JP2005324922A - Medium turnover device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably turnover a recording medium irrespective of the type of the recording medium by properly absorbing a reaction occurring by the deflection of the recording medium to smoothly move the rear end of the recording medium. <P>SOLUTION: This medium turnover device comprises a first rotating body, a second rotating body and a third rotating body rotating in pressure contact with the first rotating body, a medium carrying route guiding the recording medium, and a medium turnover means turning over and carrying the rear end of the recording medium guided to the medium carrying route. The medium turnover means comprises a fourth rotating body, a fifth rotating body directing the rear part of the recording medium to an area between the first rotating body and the third rotating body and rotating while coming into contact with the fourth rotating body, and a contacting/separating means enabling the fifth rotating body to come into contact and be separated from the fourth rotating body and bringing the fifth rotating body into pressure contact with the fourth rotating body after the recording medium is passed through a clearance between the first rotating body and the second rotating body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a medium reversing device.

Conventionally, as a medium reversing device, a medium suction conveying path and a medium reversing conveying path are provided without providing a dedicated reversing path in order to reduce the size and cost of an apparatus such as a printer to which the medium reversing apparatus is mounted. A common one has been proposed (for example, see Patent Document 1). In this case, the medium conveyed in the medium suction conveyance path by the first medium conveyance roller pair including the feed roller and the first driven roller is conveyed in the reverse direction by the reverse conveyance roller pair, and the medium The end is moved to the medium reverse conveyance path side by the rotational force of the feed roller. The medium is fed out of the medium reversing device by a second medium conveying roller pair including a feed roller and a second driven roller.
JP 2001-328759 A

  However, in the conventional medium reversing device, when the medium is strong, the medium is deformed along the medium suction conveyance path, so that the medium conveyed by the first medium conveyance roller pair is changed to the reverse conveyance roller pair. When the medium is reversed and conveyed, the rear end of the medium slips on the feed roller, and cannot be moved to the medium reverse conveyance path side. Similarly, even when the media is weak, the rear end of the medium bent (bent) in the medium suction / conveyance path slips with respect to the rotation of the feed roller, and is surely moved to the medium reverse conveyance path side. It can no longer be moved.

  The present invention solves the problems of the conventional medium reversing device and can appropriately move the trailing edge of the recording medium by properly absorbing the reaction force generated by the bending of the recording medium. An object of the present invention is to provide a medium reversing device capable of stably reversing a recording medium regardless of the type of the recording medium.

  Therefore, in the medium reversing device according to the present invention, the first rotating body, the second rotating body that rotates while being pressed against the first rotating body, and the first rotating body are rotated while being pressed against the first rotating body. Passing between a third rotating body, a medium transport path for guiding a recording medium transported by the first rotating body and the second rotating body, and between the first rotating body and the second rotating body Medium reversing means for reversing and conveying the rear end of the recording medium guided by the medium conveying path between the first rotating body and the third rotating body, The fourth rotating body, the fifth rotating body rotating with the rear portion of the recording medium facing between the first rotating body and the third rotating body and being pressed against the fourth rotating body And the fifth rotating body can be freely contacted and separated from the fourth rotating body, and the recording medium can be connected to the first rotating body and the first rotating body. After passing between the rotating body, comprising a moving means for pressing the rotating member of the fifth to the fourth rotating body.

  According to the present invention, the medium reversing device includes a first rotating body, a second rotating body that rotates while being pressed against the first rotating body, and a first rotating body that is pressed while contacting the first rotating body. 3, the medium conveyance path for guiding the recording medium conveyed by the first and second rotators, and the first and second rotators. Medium reversing means for reversing and conveying the rear end of the recording medium guided to the medium conveying path between the first rotating body and the third rotating body, A fourth rotating body, a fifth rotating body rotating with the rear portion of the recording medium facing between the first rotating body and the third rotating body and rotating in pressure contact with the fourth rotating body; And the fifth rotator is detachable from the fourth rotator, and the recording medium includes the first rotator and the second rotator. After passing between, comprises moving means for pressing the rotating member of the fifth to the fourth rotating body.

  In this case, the reaction force generated by the bending of the recording medium is appropriately absorbed, so that the rear end of the recording medium can be moved smoothly, and the recording medium can be stably reversed regardless of the type of the recording medium. Can be made.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view of a medium reversing device according to the first embodiment of the present invention, and FIG. 2 is an enlarged perspective view of a reversing roller according to the first embodiment of the present invention.

  In FIG. 1, reference numeral 10 denotes a medium reversing device according to the present embodiment, which is attached to a device such as an image forming device 17 to be described later, and reverses a medium 20 as a recording medium such as recording paper conveyed in the device. It is supposed to let you. The medium reversing device 10 has a feed roller 11 as a first rotating body that is driven by a drive source (not shown) and rotates in a direction indicated by an arrow (clockwise direction in FIG. 1). In addition, a suction roller 12 as a second rotating body that is driven by pressure contact with the feed roller 11, and a delivery roller as a third rotating body that is driven by pressure contact with the feed roller 11 similarly to the suction roller 12. 13 is disposed. C is an entrance-side transport path through which the medium 20 sucked into the medium reversing device 10 passes, and the medium 20 is transported in the direction indicated by the arrow through the entrance-side transport path c. 10 is inhaled. Further, d is an exit side conveyance path through which the medium 20 discharged from the medium reversing apparatus 10 passes, and the medium 20 reversed and discharged in the medium reversing apparatus 10 passes through the outlet side conveyance path d. It is conveyed in the direction indicated by the arrow.

  Further, a is a suction conveyance path of the medium 20 as a medium conveyance path, and is disposed substantially parallel to the conveyance direction of the medium 20 by the feed roller 11 and the suction roller 12. Further, b is a discharge conveyance path of the medium 20 as a medium conveyance path that is reversed and conveyed, and is arranged substantially parallel to the conveyance direction of the medium 20 by the feed roller 11 and the delivery roller 13.

  S1 is a sensor for detecting the position of the medium 20 sucked into the medium reversing device 10, and S2 is a sensor for detecting the position of the medium 20 to be discharged. A reversing roller 14 as a fourth rotating body and a fifth rotating body that forms a pair with the reversing roller 14 on the downstream side in the transport direction of the medium 20 transported by the feed roller 11 and the suction roller 12. A pressure roller 15 is disposed. As shown in FIG. 2, a gear 21 as a rotational force transmitting member that receives a driving force from a driving source (not shown) and transmits the driving force to the reversing roller 14 is attached to the shaft end of the reversing roller 14. Further, a torsion spring 22 as an elastic member is disposed between the gear 21 and the reverse roller 14. One end of the torsion spring 22 is fixed to the gear 21, and the other end is fixed to the reverse roller 14. Note that the gear 21 and the reversing roller 14 rotate freely with respect to each other.

  The pressure roller 15 is held by a lever 23 as a contacting / separating means having a rotating shaft 23a, and is arranged so as to be able to contact / separate the reversing roller 14 with the rotating shaft 23a of the lever 23 as a fulcrum. Is done. In order to bring the pressure roller 15 into contact with or away from the reversing roller 14, a solenoid 24 connected to the lever 23 is provided, and a spring 25 is attached to the lever 23 so that the pressure roller 15 is moved to the reversing roller. Biasing in a direction away from 14. Further, when the pressure roller 15 is in a position in contact with the reversing roller 14, the pressure roller 15 and the reversing roller 14 are arranged so that the reversal conveyance direction of the medium 20 is substantially parallel to the discharge conveyance path b. The

  Next, the configuration of the image forming apparatus 17 to which the medium reversing unit 50 and the option unit 51 including the medium reversing apparatus 10 are attached will be described.

  FIG. 3 is a schematic diagram of an image forming apparatus to which a medium reversing unit and an option unit according to the first embodiment of the present invention are attached. FIG. 4 is a schematic diagram of an option unit according to the first embodiment of the present invention. .

  Here, the image forming apparatus 17 is, for example, an electrophotographic printer, a facsimile machine, a copying machine, a printer, a multifunction machine having the functions of a facsimile machine, and a copying machine. Also good. Assuming that the image forming apparatus 17 forms an image by electrophotography, an ID cartridge is a medium in the recording mechanism section 35 that forms an image of the image forming apparatus 17 as shown in FIG. 20 is disposed along a conveyance path 32b. The ID cartridge includes a photosensitive drum as an image carrier, a charging roller that is disposed around the photosensitive drum and supplies electricity to the surface of the photosensitive drum to charge the photosensitive drum, and a charged photosensitive drum. An exposure device is provided that selectively irradiates the surface with light to form an electrostatic latent image. Further, a developing roller for conveying toner as a developer to the surface of the photosensitive drum on which the electrostatic latent image is formed, and a cleaning blade for removing the toner remaining on the surface of the photosensitive drum are provided. Further, a conveying unit that conveys the medium 20 and a transfer roller that is disposed to face the photosensitive drum and that transfers the toner image to the medium 20 conveyed by the conveying unit are also provided. In the ID cartridge, a charging process for storing the charge of the photosensitive drum is performed by the charging roller, and an exposure process for irradiating light to a position where image data on the photosensitive drum is formed is performed by the exposure device. A development process for attaching toner to the exposed portion is performed, and a transfer process for transferring the toner developed by the transfer roller to the medium 20 is performed. The fixing process for fixing the toner image on the medium 20 with heat and pressure is performed by the fixing unit 35a. Further, the image forming apparatus 17 may be an apparatus for forming a color image or an apparatus for forming a black and white image.

  The image forming apparatus 17 is loaded with a paper cassette 30 corresponding to a paper storage unit that stores the medium 20 therein, and the paper cassette 30 is parallel between a mounting position inside the apparatus and a drawing position outside the apparatus. A sheet cassette mounting unit 31 that holds the sheet 20 movably and a sheet transport unit 33 as a sheet transport unit that transports the medium 20 along the transport path 32f are mounted. A paper transport unit mounting unit 34 that holds the outer 20 in a movable manner in parallel with the drawer position, and a recording mechanism unit 35 that forms an image on the medium 20 while transporting the medium 20 along the transport path 32a.

  Reference numerals 35b and 35d denote path setting guides that set the path of the medium 20 to one of the transport path 32c, the transport path 32d, and the transport path 32g. The transport path 32c is for discharging the medium 20 to the outside from the discharge portion 35c in the case of single-sided printing, and the transport path 32d is formed at the bottom of the paper cassette 30 in the case of double-sided printing. This is for feeding into the retreat path 32e. The paper transport unit 33 is provided with a transport roller 36 and a driven roller 37 that can rotate forward and backward.

  In addition, a medium reversing unit 50 and an option unit 51 are attached to the image forming apparatus 17. The medium reversing unit 50 includes a medium reversing device 10 inside, and reverses the medium 20. In the medium reversing unit 50, a path setting guide 35e for setting the path of the medium 20 sent from the transport path 32g of the image forming apparatus 17 to either the medium reversing apparatus 10 or the transport path 32h is arranged. It is installed. The medium 20 reversed by the medium reversing device 10 is transported along the transport path 32i.

  Further, as shown in FIG. 4, the option unit 51 includes a punch unit 60, a staple unit 61, a bent portion 63, and the like. Then, processing such as punching, stapling, and bending is performed on the medium 20 on which image formation has been performed, and the processed medium 20 is discharged to the stack tray 65 via the standby lever portion 64 or the saddle tray 66. To be discharged.

  Next, the operation of the image forming apparatus 17 to which the medium reversing unit 50 and the option unit 51 having the above configuration are attached will be described.

  First, the medium 20 positioned at the top of the plurality of media 20 stacked in the paper cassette 30 is transported along the transport path 32a, and the toner is transferred when passing through the transport path 32b in the recording mechanism section 35. Then, after passing through the fixing unit 35a, the route is selected by the route setting guide 35b and the route setting guide 35d.

  In the case of single-sided printing, the medium 20 that has passed through the fixing unit 35a is sent to the conveyance path 32c and is discharged from the discharge unit 35c to the outside of the image forming apparatus 17 as it is. On the other hand, in the case of double-sided printing, the medium 20 that has passed through the fixing unit 35a is sent to the transport path 32d and passes between the transport roller 36 and the driven roller 37 that can rotate in the forward and reverse directions of the paper transport unit 33. Once (simply), it is sent to a retreat path 32e corresponding to the second transport path formed at the bottom of the paper cassette 30. Thereafter, the medium 20 is sent to the conveyance path 32f corresponding to the first conveyance path in the sheet conveyance unit 33 by the conveyance roller 36 driven in reverse, and again along the conveyance path 32b in the recording mechanism unit 35. After being conveyed and transferred to the back surface, the image is discharged from the discharge portion 35c to the outside of the image forming apparatus 17 through the fixing portion 35a and the path setting guide 35b.

  Further, when processing such as punching, stapling, or bending is performed on the medium 20 on which the image is formed, the medium 20 is sent to the conveyance path 32g and sent to the medium reversing unit 50. In the medium reversing unit 50, the route is selected by the path setting guide 35e depending on whether the medium 20 is reversed. When the medium 20 is not reversed, the medium 20 is transported along the transport path 32 h and sent to the option unit 51. On the other hand, when performing reversal, the medium 20 is sent to the medium reversing device 10.

  In this case, as shown in FIG. 1, the medium 20 is transported in the direction indicated by the arrow in the entrance-side transport path c, sucked into the medium reversing device 10, and the rotating feed roller 11 and the suction roller 12. Are conveyed along the suction conveyance path a in the direction indicated by the arrow. At this time, as shown by the solid line, the pressure roller 15 is located away from the reversing roller 14, so that the medium 20 is conveyed between the reversing roller 14 and the pressure roller 15. Then, a predetermined time t seconds after the rear end portion of the medium 20 is detected by the sensor S1, a current flows through the solenoid 24 to actuate the solenoid 24, so that the pressure roller 15 is brought into contact with the reverse roller 14. And is brought into pressure contact with the reversing roller 14. In the present embodiment, the predetermined time t is set as a time until the rear end of the medium 20 passes through the nip portion between the feed roller 11 and the suction roller 12, but the predetermined time t is arbitrarily set. The rear end of the medium 20 may pass between the feed roller 11 and the suction roller 12 and be separated. At this time, the medium 20 is pushed by the pressure roller 15 toward the discharge conveyance path b, is sandwiched between the reversing roller 14 and the pressure roller 15, and is conveyed along the discharge conveyance path b in the direction indicated by the arrow. The

  Here, the rear end of the medium 20 is sent to the feed roller 13 side by the feed roller 11, but at the same time as the medium 20 is sent to the feed roller 13 along the curved surface of the feed roller 11, the reverse roller 14 and the pressure are fed. The medium 20 is bent by the amount conveyed by the roller 15. Further, when the reaction force with respect to the conveying force generated by the bending becomes a predetermined value or more, the reversing roller 14 stops rotating against the restoring force of the torsion spring 22 or in a direction opposite to the rotation in the conveying direction. Since it rotates, the reaction force against the conveying force is absorbed and the bending is eliminated.

  Then, the medium 20 is fed between the feed roller 13 and the feed roller 11. As a result, the medium 20 is sandwiched between the feed roller 13 and the feed roller 11, reversely conveyed, discharged, and conveyed in the direction indicated by the arrow in the outlet side conveyance path d. Here, when the front end of the medium 20 is detected by the sensor S2, the solenoid 24 is turned off to stop the operation, and the pressure roller 15 is moved away from the reversing roller 14 by the restoring force of the spring 25. Return. Then, the medium 20 discharged from the medium reversing device 10 by the feed roller 13 and the feed roller 11 is transported along the transport path 32 i and sent to the option unit 51.

  Subsequently, as shown in FIG. 4, the medium 20 sent to the option unit 51 is punched by the punch unit 60 as necessary, stapled by the staple unit 61, and subjected to processing such as bending by the bending unit 63. Applied. If only punching is required, the medium 20 punched by the punch unit 60 is transported along the transport path, and after a predetermined number of sheets are stacked on the standby lever portion 64, the medium 20 is discharged onto the stack tray 65. . Further, when the staple processing is necessary, the medium 20 loaded on the standby lever portion 64 is stapled by the staple unit 61 and then discharged to the stack tray 65. Further, when the folding process is necessary, the stapled medium 20 moves until reaching the folding position in the folding part 63, and then is pushed and bent by the folding part 63 in the direction of arrow A, and is discharged to the saddle tray 66. Paper.

  Next, the control unit of the medium inverting device 10 having the above configuration will be described.

  FIG. 5 is a block diagram showing the configuration of the control unit of the medium reversing device according to the first embodiment of the present invention.

  In FIG. 5, a print control unit 70 controls the image forming apparatus 17 and the entire medium reversing unit 50 and option unit 51 connected to the image forming apparatus 17. Reference numeral 71 denotes a solenoid control unit that controls on / off of the solenoid 24, and reference numeral 73 denotes a motor control unit that controls driving of a motor 72 that is a driving source of the feed roller 11 and the reverse roller 14.

  Here, when the image forming apparatus 17 is powered on, the print control unit 70 instructs the motor control unit 73 to start driving the motor 72. When the tip of the medium 20 reaches the sensor S1 when the medium 20 is sent to the medium inverting device 10, the sensor S1 is turned on to detect the medium 20. Further, when a predetermined time t has elapsed after the rear end of the medium 20 passes the sensor S1 and the sensor S1 is turned off, the print control unit 70 issues a drive instruction to the solenoid control unit 71, and the solenoid control is performed. The unit 71 drives the solenoid 24. As a result, the feed roller 11 and the reverse roller 14 rotate.

  Subsequently, when the tip of the medium 20 that has been transported in reverse reaches the sensor S2, the sensor S2 is turned on to detect the medium 20. When the sensor S2 is turned on, the print control unit 70 again issues a drive instruction to the solenoid control unit 71, and the solenoid control unit 71 stops driving the solenoid 24. Thereby, the rotation of the feed roller 11 and the reverse roller 14 is stopped.

  Next, a time chart showing the operation of the medium inverting device 10 will be described.

  FIG. 6 is a time chart showing the operation of the medium inverting device according to the first embodiment of the present invention.

  First, at timing t0, the image forming apparatus 17 is turned on. Subsequently, at timing t1, driving of the motor 72 is started, and the feed roller 11 and the reverse roller 14 start to rotate in the direction indicated by the arrow in FIG. At the timing t2, the leading edge of the medium 20 is detected by the sensor S1, and at the timing t3, the trailing edge of the medium 20 is detected by the sensor S1.

  Subsequently, at timing t4, the solenoid 24 is driven, the pressure roller 15 is pressed against the reversing roller 14, and the conveyance of the medium 20 is started. At timing t5, the leading edge of the medium 20 that is reversely conveyed is detected by the sensor S2, and the drive of the solenoid 24 is stopped, and the pressure roller 15 is separated from the reverse roller 14. Further, at the timing t6, the rear end of the medium 20 is detected by the sensor S2.

  Thus, in this embodiment, the torsion spring 22 as an elastic member is disposed between the reversing roller 14 and the gear 21 so that the gear 21 and the reversing roller 14 rotate freely with respect to each other. Yes. Therefore, the reaction force against the reverse conveying force between the reversing roller 14 and the pressure roller 15 generated when the medium 20 is bent in the conveying path is absorbed by the torsion spring 22. Accordingly, the rear end of the medium 20 is smoothly fed to the feed roller 13 along the curved surface of the feed roller 11 as the pressure roller 15 presses the medium 20 against the discharge conveyance path b. Regardless of this, stable reverse conveyance becomes possible.

  Next, a second embodiment of the present invention will be described. In addition, what has the same structure as 1st Embodiment attaches the same code | symbol, and abbreviate | omits the description. The description of the same operation and the same effect as those of the first embodiment is also omitted.

  FIG. 7 is an enlarged perspective view of the reverse roller in the second embodiment of the present invention.

  By the way, the excessive reaction force due to the bending when the rear end of the medium 20 sucked into the medium reversing device 10 is fed to the feed roller 13 side by the feed roller 11 varies depending on the type of the medium 20, and is reversed. The reaction force varies greatly due to variations in the amount of deflection accompanying the deviation of the start timing of the roller 14.

  In the first embodiment, the torsion spring 22 can absorb and correct the remaining bending length up to a certain amount. However, due to the nature of the torsion spring 22, if the amount of absorption increases, the reaction force also increases. . Further, there is a limit to the length of the extra bending length that can be absorbed.

  Therefore, in the present embodiment, as shown in FIG. 7, the shaft 21 of the reversing roller 14 receives a driving force from a driving source (not shown) and transmits the driving force to the reversing roller 14 at the shaft 21. In addition, a torque limiter 81 is provided between the gear 21 and the reversing roller 14 so that the reversing roller 14 rotates idly when a torque exceeding a specified value is applied in the reverse direction to the reversing roller 14. Since the configuration of other points is the same as that of the first embodiment, description thereof is omitted.

  Next, the operation of the medium inverting device 10 having the above configuration will be described.

  First, the operation of sucking the medium 20 into the medium inverting device 10 is the same as that in the first embodiment. However, when an excessive reaction force is generated due to bending when the rear end of the sucked medium 20 is sent to the feed roller 13 side by the feed roller 11, the reverse roller 14 and the shaft of the reverse roller 14 are arranged. The torque limiter 81 idles and absorbs excess reaction force. Thereby, the reaction force of the medium 20 on the feed roller 11 is kept constant, and the medium 20 is sent to the feed roller 13 side.

  Thus, in the present embodiment, the torque limiter 81 is disposed between the reversing roller 14 and the gear 21. Therefore, even if an excessive reaction force is generated in the medium 20, the torque limiter 81 idles and absorbs a certain amount of reaction force, so that the range that can be corrected becomes infinite and the stability of the medium reversal function is improved. Can be made.

  Next, a third embodiment of the present invention will be described. In addition, what has the same structure as 1st and 2nd embodiment attaches | subjects the same code | symbol, and abbreviate | omits the description. Also, the description of the same operations and effects as those of the first and second embodiments is omitted.

  FIG. 8 is a schematic diagram of a medium reversing device according to the third embodiment of the present invention.

  In the present embodiment, as shown in FIG. 8, the reversing roller 14 and the driving source of the reversing roller 14 in the first and second embodiments are deleted, and the medium is conveyed to the position of the reversing roller 14. A friction material 85 is disposed as a shift member that can shift in the direction. A constant tension is applied to the friction material 85 by a spring 86 in the direction in which the medium 20 is discharged. The material of the friction material 85 is not particularly limited. For example, polyacetal resin having high sliding mobility is used.

  Next, the operation of the medium inverting device 10 having the above configuration will be described.

  First, when the medium 20 that has been sucked is reversed, the pressure roller 15 moves to the friction material 85 side. As a result, the medium 20 is sandwiched between the friction material 85 and the pressure roller 15. When the rear end of the medium 20 is fed on the feed roller 11 toward the feed roller 13, the route length is shortened by the curvature of the feed roller 11, and a reaction force is generated in the medium 20, which is shortened by the reaction force. The friction material 85 moves in the direction of increasing the route length by an amount corresponding to the route length.

  Subsequently, when the rear end of the medium 20 passes through the position where the route length is the shortest on the feed roller 11 and the route length is gradually increased and the reaction force is reduced, the friction material 85 is applied with the spring 86 which applies initial tension. Is returned together with the medium 20, and the medium 20 is sent out by the feed roller 13.

  Thus, in the present embodiment, the reversing roller 14 having the drive source is deleted, the initial tension is applied in the feeding direction of the medium 20, and the friction material is movable in the direction opposite to the feeding direction of the medium 20. 85 is arranged. Therefore, the surplus length of the medium 20 generated when the medium 20 is reversed is absorbed by the friction material 85 moving, and further, the medium 20 is transferred to the delivery roller 13 by the return of the friction material 85 corresponding to the absorbed surplus length. Can be sent in. Therefore, since the drive mechanism of the reverse roller 14 can be eliminated, the reverse mechanism can be realized at low cost.

  Next, a fourth embodiment of the present invention will be described. In addition, what has the same structure as the 1st-3rd embodiment attaches the same code | symbol, and abbreviate | omits the description. Explanation of the same operations and effects as those of the first to third embodiments is also omitted.

  FIG. 9 is a schematic diagram of a medium reversing device according to the fourth embodiment of the present invention.

  In the present embodiment, as shown in FIG. 9, a reversing guide 91 as a medium turning member is attached to the support member of the pressure roller 15. The reversing guide 91 is disposed closer to the feed roller 11 than the pressure roller 15. Even if the pressure roller 15 is in a position where it contacts the reversing roller 14, the reversing guide 91 does not contact the discharge conveyance path b. The material of the reversing guide 91 is not particularly limited (for example, metal, resin, wood, etc.), but preferably has a small friction with the medium 20.

  Next, the operation of the medium inverting device 10 having the above configuration will be described.

  First, when the reversal of the medium 20 that has been sucked is started, the pressure roller 15 moves so as to contact the reversing roller 14, and the medium 20 is tilted from the suction side to the delivery side. At this time, the reversing guide 91 disposed at the tip of the pressure roller 15 also simultaneously tilts the leading end of the medium 20 toward the sending side.

  As described above, in this embodiment, the reversing guide 91 for attaching the medium 20 to the support member of the pressure roller 15 is attached. Therefore, it is possible to reduce defects when the medium 20 is reversed.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

It is the schematic of the medium inversion apparatus in the 1st Embodiment of this invention. It is an expansion perspective view of the reverse roller in the 1st Embodiment of this invention. 1 is a schematic diagram of an image forming apparatus to which a medium reversing unit and an option unit are attached according to a first embodiment of the present invention. It is the schematic of the option unit in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the control part of the medium inversion apparatus in the 1st Embodiment of this invention. It is a time chart which shows operation | movement of the medium inversion apparatus in the 1st Embodiment of this invention. It is an expansion perspective view of the inversion roller in the 2nd Embodiment of this invention. It is the schematic of the medium inversion apparatus in the 3rd Embodiment of this invention. It is the schematic of the medium inversion apparatus in the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Medium reversing apparatus 11 Feed roller 12 Suction roller 13 Sending roller 14 Reversing roller 15 Pressure roller 20 Medium 21 Gear 22 Torsion spring 23 Lever 81 Torque limiter 85 Friction material 91 Reversing guide a Suction conveyance path b Ejection conveyance path

Claims (7)

(A) a first rotating body;
(B) a second rotating body that rotates while being pressed against the first rotating body;
(C) a third rotating body that rotates while being pressed against the first rotating body;
(D) a medium transport path for guiding a recording medium transported by the first rotating body and the second rotating body;
(E) A rear end of the recording medium guided between the first rotating body and the second rotating body and guided by the medium transport path is formed between the first rotating body and the third rotating body. Medium reversing means for reversing and conveying between,
(F) The medium inverting means
(G) a fourth rotating body,
(H) a fifth rotator rotating with the rear portion of the recording medium directed between the first rotator and the third rotator and being pressed against the fourth rotator; and
(I) The fifth rotating body is made contactable and separable from the fourth rotating body, and after the recording medium passes between the first rotating body and the second rotating body, the fifth rotating body is A medium reversing device comprising contact / separation means for press-contacting the rotating body with the fourth rotating body. The medium inverting device according to claim 1, wherein the medium inverting unit includes a reverse rotating unit that allows the fourth rotating body to rotate a predetermined amount in a direction opposite to the conveying direction when the recording medium is reversed and conveyed. The reverse rotation means includes a rotational force transmitting member that transmits rotational force to the fourth rotating body, and an elastic member that is disposed between the rotational force transmitting member and the fourth rotating body. Item 3. The medium reversing device according to Item 2. The reverse rotation means includes a rotational force transmitting member that transmits rotational force to the fourth rotating body, and a torque limiter disposed between the rotational force transmitting member and the fourth rotating body. Item 3. The medium reversing device according to Item 2. The medium reversing device according to claim 1, wherein the medium reversing unit includes a transition member arranged to be movable along the medium conveyance path instead of the fourth rotating body. 6. The medium reversing means includes a medium turning member that directs a rear portion of the recording medium between the first rotating body and the third rotating body in conjunction with the contacting / separating means. The medium inversion device according to any one of the above. The medium transport path includes a transport surface that is substantially parallel to the transport direction of the recording medium between the first rotating body and the second rotating body, and the first rotating body and the third rotating body. The medium reversing device according to claim 1, further comprising a conveyance surface substantially parallel to a conveyance direction of the recording medium.

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