Electrophoretic display devices

An electrophoretic display system, comprising:

• (a) a cell element including
• (i) an insulating fluid containing colloidal particles in suspension, said fluid and said particles having respective refractive indices that are different from each other, a substantial number of said particles having a charge of one polarity;
• (ii) a light transmissive first electrode;
• (iii) a light transmissive second electrode spaced from said first electrode, said fluid being disposed between said first and second electrodes;
• and
• (iv) a light transmissive first plate element disposed at one of said first and second electrodes;
• (b) a light transmissive second plate element disposed at the other of said first and second electrodes, said electrodes being disposed between said plate elements, said second plate element having a first surface adjacent to said electrode and a second surface more removed therefrom, said second plate element having a refractive index greater than that for said fluid;
• (c) means for selectively moving said colloidal particles to positions adjacent to said second light transmissive plate element to produce light coupling between said cell element and said second plate element;
• and
• (d) means for directing illumination to said second plate element, so that said illumination enters said second plate element and is totally internally reflected except for those positions at said first surface of said second plate element at which said particles are located.