Abstract:
A developer-conveying apparatus is provided, the developer-conveying apparatus including: a conveying member that has a rotational axis rotatably set in a container and a blade formed around the rotational axis, the conveying member conveying a developer along the rotational axis by rotation; and a static eliminating member set in the container and eliminating static electricity of the developer in the container by being brought into contact with the developer.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 U.S.C. 119 from Japanese Patent Application No. 2009-063108 filed Mar. 16, 2009. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a developer-conveying apparatus and an image-forming apparatus. 
     2. Related Art 
     In developing apparatus of image-forming apparatus such as copiers, printers, and facsimiles of electrophotographic systems, toner-conveying apparatus for conveying toners in the axial direction of conveying member by rotating the conveying member comprising a blade formed helically on the circumferential surface of the axis are generally used. It is known that a toner is aggregated and conveying ability lowers in such a conveying apparatus. 
     SUMMARY 
     According to an aspect of the present invention, there is provided a developer-conveying apparatus including: 
     a conveying member that has a rotational axis rotatably set in a container and a blade formed around the rotational axis, the conveying member conveying a developer along the rotational axis by rotation; and 
     a static eliminating member set in the container and eliminating static electricity of the developer in the container by being brought into contact with the developer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiment of the present invention will be described in detail based on the following figures, wherein: 
         FIG. 1  is a block diagram showing an example of the image-forming apparatus according to the exemplary embodiment of the invention; 
         FIG. 2  is a cross-sectional view showing schematic construction of the belt cleaning apparatus according to the exemplary embodiment of the invention; and 
         FIG. 3  is a cross-sectional view of line A-A in  FIG. 2 . 
         FIG. 4  illustrates a static eliminating member according to an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a block diagram showing an example of the image-forming apparatus according to the exemplary embodiment of the invention. This image-forming apparatus  10  has almost box-shaped body of apparatus  11 . In the lower part of the body of apparatus  11 , plural attachable and detachable paper feeding trays  12 A,  12 B for housing paper P as a recording medium are provided. In the space of the body of apparatus  11 , paper discharge port  13  to which recorded paper P is discharged is arranged, and paper conveying route  14  leading to the paper discharge port  13  from the paper feeding trays  12 A,  12 B is formed. 
     On the paper conveying route  14 , pickup roll  140  for feeding paper P one by one from the paper feeding trays  12 A,  12 B to the paper conveying route  14 , disposing roll  141  for disposing paper P, and conveying roll  142  for conveying the paper P are arranged. 
     In image-forming apparatus  10 , operation display part  15  for inputting and displaying various data, and ADF (automatic manuscript feeder)  16  are arranged on body of apparatus  11 . On the upper part of the body of apparatus  11 , read part  17  for optically reading an original image from manuscript M is provided. ADF  16  is a member for automatically feeding the manuscript M distributed to manuscript tray  18  to read part  17 , and the manuscript M read by read part  17  is discharged to manuscript discharge tray  19 . 
     Further, in image-forming apparatus  10 , image forming part  20  is arranged at the upper part of paper feeding trays  12 A,  12 B in body of apparatus  11 . Image forming part  20  is provided with photoreceptors  21 Y,  21 M,  21 C,  21 K on which toner images of respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are formed while rotating in the directions of arrows in the figure, chargers  22 Y,  22 M,  22 C,  22 K for evenly charging the surfaces of photoreceptors  21 Y,  21 M,  21 C,  21 K, exposing units  23 Y,  23 M,  23 C,  23 K for forming electrostatic latent images of respective colors of Y, M, C and K by irradiating charged photoreceptors  21 Y,  21 M,  21 C,  21 K with exposure lights modulated to respective colors based on image data of respective colors of Y, M, C and K, and developing units  24 Y,  24 M,  24 C,  24 K for forming toner images on the surfaces of photoreceptors  21 Y,  21 M,  21 C,  21 K by developing the electrostatic latent images with toners and carriers as one example of the developers in the exemplary embodiment. 
     Each of developing units  24 Y,  24 M,  24 C,  24 K has housing  240  for housing each toner. In housing  240 , developing roller  241  for supplying toners to photoreceptors  21 Y,  21 M,  21 C,  21 K, and developing the electrostatic latent images on photoreceptors  21 Y,  21 M,  21 C,  21 K with the toners, supply auger  242  for supplying toners to developing roller  241 , and stirring auger  243  for stirring toners and at the same time supplying toners to supply auger  242  are arranged. Further, toners of respective colors are supplied from toner boxes  35 Y,  35 M,  35 C,  35 K to developing units  24 Y,  24 M,  24 C,  24 K. The toner boxes may contain toners and magnetic carriers, or may contain toner alone not containing carriers. 
     Image forming part  20  is provided with photoreceptor cleaning units  26 Y,  26 M,  26 C,  26 K for collecting the toners remaining on the surfaces of photoreceptors  21 Y,  21 M,  21 C,  21 K after transfer, and static eliminating members  27 Y,  27 M,  27 C,  27 K for eliminating static electricity of photoreceptors  21 Y,  21 M,  21 C,  21 K after transfer. 
     Image forming part  20  is provided with intermediate transfer belt  33  strained by driving roll  30 , backup roll  31 , and driven roll  32 . Intermediate transfer belt  33  moves circularly in the direction of arrow in the figure contacting with photoreceptors  21 Y,  21 M,  21 C,  21 K. 
     First transfer rolls  25 Y,  25 M,  25 C,  25 K are provided on the opposite side of photoreceptors  21 Y,  21 M,  21 C,  21 K with intermediate transfer belt  33  in between. First transfer rolls  25 Y,  25 M,  25 C,  25 K transfer the toner images on the surfaces of photoreceptors  21 Y,  21 M,  21 C,  21 K to intermediate transfer belt  33  by pressure and static electricity in nip areas formed with photoreceptors  21 Y,  21 M,  21 C,  21 K. 
     Second transfer roll  34  is provided on the opposite side of backup roll  31  with intermediate transfer belt  33  in between. Second transfer roll  34  performs secondary transfer of the toner image on intermediate transfer belt  33  to paper P in nip areas formed with backup roll  31 . 
     Image forming part  20  is provided with belt cleaning unit  40 , to which the developer conveying apparatus of the invention is applied, on the upstream of photoreceptor  21 Y arranged in the conveying direction of intermediate transfer belt  33  and on the opposite side of driving roll  30  with intermediate transfer belt  33  in between. The belt cleaning unit  40  is pressed toward driving roll  30  side to scrape off and collect the toner remaining on intermediate transfer belt  33 . 
       FIG. 2  is a cross-sectional view showing schematic construction of the belt cleaning apparatus.  FIG. 3  is a cross-sectional view of line A-A in  FIG. 2 . 
     Belt cleaning unit  40  is provided with blade  41  as one example of scraping member for scraping off the toner remaining on the surface of intermediate transfer belt  33  by contacting with the surface of intermediate transfer belt  33 , container  42  for housing the collected container scraped off by blade  41  and collected, conveying member  43 , which is provided in container  42  so as to be freely rotatable, for conveying the collected toner in container  42  in the direction of the arrow in the figure by rotating, and discharging the collected toner to the collected toner tank not shown in the figure from discharge port  42   b  formed in discharge cylinder  42   a  provided so as to be protruded downward in the weight direction from the end part of container  42 , toner collapsing member  44  for collapsing the collected toner accumulated on conveying member  43 , and a motor not shown in the figure for rotating conveying member  43 . 
     As blade  41 , an elastic blade comprising an elastic member such as rubber and silicon resins may be used. In place of blade  41 , a metal scraper consisting of a metal of SUS304 and the like may be used, or after scraping off the toner with an elastic blade, the residues on intermediate transfer belt  33  may be scraped with a metal scraper. 
     Conveying member  43  is provided with rotational axis  430 , rotor blade  431  helically-formed around the rotational axis  430 , and gear  432  provided at the end part of rotational axis  430  for rotating rotational axis  430  in the direction of the arrow in  FIG. 2  by the application of torque of the motor. Conveying member  43  is attached to container  42  by bearings  45  at both end parts so as to be freely rotatable. Conveying member  43  is generally formed of resins, e.g., ABS resin, polycarbonate resin, polyacetal resin, polystyrene resin, and the like, or metals, e.g. aluminum. Incidentally, the rotor blade may not be helically-formed around rotational axis  430 , so long as it has a form capable of conveying a developer in the axial direction of rotational axis  430  in response to the rotation of rotational axis  430 , such that plural feed plates may be provided on rotational axis  430  with inclination. 
     Container  42  has first conveying route  420  to convey the collected toner, and second conveying route  421  provided leading out of first conveying route  420  on the downstream of first conveying route  420  in the conveying direction of the developer for conveying the collected developer conveyed from first conveying route  420  to the collected toner tank. The cross section of second conveying route  421  on the vertical plane in the axis direction of the rotational axis is smaller than that of first conveying route  420 . 
     Toner collapsing member  44  is provided in first conveying route  420  and on the border with second conveying route  421 . At least a part of toner collapsing member  44  is provided correspondingly on downstream end part of blade  41  in the conveying direction of the collected toner, but the entire of toner collapsing member  44  may be provided correspondingly on downstream end part of blade  41 . 
     Toner collapsing member  44  is provided with static eliminating member  440  for eliminating static electricity of the collected toner, and elastic film  441  which is an example of an elastic member and is disposed to be in touch with the rotor blade  431  of the conveying member  43 . The toner collapsing member  44  has plural (for example, 3) protrusions  44   a , the tip parts of which have the same pitch with the pitch of the rotor blade, and base  44   b  fixed to container  42  by an adhesive or screws. Here, “pitch” is the distance between continuous rotor blades in the axial direction of the rotational axis. When plural feed plates are provided with inclination, it means the distance between contiguous plates in the axial direction of the rotational axis. By making the pitch of the rotor blade and the pitch of protrusions  44   a  the same, protrusions  44   a  start contacting to rotating rotor blade with completely the same timing and released from contacting with the same timing, so that the wavelength and the phase at the time of vibration coincide, by which elastic film  441  at large moves the same. By the same movement of elastic film  441 , the performance of collapsing the collected toner is improved as compared with the case where the tips move differently. 
     Static eliminating member  440  includes nonwoven fabric of resin fiber such as polyester and the like, or a conductive material formed on the surface of the nonwoven fabric, and adhered with an adhesive on the surface of the upstream side of elastic film  441 . As static eliminating member  440 , for example, Wiping Cloth (manufactured by Japan Vilene Company, Ltd.) may be used. Static eliminating member  440  may be in contact with the earth, although not in contact with the earth in the exemplary embodiment. Further, static eliminating member  440  may be merely a bundle of fibers. 
     Elastic film  441  includes resins such as PET (polyethylene terephthalate resin) having a thickness of 0.01 to 0.5 mm, preferably 0.02 to 0.08 mm or so. From the point of restraining noise and toner splashing, proper elasticity may be given to static eliminating member  440  by selecting the thickness of elastic film  441 . 
     (Motion of Belt Cleaning Unit) 
     In the next place, the operation of belt cleaning unit  40  is described. The toner remaining on the surface of intermediate transfer belt  33  is scraped off by blade  41  of belt cleaning unit  40 , and housed in container  42 . The toner housed in container  42  is conveyed to the direction of discharge cylinder  42   a  by rotating conveying member  43 , and discharged into collected toner tank (not shown in the figure) via discharge port  42   b.    
     Even when the toner housed in container  42  is electrically aggregated, elastic film  441  has elasticity, so that elastic film  441  vibrates and physically collapses the collected toner by rotating conveying member  43 . Elastic film  441  is provided with static eliminating member  440 , and static eliminating member  440  eliminates static electricity by discharging the static electricity of the collected toner to the air, the aggregated collected toner is easily collapsed as compared with the case where the toner is charged. Further, static eliminating member  440  also functions as the damping material of elastic film  441 , and it controls the vibration of elastic film  441  and reduces noises as compared with the case where static eliminating member  440  is not provided. Thus, the collected toner aggregated in container  42  is efficiently collapsed by elimination of static electricity by static eliminating member  440  coupled with function of collapsing by elastic film  441 . By this mechanism, the collected toner aggregated in container  42  may be prevented from becoming the hindrance of conveying in container  42  and the collected toner from staying in container  42 . 
     The invention is not restricted to the exemplary embodiment and modifications may be made therein without departing from the spirit and scope thereof. For example, toner collapsing member  44  is provided in belt cleaning unit  40  in the exemplary embodiment, but it may be provided other places, for example, in photoreceptor cleaning units  26 Y,  26 M,  26 C,  26 K or developing units  24 Y,  24 M,  24 C,  24 K. 
     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.