Power Calibration for Multiple Light Sources in Displays
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Solution Overview
Problem
Electronic display systems using multiple light sources face challenges in achieving uniform brightness due to manufacturing variations and performance drift, leading to visual artifacts as small as 1% differences in brightness between light sources being perceivable by the human eye.
Innovation Solution
A power calibration system that includes detectors to measure the brightness and output intensity of light sources, and a controller to record correlation values between input power settings and detected brightness, ensuring each light source's output is calibrated to within 1% of others, using a method that involves conveying light to a display screen, detecting brightness, measuring output intensities, and recording these correlations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple light sources are used in a display system, then the display can illuminate different regions simultaneously to produce an image, but manufacturing variations and performance drift cause brightness non-uniformity that is perceptible to viewers
Solution Approach 1:
The patent applies preliminary action by performing power calibration of multiple light sources during the manufacturing process. Each light source's output power is measured and correlated with its input power setting before the display is deployed. This advance calibration creates a lookup table that compensates for manufacturing variations, ensuring brightness uniformity across all light sources without requiring post-deployment adjustment.
Solution Approach 2:
The patent implements parameter changes by adjusting the input power settings of individual light sources based on their measured output characteristics. By varying the electrical parameters (input power) of each light source according to its specific performance profile, the system compensates for manufacturing variations and achieves uniform brightness output across all light sources in the display.
2Manufacturing precision
If the output of each light source is tightly controlled to within 1% variation, then brightness uniformity is achieved, but this requires complex calibration and control mechanisms
Solution Approach 1:
The patent applies feedback by measuring the actual output power of each light source and using this information to adjust the input power settings. A control system continuously monitors the performance of each light source and modifies their operation accordingly, ensuring that brightness variations remain within acceptable limits while providing a systematic approach to managing multiple light sources.
Solution Approach 2:
The patent implements self-service by having each light source's calibration data stored in an accessible memory location that can be read by the control system. The system automatically retrieves and applies calibration values without requiring manual intervention, enabling the display to self-correct for manufacturing variations and maintain brightness uniformity through automated control.
3Manufacturing precision
If power calibration is performed on multiple light sources, then brightness uniformity is improved, but measurement and control of each light source's output intensity requires additional detectors and control mechanisms
Solution Approach 1:
The patent applies segmentation by treating each light source as an independent entity with its own calibration characteristics. Instead of attempting to control all light sources uniformly, the system divides them into individual units, measures each one's output separately, and applies specific calibration values to each. This segmented approach simplifies the measurement and control process by handling one light source at a time rather than attempting simultaneous control of all sources.
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 system ensures a highly uniform image by dynamically controlling the power output of each light source, minimizing visual artifacts and maintaining brightness uniformity across the display.
Implementation Method 1
a first detector for detecting a brightness of one or more different portions of the image formed on the display screen
Implementation Method 2
a second detector that measures at least a portional output intensity of one or more of the light sources
Data Source
AI summary
A display device with multiple light sources includes a first detector for detecting a brightness of one or more different portions of the image formed on the display device, a second detector that measures output intensities of the light sources, and a controller that records correlation values that correlate input power settings of the light sources with the detected brightness and the measured output intensities. During operation of the display device, the controller applies the correlation values to determine the proper input power settings of the light sources so that brightness uniformity among the multiple light sources can be achieved.