LCD Module Light Shielding Layer Design for Edge Leakage

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Solution Overview

Problem

Current liquid crystal display modules suffer from light leakage at the edges due to the limitations of extending the black matrix to cover the bezel, which compromises image quality and reliability, especially at circuit terminal regions where the black matrix cannot fully cover the array glass substrate, leading to potential separation under high temperature or impact.

Innovation Solution

A light shielding layer formed by opaque metallic lines on the array substrate, positioned close to the edge of the array substrate, with a first angle less than the angle between the black matrix and the bezel, reduces light leakage by blocking backlight source light, and a sealant with a black, light-shielding material is used to enhance light blocking, while ensuring the metallic lines do not interfere with signal transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the black matrix is extended toward the bezel to reduce light leakage, then light leakage is reduced, but the reliability of the liquid crystal display module is reduced because the black matrix may fall away from the common electrode under high temperature or impact

Engineering Contradiction:
Improvelight leakageVSAvoidreliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The light shielding function is segmented into two independent components: the black matrix on the color filter substrate and a separate light shielding layer on the array substrate. This segmentation allows each component to perform its function independently without compromising the other, resolving the contradiction between light leakage reduction and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A light shielding layer made of opaque metallic lines is introduced as an intermediary element on the array substrate. This intermediary provides additional light blocking capability without requiring the black matrix to extend further, thereby maintaining reliability while reducing light leakage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the black matrix is extended to cover the sealant, then light leakage is reduced, but the contact force between the common electrode and the color filter glass substrate is reduced, leading to potential separation

Engineering Contradiction:
Improvelight leakageVSAvoidcontact force
Core Design Contradiction:
Object-affected harmful factorsVSForce

Solution Approach 1:

The light shielding function is divided between the black matrix and a separate light shielding layer, allowing the black matrix to maintain its original position and contact force while the light shielding layer provides additional light blocking coverage over the sealant region.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The light shielding function is extended to another dimension by adding a light shielding layer on the array substrate, which provides light blocking capability in a different spatial plane without interfering with the mechanical contact between the black matrix and the color filter substrate.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Object-affected harmful factors

If the bezel is extended toward the display region to cover the display region, then light leakage is reduced, but the bezel width increases, going against the narrow bezel trend

Engineering Contradiction:
Improvelight leakageVSAvoidbezel width
Core Design Contradiction:
Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

Instead of extending the bezel in the horizontal dimension, the light shielding function is achieved by adding a light shielding layer in the vertical dimension on the array substrate, thereby reducing light leakage without increasing the bezel width.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

A light shielding layer is introduced as an intermediary element on the array substrate that provides light blocking capability, eliminating the need to extend the bezel and allowing the maintenance of a narrow bezel design.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 reduces light leakage at the edges of the liquid crystal display module, improving image quality and reliability by blocking light from the backlight source without affecting signal transmission through the circuit terminal regions.

Implementation Method 1

a light shielding layer formed by an opaque metallic line arranged on the array substrate and covering a region where the gate line is not arranged

Methodology Applied
Scientific EffectLight blocking: Absorption (EM radiation)

Implementation Method 2

a sealant with a black, light-shielding material is used to enhance light blocking

Methodology Applied
Scientific EffectLight blocking: Absorption (EM radiation)

Data Source

PatentEP2746844B1Liquid crystal display module
Publication Date: 2019.03.06 BOE TECHNOLOGY GROUP CO LTD
  • EP2746844B1 patent drawingFigure 1~2
  • EP2746844B1 patent drawingFigure 3~4
  • EP2746844B1 patent drawingFigure 5~6

AI summary

The present invention provides a liquid crystal display module comprising: a liquid crystal panel including a color filter substrate (200) and an array substrate (300) that are oppositely arranged to form a cell, a black matrix (202) being arranged at a position close to an edge of the color filter substrate; and a bezel (100) arranged around the liquid crystal panel, wherein a light shielding layer (302) is arranged in a region around the array substrate and close to an edge of the array substrate, and a first angle β1 between a line from an outer edge of the light shielding layer to an inner edge of the bezel and a display surface of the liquid crystal panel is less than a second angle β2 between a line from an outer edge of the black matrix to the inner edge of the bezel and the display surface of the liquid crystal panel.