Curved Switchable Shutter Antireflective Layers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Curved switchable shutters in protective headgear can cause undesirable optical phenomena such as reflections and double images due to the curvature of optical components, leading to a suboptimal viewing experience for the wearer.

Innovation Solution

Incorporating at least two antireflective layers on major surfaces of the rear and front cover plates and the switchable shutter to reduce light reflections and enhance optical clarity, with specific configurations and materials used to minimize refractive index mismatch and optimize light transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If curved optical components are used in protective headgear, then the field of view and ergonomics are improved, but reflections and double images occur due to curvature

Engineering Contradiction:
Improvefield of viewVSAvoidreflections and double images
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

An antireflective coating is applied as an intermediary layer on the curved optical components. This coating acts as a mediator between air and the optical material, reducing the refractive index mismatch and minimizing reflections and double images while preserving the curved geometry for ergonomic benefits

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The refractive index parameter is modified by applying an antireflective coating with a specific refractive index between that of air and the optical material. This parameter change reduces the optical impedance mismatch at interfaces, thereby reducing reflections and improving image quality while maintaining the curved shape

Inventive Principle:
Principle #35Parameter changes

2Reliability

If multiple optical layers are added to reduce reflections, then optical clarity is improved, but device complexity increases

Engineering Contradiction:
Improveoptical clarityVSAvoidnumber of optical layers
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of making the entire optical system complex, the antireflective treatment is applied locally only where needed - on the curved optical components that cause reflections. This localized approach improves optical clarity without unnecessarily increasing the complexity of the entire device

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

A composite optical structure is created by combining the base optical material with an antireflective coating layer. This composite approach achieves superior optical clarity by leveraging the complementary properties of both materials - the transparency of the base material and the reflection-reducing properties of the coating

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

Significantly improves the viewing experience by reducing ghosting and double images, providing a clearer and more crisp image for the wearer by effectively managing light reflections across the optical path.

Implementation Method 1

minimize refractive index mismatch and optimize light transmission

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

Incorporating at least two antireflective layers on major surfaces of the rear and front cover plates and the switchable shutter to reduce light reflections

Methodology Applied
Scientific EffectAnti-reflective coating: Anti-Reflective Coating

Data Source

PatentEP3454803B1Protective headgear comprising a curved switchable shutter and comprising multiple antireflective layers
Publication Date: 2023.11.15 3M INNOVATIVE PROPERTIES CO
  • EP3454803B1 patent drawingFigure 1~2
  • EP3454803B1 patent drawingFigure 3
  • EP3454803B1 patent drawingFigure 4~5

AI summary

Protective headgear with a curved switchable shutter and curved front and rear cover plates and including at least two antireflective layers.