LED Package with Yellow Phosphor for Blue Light Reduction

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Solution Overview

Problem

Current display devices fail to effectively reduce dangerous blue light emission while meeting requirements for wide color gamut and energy conservation, as they either rely solely on software algorithms or hardware designs that do not meet environmental protection standards.

Innovation Solution

A light emitting diode package structure incorporating a blue light emitting diode and a phosphor layer with a specific composition of green, red, and yellow phosphor powders, where the yellow phosphor powders range from 1% to 10% by weight, is used to generate white light with a wide color gamut and reduced blue light hazard, integrated into a display device's backlight module.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If software algorithms are used to reduce blue light proportion, then blue light reduction is achieved, but hardware eye protection function is not provided and users are still harmed by high energy blue light

Engineering Contradiction:

Improveblue light hazardVSAvoideye protection function

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses a phosphor layer to convert harmful high-energy blue light into beneficial visible light wavelengths. The phosphor materials absorb the dangerous blue light and re-emit it as safer wavelengths, physically eliminating the harm rather than just masking it through software algorithms.

Inventive Principle:

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

Solution Approach 2:

The patent replaces software-based blue light reduction with a hardware-based optical solution using phosphor conversion. This substitutes algorithmic processing with a physical optical mechanism that directly transforms the light spectrum at the source.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Object-affected harmful factors

If hardware design is used to reduce dangerous blue light, then blue light hazard is reduced, but wide color gamut and energy conservation specifications cannot be met

Engineering Contradiction:

Improveblue light hazardVSAvoidcolor gamut and energy efficiency

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent carefully adjusts the composition parameters of the phosphor layer, specifically controlling the weight percentage of yellow phosphor powders between 1% to 10%, to optimize the balance between blue light reduction, color gamut coverage, and energy efficiency. This parameter optimization enables simultaneous achievement of multiple competing requirements.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite phosphor layer containing multiple types of phosphor powders (yellow, green, and red) in specific proportions. This composite material approach allows the system to achieve broad spectrum coverage for wide color gamut while maintaining energy efficiency and blue light reduction capabilities.

Inventive Principle:

Principle #40Composite materials

3Illumination intensity

If yellow phosphor powders are added to the phosphor layer, then color gamut and light utilization efficiency are improved, but blue light reduction effectiveness may be compromised

Engineering Contradiction:

Improvecolor gamut and light utilization efficiencyVSAvoidblue light hazard

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by assigning specific functions to different phosphor components within the layer. The yellow phosphor (1%-10%) is optimized for color gamut and efficiency, while green and red phosphors compensate for blue light reduction. Each component has tailored properties to fulfill its specific role in the composite system.

Inventive Principle:

Principle #3Local quality

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 provides a hardware-based reduction in blue light hazard, achieving a wide color gamut and meeting energy-saving requirements, such as those set by ENERGY STAR® version 8.0, while improving light utilization efficiency and color uniformity.

Implementation Method 1

The blue light emitting diode is used to generate a first light, and the phosphor layer is disposed on the blue light emitting diode. The phosphor layer includes an encapsulation layer and a plurality of phosphor powders

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

the phosphor powders are disposed in the encapsulation layer and consist of green phosphor powders, red phosphor powders and yellow phosphor powders, and a weight percentage of the yellow phosphor powders ranges from 1% to 10%

Methodology Applied

Scientific EffectLight absorption and wavelength conversion: Absorption (EM radiation)

Data Source

PatentUS11404613B2Light emitting diode package structure and manufacturing method thereof and display device

Publication Date: 2022.08.02 WISTRON CORP

AI summary

A light emitting diode package structure and a manufacturing method thereof and a display device are provided. The light emitting diode package structure includes a blue light emitting diode and a phosphor layer. The phosphor layer is disposed on the blue light emitting diode package structure, and the phosphor layer includes an encapsulation layer and a plurality of phosphor powders. The phosphor powders are disposed in the encapsulation layer and consist of green phosphor powders, red phosphor powders, and yellow phosphor powders, in which a weight percentage of the yellow phosphor powders ranges from 1% to 10%.