LED Illuminating Device Dynamic Calibration for Degradation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional illuminating devices for image processing struggle to maintain commanded illuminance over time due to LED degradation, requiring time-consuming recalibration and affecting image quality.
Innovation Solution
An illuminating device with a control unit that calculates a uniform decline ratio in illuminance and recalibrates the conversion table by measuring illuminance at a specific output current command value, allowing for efficient recalibration in a short time by adjusting output current command values to achieve prescribed illuminance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conversion table is calibrated before shipment in correspondence with the characteristics of the incorporated LED, then the commanded illuminance can be obtained at the shipment stage, but after sufficient operating time the LED illuminance declines and the conversion table becomes incapable of coping, making it impossible to irradiate with the commanded illuminance
Solution Approach 1:
The conversion table is made dynamically adjustable rather than static. The control unit automatically updates the conversion table based on measured illuminance values, allowing the system to adapt to LED degradation over time. This transforms a fixed calibration approach into a dynamic one that maintains accuracy throughout the LED's operational lifetime.
Solution Approach 2:
The illuminating device performs self-calibration by measuring its own illuminance output and automatically adjusting the conversion table. The control unit reads illuminance values from a sensor, compares them with commanded values, and updates the conversion table without external intervention, enabling the system to maintain accuracy autonomously over time.
2Reliability
If the conversion table is recalibrated after sufficient operating time to cope with LED illuminance decline, then the commanded illuminance can be restored, but time-consuming measurement of illuminance must be performed a number of times, requiring much time for recalibration
Solution Approach 1:
The system performs preliminary calibration by establishing an initial conversion table at shipment, then uses this table to guide subsequent automatic adjustments. The control unit reads illuminance values and automatically updates the conversion table based on these readings, eliminating the need for multiple manual measurement iterations and significantly reducing recalibration time.
Solution Approach 2:
The control unit implements a feedback mechanism where illuminance sensor readings are continuously compared with commanded illuminance values. Based on this feedback, the control unit automatically adjusts the conversion table to maintain accuracy, eliminating the need for time-consuming manual recalibration while ensuring reliable illuminance control throughout the LED's operational lifetime.
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 method reduces calibration time and cost by performing illuminance measurement only once, ensuring accurate illuminance settings and maintaining image quality despite LED degradation.
Implementation Method 1
an illuminating device having an LED (light emitting diode) for irradiating a workpiece with light
Implementation Method 2
measuring the illuminance of the illuminating light emitted from the LED
Data Source
AI summary
An illuminating device includes: a calibrating output unit for reading an output current command value corresponding to a specific brightness command value and for outputting the output current command value to a light source; a ratio calculating unit for calculating a ratio between an illuminance of illuminating light emitted from the light source and a prescribed illuminance value prescribed for the specific brightness command value; an illuminance calculating unit for calculating each illuminance when each output current command value matched with each brightness command value is outputted; and a calibrating unit for calibrating a relationship between each brightness command value and each output current command value in a conversion table such that each illuminance at the time when each output current command value matched with each brightness command value is outputted is set to each prescribed illuminance value prescribed for each of the brightness command values.