Alignment Layer Thickness Modulation for Slim Bezel Display Panels

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional liquid crystal display panels face issues with light leakage and signal obstruction due to misalignment of alignment layers and damage to driving circuits from spacers, particularly when attempting to achieve a slim bezel design.

Innovation Solution

The display panel design modulates the thickness of alignment layers in different regions, allowing the conductive member to penetrate and connect electrode layers and pads effectively while preventing light leakage, and increases the thickness of alignment layers in regions with driving circuits to buffer pressure from spacers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the alignment layer is formed with uniform thickness on the entire substrate, then the alignment layer provides consistent coverage and protection, but the conductive member cannot penetrate the alignment layer to establish electrical connection between electrode layer and pad

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidalignment layer thickness uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The alignment layer is designed with different thicknesses in different regions: a first alignment layer with a first thickness in the first region and a second alignment layer with a second thickness in the second region. This local quality variation allows the conductive member to penetrate the thinner second alignment layer to establish electrical connection, while the thicker first alignment layer provides adequate coverage and protection in the display region.

Inventive Principle:

Principle #3Local quality

2Reliability

If the alignment layer thickness is reduced to allow conductive member penetration, then electrical connection is enabled, but light leakage occurs due to insufficient alignment layer coverage

Engineering Contradiction:

Improvesignal transmission reliabilityVSAvoidlight leakage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The alignment layer structure uses different thicknesses in different regions: the second alignment layer has reduced thickness in the second region to enable conductive member penetration and signal transmission, while the first alignment layer maintains greater thickness in the first region to provide adequate coverage and prevent light leakage. This local quality differentiation resolves the contradiction between signal transmission and light leakage prevention.

Inventive Principle:

Principle #3Local quality

3Stability of the object's composition

If spacers are used to maintain cell gap, then proper display medium spacing is achieved, but driving circuits are pressed and damaged causing short circuits

Engineering Contradiction:

Improvecell gap stabilityVSAvoiddriving circuit reliability

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

A buffer layer is formed between the spacer and the driving circuit to cushion and protect the driving circuit from pressure and damage. This beforehand cushioning measure prevents the driving circuit from being pressed and damaged by the spacer during assembly, thereby avoiding short circuits while maintaining proper cell gap stability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Area of stationary object

If the bezel width is reduced to achieve slim design, then usable area is increased, but misalignment occurs causing obstruction of electrical connection and light leakage

Engineering Contradiction:

Improveusable areaVSAvoidelectrical connection reliability

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The alignment layer is designed with different thicknesses in different regions to accommodate the slim bezel design. The second alignment layer has reduced thickness in the second region where the conductive member is located, enabling reliable electrical connection even with precise alignment requirements of slim bezel designs, while the first alignment layer provides adequate coverage elsewhere.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8289493B2Display panel having different thickness of alignment layers in different regions

Publication Date: 2012.10.16 AU OPTRONICS CORP

AI summary

A display panel having a first region, a second region and a third region is provided. The display panel includes an active device array substrate, an opposite substrate, a display medium between the active device array substrate and the opposite substrate, and spacers arranged between the active device array substrate and the opposite substrate for maintaining a cell gap. The active device array substrate includes an active device array in the first region, a pad in the second region, a driving circuit in the third region, and a first alignment layer covering the first region, the second region and the third region. A thickness of the first alignment layer in the third region corresponding to the driving circuit is increased to be greater than those in the first region and the second region for buffering the pressure applied by the spacers.