Light-emitting Device Phosphor Settling Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing light-emitting devices face challenges in controlling emission angle dependence of emission chromaticity, leading to unevenness in light emission color.

Innovation Solution

A method of manufacturing light-emitting devices involves measuring light distribution and controlling the degree of phosphor settling in the sealing material through adjustments in dispersant concentration and heat treatment conditions to match the light distribution of the light-emitting element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the sealing material is made thick where light emission intensity is high, then emission color uniformity is improved, but emission angle dependence of chromaticity cannot be controlled in a wide range

Engineering Contradiction:

Improveemission color uniformityVSAvoidemission angle dependence control range

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent changes the physical and chemical parameters of the sealing material, specifically the dispersant concentration and heat treatment conditions, to control the degree of phosphor settling. This allows independent control of emission color uniformity and emission angle dependence, resolving the contradiction between these two parameters.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary action by controlling the degree of phosphor settling during the sealing material preparation and curing process, before the final product is assembled. This preliminary control of phosphor distribution enables subsequent precise control of both emission color uniformity and emission angle dependence.

Inventive Principle:

Principle #10Preliminary action

2Stability of the object's composition

If the shape of the sealing material is controlled to match light distribution, then emission color uniformity is improved, but the manufacturing process becomes more complex

Engineering Contradiction:

Improveemission color uniformityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

Instead of controlling the shape of the sealing material, the patent changes the chemical parameters (dispersant concentration) and thermal parameters (heat treatment conditions) to control phosphor settling. This approach achieves the same goal of emission color uniformity while simplifying the manufacturing process.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If dispersant concentration is increased to control phosphor settling, then emission angle dependence control is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improveemission angle dependence controlVSAvoidphosphor settling control precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent performs preliminary control of phosphor settling through optimized dispersant concentration and heat treatment, creating a controlled degree of settling that facilitates subsequent precise control of emission angle dependence with reduced manufacturing precision requirements.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses dispersant concentration and heat treatment conditions as controllable parameters to achieve the desired degree of phosphor settling, providing a flexible method to control emission angle dependence while managing manufacturing precision requirements.

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 allows for precise control of emission angle dependence of emission chromaticity, enabling a wide range of chromaticity control by optimizing the phosphor settling in the sealing material based on the light-emitting element's distribution.

Implementation Method 1

curing the sealing material by heat treatment

Methodology Applied

Scientific EffectCuring: Heat Treatment

Implementation Method 2

setting a degree of settling of the phosphor in the sealing material

Methodology Applied

Scientific EffectSettling: Gravitation

Data Source

PatentUS10644192B2Method of manufacturing light-emitting device

Publication Date: 2020.05.05 TOYODA GOSEI CO LTD

AI summary

A method of manufacturing a light-emitting device includes measuring a light distribution of a light-emitting element, sealing the measured light-emitting element by a sealing material including a phosphor, and curing the sealing material by heat treatment. An emission angle dependence of emission chromaticity of the light-emitting device is controlled by setting a degree of settling of the phosphor in the sealing material according to the measured light distribution of the light-emitting element.