Movable web support and cap

A method and apparatus raise and lower a web support and move a cap over and above the web support.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application is related to co-pending U.S. patent application Ser. No. 12/200,927 filed on the same date herewith by Tanya V. Burmeister, Antonio Gomez and Mark D. Groenenboom and entitled WEB, the full disclosure of which is incorporated by reference.

BACKGROUND

Print head servicing stations sometimes include webs and caps for servicing the print heads. Size objectives sometimes limit a size of the web, necessitating more frequent and costly replacement of the web.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

FIGS. 1-3schematically illustrate printing system10according to one exemplary embodiment. Printing system10generally includes drum12, rotary actuator13, media supply14, media output16, print heads18, carriage20, actuator21, service station22and controller24. Drum12generally comprises an elongated cylinder configured to be rotationally driven about axis26by rotary actuator13while transporting media, such as paper, about axis26relative to print heads18. Rotary actuator13comprises a source of torque, such as a motor, operably coupled to drum12by a transmission (not shown).

Media supply14, schematically shown, comprises a mechanism configured to supply media to drum12. In one embodiment, media supply14comprises a mechanism configured to pick an individual sheet of media from a stack of media and to supply the individual sheet to drum12such that the sheet is wrapped at least partially about drum12. Media output16, schematically shown, comprises a mechanism to withdraw printed upon media from drum12and to transport withdrawn media to and contain withdrawn media within an output tray, bin or the like.

Print heads18comprise devices configured to dispense imaging material or fluid, such as ink, upon the medium held by drum12. In one embodiment, print heads18comprise piezo electric print heads. In another embodiment, print heads18comprise thermal inkjet print heads. As shown byFIG. 2, print heads18are arranged in an arc about axis26. As a result, print heads18are configured to print across a larger area of the media supported by drum12. In the particular embodiment, drum12has an outer surface30also arranged in an arc about axis26. Print heads18are arranged in an arc substantially identical to the arc in which surface30extends.

Carriage20comprises one or more structures configured to support print heads18in the arcuate arrangement. In addition, carriage20is configured to movably support print heads18along axis26. Actuator21comprises a linear actuator configured to move carriage20and print heads18in the directions indicated by arrows27,28so as to selectively position print heads18opposite to the media held by drum12or opposite to service station22. In one embodiment, actuator21may comprise a motor configured to drive a toothed pulley in engagement with a toothed belt coupled to carriage20. In another embodiment, actuator21may comprise other forms of a linear actuator using rack and pinion arrangements, hydraulic, pneumatic or electrical means. Although system10is illustrated as including five print heads supported by a single carriage20, system10may alternatively include a greater or fewer number of such print heads18supported by one or more carriages20. For example, in another embodiment, a separate carriage20may be provided for each print head18.

Service station22comprises a station located on an axial end of drum12such that carriage20may position print heads18opposite, or adjacent, to station22. Station22includes one or more components configured to perform servicing operations upon one or more of the print heads18. As shown byFIGS. 1-3, in the particular example shown, service station22further includes a frame30, supply spool32, take-up spool34, web drive36, web38, track or web support44, lifters46, actuator47caps48and actuator50. Frame30comprises one or more walls, panels, structures, frame members and the like configured to support supply spool32, take-up spool34, web drive36, web38, track or web support44, lifters46, caps48and actuator50relative to drum12.

Supply spool32comprises a reel configured to carry multiple windings of web38and to supply web38for use by service station22. Take-up spool34comprises a reel configured to receive used windings of web38. Web drive36comprise a mechanism configured to rotationally drive take-up spool34so as to move web38from spool32to spool34. In one embodiment, web drive36may comprise motor operably coupled to spool34by a transmission such as a gear train, a belt and pulley arrangement or a chain and sprocket arrangement. As shown byFIG. 2, web38is supported by web support44between spools32and34.

In the example illustrated, spools32and34have vertically overlapping diameters. In other words, spools32and34at least partially vertically overlap one another. In particular, spools32and34are arranged such that web38travels in a first direction from spool32, travels through a U-turn and returns to spool34by traveling in a second direction generally opposite to the first direction. Spools32and34are located on a same side of web support44. Because spools32and34have diameters that at least partially overlap, space is better utilized, allowing a larger amount of web38to be compactly stored until use. As a result, service station22may operate for longer periods of time without replacement of web38. Although take-up spool34is illustrated as being located over supply spool32, in other embodiments, this relationship may be reversed. In still other embodiments, spools32and34may alternatively be located on opposite sides of web support44.

In the example illustrated, supply spool32is removably coupled to frame30, allowing spool32to be separated from frame30. As a result, spool32is only removed and replaced upon consumption of web38. In other embodiments, spools32and34may alternatively be provided as part of a cartridge, wherein the entire cartridge is removed or swapped upon consumption of web38.

Web38comprises a band or span of material for performing servicing operations upon print heads18. In one embodiment, web is configured to interact with print heads18by receiving fluid, printing material or ink discharged from print heads18. For example, in one embodiment, print heads18include multiple nozzles. Web38facilitates spitting of ink from the nozzles to clear such nozzles. In the embodiment illustrated, web38comprises a web of material configured to physically contact the surfaces of print heads18so as to wipe print heads18. In the particular example illustrated, web38is also configured to contact the surfaces of print heads18as carriage20moves print heads18along axis26relative to web38to wipe print heads18. In other embodiments, web38may additionally be configured to be moved relative to print heads18to perform such wiping operations. In one embodiment, web38comprises a web of fluid absorbent material. In one embodiment, web38comprises a fabric material. According to one embodiment, web38is formed from a fabric material such as Evolon 100 commercially available from Freudenberg Group of Germany.

In one embodiment, web38includes non-absorbent regions52separating or isolating different absorbent regions53from one another. Non-absorbent regions52inhibit migration of fluid between adjacent absorbent regions53. Non-absorbent regions52inhibit migration of fluid deposited during spitting in one absorber region to other absorbent regions which are used for wiping. As a result, non-absorbent regions52prevent cross-contamination and increase or prolong the useful life of web38.

As shown byFIG. 2, web support44, schematically shown, comprises one or more structures configured to support and guide web38in an arc about axis26. In the particular example shown, web support44is configured to support web38about an arc substantially similar to the arc along which print heads18are arranged. In one embodiment, web support44comprises an elongate arcuate panel or surface underlying web38. In yet another embodiment, web support44comprises multiple individual surfaces that are spaced from one another in an arc. For example, in one embodiment, web support44may be formed from multiple rollers extending in the arc.

Web support44is movably coupled to frame30so as to move between a raised position (shown inFIGS. 1-3) for servicing print heads18and a retracted or lowered position (shown inFIG. 5) facilitating the capping of print heads18. In one embodiment, web support44is pivotally coupled to frame30. For example, in the embodiment illustrated, web support44is pivotally coupled to frame30about a pivot axis51. In other embodiments, web support44may be pivotally coupled to frame30about other pivot axes. In still other embodiments, web support44may alternatively be configured to translate or slide between the raised position and the lowered position such as along one or more vertical tracks, channels or grooves.

In the particular example illustrated, web support44includes a bottom support54and a top cover or panel56. Bottom support54extends below web38while top panel56extends over web38so as to sandwich and contain web38. Top panel56includes windows57which expose portions of web38. In other embodiments, top panel56may be omitted. Because web support44supports web38in an arc, web38may be used to simultaneously service multiple print heads18. As shown byFIGS. 1 and 3, web38is supported by web support44over lifters46in an arc. As shown byFIG. 1, web38is exposed through windows57. A portion of web38overlays lifters46so that web38may be raised into contact with print heads18during servicing of print heads18.

Lifters46comprise mechanisms configured to lift or elevate selected portions of web38and to press or hold such elevated portions of web38against opposite portions of print heads18to facilitate wiping of print heads18. In the example illustrated, each of lifters46includes a web backer58and an actuator60. Web backer58comprises a structure configured to move between (1) a raised position in which web backer58contacts an underside of web38and lifts the opposing portion of web38to a height sufficient to contact an associated opposing print head18and (2) a lower position in which web38is spaced from print heads18. In one embodiment, in a raised position, web backer58supports web38above web support44and in the lowered position allows web38to rest upon bottom support54of web support44. In one embodiment, web Backer58comprises a resiliently compliant member, such as a sponge or foam member. In other embodiments, web backer58may have other configurations and may be formed from other materials.

Actuator60comprises a mechanism configured to selectively move web backer58between the raised and the lowered positions. In one embodiment, actuator60may comprise one or more cams driven by a motor or other power sources. In another embodiment, actuator60may comprise electric solenoids, pneumatic or hydraulic cylinder assemblies or other actuation mechanisms which directly interact with web backer58or which drive an intermediate cam which facilitates movement of web backer58. In other embodiments where other mechanisms are provided for wiping of print heads18and where web38is merely used to receive fluid ejected from print heads18, such as during spitting or purging operations, lifters46may be omitted.

Actuator47comprises a mechanism configured to move web support44and the supported web38between the raised position and the lowered position. In the raised position, web support44and web38are appropriately positioned to facilitate servicing of print heads18. In the lowered position, web support44and web38are sufficiently retracted from print heads18or lowered with respect to print heads18to permit insertion of caps48between web38and print heads18. Such raising and lowering of web support44permits caps48and web38to share vertical space, providing a more compact design and potentially enabling web38to be provided with an increased width. The increased width of web38increases the fluid absorption capacity of web38and enables service station22to operate for longer times without replacement of web38.

In the example illustrated, actuator47is configured to pivot web support44about axis51between the raised position and the lowered position. In other embodiments, actuator47may be configured to translate or slide web support44between the raised position and the lowered position. In other embodiments, web support44may be both pivoted and translated between the raised and lowered positions.

According to one embodiment, actuator47may comprise one or more cams which are datumed directly to or about the rotational axis26of drum12. In other words, the one or more cams of actuator47have surfaces that directly contact surfaces (called datum surfaces) of one or more members that define the rotational axis26of drum12. The datum surfaces precisely locate the one or more cams of actuator47with respect to the rotational axis26. Such cams operably engage cam followers associated with web support44to raise and lower web support44. Such cams are operably coupled to a motor by a transmission such as a gear train, a belt and pulley arrangement or a chain and sprocket arrangement. Because such cams are datumed directly to the rotational axis26of drum12(shown inFIG. 1) by being directly mounted to the same structures that locates drum axis26and rotates about axis26, tolerance stack may be reduced or minimized. In one embodiment, actuator60also comprises cams which engage cam followers associated with lift members58, wherein the cams of actuator60are also datumed directly to drum axis26, further reducing tolerance stack. In other embodiments, actuator47may comprise other members configured to move web support44, such as hydraulic or pneumatic cylinder-piston assemblies, electric solenoids and the like.

Caps48comprise structures configured to cap or seal about fluid nozzle openings of print heads18. Caps48seal about such nozzle openings when print heads18are not in use. Caps48reduce or slow drying of fluid of print heads18to maintain moisture about the nozzle openings of print heads18which enhances health of the print heads18. In some embodiments, caps48may additionally be configured to provide for purging of fluid from print heads18.

In the example illustrated, caps48are coupled or connected to one another so as to move in unison with one another. Caps48move between a first position at least partially withdrawn from over and above web support44(shown inFIGS. 1 and 3) and a second position over and above web support44to a greater extent as compared to the first position. In the example illustrated, in the first position, caps48are completely withdrawn from over and above web38. In the second position, caps48project above and over web38by a distance of at least 25 mm and nominally about 38 mm in a direction along axis26.

As noted above, caps48are configured to move to the second position when web support44is in the lowered position. Because caps48share space with web support44and web38, servicing station22is more compact and web38may be provided with a greater width. As a result, the absorptive capacity of web38may be increased to increase the useful life of web38.

In the example illustrated, caps48are arranged in an arc about axis26. As a result, caps48may be more easily moved to the second position in which caps48are located between web38and print heads18. In other embodiments, caps48may have other arrangements. In other embodiments, caps48may move independent of one another

Actuator50comprises a mechanism configured to move caps48between the first position and the second position. In particular, actuator50moves caps48along axis26. In one embodiment, actuator50is configured to additionally move caps48in a direction substantially perpendicular to axis26so as to raise caps48into the sealing engagement with print heads18. In other embodiments, separate actuators may be used to raise and lower caps48with respect to print heads18. In yet other embodiments, caps48may merely move along axis26, wherein print heads18are raised and lowered with respect to caps48for capping of print heads18.

In one example embodiment, actuator50may comprise a series of linkages and/or arms configured to receive motion or force from carriage20and to transmit such force or motion to caps48so as to move caps48between the first position and the second position. For example, in one embodiment, actuator50may be configured to be engaged by carriage20as print heads18are moved leftward as seen inFIG. 1. Actuator50is configured to transmit motion to caps48to move caps48rightward as seen inFIG. 1. Upon subsequent movement of carriage20rightward as seen inFIG. 1, caps48may return to the first position, moving leftward as seen inFIG. 1, under the force supplied by a bias, such as a spring. In other embodiments, actuator50may comprise other actuation mechanisms such as a motor and can arrangement, a hydraulic or pneumatic cylinder-piston assembly or an electric solenoid. In other embodiments, caps48may alternatively be configured to move along axis26between a first position and the second position independent of one another.

Controller24comprises one or more processing units configured to generate control signals directing the operation of printing system10. Controller24may be associated with printer10or in some embodiments, may be associated with a peripheral computing device connected to printer10. Controller24generates control signals directing the positioning of media by media supply14and rotation of drum12by rotary actuator13, directing the positioning of print heads18through movement of carriage20by actuator21, directing the ejection of fluid by print heads18, and directing the servicing of print heads18at service station22.

With respect to service station22, controller24tracks operation of web drive36to control the supply of web38. Controller24generates control signals directing operation of actuators47and60to provide spitting, wiping and capping servicing operations. Controller24also generates control signals directing operation of actuator50. In some embodiments in which actuator50transmits motion or force received from movement of carriage20to caps48, controller24controls positioning of caps48through its control of actuator21which moves carriage20.

Controller24is coupled to rotary actuator13, media supply14, print heads18, actuator21, web drive36, actuators47and60and actuator50(where applicable) in a wired fashion or in a wireless fashion. For purposes of this application, the term “processing unit” shall mean a presently developed or future developed processing unit that executes sequences of instructions contained in a memory. Execution of the sequences of instructions causes the processing unit to perform steps such as generating control signals. The instructions may be loaded in a random access memory (RAM) for execution by the processing unit from a read only memory (ROM), a mass storage device, or some other persistent storage. In other embodiments, hard wired circuitry may be used in place of or in combination with software instructions to implement the functions described. For example, controller24may be embodied as part of one or more application-specific integrated circuits (ASICs). Unless otherwise specifically noted, the controller is not limited to any specific combination of hardware circuitry and software, nor to any particular source for the instructions executed by the processing unit.

FIGS. 3-5schematically illustrate service station22during different servicing operations upon print heads18(one of which is shown).FIG. 3illustrates service station22during spitting operations. As shown byFIG. 3, in response to control signal from controller24, actuator47has positioned web support44in the raised position. At the same time, actuator60, in response to control signal from controller24has lowered web backers58to lowered positions. Actuator21(shown inFIG. 1), in response to control signals from controller24locates carriage20and print heads18opposite to web38. Controller24further generates control signals directing print heads18to spit fluid onto web38. During such spitting, caps48are in the first position, withdrawn from over and above web38.

FIG. 4illustrates service station22during a wiping operation. During the wiping operation, web support44is in the raised position and caps48are in a first retracted position. However, as shown byFIG. 4, in response to control signal from controller24(shown inFIG. 1), actuators60move web backers58to raised positions in which web backers58lift and elevate web38into contact with the nozzles of print head18for wiping of print head18. In one embodiment, controller24(shown inFIG. 1) further generates control signals directing actuator21(shown inFIG. 1) to translate print heads18relative to web backers58while web backers58are in the raised position to effectuate wiping.

FIG. 5illustrates service station22in a capping operation or state. As shown byFIG. 5, controller24(shown inFIG. 1) generates control signals such that actuator60moves or maintains web backers58in the lowered position. Controller24generates control signals directing actuator47to move web support44in the direction indicated by arrow63to the lowered position. Web support44is lowered by a distance sufficient to permit one or more of caps48to be positioned between or sandwiched between print heads18and web38. In one embodiment, web support44is lowered by distance equal to or greater than a height of caps48. In one embodiment, web support44is lowered by distance of at least 14 mm.

As noted above, in one embodiment, actuators47and60comprise cams. In one embodiment, such cams may be supported on a single relational drive member so as to rotate with one another. Rotation of the rotational drive member by a motor or other rotational drive arrangement is controlled by controller24, wherein different angular positions of such cams result in web backers58being raised or lowered and/or web support44being raised or lowered.

As further shown byFIG. 5, controller24generates control signals directing actuator50to move caps48in the direction indicated by arrow65from the first position shown inFIGS. 3 and 4to the second position shown inFIG. 5. In one embodiment, caps48are linearly translated to the second position shown inFIG. 5.

Once caps48are in the second position between web38and print head18, one or both of print head18and caps48are moved towards one another until caps48are in capping or sealing engagement with print head18. In one embodiment, caps48are raised into engagement with print head18. In one embodiment, such raising of caps48is also achieved by actuator50. In embodiments where actuator50comprises a series of linkages, arms or cams which transmit force or motion from movement of carriage22so as to move caps48, controller24controls the positioning of caps48by controlling the position of carriage20with actuator21(shown inFIG. 1).

FIG. 6is a flow diagram illustrating a method100of servicing print heads18. As indicated by step110, web support44is moved to the raised position (shown inFIG. 3). If web support44is already in the raised position, such movement may be omitted. As indicated by step112and also shown byFIG. 3, fluid, such as ink, is spit or otherwise ejected from print head18onto web38. Such spitting is schematically represented by arrows113inFIG. 3. Such spitting clears nozzles of print heads18.

As indicated by step114and shown inFIG. 4, web backers58are moved to their raised positions. As noted above, such movement results in web38being moved or pressed against print head18. As indicated by step116, print heads18are wiped. In particular, carriage20is moved so as to move print heads18relative to web38and web supports58while web38is in contact with print heads18. During such wiping, before such wiping or after completion of wiping, controller24may generate control signals directing web drive36(shown inFIG. 2) to advance web38to present a fresh or clean portion of web38opposite to print head18for current wiping or subsequent wiping operations.

As indicated by step118and shown inFIG. 5, web backers58and web support44are both lowered to their lowered positions. In the embodiment illustrated, prior to such lowering, caps48have a height greater than the spacing between web38and print heads18which would otherwise inhibit positioning of caps48between print heads18and web38. As indicated by step120, caps48are moved between web38and print head18. Caps38are moved to a positions opposite to and in substantial alignment with print head18such that sealing portions of caps48surround nozzle openings (not shown) of print heads18. As indicated by step122, print heads18are capped. In particular, print heads18and caps48are moved into sealing engagement with one another. In one embodiment, caps48are raised into engagement with nozzle faces of print head18.

FIGS. 7-9illustrate printing system210, another embodiment of printing system10shown inFIG. 1. Printing system210generally includes drum212, rotary actuator213, media supply214, media output216, print heads218(one of which is shown), carriages220(one of which is shown), actuators221(one of which is shown) service station222and controller224(shown inFIGS. 7 and 9). Drum212generally comprises an elongated cylinder configured to be rotatably driven about axis226by rotary actuator213while transporting media, such as paper, about axis226relative to print heads218. Rotary actuator213, schematically shown, comprises a source of torque, such as a motor, operably coupled to drum212by a transmission (not shown).

Media supply214, schematically shown, comprises a mechanism configured to supply media to drum212. In one embodiment, media supply214comprises a mechanism configured to pick an individual sheet of media from a stack of media and to supply the individual sheet to drum212such that the sheet is wrapped at least partially about drum212. Media output216, schematically shown, comprises a mechanism configured to withdraw printed upon media from drum212and to transport withdrawn media to and contain withdrawn media within an output tray, bin or the like.

Print heads218comprise print heads configured to dispense imaging material, such as ink, upon the medium held by drum212. In one embodiment, print heads218comprise piezo electric print heads. In another embodiment, print heads218comprise thermal inkjet print heads. Print heads218are arranged in an arc about axis226. As a result, print heads218are configured to print across a larger area of the media supported by drum212. In the particular embodiment, drum212has an outer surface230also arranged in an arc about axis226. Print heads218are arranged in an arc substantially identical to the arc in which surface230extends.

Carriage220comprises one or more structures configured to support print heads218in the arcuate arrangement. In addition, carriage220is configured to movably support print heads218along axis226. Actuator221comprises a linear actuator configured to move carriage220and print heads218so as to selectively position print heads218opposite to the media held by drum212or opposite to service station222. In one embodiment, actuator221may comprise a motor (not shown) configured to drive a toothed pulley in engagement with a toothed belt coupled to carriage220. In another embodiment, actuator221may comprise other forms of a linear actuator using rack and pinion arrangements, hydraulic, pneumatic or electrical means. Although only one print head218, carriage220and actuator221is shown, in the example illustrated, system210includes 6 print heads supported by 6 carriages, wherein each print head218is independently moved or actuated by a dedicated actuator221. In other embodiments, a single carriage may move each of the multiple print heads in unison with one another. In other embodiments, system210may alternatively include a greater or fewer of such print heads218supported by one or more carriages220and driven by one or more actuators221.

Service station222comprises a station located on an axial end of drum212such that carriages220may position print heads218opposite, or adjacent, to station222. Station222includes one or more components configured to perform servicing operations upon one or more of the print heads218. As shown byFIG. 8, in the particular example shown, service station222includes a frame230, supply spool232, take-up spool234, web drive236, web238, track or web support244, lifters246, actuator260, caps248and actuator250. Frame230comprises one or more walls, panels, structures, housing members and the like configured to support supply spool232, take-up spool234, web drive236, web238, track or web support244, lifters246, caps248and actuator250relative to drum212.

Supply spool232comprises a reel configured to carry multiple windings of web238and to supply web238for use by service station222. Take-up spool234comprises a reel configured to receive used windings of web238. Web drive236comprises a mechanism configured to rotationally drive take-up spool234so as to move web238from spool232to spool234. In the embodiment illustrated, web drive236comprises a motor300(shown inFIG. 8) operably coupled to spool234by a transmission302comprising a gear train. In other embodiments, transmission302may comprise a belt and pulley arrangement or a chain and sprocket arrangement. As shown byFIG. 8, web238is supported by web support244between spools232and234.

In the example illustrated, spools232and234have vertically overlapping diameters. In other words, spools232and234at least partially vertically overlap one another. In particular, spools232and234are arranged such that web238travels in a first direction from spool232, travels through a U-turn and returns to spool234by traveling in a second direction generally opposite to the first direction. Spools232and234are located on a same side of web support244. Because spools232and234have diameters at least partially overlap, is better utilized, allowing a larger amount of web238to be compactly stored until use. As a result, service station222may operate for longer periods of time without replacement of web238. Although take-up spool234is illustrated as being located over supply spool232, in other embodiments, this relationship may be reversed. In still other embodiments, spools232and234may alternatively be located on opposite sides of web support244.

In the example illustrated, supply spool232is removably coupled to frame230, allowing spool232to be separated from frame230. As a result, spool232is only removed and replaced upon consumption of web238. In other embodiments, spools232and234may alternatively be provided as part of a cartridge, wherein the entire cartridge is removed or swapped upon consumption of web238.

Web drive236comprises a mechanism configured to drive one or both of supply spool232or take-up spool234so as to move web238across web support244and across windows257. Web drive236drives web238over web backers258. In the example illustrated, web drive236comprises a transmission, such as the set of drive gears shown, connected to the take-up spool234and operably coupled to motor300(shown inFIG. 8). Torque supplied by the motor300drives take-up spool234to pull web238from supply roll or spool232about web support244to take-up spool234as indicated by arrows306inFIG. 8. In other embodiments, web drive236may have other configurations.

Web238comprises a band or span of material for performing servicing operations upon print heads218. In one embodiment, web is configured to interact with print heads218by receiving fluid, printing material or ink discharged from print heads218. For example, in one embodiment, print heads218include multiple nozzles (not shown). Web238facilitates spitting of ink from the nozzles to clear such nozzles. In the embodiment illustrated, web238comprises a web of material configured to physically contact the surfaces of print heads218so as to wipe print heads218. In the particular example illustrated, web238is also configured to contact the surfaces of print heads218as carriage220moves print heads218along axis226relative to web238to wipe print heads218. In other embodiments, web238may additionally be configured to be moved relative to print heads218to perform such wiping operations. In one embodiment, web238comprises a web of fluid absorbent material. In one embodiment, web238comprises a fabric material. According to one embodiment, web238is formed from a fabric material such as Evolon 100 commercially available from Freudenberg Group of Germany.

In one embodiment, web238includes non-absorbent regions252separating or isolating different absorbent regions253from one another. Non-absorbent regions252inhibit migration of fluid between adjacent absorbent regions253. Non-absorbent regions252inhibit migration of fluid deposited during spitting in one absorber region to other absorbent regions which are used for wiping. As a result, non-absorbent regions252prevent cross-contamination and increase or prolong the useful life of web238.

As shown byFIG. 8, web support244comprises one or more structures configured to support web238in an arc about axis226. In the particular example shown, web support244is configured to support web238about an arc substantially similar to the arc along which print heads218are arranged. In the example illustrated, web support244includes web guide252and web cover254. Web guide252comprises an elongate arcuate panel or surface underlying web238. In yet another embodiment, guide252comprises multiple individual surfaces that are spaced from one another in an arc. For example, in one embodiment, guide252may be formed from multiple rollers extending in the arc.

Web cover254extends over web238so as to sandwich and contains web238. As shown byFIG. 7, web cover254includes windows256,257which expose portions of web238. In particular, windows256expose those portions of web238opposite to web backers258. In the example illustrated, web cover252includes three such windows256, wherein each window256exposes two web backers258for performing wiping operations on two of print heads218.

Windows257expose those portions of web238which are to receive fluid ejected or spit from print heads218. In the example illustrated, web cover254includes a separate window arcuately arranged about axis226for each of print heads218. In other embodiments, window256may comprise a continuous window through which fluid from more than one print head218may be ejected onto web238. In other embodiments, web cover254may have other configurations or may be omitted.

Web support244is movably coupled to frame230so as to move between a raised position (shown inFIG. 7) for servicing print heads218and a retracted or lowered position (shown inFIG. 10) facilitating the capping of print heads218. In the example illustrated, web support244is pivotably coupled to frame230at hinge303for pivotal movement about pivot axis251. In other embodiments, web support244may be pivotably coupled to frame230about other pivot axes. In still other embodiments, web support244may alternatively be configured to translate or slide between the raised position and the lowered position such as along one or more vertical tracks, channels or grooves.

Actuator260comprises a mechanism configured to selectively move web backer258between the raised and lowered positions. In one embodiment, actuator260may comprise one or more cams driven by a motor or other power sources. In another embodiment, actuator260may comprise electric solenoids, pneumatic or hydraulic cylinder assemblies or other actuation mechanisms which directly interact with web backer258or which drive an intermediate cam which facilitates movement of web backer58. In other embodiments where other mechanisms are provided for wiping of print heads218and where web238is merely used to receive fluid ejected from print heads218, such as during spitting or purging operations, lifters246may be omitted.

Lifters246comprise mechanisms configured to lift or elevate selected portions of web238and to press or hold such elevated portions of web238against opposite portions of print heads218to facilitate wiping of print heads218. In the example illustrated, each of lifters246includes a web backer258and an actuator260. Web backer258comprises a structure configured to move between (1) a raised position in which web backer258contacts an underside of web238and lifts the opposing portion of web238to a height sufficient to contact an associated opposing print head218and (2) a lowered position in which web238is spaced from print heads218. In one embodiment, in a raised position, web backer258supports web238above web support244and in the lowered position allows web238to rest upon web support244.

Actuators260comprise mechanisms configured to selectively move web backers258between the raised and lowered positions. As shown byFIG. 8, actuators260include datum310, lift cams313, cam drive motor314and transmission316. Datum310comprises a structure against which cams312are datumed (precisely positioned). In the example illustrated, datum310comprises a duct centered about axis226, the same axis about which drums212rotates. Because cams212are datumed (precisely positioned in space and with respect to other structures) directly to the rotational axis226of drum212by being directly mounted to datum310that locates drum axis226, tolerance stack may be reduced or minimized.

Lift cams313are each operably coupled to an associated web backer258having an associated cam follower surface317. Lift cams313are operably coupled to drive motor314by transmission316. Selective rotation of cams313by motor314raises and lowers backers258between the raised and lowered positions.

In another embodiment, actuator260may comprise electric solenoids, pneumatic or hydraulic cylinder assemblies or other actuation mechanisms which directly interact with web backers258or which drive an intermediate cam which facilitates movement of web backer258. In other embodiments where other mechanisms are provided for wiping of print heads218and where web238is merely used to receive fluid ejected from print heads218, such as during spitting or purging operations, lifters246may be omitted.

FIGS. 8-11illustrates actuator260in more detail. Actuator260comprises a mechanism configured to move web support244and the supported web38between the raised position and the lowered position. In the raised position, web support244and web238are positioned to facilitate servicing of print heads218. In the lowered position, web support244and web238are sufficiently retracted from print heads218or lowered with respect to print heads218to permit insertion of caps248between web238and print heads218. Such raising and lowering of web support244permits caps248and web238to share vertical space, providing a more compact design and potentially enabling web38to provide it with an increased width. The increased width of web238increases the fluid absorption capacity of web238and enables service station222to operate for longer times without replacement of web238.

In the example illustrated, actuator260is configured to pivot web support244about axis251between the raised position (shown inFIG. 10) and the lowered position (shown inFIG. 11). In the example illustrated, actuator260pivots web support244in at least about 5 degrees such that those portions of web support244opposite to that print heads and closest to the pivot point of web support244are raised or lowered through a distance of approximately 14 mm and such at those portions of web support244opposite to the print heads and farthest from the pivot point of web support244are raised or lowered through a distance of approximately 40 mm. In other embodiments, actuator260may be configured to translate or slide web support244between the raised position and the lowered position. In other embodiments, web support244may be both pivoted and translated between the raised and lowered positions.

As shown byFIG. 9, in the embodiment illustrated, actuator260comprises datum310, web support lift cams320(also known as service station lift cams or web module lift cams), cam drive motor314and transmission316. Datum310comprises a structure against which cams312are datumed (precisely positioned). In the example illustrated, datum310comprises a duct centered about axis226, the same axis about which drums212rotates. Because cams320are located with respect to the rotational axis226of drum212by being directly mounted to datum310that locates drum axis226, tolerance stack may be reduced or minimized.

Cams320comprise cam structures configured to rotate about datum310and to engage corresponding cam follower surfaces322(shown inFIG. 8) coupled to and carried by web support244. Cams320are irregularly shaped such that rotation of cams320against opposite associated cam followers connected to web support244pivot web support244about axis251to raise and lower web support244between the raised and lowered positions, depending upon the angular positioning of cams320.

Drive motor314applies torque to cams312via transmission316. In the example illustrated, transmission316comprises a gear train. In other embodiments, transmission316may comprise a chain and sprocket arrangement or a belt and pulley arrangement. Drive motor314rotate cams312to move web support244between the raised position and the lowered position. Because actuator260and actuators260of lifters246utilize a same drive motor247, a same transmission316and a same datum310, complexity is reduced and compactness is increased. In other embodiments, actuator260and actuators260may utilize independent motors, independent transmissions and independent datums.

As shown byFIG. 7, Caps248comprise structures configured to cap or seal about fluid nozzle openings of print heads218. Caps248seal about such nozzle openings when print heads218are not in use. Caps248maintain a moist environment about print heads218to maintain the health of the print heads218. In some embodiments, caps248may additionally be configured to provide for purging of fluid from print heads218.

In the example illustrated, caps248are coupled or connected to one another such a move in unison with one another. Caps248move between a first position at least partially withdrawn from over and above web support244(shown inFIG. 7) and a second position over and above web support244to a greater extent as compared to the first position (shown inFIG. 10). In the example illustrated, in the first position, caps248are completely withdrawn from over and above web238. In the second position, caps248project above and over web238by a distance of at least 25 mm and nominally about 38 mm in a direction along axis226.

As noted above, caps248are configured to move to the second position when web support244is in the lowered position. Because caps248share space with web support244and web238, servicing station222is more compact and web238may be provided with a greater width. As a result, the absorptive capacity of web238may be increased to increase the useful life of web238.

In the example illustrated, caps48are arranged in an arc about axis226. As a result, caps248may be more easily moved to the second position in which caps248are located between web238and print heads218. In other embodiments, caps248may have other arrangements.

Actuator250comprises a mechanism configured to move caps48between the first position (shown inFIG. 12) and the second position (shown inFIG. 13). In particular, actuator250moves caps248along axis226(shown inFIG. 7). In one embodiment, actuator250is configured to additionally move caps248in a direction substantially perpendicular to axis226so as to raise caps248into the sealing engagement with print heads218. In other embodiments, separate actuators may be used to raise and lower caps248with respect to print heads218. In yet other embodiments, caps248may merely move along axis226, wherein print heads18are raise and lowered with respect to caps248for capping of print heads218.

FIGS. 12 and 13illustrate one example of actuator250in detail.FIG. 12illustrates actuator250with caps248in the first retracted position.FIG. 13illustrates actuator250with caps248in the second extended position. As shown byFIG. 12, actuator250includes a slider guide330, slider332, cap links334, slider link336, arm338, bias340, carriage ram342and cap tab344. Slider guide330comprises one or more structures supported by frame230and configured to guide translation of slider332along axis345. In the example illustrated, slider guide330comprises one or more grooves, tracks or channels in which paper programs for not shown) extending from slider332is received and slides. In other embodiments, slider guide330may have other configurations.

Slider332(also known as a sled or carriage) comprises a member configured to slide along slider guide330along axis345. Slider332is pivotally connected to cap links334and slider link336. Slider332may have a variety of shapes and configurations.

Cap links334comprise elongate linkages extending between slider332and caps248. Cap links334each have a first end346pivotally connected to one or more of caps248and a second and348pivotally connected to slider332. Cap links334cooperate with slider332and caps248to form a four-bar linkage. This four-bar linkage facilitates vertical raising and lowering of caps248as will be described hereafter.

Slider link336comprises a linkage having opposite ends pivotally connected to slider332and arm338. Arm338comprises an elongate member pivotally coupled to frame230about axis352. Arm338has a first end354pivotally connected to link336and a second end356on an opposite side of axis352that is configured to being engaged and directly contacted by carriage ram342.

Bias340comprises one or more bias members configured to resiliently bias arm338towards clockwise angular rotation about pivot axis352as seen inFIG. 12. Bias340resiliently biases end356to the right as seen inFIG. 12and resiliently biases end354as well as slider332and caps348to the left as seen inFIG. 12. In the example illustrated, bias340comprises a tension spring having a first end connected to frame230and a second end connected to arm338between axis352and end354. In other embodiments, bias340may comprise other bias structures, such as other types of springs, at other locations.

Carriage ram342comprises a structure coupled to carriage220so as to move with carriage220. Carriage ram342is configured so as to engage end356of arm338to pivot arm338about axis352and a counter-clockwise direction against the bias of the bias340. Although illustrated as a downwardly projecting tab, carriage ram342may have a variety of sizes, shapes, configurations and locations.

Cap tab344comprises a protrusion or projection extending from one or more of caps348which are configured to be contacted, abutted or driven by carriage220when print heads218are substantially aligned over caps248. In the example illustrated, cap tab344is configured to contact and to be driven by edge358of the print head218. As shown inFIG. 13, when print head218engages and drives344, both ends of links334pivot to vertically lift or raise caps348into sealing engagement with print heads218. In other embodiments, other stop surfaces or friction clutches at the pivot point of links334may be utilized to cause links334to pivot from the tilted position shown inFIG. 12to the substantially vertical position shown aFIG. 13so as to raise caps248.

Controller224is similar to controller24(shown inFIG. 1). Controller224comprises one or more processing units configured to generate control signals directing the operation of printing system210. Comptroller224may be associated with printer210or in some embodiments, maybe associated with a peripheral computing device connected to printer210. Controller224generates control signals directing the positioning of media by media supply214and rotation of drum212by rotary actuator213, directing the positioning of print heads218through movement of carriage220by actuator221, directing the ejection of fluid by print heads18, and directing the servicing of print heads218at service station222.

With respect to service station222, controller224tracks operation web drive236to control the supply of web238. Controller224generates control signals directing operation of actuators260and260to provide spitting, wiping and capping servicing operations. Controller224also generates control signals directing operation of actuator250. In the embodiment illustrated in which actuator250transmits motion or force received from movement of carriage220to caps248, controller224controls positioning of caps248through its control of actuator221which moves carriage220. Controller224is coupled to rotary actuator213, media supply214, print heads218, actuator221, web drive236, actuators260and actuator250(where applicable) in a wired fashion or in a wireless fashion.

In contrast toFIG. 7, which illustrates web support244and web238in the raised position and illustrates caps248in the first retracted position,FIG. 14illustrates web support244and web238in the lowered position and illustrates caps248in the second extended position at least partially over web238. To achieve this state, controller224generates control signals directing motor314to rotate cams322lower web support244and web238from the raised position shown inFIG. 10to the lowered position shown inFIG. 11. Controller224further generates control signals directing actuator221to drive and translate carriage220from the first position shown inFIG. 12is to the capping position shownFIG. 13. During this translation of carriage220, carriage ram342first contacts end356of arm338. Continued movement of carriage220to the left (as seen inFIG. 12) pivots arm338about axis352to drive slider332to the right as seen inFIG. 12. Movement of slider332to the right results in caps248also being moved to the right as seen inFIG. 12from the first position to the second position in which caps248least partially overlie web238. During such translation to the right, links334are in the orientation shown inFIG. 12. Upon caps248and print heads218moving into alignment with one another (caps248moving to the right and print heads218moving to the left as seen inFIG. 13) edge358of print heads218contacts tab344. As a result, slider248moves to the right relative to caps248so as to pivot links334in a counter-clockwise direction as seen inFIG. 13. This results in caps248being vertically lifted into closer sealing engagement with print heads218. Because caps248move in a substantially horizontal path followed by a substantially vertical path, horizontal translation of caps248while in contact with printed several218is reduced or eliminated. As a result, a better sealing alignment is achieved with reduced wear to either print heads218or caps248. As noted above, because caps248share space with the underlying web238and web support244, service station222is more compact and a width of web238may be increased for greater absorptive and wiping capacity.