Abstract: An ink cartridge for an ink jet printer that supplies ink at a negative pressure is disclosed. The cartridge includes a cartridge housing having an upper chamber and a lower chamber and a first wall therebetween. The upper chamber has an aperture exposed to atmosphere and it also contains a capillary foam having a specifiable capillarity for absorbing ink. The lower chamber is airlocked until the ink level in the upper chamber is sufficiently low to allow the passage of air through the pores. A printhead is disposed at a vertical height greater than a top level of the lower chamber. A supply line is provided which conveys ink by capillary action of the nozzles to the printhead. A second capillary foam has a specifiable capillarity greater than the capillarity of the first capillary foam. The second foam is in fluidic communication with the upper and lower chambers and with the supply line.

Abstract: An ink cartridge for an ink jet printer that supplies ink at a negative pressure is disclosed. The cartridge includes a cartridge housing having an upper chamber and a lower chamber and a first wall therebetween. The upper chamber has an aperture exposed to atmosphere and it also contains a capillary foam having a specifiable capillarity for absorbing ink. The lower chamber is airlocked until the ink level in the upper chamber is sufficiently low to allow the passage of air through the pores. A printhead is disposed at a vertical height greater than a top level of the lower chamber. A supply line is provided which conveys ink by capillary action of the nozzles to the printhead. A second capillary foam has a specifiable capillarity greater than the capillarity of the first capillary foam. The second foam is in fluidic communication with the upper and lower chambers and with the supply line.

Abstract: In an ink jet printer, a printhead assembly comprising a printhead and an ink reservoir is mounted on a scanning carriage for movement across a recording medium. During printing, droplets of ink are expelled from ink channels within the printhead and the channels are replenished with ink which is drawn in from the reservoir. The reservoir is connected by supply and return lines to an ink source, and a pump is provided to deliver ink from the source along the supply line to prime the printhead and reservoir. To ensure that the reservoir is filled with ink during the priming operation, the outlet from the reservoir to the return line incorporates a flow restriction equal to, or greater than, that of the printhead.

Abstract: In an ink jet printer, an arrangement is provided for cleaning the face of the printhead in which the ink ejecting orifices are located. The arrangement includes a suction chamber directed towards, but spaced apart from, the printhead face to draw air over the printhead face and thereby remove any contamination such as ink residue and paper fibers. Advantageously, the suction chamber is formed in the cap member that is conventionally provided to engage the printhead and cap the ink ejecting orifices when the printhead is not in use. In that case, suction may also be applied to the cap member when it is in engagement with the printhead, to prime the printhead and/or to clear the ink ejecting orifices. Suction may then be maintained while the cap member is moved away from the printhead, so that air will be drawn over the printhead face.

Abstract: Means for venting the interior of the developer housing in a xerographic type copying or printing machine to control pressures therein comprising, a cover sealingly attached over a portion of the developer housing exterior and cooperative therewith to form an elongated relatively shallow exhaust chamber substantially coextensive with the developer housing, an exhaust port in the developer housing adjacent each end communicating the interior of the developer housing with the exhaust chamber, a discharge opening in the cover adjacent the center thereof, and filter means for trapping toner in the discharge opening; pressure air from the interior of the developer housing discharging through the exhaust ports and exhaust chamber to the discharge opening and the exterior, the sharp bends imposed on the air stream passing into, through, and out of the exhaust chamber causing toner entrained with the air stream to be separated from the air stream and deposited within the chamber for later removal.