Electrochromic Glass Roof Trim Layout for Wider Viewing Area

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Solution Overview

Problem

Existing motor vehicle roof designs with electrochemical shading, such as electrochromic glass panels, face challenges in integrating with thermoformed interior trims, leading to adaptation issues and limited viewing area expansion compared to mechanical shading systems.

Innovation Solution

A motor vehicle roof arrangement featuring a transparent glass panel with electrochemical shading and an interior trim, where the trim is attached to the glass panel with inclined joining means that form a flared shape, enhancing the viewing area by covering the trim edge and minimizing direct reflections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If electrochromic glass panel is used to replace mechanical shading, then viewing area is enlarged, but integration with thermoformed interior trim becomes difficult

Engineering Contradiction:
Improveviewing areaVSAvoidintegration with thermoformed trim
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The interior trim is divided into two separate parts: a first trim portion attached to the glass panel and a second trim portion attached to the vehicle body. This segmentation allows each trim portion to be independently designed and manufactured, resolving the integration difficulty between electrochromic glass and thermoformed trim while maximizing the viewing area.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If electrochromic glass panel is used to replace mechanical shading, then device complexity is reduced, but adaptation problems with existing trim layouts occur

Engineering Contradiction:
Improveshading mechanismVSAvoidadaptation to existing trim layout
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The trim is segmented into multiple portions that can be independently configured. The first trim portion is specifically adapted to the electrochromic glass panel, while the second trim portion integrates with the vehicle body. This segmentation provides adaptability to different trim layouts while maintaining the simplicity of the electrochromic shading system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The trim configuration is made dynamic by allowing different portions of the trim to be independently positioned and configured. This enables the trim system to adapt to various vehicle designs and electrochromic glass panel configurations without requiring a complete redesign of the entire trim layout.

Inventive Principle:
Principle #15Dynamics

3Area of stationary object

If glass panel size is increased to improve viewing area, then visual comfort is improved, but more roof structure becomes visible through glass

Engineering Contradiction:
Improveviewing areaVSAvoidvisibility of roof structure
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

External masking is applied selectively at specific locations around the glass panel perimeter where the roof structure is visible. This local application of masking material conceals the unwanted structural elements while preserving the maximum possible viewing area of the glass panel.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The visible roof structure is effectively 'taken out' or removed from the visual field by applying external masking material around the glass panel. This extraction of the harmful visual element allows the glass panel to be enlarged without proportionally increasing the visibility of the supporting roof structure.

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution enlarges the viewing area by up to 60% compared to mechanical shading, providing improved visual comfort and a sense of spaciousness, while reducing weight and complexity.

Implementation Method 1

a glass panel (10) with electrochemical shading, in other words with at least one electrochromic layer (101)

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Data Source

PatentEP4511260B1Arrangement of a motor vehicle roof comprising a glass roof panel
Publication Date: 2026.01.28 RENAULT SA
  • EP4511260B1 patent drawingFigure 1
  • EP4511260B1 patent drawingFigure 2~3
  • EP4511260B1 patent drawingFigure 4~5

AI summary

The invention relates to an arrangement of a motor vehicle roof comprising a glass roof panel (10') with electrochromic obscuration and an inner trim (2') for lining the underside of the roof, around the perimeter of the glass panel, the arrangement comprising a means (9) for joining the trim to the inner face (100') of the glass panel, the joining means (9) comprising at least two ends (91, 92), one of the ends (91) being secured to the trim and the other end being an attachment end (92) attaching to the inner face of the glass panel, and an inclined portion (90) extending over its height between the two ends and the inclination of which is oriented at an open angle towards the proximal edge of the glass panel.