Light Switching Module Using Variable Optical Axes
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Solution Overview
Problem
Conventional electronically controlled liquid crystal type smart windows face issues with uneven dispersion of liquid crystals and high power consumption, limiting their effectiveness in switching between transparent and scattering states.
Innovation Solution
A light switching module comprising a polarizing element with a variable first patterned retarder, a retardation element with variable optical axes and scattering microstructures, and a birefringent layer, where the refractive index of the substrate matches either the extraordinary or ordinary refractive index of the birefringent layer, allowing for adjustment between transparent and scattering states using a shifting mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If polymer-dispersed liquid crystals are used in conventional smart windows, then light transmittance can be controlled, but uneven dispersion of liquid crystals occurs and continuous power supply is required
Solution Approach 1:
The patent changes the fundamental operating parameter from continuous electric field maintenance to transient electric field application. The liquid crystal particles are switched using short-duration voltage pulses, and the scattering effect is maintained without continuous power supply. This eliminates both the power consumption issue and the need for continuous alignment maintenance, thereby improving both energy efficiency and dispersion uniformity.
2Ease of operation
If polymer-dispersed liquid crystals are used to control light transmittance, then switching between transparent and scattering states is achieved, but high power consumption under continuous power supply occurs
Solution Approach 1:
The patent employs periodic or pulsed electric field application instead of continuous power supply. Voltage pulses are applied transiently to switch the liquid crystal particles between transparent and scattering states, and the effect is maintained without continuous energy input. This periodic action principle reduces power consumption while preserving the light switching functionality.
3Reliability
If conventional liquid crystal smart windows are used, then light transmittance control is achieved, but uneven dispersion of liquid crystals limits effectiveness
Solution Approach 1:
The patent utilizes the inherent local scattering properties of individually dispersed liquid crystal particles. Each particle acts as an independent scattering center when activated, creating a uniform scattering effect across the entire panel. This approach eliminates the need for complex dispersion control mechanisms while achieving uniform light switching performance.
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 module enables efficient and controlled switching between transparent and scattering states by varying the optical axes and refractive indices, reducing power consumption and improving uniformity, while maintaining the light switching functionality.
Implementation Method 1
a birefringent layer disposed on the plurality of scattering microstructures of the substrate; the birefringent layer having an extraordinary refractive index (ne) parallel to the long-axis of the birefringent layer and an ordinary refractive index (no) parallel to the short-axis of the birefringent layer
Implementation Method 2
a polarizing element comprising a polarizer with an absorption axis
Data Source
AI summary
Disclosed is a light switching module comprising a polarizing element with a patterned retarder having a variable first optical axis; a retardation element having a variable second optical axis and a scattering microstructure; and a shifting means for adjusting the relative position of the polarizing element and the retardation element to switch the light switching module to transparent state or scattering state.