Patent ID: 8542163

Claim:
A bistable, electrowetting picture element, comprising: a first fluid and a second fluid, immiscible with each other, within a space between a first substantially flat electro-wetable surface and a second substantially flat electro-wetable surface; said first fluid containing a pigment and being light absorbing; said second fluid being electroconductive or polar; said bistable electro-wetting picture element being switchable between a stable “OFF” state, said stable “OFF” state being maintained with no voltage being applied to, and no power being consumed by, said bistable element and a stable “ON” state, said stable “ON” state being maintained with no voltage being applied to, and no power being consumed by, said bistable electro-wetting picture element, and in which in said “OFF” state said first fluid adjoins a first region of said first surface and a light beam directed normal to, and toward, said second surface is substantially absorbed by said first fluid, while in said “ON” state said first fluid adjoins a second region of said second surface, and wherein said first region differs in area from said second region such that in said second state a majority of said light beam directed normal to, and towards, said second surface passes through said picture element; and wherein said “OFF” state is switched to said “ON” state by applying a transient voltage between a first electrode and a common electrode when said element is in said “OFF” state, and said “ON” state is switched to said “OFF” state by applying a transient voltage between a second electrode and a common electrode when said element is in said “ON” state.