Smart Window Diffraction Grating Spectral Control
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Solution Overview
Problem
Conventional window technologies fail to efficiently control solar heat transmission, often blocking daylight when only heat-blocking is desired, are expensive, difficult to implement on large enclosures, and cannot be optimized for different climatic conditions.
Innovation Solution
A programmable smart window system utilizing a blazed diffraction grating and total internal reflection to selectively separate and control infrared and visible radiation, allowing for efficient rejection or acceptance of solar heat based on seasonal needs, fabricated using industrially mature materials and processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If mechanical methods (awnings, louvers, blinds) are used to block direct solar radiation, then solar heat gain is reduced, but daylight transmission is also blocked
Solution Approach 1:
The invention segments the solar spectrum into different wavelength components (visible light and infrared radiation) and applies different handling to each segment. The smart window selectively transmits visible wavelengths while blocking infrared wavelengths, achieving heat rejection without compromising daylight transmission.
Solution Approach 2:
The patent applies local quality by making different parts of the electromagnetic spectrum experience different transmission properties. The smart window material has wavelength-dependent optical properties that allow visible light to pass through while reflecting or absorbing infrared radiation, creating localized spectral selectivity.
2Object-affected harmful factors
If spectrally selective coatings are applied to window glass, then solar heat gain is reduced, but the coating property is fixed once applied
Solution Approach 1:
The invention transforms the static spectral selectivity of conventional coatings into a dynamic system. The smart window can change its optical properties in real-time based on environmental conditions, allowing it to adapt to different seasons, times of day, and weather conditions. This dynamic capability enables the window to switch between heat rejection mode and heat acceptance mode as needed.
Solution Approach 2:
The patent utilizes parameter changes by varying the optical transmission characteristics of the smart window material based on external stimuli such as temperature, voltage, or light intensity. This allows the window to adjust its infrared transmission properties dynamically, providing seasonal adaptability that fixed coatings cannot achieve.
3Ease of operation
If conventional smart windows change transmittance for all wavelength ranges, then optical control is achieved, but spectral selectivity is lost
Solution Approach 1:
The invention segments the control mechanism to operate independently on different spectral bands. The smart window system can control visible light transmission and infrared radiation transmission separately, allowing selective heat rejection while maintaining desired daylight levels. This spectral segmentation enables independent optimization of each wavelength range.
Solution Approach 2:
The patent applies local quality by creating wavelength-specific control zones within the smart window structure. Different layers or components of the smart window material respond to control signals in a wavelength-dependent manner, enabling selective modulation of infrared transmission while preserving visible light transmission characteristics.
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 solution enables cost-effective, energy-efficient control of solar radiation transmission, reducing building cooling and heating costs while maintaining daylight, and can be optimized for various times, seasons, and locations.
Implementation Method 1
a diffraction grating for separation of different spectral regions for selective rejection and/or transmission of infrared, visible and ultraviolet radiation
Implementation Method 2
a smart window having a selectively patterned micro cell array that aids in reflecting incident light having a specific range of wavelengths, dispersed by a diffraction grating
Data Source
AI summary
In an aspect, described herein is a dynamically controllable optoelectronic smart window which utilizes a diffraction grating for selective transmission or rejection of a specific region of the electromagnetic spectrum, for example the infrared, near-infrared and/or visible regions. Window embodiments described herein may further utilize a selectively controlled and/or patterned total internal reflection layer to assist with the selective rejection of a specific spectral region while allowing for transmission of another specific spectral region. In another aspect, the present invention provides methods for dynamically controlling the transmission or rejection of solar near-infrared and/or visible radiation.