Polarizing Plate Cutting Alignment for Uniform LCD Polarization
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Solution Overview
Problem
Existing methods for fabricating polarizing plates for LCD devices result in non-uniform polarization properties due to stress-induced distortion in the alignment of liquid crystal molecules, leading to color stains, decoloration, and reduced contrast ratios, particularly at the edges of the display area.
Innovation Solution
A method involving the use of a polarizing roll film cut with a knife having rectangular openings aligned parallel to the transmission axes, combined with an aging process under controlled temperature and humidity to minimize stress and ensure uniform alignment of the polarizing layers, thereby reducing distortion and enhancing polarization properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the polarizing roll film is stretched and wound to form transmission axes, then the polarization function is achieved, but the transmission axes become distorted and deviate from uniform alignment
Solution Approach 1:
The patent applies preliminary action by performing the cutting operation before the polarizing roll film is fully stretched and wound. By cutting the film while it is still in a less distorted state, the transmission axes maintain better alignment uniformity across different regions of the polarizing plate, resolving the contradiction between achieving polarization function and maintaining manufacturing precision.
2Temperature
If the polarizing plate is heated during use, then thermal expansion occurs in support layers, but stress is generated due to differential expansion causing distortion
Solution Approach 1:
The patent applies parameter changes by modifying the cutting parameters (timing and geometry of cuts) to compensate for thermal expansion effects. By cutting the polarizing roll film at specific stages before full stretching, the resulting polarizing plates have reduced internal stress that would otherwise be exacerbated by thermal expansion during use, thereby maintaining structural stability.
3Illumination intensity
If the transmission axes are not uniformly aligned, then color stains and decoloration occur, but the polarization property deteriorates
Solution Approach 1:
The patent applies preliminary action by performing the cutting operation before the polarizing roll film undergoes complete stretching and winding. This timing ensures that the transmission axes remain more uniformly aligned across different regions of the film, preventing both color stains and polarization property deterioration simultaneously.
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 method achieves a significant reduction in deviation of transmission axes, improving the contrast ratio and display quality by ensuring uniform polarization across the LCD device, including minimizing stress-induced distortions and maintaining polarization integrity even under heat exposure.
Implementation Method 1
a raw film (not shown) of large molecules is dyed by dipping in a solution of iodine (I2) or dichroic dye, and the dyed raw film is stretched to arrange the iodine (I2) molecule or the dichroic dye molecule parallel to a stretch direction
Implementation Method 2
the dyed raw film is stretched to arrange the iodine (I2) molecule or the dichroic dye molecule parallel to a stretch direction
Implementation Method 3
the first and second support layers 13a and 13b expand because of heat
Data Source
AI summary
A method of fabricating a polarizing plate includes: providing a polarizing roll film having transmission axes; and cutting the polarizing roll film with a knife having a plurality of openings each having a rectangular shape to form a plurality of polarizing plates, the plurality of openings parallel to the transmission axes.