Phosphor Light Emission Timing for High-Contrast Fluorescence Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fluorescence imaging methods, such as the ICG fluorescence method, face challenges in achieving high-contrast observations due to noise generated by visible light components being detected by near-infrared image sensors when both visible and near-infrared light are emitted simultaneously.
Innovation Solution
A light emitting device that alternately emits near-infrared and visible fluorescent components using a wavelength converter with a first phosphor converting primary light into near-infrared fluorescence and a second phosphor converting primary light into visible fluorescence, leveraging differences in afterglow times to minimize noise and enhance contrast.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a device simultaneously emits visible light and near-infrared light, then both normal observation and fluorescence imaging can be achieved, but visible light components are detected by the near-infrared image sensor generating noise and reducing observation contrast
Solution Approach 1:
The patent applies periodic action by making the visible light light source emit light in alternating intervals (on periods and off periods). During off periods, only near-infrared light is emitted, allowing the image sensor to capture fluorescence images without visible light noise. This temporal separation resolves the contradiction between dual observation capability and observation contrast.
Solution Approach 2:
The patent segments the light emission into distinct time periods: visible light on periods for normal observation, visible light off periods for fluorescence imaging. This temporal segmentation allows the same imaging system to perform both functions sequentially without interference, maintaining both versatility and measurement precision.
2Illumination intensity
If visible light is emitted together with near-infrared light, then normal visual observation is enabled, but the visible light component closer to near-infrared range is easily detected by the near-infrared light image sensor generating noise
Solution Approach 1:
The visible light source operates periodically with defined on and off intervals. During off intervals, no visible light is emitted, eliminating the harmful noise effect on the near-infrared image sensor while still providing visible illumination during on intervals. This resolves the contradiction between maintaining adequate illumination and preventing noise generation.
Solution Approach 2:
The system maintains continuous useful action by alternating between visible light illumination and fluorescence imaging modes. The periodic switching ensures that both normal observation and special fluorescence observation can be performed continuously over time, maximizing the utility of the imaging system while preventing noise interference.
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 achieves high-contrast observation results by selectively emitting near-infrared and visible light components, improving the signal-to-noise ratio and allowing for both normal and special observations without compromising image quality.
Implementation Method 1
a first phosphor that absorbs the primary light and converts the primary light into first wavelength-converted light having a longer wavelength than the primary light... The first wavelength-converted light includes fluorescence based on electron energy transition of Cr 3+
Implementation Method 2
The first wavelength-converted light includes fluorescence based on electron energy transition of Cr 3+
Implementation Method 3
a second phosphor that absorbs the primary light and converts the primary light into second wavelength-converted light having a wavelength longer than that of the primary light... the second wavelength-converted light includes a fluorescence component
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A light emitting device (10) includes a light source (5) configured to emit a primary light (6), a first phosphor (2) that absorbs the primary light (6) and converts the primary light (6) into a first wavelength-converted light (7) having a wavelength longer than that of the primary light (6), and a second phosphor (3) that absorbs the primary light (6) and converts the primary light (6) into a second wavelength-converted light (8) having a wavelength longer than that of the primary light (6). The first wavelength-converted light (7) is a fluorescence having a light component over an entire wavelength range of 700 nm or more to 800 nm or less. The second wavelength-converted light (8) is a fluorescence having a peak where a fluorescence intensity shows a maximum value in a wavelength range of 380 nm or more to less than 700 nm. The first wavelength-converted light (7) has a 1/10 afterglow time longer than that of the second wavelength-converted light (8).