Partially Transparent Optics With Spectral Absorption for Glare Reduction

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Solution Overview

Problem

Existing glare reduction methods, such as anti-reflection coatings, are ineffective across varying incident angles, polarizations, and wavelengths, mechanically fragile, and impractical for large substrates, and fail to account for human visual psychophysics and the wide dynamic range of the human visual system.

Innovation Solution

Incorporating wavelength-dependent absorbing materials into partially transparent media to reduce actual and perceived glare by optimizing the selection of materials based on the field of view illumination, object reflectance, and geometry, while considering human visual sensitivities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If high intensity LEDs are used to provide sufficient illumination, then illumination intensity is improved, but glare is increased

Engineering Contradiction:
Improveillumination intensityVSAvoidglare
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by directing different portions of the LED spectrum to different spatial locations. The blue-rich short wavelength portion (400-480nm) is directed away from the driver's line of sight to minimize glare, while the yellow-rich long wavelength portion (480-650nm) is directed toward the road surface to provide effective illumination. This spatial separation of spectral components allows the system to maintain high overall illumination intensity while eliminating the harmful glare associated with blue light.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If blue light filtering coatings are applied to reduce glare, then glare is reduced, but manufacturing complexity increases

Engineering Contradiction:
ImproveglareVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts the blue light portion of the spectrum from the overall LED output and directs it separately from the yellow light. Instead of applying complex filtering coatings to the entire optical path, the system uses selective optical elements (lenses or reflectors) to spatially separate the blue-rich short wavelength light from the yellow-rich long wavelength light. This extraction approach simplifies manufacturing compared to applying multiple spectral filtering coatings, while still achieving effective blue light glare reduction.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-affected harmful factors

If spectral composition is optimized to reduce glare, then glare is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
ImproveglareVSAvoidmanufacturing precision
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent employs adjustable optical elements such as movable lenses or reflectors that can dynamically control the direction of blue-rich short wavelength light. This dynamic adjustment capability allows the system to optimize spectral distribution and glare reduction for different driving conditions without requiring extremely precise fixed manufacturing tolerances. The optical elements can be positioned to achieve the desired separation between blue light (directed away from driver) and yellow light (directed at road), accommodating normal manufacturing variations.

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

Effectively reduces actual and perceived glare by minimizing glare intensity and spatial distribution, maintaining image quality and contrast, and adapting to different lighting conditions.

Implementation Method 1

The first optical element may be a lens that refracts blue-rich short wavelength light away from the driver's line of sight

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

or a reflector that reflects blue-rich short wavelength light away from the driver's line of sight

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

The LED headlamp has a photobiological hazard function that is below a predetermined threshold value. The photobiological hazard function may be determined based on a spectral power distribution of the LED headlamp in a wavelength range from 400 nanometers to 1400 nanometers

Methodology Applied
Scientific EffectPhotobiological hazard: Photoelectric Effect

Data Source

PatentEP3934925B1Methods and devices for reducing actual and perceived glare
Publication Date: 2026.04.15 HIGH PERFORMANCE OPTICS INC
  • EP3934925B1 patent drawingFigure 1
  • EP3934925B1 patent drawingFigure 2
  • EP3934925B1 patent drawingFigure 3

AI summary

Partially transparent devices and methods that reduce actual and/or perceived glare by incorporating absorbing materials are described. Actual and/or perceived glare can be reduced by multi-path absorption in the device. Perceived glare is further reduced by accounting for the psychophysics of human visual perception as a function of wavelength, orientation, and field illuminance.