Patent ID: 8564873
Filing Date: 2013-10-22
Classification: G02B

Abstract:
1. A display apparatus having at least one electronically controllable display element that comprises: at least one nonpolar and at least two differently colored electrically conductive or polar liquids, at least the electrically conductive or polar liquids not being miscible with the nonpolar liquid, and the electrically conductive or polar liquids always being present physically separately from one another; a fluidically sealed volume having a visible sub-volume and at least two holding volumes, connected fluidically to the visible sub-volume, each for holding exactly one of the electrically conductive or polar liquids, in each of which at least a portion of the nonpolar liquid is located when the electrically conductive or polar liquid held in the respective holding volume is present in the visible sub-volume; and at least one voltage source that is applied to a first electrode arrangement comprising an electrode that is made in one piece and that covers the entire surface of the visible sub-volume, so that selectively the entire visible sub-volume may be permeated with an electric field, wherein the visible sub-volume being of planar embodiment, having dimensions which are selected in such a way that when the first electrode arrangement is in the zero-voltage state, the electrically conductive or polar liquids are drawn into the respective holding volume as a result of Young-Laplace pressure; and the display element furthermore comprising a second electrode arrangement for selectably retaining in their holding volumes those electrically conductive or polar liquids which are not intended to be moved into the visible sub-volume by an impingement of voltage on the first electrode arrangement, the second electrode arrangement including selection electrodes having a hydrophobic surface, which are arranged in the transition region from a holding volume to the visible sub-volume and, in the zero-voltage state, are not wetted by the electrically conductive or polar liquids.