Optical body, window material, and roll screen
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Solution Overview
Problem
Existing laminated structures for shielding solar radiation specularly reflect sunlight, contributing to increased air temperatures and exacerbating the heat island effect, as they reflect sunlight towards buildings and the ground, rather than effectively directing it away.
Innovation Solution
An optical body with a first transparent layer featuring quadrangular pyramid-shaped depressions and a wavelength-selective reflecting layer that selectively reflects specific wavelength bands, ensuring an average reflection angle of 30° or more in the same quadrant as incident light, thereby reducing heat absorption and directing heat away from buildings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a laminated structure for shielding against solar radiation is affixed to flat window glass, then solar radiation can be reflected, but sunlight is specularly reflected towards other buildings and the ground, causing localized temperature rise and heat island effect
Solution Approach 1:
The patent applies asymmetry by using quadrangular pyramid-shaped depressions with ridges that rhombically intersect, creating an asymmetric surface structure that redirects reflected light away from specular reflection paths. This asymmetric geometry ensures reflected sunlight is directed at angles of 30° or more away from the incident direction, preventing concentration on adjacent buildings and ground surfaces.
Solution Approach 2:
The patent employs curved surfaces through the quadrangular pyramid-shaped depressions formed on the optical transparent layer. These curved geometric features modify the reflection pattern by scattering incident sunlight in multiple directions rather than maintaining a single specular reflection angle, thereby reducing localized temperature concentration.
2Object-affected harmful factors
If an optical body with directional reflection is used to reflect light toward the sky, then heat island effect can be inhibited, but directional reflection performance with respect to specific wavelength bands needs enhancement
Solution Approach 1:
The patent applies local quality by forming a wavelength-selective reflecting layer specifically on the quadrangular pyramid-shaped depressions. This localized functional layer selectively reflects specific wavelength bands (such as infrared radiation) while the pyramid structure provides the directional reflection geometry, combining local material property modification with geometric structure optimization.
Solution Approach 2:
The patent uses composite materials by combining an optical transparent layer with quadrangular pyramid-shaped depressions and a wavelength-selective reflecting layer. This composite structure integrates the geometric light-redirection capability of the pyramid shape with the wavelength-selective optical properties of the reflecting layer, achieving enhanced directional reflection performance for specific wavelength bands.
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
Enhances directional reflection performance, reducing the heat island effect by efficiently reflecting heat-generating wavelengths away from buildings, thus lowering surrounding temperatures and improving energy efficiency.
Implementation Method 1
a wavelength-selective reflecting layer that is formed on the depressions and selectively reflects light of a specific wavelength band
Implementation Method 2
the laminated structure can only specularly reflect incident sunlight
Implementation Method 3
causes directional reflection of the light in a direction other than a specular reflection direction
Data Source
AI summary
An optical body includes a first optical transparent layer having quadrangular pyramid-shaped depressions, a wavelength-selective reflecting layer formed on the depressions and selectively reflecting light of a specific wavelength band, and a second optical transparent layer formed on the wavelength-selective reflecting layer. When (θ, ϕ) is taken as the incident angle (θ: angle between perpendicular line relative to second optical transparent layer acting as incident surface and light incident on incident surface; ϕ: angle between specific straight line within incident surface and component resulting from projection of incident light on incident surface), with respect to incident light that is incident on the incident surface from different ϕ directions at θ=60°, the optical body has an average reflection angle of reflected light to the same quadrant as the incident light of 30° or more.