Wavelength-Converting Light Emitter Layout for Reduced Light Leakage

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Solution Overview

Problem

Existing light emitting devices face challenges in providing good visibility due to light leakage and inefficient light utilization, particularly in applications requiring long-distance illumination such as vehicle headlights.

Innovation Solution

The design incorporates wavelength converting members with specific surface configurations and a covering member to enhance light extraction and reflection, using materials like fluorescent and diffusing materials, and a light-shielding film to direct light effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a conventional light emitting device structure is used, then the device is simple to manufacture, but light leakage occurs and visibility is poor

Engineering Contradiction:

ImprovevisibilityVSAvoiddevice structure

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The light emitting device is segmented into multiple functional layers: light emitting elements, wavelength converting members with specific surface configurations, covering members with openings, and light-shielding films. This segmentation allows each component to perform its specific function optimally, improving light extraction and visibility while managing device complexity through modular design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The wavelength converting members are configured with specific surface properties at different locations - the first surface converts wavelength while the second surface has light-extracting properties. The covering member has openings positioned to expose specific areas. This local differentiation of properties optimizes light extraction efficiency and visibility without requiring complete structural redesign

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If wavelength converting members are added to improve light extraction, then visibility improves, but manufacturing complexity increases

Engineering Contradiction:

Improvelight extraction efficiencyVSAvoidmanufacturing process

Core Design Contradiction:

Illumination intensityVSEase of manufacture

Solution Approach 1:

The wavelength converting members serve multiple functions: wavelength conversion, light extraction, and structural support. By combining these functions into a single component with specifically configured surfaces, the patent reduces the total number of separate parts needed, thereby simplifying the manufacturing process while maintaining improved light extraction efficiency

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The wavelength converting members utilize composite material structures with fluorescent materials and diffusing materials combined in specific configurations. This allows simultaneous achievement of wavelength conversion and enhanced light extraction properties within a single manufacturable component, avoiding the need for multiple separate processing steps

Inventive Principle:

Principle #40Composite materials

3Illumination intensity

If light-shielding films are used to direct light effectively, then luminance improves, but light loss increases

Engineering Contradiction:

ImproveluminanceVSAvoidlight loss

Core Design Contradiction:

Illumination intensityVSLoss of energy

Solution Approach 1:

The light-shielding films, which could potentially block useful light, are strategically positioned and configured to block only parasitic light paths while allowing primary light to pass through. The openings in the covering member and the specific surface configurations convert what would be light-blocking elements into light-directing elements that improve luminance by eliminating unwanted light scattering and leakage paths

Inventive Principle:

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

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 achieves high luminance and improved visibility by minimizing light leakage and optimizing light distribution, making it suitable for long-distance applications like vehicle headlights.

Implementation Method 1

a plurality of wavelength converting members each having a first upper surface and a lower surface opposite the first upper surface

Methodology Applied

Scientific EffectWavelength conversion: Fluorescence

Implementation Method 2

using materials like fluorescent and diffusing materials, and a light-shielding film to direct light effectively

Methodology Applied

Scientific EffectLight scattering: Scattering

Data Source

PatentUS20250318329A1Light emitting device

Publication Date: 2025.10.09 NICHIA CORP

AI summary

A light emitting device includes: light emitting elements each having a light-extracting surface; wavelength converting members respectively provided with the light emitting elements and each having a first upper surface and a lower surface opposite the first upper surface; and a covering member disposed to surround each of the light emitting elements and the wavelength converting members in plan view. Each of the wavelength converting members are disposed on the respective light-extracting surface such that: the first upper surface of the wavelength converting member faces away from the respective light-extracting surface; and the lower surface of the wavelength converting member faces toward the respective light-extracting surface. The covering member has openings each overlapping the first upper surface of a respective one of the wavelength converting members in top view. The covering member has an upper surface located higher than the first upper surface of each of the wavelength converting members.