Abstract: An ink-jet pen is disclosed that has a body of resilient felted polyurethane foam mounted in an ink chamber for ink retention and backpressure. A rectangular ink pipe extends from a bottom wall of the ink chamber between the walls of the ink chamber. A wire mesh filter is mounted to the ink pipe. The ink pipe and mesh filter extend into compressive contact with the foam to locally increase the capillarity of the foam. Any air that comes out of solution collects as a bubble in the rectangular ink pipe. This bubble does not block ink flow to the printhead, however, because the corners of the rectangular ink pipe provide a fluid capillary path. The bubble tends to form in a spheroid shape and does not extend into the corners of the ink pipe. In addition, rectangular filters are used, which reduces waste and expense compared to circular filters.

Abstract: The ink-jet print cartridge, which has an internal accumulator for maintaining appropriate back pressure within the pen reservoir, and a bubble generator for providing additional regulation, is refilled by a process that provides for the reestablishment of the necessary back pressure upon refilling and that prevents leakage arising as a result of the refilling operation.

Abstract: Disclosed is a novel inkjet print cartridge (pen) in which a body of polyurethane foam is inserted into an ink chamber of the pen for ink containment and backpressure. The ink chamber has a tall narrow aspect ratio. The body of polyurethane foam is felted in the width direction of the pen to have a width less than 20% of its pre-felted width. After felting, the body of foam is cut to have a "near net size" as the interior volume of the ink chamber. Specifically, the pre-insertion volume is less than about 130% of the interior volume of the ink chamber. The substantial felting in the width direction provides sufficient stiffness to the foam that it can be inserted into the tall, narrow aspect ratio ink chamber.

Abstract: Disclosed is a novel ink jet print cartridge (pen) in which polyurethane foam is used for ink containment and backpressure. The disclosed pen uses a flexible film of low friction material wrapped around the foam before insertion into the ink chamber. Once inserted, the film covers the two major faces of the foam and a portion of the bottom face of the foam. The disclosed pen has a tall narrow aspect ratio. The low friction film minimizes problems due to wrinkling and other compression anomalies in the foam, with the associated problems of ink stranding and reduction in the positive seal with the ink pipe. One embodiment of the film is absorbent and expands when exposed to ink.

Abstract: In order that ink leakage be reduced from a compressed foam storage ink container for an inkjet printer cartridge, at least one of the walls of the container is provided relief pockets having air spaces free of the compressed foam. At least one vent channel communicates between relief pockets and ambient air pressure to provide pressure equilibrium.

Abstract: The ink-jet print cartridge, which has an internal accumulator for maintaining appropriate back pressure within the pen reservoir, and a bubble generator for providing additional regulation, is refilled by a process that provides for the reestablishment of the necessary back pressure upon refilling and that prevents leakage arising as a result of the refilling operation.

Abstract: The back pressure of an ink pen is maintained by providing a capillary member adjacent a bubble generator. Regardless of the orientation of the pen, the capillary member maintains a quantity of ink adjacent an orifice defined by the bubble generator. The quantity of ink serves to supply a liquid seal formed in the orifice. As the back pressure within the ink pen rises to its maximum level, the liquid seal within the orifice is overcome and ambient air bubbles into the reservoir to lower the back pressure. As the back pressure returns to a desirable point, ink trapped by the capillary member enters the orifice to reseal the orifice.

Abstract: In one embodiment of the invention, a flexible tape has formed on it conductors for being connected to a printhead substrate. The conductors on the tape are coated with an insulating layer, and exposed ends of the conductors extend from the layer. A headland is formed on a plastic print cartridge for receiving the printhead substrate having the exposed conductors extending from one or more edges of the printhead substrate. An adhesive bead is formed on the headland so that when the printhead is properly positioned on the headland, the adhesive contacts the conductors to encapsulate and insulate one exposed side of the conductors. A second adhesive or encapsulant bead is deposited over the opposite side of the conductors to encapsulate and insulate the remaining exposed regions of the conductors. In this manner, the combined insulating action of the insulating layer and the two insulating adhesive beads prevents the conductors from being shorted together by ink which may flow in the vicinity of the conductors.

Abstract: An ink cartridge for a thermal ink jet printer containing a separate collapsible ink reservoir which is kept under negative pressure by a pressure regulator to prevent ink leakage. The collapsible reservoir has a pair of flexible plastic membrane ink bag sidewalls each connected at their periphery to form an ink bag and an ink pressure regulator in the bag. The pressure regulator comprises a pair of spaced parallel side plates urged apart by a spring toward the adjacent bag sidewalls whereby the reservoir is collapsible against the spring pressure to an essentially flat shape to permit substantially complete dispensation of ink from the bag. Inadvertent puncture of the thin bag walls by the regulator is prevented by a protective edge guard in the form of a layer of tough plastic bonded to the outer surfaces of the sideplates, the protective layers each having a peripheral edge which extends beyond the edge of the side plate to prevent the edges of the sideplates from directly contacting the bag walls.