Optical Feedback Calibration for AMOLED Pixel Luminance Uniformity
Solution Overview
Problem
Modern display technologies face defects, variations, and non-uniformities from fabrication, leading to image deviations and significant differences in input-output response curves among pixels, resulting in propagation errors and noise effects.
Innovation Solution
An optical feedback method and system that iteratively calibrate pixels by measuring luminance, comparing with reference values, adjusting calibration data, and programming pixels to achieve accurate luminance levels, using sparse and multichannel activation patterns to correct for defects and non-uniformities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional fabrication processes are used for display manufacturing, then production efficiency is maintained, but pixel luminance uniformity and input-output response consistency deteriorate due to fabrication defects and variations
Solution Approach 1:
The patent applies preliminary action by performing calibration measurements and generating calibration data for each pixel before the display is shipped to customers. The optical feedback system measures actual luminance values and calculates compensation values in advance, storing calibration data in memory for subsequent use during normal operation. This preliminary calibration process addresses fabrication variations before the product reaches the end user.
Solution Approach 2:
The patent implements feedback by using an optical measurement device to measure the actual luminance output of each pixel, then using these measurements to generate calibration data that compensates for deviations from target luminance values. The measured luminance values feed back into the calibration process, allowing the system to iteratively improve pixel uniformity by adjusting compensation values based on actual performance data.
2Measurement precision
If pixel-level calibration is performed for all pixels, then luminance accuracy is improved, but calibration time and processing resources increase significantly
Solution Approach 1:
The patent applies segmentation by dividing the pixel array into multiple blocks or regions that can be processed independently. The optical feedback system can process calibration measurements for different pixel blocks in parallel or sequentially, reducing the overall calibration time. This segmented approach allows the system to handle large numbers of pixels without requiring all measurements to be completed simultaneously, thereby reducing processing bottlenecks and calibration time.
3Stability of the object's composition
If calibration data is stored for every pixel, then image consistency is improved, but memory requirements and data processing load increase
Solution Approach 1:
The patent applies merging by combining multiple calibration parameters into unified calibration data structures that can be efficiently stored and processed. Instead of storing separate calibration values for each pixel independently, the system consolidates calibration information in a compressed or integrated format that reduces overall data volume while maintaining the ability to apply pixel-level compensation during operation.
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 corrects pixel luminance errors at the pixel level, reducing propagation errors and noise effects, ensuring accurate and consistent image production across the display.
Implementation Method 1
measuring the luminance of pixels of the display generating luminance measurements for each pixel
Data Source
AI summary
What is disclosed are systems and methods of optical feedback for pixel identification, evaluation, and calibration for active matrix light emitting diode device (AMOLED) and other emissive displays. Optical feedback is utilized to calibrate pixel whose output luminance exceeds a threshold difference from a reference value, and may include the use of sparse pixel activation to ensure pixel identification and luminance measurement, as well as a coarse calibration procedure for programming the starting calibration data for a fine calibration stage.