Compound Glazing With Darkened Layer for Halo-Free Lighting

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Solution Overview

Problem

Existing composite panes with integrated light sources and functional elements suffer from unsightly lighting effects due to light reflection on the functional element, which varies in intensity depending on the functional element's state.

Innovation Solution

The composite pane design includes a darkened layer with low light transmittance between the light source and the functional element, preferably extending over the area between them, to absorb light that would otherwise reflect on the functional element, reducing or eliminating the halo effect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a light source is integrated into the composite pane to create lighting effects, then aesthetic appeal and functionality are improved, but unsightly lighting effects and halo formation occur due to light reflection on the functional element

Engineering Contradiction:
Improvelighting effectVSAvoidhalo effect
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

A darkened layer is introduced as an intermediary component between the light source and the functional element. This layer absorbs stray light that would otherwise reflect off the functional element and create halo effects, while allowing the desired lighting effects to proceed through the light guide and outcoupling element.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful reflected light is extracted or removed from the optical path by the darkened layer, which selectively absorbs the stray light before it can reach the functional element and create unwanted visual effects.

Inventive Principle:
Principle #2Taking out (Extraction)

2Device complexity

If the functional element is positioned close to the light source to optimize space, then device complexity is reduced, but the intensity of unwanted light reflection and halo effect increases

Engineering Contradiction:
Improvestructural simplicityVSAvoidlight reflection
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The darkened layer serves as a mediating structure that enables close positioning of the functional element to the light source without suffering from excessive light reflection. It absorbs the stray light in the narrow space between these components.

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

The darkened layer effectively prevents the formation of optically visible glows by absorbing light that would otherwise reflect on the functional element, enhancing aesthetic appeal and reducing unwanted lighting effects.

Implementation Method 1

The darkened layer effectively prevents the formation of optically visible glows by absorbing light that would otherwise reflect on the functional element

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

The light from the light source is coupled into the light guide, where it remains in the light guide by utilising the effect of total internal reflection until it hits the outcoupling element

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP4473245B1Compound glazing with light source
Publication Date: 2025.09.24 SAINT GOBAIN SEKURIT FRANCE
  • EP4473245B1 patent drawingFigure 1~1a
  • EP4473245B1 patent drawingFigure 1b
  • EP4473245B1 patent drawingFigure 2~3

AI summary

The invention relates to a composite glass sheet (100) with a light source, comprising: - an outer sheet (1) and an inner sheet (2), - a first thermoplastic film (10.1) arranged between the outer sheet (1) and the inner sheet (2), - a functional element (4) with electrically controllable optical properties, - a darkened layer (6), - an output coupling element (5) for output coupling light (3) from the inner sheet (2), and - a light source (7) arranged at a side edge (11) of the inner sheet (2) or in a cutout (9) of the inner sheet (2) and serving to input couple light (3) into the inner sheet (2), wherein the darkened layer (6) has at least one opaque region with a light transmittance of less than or equal to 50% and the opaque region is present at least in the region (8) between the light source (7) and the functional element (4).