Vehicle Laminated Glass with Asymmetric Transmittance for Reflection Control

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Solution Overview

Problem

Laminated glass with a light control element sealed inside experiences surface unevenness, leading to reflection distortion and a deteriorated appearance when viewed from outside a vehicle.

Innovation Solution

The laminated glass design includes an interior and exterior glass plate with an interlayer film and a light control element, where the transmittance of the exterior portion is lower than the interior portion, ensuring the relation Tout < Tin, which reduces reflection distortion and improves appearance by minimizing visible light reflectance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a light control element is sealed in the interlayer film, then light control functionality is achieved, but the surface of the light control element becomes uneven causing reflection distortion and deteriorated appearance

Engineering Contradiction:

Improvelight control functionalityVSAvoidreflection distortion

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The interlayer film is designed with different transmittance properties in different regions: the first region (exterior side) has lower transmittance to suppress reflection distortion, while the second region (interior side) has higher transmittance to maintain light control functionality. This local differentiation resolves the contradiction by assigning different optical qualities to different spatial zones.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the transmittance parameter of the interlayer film across different regions. By controlling the transmittance values T1 (exterior side) and T2 (interior side) such that T1 < T2, the invention optimizes both appearance and functionality, suppressing reflection distortion while preserving light control capability.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the light control element surface becomes uneven, then light control function is achieved, but appearance quality deteriorates when viewed from outside

Engineering Contradiction:

Improvelight control functionVSAvoidappearance quality

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The invention converts the harmful effect of the uneven light control element surface into a beneficial outcome. By placing a first interlayer film with specifically controlled transmittance on the exterior side, the unevenness-induced reflection distortion is suppressed, and the appearance quality is improved while the light control function is preserved.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Different regions of the interlayer film are assigned different transmittance characteristics. The exterior-side region has optimized transmittance to mask appearance defects, while the interior-side region maintains higher transmittance for functional performance.

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 reflection distortion and enhances the appearance from the outside, achieving good contrast and light shielding properties while maintaining sufficient transmittance.

Implementation Method 1

the transmittance of the exterior glass plate, the exterior portion of the interlayer film, and the substrate located on the vehicle-exterior side, of the light control layer, is Tout

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

a light control element sealed in the interlayer film, wherein the light control element has a pair of substrates and a light control layer located between the pair of substrates

Methodology Applied

Scientific EffectElectro-optic effect: Electro-Optic Effects

Data Source

PatentUS12090730B2Laminated glass

Publication Date: 2024.09.17 AGC INC

AI summary

Laminated glass for vehicles comprising an interior glass plate and an exterior glass plate, an interlayer film between the interior glass plate and the exterior glass plate, and a light control element sealed in the interlayer film, wherein the light control element has a pair of substrates and a light control layer between the pair of substrates, and the interlayer film includes an interior portion on the vehicle-interior side of the light control layer, and an exterior portion on the vehicle-exterior side of the light control layer, when the transmittance of the exterior glass plate, the exterior portion of the interlayer film, and the substrate on the vehicle-exterior side, of the light control layer, is Tout, and the transmittance of the interior glass plate, the interior portion of the interlayer film, and the substrate on the vehicle-interior side, of the light control layer, is Tin, a relation Tout<Tin is satisfied.