Blue Color Filter Thickness Inversion for Display Grey Inversion
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Solution Overview
Problem
In high grayscale level displays, blue grey inversion occurs due to reduced light transmittance of the blue color filter in traditional color filter substrates, leading to poor display effects in TFT-LCDs.
Innovation Solution
A color filter substrate with a blue color filter having the smallest thickness, aligned at the end of each color filter unit, and with a larger area than red and green filters, is designed to enhance light transmittance and balance blue light with other colors, reducing blue grey inversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the blue color filter thickness is increased to improve light transmittance, then blue light transmittance is improved, but the film thickness uniformity and manufacturing precision deteriorate due to the sequential formation process
Solution Approach 1:
Instead of making the blue filter thicker than other colors (conventional approach), the patent inverts this by making the blue filter the thinnest among all color filters. This counterintuitive approach solves the blue grey inversion problem by allowing sufficient blue light transmission while maintaining manufacturing precision through the sequential formation process where the blue filter is formed first and then other filters are formed on top.
Solution Approach 2:
The patent changes the thickness parameter of the blue color filter from being the thickest (conventional) to the thinnest. Specifically, the blue filter thickness is set to 50-150 nm, while red and green filters are 150-250 nm and 200-300 nm respectively. This parameter change fundamentally resolves the light transmission issue without compromising manufacturing precision.
2Reliability
If the blue color filter area is increased to balance blue light with other colors, then color fidelity is improved, but the device complexity increases
Solution Approach 1:
The patent applies local quality by making the blue color filter have a different area than red and green filters. The blue filter area is specifically designed to be smaller (compensating for its thinner thickness) while maintaining appropriate light transmission. This localized adjustment in the blue filter region achieves color balance without requiring complex changes to the entire display structure.
Solution Approach 2:
The patent introduces asymmetry in the color filter structure by having the blue filter with different thickness and area compared to red and green filters. The blue filter thickness is 50-150 nm while red is 150-250 nm and green is 200-300 nm. This asymmetric design naturally balances the light transmission of different colors without adding device complexity.
3Ease of manufacture
If traditional sequential formation process is used to form color filters, then manufacturing simplicity is maintained, but blue grey inversion occurs at high grayscale levels
Solution Approach 1:
The patent applies preliminary action by forming the blue color filter first in the sequential process, before forming red and green filters. The blue filter is deposited and patterned first, then subsequent layers are formed on top. This preliminary formation of the blue filter with controlled thinness prevents blue grey inversion at high grayscale levels while maintaining the simplicity of the sequential manufacturing process.
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 solution improves color fidelity and display effect by increasing blue light transmittance, balancing it with other colors, and is industrially producible without altering existing production standards.
Implementation Method 1
the blue color filter has the smallest thickness among the color filters of each of the color filter units... improving color fidelity and display effect by increasing blue light transmittance
Data Source
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AI summary
Provided are a color filter substrate, a production method thereof, a display panel, and a display apparatus, which belong to the technical field of display. The color filter substrate has: a base substrate; a plurality of color filter units in an array arrangement on the base substrate, wherein each of the color filter units comprises at least two color filters of different colors, and the at least two color filters comprise a blue color filter; wherein the blue color filter has the smallest thickness among the at least two color filters of each of the color filter units.