LCD Alignment Mark Visibility via Black Matrix Opening

Solution Overview

Problem

In liquid crystal display (LCD) devices without a gate drive IC, the alignment mark is hidden by the black matrix layer, making it difficult to sense the precise position during edge grinding and polarizer attachment processes.

Innovation Solution

Forming an alignment mark on at least one of the substrates with an opening in the black matrix layer to reveal it, allowing for accurate positioning during these processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the alignment mark is formed on the substrate without an opening in the black matrix layer, then the device structure is simpler and manufacturing is easier, but the alignment mark cannot be sensed during edge grinding and polarizer attachment processes

Engineering Contradiction:

Improveease of manufactureVSAvoiddetectability of alignment mark

Core Design Contradiction:

Ease of manufactureVSDifficulty of detecting and measuring

Solution Approach 1:

The patent extracts the alignment mark from the coverage of the black matrix layer by forming an opening in the black matrix layer at the alignment mark position. This allows the alignment mark to be visible and detectable during edge grinding and polarizer attachment processes while maintaining the overall simple structure.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The alignment mark is nested within the black matrix layer structure, with the opening in the black matrix layer revealing the alignment mark underneath. This nested configuration allows the alignment mark to be protected during manufacturing while remaining accessible for detection when needed.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Difficulty of detecting and measuring

If the alignment mark is formed on the substrate with an opening in the black matrix layer, then the alignment mark can be sensed during edge grinding and polarizer attachment processes, but the device structure becomes more complex and manufacturing becomes more difficult

Engineering Contradiction:

Improvedetectability of alignment markVSAvoidease of manufacture

Core Design Contradiction:

Difficulty of detecting and measuringVSEase of manufacture

Solution Approach 1:

The patent extracts the alignment mark from the coverage of the black matrix layer by forming an opening in the black matrix layer at the alignment mark position. This allows the alignment mark to be visible and detectable during edge grinding and polarizer attachment processes while maintaining the overall simple structure.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The alignment mark is formed on the substrate before the black matrix layer is deposited, and the opening is created in the black matrix layer to expose the alignment mark. This preliminary positioning and exposure approach simplifies subsequent manufacturing steps compared to adding alignment marks after black matrix formation.

Inventive Principle:

Principle #10Preliminary action

3Area of moving object

If the gate drive area is formed on the TFT array substrate without a gate drive IC, then the pixel area can be increased, but the alignment mark becomes hidden by the black matrix layer

Engineering Contradiction:

Improvepixel areaVSAvoiddetectability of alignment mark

Core Design Contradiction:

Area of moving objectVSDifficulty of detecting and measuring

Solution Approach 1:

The patent extracts the alignment mark from the coverage of the black matrix layer by forming an opening in the black matrix layer at the alignment mark position. This allows the alignment mark to be visible and detectable during edge grinding and polarizer attachment processes while maintaining the overall simple structure.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent positions the alignment mark in a specific location within the gate drive area and creates a corresponding opening in the black matrix layer at that position. This spatial arrangement in the planar dimension allows the alignment mark to remain visible while maximizing the pixel area in the display region.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS7808608B2Liquid crystal display device

Publication Date: 2010.10.05 LG DISPLAY CO LTD

AI summary

Disclosed herein is an LCD device having a drive area directly formed inside a non-pixel area of a substrate without an additional drive IC. The LCD device includes a first substrate having a pixel area and a non-pixel area disposed peripherally to the pixel area. The pixel area has a thin film transistor and a pixel electrode in each sub-pixel defined by gate and data lines crossing each other. A second substrate formed in opposition to the first substrate includes a color filter layer and a black matrix layer. A liquid crystal layer is formed between the first and second substrates. An opening in the black matrix layer reveals an alignment mark, which is disposed on at least one of the first substrate and the second substrate.