JP2018198379A - Image reading device and image forming apparatus including the same - Google Patents

Abstract

To provide an image reading device that can read an image of a sturdy sheet, and an image forming apparatus including the image reading device.SOLUTION: An image reading device 10 comprises: a sheet feeding tray 31; a first conveyance path 33 that has a curved part 33a; a second conveyance path 35 that branches from a branch part 33b of the first conveyance path 33; a first ejection tray 34 that is installed consecutively to the first conveyance path 33; a second ejection tray 36 that is installed consecutively to the second conveyance path 35; a third conveyance path 37 through which a sheet fed out from the second ejection tray 36 passes; a first reading part 51, a second reading part 53, and a reading module for a surface 25 that read an image of the sheet; a thickness detection sensor 72; a switching member 71 that is arranged at the branch part 33b and switches an ejection destination of the sheet between the first ejection tray 34 and second ejection tray 36; and a reading device control part 90 that switches an attitude of the switching member 71 according to information acquired by the thickness detection sensor 72.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image reading apparatus and an image forming apparatus including the image reading apparatus, and more particularly to an image reading apparatus including a conveyance path having a curved portion having a substantially C-shaped cross section along the sheet conveying direction, and an image forming apparatus including the image reading apparatus. Relates to the device.

  Some image forming apparatuses such as a copying machine, a facsimile machine, and a scanner include a document conveying device that automatically sends a plurality of documents (sheets) to a document reading unit. The document conveying device separates the documents one by one from the uppermost layer of the document stack stacked on the document placing tray (supply tray), and sends the document toward the document reading unit. The original is read by the original reading unit and then discharged onto a discharge tray provided on the most downstream side of the original conveyance path.

  In such a document conveying device, the document conveying path is formed so as to have a curved portion having a substantially C-shaped cross section along the document conveying direction. As a result, the bundle of documents placed on the document placement tray is sent out one by one from the uppermost layer, and is stacked on the discharge tray in the state of being inverted upside down. For this reason, the order of the pages of the document bundle discharged to the discharge tray is the same as the order of the pages of the document bundle placed on the document placement tray.

  An image reading apparatus including a document conveyance path having a curved portion having a substantially C-shaped cross section along the document conveyance direction is disclosed in, for example, Patent Document 1.

JP 2009-021715 A

  However, in the conventional image reading apparatus, when an image is read by automatically conveying a strong sheet such as a resin card such as a credit card or a cash card or cardboard, the sheet passes through a curved portion of the document conveyance path. In other words, the sheet image cannot be read.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an image reading apparatus capable of reading a stiff sheet image and an image forming apparatus including the image reading apparatus. Is to provide.

  In order to achieve the above object, an image reading apparatus according to a first configuration of the present invention includes a supply tray on which sheets are stacked, and a first sheet that feeds sheets stacked on the supply tray one by one from the uppermost sheet. The sheet feeding device, the sheet fed from the supply tray, and the first conveying path having a substantially C-shaped curved portion along the sheet conveying direction, and the curved portion of the first conveying path A second conveyance path that branches off from a branch portion on the upstream side in the sheet conveyance direction; a first discharge tray that is connected to the downstream side in the sheet conveyance direction of the first conveyance path and that discharges the sheet that has passed through the first conveyance path; A second discharge tray that is connected downstream of the second conveyance path in the sheet conveyance direction and discharges a sheet that has passed through the second conveyance path, and a sheet discharged on the second discharge tray is set to 1 from the topmost sheet. Second sheet sending out one sheet at a time And the sheet conveyed from the second discharge tray passes, and is arranged upstream of the sheet conveying direction with respect to the third conveying path that merges with the merging part of the first conveying path and the branch part of the first conveying path. A first reading unit that reads an image of the first surface of the sheet that passes through the first conveyance path, and a second that reads an image of the second surface of the sheet that is disposed in the second conveyance path and passes through the second conveyance path. Information relating to the reading unit, the third reading unit that is arranged on the downstream side in the sheet conveyance direction with respect to the branching unit of the first conveyance path and reads the image of the second surface of the sheet passing through the first conveyance path, and the sheet type And a switching member that is disposed in the branching unit and switches the sheet discharge destination between the first discharge tray and the second discharge tray, and controls the first sheet delivery device and the second sheet delivery device, Switching unit according to the information acquired by the acquisition unit And a control unit for switching the posture. The control unit discharges the plurality of sheets discharged to the second discharge tray to the first discharge tray through the third conveyance path and the first conveyance path.

  According to the image reading apparatus of the first configuration of the present invention, the second conveyance path that branches from the branch portion on the upstream side in the sheet conveyance direction with respect to the curved portion of the first conveyance path, and the branch portion are arranged. A switching member that switches the discharge destination between the first discharge tray and the second discharge tray, and a control unit that switches the attitude of the switching member in accordance with the information acquired by the acquisition unit. The discharged sheet passes through the third conveyance path and the first conveyance path and is discharged to the first discharge tray. Thus, for example, in the case of a sheet such as plain paper, after the image of the sheet is read by at least one of the first reading unit and the third reading unit, the sheet is discharged to the first discharge tray. In the case of a strong sheet such as thick paper, after the image of the sheet is read by at least one of the first reading unit, the second reading unit, and the third reading unit, the sheet can be discharged to the first discharge tray. . That is, for example, in the case of a sheet such as plain paper, the sheet is passed through the curved portion of the first conveyance path to read the image of the sheet, while in the case of a strong sheet such as a resin card or cardboard, the sheet is The sheet image can be read without passing through the curved portion of one conveyance path. As described above, even in the case of a strong sheet, a sheet conveyance defect does not occur, and the sheet image can be read.

  Further, the control unit discharges the plurality of sheets discharged to the second discharge tray to the first discharge tray through the third conveyance path and the first conveyance path. For example, when reading an image of a strong sheet such as a resin card or cardboard, the sheet bundle placed on the supply tray is sent one by one from the uppermost sheet and passes through the first conveyance path and the second conveyance path. When discharged to the second discharge tray, the order of the pages of the sheet bundle discharged to the second discharge tray is different from the order of the pages of the sheet bundle placed on the supply tray. Therefore, the plurality of sheets discharged to the second discharge tray are sent out one by one from the uppermost sheet, passed through the third transport path and the first transport path, and discharged to the first discharge tray, whereby the first The order of the pages of the sheet bundle discharged to the discharge tray can be returned to the original order.

1 is a cross-sectional view schematically showing a structure of an image forming apparatus including an image reading apparatus according to an embodiment of the present invention. 1 is a cross-sectional view illustrating a structure of an image reading apparatus according to an embodiment of the present invention. FIG. 4 is a cross-sectional view illustrating a structure around a branch portion of the image reading apparatus according to the embodiment of the present invention, and is a diagram illustrating a state in which a switching member is disposed so as to discharge a sheet to a first discharge tray. FIG. 3 is a cross-sectional view illustrating a structure around a branching portion of the image reading apparatus according to the embodiment of the present invention, and is a view illustrating a state in which a switching member is disposed to discharge a sheet to a second discharge tray.

  Embodiments of the present invention will be described below with reference to the drawings.

  An image forming apparatus 100 provided with an image reading apparatus 10 according to an embodiment of the present invention will be described with reference to FIGS. In FIG. 1, an image forming apparatus 100 (here, a digital multi-function peripheral is shown as an example) is a multi-function peripheral body 1 and an image reading apparatus 10 that is disposed on the top of the multi-function peripheral body 1 and reads an image of a sheet such as a document. , Is composed of.

  The MFP main body 1 includes a paper feeding unit 2 that feeds paper (recording medium), an image forming unit 3 that forms a toner image on the paper based on image data read by the image reading device 10, and a paper A fixing unit 4 for fixing the toner image, discharge rollers 6a and 6b for conveying the fixed paper and discharging it to the paper discharge units 5a and 5b, and a main body control unit 8 for controlling the multifunction machine main body 1, respectively. . The main body control unit 8 is configured to control the operation of the image forming apparatus 100 and to communicate with a reading device control unit 90 (to be described later) of the image reading device 10.

  The image reading apparatus 10 is arranged on the upper part of the multifunction machine main body 1 and reads a reading unit 20 that reads an image of a sheet such as a document, and a sheet placed on a contact glass 21 (see FIG. 2) of the reading unit 20. A platen (sheet presser) 11 that is pressed and held is provided so as to be openable and closable, and a conveyance unit 30 that automatically conveys a sheet is attached on the platen 11.

  As shown in FIG. 2, a contact glass 21 made of an automatic reading glass 21 a and a manually placed sheet glass 21 b is disposed on the upper surface of the reading unit 20. Inside the reading unit 20, a surface reading module (third reading unit) 25 is arranged. The front surface reading module 25 is a CCD sensor type reading module, and includes a light source, a condensing lens, and a CCD sensor (all not shown).

  The front surface reading module 25 reads an image of a sheet placed on the manually placed sheet glass 21b while moving in the sub-scanning direction (left-right direction in FIG. 2). Further, the front surface reading module 25 reads an image on the surface (second surface) of the sheet conveyed by the conveying unit 30 in a state of being stopped just below the automatic reading glass 21a.

  A conveyance guide 26 that scoops up the leading edge of the sheet conveyed by the conveyance unit 30 is disposed between the automatic reading glass 21a and the manually placed sheet glass 21b. A white reference plate 27 for correcting shading of the front surface reading module 25 is disposed below the conveyance guide 26.

  The transport unit 30 includes a sheet feed tray (supply tray) 31 on which sheets such as documents are stacked, and a first transport path that is disposed in the cover member 32 and through which the sheet fed from the sheet feed tray 31 passes. 33 and a first discharge tray 34 that is connected downstream of the first conveyance path 33 in the sheet conveyance direction and discharges the sheet that has passed through the first conveyance path 33 is provided.

  The first conveyance path 33 has a curved portion 33a having a substantially C-shaped cross section along the sheet conveyance direction, and is formed so as to be reversed between the registration roller pair 44 described later and the automatic reading glass 21a. Yes. A branch portion 33b is provided upstream of the curved portion 33a of the first conveyance path 33 in the sheet conveyance direction, and the second conveyance path 35 is provided from the branch portion 33b so as to extend substantially linearly in the left direction. ing. On the downstream side of the second conveyance path 35 in the sheet conveyance direction, a second discharge tray 36 for discharging the sheet that has passed through the second conveyance path 35 is provided continuously.

  Further, a merging portion 33 c is provided at the downstream end portion in the sheet conveying direction of the curved portion 33 a of the first conveying path 33. The sheet fed from the second discharge tray 36 passes through the merge portion 33c, and the downstream end in the sheet conveyance direction of the third conveyance path 37 extending substantially linearly in the right direction merges.

  A pickup roller 41, a paper feed belt 42 and a separation roller 43, a registration roller pair 44, a conveyance roller pair 45 and 46, and a first discharge roller pair 47 are arranged along the first conveyance path 33. The sheet feeding belt 42 is wound around a driving roller 48a and a driven roller 48b, and the separation roller 43 is in contact with the roller at a predetermined pressure from below. The separation roller 43 has a built-in torque limiter, and is driven to rotate with the paper feeding belt 42 only when the rotational load exceeds a predetermined torque. The pickup roller 41, the paper feed belt 42, the separation roller 43, the driving roller 48a, and the driven roller 48b constitute the first sheet feeding device of the present invention. The first sheet delivery device is controlled by a reading device controller 90 described later.

  A second discharge roller pair 49 is disposed at the downstream end of the second conveyance path 35 in the sheet conveyance direction.

  A pickup roller 65, a paper feed belt 66 and a separation roller 67 are arranged along the third conveyance path 37. The sheet feeding belt 66 is wound around a driving roller 68a and a driven roller 68b (both are shown in FIG. 3), and a separation roller 67 is in contact with a predetermined pressure from below. The separation roller 67 has a built-in torque limiter, and is driven to rotate with the paper feed belt 66 only when the rotational load exceeds a predetermined torque. The pickup roller 65, the paper feed belt 66, the separation roller 67, the driving roller 68a, and the driven roller 68b constitute the second sheet feeding device of the present invention. The second sheet delivery device is controlled by a reading device controller 90 described later.

  Further, on the upstream side in the sheet conveyance direction with respect to the branch portion 33 b of the first conveyance path 33, the first reading unit 51 formed of a contact image sensor and the first reading unit 51 are disposed across the first conveyance path 33. And a first conveyance roller 61 that conveys the sheet. The first reading unit 51 is arranged on the lower side with respect to the first conveyance path 33 and reads an image on the back surface (first surface) of the sheet passing through the first conveyance path 33. The first transport roller 61 is disposed on the upper side with respect to the first transport path 33. The first transport roller 61 has a white outer peripheral surface and is used when white reference data is acquired by shading correction of the first reading unit 51.

  In the second conveyance path 35, there are a second reading unit 53 made of a contact image sensor, and a second conveyance roller 63 that is arranged opposite to the second reading unit 53 with the second conveyance path 35 interposed therebetween and conveys the sheet. Is provided. The second reading unit 53 is arranged on the upper side with respect to the second conveyance path 35 and reads an image on the surface (second surface) of the sheet passing through the second conveyance path 35. The second transport roller 63 is disposed below the second transport path 35. The second transport roller 63 has a white outer peripheral surface, and is used when white reference data is acquired by shading correction of the second reading unit 53.

  A switching member 71 that switches the sheet discharge destination between the first discharge tray 34 and the second discharge tray 36 is provided at the branch portion 33 b of the first conveyance path 33. In addition, a thickness detection sensor (acquisition unit) 72 that detects the thickness of the sheet (information on the type of sheet) is provided on the upstream side in the sheet conveyance direction with respect to the branch portion 33 b of the first conveyance path 33. A known media sensor can be used as the thickness detection sensor 72. The detection result of the thickness detection sensor 72 is transmitted to a reading device control unit (control unit) 90 that controls the image reading device 10.

  The reading device control unit 90 controls the posture of the switching member 71 according to the thickness of the sheet detected by the thickness detection sensor 72. Specifically, when the thickness of the sheet is 0.24 mm or less, the reading device controller 90 sets the switching member 71 so that the sheet passes through the curved portion 33a and is discharged to the first discharge tray 34. Control attitude. On the other hand, when the thickness of the sheet is larger than 0.24 mm (when the sheet is strong), the reading device controller 90 discharges the sheet to the second discharge tray 36 through the second conveyance path 35. Thus, the posture of the switching member 71 is controlled.

  Note that the thickness detection sensor 72 may not be provided in order to acquire information regarding the type of sheet. For example, a user inputs a sheet thickness and material (information on the sheet type) to an operation panel (not shown), and the information is sent from the main body control unit 8 (see FIG. 1) to a transmission / reception unit (not shown) of the image reading apparatus 10. You may transmit to (acquisition part). Then, the reading device control unit 90 may control the attitude of the switching member 71 based on information acquired by the transmission / reception unit. At this time, when the sheet is, for example, a resin card, the reading device control unit 90 moves the posture of the switching member 71 so that the sheet passes through the second conveyance path 35 and is discharged to the second discharge tray 36. May be controlled.

  In addition, the reading device control unit 90 causes the second discharge tray when the predetermined number of sheets (for example, all the sheets set in the sheet feeding tray 31 and one set of sheets) are discharged to the second discharge tray. The sheet discharged to 36 passes through the third conveyance path 37 and the first conveyance path 33 and is discharged to the first discharge tray 34.

  Next, a sheet-through type image reading operation using the image reading apparatus 10 will be described. In the sheet through method, a plurality of sheets are set on the sheet feeding tray 31 with the image surface facing upward. Thereafter, when a copy start button on an operation panel (not shown) of the image forming apparatus 100 is turned on, a lift plate (not shown) is raised by an elevating mechanism (not shown), and the sheet is pressed against the pickup roller 41. Is done.

  The sheets set in the sheet feeding tray 31 are usually fed by the pickup roller 41 to the nip portion between the sheet feeding belt 42 and the separation roller 43 at the upper stage. Then, only the uppermost one of the plurality of sheets is separated by the separation roller 43 and conveyed toward the registration roller pair 44. The thickness of the sheet that has passed through the registration roller pair 44 is detected by the thickness detection sensor 72.

  When the thickness of the sheet is 0.24 mm or less, for example, the switching member 71 is disposed at the position shown in FIG. 3, and the sheet is conveyed toward the bending portion 33a. Then, the image on the surface (second surface) of the sheet is read by the surface reading module 25 through the automatic reading glass 21a. Thereafter, the sheet that has passed through the automatic reading glass 21 a is discharged to the first discharge tray 34 by the first discharge roller pair 47.

  When the thickness of the sheet is larger than 0.24 mm, for example (or when the sheet is a resin card, for example), the switching member 71 is arranged at the position shown in FIG. It is conveyed toward. Then, the image on the surface (second surface) of the sheet is read by the second reading unit 53. Thereafter, the sheet that has passed through the second reading unit 53 is discharged to the second discharge tray 36 by the second discharge roller pair 49.

  When reading both sides of the sheet, after the first reading unit 51 reads the image on the back side (first side) of the sheet, the switching member 71 switches the sheet discharge destination (sheet transport direction).

  Here, in the present embodiment, the reading device control unit 90 reads the image of the surface (second surface) of the sheet placed on the sheet feeding tray 31 as described above, and reads the sheet from the first discharge tray 34 or the sheet. The image reading mode for discharging to the second discharge tray 36, and the sheet discharged to the second discharge tray 36 through the third conveyance path 37 and the first conveyance path 33 without reading the image by the front surface reading module 25. It is possible to execute a sheet feeding mode in which the sheet is passed and discharged to the first discharge tray 34.

  For this reason, when the thickness of the sheet is larger than 0.24 mm, for example (or when the sheet is a resin card, for example), a predetermined number (one set) of sheets is discharged to the second discharge tray 36. Then, the image reading mode is switched to the sheet feeding mode. Then, a lift plate (not shown) is raised by an elevating mechanism (not shown) of the second discharge tray 36, and the sheet is pressed against the pickup roller 65.

  The sheets discharged to the second discharge tray 36 are usually sent to the nip portion between the paper feed belt 66 and the separation roller 67 by a pickup roller 65. Then, only the uppermost one of the plurality of sheets is separated by the separation roller 67, passes through the third transport path 37 and the first transport path 33, and is discharged to the first discharge tray 34. Note that the sheet conveyance speed in the sheet feeding mode is faster than the sheet conveyance speed in the image reading mode. In the sheet feed mode, sheet thickness detection and image reading are not performed.

  In the image reading mode, as described above, when the sheet thickness is, for example, 0.24 mm or less, the sheet is passed through the curved portion 33a and discharged to the first discharge tray 34. And a second mode in which the sheet is discharged to the second discharge tray 36 when it is larger than 24 mm (or when the sheet is, for example, a resin card).

  When the second mode is executed, the reading device control unit 90 continues the second mode until reading of one set of sheet images is completed. Specifically, a predetermined number (one set) of sheets is set in the sheet feeding tray 31, and the thickness of the first sheet is larger than 0.24 mm, for example (or the sheet is made of a resin card, for example). When the sheet is discharged to the second discharge tray 36, the reading device controller 90 causes all the sheets set in the sheet feed tray 31 to be transferred to the second discharge tray regardless of the detection result of the thickness detection sensor 72. The second mode is continued until discharged to 36. When the second mode is executed, the thickness detection by the thickness detection sensor 72 may not be performed until the reading of the image of one set of sheets is completed.

  Next, a detailed structure around the first reading unit 51 and the second reading unit 53 will be described.

  As shown in FIG. 3, a first contact glass 81 constituting a part of the lower conveyance surface of the first conveyance path 33 is provided above the first reading unit 51. The first reading unit 51 is pressed against the first contact glass 81 by the first biasing member 82. Therefore, the distance from the first reading unit 51 to the upper surface of the first contact glass 81, that is, the distance from the first reading unit 51 to the lower surface (first surface) of the sheet is constant.

  A first adjustment unit 83 that adjusts the gap between the first reading unit 51 and the first transport roller 61 is provided around the first reading unit 51. The first adjustment unit 83 includes, for example, a drive motor, a worm gear or an eccentric cam, and the like. The first adjustment unit 83 moves the first conveyance roller 61 in the vertical direction according to the thickness of the sheet detected by the thickness detection sensor 72 (or information acquired by the transmission / reception unit). The gap with the first transport roller 61 is adjusted.

  Specifically, when the thickness of the sheet is approximately the same as that of thin paper or plain paper, the first transport roller 61 is disposed so as to contact the first contact glass 81. As the thickness of the sheet increases, the first transport roller 61 is moved upward. When the thickness of the sheet is larger than 0.24 mm, for example, the first transport roller 61 is arranged at a predetermined distance from the first contact glass 81 as shown in FIG.

  Below the second reading unit 53, a second contact glass 85 constituting a part of the upper conveyance surface of the second conveyance path 35 is provided. The second reading unit 53 is pressed against the second contact glass 85 by the second urging member 86. For this reason, the distance from the 2nd reading part 53 to the distance from the lower surface of the 2nd contact glass 85 is constant.

  A second adjustment unit 87 that adjusts the gap between the second reading unit 53 and the second transport roller 63 is provided around the second reading unit 53. The 2nd adjustment part 87 is comprised by the drive motor, the worm gear, or eccentric cam, etc., for example. The second adjustment unit 87 moves the second reading unit 53 and the second contact glass 85 in the vertical direction according to the thickness of the sheet detected by the thickness detection sensor 72 (or information acquired by the transmission / reception unit). The gap between the second reading unit 53 and the second transport roller 63 is adjusted.

  Specifically, as the thickness of the sheet increases, the second reading unit 53 and the second contact glass 85 are moved upward. When the thickness of the sheet is larger than 0.24 mm, for example, the second contact glass 85 is arranged at a predetermined distance from the second transport roller 63.

  Note that the second adjustment unit 87 may be configured to adjust the gap between the second reading unit 53 and the second conveyance roller 63 by moving the second conveyance roller 63 in the vertical direction.

  In the present embodiment, as described above, the second conveyance path 35 that branches from the branch portion 33b on the upstream side in the sheet conveyance direction with respect to the curved portion 33a of the first conveyance path 33 and the branch portion 33b are arranged, and A switching member 71 that switches the discharge destination between the first discharge tray 34 and the second discharge tray 36, and a reader control unit 90 that switches the attitude of the switching member 71 according to the information acquired by the thickness detection sensor 72, The reading device controller 90 passes the sheet discharged to the second discharge tray 36 through the third conveyance path 37 and the first conveyance path 33 and discharges the sheet to the first discharge tray 34. Thus, for example, in the case of a sheet such as plain paper, after the image of the sheet is read by the front surface reading module 25 (or both of the front surface reading module 25 and the first reading unit 51), the sheet is removed from the first discharge tray. In the case of a strong sheet such as a resin card or cardboard, the image of the sheet is read by the second reading unit 53 (or both the second reading unit 53 and the first reading unit 51). After that, the sheet can be discharged to the first discharge tray 34 via the second discharge tray 36. That is, for example, in the case of a sheet of plain paper or the like, the sheet is passed through the curved portion 33a of the first conveyance path 33 and the image of the sheet is read. The sheet image can be read without passing through the curved portion 33 a of the first conveyance path 33. As described above, even in the case of a strong sheet, a sheet conveyance defect does not occur, and the sheet image can be read.

  In addition, the reading device control unit 90 passes the plurality of sheets discharged to the second discharge tray 36 through the third conveyance path 37 and the first conveyance path 33 and discharges them to the first discharge tray 34. For example, when an image of a strong sheet such as a resin card or cardboard is read, the sheet bundle placed on the sheet feeding tray 31 is sent out one by one from the uppermost sheet, and the first transport path 33 and the second transport path 33 are sent. When the sheet passes through the conveyance path 35 and is discharged to the second discharge tray 36, the order of the pages of the sheet bundle discharged to the second discharge tray 36 is the order of the pages of the sheet bundle placed on the sheet feeding tray 31. It will be different. Therefore, a plurality of sheets discharged to the second discharge tray 36 are fed one by one from the uppermost sheet, passed through the third transport path 37 and the first transport path 33, and discharged to the first discharge tray 34. Thus, the page order of the sheet bundle discharged to the first discharge tray 34 can be returned to the original order.

  In addition, as described above, the thickness detection sensor 72 is used as an acquisition unit that acquires information regarding the type of sheet. Accordingly, the sheet discharge destination can be switched according to the thickness of the sheet.

  Further, as described above, the reader control unit 90 can execute the sheet feeding mode in which the sheet discharged to the second discharge tray 36 is discharged to the first discharge tray 34. Thereby, by executing the sheet feeding mode, the order of the pages of the sheet bundle discharged to the first discharge tray 34 can be easily returned to the original order.

  Further, as described above, the sheet conveyance speed in the sheet feeding mode is faster than the sheet conveyance speed in the image reading mode. Thereby, the sheet passing mode can be completed in a short time.

  Further, as described above, when the second mode is executed, the reading device control unit 90 continues the second mode until reading of one set of sheet images is completed. Thus, for example, when a bundle of sheets having a thickness of about 0.24 mm is set on the sheet feeding tray 31, the mode is detected between the first mode and the second mode for each sheet due to the detection error of the thickness detection sensor 72. Can be prevented from switching. That is, in the image reading mode, it is possible to prevent sheets from being stacked on the first discharge tray 34 and the second discharge tray 36 regardless of the order of stacking on the sheet feed tray 31. For this reason, after executing the sheet feeding mode, the order of the pages of the sheet bundle discharged to the first discharge tray 34 can be easily returned to the original order.

  Further, as described above, the merging portion 33c is provided at the downstream end of the bending portion 33a in the sheet conveying direction. Thereby, for example, in the case of a strong sheet such as a resin card or cardboard, it is possible to easily prevent the sheet conveyance failure from occurring in the curved portion 33a.

  In addition, as described above, the first adjustment unit 83 that adjusts the gap between the first reading unit 51 and the first transport roller 61 according to the information acquired by the thickness detection sensor 72 is provided. Thereby, it is possible to prevent the sheet from being caught by the first reading unit 51 and the first conveyance roller 61 and causing a sheet conveyance defect.

  Further, as described above, the first adjustment unit 83 adjusts the gap between the first reading unit 51 and the first conveyance roller 61 by moving the first conveyance roller 61 in the vertical direction. Accordingly, it is possible to adjust the gap between the first reading unit 51 and the first transport roller 61 while appropriately maintaining the distance from the first reading unit 51 to the back surface (first surface) of the sheet.

  Further, as described above, the second adjustment unit 87 that adjusts the gap between the second reading unit 53 and the second conveyance roller 63 according to the information acquired by the thickness detection sensor 72 is provided. As a result, it is possible to prevent the sheet from being caught by the second reading unit 53 and the second transport roller 63 and causing a sheet transport failure.

  In addition, as described above, the second adjustment unit 87 adjusts the gap between the second reading unit 53 and the second transport roller 63 by moving the second reading unit 53 in the vertical direction. Accordingly, it is possible to adjust the gap between the second reading unit 53 and the second transport roller 63 while appropriately maintaining the distance from the second reading unit 53 to the surface (second surface) of the sheet.

  The embodiment disclosed this time is illustrative in all points and is not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, the image reading apparatus mounted on the image forming apparatus has been described as an example of the image reading apparatus of the present invention. However, the present invention can also be applied to an image scanner used separately from the image forming apparatus. It is.

  In the above embodiment, the first reading unit 51 and the second reading unit 53 are configured by contact image sensors, and the surface reading module (third reading unit) 25 is configured by a CCD sensor. The invention is not limited to this. For example, the surface reading module 25 may be configured using a contact image sensor or other reading parts.

  Moreover, in the said embodiment, when the thickness of a sheet | seat is larger than 0.24 mm, for example (or when a sheet | seat is a resin card, for example), and when reading both surfaces of a sheet | seat, the back surface ( Although an example in which the image on the first surface is read by the first reading unit 51 has been described, the image on the back surface (first surface) of the sheet may be read by the front surface reading module 25.

  Further, in the above-described embodiment, an example in which only the image on the front surface (second surface) of the sheets stacked on the sheet feeding tray 31 or the images on both the front surface (second surface) and the back surface (first surface) is read. Although shown, only the image on the back surface (first surface) of the sheets stacked on the sheet feeding tray 31 may be read.

10 Image Reading Device 25 Surface Reading Module (Third Reading Unit)
31 Sheet feeding tray (supply tray)
33 1st conveyance path 33a Bending part 33b Branching part 33c Merge part 34 1st discharge tray 35 2nd conveyance path 36 2nd discharge tray 37 3rd conveyance path 51 1st reading part 53 2nd reading part 61 1st conveyance roller 63 Second transport roller 71 Switching member 72 Thickness detection sensor (acquisition unit)
83 1st adjustment part 87 2nd adjustment part 90 Reader control part (control part)
100 Image forming apparatus

Claims (11)

A supply tray on which sheets are stacked;
A first sheet feeding device for feeding the sheets stacked on the supply tray one by one from the uppermost sheet;
A first conveyance path having a curved portion having a substantially C-shaped cross section along the sheet conveyance direction while the sheet fed from the supply tray passes;
A second conveyance path that branches from a branching portion on the upstream side in the sheet conveyance direction with respect to the curved portion of the first conveyance path;
A first discharge tray that is connected downstream of the first conveyance path in the sheet conveyance direction, and that discharges the sheet that has passed through the first conveyance path;
A second discharge tray that is connected to the downstream side of the second conveyance path in the sheet conveyance direction and discharges the sheet that has passed through the second conveyance path;
A second sheet feeding device for feeding the sheets discharged onto the second discharge tray one by one from the uppermost sheet;
A third transport path through which the sheet fed from the second discharge tray passes, and merges with a merge portion of the first transport path;
A first reading unit that is arranged on the upstream side in the sheet conveying direction with respect to the branch portion of the first conveying path and reads an image of a first surface of the sheet passing through the first conveying path;
A second reading unit that is disposed in the second conveyance path and reads an image on a second surface of a sheet passing through the second conveyance path;
A third reading unit that is disposed on the downstream side in the sheet conveyance direction with respect to the branching unit of the first conveyance path and reads an image of a second surface of the sheet passing through the first conveyance path;
An acquisition unit for acquiring information on the type of sheet;
A switching member that is disposed in the branch portion and switches a sheet discharge destination between the first discharge tray and the second discharge tray;
A control unit that controls the first sheet delivery device and the second sheet delivery device, and switches the attitude of the switching member according to the information acquired by the acquisition unit;
With
The control unit discharges a plurality of sheets discharged to the second discharge tray to the first discharge tray through the third transfer path and the first transfer path. .   The image reading apparatus according to claim 1, wherein the acquisition unit is a thickness detection sensor that is disposed upstream of the branching unit in the sheet conveyance direction and detects a thickness of the sheet.   The control unit reads an image on the second surface of the sheet placed on the supply tray and discharges the sheet to the first discharge tray or the second discharge tray, and to the second discharge tray. The image reading apparatus according to claim 1, wherein a sheet feeding mode in which discharged sheets are discharged to the first discharge tray can be executed. In the sheet feeding mode, the third reading unit does not read a sheet image,
The image reading apparatus according to claim 3, wherein a sheet conveying speed in the sheet feeding mode is faster than a sheet conveying speed in the image reading mode. The image reading mode includes a first mode for discharging a sheet to the first discharge tray and a second mode for discharging a sheet to the second discharge tray;
5. The image reading apparatus according to claim 3, wherein, when the second mode is executed, the control unit continues the second mode until reading of an image of one set of sheets is completed. .   The image reading apparatus according to claim 1, wherein the merging portion is provided at a downstream end portion of the bending portion in a sheet conveying direction. A first conveying roller disposed opposite to the first reading unit across the first conveying path and conveying a sheet;
A first adjustment unit that adjusts a gap between the first reading unit and the first transport roller according to the information acquired by the acquisition unit;
The image reading apparatus according to claim 1, further comprising: The first reading unit is disposed below the first conveyance path,
The first transport roller is disposed on the upper side with respect to the first transport path,
The image according to claim 7, wherein the first adjustment unit adjusts a gap between the first reading unit and the first conveyance roller by moving the first conveyance roller in a vertical direction. Reader. A second conveying roller disposed opposite to the second reading unit across the second conveying path and conveying the sheet;
A second adjustment unit that adjusts a gap between the second reading unit and the second transport roller according to the information acquired by the acquisition unit;
The image reading apparatus according to claim 1, further comprising: The second reading unit is disposed on the upper side with respect to the second transport path,
The second transport roller is disposed below the second transport path,
The image according to claim 9, wherein the second adjustment unit adjusts a gap between the second reading unit and the second transport roller by moving the second reading unit in a vertical direction. Reader.   An image forming apparatus comprising the image reading apparatus according to claim 1.

Images