Laminated Glass Interlayer Film for Sensor and HUD Double-Image Control

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Solution Overview

Problem

Conventional laminated glass interlayer films do not adequately address the issue of transmitted double images detected by onboard sensors, which can reduce detection accuracy.

Innovation Solution

An interlayer film for laminated glass with a maximum deviation of partial wedge angle in the onboard sensor region of 0.2 mrad or less, and specific design parameters for both the onboard sensor and HUD display regions to minimize double images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional interlayer film is used, then the basic safety function is maintained, but transmitted double images are detected by onboard sensors reducing detection accuracy

Engineering Contradiction:
Improvedetection accuracyVSAvoidtransmitted double images
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The interlayer film is designed with different wedge angle characteristics in different regions: the onboard sensor region has a maximum deviation of 0.2 mrad or less to minimize transmitted double images for sensors, while the HUD display region has a larger wedge angle (0.05 mrad or more) to reduce reflected double images for display clarity. This local differentiation resolves the contradiction by optimizing each region for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The interlayer film is segmented into functionally distinct regions with different optical properties. The onboard sensor region (600-1000 mm from one edge) is separated from the HUD display region, with each having tailored wedge angle characteristics. This segmentation allows the film to simultaneously address both transmitted double images for sensors and reflected double images for HUDs.

Inventive Principle:
Principle #1Segmentation

2Illumination intensity

If the wedge angle is increased to reduce reflected double images for HUD, then display clarity improves, but transmitted double images for onboard sensors worsen

Engineering Contradiction:
Improvedisplay clarityVSAvoiddetection accuracy
Core Design Contradiction:
Illumination intensityVSMeasurement precision

Solution Approach 1:

Different regions of the interlayer film have different wedge angle characteristics optimized for their specific functions. The HUD display region has a larger wedge angle (0.05 mrad or more) to reduce reflected double images and improve display clarity, while the onboard sensor region has a smaller maximum deviation (0.2 mrad or less) to minimize transmitted double images and maintain detection accuracy.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The interlayer film is divided into distinct functional zones: the HUD display region with larger wedge angle for display clarity, and the onboard sensor region with smaller wedge angle deviation for detection accuracy. This spatial segmentation resolves the contradiction by allowing each region to have optimal wedge angle characteristics for its purpose.

Inventive Principle:
Principle #1Segmentation

3Illumination intensity

If a wedge-shaped interlayer film is used to reduce reflected double images, then HUD display quality improves, but the film complexity increases

Engineering Contradiction:
ImproveHUD display qualityVSAvoidfilm structure complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The wedge angle parameter is strategically varied in different regions of the interlayer film. By controlling the wedge angle distribution (maximum deviation ≤0.2 mrad in sensor region, ≥0.05 mrad in HUD region), the film achieves reduced double images for both HUDs and sensors without requiring complex multi-layer structures or additional components.

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

Significantly reduces transmitted double images, enhancing the detection accuracy of onboard sensors and display clarity of head-up displays.

Implementation Method 1

Some of the light rays guided from outside the automobile to an onboard sensor are refracted without being reflected by the outer surface and the inner surface of the windshield

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

Images displayed on the HUD may be visually recognized as double images (so-called 'reflected double images') due to light rays emitted from the light source of the HUD being reflected by the inner and outer surfaces of the windshield

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4596514A1Laminated glass interlayer film, laminated glass, and manufacturing method for same
Publication Date: 2025.08.06 SEKISUI CHEMICAL CO LTD
  • EP4596514A1 patent drawingFigure 1~2
  • EP4596514A1 patent drawingFigure 3(A)~3(D)
  • EP4596514A1 patent drawingFigure 4(A)~4(D)

AI summary

An interlayer film for laminated glass including an onboard sensor region (11), wherein a maximum amount of deviation of a partial wedge angle with respect to an approximate straight line (L1) of the partial wedge angle in the onboard sensor region (11) is 0.2 mrad or less.