MVA LCD Pixel Sub-pixel Segmentation for Color Shift Reduction

Solution Overview

Problem

Liquid crystal displays (LCDs) with Multi-Domain Vertically Aligned Mode (MVA mode) suffer from color shift issues, particularly when viewed from oblique angles, where skin tones appear bluish or whitish due to non-monotonic transmittance-voltage characteristics.

Innovation Solution

A liquid crystal display is designed with a pixel unit divided into two sub-pixels, each generating distinct transmittance-voltage characteristics, allowing for a monotonic combination of these characteristics to mitigate color shift by forming two different pixel electrode voltages using a specific drive method involving pulse and clock signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If MVA mode liquid crystal display is used to provide wider viewing range, then view angle is improved, but color shift occurs when viewed from oblique direction

Engineering Contradiction:

Improveviewing angleVSAvoidcolor shift

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The pixel is divided into two sub-pixels, each with different liquid crystal material compositions. This segmentation allows each sub-pixel to contribute differently to the overall transmittance characteristics, enabling the combination to achieve monotonic T-V characteristics while maintaining wide viewing angles and reducing color shift.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses composite liquid crystal materials with different compositions in the two sub-pixels. By combining materials with different optical properties and T-V characteristics, the system achieves improved color performance and reduced color shift while maintaining the wide viewing angle advantage of MVA mode.

Inventive Principle:

Principle #40Composite materials

2Device complexity

If single liquid crystal material is used in pixel, then device structure is simple, but non-monotonic T-V characteristic causes color shift

Engineering Contradiction:

Improvepixel structureVSAvoidT-V characteristic monotonicity

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The pixel is divided into two sub-pixels, each with different liquid crystal material compositions. This segmentation allows each sub-pixel to contribute differently to the overall transmittance characteristics, enabling the combination to achieve monotonic T-V characteristics while maintaining wide viewing angles and reducing color shift.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses composite liquid crystal materials with different compositions in the two sub-pixels. By combining materials with different optical properties and T-V characteristics, the system achieves improved color performance and reduced color shift while maintaining the wide viewing angle advantage of MVA mode.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS8098220B2Liquid crystal display and operation method thereof

Publication Date: 2012.01.17 AU OPTRONICS CORP

AI summary

A pixel unit in the present invention is divided into two sub-pixels. Each sub-pixel includes a thin film transistor, a liquid crystal capacitor and a storage capacitor. The two transistors respectively located in different sub-pixels are connected to different scan lines. One of the two transistors is connected to the data line through another transistor. Therefore, two different pixel voltages are formed in a pixel.