Patterned Electrode Angle Optimization for Display Dark Band Reduction

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Solution Overview

Problem

Existing electronic devices, such as display devices, suffer from dark bands in the patterned electrode area due to increased dark-band area ratio with higher resolution or smaller pixel size, affecting display efficiency and quality.

Innovation Solution

Incorporating a chiral dopant into the liquid-crystal layer and adjusting the included angle between the absorption axis of the polarizing plate and the patterned electrode to reduce optical rotation of liquid crystals, thereby increasing light transmittance and improving brightness uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the resolution increases or pixel size decreases, then the display quality improves, but the dark-band area ratio increases affecting display efficiency

Engineering Contradiction:

Improvedisplay resolutionVSAvoiddisplay efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent applies local quality by creating different electrode patterns in different regions of the display. The patterned electrode includes main portions and sub-portions with different geometries and orientations, where each region is optimized to control light transmission locally. This allows high resolution to be maintained while reducing dark band effects in specific areas through localized structural adjustments.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs asymmetry by designing the patterned electrode with non-uniform structures. The sub-portions have different shapes, sizes, and orientations relative to the absorption axes of the polarizing plates. This asymmetric design creates varied light transmission characteristics across different regions, preventing uniform dark band formation and improving overall display efficiency while maintaining high resolution.

Inventive Principle:

Principle #4Asymmetry

2Manufacturing precision

If the patterned electrode is optimized for high resolution, then pixel size decreases, but dark bands become more prominent in the main portion

Engineering Contradiction:

Improvepixel size uniformityVSAvoidbrightness uniformity

Core Design Contradiction:

Manufacturing precisionVSIllumination intensity

Solution Approach 1:

The patent segments the patterned electrode into multiple distinct regions: main portions and multiple sub-portions. Each segment serves a specific function in light modulation. The sub-portions are strategically positioned and sized to compensate for dark band formation in the main portions, creating a segmented structure that balances resolution requirements with brightness uniformity across the display.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies inversion by placing sub-portions with different optical characteristics alongside the main portions. Instead of making the entire electrode uniform for high resolution, the design inverts the approach by introducing varied sub-structures that optically compensate for the dark band problems inherent in high-resolution main portions, thereby improving brightness uniformity through complementary design elements.

Inventive Principle:

Principle #13The other way round (Inversion)

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 dark bands in the patterned electrode area, enhancing light transmittance and display quality by optimizing the arrangement of the patterned electrode and polarizing plates in electronic devices.

Implementation Method 1

adjusting the included angle between the absorption axis of the polarizing plate and the patterned electrode to reduce optical rotation of liquid crystals

Methodology Applied

Scientific EffectOptical rotation: Polarisation

Implementation Method 2

The first polarizing plate has a first absorption axis, the second polarizing plate has a second absorption axis, and the first absorption axis is perpendicular to the second absorption axis

Methodology Applied

Scientific EffectLight absorption by polarizing plate: Absorption (EM radiation)

Data Source

PatentUS11531239B2Electronic device comprising a patterned electrode having at least one sub-portion with a first included angle between one of a plurality of branch portions and a first absorption axis

Publication Date: 2022.12.20 INNOLUX CORP

AI summary

An electronic device includes a panel including a first substrate, a second substrate, a liquid-crystal layer including a left-handed chiral dopant, a first polarizing plate, a second polarizing plate and a patterned electrode. The first polarizing plate has a first absorption axis perpendicular to a second absorption axis of the second polarizing plate. The patterned electrode has a sub-portion that includes a plurality of branch portions. A first included angle is between one of the branch portions and the first absorption axis. A second included angle is between one of the branch portions and the second absorption axis. While the patterned electrode is disposed between the first substrate and the liquid-crystal layer, the first included angle is greater than the second included angle. While the patterned electrode is disposed between the second substrate and the liquid-crystal layer, the first included angle is smaller than the second included angle.