JP2016117591A - Sheet conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the buckling of a sheet in the skew correction of the sheet.SOLUTION: A second skew correction part 120 includes: a feeding roll 130 feeding paper P; a guiding part 140 moving in a state that the paper tip of the paper P conveyed by the feeding roll 130 is made to abut thereon, thereby guiding the paper P while correcting a skew at the paper tip; and a receiving roll 150 receiving the paper P conveyed by the feeding roll 130 and subjected to the correction of the skew at the paper tip by the guiding part 140, and conveying it. The guiding part 140 guides and conveys the paper P whose tip is made to abut thereon, and after the paper P is interposed by the receiving roll 150, is shifted to a state that it separates from the paper P by moving in a direction away from the paper tip along a first conveyance path, and then retreats from the first conveyance path.SELECTED DRAWING: Figure 18

Description

  The present invention relates to a sheet conveying apparatus.

  As the prior art described in the publication, a conveying means for conveying paper sheets, a detecting means for detecting the presence or absence of paper sheets on the conveying path of the conveying means, and skewing of the paper sheets in contact with the paper sheets A skew correction means comprising a skew correction means for correcting, a driving means for driving the conveyance means and the skew correction means, and a contact point with the paper sheet in the skew correction means is configured to be movable in the conveyance direction of the paper sheet. There is a line correction device (see Patent Document 1).

JP-A-2-70639

  It is an object of the present invention to suppress sheet buckling during sheet skew correction.

  According to the first aspect of the present invention, the first conveying unit that conveys the sheet while sandwiching the sheet, the second conveying unit that conveys the sheet conveyed by the first conveying unit, and the first conveying unit convey the sheet. In a state where the leading end of the sheet in the conveying direction is abutted, the guiding unit guides the sheet to the second conveying unit, and the sheet guided by the guiding unit is sandwiched by the second conveying unit. And the retreating means for retreating the guide means from the conveyance path of the sheet and the position of the side edge of the sheet disposed on the opposite side of the retraction means in the conveyance path on the downstream side of the second conveyance means. The second conveying means includes a sensor for detecting the sheet based on the sensor after the sheet guided by the guiding means is sandwiched by the second conveying means. A sheet conveying apparatus characterized by moving the door in a direction intersecting the transport path.

According to a second aspect of the present invention, the second conveying unit moves the sheet in a direction intersecting the conveying path by moving in the same direction as the plurality of conveying units including the second conveying unit. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is characterized in that:
According to a third aspect of the present invention, the second conveying unit is configured such that the sheet guided by the guiding unit is nipped by the second conveying unit, and the nipping of the sheet by the first conveying unit is released. 3. The sheet conveying apparatus according to claim 1, wherein the sheet is moved in a direction intersecting the conveying path based on a sensor.

According to a fourth aspect of the present invention, the second transport unit includes a first roll and a second roll provided on the left and right in a direction intersecting the transport path in plan view, and the guide unit includes the first roll The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is provided on each of an outer side and an inner side of one roll and the second roll.
The invention according to claim 5 is characterized in that each of the first roll and the second roll comprises two rolls, and the guide means is further disposed between the two rolls. Item 5. The sheet conveying apparatus according to Item 4.

  According to the present invention, the buckling of the sheet in the skew correction of the sheet can be suppressed as compared with the case where the present configuration is not provided.

1 is a diagram illustrating an example of an overall configuration of an image forming apparatus to which the exemplary embodiment is applied. FIG. 10 is a diagram for explaining a relationship between each conveyance path provided in the sheet reversing device and a sheet conveyance direction in each conveyance path. It is a figure for demonstrating an example of a structure of an attitude | position correction apparatus. FIG. 6 is a perspective view of the guide unit when viewed from the downstream side in the sheet conveyance direction. FIG. 6 is a perspective view of a lower gate in a guide section when viewed from the downstream side in the sheet conveyance direction. It is a figure for demonstrating the control system of an attitude | position correction apparatus. It is FIG. (1) for demonstrating operation | movement of an attitude | position correction apparatus. It is FIG. (2) for demonstrating operation | movement of an attitude | position correction apparatus. FIG. 9 is a third diagram for explaining the operation of the attitude correction device; FIG. 10 is a diagram (No. 4) for explaining the operation of the attitude correction device. It is FIG. (5) for demonstrating operation | movement of an attitude | position correction apparatus. It is FIG. (6) for demonstrating operation | movement of an attitude | position correction apparatus. It is FIG. (7) for demonstrating operation | movement of an attitude | position correction apparatus. It is FIG. (8) for demonstrating operation | movement of an attitude | position correction apparatus. It is FIG. (9) for demonstrating operation | movement of an attitude | position correction apparatus. It is a figure for demonstrating the relationship between a receiving roll and the guide part (lower gate) which reached | attained the goal position. In the posture correction operation of the first embodiment, the guide part moving speed of the guide part, the position of the lower gate provided in the guide part, and the paper speed of the paper before and after the paper passes through the second skew correction part. It is a timing chart which shows a relationship. It is a figure for demonstrating the state of the 1st skew feeding correction part and the 2nd skew feeding correction part corresponding to the timing chart shown in FIG. In the posture correction operation of the second embodiment, the guide part moving speed of the guide part, the position of the lower gate provided in the guide part, and the paper speed of the paper before and after the paper passes through the second skew correction part. It is a timing chart which shows a relationship. It is a figure for demonstrating the state of the 1st skew feeding correction part and the 2nd skew feeding correction part corresponding to the timing chart shown in FIG. In the attitude correction operation of the third embodiment, the guide unit moving speed of the guide unit, the position of the lower gate provided in the guide unit, and the sheet speed of the sheet before and after the sheet passes through the second skew correction unit. It is a timing chart which shows a relationship. It is a figure for demonstrating the state of a 1st skew feeding correction part and a 2nd skew feeding correction part corresponding to the timing chart shown in FIG. It is a figure for demonstrating the other structural example of a lower gate.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
<Embodiment 1>
FIG. 1 is a diagram illustrating an example of the overall configuration of an image forming apparatus to which the exemplary embodiment is applied. Here, FIG. 1 shows a cross-sectional configuration when the image forming apparatus 1 is viewed from the front side.

  The image forming apparatus 1 includes an image forming unit 10 that forms an image, an intermediate transfer belt 20 on which an image formed by the image forming unit 10 is primarily transferred, and an image that is primarily transferred to the intermediate transfer belt 20 on a sheet P. A secondary transfer device 30 for secondary transfer, a paper supply device 40 for supplying the paper P toward the secondary transfer device 30, and a fixing for fixing the image secondarily transferred to the paper P by the secondary transfer device 30 Device 50. In addition, the image forming apparatus 1 reverses the front and back of the paper P that has passed through the fixing device 50 and the posture correction device 100 that corrects the posture of the paper P that is conveyed toward the secondary transfer device 30. And a reverse conveyance device 70 that conveys the paper P to the attitude correction device 100. The image forming apparatus 1 includes a control unit 80 that controls the operation of each of the above-described devices, a touch panel, and the like. The image forming apparatus 1 outputs an instruction received from the user to the control unit 80 and sends information from the control unit 80 to the user. A user interface unit (UI) 90 to be presented is further provided. The image forming apparatus 1 according to the present embodiment includes a housing 2 that accommodates each of the above-described apparatuses.

  In the image forming apparatus 1, the first transport path R <b> 1 through which the paper P transported from the paper supply device 40 toward the secondary transfer device 30 passes, and the first paper P after passing through the secondary transfer device 30 pass through. A second conveyance path R2 and a third conveyance path R3 that branches from the second conveyance path R2 downstream of the fixing device 50 and extends below the first conveyance path R1 to guide the paper P to the reverse conveyance apparatus 70; A fourth transport path R4 is provided that guides the paper P that has passed through the apparatus 70 to the first transport path R1 again. Therefore, the attitude correction device 100 is in the first transport path R1, the secondary transfer device 30 is in the boundary between the first transport path R1 and the second transport path R2, and the fixing device 50 is in the second transport path R2. The reverse conveyance device 70 is provided between the third conveyance path R3 and the fourth conveyance path R4. Further, the downstream end of the second transport path R <b> 2 in the transport direction of the paper P is connected to an opening 3 provided in the housing 2.

  Note that the image forming apparatus 1 according to the present embodiment operates in a so-called “center reference” in which the paper P of each size is transported with reference to the center position in the width direction orthogonal to the transport direction of the paper P. It has become.

  Among these, the image forming unit 10 includes a plurality of image forming units 10Y, 10M, 10C, and 10K that form toner images of respective color components by an electrophotographic method, and these image forming units 10Y, 10M, 10C, and 10K. Are arranged side by side so as to face the intermediate transfer belt 20. Here, the plurality of image forming units 10Y, 10M, 10C, and 10K form yellow, magenta, cyan, and black images, respectively.

  Each of the plurality of image forming units 10Y, 10M, 10C, and 10K includes a photosensitive drum 11 that is rotatably mounted. In each of the image forming units 10Y, 10M, 10C, and 10K, around the photosensitive drum 11, a charging device 12 that charges the photosensitive drum 11 and the photosensitive drum 11 are exposed to write an electrostatic latent image. An exposure device 13 and a developing device 14 that visualizes the electrostatic latent image on the photosensitive drum 11 with a corresponding color toner are provided. Further, in each of the image forming units 10Y, 10M, 10C, and 10K, a primary transfer device 15 that transfers each color component toner image formed on the photosensitive drum 11 to the intermediate transfer belt 20, and a residual on the photosensitive drum 11 A drum cleaning device 16 for removing toner is provided.

  Next, the intermediate transfer belt 20 is stretched around three roll members 21 to 23 that are rotatably provided. Here, the roll member 22 is used to drive the intermediate transfer belt 20. The roll member 23 is disposed opposite to the secondary transfer roll 31 with the intermediate transfer belt 20 interposed therebetween, and the secondary transfer device 30 is configured by the secondary transfer roll 31 and the roll member 23. A belt cleaning device 24 for removing residual toner on the intermediate transfer belt 20 is provided at a position facing the roll member 21 across the intermediate transfer belt 20.

  Here, in the present embodiment, the image forming unit 10, the intermediate transfer belt 20, and the secondary transfer device 30 have a function as an image forming unit.

  The paper supply device 40 is provided on the first paper supply device 40A for supplying the paper P to the first conveyance path R1, and on the downstream side in the conveyance direction of the paper P relative to the first paper supply device 40A. A second paper supply device 40B for supplying the paper P to the path R1. Here, the first paper supply device 40A and the second paper supply device 40B have a common configuration, and each of the first paper supply device 40A and the second paper supply device 40B stores a paper P. And a take-out roll 42 that takes out and transports the paper P stored in the paper storage unit 41.

  The image forming apparatus 1 according to the present embodiment is provided in each of the first transport path R1 to the fourth transport path R4, and includes a plurality of transport rolls 45 that transport the paper P existing in each transport path. The belt transport unit 46 is disposed between the secondary transfer device 30 and the fixing device 50 in the second transport path R2 and stacks and transports the sheets P existing in this region.

  Further, the fixing device 50 includes a heating roll 50A that is heated by a built-in heater (not shown), a pressing roll 50B that is disposed to face the heating roll 50A across the second transport path R2, and presses the heating roll 50A. have.

  The reverse conveyance device 70 of the present embodiment is connected to a third conveyance path R3 provided in the image forming apparatus 1, and is connected to a carry-in path Ra through which the paper P is carried from the third conveyance path R3, and to the carry-in path Ra. The paper P that is connected to the reversing path Rb that reverses the front and back of the paper P while transporting the paper P, and the reverse transport path Rb and the fourth transport path R4 provided in the image forming apparatus 1, And a carry-out route Rc for carrying out to the carry route R4. In the reverse conveyance device 70, the carry-out route Rc is arranged so as to overlap the carry-in route Ra when viewed from above, and the reverse route Rb is curved in a U shape on the front side of the carry-in route Ra and the carry-out route Rc. By doing so, it arrange | positions so that the near side of carrying-in path | route Ra and the near side of carrying-out path | route Rc may be connected. The reversing conveyance device 70 includes a carry-in roll 71 that conveys the paper P that has been carried in from the third conveyance path R3 in the carry-in path Ra, and a paper P that has been carried into the carry-in path Ra in the carry-in path Ra. A first reversing roll 72 that conveys toward the reversing path Rb, a second reversing roll 73 that conveys the paper P carried into the reversing path Rb toward the carry-out path Rc, and the reversing path Rb. The third reversing roll 74 that conveys the paper P that has been carried in from within the carry-out path Rc, and the paper P that has been carried into the carry-out path Rc toward the fourth conveyance path R4. And an unloading roll 75.

Now, an image forming operation using the image forming apparatus 1 shown in FIG. 1 will be described.
Along with receiving image information from an external device (not shown), the control unit 80 creates exposure data based on the image information and outputs it to each exposure device 13 in the image forming unit 10, and configures the image forming device 1. An operation start control signal is output to each unit.

  For example, in the yellow (Y) image forming unit 10 </ b> Y, the photosensitive drum 11 that is rotationally driven is charged by the charging device 12 and exposed by the exposure device 13 that emits light based on the exposure data supplied from the control unit 80. Is done. As a result, an electrostatic latent image related to the yellow image is formed on the photosensitive drum 11. The electrostatic latent image formed on the photosensitive drum 11 is developed by the developing device 14, and a yellow toner image is formed on the photosensitive drum 11. Similarly, in the other image forming units 10M, 10C, and 10K, magenta (M), cyan (C), and black (K) toner images are formed according to the above-described procedure.

  The toner images formed on the photoconductive drums 11 of the image forming units 10Y, 10M, 10C, and 10K are primarily transferred (transferred) to the intermediate transfer belt 20 that is rotationally driven by the primary transfer devices 15 provided corresponding to the toner images. Electrostatic transfer) and are superimposed on the intermediate transfer belt 20. Then, the superimposed toner image superimposed on the intermediate transfer belt 20 moves toward the secondary transfer position where the secondary transfer device 30 is provided as the intermediate transfer belt 20 rotates. The residual toner remaining on each photosensitive drum 11 after the primary transfer is removed by a drum cleaning device 16 provided in each image forming unit 10Y, 10M, 10C, 10K.

  On the other hand, in the paper supply device 40, the paper P stored in the paper storage portion 41 of the first paper supply device 40 </ b> A (or the second paper supply device 40 </ b> B) is taken out one by one using the take-out roll 42. It sends out to 1 conveyance path | route R1. Then, the posture correction device 100 provided in the first transport path R1 corrects the posture (tilt, position, etc.) of the paper P sent from the paper supply device 40, and also superimposes the toner image on the intermediate transfer belt 20. Is sent toward the secondary transfer position in synchronization with the timing at which it reaches the secondary transfer position.

  The superimposed toner image on the intermediate transfer belt 20 is secondarily transferred (electrostatic transfer) to the paper P passing through the secondary transfer position by the secondary transfer device 30. At this time, secondary transfer of the superimposed toner image is performed on the surface (first surface) of the paper P facing the intermediate transfer belt 20.

  Then, the sheet P on which the superimposed toner image is transferred by passing through the secondary transfer position is transported in the second transport path R2 and passes through the fixing device 50. At this time, the first surface, which is the transfer surface of the superimposed toner image on the paper P, is heated by the heating roll 50A, and the paper P is pressed by the heating roll 50A and the pressing roll 50B, thereby overlapping the paper P. The toner image is fixed. Thereafter, the paper P on which the superimposed toner image is fixed is discharged to the outside through the opening 3 from the second transport path R2. Further, residual toner remaining on the intermediate transfer belt 20 after passing through the secondary transfer position is removed by the belt cleaning device 24.

  On the other hand, when forming images on both sides of the paper P, the paper P that has passed through the fixing device 50 enters the third transport path R3 from the second transport path R2, and further reverses from the third transport path R3. Enter the transport device 70. In the reverse conveyance device 70, a process for reversing the front and back of the conveyed paper P is performed, and the paper P discharged from the reverse conveyance device 70 to the fourth conveyance path R4 is compared to that before entering. Is in an inverted state.

  The image forming unit 10 forms toner images of the respective colors according to the above-described procedure. The toner images of the respective colors are transferred to the intermediate transfer belt 20 to form a superimposed toner image, which is a secondary transfer position. Head to.

  On the other hand, the sheet P whose front and back are reversed by the reversing conveyance device 70 enters the first conveyance route R1 again from the fourth conveyance route R4 and reaches the attitude correction device 100 again. Then, the attitude correction device 100 corrects the attitude of the paper P sent from the reverse conveyance device 70, and at the same time the secondary toner position on the intermediate transfer belt 20 reaches the secondary transfer position. Send to the transfer position.

  The superimposed toner image on the intermediate transfer belt 20 is secondarily transferred (electrostatic transfer) to the paper P passing through the secondary transfer position by the secondary transfer device 30. At this time, secondary transfer of the superimposed toner image is performed on the surface (second surface) of the paper P facing the intermediate transfer belt 20.

  Then, the sheet P on which the superimposed toner image is transferred by passing through the secondary transfer position is transported in the second transport path R2 and passes through the fixing device 50. At this time, the second surface, which is the transfer surface of the superimposed toner image on the paper P, is heated by the heating roll 50A, and the paper P is pressed by the heating roll 50A and the pressing roll 50B, thereby overlapping the paper P. The toner image is fixed. Thereafter, the paper P on which the overlapping toner images are fixed on both sides by passing through the fixing device 50 is discharged to the outside through the opening 3 from the second transport path R2. Further, residual toner remaining on the intermediate transfer belt 20 after passing through the secondary transfer position is removed by a belt cleaning device (not shown). As a result, an image is formed not only on the first side of the paper P but also on the second side.

  FIG. 2 is a diagram for explaining the relationship between each conveyance path provided in the reverse conveyance apparatus 70 and the conveyance direction of the paper P in each conveyance path. 2 corresponds to the case where the reverse conveying device 70 shown in FIG. 1 is viewed from the obliquely back side.

  Here, in the present embodiment, each part of the paper P that passes through the reverse conveying device 70 is defined as follows. First, the sheet P as an example of the sheet has a rectangular shape, and the leading end of the sheet P in the conveying direction is the leading end Pl (an example of the leading end portion) of the sheet P that is carried into the carry-in path Ra from the third conveying path R3. And the tail in the transport direction is referred to as the paper trailing edge Pt. Further, in the paper P carried into the carry-in route Ra from the third transport route R3, the right end in the transport direction is referred to as a paper first side end Ps1, and the left end in the transport direction is referred to as a paper second side end Ps2. Further, in the paper P carried into the carry-in route Ra from the third transport route R3, the surface facing upward is called a paper back surface Pb, and the surface facing downward is called a paper surface Pf. In this example, the image forming surface (first surface described above) by the image forming unit 10 is the paper surface Pf, and the other surface (second surface described above) is the paper back surface Pb.

  In the carry-in route Ra, the paper back surface Pb faces upward from the third transport route R3, and the paper first side edge Ps1 and the paper second side edge Ps2 with the paper leading edge Pl as the head and the paper trailing edge Pt as the tail. The paper P is fed along the carry-in direction Da1 following the above. Further, from the carry-in route Ra, the paper back surface Pb faces upward toward the reversing route Rb, the paper first side end Ps1 is the head, the paper second side end Ps2 is the tail, and the paper front end Pl and the rear of the paper The paper P is sent out along the delivery direction Da2 that follows the end Pt.

  From the carry-in route Ra, the reverse surface Rb faces the paper back surface Pb upward, and follows the paper leading edge Pl and the paper trailing edge Pt with the paper first side end Ps1 as the head and the paper second side edge Ps2 as the tail. The paper P is sent along the reverse direction Db. The delivery direction Da2 and the reverse direction Db are in the same direction at the boundary between the carry-in route Ra and the reverse route Rb. Here, the reversing direction Db has a curved shape (U-shape), and the sheet P conveyed in the reversing path Rb is a sheet first side end Ps1 and a sheet second side end Ps2 when viewed from above. Is reversed, and the relationship between the front and back surfaces (sheet front surface Pf and paper back surface Pb) is reversed and conveyed. Thereby, from the reverse path Rb, the paper surface Pf faces upward, and the reverse direction follows the paper leading edge Pl and the paper trailing edge Pt with the paper first side end Ps1 as the head and the paper second side edge Ps2 as the tail. The paper P is sent out along Db.

  From the reverse path Rb, the paper surface Pf faces upward, and the paper discharge path Rc follows the paper leading edge Pl and the paper trailing edge Pt with the paper first side end Ps1 as the head and the paper second side edge Ps2 as the tail. The paper P is sent along the receiving direction Dc1. Note that the reversal direction Db and the receiving direction Dc1 are in the same direction at the boundary between the reversal path Rb and the carry-out path Rc. Further, from the carry-out path Rc, the sheet surface Pf faces upward toward the fourth conveyance path R4, and the sheet first side end Ps1 and the sheet first are aligned with the sheet leading edge P1 as the head and the sheet trailing edge Pt as the tail. The paper P is sent out along a carry-out direction Dc2 that follows the second side end Ps2.

  As described above, in the reverse conveyance device 70 of the present embodiment, the traveling direction of the paper P supplied from the third conveyance path R3 is changed by 90 ° in the carry-in path Ra and is supplied to the reverse path Rb. The paper P supplied from the paper is rotated 180 ° in the reversing path Rb so that the front and back are reversed and supplied to the carry-out path Rc, and the traveling direction of the paper P supplied from the reverse path Rb is 90 in the carry-out path Rc. The angle is changed and supplied to the fourth transport path R4. At this time, the carry-in direction Da1 in the carry-in route Ra and the carry-out direction Dc2 in the carry-out route Rc are in the same direction. Then, before and after passing through the reverse conveying device 70, the relationship between the sheet leading edge Pl and the sheet trailing edge Pt in the conveying direction does not change before and after the sheet P passes between the sheet first side edge Ps1 and the sheet second edge Ps2 in the conveying direction. By reversing the relationship, the paper front surface Pf and the paper back surface Pb are reversed.

  FIG. 3 is a diagram for explaining an example of the configuration of the posture correction apparatus 100. Here, FIG. 3A shows a top view of the posture correction apparatus 100 when viewed from the IIIa direction shown in FIG. 1, and FIG. 3B shows the posture correction apparatus 100 in FIG. The side view when it sees from the IIIb direction shown (when it sees from the near side in FIG. 1) is shown. Accordingly, in each of FIG. 3A and FIG. 3B, the paper P is conveyed from the left side in the drawing toward the right side in the drawing. In the following description, the moving direction of the paper P in the first transport path R1 is referred to as a transport direction D1, and a direction orthogonal to the transport direction D1 in the first transport path R1 (in this example, from the back side to the near side). The direction (heading direction) is referred to as the width direction D2, and the direction orthogonal to the transport direction D1 and the width direction D2 (in this example, the direction from the lower side to the upper side) is referred to as the retraction direction D3. In FIG. 3A, the center position in the width direction D2 of the sheet P targeted in the center reference is shown as a reference line C.

  The posture correction device 100 according to the present embodiment is provided on the most upstream side in the transport direction D1, and corrects skew of the paper P sent from the paper supply device 40 or the reverse transport device 70 (both see FIG. 1). The first skew correction unit 110 and the skew of the paper P that is provided adjacent to the first skew correction unit 110 on the downstream side in the transport direction D1 and for which the skew correction has been performed by the first skew correction unit 110. A second skew correction unit 120 that further corrects the first skew correction unit 120, the second skew correction unit 120 adjacent to the downstream side in the transport direction D1 with respect to the second skew correction unit 120, and provided on the most downstream side in the transport direction D1. And a width direction position correction unit 160 that corrects the center position in the width direction D2 of the paper P that has been subjected to the skew correction by the second skew correction unit 120 so as to coincide with the reference line C. In addition, the posture correction apparatus 100 is disposed upstream of the first skew correction unit 110 in the transport direction D1, and includes a first sensor S1 that detects the passage of the sheet P toward the first skew correction unit 110, and a first sensor S1. 2 A second detection unit that is disposed downstream of the skew feeding correction unit 120 in the transport direction D1 and upstream of the width direction position correction unit 160 in the transport direction D1, and detects the passage of the sheet P toward the width direction position correction unit 160. And a sensor S2. In the posture correction apparatus 100, the first skew correction unit 110 has a function of roughly adjusting the skew amount of the paper P, and the second skew correction unit 120 as an example of the sheet conveying device is a paper. It has a function to finely adjust the skew amount of P.

  Now, each of the first skew correction unit 110, the second skew correction unit 120, and the width direction position correction unit 160 included in the posture correction apparatus 100 will be described in order.

  First, the first skew correction unit 110 includes a left skew correction roll 110L and a right skew correction roll 110R that are arranged side by side in the width direction D2 and each convey the paper P therebetween. Here, the left skew correction roll 110L is disposed on the left side of the reference line C as viewed from the upstream side in the transport direction D1, and the right skew correction roll 110R is located on the reference line C as viewed from the upstream side in the transport direction D1. Located on the right side.

  Among these, the left skew feeding correction roll 110L is disposed below the first transport path R1, and is driven by an external drive and rotated by the left drive roll 111L (see FIG. 6 described later), and the first transport path R1. And a left driven roll 112L that is arranged to face the left driving roll 111L and rotates by a driving force received from the left driving roll 111L. Here, the left driving roll 111L extends along the width direction D2 and the left driving roll rotating shaft whose both ends are rotatably held, and the left driving roll main body fixedly attached to the left driving roll rotating shaft, It has. On the other hand, the left driven roll 112L extends along the width direction D2 and the left driven roll rotating shaft 112La whose both ends are rotatably held, and the left driven roll main body fixedly attached to the left driven roll rotating shaft 112La. 112Lb.

  The right skew feeding correction roll 110R is disposed below the first transport path R1 and faces the right drive roll 111R that rotates by receiving external driving and the right drive roll 111R across the first transport path R1. And a right driven roll 112R that is rotated by the driving force received from the right drive roll 111R. Here, the right drive roll 111R extends along the width direction D2 and the right drive roll rotation shaft 111Ra that is rotatably held at both ends thereof, and the right drive roll fixedly attached to the right drive roll rotation shaft 111Ra. And a main body 111Rb. On the other hand, the right driven roll 112R extends along the width direction D2 and the right driven roll rotating shaft 112Ra whose both ends are rotatably supported, and the right driven roll main body fixedly attached to the right driven roll rotating shaft 112Ra. 112Rb.

  In the present embodiment, the left skew correction roll 110L (actually the left drive roll 111L) and the right skew correction roll 110R (actually the right drive roll 111R) constituting the first skew correction unit 110 are respectively Are driven to rotate independently.

  Next, the second skew feeding correction unit 120 is arranged on the downstream side in the transport direction D1 when viewed from the first skew correction unit 110, transports the paper P with the paper P interposed therebetween, and sends it out downstream. The paper P is disposed on the downstream side in the transport direction D1 when viewed from the feed roll 130 and moves along the transport direction D1 while holding the front end Pl of the paper P sent from the feed roll 130. A guide unit 140 that guides the front end Pl toward the downstream side, and a downstream side in the transport direction D1 and an upstream side in the transport direction D1 with respect to the width direction position correction unit 160 as viewed from the output roll 130. A receiving roll 150 is provided that receives and transports the paper P sent by the section 140 and feeds the paper P toward the width direction position correcting section 160. .

  The delivery roll 130 as an example of the first transport means is disposed below the first transport path R1 and is rotated by receiving a drive from the outside, and a delivery drive roll sandwiching the first transport path R1. It has a delivery driven roll 132 that is disposed to face 131 and rotates by the driving force received from the delivery drive roll 131. Here, the delivery drive roll 131 extends along the width direction D2 and is provided with a delivery drive roll rotating shaft 131a whose both ends are rotatably supported, and two delivery drives fixedly attached to the delivery drive roll rotating shaft 131a. And a drive roll body 131b. On the other hand, the delivery follower roll 132 extends in the width direction D2 and has two delivery followers fixedly attached to the delivery follower roll rotating shaft 132a that is rotatably held at both ends thereof. A roll main body 132b.

  Here, one of the two delivery drive roll bodies 131b provided on the delivery drive roll 131 is disposed on the left side of the reference line C, and the other is disposed on the right side of the reference line C. Of the two driven driven roll main bodies 132b provided on the outgoing driven roll 132, one is disposed on the left side of the reference line C and is opposed to the first driven driving roll main body 131b. It is arranged on the right side of the reference line C and at a position facing the other delivery drive roll body 131b.

  Further, in the delivery roll 130 of the present embodiment, the delivery driven roll 132 can move (advance and retreat) in the retreat direction D3 or the direction opposite to the retreat direction D3 with respect to the delivery drive roll 131 (or the first transport path R1). Thus, when the delivery driven roll 132 moves in the retracting direction D3, the contact state between the delivery drive roll 131 and the delivery driven roll 132 is released, so that the non-contact state is entered. Is moved in the direction opposite to the retreat direction D3, the delivery drive roll 131 and the delivery driven roll 132 are shifted from the non-contact state to the contact state. In the following description, the position of the delivery driven roll 132 shown by the solid line in FIG. 3B (position where the delivery drive roll 131 and the delivery driven roll 132 are in contact) is referred to as an “advance position”, and FIG. A position of the delivery driven roll 132 indicated by a broken line in b) (a position where the delivery drive roll 131 and the delivery driven roll 132 are not in contact) is referred to as a “retraction position”.

  The guide unit 140 as an example of a guide means is disposed below the first transport path R1 and a part thereof is disposed so as to block the first transport path R1, and a guide base portion on which the lower gate 141 is mounted. 143. The guide unit 140 according to the present embodiment has a position shown in FIG. 3 (a position on the downstream side in the transport direction D1 from the delivery roll 130 and an upstream side in the transport direction D1 from the receiving roll 150), and FIG. Between the position shown (position overlapping with the receiving roll 150), the transfer direction D1 and the transfer direction D1 are movably attached in the opposite direction. In the following description, the position of the guide unit 140 illustrated in FIG. 3 is referred to as a “start position”, and the position of the guide unit 140 illustrated in FIG. 11 is referred to as a “goal position”. The detailed configuration of the guide unit 140 will be described later.

  The receiving roll 150 as an example of the second transport means is disposed below the first transport path R1 and receives a drive roll 151 that rotates by receiving a drive from the outside, and a receiving drive roll across the first transport path R1. The receiving driven roll 152 is disposed opposite to the receiving drive roll 151 and is rotated by the driving force received from the receiving drive roll 151. Here, the receiving drive roll 151 includes a receiving drive roll rotating shaft 151a extending along the width direction D2 and rotatably held at both ends thereof, and four receiving drives fixedly attached to the receiving drive roll rotating shaft 151a. And a drive roll main body 151b. On the other hand, the receiving driven roll 152 extends along the width direction D2 and is rotatably supported by the receiving driven roll rotating shaft 152a and the four receiving driven fixedly attached to the receiving driven roll rotating shaft 152a. A roll main body 152b.

  Here, of the four receiving drive roll bodies 151b provided in the receiving drive roll 151, two are arranged on the left side of the reference line C, and the remaining two are arranged on the right side of the reference line C. ing. Of the four receiving driven roll main bodies 152b provided on the receiving driven roll 152, two are arranged on the left side of the reference line C and at positions facing the two receiving driving roll main bodies 151b, respectively. The remaining two are arranged on the right side of the reference line C and at positions facing the remaining two receiving drive roll bodies 151b.

  Further, the receiving roll 150 (the receiving driving roll 151 and the receiving driven roll 152) of the present embodiment can be moved integrally in the width direction D2 or the direction opposite to the width direction D2. In the following description, the position of the receiving roll 150 shown in FIG. 3A (a position where the receiving roll 150 is symmetric with respect to the reference line C) is referred to as a “receiving reference position”.

  Next, the width direction position correction unit 160 is disposed on the downstream side in the transport direction D1 when viewed from the second skew correction unit 120, transports the paper P with the paper P interposed therebetween, and faces the secondary transfer device 30 (see FIG. 1). And a position correction roll 170 to be sent out. The position correction roll 170 is disposed below the first transport path R1, and is opposed to the position correction drive roll 171 that rotates upon receiving a drive from the outside, and the position correction drive roll 171 across the first transport path R1. It has a position correction driven roll 172 that is arranged and rotated by the driving force received from the position correction drive roll 171. Here, the position correction drive roll 171 is fixedly attached to the position correction drive roll rotation shaft 171a that extends along the width direction D2 and whose both ends are rotatably held, and the position correction drive roll rotation shaft 171a. It has one position correction drive roll body 171b. On the other hand, the position correction driven roll 172 extends along the width direction D2 and is fixedly attached to the position correction driven roll rotation shaft 172a that is rotatably held at both ends thereof and the position correction driven roll rotation shaft 172a. And two position correction driven roll main bodies 172b. The position correction drive roll main body 171b provided on the position correction drive roll 171 and the position correction driven roll main body 172b provided on the position correction driven roll 172 are opposed to each other across the first transport path R1. ing.

  Further, the position correction roll 170 (position correction drive roll 171 and position correction driven roll 172) of the present embodiment can move integrally in the width direction D2 or the direction opposite to the width direction D2, as with the receiving roll 150 described above. It is like that. In the following description, the position of the position correction roll 170 shown in FIG. 3A (a position where the position correction roll 170 is symmetric with respect to the reference line C) is referred to as a “position correction reference position”.

Next, a more specific description will be given of the guide unit 140 included in the second skew correction unit 120 in the posture correction apparatus 100 described above.
FIG. 4 is a perspective view of the guide unit 140 when viewed from the downstream side in the transport direction D1 of the paper P. FIG. FIG. 5 is a perspective view of the lower gate 141 in the guide unit 140 as viewed from the downstream side in the paper P conveyance direction D1.

  As described above, the guide unit 140 according to the present embodiment includes the lower gate 141 and the guide base 143. The guide unit 140 further includes a lower gate rotation driving unit 206 that generates a driving force for rotating the lower gate 141 and transmits the generated driving force to the lower gate 141.

  Among these, the guide base portion 143 includes a frame 1431 having a plate-like bottom surface portion extending along the width direction D2 and side surface portions extending from both ends of the bottom surface portion in the width direction D2 toward the retraction direction D3, 1431 and four guide rolls 1432 attached to the outside of each of the two side surfaces provided on 1431. Here, each guide roll 1432 is fitted into a plurality of guide rails (not shown) attached to the casing (not shown) of the posture correction device 100 along the transport direction D1. . As a result, the guide part 140 in which the lower gate 141 and the lower gate rotation driving part 206 are attached to the guide base part 143 can move in the direction opposite to the transport direction D1 and the transport direction D1 in the attitude correction device 100.

  Further, the lower gate 141 is arranged in the width direction D2 along with a shaft portion 1411 that is rotatably attached to both side portions of the frame 1431 of the guide base portion 143, and each is fixedly attached to the shaft portion 1411. Has six arm portions 1412 extending toward the downstream side in the transport direction D1, and six projecting portions 1413 (an example of abutment portion) provided so as to project upward on the free end side of each arm portion 1412. I have. Further, the lower gate 141 is formed on one arm portion 1412 disposed on the center side in the width direction D2, and further includes a driven portion 1414 that receives a driving force when rotating the lower gate 141 from the lower gate rotation driving portion 206. ing.

  The lower gate rotation driving unit 206 is fixedly attached to the bottom surface of the guide base 143. A rubber roll (not shown) provided on the drive shaft of the lower gate rotation drive unit 206 comes into contact with the driven part 1414 of the lower gate 141 that is rotatably attached to the guide base part 143.

  Then, by rotating the lower gate 141 in one direction, when the arm portions 1412 of the lower gate 141 are moved away from the bottom surface of the frame 1431 in the guide base portion 143, the first transport path R1 (see FIG. 3B) Each of the protrusions 1413 provided on the arm part 1412 is blocked (closed). In the following description, this state realized by the lower gate 141 is referred to as a “closed state”.

  In addition, when the lower gate 141 is rotated in the direction opposite to the one direction described above from the closed state, when the respective arm portions 1412 of the lower gate 141 are brought close to the bottom surface of the frame 1431 in the guide base 143, the first transport path R1. (See FIG. 3B) is not blocked (opened) by the protrusions 1413 provided on the respective arm portions 1412. In the following description, this state realized by the lower gate 141 is referred to as an “open state”.

  FIG. 6 is a diagram for explaining a control system of posture correction apparatus 100 of the present embodiment. Here, FIG. 6 shows components related to the posture correction apparatus 100 in the control unit 80, and description of other components (image forming unit 10 and the like) is omitted.

  A signal for detecting passage of the paper P is input to the control unit 80 from the first sensor S1 and the second sensor S2 provided in the posture correction apparatus 100.

  On the other hand, the control unit 80 rotates the left skew feed correction roll rotation drive unit 201 that rotates the left drive roll 111L (first skew correction unit 110) and the right drive roll 111R (first skew correction unit 110). A control signal is output to each of the right skew correction roll rotation driving units 202 to be driven. The control unit 80 also feeds the feed roll rotation drive unit 203 that rotates the feed drive roll 131 (send roll 130) and the feed follower roll 132 (send roll 130) in the retracting direction D3 (or the reverse direction). Control signals are respectively output to the roll advance / retreat drive unit 204. Furthermore, the control unit 80 includes a guide unit transport driving unit 205 that transports the guide base 143 (guide unit 140) in the transport direction D1 (or the reverse direction), and a lower gate rotation driving unit that rotationally drives the lower gate 141 (guide unit 140). The control signals are output to 206 (see FIG. 4). Furthermore, the control unit 80 causes the receiving roll rotation driving unit 207 to rotate the receiving driving roll 151 (receiving roll 150) and the receiving roll 150, that is, the receiving driving roll 151 and the receiving driven roll 152 in the width direction D2 (or vice versa). A control signal is output to each of the receiving roll side shift driving units 208 that are moved in the direction). Then, the control unit 80 widens the position correction roll rotation drive unit 209 that rotates the position correction drive roll 171 (position correction roll 170), and the position correction roll 170, that is, the position correction drive roll 171 and the position correction driven roll 172. A control signal is output to each of the position correction roll side shift driving units 210 that are moved along the direction D2. In the present embodiment, both of the guide part conveyance driving part 205 and the lower gate rotation driving part 206 have a function as an example of a retracting means.

Subsequently, the posture correction operation of the paper P using the posture correction apparatus 100 of the present embodiment will be described.
7 to 15 are diagrams for explaining the operation of the posture correction apparatus 100 with respect to one sheet of paper P. FIG. Hereinafter, the operation of the posture correction apparatus 100 will be described while sequentially referring to FIGS. 7 to 15 and further referring to FIGS. 7 to 15, (a) is a top view corresponding to FIG. 3 (a), and (b) is a side view corresponding to FIG. 3 (b).

  It should be noted that in the initial state during the image forming operation and before the paper P is carried into the posture correction device 100, the respective units constituting the posture correction device 100 are set as follows. .

  First, in the first skew correction unit 110, the left skew correction roll 110L rotates at the left roll rotation speed V1L, and the right skew correction roll 110R rotates at the right roll rotation speed V1R. At this time, the left side roll rotational speed V1L = the right side roll rotational speed V1R.

  Next, in the delivery roll 130 in the second skew feeding correction unit 120, the delivery driven roll 132 is in the retracted position, and the delivery drive roll 131 is rotating at the delivery roll rotational speed V2. In addition, the delivery driven roll 132 in the retracted position is stopped without rotating. At this time, the delivery roll rotation speed V2 is set to the same size as the above-described left roll rotation speed V1L and right roll rotation speed V1R.

  Subsequently, the guide unit 140 in the second skew feeding correction unit 120 is stopped in a state where it is arranged at the start position described above. Moreover, the lower gate 141 which comprises the guide part 140 is set to the closed state mentioned above.

  Further, the receiving roll 150 in the second skew correction unit 120 is in the above-described receiving reference position and is rotated at the receiving roll rotation speed V4. At this time, the receiving roll rotation speed V4 is set to the same magnitude as the above-described delivery roll rotation speed V2.

  And the position correction roll 170 in the width direction position correction | amendment part 160 exists in the position correction reference position mentioned above, and is rotating with the position correction roll rotational speed V5. At this time, the position correction roll rotation speed V5 is set to the same magnitude as the receiving roll rotation speed V4 described above.

  FIG. 7 is a diagram (No. 1) for explaining the operation of the posture correction apparatus 100. FIG. 7 shows a state before the front end Pl of the conveyed paper P passes through the portion facing the first sensor S1 and before reaching the first skew correction unit 110. In this example, the sheet rear end Pt of the sheet P is positioned at the upstream side in the transport direction D1 with respect to the portion facing the first sensor S1 at this time.

  In this example, it is assumed that the paper P is transported in a skewed state in which the right side portion at the paper leading edge Pl precedes the left side portion. Then, the first sensor S <b> 1 sends the detection result of the paper P passing through the facing portion to the control unit 80. At this time, the first skew correction unit 110 (left skew correction roll 110L, right skew correction roll 110R), second skew correction unit 120 (sending roll 130, guide unit 140, receiving roll 150) and width. The direction position correction unit 160 (position correction roll 170) maintains the initial state described above.

  FIG. 8 is a diagram (part 2) for explaining the operation of the posture correction apparatus 100. FIG. 8 shows a state before the paper leading edge Pl of the conveyed paper P passes through the first skew feeding correction unit 110 and reaches the delivery roll 130. In this example, the sheet rear end Pt of the sheet P is still located upstream in the transport direction D1 from the portion facing the first sensor S1.

  When the front end Pl of the sheet P reaches the first skew correction unit 110, the left skew correction roll 110L and the right skew correction roll 110R have a common speed (left roll rotation speed V1L = right roll rotation speed V1R). It is rotating at. At this time, the paper P is transported while being sandwiched only by both the left skew correction roll 110L and the right skew correction roll 110R. Based on the detection result of the leading end position of the paper P by the first sensor S1, the control unit 80 responds to the skew amount of the paper P while the paper P passes through the first skew correction unit 110. A speed difference is provided between the left roll rotational speed V1L and the right roll rotational speed V1R. In this example, since the right side of the paper P is ahead of the left side, the control unit 80 performs setting so that the left side roll rotational speed V1L> the right side roll rotational speed V1R. At this time, the right roll rotational speed V1R may be reduced more than before while the left roll rotational speed V1L is kept constant, or the left roll rotational speed V1L is kept constant while the right roll rotational speed V1R is kept constant. Also, the speed may be increased. Thereby, the skew state of the paper P is improved as compared with the case shown in FIG. Then, before the front end Pl of the paper P reaches the delivery roll 130, the control unit 80 sets the left-side roll rotation speed V1L and the right-side roll rotation speed V1R to the same speed (previous speed) again. Then, the first skew correction using the first skew correction unit 110 is completed. However, even if the first skew correction (coarse correction) is performed by the first skew correction unit 110, a slight skew state may remain on the paper P.

  Further, based on the detection result of the paper P by the first sensor S1, the control unit 80 moves the sending driven roll 132 from the retracted position to the advanced position until the paper leading edge Pl reaches the sending roll 130. . Along with this, the delivery follower roll 132 moved to the advance position comes into contact with the delivery drive roll 131 and starts to rotate as the delivery drive roll 131 rotates.

  FIG. 9 is a diagram (No. 3) for explaining the operation of the posture correction apparatus 100. FIG. 9 shows a state before the front end Pl of the conveyed paper P passes through the feed roll 130 and reaches the guide unit 140 that stops at the start position. In this example, the paper rear end Pt of the paper P passes through the portion facing the first sensor S1 at this time, and is positioned upstream of the first skew correction unit 110 in the transport direction D1.

  When the front end Pl of the paper P reaches the delivery roll 130, the delivery roll rotation speed V2 of the delivery roll 130 is the left roll rotation speed V1L of the left skew correction roll 110L and the right roll rotation speed of the right skew correction roll 110R. It is set to the same speed as V1R. At this time, the paper P is conveyed in a state of being sandwiched between the left skew correction roll 110L, the right skew correction roll 110R, and the delivery roll 130. For this reason, the sheet P is continuously conveyed while maintaining the state where the first skew correction (rough correction) is performed by the first skew correction unit 110.

  FIG. 10 is a diagram (No. 4) for explaining the operation of the posture correction apparatus 100. FIG. 10 shows a state before the front end Pl of the conveyed paper P reaches the guide unit 140 that stops at the start position, and before reaching the receiving roll 150. In this example, the rear end Pt of the paper P at this time passes through the first skew correction unit 110 and is located upstream of the delivery roll 130 in the transport direction D1.

  After the paper leading edge Pl of the paper P reaches the guide unit 140 that stops at the start position, the control unit 80 moves the guide unit 140 from the start position along the conveyance direction D1 at the guide unit moving speed V3. Here, the guide portion moving speed V3 is set slightly lower than the delivery roll rotation speed V2. At this time, the paper P is continuously conveyed in a state where the paper front end Pl is regulated by the guide unit 140 and is sandwiched between the delivery rolls 130. As a result, the paper leading edge Pl of the paper P conveyed at the delivery roll rotation speed V2 has six protrusions provided on the lower gate 141 set in the closed state among the guide parts 140 that move at the guide part movement speed V3. It moves in a state of hitting 1413. Thereby, the skew state of the paper P at the paper leading edge Pl is further corrected. Accordingly, a loop caused by the difference between the feed roll rotation speed V2 and the guide portion moving speed V3 occurs between the paper tip P1 and the portion sandwiched between the feed rolls 130 in the paper P. To do. Note that this loop is likely to occur on the paper front end Pl side of the paper P.

  FIG. 11 is a diagram (No. 5) for explaining the operation of the posture correction apparatus 100. FIG. 11 shows a state before the front end Pl of the conveyed paper P passes through the receiving roll 150 and reaches the position correction roll 170. At this time, the guide part 140 that has moved together with the paper leading edge Pl has reached the goal position overlapping the receiving roll 150. In this example, the paper trailing edge Pt of the paper P is still located upstream of the delivery roll 130 in the transport direction D1 at this time.

  After the paper front end Pl of the paper P passes through the receiving roll 150 and the guide unit 140 that guides the paper front end Pl reaches the goal position where it overlaps with the receiving roll 150, the control unit 80 performs the conveyance direction D1 of the guide unit 140. And the lower gate 141 provided in the guide portion 140 is rotated to shift the lower gate 141 from the closed state to the open state. At this time, the paper P is conveyed in a state of being sandwiched between both the sending roll 130 and the receiving roll 150. For this reason, even if the lower gate 141 shifts from the closed state to the open state, the sheet leading edge Pl side of the sheet P is sandwiched between the receiving rolls 150, so that the skew correction (fine correction) by the guide unit 140 is performed. It will continue to be transported while maintaining this state.

  FIG. 12 is a diagram (No. 6) for explaining the operation of the posture correction apparatus 100. FIG. 12 shows a state before the front end Pl of the conveyed paper P passes through the receiving roll 150 and reaches the position correction roll 170. In this example, the paper trailing edge Pt of the paper P is still located upstream of the delivery roll 130 in the transport direction D1 at this time.

  After the lower gate 141 in the guide unit 140 shifts from the closed state to the open state, the control unit 80 moves the guide unit 140 from the goal position to the start position in the direction opposite to the transport direction D1. At this time, since the sheet P passes over the lower gate 141 set to the open state, the lower gate 141 is continuously set to the open state.

  Further, the control unit 80 moves the lower gate 141 from the closed state to the open state, and then moves the delivery driven roll 132 from the advanced position to the retracted position. Accordingly, the delivery driven roll 132 that has moved to the retracted position stops contacting the delivery drive roll 131 and stops its rotation. As the delivery driven roll 132 moves from the advanced position to the retracted position, the paper P is sandwiched by the receiving roll 150 and is not sandwiched by the delivery roll 130, so that the loop generated in the paper P is eliminated. The As a result, the sheet P is continuously conveyed while being maintained in the state in which the skew correction (fine correction) by the guide unit 140 is performed while being sandwiched only by the receiving roll 150.

  FIG. 13 is a diagram (No. 7) for explaining the operation of the posture correction apparatus 100. FIG. 13 shows a state before the front end Pl of the conveyed paper P passes through the position correction roll 170 and reaches the secondary transfer position (not shown). In this example, the paper trailing edge Pt of the paper P passes through the sending roll 130 at this time and is located upstream of the receiving roll 150 in the transport direction D1.

  When the front end Pl of the paper P reaches the position correction roll 170, the position correction roll rotation speed V5 of the position correction roll 170 is set to a speed common to the reception roll rotation speed V4 of the reception roll 150. At this time, the paper P is conveyed while being sandwiched between the position correction roll 170 and the receiving roll 150. For this reason, the sheet P is continuously conveyed while maintaining the state where the skew correction (fine correction) by the guide unit 140 is performed.

  When the guide unit 140 returns from the goal position to the start position, the control unit 80 stops the movement of the guide unit 140 in the direction opposite to the transport direction D1. Then, after the sheet trailing edge Pt of the sheet P passes over the lower gate 141 in the guide section 140, the control unit 80 sets the lower gate 141 until the sheet leading edge Pl of the next sheet P enters. Transition from the open state to the closed state. During this time, the second sensor S2 sends the detection result of the paper P passing through the facing portion to the control unit 80.

  FIG. 14 is a diagram (No. 8) for explaining the operation of the posture correction apparatus 100. FIG. 14 shows a state before the paper leading edge Pl of the conveyed paper P passes through the position correction roll 170 and reaches the secondary transfer position (not shown). In this example, the paper trailing edge Pt of the paper P passes through the sending roll 130 at this time and is located upstream of the receiving roll 150 in the transport direction D1.

  At this time, the position correction roll rotation speed V5 of the position correction roll 170 is continuously set to the same speed as the reception roll rotation speed V4 of the reception roll 150, and the paper P is fed by the position correction roll 170 and the reception roll 150. It is transported in a sandwiched state. For this reason, the sheet P is further conveyed while maintaining the state where the skew correction (fine correction) by the guide unit 140 is performed.

  Further, the control unit 80 controls the side edge of the paper P (the first paper side edge Ps1 or the paper) by the second sensor S2 while the paper P is conveyed while being sandwiched between the receiving roll 150 and the position correction roll 170. Based on the detection result of the position of the second side end Ps2), both the receiving roll 150 and the position correction roll 170 are moved along the width direction D2 (or the reverse direction). More specifically, both the receiving roll 150 and the position correction roll 170 are moved in the same direction so that the center position of the paper P in the width direction D2 matches the reference line C. Accordingly, the receiving roll 150 moves along the width direction D2 (or the reverse direction) from the receiving reference position in a state where the paper P is sandwiched, and the position correction roll 170 is positioned in a state where the paper P is sandwiched. It moves along the width direction D2 (or the reverse direction) from the correction reference position. Then, the control unit 80 moves the receiving roll 150 and the position correction roll 170 to a position where the center position in the width direction D2 of the paper P overlaps the reference line C, and then moves the receiving roll 150 and the position correction roll. The movement of 170 in the width direction D2 (or the reverse direction) is stopped. The control unit 80 moves the receiving roll 150 and the position correction roll 170 in the width direction D2 (or the reverse direction) until the paper front end Pl of the paper P reaches a secondary transfer position (not shown). To complete. In this example, since the central position of the paper P in the width direction D2 is shifted to the left as viewed from the reference line C, the control unit 80 moves both the receiving roll 150 and the position correction roll 170 along the width direction D2. Set to move. Thereby, the side registration deviation of the paper P is improved as compared with the case shown in FIG.

  FIG. 15 is a diagram (No. 9) for explaining the operation of the attitude correction device 100. FIG. 15 shows the state after the paper leading edge Pl of the conveyed paper P reaches the secondary transfer position (not shown) and the paper trailing edge Pt of the paper P passes through the receiving roll 150 and the position correcting roll 170. Indicates the state.

  After the paper leading edge Pl of the paper P has reached the secondary transfer position, and subsequently the paper trailing edge Pt has passed the position correction roll 170, the control unit 80 receives the side-shifted receiving roll to correct the side registration deviation. 150 and the position correction roll 170 are moved toward the reception reference position and the position correction reference position, respectively. Accordingly, the posture correction for one sheet P is completed, and the posture correction apparatus 100 is reset to the state shown in FIG. When the next sheet P exists, the posture correction operation for the sheet P is continuously performed according to the above-described procedure.

  In this way, the sheet P passes through the posture correction device 100, thereby performing skew correction using the first skew correction unit 110 and the second skew correction unit 120, and the width direction position correction unit 160 (and In the state where the side registration correction using the receiving roll 150) in the second skew correction unit 120 is performed, it is supplied to the secondary transfer position, and the secondary transfer of the superimposed toner image using the secondary transfer device 30 is performed. Become. Further, for example, when executing side registration correction using the width direction position correction unit 160 (and the reception roll 150 in the second skew correction unit 120), the reception roll rotation speed V4 and the position correction roll set to the same speed. By finely adjusting (accelerating or decelerating) while synchronizing the rotation speed V5, it is possible to perform the supply timing (lead registration correction) of the paper P to the secondary transfer position.

  FIG. 16 is a diagram for explaining the relationship between the receiving roll 150 and the guide unit 140 that has reached the goal position shown in FIG. Here, FIG. 16A shows a top view when the guide unit 140 and the receiving roll 150 are viewed from above. FIG. 16B shows an XVIb-XVIb cross-sectional view in FIG. 16A, and FIG. 16C shows an XVIc-XVIc cross-sectional view in FIG.

  In a state where the guide part 140 has reached the goal position, each arm part 1412 provided in the lower gate 141 of the guide part 140 does not interfere with each receiving drive roll body 151b and each receiving driven roll body 152b in the receiving roll 150. It is in.

  On the other hand, in a state where the guide unit 140 has reached the goal position, a receiving drive roll main body of the receiving drive roll rotating shaft 151a of the receiving drive roll 151 is below each arm portion 1412 provided in the lower gate 141 of the guide unit 140. A portion where 151b is not mounted is located, and a portion where the receiving driven roll main body 152b is not mounted on the receiving driven roll rotating shaft 152a of the receiving driven roll 152 above each arm portion 1412 in the guide portion 140. Is located.

  For this reason, as shown in FIG. 16, the receiving roll 150 and the guide unit 140 that has reached the goal position overlap each other when viewed from above without interfering (contacting) with each other.

  Further, in a state in which the guide part 140 has reached the goal position, each protrusion 1413 provided on the lower gate 141 of the guide part 140 makes contact with each receiving drive roll body 151b and each receiving driven roll body 152b in the receiving roll 150. It is located on the downstream side in the transport direction D1 with respect to the nip portion. For this reason, when the guide portion 140 reaches the goal position with the paper leading edge Pl (not shown) abutting against each protrusion 1413, each receiving drive roll body 151b and each receiving driven roll body 152b in the receiving roll 150. The paper P (not shown) is sandwiched in the nip portion where the two contact with each other.

  Further, when the lower gate 141 in the guide portion 140 shifts from the closed state to the open state after the guide portion 140 reaches the goal position, each arm portion 1412 in the lower gate 141 has the receiving drive roll rotating shaft of the receiving drive roll 151. It is arranged at a position where it does not interfere with 151a (indicated by a broken line in FIG. 16B). In addition, this position does not interfere with the receiving drive roll rotating shaft 151a of the receiving drive roll 151 even when the guide unit 140 is moved in the direction opposite to the transport direction D1 in order to return the guide unit 140 from the goal position to the start position. Is selected from.

  FIG. 17 shows the guide portion moving speed V3 of the guide portion 140 and the lower gate 141 provided in the guide portion 140 before and after the sheet P passes through the second skew feeding correction portion 120 in the posture correction operation of the present embodiment. 6 is a timing chart showing the relationship between the position of the paper and the paper speed Vp of the paper P. FIG. 18 is a diagram for explaining the states of the first skew correction unit 110 and the second skew correction unit 120 corresponding to the timing chart shown in FIG. Note that the timings indicated by (a) to (f) in FIG. 17 correspond to the states shown in FIGS. 18 (a) to (f), respectively.

  As shown in FIG. 17, first, while the paper P is being transported by both the first skew feeding correction unit 110 and the delivery roll 130, the paper speed Vp becomes the first speed Va (V1L = V1R = Va). : FIG. 18 (a) to FIG. 18 (c)). Subsequently, the sheet P is not transported by both the first skew feeding correction unit 110 and the delivery roll 130 and is transported by the receiving roll 150, so that the sheet speed Vp is lower than the first speed Va. Vb (V4 = Vb: see FIG. 18D to FIG. 18F).

  Further, as the paper front end Pl of the paper P reaches the start position, the guide portion moving speed V3 of the guide portion 140 shifts from 0 to the second speed Vb as shown in FIG. 17 (FIG. 18A). FIG. 18B). Then, the guide unit 140 reaches the receiving roll 150 with the guide unit moving speed V3 set to the second speed Vb (see FIG. 18C), and the sheet P is sandwiched between the receiving rolls 150. The guide portion moving speed V3 shifts from the second speed Vb to the third speed Vc (third speed Vc> second speed Vb). At this time, since the paper speed Vp remains the second speed Vb, the lower gate 141 (more specifically, the six arm parts 1412) provided in the guide part 140 moves along the transport direction D1. Then, the sheet moves away from the leading end Pl of the sheet moving in the transport direction D1 (see FIG. 18D).

  Next, as shown in FIG. 17, the lower gate 141 provided in the guide part 140 shifts from the closed state to the open state (see FIG. 18 (e)). Thereafter, as shown in FIG. 17, after the guide portion moving speed V3 shifts from the second speed Vb to 0, the guide portion moving speed V3 shifts from 0 to the fourth speed Vd. As a result, the guide unit 140 moves from the goal position toward the start position (see FIG. 18F).

  In the present embodiment, the lower gate 141 that has moved along the transport direction D1 in a state in which the paper front end Pl of the paper P is abutted is moved along the transport direction D1 before the transition from the closed state to the open state. By moving faster than the paper P, the paper P moves away from the paper front end Pl. As a result, when the lower gate 141 shifts from the closed state to the open state, it is possible to suppress the occurrence of wrinkling or buckling of the paper P that is caused by hooking the paper leading edge Pl.

<Embodiment 2>
The basic configuration of the present embodiment is the same as that of the first embodiment, but the operation of the second skew correction unit 120 in the posture correction operation of the paper P is different from that of the first embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 19 illustrates the guide portion moving speed V3 of the guide portion 140 and the lower gate 141 provided in the guide portion 140 before and after the sheet P passes through the second skew feeding correction portion 120 in the posture correction operation of the present embodiment. 6 is a timing chart showing the relationship between the position of the paper and the paper speed Vp of the paper P. 20 is a diagram for explaining the states of the first skew correction unit 110 and the second skew correction unit 120 corresponding to the timing chart shown in FIG. Note that the timings indicated by (a) to (f) in FIG. 19 correspond to the states shown in FIGS. 20 (a) to (f), respectively.

  As shown in FIG. 19, first, while the paper P is being transported by both the first skew feeding correction unit 110 and the delivery roll 130, the paper speed Vp becomes the first speed Va (V1L = C1R = V2). = Va: See FIG. 20 (a) to FIG. 20 (c)). Subsequently, the sheet P is not transported by both the first skew feeding correction unit 110 and the delivery roll 130 and is transported by the receiving roll 150, so that the sheet speed Vp is lower than the first speed Va. It becomes the speed Vb and further becomes the fifth speed Ve that is lower than the second speed Vb (V4 = Vb → V4 = Ve: see FIGS. 20D to 20E).

  Further, as the paper front end Pl of the paper P reaches the start position, as shown in FIG. 19, the guide portion moving speed V3 of the guide portion 140 shifts from 0 to the second speed Vb (FIG. 20A). FIG. 20B). Then, after the guide unit 140 reaches the receiving roll 150 with the guide unit moving speed V3 set to the second speed Vb (see FIG. 20C), the paper P is sandwiched between the receiving rolls 150. Also, the second speed Vb is maintained. At this time, since the sheet speed Vp is decreased to the fifth speed Ve (<second speed Vb), the lower gate 141 (more specifically, the six arm portions 1412) provided in the guide portion 140 is transported. While moving along the direction D1, the sheet moves away from the paper leading edge Pl moving along the transport direction D1 (see FIG. 20D).

  Next, as shown in FIG. 19, the lower gate 141 provided in the guide part 140 shifts from the closed state to the open state (see FIG. 20 (e)). Thereafter, as shown in FIG. 19, after the guide portion moving speed V3 shifts from the second speed Vb to 0, this time, the guide portion moving speed V3 shifts from 0 to the fourth speed Vd. As a result, the guide unit 140 moves from the goal position toward the start position (see FIG. 20F).

  Also in the present embodiment, the lower gate 141 that has moved along the transport direction D1 in a state in which the front end Pl of the paper P is abutted is moved along the transport direction D1 before moving from the closed state to the open state. By moving faster than the paper P, the paper P moves away from the paper front end Pl. As a result, when the lower gate 141 shifts from the closed state to the open state, it is possible to suppress the occurrence of wrinkling or buckling of the paper P that is caused by hooking the paper leading edge Pl.

<Embodiment 3>
The basic configuration of the present embodiment is the same as that of the first and second embodiments, but the operation of the second skew correction unit 120 in the posture correction operation of the paper P is the first and second embodiments. Is different. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 21 illustrates the guide portion moving speed V3 of the guide portion 140 and the lower gate 141 provided in the guide portion 140 before and after the sheet P passes through the second skew feeding correction portion 120 in the posture correction operation of the present embodiment. 6 is a timing chart showing the relationship between the position of the paper and the paper speed Vp of the paper P. FIG. 22 is a diagram for describing the states of the first skew correction unit 110 and the second skew correction unit 120 corresponding to the timing chart shown in FIG. Note that the timings indicated by (a) to (f) in FIG. 21 correspond to the states shown in FIGS. 22 (a) to (f), respectively.

  As shown in FIG. 21, first, while the paper P is being transported by both the first skew correction unit 110 and the delivery roll 130, the paper speed Vp becomes the first speed Va (V1L = V1R = V2). = Va: See FIG. 22 (a) to FIG. 22 (c)). Subsequently, as the paper P is not transported by both the first skew feeding correction unit 110 and the delivery roll 130 and is transported by the receiving roll 150, the paper speed Vp becomes higher than the first speed Va and the second speed Vb. Is also a low fifth speed Ve (V4 = Ve: see FIGS. 22D to 22E).

  Further, as the paper front end Pl of the paper P reaches the start position, as shown in FIG. 21, the guide portion moving speed V3 of the guide portion 140 shifts from 0 to the second speed Vb (FIG. 22A). FIG. 22 (b)). Then, the guide unit 140 reaches the receiving roll 150 with the guide unit moving speed V3 set to the second speed Vb (see FIG. 22C), and the sheet P is sandwiched between the receiving rolls 150. Also, the second speed Vb is maintained. At this time, since the paper speed Vp is the fifth speed Ve (<second speed Vb), the lower gate 141 (more specifically, the six arm parts 1412) provided in the guide part 140 is in the transport direction. While moving along D1, the paper moves away from the paper leading edge Pl moving along the transport direction D1 (see FIG. 22D).

  Next, as shown in FIG. 21, the lower gate 141 provided in the guide part 140 shifts from the closed state to the open state (see FIG. 22 (e)). Then, as shown in FIG. 21, after the guide unit moving speed V3 shifts from the second speed Vb to 0, this time, the guide unit moving speed V3 shifts from 0 to the fourth speed Vd. As a result, the guide unit 140 moves from the goal position toward the start position (see FIG. 22F).

  Also in the present embodiment, the lower gate 141 that has moved along the transport direction D1 in a state in which the front end Pl of the paper P is abutted is moved along the transport direction D1 before moving from the closed state to the open state. By moving faster than the paper P, the paper P moves away from the paper front end Pl. As a result, when the lower gate 141 shifts from the closed state to the open state, it is possible to suppress the occurrence of wrinkling or buckling of the paper P that is caused by hooking the paper leading edge Pl.

Here, in the first to third embodiments, as described with reference to FIG. 5 and the like, the lower gate 141 in which each arm portion 1412 is provided with the protruding portion 1413 is used. However, the configuration of the lower gate 141 is not limited thereto. It is not something that can be done.
FIG. 23 is a diagram for explaining another configuration example of the lower gate 141. The lower gate 141 shown in FIG. 23 further includes a restricting portion 1415 formed so as to be folded back from the free end side of the protruding portion 1413 provided to protrude from each arm portion 1412 to the upstream side in the transport direction D1. The restricting portion 1415 is provided so as to face the arm portion 1412, and the arm portion 1412, the protruding portion 1413, and the restricting portion 1415 form a concave space.

  By configuring the lower gate 141 as shown in FIG. 23, when the paper front end Pl (not shown) of the paper P abuts against the protruding portion 1413, the paper P is lifted using the restricting portion 1415. It becomes possible to regulate. In addition, after the paper P is delivered to the receiving roll 150, the guide unit 140 (lower gate 141) is retracted from the paper P along the transport direction D1 using the method described in each of the first to third embodiments. By setting the distance at the time of evacuation in anticipation of the protrusion amount of the restricting portion 1415, it is possible to avoid a situation in which the paper leading edge Pl of the paper P is caught by the restricting portion 1415.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Image forming part, 20 ... Intermediate transfer belt, 30 ... Secondary transfer apparatus, 40 ... Paper supply apparatus, 50 ... Fixing apparatus, 70 ... Reverse conveyance apparatus, 80 ... Control part, 90 ... User Interface unit (UI), 100: Attitude correction device, 110: First skew correction unit, 120 ... Second skew correction unit, 130 ... Sending roll, 140 ... Guide unit, 141 ... Lower gate, 1411 ... Shaft unit, 1412 ... arm part, 1413 ... projection part, 1414 ... driven part, 143 ... guide base part, 150 ... receiving roll, 160 ... width direction position correction part, 170 ... position correction roll, D1 ... transport direction, D2 ... width direction, D3 ... Retraction direction, R1 ... first transport path, R2 ... second transport path, R3 ... third transport path, R4 ... fourth transport path, S1 ... first sensor, S2 ... second sensor

Claims (5)

First conveying means for conveying the sheet with the sheet interposed therebetween;
Second conveying means for conveying the sheet sandwiched by the first conveying means;
Guiding means for guiding the sheet to the second conveying means in a state where the leading end portion in the conveying direction of the sheet conveyed by the first conveying means is abutted;
A retracting means for retracting the guide means from the transport path of the sheet after the sheet guided by the guide means is sandwiched between the second transport means;
A sensor disposed on the opposite side to the retracting means in the transport path on the downstream side of the second transport means, and detecting a position of a side edge of the sheet,
The second conveying unit moves the sheet in a direction intersecting the conveying path based on the sensor after the sheet guided by the guiding unit is sandwiched by the second conveying unit. Sheet transport device.   The said 2nd conveyance means moves the said sheet | seat in the direction which cross | intersects the said conveyance path | route by moving to the same direction as the some conveyance means containing the said 2nd conveyance means, The said 2nd conveyance means is characterized by the above-mentioned. Sheet conveying device.   The second conveying means holds the sheet guided by the guiding means by the second conveying means and releases the nipping of the sheet by the first conveying means. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is moved in a direction intersecting with the conveying path. The second transport means has a first roll and a second roll provided on the left and right in a direction intersecting the transport path in plan view,
The sheet conveying apparatus according to claim 1, wherein the guide unit is provided on each of an outer side and an inner side of the first roll and the second roll. Each of the first roll and the second roll consists of two rolls,
The sheet conveying apparatus according to claim 4, wherein the guide unit is further disposed between each of the two rolls.

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