Abstract:
A transport apparatus includes a transport unit that includes a transport path through which a transported material is transported; and a positioning-and-holding unit that includes a positioning-and-holding member that positions constituents of the transport apparatus to each other and supports the constituents, and a plate-shaped member that works as a part of the transport path and is detachably connected with the positioning-and-holding member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2006-271631 filed on Oct. 3, 2006. 
       BACKGROUND 
       [0002]    The present invention relates to a transport apparatus and an image-forming apparatus. 
       SUMMARY 
       [0003]    According to an aspect of the invention, there is provided a transport apparatus including a transport unit that includes a transport path through which a transported material is transported; and a positioning-and-holding unit that includes a positioning-and-holding member that positions constituents of the transport apparatus to each other and supports the constituents, and a plate-shaped member that works as a part of the transport path and is detachably connected with the positioning-and-holding member. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a diagram showing an image-forming apparatus of an exemplary embodiment of the invention; 
           [0005]      FIG. 2  is a perspective view showing a supporting member of the image-forming apparatus of the exemplary embodiment; 
           [0006]      FIGS. 3(   a ),  3 ( b ) and  3 ( c ) are diagrams showing a bottom plate of the supporting member of the image-forming apparatus of the exemplary embodiment; and 
           [0007]      FIG. 4  is a perspective view showing the supporting member of the image-forming apparatus of the exemplary embodiment, 
       
    
    
       [0008]    wherein  100  denotes an image-forming apparatus;  2  denotes an image output unit;  7  denotes a reverse-transport unit;  8  denotes a supporting member;  60  denotes a reverse-transport path; and P denotes a sheet (recording medium). 
       DETAILED DESCRIPTION 
       [0009]    Hereinafter, an exemplary embodiment of the invention will be described by reference to the accompanying drawings. 
       Exemplary Embodiment 
       [0010]      FIGS. 1 to 4  are diagrams which show an exemplary embodiment of an image-forming apparatus according to the invention. 
         [0011]      FIG. 1  is a diagram showing an image-forming apparatus  100  in this exemplary embodiment. The image-forming apparatus  100  has an image input unit  1  for optically reading image information of a document  11  placed on a platen  10  and converting the image information so read into electrical image data by a CCD sensor  12  and an image output unit  2  for forming an image on a sheet P (a recording medium) based on the image data transferred from the image input unit  1 , and furthermore, the image-forming apparatus  100  has an automatic document feeder  13  for automatically feeding a document  11  on to the platen  10 . 
         [0012]    The image output unit  2  forms a toner image on a light-sensitive material drum  20  based on the image data transferred from the image input unit  1 , and thereafter transfers the toner image on to a sheet P so as to form a recorded image on the sheet P. The sheet P on which the toner image is transferred is discharged on to a discharge tray  50  via a fixing unit  4 . 
         [0013]    In addition, the light-sensitive material drum  20  rotates at a predetermined processing speed in a direction indicated by an arrowed line, and arranged on the periphery of the light-sensitive material drum  20  are a charging corotron  21  for uniformly charging a surface of the light-sensitive material drum  20  up to a predetermined background potential, a laser beam scanner  22  for exposing the light-sensitive material drum  20  with a laser beam which is modulated based on the image data so as to form an electrostatic latent image on the light-sensitive material drum  20 , a developing unit  23  for developing the electrostatic latent image on the light-sensitive material drum  20 , a pre-transfer processing corotron  24  for removing the potential on the light-sensitive material drum  20  prior to the transfer of the toner image on to the sheet P, and a cleaner  25  for removing residual toner on the light-sensitive material drum  20  after the completion of transfer of the toner image. Note that in the figure, reference numeral  26  denotes a toner cartridge which contains toner that is to be supplied to the developing unit  23 . 
         [0014]    On the other hand, s transporting belt  3  for transporting a sheet P is wound round a driving roller and a follower roller and rotates in a direction indicated by an arrowed line, and a toner image formed on the light-sensitive material drum  20  is designed to be transferred to a sheet P which is transported thereto by the transporting belt  3 . An transporting roller  30  for forming a transfer electric field between the light-sensitive material drum  20  and itself is provided in a position which faces the light-sensitive material drum  20  across the transporting belt  3 . In addition, a belt cleaner  33  is provided in a predetermined position along the transporting belt  3  for removing paper dust and/or residual toner from the surface of the transporting belt  3 . 
         [0015]    In addition, a sheet-feeding unit  5  for feeding a sheet P to the image output unit  2  is provided below the image output unit  2 . Four sheet-feeding trays  5   a  to  5   d  are equipped in the sheet-feeding unit  5  which store sheets P in different sizes. In addition, in the sheet-feeding unit  5 , pick-up rollers  51  for transporting topmost sheets stored in the individual sheet-feeding trays  5   a  to  5   d  towards the image output unit  2  are provided in order to transport sheets P to the image output unit  2  a sheet at a time, and feed rollers  52   a  and retarder rollers  52   b  are provided downstream of the pick-up rollers  51  in the direction in which sheets P are transported as double-sheet protectors which prevent plural sheets P from being fed in a superposed fashion to the image output unit  2  by the pick-up rollers  51 . In addition, plural transporting rollers  53  are provided in the sheet-feeding unit  5  along a transporting path of sheets P extending from the individual sheet-feeding trays  5   a  to  5   d  to a toner image-transferring position. Additionally, registration rollers  54  are provided just before the image-transferring position in the sheet-feeding unit  5 . The registration rollers  54  transport sheets P transported from the sheet-feeding trays  5   a  to  5   d  to the image-transferring position at a predetermined timing which is in synchronism with a writing timing at which an electrostatic latent image is written on to the light-sensitive material drum  20 . 
         [0016]    In addition, a sheet-feeding device  55  is provided at one side end portion of the image-forming apparatus  100  for feeding sheets P from an exterior portion of the image-forming apparatus  100  into an interior of the image-forming apparatus  100 . The sheet-feeding device  55  is made up of a tray  56  on which sheets P are placed and a feeding unit  57  for feeding sheets P placed on the tray  56  into the interior of the image-forming apparatus  100  a sheet at a time. The sheet-feeding unit  57  includes a pick-up roller  58  for transporting a topmost sheet of the sheets P placed on the tray  56  towards the interior of the image-forming apparatus  100 , as well as a feed roller  59   a  and a retarder roller  59   b  as a double-sheet protector which prevents plural sheets P from being transported in a superposed fashion towards the interior of the image-forming apparatus  100  by the pick-up roller  58 , the feed roller  59   a  and the retarder roller  59   b  being provided downstream of the pick-up roller  58  in the direction in which sheets P are transported. 
         [0017]    In addition, a reverse-discharging unit  6  is disposed between the fixing unit  4  and the discharge tray  50  for reversing a sheet P discharged from the fixing unit  4  so as to be discharged on to the discharge tray  50 . A reverse-transport path  60  is formed in the reverse-discharging unit  6 . The reverse-discharging path  60  is made up of a primary reverse-discharging path  62  for drawing a sheet P discharged from the fixing unit  4  thereinto and a secondary reverse-discharging path  64  for reversing the transporting direction of the sheet P so drawn in to discharge the sheet P on to the discharge tray  50 . Transporting rollers  65  are provided on the primary reverse-discharging path  62 . Transporting rollers  66  are provided on the secondary reverse-discharging path  64 . In addition, discharging rollers  67  are provided just before the discharge tray  50 . 
         [0018]    In addition, a reverse-transport unit  7  is disposed below the image output unit  2  and above the sheet-feeding trays  5   a  to  5   d  in the sheet-feeding unit  5  for reversing a sheet P on one side of which an image is formed by the image output unit  2  to transport the sheet P so reversed back to the image output unit  2  for an image to be formed on the other side thereof for double-side image formation. A reverse-transport path  70  is formed in the reverse-transport unit  7 . The reverse-transport path  70  is made up of a primary reverse-transport path  72  for drawing a sheet P discharged from the fixing unit  4  thereinto and a secondary reverse-transport path  74  for reversing the transporting direction of the sheet P so drawn in to transport the sheet P to the image output unit  2 . Transporting rollers  75  are provided on the primary reverse-transport path  72 . In addition, transporting rollers  76  are provided on the secondary reverse-transport path  74 . 
         [0019]    In addition, transporting rollers  68  are provided upstream of the registration rollers  54  in the sheet-feeding unit  5  for transporting sheets P transported from the sheet-feeding trays  5   a  to  5   d , the sheet-feeding device  55  and the reverse-transport unit  7  to the registration roller  54 . 
         [0020]    Note that the image output unit  2 , the transporting belt  3 , the fixing unit  4 , part of the sheet-feeding unit  5 , the reverse-discharging unit  6  and the reverse-transport unit  7  are supported on a supporting member  8  which is a positioning-and-holding unit. In addition, the transporting belt  3 ; the fixing unit  4 , the part of the sheet-feeding unit  5 , the reverse-discharging unit  6  and the reverse-transport unit  7  (a drawer unit U) are supported on a sliding rails  81 ,  82  which are provided slidably relative to the supporting member  8  in such a manner as to be drawn out to the front of the apparatus. 
         [0021]    In the image-forming apparatus  100  of the exemplary embodiment which is configured as has been described heretofore, the laser beam scanner  22  exposes the light-sensitive material drum  20  based on image information on a document which is captured by the image input unit  1 , and an electrostatic latent image matching the image information is written on to the light-sensitive material drum  20 . This electrostatic latent image is developed by the developing unit  23  at a timing which is slightly later than the writing timing. Then, a toner image, which is formed in this way, is transferred on a sheet P which is transported from the registration rollers  54  by the transporting roller  30  at a predetermined timing, and the sheet P on which the unfixed toner image is transferred is discharged on to the discharge tray  50  via the fixing unit  4 . 
         [0022]    Note that the sheet P, whose unfixed image has been fixed by the fixing unit  4 , is transported to the reverse-discharging unit  6  so as to be reversed thereby for discharge on to the discharge tray  50 . 
         [0023]    In addition, the sheet P, whose unfixed toner image formed on one side thereof has been fixed by the fixing unit  4 , is transported to the reverse-transport unit  7  so as to be reversed to be transported back to the image output unit  2  for an image to be formed on the other side thereof for double-side image formation and is then discharged on to the discharge tray  50 . 
         [0024]      FIG. 2  is a perspective view showing the supporting member  8  of the image-forming apparatus  100  of the exemplary embodiment. In addition,  FIG. 4  is a perspective view which shows a state in which a bottom plate  84  is removed from the supporting member  8  of the image-forming apparatus  100  of the exemplary embodiment. The supporting member  8 , which is the positioning-and-holding unit, is formed into a box-like shape which is opened at the front thereof, and positions and holds the image output unit  2 , the transporting belt  3 , the fixing unit  4 , the part of the sheet-feeding unit  5 , the reverse-discharging unit  6  and the reverse-transport unit  7 . The bottom plate  84 , which is a plate-shaped member, is provided at a bottom portion of the supporting member  8 . The bottom plate  84  of the supporting member  8  constitutes the primary reverse-transport path  72  of the reverse-transport unit  7 . The bottom plate  84  is provided detachably relative to the supporting member  8 . To be specific, the bottom plate  84  is screwed to the supporting member  8  at plural mounting locations  86  in order to enhance the rigidity of the supporting member  8 . Note that the other constituent members which make up the supporting member  8  are welded together. 
         [0025]      FIG. 3  shows diagrams depicting the bottom plate  84  of the supporting member  8  of the image-forming apparatus  100  of the exemplary embodiment.  FIG. 3(   a ) is a plan view of the bottom plate  84 .  FIG. 3(   b ) is a side view of the bottom plate  84 .  FIG. 3(   c ) is a front view of the bottom plate  84 . 
         [0026]    The bottom plate  84  is formed substantially into a rectangular shape. Plural (in this exemplary embodiment, six) protruding portions  87  are formed on the bottom plate  84 . The height of the protruding portion  87  is, for example, 2 mm or more and 6 mm or less. The protruding portions  87  are formed in a central portion of the bottom plate  84  which excludes edge portions thereof. The protruding portions  87  are formed in such a manner as to extend in a direction which intersects the direction in which sheets P are transported substantially at right angles. The length L of the protruding portion  87  in a direction in which the protruding portion  87  extends is made longer than the width of a sheet P whose size is the largest in sheets used in the image-forming apparatus  100 , the width of the sheet P being defined as extending in a direction which intersects the direction in which sheets are transported substantially at right angles. In addition, the protruding portion  87  is formed in such a manner as to be inclined at a predetermined angle θ from a base portion to an apex portion thereof in a direction in which sheets P enter the primary reverse-transport path  72 . The predetermined angle θ is, for example, 10° or more and 20° or less. The protruding portions  87  are formed at predetermined intervals W according to lengths of plural types of sheets P in the direction in which sheets P are transported. The plural type of sheets include, for example, sheets of a size of regular postcards, B5-size sheets, A4-size sheets, B4-size sheets and A3-size sheets. The predetermined interval W is an interval which enables a sheet P to stride across one or more intervals between the protruding portions  87  when the sheet P is drawn into the primary reverse-transport path  72 . Circular recessed portions  88  are formed along a front end portion of the bottom plate  84  as viewed from the top. The recessed portions  88  are provided at a central portion and a right-hand side end portion along the front end portion of the bottom plate  84 . A hole  90  is formed in a central portion of the recessed portion  88  in such a manner as to allow the pathway of a screw therethrough. Similarly, a hole  90 , which allows the pathway of a screw therethrough, is formed in a left-hand side end of the front end portion of the bottom plate. Note that threaded holes, into which screws are screwed, are formed in the mounting portions  86  of the supporting member  8  which coincide in position with the holes  90  in the bottom plate  84 . A bent portion  92 , which is L-shaped as viewed from the side, is formed at a rear end portion of the bottom plate  84 . Threaded holes  94 , into which screws are screwed, are formed in a central portion, a right-hand side end portion and a left-hand side end portion of the bent portion  92 . Note that holes, into which screws are screwed, are formed in mounting portions  86  of the supporting member  8  which coincide in position with the threaded holes  94  in the bottom plate  84 . 
         [0027]    Note that the invention is not limited to the exemplary embodiment that has been described heretofore but can be modified variously without departing from the spirit and scope of the invention. For example, while the exemplary embodiment is described as the bottom plate of the supporting member being used as a bottom surface of the reverse-transport path of the reverse-transport unit, a side plate and a top plate of the supporting member can be used as a side surface and a top surface of the reverse-transport path, respectively, or the bottom plate of the supporting member may be used as not part of the reverse-transport unit but as part of a non-reverse-transport unit. In addition, the supporting member does not denote only a member which is related to the whole of the apparatus but includes so-called subframe, unit frame and the like which support some of the constituent components of the apparatus. 
         [0028]    While in the exemplary embodiment, as a transport apparatus to which the invention can be applied, the so-called digital copier is raised which installs thereon the image-forming apparatus based on the xerography method, the invention can be applied to image-forming apparatuses which utilize methods other than the xerography such as the ink-jet method, and the invention can also be applied to a printer without an image-forming apparatus. In addition, the invention can also be applied to a sheet-feeding apparatus and a post-processing apparatus which are provided as options to an image-forming apparatus. Moreover, the invention can also widely be applied to not only an image-forming apparatus but also a document feeder for an image reader or a card reader.