TIR-Modulated Display With Conformal Electrodes and Micro-Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Beaded outward sheet displays face issues with non-uniform distribution of TIR-frustrating particles, particle settling, and non-uniform electric fields, leading to suboptimal contrast ratios and image quality over time.
Innovation Solution
Implementing a system with tethered particles, varying electrophoretic mobilities, and a polymer-dispersed low refractive index liquid medium, along with micro-cells and microcapsules to ensure uniform particle distribution and prevent settling, and conforming the rear electrode to the beaded front plane electrode to stabilize the electric field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If particles are suspended in low viscosity liquid medium, then particle mobility for TIR frustration is improved, but particle settling occurs over time leading to non-uniform distribution
Solution Approach 1:
The patent changes the physical parameter of the liquid medium by increasing its viscosity through polymer addition. This allows particles to maintain mobility for TIR frustration while preventing settling and non-uniform distribution over time, resolving the contradiction between speed and stability.
Solution Approach 2:
The patent creates a composite liquid medium by combining polymer materials with low-viscosity base liquid. This composite structure provides both the mobility enhancement from the polymer network and the settling prevention, simultaneously addressing particle mobility and distribution uniformity.
2Force
If electrodes are positioned close to beaded surface, then electric field strength for particle actuation is improved, but electric field non-uniformity increases
Solution Approach 1:
The patent introduces intermediary structures (micro-cells, spacers, or conformal coatings) that create locally uniform electric field regions between the electrodes and beaded surface. These structures ensure consistent particle actuation across different areas while maintaining strong overall electric field strength.
Solution Approach 2:
The patent uses intermediary elements such as spacers, micro-cells, or conformal coatings positioned between the electrodes and beaded surface. These intermediaries mediate the electric field distribution, ensuring both sufficient field strength for particle actuation and uniformity across the display area.
3Illumination intensity
If high refractive index beads are used, then TIR reflection efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent modifies the optical parameters of the system by selecting specific refractive index values for beads and surrounding media. This optimization allows achieving high TIR reflection efficiency while tolerating variations in bead packing, thereby reducing manufacturing precision requirements.
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
Enhances the uniformity of particle distribution, prevents particle migration, and maintains high contrast ratios by ensuring consistent TIR frustration across the display, thereby improving the long-term stability and performance of beaded outward sheet displays.
Implementation Method 1
a low refractive index liquid medium with suspended electrophoretic particles
Implementation Method 2
TIR-frustrating medium 20...A bead:liquid TIR interface is thus formed. Medium 20 contains a finely dispersed suspension of light scattering and/or absorptive particles 26
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3C
AI summary
A display comprises: an optically transparent reflective sheet having a hemispherical beaded inward surface and an opposed outward surface; a first fluid to contact the beaded surface; a rear support disposed on an opposite side of the first fluid; a plurality of charged electrophoretically mobile particles suspended in the first fluid; and means for applying a voltage across the first fluid to selectively move the particles closely adjacent the beaded surface to frustrate total internal reflection at the beaded surface of light rays passing through the reflective sheet; the first fluid having an index of refraction smaller than the index of refraction of the reflective sheet such that the light passing through the reflective sheet substantially undergoes total internal reflection at the beaded surface when the particles are not closely adjacent the beaded surface; wherein the means for applying a voltage comprises a first electrode and second electrode; and further comprising a plurality of walls extending from the reflective sheet toward the rear support and separating the first fluid into a plurality of micro-cells isolated from one another by the walls.