LCD Light Blocking Portions Positioning for Oblique Color Mixing

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Solution Overview

Problem

Liquid crystal display (LCD) devices experience color mixing when viewed from an oblique angle due to light leakage from sub pixels in the OFF state, particularly near the edges of the display.

Innovation Solution

The LCD design incorporates strategically positioned and adjusted light blocking portions (black matrices) and color filters, where the relative distance and width of black matrices to data lines are optimized based on their location, either by shifting them inward towards the center or increasing their width, to prevent light from reaching the viewer at oblique angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If light blocking portions (black matrices) are positioned to overlap data lines uniformly across the display, then manufacturing is simplified, but color mixing occurs at display edges when viewed from oblique angles

Engineering Contradiction:

Improveuniform positioning of black matricesVSAvoidcolor mixing at display edges

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by differentiating the positioning of light blocking portions based on their location. Data lines near the display center have black matrices positioned at a first relative distance, while data lines near the display edges have black matrices positioned at a second relative distance (greater than the first). This localized adjustment prevents color mixing at edges without complicating the overall manufacturing process.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If black matrices are shifted inward towards the center to prevent color mixing, then color fidelity improves at oblique angles, but the area available for color filters decreases at the display edges

Engineering Contradiction:

Improvecolor mixing suppressionVSAvoidcolor filter area at display edges

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The patent resolves this contradiction by applying local quality - the degree of inward shifting is adjusted based on location. At display edges, black matrices are shifted inward by a smaller amount compared to the center, thereby suppressing color mixing to a reasonable extent while preserving maximum color filter area for light transmission.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs parameter changes by varying the relative distance parameter between black matrices and data lines based on position. The relative distance is increased near edges compared to the center, optimizing the balance between color mixing suppression and color filter area preservation through quantitative parameter adjustment.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If the width of black matrices is increased at display edges to block oblique light, then color mixing is reduced, but device complexity and manufacturing precision requirements increase

Engineering Contradiction:

Improvelight leakage at oblique anglesVSAvoidvariable width configuration of black matrices

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies local quality by making the width of light blocking portions position-dependent. Black matrices at display edges have a greater width than those at the center, locally adapting the structure to counteract oblique light leakage where it occurs most, while maintaining uniform width in central regions to simplify manufacturing.

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 effectively suppresses color mixing by blocking light from the backlight, ensuring accurate color representation even when viewed from the sides, thereby enhancing the display's angular visibility and color fidelity.

Implementation Method 1

a light blocking film overlapping the set of data lines and having a set of light blocking portions

Methodology Applied

Scientific EffectLight blocking: Absorption (EM radiation)

Data Source

PatentUS10139664B2Preventing color mixing in liquid crystal display devices

Publication Date: 2018.11.27 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA

AI summary

An LCD panel includes a display having a right edge, a left edge, and a center line. The display includes first substrate comprising a set of data lines extending in first direction and aligned in second direction, each of the data lines having a center. The display further includes second substrate aligned with the first substrate comprising a light blocking film overlapping the set of data lines and having a set of light blocking portions extending in the first direction and aligned in the second direction, each of the light blocking portions having a center and overlapping with an associated one of the data lines. The display has a liquid crystal layer interposed between the first substrate and the second substrate and relative distance between the center of a data line and the center of an associated light blocking portion is determined based on a location of the data line.