Phosphor Backlight Unit Without Quantum Dot Sheet

Solution Overview

Problem

Existing display technologies face challenges in achieving high color reproduction while avoiding the use of toxic quantum dots and managing increased product size and material costs due to the need for additional safety measures.

Innovation Solution

A backlight unit design that omits the high color reproduction quantum dot sheet and incorporates a Nano-Organic Material (NOM) in the optical sheet, along with strategically placed phosphors to enhance color reproduction without using quantum dots, thereby reducing phosphor usage and maintaining brightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a high-color sheet including quantum dots is added to improve color reproducibility, then color reproduction is improved, but product size increases and material cost increases due to required barrier films and safety measures

Engineering Contradiction:

Improvecolor reproductionVSAvoidproduct size

Core Design Contradiction:

Measurement precisionVSVolume of stationary object

Solution Approach 1:

The patent extracts and removes the quantum dot sheet from the backlight unit structure, eliminating the need for additional barrier films and safety measures while maintaining color reproduction through alternative phosphor-based color conversion layers

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive quantum dot materials with more cost-effective phosphor materials that achieve similar color reproduction goals without requiring additional protective layers, thereby reducing overall material cost and product size

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If a high-color sheet including quantum dots is added to improve color reproducibility, then color reproduction is improved, but manufacturing cost increases due to additional barrier films and safety measures

Engineering Contradiction:

Improvecolor reproductionVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent extracts and removes the quantum dot sheet from the backlight unit structure, eliminating the need for additional barrier films and safety measures while maintaining color reproduction through alternative phosphor-based color conversion layers

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive quantum dot materials with more cost-effective phosphor materials that achieve similar color reproduction goals without requiring additional protective layers, thereby reducing overall material cost and product size

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If quantum dots are used to improve color reproducibility, then color reproduction is improved, but color uniformity deteriorates due to distribution issues

Engineering Contradiction:

Improvecolor reproductionVSAvoidcolor uniformity

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent extracts and removes the quantum dot sheet from the backlight unit structure, eliminating the need for additional barrier films and safety measures while maintaining color reproduction through alternative phosphor-based color conversion layers

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the material parameter from quantum dots to phosphors, which have better distribution characteristics and produce more uniform color output across the display panel while maintaining high color reproduction capability

Inventive Principle:

Principle #35Parameter changes

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 approach improves color reproduction, reduces manufacturing costs, and prevents uneven color distribution, while maintaining brightness and minimizing the product's size and material costs.

Implementation Method 1

a first phosphor that converts first light of a first wavelength band to second light of a second wavelength band

Methodology Applied

Scientific EffectPhosphorescence: Phosphorescence

Implementation Method 2

a second phosphor that converts first light of a first wavelength band to third light of a third wavelength band

Methodology Applied

Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentEP4628979B1Backlight unit and display device including the same

Publication Date: 2026.03.04 LG ELECTRONICS INC

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AI summary

Disclosed is a backlight unit, including a light assembly having a light emitting lamp emitting a first light of a first wavelength band and a resin cover surrounding the light emitting lamp and including a first phosphor and a second phosphor, and an optical sheet including a third phosphor and optically converting an incident light of the light assembly incident on a rear surface to emit the optically converted light to a front surface, wherein the first phosphor converts the first light into a second light of a second wavelength band greater than the first wavelength band, wherein the second phosphor converts the first light into a third light of a third wavelength band greater than the second wavelength band, and wherein the third phosphor converts the second light into the third light of the third wavelength band. Accordingly, a high color reproduction quantum dot sheet may be omitted to improve color reproduction, so that a price and a volume may be reduced.