A capping device for an ink jet printer includes a cap supported on a cap support member adapted to press the cap against a print head with a uniform pressure distribution despite variation in the positional relationship between the print head and the cap support member. The uniform pressure distributed is enhanced by supporting the cap by the support member in such a manner to permit the cap to pivot in at least two degrees of freedom. After the cap is sealed around an ink orifice of the printer, a preliminary suction operation reduces the pressure within a cavity defined by the cap and the print head. The pressure within the cavity is then returned to atmospheric pressure and then reduced again, but to a level which will not interfere with the ink meniscus level in the print head. The first period of suction lasts longer than the second suction period. By providing the capping device with tubes which resist the corrosive effects of ink and prevent gas from penetrating therethrough, excessive air buildup within the print head can be avoided.
A service station servicing an ink-jet printhead of an ink-jet printing system. The service station includes a sled structure, and an elevator mechanism coupled to the sled structure for moving the sled structure between a rest position and a sled capping position. A printhead cap is supported on the sled structure, and is movable relative to the sled structure for movement between a retracted position and a printhead capping position. The cap is adapted to surround and seal the printhead nozzles when the sled has been moved to the sled capping position and the printhead cap has been moved to the printhead capping position. A piston is carried by the sled structure, and the printhead cap is mounted to the piston. An actuating mechanism moves the piston from a retracted position to an extended position, wherein the printhead cap is positioned at the printhead capping position when the piston is moved to the extended position. The sled structure includes a set of sled datum structures adapted to mate with a corresponding set of datum features formed in a printhead carriage structure when the carriage structure is positioned at the service station as the sled structure is moved from the rest position to the sled capping position. The actuating mechanism is adapted to move the piston to the extended position after the sled structure has been moved from the rest position to the sled capping position.
An ink jet printer and control method therefor efficiently eliminates temporary ink eject defects during print interruptions. A time interval, i.e., the time lapse between a previous ink ejecting operation and a present ink ejecting operation, is evaluated before printing. If the time interval is less than a first time reference value (t1), an ink purging operation is not performed or is performed only a first minimum number of times. If the time interval is between first and second time reference values (t1.ltoreq.TI<t2), ink purging is executed a second number of times. If the time interval is greater than or equal to the second time reference value (t2.ltoreq.TI), ink purging is executed a third number of times that is less than the specified second number of times.
A dual pivoting wiper system cleans the nozzle face plate of an inkjet printhead, particularly one that dispenses a pigment based ink. An inkjet printing mechanism has a printhead service station including a sled that moves from a rest position to a wiping position. The wiping system includes a support arm with proximate and distal ends, with the proximate end pivoted to the sled and the distal end pivotally supporting an upright wiper blade. The arm is spring-biased to push the wiper blade into engagement with the printhead. During wiping, the printhead is engaged by wiper blade and the blade remains relatively upright. Any spacing variations between the printhead and the sled are accommodated by spring flexure, and any lack of parallelism of the printhead from a nominal plane is primarily accommodated by pivoting of the blade at the distal end of the support arm.
An ink jet recorder includes an ink jet head, a cap for covering the head, and a suction pump for sucking through the suction port of the cap the ink remaining between the head and cap. The cap surface can turn on an axis between a position in parallel with the jet surface of the head and a position inclined with respect to the jet surface. The cap is biased to incline at least before the cap surface contacts with the jet surface. The turning axis is positioned between a first reference plane and a second reference plane. The first plane includes the cap surface at the parallel position. The second plane is parallel with the first plane, and includes the point on the cap surface which contacts first with the jet surface. The vertical position of the cap surface does not shift between the start and end of the contact. The cap suction port is positioned below the jet ports in the jet surface.
This invention concerns a printhead capping mechanism for preventing evaporation of ink from a printhead when it is not in use. The invention has utility, for instance, in a color printer which uses a drop-on-demand inkjet printhead. The mechanism includes a cap fitted with an elastomeric seal to seal against the face of the printhead, and a sponge to catch drops ejected from the printhead during the nozzle cleaning cycle. The mechanism also includes an actuating structure operable to selectively move the cap between an engaged position to press against the printhead and a disengaged position spaced away from the printhead.
