LCD Color Conversion Layer Placement for Contrast
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Solution Overview
Problem
The polarization state of emitted light from down-conversion fluorescent materials in liquid crystal displays (LCDs) changes due to polarization characteristics, leading to light leakage in dark states and reduced contrast.
Innovation Solution
A liquid crystal display device is designed with a color conversion layer positioned on the side of the upper polarizer away from the liquid crystal layer, ensuring that polarized light is not affected by the color conversion layer before entering the upper polarizer, thus maintaining polarization state and preventing light leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the color conversion layer containing down-conversion fluorescent material is provided in the color filter substrate, then the color conversion function is improved, but the polarization state of emitted light changes causing light leakage in dark state and reduced contrast
Solution Approach 1:
The patent divides the color conversion layer into multiple sub-layers, each containing fluorescent materials with different excitation wavelengths. This segmentation allows each sub-layer to be optimized for specific wavelength conversion while maintaining overall polarization stability, preventing the light leakage issue that occurs with a single-layer design
Solution Approach 2:
The patent introduces a polarization maintaining layer between the color conversion layer and the liquid crystal layer. This intermediary layer acts as a mediator that preserves the polarization state of light passing through the color conversion layer, preventing the polarization changes that cause dark state light leakage and contrast reduction
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 configuration significantly improves the contrast of the LCD by preventing light leakage in dark states, enhancing the display's overall performance and market competitiveness.
Implementation Method 1
a color conversion layer containing a color conversion material, such as down-conversion fluorescent material
Implementation Method 2
an upper polarizer arranged on a side of the second substrate away from the first substrate
Data Source
AI summary
The present application provides a liquid crystal display device. The liquid crystal display device includes a first substrate, a second substrate, a liquid crystal layer, an upper polarizer, a color conversion layer and a third substrate. The second substrate is arranged opposite to the first substrate. The liquid crystal layer is arranged between the first substrate and the second substrate. The upper polarizer is arranged on a side of the second substrate away from the first substrate. The color conversion layer is arranged on a side of the upper polarizer away from the second substrate. The third substrate is arranged on a side of the color conversion layer away from the upper polarizer.