Abstract:
A device to regulate toner within an image forming apparatus. The regulating member has a first section and a toner regulating edge with at least one gap. The regulating member controls the amount of toner that is distributed on the surface of the toner developer roller by contacting the toner developing roller in a contact region. The gap, having at least one upper edge, may regulate toner on the toner developer roller near the contact region. The toner regulating device may prevent inadvertent toner marks that may appear on printed media.

Description:
BACKGROUND  
       [0001]     Image forming devices including printers, copiers, scanners, fax machines and other similar devices have become staples for business and home offices. Consumers have a wide variety of options to choose from when considering such purchases. Among the considerations for these consumers are cost, size and print quality. The ever-increasing demands of consumers continually fuel innovation in this technology.  
         [0002]     Print quality in image forming apparatuses has improved through use of innovations in toner, toner distribution devices and image formation. Because of these improvements, both home and business offices are able to produce professional, high quality media. Inherent with the high quality images is the prevention of inadvertent toner marks that may appear on the printed media. One common mark is a band that extends along the edge of the printed image.  
         [0003]     Image forming apparatus size and shape is a consideration for home and business offices because of space limitations and ease of use. Engineering these devices to be both easy to use and adaptable to space considerations has contributed to their popularity.  
         [0004]     Consumers of image forming apparatuses often consider cost when selecting these devices. Therefore, it is desirable for continued technological innovation in all areas, including print quality and device dimensions, to be as cost-effective as possible.  
       SUMMARY  
       [0005]     The present invention is directed to embodiments of a device for regulating toner within an image forming apparatus. One embodiment of the regulating member has a first section and a toner regulating edge. The toner regulating edge regulates the amount of toner distributed to a developer roller during image formation. At least one gap is positioned within the toner regulating edge to prevent inadvertent toner marks on printed media.  
         [0006]     The invention is also directed to methods of regulating toner within an image forming apparatus. One embodiment of the method uses a toner regulating member with at least one gap in its toner regulating edge to control toner distribution on the toner developer roller, thereby preventing inadvertent toner marks on printed media. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a perspective view illustrating a toner regulating member according to one embodiment of the present invention.  
         [0008]      FIG. 2  is a side schematic view of the toner regulating member and its positional relationship with the toner developing roller and toner adder roller according to one embodiment of the present invention.  
         [0009]      FIG. 3  is a partial side schematic view of a toner regulating member according to one embodiment of the present invention.  
         [0010]      FIG. 4  is a side schematic view of two gaps in the toner regulating member according to one embodiment of the present invention.  
         [0011]      FIG. 5  is a partial side schematic view of the toner regulating member, toner adder roller, and seal member according to one embodiment of the present invention.  
         [0012]      FIG. 6  is a partial side schematic view of a gap in the toner regulating edge according to one embodiment of the present invention.  
         [0013]      FIG. 7  is a partial side schematic view of a gap in the toner regulating edge according to one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0014]     Embodiments of the present invention are directed to a device  10  for regulating toner within an image forming apparatus.  FIG. 1  illustrates an embodiment of the regulating member  10  having a first section  20  and a toner regulating edge  30 . The toner regulating edge  30  regulates the amount of toner distributed to a developer roller  50  ( FIG. 2 ) during image formation. At least one gap  40  is positioned within the regulating edge  30 .  
         [0015]     The first section  20  may be mounted to position the regulating member  10  relative to the developer roller  50 . In one embodiment as illustrated in  FIG. 1 , the first section  20  is connected to a bracket  24 . The method of mounting the first section  20  may include clamps, screws, welding, adhesives, and various other techniques. The first section  20  may be mounted along a first edge  22  that is opposite from the toner regulating edge  30 , along one or both lateral edges  32 , an interior of the first section  20 , or a combination thereof.  
         [0016]     The toner regulating device  10  is positioned relative to a toner adder roller  52  and a toner developer roller  50  as illustrated in  FIG. 2 . The toner regulating member  10  is positioned to contact and regulate an amount of toner on the developer roller  50 . In one embodiment, the force applied by the toner regulating device  10  to the toner developing roller  50  is about 11 Newtons. In other embodiments the amount of force applied can be about 3 to about 15 Newtons. As illustrated in the embodiment of  FIG. 2 , the developer roller  50  rotates into the regulating edge section of the regulating member  10  (i.e., clockwise as illustrated in the embodiment of  FIG. 2 ). The toner adder roller  52  that contacts the developer roller  50  may also rotate in this same direction.  
         [0017]     As illustrated in  FIGS. 3 and 4 , the toner regulating member  10  is positioned for an area inward of the toner regulating edge  30  to contact the developer roller  50 . In this embodiment, the toner regulating edge  30  extends beyond and does not make contact with the developer roller  50 . The length of the contact zone  60  between the toner regulating member  10  and developer roller  50  and the position of the contact zone  60  along the member  10  may vary depending upon the application. In one embodiment, the contact zone has a length of about 1 mm. A distance defined as T is measured from the middle of the contact zone to the toner regulating edge  30 . In specific embodiments, the distance T is between about 0.6 mm and 1.4 mm.  
         [0018]      FIG. 3  illustrates one embodiment of the gap  40  extending into the toner regulating edge  30 . The gap  40  of this embodiment comprises an upper edge  45 , an inner edge  46  and an outer edge  41 . The upper edge  45  is linear and may be substantially parallel to the toner regulating edge  30 . The inner and outer edges  46 ,  41  are substantially linear and may be orientated substantially perpendicular to the toner regulating edge  30 . The corners  48  formed between the upper edge  45  and inner and outer edges  46 ,  41  may be rounded. The depth of the gap  40  is set such that at least a portion of the upper edge  45  is within the contact zone  60 .  
         [0019]      FIG. 4  illustrates a schematic view of a toner regulating member  10  having a gap  40  adjacent to each lateral edge  32 . A print zone  62  is positioned within the interior area of the toner regulating member  10  between the gaps  40 . The toner in the print zone  62  is carefully controlled to produce good print quality during image formation. The gaps  40  are positioned outside of the print zones  62  and act to remove excess toner that builds towards the outer edges of the developer roller  50 . In the embodiment of  FIG. 4 , the print zone  62  extends to the edge of the gaps  40 . In other embodiments, the print zone  62  may be positioned a distance inward from one or both gaps  40 .  
         [0020]     The depth of the gaps  40  is selected for at least a portion of the upper edges to be within the contact zone  60 . In the left-side gap  40  of  FIG. 4 , the upper edge  45  is within the contact zone  60  and acts to remove a large amount of toner from the developer roller  50 . In the right-side gap  40 , the edges  43  extend into the contact zone  60  and remove the toner as there is no separate upper edge in this shape. Removal of excess toner from the edges of the developer roller  50  reduces or eliminates excess toner being transferred to the media sheets along the lateral edges i.e., banding. The width of the gaps  40  is set to remove the banding, but not to interfere with the print zone  62 .  
         [0021]     The gap  40  extends inward from the lateral edge  32  allowing for placement of a sealing member  58  to prevent toner escape.  FIG. 5  illustrates one embodiment of sealing member  58  positioned along the lateral edge of the toner regulating member  10  and into a portion of the gap  40 . Toner is maintained within the interior section of the toner regulating member  10  and accurately transferred within the print zone  62 . Excess toner that moves laterally along the toner regulating member  10  is removed at the gap  40 . Further, the sealing member  58  prevents the toner from laterally escaping. A media sheet S is illustrated in the embodiment of  FIG. 5  illustrating a widest media size. A toner band typically forms just outside the end of the toner adder roller  52  and extends slightly past the inner edge of the seal  58 . As illustrated in  FIG. 5 , the edge of the media sheet S is positioned within this banding zone. The position of the gap  40  is chosen to eliminate this band where it corresponds with the edge of the sheet S. In this embodiment, the gap  40  inner edge is located to be inboard of the toner adder roller edge and outside of the print zone. The outer edge of the gap  40  is set to be within the width of the seal  58  and outside the media sheet edge.  
         [0022]     The shape and size of the gap  40  may vary depending upon the application. The depth is adjusted such that at least a portion of the gap  40  is positioned within the contact zone  60 . The width is established to remove an adequate amount of toner and prevent banding.  FIG. 7  illustrates another embodiment of a gap  40  having an inner edge  46  and an upper edge  45  that extends out to the lateral edge  32  of the toner regulating member  10 . In this embodiment, the upper edge  45  and the toner regulating edge  30  are substantially parallel. Another embodiment features the upper edge  46  extending at an angle relative to the toner regulating edge  30 .  FIG. 6  shows an alternate embodiment of a gap with an arcuate inner edge  46  and outer edge  41 .  FIG. 4  illustrates additional gaps  40 . The left gap  40  is spaced inward from the lateral edge  32  and includes a first edge  41  substantially perpendicular to the toner regulating edge, and an angled second edge  42 . The right gap  40  is spaced inward from the lateral edge  30  and includes two angled edges  43  extending into the contact zone  60 . Variations in the shape and size of the gap  40  are within the scope of the invention. In these alternate embodiments, the gap  40  may be arcuate in shape, have a single continuous edge, have two sides coming together at an angle, or have more than three sides. In each embodiment of the invention, the gap  40  sides  45 ,  46 ,  41 ,  42 ,  43  may be linear or non-linear.  
         [0023]     The toner regulating member  10  may be made of or coated with electrically conductive material such as resin, metal, metallic salt or ions. In one embodiment, the toner regulating member  10  is made of phosphor bronze. In one embodiment, the toner regulating member  10  has a thickness of about 0.003 inches. In another embodiment, the toner regulating member  10  is about 0.001 to about 0.01 inches thick. In one embodiment, the toner regulating member  10  is a phosphor bronze coated with a resin that is conductive and has a surface roughness of about 0.2-1.0 microns.  
         [0024]     The present invention can be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. In one embodiment, a toner regulating member  10  has a plurality of gaps  40  in the regulating edge  30 . In another embodiment, multiple toner regulating members may be mounted sequentially.