Display Device Light Blocking Planarization Layer Transistor Protection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Display devices, particularly organic light emitting display devices, face performance degradation due to external light exposure, which existing technologies have not adequately addressed.

Innovation Solution

The implementation of a display device structure that includes a second planarization layer with a light blocking portion and a light transmissive portion, where the light blocking portion has a uniform transmittance and overlaps the semiconductor patterns, effectively blocking external light and preventing performance degradation of transistors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional display device structure is used, then the device can display images using organic light emitting elements, but external light exposure causes performance degradation of transistors

Engineering Contradiction:

Improvetransistor performance stabilityVSAvoidexternal light exposure

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A light blocking layer is introduced as an intermediary component between the external environment and the transistor. This layer specifically blocks external light from reaching the transistor while allowing the transistor to function normally, thereby resolving the contradiction between maintaining transistor reliability and preventing harmful light exposure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful effect of external light into a beneficial structure by implementing a light blocking layer with specific material composition and thickness. This layer transforms the potential damage from light exposure into a protective feature that enhances transistor reliability while maintaining display functionality.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If a light blocking layer is added to block external light, then transistor performance degradation is suppressed, but device structure complexity increases

Engineering Contradiction:

Improvetransistor performance stabilityVSAvoidlayer structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The light blocking layer is designed to serve multiple functions simultaneously: it blocks external light from reaching the transistor, provides electrical insulation, and maintains structural integrity of the display device. By combining multiple functions into a single layer, the patent reduces overall device complexity while achieving reliable light blocking.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent optimizes the light blocking layer by adjusting specific parameters such as material composition, thickness, and optical properties. Through parameter optimization, the layer achieves effective light blocking with minimal impact on device complexity, balancing reliability improvement with structural simplicity.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the light blocking portion blocks all external light, then transistor protection is maximized, but light transmittance for display function is reduced

Engineering Contradiction:

Improvetransistor performance stabilityVSAvoidlight transmittance

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The light blocking layer is designed with spatially varying properties: it provides strong light blocking in regions where transistors are located while maintaining light transmittance in regions where light needs to pass through for display functionality. This local differentiation resolves the contradiction between protecting transistors and maintaining display performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The display device structure is segmented into different functional regions: light blocking portions positioned over transistor areas and light transmissive portions positioned over display areas. This segmentation allows the device to simultaneously achieve transistor protection and adequate light transmittance for image display.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution suppresses performance degradation of transistors by uniformly blocking external light, improving the display device's operational stability and maintaining image quality.

Implementation Method 1

a second planarization layer disposed on the first planarization layer and including a light blocking portion... uniformly blocking external light

Methodology Applied

Scientific EffectLight blocking: Absorption (EM radiation)

Data Source

PatentUS11563200B2Display device

Publication Date: 2023.01.24 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a first semiconductor pattern on a substrate, a first insulating layer on the first semiconductor pattern, a first gate electrode on the first insulating layer, a second insulating layer on the first gate electrode, a second semiconductor pattern on the second insulating layer, a material of the second semiconductor pattern being different from that of the first semiconductor pattern, a third insulating layer on the second semiconductor pattern, a second gate electrode on the third insulating layer, a first planarization layer overlapping the second gate electrode, a second planarization layer on the first planarization layer and including a light blocking portion, and a pixel definition layer on the second planarization layer, wherein at least a portion of the pixel definition layer directly contacts the light blocking portion of the second planarization layer.