Active Random Refraction Device for Wide Viewing Angle and Low Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing active polarization switching devices face a trade-off between achieving a high viewing angle and low driving voltage, as increasing the viewing angle necessitates higher driving voltages, and vice versa, due to the inherent characteristics of polymer stabilized cholesteric texture films and polymer dispersed liquid crystals.
Innovation Solution
An active random refraction device with a random structure made of an isotropic medium and a liquid crystal polymer, where the refractive index varies with polarization direction, and a polarization switching device that switches between orthogonal polarization directions, allowing for a low driving voltage and high response speed while maintaining a wide viewing angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the cell gap of the liquid crystal is increased to secure a viewing angle, then the viewing angle is improved, but the driving voltage increases
Solution Approach 1:
The device is divided into two independent parts: a random structure layer and a polarization switching device layer. The random structure layer is responsible for providing wide viewing angle characteristics, while the polarization switching device layer handles the switching function. This segmentation allows each component to be optimized independently, resolving the trade-off between viewing angle and driving voltage.
Solution Approach 2:
A random structure layer is introduced as an intermediary between the liquid crystal and the viewer. This random structure layer scatters light to provide wide viewing angle characteristics without requiring changes to the liquid crystal cell gap, thereby avoiding the increase in driving voltage that would result from increasing the cell gap.
2Ease of manufacture
If polymer dispersed liquid crystal is used to achieve simple manufacturing process, then ease of manufacture is improved, but high driving voltage is required to secure high viewing angle
Solution Approach 1:
The device separates the manufacturing-simple PDLC layer from the viewing angle control function by introducing a dedicated random structure layer. The PDLC layer maintains its manufacturing simplicity while the random structure layer provides the wide viewing angle characteristics, eliminating the need to increase cell gap and thus avoiding high driving voltage requirements.
3Illumination intensity
If polymer stabilized cholesteric texture film is used to reduce haze characteristics, then optical quality is improved, but high driving voltage is required to secure high viewing angle
Solution Approach 1:
The device separates the optical quality function (handled by the PSCT layer with low haze characteristics) from the viewing angle control function (handled by the random structure layer). This allows the PSCT layer to maintain its excellent optical quality without needing to increase cell gap, thereby avoiding high driving voltage requirements while the random structure layer provides wide viewing angle.
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 achieves a high viewing angle with a low driving voltage and fast response speed by separating the random structure and polarization switching device, enabling efficient control of coherence and eliminating color moire phenomena.
Implementation Method 1
a liquid crystal polymer aligned on the random structure and having refractive index characteristics that are varied according to the polarization direction of the light
Implementation Method 2
a polarization switching device configured to switch the polarization direction of the light between orthogonal first direction and second direction
Data Source
AI summary
An active random refraction device includes a random structure having the same refractive index characteristics regardless of polarization direction of light, a liquid crystal polymer on the random structure with refractive index characteristics changing according to polarization direction of the light, a polarization switching device, and a refractive surface with an inclination angle randomly distributed along the horizontal direction perpendicular to the incident direction of the light. The active random refraction device can be switched between a transmission mode and a refractive mode according to the polarization of the light.