Light-emitting device with low-refractive-index layer and scattering barrier
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Solution Overview
Problem
Existing light-emitting devices face issues with blurriness and low light utilization efficiency due to isotropic light emission from fluorescent layers, leading to absorption by substrates and black matrices, and inefficient output of light towards the light source side.
Innovation Solution
A light-emitting device design incorporating a fluorescent layer with a low-refractive-index layer and a barrier with light-scattering properties, where the low-refractive-index layer is positioned between the fluorescent layer and the substrate, and the barrier surrounds the fluorescent layer to control the incident angle and scatter light, enhancing output efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a fluorescent layer emits light isotropically, then light is emitted in all directions, but light is reflected at the substrate interface and causes blurriness and fuzziness
Solution Approach 1:
The patent applies local quality by creating different refractive index zones: a low-refractive-index layer between the fluorescent layer and substrate to control light extraction angles, and a light-scattering barrier at specific locations to redirect light. This localized modification of optical properties resolves the contradiction by enabling controlled light emission while preventing blurriness.
Solution Approach 2:
The patent introduces intermediary structures between the fluorescent layer and substrate: a low-refractive-index layer as an optical mediator to reduce reflection, and a light-scattering barrier as an intermediate element to redirect light paths. These intermediaries enable the fluorescent layer to emit light effectively while preventing interface reflection and blurriness.
2Loss of energy
If light travels toward side surfaces of the fluorescent layer, then light can be reflected by a reflective body, but light emitted toward the light source side cannot be efficiently output
Solution Approach 1:
The patent addresses light loss in multiple dimensions: the low-refractive-index layer manages light in the vertical dimension by reducing interface reflection, while the light-scattering barrier manages light in the horizontal dimension by redirecting side-emitted light toward the output. This multi-dimensional approach maximizes light output efficiency.
Solution Approach 2:
The patent recovers light that would otherwise be lost: the light-scattering barrier captures light traveling toward side surfaces and redirects it toward the output, while the low-refractive-index layer recovers light that would be reflected at the substrate interface. This recovery approach reduces energy loss and improves productivity.
3Loss of energy
If light is absorbed by a black matrix between color filter and fluorescent layers, then light loss increases, but light utilization efficiency decreases
Solution Approach 1:
The patent extracts light before it reaches the black matrix by using the light-scattering barrier to redirect light paths away from the black matrix region. This extraction prevents light absorption by the black matrix and improves overall light utilization efficiency.
4Stability of the object's composition
If the light emitted from the fluorescent layer spreads isotropically, then light emission is uniform, but part of the light is reflected at the interface between substrate and outside
Solution Approach 1:
The patent maintains uniform light emission from the fluorescent layer while locally modifying the interface region with a low-refractive-index layer. This local modification reduces reflection losses without affecting the uniformity of light emission from the fluorescent layer itself.
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 significantly improves light utilization efficiency by effectively directing fluorescence towards the output side while reducing blurriness and absorption, resulting in high-luminance emission.
Implementation Method 1
a first low-refractive-index layer which is located between the fluorescent layer and the first substrate, and the first low-refractive-index layer has a refractive index lower than that of the first substrate
Implementation Method 2
a barrier that surrounds side surfaces of the fluorescent layer, the side surfaces extending in a stacking direction of the excitation light source and the first substrate. In the light-emitting device, at least a portion of the barrier that faces the fluorescent layer has a light-scattering property
Implementation Method 3
a fluorescent layer and a first low-refractive-index layer are formed, the fluorescent layer being excited by the excitation light to emit fluorescence
Data Source
AI summary
A light-emitting device includes an excitation light source that emits excitation light; a first substrate which is disposed so as to face the excitation light source and on which a fluorescent layer and a first low-refractive-index layer are formed, the fluorescent layer being excited by the excitation light to emit fluorescence; and a barrier that surrounds side surfaces of the fluorescent layer, the side surfaces extending in a stacking direction of the excitation light source and the first substrate. At least a portion of the barrier that faces the fluorescent layer has a light-scattering property. The first low-refractive-index layer is located between the fluorescent layer and the first substrate. The first low-refractive-index layer has a refractive index lower than that of the first substrate.