Patent Publication Number: US-9891578-B2

Title: Cleaner blade sealing in an electrophotographic image forming device

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application Ser. No. 62/272,126, filed Dec. 29, 2015, entitled “Cleaner Blade Sealing for an Electrophotographic Image Forming Device,” the content of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     1. Field of the Disclosure 
     The present disclosure relates generally to image forming devices and more particularly to cleaner blade sealing for an electrophotographic image forming device. 
     2. Description of the Related Art 
     During the electrophotographic printing process, an electrically charged rotating photoconductive drum is selectively exposed to a laser beam. The areas of the photoconductive drum exposed to the laser beam are discharged creating an electrostatic latent image of a page to be printed on the photoconductive drum. Toner particles are then electrostatically picked up by the latent image on the photoconductive drum creating a toned image on the photoconductive drum. The toned image is transferred to the print media (e.g., paper) either directly by the photoconductive drum in a one-step transfer system or indirectly by an intermediate transfer member in a two-step transfer system. The toner is then fused to the media using heat and pressure to complete the print. Not all of the toner picked up by the photoconductive drum is transferred to the print media or intermediate transfer member due to inefficiencies in the image transfer process. Waste or residual toner left on the photoconductive drum after the photoconductive drum has contacted the print media or intermediate transfer member is removed before the next image is formed in order to avoid contamination of the next image. For this purpose, a cleaner blade in contact with the photoconductive drum (and, in a two-step transfer system, the intermediate transfer member) removes the waste toner from its surface. The waste toner cleaned from the surface of the photoconductive drum initially falls to a temporary waste toner sump and is then moved to a permanent waste toner reservoir where it is stored. It is important to seal the waste toner in the area around the cleaner blade and the waste toner sump in order to prevent leakage. Sealing in this area can be particularly difficult in image forming devices having a pivoting cleaner blade. 
     SUMMARY 
     A photoconductor unit for an electrophotographic image forming device according to one example embodiment includes a housing and a photoconductive drum rotatably mounted on the housing. The photoconductive drum includes a rotational axis. A cleaner blade extends longitudinally along the rotational axis of the photoconductive drum and includes a pair of longitudinal ends. The cleaner blade includes a front side that faces the photoconductive drum and a rear side opposite the front side. The cleaner blade extends upward in a cantilevered manner toward the photoconductive drum and includes a cleaning edge that contacts a surface of the photoconductive drum to remove toner from the surface of the photoconductive drum. A waste toner sump is positioned adjacent to the rear side of the cleaner blade. The waste toner sump stores toner removed from the surface of the photoconductive drum by the cleaner blade. A rear seal assembly seals between the rear side of the cleaner blade and a wall of the housing that is positioned proximate to a front portion of the waste toner sump. The rear seal assembly includes a film seal that extends in a cantilevered manner toward the rear side of the cleaner blade and that contacts the rear side of the cleaner blade along a longitudinal length of the cleaner blade. The rear seal assembly includes a second seal positioned between the rear side of the cleaner blade and the wall of the housing below the contact between the rear side of the cleaner blade and the film seal. The second seal extends along the longitudinal length of the cleaner blade. 
     A photoconductor unit for an electrophotographic image forming device according to another example embodiment includes a housing and a photoconductive drum rotatably mounted on the housing. The photoconductive drum includes a rotational axis. A cleaner blade is mounted on a bracket that is mounted on the housing. The cleaner blade extends longitudinally along the rotational axis of the photoconductive drum and includes a pair of longitudinal ends. The cleaner blade includes a front side that faces the photoconductive drum and a rear side opposite the front side. The cleaner blade extends in a cantilevered manner from the bracket toward the photoconductive drum and includes a cleaning edge that contacts a surface of the photoconductive drum to remove toner from the surface of the photoconductive drum. The cleaner blade and the bracket are pivotable relative to the photoconductive drum about a pivot axis that is parallel to the rotational axis of the photoconductive drum. A rear seal assembly seals between the rear side of the cleaner blade and a wall of the housing. The rear seal assembly includes a film seal that extends in a cantilevered manner toward the rear side of the cleaner blade and that contacts the rear side of the cleaner blade along a longitudinal length of the cleaner blade. The rear seal assembly includes a foam seal positioned between the rear side of the cleaner blade and the wall of the housing. The foam seal extends along the longitudinal length of the cleaner blade and is positioned against the bracket. 
     A cleaner assembly for an electrophotographic image forming device according to one example embodiment includes a cleaner blade having a pair of longitudinal ends. The cleaner blade extends upward in a cantilevered manner and includes a cleaning edge that extends between the pair of longitudinal ends for contacting a surface to remove toner from the surface. A waste toner sump is positioned adjacent to a rear side of the cleaner blade. The waste toner sump stores toner removed from the surface by the cleaner blade. A seal assembly seals between the rear side of the cleaner blade and a wall of the waste toner sump. The seal assembly includes a film seal that extends in a cantilevered manner toward the rear side of the cleaner blade and that contacts the rear side of the cleaner blade along a longitudinal length of the cleaner blade. The seal assembly includes a foam seal positioned between the rear side of the cleaner blade and the wall below the contact between the rear side of the cleaner blade and the film seal. The foam seal extends along the longitudinal length of the cleaner blade. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present disclosure, and together with the description serve to explain the principles of the present disclosure. 
         FIG. 1  is a block diagram depiction of an imaging system according to one example embodiment. 
         FIG. 2  is a schematic diagram of an image forming device according to one example embodiment. 
         FIG. 3  is a perspective view of an imaging unit including a developer unit and a photoconductor unit according to one example embodiment. 
         FIG. 4  is a perspective view of the imaging unit showing the developer unit separated from the photoconductor unit according to one example embodiment. 
         FIG. 5  is a cross sectional perspective view of a portion of the photoconductor unit showing the engagement between a cleaner blade and a photoconductive drum according to one example embodiment. 
         FIG. 6  is a cross sectional view of a portion of the photoconductor unit shown in  FIG. 5  showing a rear seal assembly according to one example embodiment. 
         FIG. 7  is a perspective view of an end seal assembly of the photoconductor unit according to one example embodiment. 
         FIG. 8  is an exploded view of the end seal assembly and the rear seal assembly according to one example embodiment. 
         FIG. 9  is a perspective view of a backup seal of the end seal assembly positioned against a housing of the photoconductor unit according to one example embodiment. 
         FIG. 10  is a perspective view of the rear seal assembly positioned relative to the backup seal according to one example embodiment. 
         FIG. 11  is a front elevation view of an end seal of the end seal assembly positioned relative to the rear seal assembly and the backup seal according to one example embodiment. 
         FIG. 12  is a perspective view of a portion of the end seal assembly showing a top portion of the end seal sealing a joint between a cap and a main body of the housing of the photoconductor unit according to one example embodiment. 
         FIG. 13  is a cross sectional perspective view of a portion of the photoconductor unit showing the end seal positioned against a seal that is positioned between the cap and the main body of the housing of the photoconductor unit according to one example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, reference is made to the accompanying drawings where like numerals represent like elements. The embodiments are described in sufficient detail to enable those skilled in the art to practice the present disclosure. It is to be understood that other embodiments may be utilized and that process, electrical, and mechanical changes, etc., may be made without departing from the scope of the present disclosure. Examples merely typify possible variations. Portions and features of some embodiments may be included in or substituted for those of others. The following description, therefore, is not to be taken in a limiting sense and the scope of the present disclosure is defined only by the appended claims and their equivalents. 
     Referring now to the drawings and more particularly to  FIG. 1 , there is shown a block diagram depiction of an imaging system  20  according to one example embodiment. Imaging system  20  includes an image forming device  100  and a computer  30 . Image forming device  100  communicates with computer  30  via a communications link  40 . As used herein, the term “communications link” generally refers to any structure that facilitates electronic communication between multiple components and may operate using wired or wireless technology and may include communications over the Internet. 
     In the example embodiment shown in  FIG. 1 , image forming device  100  is a multifunction machine (sometimes referred to as an all-in-one (AIO) device) that includes a controller  102 , a print engine  110 , a laser scan unit (LSU)  112 , one or more toner bottles or cartridges  200 , one or more imaging units  300 , a fuser  120 , a user interface  104 , a media feed system  130  and media input tray  140  and a scanner system  150 . Image forming device  100  may communicate with computer  30  via a standard communication protocol, such as, for example, universal serial bus (USB), Ethernet or IEEE 802.xx. Image forming device  100  may be, for example, an electrophotographic printer/copier including an integrated scanner system  150  or a standalone electrophotographic printer. 
     Controller  102  includes a processor unit and associated memory  103  and may be formed as one or more Application Specific Integrated Circuits (ASICs). Memory  103  may be any volatile or non-volatile memory or combination thereof such as, for example, random access memory (RAM), read only memory (ROM), flash memory and/or non-volatile RAM (NVRAM). Alternatively, memory  103  may be in the form of a separate electronic memory (e.g., RAM, ROM, and/or NVRAM), a hard drive, a CD or DVD drive, or any memory device convenient for use with controller  102 . Controller  102  may be, for example, a combined printer and scanner controller. 
     In the example embodiment illustrated, controller  102  communicates with print engine  110  via a communications link  160 . Controller  102  communicates with imaging unit(s)  300  and processing circuitry  301  on each imaging unit  300  via communications link(s)  161 . Controller  102  communicates with toner cartridge(s)  20 ( )and processing circuitry  201  on each toner cartridge  200  via communications link(s)  162 . Controller  102  communicates with fuser  120  and processing circuitry  121  thereon via a communications link  163 . Controller  102  communicates with media feed system  130  via a communications link  164 . Controller  102  communicates with scanner system  150  via a communications link  165 . User interface  104  is communicatively coupled to controller  102  via a communications link  166 . Processing circuitry  121 ,  201 ,  301  may include a processor and associated memory such as RAM, ROM, and/or NVRAM and may provide authentication functions, safety and operational interlocks, operating parameters and usage information related to fuser  120 , toner cartridge(s)  200  and imaging unit(s)  300 , respectively. Controller  102  processes print and scan data and operates print engine  110  during printing and scanner system  150  during scanning. 
     Computer  30 , which is optional, may be, for example, a personal computer, including memory  32 , such as RAM, ROM, and/or NVRAM, an input device  34 , such as a keyboard and/or a mouse, and a display monitor  36 . Computer  30  also includes a processor, input/output (I/O) interfaces, and may include at least one mass data storage device, such as a hard drive, a CD-ROM and/or a DVD unit (not shown). Computer  30  may also be a device capable of communicating with image forming device  100  other than a personal computer such as, for example, a tablet computer, a smartphone, or other electronic device. 
     In the example embodiment illustrated, computer  30  includes in its memory a software program including program instructions that function as an imaging driver  38 , e.g., printer/scanner driver software, for image forming device  100 . Imaging driver  38  is in communication with controller  102  of image forming device  100  via communications link  40 . Imaging driver  38  facilitates communication between image forming device  100  and computer  30 . One aspect of imaging driver  38  may be, for example, to provide formatted print data to image forming device  100 , and more particularly to print engine  110 , to print an image. Another aspect of imaging driver  38  may be, for example, to facilitate the collection of scanned data from scanner system  150 . 
     In some circumstances, it may be desirable to operate image forming device  100  in a standalone mode. In the standalone mode, image forming device  100  is capable of functioning without computer  30 . Accordingly, all or a portion of imaging driver  38 , or a similar driver, may be located in controller  102  of image forming device  100  so as to accommodate printing and/or scanning functionality when operating in the standalone mode. 
       FIG. 2  illustrates a schematic view of the interior of an example image forming device  100 . For purposes of clarity, the components of only one of the imaging units  300  are labeled in  FIG. 2 . Image forming device  100  includes a housing  170  having a top  171 , bottom  172 , front  173 , rear  174  and a pair of sides (one facing out of the page and one facing into the page as viewed in  FIG. 2 ). Housing  170  includes one or more media input trays  140  positioned therein. Trays  140  are sized to contain a stack of media sheets. As used herein, the term media is meant to encompass not only paper but also labels, envelopes, fabrics, photographic paper or any other desired substrate. Trays  140  are preferably removable for refilling. A media path  180  extends through image forming device  100  for moving the media sheets through the image transfer process. Media path  180  includes a simplex path  181  and may include a duplex path  182 . A media sheet is introduced into simplex path  181  from tray  140  by a pick mechanism  132 . In the example embodiment shown, pick mechanism  132  includes a roll  134  positioned at the end of a pivotable arm  136 . Roll  134  rotates to move the media sheet from tray  140  and into media path  180 . The media sheet is then moved along media path  180  by various transport rollers. Media sheets may also be introduced into media path  180  by a manual feed  138  having one or more rolls  139 . 
     In the example embodiment shown, image forming device  100  includes four toner cartridges  200  removably mounted in housing  170  in a mating relationship with four corresponding imaging units  300 , which are also removably mounted in housing  170 . Each toner cartridge  200  includes a reservoir  202  for holding toner and an outlet port in communication with an inlet port of its corresponding imaging unit  300  for transferring toner from reservoir  202  to imaging unit  300 . Toner is transferred periodically from a respective toner cartridge  200  to its corresponding imaging unit  300  in order to replenish the imaging unit  300 . In the example embodiment illustrated, each toner cartridge  200  is substantially the same except for the color of toner contained therein. In one embodiment, the four toner cartridges  200  contain yellow, cyan, magenta and black toner, respectively. 
     In the example embodiment illustrated, image forming device  100  utilizes what is commonly referred to as a dual component development system. Each imaging unit  300  includes a reservoir  302  that stores a mixture of toner and magnetic carrier beads. The carrier beads may be coated with a polymeric film to provide triboelectric properties to attract toner to the carrier beads as the toner and the carrier beads are mixed in reservoir  302 . Reservoir  302  and a magnetic roll  306  collectively form a developer unit. Magnetic roll  306  includes a stationary core that includes one or more permanent magnets and a rotatable sleeve that encircles the core. Reservoir  302  may include toner agitators, such as paddles, augers, etc., that stir the developer mix and present the developer mix to magnetic roll  306 . Each imaging unit  300  also includes a charge roll  308 , a photoconductive drum (PC drum)  310  and a cleaner blade (not shown) that collectively form a photoconductor unit. PC drums  310  are mounted substantially parallel to each other when the imaging units  300  are installed in image forming device  100 . In the example embodiment illustrated, each imaging unit  300  is substantially the same except for the color of toner contained therein. 
     Each charge roll  308  forms a nip with the corresponding PC drum  310 . During a print operation, charge roll  308  charges the surface of PC drum  310  to a specified voltage, such as, for example, −1000 volts. A laser beam from LSU  112  is then directed to the surface of PC drum  310  and selectively discharges those areas it contacts to form a latent image. In one embodiment, areas on PC drum  310  illuminated by the laser beam are discharged to approximately −300 volts. The permanent magnets) of magnetic roll  306  attract the carrier beads in reservoir  302  having toner thereon to the outer surface of the sleeve of magnetic roll  306 . The sleeve of magnetic roll  306  transports the carrier beads having toner thereon past a trim bar that trims the mix of carrier beads and toner to a predetermined average height on the outer surface of the sleeve. The sleeve of magnetic roll  306  then transports the carrier beads having toner thereon to the corresponding PC drum  310 . Electrostatic forces from the latent image on PC drum  310  strip the toner from the carrier beads to form a toner image on the surface of PC drum  310 . 
     An intermediate transfer mechanism (ITM)  190  is disposed adjacent to the PC drums  310 . In this embodiment, ITM  190  is formed as an endless belt trained about a drive roll  192 , a tension roll  194  and a back-up roll  196 . During image forming operations, ITM  190  moves past PC drums  310  in a clockwise direction as viewed in  FIG. 2 . One or more of PC drums  310  apply toner images in their respective colors to ITM  190  at a respective first transfer nip  197 . in one embodiment, a positive voltage field attracts the toner images from PC drums  310  to the surface of the moving ITM  190 . ITM  190  rotates and collects the one or more toner images from PC drums  310  and then conveys the toner images to a media sheet at a second transfer nip  198  formed between a transfer roll  199  and ITM  190 , which is supported by back-up roll  196 . The cleaner blade/roll removes any toner remnants on PC drum  310  so that the surface of PC drum  310  may be charged and developed with toner again. 
     A media sheet advancing through simplex path  181  receives the toner image from ITM  190  as it moves through the second transfer nip  198 . The media sheet with the toner image is then moved along the media path  180  and into fuser  120 . Fuser  120  includes fusing rolls or belts  122  that form a nip to adhere the toner image to the media sheet. The fused media sheet then passes through exit rolls  126  located downstream from fuser  120 . Exit rolls  126  may be rotated in either forward or reverse directions. In a forward direction, exit rolls  126  move the media sheet from simplex path  181  to an output area  128  on top  171  of image forming device  100 . In a reverse direction, exit rolls  126  move the media sheet into duplex path  182  for image formation on a second side of the media sheet. 
     While the example image forming device  100  shown in  FIG. 2  illustrates four toner cartridges  200  and four corresponding imaging units  300 , it will be appreciated that a monocolor image forming device  100  may include a single toner cartridge  200  and corresponding imaging unit  300  as compared to a multicolor image forming device  100  that may include multiple toner cartridges  200  and imaging units  300 . Further, although image forming device  100  utilizes ITM  190  to transfer toner to the media, toner may be applied directly to the media by the one or more photoconductive drums  310  as is known in the art. 
     While the example image forming device  100  shown in  FIG. 2  utilizes a dual component development system, in another embodiment, image forming device  100  utilizes what is commonly referred to as a single component development system. In this embodiment, a toner adder roll in each developer unit has an outer surface that is in contact with and forms a nip with the outer surface of a corresponding developer roll. As the toner adder roll and the developer roll rotate, the toner adder roll supplies toner in reservoir  302  to the developer roll. The developer roll is electrically charged and electrostatically attracts the toner particles supplied by the toner adder roll. A doctor blade positioned along each developer roll provides a substantially uniform layer of toner on the developer roll. The outer surface of the developer roll is also in contact with and forms a nip with the outer surface of a corresponding PC drum  310 . As the developer roll and PC drum  310  rotate, toner particles are electrostatically transferred from the developer roll to the latent image on PC drum  310  forming a toned image on the surface of PC drum  310 . PC drum  310  is charged by charge roll  308  and cleaned by a cleaner blade as discussed above. 
       FIGS. 3 and 4  show imaging unit  300  according to one example embodiment. Imaging unit  300  includes a developer unit  320  and a photoconductor unit (PC unit)  330 . In the example embodiment illustrated, developer unit  320  is removably coupled to PC unit  330  to permit repair or replacement of developer unit  320  independent of PC unit  330  and vice versa. In other embodiments, developer unit  320  and PC unit  330  are fixed together such that imaging unit  300  is replaced as a single unit. In the example embodiment illustrated, developer unit  320  and PC unit  330  are replaced independent of toner cartridge  200 . In other embodiments, toner cartridge  200 , developer unit  320  and PC unit  330  are replaced as a single unit. Additional configurations of toner cartridge  200 , developer unit  320  and PC unit  330  may be used as desired. PC unit  330  includes a housing  332  having PC drum  310  as well as charge roll  308  and a cleaner blade mounted thereto. Housing  332  extends generally along a rotational axis  311  of PC drum  310 . Housing  332  may also include one or more user-actuated latches  334  that couple developer unit  320  to PC unit  330  as shown in  FIG. 3  for operation in image forming device  100  and that permit a user to separate developer unit  320  from PC unit  330  when imaging unit  300  is removed from image forming device  100  as shown in  FIG. 4 . Developer unit  320  includes a housing  322  having reservoir  302  therein. Housing  322  extends generally along a rotational axis of magnetic roll  306 , which is substantially parallel to rotational axis  311  of PC drum  310 . A portion of magnetic roll  306  is exposed from reservoir  302  at one side of housing  322  for mating with PC drum  310  when developer unit  320  is coupled to PC unit  330 . When developer unit  320  is coupled to PC unit  330 , imaging unit  300  is insertable into image forming device  100  via a sliding motion along an insertion direction  326  as indicated in  FIG. 3 . 
       FIG. 5  shows a portion of PC unit  330  at a first axial end portion of PC drum  310  with the remainder of PC drum  310  and housing  332 , which would extend to the left as viewed in  FIG. 5 , cut off to more clearly illustrate the components at the axial end of PC drum  310 . The opposite axial end of PC drum  310  and housing  332  is a mirror image of the axial end shown. An operative rotational direction  312  of PC drum  310  is indicated by the arrow shown in  FIG. 5 . A cleaner blade  314  is mounted on housing  332  and extends longitudinally along the axial length of PC drum  310  to remove toner remnants from the surface of PC drum  310  as discussed above. The length of cleaner blade  314  (in the axial direction of PC drum  310 ) spans at least the largest toner image possible on the outer surface of PC drum  310 , which may be defined by, for example, the span of the laser beam of LSU  112  that creates the latent image on the surface of PC drum  310  or by the axial length of charge roll  308 . Cleaner blade  314  extends in a cantilevered manner from a bracket  316  mounted on housing  332 . In the embodiment illustrated, cleaner blade  314  extends upward at an angle from bracket  316  toward PC drum  310 . Cleaner blade  314  includes a front side  314   a  that faces PC drum  310  and a rear side  314   b  opposite front side  314   a.  A free end  314   c  of cleaner blade  314  includes a cleaning edge  314   d  that contacts the surface of PC drum  310  at a cleaner blade-PC drum nip  336  and removes toner from the surface of PC drum  310 . Toner removed from PC drum  310  by cleaner blade  314  falls into a waste toner sump  338  positioned on the rear side  314   b  of cleaner blade  314  where the waste toner is temporarily stored before being moved, e.g., by an auger, to a larger waste toner reservoir. 
       FIG. 6  shows a cross-sectional view of PC drum  310  and cleaner blade  314  illustrating the engagement between cleaner blade  314  and PC drum  310 . With reference to  FIGS. 5 and 6 , in one embodiment, bracket  316  is pivotally mounted to housing  332  such that cleaner blade  314  and bracket  316  are pivotable relative to PC drum  310  about a pivot axis  317  that is parallel to rotational axis  311  of PC drum  310 . A rear seal assembly  340  is positioned on rear side  314   b  of cleaner blade  314 . Rear seal assembly  340  restricts toner remnants removed. from the surface of PC drum  310  by cleaner blade  314  from leaking between a wall  333  of housing  332  at the front of waste toner sump  338  (proximate to PC drum  310  and cleaner blade  314 ) and rear side  314   b  of cleaner blade  314  and bracket  316 . 
     Rear seal assembly  340  includes a flexible film seal  342  that extends in a cantilevered manner from wall  333  toward rear side  314   b  of cleaner blade  314 . Film seal  342  may be composed of any relatively firm, low friction film, such as Mylar or urethane. Film seal  342  may be adhered to the front side of wall  333 . Film seal  342  extends along the longitudinal length of cleaner blade  314 . A free end  342   a  of film seal  342  contacts rear side  314   b  of cleaner blade  314  near free end  314   c  of cleaner blade  314 . In some embodiments, film seal  342  has a sufficient cantilevered length and is angled relative to cleaner blade  314  such that free end  342   a  of film seal  342  has an interference contact with rear side  314   b  of cleaner blade  314  through the entire range of pivoting motion of cleaner blade  314  such that free end  342   a  is deflected against rear side  314   b  of cleaner blade  314 . Film seal  342  aids in preventing toner from leaking between wall  333  and rear side  314   b  of cleaner blade  314 . The thin, flexible film seal  342  imparts a relatively low force, indicated by arrow F 1  in  FIG. 6 , on cleaner blade  314 . In those embodiments where cleaner blade  314  is pivotable, a lower force is desired in order to prevent the force applied to cleaner blade  314  by film seal  342  from impeding the motion of cleaner blade  314  or affecting the force of cleaner blade  314  on PC drum  310  at nip  336 . 
     In the embodiment illustrated, rear seal assembly  340  also includes a foam seal  344  positioned between rear side  314   b  of cleaner blade  314  and wall  333 . Foam seal  344  extends along the longitudinal length of cleaner blade  314  and is positioned against the rear side of cleaner blade  314  or bracket  316 . In the embodiment illustrated, foam seal  344  is positioned against the rear side of bracket  316 . Foam seal  344  is positioned below the contact between film seal  342  and cleaner blade  314  to catch any toner that falls between film seal  342  and rear side  314   b  of cleaner blade  314 . Foam seal  344  may be adhered to the front side of wall  333  and/or to film seal  342 . In one embodiment, foam seal  344  and film seal  342  are laminated together forming a unitary construction and are adhered to the front side of wall  333 . In the example embodiment illustrated, foam seal  344  has an interference contact with bracket  316  along a top, rear edge  316   a  of bracket  316 . Interference with bracket  316  along its top, rear edge  316   a  reduces the force, indicated by the arrow F 2  in  FIG. 6 , of foam seal  344  on cleaner blade  314 . As discussed above, a lower force is desired in order to prevent the force applied to cleaner blade  314  by foam seal  344  from impeding the motion of cleaner blade  314  or affecting the force of cleaner blade  314  on PC drum  310  at nip  336 . In the embodiment illustrated, the direction of the force F 2  on bracket  316  by foam seal  344  is close to pivot axis  317  of cleaner blade  314  thereby reducing the impact of any variability of the force from foam seal  344  on cleaner blade  314 . Further, placement of sealing force F 2  of foam seal  344  slightly below pivot axis  317  of cleaner blade  314  and sealing force F 1  of film seal  342  above pivot axis  317  of cleaner blade  314  allows a net reduction of the total moment on cleaner blade  314  from rear seal assembly  340  in order to avoid impeding the motion of cleaner blade  314  or affecting the force of cleaner blade  314  on PC drum  310  at nip  336 . Foam seal  344  may be composed of an open or closed cell foam. In some embodiments, an open cell foam is advantageous because open cell foam is generally softer than closed cell foam and, therefore, applies less force on bracket  316  than a closed cell foam would. In other embodiments, rear seal assembly  340  includes a second flexible film seal (not shown) that contacts the rear side  314   b  of cleaner blade  314  below the contact between film seal  342  and cleaner blade  314  in order to further aid in preventing toner from leaking between wall  333  and rear side  314   b  of cleaner blade  314 . The second film seal may be used in place or in addition to foam seal  344 . 
       FIG. 7  shows a perspective view of an end seal assembly  350  that is positioned. at each axial end of PC drum  310  and longitudinal end of cleaner blade  314  to prevent toner from leaking beyond the axial ends of PC drum  310  and the longitudinal ends of cleaner blade  314 . Cleaner blade  314  is shown in broken line in  FIG. 7  in order to more clearly illustrate the components positioned behind cleaner blade  314 . PC drum  310  is omitted from  FIG. 7  for clarity.  FIG. 8  shows an exploded view of end seal assembly  350  and rear seal assembly  340  at one longitudinal end of cleaner blade  314 . With reference to  FIGS. 7 and 8 , each end seal assembly  350  includes a backup seal  352  and an end seal  360 . Each backup seal  352  is positioned against a surface of housing  332  located behind cleaner blade  314  including wall  333  at a respective longitudinal end of cleaner blade  314 . Each backup seal  352  includes a front side  353  that faces toward PC drum  310  and a rear side  354  opposite front side  353  as well as an inboard side  355  that is axially inboard relative to PC drum  310  and an outboard side  356  that is axially outboard relative to PC drum  310 . Each backup seal  352  also includes a top end  357  and a bottom end  358 . Top end  357  is positioned upstream from bottom end  358  relative to the operative rotational direction  312  of PC drum  310 . In one embodiment, backup seal  352  is composed of a relatively soft foam material, which may be an open cell foam. 
     End seals  360  contact the outer surface of PC drum  310  at the axial ends of PC drum  310  to prevent toner on PC drum  310  from migrating to the axial ends of the surface of PC drum  310 . End seals  360  also extend along the axial edges of PC drum  310  and longitudinal edges of cleaner blade  314  to prevent toner from leaking beyond the axial edges of PC drum  310  and longitudinal edges of cleaner blade  314 . Each end seal  360  includes a front side  361  that faces toward PC drum  310  and a rear side  362  opposite front side  361  as well as an inboard side  363  that is axially inboard relative to PC drum  310  and an outboard side  364  that is axially outboard relative to PC drum  310 . Each end seal  360  also includes a top end  365  and a bottom end  366 . Top end  365  is positioned upstream from bottom end  366  relative to the operative rotational direction  312  of PC drum  310 . Each end seal  360  includes an outer leg  367  that forms the bottom end  366  of end seal  360  on its outboard side  364  and an inner leg  368  that forms the bottom end  366  of end seal  360  on its inboard side  363 . In the embodiment illustrated, outer leg  367  extends further in the operative rotational direction  312  of PC drum  310  than inner leg  368 . Inboard side  363  of the portion of outer leg  367  that extends past inner leg  368  extends along the axial edge of PC drum  310  and the longitudinal edge of cleaner blade  314  to prevent toner from leaking past the axial edge of PC drum  310  and the longitudinal edge of cleaner blade  314 . The portion of the front side  361  of each end seal  360  proximate the inboard side  363  of the end seal  360  contacts the outer surface of PC drum  310  to prevent toner on PC drum  310  from migrating to the axial end of the surface of PC drum  310 . In the embodiment illustrated, each end seal  360  includes a foam backing  369  and a lower friction (relative to the foam backing  369 ) felt or suede material  370  adhered on the front side of the foam backing  369 . Foam backing  369  may be composed of a more firm foam material than backup seal  352  and may be composed of a closed cell foam. In some embodiments, the foam backing  369  and the felt/suede material  370  are laminated together forming a unitary construction. However, end seals  360  may have any suitable construction and may be formed of other suitable materials. 
       FIGS. 8-11  illustrate the layering of rear seal assembly  340  and end seal assembly  350  at each axial end of PC drum  310  and longitudinal end of cleaner blade  314  to prevent against toner leakage according to one example embodiment. As discussed above, backup seal  352  is positioned against a surface of housing  332  located behind cleaner blade  314  at the longitudinal end of cleaner blade  314 , including an axial end portion of wall  333 . For example,  FIG. 9  shows backup seal  352  positioned against housing  332  with all other components removed 
       FIG. 10  shows rear seal assembly  340  positioned relative to backup seal  352 . As shown in  FIG. 10 , at the axial ends of PC drum  310  and longitudinal ends of cleaner blade  314 , a rear side of rear seal assembly  340  is positioned against front side  353  of a bottom portion of backup seal  352 . A longitudinal end  343  of film seal  342  is positioned axially between inboard side  355  and outboard side  356  of backup seal  352 . In the embodiment illustrated, foam seal  344  (and the portion of film seal  342  positioned on the rear side of foam seal  344 ) extends further axially outboard than backup seal  352 . 
       FIG. 11  shows end seal assembly  350  and rear seal assembly  340  at one axial end of PC drum  310  and longitudinal end of cleaner blade  314  with PC drum  310 , cleaner blade  314  and bracket  316  omitted for clarity. Rear side  362  of end seal  360  is positioned against front side  353  of backup seal  352 . An upper portion of end seal  360  may extend above top end  357  of backup seal  352  with rear side  362  of the upper portion of end seal  360  positioned against housing  332 . Longitudinal end  343  of film seal  342  (indicated in broken line in  FIG. 11 ) is positioned axially between inboard side  363  and outboard side  364  of outer leg  367  such that rear side  362  of outer leg  367  lays on longitudinal end  343  of film seal  342 . In this manner, longitudinal end  343  of film seal  342  is sandwiched between rear side  362  of outer leg  367  of end seal  360  and front side  353  of backup seal  352  in order to prevent toner from leaking from longitudinal end  343  of film seal  342 . In the embodiment illustrated, bottom end  366  of outer leg  367  has an interference contact with a top end  345  of foam seal  344  forming a continuous seal for waste toner sump  338  outboard of cleaner blade  314 . In this embodiment, bottom end  366  of inner leg  368  is spaced above free end  342   a  of film seal  342  and free end  314   c  of cleaner blade  314  so that end seal  360  does not apply an undesired force to free end  314   c  of cleaner blade  314 . 
     With reference to  FIGS. 5 and 12 , in some embodiments, housing  332  includes a lid or cap  380  attached to a main body  382  of housing  332 . In one embodiment, cap  380  retains a supply of lubricant, for example, zinc stearate, to be applied to the surface of PC drum  310  during operation. In the embodiment illustrated, cap  380  extends along the axial length of PC drum  310  and is positioned upstream from cleaner blade  314  relative to the operative rotational direction  312  of PC drum  310 . 
     As shown in  FIG. 12 , in the embodiment illustrated, a seam or joint  384  is formed where cap  380  meets main body  382  on the front of housing  332 . In this embodiment, top end  365  of end seal  360  extends above joint  384  and into a recess  386  formed on the front of cap  380 .  FIG. 13  shows an axial end portion of housing  332  with cap  380  removed. As shown in  FIG. 13 , housing  332  may include a seal  388  positioned between main body  382  and cap  380  at each axial end of housing  332  (relative to the rotational axis of PC drum  310 ). In the embodiment illustrated, rear side  362  of the portion of end seal  360  positioned in recess  386  is positioned against seal  388  forming a continuous seal for waste toner sump  338  at joint  384  formed by cap  380  and main body  382 . 
     As shown in  FIGS. 5 and 13 , housing  332  may include an entry seal  390  that extends along the axial length of PC drum  310 , from the end seal  360  at one end to the end seal  360  at the other end. Entry seal  390  is positioned upstream from cleaner blade  314  relative to the operative rotational direction  312  of PC drum  310  to provide additional sealing of waste toner sump  338 . A lubricant brush may extend along the length of PC drum  310  and be positioned between entry seal  390  and cleaner blade  314  to apply a lubricant, e.g., zinc stearate, to the surface of PC drum  310  during operation. In the embodiment illustrated, entry seal  390  is positioned across front side  361  of the portion of end seal  360  positioned in recess  386 . In the embodiment illustrated, entry seal  390  includes a flexible film composed of, for example, Mylar or urethane. 
     The foregoing description illustrates various aspects of the present disclosure. It is not intended to be exhaustive. Rather, it is chosen to illustrate the principles of the present disclosure and its practical application to enable one of ordinary skill in the art to utilize the present disclosure, including its various modifications that naturally follow. All modifications and variations are contemplated within the scope of the present disclosure as determined by the appended claims. Relatively apparent modifications include combining one or more features of various embodiments with features of other embodiments.