JP2008174372A - Automatic document feeder, document reader and image scanner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic document feeder with a simple, compact constitution capable of automatically unbending the document set in a Z-folded state to feed to a document reading position. <P>SOLUTION: The automatic document feeder 107 is equipped with a pick-up roller 32 for transferring a Z-folded document 3, a separation part 28 for separating the document 3 transferred by the pick-up roller 32, and a resistance applying part 46 which is disposed rather on the tail end side in the feeding direction than the contact position relative to the document 3 of the pick-up roller 32 and sucking the folded part 6 of the Z-folded document 3 by a suction port 72. The resistance force due to suction of the document 3 through the suction port 72 is smaller than the feed force of the separation roller 31 of the separation part 28. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automatic document feeder provided in a document reading device. Specifically, the present invention relates to a configuration of an automatic document feeder that automatically conveys a document set in a Z-folded state.

  In Patent Document 1, for example, a sheet cut into a rectangular shape is expanded horizontally, and then folded back into two at a half position in the longitudinal direction. A document folded outward at a half position in the longitudinal direction of the sheet portion is referred to as a Z-fold document, and it is pointed out that such a Z-fold document may be mixed in a normal document.

Patent Document 1 proposes the following configuration in order to automatically stretch and transport the above Z-folded document. That is, a turn roller and a switching guide are provided, and the switching guide initially guides the leading side of the Z-folded document so as to be conveyed along the turn roller in a curved shape. On the other hand, the switching guide is switched by a solenoid before the folded portion of the Z-folded document enters, and the folded portion of the document is extended by guiding the folded portion to the folding space.
Japanese Patent Laid-Open No. 5-116795

  However, in the configuration of Patent Document 1, it is necessary to install a document conveyance path that is greatly curved in order to extend the fold of the Z-folded document, and there remains room for improvement in terms of downsizing the device. It was. Further, since the original is folded inside the apparatus, the configuration inside the apparatus becomes complicated, and maintenance when the original is jammed inside is difficult.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to a first aspect of the present invention, an automatic document feeder having the following configuration is provided. That is, a pickup roller for feeding a Z-folded document, a separation unit that transports the document fed by the pickup roller while separating it, and a rear end side of the document transport direction with respect to the pickup roller and the Z A resistance applying unit that sucks the upper surface of the folded portion of the folded document.

  Accordingly, it is possible to read an image in a state where the Z-fold original is automatically expanded and stretched with a simple and compact configuration. Further, by sucking the folded portion of the Z-folded document upward, a vertical gap is formed in the folded portion of the Z-folded document, and the folded portion can be smoothly developed by this gap. Further, the height of the upper surface of the document varies depending on the number of Z-folded documents set. According to the present embodiment, the folded portion is sucked to the resistance applying portion regardless of the height of the upper surface of the document. Stable resistance. As a result, the Z-folded document can be unfolded reliably and smoothly.

  According to a second aspect of the present invention, an automatic document feeder having the following configuration is provided. That is, a pickup roller for feeding a Z-folded document, a separation unit that transports the document fed by the pickup roller while separating it, and a rear end side of the document transport direction with respect to the pickup roller and the Z A resistance applying portion having a resistance pad that contacts the upper surface of the folded portion of the folded document.

  Accordingly, it is possible to read an image in a state where the Z-fold original is automatically expanded and stretched with a simple and compact configuration. In addition, since a relatively strong resistance can be applied to the folded portion by the contact of the resistance pad, the Z-folded document can be reliably developed.

  According to a third aspect of the present invention, an automatic document feeder having the following configuration is provided. That is, a pickup roller for feeding a Z-folded document, a separation unit that transports the document fed by the pickup roller while separating it, and a rear end side of the document transport direction with respect to the pickup roller and the Z A resistance applying unit having a resistance roller that contacts the upper surface of the folded portion of the folded document.

  Accordingly, it is possible to read an image in a state where the Z-fold original is automatically expanded and stretched with a simple and compact configuration. Further, since the resistance roller is in rolling contact with the upper surface of the document, damage due to dragging of the document can be prevented.

  In the automatic document feeder, a torque limiter is preferably connected to the resistance roller.

  As a result, a uniform resistance corresponding to the torque limit value of the torque limiter can be applied to the folded portion, so that the Z-folded document can be developed stably and smoothly.

  In the automatic document feeder, it is preferable that the resistance applied by the resistance applying unit to the folding unit is smaller than the conveying force of the separating unit.

  As a result, the developed document can be reliably conveyed by the separating unit regardless of the resistance of the resistance applying unit. In addition, for example, even when an A3 size original folded in Z and an A4 size original are mixed and set, the A4 original can be reliably conveyed.

  In the automatic document feeder, a conveyance roller for conveying the document is provided on the downstream side in the conveyance direction from the separation unit, and the resistance force that the resistance applying unit applies to the folding unit is the conveyance force of the conveyance roller. Preferably it is smaller.

  Thereby, the developed document can be reliably conveyed by the conveying roller regardless of the resistance of the resistance applying unit.

  According to a fourth aspect of the present invention, an automatic document feeder having the following configuration is provided. That is, a pickup roller that feeds a Z-folded document, a separation unit that transports the document fed by the pickup roller while separating it, and a Z-folded document that is disposed on the trailing side in the document transport direction from the pickup roller. A reverse conveyance unit having a reverse conveyance roller that is in contact with the upper surface of the folding part and conveys in the direction opposite to the conveyance direction.

  Accordingly, it is possible to read an image in a state where the Z-fold original is automatically expanded and stretched with a simple and compact configuration. Further, the Z-folded document can be quickly developed by reversely conveying the folding portion. Further, since the reverse conveying roller is in rolling contact with the upper surface of the document, damage due to dragging of the document can be prevented.

  In the automatic document feeder, a torque limiter is preferably connected to the reverse conveyance roller.

  As a result, the reverse conveyance torque of the reverse conveyance roller can be made constant, so that the reliability and stability of the Z-fold original can be further improved.

  In the automatic document feeder, a clutch mechanism is preferably connected to the reverse conveying roller.

  Thus, by disconnecting the clutch mechanism except when the Z-folded document is unfolded, unnecessary resistance of the reverse transport roller with respect to the transport of the document can be prevented.

  In the automatic document feeder, the timing at which the resistance applying unit starts to apply resistance or the timing at which the reverse conveying unit starts reverse conveyance is after the conveyance of the original by the separating unit is started. Is preferred.

  As a result, the application of resistance by the resistance applying unit or the reverse conveyance of the reverse conveyance unit is started after the leading side of the original can be reliably conveyed by the separation unit, so that the non-delivery of the original can be prevented.

  In the automatic document feeder, it is preferable that the application of resistance by the resistance applying unit or the reverse conveyance of the reverse conveying unit is stopped when the document is conveyed by a predetermined distance.

  This prevents unnecessary resistance to conveyance after the Z-folded document is unfolded, so that the document can be conveyed more smoothly.

  In the document reading apparatus, the resistance applying unit or the reverse conveying unit is attached to a support arm, and the support arm is a fold extension position above a document tray on which a document is set and a retreat retracted from the fold extension position. It is preferable to be configured to be movable between positions.

  As a result, by moving the support arm to the retracted position, the resistance applying unit and the reverse conveying unit do not interfere with the work of setting or removing the original or the maintenance work such as removing the jammed original. Can be improved.

  According to another aspect of the present invention, there are provided a document reading device and an image scanner device provided with the automatic document feeder.

  Next, embodiments of the invention will be described. FIG. 1 is a front sectional view showing an image scanner device according to an embodiment of the present invention, and FIG. 2 is a perspective view of the image scanner device.

  As shown in FIGS. 1 and 2, an image scanner device 101 as an image reading device includes a document table 102 on which a platen glass on which a read document is placed is disposed, and presses the read document onto the platen glass. A manuscript table cover 103 and an operation panel 104 for instructing reading start of the manuscript and the like.

  The document table cover 103 is provided with an auto document feeder (automatic document feeder) 107. The auto document feeder 107 includes a document tray 11 provided on the upper part of the document table cover 103 and a paper discharge tray 12 provided below the document tray.

  As shown in FIG. 1, a curved document transport path 13 that connects the document tray 11 and the discharge tray 12 is formed inside the document table cover 103. Document reading positions P1, P2 are set in the middle of the document transport path 13. With this configuration, the originals 3 set on the original tray 11 are separated one by one and conveyed along the curved original conveying path 13, and after passing through the original reading positions P1 and P2, the paper is discharged. It is discharged to the tray 12.

  As shown in FIG. 1, a scanner unit (original reading unit) 21 is provided inside the original table 102. The scanner unit 21 includes a light source 22 that emits light to the document reading position P1, reflection mirrors 23, 24, and 25 that reflect reflected light from the document 3, and a condensing lens 26 that converges the reflected light. And a charge coupled device (CCD) 27 for converting the converged light into an electric signal and outputting the electric signal.

  With this configuration, the document 3 transported along the document transport path 13 is scanned at the document reading position P1, and the reflected light from the document 3 is guided to the CCD 27 to form an image. As a result, the CCD 27 can output an electrical signal corresponding to the read content. This signal and a signal of the contact image sensor 67 described later are transmitted via a communication cable to a host device such as a personal computer connected to the image scanner device 101 after appropriate conversion processing.

  Next, a detailed configuration of the document transport path 13 will be described. As shown in FIG. 1, a separation roller 31 and a pickup roller 32 are provided at a location where the document 3 is supplied from the document tray 11 to the document transport path 13. A swing arm 33 is attached so as to be swingable about the axis of the separation roller 31, and a pickup roller 32 is supported on the tip side of the swing arm 33. A configuration for driving the separation roller 31, the pickup roller 32, and the swing arm 33 will be described later.

  A separation pad 34 is installed at a position facing the separation roller 31, and the separation pad 34 is pressed against the peripheral surface of the separation roller 31 by a spring. A separation unit 28 is constituted by the separation roller 31 and the separation pad 34, and the separation roller 31 is driven in a state where the document 3 is nipped between the separation roller 31 and the separation pad 34, whereby one document 3 is obtained. Can be separated one by one.

  A document detection sensor 68 is provided at a position immediately downstream of the separation roller 31. The document detection sensor 68 is configured to detect that the document 3 is supplied from the document tray 11 and conveyed by the separation roller 31.

  A plurality of conveying rollers 61, 62, 63, 64 are provided downstream of the separation roller 31. Thereby, the document 3 conveyed downstream by the driving of the separation roller 31 is further nipped by the conveyance rollers 61, 62, 63 and further conveyed, and passes the document reading position P1. At this time, information on the document 3 is read by the scanner unit 21.

  The document 3 is further transported by driving the transport roller 64 and passes the document reading position P2. The document reading position P2 is provided with a contact image sensor 67, and the content on the back side of the document 3 can be scanned while the document 3 is nipped between the contact image sensor 67 and the platen roller 65. It is like that. The document 3 whose contents on both the front and back sides are read at the two document reading positions P1 and P2 is conveyed by the sheet discharge roller 70 and discharged onto the sheet discharge tray 12.

  Next, a configuration around the separation roller 31 and the pickup roller 32 will be described in detail with reference to a perspective view of a main part in FIG.

  As shown in FIG. 3, a drive shaft 41 is disposed concentrically with the separation roller 31, and a first clutch 51 is interposed between the drive shaft 41 and the separation roller 31. The first clutch 51 is configured as a one-way clutch. When the drive shaft 41 rotates in the direction of the arrow in FIG. 3, it transmits it to the separation roller 31, while when the drive shaft 41 rotates in the opposite direction, When the separation roller 31 rotates at a higher speed than the drive shaft 41 (including when the drive shaft 41 is stopped), the separation roller 31 is automatically cut, and the drive shaft 41 is configured to idle with respect to the separation roller 31. Yes.

  The swing arm 33 has a structure in which a pair of arm bodies 35, 35 arranged so as to sandwich the separation roller 31 are connected by a beam portion 36. The base portion of each arm body 35 is supported by the drive shaft 41, and the roller shaft 42 is supported by the tip portion of the swing arm 33. The pickup roller 32 is rotatably supported on the roller shaft 42. The pickup roller 32 is disposed so as to be sandwiched between the two arm bodies 35 and 35.

  A driving pulley 43 is integrally fixed to the driving shaft 41 at a position on one side of the separation roller 31. On the other hand, a driven pulley 44 is rotatably supported on the roller shaft 42 at a position on one side of the pickup roller 32. An endless transmission belt 45 is stretched between the drive pulley 43 and the driven pulley 44.

  A second clutch 52 is interposed between the driven pulley 44 and the pickup roller 32. Similarly to the first clutch 51, the second clutch 52 is also configured as a one-way clutch. When the driven pulley 44 rotates in the direction of the arrow in FIG. Is rotated in the opposite direction, and when the pickup roller 32 rotates at a higher speed than the driven pulley 44 (including when the driven pulley 44 is stopped), the driven pulley 44 is moved to the pickup roller 32. On the other hand, it is configured to idle.

  A torque limiter 53 is disposed between the driven pulley 44 and the arm body 35 on one side. When the driven pulley 44 rotates in the direction of the arrow in FIG. 3, the torque limiter 53 transmits the torque to the arm body 35 to rotate the swing arm 33 downward, while the torque is a predetermined value. When the value is exceeded, the driven pulley 44 is configured to idle with respect to the arm body 35.

  With the above configuration, when the drive shaft 41 is rotated in the direction of the arrow in FIG. 3 by the electric motor of the drive unit (not shown), the rotation is transmitted to the separation roller 31 by the first clutch 51 and the separation roller 31 rotates. Further, since the drive pulley 43 rotates integrally with the drive shaft 41, this rotation is transmitted to the driven pulley 44 via the transmission belt 45, and the driven pulley 44 rotates in the direction of the arrow in FIG. The rotation of the driven pulley 44 is transmitted to the pickup roller 32 by the second clutch 52, and the pickup roller 32 rotates. Further, since the rotation of the driven pulley 44 is transmitted to the arm body 35 via the torque limiter 53, the swing arm 33 starts to rotate downward from the position indicated by the chain line in FIG.

  The pickup roller 32 descends as the swing arm 33 rotates downward, and contacts the uppermost document 3 among the documents 3 set on the document tray 11. As a result, the document 3 is fed by the pickup roller 32 and sent to the nip portion between the separation roller 31 and the separation pad 34. Since the swing arm 33 receives a reaction force when the pickup roller 32 comes into contact with the document 3, the torque limiter 53 does not transmit the rotation of the driven pulley 44 to the arm body 35, and the swing arm 33 moves downward. Stops turning.

  The documents 3 are separated one by one at the nip portion between the separation roller 31 and the separation pad 34 and then conveyed downstream to the conveyance roller 61 (FIG. 1). Here, since the peripheral speed of the rotating transport roller 61 is set to be larger than the peripheral speed of the separation roller 31, the separation roller 31 rotates around the document 3 transported by the transport roller 61. The rotation speed of the separation roller 31 exceeds the rotation speed of the drive shaft 41. As a result, the first clutch 51 is disconnected, and the separation roller 31 rotates idly with respect to the drive shaft 41.

  Thereafter, when the document 3 sent by the transport roller 61 passes through the nip portion between the separation roller 31 and the separation pad 34, the separation roller 31 is not rotated along with the document 3, so that the first clutch 51 is connected again. As a result, the separation roller 31 is driven again by the drive shaft 41, and the conveyance of the next document 3 fed by the pickup roller 32 is started.

  Next, when it is detected by an unillustrated sensor that the document 3 has disappeared from the document tray 11, an electric motor of a drive unit (not shown) drives the drive shaft 41 in the direction opposite to the arrow in FIG. Then, the reverse rotation of the drive shaft 41 is transmitted to the driven pulley 44 via the drive pulley 43 and the transmission belt 45, and the reverse rotation of the driven pulley 44 is transmitted to the arm body 35 via the torque limiter 53. As a result, the swing arm 33 rotates upward, and the pickup roller 32 rises to the position of the chain line in FIG. Note that when the drive shaft 41 rotates in the reverse direction, the first clutch 51 and the second clutch 52 are disconnected, so that the separation roller 31 and the pickup roller 32 do not rotate in the reverse direction.

  Next, a Z-folded document that can be set on the document tray 11 of the image scanner apparatus 101 of the present embodiment will be described in detail with reference to the perspective view of FIG.

  That is, as shown in FIG. 4, the Z-folded document 3 is folded into two so as to divide the rectangular document into approximately two equal parts in the longitudinal direction, and the folded one side is further divided into approximately two equal parts. It is configured to be folded outward. As a result, the Z-folded document 3 has a bottom portion 4 having a size that is ½ of the original document, and a first folded portion having a size of ¼ that is folded upward from the bottom portion 4 with the first fold 7 as a boundary. Part 5 and a second folded part 6 having a size of 1/4 that is folded upward from the first folded part 5 with the second fold line 8 as a boundary.

  For example, when a Japanese industrial standard A3 size document is Z-folded as shown in FIG. 4, it becomes a half size, that is, an A4 size. For this reason, since it can be stored in the same size as other A4-size originals, it is convenient for filing and can be stored in a compact space. Similarly, when a Japanese industry standard B4 size document is Z-folded, it can be stored in the same size as a B5 size document or the like.

  Next, a configuration for unfolding and extending the Z-fold original 3 will be described. That is, as shown in FIGS. 1 and 2, a support arm 71 is provided above the document tray 11, and a suction port 72 is formed on the lower surface of the support arm 71 (the surface facing the document tray 11). Yes. As shown in FIG. 1, the suction port 72 is connected to a negative pressure source (not shown) via a tube 73 disposed in the support arm 71. The suction port 72, the tube 73, and the like constitute a resistance applying unit 46 that applies resistance to the conveyance of the document 3.

  As shown in FIG. 2, the base of the support arm 71 is rotatably supported by the document table cover 103 and can be rotated as indicated by an arrow. As a result, the support arm 71 can be switched between a suction position (fold extension position) indicated by a solid line in FIG. 2 and a retracted position indicated by a chain line. By moving the support arm 71 to the retracted position, the work of setting and removing the original 3 on the original tray 11, the maintenance work, and the like are facilitated.

  With this configuration, first, the operator moves the support arm 71 to the retracted position, and stacks a plurality of Z-folded documents 3 on the document tray 11. At this time, each Z-folded document 3 is placed on the document tray 11 so that the bottom 4 is on the lower side. Then, the operator moves the support arm 71 to the suction position and gives an instruction to start scanning from the operation panel 104 (FIG. 2), whereby the image scanner device 101 starts reading a document.

  The state immediately after the start of scanning is shown in FIG. 5A. As shown in FIG. 5A, when scanning is started, the pickup roller 32 descends as described above, and the bottom of the Z-folded document 3 is displayed. The document 3 is rotated while being brought into contact with the top side of 4 and the original 3 is fed. At this time, a valve (not shown) connected to the tube 73 is closed, and air is not sucked from the suction port 72.

  Then, the leading portion of the fed document 3 is nipped between the separation roller 31 and the separation pad 34, and the separation roller 31 rotates in this state, whereby the document 3 is separated one by one and directed downstream. Are transported.

  The state immediately after the leading edge of the conveyed document 3 is detected by the document detection sensor 68 is shown in FIG. 5B, and a control unit (not shown) that receives the document detection signal from the document detection sensor 68 A valve connected to the tube 73 is opened, and suction from the suction port 72 is started. As a result, as shown in FIG. 5C, the second folding portion 6 of the Z-folded document 3 (in other words, the upper surface of the document on the end side in the conveyance direction with respect to the contact position of the pickup roller 32 with respect to the document 3) It is adsorbed by 72 and held so as not to be conveyed downstream.

  Accordingly, when the document 3 is conveyed by the separation roller 31 or the downstream conveyance roller 61 (FIG. 1) in this state, the first folding portion 5 of the Z-fold document 3 is moved as shown in FIG. While being deployed to be pulled out, it is pulled downstream.

  Here, the pressure of the negative pressure source or the like is set so that the resistance force due to the suction of the suction port 72 is smaller than the transport force of the separation roller 31 and the transport roller 61 on the downstream side. As a result, when the conveyance proceeds from the state of FIG. 5D and the Z-folded document 3 is in a tensioned state, the second folded portion 6 that has been attracted to the lower surface of the support arm 71 is pulled downstream and sucked. It is removed from the mouth 72 and conveyed downstream. As described above, the Z-folded original 3 can be automatically developed and supplied to the original conveying path 13, and the image can be read with the original 3 stretched.

  As described above, the auto document feeder 107 provided in the image scanner apparatus 101 of the present embodiment separates the pickup roller 32 for feeding the Z-folded document 3 and the document 3 fed by the pickup roller 32. The separation unit 28 that conveys the paper while the pickup roller 32 is disposed at the end in the document conveyance direction, and the resistance applying unit 46 that sucks the upper surface of the second folded portion 6 of the Z-folded document 3 is provided.

  Accordingly, it is possible to read an image in a state where the Z-fold original 3 is automatically developed and stretched with a simple and compact configuration. Further, by sucking the second folded portion 6 of the Z-folded document 3 upward, a gap is formed in the folded direction of the Z-folded document 3 as shown in FIG. 5C, and the first folded by this gap. The part 5 can be pulled out and deployed smoothly. Further, the height of the upper surface of the original varies depending on the number of Z-folded originals 3 set on the original tray 11, but according to the present embodiment, the second folding portion is independent of the height of the upper surface of the original. 6 can be attracted to the resistance applying portion 46 to provide a stable resistance force. As a result, the Z-folded document 3 can be unfolded reliably and smoothly.

  Further, the resistance force applied to the second folding portion 6 of the document 3 by the suction port 72 of the resistance applying portion 46 is smaller than the conveying force of the separation roller 31 and smaller than the conveying force of the conveying roller 61. Is set.

  Thereby, the developed document 3 can be reliably conveyed by the separation roller 31 and the conveyance roller 61 regardless of the resistance of the resistance applying unit 46. In addition, for example, even when an A3 size original folded in Z and an A4 size original are mixed and set, the A4 original can be reliably conveyed.

  In addition, when the suction port 72 sucks the second folded portion 6 of the Z-folded document 3 and starts to give resistance, the conveyance of the document 3 is started by the separation roller 31 of the separation unit 28, and this is designated as the document. It is controlled by a control unit (not shown) so that it is after the detection sensor 68 has detected.

  As a result, since the resistance is applied by the resistance applying unit 46 after the leading side of the document 3 can be reliably conveyed, it is possible to prevent the document 3 from being unfed. In addition, for example, even when an A3 size original folded in Z and an A4 size original are mixed and set, the A4 original can be reliably conveyed.

  In the configuration of the auto document feeder 107, when the document 3 is conveyed by a predetermined distance (for example, at the time of FIG. 5D), the valve is closed to stop the suction from the suction port 72, It can also be controlled to cancel the application of resistance.

  In this case, no resistance is generated when the document 3 is transported by the downstream transport roller 61 or the like, so that the document 3 can be transported more smoothly.

  In the auto document feeder 107, the resistance applying unit 46 is attached to a support arm 71. The support arm 71 has a crease extending position (solid line in FIG. 2) above the document tray 11 on which the document 3 is set. In addition, it is configured to be movable between a retracted position (chain line in FIG. 2) retracted from the crease extension position.

  As a result, by moving the support arm 71 to the retracted position, the resistance applying portion 46 does not get in the way during the work of setting or removing the original 3 on the original tray 11 or the maintenance work such as removing the jammed original. , Workability is improved.

  Next, a first modification of the auto document feeder will be described with reference to FIG. Note that, in the modified examples described below, the same or similar members as those in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The resistance applying portion 47 provided in the auto document feeder 117 of the first modification shown in FIG. 6 supports the elevating member 75 on the support arm 71 so as to be movable up and down, and the lower surface of the elevating member 75 (with the document tray 11 and A friction pad (resistive pad) 76 made of, for example, rubber or the like is fixed to the facing surface. Further, a spring (biasing member) (not shown) is attached to the elevating member 75, and the elevating member 75 is urged downward by this spring.

  A solenoid (not shown) is connected to the elevating member 75, whereby the elevating member 75 can be moved up and down to bring the friction pad 76 into contact with or away from the upper surface of the document 3. Further, for example, when the support arm 71 is retracted to the retracted position indicated by the chain line in FIG. 2, the elevating member 75 is lifted by the solenoid so that the document 3 and the document tray 11 are not dragged by the friction pad 76. Yes. In the present modification, the resistance applying portion 47 is configured by the friction pad 76, the elevating member 75, the solenoid, and the like.

  In the configuration of the first modification, the elevating force of the spring is applied to the elevating member 75 of the resistance applying unit 47 of FIG. 6 at the same timing as the suction of the air from the suction port 72 is started in the embodiment shown in FIG. The second folded portion 6 of the Z-folded document 3 is pressed by the friction pad 76. As a result, resistance to conveyance is imparted to the second folding unit 6, so that the Z-folded document 3 can be unfolded and fed to the document conveyance path 13 as shown in FIG.

  As described above, in the auto document feeder 117 according to the first modified example, the auto document feeder 117 is disposed on the rear side in the document conveying direction with respect to the pickup roller 32 and contacts the upper surface of the second folding portion 6 of the Z-folded document 3. A resistance applying portion 47 having a friction pad 76 is provided.

  Accordingly, it is possible to read an image in a state where the Z-fold original 3 is automatically developed and stretched with a simple and compact configuration. Further, since a relatively strong resistance force can be applied to the second folded portion 6 by the contact with the friction pad 76, the Z-folded document 3 can be reliably developed.

  In the configuration of the first modification, the elevating member 75 is raised and the friction pad 76 is separated from the document 3 when the document 3 is conveyed by a predetermined distance and the Z-fold document 3 is almost unfolded. Is controlling.

  Accordingly, the friction pad 76 does not hinder the conveyance of the document 3 by the conveyance roller 61 and the like, and a smooth document conveyance can be realized.

  It should be noted that the friction coefficient of the friction pad 76 can be set so that the frictional resistance force that the friction pad 76 applies to the second folded portion 6 is smaller than the conveying force of the separation roller 31 and the conveying roller 61.

  In this case, the document 3 can be reliably conveyed to the downstream side by the conveying roller 61 or the like regardless of the resistance by the friction pad 76.

  Next, a second modification will be described with reference to FIG. The resistance applying unit 48 provided in the auto document feeder 127 of the second modification shown in FIG. 7 rotates a resistance roller 77 made of a rubber roller or the like on an elevating member 75 supported so as to be movable up and down like the first modification. Supports freely.

  The elevating member 75 can be moved up and down by a solenoid (not shown) as in the first modification. Further, a torque limiter 78 is connected to the resistance roller 77. When the torque acting on the resistance roller 77 is less than a predetermined value (torque limit value), the resistance roller 77 is stationary, and only when a torque exceeding the predetermined value is applied. The resistance roller 77 is configured to rotate.

  With this configuration, at the same timing as the start of air suction from the suction port 72 in the embodiment shown in FIG. 5, the elevating member 75 of the resistance applying portion 48 in FIG. The second folding portion 6 of the Z-folded document 3 is pressed by the roller 77. As a result, the resistance roller 77 imparts resistance to conveyance to the second folding unit 6, so that the Z-fold document 3 can be unfolded and fed to the document conveyance path 13 as shown in FIG. 7.

  As described above, the auto document feeder 127 of the second modified example is disposed on the rear side in the document conveying direction from the pickup roller 32 and is in contact with the upper surface of the second folding portion 6 of the Z-folded document 3. The resistance application part 48 which has 77 is provided.

  Accordingly, it is possible to read an image in a state where the Z-fold original 3 is automatically developed and stretched with a simple and compact configuration. In addition, since the resistance roller 77 is in rolling contact with the upper surface of the document 3, damage due to dragging of the document 3 can be prevented.

  In the auto document feeder 127, a torque limiter 78 is connected to the resistance roller 77.

  As a result, a uniform resistance corresponding to the torque limit value of the torque limiter 78 can be applied to the second folding portion 6, so that the Z-folded document 3 can be unfolded stably and smoothly.

  Here, the torque limit value of the torque limiter 78 is set smaller than the torque corresponding to the conveying force of the separation roller 31, and is set smaller than the torque corresponding to the conveying force of the conveying roller 61.

  As a result, regardless of the resistance by the resistance roller 77, the document 3 can be reliably conveyed downstream by the conveyance roller 61 or the like.

  Next, a third modification will be described with reference to FIG. The auto document feeder 137 of the third modified example shown in FIG. 8 has a lifting member 75 disposed below the support arm 71, and a reverse conveying roller 79 made of a rubber roller or the like is rotatably supported on the lifting member 75. ing.

  An electric motor 80 is connected to the roller shaft of the reverse conveying roller 79, and an electromagnetic clutch (clutch mechanism) 81 and a torque limiter 82 are interposed between the reverse conveying roller 79 and the electric motor 80. The torque limit value of the torque limiter 82 is set smaller than the torque corresponding to the conveying force of the separation roller 31 and smaller than the torque corresponding to the conveying force of the conveying roller 61. In this modification, the reverse conveying roller 79, the electric motor 80, the electromagnetic clutch 81, the torque limiter 82, and the like constitute a reverse conveying portion 49 for reversely conveying the document 3.

  With the above configuration, the electromagnetic clutch 81 of the reverse conveying portion 49 of FIG. 8 is connected and the electric motor 80 is connected at the same timing as the suction of the air from the suction port 72 is started in the embodiment shown in FIG. To drive. Then, the reverse conveying roller 79 that is in contact with the second folding portion 6 of the Z-folded document 3 (in other words, the upper surface of the document 3 at the end in the conveyance direction with respect to the contact position of the pickup roller 32 with respect to the document 3) Drive in the opposite direction.

  As a result, as shown in FIG. 8, the Z-folded original 3 can be unfolded and supplied to the original conveying path 13 in an expanded state. Further, since the load during rotation of the reverse conveying roller 79 is made constant by the torque limiter 82, the Z-fold original 3 can be unfolded smoothly.

  In the present modification, the electric motor 80 is stopped and the electromagnetic clutch 81 is controlled to be disengaged when the Z-fold original 3 is stretched and conveyed for a predetermined distance. Accordingly, after the original 3 is further conveyed by the conveying roller 61 and the original 3 is tightly attached, the reverse conveying roller 79 is rotated around the original 3, but the electromagnetic clutch 81 is disconnected. Therefore, the accompanying rotation of the reverse conveyance roller 79 does not become an excessive resistance to the document conveyance.

  As described above, the auto document feeder 137 according to this modification is in contact with the upper surface of the document 3 at the end in the conveyance direction with respect to the contact position of the pickup roller 32, and the document 3 by the separation roller 31, the conveyance roller 61, or the like. The reverse conveyance part 49 which has the reverse conveyance roller 79 conveyed in the direction opposite to this conveyance direction is provided.

  Accordingly, it is possible to read an image in a state where the Z-fold original 3 is automatically developed and stretched with a simple and compact configuration. Further, the Z-folded document 3 can be quickly stretched and unfolded by reversely transporting the second folding unit 6. Further, since the reverse conveyance roller 79 is in rolling contact with the upper surface of the document 3, damage due to dragging of the document 3 can be prevented.

  Further, in the auto document feeder 137 of this modification, a torque limiter 82 is connected to the reverse conveying roller 79.

  As a result, the reverse conveyance torque of the reverse conveyance roller 79 can be made constant, so that the reliability and stability of the Z-fold original 3 can be further improved.

  The torque limit value of the torque limiter 82 is set smaller than the torque corresponding to the conveying force of the separation roller 31 and the conveying roller 61.

  Accordingly, the document 3 can be reliably conveyed to the downstream side by the conveyance roller 61 or the like regardless of the reverse conveyance driving of the reverse conveyance roller 79.

  Further, an electromagnetic clutch 81 is connected to the reverse conveying roller 79.

  Thus, by disconnecting the electromagnetic clutch 81 except when the Z-folded document 3 is unfolded, unnecessary resistance of the reverse conveying roller 79 to the conveyance of the document 3 can be prevented.

  Further, in the auto document feeder 137 of this modification, the timing at which the reverse conveyance roller 79 starts reverse conveyance is controlled to be after the separation roller 31 has started conveyance of the document 3.

  As a result, reverse conveyance by the reverse conveyance unit 49 is performed after the leading side of the original 3 can be reliably conveyed, so that non-feed of the original 3 can be prevented.

  Further, in the auto document feeder 137 according to this modification, when the document 3 is conveyed by a predetermined distance, the reverse conveyance of the reverse conveyance roller 79 is controlled to be stopped.

  Thus, the reverse conveyance unit 49 does not hinder the conveyance of the document 3 by the conveyance roller 61 and the like, and smooth document conveyance can be realized.

  Although the preferred embodiment of the present invention and a plurality of modifications thereof have been described above, the above configuration can be changed as follows, for example.

  As long as the resistance applying portions 46, 47, 48 and the reverse conveying portion 49 are arranged so as to face the second folding portion 6 of the Z-folded document 3 shown in FIG. Can do. Moreover, it can change to the structure which arrange | positions two or more resistance provision parts 46, 47, 48, and the reverse conveyance part 49. FIG.

  In the third modified example (FIG. 8), the reverse conveying roller 79 is a fan-shaped roller, and the circumferential surface of the fan-shaped roller is separated from the second folded portion 6 when the development of the Z-fold original 3 is almost completed. It is possible to change to a configuration in which the rotation is reversed while adjusting the phase. In this case, the electromagnetic clutch 81 and the like can be omitted.

  Instead of providing the document detection sensor 68, for example, the time from the start of feeding by the pickup roller 32 is measured by the timer circuit of the control unit, etc., so that the leading edge of the document 3 is nipped by the separation unit 28. After a lapse of time, it is possible to change to a configuration in which resistance application by the resistance application units 46, 47, and 48 and reverse conveyance of the reverse conveyance unit 49 are started.

  The separation unit 28 is not limited to the case where the separation roller 31 and the separation pad 34 are configured. For example, the separation unit 28 can be changed to a configuration in which the separation roller and the retard roller are arranged to face each other. Further, the positions and the number of the transport rollers 61, 62, 63, 64 on the downstream side of the separation unit 28 can be arbitrarily changed according to circumstances.

  Switching between the crease extending position and the retracted position of the support arm 71 may be performed manually by an operator or automatically by a driving means such as a motor. Moreover, it can replace with raising / lowering the raising / lowering member 75 illustrated in FIGS. 6-8, for example, and can change into the structure which raises / lowers the support arm 71 whole.

  The shape of the friction pad 76 of the first modified example (FIG. 6) is not limited to an arc shape, and can be changed to any other shape. Further, for example, the one-way clutch can be changed to be connected to the resistance roller 77 in FIG. 7 or the reverse conveyance roller 79 in FIG. 8.

  The auto document feeder configured as described above can be applied not only to an image reading unit for both an auto document feeder and a flood bed, but also to an image reading unit dedicated to the auto document feeder. The auto document feeder is not limited to an image scanner device, but can be applied to, for example, a copy machine, a facsimile machine, a copy facsimile multifunction machine, and the like.

1 is a front sectional view showing a configuration of an image reading portion of an image scanner device according to an embodiment of the present invention. The perspective view of an image scanner apparatus. The main part perspective view which shows the structure of the isolation | separation part of an auto document feeder, and a pick-up roller in detail. The perspective view explaining a Z-fold original. FIG. 5A is an explanatory diagram illustrating a state immediately after the conveyance of the Z-folded document is started. FIG. 5B is an explanatory diagram showing a state in which the leading edge of the document is detected by the document detection sensor and suction is started from the suction port. FIG. 5C is an explanatory diagram illustrating a state in which the leading portion is conveyed while sucking and holding the second folded portion of the document with the suction port. FIG. 5D is an explanatory view showing a state in which the document is conveyed downstream while being developed. The front sectional view showing the 1st modification of an auto document feeder. Front sectional drawing which shows the 2nd modification of an auto document feeder. Front sectional drawing which shows the 3rd modification of an auto document feeder.

Explanation of symbols

Reference Signs List 3 Z-folded document 5 First folding section 6 Second folding section 28 Separating section 31 Separating roller 32 Pickup rollers 46, 47, 48 Resistance applying section 49 Reverse conveying section 71 Support arm 72 Suction port 76 Friction pad (resistance pad)
77 Resistance roller 79 Reverse conveying roller 101 Image scanner device 107, 117, 127, 137 Auto document feeder

Claims (14)

A pickup roller for feeding a Z-folded document;
A separation unit that conveys the original fed by the pickup roller while separating the original;
A resistance applying unit that is disposed on the rear side in the document conveying direction with respect to the pickup roller and sucks the upper surface of the folded portion of the Z-folded document;
An automatic document feeder characterized by comprising: A pickup roller for feeding a Z-folded document;
A separation unit that conveys the original fed by the pickup roller while separating the original;
A resistance applying unit disposed on the rear side in the document conveying direction with respect to the pickup roller and having a resistance pad contacting the upper surface of the folded portion of the Z-folded document;
An automatic document feeder characterized by comprising: A pickup roller for feeding a Z-folded document;
A separation unit that conveys the original fed by the pickup roller while separating the original;
A resistance applying unit that is disposed on the rear side in the document conveying direction with respect to the pickup roller and includes a resistance roller that contacts an upper surface of the folded portion of the Z-folded document;
An automatic document feeder characterized by comprising: The automatic document feeder according to claim 3,
An automatic document feeder, wherein a torque limiter is connected to the resistance roller. An automatic document feeder according to any one of claims 1 to 4,
The automatic document feeder according to claim 1, wherein the resistance imparted by the resistance imparting portion to the folding portion is smaller than the transport force of the separating portion. An automatic document feeder according to any one of claims 1 to 5,
A transport roller for transporting the document is provided on the downstream side in the transport direction from the separation unit,
An automatic document feeder, wherein a resistance force applied by the resistance applying portion to the folding portion is smaller than a conveying force of the conveying roller. A pickup roller for feeding a Z-folded document;
A separation unit that conveys the original fed by the pickup roller while separating the original;
A reverse conveying unit that is disposed on the rear side in the document conveying direction with respect to the pickup roller and has a reverse conveying roller that contacts the upper surface of the folded portion of the Z-folded document and conveys it in the direction opposite to the conveying direction;
An automatic document feeder characterized by comprising: The automatic document feeder according to claim 7,
An automatic document conveying device, wherein a torque limiter is connected to the reverse conveying roller. The automatic document feeder according to claim 7 or 8,
An automatic document feeder, wherein a clutch mechanism is connected to the reverse feeding roller. An automatic document feeder according to any one of claims 1 to 9,
The automatic document feeder according to claim 1, wherein the timing at which the resistance applying unit starts to apply resistance or the timing at which the reverse conveying unit starts reverse conveyance is after the conveyance of the original by the separating unit is started. An automatic document feeder according to any one of claims 1 to 10,
An automatic document conveying apparatus, wherein when a document is conveyed by a predetermined distance, the application of resistance by the resistance applying unit or the reverse conveyance of the reverse conveying unit is stopped. An automatic document feeder according to any one of claims 1 to 11,
The resistance applying unit or the reverse conveying unit is attached to a support arm, and the support arm is movable between a fold extending position above a document tray on which a document is set and a retreat position retracted from the fold extending position. An original reading apparatus characterized by being configured.   A document reading apparatus comprising the automatic document feeder according to claim 1.   An image scanner device as the document reading device according to claim 13.

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