Windshield Mask Layer Distortion Control

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Solution Overview

Problem

The integration of a measurement device on the windshield's mask layer leads to thermal expansion differences between the ceramic mask layer and the glass, causing distortion and refractive issues that can impair the accuracy of light emission and reception, affecting distance calculations and information acquisition.

Innovation Solution

A windshield design with a glass sheet, an information acquisition device, and a mask layer where the glass and mask layer have different heat shrinkage percentages, with the device positioned to minimize distortion influence, and an electromagnetic wave blocking film to prevent interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the measurement device is arranged on the mask layer to conceal it from the outside, then the aesthetic appearance is improved, but thermal expansion differences cause distortion near the boundary between the mask layer and the opening region

Engineering Contradiction:
Improvevisual appearanceVSAvoiddistortion near boundary
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

A heat-resistant adhesive layer is introduced as an intermediary between the mask layer and the glass sheet. This adhesive layer has a thermal expansion coefficient that is different from both the mask layer and the glass, serving as a buffer to absorb thermal expansion differences and prevent distortion at the boundary between the mask layer and the opening region.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If the mask layer absorbs heat during molding, then the glass sheet can be molded into a curved shape, but the thermal expansion difference between the mask layer and glass causes distortion

Engineering Contradiction:
Improvecurved shapeVSAvoiddistortion
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The heat-resistant adhesive layer acts as a mediator that allows the glass sheet to be molded into a curved shape while compensating for thermal expansion differences. The adhesive layer's different thermal expansion coefficient from both the mask layer and glass enables it to absorb the stress caused by differential expansion during heating and molding, preventing distortion.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the opening in the mask layer is positioned close to the boundary, then the device structure is simplified, but light refraction due to distortion affects measurement accuracy

Engineering Contradiction:
Improvedevice structureVSAvoiddistance calculation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The heat-resistant adhesive layer prevents distortion at the boundary between the mask layer and the opening region, ensuring that light passes through without refraction errors. This maintains measurement accuracy even when the opening is positioned close to the boundary, allowing for simplified device structures.

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

Ensures accurate information processing by reducing distortion effects on light emission and reception, allowing precise distance calculations and improved data acquisition from the outside environment.

Implementation Method 1

the mask layer has a dark color such as black and thus absorbs a larger amount of heat in the glass sheet compared with the region in which the mask layer is not formed

Methodology Applied
Scientific EffectHeat absorption: Absorption (EM radiation)

Implementation Method 2

since the thermal expansion coefficient of the mask layer made of ceramic is different from that of the glass sheet, the amount of expansion caused by heat absorption is different

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

the glass sheet and the mask layer have different heat shrinkage percentages and are molded together by being heated

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3118036B1windshield
Publication Date: 2019.12.11 NIPPON SHEET GLASS CO LTD
  • EP3118036B1 patent drawingFigure 1~2
  • EP3118036B1 patent drawingFigure 3~4(b)
  • EP3118036B1 patent drawingFigure 5~6

AI summary

A windshield according to the present invention is a windshield to which an information acquisition device that emits and/or receives light to acquire information from an outside of a vehicle can be attached, and that includes a glass sheet, and a mask layer that is formed on the glass sheet and blocks a visual field from the outside of the vehicle, and at least one opening is formed in the mask layer. The glass sheet and the mask layer have different heat shrinkage percentages and are molded together by being heated. The information acquisition device is configured to be capable of using the information while reducing an influence of distortion that occurs in a predetermined range from an inner peripheral edge of the opening toward a center of the opening due to the molding.