System and method for servicing non-scanning printhead

A system for servicing a non-scanning printhead includes a servicing plate, a servicing component mounted on the servicing plate and adapted to service the non-scanning printhead, and a drive system adapted to move the servicing plate between a storage position and a service position such that the servicing component is spaced from the non-scanning printhead when the servicing plate is in the storage position and the servicing component is adapted to service the non-scanning printhead when the servicing plate is in the service position.

BACKGROUND

An inkjet printing system may include a printhead and an ink supply which supplies liquid ink to the printhead. The printhead ejects ink drops through a plurality of orifices or nozzles and toward a print medium, such as a sheet of paper, so as to print onto the print medium. Typically, the orifices are arranged in one or more arrays such that properly sequenced ejection of ink from the orifices causes characters or other images to be printed upon the print medium as the printhead and the print medium are moved relative to each other.

Use of the inkjet printing system may result in the accumulation of ink and particles, such as dust or paper fibers, on the printhead. To ensure quality print jobs, it is desirable that the accumulated ink and particles be removed from the printhead to prevent the accumulated ink and particles from dropping onto the print medium or obstructing the ejection of ink from the nozzles. In addition, during non-use of the inkjet printing system, the nozzles are exposed to air which, consequently, may cause the ink to dry out and clog the nozzles.

In order to ensure quality print jobs it would be desirable to service and maintain the printhead to avoid the aforementioned problems.

SUMMARY OF THE INVENTION

A system for servicing a non-scanning printhead includes a servicing plate, a servicing component mounted on the servicing plate and adapted to service the non-scanning printhead, and a drive system adapted to move the servicing plate between a storage position and a service position such that the servicing component is spaced from the non-scanning printhead when the servicing plate is in the storage position and the servicing component is adapted to service the non-scanning printhead when the servicing plate is in the service position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which embodiments of the invention may be practiced. In this regard, directional terminology such as “up,” “down,” “forward,” “backward,” “leading,” “trailing,” “above,” “below,” etc., is used with reference to the orientation of the figure(s) being described. Because components of the embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

FIG. 1illustrates one embodiment of an inkjet printing system10including a system for servicing a non-scanning printhead. Inkjet printing system10includes an inkjet printhead assembly12, an ink supply assembly14, a mounting assembly16, a print media transport assembly18, a service station assembly20, and an electronic controller22. In one embodiment, inkjet printhead assembly12includes one or more printheads24which eject drops of ink through a plurality of orifices or nozzles13and toward an embodiment of media, such as print medium19, so as to print onto print medium19. Print medium19includes any type of suitable sheet material, such as paper, cardstock, transparencies, Mylar, cloth, and the like. Typically, nozzles13are arranged in one or more columns or arrays such that properly sequenced ejection of ink from nozzles13causes characters, symbols, and/or other graphics or images to be printed upon print medium19as inkjet printhead assembly12and print medium19are moved relative to each other.

Ink supply assembly14supplies ink to inkjet printhead assembly12and includes a reservoir15for storing ink. As such, ink flows from reservoir15to inkjet printhead assembly12. In one embodiment, inkjet printhead assembly12and ink supply assembly14are housed together to form an inkjet cartridge or pen26(FIG.3). In another embodiment, ink supply assembly14is separate from inkjet printhead assembly12and supplies ink to inkjet printhead assembly12through an interface connection, such as a supply tube. In either embodiment, reservoir15of ink supply assembly14may be removed, replaced, and/or refilled.

Mounting assembly16supports inkjet printhead assembly12relative to print media transport assembly18. Print media transport assembly18positions print medium19relative to inkjet printhead assembly12. Thus, a print zone17is defined adjacent to nozzles13in an area between inkjet printhead assembly12and print medium19. In one embodiment, inkjet printhead assembly12is a non-scanning or fixed printhead assembly. As such, mounting assembly16fixes inkjet printhead assembly12at a prescribed position relative to print media transport assembly18. Thus, print media transport assembly18advances or positions print medium19relative to inkjet printhead assembly12.

Service station assembly20includes at least one servicing component for wiping, capping, spitting, and/or priming of inkjet printhead assembly12in order to maintain functionality of inkjet printhead assembly12and, more specifically, nozzles13, as will be further described below. Functions of service station assembly20rely on relative motion between service station assembly20and inkjet printhead assembly12.

Electronic controller22communicates with inkjet printhead assembly12, mounting assembly16, print media transport assembly18, and service station assembly20. Electronic controller22receives data23from a host system, such as a computer, and includes memory for temporarily storing data23. Typically, data23is sent to inkjet printing system10along an electronic, infrared, optical or other information transfer path. Data23represents, for example, a document and/or file to be printed. As such, data23forms a print job for inkjet printing system10and includes one or more print job commands and/or command parameters.

In one embodiment, electronic controller22provides control of inkjet printhead assembly12including timing control for ejection of ink drops from nozzles13. As such, electronic controller22defines a pattern of ejected ink drops which form characters, symbols, and/or other graphics or images on print medium19. Timing control and, therefore, the pattern of ejected ink drops is determined by the print job commands and/or command parameters.

In one embodiment, as illustrated inFIG. 2, print medium19is a continuous form or continuous web print medium19. As such, print medium19may include a plurality of continuous print medium sections30. Print medium sections30represent, for example, individual sheets, forms, labels, or the like which may be physically separated from each other by cutting or tearing along, for example, perforated lines191. In addition, print medium19may include a continuous roll of unprinted paper with print medium sections30individually delineated by indicia, openings, or other markings. Since inkjet printhead assembly12is fixed, print medium19moves relative to inkjet printhead assembly12during printing. More specifically, print medium19is advanced relative to inkjet printhead assembly12in a direction indicated by arrow32.

FIG. 3illustrates one embodiment of a portion inkjet printing system10. Inkjet printing system10includes a printhead24, a service station assembly20, a platen40, and a printhead mounting plate50. Platen40, as part of print media transport assembly18, supports print medium19so that print medium19may be advanced relative to platen40in a direction perpendicular to a plane defined byFIG. 3, as indicated by direction arrow42. Printhead mounting plate50, as part of mounting assembly16, is positioned to support printhead24relative to platen40and print medium19.

In one embodiment, printhead mounting plate50includes a printhead aperture52and a clearance aperture54(FIGS.3and11). Printhead aperture52receives printhead24such that printhead24extends through printhead aperture52towards print medium19. Clearance aperture54is sized and shaped to receive service station assembly20such that service station assembly20may be selectively moved into and out of printhead mounting plate50. Accordingly, service station assembly20is movably connected to printhead mounting plate50, as will be further described below.

In one embodiment, as illustrated inFIG. 3, service station assembly20includes a drive system60, a servicing plate62, and first and second servicing components64and66, respectively. Drive system60effectuates movement of servicing plate62relative to printhead mounting plate50and, therefore, printhead24, as described below, to service printhead24. Servicing plate62supports servicing components64and66and includes a leading end68and a trailing end70. Leading end68is located nearer printhead24than is trailing end70. Servicing components64and66are each mounted on and move with servicing plate62. Servicing components64and66and servicing plate62collectively form a service station67. In one embodiment, servicing components64and66are mounted adjacent to and/or toward leading end68of servicing plate62.

Servicing components64and66are positioned on servicing plate62such that each servicing component64and66interacts with or services printhead24when servicing plate62is in a corresponding service position. For example, servicing component64services printhead24when servicing plate62is in a first service position, and servicing component66services printhead24when servicing plate62is in a second service position. Notably, servicing plate62may support one servicing component or a number of servicing components, such as a wiper, a cap and a spring, and/or a spittoon, in a variety of different configurations and, therefore, may service printhead24from a variety of different service positions or combinations thereof.

In one embodiment, servicing component64may include a rubber blade or wiper72. Wiper72is supported by servicing plate62and extends upwardly (with respect to the orientation ofFIG. 3) from servicing plate62. As such, wiper72may be selectively passed across printhead24to scrape printhead24and remove any residual ink, collected fibrous material, or other debris that may collect on printhead24.

In one embodiment, servicing component66may include a cap74. Cap74is sized to cover a front face25of printhead24to seal and protect nozzles13(FIG. 1) from drying out during periods of non-use. In one embodiment, servicing component66may include one or more springs76which bias cap74against printhead24.

As described above, drive system60moves servicing plate62relative to printhead mounting plate50and, therefore, printhead24. In one embodiment, drive system60is connected to servicing plate62near trailing end70opposite of servicing components64and66such that drive system60does not interfere with the interaction between servicing components64and66and printhead24.

In one embodiment, as illustrated inFIG. 3, drive system60includes a drive block80, a drive element82, a drive feature84, and a drive actuator86. Drive block80is connected to and extends between servicing plate62and drive element82. Drive block80may be connected to servicing plate62directly or by a drive arm88, which extends along or near trailing end70of servicing plate62.

In one embodiment, drive feature84is associated with printhead mounting plate50and drive element82is connected to servicing plate62. Drive element82interacts with drive feature84to move servicing plate62relative to printhead mounting plate50. More particularly, drive element82and drive feature84interact to guide servicing plate62and, therefore, service station67between a storage position, as illustrated inFIG. 3, and one or more service positions.

In the storage position, servicing plate62is positioned in clearance aperture54and recessed at least partially within printhead mounting plate50. Thus, service station assembly20does not interfere with the spacing between printhead24and print medium19during the printing process. In the service positions, servicing plate62is displaced from clearance aperture54and positioned between printhead mounting plate50and platen40to facilitate servicing of printhead24with servicing components64and66.

In one embodiment, drive actuator86is coupled with printhead mounting plate50and drive block80to move drive block80and, therefore, servicing plate62as drive element82interacts with drive feature84. More specifically, drive actuator86is secured to printhead mounting plate50such that actuation of drive actuator86generates movement of drive block80relative to printhead mounting plate50. Alternatively, drive actuator86may be directly coupled with drive element82, drive arm88, or servicing plate62, rather than drive block80, to move servicing plate62relative to printhead24. Drive actuator86may include a ballscrew, a leadscrew, an air cylinder, a hydraulic cylinder, or other actuation device.

In one embodiment, drive element82includes a cam follower90and drive feature84includes a cam slot92. Cam follower90fits within and follows cam slot92to guide and move servicing plate62relative to printhead mounting plate50. In one embodiment, cam slot92is formed in a sidewall of printhead mounting plate50and cam follower90includes a pin which fits into cam slot92.

In one embodiment, cam slot92includes cam slot regions94,96, and98. Cam slot regions94,96, and98define a single slot which forms cam surfaces which guide cam follower90and move servicing plate62between the storage position and the service positions. In one embodiment, cam slot region94is oriented at a non-parallel angle with respect to cam slot region96for moving servicing plate62from the storage position to a first service position. In addition, cam slot region96communicates with cam slot region94and extends between cam slot region94and cam slot region98. Cam slot region96is oriented such that servicing plate62can move back and forth relative to printhead24to service printhead24. Furthermore, cam slot region98communications with cam slot region96opposite of cam slot region94and is oriented at a non-parallel angle with respect to cam slot region96for moving servicing plate62to a second service position.

In one embodiment, cam slot region94is longer and extends further upwardly from cam slot region96than cam slot region98. Thus, servicing plate62may be recessed within clearance aperture54of printhead mounting plate50when in the storage position. Notably, cam slot92may be formed in a number of configurations for supporting and guiding cam follower90and, consequently, servicing plate62in and between the storage position and one or more service positions.

In one embodiment, as illustrated inFIG. 3, inkjet printing system10includes a lift actuator100. Lift actuator100is coupled with printhead mounting plate50to selectively move printhead mounting plate50towards and away from platen40and, therefore, position printhead24relative to print medium19. While lift actuator100is illustrated as being coupled with printhead mounting plate50and platen40, it is understood that lift actuator100may be coupled with printhead mounting plate50and other components of inkjet printing system10so as to provide relative positioning between printhead mounting plate50and platen40.

In one embodiment, as illustrated inFIGS. 3 and 4, lift actuator100moves printhead mounting plate50between a printing position, as illustrated inFIG. 3, and a servicing position, as illustrated in FIG.4. In the printing position, printhead mounting plate50is spaced a distance D1from platen40. In the servicing position, printhead mounting plate50is spaced a distance D2from platen40. Notably, when printhead mounting plate50is in the printing position, printhead24is positioned to print onto print medium19. Conversely, when printhead mounting plate50is in the servicing position, printhead24is positioned to be serviced by service station assembly20. Thus, distance D2is greater than distance D1to facilitate positioning of servicing plate62between printhead mounting plate50and platen40for servicing of printhead24with servicing components64and66, as described below.

FIGS. 3-6illustrate one embodiment of servicing printhead24with service station assembly20.FIG. 3illustrates one embodiment of printhead mounting plate50when in the printing position and servicing plate62when in the storage position. Printhead mounting plate50remains in the printing position during a printing process. In one embodiment, when servicing plate62is in the storage position, servicing plate62is positioned in clearance aperture54of printhead mounting plate50. As such, servicing plate62is recessed at least partially within printhead mounting plate50and is positioned so that servicing plate62is held above (with respect to the orientation ofFIG. 3) front face25of printhead24. As such, service station assembly20does not interfere with the spacing between printhead24and print medium19during the printing process.

In one embodiment, as illustrated inFIG. 4, to service printhead24, lift actuator100effectuates movement of printhead mounting plate50to the servicing position. As such, printhead24is spaced a distance D3from platen40so that space is created between printhead24and platen40to facilitate servicing of printhead24.

Once printhead24is spaced from platen40, as illustrated inFIG. 4, drive actuator86is actuated to move drive system60so that servicing plate62moves relative to printhead mounting plate50. In particular, the initial motion imparted by drive actuator86translates cam follower90along cam slot92, namely along cam slot region94to cam slot region96. Since cam follower90is connected to servicing plate62via, for example, drive block80, movement of cam follower90along cam slot region94to cam slot region96induces movement of servicing plate62from the storage position, as illustrated inFIG. 4, to a first service position, as illustrated in FIG.5.

In one embodiment, as illustrated inFIG. 5, the first service position of servicing plate62enables wiper72to contact printhead24. The first service position may include a plurality of positions in which cam follower90is supported by cam slot region96such that drive actuator86moves cam follower90along cam slot region96to selectively move wiper72in and out of contact with printhead24. In one embodiment, drive actuator86may be selectively actuated in the directions indicated by double arrow87to move cam follower90along cam slot region96and selectively move wiper72back and forth across printhead24. Notably, the substantially horizontal orientation of cam slot region96facilitates back and forth movement of servicing plate62while maintaining contact between wiper72and printhead24.

As illustrated inFIG. 6, subsequent actuation of drive actuator86moves servicing plate62to a second service position. More particularly, servicing plate62is moved to the second service position as cam follower90is driven along cam slot region96to cam slot region98so that servicing plate62moves up and under printhead24permitting cap74to mate with and cap printhead24. In one embodiment, printhead aperture52is sized to receive wiper72so that cap74can effectively seal printhead24as servicing plate62moves up and under printhead24.

Drive actuator86may also be actuated to impart return movement of servicing plate62from the second service position back to the first service position and from the first service position back to the storage position. Otherwise stated, drive actuator86may be actuated to move cam follower90down cam slot region98, across cam slot region96, and up cam slot region94, thereby, returning servicing plate62to the storage position. Furthermore, servicing plate62may move from the first service position back to the storage position without moving to the second service position.

FIG. 7illustrates another embodiment of an inkjet printing system. Inkjet printing system10′ includes printhead24, service station assembly20, platen40, and printhead mounting plate50, as described above. Inkjet printing system10′, however, includes a lift actuator100′. Lift actuator100′ is coupled with printhead mounting plate50to move printhead mounting plate50relative to platen40. Lift actuator100′ distances or spaces printhead24from platen40and print medium19by tilting printhead mounting plate50away from platen40to position printhead mounting plate50in a printhead servicing position. As such, servicing station assembly20may service printhead24in the manner described above. It is understood that lift actuator100′ may also lift and tilt printhead mounting plate50away from platen40to position printhead mounting plate50in the printhead servicing position.

As illustrated in the embodiment ofFIGS. 3-7, drive feature84is associated with printhead mounting plate50and drive element82is connected to servicing plate62. More specifically, cam slot92is formed in printhead mounting plate50and cam follower90is secured to drive block80which, in turn, is connected to servicing plate62. As such, drive block80, cam follower90, and servicing plate62move as a unit. Thus, actuation of drive block80causes drive block80and, therefore, cam follower90to move within cam slot92relative to printhead mounting plate50to guide servicing plate62and, therefore, service station67between the storage position, as illustrated inFIGS. 3 and 4, and one or more service positions, as illustrated, for example, inFIGS. 5 and 6.

As illustrated in the embodiment ofFIGS. 8-10, however, drive element82is connected to printhead mounting plate50and drive feature84is associated with servicing plate62. More specifically, cam follower90is secured to printhead mounting plate50and cam slot92is formed in drive block80which, in turn, is connected to servicing plate62. As such, drive block80, cam slot92, and servicing plate62move as a unit. Thus, actuation of drive block80causes drive block80and, therefore, cam slot92to move along cam follower90relative to printhead mounting plate50to guide servicing plate62and, therefore, service station67between the storage position, as illustrated inFIG. 8, and one or more service positions, as illustrated, for example, inFIGS. 9 and 10.

In one embodiment, as illustrated inFIG. 11, inkjet printing system10, as does inkjet printing system10′, includes a plurality of printheads24and a plurality of service stations67each including a respective servicing plate62and one or more servicing components64and/or66. In this embodiment, printhead mounting plate50includes a plurality of printhead apertures52and a plurality of clearance apertures54. Each printhead24is received by a corresponding printhead aperture52such that each printhead24protrudes from a respective printhead aperture52toward platen40and print medium19(FIGS.3-10). Clearance apertures54are sized and shaped to allow service stations67to be selectively moved into and out of printhead mounting plate50between the storage position and one or more service positions, as described above.

In one embodiment, as illustrated inFIG. 11, printheads24and, therefore, printhead apertures52are spaced apart and staggered such that each printhead24is aligned with and/or overlaps at least one adjacent printhead24. In one embodiment, printheads24are arranged in a stair-step manner. In another embodiment, printheads24are arranged in a plurality of stair-step patterns.

Service stations67are arranged to correspond with the arrangement of printheads24such that each service station67can service a corresponding printhead24. For example, as illustrated inFIG. 11, a stair-step arrangement of printheads24results in a corresponding stair-step arrangement of service stations67. In one embodiment, service stations67are each joined to drive arm88such that movement of drive arm88causes simultaneous movement of service stations67.