Electrophoretic Fluid Color Saturation via Particle Spacing
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Solution Overview
Problem
Electrophoretic displays (EPDs) face challenges in achieving good saturated color and a limited range of colors, making it difficult to produce high-quality color representations.
Innovation Solution
The use of electrophoretic fluids comprising a solvent, specific dyes, white particles, and colored particles (red, green, blue, magenta, cyan, yellow, and their mixtures) that are oppositely charged, allowing for vertical movement to create multiple color states through particle spacing control, enabling dual-state or multi-color pixel displays with enhanced color saturation and reflectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If black particles and white particles with dyed solvent are used to generate high color saturation and high reflectivity, then color saturation and reflectivity are improved, but the color range is limited to Black vs. Colour or 3 state pixels of Black vs. Colour vs. White
Solution Approach 1:
The invention divides the particle system into multiple independently controllable colored particle sets (red, green, blue, magenta, cyan, yellow) instead of using a single black particle type. Each colored particle set can be independently positioned and controlled, enabling continuous color variation through different combinations and spacing arrangements, thus expanding the color range while maintaining high saturation and reflectivity.
Solution Approach 2:
The invention introduces particle spacing as an additional control dimension beyond just particle composition. By controlling the spacing between particles and between different colored particle sets, the system can dynamically adjust color properties and create intermediate color states, transforming a limited 3-state system into a multi-state continuous color control system.
2Ease of operation
If multiple sets of colored particles with different colors but same electric charge sign and similar electrophoretic mobilities are used, then particles move together showing one color state, but the ability to display multiple color states is reduced
Solution Approach 1:
The invention assigns different electric charge signs to different colored particle sets (e.g., red particles with positive charge, green particles with negative charge). This local differentiation in charge properties enables independent control of each colored particle set through applied electric fields, allowing selective positioning and combination of different colors to create multiple color states while maintaining ease of electrical control.
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 extends the color range and provides high color saturation in EPDs, allowing for multiple color states and improved reflectivity, enabling the creation of complex color combinations and tunable color gamuts suitable for various applications.
Implementation Method 1
electrophoretic fluids comprising a solvent, specific dyes, white particles, and colored particles (red, green, blue, magenta, cyan, yellow, and their mixtures) that are oppositely charged, allowing for vertical movement to create multiple color states through particle spacing control
Data Source
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AI summary
This invention relates to electrophoretic fluids comprising a solvent, a dye, white particles, and coloured particles selected from red, green, blue, magenta, cyan, yellow particles, and mixtures thereof, and electrophoretic display devices comprising such fluids.