Abstract:
A cleaning apparatus in a waste toner removal system of an image forming device includes a waste toner moving device that is movably mounted in a waste toner housing. The housing has an inlet where waste toner enters the housing. The toner moving device is movable between a first position and a second position to displace accumulated toner within the housing. The toner moving device is spring-biased toward the first position. A rotating actuator displaces the toner moving device from the first position to the second position to move the toner in the housing away from the inlet. The toner moving device is also self-cleaning via vibration and impact movements.

Description:
BACKGROUND 
   During the image forming process, toner is transferred from toner carrying members to print or copy media. Inefficiencies in the transfer process cause residual toner to remain on the toner carrying members or other transport members, such as transport belts, intermediate transfer belts/drums, and photoconductive members. Residual toner may also be created during registration, color calibration, paper jams, and over-print situations. This residual toner should be cleaned before it affects the quality of subsequent images. The residual or waste toner is commonly removed by a blade or other means and the removed toner is stored in a waste toner housing. 
   The effectiveness of a waste toner cleaner can be limited by back-pressure exerted at the cleaner throat by waste toner that accumulates in the housing. The cleaner throat is the area between a waste toner cleaner blade, a waste toner cleaner seal, and the surface being cleaned by the blade. Toner that is removed by the blade enters a waste toner cleaner housing at the throat. Back-pressure in this throat area may be generated by the sheer weight of the accumulated toner and may also be imparted through the accumulated toner pile by other devices in the housing, such as an auger that operates to move the waste toner to a location away from the cleaner blade. In any case, back pressure at the entrance to the housing can compromise the effectiveness of the cleaner by preventing newly cleaned waste toner from flowing into the cleaner housing. 
   SUMMARY 
   The present invention is directed to a cleaning apparatus applicable in a waste toner removal system for an image forming device. The invention includes a waste toner moving device that is movably mounted in a waste toner housing. The housing has an inlet where a cleaning blade is attached to remove toner from a transfer body. Waste toner that is removed by the blade enters the housing through the inlet. The waste toner housing includes an auger that rotates to move the toner within the housing. A drive gear is coupled to the auger to rotate the auger from a drive source. The toner moving device is pivotally mounted in the housing and is movable between a first position and a second position. The toner moving device is spring-biased toward the first position. A cam coupled to the gear displaces the toner moving device from the first position to the second position to move the toner in the housing away from the inlet and toward the auger. A portion of the toner moving device also contacts the auger when the toner moving device is in the first position. This contact between the toner moving device and the auger causes a vibration that inhibits the accumulation of toner on the toner moving device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a functional block diagram of an image forming apparatus according to one embodiment of the present invention; 
       FIG. 2  illustrates a side cross-sectional view of the waste toner cleaner according to one embodiment of the present invention; 
       FIG. 3  illustrates a side cross-sectional view of the waste toner cleaner according to one embodiment of the present invention; 
       FIG. 4  illustrates a perspective view of the waste toner cleaner according to one embodiment of the present invention; 
       FIG. 5  illustrates a partial detailed perspective view of the waste toner cleaner according to one embodiment of the present invention; 
       FIG. 6  is a partial side view and the first in a sequence showing the actuator movement according to one embodiment of the present invention; 
       FIG. 7  is a partial side view and the second in a sequence showing the actuator movement according to one embodiment of the present invention; 
       FIG. 8  is a partial side view and the last in a sequence showing the actuator movement according to one embodiment of the present invention; and 
       FIG. 9  is a detail view of the chopping wall of the toner moving member according to one embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
   The present invention is directed to a cleaner apparatus for a waste toner system within an image forming device as generally illustrated in  FIG. 1 .  FIG. 1  depicts a representative image forming device, indicated generally by the numeral  10 . The image forming device  10  comprises a main media sheet stack  16 . Media sheets may also be introduced through a manual input  20 . The term “image forming device” and the like is used generally herein as a device that produces images on a media sheet. Examples include but are not limited to a laser printer, ink-jet printer, fax machine, copier, and a multi-functional machine. Examples of an image forming device include Model Nos. C750 and C752 available from Lexmark International, Inc. of Lexington, Ky. 
   Within the image forming apparatus body  12 , the image forming apparatus  10  includes a plurality of removable image formation cartridges  26 , each with a similar construction but distinguished by the toner color contained therein. In one embodiment, the apparatus  10  includes a black cartridge (K), a magenta cartridge (M), a cyan cartridge (C), and a yellow cartridge (Y). Each cartridge  26  forms an individual monocolor image that is combined in layered fashion with images from the other cartridges to create the final multi-colored image. The image forming apparatus further includes an intermediate transfer mechanism (ITM) belt  24 , one or more imaging devices  30 , a fuser  32 , and a waste toner cleaner  40  as well as various rollers, actuators, sensors, optics, and electronics (not shown) as are conventionally known in the image forming apparatus arts, and which are not further explicated herein. 
   The internal components of removable image formation cartridges  26  are not specifically identified in  FIG. 1 , but are briefly described. Each image formation cartridge  26  is a removable cartridge that may include a reservoir holding a supply of toner, a developer roller for applying toner to develop a latent image on a photoconductive drum, and a photoconductive (PC) drum  14 , which may comprise, for example, an aluminum hollow-core drum coated with one or more layers of light-sensitive organic photoconductive materials. The image formation cartridge  26  may additionally include various rollers, paddles, augers and blades, as well known in the art. Note that this description is representative only—various image formation devices may organize these components into a plurality of cartridges. 
   The operation of the image forming apparatus  10  is conventionally known. Upon command from control electronics, a single media sheet is “picked,” or selected, from either the primary media stack  16  or the manual input  20 . Regardless of its source, the media sheet is transported to transfer location  22  to receive a toner image from the ITM belt  24 . The ITM belt  24  is endless and rotates in the direction indicated by arrow R around a series of rollers adjacent to the PC drums  14  of the respective image formation cartridges  26 . Toner is deposited from each PC drum  14  as needed to create a full color image on the ITM belt  24 . The ITM belt  24  and each PC drum  14  are synchronized so that the toner from each PC drum  14  precisely aligns on the ITM belt during a single pass. 
   The media sheet may receive an electrostatic charge before contacting the ITM belt  24  at the transfer location  22  to assist in attracting the toner from the belt  24 . The sheet and attached toner next travel through a fuser  32  having a pair of rollers and a heating element that heats and fuses the toner to the sheet. The paper with fused image is then transported out of the printer body  12  for receipt by a user. 
   In the image forming apparatus shown in  FIG. 1 , four image formation cartridges  26  are arrayed along the ITM belt  24 . A full color image is formed on the ITM belt and the color image is subsequently transferred to a print media sheet at a secondary transfer location  22 . Other devices may use an intermediate transfer drum instead of belt  24 . In other conventional image forming devices, print media sheets are transported by a transfer belt similar in configuration to belt  24 , but a full color image is formed directly on the media sheet by successively transferring images from the four respective image formation cartridges  26  (cyan, yellow, magenta, and optionally black) onto the media sheet. In either of these configurations, residual toner that remains on the belt  24  following the image formation process is removed by a waste toner cleaner  40 . Residual toner that remains on belt  24  following color calibration and/or paper registration processes must also be cleaned by the waste toner cleaner  40 . 
     FIGS. 2 and 3  illustrate a side cross-sectional view of the waste toner cleaner  40 . The waste toner cleaner  40  is comprised of a blade  42 , blade bracket  44 , lower seal  46 , auger  48 , and cleaner apparatus  50  all contained within or coupled to a housing  52 . The waste toner cleaner  40  is positioned so that cleaner blade  42  is in contact with a surface to be cleaned. The surface to be cleaned may be part of a number of different electrophotographic components, including intermediate transfer member belts, photoconductor belts, photoconductor drums, and media transport belts. In the orientation shown in  FIGS. 2 and 3 , the surface to be cleaned moves past the waste toner cleaner  40  at the inlet to the housing  58 . As the surface to be cleaned moves past the waste toner cleaner  40 , the cleaner blade  42  removes toner from that surface. The removed toner is guided at inlet  58  into the interior of the housing  52  by lower seal  46 . The removed toner accumulates in the housing on floor  60 , which is sloped gradually downward and rearward away from the inlet  58 . The auger  48  rotates to transport the waste toner to a separate part of housing  52  or to a remote storage container (not shown). In the embodiments shown in the Figures, the auger  48  is depicted as a coiled wire, although other conveyors known to those skilled in the art, including screws or other equivalent devices, may be used. The auger  48  is rotatively driven by a gear  76  (see  FIGS. 4 through 8 ) that is driven by an external drive source (not shown). 
   The cleaner apparatus  50  comprises a toner moving member  54  that is pivotally attached to the housing  52  at pivot point  56 . The toner moving member  54  is depicted in  FIG. 2  in a first position and is depicted in  FIG. 3  in a second position. These positions are described in further detail below. The toner moving member  54  is a generally elongate structure (see also  FIG. 4 ) that spans much of the width of the cleaner housing  52  and has a generally inverted-L shape cross section. The upper portion of the inverted-L shape is defined by a shelf  66 , while the lower portion of the inverted-L shape is defined by a chopping wall  68 . The chopping wall  68  may advantageously be subdivided into upper  68   a  and lower  68   b  sections. The toner moving member  54  is supported at its ends by side walls  62 . Protrusions  64  extending from side walls  62  are engaged by corresponding pivot supports  72  located within the housing  52 . In one embodiment, protrusions  64  are embodied as dowel pins that are inserted into holes in the side walls  62 . In another embodiment, the protrusions  64  are an integral part of the toner moving member body  54 . When supported in this manner, pivot point  56  coincides with the center axis of protrusions  64 . 
   The toner moving member  54  is pivotable between two positions about pivot point  56 . In  FIG. 2 , toner moving member  54  is in a first position where the leading edge  70  of the lower section  68   b  of chopping wall  68  is spaced away from the floor  60  of housing  52 . By comparison, the toner moving member  54  shown in  FIG. 3  is in a second position where the leading edge  70  of the lower section  68   b  of chopping wall  68  is closer to the floor  60  of housing  52 . In one embodiment, the leading edge  70  actually contacts the floor  60  in the second position. In one embodiment, the leading edge  70  is adjacent to the floor  60  in the second position. In another embodiment, the leading edge  70  is spaced away from the floor  60  in the second position, but is still in closer proximity to the floor than in the first position. In one embodiment, the toner moving member  54  is biased by a spring  71  or other resilient member towards the first position. 
   Pivot point  56  is positioned vertically above the floor  60  of housing  52  so that as the toner moving member  54  travels between the first and second positions, the leading edge  70  is contactable with the floor  60 . In one embodiment, the lower edges  74  of side walls  62  remain out of contact with the floor  60  so as not to impede the motion of the toner moving member  54 . In one embodiment, the pivot point  56  is positioned at nearly the same vertical height as the leading edge  70  in the second position described above. In other embodiments, the position of pivot point  56  may advantageously be placed at higher points in space, as design constraints permit, to allow the leading edge  70  to pass a horizontal apex and travel away from the inlet  58  and away from blade  42  as the toner moving member  54  approaches the second position. In this latter configuration, the movement of the leading edge  70  will therefore have a horizontal component that will aid in moving waste toner away from the inlet  58  and towards the auger  48 . 
   In addition to using the motion of the leading edge  70  (as just described) to displace waste toner within housing, the shape of the leading edge  70  and chopping wall  68  also advantageously cooperate to displace waste toner away from the blade  42 .  FIG. 9  shows a detail view of the orientation of the upper  68   a  and lower  68   b  sections of chopping wall  68  relative to the floor  60  of housing  52  when the toner moving member  54  is in the second position (as shown in  FIG. 3 ). As shown in  FIG. 9 , the upper  68   a  and lower  68   b  sections of the chopping wall  68  are disposed at different angles relative to the floor  60  of housing  52 , although both sections  68   a ,  68   b  are tilted away from the inlet  58  and blade  44 . The lower section  68   b  is more acutely oriented than the upper section  68   a  relative to the floor  60 . In other words, the lower section  68   b  is tilted at an angle Θ 1  relative to floor  60  that is less than the angle Θ 2  at which the upper section  68   a  is tilted. The orientation of the upper  68   a  and lower  68   b  sections aid in directing waste toner away from the inlet in generally the left to right direction in  FIG. 9 . Thus, the design of the chopping wall  68  moves the toner away from the blade  44  towards the auger  48  and advantageously prevents toner build-up that could cause back-pressure on the blade  44 . 
   If the angle Θ 1  is too small, the lower section  68   b  will compact waste toner against floor  60  instead of displacing the toner away from the inlet. If the angle Θ 1  is too large, the waste toner will remain stagnant on the floor  60  and not move towards the auger  48 . The angle Θ 1  is selected to be in the range between about 25° and 65°. In one embodiment, the angle Θ 1  is selected to be in the range between about 40° and 45°. In one specific embodiment, the angle Θ 1  is selected to be 42°. 
   The angle Θ 2  is less acute than Θ 1  to inhibit adhesion of waste toner to the chopping wall  68 . Thus, a more vertical orientation is desirable and the angle Θ 2  is selected to be in the range between about 65° and 90°. In one embodiment, the angle Θ 2  is selected to be in the range between about 75° and 80°. In one specific embodiment, the angle Θ 2  is selected to be 77°. 
   In one embodiment, the chopping wall  68  does not have upper and lower sections  68   a ,  68   b , but instead is comprised of a single flat section that is disposed at a fixed angle relative to the floor  60  of housing  52 . In another embodiment, the chopping wall  68  is comprised of a curved wall that has a constant radius. In another embodiment, the chopping wall  68  is comprised of a curved wall that has a lower leading portion that is more acutely oriented than an upper portion. A variety of configurations for the chopping wall  68  that incorporate the teachings herein may be employed as will be understood by those skilled in the art. 
   Referring now to  FIG. 4 , a perspective view of the cleaner apparatus  50  is provided. As discussed above, the toner moving member  54  includes a reciprocating chopping wall  68  and upper shelf  66 . The toner moving member is pivotable about protrusions  64  that extend from the side walls  62 .  FIG. 4  also shows the auger  48  as a spiraled body adapted to displace waste toner within or from the waste toner housing  52 . The waste toner housing  52  and other components of the waste toner cleaner  40  (e.g., blade  44 , seal  46 ) are omitted for clarity. The auger  48  is driven by a drive gear  76  that is rotated by a drive source that is not explicitly shown in the Figures, but is understood by those skilled in the art to be a motor and/or a drive train capable of imparting a rotational force to the waste toner auger  48 . The drive gear  76  shown in  FIGS. 4 through 8  rotates in a direction indicated by the arrow labeled R. This gear rotation, in turn, rotates the auger so as to displace toner in the direction indicated by the arrow labeled T. 
   As shown in  FIGS. 3 ,  4 , and  5 , the upper shelf  66  of toner moving member  54  extends substantially perpendicular from the upper portion  68   a  of the chopping wall  68 . The shelf  66  has a contact portion  66   a  that extends a larger distance away from the chopping wall  68  and towards auger  48  than the remainder of the shelf  66 . Wall  78  shown in  FIG. 5  represents the transition area between the contact portion  66   a  and the remainder of the shelf  66 . The contact portion  66   a  advantageously protrudes a sufficient amount as to permit tabs  80  to contact auger  48 . As discussed above, the toner moving member  54  is biased toward the first position where the chopping wall  68  is elevated from floor  60  of the waste toner cleaner housing  52 . In this first position, the contact portion  66   a  of shelf  66  is placed close to the auger  48 . 
   A plurality of triangular-shaped tabs  80  extend outward from the end of contact portion  66   a  of shelf  66 . These tabs  80  extend farther towards the auger  48  than does the contact portion  66   a . As a result of this protrusion, the individual turns (e.g.,  48   a  and  48   b  shown in  FIG. 5 ) of the auger  48  periodically come into contact with the tabs  80  as the auger rotates. As discussed above, the auger  48  tends to displace waste toner in the direction indicated by the arrow T. Consequently, the individual turns of the auger  48  also tend to move in this direction. The tabs  80  are generally triangle-shaped with the leading edge  82  (i.e., the edge closest to drive gear  76 ) having a more gradual slope than the trailing edge  84 . As the auger  48  rotates, the individual auger turns  48   a ,  48   b  initially contact the tabs  80  at the leading edge  82 . The motion of the auger  48  in sliding contact with the tabs  80  vibrates the toner moving member  54 . The interference between the tabs  80  and the auger  48  also creates a small displacing force. This small displacing force tends to pivot the toner moving member  54  against the bias of spring  71  a small amount out of the first position in the direction of the second position. In essence, the auger  48  displaces the toner moving member by the tabs  80  until the individual auger turns  48   a ,  48   b  move past the tabs  80 . Once the auger turns  48   a ,  48   b  come out of contact with the tabs  80 , the toner moving member  54  returns to the first position under the influence of spring  71 . The slope of the trailing edge  84  of tabs  80  is sharp to permit the auger  48  to quickly lose contact with the tabs  80  and allow the toner moving member  54  to rapidly return to the first position. This rapid movement imparts a jarring motion that tends to loosen any waste toner that may accumulate on the toner moving member  54 . The jarring motion may also be of a sufficient magnitude to vibrate the remainder of the housing  52 , housing blade  44 , and lower seal  46  to loosen accumulated waste toner. 
   Referring still to  FIGS. 4 and 5  with additional attention now to  FIGS. 6 through 8 , the drive gear  76  is coupled to the auger  48  by a shaft  86 . For clarity,  FIGS. 6–8  show only the drive mechanism that operates to deflect the waste toner cleaner apparatus  50  between the first (up) position and the second (down) position. The shaft  86  protrudes through the drive gear  76  and through the waste toner cleaner housing  52  so that the auger  48  can be driven by an external drive source (not shown). An actuator, depicted generally by the number  88 , is also coupled to the shaft  86 . In the embodiment shown in the Figures, actuator  88  is advantageously embodied as a cam  90  that has a single eccentric lobe  92  that causes the toner moving member  54  to deflect downward from the first position to the second position as described above. Once per revolution of shaft  86  (and hence, gear  76 ), the cam lobe  92  comes into contact and moves a deflecting arm  94  of pivot linkage, which is indicated generally by reference numeral  96 . In one embodiment, the pivot linkage  96  is implemented as a bail, or a twisted wire member with the shape shown in the Figures. The pivot linkage  96  is mounted to the waste toner housing  52  at horizontal mounting segments  98  and  99 . The cam lobe  92  contacts the deflecting arm  94 , which causes the pivot linkage to pivot about horizontal segments  98 ,  99 . As the deflecting arm  94  pivots, a lower urging segment  100  pivots about horizontal segments  98 ,  99  in the same rotational direction as the deflecting arm  94 . 
   The lower urging segment  100  rests within a channel  102  in the toner moving member  54  that is bounded on opposite sides by walls  104 ,  106 . As the deflecting arm is moved by cam lobe  92 , the urging segment  100  tends to push on wall  106 . The point of contact between urging segment  100  and wall  106  is above pivot point  56 . Consequently, toner moving member  54  rotates in a direction indicated by the arrow D shown in  FIG. 6 . As cam  90  continues to rotate while contacting the deflecting arm  94 , the pivot linkage  96  continues to rotate about horizontal segments  98 ,  99 .  FIG. 7  shows the cleaner apparatus  50 , including toner moving member  54  and pivot linkage  96  rotated into the second, downward position described above. As the cam  90  continues to rotate out of contact with the deflecting arm  94  as shown in  FIG. 8 , the bias spring  71  (not shown in  FIGS. 6–8 ) tends to return the cleaner apparatus  50  to the first position. In this manner, the toner moving member  54  deflects between the first and second positions to displace toner along the waste toner housing floor  60 . 
   In one embodiment, the pivot linkage  96  is a resilient drive bail that is rigid enough to impart the urging forces described. However, the resilient nature of the pivot linkage  96  tends to buffer impact forces that may otherwise be transmitted to the toner moving member  54  by the actuator  88 . Design constraints will invariably determine the shape and configuration of the actuator  88 , drive linkage  96 , and toner moving member  54 . Thus, the design shown in the Figures is one particular embodiment. Other designs may capture the essence of the teachings herein. For instance, in one embodiment, it may be desirable to have the actuator  88  directly contact the toner moving member  54  in order to deflect the toner moving member  54  between the first and second positions. In addition, a spring  71  has been shown in  FIGS. 2 and 3  as providing a biasing force tending to hold the waste toner cleaner apparatus  50  in the first position. In another embodiment, a separate spring may be used to bias the drive linkage  96 . Furthermore, a cam actuator  90  has been shown as providing the initiation force that drives the cleaner apparatus  50  toward the second position. In other embodiments, a cam with multiple lobes or a rotating body with one or more recesses may be used to provide the impetus that deflects the cleaner apparatus  50  as described. Alternatively, the cleaner apparatus  50  may be spring biased toward the second position while an actuator permits periodic transitions to the first position. 
   The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. For instance, the embodiments described have been depicted in use with a waste toner cleaner  40  that uses a blade  44 . Other cleaners known by those skilled in the art, such as foam or brush rollers can also be employed. Furthermore, while the embodiments discussed have been described in the context of a waste toner mover  54  that pivots about point  56 , may be desirable to implement a linearly actuating waste toner mover. The waste toner mover  54  may be incorporated in a variety of image forming devices including, for example, printers, fax machines, copiers, and multi-functional machines including vertical and horizontal architectures as are known in the art of electrophotographic reproduction. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.