UV LED Gas Analysis with Threshold Current Feedback
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Solution Overview
Problem
The intensity of ultraviolet light generated by solid-state light emitting devices decreases over time, leading to increased temperature and reduced lifespan, necessitating frequent replacements and affecting analysis accuracy.
Innovation Solution
A control unit supplies a constant first current to an LED light source, switching to a larger second current when intensity falls below a threshold, thereby maintaining light intensity and reducing temperature-related changes, allowing continuous analysis without frequent replacements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the current supplied to the solid-state light emitting device is continuously increased to maintain constant ultraviolet light intensity, then the light intensity is maintained, but the device temperature increases and lifespan is shortened
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the current supplied to the solid-state light emitting device based on detected ultraviolet light intensity. When intensity decreases below a threshold, current is increased; when intensity is sufficient, current is maintained or reduced. This dynamic parameter adjustment maintains light intensity while preventing continuous current increase that would cause overheating and reduce device lifespan.
2Illumination intensity
If the current supplied to the solid-state light emitting device is continuously increased to maintain constant ultraviolet light intensity, then the light intensity is maintained, but temperature of the device increases
Solution Approach 1:
The patent implements feedback control by using a detector to monitor the intensity of ultraviolet light emitted by the solid-state light emitting device and adjusting the supplied current accordingly. This closed-loop feedback system ensures light intensity is maintained only when necessary, preventing continuous current increase that would cause temperature rise and device degradation.
3Measurement precision
If the solid-state light emitting device is frequently replaced to maintain analysis accuracy, then analysis accuracy is maintained, but operational continuity is disrupted
Solution Approach 1:
The patent uses feedback control to monitor ultraviolet light intensity and adjust current dynamically. This maintains analysis accuracy by ensuring sufficient light intensity for gas detection while extending device operation between replacements, thereby improving operational continuity and reducing interruptions for device replacement.
Solution Approach 2:
By dynamically changing the current parameter based on detected light intensity, the system maintains measurement precision throughout the device's operational life, extending the period between replacements and improving overall productivity and operational continuity.
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
Stable and prolonged analysis of gases is achieved by suppressing LED temperature increases and extending device lifespan, reducing replacement frequency and maintaining analysis accuracy.
Implementation Method 1
The LED light source is configured to output ultraviolet light toward the measurement cell
Implementation Method 2
emits ultraviolet light to an analysis target gas having absorption characteristic in an ultraviolet wavelength region
Data Source
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AI summary
To suppress variation in characteristics of an device for outputting ultraviolet light and to decrease replacement frequency of the device, an analysis device (100) includes a measurement cell (1), an LED light source (3), and a control unit (9). An analysis target gas is introduced into the measurement cell (1). The LED light source (3) outputs ultraviolet light (L) toward the measurement cell (1). The control unit (9) supplies a constant first current (I1) to the LED light source (3), and when intensity of the ultraviolet light (L) output from the LED light source (3) supplied with the first current (I1) decreases to a predetermined threshold value (Th) or lower, it supplies the LED light source (3) with a second current (I2) larger than the first current (I1).