Automated LCD Inspection Apparatus for Pixel Defect Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current inspection methods for liquid crystal display devices rely on visual inspection, which is time-consuming and prone to variability in detecting fine pixel defects, leading to reduced productivity and inconsistent quality.

Innovation Solution

An automated inspection apparatus using a carrier, backlight unit, exterior-light shield, and vision cameras to irradiate and analyze the liquid crystal panel screen, converting optical signals into digital data for defect detection on a per-pixel basis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If visual inspection by inspectors is used, then device complexity is reduced and ease of operation is improved, but inspection time increases and productivity decreases

Engineering Contradiction:

Improveease of operationVSAvoidproductivity

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent replaces the mechanical visual inspection system (inspectors using eyes and brains) with an automated optical inspection system comprising illumination units, imaging units, and analysis units. This substitution eliminates manual inspection while dramatically improving inspection speed and productivity, directly resolving the contradiction between ease of operation and productivity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If visual inspection by inspectors is used, then device complexity is reduced, but measurement precision and manufacturing precision deteriorate due to variability in detecting fine pixel defects

Engineering Contradiction:

Improvedevice complexityVSAvoidinspection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces human visual inspection with an automated optical system that uses imaging units to capture images and analysis units to process them, eliminating human variability and achieving consistent, high-precision detection of fine pixel defects while maintaining relatively simple device architecture.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates optical copies (images) of the liquid crystal display screen using imaging units, which are then analyzed digitally. This copying approach allows for precise, repeatable measurement of pixel defects without requiring complex physical measurement equipment, thus improving measurement precision while keeping device complexity manageable.

Inventive Principle:

Principle #26Copying

3Ease of operation

If visual inspection by inspectors is used, then ease of operation is improved, but loss of time increases and productivity decreases

Engineering Contradiction:

Improveease of operationVSAvoidinspection time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The patent implements continuous automated inspection where illumination units continuously illuminate the screen, imaging units continuously capture images, and analysis units continuously process data. This continuous operation eliminates the intermittent nature of manual inspection, dramatically reducing inspection time and increasing productivity while maintaining operational simplicity.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent replaces slow manual visual inspection with rapid automated optical inspection, where images are captured and analyzed in seconds rather than minutes or hours, directly addressing the time loss issue while keeping the system easy to operate.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach significantly reduces inspection time, enhances accuracy, and ensures consistent product quality by enabling precise detection of defects, thereby improving manufacturing efficiency and productivity.

Implementation Method 1

a backlight unit to irradiate light to a lower surface of the glass panel being transported by the carrier

Methodology Applied

Scientific EffectLight irradiation: Light

Implementation Method 2

sensing optical signals emitted from the glass panel and converting the optical signals into digital sensing signals by use of a plurality of vision cameras

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS7808630B2Inspection apparatus for liquid crystal display device and inspection method using same

Publication Date: 2010.10.05 LG DISPLAY CO LTD

AI summary

An inspection apparatus and inspection method for liquid crystal display devices are disclosed, wherein a final inspection for completely manufactured liquid crystal display devices is performed using a visual-light inspection apparatus, whereby high productivity due to improved inspection accuracy and reduced inspection time can be accomplished. With the inspection apparatus and inspection method, defects of a plurality of glass panels can be automatically inspected based on analyzed information of an entire screen of each glass panel using a plurality of vision cameras, whereby improved inspection accuracy and improved product quality can be accomplished and reduced inspection time can result in improved productivity of liquid crystal display devices. Further, by quantifying screen defects of the plurality of glass panels, defects of glass panels due to failures of manufacturing processes or design failures and other problems attendant on the defects can be prevented.