Patent Publication Number: US-2020299095-A1

Title: Sheet transport device, image reading device, and image forming apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2019-054061 filed Mar. 22, 2019. 
     BACKGROUND 
     (i) Technical Field 
     The present disclosure relates to sheet transport devices, image reading devices, and image forming apparatuses. 
     (ii) Related Art 
     Japanese Unexamined Patent Application Publication No. 2002-62693 discloses a known automatic document feeding device provided with a feed tray on which a document to be fed to a read position is placed and an output tray that accommodates the document output after a reading process. The output tray is disposed below the feed tray. The automatic document feeding device performs an image reading process while the document is transported between the feed tray and the output tray. The automatic document feeding device has a mechanism for moving the document accommodated in the output tray toward the rear end of the output tray. 
     Japanese Unexamined Patent Application Publication No. 2017-165498 also discloses a known automatic document feeding device that feeds and transports documents one-by-one for reading images from the documents. The automatic document feeding device includes a first transport path for transporting a document from which an image is read to a first output position, a second transport path for transporting a document from which an image is read to a second output position provided above the first output position, a switching unit for transporting a document to either one of the first transport path and the second transport path in accordance with the size of the document, and an accommodation section for accommodating the documents output from the first output position and the second output position. The first transport path is used for transporting documents of smaller sizes than those in the second transport path. 
     SUMMARY 
     Aspects of non-limiting embodiments of the present disclosure relate to a sheet transport device, an image reading device, and an image forming apparatus that may facilitate retrieval of output small-size sheets, as compared with a configuration not having a retrieval space that allows for retrieval of sheets accommodated in a sheet accommodation section from upstream in the transport direction. 
     Aspects of certain non-limiting embodiments of the present disclosure address the above advantages and/or other advantages not described above. However, aspects of the non-limiting embodiments are not required to address the advantages described above, and aspects of the non-limiting embodiments of the present disclosure may not address advantages described above. 
     According to an aspect of the present disclosure, there is provided a sheet transport device including a transport unit, a load section, and a sheet accommodation section. The transport unit has a transport path along which a sheet read at a read position is transported to an output unit. The sheet output by the output unit is loaded onto the load section. The sheet accommodation section is disposed downstream in an output direction of the sheet from an inner wall surface extending upward adjacent to the load section and has a recess capable of accommodating a sheet of a predetermined minimum size. A retrieval space through which the sheet accommodated in the sheet accommodation section is retrievable is provided by exposing the transport path in a direction opposite to a loading direction of the sheet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present disclosure will be described in detail based on the following figures, wherein: 
         FIG. 1  is a cross-sectional view schematically illustrating the internal configuration of an image forming apparatus; 
         FIG. 2  is a cross-sectional view illustrating the internal configuration of an image reading device; 
         FIG. 3  is a perspective view illustrating a sheet load section and an automatic sheet feeder of the image reading device in a state where they are opened upward; 
         FIG. 4  is a perspective view illustrating an output tray of the image reading device; 
         FIG. 5  is a cross-sectional view schematically illustrating how sheets are transported in the image reading device; 
         FIG. 6  is a perspective view illustrating a state where a sheet transport path of the automatic sheet feeder is exposed by raising the sheet load section and the automatic sheet feeder upward; 
         FIG. 7  is a cross-sectional view schematically illustrating the image reading device in a state where the sheet transport path is exposed; 
         FIG. 8  is a cross-sectional view schematically illustrating how a sheet accommodation section according to a first modification is accessed in an image reading device having the sheet accommodation section; 
         FIG. 9  is a cross-sectional view schematically illustrating how a sheet accommodation section according to a second modification is accessed in an image reading device having the sheet accommodation section; and 
         FIG. 10  illustrates how small-size sheets are transported and output to an output tray in an image reading device according to a comparative example not equipped with a sheet accommodation section. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will be described in further detail below with reference to exemplary embodiments and specific examples. However, the present disclosure is not to be limited to these exemplary embodiments and specific examples. 
     Furthermore, in the following description with reference to the drawings, it should be noted that the drawings are schematic and that the dimensional ratios are different from the actual dimensional ratios. For providing an easier understanding, components other than those necessary for the description are omitted, where necessary. 
     1. Overall Configuration and Operation of Image Forming Apparatus 
       FIG. 1  is a cross-sectional view schematically illustrating the internal configuration of an image forming apparatus  1  according to an exemplary embodiment.  FIG. 2  is a cross-sectional view illustrating the internal configuration of an image reading device  2 .  FIG. 3  is a perspective view illustrating a sheet load section  21  and an automatic sheet feeder  22  of the image reading device  2  in a state where they are opened upward. The overall configuration and the operation of the image forming apparatus  1  will be described below with reference to the drawings. 
     1.1. Overall Configuration 
     The image forming apparatus  1  includes the image reading device  2  that reads an image from a sheet S, such as a document, and converts it into image data, an image forming unit  3  as an image recorder that prints the read image data onto paper as a recording medium, an operational information unit  4  as a user interface, and an image processor  5 . 
     The image reading device  2  includes the sheet load section  21 , the automatic sheet feeder  22 , and an image reader  23  as an example of an imaging unit. The automatic sheet feeder  22  transports the sheet S placed on the sheet load section  21  to a read position of the image reader  23 . An image read by an image sensor (not shown), such as a charge-coupled device (CCD) line sensor, of the image reader  23  is converted into image data as an electric signal. 
     The image forming unit  3  includes a paper feeding device  32 , exposure devices  33 , photoconductor units  34 , developing devices  35 , a transfer device  36 , and a fixing device  37 , and forms image information received from the image processor  5  as a toner image onto paper P fed from the paper feeding device  32 . 
     The operational information unit  4  as a user interface is disposed on the front surface of the image reading device  2 . The operational information unit  4  is constituted of a combination of, for example, a liquid crystal display panel, various control buttons, and a touchscreen. A user of the image forming apparatus  1  may input various settings and a command via the operational information unit  4 . Moreover, various types of information are displayed to the user of the image forming apparatus  1  via the liquid crystal display panel. 
     The image processor  5  generates image data from the image read by the image reading device  2  and from print information transmitted from an external apparatus (such as a personal computer). 
     1.2. Image Forming Unit 
     Paper P designated in a print job for each printing process is fed from the paper feeding device  32  to the image forming unit  3  in accordance with an image formation timing of the image forming unit  3 . 
     The photoconductor units  34  individually include photoconductor drums  341  that are provided parallel to one another above the paper feeding device  32  and that are rotationally driven. The developing devices  35  form yellow (Y), magenta (M), cyan (C), and black (K) toner images on the corresponding photoconductor drums  341  having electrostatic latent images formed thereon by the exposure devices  33 . 
     The toner images formed on the photoconductor drums  341  of the respective photoconductor units  34  are sequentially electrostatically transferred (first-transferred) onto an intermediate transfer belt  361  of the transfer device  36 , so that a superposed toner image constituted of toners of the respective colors is formed. The superposed toner image on the intermediate transfer belt  361  is collectively transferred by a second-transfer roller  362  onto the paper P transported from a pair of registration rollers  321  and guided by a transport guide. 
     In the fixing device  37 , a fixation nip FN (fixation region) is formed by a pressure contact area of a pair of heating module  371  and pressing module  372 . 
     The paper P having the toner image collectively transferred thereon by the transfer device  36  is transported to the fixation nip FN of the fixing device  37  via a transport guide  363  in a state where the toner image is not fixed on the paper P yet. Then, the pair of heating module  371  and pressing module  372  fixes the toner image onto the paper P in accordance with heating and pressing functions. 
     The paper P having the fixed toner image formed thereon is guided to a switch gate  374  and is output from a first pair of output rollers  373  so as to be accommodated in a paper output tray TR 1  at the upper surface of the image forming apparatus  1 . If the paper P is to be inverted for duplex printing or is to be output with the image recorded face thereof facing upward, the transport direction of the paper P is switched toward a transport path  375  by the switch gate  374 . 
     1.3. Image Reading Device 
     The image reading device  2  includes the sheet load section  21 , the automatic sheet feeder  22 , and the image reader  23 . As shown in  FIG. 3 , the sheet load section  21  and the automatic sheet feeder  22  are connected to the image reader  23  such that they are openable and closable thereabove by a hinge mechanism  24 . 
     The sheet load section  21  includes a sheet tray  212  on which one or more sheets S having images recorded thereon are placed. 
     The automatic sheet feeder  22  includes a nudger roller  221  that fetches the sheets S loaded on the sheet tray  212  sequentially from the top, and also includes a separator  220  constituted of a feed roller  222  and a retardation roller  223 . 
     In the separator  220 , the feed roller  222  and the retardation roller  223  form a pair that separates sheets S from each other, if multiple stacked sheets S are fed to a nip N, so as to transport the sheets S one-by-one to the image reader  23 . 
     In a sheet transport path G 1 , a takeaway roller  250  is disposed at a position downstream of the feed roller  222  in the transport direction of the sheet S. The takeaway roller  250  transports the sheet S fed by the feed roller  222  to a pre-registration roller  260 . 
     A registration roller  270  that adjusts the transport timing of the sheet S is disposed downstream of the pre-registration roller  260 . The pre-registration roller  260  corrects a skew of the sheet S by forming a loop in a state where the leading edge of the sheet S is in abutment with the registration roller  270  in a stopped state. The registration roller  270  is rotationally driven in accordance with a timing for starting a reading process. In a state where the loop of the sheet S is maintained by the takeaway roller  250  and the pre-registration roller  260 , the sheet S is pressed against a sheet passing surface PG 1  by a platen roller  280  so that the front face of the sheet S is read by the image reader  23 . 
     A sheet placement surface PG 2  that supports a sheet S placed thereon by an operator is disposed to the right of the sheet passing surface PG 1 . A sheet guide PG 3  is disposed between the sheet passing surface PG 1  and the sheet placement surface PG 2 . The sheet S passing over the sheet passing surface PG 1  is guided to the sheet guide PG 3  so as to be transported to a read sensor  232 . The sheet S whose front face is read by the image reader  23  is transported along a sheet transport path G 2  while the rear face of the sheet S is read by the read sensor  232 , and is output by an output roller  290  to an output tray  216  provided below the sheet load section  21 . 
     An image reading sensor  231  that optically reads an image of a sheet S and converts it into an electric signal is provided below the sheet placement surface PG 2 . Specifically, the image reading sensor  231  reads an image from a sheet S passing over the sheet passing surface PG 1  or from a sheet S set on the sheet placement surface PG 2 . The read image is converted into image data as an electric signal. 
     2. Configuration and Operation of Output Tray 
       FIG. 4  is a perspective view illustrating an output tray  216  of the image reading device  2 .  FIG. 5  is a cross-sectional view schematically illustrating how sheets S are transported in the image reading device  2 .  FIG. 6  is a perspective view illustrating a state where the sheet transport path G 2  of the automatic sheet feeder  22  is exposed by raising the sheet load section  21  and the automatic sheet feeder  22  upward.  FIG. 7  is a cross-sectional view schematically illustrating the image reading device  2  in a state where the sheet transport path G 2  is exposed.  FIG. 10  illustrates how small-size sheets are transported and output to an output tray TR 2  in an image reading device  200  according to a comparative example not equipped with the sheet accommodation section  218 . 
     The configuration and operation of an output unit will be described below with reference to the drawings. 
       FIG. 10  illustrates how small-size sheets are transported and output to the output tray TR 2  in the image reading device  200  according to the comparative example not equipped with the sheet accommodation section  218 . 
     As an example of sheets of a minimum size Smn, business cards NC are placed on the sheet tray  212 . Side guides  215  are positioned at the opposite lateral edges of the business cards NC, and a reading process is commenced. The business cards NC on the sheet tray  212  are fed by the nudger roller  221  in a state where they are positioned in the width direction by the side guides  215 , and are transported one-by-one to the image reader  23 . 
     Each business card NC whose image is read by the image reader  23  is output by the output roller  290  to the output tray TR 2  provided below the sheet load section  21 . Unlike a normal sheet, a business card NC has a small size but has a large basis weight. As schematically shown in  FIG. 10 , the business cards NC tend to be output and stacked disorderly on the output tray TR 2 , possibly altering the proper order of the business cards NC. There is also a problem in that the stacked position of the output sheets is at the upstream side, in the sheet output direction, of the output tray TR 2  covered by the sheet tray  212 , thus making it difficult to access the stacked business cards NC (see an arrow A in  FIG. 10 ). 
     The output tray  216  according to this exemplary embodiment is provided below the sheet tray  212  and receives sheets S output from the output roller  290  after the reading process. The output tray  216  is provided adjacent to an inner wall surface  217  at the downstream side in the sheet output direction with respect to the inner wall surface  217  provided below the output roller  290 . 
     A sheet load surface  216   a  of the output tray  216  is provided with a sheet guide  216   b  that gently slopes downstream in the sheet output direction, so as to hold a sheet S output from the output roller  290  in a state where the sheet S is readily retrievable by a user. 
     The sheet load surface  216   a  of the output tray  216  is provided with a sheet accommodation section  218 . The sheet accommodation section  218  is formed as a recess  218   a  extending downstream in the sheet output direction from the inner wall surface  217 , such that the recess  218   a  is capable of accommodating sheets S of the predetermined minimum size Smn. Examples of sheets of the minimum size Smn in this exemplary embodiment include business cards NC and receipts RP. 
     The sheet load surface  216   a  of the output tray  216  is provided with ribs  216   c  at the opposite sides of the sheet accommodation section  218  in a direction intersecting the sheet output direction. The ribs  216   c  gently slope downstream in the sheet output direction along the recess  218   a  of the sheet accommodation section  218 , so as to guide a sheet S of a size other than the minimum size Smn without causing the sheet S to fall into the recess  218   a  of the sheet accommodation section  218 , and also to reduce the output resistance on the sheet load surface  216   a.    
       FIG. 5  illustrates how small-size sheets and normal-size sheets are transported and output to the output tray  216  in the image reading device  2  having the sheet accommodation section  218  in the output tray  216 . 
     When the business cards NC having the minimum width are placed on the sheet tray  212  of the sheet load section  21  and a reading process is commenced, the business cards NC on the sheet tray  212  are fed by the nudger roller  221  in a state where the business cards NC are positioned in the width direction by the side guides  215 , and are transported one-by-one to the image reader  23 . 
     Each business card NC whose image is read by the image reader  23  is output by the output roller  290  so as to be accommodated in the sheet accommodation section  218  provided in the sheet load surface  216   a  of the output tray  216 . The sheet accommodation section  218  has the recess  218   a  and is provided with a gentle slope surface  218   c  at the downstream side thereof in the output direction. The business cards NC as small-size sheets are stacked in the recess  218   a  in a state where the proper order thereof is not altered and disorderly orientation of output sheets is suppressed. 
     As shown in  FIG. 5 , a sheet S having a size other than the minimum size Smn is guided by the sheet guide  216   b  from the ribs  216   c  provided at the opposite sides of the sheet accommodation section  218  in the direction intersecting the sheet output direction, so as to be stacked on the sheet load surface  216   a  of the output tray  216 . 
     The sheet accommodation section  218  provided in the output tray  216  having such a configuration is integrated with a lower guide chute SH, serving as the lower surface of the sheet transport path G 2  at the upstream side of the output roller  290  in the sheet transport direction, via the inner wall surface  217 . With regard to the lower guide chute SH, as shown in  FIG. 6 , the lower guide chute SH is exposable in an accessible manner from the outside by exposing the sheet transport path G 2  by opening the sheet load section  21  and the automatic sheet feeder  22  upward and rotating a control lever LV downward in a direction opposite to the stacking direction of the sheets S. 
     As shown in  FIG. 7 , the sheet accommodation section  218  has a rotation shaft  218   b  for exposing the sheet transport path G 2  at the downstream side of the sheet accommodation section  218  in the output direction. 
     In detail, the rotation shaft  218   b  is provided at a position where the distance between the lower guide chute SH and the sheet accommodation section  218  is increasable to allow for retrieval of sheets S when a retrieval space RM for retrieving small-size sheets accommodated in the recess  218   a  by accessing the sheet accommodation section  218  from upstream in the transport direction of the sheets S is to be formed. 
     The lower guide chute SH serving as a surface of the sheet transport path G 2  and the sheet accommodation section  218  provided in the output tray  216  are integrated with each other with the inner wall surface  217  interposed therebetween in this manner (indicated as a hatched area in  FIG. 7 ), so that, by rotating the lower guide chute SH about the rotation shaft  218   b , the retrieval space RM for accessing the sheet accommodation section  218  from upstream in the sheet transport direction may be formed. 
     Accordingly, in a case where business cards NC as small-size sheets are stacked in the sheet accommodation section  218 , the control lever LV is operated to rotate the lower guide chute SH about the rotation shaft  218   b  in a state where the sheet load section  21  and the automatic sheet feeder  22  are opened upward, so that the sheet accommodation section  218  may be accessed from upstream in the sheet transport direction, whereby the business cards NC stacked in the sheet accommodation section  218  may be retrieved. 
     First Modification 
       FIG. 8  is a cross-sectional view schematically illustrating how a sheet accommodation section  218 A according to a first modification is accessed in an image reading device  2  having the sheet accommodation section  218 A. 
     The sheet accommodation section  218 A according to the first modification is entirely box-shaped and is disposed in a detachable manner from the sheet load surface  216   a  of the output tray  216 . 
     In a case where business cards NC as small-size sheets are stacked in the sheet accommodation section  218 A, the lower guide chute SH is rotated about the rotation shaft  218   b  in a state where the sheet load section  21  and the automatic sheet feeder  22  are opened upward, so that the sheet accommodation section  218 A may be accessed from upstream in the sheet transport direction, whereby the sheet accommodation section  218 A accommodating the business cards NC may be retrieved. 
     Second Modification 
       FIG. 9  is a cross-sectional view schematically illustrating how a sheet accommodation section  218 B according to a second modification is accessed in an image reading device  2  having the sheet accommodation section  218 B. 
     The sheet accommodation section  218 B according to the second modification is entirely box-shaped and is disposed in a liftable manner about a rotation shaft  218 Ba relative to the sheet load surface  216   a  of the output tray  216 . In particular, the sheet accommodation section  218 B may have a latch mechanism that maintains the orientation of the sheet accommodation section  218 B in a lifted state. 
     In a case where business cards NC as small-size sheets are stacked in the sheet accommodation section  218 B, the lower guide chute SH is rotated about the rotation shaft  218 Ba in a state where the sheet load section  21  and the automatic sheet feeder  22  are opened upward, so that the sheet accommodation section  218 B may be accessed from upstream in the sheet transport direction, whereby the business cards NC stacked in the sheet accommodation section  218 B may be retrieved more readily while the sheet accommodation section  218 B is lifted. 
     In this exemplary embodiment, the sheet transport path G 2  is exposed in the direction opposite to the stacking direction of the sheets S, so that the sheet accommodation section  218  provided on the output tray  216  covered by the sheet tray  212  is accessible without having to flip the sheet tray  212  upward, thereby facilitating the retrieval of the stacked small-size sheets. 
     The foregoing description of the exemplary embodiments of the present disclosure has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments chosen and described in order to best explain the principles of the disclosure and its practical applications, thereby enabling others skilled in the art to understand the disclosure for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the following claims and their equivalents.