Dual LCD Panel Defect Compensation via Gray Scale Adjustment
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Solution Overview
Problem
Liquid crystal displays (LCDs) suffer from defects such as light spot and black spot defects, which deteriorate image quality, with a higher tolerance for black spot defects leading to the scrapping of LCDs with light spot defects above a threshold and conversion of some below-threshold light spot defects to black spot defects, while black spot defects are less perceptible but still detrimental.
Innovation Solution
An LCD apparatus comprising a first and second panel with a data processor that generates image data and adjusts the gray scale level of overlapping pixels based on the position of defective pixels, either making them darker to hide light spot defects or brighter to compensate for black spot defects, thereby mitigating their impact on image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If LCD panels with light spot defects are scrapped to maintain image quality, then image quality is improved, but manufacturing yield and productivity deteriorate
Solution Approach 1:
The patent converts the harmful light spot defects into beneficial black spot defects through inspection processes, allowing panels that would otherwise be scrapped to be retained and used. The defective pixels are then compensated through image processing techniques that convert light spot defect data into corresponding black spot defect corrections, transforming a quality issue into an acceptable characteristic.
Solution Approach 2:
The patent changes the parameter representation of defects by converting light spot defect information into black spot defect equivalents through inspection and data processing. By changing how defects are characterized and compensated (from light spot to black spot methodology), panels with defects can be utilized without compromising perceived image quality.
2Productivity
If LCD panels with black spot defects are retained due to lower perceptibility, then manufacturing yield improves, but image quality deteriorates
Solution Approach 1:
The patent implements feedback mechanisms where the positions and characteristics of defective pixels are detected, stored, and used to generate compensation data. The inspection results feed into image processing algorithms that apply corrective measures to the displayed image, creating a closed-loop system that maintains image quality while accepting panels with defects.
Solution Approach 2:
The patent performs preliminary inspection and defect mapping during manufacturing, storing defect position information before the product reaches the customer. By identifying and recording defective pixel locations in advance, the system can pre-calculate compensation strategies and apply corrections during operation, preventing quality issues rather than reacting to them.
3Manufacturing precision
If gray scale levels are adjusted to compensate for black spot defects, then image quality improves, but device complexity increases
Solution Approach 1:
The patent enables the display system to self-correct for defects through automated image processing. The system uses stored defect information to automatically generate and apply compensation data without requiring manual intervention or complex external control systems. The display device serves its own quality correction needs through integrated processing.
Solution Approach 2:
The patent creates a digital copy or map of the defect positions and characteristics, then uses this copied information to generate compensation patterns. By working with data representations rather than physically modifying the display hardware, the system achieves quality correction with minimal added complexity.
Data Source
AI summary
An apparatus and method for a liquid crystal display (LCD). The LCD can include a first LCD panel, a second LCD panel stacked on the first LCD panel, and a data processor that generates, based on an external input image signal, a first image data for the first LCD panel and a second image data for the second LCD panel. The data processor may further include a memory storing a position of a defective pixel of a white spot and a controller changing a gray scale level of a first pixel using the position of the defective pixel, the first pixel at least partially overlapping the position of the defective pixel, wherein the defective pixel is in the first LCD panel and the first pixel is in the second LCD panel.