Patent Publication Number: US-8991809-B2

Title: Post-processing apparatus and image forming apparatus

Description:
INCORPORATION BY REFERENCE 
     This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2012-282156 filed on Dec. 26, 2012, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     The present disclosure relates to a post-processing apparatus and an image forming apparatus. 
     Conventionally, a post-processing apparatus is known which executes various types of post-processing such as stapling processing for a printed paper sheet outputted from an image forming apparatus. 
     Such a post-processing apparatus capable of executing stapling processing at least includes, for example, a staple unit, and a processing tray for stacking paper sheets to be processed by stapling processing. Upon execution of the stapling processing, the post-processing apparatus receives printed paper sheets outputted from the image forming apparatus one by one, to convey them to the processing tray, so that the printed paper sheets are stacked on the processing tray. Thereafter, the staple unit performs stapling processing for a plurality of paper sheets (sheet bundle) stacked on the processing tray. 
     In addition, conventionally, also known is a post-processing apparatus having an automatic mode for executing stapling processing for paper sheets fed from the image forming apparatus, and a manual mode for executing stapling processing for paper sheets manually fed onto the processing tray by a user. 
     SUMMARY 
     A post-processing apparatus according to one aspect of the present disclosure includes a processing tray, a conveyance portion, a staple unit, an operation portion, a mode switching portion, a cover, and an open/close detection portion. On the processing tray, a paper sheet to be processed by stapling processing can be stacked. The conveyance portion conveys a paper sheet to the processing tray. The staple unit has an automatic mode and a manual mode as processing modes for the stapling processing. In the automatic mode, the staple unit executes the stapling processing for a paper sheet conveyed to the processing tray by the conveyance portion. In the manual mode, the staple unit executes the stapling processing for a paper sheet stacked on the processing tray by a user. The operation portion receives an operation for switching between the automatic mode and the manual mode. The mode switching portion performs switching between the automatic mode and the manual mode in response to an operation on the operation portion. The cover is attached in an openable and closable manner so as to cover the operation portion when the cover is closed and expose the operation portion when the cover is opened. The open/close detection portion detects whether the cover is opened or closed. While the open/close detection portion is detecting that the cover is opened, when the operation portion has received an operation for switching to the manual mode, the mode switching portion switches the automatic mode to the manual mode. 
     An image forming apparatus according to another aspect of the present disclosure includes a post-processing apparatus and a printing portion. The printing portion executes a print job and feeds a printed paper sheet to the post-processing apparatus. The post-processing apparatus includes a processing tray, a conveyance portion, a staple unit, an operation portion, a mode switching portion, a cover, and an open/close detection portion. On the processing tray, a paper sheet to be processed by stapling processing can be stacked. The conveyance portion conveys a paper sheet to the processing tray. The staple unit has an automatic mode and a manual mode as processing modes for the stapling processing. In the automatic mode, the staple unit executes the stapling processing for a paper sheet conveyed to the processing tray by the conveyance portion. In the manual mode, the staple unit executes the stapling processing for a paper sheet stacked on the processing tray by a user. The operation portion receives an operation for switching between the automatic mode and the manual mode. The mode switching portion performs switching between the automatic mode and the manual mode in response to an operation on the operation portion. The cover is attached in an openable and closable manner so as to cover the operation portion when the cover is closed and expose the operation portion when the cover is opened. The open/close detection portion detects whether the cover is opened or closed. While the open/close detection portion is detecting that the cover is opened, when the operation portion has received an operation for switching to the manual mode, the mode switching portion switches the automatic mode to the manual mode. 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description with reference where appropriate to the accompanying drawings. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of an image forming apparatus provided with a post-processing apparatus according to one embodiment of the present disclosure; 
         FIG. 2  is a diagram of the post-processing apparatus shown in  FIG. 1 ; 
         FIG. 3  is a diagram of an operation portion provided on the post-processing apparatus shown in  FIG. 1 ; 
         FIG. 4  is a diagram showing a cover attached in an openable and closable manner on the operation portion of the post-processing apparatus shown in  FIG. 1 ; 
         FIG. 5  is a block diagram showing the hardware configuration of the image forming apparatus provided with the post-processing apparatus shown in  FIG. 1 ; 
         FIG. 6  is a flowchart for explaining an operation performed when the processing mode for stapling processing is switched to a manual mode in the post-processing apparatus shown in  FIG. 1 ; and 
         FIG. 7  is a flowchart for explaining an operation performed when the processing mode for stapling processing is switched to an automatic mode in the post-processing apparatus shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an image forming apparatus provided with a post-processing apparatus according to one embodiment of the present disclosure will be described, using an image forming apparatus (multifunction peripheral) capable of executing plural kinds of jobs, as an example. 
     (Configuration of Image Forming Apparatus Provided with Post-Processing Apparatus) 
     As shown in  FIG. 1 , an image forming apparatus  100  of the present embodiment includes an operation panel  101 , a document sheet conveying portion  102 A, an image reading portion  102 B, a sheet feed portion  103 , a paper sheet conveyance portion  104 , an image forming portion  105 , and a fixing portion  106 . Among these portions, each of the sheet feed portion  103 , the paper sheet conveyance portion  104 , the image forming portion  105 , and the fixing portion  106  is a mechanism portion needed for executing a job (print job) accompanied with printing, and correspond to a “printing portion” of the present disclosure. Hereinafter, the mechanism portion needed for executing a print job may be referred to as a printing portion  107 . 
     The operation panel  101  includes a liquid crystal display portion  11  with a touch panel. The liquid crystal display portion  11  displays software keys and/or menus for receiving various settings. In addition, the operation panel  101  is provided with a numeric keypad for receiving numeric input, and/or a hardware key such as a start key for receiving an instruction to execute various jobs. 
     The document sheet conveying portion  102 A is attached in an openable and closable manner to the image reading portion  102 B around a rotational axis (not shown) as a fulcrum provided on the apparatus back surface side of the image reading portion  102 B. The document sheet conveying portion  102 A pulls out a document sheet D set on a document sheet set tray  21 , feeds the document sheet D to above a conveyance reading contact glass C 1 , and discharges the document sheet D to a document sheet discharge tray  22 . In addition, the document sheet conveying portion  102 A also functions to hold a document sheet D placed on a placement reading contact glass C 2 . 
     The image reading portion  102 B scans a document sheet D to generate image data of an image of the document sheet D. The image reading portion  102 B includes optical members such as an exposure lamp, a mirror, a lens, and an image sensor (they are not shown). The image reading portion  102 B radiates light onto a document sheet D passing above the conveyance reading contact glass C 1  or a document sheet D placed on the placement reading contact glass C 2 . Then, the image reading portion  102 B performs A/D conversion for an output value of the image sensor receiving a reflected light from the document sheet D, thereby generating image data of an image of the document sheet D. 
     The sheet feed portion  103  includes cassettes  31  for accommodating paper sheets P, and feeds a paper sheet P in each cassette  31  to a main body conveyance path  10 . The sheet feed portion  103  is provided with a pickup roller  32  for pulling out a paper sheet P in each cassette  31 . In addition, the sheet feed portion  103  is provided with a sheet feed roller pair  33  for preventing multi feed of paper sheets P taken out from each cassette  31  while feeding a paper sheet P to the main body conveyance path  10 . 
     The paper sheet conveyance portion  104  conveys a paper sheet P fed to the main body conveyance path  10 , along the main body conveyance path  10 , and guides the paper sheet P through the image forming portion  105  and the fixing portion  106  to a carry in port  201  of a post processing apparatus  200  described later. The paper sheet conveyance portion  104  includes a plurality of conveying roller pairs  41  rotatably provided on the main body conveyance path  10 . One pair of the plurality of conveying roller pairs  41  is a registration roller pair  42  which causes a paper sheet P to stand by before the image forming portion  105  and feeds the paper sheet P to the image forming portion  105  in accordance with a timing of formation of an electrostatic latent image in the image forming portion  105 . 
     The image forming portion  105  forms a toner image based on image data of an image to be printed, and transfers the toner image onto a paper sheet P. The image forming portion  105  includes a photosensitive drum  51 , a charging device  52 , an exposure device  53 , a developing device  54 , a transfer roller  55 , and a cleaning device  56 . 
     Upon image forming, the photosensitive drum  51  is rotationally driven while the charging device  52  charges the surface of the photosensitive drum  51  at a predetermined potential. The exposure device  53  includes a light emitting device (not shown) which outputs a light beam L for exposure, and turns on and off the light emitting device to scan and expose the surface of the photosensitive drum  51  to light. Thus, an electrostatic latent image is formed on the surface of the photosensitive drum  51 . The developing device  54  supplies toner onto the electrostatic latent image formed on the surface of the photosensitive drum  51 , thereby developing the image. 
     The transfer roller  55  can be rotated while being pressed against the surface of the photosensitive drum  51 . At an appropriate timing, the registration roller pair  42  causes a paper sheet P to enter between the transfer roller  55  and the photosensitive drum  51 . Thus, a toner image formed on the surface of the photosensitive drum  51  is transferred onto the paper sheet P. Thereafter, the cleaning device  56  removes residual toner and the like on the surface of the photosensitive drum  51 . 
     The fixing portion  106  heats and pressurizes the toner image transferred on the paper sheet P, to fix the toner image. The fixing portion  106  includes a fixing roller  61  including a heat source, and a pressure roller  62  to be pressed against the fixing roller  61 . A paper sheet P having a toner image transferred thereon passes between the fixing roller  61  and the pressure roller  62 , and thereby is heated and pressurized. Thus, the toner image is fixed on the paper sheet P, whereby printing is completed. 
     The image forming apparatus  100  is provided with the post-processing apparatus  200  which performs post-processing for a printed paper sheet P. The post-processing apparatus  200  has the carry-in port  201  to be connected to the main body conveyance path  10 , and receives a printed paper sheet P fed via the carry-in port  201 . The post-processing apparatus  200  performs, for example, punching processing, stapling processing, and folding processing for a printed paper sheet P. 
     (Configuration of Post-Processing Apparatus) 
     As shown in  FIG. 2 , the post-processing apparatus  200  conveys a paper sheet P carried in from the carry-in port  201 , along a post-processing conveyance path  20 , and performs post-processing for the paper sheet P. Therefore, the post-processing apparatus  200  is provided with a plurality of conveying roller pairs  202  for conveying a paper sheet P. It is noted that the conveying roller pairs  202  correspond to a “conveyance portion” of the present disclosure. 
     The post-processing apparatus  200  includes a punch unit U 1 , a staple unit U 2 , a booklet unit U 3 , and the like. The punch unit U 1  performs punching processing for a paper sheet P. The staple unit U 2  performs stapling processing for a paper sheet P. The booklet unit U 3  performs folding processing for a paper sheet P. 
     The punch unit U 1  is located upstream (near the carry-in port  201 ) of the post-processing conveyance path  20  in the conveyance direction of a paper sheet P. The post-processing conveyance path  20  branches into three conveyance paths  20   a ,  20   b , and  20   c  on the downstream of the punch unit U 1  in the conveyance direction of a paper sheet P. 
     The conveyance path  20   a  leads to a sheet discharge tray  203 . When stapling processing and/or folding processing are not performed, a paper sheet P having passed through the punch unit U 1  is discharged to the sheet discharge tray  203  via the conveyance path  20   a.    
     The conveyance path  20   b  leads to another sheet discharge tray  204  different from the sheet discharge tray  203 . A processing tray  205  is provided on a conveyance route defined by the conveyance path  20   b  (specifically, immediately before the sheet discharge tray  204 ). When stapling processing is performed, a paper sheet P is conveyed to the processing tray  205  via the conveyance path  20   b , so that a plurality of paper sheets P are stacked on the placement surface of the processing tray  205 . It is noted that stapling processing is performed for a bundle of a plurality of paper sheets P (hereinafter, may be simply referred to as a sheet bundle) stacked on the placement surface of the processing tray  205 . 
     The conveyance path  20   c  leads to the booklet unit U 3 . When folding processing is performed, a paper sheet P is conveyed to the booklet unit U 3  via the conveyance path  20   c.    
     A refuge portion  206  for temporarily evacuating a paper sheet P conveyed from the punch unit U 1  is provided at a portion where the post-processing conveyance path  20  branches. At the refuge portion  206 , a paper sheet P is wound on a refuge drum  206   a  which is rotationally driven, whereby the paper sheet P is evacuated (conveyance of the paper sheet P to the processing tray  205  is delayed). 
     A plurality of switching claws  207   a ,  207   b , and  207   c  for switching the conveyance path of a paper sheet P are provided at a portion where the post-processing conveyance path  20  branches (around the refuge drum  206 ). When stapling processing and/or folding processing are not performed, the switching claw  207   a  is turned in a direction to open an entrance port of the conveyance path  20   a . Thus, a paper sheet P having passed through the punch unit U 1  enters the conveyance path  20   a , to be conveyed to the sheet discharge tray  203 . 
     When stapling processing is performed, the switching claw  207   a  is turned in a direction to close the entrance port of the conveyance path  20   a . At this time, if evacuation of a paper sheet P is not needed, the switching claw  207   b  is turned in a direction to open an entrance port of the conveyance path  20   b . Thus, the paper sheet P enters the conveyance path  20   b , to be guided to the processing tray  205 . On the other hand, if evacuation of a paper sheet P is needed, the switching claw  207   b  is turned in a direction to close the entrance port of the conveyance path  20   b . Thus, the paper sheet P enters the refuge portion  206  without entering the conveyance path  20   b.    
     Here, the processing tray  205  is disposed so as to be inclined obliquely downward from its one end (sheet discharge tray  204  side) toward the other end. A discharge roller pair  208  (upper roller  208   a  and lower roller  208   b ) for discharging a paper sheet P to the sheet discharge tray  204  is provided at the one end of the processing tray  205 . One end of an arm  209  is connected with the upper roller  208   a , and a rotational axis  210  is connected with the other end of the arm  209 . Thus, when the one end of the arm  209  is turned upward around the rotational axis  210  as a fulcrum, the upper roller  208   a  is moved upward, whereby the upper roller  208   a  can be separated from the lower roller  208   b . On the other hand, when the one end of the arm  209  is turned downward around the rotational axis  210 , the upper roller  208   a  is moved downward, whereby the upper roller  208   a  can be brought close to the lower roller  208   b.    
     When a paper sheet P is to be stacked on the processing tray  205 , the upper roller  208   a  is separated from the lower roller  208   b , and the leading end of the paper sheet P is caused to enter between the upper roller  208   a  and the lower roller  208   b . Thereafter, the paper sheet P is moved obliquely downward along the placement surface of the processing tray  205  by, for example, a paddle (not shown) (or the paper sheet P is moved obliquely downward along the placement surface of the processing tray  205  by self-weight). The staple unit U 2  is located at the other end of the processing tray  205 , and performs stapling processing for a sheet bundle stacked on the processing tray  205 . 
     When the sheet bundle processed by stapling processing is to be discharged to the sheet discharge tray  204 , the upper roller  208   a  is brought close to the lower roller  208   b , whereby the sheet bundle is held between the upper roller  208   a  and the lower roller  208   b . Then, the upper roller  208   a  and the lower roller  208   b  are rotated, whereby the sheet bundle processed by stapling processing is discharged to the sheet discharge tray  204  via a discharge port  211 . 
     Guides  205   a  that can be moved in the width direction of a paper sheet P (direction perpendicular to the conveyance direction) are provided on the processing tray  205 . The guides  205   a  thus provided on the processing tray  205  enable a sheet bundle stacked on the processing tray  205  to be shifted in the width direction of a paper sheet P. That is, a sheet bundle to be discharged to the sheet discharge tray  204  is shifted in the width direction of a paper sheet P, whereby sheet bundles can be sorted. 
     When folding processing is performed, the switching claw  207   a  is turned in a direction to close the entrance port of the conveyance path  20   a  and the switching claw  207   b  is turned in a direction to close the entrance port of the conveyance path  20   b  while the switching claw  207   c  is turned in a direction to open an entrance port of the conveyance path  20   c . Thus, a paper sheet P enters the conveyance path  20   c , to be guided to the booklet unit U 3 . 
     (Automatic Mode and Manual Mode in Stapling Processing) 
     The post-processing apparatus  200  can be switched between an automatic mode and a manual mode in stapling processing. For example, at start of the image forming apparatus  100  (post-processing apparatus  200 ), the processing mode for the stapling processing is set at the automatic mode. In the state of the automatic mode, when a mode switching operation is performed, the automatic mode is switched to the manual mode. 
     In the automatic mode, the image forming apparatus  100  (printing portion  107 ) executes a print job and feeds a printed paper sheet P to the post-processing apparatus  200 . Then, the staple unit U 2  executes stapling processing for the paper sheets P (a sheet bundle composed of a plurality of stacked paper sheets P) conveyed to the processing tray  205  by the conveying roller pairs  202 . 
     On the other hand, in the manual mode, the staple unit U 2  executes stapling processing for paper sheets P stacked on the processing tray  205  by a user in response to an execution instruction from the user. A user can perform a switching instruction from the automatic mode to the manual mode or an execution instruction of stapling processing, by performing an operation on a mode switching operation portion  220  (see  FIG. 3 ) provided on the post-processing apparatus  200 . It is noted that the configuration of the mode switching operation portion  220  will be described later in detail. 
     When the processing mode for the stapling processing is switched from the automatic mode to the manual mode, the upper roller  208   a  is moved in a direction (upward) to be separated from the lower roller  208   b , whereby a gap occurs between the upper roller  208   a  and the lower roller  208   b . This enables a sheet bundle to be inserted from the discharge port  211  so that the sheet bundle is stacked on the processing tray  205 . 
     (Configuration of Mode Switching Operation Portion) 
     On the apparatus front surface side of the post-processing apparatus  200 , the mode switching operation portion  220  is provided (see  FIG. 1 ) for receiving from a user an operation to switch the processing mode for stapling processing including the automatic mode and the manual mode. It is noted that the mode switching operation portion  220  corresponds to an “operation portion” of the present disclosure. 
     In light of operability for a user, such a mode switching operation portion  220  may be exposed out of the housing of the post-processing apparatus  200 . However, in the case where the mode switching operation portion  220  is exposed out of the housing of the post-processing apparatus  200 , a user may touch the mode switching operation portion  220  unintentionally, so that the processing mode for stapling processing may be switched from the automatic mode to the manual mode. When the processing mode for stapling processing has been thus switched to the manual mode by a user touching the mode switching operation portion  220  unintentionally, the user who has touched the mode switching operation portion  220  may not recognize that the processing mode for stapling processing has been switched to the manual mode. Therefore, the processing mode for stapling processing is not switched to the automatic mode and is left to be the manual mode (a job in the automatic mode is left in the unexecuted state). In this case, a user who desires to execute a job in the automatic mode needs to perform a switching operation to the automatic mode. As a result, convenience for a user is reduced. In contrast, as described below, the post-processing apparatus  200  according to the embodiment of the present disclosure prevents unintentional switching of the processing mode for stapling processing, thereby improving convenience for a user. 
     As shown in  FIG. 3 , the mode switching operation portion  220  includes a switching key CK for receiving switching between the automatic mode and the manual mode, and an execution key PK for receiving an execution instruction of stapling processing in the manual mode. In addition, the mode switching operation portion  220  is provided with a plurality of indication lamps  221  ( 221   a ,  221   b , and  221   c ) which indicate the present setting related to the staple position in the manual mode. 
     The indication lamp  221  is turned on when the automatic mode is switched to the manual mode and turned off when the manual mode is switched to the automatic mode. Specifically, in the automatic mode, all the indication lamps  221   a  to  221   c  are turned off. Thus, a user recognizes that the present processing mode is the automatic mode. When the switching key CK is pressed in the automatic mode, the automatic mode is switched to the manual mode, and one of the plurality of indication lamps  221  is turned on. Thus, a user recognizes that the automatic mode has been switched to the manual mode. 
     For example, when the switching key CK is pressed in the automatic mode, the automatic mode is switched to the manual mode and the indication lamp  221   a  is turned on first. Then, when the switching key CK is repeatedly pressed, the indication lamp  221  to be turned on is changed in order, the indication lamp  221   a →the indication lamp  221   b →the indication lamp  221   c . That is, the setting of the staple position in the manual mode is sequentially changed. Then, if the switching key CK is pressed when the indication lamp  221   c  is on, the manual mode is switched to the automatic mode and all the indication lamps  221   a  to  221   c  are turned off. 
     As shown in  FIG. 4 , a cover  222  is attached in an openable and closable manner at a portion where the mode switching operation portion  220  is provided. The cover  222 , when closed, covers the mode switching operation portion  220 . On the other hand, the cover  222 , when opened, exposes the mode switching operation portion  220 , so that the mode switching operation portion  220  can be operated. 
     (Hardware Configuration of Image Forming Apparatus Provided with Post-Processing Apparatus) 
     As shown in  FIG. 5 , the image forming apparatus  100  includes a main control portion  110  which performs overall control of the apparatus. The main control portion  110  includes a main CPU  111 , an image processing portion  112 , and a storage portion  113 . The image processing portion  112  is composed of an ASIC dedicated for image processing, etc., and performs various types of image processing (expansion/reduction, density conversion, data form conversion, etc.) for image data. The storage portion  113  includes a ROM, a RAM, and the like. For example, a program and data needed for execution of a job is stored in the ROM, and such a program and data are developed on the RAM. 
     A panel control portion  120  and a scan control portion  130  are connected to the main control portion  110 . The panel control portion  120  includes a CPU and a memory (not shown), and controls the display operation of the operation panel  101  by receiving an instruction from the main control portion  110 . The scan control portion  130  includes a CPU and a memory (not shown), and controls the document sheet conveying operation of the document sheet conveying portion  102 A and/or the scan operation of the image reading portion  102 B by receiving an instruction from the main control portion  110 . 
     An engine control portion  140  is connected to the main control portion  110 . The engine control portion  140  includes an engine CPU  141  and a memory  142 , and controls a printing operation of the printing portion  107  (the sheet feed portion  103 , the paper sheet conveyance portion  104 , the image forming portion  105 , and the fixing portion  106 ) by receiving an instruction from the main control portion  110 . 
     A post-processing control portion  150  is connected to the engine control portion  140 . The post-processing control portion  150  includes a CPU  151  and a memory  152 . The post-processing control portion  150  controls the post-processing operation executed by the post-processing apparatus  200  by receiving an instruction from the main control portion  110  via the engine control portion  140 . 
     The post-processing control portion  150  is connected to the mode switching operation portion  220 . The post-processing control portion  150  switches the processing mode for stapling processing including the automatic mode and the manual mode in response to an operation on the mode switching operation portion  220 . That is, the post-processing control portion  150  corresponds to a “mode switching portion” of the present disclosure. 
     The post-processing control portion  150  is connected to a cover open/close detection sensor  223  capable of detecting whether the cover  222  (cover for covering the mode switching operation portion  220 ) is opened or closed. The cover open/close detection sensor  223  changes its output depending on whether the cover  222  is opened or closed. Thus, based on the output of the cover open/close detection sensor  223 , whether the cover  222  is opened or closed can be detected. The output of the cover open/close detection sensor  223  is received by the post-processing control portion  150 , and the post-processing control portion  150  detects whether the cover  222  is opened or closed. That is, the post-processing control portion  150  connected to the cover open/close detection sensor  223  corresponds to an “open/close detection portion” of the present disclosure. 
     A communication portion  160  is also connected to the main control portion  110 . The communication portion  160  is connected to an external apparatus  300  via a network, and communicates with the external apparatus  300  by receiving an instruction from the main control portion  110 . Thus, printing can be performed based on image data transmitted from the external apparatus  300 . In addition, it is also possible to transmit image data to the external apparatus  300 . The external apparatus  300  is, for example, a user terminal, a server, a facsimile apparatus, etc. 
     (Switching of Processing Mode for Stapling Processing) 
     In the present embodiment, since the mode switching operation portion  220  is covered by the cover  222 , an operation on the mode switching operation portion  220  cannot be performed unless the cover  222  is opened. Therefore, when a user is to switch the processing mode for stapling processing from the automatic mode to the manual mode, the user opens the cover  222  first. 
     At this time, the post-processing control portion  150  detects that the cover  222  has been opened, based on the output of the cover open/close detection sensor  223 . Then, while the post-processing control portion  150  is detecting that the cover  222  has been opened, when the mode switching operation portion  220  has received an operation for switching to the manual mode, the post-processing control portion  150  transmits a switching request from the automatic mode to the manual mode, to the main control portion  110 . Then, the post-processing control portion  150  receives an instruction from the main control portion  110  and switches the automatic mode to the manual mode. 
     It is noted that after the main control portion  110  has instructed the post-processing control portion  150  to switch the automatic mode to the manual mode, the main control portion  110  prohibits execution of a print job (a printed paper sheet P is not fed to the post-processing apparatus  200 ) until the main control portion  110  receives a switching request from the manual mode to the automatic mode from the post-processing control portion  150 . Therefore, in the manual mode, a print job cannot be executed in the image forming apparatus  100 . 
     In addition, after the post-processing control portion  150  has switched the processing mode to the manual mode, when the post-processing control portion  150  has detected that the cover  222  has been closed, the post-processing control portion  150  transmits a switching request from the manual mode to the automatic mode to the main control portion  110  even if the mode switching operation portion  220  has not received an operation for switching to the automatic mode. Then, the post-processing control portion  150  receives an instruction from the main control portion  110  and switches the manual mode to the automatic mode. At this time, since the manual mode has been switched to the automatic mode, a print job can be executed in the image forming apparatus  100 . 
     In addition, after the post-processing control portion  150  has switched the processing mode to the manual mode, when the mode switching operation portion  220  has received an operation for switching to the automatic mode, the post-processing control portion  150  transmits a switching request from the manual mode to the automatic mode to the main control portion  110  even if the post-processing control portion  150  has not detected that the cover  222  has been closed. Then, the post-processing control portion  150  receives an instruction from the main control portion  110  and switches the manual mode to the automatic mode. 
     Hereinafter, with reference to a flowchart in  FIG. 6 , an operation performed when the processing mode for stapling processing is switched from the automatic mode to the manual mode will be described. 
     First, “START” in the flowchart in  FIG. 6  indicates the start of the image forming apparatus  100  (post-processing apparatus  200 ). It is noted that at the start, the processing mode for stapling processing is set at the automatic mode (the cover  222  is closed). 
     In step S 1 , the post-processing control portion  150  detects whether the cover  222  is opened or closed, based on the output of the cover open/close detection sensor  223 , to determine whether or not the cover  222  has been opened. As a result, if the cover  222  has been opened, the process shifts to step S 2 . On the other hand, if the cover  222  has not been opened (the cover  222  is closed), the processing mode for stapling processing is not switched and is kept in the automatic mode, and the determination of step S 1  is repeated. 
     In step S 2 , the post-processing control portion  150  determines whether or not the mode switching operation portion  220  has received a mode switching operation for switching to the manual mode. As a result, if the mode switching operation portion  220  has received the mode switching operation, the process shifts to step S 3 . On the other hand, if the mode switching operation portion  220  has not received the mode switching operation, the processing mode for stapling processing is not switched and is kept in the automatic mode, and the determination of step S 2  is repeated. 
     In step S 3 , the post-processing control portion  150  switches the processing mode for stapling processing from the automatic mode to the manual mode. 
     Next, with reference to a flowchart in  FIG. 7 , an operation performed when the processing mode for stapling processing is switched from the manual mode to the automatic mode will be described. 
     First, “START” in the flowchart in  FIG. 7  indicates a time when the processing mode for stapling processing has been switched from the automatic mode to the manual mode. That is, at the start, the processing mode for stapling processing is set at the manual mode (the cover  222  is opened). 
     In step S 11 , the post-processing control portion  150  determines whether or not the mode switching operation portion  220  has received a mode switching operation for switching to the automatic mode. As a result, if the mode switching operation portion  220  has received the mode switching operation, the process shifts to step S 12 . On the other hand, if the mode switching operation portion  220  has not received the mode switching operation, the process shifts to step S 13 . 
     In step S 12 , the post-processing control portion  150  switches the processing mode for stapling processing from the manual mode to the automatic mode. 
     In step S 13 , the post-processing control portion  150  detects whether the cover  222  is opened or closed, based on the output of the cover open/close detection sensor  223 , to determine whether or not the cover  222  has been closed. As a result, if the cover  222  has been closed, the process shifts to step S 12  to switch the processing mode for stapling processing from the manual mode to the automatic mode. On the other hand, if the cover  222  has not been closed (the cover  222  is opened), the processing mode for stapling processing is not switched and is kept in the manual mode, and the process returns to step S 11 . 
     As described above, the post-processing apparatus  200  of the present embodiment includes the processing tray  205  for stacking thereon a paper sheet P to be processed by stapling processing, the conveying roller pair  202  (conveyance portion) that conveys a paper sheet P to the processing tray  205 , the staple unit U 2  that, in the automatic mode, executes stapling processing for the paper sheet P conveyed to the processing tray  205  by the conveying roller pair  202 , and in the manual mode, executes stapling processing for a paper sheet P stacked on the processing tray  205  by a user, the mode switching operation portion  220  (operation portion) that receives an operation for switching between the automatic mode and the manual mode, the cover  222  attached in an openable and closable manner so as to cover the mode switching operation portion  220  when the cover  222  is closed and expose the mode switching operation portion  220  when the cover  222  is opened, and the post-processing control portion  150  (open/close detection portion, mode switching portion) that detects whether the cover  222  is opened or closed, and performs switching between the automatic mode and the manual mode in response to an operation on the mode switching operation portion  220 . While the post-processing control portion  150  is detecting that the cover  222  is opened, when the mode switching operation portion  220  has received an operation for switching to the manual mode, the post-processing control portion  150  switches the processing mode for stapling processing from the automatic mode to the manual mode. 
     According to the configuration of the present embodiment, while the post-processing control portion  150  is detecting that the cover  222  is opened, when the mode switching operation portion  220  has received an operation for switching to the manual mode, the post-processing control portion  150  switches the automatic mode to the manual mode. That is, in order to switch the processing mode for stapling processing from the automatic mode to the manual mode, a user needs to open the cover  222  first and perform an operation for switching to the manual mode on the mode switching operation portion  220  while the cover  222  is opened (the mode switching operation portion  220  is exposed). Therefore, occurrence of trouble can be prevented in which a user unintentionally touches the mode switching operation portion  220  and thereby the processing mode for stapling processing is switched to the manual mode. As a result, the processing mode for stapling processing can be prevented from being left to be the manual mode (a job in the automatic mode is left in the unexecuted state), whereby convenience for a user is improved. 
     It is to be understood that the embodiments herein are illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims.