Abstract:
In one embodiment, an article comprises a spacer configured to increase a dimension of only a portion of a guide part on a print cartridge when the spacer is fastened to the guide part and a fastener allowing the spacer to be removably fastened to the guide part.

Description:
CLAIM OF PRIORITY  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/616,776, filed on Oct. 6, 2004, and titled SPACER FOR PRINT CARTRIDGE. 
     
    
     BACKGROUND  
       [0002]     Printers, copiers and facsimile machines use modular print components. For example, many laser printers use a replaceable print cartridge that houses the toner reservoir, the photoconductor drum assembly, and the charge and developer roller assemblies. It is advantageous to package a new printer for storage and shipping with the print cartridge installed in the printer. Two problems should be addressed when considering packaging a printer with the print cartridge installed. First, the so-called “rub memory” in which the charge characteristics of the photoconductor drum is changed by the transfer roller rubbing against the photoconductor drum during handling of the packaged printer. Second, the softer transfer roller can be permanently deformed when pressed against the photoconductor drum in one position for the comparatively long period a new printer may remain packaged. Both of these problems are eliminated if the photoconductor drum and the transfer roller are separated in the printer package. 
     
    
     DRAWINGS  
       [0003]      FIG. 1  is a schematic view illustrating the major components and operational characteristics of a laser printer.  
         [0004]      FIG. 2  is a side view illustrating a laser printer such as the one shown in  FIG. 1 .  
         [0005]      FIGS. 3 and 4  are perspective views of a print cartridge such as might be used in the printer of  FIG. 2  with packaging spacers according to one embodiment of the invention.  
         [0006]      FIGS. 5 and 6  are side views illustrating a print cartridge such as the one shown in  FIGS. 3 and 4  installed in a printer.  FIG. 5  shows the print cartridge with packaging spacers.  FIG. 6  shows the print cartridge without packaging spacers.  
         [0007]      FIGS. 7 and 8  are detail perspective views illustrating a packaging spacer according to an embodiment of the invention.  
         [0008]      FIGS. 9 and 10  are perspective views illustrating another embodiment of a packaging spacer. 
     
    
     DESCRIPTION  
       [0009]     Embodiments of the present invention were developed in an effort to separate the photoconductor drum from the transfer roller in a laser printer when the print cartridge is installed in the printer for packaging and shipping. Embodiments of a new spacer that may be used to separate the photoconductor drum from the transfer roller, therefore, will be described with reference to laser printing and print cartridges used in laser printers. Embodiments of the spacer, however, are not limited to use in laser printers. Rather, embodiments may be used in any application or environment which might benefit from such a spacer. The exemplary embodiments shown in the figures and described below illustrate but do not limit the invention. Other forms, details, and embodiments may be made and implemented. Hence, the following description should not be construed to limit the scope of the invention, which is defined in the claims that follow the description.  
         [0010]     “Printer” as used in this document means any printing device and includes devices commonly referred to as copiers, printers, faxes and so-called “all-in-one” or “multifunction” devices.  
         [0011]     In as much as the art of laser printing is well known, the basic components of one exemplary laser printer  10  in  FIG. 1  are shown schematically and their operation described only briefly. In general, and referring to  FIG. 1 , document generating software on a personal computer, a scanner or some other input device transmits data representing the desired print image to input  12  on printer  10 . This data is analyzed in formatter  14 . Formatter  14  typically consists of a microprocessor and related programmable memory. Formatter  14  formulates and stores an electronic representation of each page to be printed. Once a page has been formatted, the data representing each page is sent to a printer controller  16 . Controller  16 , which also includes a microprocessor and related programmable memory, directs and manages the operation of print engine  18 . Formatter  14  and controller  16  are often integrated together as a single processor/memory component of printer  10 . The page data is used by controller  16  to modulate the light beam produced by laser  20  such that the beam of light  21  “carries” the data. The light beam  21  is reflected off a multifaceted spinning mirror  22 . As each facet of mirror  22  spins through light beam  21 , it reflects or “scans” the beam across the surface of photoconductive drum  24  to reproduce the page on the drum  24 .  
         [0012]     Charging roller  26  charges photoconductive drum  24  to a relatively high substantially uniform polarity at its surface. The areas of drum  24  exposed to light beam  21  are discharged. The unexposed background areas of drum  24  remain fully charged. This process creates a latent electrostatic image on conductive drum  24 . Toner is electrostatically transferred from toner reservoir  27  by developing roller  28  onto photoconductive drum  24  according to the data previously recorded on the drum. The toner is thereafter transferred from photoconductive drum  24  onto paper or other media sheet  30  as sheet  30  passes between drum  24  and transfer roller  32 . The toner is fused to the sheet at fuser  33 . Fuser  33  includes fuser rollers  34  and  35  that apply heat and pressure to each sheet as it passes between the rollers. Drum  24  is cleaned of excess toner with cleaning blade  36 , completely discharged by discharge lamp  38  and then recharged by charging roller  26 .  
         [0013]      FIG. 2  is a side view illustrating a laser printer such as printer  10  shown in  FIG. 1 . Referring now also to  FIG. 2 , each media sheet  30  is pulled into the pick/feed area  40  by feed roller  42  from a media tray  44 . As the leading edge of sheet  30  moves through pick/feed area  40 , it is engaged by transport rollers  45  which advance sheet  30  to registration rollers  46 . Registration rollers  46  advance sheet  30  to image area  48  until it is engaged by drum  24  and transfer roller  32  and toner is applied as described above. Media sheet  30  advances to fuser  33  and on to output rollers  50 .  
         [0014]     Photoconductor drum  24 , charging roller  26 , toner reservoir  27  and developer roller  28  are housed in a removable print cartridge  52 . One such print cartridge  52  is illustrated in  FIGS. 3 and 4 .  FIGS. 5 and 6  are side views illustrating a print cartridge such as print cartridge  52  installed in a printer  10 .  FIG. 5  shows the print cartridge with a packaging spacer.  FIG. 6  shows the print cartridge without a packaging spacer. Referring to  FIGS. 3-6 , cartridge  52  includes a housing  54  that supports photoconductor drum  24  at each end so that drum  24  can rotate within housing  54 . One end of drum  24  (not shown) exposed through an opening in housing  54  is typically fitted with a gear or other driven mechanism that can engage a gear or other driving mechanism when cartridge  52  is installed in printer  10 .  
         [0015]     Projections  56  are formed on each end of housing  54  to guide cartridge  52  into the correct position in printer  10 . In the embodiment shown in  FIGS. 4-6 , projections  56  are round pins that project out from cartridge housing  54  at each end of photoconductor drum  24 . Guide pins  56  ride in a slot  58  ( FIGS. 5-6 ) in the printer chassis or printer housing to guide cartridge  52  into the correct position in printer  10 , as shown in  FIGS. 5 and 6 . Although pins in slots are commonly used in laser printers to correctly position the print cartridge in the printer, other positioning structures may be used.  
         [0016]     Referring now also  FIGS. 7-8 , a removable spacer structure  60  fits on to projections  56 . Spacer structure  60  includes a spacer  62 , a cap  64  and an L shaped arm  66  that extends out from spacer  62 . Each spacer  62  fits around the bottom of a guide pin  56  to raise photoconductor drum  24  up out of contact with transfer roller  32 , as best seen by comparing  FIGS. 5 and 6 . Cap  64  and arm  66  are optional parts configured to help hold spacer  62  in the correct position on pin  56 . The housing  54  of the print cartridge  52  shown in  FIGS. 3 and 4  includes a rectangular projection  68  adjacent to each guide pin  56 . An L shaped arm  66  conforming to a portion of the perimeter of projection  68 , therefore, can be used to help position spacer  62  along the bottom of guide pin  56 . In the embodiment shown, arm  66  also may be used to remove spacer structure  60 . The tag end  70  of a toner dam  72  is slipped through a slot in arm  66  when spacer structure  60  is snapped in to place on guide pin  56 . Spacer structure  60  pops off guide pin  56  when a user pulls on end  70  to peel toner dam  72  out of cartridge  52 . Utilizing a packaging spacer on the print cartridge, such as spacer  62  in  FIGS. 3-7 , means the user can remove the spacer without reaching into the printer. When the user first unpacks the printer and removes the print cartridge; the spacers come out with the cartridge into plain view for easy removal. Coloring the spacers differently from the housing of the print cartridge also helps ensure easy removal for the user.  
         [0017]     In the embodiment shown, spacer  62  forms a portion of a truncated ring to effectively increase the diameter of the lower part of a round guide pin  56 . In general, the spacer is configured to increase the lower dimension of the projecting guide structure on the print cartridge enough to raise the photoconductor off the transfer roller. Any suitable removable fastener may be used to hold the spacer in place on the guide structure. For example, in the embodiment shown, a slight interference fit between spacer structure  60  and pin  56 /projection  68  along the length of spacer  62  and arm  66  allows spacer structure  60  to snap into position over pin  56 . Other suitable fasteners include a releasable adhesive or small clips that clasp on to the guide pin (or on to the spacer structure if the clips are formed on the guide pin).  
         [0018]      FIGS. 9 and 10  show a spacer structure  74  configured for use on an annular guide  76 . Annular guide  76  surrounds an opening in housing  54  that exposes the gear or other driven mechanism on the end of photoconductor drum  24 . Spacer structure  74  includes a spacer  78 , an annular cap  80  and an L shaped arm  82 . Annular cap  80  fits into the opening in housing  54  and over the gear. Spacer  78  fits around the bottom of guide  76  to raise photoconductor drum  24  up out of contact with transfer roller  32  when print cartridge  52  is installed in printer  10 . The truncated annular gap  84  fits over the lower part of guide  76 . In the embodiment shown in  FIGS. 9 and 10 , spacer  78  forms a truncated ring to effectively increase the thickness of the lower part of an annular guide  76 . Cap  80  on spacer structure  74  ( FIGS. 9 and 10 ) and cap  64  on spacer  60  ( FIGS. 7 and 8 ) prevents the drive gear or other drive mechanism from engaging the driven gear or other driven mechanism in print cartridge  52 . The caps, therefore, help ensure that photoconductor drum  24  cannot be driven in the event a user fails to remove the spacer structures prior to attempting to use the printer.  
         [0019]     As noted at the beginning of this Description, the exemplary embodiments shown in the figures and described above illustrate but do not limit the invention. Other forms, details, and embodiments may be made and implemented. Therefore, the foregoing description should not be construed to limit the scope of the invention, which is defined in the following claims.