Reflective Display Panel Color Filter for Yellow Tint Compensation
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Solution Overview
Problem
Reflective display panels with a film thickness between 1200 Å and 1700 Å exhibit a yellowish background color due to the transparent electrode layer, affecting display quality.
Innovation Solution
A reflective display panel design with a color filter layer comprising three filter patterns, each with specific absorbance ranges in different wavelength bands, to control and improve the background color to a closer white appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the transparent electrode layer film thickness is controlled between 1200 Å and 1700 Å to achieve high conductivity, then the electrical conductivity is improved, but the background color becomes yellowish which deteriorates display quality
Solution Approach 1:
A color filter layer is introduced as an intermediary component between the transparent electrode layer and the liquid crystal layer. This color filter layer absorbs yellow light wavelengths while transmitting other visible light wavelengths, thereby compensating for the yellowish tint caused by the transparent electrode layer and achieving a whiter background color without changing the electrode thickness
Solution Approach 2:
The patent applies color filtering technology by designing a color filter layer with specific absorbance characteristics. The filter layer selectively absorbs yellow light (wavelengths around 570-590 nm) while transmitting other wavelengths, thereby changing the perceived background color from yellowish to white. This is achieved by controlling the absorbance values at different wavelengths as specified in the patent
2Reliability
If the film thickness is increased to improve conductivity, then electrical performance is improved, but the yellowish tint intensifies which worsens color accuracy
Solution Approach 1:
The color filter layer serves as a mediator that compensates for color distortion. By positioning this layer in the optical path between the transparent electrode and the viewer, it selectively removes yellow wavelengths that become more pronounced with increased electrode thickness, thereby maintaining color accuracy even when electrical performance is optimized through thicker films
Solution Approach 2:
The patent changes the optical parameters of the display system by introducing a layer with specific absorbance characteristics. The color filter layer has controlled absorbance values at different wavelengths (e.g., low absorbance in blue and green regions, high absorbance in yellow region), which compensates for the parameter changes (increased yellow tint) resulting from increased electrode thickness for improved conductivity
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 absorbance distribution of the filter patterns significantly reduces the yellowish tint, achieving a white background color by optimizing hue parameters a* and b* in the CIELAB color space.
Implementation Method 1
Absorbance of the first filter pattern in a wavelength range between 630 nm and 780 nm is less than 0.05, and absorbance in a wavelength range between 530 nm and 580 nm is greater than or equal to 0.25 and less than or equal to 0.9
Data Source
AI summary
A reflective display panel including a first substrate, a second substrate, a liquid crystal layer, a pixel driving layer, a color filter layer, and a polarizer. The pixel driving layer is provided with a reflective layer overlapping the color filter layer. Absorbance of a first filter pattern of the color filter layer is greater than or equal to 0.25 and less than or equal to 0.9 in a wavelength range between 530 nm and 580 nm. Absorbance of a second filter pattern of the color filter layer is greater than or equal to 0.8 and less than or equal to 1.25 in a wavelength range between 630 nm and 680 nm. Absorbance of a third filter pattern of the color filter layer is greater than or equal to 0.95 and less than or equal to 1.3 in a wavelength range between 580 nm and 630 nm.