Interference Lens Coating for Screen Glare and Visual Fatigue
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Solution Overview
Problem
Existing optical articles fail to effectively address visual fatigue caused by strong brightness imbalances between digital screens and backgrounds, and conventional tinted lenses are not tailored for this purpose or are aesthetically unappealing.
Innovation Solution
An optical article with an interferential multilayer coating that varies visible light reflection and transmission based on the angle of incidence, providing higher reflection for high angles and lower reflection for low angles, tailored for specific viewing conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If normal tinted lenses are used to decrease overall light entering the eye, then the amount of light is reduced, but the difference in luminance between screens and background is not addressed
Solution Approach 1:
The optical article implements angle-dependent optical properties through the interferential multilayer coating, where different regions of the lens (corresponding to different viewing angles) have different transmission characteristics. Central vision (low angles) maintains high transmission for screen viewing, while peripheral vision (high angles) has reduced transmission to block background glare, thus addressing luminance imbalance locally rather than uniformly across the entire lens
2Object-affected harmful factors
If gradient tinted lenses are used to address luminance contrast between screen and background, then visual comfort is improved, but they are not widely used due to being unsightly and not tailored for digital screen viewing
Solution Approach 1:
The patent applies parameter changes by making the optical properties of the lens dependent on the angle of incidence rather than using a fixed gradient tint. The interferential multilayer coating creates angle-dependent transmission characteristics that can be precisely tailored for digital screen viewing conditions, while maintaining aesthetic appearance from the front view. This allows customization of the angle-dependent parameters to match specific digital viewing scenarios
Solution Approach 2:
The interferential multilayer coating serves multiple functions simultaneously: it maintains aesthetic appearance (functioning as a standard anti-reflective coating from the front), provides angle-dependent glare reduction for digital screens, and can be customized for different viewing conditions. This multi-functionality explains why it is widely adopted in digital lens applications
3Illumination intensity
If automatic screen brightness adjusting algorithms are used, then some luminance adjustment is achieved, but they have limits on luminance range and are not sensitive enough for quick adjustment
Solution Approach 1:
The optical article acts as an intermediary device between the user and the visual environment, providing passive optical compensation for luminance imbalance. Instead of relying on active electronic control of screen brightness (which has latency and range limitations), the optical article immediately and passively adjusts the light reaching the eye based on viewing angle, providing instant response without electronic processing delays
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
Reduces glare in peripheral vision, preserves central vision, and enhances visual comfort by minimizing visual fatigue in digital screen viewing scenarios.
Implementation Method 1
the front face comprises an interferential multilayer coating comprising a stack of dielectric layers
Implementation Method 2
providing the optical article with a mean visible light reflection factor Rv that is a function of the angle of incidence
Data Source
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AI summary
The invention concerns an optical article (10) comprising a front face (11) adapted to receive incident optical beams (20, 21) and a back face (12) through which transmitted optical beams (30, 31) exit to reach an eye (1), wherein the front face (11) comprises an interferential multilayer coating (13) comprising a stack of dielectric layers. According to the invention, the interferential multilayer coating (13) provides the optical article (10) with a mean visible light reflection factor Rv that is lower than or equal to 2.0% over a range of angle of incidence comprised between 0 and 20 degrees, and that is higher than or equal to 2.0% over a range of angle of incidence comprised between 40 degrees and 60 degrees, said optical article having a higher mean visible light transmittance (Tv) for low incidence angles and a lower mean visible light transmittance (Tv) for high incidence angles.