Spectacle Lens Multilayer Films Selective Blue Light Blocking

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Solution Overview

Problem

Existing spectacle lenses that block blue light also tend to impair the transmission of visible light, as they increase reflectance not only in the blue region but also in other visible light regions.

Innovation Solution

The spectacle lens features multilayer films on both surfaces, with a high reflectance in the purple region (≥ 20%) and low reflectances in the ultraviolet and red regions, ensuring effective blue light blocking while maintaining visible light transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the reflectance for blue light is increased to block blue light, then blue light blocking effect is improved, but the transmission of visible light is impaired

Engineering Contradiction:
Improveblue light blocking effectVSAvoidvisible light transmission
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent applies local quality by designing multilayer films with different reflectance characteristics for different wavelength regions. The film structure is optimized to achieve high reflectance specifically in the blue light region (400-500 nm) while maintaining low reflectance in other visible light regions, thereby blocking blue light without impairing overall visible light transmission.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by precisely controlling the thickness and optical properties of multiple film layers. By adjusting the optical parameters (refractive index, thickness) of each layer in the multilayer film structure, the reflectance is optimized at specific wavelengths to achieve selective blue light blocking while maintaining good visible light transmission.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the mean reflectance in the blue region is increased to block blue light, then blue light blocking is improved, but the reflectance in other visible light regions also increases

Engineering Contradiction:
Improveblue light blockingVSAvoidexcessive reflectance in visible light regions
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent implements local quality by creating wavelength-selective reflectance through multilayer film design. Each layer is optimized to contribute to high reflectance in the blue region while maintaining low reflectance in other visible regions, achieving spatial separation of reflectance characteristics across different wavelength bands.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs composite materials in the form of a multilayer film structure combining multiple materials with different optical properties. This composite structure enables independent optimization of reflectance for different wavelength regions, achieving high blue light reflectance without excessive reflectance in other visible light regions.

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 configuration ensures the transmission of visible light while effectively blocking blue light, particularly in the purple region, thereby improving the wearer's visual experience.

Implementation Method 1

the sum of mean reflectances on both surfaces of the lens in a wavelength band of 400-440 nm is ≥ 20.0%

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3859436B1Spectacle lens
Publication Date: 2025.04.23 HOYA LENS THAILAND LTD
  • EP3859436B1 patent drawingFigure 1~2

AI summary

Provided is a spectacle lens including multilayer films on both surfaces of a lens substrate, in which a sum of mean reflectances on both surfaces of the spectacle lens in a wavelength band of 360 to 400 nm is 6.0% or less, a sum of the mean reflectances on both surfaces of the spectacle lens in a wavelength band 400 to 440 nm is 20.0% or more, and a sum of the mean reflectances on both surfaces of the spectacle lens in a wavelength band 480 to 680 nm is 2.0% or less.