LED Light Source with Segmented Luminophore Layer
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Solution Overview
Problem
Existing light-emitting diodes (LEDs) face issues with quantum efficiency loss and low color rendering index due to multiple wavelength conversion and poor thermal conductivity, which limits luminous flux density and degrades luminophores, while solutions like ceramic luminophore layers are inefficient for red production and require multiple LEDs for high color rendering.
Innovation Solution
A light source with an LED chip featuring a luminophore layer comprising adjacently arranged regions of different luminophores, where one region is a ceramic layer with a doped activator and the other is a filler embedded in silicone, allowing precise adjustment of the color locus and improved heat dissipation, and optionally including recesses for additional luminophores.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If multiple luminophores are mixed in a single luminophore layer, then wavelength conversion is achieved, but quantum efficiency loss occurs due to multiple wavelength conversion and reabsorption
Solution Approach 1:
The luminophore layer is segmented into multiple adjacent regions, each containing a different luminophore. This spatial segmentation prevents multiple wavelength conversions and reabsorption losses that occur when luminophores are mixed, thereby improving quantum efficiency while maintaining the ability to generate mixed light with high color rendering index.
Solution Approach 2:
Different regions of the luminophore layer are assigned different luminophores based on local requirements. Each region optimizes its wavelength conversion locally, reducing overall energy loss. The adjacently arranged regions with different luminophores enable precise control over the spectral output while minimizing reabsorption and conversion losses.
2Ease of manufacture
If silicon is used as the base material for the luminophore layer, then ease of manufacture is improved, but thermal conductivity is poor leading to high temperatures and luminophore degradation
Solution Approach 1:
The invention uses a composite structure where ceramic luminophores are embedded in a silicone base material. The ceramic regions provide high thermal conductivity pathways to conduct heat away from the luminophores, while the silicone provides ease of manufacture and optical properties. This composite approach resolves the contradiction between manufacturing simplicity and thermal management.
3Temperature
If ceramic luminophore layers are used, then thermal conductivity is improved, but red luminophore production becomes inefficient and expensive
Solution Approach 1:
Different regions use different base materials optimized for their specific luminophore requirements. Regions with red luminophores use silicone base material which is easier and more economical to manufacture, while other regions may use ceramic base materials where they provide thermal management benefits. This local optimization allows red luminophores to be produced efficiently while maintaining overall thermal conductivity.
4Device complexity
If a single luminophore layer with mixed luminophores is used, then device complexity is reduced, but color homogeneity is poor at large emission angles
Solution Approach 1:
The luminophore layer is divided into multiple adjacent regions, each with a specific luminophore composition optimized for its function. This segmentation maintains a relatively simple single-layer structure while improving color homogeneity through controlled spatial distribution of different luminophores, reducing angular dependence of color output.
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 configuration achieves high color rendering index with reduced reabsorption, efficient wavelength conversion, and improved thermal management, enabling precise color adjustment and increased luminous flux density while being economically viable for producing mixed light.
Implementation Method 1
The first luminophore converts the primary light partially into a first secondary light with a longer wavelength
Implementation Method 2
the second luminophore converts the primary light partially into a second secondary light with a different even longer wavelength
Implementation Method 3
The ceramic base material (without activator) is typically transparent or translucent... are thermally conductive to a high degree (at about 10 W/(m·K))
Data Source
AI summary
A light source may include an LED chip having a light-emitting surface, on which a luminophore layer is arranged. The luminophore layer may include adjacently arranged regions having different luminophores. A lighting device may include at least one light source.