Light Emission Spectrum Shaping for Visible and Near-Infrared Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light emitting devices that combine a light emitting element and a phosphor to produce near-infrared light often compromise visibility for human observation and fail to effectively separate visible and near-infrared light components, leading to complex device configurations and reduced signal/noise ratios in detectors.
Innovation Solution
A light emitting device comprising multiple light emitting elements and phosphors that emit distinct visible and near-infrared light components, with a spectral distribution featuring a trough portion between 650 nm and 750 nm to separate visible and near-infrared light, allowing for simultaneous human visibility and sensitive detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional light emitting device combines a light emitting element and a phosphor to emit near-infrared light, then the detector can detect the near-infrared component with good sensitivity, but the inspection object becomes hard to see or gives a feeling of discomfort to human eyes
Solution Approach 1:
The light emitting device is segmented into multiple light emitting elements, each emitting different wavelength components (blue, green, red visible light and near-infrared light). This segmentation allows independent optimization of each wavelength component's intensity to simultaneously satisfy detector sensitivity requirements and human eye comfort requirements.
Solution Approach 2:
Different regions of the spectral distribution are assigned different quality characteristics. The visible light regions (blue, green, red) are optimized for human eye visibility and comfort, while the near-infrared region is optimized for detector sensitivity. This local quality differentiation resolves the contradiction between detector performance and human observation.
2Measurement precision
If a conventional light emitting device emits near-infrared light with high intensity for detector detection, then the signal/noise ratio of the detector improves, but additional optical filters are required which complicates the device configuration
Solution Approach 1:
The near-infrared light component is extracted as a separate emission component from the visible light components. By using distinct light emitting elements for different wavelength ranges, the near-infrared component can be detected directly without requiring optical filters to separate it from visible light, thus simplifying the overall device configuration while maintaining high signal/noise ratio.
3Device complexity
If a conventional light emitting device uses a single phosphor for wavelength conversion, then the device configuration is simple, but the spectral distribution cannot be optimized for both visible observation and near-infrared detection simultaneously
Solution Approach 1:
The wavelength conversion system is segmented into multiple phosphors, each responsible for converting specific wavelength ranges to desired output wavelengths. This segmentation enables independent optimization of the spectral distribution for both visible observation and near-infrared detection, achieving dual functionality without excessive complexity.
Solution Approach 2:
The light emitting device achieves multi-functionality by incorporating multiple light emitting elements and phosphors that work together to produce a composite spectral distribution. The system simultaneously provides visible light for human observation and near-infrared light for detector detection, making it adaptable to both functions without requiring separate devices.
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 device enables effective inspection of objects both visually and using near-infrared detection, improving signal/noise ratios and reducing device complexity by emitting a tailored spectral distribution with controlled light components.
Implementation Method 1
a first phosphor that emits a third light component... The third light component is a visible light component that is derived from first wavelength-converted light emitted by the first phosphor
Implementation Method 2
a second phosphor that is different from the first phosphor and emits a fourth light component... The fourth light component is a near-infrared light component that is derived from second wavelength-converted light emitted by the second phosphor
Data Source
AI summary
A light emitting device includes: a first light emitting element that emits a first light component; a second light emitting element that emits a second light component; a first phosphor that emits a third light component; and a second phosphor that emits a fourth light component. A spectral distribution of the output light has a trough portion within a wavelength range of 650 nm or more and 750 nm or less, and a minimum intensity value within the wavelength range is less than 30% of a maximum intensity value within a wavelength range of 380 nm or more and 2500 nm or less.