Rotating disk cleaning assembly apparatus and method for an ink jet print head with fixed gutter

Information

  • Patent Grant
  • 6554391
  • Patent Number
    6,554,391
  • Date Filed
    Thursday, July 20, 2000
    24 years ago
  • Date Issued
    Tuesday, April 29, 2003
    21 years ago
Abstract
A self-cleaning printer system (400) with cleaning liquid (300) and cleaning mechanism (140) with a rotating disk cleaning assembly (32) can be used to remove contaminants from a print head (16) in the self-cleaning ink jet printer system (400). A rotating disk cleaning assembly (32) is disposed relative to the surface (15) of a print head (16) for directing a flow of cleaning liquid (300) along the surface (15) and to direct sliding contact of a disk (190) to clean the contaminants from the surface (15). The rotating disk cleaning assembly (32) is configured to introduce cleaning liquid (300) to the print head surface (15) to facilitate and augment cleaning by the disk (190). Flow of the cleaning liquid (300) is facilitated by vacuum pump (36) which directs cleaning liquid (300) from a cleaning liquid reservoir (270) to the rotating disk cleaning assembly (32).
Description




FIELD OF THE INVENTION




This invention generally relates to a self-cleaning ink jet printer and methods for cleaning the same, and more particularly to a rotating disk cleaning assembly for an ink jet printer having a fixed canopy-type gutter.




BACKGROUND OF THE INVENTION




An ink jet printer produces images by ejecting ink droplets onto a receiver medium in an image-wise fashion. The advantages of non-impact, low-noise, low energy use, and low cost operation in addition to the capability of the printer to print on plain paper mediums are largely responsible for the wide acceptance of ink jet printers in the marketplace.




“On demand” ink jet printers utilize a pressurization actuator to produce the ink jet droplet at orifices of a print head. In this regard, either one of two types of actuators may be used including heat actuators and piezoelectric actuators. With heat actuators, a heater placed at a convenient location heats the ink and a quantity of the ink will phase change into a gaseous steam bubble and raise the internal ink pressure sufficiently for an ink droplet to be expelled onto the recording medium. With respect to piezoelectric actuators, a piezoelectric material possessing properties such that an electric field is produced when a mechanical stress is applied. The converse also holds true; that is, an applied electric field will produce a mechanical stress in the material. Some naturally occurring materials possessing these characteristics are quartz and tourmaline. The most commonly produced piezoelectric ceramics are lead zirconate titanate, barium titanate, lead titanate, and lead metaniobate.




In the case of “continuous” ink jet printers, electrostatic charging tunnels are placed close to the point where ink droplets are being ejected in the form of a stream. Selected droplets are electrically charged by the charging tunnels. The charged droplets are deflected downstream by the presence of deflector plates that have a predetermined electric potential difference between them. A gutter may be used to intercept the charged droplets, while the uncharged droplets are free to strike the recording medium.




Recently a new type of continuous ink jet printer has been disclosed. U.S. Pat. Nos. 6,079,821 and 6,234,620 issued to Chwalek et al. and Faisst, Jr. et al., respectively, describe a continuous ink jet printer in which on demand asymmetric heating of an ink jet causes selected drops to deflect. In one mode of operation, selected drops are deflected toward an image-recording medium while the other drops are intercepted in a canopy-type gutter that is placed in close proximity (for example, 3 mm) to the ink jet nozzle plate.




Inks for high-speed ink jet printers, whether of the “continuous” or “piezoelectric” type, must have a number of special characteristics. For example, the ink should incorporate a nondrying characteristic, so that drying of ink in the ink ejection chamber is hindered or slowed to such a state that by occasional spitting of ink droplets, the cavities and corresponding nozzles are kept open. The addition of glycol facilitates free flow of ink through the ink jet chamber. Of course, the ink jet print head is exposed to the environment where the ink jet printing occurs. Thus, the previously mentioned nozzles are exposed to many kinds of air born particulates. Particulate debris may accumulate on surfaces formed around the nozzles and may accumulate in the nozzles and chambers themselves. That is, the ink may combine with such particulate debris to form an interference burr that blocks the nozzle or that alters surface wetting to inhibit proper formation of the ink droplet. The particulate debris should be cleaned from the surface and nozzle to restore proper droplet formation. In the prior art, this cleaning is commonly accomplished by brushing, wiping, spraying, vacuum suction, and/or spitting of ink through the nozzle.




Thus, ink jet printers can be said to have the following problems: the inks tend to dry-out in and around the nozzles resulting in clogging of the nozzles; and the wiping of the nozzle plate causes wear on plate and wiper, the wiper itself producing particles that clog the nozzle. In addition, cleaning an ink jet nozzle plate that has limited accessibility due to the placement of a fixed gutter poses extra demands on the design of cleaning members and on methods used.




Ink jet print head cleaners are known. For example, a print head wiping system for ink jet print heads is disclosed in U.S. Pat. No. 5,614,930, entitled “Orthogonal Rotary Wiping System For Ink jet Printheads” issued Mar. 25, 1997 in the name of William S. Osborne et al. The Osborne et al. patent discloses a rotary service station, which incorporates a wiper-supporting tumbler. The tumbler rotates to wipe the print head along a length of a linearly aligned nozzle. In addition, a wiper scraping system scrapes the wipers to clean the wipers. However, Osborne et al. do not disclose use of an external solvent to assist cleaning and also does not disclose complete removal of the external solvent. In addition, a wiper scraping system is limited by the size constraints imposed by the print head itself. This is particularly true for fixed gutter ink jet print head systems, which partially encloses the print head surfaces. Fixed gutter systems require a mechanism that can work within small tolerances imposed by the integrated gutter in order to clean the print head. The Osborne et al. cannot tolerate the stresses demanded by the tight spacing and limited size of current ink jet print heads.




Therefore, there is a need to provide a suitable ink jet printer with a cleaning mechanism, and method of assembling the same, wherein the cleaning mechanism is capable of cleaning the print head surface within the confines of small tolerances and limited spacing. There is also a need to supply cleaning liquid to lubricate and aid cleaning in a manner that does not cause wear of the print head nozzle plate. Furthermore, there is a need for a cleaning mechanism that can operate within the limited spacing imposed by an fixed canopy-type gutter.




SUMMARY OF THE INVENTION




It is an object of the present invention to provide a self-cleaning ink jet printer with a cleaning mechanism and method of assembling the same, wherein a surface of a print head belonging to the printer is effectively cleaned.




It is another object of the present invention to provide an ink jet print head assembly that includes a cleaning mechanism and method of assembling the same that can be utilized in fixed gutter continuous ink jet printers.




With the above objects in view, disclosed is a cleaning mechanism composed of a rotating disk cleaning assembly for use in a self-cleaning printer. The self-cleaning printer includes a print head having a print head surface and an ink channel therein, and a structural member that functions as a gutter for collecting ink disposed opposite to the print head surface. The cleaning mechanism is adapted to clean contaminant from the print head surface.




According to an exemplary embodiment of the present invention, a self-cleaning printer is disclosed, wherein the self-cleaning printer includes a print head defining a plurality of ink channels therein, each ink channel terminating in a nozzle. The print head also has a surface thereon surrounding all the nozzles. The print head is capable of jetting ink through the nozzles, such that ink jets are subsequently heated to cause ink drops to form and to selectively deviate for printing. Ink drops are intercepted by either a receiver or a gutter. In one method of operation, ink is selectively deflected onto a receiver (e.g., paper or transparency) supported by a platen disposed adjacent the print head, while the non-deflected ink drops are intercepted by the gutter.




Ink intercepted by the gutter may be recycled. Contaminant such as an oily film-like deposit or particulate matter may reside on the surface and may completely or partially obstruct the nozzle. The oily film may be, for example, grease and the particulate matter may be particles of dirt, dust, metal and/or encrustations of dried ink. Presence of the contaminant interferes with proper ejection of the ink droplets from their respective nozzles and therefore may give rise to undesirable image artifacts, such as banding. It is therefore desirable to clean the contaminant from the surface and the nozzles.




Therefore, a cleaning mechanism is disposed relative to the surface and/or the nozzle, such that a flow of cleaning liquid may be directed along the surface and/or across the nozzle. The cleaning mechanism is disposed relative to the surface and/or the nozzle so as to direct a rotating disk cleaning assembly to clean the contaminant from the surface and/or nozzle via contact with the rotating disk cleaning assembly. As described in detail herein, ink delivered by the print head may be used as cleaning liquid. Ink squirted onto to the rotating disk is used to facilitate and augment cleaning by the rotating disk cleaning assembly. The rotating disk rotates by the rotating action of the internal rotating member, which in turn is connected to a driver that is driven by a motor. The rotating disk is surrounded by a soft and preferably porous covering. The rotating disk and soft covering upon sliding and rotating contact with a print head surface work together to remove contaminants from the print head surface. The soft covering surrounding the rotating disk also serves to hold contaminants and cleaning liquid during cleaning.




In another embodiment, cleaning liquid may be supplied to the print head surface through channels provided in the gutter. In yet another embodiment, the rotating disk cleaning assembly may be combined with an ultrasonic transducer.




A feature of the present invention is the provision of a rotating disk cleaning assembly with channels for liquid that fit in the restricted space between the print head surface and the gutter and is capable removing contaminant from the surface and/or nozzle.




Another feature of the present invention is the provision of a piping circuit to deliver and remove cleaning liquid from the print head surface.




Yet, another feature of the present invention is the provision of a mechanism to align and transport the rotating disk during cleaning operation.




Yet, another feature of the present invention is the provision of an ultrasonic transducer to energize the cleaning action by the rotating disk and the cleaning liquid.




An advantage of the present invention is that the cleaning assembly belonging to the invention cleans the contaminant from the surface and/or nozzle in the confined space between the print head surface and the fixed gutter.




These and other objects, features and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description taken in conjunction with the appended drawings which show and describe illustrative embodiments of the invention.











BRIEF DESCRIPTION OF THE DRAWINGS




While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter of the present invention, it is believed the invention will be better understood from the following detailed description taken in junction with the accompanying drawings wherein:





FIG. 1A

is a simplified block schematic diagram of a first embodiment printer system equipped with a page width print head with fixed gutter and cleaning mechanism disposed adjacent to the print head;





FIG. 1B

is a simplified block schematic diagram of a first embodiment printer, the printer equipped with a reciprocating print head with fixed gutter and cleaning mechanism disposed adjacent to the print head;





FIG. 2

is an isotropic view of the print head with fixed gutter, the print head defining a plurality of channels therein, each channel terminating in a nozzle;





FIG. 3

is a side view of a print head according to the invention, showing deflected ink drops directed toward a receiving medium and non-deflected ink drops intercepted by the fixed gutter;





FIG. 4

is a fragmented view in cross-section of the print head shown in

FIG. 3

;





FIG. 5

is a fragmented view in cross-section of a contaminated print head with schematic representation of misaligned ink drops due to contamination;





FIG. 6

is a perspective view of a rotating disk cleaning assembly having a rotating disk and shaft for removing contaminant from a print head surface, in accordance with a preferred embodiment of the present invention;





FIG. 7

is a simplified block schematic diagram of a second embodiment printer system equipped with a page width print head with fixed gutter and rotating disk cleaning assembly disposed adjacent to the print head;





FIG. 8

is a simplified block schematic diagram of a third embodiment printer equipped with a reciprocating print head with fixed gutter and cleaning mechanism disposed on the same block as print head;





FIG. 9

shows an isometric view of print head with a rotating disk cleaning assembly aligned for widthwise translation;





FIG. 10

is a simplified block schematic diagram of a fourth embodiment printer system equipped with a modified gutter for facilitating the flow of a cleaning liquid onto the rotating disk; and





FIG. 11

is a side view of a print head with a modified gutter according to the fourth embodiment printer system shown in FIG.


10


.




Numerals and parts in the detailed description correspond to like references in the figures unless otherwise indicated.











DETAILED DESCRIPTION OF THE INVENTION




The present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art.




Therefore, referring to

FIGS. 1A and 1B

, therein are shown first and second examples of a first embodiment self-cleaning printer system denoted generally as


400


and


410


, respectively, according to the invention. The self-cleaning printer systems


400


and


410


utilize an image source


10


, such as a scanner or a computer, that provides the raster image data, outline image data in the form of a page description language, or other forms of digital image data. The image source


10


is converted to half-toned bitmap image data by an image-processing unit


12


, which stores the image data in memory. A plurality of heater control circuits


14


read the data from memory within the image-processing unit


12


and apply time-varying electrical pulses to a set of nozzle heaters


50


that are part of a print head


16


. The action of the nozzle heaters


50


(shown in

FIGS. 4 and 5

) and print head


16


during printing is shown in

FIG. 3

wherein the electrical pulses are applied at an appropriate time, and to the appropriate nozzle, so that drops


23


form a continuous ink jet stream to create spots on a recording medium


18


, typically paper, in an appropriate position designated by the data in the memory of the image processing unit


12


. Non-deflected ink drops


21


formed in the non-printing area are intercepted by a gutter


17


, which is fixed in relation to the print head


16


.




Referring to

FIGS. 1A and 1B

, recording medium


18


is moved relative to the print head


16


by a recording medium transport system


20


, which is electronically controlled by a paper transport control system


22


, and which, in turn, is controlled by a micro-controller


24


. The paper medium transport system


22


shown in

FIGS. 1A and 1B

is shown in schematic form only, and many different mechanical configurations are possible, as is known to those of skill in the art. For example, a transfer roller could be used as a paper medium transport system


22


to facilitate transfer of the ink drops


23


to recording medium


18


. Such transfer roller technology is well known in the art. In the case of page width print heads, it is most convenient to move the recording medium


18


past a stationary print head. However, in the case of a scanning print system (as shown schematically in FIG.


1


B), it is usually most convenient to move the print head along one axis (the sub-scanning direction) and the recording medium


18


along an orthogonal axis (the main scanning direction) in a relative raster motion.




Referring to

FIGS. 1A

,


1


B,


3


and


4


, ink is contained in an ink reservoir


28


under pressure. In the non printing state, continuous ink jet drop streams are unable to reach the recording medium


18


due to the position of gutter


17


that blocks the stream to allow a portion of the ink to be recycled by an ink recycling unit


19


. The ink-recycling unit


19


reconditions the ink and feeds it back to ink reservoir


28


. Such ink recycling units are well known in the art. The ink pressure suitable for optimal operation will depend on a number of factors, including geometry and thermal properties of the nozzles and thermal properties of the ink. A constant ink pressure can be achieved by applying pressure to ink reservoir


28


under the control of ink pressure regulator


26


.




The ink is distributed to the back surface of the print head


16


by an ink channel device


30


and through ink channel


31


, as shown in FIG.


4


. The ink preferably flows through slots and/or holes etched through silicon substrate of print head


16


to its print head surface


15


, where a plurality of nozzles


25


and heaters


50


are situated.

FIG. 2

is an isotropic view of the print head


16


and gutter


17


. With print head


16


fabricated from silicon, it is possible to integrate heater control circuits


14


with the print head


16


. In operation, non-deflected ink drops


21


are intercepted by gutter


17


, while deflected ink drops


23


land on the recording medium


18


. Deflection may be caused by a variety of methods including the asymmetric heating method discussed in U.S. Pat. No. 6,079,821 issued to Chwalek et al.




Turning now to

FIG. 5

, it has been observed that the print head surface


15


may become fouled by contaminant


55


. Contaminant


55


may be, for example, an oily film or particulate matter residing on the surface of print head surface


15


. Contaminant


55


also may partially or completely obstructs one or more of the plurality of nozzles


25


. The particulate matter may be, for example, particles of dirt, dust, metal and/or encrustations of dried ink. The oily film may be, for example, grease or the like. Presence of contaminant


55


is undesirable because when contaminant


55


completely obstructs one or more of the plurality of nozzles


25


, ink is prevented from being ejected from nozzle


25


. In this regard, the terms “nozzle” and “nozzles” are used interchangeably throughout either in the singular or plural as may be appropriate.




In addition, when contaminant


55


partially obstructs nozzle


25


, flight of ink droplets


60


may be diverted from first axis


63


to travel along a second axis


65


(as shown). If ink droplets


60


travels along second axis


65


, ink droplets


60


will land on recording medium


18


in an unintended location. In this manner, such complete or partial obstruction of nozzle


25


leads to printing artifacts such as “banding”, a highly undesirable result. A similar printing artifact results if non-selected drops


21


travel on third axis


66


. Also, the presence of contaminant


55


may alter surface wetting and inhibit proper formation of droplets


60


. Therefore, it is desirable to clean (i.e., remove) contaminant


55


to avoid these and other printing artifacts.




Therefore, the self-cleaning printer systems


400


and


410


are equipped with a cleaning mechanism


140


that can be used for simultaneously removing contaminant


55


from the print head surface


15


of the print head


16


and the nozzles


25


, according to the invention. In particular, the self-cleaning printer system


400


of

FIG. 1A

is of the page width print head variety, while self-cleaning printer system


410


of

FIG. 1B

illustrates a scanning type print head. The differences between a page width print head and a scanning type print head are well understood by those of ordinary skill. The cleaning mechanism


140


includes a rotating disk cleaning assembly


32


, disposed for directing cleaning liquid


300


carried in or on a soft absorbent covering


195


on disk


190


to surface


15


and nozzles


25


. Disk


190


moves along the print head surface


15


and across nozzles


25


to clean contaminant


55


therefrom. Disk


190


may be constructed of a soft absorbent material such as felt, polyurethane sponge or expanded polytetrafluroethylene so that cleaning liquid supplied to it is absorbed by the soft absorbent covering. During cleaning, cleaning liquid


300


in or on soft absorbent covering


195


provides chemical cleaning and lubrication between disk


190


and print head surface


15


. Alternatively, disk


190


may be constructed of a stiff material such as plastic or metal coated with soft absorbent material


195


. The stiff material


193


is perforated to allow cleaning liquid


300


supplied to it to wick through and get absorbed by soft absorbent covering


195


. The cleaning liquid


300


mentioned hereinabove may be any suitable liquid solvent composition, such as ink, water, isopropanol, diethylene glycol, diethylene glycol monobutyl ether, octane, acids and bases, surfactant solutions and any combination thereof. Complex liquid compositions may also be used, such as microemulsions, micellar surfactant solutions, vesicles and solid particles dispersed in the cleaning liquid


300


.




To better understand the implementation of print head cleaning assembly


32


and, in particular, the disk


190


, reference is made to FIG.


6


.

FIG. 6

is a perspective view of a section of rotating disk cleaning assembly


32


having a disk


190


and a shaft


191


for removing contaminant from a print head surface


15


, in accordance with a preferred embodiment of the present invention. The disk


190


can be constructed by laminating a perforated metal or plastic disk


193


with a soft absorbent material


195


. Arrow


604


indicates the motion of disk


190


when driven by a motor (not shown) coupled to shaft


191


. In first embodiment self-cleaning printer systems


400


and


410


, cleaning liquid is supplied to the absorbent covering


195


through channels (not shown) in cleaning assembly block


180


prior to engagement of disk


190


with print head surface


15


.




In operation, upon receiving an electronic signal from micro-controller


24


via cleaning assembly control


40


, pump


36


is activated causing cleaning liquid


300


to be moved from cleaning liquid reservoir


270


through filter


280


and sprayed onto surface of disk


190


. Cleaning assembly control


40


also activates disk motor (not shown) causing the disk


190


to rotate. Micro-controller


24


also sends as electronic signal to print head transport control


42


, which causes print head


16


to assume a “maintenance” position by translating toward disk


190


following the direction of arrow


44




a


. Preferably, disk


190


is pre-aligned with print head surface


15


of print head


16


so that when print head


16


reaches disk


190


, print head surface


15


and nozzles


25


are in contact with soft absorbent material


195


of disk


190


. Thus, as print head


16


continues to travel along direction of arrow


44




a


, contaminant


55


on print head surface


15


and in nozzles


25


is removed by the disk


190


. After cleaning, print head


16


is translated back along direction of arrow


44




b


to its normal printing position.




As can be appreciated by those of ordinary skill, the process of engaging disk


190


with print head surface


15


described above is one of many methods of using cleaning assembly


32


to clean print head surface


15


and nozzles


25


. For example rather than having print head surface


15


moved towards disk


190


, cleaning assembly


32


may be optionally equipped with its own translation capability wherein the cleaning assembly


32


moves from a “home” position to a cleaning position that enables the disk


190


to come into contact with the print head surface


15


.




Referring to

FIG. 7

, therein is shown an example of self cleaning ink jet printer system, denoted generally as


420


in which cleaning assembly


32


may be translated for the purpose of cleaning print head surface


15


and nozzles


25


of print head


16


. By way of example only, print head cleaning assembly


32


may be supported on an elevator (not shown) and lifted in direction of arrow


46




b


to appropriate location in order to engage the disk


190


with print head surface


15


of print head


16


. This corresponds to the cleaning position of the cleaning assembly


32


. Similarly, translation of cleaning assembly


32


along arrows


70




a


and 70


b


may also be utilized to aid optimal engagement of disk


190


with print head surface


15


of print head


16


. After print head surface


15


and nozzles


25


have been cleaned, print head


16


is translated back to its printing position, and print head cleaning assembly


32


is lowered to its rest or home position along arrow


46




a.






When required, disk


190


may be replaced or cleaned. Disk


190


may be cleaned using cleaning liquid supply to cleaning assembly block


180


. For example, cleaning liquid


300


may be suctioned from the cleaning liquid reservoir


270


and directed through piping segment


38




a


and squirted onto disk


190


during cleaning. Used cleaning liquid can be returned to cleaning liquid reservoir


270


via piping segment


38




b


. Alternatively, a mechanism (not shown) may be provided to lower disk


190


so that it is in contact with vacuum slots (not shown) provided in cleaning assembly block


180


. Cleaning liquid


300


supplied to disk


190


by pump


36


may now be sucked away by vacuum pump


34


.




Referring to

FIGS. 8 and 9

therein is shown an example of a third embodiment self cleaning ink jet printer system, denoted generally as


430


, in which a print head cleaning assembly


33


is provided on the same block as print head


16


. In order to clean print head surface


15


and nozzles


25


, disk


190


translates back and forth on guide rail


77


following arrows


75




a


and


75




b


. According to the third embodiment of printer system


430


, rotating disk cleaning assembly


33


is mounted on print head


16


and pre-aligned with surface


15


and gutter


17


. Upon receiving an appropriate electrical signal from cleaning assembly controller


40


and micro-controller


24


, rotating disk cleaning assembly


33


is activated to translate along the direction of seventh arrow


75




a


using guide rail


77


, as shown in FIG.


9


. The motor driving the rotating disk cleaning assembly


33


is not shown.




As before, disk


190


is covered with a soft absorbent material


195


and may be cleaned on pad


90


. Cleaning liquid


300


is supplied via duct


500


and recycled through duct


510


. Further more, a separate duct (not shown) may be provided to supply vacuum suction to disk


190


during cleaning.




Referring to

FIGS. 10 and 11

therein is shown an example of a fourth embodiment self cleaning ink jet printer system


440


capable of removing contaminant


55


from surface


15


and nozzles


25


. In particular, ink jet printer system


440


has a disk


190


that is supplied with cleaning liquid


300


through modified gutter


17




a


. Cleaning liquid


300


is pumped to modified gutter


17




a


through valve


520


and piping segment


530


by pump


36


. To facilitate the flow of cleaning liquid, modified gutter


17




a


has an internal duct


85


, which delivers cleaning liquid


300


onto a soft absorbent covering


195


on the disk


190


. Delivery of cleaning liquid through modified gutter


17




a


is compatible with previously discussed self cleaning printer systems, i.e., modified gutter


17




a


, valve


520


and piping segment


530


may readily be added to self cleaning printer systems


400


,


410


,


420


and


430


.




While the invention has been described with particular reference to its preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements of the preferred embodiments without departing from the invention. For example, it will be appreciated that

FIGS. 7

,


8


,


9


, and


11


depict a page width print head by way of example only. Scanning type print heads that are smaller than page width size can also be cleaned using a variation of the method described above. In yet another variation, rather that use a cleaning liquid


300


for cleaning print head surface


15


and nozzles


25


of print head


16


, ink


29


may be squirted out of nozzles


25


on to soft absorbent covering


195


on disk


190


during cleaning. At the end of the cleaning cycle, disk


190


and soft absorbent covering


195


may be cleaned with cleaning liquid


300


by the methods described above. In yet another variation, cleaning assemblies


32


and


33


may be coupled to an ultrasonic transducer to enhance cleaning of print head print head surface


15


and nozzles


25


. In addition, many modifications may be made to adapt a particular situation and material to a teaching of the present invention without departing from the essential teachings of the invention.















PARTS LIST


























 10




image source







 12




image processing unit







 14




heater control circuits







 15




front surface







 16




print head







 17




gutter







 17a




modified gutter







 18




recording medium







 19




ink recycling unit







 20




recording medium transport system







 21




non-deflected ink drop







 22




recording medium transport control system







 23




deflected ink drop







 24




micro-controller







 25




nozzle







 26




ink pressure regulator







 28




ink reservoir







 29




ink







 30




ink channel device







 31




ink channel







 32




rotating disk cleaning assembly







 33




rotating disk cleaning assembly on print head







 34




vacuum pump







 36




circulation pump







 38a




piping segment







 38b




piping segment







 40




cleaning assembly motion control







 42




cleaning assembly motion control







 44a




first arrow







 44b




second arrow







 6a




third arrow







 46b




fourth arrow







 50




nozzle heaters







 55




contaminant







 60




ink droplet







 63




first axis







 65




second axis







 70a




fifth arrow







 70b




sixth arrow







 75a




seventh arrow







 75b




eighth arrow







 77




guide rail







 79a




ninth arrow







 79b




tenth arrow







 90




pad







180




cleaning assembly block







190




rotating disk







191




rotating shaft







193




perforated metal or plastic disk







195




soft absorbent covering







300




cleaning liquid







400




first embodiment printer system







410




second example of first embodiment printer system







420




third example of first embodiment printer system







430




third embodiment printer system







440




fourth embodiment printer system







500




supply duct







510




return duct







520




control valve







530




piping segment







604




arrows














Claims
  • 1. A self-cleaning ink jet printer system, comprising:a print head having a surface thereon; an ink reservoir containing ink; a gutter integrally connected to said print head for intercepting said ink in a non-printing mode; and a rotating disk cleaning assembly for cleaning said print head surface, said rotating disk cleaning assembly including a disk having a planar surface that interacts with said print head surface, said planar surface being flat such that the interaction of said, planar surface with said print head surface remains constant during cleaning.
  • 2. The ink jet printer system of claim 1, wherein said rotating disk cleaning assembly comprises:a shaft having an internal rotating member, said internal rotating member of said shaft connected to said disk for coming into direct rotating sliding contact with said print head surface to thereby remove contaminants from said print head surface; and a motor for driving said shaft.
  • 3. The ink jet printer system of claim 2, further comprising an absorbent covering surrounding said disk.
  • 4. The ink jet printer system of claim 3 further comprising a means for translating said rotating disk cleaning assembly towards said print head surface so that said soft covering touches said print head surface during rotation of said disk thereby permitting contaminants to be removed from said print head surface.
  • 5. The ink jet printer system of claim 2, further comprising a cleaning assembly control configured to cause said rotating disk cleaning assembly to assume a cleaning position.
  • 6. The ink jet printer system of claim 5, wherein said cleaning assembly control is further configured to cause said rotating disk cleaning assembly to assume a normal printing position after cleaning of said printer head surface.
  • 7. The ink jet printer system of claim 2, further comprising a micro-controller configured to send an electronic signal that causes said print head to assume a maintenance position wherein said print head surface is translated towards said rotating disk cleaning assembly.
  • 8. The ink jet printer system of claim 2, further comprising a block supporting said print head and wherein said rotating disk cleaning assembly is mounted on said block adjacent said print head.
  • 9. The ink jet printer system of claim 8, further comprising a guide rail configured to permit said disk to translate along an areas spanned by said print head surface.
  • 10. The ink jet printer system of claim 2, wherein said rotating disk cleaning assembly is mounted on said print head and pre-aligned with said print head surface.
  • 11. The ink jet printer system of claim 1, further comprising a mounting block for supporting said rotating disk cleaning assembly.
  • 12. The ink jet printer system of claim 1, further comprising:a reservoir for storing a cleaning liquid; a first piping segment providing a flow channel in a first direction between said reservoir and said rotating disk cleaning assembly; and a pump for directing a cleaning liquid from said reservoir to said rotating disk cleaning assembly via said first piping segment.
  • 13. The ink jet printed system of claim 12, further comprising a second piping segment providing a flow channel in a second direction between said reservoir and said rotating disk cleaning assembly so that used cleaning liquid is returned to said cleaning reservoir.
  • 14. The ink jet printer system of claim 1, wherein said disk surface is located on a radial surface of said disk.
  • 15. A self-cleaning ink jet printer system comprising:a print head having a surface thereon; an ink reservoir containing ink; a gutter integrally connected to said print head for intercepting said ink in a non-printing mode; a rotating disk cleaning assembly for cleaning said print head surface, said rotating disk cleaning assembly including a disk; and an absorbent covering surrounding said disk, wherein said gutter further comprises an internal duct adapted to deliver a cleaning liquid to said absorbent covering.
  • 16. A cleaning mechanism for a self-cleaning ink jet printer with a print head having a print head surface containing a plurality of orifices therein, said printer having a gutter integrally connected to said print head for intercepting ink in a non-printing mode, said cleaning assembly comprising:a rotating disk cleaning assembly for cleaning said print head surface, said rotating disk cleaning assembly including a disk having a planar surface that interacts with said printhead surface, said planar surface being flat such that the interaction of said planar surface with said printhead surface remains constant during cleaning; a means for moving, positioning, and aligning said rotating disk cleaning assembly; a means for delivery of a cleaning liquid to said rotating disk cleaning assembly; a vacuum pump to provide suctioning of said cleaning liquid; and a cleaning liquid reservoir, wherein said cleaning liquid is delivered to said rotating disk cleaning assembly by said means for delivery and suctioned back by said vacuum pump so that contaminants are removed from said print head surface through the suctioning action of said vacuum pump before being discharged into said cleaning liquid reservoir.
  • 17. The cleaning mechanism of claim 16, wherein said rotating disk cleaning assembly further comprises:a shaft connected to said disk for coming into direct contact with said print head to thereby remove contaminants from said print head surface; and a motor for driving said shaft.
  • 18. The cleaning mechanism of claim 17, wherein said disk is surrounded by an absorbent covering that upon contact with said print head surface permits contaminants to be removed.
  • 19. The cleaning mechanism of claim 16, further comprising a pump configured to assist in delivering cleaning liquid from said cleaning liquid reservoir to said rotating disk cleaning assembly.
  • 20. The cleaning mechanism of claim 16, further comprising an ultrasonic transducer configured to assist in delivering cleaning liquid from said cleaning liquid reservoir to said rotating disk cleaning assembly.
  • 21. The cleaning mechanism of claim 16 wherein said rotating disk cleaning assembly is mounted to said print head.
  • 22. A cleaning mechanism for a self-cleaning ink jet printer with a print head having a print head surface containing a plurality of orifices therein, said printer having a gutter integrally connected to said print head for intercepting ink in a non-printing mode, said cleaning assembly comprising:a rotating disk cleaning assembly for cleaning said print head surface; a means for moving, positioning, and aligning said rotating disk cleaning assembly; a means for delivery of a cleaning liquid to said rotating disk cleaning assembly; a vacuum pump to provide suctioning of said cleaning liquid; and a cleaning liquid reservoir, wherein said cleaning liquid is delivered to said rotating disk cleaning assembly by said means for delivery and suctioned back by said vacuum pump so that contaminants are removed from said print head surface through the suctioning action of said vacuum pump before being discharged into said cleaning liquid reservoir and said means for delivery comprises an internal duct in said gutter.
  • 23. In a self-cleaning ink jet printer, a method for cleaning an ink jet printer head having a print head surface thereon, said ink jet printer including a fixed gutter assembly, a rotating disk cleaning assembly for removing contaminants from said print head surface and a controller, said method comprising the steps of:(a) translating said rotating disk cleaning assembly from a pre-defined home position to a cleaning position; (b) causing said rotating disk cleaning assembly to come in contact with said print head surface and remove contaminants therefrom, said rotating disk cleaning assembly including a disk having a planar surface that interacts with said printhead surface, said planar surface being flat such that the interaction of said planar surface with said printhead surface remains constant during cleaning; and (c) translating said rotating disk cleaning assembly from said cleaning position to said defined home position.
  • 24. The method of claim 23 further comprising the step of translating said print head to pre-defined maintenance position prior to said step of translating said rotating disk cleaning assembly to said cleaning position.
  • 25. The method of claim 24 further comprising the step of translating said print head to a pre-defined printing position following said step of translating said rotating disk cleaning assembly from said cleaning position to said defined home position.
  • 26. In a self-cleaning ink jet printer, a method for cleaning an ink jet printer head having a print head surface thereon, said ink jet printer including a fixed gutter assembly, a rotating disk cleaning assembly for removing contaminants from said print head surface and a controller, said method comprising the steps of:translating said rotating disk cleaning assembly from a pre-defined home position to a cleaning position; causing said rotating disk cleaning assembly to come in contact with said print head surface and moving said rotating disk cleaning assembly at a pre-determined speed and for a pre-determined distance in order to avoid colliding with said fixed gutter assembly; and translating said rotating disk cleaning assembly from said cleaning position to said defined home position.
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4800403 Accattino et al. Jan 1989 A
4829318 Racicot et al. May 1989 A
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4968994 Hock et al. Nov 1990 A
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5574485 Anderson et al. Nov 1996 A
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5914734 Rotering et al. Jun 1999 A
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59014964 Jan 1994 JP