Corrugated Electrode Edges for Passive Matrix Display Zone Visibility

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Solution Overview

Problem

Miniaturizing direct lit large-display backlights for mobile devices faces challenges in achieving uniformity and sufficient zone count due to reduced thickness, leading to visibility issues with rectangular edge patterns caused by parallax between passive matrix LC elements and the main display.

Innovation Solution

The use of corrugated electrode edges in the passive matrix display system, where opposing adjacent electrodes have similar corrugations to break up straight lines, reducing zone visibility by matching the corrugation size to the parallax error, thereby minimizing the rectangular edge pattern visibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a passive matrix LC panel is placed between the backlight and main display to create 2D active dimming zones, then zone control capability is improved, but zone edges become visible due to parallax between the LC elements and main display

Engineering Contradiction:

Improvezone control capabilityVSAvoidzone edge visibility

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry by making the electrode edges non-straight and giving them a curved or irregular shape. This asymmetric edge design prevents the formation of straight line patterns that are visible through the display, thereby eliminating the rectangular edge pattern artifact while maintaining zone control functionality

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent employs curvature by replacing straight electrode edges with curved edges. The curved electrode edges scatter light differently and prevent the formation of sharp, visible rectangular patterns, thus reducing zone edge visibility while preserving the active dimming zone control capability

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Length of moving object

If the backlight thickness is reduced for mobile device miniaturization, then device size is improved, but uniformity and zone count are compromised

Engineering Contradiction:

Improvebacklight thicknessVSAvoiduniformity and zone count

Core Design Contradiction:

Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent changes the geometric parameters of the electrode structures by introducing curved edges with specific radii and patterns. This parameter modification allows the system to maintain adequate zone count and uniformity even in thinned backlight configurations suitable for mobile devices

Inventive Principle:

Principle #35Parameter changes

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 reduces zone visibility and maintains high efficiency in active dimming for mobile displays, enhancing image quality by eliminating the rectangular edge pattern artifact.

Implementation Method 1

a liquid crystal layer positioned between the first substrate and the second substrate

Methodology Applied

Scientific EffectLiquid crystal electro-optic effect: Electro-Optic Effects

Implementation Method 2

The corrugations break up the straight lines that interfere with the straight lines of the main display pixels

Methodology Applied

Scientific EffectLight diffraction: Diffraction

Implementation Method 3

zone edges of the passive matrix LC elements are well defined and sharp, and such edges may be seen in different places on the main display because of parallax between the eyes

Methodology Applied

Scientific EffectParallax: Parallax

Data Source

PatentUS10451936B1Thin two-dimensional dimming backlight with low zone visibility

Publication Date: 2019.10.22 SHARP KK

AI summary

A passive matrix display has corrugated electrode edges to reduce zone visibility within a display system. A passive matrix display includes a first substrate and a second substrate; a liquid crystal layer positioned between the first and second substrates; a patterned electrode layer formed on the first substrate comprising a plurality of individual electrodes, wherein adjacent individual electrodes are separated by an electrode gap; and a second electrode layer formed on the second substrate. At least a portion of opposing edges of adjacent individual electrodes at the electrode gap include corrugations. The elements of the corrugations may be any suitable shapes and/or sizes as may be suitable for any particular application. The corrugations may be uniformly shaped or varying, symmetric or asymmetric about a horizontal axis, and/or may have a regular or irregular pattern. Another aspect is a display system including the enhanced passive matrix display that reduces zone visibility.