US Patent 7668488 Liquid electro-photography printing device binary ink developer having suction cavities

A binary ink developer (BID) for a liquid electro-photography (LEP) printing device includes a sponge roller to absorb unused ink. The BID includes a squeezer roller to release the unused ink absorbed by the sponge roller for reuse. The squeezer roller releases the unused ink absorbed by the sponge roller by compressing the sponge roller. Compression of the sponge roller results in ink foam. The BID includes a mechanism having a wall, and a housing that together with the wall of the mechanism defines a passageway between the housing and the wall. The passageway is exposed externally to the BID. The BID includes one or more suction cavities defined within the wall of the mechanism through which the ink foam moves back from the passageway.