Light-Signalling Glass Panel with Segmented PVB Interlayer

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Solution Overview

Problem

The existing light signaling glazing technologies for vehicle windshields face challenges such as high scrap rates and increased manufacturing costs, particularly due to total cutting around printed circuit boards (PCBs) which can lead to poor assembly, bubbles, delamination, and aesthetic defects.

Innovation Solution

A laminated glazing system with a lamination insert having through openings surrounding the edges of inorganic light-emitting diodes on a PCB, allowing for local cutouts and minimizing the thickness of the diodes to avoid weakening the glass, while using a single sheet of polyvinyl butyral (PVB) for the interlayer to reduce material costs and air bubbles, and employing flexible PCBs to accommodate curved glazing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If total cutting around the PCB is performed, then the assembly process is simplified, but the risk of poor assembly, bubbles, delamination, and aesthetic defects increases

Engineering Contradiction:
Improveassembly processVSAvoidassembly quality
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The lamination insert is segmented with through openings that correspond to the diode positions, allowing the insert to be divided into functional zones (transparent areas for diodes and opaque areas for light blocking). This segmentation enables precise positioning of diodes while maintaining structural integrity and preventing assembly defects.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lamination insert exhibits local quality variations through its through openings - transparent in diode regions and opaque in other regions. This local differentiation allows the insert to serve multiple functions: structural support, light blocking where needed, and diode positioning where openings exist, thereby improving assembly quality without simplifying the entire process.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If the diodes are made thicker to ensure proper seating, then the assembly stability improves, but the structural integrity of the glass is weakened

Engineering Contradiction:
Improveassembly stabilityVSAvoidglass strength
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The lamination insert acts as an intermediary element between the diodes and the glass layers. It provides a stable mounting surface for the diodes through its through openings while maintaining the overall glass structure integrity. The insert mediates the mechanical connection, allowing proper diode seating without requiring thicker diodes that would compromise glass strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If multiple sheets of PVB are used for the lamination insert, then the structural support is improved, but the number of air bubbles and manufacturing complexity increases

Engineering Contradiction:
Improvestructural supportVSAvoidnumber of layers
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The lamination insert is constructed as a composite material structure combining PVB (polyvinyl butyral) with transparent and opaque regions. This composite approach provides enhanced structural support and optical properties within a single integrated layer, eliminating the need for multiple separate PVB sheets while reducing air bubble formation and manufacturing complexity.

Inventive Principle:
Principle #40Composite materials

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 approach reduces scrap rates and manufacturing costs by ensuring precise assembly, minimizing air bubbles, and maintaining the structural integrity of the glass, while providing efficient and reliable light signaling for vehicle safety features.

Implementation Method 1

a set of inorganic light-emitting diodes on a so-called front face, opposite face F3 of a printed circuit board called a PCB board, capable of emitting signaling light

Methodology Applied
Scientific EffectLight-emitting diode: Light Emitting Diode

Data Source

PatentEP3221144B1Light-signalling glass panel, vehicle including same and manufacture
Publication Date: 2021.03.24 SAINT GOBAIN VITRAGE SA
  • EP3221144B1 patent drawingFigure 1~5
  • EP3221144B1 patent drawingFigure 1bis~2bis
  • EP3221144B1 patent drawingFigure 1'~2'

AI summary

The present invention relates to a light-signalling glass panel of a vehicle forming a laminated vehicle windscreen (100) including: a first glass panel (1'), forming an outer glass panel, with first and second main surfaces (11', 12') respectively referred to as surface F1 and surface F2; a lamination insert (2) made of polymer material with a thickness e1 of at most 1.8 mm; a second glass panel (1), forming an inner glass panel, with third and fourth main surfaces (11, 12) respectively referred to as surface F3 and surface F4, the surfaces F2 and F3 being the inner surfaces of the laminated glass panel; a set of diodes (4) on a so-called front surface (30) of a PCB card (3), the set having a thickness e2≤e1, each diode emitting towards the inner glass, and each diode having an edge. For each of the diodes, the lamination insert comprises a through opening (20) surrounding the edge of the diode, and the lamination insert is, additionally, between the surface F3 and the front surface of the PCB card.