| abstract |
The invention provides a working fluid for an electrophoretic image display device including a dispersion of a species of finely divided particles of an opaque dielectric material suspended in a suspension medium, each of the said particles which are transportable within the suspension medium under the influence of an electric field, has a chemical compound adsorbed on the surface thereof, the chemical compound is such that the molecules thereof exert an attractive force towards each other in the absence of the electric field. |