Light Waveguide Coating for Thin Display Color Enrichment

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Solution Overview

Problem

Existing display technologies face challenges in integrating color-enriching nanostructures like quantum dots without significantly increasing thickness, particularly in devices like tablets and mobile phones where physical fineness is crucial.

Innovation Solution

Coating the upper and lower surfaces of a light waveguide in displays with transparent metal oxide nanoparticles to form an oxygen and moisture barrier, followed by applying quantum dots and nanoplates for color enrichment, and then re-coating with another barrier layer to maintain a thin structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If quantum dot films are inserted as a new layer into displays to increase color richness, then color richness is improved, but display thickness increases

Engineering Contradiction:
Improvecolor richnessVSAvoiddisplay thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent transitions from inserting quantum dots as a separate bulk layer (3D volume approach) to coating quantum dots on the surface of the light guide plate (2D surface approach). This dimensional change allows color enrichment without adding significant thickness, as the quantum dots are applied as a thin surface layer rather than a bulk insert.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent creates a composite structure by combining quantum dot materials with the existing light guide plate material. The quantum dots are coated onto the light guide plate surface to form an integrated composite structure that provides both light guiding and color enrichment functions without requiring separate discrete layers.

Inventive Principle:
Principle #40Composite materials

2Reliability

If quantum dot films are mounted on light guide plates to provide color enrichment, then color gamut is widened, but device complexity increases

Engineering Contradiction:
Improvecolor gamutVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the color enrichment function with the existing light guide plate structure by coating quantum dots directly onto it. This integration combines multiple functions (light guiding and color conversion) into a single unified structure, reducing the number of separate components and simplifying the overall device architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The light guide plate is transformed into a multi-functional component that simultaneously performs light guiding and color enrichment through the integrated quantum dot coating. This universalization of the light guide plate's function reduces the need for separate dedicated color conversion layers.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If barrier films are added to protect quantum dots from moisture and oxygen, then protection is improved, but thickness increases

Engineering Contradiction:
Improveprotection from moisture and oxygenVSAvoidfilm thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent employs thin film barrier layers coated directly onto the quantum dot structure. These thin films provide effective moisture and oxygen protection while maintaining minimal thickness, as they are applied as conformal coatings rather than thick discrete barrier films.

Inventive Principle:
Principle #30Flexible shells and thin films

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

Achieves color enrichment with a reduced thickness, ensuring a physically fine structure without adding extra thickness, suitable for small-area displays.

Implementation Method 1

coating materials, which form an oxygen and moisture barrier, on lower and upper surface of a light waveguide being used in displays by spray coating

Methodology Applied
Scientific EffectSpray coating: Spray

Implementation Method 2

coating color enriching materials on the light waveguide, which is coated with an oxygen and moisture barrier on the upper and lower surface thereof, by spray coating

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP4085298B1A method for enhancing color richness of displays
Publication Date: 2025.06.25 BILKENT UNIVERSITESI ULUSAL NANOTEKNOLOJI ARASTIRMA MERKEZI
  • EP4085298B1 patent drawingFigure 1

AI summary

The present invention relates to a method (100) for widening color space with a much reduced thickness compared to film applications, by coating lower and upper surfaces of a light waveguide -that is used within displays such as tablet and mobile phone- with color enriching materials.