LCD Picture Quality Testing Apparatus for Gray Inversion and Color Shift
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Solution Overview
Problem
Conventional liquid crystal displays (LCDs) experience gray inversion and color shift when their screen moves, but there are no effective methods to measure these phenomena, relying on human evaluation.
Innovation Solution
A picture quality testing apparatus and method that includes an LCD displaying a test pattern, a CCD camera to photograph the pattern, and a rotating mechanism to measure transmittance and viewing angles for gray inversion and color shift, using a measurer to detect these issues up to one-third toward the interior of the LCD panel from the signal pad region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If human evaluation is used to assess gray inversion and color shift, then subjective perception is obtained, but measurement precision and objectivity are poor
Solution Approach 1:
The patent replaces the mechanical human evaluation system with an automated optical measurement system consisting of a light source, image pickup device (CCD camera), and computer processing system. This substitution eliminates subjective human perception and provides objective, quantifiable measurements of gray inversion and color shift through transmittance analysis at different viewing angles.
Solution Approach 2:
The patent introduces an intermediary measurement system that uses a light source to illuminate the LCD and a CCD camera to capture the transmitted light patterns. This intermediary system acts as a mediator between the LCD display and the evaluation process, enabling precise measurement of optical properties without direct human intervention while maintaining measurement accuracy.
2Reliability
If no standardized testing method is used, then evaluation is simple, but reliability and consistency of results are poor
Solution Approach 1:
The patent segments the measurement process into distinct components: a light source for illumination, an image pickup device for capturing light patterns, a computer for processing images and calculating transmittance values, and a rotating mechanism for varying viewing angles. This segmentation enables standardized, repeatable measurements while maintaining system reliability through modular design.
Solution Approach 2:
The patent systematically changes the viewing angle parameter by rotating either the LCD or the image pickup device to measure transmittance at multiple angles. This parameter variation enables comprehensive characterization of gray inversion and color shift phenomena, improving reliability through multi-angle data collection and standardized analysis protocols.
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
Accurately measures viewing angles for gray inversion and color shift without human error, standardizing the measurement based on LCD characteristics, enabling precise evaluation of picture quality.
Implementation Method 1
a measurer for measuring the transmittance of the test pattern photographed by the image pickup device
Data Source
AI summary
Disclosed is a picture quality testing apparatus and method of a liquid crystal display which can measure at least any one of gray inversion and color shift. An apparatus for testing the picture quality of a liquid crystal display includes a liquid crystal display for displaying a test pattern, an image pickup device for photographing the test pattern of the liquid crystal display, a measurer for measuring the transmittance of the test pattern photographed by the image pickup device, and a rotating means for rotating at least one of the liquid crystal display and the image pickup device while the image pickup device photographs the test pattern.