Liquid Crystal Display with Transmissive Diffraction Grating

Solution Overview

Problem

Conventional liquid crystal display devices in IPS or FFS modes face challenges in accelerating response speed and improving alignment stability, particularly in maintaining the initial alignment state under electric fields.

Innovation Solution

The display device incorporates a transmissive diffraction grating with a second liquid crystal layer having fixed alignment directions, combined with a display panel featuring pixel electrodes with branch and trunk portions, and a first liquid crystal layer driven by an electric field between the pixel and common electrodes, optimizing the alignment and response of liquid crystal molecules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional FFS mode is used, then the display device can operate with standard alignment, but the response speed is slow and alignment stability is poor

Engineering Contradiction:

Improveresponse speedVSAvoidalignment stability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The pixel electrode is divided into multiple branch portions extending in the first direction and connected by a trunk portion. This segmentation creates multiple alignment regions that work together to improve both response speed and alignment stability, as each branch portion can independently contribute to the electric field distribution and liquid crystal alignment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The alignment film is configured with different alignment directions in different regions: a first alignment direction in the branch portions and a second alignment direction in the trunk portion. This local quality variation allows different parts of the pixel electrode to optimize for different functions, improving overall performance.

Inventive Principle:

Principle #3Local quality

2Speed

If the pixel electrode uses a simple structure, then the device complexity is low, but the response speed and alignment stability cannot be improved

Engineering Contradiction:

Improveresponse speedVSAvoidpixel electrode structure complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The pixel electrode is divided into multiple branch portions extending in the first direction and connected by a trunk portion. This segmentation creates multiple alignment regions that work together to improve both response speed and alignment stability, as each branch portion can independently contribute to the electric field distribution and liquid crystal alignment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The trunk portion serves multiple functions: it connects the branch portions electrically, provides a region with a different alignment direction (second alignment direction) to enhance alignment stability, and contributes to the overall electric field distribution. This multi-functionality improves performance without adding excessive complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If the alignment film has uniform alignment direction, then the manufacturing process is simple, but the alignment stability under electric field is poor

Engineering Contradiction:

Improvealignment stabilityVSAvoidalignment film configuration complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The alignment film is configured with different alignment directions in different regions: a first alignment direction in the branch portions and a second alignment direction in the trunk portion. This local quality variation allows different parts of the pixel electrode to optimize for different functions, improving overall performance.

Inventive Principle:

Principle #3Local quality

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 configuration enhances the response speed and stability of liquid crystal alignment, improving the display's brightness and operational efficiency compared to traditional FFS modes.

Implementation Method 1

The liquid crystal molecules of the liquid crystal layer are driven by using an electric field generated between the pixel electrode and the common electrode

Methodology Applied

Scientific EffectElectric field: Electric Field

Implementation Method 2

a transmissive diffraction grating provided in a location between the illumination device and the first polarizer or in a location facing the second polarizer

Methodology Applied

Scientific EffectDiffraction: Diffraction

Data Source

PatentUS11686978B2Display device

Publication Date: 2023.06.27 MAGNOLIA WHITE CORP

AI summary

According to one embodiment, a display device includes an illumination device, a display panel, a first polarizer attached to the display panel, a second polarizer attached to the display panel, and a transmissive diffraction grating provided in a location between the illumination device and the first polarizer or in a location facing the second polarizer. The diffraction grating includes a third substrate, a fourth substrate, and a second liquid crystal layer provided between the third substrate and the fourth substrate, containing a plurality of liquid crystal molecules, and cured in a state where alignment directions of the liquid crystal molecules are fixed.