Waste ink collection system for an ink jet printer

Information

  • Patent Grant
  • 6273547
  • Patent Number
    6,273,547
  • Date Filed
    Wednesday, October 27, 1999
    24 years ago
  • Date Issued
    Tuesday, August 14, 2001
    22 years ago
Abstract
A maintenance station for an ink jet printer includes a frame and a device, such as for example a cylindrical drum, rotatably coupled to the frame for collecting waste ink. A ratchet drive assembly is coupled to the frame for effecting rotation of the device. The ratchet drive assembly includes a ratchet gear coupled to the device, wherein the ratchet gear has a plurality of teeth. A distal end of a back-check member engages the teeth of the ratchet gear for effecting a rotation of the device in a first direction and prevents a rotation of the device in a direction opposite to the first direction. The rotation of the device is effected as the printhead cap is moved in a vertical direction.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to the handling of waste ink accumulated in an ink jet printer system, and more particularly, to an apparatus for decreasing ink misting during a printhead nozzle purge operation.




2. Description of the Related Art




Ink jet printers require maintenance operations to keep the nozzles of the print cartridge operating properly. Such maintenance operations typically include the steps of wiping the nozzle area of the print cartridge, firing the nozzles at prescribed intervals to purge the nozzles (spitting), and capping the cartridge during idle periods to prevent the jetted ink which remains on the nozzle plate from drying and clogging one or more of the nozzles of the nozzle plate. Typically, the spitting operation occurs at a location in the maintenance station. Over a period of time, the solids in the waste ink accumulate in the maintenance station, and the resulting waste ink build-up can affect the operation of the maintenance assembly.




Ink jet printers have been plagued with the problem of ink mist from maintenance operations drifting around and landing on the print media which is being printed. The mist is generated when the printer stops periodically to clean and clear the printing nozzles by spitting ink. When the printer resumes printing on the print media, airborne mist from the maintenance operation is drawn by the carrier movement and drifts onto the paper. This results in a noticeable image defect on the paper, and tends to also contaminate other printer mechanisms.




One previous attempt to control and collect the mist ink is to perform the spitting operation on-page. Other printers have used fans and absorbent pads in attempts to collect and contain the mist ink. However, with the more prevalent use of higher non-volatile constituents in ink formulations, residual or waste ink build-up interferes with the operation of printing by contaminating the printheads. Furthermore, passive collection systems, such as pads and venturies, have limited effectiveness and limited capability to store non-volatile waste ink. Active systems, such as fans, can be effective, but are complex and expensive to implement.




Other attempts have included providing a rotating annular wheel for receiving waste ink discharged by an ink jet printhead which is driven by a rotary capping assembly which is rotated by a motor and gear or belt. Such a configuration, however, is not readily adaptable for use with sled-type maintenance assemblies, since such sled-type maintenance assemblies do not include a source of rotary motion. In addition, a curvature of the annular wheel is not uniformly spaced from the generally parallel columns of nozzles of the printhead, thereby limiting its effectiveness for waste ink mist recovery.




Accordingly, a need exists for a printing system which includes a simple and effective drive mechanism to provide rotary power to a sled-type maintenance assembly and provides improved waste ink mist recovery.




SUMMARY OF THE INVENTION




One aspect of the invention is a maintenance station for an ink jet printer which includes a frame. A device, such as for example a cylindrical drum, is rotatably coupled to the frame for collecting waste ink. A ratchet drive assembly is coupled to the frame for effecting rotation of the device.




In preferred embodiments of the invention, the ratchet drive assembly includes a ratchet gear coupled to the device, wherein the ratchet gear has a plurality of teeth. A distal end of a back-check member engages the teeth of the ratchet gear for effecting a rotation of the device in a first direction. The back-check member effects the rotation of the device in the first direction and prevents a rotation of the device in a direction opposite to the first direction. Also, preferably, rotation of the device is effected as the printhead cap is moved in a vertical direction.




Another aspect of the invention is a maintenance station for an ink jet printer having a carriage assembly for moving an ink jet printhead along a linear scanning path. The ink jet printhead includes a column of nozzles. The maintenance assembly includes a frame and a printhead capping assembly coupled to the frame. The printhead capping assembly has a printhead cap for engaging the printhead during a capping operation. The printhead capping assembly is located on the frame along the linear scanning path of the ink jet printhead. A cylindrical drum having a cylindrical surface is rotatably coupled to the frame and positioned adjacent the printhead capping assembly. The cylindrical drum is orientated such that an axis of rotation of the cylindrical drum is substantially perpendicular to the linear scanning path of the ink jet printhead. The orientation may also provide a substantially uniform spacing between the column of printhead nozzles and the cylindrical surface of the cylindrical drum.




Still another aspect of the invention is a printer for printing with an ink jet printhead. The printer includes a printer frame, and a carriage assembly coupled to the printer frame, wherein the carriage assembly moves the ink jet printhead along a linear scanning path. A maintenance assembly frame is coupled to the printer frame. A device, such as a cylindrical drum, is rotatably coupled to the maintenance frame for collecting waste ink ejected by said printhead. A ratchet drive assembly is coupled to the maintenance frame for effecting rotation of the device.




An advantage of the present invention is the inclusion of a rotatable cylindrical drum for controlling misting and a rotary drive therefor for use in a maintenance assembly having a maintenance sled which moves in a substantially linear motion.




Another advantage is that the rotatable cylindrical drum is oriented to provide a uniform spacing between the columns of printhead nozzles and a cylindrical surface of the cylindrical drum to thereby effectively control ink misting during a printhead nozzle purge operation.











BRIEF DESCRIPTION OF THE DRAWINGS




The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:





FIG. 1

is a partial, perspective view of the frame assembly of an ink jet printer including a maintenance assembly in accordance with the invention;





FIG. 2

is an enlarged sectional side view of a portion of the maintenance assembly of the invention, with a printhead in a spitting position;





FIG. 3

is a graphical illustration of the relationship between the printhead and a cylindrical drum portion of the maintenance assembly when the printhead is in the spitting position; and





FIG. 4

is an enlarged sectional side view of a portion of the maintenance assembly of the invention, with the printhead in the capping position.











Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.




DETAILED DESCRIPTION OF THE INVENTION




Referring now to the drawings and particularly to

FIG. 1

, there is shown a portion of an ink jet printer


10


which includes a printer frame


12


, a printhead carrier assembly


14


, and a maintenance assembly


16


in accordance with the present invention. Positional terms such as left, right, top, bottom, upper, lower, clockwise or counter-clockwise are assigned based on the orientation of printer


10


in FIG.


1


and should not be considered limiting terminology.




Printer frame


12


includes a bottom frame member


18


, two side frame members


20




a,




20




b,


a rear frame member


22


, and a top frame member


24


. Side frame members


20




a,




20




b


are attached to, and extend generally vertically upwardly from, opposing ends


26




a,




26




b,


respectively, of bottom frame member


18


. Top frame member


24


is mounted and positioned generally parallel to bottom frame member


18


. Rear frame member


22


is disposed between side frame members


20




a,




20




b,


generally above bottom frame member


18


and below top frame member


24


.




Top frame member


24


includes a horizontally extending guide portion


30


and a vertically upwardly extending guide rail


32


disposed at the rear side of guide portion


30


. Guide rail


32


is adapted to slidably receive printhead carrier assembly


14


and permit reciprocating movement of printhead carrier assembly


14


in relation to guide rail


32


in a linear scanning path in the directions depicted by arrows


34


, which is substantially perpendicular to a sheet (S) feed direction


33


.




Printhead carrier assembly


14


includes a carriage


36


which holds two print cartridges


38




a,




38




b,


wherein print cartridge


38




a


contains magenta, yellow and cyan colored pigment based inks and print cartridge


38




b


contains a black dye based ink. In general, pigment based inks contain more solid components than dye based inks.




Referring to

FIGS. 1 and 2

, each of print cartridges


38




a,




38




b


includes an ink reservoir


40




a,




40




b


and a printhead


42




a,




42




b


respectively. Each of printheads


42




a,




42




b


includes a nozzle plate containing at least two columns of ink jet nozzles for selectively ejecting ink from the corresponding ink reservoirs


40




a,




40




b.


Although each of print cartridges


38




a,




38




b


are shown as forming an integral unit, those skilled in the art will recognize that the reservoirs


40




a,




40




b


may be mounted remotely from the printheads


42




a,




42




b


and connected to the printhead via a conduit. In such a configuration, printhead carrier assembly


14


would not need to carry the ink reservoir.




As shown graphically by dashed lines in

FIG. 1

, printer


10


includes a print zone


44


and a maintenance zone


46


. Maintenance zone


46


includes a maintenance start position


48


and a capping region


49


. The reciprocating movement of printhead carrier assembly


14


along guide rail


32


is effected by a drive means (not shown) of a type known in the art, such as a belt coupled to a stepper motor. The movement of printhead carrier assembly


14


and the ejection of ink from print cartridges


38




a,




38




b


are controlled by a microprocessor control means, types of which are known in the art. During operation, printhead carrier assembly


14


is moved by the drive means to position printheads


42




a,




42




b


at various locations within the predetermined limits of permitted travel of printhead carrier assembly


14


. Included in the limited travel of printhead carrier assembly


14


is print zone


44


and maintenance zone


46


, including start position


48


and capping region


49


.




Maintenance assembly


16


is attached to printer frame


12


above bottom frame member


18


. Maintenance assembly


16


includes a maintenance frame


50


and a maintenance sled


52


. Preferably, maintenance assembly


16


is located such that a left end


56


of maintenance sled


52


generally defines the location of maintenance start position


48


for printhead carrier assembly


14


.




Maintenance frame


50


is a generally rectangular structure formed by vertical sides


58




a,




58




b,




58




c,


and


58




d.


Vertical side


58




a


includes two ramped surfaces


60




a,




60




b,


and vertical side


58




b


includes two ramped surfaces


60




c,




60




d.


Ramped surfaces


60




a,




60




b,




60




c,




60




d


provide vertical support for maintenance sled


52


. Each of ramped surfaces


60




a,




60




b,




60




c,




60




d


is upwardly inclined towards vertical side


58




c


and each contains three distinct elevations: a printing elevation, a wiping elevation, and capping elevation.




Maintenance frame


50


further includes a print latch


62


pivotally coupled at the intersection of vertical sides


58




b,




58




d.


Print latch


62


contains a stop surface


64


and a spring (not shown). Print latch


62


functions to actively control the placement of maintenance sled


52


along ramped surfaces


60




a,




60




b,




60




c,




60




d.


When print latch


62


is in the open position sled


52


is allowed to migrate along ramped surfaces


60




a,




60




b,




60




c,




60




d


to the lower, or printing, elevation. When print latch


62


is in the closed position sled


52


is prohibited from migrating along ramped surfaces


60




a,




60




b,




60




c,




60




d


to the printing elevation. The spring biases print latch


62


towards the closed position. The structure and operation of print latch


62


is well known in the art.




Maintenance sled


52


is disposed within the open interior of maintenance frame


50


. Maintenance sled


52


includes a generally rectangular frame


68


having four dowel members


70




a,




70




b,




70




c


and


70




d


which extend horizontally outward from rectangular frame


68


. Dowel members


70




a,




70




b,




70




c,




70




d


are supported by the corresponding ramped surfaces


60




a,




60




b,




60




c,




60




d


on maintenance frame


50


and are guided along ramped surfaces


60




a,




60




b,




60




c,




60




d


to raise or lower maintenance sled


52


relative to maintenance frame


50


.




Maintenance sled


52


includes a pair of printhead wipers


72




a,




72




b;


a pair of cap assemblies


74




a,




74




b;


a pair of cavities


76




a,




76




b


and a pair of rotary waste ink collection assemblies


78




a,




78




b.


Each printhead wiper


72




a,




72




b


is made of an elastic material, such as Texin 480-A (Mites, Inc.), and is secured to rectangular frame


68


. Printhead wipers


72




a,




72




b


remove excess ink from the exterior of the nozzles on printheads


42




a,




42




b,


respectively.




Cavities


76




a,




76




b,


are located in rectangular frame


68


to the right of printhead wipers


72




a,




72




b,


respectively.




The structures and operation of the components of maintenance assembly


16


associated with printhead


42




b


will now be described in detail. It is to be understood that the discussion which follows is also applicable to the components of maintenance assembly


16


associated with printhead


42




a,


but for the sake of brevity, will not be discussed in detail below.




Cap assemblies


74




a,




74




b


are substantially identical, and are positioned to the right of cavities


76




a,




76




b,


respectively, and a discussion of one will be equally applicable to the other. Each cap assembly


74




a,




74




b


includes a printhead cap


80




a,




80




b.



FIG. 2

shows in detail the structure of cap assembly


74




b,


which is substantially identical to cap assembly


74




a.


For the sake of brevity, only the structure of cap assembly


74




b


will be discussed in detail below. As shown in

FIG. 2

, cap assembly


74




b


includes printhead cap


80




b


slidably mounted via post


81


to a base


82


for vertical movement, i.e., perpendicular movement with respect to base


82


, which in turn is connected to rectangular frame


68


of maintenance sled


52


. A spring


84


biases printhead cap


80




b


away from base


82


.




Positioned within each of cavities


76




a,




76




b


is a corresponding rotary waste ink collection assembly


78




a,




78




b,


respectively. Rotary waste ink collection assemblies


78




a,




78




b


are substantially identical, and a discussion of one will be equally applicable to the other. For the sake of brevity, only the structure of rotary waste ink collection assembly


78




b


will be described in detail below.




Referring again to

FIG. 1

, maintenance sled


52


further includes a capping tab


86


which extends vertically upward from rectangular frame


68


. Capping tab


86


facilitates the movement of maintenance sled


52


to the wiping elevation or to the capping elevation along ramped surfaces


60




a,




60




b,




60




c,




60




d


when contacted by carriage


36


.




As shown in

FIG. 1

, rotary waste ink collection assemblies


78




a,




78




b,


include a cylindrical drum


90




a,




90




b.



FIG. 2

further shows an axle


92


, a scraper


94


and a ratchet mechanism


96


for rotary waste ink collection assembly


78




b.






Cylindrical drums


90




a,




90




b


includes a cylindrical waste ink collection surface


98




a,




98




b,


respectively. Ratchet mechanism


96


includes a ratchet gear


100


and a back-check member


102


. Ratchet gear


100


is shown partially broken-away to expose a drum end


104


of cylindrical drum


90


, to which ratchet gear


100


is attached. An axis


106


defines an axis of rotation of axle


92


which extends along axis


106


from opposing ends of cylindrical drum


90


to engage opposing sidewalls of rectangular frame


68


to rotatably mount cylindrical drum


90


and ratchet gear


100


within cavity


76




b.


Rectangular frame


68


includes a pair of holes or slots to mount axle


92


of cylindrical drum


90


. Axis


106


about which cylindrical drum


90


rotates is located to be in a horizontal plane substantially perpendicular to the direction of reciprocation


34


of printhead carriage


36


. As a result, and as graphically depicted in

FIG. 3

, cylindrical drum


90




b


is positioned such that axis of rotation


106


is substantially perpendicular to scanning direction


34


of reciprocating printheads


42




a,




42




b.


Also, the axis of rotation


106


is such that print nozzles


107


of printhead


42




b,


which are arranged in columns, are substantially uniformly spaced from cylindrical waste ink collection surface


98




b


of the cylindrical drum


90




b


during a printhead spitting, or purging, operation which helps to control misting of the purged ink. In some applications, however, it may be desirable for the axis of rotation


106


of cylindrical drum


90




b


to be slightly inclined with respect to a plane of base


82


.




Referring again to

FIG. 2

, back-check member


102


is mounted to printhead cap


80




b


and is movable therewith. Back-check member


102


includes a distal end


108


which extends outwardly and upwardly from printhead cap


80




b.


Distal end


108


is sized and positioned to engage the teeth


110


of ratchet gear


100


to permit a one-way rotation of ratchet gear


100


, and in turn cylindrical drum


90


, in the direction indicated by arrow


112


, and also prevents a rotation of cylindrical drum


90


in a direction opposite to the direction depicted by arrow


112


.




Referring to

FIG. 1

, during use of printer


10


, printing operations occur in a conventional manner that is well understood in the art. A sheet (S) of print media, such as paper, is carried under printheads


42




a,




42




b,


but above bottom frame member


18


. The sheet (S) is carried by a series of rollers (not shown) in the direction shown by arrow


33


. As the sheet is being carried, printheads


42




a,




42




b


reciprocally traverse print zone


44


. Under the control and at locations selected by a microprocessor control means, print cartridges


38




a,




38




b


selectively eject ink from the respective nozzles of printheads


42




a,




42




b


onto sheet (S).




During a maintenance operation, printheads


42




a,




42




b


are moved into maintenance zone


46


to have a maintenance cycle performed. Two types of maintenance cycles are possible: a printing maintenance cycle and a printhead storage maintenance cycle. Both types of maintenance cycles, i.e., the printing maintenance cycle and the printhead storage maintenance cycle, are effected by maintenance assembly


16


. The operation of rotary waste ink collection assemblies


78




a,




78




b


will now be discussed in relation to the maintenance cycles, i.e., the printing maintenance cycle and printhead storage maintenance cycle, and will be discussed with reference to

FIGS. 1-4

.





FIG. 2

shows the orientation of printhead cap


80




b


and back-check member


102


when printhead


42




b


is in the spitting position.

FIG. 4

shows the orientation of printhead cap


80




b


and back-check member


102


when printhead


42




b


is in the capping position and after maintenance sled


52


is placed at the capping elevation. Some of the discussion that follows describes the details of operation of only rotary waste ink collection assembly


78




b


shown in

FIGS. 2 and 4

, but it is to be understood that the discussion that follows directed specifically to rotary waste ink collection assembly


78




b


is equally applicable to the operation of rotary waste ink collection assembly


78




a.






In a printing maintenance cycle, printhead carrier assembly


14


moves to the right along guide rail


32


to maintenance zone


46


. Printhead carrier assembly


14


passes maintenance start position


48


and as printhead carrier assembly


14


moves farther to the right, the rightward leading side of carriage


36


contacts capping tab


86


of maintenance sled


52


. This contact causes maintenance sled


52


to move to the right with the printhead carrier assembly


14


. The rightward movement of carriage


36


causes print latch


62


to momentarily reside in the open position thereby releasing maintenance sled


52


from the lower, or printing, elevation. Also, the rightward movement of carriage


36


raises maintenance sled


52


to the wiping, or mid-level, elevation because dowel members


70




a,




70




b,




70




c,




70




d


of maintenance sled


52


are guided along ramped surfaces


60




a,




60




b,




60




c,




60




d.






Once maintenance sled


52


reaches the wiping elevation, print latch


62


resumes the closed position thereby impeding maintenance sled


52


from migrating back down ramped surfaces


60




a,




60




b,




60




c,




60




d


to the printing elevation due to stop surface


64


on print latch


62


. After print latch


62


resumes the closed position, printhead carrier assembly


14


begins to travel back to the left towards print zone


44


. As printhead carrier assembly


14


moves farther to the left, the nozzles of printheads


42




a,




42




b


are wiped by printhead wipers


72




a,




72




b


to remove excess ink from the nozzles and a portion of the leftward leading side of carriage


36


contacts print latch


62


causing print latch


62


to assume the open position. Once print latch


62


is in the open position, dowel members


70




a,




70




b,




70




c,




70




d


of maintenance sled


52


migrate down ramped surfaces


60




a,




60




b,




60




c,




60




d


from the mid-level wiping elevation to the lower printing elevation due to gravity.




Print cartridges


38




a,




38




b


are positioned over discharge cavities


76




a,




76




b,


respectively. Ink is ejected from the nozzles in printheads


42




a,




42




b.


The ejected ink, or waste ink


118


, falls onto the cylindrical waste ink collection surfaces


98




a,




98




b


of each of cylindrical drums


90




a,




90




b


of rotary waste ink collection assemblies


78




a,




78




b.


After ink is ejected, printhead carrier assembly


14


enters print zone


44


ready to begin printing.




Ink may be ejected from the nozzles of printheads


42




a,




42




b


while maintenance sled


52


is in the mid-level wiping elevation or the lower level printing elevation.




The printhead storage maintenance cycle is generally analogous to the printing maintenance cycle, except that printhead carrier assembly


14


does not stop its rightward motion when maintenance sled


52


is at the wiping elevation. Instead, printhead carrier assembly


14


continues to move to the right, thereby further moving maintenance sled


52


to the right until dowel members


70




a,




70




b,




70




c,




70




d


of maintenance sled


52


are at the capping, or upper, elevation of ramp surfaces


60




a,




60




b,




60




c,




60




d.






Referring to

FIG. 4

, when maintenance sled


52


moves to the capping, or upper, position, printhead cap


80




b


engages printhead


42




b


and printhead cap


80




b


is forced relatively downward in the direction indicated by arrow


114


, e.g. vertically, toward base


82


, thereby placing spring


84


in a state of compression. Since distal end


108


of back-check member


102


extends outwardly and upwardly from printhead cap


80




b,


distal end


108


passes over teeth


110


during the movement in the direction of arrow


114


without effecting rotation of cylindrical drum


90




b.


When maintenance sled


52


is at the capping elevation, caps


80




a,




80




b,


respectively form an air seal around the nozzles on printheads


42




a,




42




b


to prevent the ink on the nozzles from drying.




Once printhead carrier assembly


14


begins to move to the left toward print zone


44


, maintenance sled


52


migrates down ramp surfaces


60




a,




60




b,




60




c




60




d


from the capping elevation to the wiping elevation, thereby disengaging caps


80




a,




80




b


from the respective printheads


42




a,




42




b.


As stated earlier, when printheads


42




a,




42




b


are positioned over cylindrical waste ink collection surfaces


98




a,




98




b


of cylindrical drums


90




a,




90




b,


printheads


42




a,




42




b


eject, or spit, waste ink


118


from the nozzles onto cylindrical waste ink collection surfaces


98




a,




98




b


and are wiped by printhead wipers


72




a,




72




b


as printhead carrier assembly


14


moves to the left. In addition, as caps


80




a,




80




b


are disengaging printheads


42




a,




42




b,


their respective rotary waste ink collection assemblies are activated for rotation.




Referring again to

FIGS. 1 and 4

, as maintenance sled


52


begins to migrate down ramp surfaces


60




a,




60




b,




60




c




60




d


from the capping elevation to the wiping elevation, distal end


108


of back-check member


102


engages teeth


110


, and both printhead cap


80




b


and back-check member


102


move relatively upwardly (e.g., vertically) with respect to base


82


in the direction depicted by arrow


116


to cause cylindrical drum


90




b


to rotate in the direction of arrow


112


. As a result of the rotation of cylindrical drum


90




b,


a portion of the waste ink


118


collected on cylindrical waste ink collection surface


98




b


is removed by scraper


94


, which then falls toward printer bottom frame member


18


. Scraper


94


is positioned so as to remove at least a portion of the waste ink


118


. As shown in

FIG. 4

, scraper


94


is positioned below cylindrical drums


90




a,




90




b;


however, scraper


94


may be positioned along side, above, or even in contact with cylindrical drums


90




a,




90




b.


It should be noted that the position of scraper


94


is limited only to the extent that it should not interfere with the ejection of ink from printheads


42




a,




42




b.






Although the invention is described above in relation to a printing system having two printheads, those skilled in the art will recognize that the invention is equally applicable to and adaptable to a system having a single printhead, or a system having more than two printheads.




While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.



Claims
  • 1. A maintenance station for an ink jet printer, comprising:a frame; a device rotatably coupled to said frame for collecting waste ink; and a ratchet drive assembly coupled to said frame for effecting rotation of said device, wherein said ratchet drive assembly comprises a ratchet gear coupled to said device, said ratchet gear having a plurality of teeth, and a back-check member having a distal end which engages said teeth for effecting a rotation of said device in a first direction.
  • 2. A The maintenance station of claim 1, wherein said back-check member prevents a rotation of said device in a direction opposite to said first direction.
  • 3. The maintenance station of claim 1, further comprising a scraper for removing at least a portion of said waste ink from said device as said device is rotated.
  • 4. The maintenance station of claim 3, wherein said device is a cylindrical drum having an end.
  • 5. The maintenance station of claim 4, wherein said ratchet gear is attached to said end of said cylindrical drum.
  • 6. A maintenance station for an ink jet printer, comprising:a frame; a device rotatably coupled to said frame for collecting waste ink; a ratchet drive assembly coupled to said frame for effecting rotation of said device, wherein said ratchet drive assembly comprises a ratchet gear coupled to said device, said ratchet gear having a plurality of teeth, and a back-check member having a distal end which engages said teeth for effecting a rotation of said device in a first direction; and a printhead capping assembly coupled to said frame, said printhead capping assembly having a printhead cap for engaging said printhead during a capping operation, said printhead capping assembly being coupled to said back-check member.
  • 7. The maintenance station of claim 6, wherein said rotation of said device is effected as said printhead cap is moved in a vertical direction.
  • 8. The maintenance station of claim 6, wherein said rotation of said device is effected as said printhead cap disengages said printhead.
  • 9. A maintenance station for an ink jet printer having a carriage assembly for moving an ink jet printhead having a column of nozzles along a linear scanning path, comprising:a frame; a printhead capping assembly coupled to said frame, said printhead capping assembly having a printhead cap for engaging said printhead during a capping operation, said printhead capping assembly being located on said frame along said linear scanning path of said ink jet printhead; and a cylindrical drum having a cylindrical surface, said cylindrical drum being rotatably coupled to said frame and positioned adjacent said printhead capping assembly, said cylindrical drum being orientated such that an axis of rotation of said cylindrical drum is substantially perpendicular to said linear scanning path of said ink jet printhead.
  • 10. The maintenance assembly of claim 9, wherein said cylindrical drum is further oriented to provide a substantially uniform spacing between said column of nozzles and said cylindrical surface of said cylindrical drum.
  • 11. The maintenance station of claim 9, further comprising a ratchet drive assembly coupled to said frame for effecting a rotation of said cylindrical drum.
  • 12. A maintenance station for an ink jet printer having a carriage assembly for moving an ink jet printhead having a column of nozzles along a linear scanning path, comprising:a frame; a printhead capping assembly coupled to said frame, said printhead capping assembly having a printhead cap for engaging said printhead during a capping operation, said printhead capping assembly being located on said frame along said linear scanning path of said ink jet printhead; a cylindrical drum having a cylindrical surface, said cylindrical drum being rotatably coupled to said frame and positioned adjacent said printhead capping assembly, said cylindrical drum being orientated such that an axis of rotation of said cylindrical drum is substantially perpendicular to said linear scanning path of said ink jet printhead; and a ratchet drive assembly coupled to said frame for effecting a rotation of said cylindrical drum, wherein said ratchet drive assembly comprises a ratchet gear coupled to said cylindrical drum, said ratchet gear having a plurality of teeth, and a back-check member coupled to said capping assembly, said back-check member having a distal end which engages said teeth.
  • 13. The maintenance station of claim 12, wherein said rotation of said cylindrical drum is effected as said printhead capping assembly disengages said printhead.
  • 14. The maintenance station of claim 13, wherein said cylindrical drum is located such that said nozzles are positioned to be substantially uniformly spaced from said cylindrical surface of said cylindrical drum during a nozzle purging operation.
  • 15. A printer for printing with an ink jet printhead, comprising:a printer frame; a carriage assembly coupled to said printer frame, said carriage assembly moving said ink jet printhead along a linear scanning path; a maintenance assembly frame coupled to said printer frame; a device rotatably coupled to said maintenance frame for collecting waste ink ejected by said printhead; and a ratchet drive assembly coupled to said maintenance frame for effecting rotation of said device, said ratchet drive assembly comprises a ratchet gear coupled to said device, said ratchet gear having a plurality of teeth, and a back-check member having a distal end which engages said teeth for effecting a rotation of said device in a first direction.
  • 16. The printer of claim 15, wherein said back-check member prevents a rotation of said device in a direction opposite to said first direction.
  • 17. The printer of claim 15, further comprising a printhead capping assembly coupled to said maintenance frame, said printhead capping assembly having a printhead cap for engaging said printhead during a capping operation, said printhead capping assembly being coupled to said back-check member to effect movement of said back-check member.
  • 18. The printer of claim 17, wherein said rotation of said device is effected as said printhead cap disengages said printhead after a printhead capping operation.
  • 19. The printer of claim 15, wherein said device is a cylindrical drum having an end.
  • 20. The printer of claim 19, further comprising a ratchet gear attached to said end of said cylindrical drum.
  • 21. The printer of claim 15, further comprising a scraper for removing at least a portion of said waste ink from said device as said device is rotated.
  • 22. The printer of claim 21, wherein said device comprises a cylindrical drum.
US Referenced Citations (7)
Number Name Date Kind
4558326 Kimura et al. Dec 1985
4701771 Ikeda Oct 1987
5517222 Sugiyama et al. May 1996
5614930 Osborne et al. Mar 1997
5617124 Taylor et al. Apr 1997
5712668 Osborne et al. Jan 1998
5742303 Taylor et al. Apr 1998