JP2017183809A - Image reader and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify work for extracting only a document having a blank face from a document bundle.SOLUTION: An image reader comprises a document set tray, a first eject tray, a second eject tray, a main feed path, a switch-back feed path, a pull-in feed path, a document feed part, an image read part, a control part and a reception part. The control part causes front-side reading to be performed, thereby determining whether a front side of a document is a blank face and, in the case where the front side is a non-blank face, causes rear-side reading to be performed, thereby determining whether a rear side of the document is a blank face. A document of which the front side is determined as a blank face by the front-side reading is ejected into the first eject tray, a document of which the rear side is determined as a blank face by the rear-side reading is also ejected into the first eject tray, and a document of which the rear side is determined as a non-blank face by the rear-side reading is ejected into the second eject tray.SELECTED DRAWING: Figure 15

Description

  The present invention relates to an image reading apparatus and an image forming apparatus for reading a document.

  When one side of the front and back sides of a document is a blank page, the document can be reused. For example, a document having a blank sheet can be reused as copy paper or memo paper.

  Here, in the conventional image forming apparatus, it is determined whether or not a document housed in the apparatus as a copy sheet is a document having a blank surface. Some print images. Such an image forming apparatus is disclosed in Patent Document 1, for example.

  The image forming apparatus disclosed in Patent Document 1 includes a reading unit disposed in the middle of a sheet conveyance path from a paper feed cassette that stores copy sheets to a printing position, reads a document being conveyed by the reading unit, and reads the result. Based on the above, it is determined whether or not the document being conveyed has a blank surface. If the document being transported has a blank surface, an image is printed on the blank surface of the document. On the other hand, if the document being conveyed does not have a blank page, printing on the document is not performed.

JP 10-97112 A

  In Patent Document 1, when a document bundle containing a mixture of a document having a blank page and a document having no blank page is stored in a paper feed cassette, the document having a blank page is used as a copy sheet. That is, an image is printed on the blank surface of a document having a blank surface.

  For this reason, if you want to take out only a document with a blank surface from a document bundle that contains a document with a blank page and a document without a blank page and reuse it as memo paper, check each document in the document bundle one by one However, it is necessary to sort a document having a blank page and a document having no blank page. Therefore, it is not convenient for a user who wants to reuse a manuscript with a blank page as a memo paper because a complicated sorting operation must be performed.

  The present invention has been made to solve the above-described problems, and an image reading apparatus and an image that can simplify the operation of taking out only a document having a blank page from a document bundle (sorting operation performed by a user). An object is to provide a forming apparatus.

  In order to achieve the above object, an image reading apparatus of the present invention includes a document set tray on which a document is set, a first discharge tray on which a document is discharged, a second discharge tray on which a document is discharged, and a document A main conveyance path from the set tray to the first discharge tray via a predetermined reading position and a position upstream of the reading position of the main conveyance path from the second discharge tray in the document conveyance direction. A switchback conveyance path that merges with the main conveyance path, a pull-in conveyance path that branches from the main conveyance path at a branch position downstream of the reading position of the main conveyance path in the document conveyance direction, and merges with the switchback conveyance path, and a document set When the original is fed from the tray to the main conveyance path and conveyed along the main conveyance path, and the orientation of the front and back sides of the document at the reading position is reversed, the reading position A document transport unit that causes the document to enter the switchback transport path via the pull-in transport path, then switches back the document in the switchback transport path, and returns the switched back document from the switchback transport path to the main transport path; The image reading unit that reads the document when the document conveyed along the main conveyance path passes the reading position, the document conveying operation of the document conveying unit, and the image reading operation of the image reading unit are controlled, and the document reading Based on the image data of the document obtained by the above, it is determined whether the reading surface of the document is a blank page or a non-blank page, and a document in which at least one side of the document is a blank page and a document in which both sides are non-blank pages The control unit that executes the sorting process for sorting the process, the start instruction for the sort process, and whether to execute the sort process in the standard mode are received. Including kicking and receiving unit, the. When the receiving unit receives an instruction to start the sorting process in the standard mode, the control unit determines whether or not the surface of the document is a blank surface by causing the surface to read the surface of the document. When the front surface of the document is a non-blank surface, it is determined whether or not the back surface of the document is a blank paper surface by switching the document back and then reading the back surface of the document. In addition, the control unit discharges a document whose front surface is determined to be a blank page surface to the first discharge tray, and discharges a document whose rear surface is determined to be a blank page surface to the first discharge tray. Then, the document that is determined to be the non-blank surface by reading the back surface is discharged to the second discharge tray.

  In the configuration of the present invention, when a bundle of documents is set on the document set tray and an instruction to start sorting processing in the standard mode is issued, the document having a blank page is discharged to the first discharge tray and the document having no blank page is provided. Is discharged to the second discharge tray. That is, a plurality of documents constituting a document bundle are classified into a document having a blank page and a document having no blank page. Accordingly, it is possible to take out only a document having a blank surface from the document bundle without performing a complicated operation (such as an operation of checking each document of the document bundle one by one). That is, the sorting operation performed by the user is simplified.

  According to the configuration of the present invention, it is possible to simplify the operation (sorting operation performed by the user) of taking out only the original having a blank page from the original bundle.

The figure which shows the whole structure of the multifunctional device by one Embodiment of this invention. The figure which shows each structure of the document conveyance unit and image reading unit which were installed in the multifunctional machine by one Embodiment of this invention (figure when a switching claw exists in a closed position) The figure which shows each structure of the document conveyance unit and image reading unit which were installed in the multifunctional device by one Embodiment of this invention (figure when a switching claw exists in an open position) The figure which shows the hardware constitutions of the multifunctional device by one Embodiment of this invention The figure which shows the area | region used as the object of blank sheet determination in the 1st sorting process in 1st standard mode. The figure which shows the document conveyance path | route in the 1st sorting process in 1st standard mode (The figure which shows the document conveyance path | route when the surface is a blank surface) The figure which shows the original conveyance path | route in the 1st sorting process in 1st standard mode (The figure which shows the original conveyance path when the back side is a blank page) The figure which shows the document conveyance path | route in the 1st sorting process in 1st standard mode (The figure which shows the document conveyance path | route when both front and back is not a blank surface) The figure which shows the alerting message displayed when the 1st sorting process in 1st standard mode is completed. The figure which shows the discharge state of a document when the 1st sorting process in the 1st standard mode is completed The figure which shows the area | region used as the object of blank sheet determination in the 2nd sorting process in 1st standard mode. The figure which shows the document conveyance path | route in the 2nd sorting process in 1st standard mode (The figure which shows the document conveyance path | route when both front and back is not a blank surface) The figure which shows the undecided area | region which is not an object of blank page determination in the sorting process in the first standard mode The figure which shows the original conveyance path | route in the sorting process in 2nd standard mode (The figure which shows the original conveyance path when the back side is a blank page) Flow chart for explaining the flow when the sorting process is executed in the standard mode The figure which shows the discharge state of the original when the sorting process in the speed switching mode is completed The figure which shows the alerting | reporting message displayed when it is judged that the back side of the document currently conveyed is a blank page in the sorting process in the sequential notification mode.

  An embodiment of the present invention will be described by taking as an example a multi-function peripheral equipped with a plurality of types of functions such as a scan function and a print function.

<< Overall configuration of MFP >>
As shown in FIG. 1, the multifunction peripheral 100 according to the present embodiment includes a document transport unit 1 and an image reading unit 2. The document transport unit 1 and the image reading unit 2 are disposed above the main body of the multifunction machine 100. The configurations of the document transport unit 1 and the image reading unit 2 will be described in detail later.

  The multifunction device 100 also includes a printing unit 7 including a paper feeding unit 3, a paper transport unit 4, an image forming unit 5, and a fixing unit 6. The printing unit 7 transports the paper P along the paper transport path 70 and forms a toner image based on image data of an image to be printed (for example, image data of the document D). Then, the printing unit 7 prints (transfers) the toner image on the paper P being conveyed.

  The paper feed unit 3 includes a pickup roller 31 and a paper feed roller pair 32, and feeds the paper P stored in the cassette 33 to the paper transport path 70. The paper transport unit 4 includes a plurality of transport roller pairs 41, transports the paper P along the paper transport path 70, and discharges the printed paper P to the paper discharge tray 71.

  The image forming unit 5 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. The image forming unit 5 forms a toner image and transfers the toner image onto the paper P. The fixing unit 6 includes a heating roller 61 and a pressure roller 62 and heats and pressurizes the toner image transferred to the paper P to fix it on the paper P.

  The multifunction device 100 also includes an operation panel 8. The operation panel 8 includes a touch panel display 81 (liquid crystal display panel with a touch panel) and hardware keys 82. The touch panel display 81 displays software keys and receives various settings from the user. A plurality of hardware keys 82 are provided on the operation panel 8. For example, the hardware key 82 includes a start key for receiving an instruction to start various processes (for example, a sorting process described later) from the user. The operation panel 8 corresponds to a “reception unit” and a “display unit”.

<< Configurations of Document Feeding Unit and Image Reading Unit >>
As shown in FIG. 2, the document conveying unit 1 is installed to be rotatable with respect to the reading housing 200 of the image reading unit 2. In the reading housing 200, the contact reading glass G1 for conveyance reading and the contact glass G2 for placement reading are fitted in different positions. When the conveyance reading is executed, the document D is automatically conveyed on the contact glass G1 by the document conveyance unit 1, and the document D passing over the contact glass G1 is read. When the placement reading is executed, the document D placed on the contact glass G2 is read.

  First, the document transport unit 1 will be described. The document transport unit 1 includes a document setting tray 110 on which a document D is set and a document discharge tray 111 on which the document D is discharged. Further, the document transport unit 1 includes a switchback tray 112 installed above the document discharge tray 111. The document discharge tray 111 corresponds to a “first discharge tray”, and the switchback tray 112 corresponds to a “second discharge tray”.

  The document transport unit 1 is provided with a document transport path for transporting the document D. The document transport path includes a main transport path MP, a switchback transport path SP, and a pull-in transport path DP.

  The main transport path MP reaches the document discharge tray 111 from the document set tray 110 via a reading position RP (a position where the document D is read when transport reading is performed and a predetermined position on the contact glass G1). As a result, when the document D is fed from the document setting tray 110 to the main transport path MP and the document D is transported along the main transport path MP, the document D being transported passes through the reading position RP. When the document D fed from the document setting tray 110 to the main conveyance path MP passes the reading position RP, the surface of the document D (the surface facing upward when the document D is set on the document setting tray 110) is Opposite the contact glass G1. Accordingly, the surface of the document D is read at the reading position RP.

  The switchback transport path SP is a transport path for switching back the document D and returning the switched back document D to the main transport path MP (reversing the direction of the front and back surfaces of the document D at the reading position RP). . The switchback transport path SP reaches from the switchback tray 112 to a position upstream of the reading position RP of the main transport path MP in the document transport direction, and joins the main transport path MP at this position.

  The pull-in conveyance path DP is a conveyance path (a connection path connecting the main conveyance path MP and the switchback conveyance path SP) for drawing the document D from the main conveyance path MP to the switchback conveyance path SP. The drawing-in conveyance path DP branches from the main conveyance path MP at a position downstream of the reading position RP of the main conveyance path MP in the document conveyance direction, and joins the switchback conveyance path SP.

  Hereinafter, a reference numeral P1 is assigned to the branch position between the main transport path MP and the pull-in transport path DP, and a reference position P2 is added to the junction position between the pull-in transport path DP and the switchback transport path SP, and the switchback transport path MP and the main A description will be given by adding a reference symbol P3 to the joining position with the transport path MP.

  The document transport unit 1 includes a document transport unit 10 for transporting the document D along the document transport path (main transport path MP, switchback transport path SP, and pull-in transport path DP). The document transport unit 10 includes a paper feed mechanism 11. The paper feed mechanism 11 pulls out the original D set on the original set tray 110 from the original set tray 110 and feeds it to the main transport path MP. The configuration of the paper feed mechanism 11 is not particularly limited.

  The document transport unit 10 further includes a transport roller pair 12 (including a registration roller pair 13 and a discharge roller pair 14), a reverse roller pair 15, and a switching claw 16.

  A plurality of transport roller pairs 12 are arranged along the main transport path MP. Then, when the document D is fed to the main transport path MP, the transport roller pair 12 transports the document D along the main transport path MP. As a result, the document D fed to the main transport path MP passes through the reading position RP.

  Among the plurality of transport roller pairs 12, the transport roller pair 12 disposed in the vicinity of the merging position P <b> 3 (position downstream of the merging position P <b> 3 in the document transport direction) functions as the registration roller pair 13. The registration roller pair 13 temporarily stops the progress of the document D and then transports the document D toward the reading position RP.

  Of the plurality of transport roller pairs 12, the transport roller pair 12 disposed at the discharge port 111P (the most downstream side of the main transport path MP in the document transport direction) to the document discharge tray 111 of the main transport path MP is discharged. It functions as a roller pair 14. The discharge roller pair 14 is rotated by receiving a driving force from a motor different from the motor for rotating the other transport roller pair 12. For this reason, only the discharge roller pair 14 among the plurality of transport roller pairs 12 can be rotated at high speed.

  The reverse roller pair 15 is disposed in the switchback conveyance path SP, and reverses the front and rear in the conveyance direction of the document D drawn into the switchback conveyance path SP (that is, switches back). The reverse roller pair 15 can be switched between forward and reverse rotation. The switching claw 16 is for switching the conveyance path of the document D at the branch position P1, and is installed to be rotatable. Specifically, the switching claw 16 opens a position for closing the document conveyance path from the branch position P1 to the drawing conveyance path DP (see FIG. 2) and an opening for opening the document conveyance path from the branch position P1 to the drawing conveyance path DP. It rotates between positions (see FIG. 3).

  When the orientation of the front and back surfaces of the document D at the reading position RP is reversed, the reversing roller pair 15 rotates forward (rotates in the direction in which the document D is conveyed toward the switchback tray 112). Moreover, the switching claw 16 rotates toward the open position (from the state shown in FIG. 2 to the state shown in FIG. 3). As a result, the document D being transported (the document D that has reached the reading position RP) enters the drawing transport path DP from the branch position P1. Then, the document D that has entered the pull-in conveyance path DP is pulled into the switchback conveyance path SP from the merging position P2.

  Thereafter, the reversing roller pair 15 continues to rotate normally until the rear end of the document D in the transport direction passes the merging position P2. Then, the reverse roller pair 15 rotates in the reverse direction after the rear end in the transport direction of the document D passes the merging position P2 and before the rear end in the transport direction of the document D passes through the installation position of the reverse roller pair 15. That is, the reverse roller pair 15 switches back the document D and transports the document D along the switchback transport path SP.

  The document D transported along the switchback transport path SP returns from the merge position P3 to the main transport path MP, is transported along the main transport path MP again, and reaches the reading position RP. At this time, the document D that has reached the reading position RP is switched back in the switchback transport path SP. Therefore, the orientation of the front and back surfaces of the document D at the reading position RP is reversed. That is, the back surface of the document D (the surface facing downward when the document D is set on the document setting tray 110) faces the contact glass G1. For this reason, the back side of the document D can be read at the reading position RP.

  Here, the document transport unit 1 is provided with a document transport sensor for detecting the presence or absence of the document D at a predetermined detection position in the main transport path MP (or the front end of the document D and the passage of the rear end). It is done. For example, the document transport sensor includes a paper feed sensor SS1, a registration sensor SS2, a timing sensor SS3, and a discharge sensor SS4.

  The paper feed sensor SS1 is a sensor whose detection position is a position near the paper feed mechanism 11 (a position downstream of the paper feed mechanism 11 in the document transport direction). The control unit 310 described later determines, for example, whether or not a non-feed jam (an error that the document D is not fed from the document set tray 110 to the main transport path MP) has occurred based on the output value of the sheet feed sensor SS1. To do.

  The registration sensor SS2 is a sensor whose detection position is a position near the registration roller pair 13 (a position upstream of the registration roller pair 13 in the document conveyance direction). The control unit 310 to be described later determines, for example, whether the leading end of the document D in the transport direction has reached the installation position of the registration roller pair 13 based on the output value of the registration sensor SS2. Then, the control unit 310 rotates the registration roller pair 13 a predetermined time after the leading end of the document D in the conveyance direction reaches the installation position of the registration roller pair 13.

  The timing sensor SS3 is a sensor whose detection position is a position in the vicinity of the conveyance roller pair 12 on the upstream side in the document conveyance direction of the reading position RP (a position on the upstream side in the document conveyance direction of the conveyance roller pair 12). The control unit 310 to be described later measures the reading start timing of the document D at the reading position RP based on, for example, the output value of the timing sensor SS3.

  The discharge sensor SS4 is a sensor whose detection position is a position near the discharge roller pair 14 (a position upstream of the discharge roller pair 14 in the document transport direction). For example, based on the output value of the discharge sensor SS4, the control unit 310, which will be described later, determines whether or not the rear end in the transport direction of the document D has passed the installation position of the discharge roller pair 14 (the document D is discharged to the document discharge tray 111). Whether or not).

  Although not shown in FIGS. 2 and 3, the document transport unit 1 is provided with size sensors SS11 and SS12 (see FIG. 4) for detecting the size of the document D. The size sensor SS11 is a sensor for detecting the size of the document D in the main scanning direction (width direction). The size sensor SS12 is a sensor for detecting the size of the document D in the sub-scanning direction orthogonal to the main scanning direction (length in the conveyance direction of the document D).

  The size sensor SS11 is provided on the document set tray 110 and changes the output value according to the position of the pair of regulating plates 113 in the main scanning direction. The pair of restricting plates 113 are for restricting the position of the document D set on the document setting tray 110 in the main scanning direction (positioning the document D). For example, the pair of restriction plates 113 are slidably attached to the document set tray 110.

  A plurality of size sensors SS12 are provided on the document set tray 110. The plurality of size sensors SS12 are arranged at intervals in the sub-scanning direction. Each of the plurality of size sensors SS12 changes the output value depending on whether or not the document D is present at the corresponding detection position.

  Next, the image reading unit 2 will be described. The image reading unit 2 includes an image reading unit 20. The image reading unit 20 includes a lamp 21, a mirror 22, a lens 23, an image sensor 24, and the like. Each component of the image reading unit 20 is held inside the reading housing 200.

  The lamp 21 has a plurality of LED elements, and generates light that irradiates the document D. Although not shown, the plurality of LED elements are arranged in a line in the main scanning direction. The lamp 21 irradiates the contact glass G1 with light when reading the document D conveyed on the contact glass G1 (the light transmitted through the contact glass G1 irradiates the document D). On the other hand, when reading the document D placed on the contact glass G2, the lamp 21 emits light toward the contact glass G2 (light transmitted through the contact glass G2 irradiates the document D). The reflected light reflected by the document D is reflected by the mirror 22 and guided to the lens 23. The lens 23 collects the reflected light.

  The image sensor 24 reads the document D line by line by receiving the reflected light reflected by the document D (light collected by the lens 23). The image sensor 24 includes a CCD having a plurality of photoelectric conversion elements arranged in a line in the main scanning direction. When the reflected light is received, the image sensor 24 performs photoelectric conversion for each pixel in units of lines and accumulates electric charges. Then, the image sensor 24 outputs an analog signal corresponding to the accumulated charge. That is, the analog output for each pixel of the image sensor 24 varies according to the amount of reflected light.

<< Hardware configuration of MFP >>
As illustrated in FIG. 4, the multifunction peripheral 100 includes a control unit 310. The control unit 310 includes a CPU 311, a memory 312 (ROM, RAM, etc.) and an image processing module 313. The CPU 311 operates based on a control program and data. The control program and data are stored in the memory 312. The image processing module 313 includes an image processing circuit, an image processing memory, and the like, and performs various types of image processing on the image data.

  The control unit 310 is connected to the printing unit 7 and controls the printing operation of the printing unit 7. The control unit 310 is connected to the operation panel 8 and controls the display operation of the operation panel 8 or detects an operation performed on the operation panel 8.

  The control unit 310 is connected to the document transport unit 1 and the image reading unit 2. The control unit 310 controls the document conveyance operation of the document conveyance unit 1 and the image reading operation of the image reading unit 2. That is, the control unit 310 feeds and transports the document D, discharges the document D, switches the transport route of the document D (rotation of the switching claw 16), switches back the document D, and the like to the document transport unit 10. Let it be done. Further, the control unit 310 causes the image reading unit 20 to read the document D.

  The control unit 310 performs drive control of a motor for rotating various rotators constituting the document conveying unit 10 (controls various rotators appropriately) as control of the document conveying operation of the document conveying unit 1. Examples of the motor include a paper feed motor M1, a transport motor M2, a discharge motor M3, and a reverse motor M4.

  The paper feed motor M1 is a motor for operating the paper feed mechanism 11. The conveyance motor M <b> 2 is a motor for rotating the conveyance roller pair 12 (including the registration roller pair 13) other than the discharge roller pair 14 among the plurality of conveyance roller pairs 12. The discharge motor M3 is a motor for rotating the discharge roller pair 14. The reversing motor M4 is a motor for rotating the reversing roller pair 15.

  Moreover, the control part 310 controls the drive source (not shown) for rotating the switching nail | claw 16, and rotates the switching claw 16 appropriately. That is, the control unit 310 controls the opening and closing of the document conveyance path from the reading position RP to the drawing conveyance path DP. The drive source for rotating the switching claw 16 is not particularly limited, and a solenoid or a motor can be used.

  In order to control the document conveying operation (such as driving of the motor) of the document conveying unit 1, document control sensors (paper feed sensor SS1, registration sensor SS2, timing sensor SS3, and discharge sensor SS4) are connected to the control unit 310. Then, the control unit 310 detects the presence or absence of the document D (corresponding to the leading end of the document D and passing through the trailing end) at the corresponding detection position based on each output value of the document transport sensor.

  In addition, size sensors SS11 and SS12 are connected to the control unit 310. The control unit 310 detects the size of the document D in the main scanning direction (width direction) based on the output value of the size sensor SS11, and the size of the document D in the sub-scanning direction (conveyance of the document D) based on the output value of the size sensor SS12. Direction length).

  By the way, the detection of the length of the document D in the transport direction can be performed based on the output value of the document transport sensor. For example, the controller 310 detects the passage of the trailing edge of the document D at the same detection position after detecting the arrival of the leading edge of the document D at a detection position of a certain document conveyance sensor (for example, the paper feed sensor SS1 or the registration sensor SS2). The length of the document D in the conveyance direction is detected based on the time until the completion. Alternatively, an input of a size value indicating the size of the document D may be received from the user via the operation panel 8, and the size detection of the document D may be performed based on the size value input to the operation panel 8.

<< Sorting process >>
The MFP 100 according to the present embodiment has a sorting function, and is the reading surface of the document D based on the image data of the document D obtained by reading the document D being a blank surface (a surface on which no image exists)? It is determined whether the surface is a non-blank surface (the surface on which the image exists), and at least one side of the front and back surfaces is a document D (for example, referred to as a back paper) and both sides are a non-blank surface. It is possible to execute processing for sorting D. Note that the sorting process is executed by the control unit 310.

  Here, the control unit 310 executes the sorting process in any one of the standard mode, the speed switching mode, and the sequential notification mode. It is set by the user in which mode the sorting process is executed. For example, the operation panel 8 shows three modes of the sorting process as options, and accepts a selection as to which mode the sorting process is executed from the user.

  When the execution mode of the sorting process is selected and an operation for instructing the start of the sorting process is performed, the control unit 310 determines that the start instruction of the sorting process has been accepted, and the selected mode is selected from the three execution modes. Execute sorting process with. For example, when the control unit 310 detects an operation on the start key as the hardware key 82, the control unit 310 determines that an instruction to start the sorting process has been received.

  When the operation panel 8 receives an instruction to start sorting processing (operation on the start key), the control unit 310 causes the document transport unit 10 to feed and transport the document D set on the document set tray 110 and transport the document D. The front side of the original document D is read by the image reading unit 20, and it is determined whether or not the surface of the document D is a blank page (perform blank page determination). If the result of this blank page determination is that the front side of the document D is a non-blank page, the control unit 310 causes the document transport unit 10 to switch back the document D and causes the image reading unit 20 to scan the back side of the document D. . Then, control unit 310 determines whether the back side of document D is a blank page (performs blank page determination).

<Standard mode>
When the standard mode is selected as the sorting process execution mode, the control unit 310 detects the length of the document D in the conveyance direction. For example, the control unit 310 detects the length of the document D in the conveyance direction based on the output value of the size sensor SS12. Alternatively, the length of the document D in the transport direction may be detected based on the size value (value indicating the length of the document D in the transport direction) input to the operation panel 8. Further, after the document D is fed from the document set tray 110 to the main transport path MP, the length of the document D in the transport direction is detected based on the output value of the document transport sensor (such as the paper feed sensor SS1 or the registration sensor SS2). May be performed. Note that the length of the document D in the conveyance direction is also detected when the sorting process is executed in the speed switching mode or the sequential notification mode.

  After detecting the conveyance direction length of the document D, the control unit 310 determines the threshold length obtained by subtracting a predetermined margin from the document conveyance distance between the reading position RP and the branch position P1. Judge whether it is longer than this. As a result, if the length in the conveyance direction of the document D is longer than the threshold length, the control unit 310 executes the sorting process in one of the first standard mode and the second standard mode. Note that the user may be able to select which of the first standard mode and the second standard mode to execute the sorting process (the operation panel 8 receives the selection). On the other hand, if the conveyance direction length of the document D is equal to or less than the threshold length, the control unit 310 executes the sorting process in the third standard mode.

(First standard mode)
When the sorting process is executed in the first standard mode, the control unit 310 requires the document D to travel a distance corresponding to the threshold length after the leading end of the document D in the conveyance direction reaches the reading position RP. When the time has elapsed, it is determined that the blank sheet determination time point (the time point at which blank sheet determination should be performed) has come. For example, the control unit 310 determines whether or not the leading end of the document D in the transport direction has reached the reading position RP based on the elapsed time after the leading end of the document D is detected at the detection position of the timing sensor SS3. To do. In the first standard mode, when the blank sheet determination time is reached, the leading end of the document D in the conveyance direction has not yet reached the branch position P1.

  When the blank sheet determination time is reached, the control unit 310 uses the image data of a partial area of the document D obtained by reading until the required time elapses after the leading end of the document D in the transport direction reaches the reading position RP. Based on this, it is determined whether or not the reading surface of the document D is a blank sheet surface (blank sheet determination is performed). That is, as shown in FIG. 5, an image of a front end side region that is an area from the front end in the transport direction of the original D to a position that is back by the threshold length toward the upstream side in the transport direction of the original D on the reading surface of the original D. Based on the data, it is determined whether or not the reading surface of the document D is a blank surface. Therefore, even if an image exists in an area other than the front end side area of the document D, if the image does not exist in the front end area of the document D, it is determined that the reading surface of the document D is a blank page. The In FIG. 5, the front end side area of the document D is hatched.

  In the first standard mode, both the case where the front surface of the document D is read as a reading surface (when the front surface is read) and the case where the back surface of the document D is read as a reading surface (when the back surface reading is performed) Whether or not the reading surface of the document D is a blank sheet surface based on the image data of a partial area of the document D obtained by reading until the required time elapses after the leading edge of the document D reaches the reading position RP. Is judged. However, since the document D is switched back in the back side reading, the rear end in the transport direction of the document D before the switch back becomes the front end in the transport direction.

  When it is determined that the surface of the document D is a blank sheet surface by reading the front surface, the control unit 310 discharges the document D from the reading position RP as it is toward the document discharge tray 111 and places the document D on the document discharge tray 111. Let At this time, of the front and back surfaces of the document D placed on the document discharge tray 111, the surface determined to be a blank sheet surface is turned downward. FIG. 6 shows the transport path of the document D in this case. In FIG. 6, the transport path of the document D is indicated by a bold line.

  On the other hand, when it is determined that the surface of the document D is a non-blank surface surface by surface reading, the control unit 310 rotates the switching claw 16 to the open position (from the state shown in FIG. 2 to the state shown in FIG. 3). ). That is, the document conveyance path from the main conveyance path MP to the drawing conveyance path DP is opened. As a result, the document D enters the pull-in transport path DP, and the document D is pulled into the switchback transport path SP via the pull-in transport path DP.

  Here, there is a time delay from when the controller 310 determines that the surface of the document D is a non-blank surface at the time of blank sheet determination until the rotation of the switching claw 16 to the open position is completed. For this reason, when the length corresponding to the document conveyance distance from the reading position RP to the branching position P1 is set as the threshold length, the leading end of the document D in the conveyance direction is branched before the rotation of the switching claw 16 to the open position is completed. The document D that has reached the position P1 and whose surface is determined to be a non-blank surface cannot enter the pull-in conveyance path DP. Therefore, the length obtained by subtracting the margin from the document conveyance distance from the reading position RP to the branch position P1 (the length considering the time delay described above) is set as the threshold length.

  After pulling the document D into the switchback transport path SP, the control unit 310 is after the rear end in the transport direction of the document D has passed the merging position P2 and the rear end in the transport direction of the document D is the reverse roller pair 15. The reverse roller pair 15 is reversely rotated at a timing before passing the installation position. At this time, the control unit 310 rotates the switching claw 16 to the closed position (from the state shown in FIG. 3 to the state shown in FIG. 2). As a result, the document D is switched back and the document D returns to the main transport path MP. For example, the control unit 310 determines the elapsed time after the leading end of the document D in the transport direction reaches the detection position of the timing sensor SS3, the document transport distance from the detection position of the timing sensor SS3 to the merge position P2, and the document D. Based on the length in the conveyance direction, it is determined whether or not the trailing end of the document D in the conveyance direction has passed the merging position P2.

  When the document D is switched back, the control unit 310 causes the document D to be read again (reverse scanning is performed). Then, the control unit 310 determines whether or not the back side of the document D is a blank page at the blank page determination time.

  When it is determined that the back side of the document D is a blank sheet surface by reading the back side, the control unit 310 discharges the document D from the reading position RP as it is toward the document discharge tray 111 and places the document D on the document discharge tray 111. Let At this time, of the front and back surfaces of the document D placed on the document discharge tray 111, the back surface determined to be a blank sheet surface is turned downward. FIG. 7 shows the transport path of the document D in this case. In FIG. 7, the transport path of the document D is indicated by a bold line.

  On the other hand, when it is determined that the back surface of the document D is a non-blank surface by reading the back surface, the control unit 310 rotates the switching claw 16 to the open position (from the state shown in FIG. 2 to the state shown in FIG. 3). ). As a result, the document D enters the pull-in transport path DP, and the document D is pulled into the switchback transport path SP via the pull-in transport path DP. Then, the control unit 310 causes the document D to be discharged toward the switchback tray 112 without being switched back, and places the document D on the switchback tray 112. FIG. 8 shows the transport path of the document D in this case. In FIG. 8, the transport path of the document D is indicated by a bold line.

  As a result, the downstream portion in the transport direction of each document D placed on the document discharge tray 111 (the portion on the right side when viewed from the front of the apparatus) is all blank. That is, only the document D determined to have a blank surface by the control unit 310 is placed on the document discharge tray 111. Further, the surface of the document D placed on the document discharge tray 111 having a blank portion faces downward.

  When the first sorting process in the first standard mode is completed (when only the document D having a blank page is placed on the document discharge tray 111), the control unit 310 notifies the notification message as shown in FIG. MG1 is displayed on the operation panel 8. Then, by displaying the notification message MG1, the document D already placed (discharged) on the document discharge tray 111 is reset on the document set tray 110, and then the second sorting process in the first standard mode is performed. Prompt the user to start.

  The notification message MG1 includes a blank sheet surface so that the document end that is the trailing edge in the conveyance direction when the document D is discharged to the document discharge tray 111 is the leading edge in the conveyance direction when feeding from the document setting tray 110. A message for resetting the document D on the document set tray 110 is included so that the determined document surface becomes a reading surface for front side reading.

  For example, in the configuration in which the document D is transported along the transport path shown in FIGS. 6 and 7, when the first sorting process is completed, the state shown in FIG. 10 is obtained. In FIG. 10, the code DE is attached to the rear end in the transport direction of the document D placed on the document discharge tray 111, and the code DS is attached to the surface of the document D that is determined to be a blank sheet surface.

  In this case, if the original D placed on the original discharge tray 111 is reset to the original set tray 110 without changing the horizontal direction, the original D is conveyed to the original discharge tray 111 when discharged. The document end that has been the rear end in the direction becomes the front end in the transport direction when feeding from the document set tray 110. Further, if the original D placed on the original discharge tray 111 is reversed in the vertical direction and the original D is set again on the original set tray 110, the original surface determined to be a blank sheet surface is read for front side reading. It becomes a surface.

  Therefore, for example, it is preferable to include in the notification message MG1 a message “Please do not change the orientation of the original in the horizontal direction when resetting”. Furthermore, it is preferable to include in the notification message MG1 a message “Please reverse the vertical direction of the original when resetting”.

  When the operation panel 8 receives an instruction to start the second sorting process in the first standard mode, the control unit 310 feeds the original D and performs the same as when the first sorting process is performed in the first standard mode. In addition to carrying, the front side of the original D is read. Then, the control unit 310 reads the document D based on the image data of a partial area of the document D obtained by reading until the required time elapses after the leading end of the document D in the transport direction reaches the reading position RP. It is determined whether or not the side is a blank page (perform blank page determination).

  Here, as shown in FIG. 11, in the second sorting process, an area A2 (tip side area) opposite to the area A1 (tip side area) subjected to blank page determination in the first sorting process is displayed. This is the target of blank page determination. In FIG. 11, regions A1 and A2 are hatched differently.

  When it is determined that the surface of the document D is a blank sheet surface by reading the front surface, the control unit 310 discharges the document D from the reading position RP as it is toward the document discharge tray 111 and places the document D on the document discharge tray 111. Let At this time, of the front and back surfaces of the document D placed on the document discharge tray 111, the surface determined to be a blank sheet surface is turned downward. In this case, the transport path of the document D is the same as the transport path of the document D shown in FIG.

  On the other hand, when it is determined that the surface of the document D is a non-blank surface surface by surface reading, the control unit 310 rotates the switching claw 16 to the open position (from the state shown in FIG. 2 to the state shown in FIG. 3). ). As a result, the document D enters the pull-in transport path DP, and the document D is pulled into the switchback transport path SP via the pull-in transport path DP. Then, the control unit 310 causes the document D to be discharged toward the switchback tray 112 without being switched back, and places the document D on the switchback tray 112. FIG. 12 shows the transport path of the document D in this case. In FIG. 12, the transport path of the document D is indicated by a bold line.

  As a result, only the document D determined that at least one side of the document D is a blank sheet surface is placed on the document discharge tray 111. Further, all the blank pages of the originals D placed on the original discharge tray 111 face downward.

  If the length of the document D in the conveyance direction is longer than twice the threshold length, as shown in FIG. 13, the area A1 subjected to blank sheet determination in the first sorting process and the second time In this sorting process, an undetermined area A3 (an area that has not been hatched) occurs between the area A2 that is the target of blank page determination. Even if an image exists in the undetermined area A3 of the document D, if there are no images in the areas A1 and A2, the document D is discharged to the document discharge tray 111 as a document D having a blank surface. Therefore, when the length of the document D in the conveyance direction is longer than twice the threshold length, although not shown, the confirmation operation of the document D discharged to the document discharge tray 111 (whether it has a blank surface or not) A message for prompting the user to perform a final confirmation) may be displayed on the operation panel 8.

  When the sorting process is executed in the first standard mode, as described above, the document D having a blank page is discharged to the document discharge tray 111, and the document D having no blank page is discharged to the switchback tray 112. The That is, a plurality of documents D forming a document bundle set on the document set tray 110 is sorted into a document D having a blank page and a document D having no blank page. Accordingly, it is possible to take out only the document D having a blank surface from the document bundle without performing a complicated operation (such as an operation of checking each document D of the document bundle one by one). That is, the sorting operation performed by the user is simplified.

  In addition, since the orientations of the white pages of the originals D placed on the original discharge tray 111 are aligned (downward), the white bundle of each original D is taken out after the original bundle placed on the original discharge tray 111 is taken out. The work of aligning the direction of the paper is also unnecessary. Thereby, the sorting operation performed by the user is further simplified.

  It should be noted that the conveyance (paper feeding) of the document D necessary for the execution of the sorting process is performed by the document transport unit 1, and the reading of the document D necessary for the execution of the sorting process is performed by the image reading unit 2. That is, each process necessary for executing the sorting process is performed by an existing unit. Therefore, even if the sorting function is installed in the multifunction device 100, the number of parts does not increase (cost increase can be suppressed).

(2nd standard mode)
When the sorting process is executed in the second standard mode, the control unit 310 causes the document D to be read while the document D is entered from the pull-in transport path DP into the switchback transport path SP. For example, the control unit 310 rotates the switching claw 16 to the open position at the start of the sorting process (from the state shown in FIG. 2 to the state shown in FIG. 3).

  Then, control unit 310 determines that the blank sheet determination time has come when reading of the entire area from the leading edge in the conveying direction to the trailing edge in the conveying direction is completed. That is, the control unit 310 sets a distance corresponding to the length in the conveyance direction of the document D (the length from the conveyance direction front end to the conveyance direction rear end) after the conveyance direction front end of the document D reaches the reading position RP. When the time required for the document D to pass has elapsed, it is determined that the blank sheet determination time has come. The control unit 310 determines whether or not the leading end of the document D in the transport direction has reached the reading position RP based on the elapsed time since the leading end of the document D is detected at the detection position of the timing sensor SS3. To do. Further, the control unit 310 determines whether or not the trailing end of the document D in the transport direction has passed the reading position RP based on the elapsed time after the trailing end of the document D is detected at the detection position of the timing sensor SS3. Judging. In the second standard mode, when the blank sheet determination time is reached, the leading end of the document D in the transport direction has already entered the switchback transport path SP (the pull-in transport path DP).

  When the blank sheet determination time is reached, the control unit 310 determines whether the reading surface of the document D is a blank sheet surface based on the image data of the entire area from the leading end in the transport direction of the document D to the trailing end in the transport direction. (Blank paper is determined). In this case, if an image does not exist over the entire area of the reading surface of the document D, it is determined that the reading surface of the document D is a blank surface, and if an image exists at least in part, It is determined that the reading surface is a non-blank surface.

  When it is determined that the surface of the document D is a blank sheet surface by reading the front side, the control unit 310 switches back the document D in the switchback transport path SP, and the document D is switched from the switchback transport path SP to the main transport path MP. Return (convey along the main conveyance path MP). Note that the switchback processing in the second standard mode (processing for switching back the document D) is the same as the switchback processing in the first standard mode. At this time, the control unit 310 rotates the switching claw 16 to the closed position (from the state shown in FIG. 3 to the state shown in FIG. 2).

  Thereafter, the control unit 310 discharges the document D returned to the main transport path MP as it is toward the document discharge tray 111 and places the document D on the document discharge tray 111. At this time, of the front and back surfaces of the document D placed on the document discharge tray 111, the front surface determined to be a blank sheet surface is directed upward. In this case, the transport path of the document D is the same as the transport path of the document D shown in FIG.

  On the other hand, when it is determined that the front surface of the document D is a non-blank surface by surface reading, the control unit 310 switches back the document D in the switchback transport path SP, and the document D is switched from the switchback transport path SP to the main. The paper is returned to the transport path MP (conveyed along the main transport path MP), and the original D is read again (back side reading is performed). Then, the control unit 310 determines whether or not the back side of the document D is a blank page at the blank page determination time.

  When it is determined that the back surface of the document D is a blank surface by reading the back surface, the control unit 310 switches back the document D in the switchback transport path SP, and the document D is switched from the switchback transport path SP to the main transport path MP. Return (convey along the main conveyance path MP). Further, the control unit 310 rotates the switching claw 16 to the closed position (from the state shown in FIG. 3 to the state shown in FIG. 2).

  Thereafter, the control unit 310 discharges the document D returned to the main transport path MP as it is toward the document discharge tray 111 and places the document D on the document discharge tray 111. At this time, of the front and back surfaces of the document D placed on the document discharge tray 111, the back surface determined to be a blank sheet surface is turned upward. FIG. 14 shows the conveyance path of the document D in this case. In FIG. 14, the transport path of the document D is indicated by a bold line.

  On the other hand, when it is determined that the back surface of the document D is a non-blank surface by reading the back surface, the control unit 310 directs the document D drawn into the switchback transport path PS toward the switchback tray 112 without switching back. The original D is placed on the switchback tray 112. In this case, the transport path of the document D is the same as the transport path of the document D shown in FIG.

  As a result, only the document D in which at least one side of the document D is a blank surface (the document D in which all areas on one side of the document D are blank) is placed on the document discharge tray 111. Further, all the blank surfaces of the originals D placed on the original discharge tray 111 face upward.

  When the sorting process is executed in the second standard mode, as described above, the document D having a blank page is discharged to the document discharge tray 111, and the document D having no blank page is discharged to the switchback tray 112. The Thus, when the sorting process is executed in the second standard mode, the same effect as that when the sorting process is executed in the first standard mode can be obtained.

  Further, when the sorting process is executed in the second standard mode, unlike the case where the sorting process is executed in the first standard mode, the operation of resetting the document bundle discharged to the document discharge tray 111 to the document set tray 110 is performed. Is no longer necessary. Thereby, the sorting operation performed by the user is further simplified.

(Third standard mode)
When the sorting process is executed in the third standard mode, the control unit 310 determines that the blank sheet determination time has come when reading of the entire area from the leading edge in the conveying direction to the trailing edge in the conveying direction is completed. In the third standard mode, it is determined whether or not the blank sheet determination time has come, by the same method as in the second standard mode. However, in the third standard mode, since the length of the document D in the transport direction is equal to or less than the threshold length, the blank sheet determination time comes before the leading end of the document D in the transport direction reaches the branch position P1.

  When the blank sheet determination time is reached, the control unit 310 determines whether the reading surface of the document D is a blank sheet surface based on the image data of the entire area from the leading end in the transport direction of the document D to the trailing end in the transport direction. (Blank paper is determined). In this case, if an image does not exist over the entire area of the reading surface of the document D, it is determined that the reading surface of the document D is a blank surface, and if an image exists at least in part, It is determined that the reading surface is a non-blank surface.

  When it is determined that the surface of the document D is a blank sheet surface by reading the front surface, the control unit 310 discharges the document D from the reading position RP as it is toward the document discharge tray 111 and places the document D on the document discharge tray 111. Let At this time, of the front and back surfaces of the document D placed on the document discharge tray 111, the surface determined to be a blank sheet surface is turned downward. In this case, the transport path of the document D is the same as the transport path of the document D shown in FIG.

  On the other hand, when it is determined that the front surface of the document D is a non-blank surface surface by reading the front surface, the control unit 310 switches back the document D and then reads the document D again (performs back surface reading). . The switchback process in the third standard mode is the same as the switchback process in the first standard mode. At this time, the control unit 310 rotates the switching claw 16 to the closed position (from the state shown in FIG. 3 to the state shown in FIG. 2).

  When it is determined that the back side of the document D is a blank sheet surface by reading the back side, the control unit 310 discharges the document D from the reading position RP as it is toward the document discharge tray 111 and places the document D on the document discharge tray 111. Let At this time, of the front and back surfaces of the document D placed on the document discharge tray 111, the back surface determined to be a blank sheet surface is turned downward. In this case, the transport path of the document D is the same as the transport path of the document D shown in FIG.

  On the other hand, when it is determined that the back surface of the document D is a non-blank surface by reading the back surface, the control unit 310 rotates the switching claw 16 to the open position (from the state shown in FIG. 2 to the state shown in FIG. 3). ). As a result, the document D enters the pull-in transport path DP, and the document D is pulled into the switchback transport path SP via the pull-in transport path DP. Then, the control unit 310 causes the document D to be discharged toward the switchback tray 112 without being switched back, and places the document D on the switchback tray 112. In this case, the transport path of the document D is the same as the transport path of the document D shown in FIG.

  As a result, only the document D in which at least one side of the document D is a blank surface (the document D in which all areas on one side of the document D are blank) is placed on the document discharge tray 111. Further, all the blank pages of the originals D placed on the original discharge tray 111 face downward.

  When the sorting process is executed in the third standard mode, that is, when the transport length of the document D is short (when the document length is equal to or less than the threshold length), the document D having a blank surface is the document discharge tray 111 as described above. The document D that is discharged and does not have a blank sheet surface is discharged to the switchback tray 112. Thus, when the sorting process is executed in the third standard mode, the same effect as that when the sorting process is executed in the first standard mode is obtained.

  When the sorting process is performed in the third standard mode, the document D is transported along the same document transport path as that in the first standard mode. That is, when it is determined that the front side of the document D is a blank page surface by reading the front side and when the back side of the document D is determined to be a blank page side by reading the back side, the document D is not switched back and is directly the document. It is discharged to the discharge tray 111 (the number of switchbacks is reduced). Further, it is not necessary to execute the sorting process again. Thereby, the sorting process can be completed promptly.

(Flow of sorting process)
Hereinafter, a flow when the sorting process is executed in the standard mode will be described with reference to the flowchart shown in FIG. The flowchart shown in FIG. 15 starts when the operation panel 8 receives an instruction to start sorting processing.

  In step S <b> 1, the control unit 310 detects the length in the transport direction of the document D (document D to be processed in the sorting process) set on the document setting tray 110. In step S2, control unit 310 determines whether or not the length of document D in the conveyance direction is longer than the threshold length. As a result, when the control unit 310 determines that the length in the conveyance direction of the document D is longer than the threshold length, the control unit 310 proceeds to step S3 and determines that the length in the conveyance direction of the document D is equal to or less than the threshold length. When 310 judges, it transfers to step S4.

  When the process proceeds to step S3, the control unit 310 selects the first standard mode or the second standard mode as the execution mode of the sorting process. When the process proceeds to step S4, the control unit 310 selects the third standard mode as the sorting process execution mode. When the execution mode of the sorting process is selected by the control unit 310, the process proceeds to step S5.

  In step S5, the control unit 310 starts the sorting process in a mode selected from the first standard mode (second standard mode) and the third standard mode. That is, the control unit 310 causes the paper feeding mechanism 11 to feed the original D set on the original setting tray 110 to the main transport path MP. The document transport unit 10 transports the document D along the main transport path MP when the document D is fed to the main transport path MP. In step S <b> 6, the control unit 310 causes the image reading unit 20 to read the front side of the document D.

  In step S <b> 7, the control unit 310 determines whether or not the surface of the document D is a blank page based on the image data obtained by the surface reading. As a result, when the control unit 310 determines that the surface of the document D is a blank sheet surface, the process proceeds to step S8. In step S8, the control unit 310 causes the document transport unit 10 to discharge the document D to the document discharge tray 111. At this time, if the execution mode is the first standard mode or the third standard mode, the document transport unit 10 discharges the document D to the document discharge tray 111 without switching back, and the execution mode is the second standard mode. For example, the document D is switched back and then discharged to the document discharge tray 111.

  If the controller 310 determines in step S7 that the surface of the document D is a non-blank surface, the process proceeds to step S9. In step S <b> 9, the control unit 310 causes the document conveying unit 10 to switch back the document D and causes the image reading unit 20 to perform the back side reading on the document D.

  In step S <b> 10, the control unit 310 determines whether the back surface of the document D is a blank paper surface based on the image data obtained by the back surface reading. As a result, when the control unit 310 determines that the back surface of the document D is a blank sheet surface, the process proceeds to step S8. That is, the control unit 310 causes the document transport unit 10 to discharge the document D to the document discharge tray 111.

  In step S10, when the control unit 310 determines that the back surface of the document D is a non-blank surface, the process proceeds to step S11. In step S <b> 11, the control unit 310 causes the document conveying unit 10 to discharge the document D to the switchback tray 112.

  After the document D is discharged to the document discharge tray 111 or the switchback tray 112, the process proceeds to step S12. In step S <b> 12, the control unit 310 determines whether or not the document D remains on the document set tray 110. For example, the document set tray 110 is provided with a document presence / absence sensor for detecting whether or not the document D is set (the presence or absence of the document D). Then, control unit 310 determines whether or not document D remains on document set tray 110 based on the output value of the document presence / absence sensor.

  If the control unit 310 determines that the document D remains in step S12, the process proceeds to step S5. On the other hand, when the control unit 310 determines that the document D does not remain, this flow ends.

<Speed switching mode>
When the sorting process execution mode is the speed switching mode, as in the case of executing the sorting process in the standard mode, the control unit 310 first determines the surface of the document D based on the image data of the document D obtained by the surface reading. Is a blank page (blank page determination is performed). As a result of the determination, if the front surface of the document D is a non-blank surface, the control unit 310 determines whether the back surface of the document D is a blank paper surface based on the image data of the document D obtained by reading the back surface. Yes (perform blank page determination).

  When it is determined that the front surface of the document D is a blank sheet surface by reading the front surface, the control unit 310 discharges the document D onto the document discharge tray 111. When it is determined that the back side of the document D is a blank page surface by reading the back side, the control unit 310 discharges the document D to the document discharge tray 111. Further, when it is determined that the back surface of the document D is a non-blank surface by reading the back surface, the control unit 310 discharges the document D to the document discharge tray 111. That is, in the speed switching mode, the document D having a blank page is discharged to the document discharge tray 111, and the document D having no blank page is also discharged to the document discharge tray 111.

  For example, when the original D is read (when the original D passes the reading position RP), the original D is not drawn into the switchback conveyance path SP, that is, the same time as in the first standard mode or the third standard mode. When performing the blank page determination, the control unit 310 causes the document D to be discharged from the reading position RP to the document discharge tray 111 as it is when the back side reading determines that the back side of the document D is a non-blank side.

  Further, when the original D is read (when the original D passes through the reading position RP), the original D is drawn into the switchback conveyance path SP, that is, when blank sheet determination is performed at the same time as in the second standard mode. When the back side reading determines that the back side of the document D is a non-blank surface, the control unit 310 switches back the document D and discharges it to the document discharge tray 111.

  Here, in the speed switching mode, when discharging a document D that does not have a blank page (a document D that has been determined that the back side is a non-blank side by reading the back side) to the document discharge tray 111, the control unit 310 uses the discharge roller. The rotational speed of the pair 14 is switched. Specifically, when the document D to be discharged is nipped only by the discharge roller pair 14, the control unit 310 increases the rotation speed of the discharge roller pair 14 from the normal speed. The normal speed is the rotation speed of the discharge roller pair 14 when discharging the document D having a blank paper surface to the document discharge tray 111.

  As a result, the conveyance force in the conveyance direction (the force by which the document D advances in the conveyance direction) is greater for the document D that does not have a blank surface than the document D that has a blank surface. Therefore, as shown in FIG. 16, the discharge position (position at the rear end in the conveyance direction) of the document D having a blank surface (labeled D1 in FIG. 16) is the discharge port 111P to the document discharge tray 111 on the main conveyance path MP. In contrast, the discharge position of the document D that does not have a blank surface (indicated by reference numeral D2 in FIG. 16) is a position farther from the discharge port 111P. That is, the discharge position of the document D2 is shifted to the downstream side in the document transport direction from the discharge position of the document D1 (the document D1 and the document D2 are sorted).

  When the original D1 having a blank surface is discharged to the original discharge tray 111 (when the original D1 is nipped only by the discharge roller pair 14), the rotation speed of the discharge roller pair 14 is set higher than the normal speed. May be faster.

  When the sorting process is executed in the speed switching mode, as described above, both the original D1 having a blank surface and the original D2 having no blank surface are discharged to the original discharge tray 111. The placement position of the document D2 is shifted from the placement position of the document D1. Accordingly, it is possible to easily sort the document D1 having a blank page and the document D2 having no blank page (without performing complicated work).

<Sequential notification mode>
When the execution mode of the sorting process is the sequential notification mode, as in the case of executing the sorting process in the standard mode, the control unit 310 first determines the surface of the document D based on the image data of the document D obtained by the surface reading. Is a blank page (blank page determination is performed). As a result of the determination, if the front surface of the document D is a non-blank surface, the control unit 310 determines whether the back surface of the document D is a blank paper surface based on the image data of the document D obtained by reading the back surface. Yes (perform blank page determination).

  When it is determined that the front surface of the document D is a blank sheet surface by reading the front surface, the control unit 310 discharges the document D onto the document discharge tray 111. When it is determined that the back side of the document D is a blank page surface by reading the back side, the control unit 310 discharges the document D to the document discharge tray 111. Further, when it is determined that the back surface of the document D is a non-blank surface by reading the back surface, the control unit 310 discharges the document D to the document discharge tray 111. In other words, in the sequential notification mode, the document D having a blank page is discharged to the document discharge tray 111, and the document D having no blank page is also discharged to the document discharge tray 111.

  For example, when the original D is read (when the original D passes the reading position RP), the original D is not drawn into the switchback conveyance path SP, that is, the same time as in the first standard mode or the third standard mode. When performing the blank page determination, the control unit 310 causes the document D to be discharged from the reading position RP to the document discharge tray 111 as it is when the back side reading determines that the back side of the document D is a non-blank side.

  Further, when the original D is read (when the original D passes through the reading position RP), the original D is drawn into the switchback conveyance path SP, that is, when blank sheet determination is performed at the same time as in the second standard mode. When the back side reading determines that the back side of the document D is a non-blank surface, the control unit 310 switches back the document D and discharges it to the document discharge tray 111.

  Here, in the sequential notification mode, when it is determined that the back surface of the document D is a non-blank surface by reading the back surface, the control unit 310 interrupts the transport of the document D. At this time, control unit 310 causes operation panel 8 to display notification message MG2 as shown in FIG. Then, by displaying the notification message MG2, the user is prompted to perform the sorting process start instruction again after the document D already placed (discharged) on the document discharge tray 111 is removed.

  After the notification message MG2 is displayed, the control unit 310 receives an instruction for resuming the sorting process (when the start key is pressed), and the document D (white) that is determined to be a blank page by reading the back side. The conveyance of the original D) having no paper surface is resumed. Then, the control unit 310 discharges the document D from the reading position RP toward the document discharge tray 111 and places the document D on the document discharge tray 111. At this time, the document D (document D having a blank page) already placed on the document discharge tray 111 is removed by the user. For this reason, even when the document D that does not have a blank page is discharged to the document discharge tray 111, the document D that has a blank page and the document D that does not have a blank page are not mixed on the document discharge tray 111. .

  When the sorting process is executed in the sequential notification mode, as described above, when it is determined that the document D being transported is a document D that does not have a blank page, the transport of the document D is interrupted. If the document D (document D having a blank surface) already discharged to the document discharge tray 111 at that time is taken out from the document discharge tray 111, the document D having a blank surface and the document D having no blank surface are obtained. There is no mixing. Accordingly, it is possible to easily classify the document D having a blank page and the document D having no blank page (without performing complicated work).

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the description of the above-described embodiment but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

8 Operation panel (reception part, display part)
DESCRIPTION OF SYMBOLS 10 Document conveyance part 20 Image reading part 110 Document set tray 111 Document discharge tray (1st discharge tray)
112 Switchback tray (second discharge tray)
310 Control Unit DP Pull-in Transport and MP Main Transport Path SP Switchback Transport Path

Claims (8)

A document set tray on which documents are loaded,
A first discharge tray from which documents are discharged;
A second discharge tray from which documents are discharged;
A main transport path from the document set tray to the first discharge tray via a predetermined reading position;
A switchback conveyance path that reaches from the second discharge tray to a position upstream of the reading position of the main conveyance path in the document conveyance direction, and merges with the main conveyance path at the position;
A pull-in conveyance path that branches from the main conveyance path at a branch position downstream of the reading position of the main conveyance path in the document conveyance direction and joins the switchback conveyance path;
When a document is fed from the document set tray to the main transport path and transported along the main transport path, and the orientation of the front and back surfaces of the document at the scanning position is reversed, the scanning position After a document enters the switchback transport path via the pull-in transport path, the document is switched back on the switchback transport path, and the switched back document is returned from the switchback transport path to the main transport path. A document transport section;
An image reading unit that reads a document when the document conveyed along the main conveyance path passes through the reading position;
Controls the document conveying operation of the document conveying unit and the image reading operation of the image reading unit, and the reading surface of the document is a blank surface or a non-blank surface based on the image data of the document obtained by reading the document. A control unit that executes a sorting process for sorting a document in which at least one side of the document is the blank page and a document in which both sides are the non-blank page;
A receiving unit that receives an instruction to start the sorting process and receives whether or not to execute the sorting process in a standard mode;
When the receiving unit receives an instruction to start the sorting process in the standard mode,
The control unit determines whether or not the surface of the document is the blank surface by performing surface reading for reading the surface of the document, and if the surface of the document is the non-blank surface, Determine whether the back side of the document is the blank surface by performing back side scanning that reads the back side of the document after switching back,
The control unit discharges the document whose front side is determined to be the blank sheet surface by the front side reading to the first discharge tray, and also the document whose rear side is determined to be the blank page side by the back side reading is also the first. An image reading apparatus, wherein the document is discharged to a discharge tray, and a document whose rear surface is determined to be the non-blank surface by reading the back surface is discharged to the second discharge tray. When the document conveyance direction length is longer than the threshold length obtained by subtracting a predetermined margin from the document conveyance distance between the reading position and the branch position,
When the time required for the document to travel a distance corresponding to the threshold length has elapsed after the leading edge of the document in the conveyance direction has reached the reading position, the leading edge in the conveyance direction of the document is A determination is made as to whether or not the reading surface of the document is the blank page based on the image data of a partial area of the document obtained by reading the document until the required time elapses from
When it is determined that the surface of the document is the blank surface by the surface reading, the control unit discharges the document as it is from the reading position to the first discharge tray, and the surface of the document by the surface reading is the non-white surface. When it is determined that the page is a paper surface, the control unit switches back the document and causes the back side scanning to be performed.
When the back side reading determines that the back side of the document is the blank page, the control unit discharges the document as it is from the reading position to the first discharge tray, and the back side of the document is the non-white side by the back side reading. 2. The apparatus according to claim 1, wherein when it is determined that the sheet is a paper surface, after the document is caused to enter the switchback conveyance path from the pull-in conveyance, the document is discharged as it is to the second discharge tray without being switched back. The image reading apparatus described. With a display,
When the sorting process is completed, the control unit prompts the user to reinstruct the sorting process start instruction after resetting the document already discharged to the first discharge tray to the document set tray. Display a message on the display,
The notification message is such that the document end that is the rear end in the transport direction when the document is discharged to the first discharge tray is the front end in the transport direction when feeding from the document set tray, and The image reading apparatus according to claim 2, further comprising: a message for resetting the original on the first discharge tray so that the determined original surface becomes the reading surface for the front side reading. When the document conveyance direction length is longer than the threshold length obtained by subtracting a predetermined margin from the document conveyance distance between the reading position and the branch position,
The control unit causes the document to be read while allowing the document to enter the switchback conveyance path from the pull-in conveyance path, and when reading of the entire area from the leading edge in the conveyance direction to the trailing edge in the conveyance direction is completed, It is determined whether the reading surface of the document is the blank page based on the image data of the entire area,
When determining that the surface of the document is the blank sheet surface by the surface reading, the control unit switches the document back and then discharges the document to the first discharge tray. When determining that it is a non-blank page, the control unit switches the document back and performs the back side reading,
When the back side scanning determines that the back side of the document is the blank sheet side, the control unit switches back the document again and then discharges the document to the first discharge tray. 2. The control unit according to claim 1, wherein when it is determined that the sheet is a non-blank sheet surface, the control unit causes the document that has entered the switchback conveyance path to be directly discharged to the second discharge tray without being switched back. The image reading apparatus described. When the document conveyance direction length is equal to or less than a threshold length obtained by subtracting a predetermined margin from the document conveyance distance between the reading position and the branch position,
The control unit determines whether the reading surface of the document is the blank sheet surface based on the image data of the entire area when reading of the entire area from the leading edge in the conveying direction to the trailing edge in the conveying direction is completed. ,
When it is determined that the surface of the document is the blank surface by the surface reading, the control unit discharges the document as it is from the reading position to the first discharge tray, and the surface of the document by the surface reading is the non-white surface. When it is determined that the page is a paper surface, the control unit switches back the document and causes the back side scanning to be performed.
When the back side reading determines that the back side of the document is the blank page, the control unit discharges the document as it is from the reading position to the first discharge tray, and the back side of the document is the non-white side by the back side reading. 2. The apparatus according to claim 1, wherein when the paper is determined to be a paper surface, the original is allowed to enter the switchback conveyance path from the pull-in conveyance path, and is then discharged as it is to the second discharge tray without being switched back. The image reading device according to any one of? The document transport unit includes a pair of discharge rollers that are disposed near the discharge port to the first discharge tray of the main transport path and discharge the document to the first discharge tray by rotating,
The accepting unit accepts whether or not to execute the sorting process in a speed switching mode;
When the reception unit receives an instruction to start the sorting process in the speed switching mode,
The control unit discharges the document having the blank sheet surface to the first discharge tray, and discharges the document having no blank sheet surface to the first discharge tray,
The control unit controls the rotation speed of the discharge roller pair when one of the originals having the blank page and the original not having the blank page is nipped only by the discharge roller pair. The image reading apparatus according to claim 1, wherein the image reading device is set to be faster than a rotation speed when discharging the other document different from the one document. With a display,
The accepting unit accepts whether or not to execute the sorting process in a sequential notification mode,
When the reception unit receives an instruction to start the sorting process in the sequential notification mode,
The control unit discharges the document having the blank sheet surface to the first discharge tray, and discharges the document having no blank sheet surface to the first discharge tray,
The control unit is configured to interrupt the conveyance of the document and prompt the user to remove the document that has already been discharged to the first discharge tray when the back surface reading determines that the back surface of the document is the non-blank surface. The message is displayed on the display unit, and then, when the receiving unit receives an instruction to restart the sorting process, the conveyance of the document is restarted. Image reading device.   An image forming apparatus comprising the image reading apparatus according to claim 1.

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