LED Drive Current Adjustment for Irradiance Step Response
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Solution Overview
Problem
LED arrays face inconsistency in irradiance output when switching between different levels, which affects manufacturing processes requiring precise light intensity for curing various materials.
Innovation Solution
A method is implemented to adjust the current supplied to LEDs using a linearized current adjustment, ensuring a substantially constant irradiance level by modifying the current based on desired output levels, thereby simplifying computational processing and improving output consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LED array irradiance is changed between different levels, then manufacturing flexibility is improved, but irradiance consistency deteriorates
Solution Approach 1:
The system pre-calculates and stores compensation values for different irradiance levels based on temperature conditions. When a step change in irradiance is commanded, the pre-computed compensation factors are immediately applied to adjust the LED drive current, eliminating the need for real-time iterative calculations and ensuring consistent irradiance output across different lighting levels.
Solution Approach 2:
The system implements a feedback mechanism where temperature sensors continuously monitor LED array temperature, and this information is used to dynamically adjust the drive current through compensation algorithms. The feedback loop ensures that irradiance consistency is maintained by counteracting temperature-induced variations in real-time during step transitions.
2Illumination intensity
If LED drive current is adjusted to change irradiance levels, then irradiance output is improved, but irradiance stability deteriorates
Solution Approach 1:
The system applies preliminary anti-action by pre-calculating compensation factors that counteract the expected irradiance instability caused by temperature changes during step transitions. Before the actual irradiance change occurs, the system adjusts the drive current using pre-computed factors that anticipate and prevent the stability issue, rather than reacting to it after it occurs.
Solution Approach 2:
The system changes the drive current parameter dynamically based on temperature conditions and desired irradiance levels. By adjusting the drive current using temperature-compensated calculations, the system maintains irradiance stability while achieving the desired output intensity, effectively decoupling irradiance level changes from stability degradation.
3Measurement precision
If real-time temperature compensation is implemented, then irradiance accuracy is improved, but computational complexity increases
Solution Approach 1:
The system performs preliminary calculations offline to generate compensation lookup tables for different temperature and irradiance level combinations. During real-time operation, the system simply queries these pre-computed tables and applies the stored compensation factors, reducing real-time computational complexity from complex iterative calculations to simple table lookups and arithmetic operations.
Solution Approach 2:
The system creates simplified mathematical models or lookup tables that copy the essential characteristics of the complex temperature-irradiance relationship. Instead of performing full physical simulations in real-time, the system uses pre-computed representations that capture the key behavior, achieving high irradiance accuracy with minimal computational overhead during step transitions.
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 allows for fast and accurate changes between different lighting output levels, enhancing the consistency and reliability of LED array irradiance, closely following step changes in desired output without significant variations.
Implementation Method 1
Some types of solid-state lighting devices may include laser diodes and light-emitting diodes (LEDs)
Data Source
AI summary
A system and method for operating one or more light emitting devices is disclosed. In one example, the intensity of light provided by the one or more light emitting devices is adjusted responsive to a temperature of the one or more light emitting device. The light is adjusted via modifying a current supplied to the one or more light emitting devices.