Patent Publication Number: US-7912399-B2

Title: Apparatus for charging a photoconductor and cleaning a scorotron grid

Description:
BACKGROUND 
     Disclosed herein is an apparatus for charging a photoconductor and cleaning a scorotron grid. 
     Presently, in electrostatographic or xerographic printing, an electrostatic latent image is formed on a charge-retentive imaging surface, such as the surface of a photoconductor, and then developed with an application of toner particles. The toner particles adhere electrostatically to the suitably-charged portions of the photoconductor. The toner particles are then transferred, by the application of electric charge, to media, such as print sheets, to form the desired image on the media. An electric charge can also be used to separate or “detack” the print sheet from the photoreceptor. 
     For the initial charging, transfer, or detack of an imaging surface, a scorotron can be used to apply a predetermined charge to the imaging surface. A scorotron includes a conductor, which is electrically biased and thereby supplies ions for charging the imaging surface. The conductor typically comprises one or more wires, such as corona wires, and/or a metal bar forming saw-teeth, such as a pin array. The conductor can extend parallel to the imaging surface along a direction perpendicular to a direction of motion of the imaging surface. Other structures, such as a screen grid, a conductive shield and/or a nonconductive housing, are typically present in a scorotron charging device, and some of these may be electrically biased as well. 
     A scorotron can become contaminated with debris, which results in non-uniform charging of the photoconductor and ultimately results in image quality defects. A flat cleaning brush can be used against the bottom of scorotron grid to periodically remove the debris from the grid. The brush traverses the grid by manual or automated operation. Unfortunately, the flat brush tends to deflect the center of grid, which results in the brush making reduced or no contact in center, where best cleaning is actually required. 
     Thus, there is a need for an improved apparatus for cleaning a scorotron grid that charges a photoconductor. 
     SUMMARY 
     An apparatus for cleaning a scorotron grid that charges a photoconductor is disclosed. The apparatus can include a scorotron frame and a scorotron charge member coupled to the scorotron frame, where the scorotron charge member can be configured to generate an electric field. The apparatus can include a scorotron charging grid coupled to the scorotron frame, the scorotron charging grid having a length axis, a width axis, and a height axis, and the scorotron charging grid including a scorotron charging grid surface having a plurality of openings. The apparatus can include a scorotron charging grid cleaner coupled to the scorotron charging grid, where the scorotron charging grid cleaner can be configured to travel along the scorotron charging grid length axis and clean the scorotron charging grid. The scorotron charging grid cleaner can include a scorotron charging grid cleaner center and scorotron charging grid cleaner ends at opposite ends from the scorotron charging grid cleaner center along the width axis. The scorotron charging grid cleaner can extend further in a direction of the height axis at the scorotron charging grid cleaner center than at the scorotron charging grid cleaner ends. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to describe the manner in which advantages and features of the disclosure can be obtained, a more particular description of the disclosure briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the disclosure will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG. 1  is an exemplary cut away view of an apparatus useful in printing; 
         FIG. 2  is an exemplary top view of an apparatus; 
         FIG. 3  is an exemplary illustration of an apparatus; 
         FIG. 4  is an exemplary illustration of an apparatus; 
         FIG. 5  is an exemplary exploded view of a scorotron; and 
         FIG. 6  is an exemplary illustration of a printing apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments include an apparatus useful in charging a photoconductor in printing. The apparatus can include a scorotron frame and a scorotron charge member coupled to the scorotron frame, where the scorotron charge member can be configured to generate an electric field. The apparatus can include a scorotron charging grid coupled to the scorotron frame, the scorotron charging grid having a length axis, a width axis, and a height axis, and the scorotron charging grid including a scorotron charging grid surface having a plurality of openings. The apparatus can include a scorotron charging grid cleaner coupled to the scorotron charging grid, where the scorotron charging grid cleaner can be configured to travel along the scorotron charging grid length axis and clean the scorotron charging grid. The scorotron charging grid cleaner can include a scorotron charging grid cleaner center and scorotron charging grid cleaner ends at opposite ends from the scorotron charging grid cleaner center along the width axis. The scorotron charging grid cleaner can extend further in a direction of the height axis at the scorotron charging grid cleaner center than at the scorotron charging grid cleaner ends. 
     The embodiments further include a scorotron useful in charging a photoconductor in printing. The scorotron can include a scorotron frame and a scorotron charge member coupled to the scorotron frame, where the scorotron charge member can be configured to generate an electric field. The scorotron can include a scorotron charging grid coupled to the scorotron frame, the scorotron charging grid having a length axis, a width axis, and a height axis, and the scorotron charging grid including a scorotron charging grid surface having a plurality of openings. The scorotron can include a scorotron charging grid cleaner coupled to the scorotron charging grid, the scorotron charging grid cleaner configured to travel along the scorotron charging grid length axis and clean the scorotron charging grid, the scorotron charging grid cleaner including a scorotron grid cleaner surface configured to contact the scorotron charging grid surface, where the scorotron grid cleaner surface can have a convex arched profile. 
     The embodiments further include an apparatus useful in printing. The apparatus can include a media transport configured to transport media and a photoconductor configured to generate an image on the media. The apparatus can include a scorotron frame and a scorotron charge member coupled to the scorotron frame, where the scorotron charge member can be configured to generate an electric field. The apparatus can include a scorotron charging grid coupled to the scorotron frame, the scorotron charging grid having a length axis, a width axis, and a height axis, the scorotron charging grid including a scorotron charging grid surface having a plurality of openings, and the scorotron charging grid surface being deflectable in a direction of the height axis. The apparatus can include a scorotron charging grid cleaner coupled to the scorotron charging grid, the scorotron charging grid cleaner configured to travel along the scorotron charging grid length axis and clean the scorotron charging grid, the scorotron charging grid cleaner including a scorotron charging grid cleaner center and scorotron charging grid cleaner ends at opposite ends of the scorotron charging grid cleaner center along the width axis, and the scorotron charging grid cleaner extending further in a direction of the height axis at the scorotron charging grid cleaner center than at the scorotron charging grid cleaner ends. The scorotron charging grid and the charge member can be configured to generate a surface potential on the photoconductor. 
       FIG. 1  is an exemplary cut away view of an apparatus  100  and  FIG. 2  is an exemplary top view of an apparatus  100 . The apparatus  100  may be part of a printer, may be a multifunction media device, may be a xerographic machine, or may be any other device that uses a scorotron to charge a photoconductor  105  in printing. The photoconductor  105  can be a conductor, a photoreceptor, or any other device that can create an electrostatic latent image on a surface charged by a scorotron. For example, the photoconductor  105  can be a device that receives light to create an electrostatic latent image on its surface after being charged by a scorotron. 
     The apparatus  100  can include a scorotron frame  110  and a scorotron charge member  120  coupled to the scorotron frame  110 . The scorotron charge member  120  can be configured to generate an electric field. The scorotron charge member  120  can be a charge wire, can be a pin array, or can be any other member useful for generating an electric field or for producing corona to charge a photoconductor  105 . 
     The apparatus  100  can include a scorotron charging grid  130  coupled to the scorotron frame  110 . The scorotron charging grid  130  can be located between the scorotron charge member  120  and the photoconductor  105  and the scorotron charging grid  130  and the scorotron charge member  120  can be configured to generate a surface potential on the photoconductor  105 . The scorotron charging grid  130  can have a length axis  131 , a width axis  132 , and a height axis  133 . The scorotron charging grid  130  can include a scorotron charging grid surface  134  having a plurality of openings  135 . The scorotron charge member  120  can be configured to produce a charge to generate the electric field and the scorotron charging grid  130  can be configured to diffuse the charge from the scorotron charge member  120  through the plurality of openings  135 . The scorotron charging grid surface  134  can be deflectable in a direction of the height axis  133 . 
     The apparatus  100  can include a scorotron charging grid cleaner  140  coupled to the scorotron charging grid  130 . The scorotron charging grid cleaner  140  can be configured to travel along the scorotron charging grid length axis  131  and clean the scorotron charging grid  130 . The scorotron charging grid cleaner  140  can be configured to travel between the scorotron charge member  120  and the scorotron charging grid  130  when cleaning the scorotron charging grid  130 . The scorotron charging grid cleaner  140  can include a scorotron charging grid cleaner center  141  and scorotron charging grid cleaner ends  142  at opposite ends of the scorotron charging grid cleaner  140  from the scorotron charging grid cleaner center  141  along the width axis  132 . The scorotron charging grid cleaner  140  can extend further in a direction of the height axis  133  at the scorotron charging grid cleaner center  141  than at the scorotron charging grid cleaner ends  142 . The scorotron charging grid cleaner  140  can have a scorotron grid cleaner surface  143  configured to contact the scorotron charging grid surface  134  and the scorotron grid cleaner surface  143  can have an arched profile. The scorotron charging grid cleaner  140  can have a cleaning member, such as a brush  144 , abutting the scorotron charging grid  130  and a moving mechanism  150  configured to move the scorotron charging grid cleaner  140  along the scorotron charging grid length axis  131 . The scorotron charging grid cleaner surface  143  can have or can be a scorotron charging grid cleaning brush  144 . 
     The scorotron charging grid  130  can include a scorotron charging grid center  136  and scorotron charging grid ends  137  at opposite sides of the scorotron charging grid center  136  along the width axis  132  and the scorotron charging grid  130  can deflect more in a direction of the height axis  133  at the scorotron charging grid center  136  than at the scorotron charging grid ends  137  when the scorotron charging grid cleaner  140  cleans the scorotron charging grid  130 . The scorotron charging grid cleaner  140  can extend further in the height axis  133  at the scorotron charging grid cleaner center  141  than at the scorotron charging grid cleaner ends  142  to substantially correspond to deflection of the scorotron charging grid  130  when the scorotron charging grid cleaner  140  cleans the scorotron charging grid  130 . 
     According to a related embodiment, the apparatus  100  can be a scorotron  100  useful in charging a photoconductor  105  in printing. The scorotron  100  can include a scorotron frame  110 . The scorotron  100  can include a scorotron charge member  120  coupled to the scorotron frame  110 , where the scorotron charge member  120  can be configured to generate an electric field. The scorotron  100  can include a scorotron charging grid  130  coupled to the scorotron frame  110 . The scorotron charging grid  130  can have a length axis  131 , a width axis  132 , and a height axis  133 . The scorotron charging grid  130  can include a scorotron charging grid surface  134  having a plurality of openings  135 . The scorotron charging grid surface  134  can be deflectable in a direction of the height axis  133 . The scorotron  100  can include a scorotron charging grid cleaner  140  coupled to the scorotron charging grid  130 . The scorotron charging grid cleaner  140  can be configured to travel along the scorotron charging grid length axis  131  and can be configured to clean the scorotron charging grid  130 . The scorotron charging grid cleaner  140  can include a scorotron grid cleaner surface  143  configured to contact the scorotron charging grid surface  134 . The scorotron grid cleaner surface  143  can have a convex arched profile. The scorotron grid cleaner surface  143  can be either a scorotron charging grid cleaning brush  144  or a mount for the scorotron charging grid cleaning brush  144 . For example, the brush  144  can have longer or more bristles in the center  141  of the scorotron grid cleaner or the brush  144  can have substantially consistent length bristles on the scorotron grid cleaner surface  143  and a mount for the scorotron charging grid cleaning brush  144  can have a convex arched profile. 
     The scorotron charging grid cleaner surface  143  can include a scorotron charging grid cleaner center  141  and scorotron charging grid cleaner ends  142  at opposite ends from the scorotron charging grid cleaner center  141  along the width axis  132 . The scorotron charging grid cleaner  141  can extend further in a direction of the height axis  133  at the scorotron charging grid cleaner center  141  than at the scorotron charging grid cleaner ends  142 . The scorotron charging grid cleaner  140  can extend further in the height axis  133  at the scorotron charging grid cleaner center  141  than at the scorotron charging grid cleaner ends  142  to substantially correspond to deflection of the scorotron charging grid  130  when the scorotron charging grid cleaner  140  cleans the scorotron charging grid  130 . 
       FIG. 3  is an exemplary illustration of an apparatus  100  when not cleaning the scorotron charging grid  130 . As shown, when the scorotron charging grid cleaner  140  is not cleaning the scorotron charging grid  130 , the scorotron charging grid surface  134  may not necessarily deflect in a direction of the height axis  133  and may stay substantially planar. 
       FIG. 4  is an exemplary illustration of an apparatus  200  useful in printing according to another embodiment. The apparatus  200  can include a media transport  210  configured to transport media  215 . The apparatus  200  can include a photoconductor  105  configured to generate an image on the media  215 . The apparatus  200  can include the scorotron  100  from the previous embodiments and can include an image generation module  220 . The scorotron  100  can charge the photoconductor  105  and the image generation module  220  can generate an image on the charged photoconductor  105 . The photoconductor  105  can then transfer the image to the media  215 . 
     As shown in previous embodiments, the scorotron can include a scorotron frame  110 . The scorotron  100  can include a scorotron charge member  120  coupled to the scorotron frame  110 . The scorotron charge member  120  can be configured to generate an electric field. The scorotron  100  can include a scorotron charging grid  130  coupled to the scorotron frame  110 . The scorotron charging grid  130  can have a length axis  131 , a width axis  132 , and a height axis  133 . The scorotron charging grid  130  can include a scorotron charging grid surface  134  having a plurality of openings  135 . The scorotron charging grid surface  134  can be deflectable in a direction of the height axis  133 . The scorotron  100  can include a scorotron charging grid cleaner  140  coupled to the scorotron charging grid  130 . The scorotron charging grid cleaner  140  can be configured to travel along the scorotron charging grid length axis  131  and clean the scorotron charging grid  130 . The scorotron charging grid cleaner  140  can include a scorotron charging grid cleaner center  141  and scorotron charging grid cleaner ends  142  at opposite ends from the scorotron charging grid cleaner center  141  along the width axis  132 . The scorotron charging grid cleaner  140  can extend further in a direction of the height axis  133  at the scorotron charging grid cleaner center  141  than at the scorotron charging grid cleaner ends  142 . The scorotron charging grid cleaner  140  can extend further in a direction of the height axis  133  at the scorotron charging grid cleaner center  141  than at the scorotron charging grid cleaner ends  142  to substantially correspond to deflection of the scorotron charging grid  130  when the scorotron charging grid cleaner  140  cleans the scorotron charging grid  130 . The scorotron charging grid cleaner  140  can include a cleaning member  144  abutting the scorotron charging grid  130  and a moving mechanism  150  configured to move the scorotron charging grid cleaner  140  along the scorotron charging grid length axis  131 . The scorotron charging grid  130  and the scorotron charge member  120  can be configured to generate a surface potential on the photoconductor  105 . 
       FIG. 5  is an exemplary exploded view of a scorotron  500 . The scorotron  500  can be provided along a direction of a rotational axis of a photoconductor  105  shown in the other embodiments. The scorotron  500  can include a scorotron charge member, such as two corotron wires  516 , a grid electrode  518 , such as a scorotron charging grid, and a cleaning mechanism  520 , such as a scorotron charging grid cleaner. The grid electrode  518  can be disposed so as to be positioned between the corotron wires  516  and a photoconductor. The cleaning mechanism  520  can move in a direction orthogonal to the moving direction of a photoconductor, and can clean the grid electrode  518 . For example, an electrode short side direction, such as along the width axis  132 , of the scorotron  500  can be a direction orthogonal to the corotron wires  516  and can be oriented the same as the moving direction, such as the rotating direction, of a photoconductor. 
     The cleaning mechanism  520  can have a brush  522  and can have a moving mechanism  524 . The brush  522  can press-contact the grid electrode  518  from the side at which the corotron wires  516  are disposed. The moving mechanism  524  can slide the brush  522  along a rotational axis direction of a photoconductor, such as along the length axis  131 , in a state in which the brush  522  press-contacts the grid electrode  518 . The cleaning mechanism  520  can clean the grid electrode  518  due to the brush  522  sliding along the length axis  131 . The grid electrode  518  can be shaped so as to be long in the length axis  131  direction of the scorotron  100 . An opening pattern  526  can be formed in the grid electrode  518  so that the grid electrode  518  is mesh-like. 
       FIG. 6  illustrates an exemplary printing apparatus  600  that can include the apparatus  100 . As used herein, the term “printing apparatus” encompasses any apparatus, such as a digital copier, bookmaking machine, multifunction machine, and other printing devices that perform a print outputting function for any purpose. The printing apparatus  600  can be used to produce prints from various media, such as coated, uncoated, previously marked, or plain paper sheets. The media can have various sizes and weights. In some embodiments, the printing apparatus  600  can have a modular construction. As shown, the printing apparatus  600  can include at least one media feeder module  602 , a printer module  606  adjacent the media feeder module  602 , an inverter module  614  adjacent the printer module  606 , and at least one stacker module  616  adjacent the inverter module  614 . 
     In the printing apparatus  600 , the media feeder module  602  can be adapted to feed media  604  having various sizes, widths, lengths, and weights to the printer module  606 . In the printer module  606 , the scorotron  100  can charge a photoreceptor belt  607 . Toner can be transferred from an arrangement of developer stations  610  to the charged photoreceptor belt  607  to form toner images on the photoreceptor belt  607 . The toner images can be transferred to the media  604  fed through a paper path. The media  604  can be advanced through a fuser  612  adapted to fuse the toner images on the media  604 . The inverter module  614  can manipulate the media  604  exiting the printer module  606  by either passing the media  604  through to the stacker module  616 , or by inverting and returning the media  604  to the printer module  606 . In the stacker module  616 , printed media can be loaded onto stacker carts  617  to form stacks  620 . 
     Embodiment can provide an arched or crowned shaped support mount for a cleaning brush in a grid cleaner assembly. Mounting the brush on the arched shaped support mount can compensate for grid deflection due to the pressure and load exerted on the underside of the grid during the cleaning process. For example, grid deflection can occur when the brush presses against the otherwise unsupported grid during cleaning operations. Embodiments can improve cleaning reliability and cleaning uniformity across the grid and in the center of the grid, can provide for more effective and consistent cleaning, and can reduce charging non-uniformity. 
     While this disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in the other embodiments. Also, all of the elements of each figure are not necessary for operation of the embodiments. For example, one of ordinary skill in the art of the embodiments would be enabled to make and use the teachings of the disclosure by simply employing the elements of the independent claims. Accordingly, the preferred embodiments of the disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure. 
     In this document, relational terms such as “first,” “second,” and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, relational terms, such as “top,” “bottom,” “front,” “back,” “horizontal,” “vertical,” and the like may be used solely to distinguish a spatial orientation of elements relative to each other and without necessarily implying a spatial orientation relative to any other physical coordinate system. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “a,” “an,” or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. Also, the term “another” is defined as at least a second or more. The terms “including,” “having,” and the like, as used herein, are defined as “comprising.”