Color Filter Light Recycling for Display Efficiency

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Solution Overview

Problem

Current color filters in organic light-emitting display devices face challenges in achieving improved light efficiency and color reproducibility, leading to suboptimal performance in displaying colors with high accuracy and minimal light loss.

Innovation Solution

A color filter design featuring a substrate with pixel areas and light blocking regions, incorporating a light blocking layer, color conversion layers, and a light reflection layer to selectively transmit and convert incident light into specific colors, along with a partition wall to prevent light mixing, enhancing light recycling and color accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional color filter structure is used, then the device complexity is low, but the light efficiency and color reproducibility are insufficient

Engineering Contradiction:
Improvecolor reproducibilityVSAvoidcolor filter structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The color filter is divided into multiple functional layers: a light blocking layer for defining pixel regions, a color conversion layer for wavelength transformation, and a light reflection layer for light recycling. Each layer performs a specific function to collectively improve color reproducibility and light efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A light reflection layer is introduced as an intermediary between the color conversion layer and the substrate. This intermediary component reflects unabsorbed light back through the color conversion layer, enabling light recycling and improving overall light efficiency without complicating the fundamental filter structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If light recycling is implemented, then the light efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improvelight efficiencyVSAvoidcolor filter structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The light reflection layer converts what would otherwise be wasted light (that passes through the color filter without being absorbed) into a beneficial resource by reflecting it back through the color conversion layer. This transforms potential energy loss into useful light output, improving light efficiency.

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

Solution Approach 2:

Instead of discarding light that passes through the color filter without being fully absorbed, the system recovers this light through the light reflection layer and reuses it by reflecting it back through the color conversion layer, thereby improving overall light efficiency.

Inventive Principle:
Principle #34Discarding and recovering

3Measurement precision

If partition walls are added to prevent light mixing, then the color accuracy is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvecolor accuracyVSAvoidpartition wall alignment
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The light blocking layer is extracted as a separate functional element that defines pixel regions and prevents light mixing between adjacent pixels. By dedicating this function to a specific layer, the design achieves color accuracy without requiring complex integration of multiple functions in single layers.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The solution significantly improves light efficiency and color reproducibility by effectively recycling light and preventing color mixing, resulting in enhanced display performance with reduced power consumption.

Implementation Method 1

a first color conversion layer on a first pixel area among the plurality of pixel areas and configured to convert incident light into light of a first color

Methodology Applied
Scientific EffectColor conversion: Photoluminescence

Implementation Method 2

a light reflection layer between the first color conversion layer and the first color filter layer and including a reflective material

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

a first color filter layer on the first pixel area and between the substrate and the first color conversion layer and configured to selectively transmit the light of the first color emitted from the first color conversion layer

Methodology Applied
Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentEP3872539B1Color filter and display device comprising same
Publication Date: 2024.12.25 SAMSUNG DISPLAY CO LTD
  • EP3872539B1 patent drawingFigure 1
  • EP3872539B1 patent drawingFigure 2
  • EP3872539B1 patent drawingFigure 3

AI summary

Provided is a color filter having improved light efficiency and color reproducibility. The color filter includes: a substrate having a plurality of pixel areas and a light blocking area surrounding the plurality of pixel areas; a light blocking layer on the light blocking area; a first color conversion layer on a first pixel area among the plurality of pixel areas and configured to convert incident light into light of a first color; a first color filter layer between the substrate and the first color conversion layer and configured to selectively transmit the light of the first color emitted from the first color conversion layer; and a light reflection layer between the first color conversion layer and the first color filter layer and including a reflective material.