reflection, then contrast is improved, but brightness decreases

Engineering Contradiction:

Improveexternal light reflectionVSAvoidbrightness

Core Design Contradiction:

Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

Inventive Principle:

Principle #3Local quality

3Reliability

If metallic materials such as gate electrode and source and drain electrodes are used in the thin film transistor, then electrical conductivity is improved, but external light reflection increases

Engineering Contradiction:

Improveelectrical conductivityVSAvoidexternal light reflection

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The black matrix is positioned in non-emission regions to selectively block external light reflection from metallic components. This localized approach allows metallic materials to be used in emission regions for their excellent electrical conductivity while preventing their harmful reflective effect in non-emission regions where they would otherwise be visible.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8519612B2Organic light emitting diode display device and method of fabricating the same

Publication Date: 2013.08.27 SAMSUNG DISPLAY CO LTD

AI summary

An organic light emitting diode (OLED) display device and a method of fabricating the OLED display device, the OLED display device includes a substrate including an emission region and a non-emission region, a black matrix disposed in a region excluding a part of the emission region, a buffer layer disposed on the entire surface of the substrate, a semiconductor layer disposed on the buffer layer in the non-emission region, a gate electrode disposed on the semiconductor layer, a gate insulating layer insulating the semiconductor layer from the gate electrode and formed on the entire surface of the substrate, a first electrode formed on the gate insulating layer in the emission region, source and drain electrodes electrically connected with the semiconductor layer and the first electrode, an interlayer insulating layer insulating the source and drain electrodes from the gate electrode and opening a part of the first electrode, a pixel defining layer opening a part of the first electrode and disposed on the entire surface of the substrate, an organic layer disposed on the first electrode, and a second electrode disposed on the entire surface of the substrate. Here, the first electrode includes a transparent conductive oxide layer.