Display Light Source Power Calibration via Dynamic Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic display systems with multiple light sources face challenges in achieving uniform brightness due to manufacturing variations and performance drift, leading to visual artifacts from small mismatches in light source power output, which are perceptible to the human eye.
Innovation Solution
A light-based display device with a controller that modulates input current to each light source based on correlation values and measured output intensities to adjust and calibrate power output, ensuring uniformity by determining inputs from display values and desired output intensities, and measuring output intensities to make necessary adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple light sources are used in a display system, then the display can cover larger areas and provide higher brightness, but manufacturing variations and performance drift cause brightness non-uniformity that is perceptible to viewers
Solution Approach 1:
The system performs preliminary calibration by measuring the actual output of each light source and storing correlation values that map desired output intensities to required input currents. This preliminary action compensates for manufacturing variations before the display is used, ensuring brightness uniformity without requiring extremely tight manufacturing tolerances.
Solution Approach 2:
The system implements feedback control by continuously monitoring the actual brightness output of each light source and adjusting the input current dynamically. The controller uses measured output intensities and stored correlation values to modulate input currents in real-time, maintaining uniform brightness despite performance drift over time or environmental changes.
2Manufacturing precision
If the output of each light source is tightly controlled to less than 1% variation, then brightness uniformity is achieved, but this requires complex calibration and control mechanisms to compensate for manufacturing variations and drift
Solution Approach 1:
The system performs preliminary calibration by measuring the actual output of each light source and storing correlation values that map desired output intensities to required input currents. This preliminary action compensates for manufacturing variations before the display is used, ensuring brightness uniformity without requiring extremely tight manufacturing tolerances.
Solution Approach 2:
The system changes the control parameter from directly controlling absolute output intensity to controlling the relationship between input current and desired output through correlation values. By storing and using these correlation values, the system simplifies the control mechanism while achieving the required precision through parameter transformation rather than complex hardware control.
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 solution effectively maintains uniform brightness across the display by dynamically controlling the power output of each light source, minimizing visual artifacts and ensuring a high level of accuracy in brightness uniformity, even with variations and drift over time.
Implementation Method 1
light sources for producing light that is conveyed to the display screen
Data Source
AI summary
A display device with multiple light sources includes a detector that dynamically measures output intensities of the light sources as the light sources are producing light to cause an image to be formed on a display screen. A controller for the display device compares the measured output intensities with desired output intensities determined from factory-calibrated correlation values and adjusts the inputs to the light sources to compensate for drift and other similar effects, so that brightness uniformity among the multiple light sources can be achieved.