Stacked Light Source With Phosphor Layers for Color Adjustment
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Solution Overview
Problem
Existing light sources that adjust color of mixed-color light are often large in size due to the configuration of multiple light-emitting regions and wavelength conversion layers.
Innovation Solution
A light-emitting element with stacked first and second light-emitting parts, each including semiconductor layers and light-emitting layers, and a wavelength conversion member with stacked phosphor layers excited by different lights, allowing for compact design and color adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple light-emitting regions and wavelength conversion layers are used to adjust color of mixed-color light, then color adjustment capability is improved, but device size increases
Solution Approach 1:
The patent merges multiple light-emitting parts into a single integrated light-emitting element with stacked semiconductor layers, where each layer emits different wavelengths. This combines what would traditionally be separate light sources into one compact unit, enabling color adjustment without requiring multiple discrete components that would increase device volume.
Solution Approach 2:
The patent transitions from a planar arrangement of multiple light-emitting regions to a vertical stacked structure of semiconductor layers. By organizing the light-emitting parts in the thickness direction rather than spreading them out laterally, the invention achieves color adjustment capability while minimizing the device's footprint and overall size.
2Volume of moving object
If multiple light-emitting parts are integrated in a compact structure, then device size is reduced, but light extraction efficiency may deteriorate
Solution Approach 1:
The light-emitting element is segmented into multiple semiconductor layers, each responsible for emitting specific wavelengths. This segmentation allows each layer to be optimized for its specific emission function while maintaining compact vertical stacking, preventing light trapping issues that would arise from a monolithic structure and improving overall light extraction efficiency.
Solution Approach 2:
Each semiconductor layer is designed with specific local properties optimized for its emission wavelength, and the wavelength conversion layers are positioned specifically to convert light from certain layers. This localized optimization ensures efficient light extraction and conversion at each stage, preventing energy loss despite the compact integrated structure.
3Device complexity
If stacked semiconductor layers are used to emit different wavelengths, then device complexity is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The multiple semiconductor layers are nested vertically in a stacked configuration, with each layer containing a light-emitting part. This nesting approach consolidates what would be separate horizontal components into a vertical hierarchy, reducing overall device complexity while the standardized layer structure facilitates consistent manufacturing processes.
Solution Approach 2:
The invention uses composite structures combining multiple semiconductor layers with different bandgaps, each emitting specific wavelengths. This composite material approach allows precise control of optical properties through material composition rather than complex geometric arrangements, reducing manufacturing precision requirements for structural alignment while maintaining wavelength control.
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 enables a reduced size light source capable of emitting mixed-color light with adjustable color temperature and chromaticity, improving light extraction efficiency and reducing color unevenness.
Implementation Method 1
a first phosphor layer configured to be excited by the first light and emit third light
Implementation Method 2
a second phosphor layer configured to be excited by the second light and emit fourth light
Data Source
AI summary
A light source includes: a light-emitting element including: a first light-emitting part configured to emit first light, and a second light-emitting part configured to emit second light having a peak emission wavelength different from a peak emission wavelength of the first light, wherein: the first light-emitting part and the second light-emitting part are stacked in a first direction; and a wavelength conversion member disposed on the light-emitting element, the wavelength conversion member including: a first phosphor layer configured to be excited by the first light and emit third light, and a second phosphor layer configured to be excited by the second light and emit fourth light having a peak emission wavelength different from a peak emission wavelength of the third light, wherein: the first phosphor layer and the second phosphor layer are stacked in the first direction.