Chamfered Front Window Light Shielding for LCD

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Solution Overview

Problem

Liquid crystal display devices suffer from double image phenomena and reduced contrast due to light reflection and leakage, especially when viewed from large angles, as existing solutions do not effectively address light shielding at the periphery of the screen with a front window.

Innovation Solution

A liquid crystal display device configuration where the front window is bonded to the counter substrate using an adhesive with a refractive index similar to glass, and a light shielding member is applied along the chamfered portion of the front window, combined with a frame-like light shielding tape to prevent light intrusion from the periphery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a front window is spaced apart from the liquid crystal display panel to mechanically protect it, then mechanical protection is improved, but double image phenomenon occurs due to light reflection

Engineering Contradiction:

Improvemechanical protectionVSAvoiddouble image phenomenon

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

A light shielding member is introduced as an intermediary component between the front window and the liquid crystal display panel. This member selectively blocks light paths that would cause double image while allowing mechanical spacing to be maintained for protection. The light shielding member acts as a mediator that resolves the conflict between mechanical protection and optical quality.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The space between the front window and the liquid crystal display panel is segmented into different functional zones using the light shielding member. This segmentation allows the front window to maintain mechanical spacing for protection while specific regions are controlled to prevent harmful light reflections that cause double image.

Inventive Principle:

Principle #1Segmentation

2Illumination intensity

If light shielding surfaces are applied to end faces of substrates to prevent light reflection, then contrast is improved, but light leakage occurs at the periphery when a front window is used

Engineering Contradiction:

ImprovecontrastVSAvoidlight leakage at periphery

Core Design Contradiction:

Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The light shielding structure is applied locally at the periphery where the front window meets the substrate, rather than uniformly across the entire surface. The light shielding member is positioned specifically at the chamfered portion of the front window's lower surface, providing targeted light blocking where needed while maintaining transparency in the display area.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The light shielding member is pre-positioned at the chamfered portion of the front window before final assembly. This preliminary placement ensures that light leakage paths are blocked in advance, preventing peripheral light leakage that would occur with conventional light shielding surfaces on substrates alone.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If the front window is bonded directly to the liquid crystal display panel, then device complexity is reduced, but light reflection at the bonding interface causes image quality deterioration

Engineering Contradiction:

Improvestructure simplicityVSAvoidlight reflection at interface

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The light shielding member serves as an intermediary element in the bonding structure between the front window and the liquid crystal display panel. While this adds a component, it prevents light reflection at the bonding interface that would otherwise occur with direct bonding, thereby maintaining image quality while achieving a relatively simple overall structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 shields light from the backlight and external light, maintaining high contrast even when viewed from oblique angles, thereby enhancing image quality by preventing light leakage at the screen's periphery.

Implementation Method 1

a front window is bonded onto the polarizing plate with a UV-ray curable resin

Methodology Applied

Scientific EffectPhotopolymerisation: Photopolymerisation

Implementation Method 2

bonding the front window and the counter substrate with an adhesive having a refractive index approximate to that of glass

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS9025115B2Liquid crystal display device

Publication Date: 2015.05.05 MAGNOLIA WHITE CORP

AI summary

Light emitted by a backlight can be prevented from leaking through a chamfered portion of a front window of a liquid crystal display device.An upper polarizing plate is bonded over the counter substrate, and a front window is bonded over the upper polarizing plate with a UV-curable resin adhesive. The front window is chamfered and a light shielding member is formed on the chamfered portion. The UV adhesive exists between the chamfered portion and the surface of the upper polarizing plate or the counter substrate, and an outer end of the polarizing plate exists at a point outer than an outer end of the front window. Since the light shielding member for the chamfered portion is formed, light from the backlight does not penetrate from the chamfered portion. Thus, light leakage at a periphery of a screen can be prevented even when the view angle is large.