Activable Electrochromic Spectacle Lens with Three-State Control

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Solution Overview

Problem

Existing spectacle lenses lack an intermediate state that can effectively filter harmful wavelengths, such as high energy blue light, and provide increased contrast or visual comfort, while also being unable to switch between states on demand or in response to varying light conditions.

Innovation Solution

A spectacle lens with an activable optical filter that can be switched between three configurations: a clear state for unaltered color perception, an intermediate state for filtering harmful wavelengths and improving contrast, and a glare protection state, using an electrochromic device with transparent electrodes and resistive means to control light transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If photochromic lenses are used to protect eyes from UV rays and strong luminosity, then protection is provided, but the lenses cannot be activated on demand or automatically in specific conditions and are not activated by artificial light or indoor

Engineering Contradiction:
Improveactivation controlVSAvoidmanual control capability
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the optical filter switchable between multiple states (clear, intermediate, dark) rather than fixed. The electrochromic device enables dynamic adjustment of light transmission, allowing the lens to adapt to varying lighting conditions and user needs, resolving the contradiction between automatic adaptation and manual control capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the optical parameters of the lens by using an electrochromic device that can switch between different transmission states. This allows the lens to modify its light filtering properties dynamically, providing both automatic response to lighting conditions and manual activation capability through the switching mechanism.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If activable solar lenses are used to switch from clear state to low light transmission state, then protection from strong luminosity is provided, but no intermediate state is available to filter harmful wavelengths and increase contrast

Engineering Contradiction:
Improveharmful wavelength filteringVSAvoidnumber of switching states
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent segments the optical filter's functionality by dividing it into multiple discrete states (clear, intermediate, dark) rather than a single binary transition. This segmentation allows the lens to provide different levels of protection and visual enhancement, including an intermediate state that specifically filters harmful wavelengths while maintaining contrast enhancement capabilities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by providing different optical properties in different states of the same lens. The intermediate state specifically targets harmful wavelength filtering while the dark state provides overall glare protection, allowing each state to be optimized for specific visual needs without requiring separate lenses.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If pixelated lenses are used in active glasses, then switching capability is provided, but the lenses are not completely transparent and are difficult to control with limited pixels causing dye discontinuities

Engineering Contradiction:
Improveswitching capabilityVSAvoidoptical uniformity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent extracts the pixelated structure from the optical filter design and replaces it with a continuous electrochromic layer. This removal of the pixelated architecture eliminates the associated problems of dye discontinuities and optical non-uniformity while retaining the switching capability through the electrochromic device's ability to change state uniformly across the entire lens surface.

Inventive Principle:
Principle #2Taking out (Extraction)

4Adaptability or versatility

If electrochromic cell with variable thickness is used to obtain gradient of light transmission, then light transmission gradient is achieved, but the gradient is permanently defined and does not allow uniform tint on the entire spectacle lens

Engineering Contradiction:
Improvelight transmission controlVSAvoiduniform tint capability
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent applies dynamics by replacing the permanently defined gradient thickness with a dynamically controllable electrochromic system. The uniform thickness electrochromic cell can be switched to different states, providing both uniform tint across the entire lens and the ability to adjust light transmission levels as needed, eliminating the limitation of fixed gradient patterns.

Inventive Principle:
Principle #15Dynamics

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 spectacle lens provides enhanced visual comfort and protection by allowing dynamic switching between states, effectively filtering harmful wavelengths and reducing glare, while maintaining clear vision when needed.

Implementation Method 1

an activable optical filter comprising at least an electrochromic device and being configured to be actively switched between at least three configurations

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Data Source

PatentEP3701322B1Spectacle lens comprising an activable optical filter and optical equipment comprising such spectacle lens
Publication Date: 2025.02.12 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)
  • EP3701322B1 patent drawingFigure 1~3
  • EP3701322B1 patent drawingFigure 4~5
  • EP3701322B1 patent drawingFigure 6a~8

AI summary

The invention concerns a spectacle lens comprising an activable optical filter comprising at least an electrochromic device and being configured to be actively switched between at least three configurations, wherein: - in the first configuration, the activable optical filter is uniform, - in the second configuration, the activable optical filter attenuates selectively light from a localized light source, - in the third configuration, the activable optical filter is uniform, and - the chromaticity difference ΔChrom between each of the configurations is smaller than or equal to 20.