US Patent 7413300 Recirculation assembly

An ink recirculation assembly includes a main ink inlet configured to receive ink from an ink source, a main ink outlet configured to direct ink toward an ink source, and a channel extending from the main ink inlet to the main ink outlet. The channel includes an inlet portion and an outlet portion. A pressure differential is formed across the inlet and outlet portions, for example, by a constrictor separating said portions. The inlet portion is configured to move ink from the main ink inlet to openings formed in the inlet portion, said openings configured to direct ink toward ink inlet channels for each of multiple printhead modules. An outlet portion is configured to move ink away from openings formed in the outlet portion toward the main ink outlet, said openings configured to receive ink from ink outlet channels for each of the multiple printhead modules.