PDLC Film Structure with Segmented Electrodes for Fast Response
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Solution Overview
Problem
Conventional PDLC films exhibit a short rise time but a long fall time due to low anchoring energy of the polymer matrix on liquid crystal molecules, leading to slow return to the scattering state when the voltage is removed.
Innovation Solution
Incorporating a second thin film field effect transistor and transparent electrode on the PDLC film structure, allowing for controlled polarity changes between the electrodes to generate a lateral electric field, facilitating faster return to the scattering state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a conventional PDLC film uses a larger liquid crystal ratio with larger liquid crystal mesh, then the rise time is shortened (faster response when voltage is applied), but the fall time is prolonged (slower return to scattering state when voltage is removed)
Solution Approach 1:
The patent segments the electrode structure by introducing a second transparent electrode and dividing control into multiple independent thin film field effect transistors (first TFT and second TFT). This segmentation allows independent control of different electrode regions, enabling the application of different polarities to different areas. The segmented electrode control facilitates the generation of lateral electric fields that accelerate the return of liquid crystal molecules to the scattering state, thereby reducing fall time while maintaining fast rise time.
Solution Approach 2:
The patent applies inversion by reversing the polarity configuration between the first and second transparent electrodes. Instead of applying the same polarity to both electrodes (conventional approach), the patent applies opposite polarities through the first and second TFTs. This polarity inversion creates a lateral electric field that acts in the opposite direction to the vertical field, effectively pushing liquid crystal molecules back to their random scattering state more rapidly, thus solving the long fall time problem.
2Speed
If the anchoring energy of the polymer matrix on liquid crystal molecules is reduced, then the rise time is shortened, but the fall time is lengthened
Solution Approach 1:
The patent introduces dynamic control through the use of thin film field effect transistors that can rapidly switch between different states. The first and second TFTs dynamically adjust the polarity and magnitude of electric fields applied to different electrode regions. This dynamic control allows the system to optimize the electric field configuration during both the rise phase (voltage application) and fall phase (voltage removal), enabling fast response times without being constrained by the static anchoring energy characteristics of the polymer matrix.
Solution Approach 2:
The patent changes the electrical parameters by applying different polarities and magnitudes of voltage to different electrode regions through the first and second TFTs. By dynamically adjusting these electrical parameters, the system creates varying electric field configurations that compensate for the low anchoring energy condition. The parameter changes in voltage polarity and magnitude enable rapid reorientation and return of liquid crystal molecules, addressing both the rise time and fall time requirements.
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 approach reduces the overall response time by enabling quicker transition of liquid crystal molecules from the transmission to the scattering state, addressing the long fall time issue in conventional PDLC films.
Implementation Method 1
When a voltage is applied, the liquid crystal molecules are arranged along the direction of the electric field, so that the incident light is not refracted and reflected but is transmitted out
Implementation Method 2
This material can achieve an electro-optical response characteristic by using the anisotropy of the liquid crystal molecules
Implementation Method 3
the incident light is repeatedly refracted and reflected at the interfaces between the liquid crystal molecules and the polymer matrix
Implementation Method 4
the incident light is repeatedly refracted and reflected at the interfaces between the liquid crystal molecules and the polymer matrix
Implementation Method 5
exhibiting a milky scattering state
Data Source
AI summary
A PDLC film structure, a manufacturing method and a controlling method thereof are provided. The PDLC film structure comprising: a first substrate and a second substrate disposed facing each other; and a PDLC layer filled between the first substrate and the second substrate. A transparent electrode is provided on a surface of the first substrate which faces the second substrate, and a plurality of control units are provided on a surface of the second substrate which faces the first substrate, each control unit comprising a first thin film field effect transistor and a first transparent electrode connected thereto, and a second thin film field effect transistor and a second transparent electrode connected thereto.