Patent Publication Number: US-8971787-B2

Title: Paper edge cleaner and image forming apparatus using the paper edge cleaner

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority pursuant to 35 U.S.C. §119 to Japanese Patent Application No. 2011-192183, filed on Sep. 3, 2011, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     The exemplary embodiments described herein relate to a paper edge cleaner for an image forming apparatus such as a copier, a printer, a facsimile machine, a printer, etc. and to an image forming apparatus that has a paper edge cleaner. 
     2. Description of the Related Art 
     An electrophotographic image-forming apparatus makes a copy or a print by transferring a toner image to paper, and fixes the toner image on the paper using heat and pressure. Many types of paper can be used. Moreover, a high image quality and a uniform glossiness are required for a full-color image, such as a photograph or a computer graphics image. 
     Uniform glossiness is prevented by a cutting burr that is made on a paper edge when the paper is cut, because the burr damages a fixing member in a fixing unit. When a plurality of same size papers are continuously used, the cutting burr on the edge of the paper contacts a same place on the fixing member and damages a surface on the fixing member at a fixing nip. Such damage causes an uneven glossiness line and a poor image. To solve this problem, applications JPH10-218459 and JP2005-179041 describe crushing the burr at the paper edge by a strong pressure provided by a pair of rollers. 
     However, the above-described rollers for crushing the burr have the following problems. Such rollers need a high pressure to crush the cutting burr on the paper. Therefore, such a roller system requires a big roller and a strong frame to maintain the high pressure, along with a strong driving source. This makes the apparatus bigger. Moreover, in this system, an impulsive sound occurs when the paper passes through the rollers. 
     SUMMARY 
     An exemplary embodiment provides a paper edge cleaner, comprising: a paper guide; a paper-carrying roller to transport a paper along the paper guide; a first grinder to grind both sides of the paper parallel to a direction of paper movement at a first surface; and a first support to support the paper when contacted by the first grinder. 
     Another exemplary embodiment provides an image forming method, comprising: feeding paper from a paper feeding unit; transporting the paper along a paper guide; grinding, using a grinder, both sides of the paper parallel to a direction of paper movement at a first surface, wherein the grinding step includes supporting the paper when contacted by the grinder; and forming an image on the paper grinded in the grinding step. 
     Another exemplary embodiment provides an image forming apparatus, comprising: a paper feeder to feed paper; an image forming device to form an image on the paper; and a paper edge cleaner provided between the paper feeder and the image forming device, the paper edge cleaner including a paper guide; a paper-carrying roller to transport the paper along the paper guide; a first grinder to grind both sides of the paper parallel to a direction of paper movement at a first surface; and a first support to support the paper when contacted by the first grinder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the exemplary embodiments described herein and many of the attendant advantages thereof will be more readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1  is a schematic diagram showing an exemplary configuration of an image forming apparatus; 
         FIG. 2  is an enlarged lateral view of a paper edge cleaner  20  used in the image forming apparatus shown in  FIG. 1  in the first embodiment; 
         FIG. 3  is a plan view from above of the paper edge cleaner  20  in the first embodiment with a smaller scale than  FIG. 2 ; 
         FIG. 4  is an enlarged lateral view of a paper edge cleaner  20  used in the image forming apparatus shown in  FIG. 1  in the second embodiment similar to  FIG. 2 ; 
         FIG. 5  is a plan view from above of the paper edge cleaner  20  in the second embodiment similar to  FIG. 3 ; 
         FIG. 6  is an enlarged lateral view of a paper edge cleaner  20  used in the image forming apparatus shown in  FIG. 1  in the third embodiment similar to  FIG. 2 ; 
         FIG. 7  is a plan view from above of the paper edge cleaner  20  in the third embodiment similar to  FIG. 3 ; 
         FIG. 8  is an enlarged lateral view of a paper edge cleaner  20  used in the image forming apparatus shown in  FIG. 1  in the fourth embodiment similar to  FIG. 2 ; 
         FIG. 9  is a plan view from above of the paper edge cleaner  20  in the fourth embodiment similar to  FIG. 3 ; 
         FIG. 10  is an enlarged lateral view of a paper edge cleaner  20  used in the image forming apparatus shown in  FIG. 1  in the fifth embodiment similar to  FIG. 2 ; 
         FIG. 11  is a plan view from above of the paper edge cleaner  20  in the fifth embodiment similar to  FIG. 3 ; and 
         FIG. 12  is a lateral view of a driving member to move the first grinding member from a position distant from the paper to a position in which the first grinding member presses the paper. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  schematically illustrates an image forming apparatus according to a first embodiment. The image forming apparatus  100  is a tandem-type, full-color electrophotography apparatus that is used in copiers or digital multi-functional apparatuses. 
     The image forming apparatus has a internal paper-eject structure that includes output paper tray  2  provided between an image scanner  5  and an image forming unit in a machine body  1 . An openable and closable auto-document feeder (ADF)  3  is provided on the machine body  1 . ADF  3  includes a document-setting board  3   a  and a document-carrying belt  3   b . The image forming apparatus includes a contact glass  4  under the ADF. 
     The image scanner  5  under the contact glass  4  has an optical system including a light source and an imaging element. A document is set on the contact glass by a user or is fed to the contact glass by the ADF  3 , where an image on the document is read by the scanner. The image forming apparatus includes an intermediate transfer belt  9  in a middle of the machine body  1 , as shown in  FIG. 1 . Image forming units are provided under the intermediate transfer belt  9 . The image forming units include an image forming unit for yellow, cyan, magenta, and black toner side-by-side along the intermediate transfer belt. 
     Each image forming unit includes a charger to charge a surface of each photoconductor  6 Y,  6 C,  6 M, and  6 K, and developing units  7 Y,  7 C,  7 M, and  7 K to develop each electrostatic latent image on the surface of each photoconductor that is formed by a writing unit. Primary transfer rollers  8 Y,  8 C,  8 M, and  8 K face each photoconductor  6 Y,  6 C,  6 M, and  6 K across the intermediate transfer belt  9 . 
     There are two feeding paper trays  15  in a lower part of the machine body  1  that accommodate paper P as a recording medium. Further, there are corresponding paper feeding rollers  17  as paper feeding means to feed paper P from each paper feeding tray  15 , several pairs of carrying rollers  18 , and a registration roller  11  in the machine body  1 . Further, the image forming apparatus includes a secondary transfer roller  10  contacting the intermediate transfer roller  9 , and a fixing unit  12  over the secondary transfer roller  10 . 
     The thin solid line in  FIG. 1  shows a paper path  13  that is formed by several guide plates. The paper path  13  includes several pairs of carrying rollers, switching craws for switching a paper movement, and a pair of output paper rollers  14  at the end of the paper path  13 . In a paper path  19  for double-faced printing, paper P, which has a toner image fixed on one side by a fixing unit  12 , is reversed from front to back and carried to the registration roller  11 . 
     A paper edge cleaner  20  is provided between the registration roller  11  and the secondary transfer roller  10  in the paper carrying path  13 . Details of the paper edge cleaner are described below. Toner bottles  16 Y,  16 C,  16 M, and  16 K supply color toner to each developing unit  7 Y,  7 C,  7 M, and  7 K under the output paper tray  2  in the machine body  1 . 
     The image forming apparatus  100  prints an image on paper P based on original document image data read by the image scanner  5  or print data sent from a host apparatus, such as a personal computer connected to a network. Each color toner image is formed on each respective photoconductor  6 Y,  6 C,  6 M, and  6 K in each corresponding image forming unit. Each color toner image is transferred to the intermediate transfer belt  9  sequentially and superimposed thereon. Then, a full color toner image is formed on the intermediate transfer belt. The full color toner image is carried to the secondary transfer unit in which the secondary transfer roller  10  faces the intermediate transfer belt  9 . 
     Further, paper P in one of feeding paper trays  15  is carried to the registration roller  11  by the paper feeding roller  17  and pairs of carrying rollers  18 . The paper is then sent by the registration roller  11  to meet the transferred toner image on the intermediate transfer belt  9  at the secondary transfer roller. After a paper edge cleaner removes cutting burr from the paper, the toner image on the intermediate transfer belt  9  is transferred to the paper P by the secondary transfer roller  10 . 
     The paper P with the transferred toner image is carried to a fixing unit  12 . The toner image is fixed by heat and pressure in the fixing unit  12 . Thus, the paper with the fixed toner image is outputted to the output paper tray  2  by the pair of outputting paper rollers  14 . When another toner image is formed on the other side of the paper, the paper with the fixed toner image on one side is carried to the paper path  19  for double-face printing, is held by the registration roller  11 , and another toner image is transferred to the other side of the paper. The toner image is fixed in the fixing unit  12  and is output to the output paper tray  2 . 
     Details of a first embodiment of the paper edge cleaner  20  between the registration roller  11  and the secondary transfer roller  10  on the paper carrying path  13  is explained below with reference to  FIGS. 2-11 .  FIG. 2  is an enlarged lateral view of a paper edge cleaner  20  in the first embodiment.  FIG. 3  is a plan view from above of the paper edge cleaner  20  in the first embodiment in a smaller scale than that shown in  FIG. 2 . 
     The first embodiment is explained with reference to  FIG. 2  and  FIG. 3 . The paper edge cleaner  20  includes two pairs of guide plates  21 ,  22  provided between the registration roller  11  and the secondary transfer roller  10  to form the paper carrying path  13 , an elastic grinding plate  32  as a first grinding member provided in a space  24  shown in  FIG. 2 , a pair of carrying rollers  41  provided upstream of guide plates  21 , a pair of carrying rollers  42  provided downstream of guide plate  22 . The pairs of rollers  41 ,  42  carry paper along the guide plates  21 ,  22 . 
     In the following explanation, “upstream” means upstream in the paper P movement, e.g., the left side in  FIG. 2 , and the down side in  FIG. 3 . “Downstream” means downstream in the paper P movement, e.g., the right side in  FIG. 2  and the up side in  FIG. 3 . The space  24  between the guide plate  21  and the guide plate  22  in  FIG. 3  is shown bigger than that in  FIG. 2  for convenience. The plan views in other embodiments are similar. 
     The pair of carrying rollers  41  includes two carrying rollers  41  a fixed at an interval on the same axis  41   c  shown in  FIG. 3 , and two carrying rollers  41   b  fixed at an interval on the same axis  41   d  shown in  FIG. 2 . Upstream from guide plates  21 , a pair of holes  21  a are formed at intervals in the width direction of the paper carrying path. The carrying roller  41   a  and the carrying roller  41   b  are set parallel and contact each other in the hole  21   a  of the upstream guide plate  21 , as shown in  FIG. 2 . The carrying rollers rotate in the arrow direction shown, pinch the paper P, and carry it in the direction of arrow A in  FIG. 2  between the pair of guide plates  21  in the paper carrying path  13 . 
     The pair of carrying rollers  42  include two carrying rollers  42   a  fixed at an interval on the same axis  42   c  shown in  FIG. 3  and two carrying rollers  42   b  fixed at an interval on the same axis  42   d  shown in  FIG. 2 . In the downstream guide plates  22 , a pair of holes  22   a  are formed at intervals in the width direction of the paper carrying path. The carrying roller  42   a  and the carrying roller  42   b  are set parallel and contact each other in the hole  22   a  of the upstream guide plate  21 , as shown in  FIG. 2 . The carrying rollers rotate in the arrow direction shown, pinch the paper P, and carry it in the direction of arrow A in FIG.  2  between the pair of guide plates  22  in the paper carrying path  13 . 
     Rails  30  shown in  FIGS. 2 and 3  are provided in a direction perpendicular to the paper movement. The rails  30  are provided under the paper carrying path  13  including the upstream pair of guide plates  21 , the downstream pair of guide plates  22 , and the space  24  between them, as shown  FIG. 2 . The rails  30  have base units  31  on the right and left sides that are movable in a plane parallel to the paper carrying path  13  and in a direction perpendicular to the paper movement shown by arrow B in  FIG. 3 . 
     A pair of elastic grinding plates  32  as a paper edge cleaner are provided in the paper carrying path  13  inside of the base units  31 . Each elastic grinding plate has a SUS plate spring  32   a  attached to a grinding sheet  32   b  as a lapping film. To avoid getting the tip of the paper hung up on the elastic grinding plates  32 , an upstream side of the plate spring  32   a  has a beveled form, as shown in  FIG. 3 , that increases width gradually from upstream to downstream, and is shaped to go down gradually and contact the paper carrying path shown in  FIG. 2 . 
     Facing members  33  are provided in the rails  30  under the pairs of guide plates  21 ,  22  to face each base unit  31  at a predetermined distance. A pair of supporting rollers is supported rotatable between a base unit  31  and a facing member  33 . Each supporting roller supports the paper P pressed against the elastic grinding plate  32  to keep the paper P in the paper carrying path  13 . The supporting rollers have an elastic layer. The supporting rollers are supported by a plastic axis, and are driven by the paper P to rotate. 
     In the first embodiment, a controller receives print information, identifies a width and type of the paper, drives base units  31  symmetrically along the rails  30  in a direction of the arrow B shown in  FIG. 3 , and sets the position of the base units suitable for the paper P. Hence the position of the elastic grinding plates is adjusted to contact both sides of the paper. 
     The registration roller  11  shown in  FIG. 1  carries the paper P to the paper edge cleaner  20 . The paper P is pinched by the pair of paper carrying rollers  41  shown in  FIG. 2  and  FIG. 3  and carried along a direction of the arrow A along the paper carrying path  13 . Both sides parallel to the paper movement of the paper P are pinched by the elastic grinding plates  32  and the supporting rollers  34 , and are moved between them. Edges on both sides of the paper P are grinded by the grinding sheet  32   b  on the elastic grinding plates  32 . Therefore, the cutting burr on the edges is removed. 
     After a tip of the paper P is pinched by the pair of carrying rollers  42 , the paper P is carried in a direction of the arrow A by the pair of carrying rollers  42 . When the paper type identified by the controller does not need grinding of the edge of the paper, cams  51 , 52  shown in  FIG. 12  make the elastic grinding plates  32  move upward and separate from the paper path. First, cam  52  rotates to separate from rods  54 . Next, cam  51  rotates to lift the rods  54 . Tips of the rods  54  are fixed on the elastic grinding plates  32 . Then, they separate the elastic grinding plates  32  from the paper path. When a type of the paper is a hard, thick paper, cams  51 , 52  make the elastic grinding plates  32  press both sides of the paper. The cam  51  rotates to depart from the rods  54 . Next, the cam  52  is rotated precisely by a pulse motor to change pressure from the rods to the paper sides. The supporting rollers  34  can move to modify the pressure. 
     Because the grinding sheets  32   b  on the elastic grinding plates  32  grind both sides of the paper carried to the secondary transfer, the cutting burr of the paper can be removed. Therefore, in the image forming apparatus  100  having this paper edge cleaner, because the side of the paper does not cause damage to a surface of the fixing member, a poor image, e.g., having an uneven glossiness line, is prevented. 
     In the first embodiment, a tip of the paper does not get hung up on the elastic grinding plates  32  because the upstream side of the plate spring  32   a  has a beveled form that increases in width gradually from upstream to downstream, and bends down gradually to contact the paper carrying path. However, it is acceptable that the plate spring  32   a  at least bends down gradually to contact the paper carrying path, without having the beveled form. 
     A second embodiment of the paper edge cleaner is explained with reference to  FIG. 4  and  FIG. 5 .  FIG. 4  is a lateral view of the second embodiment similar to  FIG. 2  in the first embodiment.  FIG. 5  is a plan view of the second embodiment similar to  FIG. 3  in the first embodiment. In these figures, the same parts shown in  FIG. 2  and  FIG. 3  have the same reference numbers, and their detailed explanation is not repeated. 
     A difference between the first embodiment and the second embodiment is the paper edge cleaners that are set inside of the base units  31 . A pair of grinding rollers  36  serving as the paper edge cleaner is attached as shown in  FIG. 4  and  FIG. 5 , instead of the elastic grinding plates  32  in the first embodiment. 
     Each grinding roller  36  has a conical shape whose top is located in the paper carrying path  13 , and whose bottom is supported rotatably at an axis  36   b  in each base unit  31 . A conical surface of the grinding rollers is covered by fine abrasives  36   a . Both sides of the paper carried along the paper path  13  are pinched by the pair of grinding rollers  36  and the supporting rollers  34  and are grinded. 
     In the second embodiment, a controller receives print information, identifies a width and type of the paper, drives base units  31  symmetrically along the rails  30  in a direction of the arrow B shown in  FIG. 5 , and sets the position of the base units suitable for the paper P. Hence the position of the grinding rollers is adjusted to contact both sides of the paper. 
     The paper P is carried by the pair of paper carrying rollers  41  in a direction of the arrow A shown in  FIG. 4  and  FIG. 5 . Both sides of the paper P are pinched by the grinding roller  36  and the supporting rollers  34  and moved between them. Edges on both sides of the paper P are grinded by the grinding roller  36 . Therefore, the cutting burr on the edges is removed. 
     It is preferable that the grinding rollers  36  have an amount of rotational load and skid on the paper P to grind it. The second embodiment has the same effect as the first embodiment. An alternative embodiment for thick papers and paper that does not need grinding can be similarly provided. 
     A third embodiment of the paper edge cleaner is explained with reference to  FIG. 6  and  FIG. 7 .  FIG. 6  is a lateral view of the third embodiment similar to  FIG. 2  in the first embodiment.  FIG. 7  is a plan view of the third embodiment similar to  FIG. 3  in the first embodiment. In these figures, the same parts shown in  FIG. 2  and  FIG. 3  have the same reference numbers and their detailed explanation is not repeated. 
     A difference between the first embodiment and the third embodiment is two pairs of elastic grinding plates  32 X,  32 Y along the paper carrying path  13  in the large space  24  between the upstream pair of guide plates  21  and the downstream pair of guide plates  22 , as shown in  FIG. 6  and  FIG. 7 . The paper edge cleaner includes a pair of base units  31 A in the upstream of the paper movement (the direction of the arrow A) and a pair of base units  31 B arranged on the opposite side of the paper carrying path from the pair of base units  31 A. The third embodiment includes facing members  33 , supporting rollers  34 , and rails  30  for supporting them in the upstream side and the downstream side. 
     A pair of elastic grinding plates  32 X is provided on one side of the paper carrying path  13  inside of the base units  31 A facing each other to contact with a surface on the one side of the paper. Another pair of elastic grinding plates  32 Y is provided on an opposite side of the paper carrying path  13  inside of the base units  31 B, facing each other to contact with another surface on the opposite side of the paper. Further, there is a pair of short guide plates  23  in a middle of the space  24 , as shown in  FIG. 6 . 
     In the third embodiment, a controller receives print information, identifies a width and type of the paper, drives base units  31 A,  31 B symmetrically along the rails  30  in a direction of the arrow B shown in  FIG. 7 , and sets the position of the base units suitable for the paper P. Then the grinding sheet  32   b  on the elastic grinding plate  32 X contacts one surface on both sides of the paper. The grinding sheet  32   b  on the elastic grinding plate  32 Y contacts another surface on both sides of the paper. 
     The paper P is carried by the pair of paper carrying rollers  41  in a direction of the arrow A shown in  FIG. 6  and  FIG. 7 . Both sides of the paper P are pinched by the elastic grinding plates  32 X and the supporting rollers  34  and moved between them. The edges of one surface on both sides of the paper P are grinded by the grinding sheet  32   b . Therefore, the cutting burr on the edges of one surface is removed. Next, the paper P is carried to the grinding plate  32 Y. Both sides of the paper P are pinched by the elastic grinding plates  32 Y and the supporting rollers  34  and moved between them. The edges of another surface on both sides of the paper P are grinded by the grinding sheet  32   b . Therefore, the cutting burr on the edges of another surface is removed. 
     The exemplary paper edge cleaner according to the third embodiment can remove cutting burr on surfaces on both sides of the paper because it grinds the paper surfaces in the paper carrying path  13 . Thus, this embodiment has the same effect as the other embodiments described above. The above modifications for the paper type also apply to this embodiment. Either the elastic grinding plates  32 X or the elastic grinding plates  32 Y or both can be replaced by the grinding rollers similar to the grinding rollers  36  in the second embodiment shown in  FIG. 4  and  FIG. 5 . 
     A fourth embodiment of the paper edge cleaner is explained with reference to  FIG. 8  and  FIG. 9 .  FIG. 8  is a lateral view of the fourth embodiment similar to  FIG. 2  in the first embodiment.  FIG. 7  is a plan view of the fourth embodiment similar to  FIG. 3  in the first embodiment. In these figures, the same parts shown in  FIG. 2  and  FIG. 3  have the same reference numbers and their detailed explanation is not repeated. 
     A difference between the first embodiment and the fourth embodiment is two pairs of the elastic grinding plates  32 R,  32 F along the paper carrying path  13  in the large space  24  between the upstream pair of guide plates  21  and the downstream pair of guide plates  22 , as shown in  FIG. 8  and  FIG. 9 . This arrangement is similar to that of the third embodiment. However, in the fourth embodiment, a downstream side structure, i.e., the base unit  31 B, the facing member  33 , the supporting roller  34 , and rails  30 , is similar to the upstream side structure of the first embodiment shown in  FIG. 2  and  FIG. 3 . 
     Rough grinding sheets  32   c  are attached to the plate springs  32   a  of the upstream elastic grinding plates  32 R. Fine grinding sheets  32   d  are attached to the plate springs  32   a  of the downstream elastic grinding plates  32 F. Further, there is a pair of short guide plates  23  in the middle of the space  24 , as shown in  FIG. 8 . 
     In the fourth embodiment, a controller receives print information, identifies a width and type of the paper, drives base units  31 A,  31 B symmetrically along the rails  30  in a direction of the arrow B shown in  FIG. 9 , and sets the position of the base units suitable for the paper P. Then, the grinding sheet  32   c  on the elastic grinding plate  32 R contacts one surface on both sides of the paper. The grinding sheet  32   d  on the elastic grinding plate  32 F contacts a same surface on both sides of the paper. 
     The paper P is carried by the pair of paper carrying rollers  41  in the direction of the arrow A shown in  FIG. 8  and  FIG. 9 . Both sides of the paper P are pinched by the elastic grinding plates  32 R and the supporting rollers  34  and moved between them. The edges on both sides of the paper P are grinded by the rough grinding sheet  32   c . Therefore, larger cutting burrs on the edges of one surface are removed. 
     Next, the paper P is carried to the grinding plate  32 F. Both sides of the paper P are pinched by the elastic grinding plates  32 F and the supporting rollers  34  and moved between them. The edges on both sides of the paper P are grinded by the fine grinding sheet  32   d . Therefore, smaller cutting burrs on the edges are removed. Thus, the edges on both sides of the paper P become smooth. 
     In this embodiment, larger cutting burrs can be removed by the rough grinding sheets  32   c  of the upstream elastic grinding plates  32 R. Further, smaller cutting burrs can be removed by the fine grinding sheets  32   d  of the downstream elastic grinding plates  32 F. Thus, the paper edges become smoother. 
     The effect of this embodiment is similar to the effect of the other embodiments described above. The above modifications for the paper type also apply to this embodiment. Further, either the elastic grinding plates  32 R or the elastic grinding plates  32 F or both can be replaced by the grinding rollers such as the grinding rollers  36  used in the second embodiment, as shown in  FIG. 4  and  FIG. 5 . 
     It is preferable that some pairs of the paper edge cleaner are provided in the direction of the paper movement. Especially, it is preferable that each paper edge cleaner have a different surface roughness in the direction of the paper movement. Further, it is more preferable that downstream paper edge cleaners have finer grinding surfaces. 
     A fifth embodiment of the paper edge cleaner is explained with reference to  FIG. 10  and  FIG. 11 .  FIG. 10  is a lateral view of the fifth embodiment similar to  FIG. 2  in the first embodiment.  FIG. 11  is a plan view of the fifth embodiment similar to  FIG. 3  in the first embodiment. In these figures, the same parts shown in  FIG. 2  and  FIG. 3  have the same reference numbers and their detailed explanation is not repeated. 
     A difference between the first embodiment and the fifth embodiment is pairs of rotatable paper dust-cleaning brushes  37  facing each other across the paper carrying path  13  inside of the base unit  31  as a paper dust cleaner. 
     The paper dust-cleaning brushes are provided inside of the base unit  31  downstream from the elastic grinding plates  32  including the plate springs  32   a  and the grinding sheets  32   b . Air suction ports  38  connected with an air suction pump are provided near bases of the paper dust-cleaning brushes to suction paper dust present in the paper dust-cleaning brushes. 
     In the fifth embodiment, the grinding sheets  32   b  of the elastic grinding plates  32  grind edges on both sides of the paper carried along the paper carrying path  13 , and remove cutting burr in a manner similar to the first embodiment. The paper dust cleaning brushes  37  contact both surfaces at both edges of the paper P and clean paper dust residing there. The paper dust is suctioned to the air suction port  38  by the air suction pump. As a result, skidding of the paper movement and contamination by paper dust are prevented. 
     The exemplary paper edge cleaner according to this embodiment has paper dust cleaning brushes  37  downstream of the paper movement from the base units  31  of the first embodiment. Similarly, the paper dust-cleaning brush can be provided downstream of the paper movement from the base units  31  of the second to fourth embodiments. The paper dust-cleaning brushes may be provided not only in the base units  31 , but also in another part independently downstream of the paper movement from the base units attached to the paper edge cleaners. 
     The image forming apparatus  100  has a paper edge cleaner  20  in various embodiments between the registration roller  11  and the secondary transfer roller  10  in the paper carrying path  13 . However, the location of the paper edge cleaner is not limited to this. The paper edge cleaner  20  can be set anywhere between the paper feeding device to feed the paper (paper feeding roller  17  in  FIG. 1 ) and the transfer part to transfer a toner image to the paper fed by the feeding device in the paper carrying path. Further, a paper carrying means is not limited only to rollers, but can also include belts. 
     The image forming apparatus is not limited to a tandem-type, intermediate-transfer, full-color apparatus. Other embodiments in other color printers can include a direct transfer system or another intermediate transfer system, black and white printers, copiers or fax machines including a scanner, and one of the above printers and multi-functional digital machines. 
     Numerous additional modifications and variations of the disclosed exemplary embodiments are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the embodiments may be practiced otherwise than as specifically described herein.