Abstract: A heat sink for a thermal ink jet printhead has improved resistance to the corrosive effects of ink by forming a chromate film on a copper plated metal substrate. In one described embodiment, a thermal ink jet printer is formed by bonding together a channel plate and a heater plate. Resistors and electrical connections are formed in the surface of the heater plate. The heater plate is bonded to a heat sink comprising a zinc substrate having a copper film plated on one surface. The copper plated heat sink is immersed in a chromic acid and water bath. Metal anodes are placed within the bath and a field is applied for a period of time sufficient to form a polymeric chromate film on the copper plated surface. The chromate film has improved resistance to ink corrosion and exhibits a stronger printhead to heat sink bonding strength.

Abstract: An ink cartridge for an ink jet printer has an ink supply in a housing and a printhead assembly fixedly attached thereto. The ink is contained in an absorbent material in the housing which is partitioned from the printhead assembly by a housing wall having a vent and an ink outlet. The ink flow path from the housing outlet to the printhead inlet is produced by a recess in the outer surface of the housing wall and a film member bonded thereover by a thermosetting adhesive. The film member has a slot therethrough, and the adhesive is the type not attacked by the ink. The surface of the film member opposite the surface bonded to the housing wall is coated with the same thermosetting adhesive which bonds to the printhead assembly surface containing the ink inlet.

Abstract: An interference fit elastomer covered roller including a shaft and an elastomeric tube covering the shaft, for use in contact with fluids includes fluid seals at the ends of the shaft comprising a topographical feature on the shaft defining at least one circumferential edge at a change in radius of hte shaft, effective for concentrating stress in the elastomeric tube around the edge to provide liquid sealing action.