Phosphor Illumination Timing Control for Color Adjustment and Heat Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing illumination systems that adjust color by mixing light from multiple phosphors face challenges in reducing phosphor deterioration due to heat from excitation light, especially when trying to adjust the color of the emitted light.
Innovation Solution
The illumination system incorporates a controller that manages the emission and non-emission cycles of multiple light sources, ensuring that each wavelength converter is not simultaneously heated by excitation light. This is achieved by shifting the emission periods of different light sources, allowing the substrate to act as a heat sink and reducing thermal stress on the phosphors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple light sources simultaneously irradiate multiple wavelength converters with excitation light to enable color adjustment, then the color versatility is improved, but the phosphor deterioration accelerates due to simultaneous heating
Solution Approach 1:
The controller causes each light source to repeat emission and non-emission of excitation light in constant cycles, with shifted emission periods between different light sources. This periodic operation allows wavelength converters to be irradiated alternately rather than simultaneously, reducing thermal accumulation and phosphor deterioration while maintaining color adjustment capability over time.
Solution Approach 2:
The system dynamically adjusts the emission timing of each light source through shifted cycles. The controller coordinates the start timing of each light source so that emission periods do not overlap, creating a dynamic time-division multiplexing scheme that optimizes both color versatility and phosphor durability.
2Reliability
If the emission periods of multiple light sources are shifted to reduce simultaneous heating, then the phosphor deterioration is reduced, but the time efficiency decreases due to non-overlapping emission cycles
Solution Approach 1:
While emission periods are shifted between light sources, the system maintains continuous useful action by ensuring that at least one light source is emitting at any given time. The controller coordinates cycles so that the non-emission period of one light source coincides with the emission period of another, maintaining continuous illumination output while preventing simultaneous heating of multiple wavelength converters.
Solution Approach 2:
The systematic periodic cycling of light sources with optimized phase shifts ensures that the overall light output remains efficient. By carefully designing the cycle duration and shift amount, the system achieves both thermal management and high productivity, as the alternating emission patterns prevent thermal accumulation while maintaining near-continuous illumination.
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 effectively reduces the deterioration of phosphors by minimizing simultaneous heating, thereby extending the lifespan of the illumination system while allowing for color adjustment of the emitted light.
Implementation Method 1
a first wavelength converter that emits fluorescence with a first wavelength spectrum in response to excitation light from the first light source and a second wavelength converter that emits fluorescence with a second wavelength spectrum different from the first wavelength spectrum in response to excitation light from the second light source
Implementation Method 2
allowing the substrate to act as a heat sink and reducing thermal stress on the phosphors
Data Source
AI summary
An illumination system includes light sources including a first light source and a second light source, a substrate, wavelength converters including a first wavelength converter and a second wavelength converter on the substrate, a light guide, and a controller. The light guide guides fluorescence from the wavelength converters. When causing each light source to repeat emission/non-emission of excitation light in constant cycles, in an operation period of one cycle, the controller causes the second light source to emit no excitation light toward the second wavelength converter for at least a portion of a first emission period during which the first light source emits excitation light toward the first wavelength converter, and the first light source to emit no excitation light toward the first wavelength converter for at least a portion of a second emission period during which the second light source emits excitation light toward the second wavelength converter.