US Patent 7032994 Interconnect circuit

A print cartridge includes a cartridge body having a lower portion and a vertical wall. A printhead is attached to the lower portion of the cartridge body. A contact array having a first pair of columnar arrays of contact areas and a second pair of columnar arrays of contact areas is disposed on the vertical wall of the cartridge. The columnar arrays extending along at least one half of the height of a region occupied by the contact array. The columnar arrays of each pair of columnar arrays converge toward each other in a direction toward the lower portion of the cartridge body.