Chromatic Reflective Unit for Bird-Safe Glass

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Solution Overview

Problem

Existing mirror systems fail to effectively replicate the natural sky and sun illumination, leading to inhomogeneities in color and luminance, which disrupt the desired optical and visual effects, and can be hazardous for birds due to mirror-like facades being mistaken for the sky.

Innovation Solution

A chromatic reflective unit comprising a reflective layer and a chromatic diffusing layer with nanoparticles embedded in a matrix, providing a higher specular reflectance in the red and diffuse reflectance in the blue, with specific refractive index ratios and particle distributions to mimic natural sky and sun illumination while minimizing the visibility of reflective surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a mirror-like reflective surface is used to enhance space perception and visual depth, then the aesthetic and optical effects are improved, but birds may mistake the reflective surface for the sky and collide with it

Engineering Contradiction:
Improvevisual depth perceptionVSAvoidbird collision risk
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating different optical properties at different locations within the same surface. The back surface remains highly reflective for interior space enhancement, while the front surface incorporates nanoparticles that scatter light to create sky-like appearance, preventing bird collisions. This spatial differentiation of optical properties resolves the contradiction between aesthetic reflection and bird safety.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining a reflective back surface with a front surface containing suspended nanoparticles in a binder. This composite structure enables the facade to simultaneously exhibit mirror-like reflection for interior enhancement and sky-like scattering for bird safety, resolving the contradiction through material composition rather than simple surface treatment.

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If a reflective layer is added to enhance visual perception, then the optical effect is improved, but inhomogeneities in color and luminance increase

Engineering Contradiction:
Improvevisual perceptionVSAvoidcolor and luminance uniformity
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by carefully controlling the nanoparticle size (10-100 nm), concentration, and refractive index to optimize the scattering properties. By adjusting these parameters, the front surface achieves uniform sky-like appearance while the back surface maintains consistent mirror reflection, resolving the contradiction between enhanced visual perception and color/luminance uniformity.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If nanoparticles are embedded in a matrix to provide chromatic diffusing properties, then the diffuse reflectance is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvediffuse reflectanceVSAvoidmanufacturing process
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent applies porous materials by using a porous substrate or matrix structure that can easily accommodate and distribute nanoparticles. This porous structure simplifies the manufacturing process compared to dense material infiltration, as nanoparticles can be more easily incorporated during coating or deposition processes while maintaining the desired optical scattering properties.

Inventive Principle:
Principle #31Porous 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

The chromatic reflective unit effectively reduces color and luminance inhomogeneities, providing a realistic sky and sun appearance while minimizing the risk of birds colliding with mirror-like facades by optimizing reflectance and diffusivity across the visible spectrum.

Implementation Method 1

the chromatic diffusing layer comprises a plurality of nanoparticles embedded in a matrix, and is configured to provide for a specular reflectance that is larger in the red than in the blue and for a diffuse reflectance that is larger in the blue than in the red

Methodology Applied
Scientific EffectRayleigh scattering: Rayleigh Scattering

Implementation Method 2

incident light passing the chromatic diffusing layer is reflected by the reflecting layer

Methodology Applied
Scientific EffectSpecular reflection: Reflection

Data Source

PatentEP3322933B1Chromatic reflective unit
Publication Date: 2022.12.28 COELUX
  • EP3322933B1 patent drawingFigure 1~2(b)
  • EP3322933B1 patent drawingFigure 3~7
  • EP3322933B1 patent drawingFigure 8~9

AI summary

A chromatic diffusing layer (510) comprises a plurality of nanoparticles (37) embedded in a matrix (39), for Rayleigh-like scattering with an average size d in the range 10nm≤d≤240nm, and a ratio between the blue and red scattering optical densities Log[R(450nm)3/Log[R(630nm)] of said chromatic reflective unit falls in the range 5≥γ≥2.5, where R(λ) is the monochromatic normalized specular reflectance of the chromatic reflective unit, which is the ratio between the specular reflectance of the chromatic reflective unit and the specular reflectance of a reference sample identical to the chromatic reflective unit except for the fact that the chromatic diffusing layer does not contain nanoparticles with the size d in the range 10nm ≤d≤240nm and for the direction normal to the reflective layer (508) of the chromatic reflective unit (506), the monochromatic normalized specular reflectance R(λ) of the chromatic reflective unit at a wavelength of 450nm is in the range from about 0.0025 to about 0.15, such as defined by the equations 0.0025≤R(450nm)≤0.15, 0.0025≤R(450nm) ≤0.05, 0.0025≤R(450nm) ≤0.04.