Windshield Water-Absorbing Film for Camera Light Path Anti-Fogging

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Solution Overview

Problem

Existing windshields suffer from fogging issues in the light path space due to high humidity, which affects the accuracy of information acquisition devices like cameras and radar systems, and conventional drying agents like silica gel are not suitable for narrow spaces.

Innovation Solution

A windshield with a water-absorbing film that exhibits superior water absorption characteristics in high humidity regions, preventing condensation and fogging by satisfying specific conditions such as downward convex water vapor adsorption and desorption isotherms, and is disposed on the glass sheet or fixing members to maintain high accuracy of information acquisition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a drying agent like silica gel is placed in the light path space, then water vapor condensation can be absorbed, but the drying agent cannot be fixed in narrow light path spaces due to space constraints

Engineering Contradiction:
Improveprevention of water vapor condensationVSAvoidlight path space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent applies porous materials by forming a water-absorbing film with porous structure on the interior-facing surface of the glass sheet. The porous structure allows the film to absorb water vapor effectively while maintaining a thin profile that fits within narrow light path spaces, resolving the contradiction between condensation prevention capability and space constraint

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent implements flexible shells and thin films by creating a water-absorbing film that can be directly formed on the glass sheet surface. This thin film structure provides the necessary water vapor absorption functionality without requiring the bulk space of granular drying agents like silica gel, thus solving the space limitation problem in narrow light path regions

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If conventional drying agents are used, then water absorption function is provided, but fogging occurs in high humidity conditions due to insufficient water absorption characteristics

Engineering Contradiction:
Improvefogging prevention in high humidityVSAvoidwater absorption capacity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes by optimizing the water absorption characteristics of the film through specific compositional parameters and structural parameters. The water-absorbing film is designed with enhanced water vapor adsorption capacity that exceeds conventional drying agents, enabling effective fogging prevention even in high humidity conditions while maintaining appropriate thickness for narrow spaces

Inventive Principle:
Principle #35Parameter changes

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 water-absorbing film effectively prevents condensation in narrow light path spaces, ensuring high accuracy of information acquisition devices by maintaining clear visibility and reducing fogging, even in high humidity conditions.

Implementation Method 1

a water-absorbing film that exhibits superior water absorption characteristics in high humidity regions, preventing condensation and fogging

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3553038B1Windshield, glass product for windshield, and antifogging member
Publication Date: 2025.11.26 NIPPON SHEET GLASS CO LTD
  • EP3553038B1 patent drawingFigure 1
  • EP3553038B1 patent drawingFigure 2
  • EP3553038B1 patent drawingFigure 3

AI summary

Provided is a windshield 1 suitable for preventing fogging of a glass sheet facing a light path space and for maintaining high accuracy of information acquired by an information acquisition device. A water-absorbing film 81 or an anti-fogging member 8 including the water-absorbing film 81 is disposed on a surface in contact with a light path space 41, the surface being at least one selected from a surface of a glass sheet 5 and a surface of members 61 and 62 serving the function of fixing of an information acquisition device 2 and/or light shielding for the light path space. The water-absorbing film has a saturated water absorption Ws of 1 g/m2 or more. The water-absorbing film satisfies at least one condition selected from the condition A1 that a water vapor adsorption isotherm is a downwardly convex curve at a relative humidity of 20 to 90% and the condition B1 that an increase in water absorption AbH with increasing relative humidity from 70% to 95% is more than 35% of Ws.