Waveguiding Substrate Light-Deflecting Grooves One-Way Visibility
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Solution Overview
Problem
Existing window technologies fail to effectively provide one-way visibility control, allowing external observers to see inside while preventing internal views of the exterior, thus compromising privacy.
Innovation Solution
A visibility control device with a waveguiding substrate featuring microscopic light-deflecting grooves that deflect light outward, creating a dazzling effect for external observers while allowing clear internal views, utilizing a planar waveguide with light sources and grooves that appear as a uniform surface to prevent individual groove discernment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a traditional transparent window is used, then clear visibility in both directions is achieved, but privacy protection is compromised as external observers can see inside
Solution Approach 1:
The waveguiding substrate incorporates light-deflecting grooves that create localized light deflection zones. These grooves have specific geometric properties (width smaller than 10 μm, distance between adjacent grooves smaller than 0.6 mm) that cause light to be deflected preferentially in one direction, creating different optical qualities for internal and external observers
Solution Approach 2:
The light-deflecting grooves are designed with asymmetric light deflection characteristics. The grooves deflect light primarily towards the outside region, creating an asymmetric optical effect where the substrate appears as a clear window to internal observers but as a bright luminous area to external observers, thereby providing one-way visibility control
2Object-affected harmful factors
If an optically diffusing layer is added to prevent external viewing, then privacy is protected, but optical transmittance and view clarity are reduced
Solution Approach 1:
The waveguiding substrate contains an array of light-deflecting grooves that form a porous-like structure at the micro-scale. This groove array allows the substrate to control light propagation directionally while maintaining high optical transmittance, as the grooves are sufficiently narrow and closely spaced to not significantly block light transmission
3Object-affected harmful factors
If light-deflecting grooves are made larger to improve light deflection effect, then privacy protection increases, but the grooves become visible and obstruct the clear view from inside
Solution Approach 1:
The groove dimensions are optimized within specific parameter ranges: groove width smaller than 10 μm and distance between adjacent grooves smaller than 0.6 mm. These parameter choices ensure that the grooves are below the resolution threshold of human vision, making them imperceptible to internal observers while still being sufficient to deflect light effectively for external observers
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 device ensures privacy by preventing external observers from viewing inside while allowing internal individuals to see outside, with high optical transmittance and minimal optical attenuation, maintaining a clear and unobstructed view internally.
Implementation Method 1
The waveguided light is confined to the substrate by total internal reflection
Implementation Method 2
The substrate may comprise a plurality of light-deflecting grooves to extract light from the waveguide and project deflected light towards an outside region
Data Source
Figure 1a~1b
Figure 2a~2c
Figure 3a~3d
AI summary
A visibility control device (500) comprises:- one or more light sources (LED1) to provide input light (B0),- a waveguiding substrate (SUB1), which has a first major surface (SRF1) and a second major surface (SRF2),- a plurality of light-deflecting grooves (G1) implemented on at least one major surface (SRF1, SRF2) of the substrate (SUB1),wherein the device (500) is arranged to form guided light (B1) by coupling the input light (B0a) into the substrate (SUB1), wherein the grooves (G1) are arranged to form deflected light (B2) by coupling the guided light (B1a) out of the substrate (SUB1) through the second major surface (SRF2) of the substrate (SUB1).