Backlight Pixel Feedback Control for Display Color Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optoelectronic devices, such as LCDs with backlight units (BLUs), face issues with non-uniform light emission, calibration challenges, and color balance shifts over time due to LED fabrication tolerances, aging, and temperature variations, as well as external light interference.
Innovation Solution
The implementation of an optoelectronic device with a backlight panel comprising an array of light emitting pixels, each containing subpixels with light emitting diodes (LEDs) and photodetectors. The control circuit adjusts the light emission level of each subpixel based on the detected reflected light, enabling active white color balance and brightness adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional BLUs use blue LEDs with fixed emission characteristics, then the device structure is simple, but the light emission uniformity and color balance deteriorate over time due to LED fabrication tolerances, aging, and temperature variations
Solution Approach 1:
The patent implements a feedback mechanism where photodetectors continuously monitor the actual light emission of each subpixel and send signals to a control circuit. The control circuit compares the detected light levels with target values and dynamically adjusts LED driving currents to compensate for variations caused by aging, temperature, and fabrication tolerances, thereby maintaining stable color balance and luminance uniformity over time.
Solution Approach 2:
The system performs self-calibration and self-adjustment without external intervention. Each light emitting pixel contains integrated photodetectors that automatically measure its own emission characteristics, and the control circuit autonomously computes and applies correction factors to maintain optimal performance throughout the device's operational lifetime.
2Productivity
If manual calibration methods are used for BLU, then the device complexity is low, but the calibration time and cost increase significantly
Solution Approach 1:
The automated calibration system uses photodetectors to provide real-time feedback on actual light emission levels during the calibration process. The control circuit processes this feedback information and automatically adjusts LED driving parameters, eliminating the need for manual measurement and adjustment while significantly reducing calibration time and improving precision.
Solution Approach 2:
The patent replaces manual mechanical calibration procedures with an automated optical-electrical system. Instead of physically adjusting components by hand, the system uses photodetectors to measure emission and electronic control circuits to adjust LED currents, substituting mechanical operations with automated sensing and control.
3Adaptability or versatility
If external light sources are present, then the display can be viewed in various lighting conditions, but the perceived image quality deteriorates due to projected shapes and shadows on the display
Solution Approach 1:
The system uses photodetectors to detect not only the backlight emission but also the impact of external light sources on the display. The control circuit processes this information and dynamically adjusts the backlight emission patterns to compensate for external light interference, reducing the visibility of projected shapes and shadows while maintaining overall image quality across various ambient lighting conditions.
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 solution achieves uniform light emission across the display, facilitates faster and cheaper BLU calibration, maintains active white color balance over time, and adjusts brightness against ambient temperature changes, thereby enhancing the display's HDR experience and image quality.
Implementation Method 1
at least one photodetector positioned on the substrate and arranged to detect an amount of reflected light emitted by said subpixel and reflected by the display panel
Data Source
AI summary
An optoelectronic device includes a backlight panel illuminating a display panel. The backlight panel includes an array of light emitting pixels, each light emitting pixel having at least one subpixel with one or more light emitting diodes positioned on a substrate. The pixel further includes at least one photodetector positioned on the substrate and arranged to detect an amount of reflected light emitted by said subpixel and reflected by the display panel.