Polarization Selective Optic for Glare Control
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Solution Overview
Problem
Conventional luminaires experience glare issues due to Fresnel reflections when unpolarized light strikes wet or polished surfaces, which can be visually disturbing and dangerous, especially in outdoor settings like streetlights.
Innovation Solution
Incorporating a polarization selective optic with a liquid crystal lenticular array and quarter waveplate, or a polarizing meta-lens, to steer transversely magnetic (TM) waves to the far field and transversely electric (TE) waves to the near field, reducing glare by controlling the polarization state of light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If unpolarized light is used for illumination, then the illumination intensity is high, but glare is generated due to Fresnel reflections on wet or polished surfaces
Solution Approach 1:
The patent changes the polarization parameter of light by using a polarization selective optic to convert unpolarized light into polarized light with specific orientation, thereby reducing Fresnel reflections and glare while maintaining illumination intensity
Solution Approach 2:
The patent converts the harmful effect of light reflection into a beneficial outcome by using polarization control to redirect reflected light away from observers, transforming glare into useful illumination that does not disturb viewers
2Object-affected harmful factors
If a polarization selective optic is added to control glare, then glare is reduced, but the device complexity increases
Solution Approach 1:
The patent introduces a polarization selective optic as an intermediary component between the light source and the environment, which selectively controls polarization states to reduce glare without requiring complex active control systems
Solution Approach 2:
The polarization selective optic is implemented as a separate modular component that can be integrated into existing luminaire designs, allowing glare control functionality to be added without redesigning the entire lighting system
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
This solution effectively minimizes glare by directing TM waves at grazing angles to the far field and TE waves at non-grazing angles, reducing Fresnel reflections and improving visibility, while maintaining high optical efficiency.
Implementation Method 1
the polarization selective optic converts incoming light rays into polarized light rays
Implementation Method 2
When unpolarized light strikes a wet surface (e.g., a road after rainfall) or a polished surface at a high angle between the unpolarized light and the surface, a strong Fresnel reflection is created
Implementation Method 3
the polarization selective optic outputs a polarized beam pattern for illumination lighting
Data Source
AI summary
An example lighting device includes a luminaire having an illumination light source including an illumination light source configured to be driven by electrical power to emit incoming light rays. Luminaire further includes a polarization selective optic coupled to the illumination light source to receive the incoming light rays emitted by the illumination light source and output polarized light rays for illumination lighting. Based on the incoming light rays, the polarization selective optic outputs the polarized light rays including a TM wave. Polarization selective optic steers the TM wave to be outputted to a far field at a grazing angle. Polarization selective optic steers a substantially non-TM wave away from the far field at the grazing angle. Lighting device further includes an illumination light source driver to control a light source operation of the illumination light source.