Abstract:
A method for manufacturing a cleaning device of the image forming apparatus, the method includes: applying a liquid material to an area outer than an edge located at an end portion of a toner accommodating portion in the longitudinal direction of a toner removing member, wherein the liquid material is applied so as to satisfy one of the predetermined conditions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based on and claims priority under 35 U.S.C. 119 from Japanese Patent Application No. 2008-257329 filed Jun. 20, 2008. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    This invention relates to a method for producing a cleaning device when members relative to removal of developer are mounted in a housing through a liquid material and the cleaning device using the method. 
         [0004]    2. Related Art 
         [0005]    Previously known are image forming apparatuses in which an image is formed on a recording medium by transferring and fixing an developed image formed on the surface of an image carrier holding the developed image of toner. Some of these image forming apparatus are provided with a cleaning device in which unnecessary things such as residual toner left on the surface of an image holder after the developed image has been transferred onto the recording medium are cleaned by bringing the tip of a blade into contact with the surface of the image holder. 
         [0006]    As described above, some cleaning devices for cleaning unnecessary things recover the unnecessary things scraped off by the blade into a box and also secure the blade at a position of a box. 
         [0007]    Some of these cleaning devices cover a square opening connected to the inside of the box with a square blade and press the remaining opening region onto the image holder so that the unnecessary things scraped off by the tip of the blade, which is a part of the peripheral edge of the remaining opening region, is guided into the box through the remaining opening region. 
         [0008]    Further, in the image forming apparatus provided with such a cleaning device, in order to prevent leakage of unnecessary things from the gap between the blade and box, a solid elastic sealing material serving as a blocking material is inserted in the gap. 
         [0009]    However, there is a problem that it takes time to cut the solid elastic sealing material according to the shape of the overlapping area of the peripheral edge of the square opening and the square blade and affix the solid elastic sealing material thus cut to the peripheral edge of the opening. 
       SUMMARY 
       [0010]    According to an aspect of the present invention, a method for producing a cleaning device of the image forming apparatus, the cleaning device including: a toner image carrier that has a surface moving in the predetermined direction and holding a toner image; a toner removing member that is in contact with the surface of the toner image carrier along a crossing direction that crosses a moving direction of the surface of the toner image carrier, the toner removing member removing a toner that remains on the surface of the toner image carrier after toner image is transferred; a supporting member that supports the toner removing member; a sliding member that is arranged at a location being an upstream side of the toner removing member in the moving direction of the surface of the toner image carrier, and is in contact with the surface of the toner image carrier; a housing that includes a toner accommodating portion that accommodates the toner removed by the toner removing member, the housing being attached to the toner removing member and the supporting member through a liquid material solidifying after coated in liquid; and a sealing member that is arranged at a location being an upstream side of the sliding member in the moving direction of the surface of the toner image carrier, and seals a space between the toner image carrier and the housing, the method includes applying the liquid material to an area outer than an edge located at an end portion of the toner accommodating portion in the longitudinal direction of the toner removing member, wherein the liquid material is applied so as to satisfy one of the following conditions (1) to (3): 
         [0011]    (1) applied amount of the liquid material for a closest approach distance between the housing and the toner removing member or the supporting member is larger in an area opposite to a step portion between the toner removing member and the supporting member than an area where the supporting member and the housing are opposite to each other; 
         [0012]    (2) applied amount of the liquid material for a closest approach distance between the housing and the toner removing member or the supporting member is larger In an area opposite to a boundary 
         [0013]    between the toner removing member and the sliding member than an area where the supporting member and the housing are opposite to each other; and 
         [0014]    (3) applied amount of the liquid material for a closest approach distance between the housing and the toner removing member or the supporting member is larger in an area opposite to a boundary between the sliding member and the sealing member than an area where the supporting member and the housing are opposite to each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    Exemplary embodiment of the present invention will be described in detail based on the following figures, wherein: 
           [0016]      FIG. 1  is a schematic sectional view of an image forming apparatus; 
           [0017]      FIG. 2  is a partial appearance view of the cleaning device; 
           [0018]      FIG. 3  is a view of the blade supporting plate holding the blade; 
           [0019]      FIG. 4  is a view showing a cleaning frame; 
           [0020]      FIG. 5  is a flowchart showing the flow of the method of assembling the cleaning device; 
           [0021]      FIG. 6  is a view showing the state where a blade supporting plate is secured to the cleaning frame; 
           [0022]      FIG. 7  is a view showing the manner that a photosensitive drum is assembled with a holding portion of the cleaning frame; 
           [0023]      FIGS. 8A and 8B  are sectional views of the cleaning device assembled with the photosensitive drum; and 
           [0024]      FIGS. 9A and 9B  are sectional view of the cleaning device assembled with the photosensitive drum. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    The mode for carrying out this invention will be described below. 
         [0026]      FIG. 1  is a schematic sectional view of an image forming apparatus. 
         [0027]    In an image forming apparatus  1  shown in  FIG. 1 , onto the surface of a photosensitive drum  10  rotating in the direction of arrow A, which is an example of a toner holder, supplied with a charge by a charging roll  11 , exposure light produced by an exposure device  12  formed on the basis of image data transmitted from the outside is put, thereby to form an electrostatic latent image. The electrostatic latent image thus formed is developed with the toner accommodated in a developing device  13  having a developing roll  131  rotating in the direction of arrow C. The developed image obtained by this development is pulled out from a sheet cassette (not shown), transferred on to a recording sheet transported in the direction of arrow B by a transfer roll  14  rotating in the direction of arrow D and fixed by a fixing device  15 , thereby forming an image on the recording sheet. It should be noted that this image forming apparatus  1  is a monochromatic image dedicated machine. 
         [0028]    In  FIG. 1 , there is shown a cleaning device  2  for removing the residue left on the surface of the photosensitive drum  10  which is in contact with an area of the photosensitive drum  10  where the developed image has been transferred on the recording sheet. 
         [0029]      FIG. 2  is a partial appearance view of the cleaning device. 
         [0030]    In  FIG. 2 , illustrated is the one end of the cleaning device  2  when the cleaning device  2  shown in  FIG. 1  is seen from the developing device  13  side through the photosensitive drum  10 . The cleaning device  2  is laterally symmetrical so that only this end will be explained below. 
         [0031]    The cleaning device  2  includes a cleaning frame  21  which is an example of a box in this invention; a blade  22  which is an example of a toner removing member in this invention; a blade supporting plate  23  supporting the blade  22  which is an example of a supporting member; a film member  24  which is an example of a sealing member; and a felt member  25  which is an example of a sliding member. 
         [0032]    The blade  22  is made of rubber to remove the residue left on the surface of the photosensitive drum  10  with which the tip  221  of the blade  22  is brought into contact. 
         [0033]    The blade supporting plate  23  is a metallic plate supporting the blade  22  and secured to the cleaning frame  21  by an anchoring screw  230 . 
         [0034]    The cleaning frame (housing)  21  has a concave space  210   a  for accommodating the residue removed from the surface of the photosensitive drum  10 , and includes a body  210  screwed with the blade supporting plate  23  supporting the blade  22  at an area of the edge  210   b  of the concave space  210   a  (see  FIG. 4 ) and a holding portion  211  for rotatably holding both ends of the photosensitive drum  10 . The body  210  is provided with a boss  2101  used to position the blade supporting plate  23  and also a boss  2102  used to arrange the cleaning frame  21  at a predetermined position of the image forming apparatus  1 . Further, although described later in detail, screwing the blade supporting plate  23  supporting the blade  22  to the cleaning frame  21  is done while involving a thermoplastic elastomer  20  (see  FIG. 6 ) which is a sealing member applied to an edge  210   b  of the concave space  210   a  of the cleaning frame  21 . 
         [0035]    The felt member  25  is composed of a surface, i.e. a felt layer  251  and its underlying layer i.e. an elastic layer  252  (see  FIG. 7 ). The elastic layer  252  is slightly crushed in a state where the photosensitive drum  10  is held by the holding portion  211  of the cleaning frame  21 . Thus, the felt layer  251  is brought in closely contact with the photosensitive drum  10  so that leakage of the residue can be prevented. 
         [0036]    The felt member  25  has also a protrusion  250  protruding toward the edge  210   b  of the concave space  210   a.  In  FIG. 2 , shown is the manner that the side face of the protrusion  250  and the face on the blade side of the portion other than the protrusion  250  of the felt member  25  are conformed to the corner of the blade  22 . Now, although a contact area with the photosensitive drum  10  is formed of the felt layer  251 , it may be formed of the material other than the felt material, having a small friction coefficient enough to not obstruct the rotation of the photosensitive drum  10  when brought into contact with the photosensitive drum  10 . 
         [0037]    The film member  24  is formed of a polyurethane sheet. Its tip  241  is brought into contact with the photosensitive drum  10  in a state where it is held in the holding portion  211  of the cleaning frame  21  so that leakage of the residue can be prevented. 
         [0038]      FIG. 3  is a view of the blade supporting plate In the state where it supports the blade. 
         [0039]    In  FIG. 3 , shown is the blade supporting plate  23  holding the blade  22  before it is screwed to the cleaning frame  21  of the cleaning device  2 , with its face in contact with the cleaning frame  21  being directed upward. Also in  FIG. 3 , shown is the manner providing a slot  23   a  through which the anchoring screw  230  shown in  FIG. 2  passes and a slot  23   b  through which the boss  2101  of the cleaning frame  21  passes. 
         [0040]      FIG. 4  is a view of the cleaning frame. 
         [0041]    In  FIG. 4 , shown is the cleaning frame  21  in a state before the blade supporting plate  23 , felt member  25  and film member  24  are attached to the body  210 . Now, the edge  210   b  of the concave space  210   a  accommodating the residue is exposed. A peripheral edge segment AA, a peripheral edge segment BB and a peripheral edge segment CC, which encircle the edge  210   b  of the concave space  210   a,  exist in a first plane constituted by an upper surface of the body  210  while a peripheral edge segment DD exists In a second plane crossing the first plane. 
         [0042]    Now, the peripheral edge segment BB and peripheral edge segment CC refers to not only a region along the area constituting edges  2101   a,   2102   a  forming the concave space  210   a  in an axial direction of the photosensitive drum  10  nearly orthogonal to the moving direction of the photosensitive drum  10 , but also, as in this embodiment, a region between the area constituting the edges  2101   a,    2102   a  and the ends of the blade  22  in the axial direction of the photosensitive drum  10 . The peripheral edge segment AA refers to not only a region along the area constituting an edge  2103   a  forming the edge  210   b  of the concave space  210   a  on the side where the blade supporting plate  23  is arranged, but also as in this embodiment, a region outer than the area forming the edge  2103   a  with respect to the concave space  210   a  and where the blade supporting plate  23  and the cleaning frame  21  are opposite to each other. Further, the peripheral edge segment DD refers to not only a region along the area constituting the edge forming the edge  210   b  of the concave space  210   a  on the side where the film member  24  is arranged, but also, as in this embodiment, a region between the area forming this edge and the film member  24 . 
         [0043]    Now referring to  FIGS. 4 to 7 , a brief explanation will be given of a method for assembling the cleaning device  2 . 
         [0044]      FIG. 5  is a flowchart showing the flow of the method of assembling the cleaning device. 
         [0045]    As shown in  FIG. 5 , in step S 1 , the thermoplastic elastomer  20  applied in a liquid state and solidified to block the gaps among the members is applied to the peripheral edge segment AA, peripheral edge segment BB, and peripheral edge segment CC constituting the peripheral edge of the edge  210   b  of the concave space  210   a  of the cleaning frame  21 . In step S 2 , the blade supporting plate  23  supporting the blade  22  is screwed to be secured the cleaning frame  21 . At this stage, the respective segments of the peripheral edge segment AA, peripheral edge segment BB, and peripheral edge segment CC of the peripheral edge of the edge  210   b  of the concave space  210   a  are covered with the blade  22  and blade supporting plate  23  supporting the blade  22  so that the edge  210   b  of the concave space  210   a  becomes the state narrowed as compared with the state shown in  FIG. 4 . 
         [0046]      FIG. 6  is a view showing the state where a blade supporting plate is secured to a cleaning frame. In  FIG. 6 , the portion covered with the members and not seen of the peripheral edge of the edge  210   b  of the concave space  210   a  is illustrated in a one-dot chain line and the portion covered with the members and not seen of the thermoplastic elastomer  20  applied on the peripheral edge segments is illustrated in a dotted line. 
         [0047]      FIG. 6  shows the state where the portion covered with the blade  22  and the blade supporting plate  23  supporting the blade  22  of the thermoplastic elastomer  20  applied to the peripheral edge segments AA, BB and CC constituting the peripheral edge of the edge  210   b  of the concave space  210   a  is compressed to be enlarged by securing the blade supporting plate  23  supporting the blade  22  to the cleaning frame  21 . Returning to  FIG. 5 , the explanation will be continued. 
         [0048]    Next, in step S 3 , the felt member  25  is affixed to a felt affixing plane  2103  (see  FIG. 4 ). In step S 4 , the film member  24  is affixed to the peripheral edge segment DD. Now, the end of the film member  24  is affixed to the peripheral edge segment DD by a double-faced tape not shown. In step S 5 , the photosensitive drum  10  is assembled with the holding portion  211  of the cleaning frame  21 . 
         [0049]      FIG. 7  is a view showing the state where the photosensitive drum is assembled with the holding portion of the cleaning frame. In order to avoid complication, in the film member  24  is not shown in  FIG. 7 . 
         [0050]    In  FIG. 7 , shown is the case when the peripheral edge segment BB is seen In the direction of arrow X in  FIG. 6 . Now, illustrated is the manner where the felt member  25  is affixed to the felt affixing plane  2103  by the double-faced tape  26 , As described above, when the photosensitive drum  10  is assembled with the holding portion  211  of the cleaning frame  21 , the elastic layer  252  of the felt member  25  is slightly compressed so that the felt layer  251  is brought into closely contact with the photosensitive drum  10 . At this time, the thermoplastic elastomer  20  on the film member  24  side in the peripheral edge segment BB is also compressed between the double-sided face tape  26  at the projection  250  of the felt member  25  explained in  FIG. 2  and the peripheral edge segment BB. In this way, both ends of the blade  22  whose contact pressure for the surface of the photosensitive drum  10  is likely to be lowered as compared with the other portion are supported by repulsion force due to compression of the thermoplastic elastomer  20  having elasticity so that positional changes in the contact pressure of the blade  22  for the surface of the photosensitive drum  10  are prevented, thereby suppressing deflective abrasion of the surface of the photosensitive drum  10 . Thus, the method for assembling the cleaning device  2  has been schematically described. This cleaning device  2  is a first embodiment common to the first, second and third toner removing devices according to this invention. 
         [0051]    In the following, a detailed explanation will be given of sealing, using the thermoplastic elastomer  20 , the gap between the peripheral edge segments BB, CC, and the blade  22 , blade supporting plate  23  and felt member  25  in the cleaning device  2 . The liquid material applying method described below is a first embodiment common to the first, second and third liquid applying methods according to this invention. 
         [0052]      FIG. 8  is a sectional view of the cleaning device assembled with the photosensitive drum. 
         [0053]      FIG. 8A  shows the manner when the section indicated by one-dot chain line in  FIG. 7  is seen from the direction of arrow Y. As seen, the tip  241  of the film member  24  affixed to the peripheral edge segment DD by the double-sided tape  26  is involved into the felt member  25  side. Thus, leakage of the residue from the film member  24  side is suppressed. 
         [0054]    Further, as seen from  FIG. 8A , the gap between the cleaning frame  21  and the film member  24 , felt member  25 , blade  22  and blade supporting plate  23  is made uniform. 
         [0055]      FIG. 8B  shows the manner when the section of the cleaning frame  21  applied with the thermoplastic elastomer  20  in the peripheral edges A, B and C before the blade supporting plate  23  and others are assembled is seen from the direction of arrow Y in  FIG. 7 . As seen from  FIG. 8B , the applied quantity of the thermoplastic elastomer  20  is larger in the area corresponding to the step portion between the blade  22  and the blade supporting plate  23  and the area corresponding to the portion sandwiched by the film member  24  and felt member  25 , where the thermoplastic elastomer  20  is resistant to spread, than at other areas. 
         [0056]    In the liquid material applying method according to this embodiment, the applied quantity of the thermoplastic elastomer  20  to the cleaning frame  21  of the cleaning device  2  with a uniform gap between the cleaning frame  21  and the members assembled with the cleaning frame  21  is made larger in the areas where the unnecessary things are more likely to leak than the other areas, among the respective areas of the cleaning frame  21 , i.e. the area corresponding to the step portion between the blade  22  and the blade supporting plate  23  and the area corresponding to the portion sandwiched by the film member  24  and felt member  25 , where the thermoplastic elastomer  20  is resistant to spread, than at the other areas. Under this condition, the respective members are secured to the cleaning frame  21  from above the applied thermoplastic elastomer  20  while compressing the applied thermoplastic elastomer  20  in the order of step S 2  et seq. in  FIG. 5 . Thus, the thermoplastic elastomer  20  can be surely filled in the areas where the thermoplastic elastomer  20  is resistant to spread so that the capability of blocking the gap can be improved. Accordingly, in accordance with the liquid material applying method in this embodiment, the capability of blocking the gap can be improved. 
         [0057]    Next, an explanation will be given of a second embodiment common to the first, second and third liquid applying methods according to this invention. 
         [0058]    The liquid material applying method according to this embodiment is different from the liquid material applying method according to the first embodiment as follows. The liquid material applying method according to first embodiment is directed to the cleaning device with the uniform gap between the cleaning frame  21  and the members assembled therewith, and gives the areas where the thermoplastic elastomer  20  is resistant to spread the applied quantity of the thermoplastic elastomer larger than the other areas. On the other hand, the liquid material applying method according to this embodiment is directed to the cleaning device with the gap between the cleaning frame  21  and the members assembled therewith, narrower in the area where the thermoplastic elastomer  20  is resistant to spread than the other areas, and applies the thermoplastic elastomer  20  uniformly to all the areas. 
         [0059]      FIG. 9  is a sectional view of the cleaning device assembled with the photosensitive drum  10 . In  FIG. 9 , like reference symbols refer to like functional members in  FIG. 8 . The cleaning device  2  shown in  FIG. 9  Is a second embodiment common to the first, second and third toner removing devices according to this invention. 
         [0060]    As seen from  FIG. 9A , the gap between the cleaning frame  21  and the film member  24 , felt member  25 , blade  22  and blade supporting plate  23 , which constitute the cleaning device  2  is narrower in the area where the residue is likely to leak, i.e. where the thermoplastic elastomer  20  is resistant to spread, than at other areas. 
         [0061]      FIG. 9B  shows a view of the cleaning frame  21  applied with the thermoplastic elastomer  20  in the peripheral edges AA, BB and CC before the blade supporting plate  23  and others are assembled when the section indicated by the one-dot chain line in  FIG. 7  is seen from the direction of arrow Y. As seen from  FIG. 9B , the applied quantity of the thermoplastic elastomer  20  is made uniform irrespectively of whether or not the area at issue is the area where the thermoplastic elastomer  20  is resistant to spread. 
         [0062]    In the liquid material applying method according to this embodiment, the applied quantity of the thermoplastic elastomer  20  to the cleaning frame  21  of the cleaning device  2  with the gap between the cleaning frame  21  and the members assembled with the cleaning frame  21  is being narrower in the areas where the thermoplastic elastomer  20  is resistant to spread than at the other areas is made uniform irrespectively of whether or not the area at issue is the where the residue is more likely to leak than the other areas, among the respective areas of the cleaning frame  21 . Under this condition, the respective members are secured to the cleaning frame  21  from above the applied thermoplastic elastomer  20  while crushing the applied thermoplastic elastomer  20  In the order of step S 2  et seq. in  FIG. 5 . In this way also, the thermoplastic elastomer  20  can be surely filled in the area where the thermoplastic elastomer  20  is resistant to spread so that the blocking capability of the gap can be improved. Accordingly, in accordance with the liquid material applying method in this embodiment, the blocking capability can be improved. 
         [0063]    The foregoing description of the embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention defined by the following claims and their equivalents.