Light Valve Panel Asymmetric Electrode Design for LCD Contrast

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Solution Overview

Problem

Liquid crystal displays face limitations in displaying dark images due to uniform backlight irradiation, leading to reduced contrast ratios and poor luminance distribution, which affects image quality, especially at side viewing angles.

Innovation Solution

A light valve panel with a liquid crystal layer, a first electrode in a matrix form, and a second electrode, where the angle between the light valve data line and the vertical edge of the block is greater than 0° and less than 90°, allowing for adjustable light transmission based on input image luminance, thereby optimizing light distribution and contrast.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If uniform backlight irradiation is used, then the display panel can be driven with simple structure, but the contrast ratio is limited and dark image display is poor

Engineering Contradiction:
Improvebacklight structureVSAvoidcontrast ratio
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The backlight unit is divided into multiple independently controllable light sources corresponding to different regions of the display panel. Each light source can be adjusted individually to match the luminance distribution of the input image, enabling localized brightness control and improved contrast ratio without requiring complete structural redesign of the entire backlight system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the backlight unit are configured with different light emission characteristics to match the local luminance requirements of the display content. By adjusting the luminance of each light source according to the input image characteristics, the system achieves optimized local contrast and dark image display while maintaining overall system simplicity.

Inventive Principle:
Principle #3Local quality

2Device complexity

If the light valve data line is connected perpendicular to the block edge, then the connection is simple, but moiré phenomena and color distortion occur at side viewing angles

Engineering Contradiction:
Improveelectrode connection structureVSAvoidmoiré phenomena and color distortion
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The light valve data line is intentionally connected at an oblique angle rather than perpendicular to the block edge. This asymmetric connection angle breaks the regular geometric pattern that causes moiré interference, thereby eliminating moiré phenomena and color distortion at side viewing angles while adding minimal complexity to the electrode connection structure.

Inventive Principle:
Principle #4Asymmetry

3Device complexity

If the block size is large, then the light transmission control is simplified, but the luminance uniformity and contrast ratio deteriorate

Engineering Contradiction:
Improvelight transmission controlVSAvoidluminance uniformity
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The display area is divided into multiple smaller blocks with individual light transmission control. Each block is further divided into multiple sub-regions that can be independently adjusted. This segmentation enables fine-grained luminance control to achieve uniform brightness distribution and high contrast ratio, while the overall control structure remains simplified through systematic organization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The light transmission characteristics of each block are dynamically adjusted based on the luminance distribution of the input image. By real-time modulation of the light valve parameters for different blocks, the system achieves optimal luminance uniformity and contrast ratio adaptation to various display content without requiring fixed block size optimization.

Inventive Principle:
Principle #15Dynamics

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 enhances the contrast ratio and image quality by precisely controlling light irradiation on the display panel, reducing color distortion and moiré phenomena, and improving luminance uniformity at both front and side viewing angles.

Implementation Method 1

A liquid crystal display displays an image by controlling an electric field applied to liquid crystal molecules based on a data voltage

Methodology Applied
Scientific EffectLiquid crystal modulation: Liquid Crystals

Implementation Method 2

controlling an amount of light incident on a display panel based on a luminance distribution of an input image

Methodology Applied
Scientific EffectElectro-optic effect: Electro-Optic Effects

Data Source

PatentEP3252530B1Light valve panel and liquid crystal display using the same
Publication Date: 2019.07.03 LG DISPLAY CO LTD
  • EP3252530B1 patent drawingFigure 1~2
  • EP3252530B1 patent drawingFigure 3~5
  • EP3252530B1 patent drawingFigure 6(A)~6(C)

AI summary

A light valve panel and a liquid crystal display using the same are discussed. The light valve panel according to an embodiment includes a liquid crystal layer, a first electrode arranged in a matrix form and including a block corresponding one-to-one with a light valve data line, and a second electrode facing the first electrode with the liquid crystal layer interposed therebetween. An angle between a vertical edge of the block and the light valve data line is greater than 0° and less than 90°. The liquid crystal display device according to another embodiment includes a display panel, a backlight unit, and a light valve panel.