LED Current Control Circuit Using Feedback for Curing Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid-state lighting devices, such as LEDs, face challenges in precisely controlling light intensity for effective curing of photo-sensitive media, as current variations or different exposure durations can result in inconsistent curing times, which may not meet desired levels of curing.
Innovation Solution
A system with a controller that adjusts current flow through a lighting array using feedback mechanisms, such as variable resistance devices or buck voltage regulators, to maintain desired light intensity by monitoring and adjusting current flow, ensuring precise control over light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current flow through lighting array is not precisely controlled, then device complexity is reduced, but light intensity control precision deteriorates
Solution Approach 1:
The patent implements a feedback control mechanism where a sense resistor measures the actual current flowing through the lighting array, and this measured current is fed back to the control circuit. The control circuit compares the measured current with the desired current and adjusts the PWM duty cycle accordingly to maintain precise light intensity control. This closed-loop feedback system resolves the contradiction by achieving precise control without requiring overly complex open-loop control mechanisms.
Solution Approach 2:
The patent introduces a sense resistor as an intermediary component that indirectly measures the current through voltage measurement. Instead of directly measuring current, the system measures the voltage drop across the sense resistor and uses this information to control the lighting array current. This intermediary approach simplifies the control circuit while maintaining measurement precision.
2Adaptability or versatility
If varying current is supplied to lighting devices, then adaptability to different curing requirements is improved, but curing consistency deteriorates
Solution Approach 1:
The patent implements dynamic current control through PWM modulation, allowing the lighting array current to be adjusted in real-time based on feedback from the sense resistor. This dynamic adjustment capability enables the system to adapt to different curing requirements while maintaining consistent curing results through closed-loop control, resolving the contradiction between adaptability and consistency.
Solution Approach 2:
The feedback mechanism continuously monitors the actual current through the lighting array and adjusts the PWM duty cycle to maintain the desired current level. This ensures that regardless of variations in lighting array characteristics or environmental conditions, the current remains consistent, thereby ensuring curing consistency while allowing adaptability through programmable current profiles.
3Illumination intensity
If higher current is supplied to lighting array, then light intensity is improved, but power consumption increases
Solution Approach 1:
The patent uses PWM modulation to deliver the required light intensity with partial action. Instead of continuously supplying high current, the system supplies high current in pulsed intervals controlled by the PWM duty cycle. This allows the lighting array to achieve the desired light intensity while reducing average power consumption, as the current is applied only when needed to maintain the required light output level.
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 enhances light intensity control, reduces power consumption, and maintains a flexible and cost-effective design by providing efficient electrical current management, leading to improved curing consistency and reduced energy usage.
Implementation Method 1
Solid-state lighting devices may consist of laser diodes or light-emitting diodes (LEDs) as examples
Data Source
Figure 1
Figure 2
Figure 3
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 current feedback from the one or more light emitting devices.