OLED Touch Layer Recessed Portions for Light Transmittance

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Solution Overview

Problem

Conventional direct on cell touch (DOT) structures in OLED display panels suffer from reduced light transmittance due to the thickness of insulating dielectric layers, which causes light shielding and absorption.

Innovation Solution

The implementation of recessed portions on the insulating dielectric layer, corresponding to pixel units, allows light to be emitted without absorption or refraction, enhancing light transmittance through a smooth mirror surface structure and selective etching process, and the use of multiple dielectric and metal layers with via holes for electrical connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If insulating dielectric layers are made thicker to achieve better electrical insulation, then electrical insulation performance is improved, but light transmittance deteriorates due to light shielding and absorption

Engineering Contradiction:

Improveelectrical insulation performanceVSAvoidlight transmittance

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The touch layer is segmented into multiple functional sub-layers: insulating dielectric layers for electrical insulation, transparent conductive layers for electrical connectivity, and recessed portions for light transmission. This segmentation allows each layer to optimize its specific function without compromising overall performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The insulating dielectric layer features localized recessed portions at pixel unit positions where light transmission is critical, while maintaining sufficient thickness in non-pixel areas for electrical insulation. This local quality variation resolves the contradiction by providing thick insulation where needed and thin/transmissive structures where light passage is required.

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If insulating dielectric layers are made thinner to improve light transmittance, then light transmittance is improved, but electrical insulation performance deteriorates

Engineering Contradiction:

Improvelight transmittanceVSAvoidelectrical insulation performance

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The touch layer employs composite material structures combining insulating dielectric materials with transparent conductive materials in specific patterns. This composite approach provides both electrical insulation and connectivity functions simultaneously, eliminating the need for thick insulating layers that would block light.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

Transparent conductive layers act as intermediary elements between the insulating dielectric layers and the pixel units below. These intermediaries provide electrical connectivity pathways while allowing light to pass through to the pixel units, resolving the insulation-transmittance contradiction.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Illumination intensity

If recessed portions are added to the insulating dielectric layer, then light transmittance is improved, but device complexity increases

Engineering Contradiction:

Improvelight transmittanceVSAvoidstructure complexity

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The recessed portions are formed in the insulating dielectric layer during the manufacturing process before subsequent layer deposition. This preliminary action integrates the light-transmission feature into the base structure, avoiding the need for additional complex components or post-processing steps.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The recessed portions serve multiple functions simultaneously: they reduce light shielding, provide access to pixel units, and define structural boundaries. By merging multiple functions into a single structural feature, the design avoids increasing overall device complexity while achieving improved light transmittance.

Inventive Principle:

Principle #5Merging (Combining)

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

Significantly improves light transmittance by preventing light absorption and refraction, while maintaining touch functionality and structural integrity, thereby enhancing the display panel's performance.

Implementation Method 1

a juncture of each of the recessed portions and the insulating dielectric layer is configured with a smooth mirror surface structure

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS11380873B2Display panel and electronic device including tough layer with recessed portions

Publication Date: 2022.07.05 WUHAN CHINA STAR OPTOELECTRONICS SEMICONDUCTOR DISPLAY TECHNOLOGY CO LTD

AI summary

A display panel and an electronic device are disclosed. The display panel includes a light-emitting layer, an encapsulation layer, and a touch layer. The light-emitting layer includes a plurality of pixel units and a plurality of isolating units disposed among the pixel units. The touch layer includes at least an insulating dielectric layer covering the encapsulation layer, and a plurality of touch units. The touch layer further includes a plurality of recessed portions disposed on the insulting dielectric layer and corresponding to the pixel units.