VA Display Pixel Sub-pixel Voltage Division for Side Visibility

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Solution Overview

Problem

Vertically aligned liquid crystal display devices face challenges with side visibility compared to front visibility, and maintaining uniform display quality across sub-pixels is difficult due to varying voltage ratios.

Innovation Solution

The display device incorporates a pixel structure with two sub-pixels and a voltage division reference line, where the data voltage is divided between the sub-pixels using a third switching element, ensuring consistent voltage levels across the sub-pixels to enhance side visibility and uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a vertically aligned liquid crystal display device is used, then contrast ratio is improved and wide reference viewing angle is achieved, but side visibility deteriorates compared to front visibility

Engineering Contradiction:
Improvecontrast ratioVSAvoidside visibility
Core Design Contradiction:
Illumination intensityVSEase of operation

Solution Approach 1:

The pixel is divided into two sub-pixels (first sub-pixel and second sub-pixel) with different voltage control mechanisms. The first sub-pixel uses a conventional switching element while the second sub-pixel uses a voltage division circuit with a third switching element and voltage division reference line, allowing independent voltage optimization for each sub-pixel to improve side visibility while maintaining high contrast ratio

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different voltage division ratios are applied to different sub-pixels based on their specific positions and functions. The second sub-pixel receives a divided voltage through the third switching element and voltage division reference line, creating localized voltage optimization that enhances side visibility without compromising the overall contrast ratio performance of the vertically aligned liquid crystal display device

Inventive Principle:
Principle #3Local quality

2Ease of operation

If one pixel is divided into two sub-pixels with different voltage control, then side visibility is improved, but display quality uniformity deteriorates due to varying voltage ratios

Engineering Contradiction:
Improveside visibilityVSAvoiddisplay quality uniformity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The voltage division reference line is designed to provide stable reference voltages to the third switching element, ensuring that the voltage division ratio between the first and second sub-pixels remains constant. This equipotential design approach maintains uniform display quality across different pixels by preventing voltage ratio variations that would otherwise cause display quality inconsistencies

Inventive Principle:
Principle #12Equipotentiality

Solution Approach 2:

The voltage division reference line acts as a feedback mechanism that monitors and stabilizes the voltage distribution to the second sub-pixel. By providing a stable reference voltage, the system can maintain consistent voltage ratios across all pixels, ensuring uniform display quality while achieving improved side visibility through the differentiated voltage control of the two sub-pixels

Inventive Principle:
Principle #23Feedback

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 improves side visibility and maintains uniform display quality by ensuring consistent voltage levels across sub-pixels, addressing the inherent limitations of vertically aligned liquid crystal display devices.

Implementation Method 1

A voltage may be applied to the electric field generation electrodes to generate an electric field in the liquid crystal layer, and thus, alignment of liquid crystal molecules in the liquid crystal layer is determined, and the polarization of incident light is controlled

Methodology Applied
Scientific EffectLiquid crystal alignment and polarization control: Liquid Crystals

Data Source

PatentEP3588182B1Display device
Publication Date: 2021.08.04 SAMSUNG DISPLAY CO LTD
  • EP3588182B1 patent drawingFigure 1
  • EP3588182B1 patent drawingFigure 2
  • EP3588182B1 patent drawingFigure 3

AI summary

A display device includes: a gate line (121); a semiconductor pattern, SP, on the gate line (121); a data line (171-1); a voltage division reference line (177); and first to third switching elements (T1, T2, T3) overlapping the SP. The first switching element (T1) includes a first source electrode, SE, connected to the data line (171-1), a first drain electrode, DE, spaced apart from the first SE, and a first gate electrode, GE, connected to the gate line (121). The second switching element (T2) includes a second SE connected to the data line (171-1), a second DE spaced apart from the second SE, and a second GE connected to the gate line (121). The third switching element (T3) includes a third SE connected to the voltage division reference line (177), a third DE connected to the second SE, and a third GE connected to the gate line (121). The first SE, the first DE, the second SE, and the second DE are sequentially arranged across and on the SP in a first direction.