Patent Publication Number: US-6340220-B1

Title: Transferring spittoon system for waste inkjet ink

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to inkjet printing mechanisms, and more particularly to a storage and spittoon system for handling waste inkjet ink that has been spit from an inkjet printhead during a nozzle clearing, purging or “spitting” routine. 
     BACKGROUND OF THE INVENTION 
     Inkjet printing mechanisms use cartridges, often called “pens,” which eject drops of liquid colorant, referred to generally herein as “ink,” onto a page. Each pen has a printhead formed with very small nozzles through which the ink drops are fired. To print an image, the printhead is propelled back and forth across the page, ejecting drops of ink in a desired pattern as it moves. The particular ink ejection mechanism within the printhead may take on a variety of different forms known to those skilled in the art, such as those using piezo-electric or thermal printhead technology. For instance, two earlier thermal ink ejection mechanisms are shown in U.S. Pat. Nos. 5,278,584 and 4,683,481. In a thermal system, a barrier layer containing ink channels and vaporization chambers is located between a nozzle orifice plate and a substrate layer. This substrate layer typically contains linear arrays of heater elements, such as resistors, which are energized to heat ink within the vaporization chambers. Upon heating, an ink droplet is ejected from a nozzle associated with the energized resistor. By selectively energizing the resistors as the printhead moves across the page, the ink is expelled in a pattern on the print media to form a desired image (e.g., picture, chart or text). 
     To clean and protect the printhead, typically a “service station” mechanism is supported by the printer chassis so the printhead can be moved over the station for maintenance. For storage, or during non-printing periods, the service stations usually include a capping system which substantially seals the printhead nozzles from contaminants and drying. Some caps are also designed to facilitate priming, such as by being connected to a pumping unit that draws a vacuum on the printhead. During operation, clogs in the printhead are periodically cleared by firing a number of drops of ink through each of the nozzles in a process known as “spitting,” with the waste ink being collected in a “spittoon” reservoir portion of the service station. After spitting, uncapping, or occasionally during printing, most service stations have an elastomeric wiper that wipes the printhead surface to remove ink residue, as well as any paper dust or other debris that has collected on the printhead. The wiping action is usually achieved through relative motion of the printhead and wiper, for instance by moving the printhead across the wiper, by moving the wiper across the printhead, or by moving both the printhead and the wiper. 
     As the inkjet industry investigates new printhead designs, the tendency is toward using permanent or semi-permanent printheads in what is known in the industry as an “off-axis” printer. In an off-axis system, the printheads carry only a small ink supply across the printzone, with this supply being replenished through tubing that delivers ink from an “off-axis” stationary reservoir placed at a remote stationary location within the printer. Narrower printheads may lead to a narrower printing mechanism, which has a smaller “footprint,” so less desktop space is needed to house the printing mechanism during use. Narrower printheads are usually smaller and lighter, so smaller carriages, bearings, and drive motors may be used, leading to a more economical printing unit for consumers. 
     To improve the clarity and contrast of the printed image, recent research has focused on improving the ink itself. To provide quicker, more waterfast printing with darker blacks and more vivid colors, pigment-based inks have been developed. These pigment-based inks have a higher solid content than the earlier dye-based inks, which results in a higher optical density for the new inks. Both types of ink dry quickly, which allows inkjet printing mechanisms to form high quality images on readily available and economical plain paper, as well as on recently developed specialty coated papers, transparencies, fabric and other media. However, the combination of small nozzles and quick-drying ink leaves the printheads susceptible to clogging, not only from dried ink or minute dust particles, such as paper fibers, but also from the solids within the new inks themselves. 
     When spitting these new pigment-based inks onto the flat bottom of a conventional spittoon, over a period of time the rapidly solidifying waste ink grew into a stalagmite of ink residue. Eventually, in prototype units, the ink residue stalagmite grew to contact the printhead, which then either could interfere with printhead movement, print quality, or contribute to clogging the nozzles. Indeed, these stalagmites even formed ink deposits along the sides of the entranceway of prototype narrow spittoons, and eventually grew to meet one another and totally clog the entrance to the spittoon. To avoid this phenomenon, conventional spittoons had to be wide enough to handle these high solid content inks. This extra width increased the overall printer width, which then defeated the narrowing advantages realized by using an off-axis printhead system. 
     A ferris wheel spittoon system was disclosed in U.S. Pat. No. 5,617,124, currently assigned to the present assignee, the Hewlett-Packard Company. This system proposed an elastomeric ferris wheel as a spit surface. Ink residue was removed from the wheel with a rigid plastic scraper that was oriented along a radial of the wheel so the scraper edge approached the spitting surface at a substantially perpendicular angle. The scraper was located a short distance away from the surface of the wheel, so it unfortunately could not completely clean the spitting surface. Furthermore, by locating the scraper a distance from the spit surface, the scraper was ineffective in removing any liquid ink residue from the wheel. This earlier ferris wheel spittoon system failed to provide for adequate storage of the ink residue after removal from the ferris wheel during the desired lifespan of a printer. 
     One remedy for this ink residue storage problem was first commercially available in the Hewlett-Packard Company&#39;s DeskJet® 2000C Professional Series color inkjet printer, which scraped the black ink residue from the surface of a ferris wheel type spit wheel and collected the residue in a storage bucket. A ratchet mechanism was used to rotate the spit wheel past a scraper which was spring-biased against the wheel and located to direct the residue into the storage bucket. In this system, the capacity of the storage bucket was approximately 55 cc (cubic centimeters) of residue; however, given the consistency of the pigment-based black ink as it dried, which is similar to tar, the waste ink did not pack efficiently into the available volume of the storage bucket. While this system works well for the lifetime of typical desktop printers, for heavy volume printers, such as those which are networked or used as short run press printers, the storage bucket capacity was inadequate. Indeed, as future printers are designed, there is a tendency to move toward using pigment-based color inks, as well as pigment-based black inks, so the ability to store waste ink residue will increase. Various design constraints on the printer, such as the footprint, means that merely adding a larger bucket is not feasible. 
     Thus, it would be desirable to have a spittoon system which provides for ink residue storage during the lifespan of the inkjet printing unit without increasing the overall size or “footprint” of the unit. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, a transferring spittoon system is provided for receiving ink residue spit from an inkjet printhead in an inkjet printing mechanism. The spittoon system includes a temporary storage container that receives ink residue which has been spit from the inkjet printhead. The temporary storage container has an exit opening. The spittoon system also has a permanent storage container, and a transfer mechanism. The transfer mechanism receives the ink residue from the temporary storage container exit opening and transfers the ink residue to the permanent storage container. 
     According to another aspect of the present invention, a method of purging ink residue from an inkjet printhead in an inkjet printing mechanism is provided. This method includes the step of providing a temporary storage container, a permanent storage container and a transfer mechanism. In a collecting step, ink residue spit from the printhead is collected in the temporary storage container. The method also includes the step of transferring the collected ink residue from temporary storage container to the permanent storage container using the transfer mechanism. Finally, in a storing step, the ink residue is stored in the permanent storage container. 
     According to a further aspect of the present invention, an inkjet printing mechanism may be provided with a transferring spittoon system for handling waste inkjet ink as described above. 
     An overall goal of the present invention is to provide an inkjet printing mechanism which prints sharp vivid images over the life of the printhead and the printing mechanism. 
     Still another goal of the present invention is to provide a transferring spittoon system that efficiently removes the waste ink residue from a spitting surface and then moves this residue to a location remote from the spit wheel for storage over the expected lifespan of an inkjet printing mechanism. 
     Another goal of the present invention is to provide a long-life spittoon system and method for receiving ink spit from printheads in an inkjet printing mechanism to provide consumers with a reliable, robust inkjet printing unit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of one form of an inkjet printing mechanism, here, an inkjet printer, including a printhead service station having one form of a transferring spittoon system of the present invention for servicing inkjet printheads. 
     FIG. 2 is a perspective view of one form of a waste ink receiving portion of the service station of FIG. 1, including a spit wheel which receives ink residue spit from an inkjet printhead during a spitting routine, a scraper which removes the ink residue from the spit wheel and a temporary storage container or bucket which holds the scraped liquid and semi-solid ink residue prior to transfer to a permanent storage location 
     FIG. 3 is a perspective view of the service station of FIG. 1 including one form of a first embodiment of a transferring spittoon system having an auger transfer mechanism for moving ink residue from the temporary storage container to a permanent storage location. 
     FIGS. 4 and 5 are perspective views of one form of an indexing mechanism for rotating the spit wheel of FIGS. 2 and 3, with: 
     FIG. 4 showing a presetting motion; and 
     FIG. 5 showing the indexing motion. 
     FIGS. 6 and 7 are schematic side elevational views of one form of an indexing mechanism for rotating the auger transfer mechanism of FIG. 3, with: 
     FIG. 6 showing a presetting motion; and 
     FIG. 7 showing the indexing motion. 
     FIG. 8 is a perspective view of the service station of FIG. 1 including one form of a first embodiment of a transferring spittoon system having a conveyor belt transfer mechanism for moving ink residue from the temporary storage container to a permanent storage location. 
     FIG. 9 is a perspective view of the service station of FIG. 1 including one form of a first embodiment of a transferring spittoon system having a turntable transfer mechanism for moving ink residue from the temporary storage container to a permanent storage location. 
     FIG. 10 is a schematic top plan view of one form of an indexing mechanism for rotating the turntable transfer mechanism of FIG.  9 . 
     FIG. 11 is a schematic front elevational view of one form of an indexing mechanism for rotating the turntable transfer mechanism of FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates an embodiment of an inkjet printing mechanism, here shown as an “off-axis” inkjet printer  20 , constructed in accordance with the present invention, which may be used for printing for business reports, correspondence, desktop publishing, and the like, in an industrial, office, home or other environment. A variety of inkjet printing mechanisms are commercially available. For instance, some of the printing mechanisms that may embody the present invention include plotters, portable printing units, copiers, video printers, and facsimile machines, to name a few, as well as various combination devices, such as a combination facsimile/printer. For convenience the concepts of the present invention are illustrated in the environment of an inkjet printer  20 . 
     While it is apparent that the printer components may vary from model to model, the typical inkjet printer  20  includes a frame or chassis  22  surrounded by a housing, casing or enclosure  24 , typically of a plastic material. Sheets of print media are fed through a printzone  25  by a media handling system  26 . The print media may be any type of suitable sheet material, such as paper, card-stock, transparencies, photographic paper, fabric, mylar, and the like, but for convenience, the illustrated embodiment is described using paper as the print medium. The media handling system  26  has a feed tray  28  for storing sheets of paper before printing. A series of conventional paper drive rollers driven by a DC (direct current) or stepper motor and drive gear assembly (not shown), may be used to move the print media from the input supply tray  28 , through the printzone  25 , and after printing, onto a pair of extended output drying wing members  30 , shown in a retracted or rest position in FIG.  1 . The wings  30  momentarily hold a newly printed sheet above any previously printed sheets still drying in an output tray portion  32 , then the wings  30  retract to the sides to drop the newly printed sheet into the output tray  32 . The media handling system  26  may include a series of adjustment mechanisms for accommodating different sizes of print media, including letter, legal, A-4, envelopes, etc., such as a sliding length adjustment lever  34 , a sliding width adjustment lever  36 , and an envelope feed port  38 . 
     The printer  20  also has a printer controller, illustrated schematically as a microprocessor  40 , that receives instructions from a host device, typically a computer, such as a personal computer (not shown). The printer controller  40  may also operate in response to user inputs provided through a key pad  42 , which may include a display screen, located on the exterior of the casing  24 . A monitor coupled to the computer host may be used to display visual information to an operator, such as the printer status or a particular program being run on the host computer. Personal computers, their input devices, such as a keyboard and/or a mouse device, and monitors are all well known to those skilled in the art. 
     A carriage guide rod  44  is supported by the chassis  22  to slidably support an off-axis inkjet pen carriage system  45  for travel back and forth across the printzone  25  along a scanning axis  46 . The carriage  45  is also propelled along guide rod  44  into a servicing region, as indicated generally by arrow  48 , located within the interior of the housing  24 . A conventional carriage drive gear and DC (direct current) motor assembly may be coupled to drive an endless belt (not shown), which may be secured in a conventional manner to the carriage  45 , with the DC motor operating in response to control signals received from the controller  40  to incrementally advance the carriage  45  along guide rod  44  in response to rotation of the DC motor. To provide carriage positional feedback information to printer controller  40 , a conventional encoder strip may extend along the length of the printzone  25  and over the service station area  48 , with a conventional optical encoder reader being mounted on the back surface of printhead carriage  45  to read positional information provided by the encoder strip. The manner of providing positional feedback information via an encoder strip reader may be accomplished in a variety of different ways known to those skilled in the art. 
     In the printzone  25 , a media sheet receives ink from an inkjet cartridge, such as a black ink cartridge  50  and three monochrome color ink cartridges  52 ,  54  and  56 , shown schematically in FIG.  2 . The cartridges  50 - 56  are also often called “pens” by those in the art. The black ink pen  50  is illustrated herein as containing a pigment-based ink. While the illustrated color pens  52 - 56  each contain a dye-based ink of the colors cyan, magenta and yellow, respectively. It is apparent that other types of inks may also be used in pens  50 - 56 , such as paraffin-based inks, as well as hybrid or composite inks having both dye and pigment characteristics. 
     The illustrated pens  50 - 56  each include small reservoirs for storing a supply of ink in what is known as an “off-axis” ink delivery system, which is in contrast to a replaceable cartridge system where each pen has a reservoir that carries the entire ink supply as the printhead reciprocates over the printzone  25  along the scan axis  46 . Hence, the replaceable cartridge system may be considered as an “on-axis” system, whereas systems which store the main ink supply at a stationary location remote from the printzone scanning axis are called “off-axis” systems. In the illustrated off-axis printer  20 , ink of each color for each printhead is delivered via a conduit or tubing system  58  from a group of main stationary reservoirs  60 ,  62 ,  64  and  66  to the on-board reservoirs of pens  50 ,  52 ,  54  and  56 , respectively. The stationary or main reservoirs  60 - 66  are replaceable ink supplies stored in a receptacle  68  supported by the printer chassis  22 . Each of pens  50 ,  52 ,  54  and  56  have printheads  70 ,  72 ,  74  and  76 , respectively, which selectively eject ink to from an image on a sheet of media in the printzone  25 . The concepts disclosed herein for cleaning the printheads  70 - 76  apply equally to the totally replaceable inkjet cartridges, as well as to the illustrated off-axis semi-permanent or permanent printheads, although the greatest benefits of the illustrated system may be realized in an off-axis system where extended printhead life is particularly desirable. 
     The printheads  70 ,  72 ,  74  and  76  each have an orifice plate with a series of ink-ejecting nozzles which may be manufactured in a variety of conventional ways well known to those skilled in the art. The nozzles of each printhead  70 - 76  are typically formed in at least one, but typically two linear arrays along the orifice plate. Thus, the term “linear” as used herein may be interpreted as “nearly linear” or substantially linear, and may include nozzle arrangements slightly offset from one another, for example, in a zigzag arrangement. Each linear array is typically aligned in a longitudinal direction perpendicular to the scanning axis  46 , with the length of each array determining the maximum image swath for a single pass of the printhead. The illustrated printheads  70 - 76  are thermal inkjet printheads, although other types of printheads may be used, such as piezoelectric printheads. The thermal printheads  70 - 76  typically include a plurality of resistors which are associated with the nozzles. Upon energizing a selected resistor, a bubble of gas is formed which ejects a droplet of ink from the nozzle and onto a sheet of paper in the printzone  25  under the nozzle. The printhead resistors are selectively energized in response to firing command control signals delivered by a multi-conductor strip  78  from the controller  40  to the printhead carriage  45 . 
     Transferring Spittoon System For Handling Waste Inkjet Ink 
     FIG. 2 illustrates one form of a service station  80  constructed in accordance with the present invention for servicing the black and color printheads  70 - 76 . The service station  80  has a main frame  82  that is supported by the printer chassis  22  in the servicing region  48  within the printer casing  24 . The service station frame  82  has an outboard sidewall  83  and an inboard sidewall  84 , with “inboard” referring to the direction of the positive X axis toward the printzone  25  and “outboard referring to the opposite direction. The inboard sidewall  84  supports a portion of a transferring spittoon system  85 , constructed in accordance with the present invention as a portion of the service station  80  for handling waste inkjet ink deposited in particular by the black printhead  70 . The service station  80  may also include a conventional absorbent color ink spittoon (not shown) to receive ink spit from the color printheads  72 - 76 , which in the illustrated embodiment dispense dye-based inks, as opposed to the black pen  50  which dispenses a pigment-based ink. 
     The service station  80  also includes a motor and drive gear assembly  86  which is supported by the outboard sidewall  83 . The drive assembly  86  is coupled to drive a spindle gear  87 , with only one gear and a portion of the drive shaft being shown in FIG.  2 . The spindle gear  87  drives a pallet  88  back and forth in the positive and negative Y-axis directions through engagement with a rack gear  89  located along an undersurface of the pallet  88 . The pallet  88  may support a variety of servicing mechanisms, such as printhead caps and wipers (not shown), which are not the subject of the present invention. The pallet  88  is coupled through a mechanism described further below to drive a spittoon wheel portion  90  of the transferring spittoon system  85 . The motor assembly  86  rotates in response to control signals received from the printer controller  40  to drive the pallet  88 . 
     The transferring spittoon system  85  includes a spindle or axle  92  which projects outwardly the service station frame sidewall  84  to rotationally support the spit wheel  90 . A back-up wheel scraper  94  extends from the sidewall  84  to stop any gross accumulation of ink residue, which may have inadvertently adhered to the spit wheel, from passing under and possibly damaging the printhead  70 . The spit wheel  90  has an outer rim  95 , which preferably has a concave shaped cross section, to serve as a spit platform for receiving waste ink spit  96  from the black pen  50 , which is the only printhead in the illustrated embodiment carrying a pigment-based ink. Preferably, the spit wheel  90  is mounted to receive the ink spit  96  along a descending portion thereof, as the wheel  90  is rotated in the direction of arrow  97 . Locating the spit wheel rim  95  close to the printhead was found to significantly reduce the amount of airborne ink aerosol generated during a spitting routine, probably because more ink aerosol particles are captured through impact with the wheel before being carried away to undesirable locations by air currents inside the printer. The spit wheel  90  also defines a series of alignment holes, such as holes  98 , which may be used during manufacture of the service station  80  to verify the spittoon wheel assembly and operation. Preferably, the spit wheel  90  is constructed of an ink-resistant, non-wetting material with dimensional stability, such as a glass fiber filled blend of polyphenylene oxide and polyethylene. 
     Another main component of the ink storage and spittoon system  85  is an ink residue storage container or bucket  100 , which has a hollow body  102  that is preferably covered by a cover portion  104  extending outwardly from the service station frame sidewall  84 . The spit wheel  90  rotates to transport ink  96  deposited thereon into the container  100  where the liquid components of the ink waste ink evaporate and the remaining solid ink residuals  96 ′ are temporarily stored. Together, the container body  102  and cover portion  104  define a storage cavity or chamber  105  therein for receiving and holding this partially dried and liquid ink spit residue  96 ′ prior to transfer to a permanent storage location. Optionally, an absorbent pad (not shown) may be placed within the storage chamber  105  to absorb ink residue liquid components while they evaporate. The container body  102  is preferably pivotally mounted to the frame sidewall  84  at a pivot post  108  which projects outwardly from wall  84 . The container  100  pivots around post  108  and is resiliently pulled toward the spit wheel  90  by a biasing member, such as a tension spring  110  which joins a mounting tab portion  112  that extends outwardly from the sidewall  84 . The service station frame  82 , the spit wheel  90 , and the storage bucket  100  may have other mating features to align the wheel and bucket to guide the solidifying residue  96 ′ from the wheel rim  95  into the bucket. 
     Another main component of the transferring spittoon system  85  is a spit wheel scraper  120 , which may be molded integrally with the bucket  100  beneath a chamber entrance portal that is defined by the container body  102  and/or the cover portion  104 . It is apparent that the wheel scraper  120  may also be constructed as a separate member attached to the bucket, in the same manner as the spit wheel, wheel scraper, and bucket assembly of the spittoon system first sold in the Hewlett-Packard Company&#39;s DeskJet® 2000C Professional Series color inkjet printer, described in the Background section above. In this earlier printer, the scraper was constructed of an ink-resistant, non-wetting, low density polyethylene that was soft enough to have a compliant nature to allows the scraper to conform to the concave contour of the wheel rim. In the illustrated embodiment, the scraper  120  is constructed of the same hard plastic material as the bucket body  102 . 
     FIG. 3 illustrates a first embodiment of a transferring mechanism, here illustrated as an indexed auger mechanism  125  constructed in accordance with the present invention for transferring ink residue  96 ′ from the bottom of the storage bucket  100  to a permanent storage location within a permanent storage chamber  128  defined by a lower portion of the service station frame  82 . The auger transfer mechanism  125  includes an auger or screw member  130  which extends through an opening  132  defined by the storage bucket body  102  to extend into the container cavity  105 . The auger  130  may be pivotally mounted to the bucket body  102 , for instance using a bearing or bushing member  134 , with the opposite end of the auger  130  being pivotally mounted to the exterior of the frame outboard sidewall  83  using another bearing or bushing member  136 . Ink residue removed from the spit wheel rim  95  by scraper  120  follows ink residue  96 ′ to the bottom of the storage container  100 . This ink residue  96 ′ is removed by auger  130  as it rotates, for instance in the direction of arrow  138 , to transport the residue  96 ′ from the temporary storage bucket  100  to the permanent storage location chamber  128 , where it is deposited as ink residue  96 ″. 
     While rotation of the spit wheel  90  and the auger  130  may be accomplished through the incorporation of a separate motor or motors, it is preferable to use the service station motor and gear assembly  86  to provide the indexing motion to turn both wheel  90  and auger  130 . One manner of accomplishing these rotations are shown in FIGS. 4-7, with FIGS. 4 and 5 illustrating rotation of the spit wheel  90 , and FIGS. 6 and 7 illustrating the indexing rotation of the auger  130 . 
     First referring to FIGS. 4 and 5, a ratcheting arm  140  is supported by the pallet  88  as shown in FIG.  4 . Moving the pallet  88  in a forward direction, as indicated by arrow  141 , advances the spit wheel  90  in the direction of arrow  97 , while retreating the pallet  88  in a rearward direction, indicated by arrow  142 , resets the ratchet mechanism. As better shown in FIG. 5 with the pallet  88  and rack gear  89  removed from the view for clarity, the interior surface of the spit wheel  90  contains a series of ratchet teeth  144 . Each ratchet tooth  145  has an active tooth surface  145  and a passive surface  146 . To push the ratchet arm  140  into positive contact with the ratchet teeth  144 , the ratchet arm  140  includes a biasing member such as biasing arm  147  which has a notched distal end  148  that rides along a biasing surface  149  of a slot defined by the service station inboard sidewall  84 . 
     FIG. 5 has the pallet  88  moving in the forward direction of arrow  141  so the ratchet arm  140  engages the active surface  145  of one of the ratchet teeth  144  to advance the spit wheel  90  in the direction of arrow  97 . This forward motion  97  of the wheel  90  causes the scraper  120  (FIGS. 2 and 3) to remove the ink residue  96  from the rim  95 , after which the residue falls into the storage bucket  100 . In FIG. 4, to reset the ratchet arm for the next incremental rotation of the spit wheel  90 , the pallet  88  is moved in the rearward direction of arrow  142 . This rearward motion of pallet  88  allows the ratchet arm  140  to slide over the passive surface  146  of the next tooth in a clockwise direction in the view of FIG. 4, to ready the ratchet arm for another indexing stroke positioned against the active surface  145  of this next tooth. During this pre-setting stroke of FIG. 4, the spit wheel  90  remains stationary. 
     Turning to FIGS. 6 and 7, the indexing operation of the auger  130  is shown. An auger ratcheting arm  150  is pivotally coupled to an activation arm  152  at pivot post  154 . The activation arm  152  is pivotally attached to a pivot post  155 , extending outwardly from the service station frame sidewall  83  (see FIG.  3 ). An activation biasing member such as spring  156  couples the activation arm  152  to the service station frame sidewall  83 , while a ratcheting arm biasing spring  158  pulls the ratchet arm  150  toward the activation arm  152 . The auger  130  is coupled to be driven by a ratchet wheel  160  which has a plurality of ratchet teeth  162 . Each tooth  162  has a passive surface  164  and an active surface  165 . 
     FIG. 6 shows the presetting step, where the pallet  88  moves in the forward direction of arrow  141 , and engages the activation arm  152 . Here we see the activation arm  152  being rotated in the direction of arrow  166  around pivot  155 , with this action serving to stretch the tension spring  156 . During this presetting step, the ratchet arm  150  slides over the passive surface  164  of an engaged tooth, with this action serving to stretch the spring  158  as the ratchet arm  150  pivots in a counterclockwise direction around pivot post  154 . Indeed, under the force of tension provided by spring  158 , the ratchet arm  150  slides across the passive surface  164  of an engaged tooth and then drops down to engage the active surface  165  of this tooth. 
     As shown in FIG. 7, after the ratchet arm  150  drops off of the passive surface  164  of a tooth and engages the active surface  165 , the pallet  88  is free to begin moving in the rearward direction of arrow  142 . As the pallet  88  is moved in the forward direction  142 , under the influence of spring  156 , the activation arm rotates around pivot  155  in the direction of arrow  168 . Since the ratchet arm  150  is now engaged with the active surface  165  of a tooth, the ratchet wheel  160 , as well as the auger  130 , rotate in the direction of arrow  138  to scoop more residue  96 ′ from the storage bucket  100 , and deposit previously scraped residue  96 ″ inside the permanent storage chamber  128  (see FIG.  3 ). 
     FIG. 8 illustrates a second embodiment of the transferring spittoon system, here illustrated as a conveyor mechanism  170 , constructed in accordance with the present invention. Here, different from the temporary storage bucket  100  in FIGS. 2-4, a storage bucket  100 ′ has a body  102 ′ which defines a bottomless opening  171  therethrough, leaving a chamber  105 ′ defined by body  102 ′ and cover  104 . The ink residue  96 ′ removed from the spit wheel  90  by scraper  120  lands upon an endless conveyor belt  172  running under the bucket opening  171 . The conveyor belt  172  is driven in the direction of arrow  173  by a drive roller  174 , which may be pivotally supported by the service station walls by conventional bearings or bushings (not shown). The drive roller  174  is coupled to a drive motor  175  which operates in response to signals received form the controller  40 . The belt  172  also loops around an idler roller  176 , which may be pivotally mounted to the temporary storage bucket body  102 ′ using bearings or bushings, such as bushing  177 . Rather than relying on the mere force of gravity to remove the ink residue  96 ′ from the surface of the endless belt  172 , it is preferable to include a scraper member  178 , which may be supported by the base of the permanent storage cavity  128 . The scraper  178  removes the residue  96 ′ from the belt  172  and it is deposited as  96 ″ in cavity  128 . As an alternate to the drive motor  175 , it is apparent that a ratcheting, linkage, or other mechanism may be used in conjunction with the platform  88  to incrementally advance the conveyor belt  172  in the direction of arrow  173 . 
     FIG. 9 illustrates a third embodiment of a transferring spittoon system, here shown as a turntable mechanism  180 , constructed in accordance with the present invention to the permanent storage location  128 . The turntable system  180  includes a turntable member  182  pivotally mounted at pivot shaft  184 , which projects upwardly from the bottom surface of the storage cavity  128 . The turntable  182  includes a ratchet wheel  185 , which turns the turntable in the direction of arrow  186 , as described further below with respect to FIGS. 10 and 11. 
     In the turntable transferring spittoon system  180 , a temporary storage bucket  100 ′ as described above with respect to FIG. 8 may be used. Here, the turntable  182  extends under opening  171  in the temporary bucket  100 ′ to receive ink residue  96 ′. The ink residue  96 ′ is transferred by turning of the turntable  182  in the direction of arrow  186 . A slow indexing motion of the turntable  182  allows additional liquid volatiles to evaporate from the ink residue composition  96 ′. The ink residue  96 ′ traverses around the surface of the turntable  182  until encountering a scraper member  188 , which may extend upwardly from the bottom of the storage cavity  128 . The scraper  188  serves to remove the ink residue  96 ′ from the surface of the turntable  182 , and deposit it as residue  96 ″ inside the storage chamber  128 . While the scraper  188  may be stationarily mounted to the bottom of the storage cavity  128 , preferably, it is pivotally mounted as described further below with respect to FIGS. 10 and 11. 
     Turning to FIGS. 10 and 11, the indexing operation of the spit wheel  182  is described. In FIG. 10, the pallet  88  includes a mounting bracket  189  which supports an activation arm or a pawl member  190 . As the pallet  88  moves forward in the direction of arrow  141 , the pawl  190  engages the ratchet wheel  185  to advance the turntable  182  in the direction of arrow  186 . As better shown in FIG. 11, preferably the pawl  190  is pivotally mounted to the pallet  88  at a pivot post  192 , and biased by a biasing member, such as spring  194 , into positive contact with the ratchet wheel  185 . To advance the turntable  182  in the direction of arrow  186 , the ratchet wheel  185  includes a series of ratchet teeth  195 , having an active surface  196  and a passive surface  198 . As the pallet  88  moves in the forward direction  141 , the pawl  190  is pulled into positive engagement with the active surface  196  of an engaged tooth  195 , to drive the turntable  182  in the direction of arrow  186 . When the pallet  88  retreats in the direction of arrow  142 , the pawl  190  slides over the passive surface  198  of the next tooth in the clockwise direction of FIG. 10, and then is pulled into engagement with the active surface of this next tooth by the biasing action of return spring  194 . 
     Returning to the scraping action of scraper  188 , the preferred mounting scheme is also shown in FIGS. 10 and 11. Preferably, the scraper  188  is biased by a spring  200  toward the collection surface of turntable  182 , with the scraper  188  being pivoted at post  202  to a support member  204  which extends upwardly from the base of the storage cavity  128 . While the spring biased scraper  188  is believed to provide a more active scraping action against the transfer wheel  182 , in some implementations it may be preferable to stationarily mount the scraper  188  to the base of cavity  128 , or other locations on the service station frame  82 . 
     Conclusion 
     A variety of advantages are realized using the transferring ink storage and spittoon system  80 , whether used with the auger transferring mechanism  125 , the conveyor belt mechanism  170 , or the turntable mechanism  180 . The primary advantage of these transferring mechanisms is the increased waste ink storage capacity for handling the pigment-based residue of the black pen  50 . In contrast, the residue from the dye-based color inks has volatile components which readily dry when initially absorbed by an absorbent pad, leaving little solid residue in the pad. While a dye-based ink may be used in the black pen  50 , the pigment-based black ink bonds on the surface of a printed sheet, yielding a crisp, sharp image with very little, if any bleeding of the edges, which has been known to occur when using dye-based black inks. Thus, while servicing the pigment-based black inks and handling the waste ink residue may be considered a nuisance at best, the resulting drastic improvement in the image quality has been deemed well worth the effort. Now use of the transferring ink storage systems  125 ,  170 ,  180  allows the expansion of pigment-based black inks to high volume printing environments, such as networked printers and short run press printers, because the ink residue storage volume has been greatly increased. Indeed, the transferring ink storage systems  125 ,  170 ,  180  have approximately eight times the storage volume of the Hewlett-Packard Company&#39;s DeskJet® 2000C Professional Series color inkjet printer which was described in the Background section above. This greater permanent storage capacity for the ink residue provides a volumetric efficiency that increases the lifespan of the printer  20 , while providing consumers with an economical, robust printing unit.