Cleaning orifices in ink jet printing apparatus

Information

  • Patent Grant
  • 6281909
  • Patent Number
    6,281,909
  • Date Filed
    Thursday, September 24, 1998
    25 years ago
  • Date Issued
    Tuesday, August 28, 2001
    22 years ago
Abstract
An ink jet printer having an ink jet head and defining a structure having a device including a structure defining a plurality of orifices for ejecting ink droplets includes defining an ink cleaning cavity spaced from the printing position for receiving cleaning fluid; a roller disposed in the cleaning cavity and partially submerged in the cleaning fluid and spaced from the structure is rotated so that the fluid coats the roller and is carried by surface tension around the roller; and the structure is brought into proximity with the cleaning roller so that the orifices are cleaned by the cleaning fluid carried on the roller and delivered through the cleaning cavity to the structure.
Description




FIELD OF THE INVENTION




This invention relates to the cleaning of ink jet print head apparatus having multiple orifices.




BACKGROUND OF THE INVENTION




Many different types of digitally controlled printing systems of ink jet printing apparatus are presently being used. These ink jet printers use a variety of actuation mechanisms, a variety of marking materials, and a variety of recording media. For home applications, digital ink jet printing apparatus is the printing system of choice because low hardware cost make the printer affordable to every one. Another application for digital ink jet printing uses large format printers. It is a further requirement that these large format printers provide low cost copies with an ever improving quality. Ink jet printing technology is the first choice in today's art. Thus, there is a need for improved ways to make digitally controlled graphic arts media, such as billboards, large displays, and home photos for example, so that quality color images may be made at a high-speed and low cost, using standard or special paper.




Ink jet printing has become recognized as a prominent contender in the digitally controlled, electronic printing arena because of its nonimpact, lownoise characteristics, its use of papers from plain paper to specialized high gloss papers and its avoidance of toner transfers and fixing. Ink jet printing mechanisms can be categorized as either continuous ink jet or droplet on demand ink jet. Continuous ink jet printing dates back to at least 1929. See U.S. Pat. No. 1,941,001 to Hansell.




U.S. Pat. No. 3,373,437, issued to Sweet et al. in 1967, discloses an array of continuous ink jet orifices wherein ink droplets to be printed are selectively charged and deflected towards the recording medium. This technique is known as binary deflection continuous ink jet, and is used by several manufacturers, including Elmjet and Scitex.




U.S. Pat. No. 3,416,153, issued to Hertz et al. in 1966, discloses a method of achieving variable optical density of printed spots in continuous ink jet printing using the electrostatic dispersion of a charged droplet stream to modulate the number of droplets which pass through a small orifice. This technique is used in ink jet printers manufactured by Iris.




U.S. Pat. No. 3,878,519, h issued to Eaton in 1974, discloses a method and apparatus for synchronizing droplet formation in a liquid stream using electrostatic deflection by a charging tunnel and deflection plates.




U.S. Pat. No. 4,346,387, issued to Hertz in 1982 discloses a method and apparatus for controlling the electric charge on droplets formed by the breaking up of a pressurized liquid stream at a droplet formation point located within the electric field having an electric potential gradient. Droplet formation is effected at a point in the field corresponding to the desired predetermined charge to be placed on the droplets at the point of their formation. In addition to charging tunnels, deflection plates are used to actually deflect droplets.




Conventional continuous ink jet utilizes electrostatic charging tunnels that are placed close to the point where the droplets are formed in a stream. In this manner individual droplets may be charged. The charged droplets may be deflected downstream by the presence of deflector plates that have a large potential difference between them. A gutter (sometimes referred to as a “catcher”) may be used to intercept the charged droplets, while the uncharged droplets are free to strike the recording medium. If there is no electric field present or if the break off point from the droplet is sufficiently far from the electric field (even if a portion of the stream before droplets break off is in the presence of an electric field), then charging will not occur.




The on demand type ink jet printers are covered by hundreds of patents and describe two techniques for droplet formation. At every orifice, (about 30 to 200 are used for a consumer type printer) a pressurization actuator is used to produce the ink jet droplet. The two types of actuators are heat and piezo materials. The heater at a convenient location heats ink and a quantity will phase change into a gaseous steam bubble and raise the internal ink pressure sufficiently for an ink droplet to be expelled to a suitable receiver. The piezo ink actuator incorporates a piezo material. It is said to possess piezo electric properties if an electric charge is produced when a mechanical stress is applied. This is commonly referred to as the “generator effect” “The converse also holds true; an applied electric field will produce a mechanical stress in the material. This is commonly referred to as the “motor effect”. Some naturally occurring materials possessing this characteristics are: quartz and tourmaline. Some artificially produced piezoelectric crystals are: Rochelle salt, ammonium dihydrogen phosphate (ADP) and lithium sulphate (LH). The class of materials used for piezo actuators in an ink jet print head possessing those properties includes polarized piezoelectric ceramics. They are typically referred to as ferroelectric materials. In contrast to the naturally occurring piezoelectric crystals, ferroelectric ceramics are of the “polycrystalline” structure. The most commonly produced piezoelectric ceramics are: lead zirconate titanate, barium titanate, lead titanate, and lead metaniobate. For the ink jet print head a ferroelectric ceramic is machined to produce ink chambers. The chamber is water proofed by gold plating and becomes a conductor to apply the charge and cause the piezo “motor effect”. This “motor effect” causes the ink cavity to shrink, raise the internal pressure, and generate an ink droplet.




Inks for high speed jet droplet printers must have a number of special characteristics. Typically, water-based inks have been used because of their conductivity and viscosity range. Thus, for use in a jet droplet printer the ink must be electrically conductive, having a resistivity below about 5000 ohm-cm and preferably below about 500 ohm-cm. For good flow through small orifices water-based inks generally have a viscosity in the range between about 1 to 15 centipoise at 25 degree C.




Over and above this, the ink must be stable over a long period of time, compatible with the materials comprising the orifice plate and ink manifold, free of living organisms, and functional after printing. The required functional characteristics after printing are: smear resistance after printing, fast drying on paper, and waterproof when dry. Examples of different types of water-based jet droplet printing inks are found in U.S. Pat. No. 3,903,034; 3,889,269; 3,870,528; 3,846,141; 3,776,642; and 3,705,043.




The ink also has to incorporate a nondrying characteristic in the jet cavity so that the drying of ink in the cavity is hindered or slowed to such a degree that through occasional spitting of ink droplets the cavities can be kept open. The addition of glycol will facilitate the free flow of ink through the ink jet. Ink jet printing apparatus typically includes an ink jet print head that is exposed to the various environment where ink jet printing is utilized. The orifices are exposed to all kinds of air born particles. Particulate debris accumulates on the surfaces, forming around the orifices. The ink will combine with such particulate debris to form an interference burr to block the orifice or cause through an altered surface wetting to inhibit a proper formation of the ink droplet. That particulate debris has to be cleaned from the orifice to restore proper droplet formation. This cleaning commonly is achieved by wiping, spraying, vacuum suction, and/or spitting of ink through the orifice. The wiping is the most common application.




Inks used in ink jet printers can be said to have the following problems:




1) they require a large amount of energy to dry after printing;




2) large printed areas on paper usually cockle because of the amount of water present;




3) the printed images are sensitive to wet and dry rub;




4) the compositions of the ink usually require an anti-bacterial preservative to minimize the growth of bacteria in the ink;




5) the inks tend to dry out in and around the orifices resulting in clogging;




6) the wiping of the orifice plate causes wear on plate and wiper;




7) the wiper itself generates particles that clog the orifice;




8) cleaning cycles are time consuming and slow the productivity of ink jet printers. It is especially of concern in large format printers where frequent cleaning cycles interrupt the printing of an image; and




9) when a special printing pattern is initiated to compensate for plugged or badly performing orifices, the printing rate declines.




Some of these problems may be overcome by the use of polar, conductive organic solvent based ink formulations. However, the use of non-polar organic solvents is generally precluded by their lack of electrical conductivity. The addition of solvent soluble salts can make such inks conductive, but such salts are often toxic, corrosive, and unstable.




SUMMARY OF THE INVENTION




It is an object of the invention to provide an ink jet printing apparatus wherein cleaning can be effectively accomplished with a minimum number of parts and operations.




It is another object of this invention to provide for cleaning of ink jet printing apparatus orifices which is accomplished in a minimum time cycle.




It is a further object of the present invention to provide for cleaning a particulate debris thereby eliminating the need of traditional wiper blades.




These objects are achieved by an ink jet printer having a printhead with a source of cleaning fluid and a cleaning member having a surface partially dipped in the cleaning fluid. A first drive mechanism moves the cleaning member surface, creating a continuous flow of cleaning fluid on the surface. A second drive mechanism advances the printhead and the cleaning member surface into a proximate and separate relation, wherein at least one of a plurality of orifices of the printhead enters the continuous flow of fluid.




ADVANTAGES OF THE INVENTION




Rapid cleaning of orifices in accordance with the present invention can be accomplished in such a short time because of the efficiency of cleaning apparatus in accordance with the present invention.




The cleaning fluid on the roller is replenished at a predetermined rate and removes waste ink and particulate debris permanently from the ink jet print head.




Another advantage of this invention is that the cleaning fluid on the roller can have a substantial thickness thereby minimizing the requirements for mechanical tolerances.




Another advantage of this cleaning technique is that with no mechanical rubbing, the wear of the delicate orifice plate is eliminated or greatly reduced. The replacement of the ink jet head will be less frequent and more of the orifices will stay functional to result in a higher image quality.




Another advantage is that individual inks can be cleaned by selecting the rotation rate of the roller to change the turbulence or agitation rate. In this way, the speed of the roller can be selected to match the cleaning needs of a particular ink. In other words, red, green, and blue inks in the same cartridge can have different roller speeds.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a prior art cross sectional schematic view of a typical piezo electric ink jet print head;





FIG. 2

is a schematic showing an ink droplet exit orifice in the

FIG. 1

structure and an elastomeric wiper blade commonly used for cleaning the orifice plate;





FIG. 3

the ink droplet as it begins to form in the orifice of

FIG. 1

;





FIG. 4

shows the ink droplet after formation with the orifice of

FIG. 1

;





FIG. 5

shows the interference of the particulate debris with the formation of an ink droplet;





FIG. 6

shows that a particulate material can cause a change of direction of ink droplets;





FIG. 7

shows a schematic of ink jet printing apparatus in accordance with the present invention which shows a print head and a cleaning station;





FIG. 8

shows the same as

FIG. 7

but a different perspective for clarification of illustration;





FIG. 9

shows the cleaning mechanism in accordance with the present invention;





FIG. 10

shows an enlargement of the cleaning fluid coating depicting its turbulent counter clockwise flow; and





FIG. 11

shows a schematic view of another embodiment of the present invention which depicts an ink jet print head and a head cleaning device.











DETAILED DESCRIPTION OF THE INVENTION





FIG. 1

shows a prior art cross sectional view of an ink jet print head


1


. Orifices defining structures such as the depicted outlet plate


5


includes orifice


9


having a diameter “d” and can be manufactured by electro-forming or sheet metal fabrication methods. It will be understood that the outlet plate


5


actually includes a plurality of orifices for forming multiple ink droplets. The outlet plate


5


is glued to the piezo walls


3


. Ink


2


is included in a pumping cavity


8


. An inlet orifice


7


formed in a inlet plate


4


permits ink to be delivered to the pumping cavity


8


. A meniscus


6


of ink is formed in the orifice


9


.





FIG. 2

shows the outlet plate


5


with the ink outlet meniscus


6


and a elastomeric wiper blade


10


in contact with the outlet orifice plate. The blade is in position to wipe across the diameter “d” of the orifice


9


to clean any ink or other particulate debris that could interfere with the proper functioning of the ink jet print head


1


.





FIG. 3

shows the meniscus


6


as it changes from an inward curve to an outward curve during the early stages before an actual ink droplet is manufactured. For reference and clarity the elastomeric wiper blade


10


and the outlet orifice plate


5


are also shown.





FIG. 4

shows the completed ink droplet


30


, and its direction which is indicated by the arrow “X”. Also shown are (as often is the case when an ink droplet is formed) two ink droplet satellites


31


. The formation of satellites


31


is chaotic and can incorporate any number of ink droplet satellites


31


from 0 up to 10. These numbers of satellites


31


have been observed. Note that the outlet meniscus


6


has returned to the original state.





FIG. 5

shows how a debris


40


can interfere with the meniscus


6


during the ink droplet formation. As the ink


2


touches the debris


40


, the droplet formation can be completely stopped by the ink surface condition change, due to the presence of the debris


40


. Again outlet orifice plate


5


and elastomeric wiper blade


10


are shown for clarity.





FIG. 6

shows another defect caused by the presence of a debris


40


. The direction of the droplet


30


with satellites


31


shown as “X” is changed and will result in a degradation of the image. Again outlet orifice plate


5


and elastomeric wiper blade


10


are shown for clarity. Note that the outlet meniscus


6


has returned to the original state but debris


40


can also interfere with that process.





FIG. 7

shows an ink jet printing apparatus


79


in accordance with the present invention, an ink jet head


75


, a drive motor


70


linked with a gearbox


71


, an ink jet head belt drive wheel


74


, and the ink jet head drive belt


72


to drive the ink jet head


75


back and for across the print paper


85


. The ink jet droplets are controlled by the position of the ink jet head


75


. This position is monitored by a position encoder strip


76


and the image input from computer


100


. The same computer controls the ink jet print head


75


, drive motor


70


, the cleaning roller drive motor


83


which rotates at a desired velocity the cleaning roller


91


. Also shown are the guide


84


for back and forth translation of the ink jet head


75


. The ink jet generates an image


81


(shown in

FIG. 8

) on the print paper


85


. The print paper


85


is supported by the platen roller


78


and registration of the paper is controlled by the capstan roller


88


. Both rollers, platen


78


and capstan


88


are driven by a motor not shown and are controlled by the computer


100


. Also shown is a cleaning roller


91


with the cleaning roller drive belt


82


connecting the cleaning drive motor


83


to the cleaning roller


91


. A mounting structure


87


supports all the associated mechanism for the ink jet printer


79


.





FIG. 8

shows the same printer as

FIG. 7

but in a 90 degree rotated position. It can now be visualized how the ink jet head


75


with ink droplets


77


move across the paper


85


driven by the ink jet print head drive motor


70


, a gearbox


71


to match motor speed with print speed. An ink jet head drive belt


72


driven by the belt drive wheel


74


drives the ink jet print head


75


across the total width of the print paper


85


. The position of the print head


75


is metered by the position encoder strip


76


. At the right location determined by the computer


100


(shown in

FIG. 7

) and the encoder strip


76


a ink droplet


77


is deposited to form the image


81


. When the ink jet print head


75


reaches the far end of the print paper


85


it de-accelerates in the indicated direction and distance of arrow “d”. When reversing′ indicated by the direction and distance of arrow “a”, the print head


75


re-accelerates to the correct print speed. This turn around deceleration (“d”) and re-acceleration (“a”) time is used to accomplish the cleaning without added time for the ink jet print head


75


. The cleaning station


89


is mounted at the far right side end of the ink jet printer


79


and consists of a cleaning fluid tank


92


, a cleaning roller


91


, cleaning roller drive motor


83


, and a cleaning roller drive belt


82


. A number of different cleaning fluids can be used in accordance with the present invention. For example, such fluids can include plain water, distilled water, alcohol or other water miscible solvents, and surfactants such as Zonyl, FSN (duPont). See also the disclosure of the above referenced commonly assigned U.S. patent application Ser. No. 09/159,979 filed concurrently herewith, now U.S. Pat. No. 5,997,127, entitled “Adjustable Vane Used in Cleaning Orifices in Inkjet Printing Apparatus” to Werner Fassler et al., the disclosure of which is incorporated herein by reference.





FIG. 9

shows the rotating cleaning roller


91


mounted to a shaft


93


is partially submerged in the cleaning fluid and spaced from the structure defining the orifices


9


. The cleaning roller


91


, as it rotates, carries by surface tension a coating


94


of cleaning liquid


95


to the outlet orifice plate


5


. The roller or the roller surface is made from a material which can be surface coated by the cleaning fluid. Such roller surface material can be selected from the group consisting of aluminum, teflon, polyvinyl chloride, stainless steel, glass, and titanium. The liquid will fill the cleaning cavity


80


. The liquid surface friction between the stationary outlet orifice plate


5


and the rotating cleaning roller


91


will cause a great amount of turbulence and liquid shearing to remove dirt and ink from the outlet orifice plate


5


in and near the orifices


6


. An arrow marked “r” indicates one of the possible two the rotational direction of the cleaning roller


91


.





FIG. 10

shows in an enlarged form how the fluid friction shown by vectors


101


causes the flow of the cleaning fluid to shear dirt and other particles


40


permanently from the outlet orifice plate


5


. The vectors


101


indicate the flow of fluid in the cleaning cavity


80


caused by surface friction of orifice plate


5


and cleaning roller


91


.





FIG. 11

shows another embodiment of the invention cleaning an ink jet print head. The ink jet print head has moved (see arrows) from the print position (not shown) to a cleaning position. The head cleaning device


111


includes a cleaning liquid collection vessel


113


, cleaning liquid supply


115


and exit


117


channels, and a rotating cleaning roller


119


mounted onto a shaft


121


. A wall


147


separates the channels


115


and


117


. Cleaning head


111


is brought into contact with outlet orifice plate


123


and a leak-proof seal is created by elastomer


125


at bottom of cleaning head


111


. The outlet orifice plate


123


has a plurality of orifices of which only one orifice


151


is shown. Cleaning liquid


127


is pumped from cleaning liquid reservoir


133


into cleaning liquid supply channel


115


(by pump


131


with valves


137


and


139


in the open position and valve


141


in the closed position). Cap and vent


128


is provided on the reservoir


133


. The head cleaning device


111


is substantially filled with cleaning liquid


127


. Cleaning roller


119


(driven “by a cleaning roller drive motor (not shown) controlled” by computer


100


shown in

FIG. 7

) is rotated at the desired rotation rate. The rotation of the cleaning roller creates shear forces in the gap


118


, thus producing a cleansing/scrubbing action capable of dislodging particles and/or debris accumulating around ink jet orifices. The size of gap


118


is controlled by the location of the cleaning roller, the diameter of the cleaning roller and the thickness of the elastomer seal


125


. The dislodged debris is carried away by the cleaning liquid exiting in exit channel


117


. However, particles and fibers may adhere to rotating cleaning roller


119


, in which case the contaminated rotating cleaning roller


119


will most likely abrade outlet orifice plate


123


. In order to minimize this, a scraper blade


149


attached to the roller end of wall


147


and in contact with cleaning roller


119


removes particles adhering to the roller and also prevents particles form entering the supply channel


115


. It is preferred but not necessary that the scraper be flexible and in contact with cleaning roller


119


. The exiting cleaning liquid preferably is re-circulated. A filter


129


interposed between the cleaning liquid reservoir


133


and pump


131


ensures that cleaning liquid entering the supply channel


115


is free of particles and fibers. A second filter


135


is also preferably used to filter cleaning liquid from exit channel


117


before entering reservoir


133


. The cleaning liquid is fed into device


111


at a steady rate by pump


131


. At a desired time, pump


131


is turned off and valve


139


is closed. Valve


137


(a 3-way valve) is positioned so that it is open to atmosphere only. Vacuum pump


143


is activated and valve


141


is opened to suck trapped cleaning liquid between valves


137


and


139


into collection receptacle


145


. This operation prevents spillage of cleaning liquid when the device


111


is detached from outlet orifice plate


123


. Further, the outlet orifice plate


123


is substantially dry, permitting the ink jet print head to function without impedance from liquid drops around the orifices. Cleaning liquid in collection receptacle


145


may be poured back into cleaning liquid reservoir


133


or can be pumped back into cleaning liquid reservoir


133


(pump and piping is not shown).




Although the cleaning roller surface


153


is shown spaced from the plate


123


, it can be in direct contact with plate. In such a case the roller surface


153


should be formed of a soft absorbent material such as porous elastomeric material which can carry cleaning liquid


127


. In this case it is preferable that the scraper blade


149


presses against the roller surface


153


so that cleaning fluid and debris is squeezed out of the porous roller surface


153


. For this purpose, it is preferable that the scraper blade


149


be constructed out of a stiff material made of plastic.




It is understood that the device


111


would function without wall


147


and scraper blade


149


. In this case however, channels


115


and


117


would be combined to create one chamber with an inlet and an out let for the cleaning solution. This modification to head cleaning device


111


is not shown. The head cleaning device


111


will also function if the device is primed with cleaning liquid and connected to a cleaning liquid reservoir. When the cleaning roller rotates, cleaning liquid is siphoned from cleaning solution reservoir and pumped through device


111


. The cleaning roller therefore has a dual function in that it cleans the outlet orifice plate


123


and also acts as a pump. This embodiment is not shown. The device


111


may also be configured to utilize a variety of cleaning liquids by incorporating appropriate valves and plumbing (not shown).




The invention has been described in detail, with particular reference to certain preferred embodiments thereof, but it should be understood that variations and modifications can be effected with the spirit and scope of the invention.




PARTS LIST






1


ink jet print head






2


ink






3


piezo material






4


inlet plate






5


outlet plate






6


outlet meniscus






7


inlet orifice






8


pumping cavity






9


outlet orifice






10


elastomeric wiper blade






30


ink droplet






31


satellite






40


debris as particles






70


ink jet head drive motor






71


gearbox






72


ink jet head drive belt






74


drive wheel






75


ink jet head






76


encoder strip






77


ink droplets






78


platen roller






79


ink jet printer






80


cavity space






81


image






82


cleaning roller drive belt






83


cleaning roller drive motor






84


guide






85


print paper






87


mounting structure




PARTS LIST (con't)






88


capstan roller






89


cleaning station






91


cleaning roller






92


cleaning fluid tank






93


shaft






94


surface coating






95


cleaning liquid






100


computer






101


vectors






111


head cleaning device






113


cleaning liquid collection vessel






115


cleaning liquid supply channel






116


cleaning liquid exit channel






117


exit channel






118


gap






119


rotating cleaning roller






121


shaft






123


outlet orifice plate






125


elastomer






127


cleaning liquid






128


cap and vent






129


first filter






131


pump






133


cleaning liquid reservoir






135


second filter






137


first valve, 3-way valve






139


second valve






141


third valve






143


vacuum pump




PARTS LIST (con't)






145


collection receptacle






147


wall






149


scraper blade






151


orifice






153


cleaning roller surface



Claims
  • 1. An ink jet printer having a printhead defining a plurality of orifices for ejecting ink droplets, said printer comprising:a source of cleaning fluid; a cleaning member having a surface partially dipped in the cleaning fluid; a first drive mechanism to move the cleaning member surface creating a flow of cleaning fluid on the surface; and a second drive mechanism to advance the printhead and the cleaning member surface into a proximate and separate relation wherein at least one of the orifices of the printhead enter flow of cleaning fluid.
  • 2. The inkjet printer of claim 1 wherein the proximate and separate relation is defined so that at least one of the orifices are entered into the flow of fluid to disrupt the flow of cleaning fluid in a manner that creates a turbulent flow about the at least one orifice.
  • 3. The ink jet printer of claim 1 wherein the cleaning member is a rotating roller.
  • 4. The inkjet printer of claim 3 wherein the roller surface is selected from the group consisting of aluminum, teflon, polyvinyl chloride, stainless steel, glass and titanium.
  • 5. The inkjet printer of claim 1 wherein the surface is made from a material which can be surface coated by the cleaning fluid.
  • 6. The inkjet printer of claim 1 wherein the surface is selected from the group consisting of aluminum, teflon, polyvinyl chloride, stainless steel, glass and titanium.
  • 7. The inkjet printer of claim 1 wherein said second drive mechanism advances the printhead relative to the surface so that selected ones of the orifices of the printhead are entered into the flow of cleaning fluid.
  • 8. The inkjet printer of claim 1 wherein said second drive mechanism also advances the surface relative to the printhead so that the flow of cleaning fluid is advanced to create a flow of cleaning fluid about selected ones of the orifices of the printhead.
  • 9. The inkjet printer of claim 1 further comprising an exit channel and wherein the moving cleaning member surface causes cleaning fluid to flow into the exit channel.
  • 10. An inkjet printer having a printhead and including a structure defining a plurality of ink drop ejection orifices, comprising:a liquid collection vessel adapted to contain a cleaning fluid; a roller partially submerged in the cleaning fluid; a first motor fixed to and rotating the roller to create a flow of cleaning fluid about the roller; and a second motor to variably position the roller and the printhead between two separated positions, a distal position and a proximate position wherein at least one orifice of the printhead enters into the flow of cleaning fluid.
  • 11. The printer of claim 10 wherein said proximate position is defined to introduce the at least one orifice into the flow of cleaning fluid so as to create turbulent flow about at least one orifice.
  • 12. The printer of claim 10 wherein said proximate position is defined by a stop that prevents advancing the printhead into contact with the roller.
  • 13. The printer of claim 10 further comprising a used cleaning fluid chamber disposed proximate to the liquid collection vessel.
  • 14. The printer of claim 13 further comprising a blade in communication with the roller for separating used cleaning fluid from the roller and directing the used cleaning fluid into the used cleaning fluid chamber.
  • 15. The ink jet printer of claim 10 wherein the surface is made from a material which can be surface coated by the cleaning fluid.
  • 16. The ink jet printer of claim 10 wherein the roller surface material is selected from the group consisting of aluminum, teflon, polyvinyl chlorine, stainless steel, glass, and titanium.
  • 17. An inkjet printer having an printhead defining a plurality of orifices for ejecting ink droplets, comprising:a) means defining an ink cleaning cavity spaced from the printing position for receiving cleaning fluid; b) a surface disposed in the cleaning cavity and partially submerged in the cleaning fluid and spaced from the printhead; c) means for moving the surface to draw a flow of cleaning fluid across the moving surface; and d) means for bringing the printhead orifices into a proximate and separate relation to the moving surface so that the orifices are injected into the flow of cleaning fluid and are cleaned by the cleaning fluid.
  • 18. The ink jet printer of claim 17 wherein the means for bringing the structure into a proximate and separate relation with the moving surface to create a turbulence of the cleaning fluid about at least one orifice.
  • 19. The ink jet printer of claim 17 wherein the surface is made from a material which can be surface coated by the cleaning fluid.
  • 20. The ink jet printer of claim 17 wherein the roller surface material is selected from the group consisting of aluminum, teflon, polyvinly chlorine, stainless steel, glass, and titanium.
  • 21. An ink jet printer having a print head defining a plurality of orifices for ejecting ink droplets, said printer comprising:a supply of cleaning fluid; a cleaning surface in partial contact with the supply of cleaning fluid; a first drive mechanism to rotate the cleaning surface so that the rotation of the cleaning surface impels cleaning fluid from the supply to form a flow of cleaning fluid about the cleaning surface; a second motor to variably position the cleaning surface and the print head between two separated positions, a distal position and a proximate position wherein at least one orifice of the print head enters into the flow of cleaning fluid.
  • 22. The inkjet printer of claim 21 wherein the proximate and separate relation is defined so that at least one of the orifices are entered into the flow of fluid to disrupt the flow of cleaning fluid in a manner that creates a turbulent flow about the at least one orifice.
  • 23. The ink printer of claim 21 wherein the cleaning surface is a rotating roller.
  • 24. The inkjet printer of claim 21 wherein second drive mechanism advances the print head relative to the surface so that selected ones of the orifices of the print head are entered into the flow of cleaning fluid.
  • 25. The inkjet printer of claim 21 further comprising an exit channel wherein the moving cleaning member surface impels cleaning fluid to flow from the cleaning fluid source across the cleaning member surface and into the exit channel.
CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly assigned entitled U.S. Pat. No. 5,997,127 issued on Dec. 7, 1999 “entitiled Adjustable Vane Used in Cleaning Orifices in Inkjet Printing Apparatus” to Werner Fassler et al., the disclosure of which is incorporated herein by reference.

US Referenced Citations (20)
Number Name Date Kind
3373437 Sweet et al. Mar 1968
3416153 Hertz et al. Dec 1968
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