JP2013052929A - Sheet conveying device, image reading device, method of controlling sheet conveying device, sheet conveying system, and image reading system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet conveying device, an image reading device, a method of controlling the sheet conveying device, and a sheet conveying system, that can satisfactorily convey a sheet irrespective of the thickness of a sheet by using a plurality of conveyance passages, and to provide an image reading system.SOLUTION: The sheet conveying device includes: a U-turn path performing the conveyance by reversing the front and back of a sheet from a sheet feeding part; a sheet conveyance passage (and straight path) performing straight conveyance without reversing the front and back of a sheet from the sheet feeding part; a conveyance passage switching means for performing the switching to either one of the U-turn path and the straight path; a thick sheet detection means for detecting a thick sheet having a thickness equal to or more than a predetermined threshold; and a control part controlling the sheet conveyance from the sheet feeding part. The control part stops the conveyance of the thick sheet when the thick sheet detection means detects the thick sheet in a switched state to the U-turn path by the conveyance passage switching means, or continues the conveyance of the thick sheet by performing the switching from the U-turn path to the straight path by the conveyance passage switching means.

Description

  The present invention relates to an image reading apparatus such as a copying machine, a printer, a scanner, and a facsimile, or a sheet conveying apparatus mounted on an image forming apparatus, an image reading apparatus, a method for controlling the sheet conveying apparatus, a sheet conveying system, and an image reading system. .

  Known as multifunction devices and copiers that function as printers, scanners, facsimiles, etc., are equipped with a sheet transport device that feeds and transports sheets placed on the paper feed unit in order and discharges them to the paper discharge unit ing. For example, a feed having a configuration in which a plurality of sheets are separated and fed one by one in order from the paper feed unit, and then a U-turn shaped sheet conveyance path is conveyed from top to bottom and discharged to a paper discharge unit. An apparatus has been proposed (see Patent Document 1).

JP 2007-306146 A

  The image reading device disclosed in Patent Document 1 has a configuration in which a thin sheet (for example, plain paper) that is relatively weak can be efficiently conveyed and read one by one, but the image is relatively strong. It is not a configuration in which a thick sheet (for example, a plastic card, a driver's license, an insurance card, etc.) can be conveyed and read. The thick sheet can be read by scanning the image reading unit along the document placing platen on the upper part of the lower unit. However, each time the thick sheet is lifted, the thick sheet is placed on the document placing platen. It is necessary to set a sheet, which may be very complicated.

  Note that the above-described problem does not occur only in the image reading apparatus, and may occur in a sheet conveying apparatus that conveys a wide variety of sheets and a sheet processing apparatus including such a sheet conveying apparatus. is there.

  The present invention provides a sheet conveying apparatus, an image reading apparatus, a sheet conveying apparatus control method, a sheet conveying system, and an image reading system that can convey a sheet satisfactorily regardless of the thickness of the sheet using a plurality of conveying paths. To do.

  The sheet conveying apparatus according to the present invention includes a first conveying path for conveying the sheet front and back from the sheet feeding unit, and a second conveying path for conveying the sheet linearly from the sheet feeding unit without inverting the sheet front and back. A conveyance path switching unit that switches to one of the first conveyance path and the second conveyance path, a thick sheet detection unit that detects a thick sheet having a thickness equal to or greater than a predetermined threshold, and the sheet feeding unit. Control means for controlling the sheet conveyance of the thick sheet when the thick sheet detection means detects the thick sheet in a state where the conveyance path switching means has switched to the first conveyance path. The conveyance of the thick sheet is continued by switching the first conveyance path to the second conveyance path by the conveyance path switching means. Thereby, the structure which can convey a sheet | seat irrespective of the thickness of a sheet | seat using a some conveyance path is realizable.

  In the present invention, the control unit resumes the conveyance of the thick sheet when the conveyance path switching unit switches from the first conveyance path to the second conveyance path after stopping the conveyance of the thick sheet. It is preferable to make it. As a result, after the thick sheet conveyance is stopped, the thick sheet conveyance can be continuously resumed.

  Furthermore, in the present invention, the first conveying path has a reverse path of the front and back sides of the sheet branched from the second conveying path, and the thick sheet detecting means is disposed upstream of the second conveying path in the sheet conveying direction. It is preferable that the transport path switching means is disposed at a portion where the second transport path branches from the second transport path. Thereby, the structure which can convey a sheet | seat irrespective of the thickness of a sheet | seat using a some conveyance path is realizable.

  In the present invention, on the upstream side in the sheet conveyance direction of the second conveyance path, a conveyance roller that conveys the sheet toward the downstream side in the conveyance direction, and a driven roller that is urged and rotated by the conveyance roller side, And the thick sheet detecting means has means for measuring the thickness of the sheet based on a movement amount of the driven roller in a direction away from the conveying roller. As a result, the thickness of the sheet can be reliably measured, and optimal conveyance can be performed according to the thickness of the sheet using a plurality of conveyance paths.

  Furthermore, in the present invention described above, a conveyance roller that conveys the sheet along the second conveyance path, a driven roller that is disposed to face the conveyance roller, and a bias that biases the driven roller toward the conveyance roller. And a biasing receiving portion having a regular polygonal cross-sectional shape perpendicular to the axial direction of the rotating shaft on the rotating shaft of the driven roller. It is provided. Accordingly, the biasing means is reliably brought into contact with the rotation shaft after assembling the driven roller (with the rotation shaft) of the main body of the sheet conveying apparatus without considering the position around the rotation shaft of the driven roller. As a result, assembly workability can be improved.

  In the present invention, the control unit stops sheet conveyance when the conveyance path is switched by the conveyance path switching unit during sheet conveyance. Thereby, damage of a sheet | seat etc. can be prevented.

  Furthermore, in the present invention described above, the display device further includes a display unit for displaying that the sheet conveyance is stopped, and the control unit instructs the display unit to display that the sheet conveyance is stopped when the sheet conveyance is stopped. It is characterized by doing. Thereby, it becomes easy for the user to grasp the stopped state of the sheet conveyance, and user convenience can be improved.

  In the present invention, the conveyance roller that conveys the sheet along the conveyance path, a driven roller that is disposed to face the conveyance roller, and an urging unit that urges the driven roller toward the conveyance roller. The rotating shaft of the driven roller is provided with a biasing receiving portion that is a portion biased by the biasing means and whose cross-sectional shape perpendicular to the axial direction of the rotating shaft is a regular polygon. It is characterized by being. Accordingly, the biasing means is reliably brought into contact with the rotation shaft after assembling the driven roller (with the rotation shaft) of the main body of the sheet conveying apparatus without considering the position around the rotation shaft of the driven roller. As a result, assembly workability can be improved.

  Furthermore, the present invention can also be applied to an image reading apparatus including the sheet conveying device described above. Accordingly, it is possible to realize an image reading apparatus that can satisfactorily convey a sheet using a plurality of conveyance paths regardless of the thickness of the sheet.

  In addition, the control method of the sheet conveying apparatus according to the present invention includes a reverse conveying mode for conveying the sheet front and back from the sheet feeding unit and a straight conveying mode for conveying the sheet linearly without inverting the sheet front and back. In controlling the sheet conveying apparatus, the conveyance of the thick sheet is stopped when the thick sheet detecting unit detects a thick sheet having a thickness equal to or larger than a predetermined threshold in the state where the conveyance mode switching unit switches to the reverse conveyance mode. Alternatively, the transport mode switching unit switches the reverse transport mode to the straight transport mode and continues the transport of the thick sheet. Thereby, sheet conveyance can be performed satisfactorily regardless of the thickness of the sheet.

  Furthermore, the sheet conveying system according to the present invention includes a first conveying path that conveys the sheet front and back from the sheet feeding unit and the second conveying that linearly conveys the sheet feeding unit without inverting the sheet front and back. A conveyance path switching unit that switches to one of the first conveyance path and the second conveyance path, a thick sheet detection unit that detects a thick sheet having a thickness equal to or greater than a predetermined threshold, and the sheet feeding Control means for controlling the conveyance of the sheet from the section, and the control means detects the thick sheet when the thick sheet detection means detects the thick sheet in a state where the conveyance path switching means switches to the first conveyance path. The conveyance of the thick sheet is continued by stopping conveyance of the sheet or switching from the first conveyance path to the second conveyance path by the conveyance path switching unit. . Thereby, it is possible to satisfactorily convey the sheet using a plurality of conveyance paths regardless of the thickness of the sheet.

  The image reading system according to the present invention includes a first conveyance path that conveys the sheet front and back from the sheet feeding unit and the second conveyance that linearly conveys the sheet from the sheet feeding unit without being reversed. A thick sheet having a thickness equal to or greater than a predetermined threshold, an image reading unit that reads an image of the conveyed sheet, a conveyance path switching unit that switches to one of the first conveyance path and the second conveyance path A thick sheet detecting means for detecting the sheet and a control means for controlling the sheet conveyance from the sheet feeding unit, wherein the control means is switched to the first conveyance path by the conveyance path switching means. When the thick sheet detecting unit detects the thick sheet, the conveyance of the thick sheet is stopped, or the conveyance path switching unit switches from the first conveyance path to the second conveyance path before Characterized in that to continue the conveyance of thick sheets. Thereby, it is possible to satisfactorily convey the sheet using a plurality of conveyance paths regardless of the thickness of the sheet.

  According to the present invention, a sheet can be favorably transported using a plurality of transport paths regardless of the thickness of the sheet.

1 is a side cross-sectional view showing a general overall configuration of an image reading apparatus according to an embodiment of the present invention. The schematic perspective view which shows the thick sheet | seat detection means which concerns on Embodiment 1 of this invention. The schematic perspective view which shows the thick sheet | seat detection means which concerns on Embodiment 1 of this invention. The principal part perspective view of the thick sheet detection unit which concerns on Embodiment 1 of this invention. FIG. 3 is a perspective view showing a main part around a registration roller according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view showing a main part around a registration roller according to Embodiment 1 of the present invention. FIG. 2 is a schematic perspective view illustrating a paper discharge unit switching unit according to the first embodiment of the present invention. FIG. 2 is a schematic perspective view illustrating a paper discharge unit switching unit according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view illustrating a paper discharge unit switching unit according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view illustrating a paper discharge unit switching unit according to the first embodiment of the present invention. The perspective view at the time of the straight path conveyance which concerns on Embodiment 1 of this invention. FIG. 3 is a perspective view illustrating a configuration for automatically switching a conveyance path according to the first embodiment of the present invention. FIG. 3 is a perspective view illustrating a configuration for automatically switching a conveyance path according to the first embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing an image reading apparatus according to Embodiment 2 of the present invention.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention with reference to an accompanying drawing is demonstrated in detail. The following embodiment is an example for realizing the present invention, and the present invention is not limited to the following embodiment. The dimensions, materials, shapes, relative arrangements, and the like of the components of this embodiment should be appropriately modified or changed according to the configuration of the apparatus to which the present invention is applied and various conditions without departing from the spirit of the present invention. is there.

(Embodiment 1)
<Schematic structure of image reading apparatus>
FIG. 1 is a side sectional view showing a general overall configuration of an image reading apparatus according to an embodiment of the present invention. The image reading apparatus 10 includes a sheet conveying apparatus that conveys a sheet (original) S and an image reading unit that reads images on the front and back surfaces of the sheet S conveyed by the sheet conveying apparatus. The components of the sheet conveying apparatus are elements related to the conveyance of the sheet S in the image reading apparatus 10, and the components of the image reading unit are elements related to the image reading of the sheet S.

  Specifically, the image reading apparatus 10 includes a lower unit 21 as a first unit disposed on the lower side and a second unit disposed on the upper side with the sheet conveyance path 11 that conveys the sheet S as a boundary. And an upper unit 22. Further, the image reading apparatus 10 includes an intermediate unit 23 that is positioned with respect to the lower unit 21 by the lower rotary hinge shaft 12a.

  Further, in the image reading apparatus 10, a curved U-turn path (first conveyance path) 13 is formed between the upper unit 22 and the intermediate unit 23 for conveying the sheet S so as to be reversed upside down. The U-turn path 13 is formed by a curved guide (first guide) of the intermediate unit 23 and a curved guide (second guide) inside the upper unit 22.

  The upper unit 22 has an upper rotary hinge shaft 12 b that is a first hinge shaft that is orthogonal to the sheet conveyance direction of the sheet conveyance path 11 and parallel to the sheet conveyance surface of the sheet conveyance path 11. The upper unit 22 is rotatable in the direction of the arrow α with the upper rotary hinge shaft 13 as a rotation center.

  The image reading apparatus 10 also feeds the sheet S on which the sheet S is placed, a pickup roller 31 that sends the sheet S to the sheet conveyance path 11, and a sheet S picked up by the pickup roller 31 into the apparatus. And a roller 32. When a plurality of sheets S are fed by the pickup roller 31, the plurality of sheets S are separated one by one by a separation roller 33 that rotates in a direction opposite to the rotation direction of the feed roller 32. It is sent out to the conveyance path 11. A portion where the sheet S on the paper feed tray 14 side of the image reading apparatus 10 is taken into the apparatus main body is a sheet feeding unit to the sheet conveyance path 11, and the sheet feeding unit includes the paper feeding tray 14 and the sheet. Supply section. The image reading apparatus 10 according to the present embodiment has a configuration having one sheet feeding unit (sheet feeding unit) on the sheet feeding tray 14 side.

  Further, a front surface image reading unit 41 that reads a front surface image of the sheet S and a back surface that is disposed opposite to the front surface image reading unit 41 and reads a back surface image of the sheet S in the sheet conveyance path 11 of the image reading apparatus 10. An image reading unit 42 is provided. A registration roller pair (conveying roller pair) 34 for conveying the sheet S at a constant speed in order to read an image at a constant speed before and after the front surface image reading unit 41 and the back surface image reading unit 42 in the sheet conveying direction. Is provided. The registration roller pair 34 includes a registration roller 34a that is driven to rotate, and a driven roller 34b that nips and conveys the sheet S between the registration roller 34a. In the present embodiment, although details will be described later, a thick sheet detecting means 100 for detecting a sheet (thick sheet) S having a predetermined thickness or more is connected to the driven roller 34b.

  In addition, a registration sensor 15 that adjusts the timing of reading the image of the sheet S is disposed on the upstream side in the sheet conveyance direction of the front surface image reading unit 41 and the back surface image reading unit 42. The registration sensor 15 is a sensor that detects the arrival and passage of the sheet S. In the reading operation of the sheet image by the front surface image reading unit 41 and the back surface image reading unit 42, the registration sensor 15 detects the arrival of the sheet S. Be started at or after.

  Here, in the image reading apparatus 10, the surface image of the sheet S is read by the surface image reading unit 34. The surface image reading unit 41 reads the image information of the sheet S through the contact glass 41a. It has. Similarly, the back side image of the sheet S is read by the back side image reading unit 42. The back side image reading unit 42 also includes a line image sensor 42b that reads the image information of the sheet S through the contact glass 42a.

  In the image reading apparatus 10 having the above-described configuration, a U-turn conveyance roller pair 35 that conveys the sheet S while holding the sheet S is provided at a substantially central portion of the U-turn path 13 that follows the sheet conveyance path 11. The U-turn path 13 is formed by a curved curve, and the sheet S that has passed through the U-turn path 13 is discharged to the upper discharge tray 16 by the discharge roller pair 36.

  Note that the registration roller pair 34, the U-turn conveyance roller pair 35, and the paper discharge roller pair 36 are arranged at equal intervals corresponding to the minimum size of the sheet S that can be conveyed by the U-turn path 13. Further, a motor (not shown) for rotating the paper discharge roller pair 36 is provided separately from a motor (not shown) for rotating the registration roller pair 34 and the U-turn conveying roller pair 35 in order to drive only when necessary. It has been.

  On the other hand, in addition to the U-turn path 13, the image reading apparatus 10 communicates with a straight path 11 a as a conveyance path following the sheet conveyance path 11, and the sheet S that has passed through the straight path 11 a is in the lower discharge tray 17. The paper is discharged. In other words, the image reading apparatus (sheet conveying apparatus) of the present embodiment has a first conveying path (U-turn path 13) that conveys the sheet from the side of one sheet feeding unit on which the pip-up roller 31 and the like are arranged with the front and back sides reversed. ) And a second conveyance path (sheet conveyance path 11 and straight path 11a) that conveys the sheet linearly without reversing the front and back of the sheet. 1 shows a state in which the lower discharge tray 17 that receives the sheet S discharged from the straight path 11a is folded, the lower discharge tray 17 is abbreviated as the straight path 11a by rotating when necessary. It can be deployed in parallel.

  Here, a flapper 50 serving as a conveyance path switching unit is disposed at a branch point between the U-turn path 13 and the straight path 11a. The flapper 50 is closed when the lower discharge tray 17 is closed (that is, FIG. 1 state), the sheet S is guided to the U-turn path 13. On the other hand, the flapper 50 is linked to the rotation of the lower paper discharge tray 17 when the lower paper discharge tray 17 is opened, and the straight path 11a via an interlock mechanism (not shown in FIG. 1) which will be described in detail later. The conveyance direction of the sheet S is switched to the side. Note that the switching of the conveyance direction of the sheet S by the flapper 50 may be manually performed separately using a switching lever or the like.

  Note that the image reading apparatus 10 of the present embodiment described above is provided with a control unit (control means) 60 including a CPU or the like that performs control of conveyance of the sheet S, image reading of the sheet S, and the like. Actually, the image reading device 10 is communicably connected to an external device (computer or the like) (not shown), and the control unit of the image reading device 10 generates a control signal generated by a control program (driver or the like) of the external device by a user operation. 60 is received, and driving of the sheet S and image reading are controlled.

<Sheet Conveying Operation in Image Reading Apparatus>
In the image reading device 10, when an image reading instruction is issued from an external device (not shown) connected to the image reading device 10, drive control by the control unit 60 is started. First, the pickup roller 31 is lowered, The sheet S placed on the sheet feeding tray 1 comes into contact. As a result, sheet feeding (take-in) of the sheet S into the image reading apparatus 10 is started, and the fed sheet S is sent out to the sheet transport path 11 by the feed roller 32. At this time, as described above, even when a plurality of sheets S have been fed, only one sheet S is sent out to the sheet conveyance path 11 by the feed roller 32 and the separation roller 33.

  The sheet S sent to the sheet conveyance path 11 is conveyed by the registration roller pair 34 at a conveyance speed that matches the reading resolution of the front surface image reading unit 41 or the back surface image reading unit 42. When the leading edge of the sheet S reaches the registration sensor 15, the reading timing is measured based on a detection signal indicating that the leading edge of the sheet S has reached the registration sensor 15, and the image reading unit (the surface image reading unit 41 and / or Image reading by the back image reading unit 42) is started. The image data read by the image reading unit is transmitted by the control unit 60 to, for example, an external apparatus that has issued an image reading instruction.

  By the way, when the sheet S is a sheet (thin sheet) that is not easily bent such as thick paper, the lower sheet discharge tray 17 is closed (that is, the state shown in FIG. 1) unless particularly required. There is no problem. Thus, as described above, when the flapper 450 sets the sheet conveyance direction to the U-turn path 13, the sheet S that has passed through the image reading unit is conveyed to the U-turn path 13 by the registration roller pair 34. The sheet S conveyed to the U-turn path 13 passes through the U-turn conveyance roller pair 35 and is then discharged to the upper discharge tray 16 at a specific speed by the discharge roller pair 36.

  On the other hand, when the sheet S is a sheet such as thick paper that is difficult to bend (thick sheet), if the lower sheet discharge tray 17 is kept open, the leading end of the flapper 50 is lifted upward and the sheet is conveyed. The direction is switched to the straight path 11a. The sheet S conveyed to the straight path 11 a by the registration roller pair 34 is discharged to the lower discharge tray 17. When the conveyance path is switched to the straight path 11a as described above, control for stopping the rotation of the discharge roller pair 36 may be performed in order to reduce power consumption of the image reading apparatus 10.

  <Thick Sheet Detection Unit and its Peripheral Structure> The thick sheet detection unit 100 for detecting a thick sheet having a predetermined threshold value or more will be described in detail below with reference to FIGS.

  As shown in FIGS. 2 and 3, the thick sheet detecting means 100 includes a thick sheet detecting table 101 and a thick sheet detecting lever 102 that is pivotally supported by the thick sheet detecting table 101 and is rotatable in the e and f directions. A slit presser 103, a thick sheet detection lever 102, a slit 104 sandwiched between the slit presser 103, and a thick sheet detection lever pressing spring 105 that presses the thick sheet detection lever 102 in the f direction. A thickness detection board 107 on which the encoder 106 is mounted is locked to the thick sheet detection table 101.

FIG. 4 shows an exploded view of the thick sheet detection unit 110. As shown in FIG. 4, the thick sheet detection unit 110 includes a thick sheet detection lever 102, a slit presser 103, and a slit 104. The front boss 111 and the rear boss 112 of the slit presser 103 are assembled while passing through the front hole 113 and the rear hole 114 of the slit 104. As a result, the position of the slit 104 is determined with respect to the slit presser 103. Further, the front boss 111 and the rear boss 112 of the slit presser 103 are assembled while passing through the front hole 115 and the rear hole 116 of the thick sheet detection lever 102. Then, the position of the thick sheet detection lever 102 with respect to the slit presser 103 is determined. At that time, the front claw 117 and the rear claw 118 of the slit presser 103 are respectively engaged with the front hooking portion 119 and the rear hooking portion 120 of the thick sheet detection lever 102.

  Next, the operation of the thick sheet detecting unit 100 will be described with reference to FIGS. The driven shaft 344 of the driven roller 34b is pressed (biased) toward the registration roller 34a (in the direction of the arrow β) by a driven spring 340 that is a biasing means. Thus, when the sheet S is nipped between the registration roller 34a and the driven roller 34b, the driven roller 34b moves in the arrow γ direction by the thickness of the sheet S. The rotating shaft 344 of the driven roller 34b is provided with a biasing receiving portion 344a that is a portion to which the driven spring 340 is biased and whose cross-sectional shape orthogonal to the axial direction of the rotating shaft 344 is a regular polygon. Yes.

  Here, the driven shaft 34b and the bias receiving portion 344a of the driven spring 340 will be described in detail with reference to FIGS. FIG. 5 is a perspective view around the registration roller, and FIG. 6 is a cross-sectional view around the registration roller. The driven shaft 34 b of the registration roller pair 34 is urged toward the registration roller 34 a by a driven spring 340. The driven shaft 34b is provided with an urging receiving portion 344a that is a flat surface portion that has four sides, and the urging receiving portion 344a is in contact with the driven spring 340. The urging receiving portion 344a and the driven spring 340 come into contact with each other, thereby also serving as a rotation stopper for the driven shaft 34b. The shape of both end surfaces of the driven shaft 34b is round. For this reason, even if it moves up and down, it is not caught and stable operation is possible. By making the driven shaft 34b into four directions, the driven spring 340 can always come into contact with the biasing receiving portion 344a regardless of the orientation of the driven shaft 34b. As described above, in this embodiment, the driven shaft 34b has four sides to improve assemblability. As a result, the driven spring 340 is reliably applied to the rotating shaft 344 after assembling the driven roller 34b (with the rotating shaft 344) of the apparatus main body without considering the position of the driven roller 34b around the rotating shaft 344. The assembly workability can be improved.

  Further, since the abutting surface 102a of the thick sheet detecting lever 102 is in contact with the driven shaft 344, the thick sheet detecting lever 102 also moves in the arrow γ direction (see FIG. 3) by the amount of movement of the driven roller 34b. The amount of movement of the driven roller 34b here substantially corresponds to the thickness of the thick sheet. Therefore, when the amount of movement of the driven roller 34b exceeds a predetermined value (threshold value), the sheet is set to a thick sheet, and the control unit 60 controls to stop the sheet conveyance. As a result, the thick sheet is forcibly conveyed to the U-turn path 13 side, and there is no possibility that the thick sheet will be bent or jammed, and damage to the apparatus main body and thick sheet can be prevented. Further, since the driven roller 34b can be moved up and down stably, there is an effect that accurate thickness detection is possible and high detection accuracy can be realized. Thereafter, by switching from the U-turn path 13 to the straight path 11a, the transport of the thick sheet that has been temporarily stopped can be resumed toward the straight path 11a. As shown in FIG. 3, the thick sheet detection lever 102 is supported so as to be rotatable about the rotating boss 130, and therefore rotates with the rotating boss 130 as a fulcrum. Then, the encoder 106 mounted on the thickness detection substrate 107 detects the rotation amount of the slit 104 held between the thick sheet detection lever 102 and the slit presser 103. That is, the thick sheet can be reliably detected based on the amount of movement of the driven roller 34b in the arrow γ direction.

  Here, when the thick sheet S having a relatively large thickness is conveyed (for example, when a card having a thickness of 0.2 mm or more is conveyed as a threshold value), the control unit 60 of the image reading apparatus 10 performs image processing. Set to stop the reading operation. This setting may be set in advance from an external device connected to the image reading apparatus 10, or may be set in advance by an operation unit (not shown) of the image reading apparatus 10. Thereby, when the thick sheet detecting unit 100 detects a thick sheet, the conveying operation of the sheet S can be stopped.

  Further, when the user changes the U-turn path 13 to the straight path 11a with the conveyance operation of the sheet S stopped, a conveyance path switching detection sensor (not shown) detects that the conveyance path (path) has been changed, and the conveyance is performed. Resume operation. Then, the user can continue the scanning operation without taking out the sheet S from the inside of the apparatus. Of course, the scanning operation may be continued by pressing an operation button (for example, a start button) (not shown) of the image reading apparatus 10 after switching to the straight path 11a. In this embodiment, for example, the sheet S is set to have a thickness (0.2 mm) as a threshold value (set value or fixed value), and when a thicker sheet S is detected, the conveyance operation is stopped. Of course, the present invention is not limited to this.

<Conveyance path switching structure>
Hereinafter, switching between the U-turn path 13 and the straight path 11a will be described in detail with reference to FIGS. As shown in FIG. 7, the hinge 171 of the lower paper discharge tray 17 and the hinge 51 of the flapper 50 are rotatably supported by the lower unit 21 (see FIG. 1). The lower paper discharge tray 17 is provided with a handle 172 for the user to open and close the lower paper discharge tray 17. The lower discharge tray 17 can rotate in the a and b directions, and the flapper 50 can rotate in the c and d directions. The lower discharge tray 17 is provided with an abutting portion 173 that presses the protruding portion 52 of the flapper 50 when the lower discharge tray 17 is closed to the apparatus main body side.

  The lower paper discharge tray 17 is provided with a paper discharge switching unit 174 for switching the flapper 50 to the straight path 11a. On the other hand, the flapper 50 is provided with a flapper switching unit 53 for contacting the paper discharge switching unit 174 of the lower paper discharge tray 17 to switch to the straight path 11a.

  FIG. 8 is a diagram when switching to the U-turn path 13. As shown in FIG. 8, when switching to the U-turn path 13, the abutting portion 173 of the lower discharge tray 17 always presses the protruding portion 52. Then, even if force is applied to the flapper 50 during sheet conveyance, the flapper 50 does not rattle.

  Here, switching between the U-turn path 13 and the straight path 11a will be described in detail with reference to FIGS. FIG. 9 is a diagram showing the relationship between the lower sheet discharge tray 17 and the flapper 50 when switching to the U-turn path 13, and FIG. 10 is a diagram showing the relationship between the lower sheet discharge tray 17 and the flapper 50 when switching the straight path 11a.

  When the user switches from the U-turn path 13 to the straight path 11a, the user holds the handle 172 of the lower discharge tray 17 and operates in the direction of arrow b. Then, the paper discharge switching unit 174 of the lower paper discharge tray 17 comes into contact with the flapper switching unit 54 of the flapper 50 and rotates the flapper 50 in the direction of arrow d. When the rotation operation is performed until the state shown in FIGS. 9 to 10 is reached, a part of the lower discharge tray 17 hits the lower unit 21 and the rotation is restricted. By the above operation, the flapper 50 rotates and switches to the straight path 11a. FIG. 11 shows the positional relationship between the lower paper discharge tray 17 and the flapper 50 when the straight path 11a is reached. The sheet S is conveyed along a path like an arrow.

  In the above structural example, the user operates the handle 172 of the lower discharge tray 17 to perform the rotation operation, thereby switching the U-turn path 13 and the straight path 11a. However, FIG. 12 and FIG. 13 show configurations that can be switched without user operation. As shown in FIG. 12, a connecting member 70 is connected to a part of the flapper 50. Further, a solenoid 71 is locked to the connecting member 70 and operates in conjunction with the iron core 72 of the solenoid 71. The connecting member 70 is locked to the tip of the flapper 50 and operates integrally.

  Next, automatic switching between the U-turn path 13 and the straight path 11a will be described. In the state shown in FIG. 12, when a current is supplied from a power source (not shown) to the solenoid 71, the iron core 72 is pulled in the direction of arrow e. Then, as shown in FIG. 13, the flapper 50 operates so that the tip of the flapper 50 is lifted, and the straight path 11 a is brought about. At that time, the lower discharge tray 17 is also opened in conjunction. Thereby, it is possible to automatically switch from the U-turn path 13 to the straight path 11a without any user operation.

(Embodiment 2)
FIG. 14 is a schematic sectional view showing an image reading apparatus according to Embodiment 2 of the present invention. In the first embodiment described above, the image reading apparatus 10 having the lower discharge tray 17 is described as an example. However, in this embodiment, the straight-pass discharge tray is not provided, and the image reading apparatus is directly connected from the straight path. It is an example of composition which discharges a sheet outside. In the present embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals and redundant description is omitted.

  As illustrated in FIG. 14, the image reading apparatus 10 </ b> A according to the present exemplary embodiment includes a U-turn path 13 that reverses and conveys a sheet from a sheet feeding unit such as a sheet feeding tray 14, and the sheet feeding unit from the sheet feeding unit. A straight path 11a that conveys linearly without being reversed, a flapper 50 that switches to one of the U-turn path 13 and the straight path 11a, and a thick sheet detecting means 100 that detects a thick sheet having a thickness equal to or greater than a predetermined threshold value. And a control unit 60 for controlling sheet conveyance from the sheet feeding unit.

  The control unit 60 switches the U-turn path 13 from the U-turn path 13 to the straight path 11a when the thick sheet detecting unit 100 detects the thick sheet in the state where the flapper 50 switches to the U-turn path 13. As a result, the thick sheet is continuously conveyed not to the U-turn path 13 but to the straight path 11a, and is discharged out of the apparatus as it is. That is, the thick sheet is forcibly conveyed to the U-turn path 13 side, and there is no possibility that the thick sheet will be bent or jammed, and damage to the apparatus main body and thick sheet can be prevented. In addition, although the mechanism demonstrated in FIG.12 and FIG.13 of Embodiment 1 mentioned above can be employ | adopted for the automatic switching of the flapper 50, it is not limited to this.

(Other embodiments)
As mentioned above, although this invention was demonstrated based on Embodiment 1, this invention is not limited to Embodiment 1 mentioned above. For example, in the first and second embodiments described above, the control unit 60 may stop the sheet conveyance when the conveyance path is switched by the conveyance path switching unit (the flapper 50) during the sheet conveyance. Thereby, damage to the sheet can be prevented in advance.

  In the present invention, the sheet conveying apparatus or the image reading apparatus is provided with a display unit that displays that the sheet conveyance is stopped, and the control unit indicates that the sheet conveying is stopped on the display unit when the sheet conveyance is stopped. May be instructed to be displayed. Thereby, it becomes easy for a user to grasp the stop state of sheet conveyance, and user convenience can be improved.

  In the first embodiment described above, an example in which the sheet conveying apparatus of the present invention is applied to an image reading apparatus has been described, but the present invention is not limited to this. For example, not only a sheet feeding device that feeds a document or paper (sheet), but also a device (image forming device) that performs various processes such as image formation while conveying a document as a sheet, a multifunction device, etc. Alternatively, the present invention can also be applied to a system (sheet conveyance system, image reading system) including these apparatuses and an information processing apparatus such as a computer. When the present invention is applied to the system in this way, for example, when a thick sheet is detected on the sheet conveying apparatus side in the U-turn path conveying mode, the fact is transmitted to the information processing apparatus, and the information processing apparatus conveys the sheet. The apparatus may be instructed to stop sheet conveyance. In this case, the CPU of the information processing apparatus can be a control unit for performing substantial control such as sheet conveyance. In addition, the present invention is not intended only for the above-described apparatus or system. The reverse conveyance mode in which the sheet is reversed and conveyed from the sheet feeding unit, and the sheet is conveyed linearly without being reversed. In controlling the sheet conveying apparatus having the straight conveyance mode, when the thick sheet detecting unit detects a thick sheet having a thickness equal to or greater than a predetermined threshold in the state where the conveyance mode switching unit is switched to the reverse conveyance mode, the thick sheet is detected. The control method of the sheet conveying apparatus that stops conveyance or switches the reverse conveyance mode to the straight conveyance mode by the conveyance mode switching unit and continues the conveyance of the thick sheet can also be targeted.

  In the present invention, the thick sheet detecting means described above is not provided, a conveyance roller that conveys the sheet along the conveyance path, a driven roller that is disposed to face the conveyance roller, and a driven roller on the conveyance roller side. The rotating shaft of the driven roller is a portion that is biased by the biasing means, and the cross-sectional shape perpendicular to the axial direction of the rotating shaft is a regular polygon. The structure provided with the receiving part can be characterized. Accordingly, the biasing means is reliably brought into contact with the rotation shaft after assembling the driven roller (with the rotation shaft) of the main body of the sheet conveying apparatus without considering the position around the rotation shaft of the driven roller. As a result, the assembly workability can be improved, and as a result, it is very effective in reducing the manufacturing cost and the product cost.

DESCRIPTION OF SYMBOLS 10 Image reader 11 Sheet conveyance path 11a Straight path 12 Lower rotation hinge shaft 13 U-turn path 14 Paper feed tray 15 Registration sensor 16 Upper paper discharge tray (U-turn path paper discharge tray)
17 Lower output tray (Straight path output tray)
21 Lower Unit 22 Upper Unit 23 Intermediate Unit 31 Pickup Roller 32 Feeding Roller 33 Separation Roller 34 Registration Roller Pair 34a Registration Roller 34b Followed Roller 35 U-Turn Conveying Roller Pair 36 Paper Discharge Roller Pair 41 Front Image Reading Unit 42 Back Image Reading Unit 50 Flapper 60 Control unit of image reading apparatus

Claims (12)

A first conveyance path that conveys the sheet by reversing the front and back of the sheet from the sheet feeding unit;
A second conveyance path that conveys the sheet linearly without inverting the front and back of the sheet from the sheet feeding unit;
A transport path switching means for switching to one of the first transport path and the second transport path;
A thick sheet detecting means for detecting a thick sheet having a thickness equal to or greater than a predetermined threshold;
Control means for controlling sheet conveyance from the sheet feeding unit,
When the thick sheet detection unit detects the thick sheet in a state where the control unit switches to the first conveyance path by the conveyance path switching unit, the control unit stops conveyance of the thick sheet or switches the conveyance path. The sheet conveying apparatus, wherein the thick sheet is continuously conveyed by switching from the first conveying path to the second conveying path by means.   The control unit, after stopping the conveyance of the thick sheet, resumes the conveyance of the thick sheet when the conveyance path switching unit switches from the first conveyance path to the second conveyance path. Item 2. The sheet conveying apparatus according to Item 1.   The first conveyance path has a reverse path of the front and back sides of the sheet branched from the second conveyance path, and the thick sheet detection means is disposed on the upstream side of the second conveyance path in the sheet conveyance direction. 3. The sheet conveying apparatus according to claim 1, wherein the conveyance path switching unit is disposed at a portion branched from the two conveyance paths to the first conveyance path. On the upstream side in the sheet conveyance direction of the second conveyance path, a conveyance roller that conveys the sheet toward the downstream side in the conveyance direction and a driven roller that is urged and rotated by the conveyance roller side are disposed.
The said thick sheet detection means has a means to measure the thickness of the said sheet | seat based on the movement amount of the said driven roller in the direction away from the said conveyance roller, The any one of Claims 1-3 characterized by the above-mentioned. Sheet transport device. A conveyance roller that conveys the sheet along the second conveyance path, a driven roller that is disposed to face the conveyance roller, and an urging unit that urges the driven roller toward the conveyance roller.
The rotating shaft of the driven roller is provided with an urging receiving portion that is a portion urged by the urging means and whose cross-sectional shape perpendicular to the axial direction of the rotating shaft is a regular polygon. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus.   6. The sheet conveying apparatus according to claim 1, wherein the control unit stops sheet conveyance when conveyance path switching is performed by the conveyance path switching unit during sheet conveyance. . It further comprises display means for displaying that the sheet conveyance has stopped,
The sheet conveying apparatus according to claim 1, wherein the control unit instructs the display unit to display that the sheet conveyance is stopped when the sheet conveyance is stopped. . A conveyance roller that conveys the sheet along the conveyance path, a driven roller that is disposed to face the conveyance roller, and an urging unit that urges the driven roller toward the conveyance roller.
The rotating shaft of the driven roller is provided with an urging receiving portion that is a portion urged by the urging means and whose cross-sectional shape perpendicular to the axial direction of the rotating shaft is a regular polygon. A sheet conveying apparatus that is characterized.   An image reading apparatus comprising the sheet conveying apparatus according to claim 1. In controlling a sheet conveying apparatus having a reversal conveying mode for reversing and conveying the sheet front and back from the sheet feeding unit and a straight conveying mode for conveying the sheet linearly without inverting the sheet front and back,
When the thick sheet detecting means detects a thick sheet having a thickness equal to or greater than a predetermined threshold value while being switched to the reverse conveyance mode by the conveyance mode switching means, the conveyance of the thick sheet is stopped or the conveyance mode switching means The sheet conveying apparatus is controlled by switching from the reverse conveying mode to the straight conveying mode to continue conveying the thick sheet. A first conveyance path that conveys the sheet by reversing the front and back of the sheet from the sheet feeding unit;
A second conveyance path that conveys the sheet linearly without inverting the front and back of the sheet from the sheet feeding unit;
A transport path switching means for switching to one of the first transport path and the second transport path;
A thick sheet detecting means for detecting a thick sheet having a thickness equal to or greater than a predetermined threshold;
Control means for controlling sheet conveyance from the sheet feeding unit,
The control unit stops conveyance of the thick sheet when the thick sheet detection unit detects the thick sheet in a state where the control unit switches to the first conveyance path by the conveyance path switching unit, or the conveyance path switching unit The sheet conveying system is characterized in that the thick sheet is continuously conveyed by switching from the first conveying path to the second conveying path. A first conveyance path that conveys the sheet by reversing the front and back of the sheet from the sheet feeding unit;
A second conveyance path that conveys the sheet linearly without inverting the front and back of the sheet from the sheet feeding unit;
Image reading means for reading an image of the conveyed sheet;
A transport path switching means for switching to one of the first transport path and the second transport path;
A thick sheet detecting means for detecting a thick sheet having a thickness equal to or greater than a predetermined threshold;
Control means for controlling sheet conveyance from the sheet feeding unit,
The control unit stops conveyance of the thick sheet when the thick sheet detection unit detects the thick sheet in a state where the control unit switches to the first conveyance path by the conveyance path switching unit, or the conveyance path switching unit The image reading system is characterized in that the thick sheet is continuously conveyed by switching from the first conveying path to the second conveying path.

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