Sheet transport device and image formation system

Abstract

To provide a configuration that can correct the positional deviation of the sheet in the width direction while suppressing the enlargement of the device.SOLUTION: A pair of regulating guides 14A and 14B can guide both end edges of a sheet S4, which is being transported while being clamped between a transport belt 12 and a sphere 20, in a sheet width direction Y. Furthermore, the pair of regulating guides 14A and 14B can move between a guiding position that guides the end edges of the sheet and a retracted position that is away from the end edges of the sheet. A pair of transport rollers 402, which are positioned downstream in a transport direction X of the transport belt 12, can move between a nip position that can clamp and transport the sheet and a nip release position that separates the transport rollers 402 from the nip position. Additionally, when moving the pair of regulating guides 14A and 14B from the retracted position to the guiding position, a nip release operation to set the transport rollers 402 to the nip release position can be executed.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to a sheet conveying device for conveying a sheet.

Background Art

[0002] In a sheet conveying device for conveying a sheet, there is a possibility that the sheet may be displaced during conveyance due to various factors. And if the sheet is conveyed to, for example, an image forming device that forms an image on the sheet while the displacement occurs, problems such as the image being displaced with respect to the sheet will occur. For this reason, a sheet conveying device that corrects the displacement of the sheet during conveyance is known (for example, Patent Document 1).

[0003] Patent Document 1 discloses a configuration having a fixed reference guide provided on one side in the width direction intersecting the sheet conveying direction, a conveying belt provided inclined with respect to the reference guide, and a sphere. In the case of the sheet conveying device described in Patent Document 1, the sheet is conveyed while being sandwiched between the conveying belt and the sphere, so that the edge in the width direction of the sheet abuts against the reference guide. And the side registration (displacement of the edge in the width direction of the sheet) and side skew (tilt of the edge in the width direction of the sheet with respect to the sheet conveying direction) of the sheet are corrected simultaneously.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the case of the sheet conveying device described in Patent Document 1, while conveying the sheet by a conveying belt provided obliquely, the edge in the width direction of the sheet is abutted against a reference guide. That is, the sheet is conveyed obliquely to correct misalignment and the like. For this reason, it is necessary to convey the sheet until it abuts against the reference guide, and furthermore, it is necessary to convey the sheet to some extent even after it abuts. Therefore, there is a risk that the device will become large in order to secure the length for conveying the sheet in this way. In particular, in order to enable correction of misalignment of a sheet having a long length in the conveying direction, it is necessary to further secure the length for conveying the sheet, and there is a risk that the device will become even larger.

[0006] An object of the present invention is to provide a configuration capable of correcting misalignment in the width direction of a sheet while suppressing an increase in the size of the device.

Means for Solving the Problems

[0007] The present invention relates to a sheet conveying device that conveys a sheet in a conveying direction, having a conveying surface extending along the conveying direction, and an endless conveying belt that conveys the sheet received on the conveying surface in the conveying direction; a plurality of spheres arranged along the conveying direction at a position facing the conveying surface, capable of rotating in an arbitrary direction while sandwiching the sheet between the spheres and the conveying surface; a pair of restricting guides arranged on both sides of the conveying belt in the sheet width direction intersecting the conveying direction, capable of guiding both end edges in the sheet width direction of the sheet conveyed while being sandwiched between the conveying belt and the spheres; guide moving means capable of moving the pair of restricting guides to a guide position for guiding both end edges in the sheet width direction of the sheet and a retracted position retracted from both end edges in the sheet width direction of the sheet relative to the guide position; a pair of conveying rollers arranged on the downstream side in the conveying direction of the conveying belt, sandwiching the sheet and conveying the sheet in the conveying direction; and roller moving means capable of moving at least one of the pair of conveying rollers to a nip position capable of sandwiching and conveying the sheet and a nip release position separating the pair of conveying rollers from the nip position. The roller moving means is capable of performing a nip release operation of setting the pair of conveying rollers to the nip release position when the guide moving means moves the pair of restricting guides from the retracted position to the guide position.

[0008] The present invention relates to a sheet conveying device for conveying a sheet in a conveying direction, having a conveying surface extending along the conveying direction, and an endless conveying belt for conveying the sheet received on the conveying surface in the conveying direction; a plurality of spheres arranged along the conveying direction at positions facing the conveying surface, rotatable in an arbitrary direction while sandwiching the sheet between the spheres and the conveying surface; a pair of restricting guides arranged on both sides of the conveying belt in the sheet width direction intersecting the conveying direction, capable of guiding both end edges in the sheet width direction of the sheet conveyed while being sandwiched between the conveying belt and the spheres; guide moving means capable of moving the pair of restricting guides to a guide position for guiding both end edges in the sheet width direction of the sheet and a retracted position retracted from both end edges in the sheet width direction of the sheet with respect to the guide position; a pair of conveying rollers arranged on the upstream side in the conveying direction of the conveying belt, for sandwiching and conveying the sheet in the conveying direction; and roller moving means capable of moving at least one of the pair of conveying rollers to a nip position capable of sandwiching and conveying the sheet and a nip release position separating the pair of conveying rollers from the nip position. The roller moving means is capable of executing a nip release operation of setting the pair of conveying rollers to the nip release position when the guide moving means moves the pair of restricting guides from the retracted position to the guide position.

Advantages of the Invention

[0009] According to the present invention, it is possible to correct the displacement in the width direction of the sheet while suppressing the increase in the size of the device.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Mode for Carrying Out the Invention

[0011] The embodiments will be described with reference to FIGS. 1 to 15. First, the image forming system of the present embodiment will be described with reference to FIG. 1.

[0012] [Image Forming System] FIG. 1 is a cross-sectional view schematically showing an example of an image forming system including a multi-stage feeding device and an image forming device according to the present embodiment. In the following description, as an image forming device having an image forming unit, a laser printer system using an electrophotographic method (hereinafter simply referred to as a printer) will be described as an example. Note that the image forming device constituting the image forming system may be a copying machine, a facsimile machine, a multifunction machine, or the like in addition to the printer. Further, the image forming device may have a configuration of another method such as an inkjet method regardless of the electrophotographic method.

[0013] The image forming system 1000 of the present embodiment includes an image forming device 100, a multi-stage feeding device 200 as a sheet feeding device connected to the image forming device 100, and a feeding deck 500. The multi-stage feeding device 200 has a plurality of storage bins each capable of storing a plurality of sheets, and can feed sheets from each storage bin to the image forming device 100, as will be described in detail later. The feeding deck 500 also has a storage bin capable of storing a plurality of sheets, and is arranged upstream of the multi-stage feeding device 200 in the sheet conveyance direction. Further, the sheets fed from the feeding deck 500 are conveyed to the image forming device 100 via a relay conveyance device 400 provided in the multi-stage feeding device 200. Examples of the sheet include paper such as plain paper, thin paper, and thick paper, and plastic sheets.

[0014] The image forming device 100 forms a toner image (image) on a sheet in response to an image signal from a document reading device 102 connected to the image forming device main body 101 or a host device such as a personal computer communicably connected to the image forming device main body 101. In the case of the present embodiment, the document reading device 102 is arranged above the image forming device main body 101.

[0015] When reading a document, the document reading device 102 irradiates light from a scanning optical system light source onto the document placed on the platen glass 103, and reads the document image by inputting the reflected light into the CCD. Further, the document reading device 102 is provided with an automatic document feeder (ADF) 104, and can also automatically convey the document placed on the tray 105 to the reading unit of the document reading device 102 by the ADF 104 and read the document image. Then, the read document image is converted into an electrical signal and transmitted to the laser scanner 113 of the image forming unit 110 described later. Note that the laser scanner 113 may also receive the image data transmitted from a personal computer or the like as described above.

[0016] The image forming apparatus 100 includes an image forming unit 110, a plurality of sheet feeding devices 120, a sheet conveying device 130, and the like. The image forming apparatus 100 is controlled by a control unit 140. The control unit 140 has a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU controls each unit while reading a program corresponding to the control procedure stored in the ROM. Further, work data and input data are stored in the RAM, and the CPU controls by referring to the data stored in the RAM based on the above-described program and the like.

[0017] Each of the plurality of sheet feeding devices 120 includes a cassette 121 that stores the sheet S, a pickup roller 122, and a separation conveyance roller pair 125 including a feed roller 123 and a retard roller 124. The sheet S stored in the cassette 121 is separated and fed one by one by the pickup roller 122 that moves up and down and rotates at a predetermined timing and the separation conveyance roller pair 125.

[0018] The sheet conveyance device 130 includes a pair of conveyance rollers 131 and a pair of registration rollers 133. The sheet S fed from the sheet feeding device 120 is passed through the sheet conveyance path 134 by the pair of conveyance rollers 131 and then guided to the pair of registration rollers 133. After that, the sheet S is fed into the image forming unit 110 at a predetermined timing by the pair of registration rollers 133.

[0019] In addition, the sheets conveyed from the multi-stage feeding device 200 or the feeding deck 500 described later via the pair of conveyance rollers 201 are conveyed into the image forming apparatus 100 via the connection path 202 to the image forming apparatus 100. Then, the sheets conveyed from the multi-stage feeding device 200 or the feeding deck 500 into the image forming apparatus 100 are fed into the image forming unit 110 at a predetermined timing via the pair of registration rollers 133 in the same manner as the sheets conveyed from the sheet feeding device 120 in the image forming apparatus 100.

[0020] The image forming unit 110 includes a photosensitive drum 111, a charger 112, a laser scanner 113, a developing device 114, a transfer device 115, a cleaner 117, etc. At the time of image formation, the photosensitive drum 111 is rotationally driven in the direction of the arrow in the figure. First, the surface of the photosensitive drum 111 is uniformly charged by the charger 112. Then, an electrostatic latent image is formed on the photosensitive drum 111 by irradiating the charged photosensitive drum 111 with laser light from the laser scanner 113 that emits light according to the image signal. Further, the electrostatic latent image formed on the photosensitive drum 111 in this way is then visualized as a toner image by the developing device 114.

[0021] After that, the toner image on the photosensitive drum 111 is transferred to the sheet S by the transfer device 115 in the transfer unit 116. Further, the sheet S onto which the toner image has been transferred in this way is conveyed to the fixing device 150 for fixing the toner image, and then discharged to the external discharge tray 152 by the discharge rollers 151.

[0022] When forming a toner image on the back surface of the sheet S, the sheet S discharged from the fixing device 150 is conveyed to the reverse conveyance path 160. Then, with the front and back sides reversed by the reverse conveyance path 160, the sheet S is conveyed to the transfer unit 116 of the image forming unit 110 again. The sheet S with the toner image transferred to its back surface is conveyed to the fixing device 150, and after the toner image is fixed, it is discharged to the discharge tray 152 by the discharge roller 151. Note that the transfer residual toner remaining on the photosensitive drum 111 after transfer is removed by the cleaner 117.

[0023] [Multi-stage feeding device] Next, the outline of the multi-stage feeding device 200 will be described with reference to FIG. 1. The multi-stage feeding device 200 includes a plurality of storage bins 210a to 210c, a relay conveyance device 400, and the like. In the present embodiment, three storage bins 210a to 210c are arranged in three stages vertically, and the relay conveyance device 400 is disposed between the lowermost storage bin 210c and the second storage bin 210b from the top.

[0024] The sheet fed from the uppermost storage bin 210a is conveyed to the conveyance path 212, the sheet fed from the second storage bin 210b from the top is conveyed to the conveyance path 213, and the sheet fed from the lowermost storage bin 210c is conveyed to the conveyance path 214. Also, the sheet conveyed from the relay conveyance device 400 is conveyed to the conveyance path 215. The conveyance path 213 merges with the conveyance path 212 midway. Also, the conveyance paths 212, 214, and 215 merge at the merge point 216, are conveyed to the conveyance roller pair 201 through the conveyance path 217, and are conveyed to the image forming apparatus 100 via the connection path 202.

[0025] Also, in the conveyance path 212 after merging with the conveyance path 213, the relay conveyance device 400, and the conveyance path 214, double-feed detection sensors for detecting double-feeding of the sheet are respectively arranged. And the sheet for which double-feeding is detected by the double-feed detection sensor is conveyed to the conveyance path 217. Below the conveyance path 217, a double-feed sheet storage unit (escape tray) 218 for storing the sheet for which double-feeding is detected is arranged. The sheet for which double-feeding is detected and conveyed to the conveyance path 217 is conveyed to the double-feed sheet storage unit by switching the conveyance path by a switching member 219 provided in the conveyance path 217.

[0026] Also, each part of the multi-stage feeding device 200 is controlled by a control unit 203. The control unit 203 has a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). Also, the control unit 203 can communicate with the control unit 140 of the image forming apparatus 100, and controls the sheet feeding timing and the like by communicating with the control unit 140.

[0027] The sheet fed from the upstream feeding deck 500 is conveyed to the relay conveyance device 400 through the conveyance path 512. Also, the multi-stage feeding device 200 can feed the sheet manually. The sheet fed manually is conveyed to a conveyance path 510 that merges with the conveyance path 512, and is conveyed to the relay conveyance device 400 through the conveyance path 512 by a pair of conveyance rollers 511.

[0028] As will be described in detail below, the relay conveyance device 400 includes a position shift correction unit 410 including a conveyance belt 12 or the like, a pair of conveyance rollers 401 on the upstream side of the position shift correction unit 410 in the sheet conveyance direction, a pair of conveyance rollers 402 on the downstream side of the position shift correction unit 410 in the sheet conveyance direction, and the like. The sheet conveyed through the conveyance path 512 is sent to the position shift correction unit 410 by the pair of conveyance rollers 401. After the side registration (position shift of the edge in the sheet width direction) and side skew (inclination of the edge in the sheet width direction with respect to the sheet conveyance direction) of the sheet are corrected by the position shift correction unit 410, the sheet is delivered to the downstream pair of conveyance rollers 402. Then, the sheet is conveyed to the conveyance path 215 by the pair of conveyance rollers 402 and 403. In this way, the relay conveyance device 400 corrects the position shift and the like of the sheet conveyed from the upstream feeding deck 500 or the like and delivers it to the downstream image forming device 100.

[0029] [Relay Conveyance Device] Next, the relay conveyance device 400 as a sheet conveyance device will be described. First, the schematic configuration of the relay conveyance device 400 will be described with reference to FIGS. 2 to 5. The relay conveyance device 400 includes an upstream pair of conveyance rollers 401, a downstream pair of conveyance rollers 402, the above-described position shift correction unit 410, and the like, and conveys the sheet in the conveyance direction X. The position shift correction unit 410 includes a conveyance belt 12, a plurality of spheres 20, a pair of regulation guides 14A and 14B, a guide moving unit 420, and the like.

[0030] The conveyance belt 12 is disposed downstream (in the conveyance direction downstream) of the pair of conveyance rollers 401 in the conveyance direction X as a conveyance member for conveying the sheet. The conveyance belt 12 is an endless belt wound around pulleys 11A and 11B, and has a conveyance surface 12A extending along the conveyance direction X. A motor M1 as a drive source is connected to one of the pulleys 11A, and the conveyance belt 12 rotates by the drive of the motor M1. Such a conveyance belt 12 conveys the sheet delivered to the conveyance surface 12A from the pair of conveyance rollers 401 on the upstream side in the conveyance direction X in the conveyance direction X.

[0031] A plurality of spheres 20 are arranged along the conveying direction X at positions facing the conveying surface 12A of the conveying belt 12. In the present embodiment, the plurality of spheres 20 are arranged above the conveying belt 12. The plurality of spheres 20 are rotatable in any direction while sandwiching the sheet between them and the conveying surface 12A. For this purpose, the plurality of spheres 20 are rotatably held in any direction on a holding plate 18 provided above the conveying belt 12 respectively. That is, as shown in FIGS. 2 and 3, the holding plate 18 is a long plate arranged along the conveying direction X at a position spaced a predetermined distance from the conveying surface 12A above the conveying belt 12, and has a plurality of holding holes 18A spaced apart from each other in the conveying direction X. And the spheres 20 are rotatably held in the holding holes 18A respectively.

[0032] As shown in FIG. 4, the sphere 20 is exposed from the holding hole 18A, placed on the conveying surface 12A of the conveying belt 12, and is rotatable in any direction. The spheres 20 are each in contact with the conveying surface 12A by their own weight. Note that the number of the spheres 20 may be set according to the pressing force required for the sheet conveyed on the conveying belt 12. Further, since the sheet is conveyed while slipping on the conveying belt 12 as described later, the sphere 20 is preferably made of a material such as glass or plastic having a relatively low coefficient of friction. In the present embodiment, the configuration in which the plurality of spheres 20 are arranged in a row along the conveying direction X has been described, but the plurality of spheres 20 may be arranged in a plurality of rows such as two rows along the conveying direction X respectively.

[0033] A pair of regulating guides 14A and 14B are arranged on both sides of the conveyor belt 12 with respect to the sheet width direction Y (the direction orthogonal to the conveying direction in this embodiment) intersecting the conveying direction X. And the pair of regulating guides 14A and 14B can guide both end edges (both end edges in the sheet width direction) of the sheet conveyed while being sandwiched between the conveyor belt 12 and the sphere 20 in the sheet width direction Y. Note that the regulating guide 14B arranged on one side with respect to the sheet width direction Y can guide one end edge in the sheet width direction of the sheet conveyed while being sandwiched between the conveyor belt 12 and the sphere 20. Also, the regulating guide 14A arranged on the other side with respect to the sheet width direction Y can guide the other end edge in the sheet width direction of the sheet conveyed while being sandwiched between the conveyor belt 12 and the sphere 20.

[0034] As shown in FIG. 5, the pair of regulating guides 14A and 14B each have a side plate portion 15, a lower plate portion 16, and an upper plate portion 17, and an end portion of the sheet S conveyed by the conveyor belt 12 can enter the space surrounded by these plate portions 15, 16, and 17. The pair of regulating guides 14A and 14B are supported by support shafts 421A and 421B (see FIG. 3) so as to be movable between a guide position and a retracted position by a guide moving portion 420 described later. The support shafts 421A and 421B are each arranged substantially parallel to the sheet width direction Y and support the end portion side in the conveying direction X of the pair of regulating guides 14A and 14B. The pair of regulating guides 14A and 14B are movable in the sheet width direction Y along the support shafts 421A and 421B.

[0035] The side plate portion 15 has a guide surface 15A facing an end edge (end edge in the sheet width direction) in the sheet width direction Y of the sheet S conveyed while being sandwiched between the conveyor belt 12 and the sphere 20 at the guide position. The guide surface 15A is arranged parallel to the conveying direction X. Also, the guide surface 15A is a surface orthogonal to the conveying direction X and the sheet width direction Y respectively, and in this embodiment, is a surface along the substantially vertical direction.

[0036] The lower plate portion 16 is arranged so as to be orthogonal to the side plate portion 15, and has a support surface 16A that supports the edge of the sheet S in the sheet width direction Y that is conveyed while being sandwiched between the conveyance belt 12 and the spherical body 20 at the guide position. The support surface 16A extends substantially horizontally from the lower end portion in the vertical direction of the guide surface 15A. Further, the support surface 16A is located below the conveyance surface 12A of the conveyance belt 12 in the vertical direction.

[0037] Here, if we consider the case where the support surface 16A and the conveyance surface 12A are at the same height, or the support surface 16A is located above the conveyance surface 12A in the vertical direction. In this case, when a sheet S with high stiffness such as cardboard is conveyed between the conveyance belt 12 and the spherical body 20 in a downward curled state (a state where both end edges in the width direction Y are lower than the center) as shown in FIG. 5, both end edges in the width direction Y of the sheet S are supported by the support surface 16A. At this time, the central portion of the sheet S in the width direction Y is in a lifted state (a bridged state), pushing up the spherical body 20. As a result, the conveyance belt 12 and the spherical body 20 are in a separated state, and the conveyance force of the conveyance belt 12 cannot be transmitted to the sheet S, and there is a risk of conveyance failure. For this reason, in the present embodiment, the support surface 16A is arranged below the conveyance surface 12A of the conveyance belt 12 in the vertical direction.

[0038] The upper plate portion 17 has an opposing surface 17A that is arranged to oppose the support surface 16A. The opposing surface 17A is located above the edge of the sheet S in the sheet width direction Y that is conveyed while being sandwiched between the conveyance belt 12 and the spherical body 20 at the guide position. Further, the opposing surface 17A is formed substantially parallel to the support surface 16A.

[0039] As shown in FIGS. 2 and 3, the guide moving portion 420 has a first moving portion 420A that moves the regulating guide 14A among a pair of regulating guides 14A and 14B, and a second moving portion 420B that moves the other regulating guide 14B. Further, the guide moving portion 420 has a motor M2 that generates a driving force for moving the regulating guide 14A, and a motor M3 that generates a driving force for moving the other regulating guide 14B.

[0040] The first moving part 420A includes a pair of pulleys 422A and 423A, an endless belt 424A wound around both pulleys 422A and 423A, and a connecting part 425A that connects the belt 424A and the regulating guide 14A. Similarly, the second moving part 420B includes a pair of pulleys 422B and 423B, an endless belt 424B wound around both pulleys 422B and 423B, and a connecting part 425B that connects the belt 424B and the other regulating guide 14B.

[0041] Also, as shown in FIG. 2, the first moving part 420A is driven by a motor M2 as a driving source, and the second moving part 420B is driven by a motor M3 as a driving source. That is, in the case of this embodiment, the motors as the driving sources for moving the pair of regulating guides 14A and 14B are separate, and the pair of regulating guides 14A and 14B can move independently. For this reason, the pulley 422A of the first moving part 420A is connected to a pulley 427A via a connecting shaft 426A, and the pulley 427A has a belt 428A wound around it and a pulley that is rotationally driven by the motor M2. Then, the rotational drive of the motor M2 is transmitted to the belt 424A via the belt 428A, the pulley 427A, the connecting shaft 426A, and the pulley 422A. As described above, since the regulating guide 14A is connected to the belt 424A via the connecting part 425A, the regulating guide 14A moves in the sheet width direction Y along the support shafts 421A and 421B due to the drive of the motor M2.

[0042] Similarly, the pulley 422B of the second moving part 420B is connected to a pulley 427B via a connecting shaft 426B, and the pulley 427B has a belt 428B wound around it and a pulley that is rotationally driven by the motor M3. Then, the rotational drive of the motor M3 is transmitted to the belt 424B via the belt 428B, the pulley 427B, the connecting shaft 426B, and the pulley 422B. As described above, since the other regulating guide 14B is connected to the belt 424B via the connecting part 425B, the other regulating guide 14B moves in the sheet width direction Y along the support shafts 421A and 421B due to the drive of the motor M3.

[0043] By driving the motors M2 and M3 in this way, the regulation guides 14A and 14B are moved to the guide position and the retracted position, respectively. In the case of this embodiment, the motors M2 and M3 are pulse motors (stepping motors), and the positions of the regulation guides 14A and 14B are controlled by the number of pulses sent to the motors. Further, the regulation guides 14A and 14B each have a home position, and sensors for detecting the regulation guides 14A and 14B are provided at the home positions, respectively. For this reason, the positions of the regulation guides 14A and 14B are detected at the home position, and thereafter, the regulation guides 14A and 14B are moved to the guide position and the retracted position by the number of pulses sent to the motors.

[0044] In the case of this embodiment, the motor M1 that drives the above-described conveyor belt 12, the motors M2 and M3 that move the regulation guides 14A and 14B, and the motors M5, M7, and M8 described later are arranged on the side of the other regulation guide 14B. In particular, with respect to the conveyance direction X, it is preferable to arrange the motors within the conveyance range of the sheet of the position deviation correction unit 410 on the back side (the side of one regulation guide 14B) with respect to the conveyor belt 12. This is because, as will be described in detail later, the jammed sheet is removed from the front side (the side of the other regulation guide 14A).

[0045] In the case of this embodiment, as shown in FIGS. 3 and 4, a double feed detection sensor 430 for detecting double feeding of the sheet is arranged between the upstream conveyance roller pair 401 and the conveyor belt 12. The double feed detection sensor 430 is a sensor that detects, for example, by ultrasonic waves that two or more sheets are conveyed overlapping each other. When the control unit 203 (FIG. 1) of the multi-stage feeding device 200 detects double feeding of the sheet by the double feed detection sensor 430, the double-fed sheet is conveyed to the double-fed sheet storage unit 218 described above via the relay conveyance device 400 and the conveyance paths 215 and 217.

[0046] Also, in the case of this embodiment, as shown in FIG. 3 and FIG. 13 to be described later, with respect to the sheet width direction Y, opposing members 450 and 460 that face the lower surface of the sheet conveyed by the conveyor belt 12 are disposed between the conveyor belt 12 and the pair of regulating guides 14A and 14B. The opposing members 450 and 460 support the end of the sheet in the event that the end of the sheet is conveyed without being supported by either of the regulating guides 14A and 14B. The detailed configuration of the opposing members 450 and 460 will be described later.

[0047] The relay conveyor device 400 configured as described above sandwiches the sheet delivered from the conveyor roller pair 401 upstream in the conveyance direction X between the conveyor belt 12 and the sphere 20. Then, the sheet is conveyed by the rotation of the conveyor belt 12. At this time, as will be described in detail later, both ends in the width direction Y of the sheet conveyed to the conveyor belt 12 are abutted against the guide surfaces 15A of the pair of regulating guides 14A and 14B. When the sheet is abutted against the guide surface 15A, the sheet is conveyed in a direction parallel to the guide surface 15A while slipping between the conveyor belt 12 along the guide surface 15A at both side ends. At this time, the sheet is sandwiched between the conveyor belt 12 by the sphere 20, and since the sphere 20 can rotate in an arbitrary direction, the sheet can move while slipping in an arbitrary direction on the conveyor belt 12. Thereby, the side registration and side skew of the sheet are corrected.

[0048] [Regulating Guide] Next, the detailed configuration of the pair of regulating guides 14A and 14B will be described with reference to FIGS. 6(a) to (d). In FIGS. 6(a) to (d), only the regulating guide 14A is shown, but the other regulating guide 14B has the same configuration. As shown in FIG. 5, the regulating guide 14A includes a side plate portion 15 having a guide surface 15A, a lower plate portion 16 having a support surface 16A, and an upper plate portion 17 having an opposing surface 17A.

[0049] As shown in FIGS. 6(a) and 6(b), the lower plate portion 16 and the upper plate portion 17 are continuously provided over substantially the entire longitudinal direction of the regulation guide 14A. Since the regulation guide 14A is arranged substantially parallel to the conveyance direction X as shown in FIG. 2 etc., a predetermined region A is defined as the range in which the lower plate portion 16 and the upper plate portion 17 are continuous with respect to the conveyance direction X. Therefore, in the present embodiment, the support surface 16A of the lower plate portion 16 and the opposing surface 17A of the upper plate portion 17 are continuously provided over the predetermined region A with respect to the conveyance direction X. The predetermined region A is substantially the entire region where the sheet is conveyed by the position deviation correction unit 410.

[0050] On the other hand, as shown in FIGS. 6(a) to 6(c), the side plate portion 15 is continuously provided over a guide region B which is a region shorter than the predetermined region A. In the present embodiment, the upstream end (upstream end in the conveyance direction) B1 of the side plate portion 15 in the conveyance direction X is located on the downstream side of the upstream end A1 of the predetermined region A in the conveyance direction X. That is, the upstream end B1 of the guide surface 15A of the side plate portion 15 in the conveyance direction X is located on the downstream side of the upstream end A1 of the predetermined region A. Also, the guide surface 15A is continuously provided up to the downstream end A2 of the predetermined region A with respect to the conveyance direction X. Therefore, the position of the downstream end B2 of the side plate portion 15 in the conveyance direction X and the position of the downstream end A2 of the predetermined region A in the conveyance direction X are substantially the same position with respect to the conveyance direction X.

[0051] In the present embodiment, a notch 19C is provided on the upstream side of the upstream end B1 of the side plate portion 15. And, an outer side plate portion 19 which is located outside the side plate portion 15 in the sheet width direction Y is arranged in a part of this notch 19C. The outside in the sheet width direction Y is the side that is farther from the conveyance belt 12 with respect to the sheet width direction Y. For this reason, as shown in FIG. 6(c), the inner surface 19A of the outer side plate portion 19 is located outside the guide surface 15A which is the inner surface of the side plate portion 15 in the sheet width direction Y. Also, with respect to the conveyance direction X, an inclined plate portion 19B which is inclined so as to approach the side plate portion 15 toward the downstream is provided between the outer side plate portion 19 and the side plate portion 15.

[0052] The pair of regulating guides 14A and 14B are each configured as described above, so that the distance in the width direction Y between the inner surfaces 19A of the outer plate portions 19 on the upstream side in the conveying direction X is wider than the distance in the width direction Y between the guide surfaces 15A of the side plate portions 15. Therefore, as will be described in detail later, both end edges in the width direction Y of the sheet delivered from the upstream conveying roller pair 401 to the conveying belt 12 are positioned between the inner surfaces 19A on the upstream side in the conveying direction X, and are positioned between the guide surfaces 15A as they are conveyed downstream.

[0053] Note that the outer plate portion 19 and the inclined plate portion 19B may be omitted. However, if the end portion of the sheet in the width direction Y delivered from the upstream conveying roller pair 401 to the conveying belt 12 is positioned within the notch 19C, there is a risk that the end portion of the sheet will be caught by the upstream end B1 of the side plate portion 15 when the sheet is further conveyed. For this reason, in the present embodiment, the outer plate portion 19 and the inclined plate portion 19B are provided so that even when the sheet is conveyed while being displaced in the width direction Y from the normal position, the outer plate portion 19 regulates its position, and the inclined plate portion 19B guides the end portion of the sheet to the guide surface 15A of the side plate portion 15.

[0054] [Contact and separation configuration of the conveying roller pair] Next, with reference to FIGS. 1 and 2 and using FIGS. 7, 8(a), and (b), the contact and separation configuration of the conveying roller pairs 401 to 403 will be described. As described above, conveying roller pairs 401 to 403 are arranged upstream and downstream in the conveying direction X of the conveying belt 12, respectively. The conveying roller pairs 401 to 403 each have a driving roller 32 and a driven roller 33 as a pair of conveying rollers. The driving roller 32 is an elastic roller provided with an elastic body such as rubber around the rotating shaft 32a. The driven roller 33 forms a nip portion that contacts the driving roller 32 and sandwiches and conveys the sheet. The driving roller 32 of the conveying roller pair 401 can be independently rotationally driven by a motor M4, the driving roller 32 of the conveying roller pair 402 can be independently rotationally driven by a motor M5, and the driving roller 32 of the conveying roller pair 403 can be independently rotationally driven by a motor M6.

[0055] In this embodiment, the conveying roller pair 402 and 403 arranged on the downstream side (downstream in the conveying direction) of the conveying belt 12 in the conveying direction X has a configuration in which the driving roller 32 and the driven roller 33 can be brought into contact with and separated from each other. The conveying roller pair 402 is driven by the motor M7, and the conveying roller pair 403 is driven by the motor M8, and each can independently bring the driving roller 32 and the driven roller 33 into contact with and separate from each other. Since the configurations of the conveying roller pairs 402 and 403 are the same, hereinafter, regarding the contact / separation configuration, taking the conveying roller pair 402 as an example, it will be described with reference to FIGS. 7, 8(a), and 8(b).

[0056] The contact / separation mechanism 31 for bringing the driving roller 32 and the driven roller 33 into contact with and separating them has a compression spring 34 as a biasing means, a support member 35, a motor M7, a separation cam 36, and a link member 37. The contact / separation mechanism 31 corresponds to a roller moving means that can move at least one of the pair of conveying rollers, that is, the driven roller 33, to a nip position where the sheet can be sandwiched and conveyed, and a nip release position where the pair of conveying rollers is separated from the nip position.

[0057] The compression spring 34 is a spring that biases the driven roller 33 toward the driving roller 32. The support member 35 supports the rotation shaft 33a of the driven roller 33 and is supported so as to be swingable about the swing shaft 37a. Further, the support member 35 is biased by the compression spring 34 in a direction to press the driven roller 33 toward the driving roller 32 about the swing shaft 37a. The support member 35 is fixed to the swing shaft 37a and rotates together with the swing shaft 37a to move the driven roller 33 in a direction toward the driving roller 32 and a direction away from the driving roller 32.

[0058] The motor M7 rotationally drives the separation cam 36 via the pulleys 38a, 38b and the belt 38c. The pulley 38a is fixed to the drive shaft of the motor M7, and the pulley 38b is fixed to the rotation shaft 36a of the separation cam 36. The belt 38c is an endless belt wound around the pulleys 38a and 38b. The separation cam 36 is an eccentric cam whose center of the outer peripheral surface is eccentric from the center of the rotation shaft 36a, and rotates together with the rotation shaft 36a by the drive of the motor M7.

[0059] The link member 37 is fixed to the swing shaft 37a and is provided so as to be swingable together with the swing shaft 37a. Therefore, the link member 37 rotates synchronously with the support member 35 via the swing shaft 37a. The link member 37 is arranged to contact the separation cam 36 when the support member 35 is urged by the compression spring 34.

[0060] When the separation cam 36 is in the phase shown in Fig. 8(a), the driven roller 33 is pressed against the driving roller 32 by the urging force of the compression spring 34. The state in Fig. 8(a) is the nip position. When the separation cam 36 is rotationally driven by, for example, 180° by the motor M7 from this state, as shown in Fig. 8(b), the link member 37 is pushed by the separation cam 36 and swings counterclockwise in the figure about the swing shaft 37a. Then, the support member 35 connected via the link member 37 and the swing shaft 37a swings in the same direction about the swing shaft 37a. Since the driven roller 33 is supported by the support member 35 via the rotating shaft 33a, the driven roller 33 moves away from the driving roller 32 due to the swing of the support member 35. That is, the driven roller 33 is moved to the nip release position.

[0061] When moving the driven roller 33 from the nip release position to the nip position, the separation cam 36 may be further rotated by 180° by the motor M7 from the state in Fig. 8(b). Note that the contact and separation mechanism for contacting and separating the driving roller 32 and the driven roller 33 may be configured to move both the driving roller 32 and the driven roller 33. Also, in the above example, the contact and separation mechanism is driven by a motor, but the contact and separation of a pair of conveying rollers may be performed by another driving source such as a solenoid.

[0062] Also, in the above example, the conveying roller pair 402, 403 on the downstream side in the conveying direction X of the conveying belt 12 can be contacted and separated, but only the conveying roller pair 402 may be made contactable and separable. Further, the conveying roller pair 401 on the upstream side in the conveying direction X of the conveying belt 12 may be made contactable and separable. In this case, only the upstream conveying roller pair 401 may be made contactable and separable, or the downstream conveying roller pair 402 and further the conveying roller pair 403 may also be made contactable and separable.

[0063] [Sheet Conveying Operation] Next, the sheet reaction operation in the relay conveying device 400 of the present embodiment will be described with reference to FIGS. 2, 3, etc., and FIGS. 9(a) to (d) and FIG. 10. In the present embodiment, the control unit 203 (FIG. 1) controls the motors M2 and M3 (FIG. 2) according to the conveying state of the sheet, so as to change the positions of the pair of regulating guides 14A and 14B in the sheet width direction Y. As described above, by controlling the motors M2 and M3, the guide moving unit 420 (FIG. 2) can be driven to move the pair of regulating guides 14A and 14B to the guide position and the retracted position.

[0064] Here, the guide position is a position where the guide surfaces 15A of the pair of regulating guides 14A and 14B can guide the edges in the sheet width direction Y of the sheet being conveyed while being sandwiched between the conveying belt 12 and the sphere 20. In the present embodiment, the guide position is a position where the distance between the guide surfaces 15A of the pair of regulating guides 14A and 14B (between the guide surfaces) is longer than the length of the sheet in the sheet width direction Y of the sheet being conveyed while being sandwiched between the conveying belt 12 and the sphere 20.

[0065] Specifically, when the sheet is conveyed in a state where the central position in the sheet width direction Y of the sheet coincides with the central position between the guide surfaces 15A on both sides and the edges in the sheet width direction Y of the sheet are parallel to the guide surface 15A (central reference), the position where the edges in the sheet width direction Y of the sheet and the guide surface 15A have a predetermined interval is the guide position. This predetermined interval can be appropriately set by the device, but it is an interval that allows the deviation between the sheet and the image formed on the sheet even if the sheet deviates within this interval. This predetermined interval is, for example, 0.5 mm. That is, at the guide position, the guide surfaces 15A of the pair of regulating guides 14A and 14B are respectively 0.5 mm away from the edges in the sheet width direction Y of the sheet. This guide position can be appropriately changed by the control unit 203 according to the sheet size.

[0066] In this way, at the guide position, since the pair of regulating guides 14A and 14B are positioned at a location where the distance between the guide surfaces 15A of the pair of regulating guides 14A and 14B is longer than the length of the sheet in the sheet width direction Y, the conveyance load of the sheet conveyed by the conveyance belt 12 can be suppressed. For example, if the distance between the guide surfaces is the same as the length of the sheet in the width direction Y, the sheet will be conveyed while the end portion of the sheet rubs against the guide surface, resulting in an increase in conveyance resistance. In particular, in this embodiment, since the sheet is conveyed while being sandwiched between the conveyance belt 12 and the sphere 20, the nip pressure for sandwiching the sheet between the conveyance belt 12 and the sphere 20 is small. Therefore, if the conveyance resistance of the sheet is large, there is a risk that conveyance failures such as a delay in the conveyance of the sheet or a stop in the conveyance of the sheet will easily occur. For this reason, in this embodiment, the conveyance resistance of the sheet is suppressed by positioning the pair of regulating guides 14A and 14B as described above at the guide position.

[0067] In addition, as described above, it is preferable to convey the sheet with a central reference and correct the side registration and side skew of the sheet (perform an alignment operation) as described later. This is because, in this embodiment, the sheet is slipped between the conveyance belt 12 and the sphere 20 and the side skew is corrected while rotating the sheet. That is, by starting the alignment operation at a position where the center of gravity of the sheet S substantially coincides with the central portions of the regulating guides 14A and 14B (central reference), damage to the sheet during the alignment operation can be reduced.

[0068] On the other hand, the retracted position is a position where the guide surfaces 15A of the pair of regulating guides 14A and 14B are retracted from the edge in the width direction Y of the sheet with respect to the guide position. In other words, the interval in the width direction Y between the guide surfaces 15A of the pair of regulating guides 14A and 14B at the retracted position is wider than the interval in the width direction Y between the guide surfaces 15A of the pair of regulating guides 14A and 14B at the guide position. In the present embodiment, the position where the interval from the edge in the width direction Y of the sheet conveyed based on the above-mentioned center reference is 5 mm is defined as the retracted position. Note that the sheet S is transferred to the conveying belt 12 in a state where the regulating guides 14A and 14B are in the retracted position. In this state, the vertical movement of the sheet S is restricted by the support surface 16A and the opposing surface 17A. Thereby, even if the sheet S is curled, when the regulating guides 14A and 14B move from the retracted position to the guide position, both end edges of the sheet S can be accommodated in the region surrounded by the guide surface 15A, the support surface 16A, and the opposing surface 17A.

[0069] With reference to FIGS. 9(a) to (d) and FIG. 10, the operations of the pair of regulating guides 14A and 14B when two sheets S1 and S2 are continuously conveyed to the relay conveying device 400 will be described. First, as shown in FIG. 9(a), when the first sheet S1 is conveyed from the upstream conveying roller pair 401 to the conveying belt 12, the control unit 203 moves the pair of regulating guides 14A and 14B to the retracted position. This is because when the sheet S1 is transferred to the conveying belt 12, if the pair of regulating guides 14A and 14B are in the guide position, there is a risk that if the sheet S1 is skewed or displaced in the width direction Y, the end of the sheet S1 may interfere with one of the regulating guides 14A and 14B, resulting in a conveyance failure of the sheet S1.

[0070] Next, as shown in FIG. 9(b), after the rear end (upstream end) of the first sheet S1 delivered from the pair of conveying rollers 401 has passed through the pair of conveying rollers 401, the control unit 203 moves the pair of regulating guides 14A and 14B from the retracted position to the guiding position. In the present embodiment, the pair of regulating guides 14A and 14B are moved from the retracted position to the guiding position while the sheet S1 delivered to the conveying belt 12 is within the predetermined area A (within the predetermined area in FIG. 6(b)). Thereby, correction (alignment operation) of side registration and side skew of the sheet S1 is performed.

[0071] That is, when the sheet S1 is on the upstream side in the conveying direction X, the regulating guides 14A and 14B are located at the retracted position, and both end edges of the sheet S1 are separated from the guide surface 15A. Then, as the sheet S1 is further conveyed downstream and after the rear end of the sheet S1 has passed through the pair of conveying rollers 401, the regulating guides 14A and 14B move to the guiding position. Then, the guide surface 15A is brought into contact with both end edges in the width direction Y of the sheet S1. When the sheet S1 abuts against the guide surface 15A, while slipping between the sheet S1 and the conveying belt 12 while guiding the edge along the guide surface 15A, the sheet S1 is conveyed in a direction parallel to the guide surface 15A. Thereby, side registration and side skew of the sheet S1 are corrected.

[0072] In the present embodiment, the control unit 203 is configured to move the pair of regulating guides 14A and 14B from the retracted position to the guiding position while the sheet is being conveyed while being sandwiched between the conveying belt 12 and the sphere 20. Thereby, correction of side registration and side skew of the sheet can be performed without stopping the conveyance of the sheet, and productivity can be increased. However, an alignment operation of moving the pair of regulating guides 14A and 14B from the retracted position to the guiding position may be performed after once stopping the conveyance of the sheet. In this case, although the productivity decreases, misalignment correction and the like can be performed more reliably.

[0073] Next, as shown in FIG. 9(c), when the leading edge of the second sheet S2 delivered from the pair of conveying rollers 401 enters the predetermined region A on the conveying belt 12, the pair of regulating guides 14A and 14B are kept in the guide position. At this time, the first sheet S1 is being guided by the guide surface 15A in the guide region B (FIG. 6(b)). That is, in the present embodiment, while the first sheet S1 is being guided by the pair of regulating guides 14A and 14B, the second sheet S2 starts to enter the predetermined region A.

[0074] Here, as shown in FIG. 10, on the upstream side of the upstream end B1 (FIG. 6(b)) of the guide surface 15A in the conveying direction X, there is an inner surface 19A of the outer plate portion 19 which is wider in spacing than the guide surfaces 15A. In FIG. 10, the inner surface 19A is inclined toward the guide surface 15A as it goes downstream, but the inner surface 19A may be a surface parallel to the conveying direction X. In any case, since the inner surface 19A is located outside the guide surface 15A in the sheet width direction Y, even when the pair of regulating guides 14A and 14B are in the guide position, the spacing between the inner surfaces 19A is wider than the spacing between the guide surfaces 15A. Therefore, even if the second sheet S2 enters the predetermined region A while skewing or shifting in the width direction Y in this state, the end of the sheet S2 is less likely to interfere with the pair of regulating guides 14A and 14B. For this reason, in the present embodiment, even if the second sheet S2 is conveyed at the above-described timing, conveyance failure of the sheet is less likely to occur, and productivity can be improved.

[0075] Then, as shown in FIG. 9(d), before the leading edge of the second sheet S2 reaches the upstream end B1 in the conveyance direction X of the guide surface 15A, the control unit 203 moves the pair of regulating guides 14A and 14B from the guide position to the retracted position. At this time, the alignment operation of the first sheet S1 is completed, and the sheet S1 has been delivered to the downstream conveyance roller pair 402. Therefore, even if the pair of regulating guides 14A and 14B are moved to the retracted position, the posture of the sheet S1 is not affected. Further, since the pair of regulating guides 14A and 14B are moved to the retracted position before the second sheet S2 reaches the guide surface 15A, when the end of the second sheet S2 exceeds the inner surface 19A of the outer plate portion 19, interference with the upstream end B1 of the guide surface 15A is suppressed, and the occurrence of sheet conveyance failure can be suppressed.

[0076] After that, as described after FIG. 9(b), after the trailing edge of the second sheet S2 has passed through the conveyance roller pair 401, the control unit 203 moves the pair of regulating guides 14A and 14B from the retracted position to the guide position. In the present embodiment, after the leading edge of the second sheet S2 has passed through the upstream end B1 in the conveyance direction X of the guide surface 15A, the pair of regulating guides 14A and 14B are moved from the retracted position to the guide position. Then, the alignment operation of the second sheet S2 is performed. If there are subsequent sheets from the third sheet onwards, the operations of FIGS. 9(c), (d), and (b) are continued, and if it is the last sheet, it is directly delivered to the conveyance roller pair 402 to complete the sheet alignment operation.

[0077] Note that the position in the conveyance direction X of the sheet described above can be grasped by the control unit 203 based on, for example, the sheet size, the sheet detection timing of a sensor that detects a sheet at any position in the sheet conveyance path, and the sheet conveyance speed.

[0078] Thus, in the case of this embodiment, after the trailing edge of the sheet delivered to the conveyor belt 12 passes through the upstream conveyor roller pair 401, the pair of regulating guides 14A and 14B are moved from the retracted position to the guide position. For this reason, when the sheet is delivered to the conveyor belt 12, it is possible to make it difficult for the pair of regulating guides 14A and 14B to interfere with the sheet. Also, while the sheet is being conveyed by the upstream conveyor roller pair 401, the pair of regulating guides 14A and 14B are not positioned at the guide position, so it is possible to suppress the sheet being conveyed by the conveyor roller pair 401 from bending by coming into contact with any of the regulating guides.

[0079] Furthermore, since the pair of regulating guides 14A and 14B are moved to the guide position after the trailing edge of the sheet has passed through the conveyor roller pair 401, for example, even if the sheet is conveyed obliquely and does not hit the regulating guide, displacement of the sheet can be corrected. For this reason, it is possible to correct displacement of the sheet without increasing the length for conveying the sheet, and it is possible to suppress an increase in the size of the apparatus. That is, while suppressing an increase in the size of the apparatus, displacement in the width direction Y of the sheet can be corrected.

[0080] [Conveying operation of cardboard] Next, the conveying operation of the sheet S3 (for example, cardboard) having a basis weight of a predetermined value or more will be described with reference to FIGS. 11(a) to (c). The predetermined value is, for example, 100 g / m 2 Here, when the stiffness is high as in the case of a sheet having a basis weight of a predetermined value or more, as described above, when correcting side registration or the like by sandwiching both edge portions of the sheet with the pair of regulating guides 14A and 14B or guiding with a minute gap from the guide surface 15A, there is a risk that the conveying resistance will increase. When the conveying resistance increases, conveyance delay of the sheet or the like will occur. Therefore, in this embodiment, in the case of a sheet such as cardboard, the regulating guides 14A and 14B are brought into contact with the edge portion of the sheet one by one to correct side registration and side skew. This will be specifically described below.

[0081] First, in the case of this embodiment, as described above, the guide moving unit 420 (FIG. 2) can move the restricting guides 14A and 14B independently. That is, the first moving unit 420A (FIG. 2) of the guide moving unit 420 can move one of the pair of restricting guides 14A and 14B to a first guide position for guiding one edge of the sheet in the width direction Y of the sheet and to a first retracted position retracted from one edge of the sheet with respect to the first guide position. Similarly, the second moving unit 420B (FIG. 2) of the guide moving unit 420 can move the other restricting guide 14B of the pair of restricting guides 14A and 14B to a second guide position for guiding the other edge of the sheet in the width direction Y of the sheet and to a second retracted position retracted from the other edge of the sheet with respect to the second guide position.

[0082] As shown in FIG. 11(a), when a sheet S3 such as cardboard is delivered to the conveying belt 12, the pair of restricting guides 14A and 14B are in the retracted positions. That is, one restricting guide 14A is in the first retracted position and the other restricting guide 14B is in the second retracted position, respectively.

[0083] Next, as shown in FIG. 11(b), after the rear end of the sheet S3 has passed through the pair of conveying rollers 401 (FIG. 3 etc.), the control unit 203 moves one of the restricting guides 14A to the first guide position and positions the other restricting guide 14B at the second retracted position. That is, the guide surface 15A of one of the restricting guides 14A is abutted against one edge of the sheet S3, and while the other restricting guide 14B remains in the second retracted position, the guide surface 15A of the restricting guide 14B is retracted from the other edge of the sheet S3.

[0084] Thereafter, as shown in FIG. 11(c), the control unit 203 moves the other restricting guide 14B to the second guide position and moves one of the restricting guides 14A to the first retracted position. That is, the guide surface 15A of the other restricting guide 14B is abutted against the other edge of the sheet S3, and while moving one of the restricting guides 14A to the first retracted position, the guide surface 15A of the restricting guide 14A is retracted from one edge of the sheet S3.

[0085] In this embodiment, the regulation guides 14A and 14B are thus abutted against the edges of the sheet S3 one by one, and during the abutting, the regulation guide on the opposite side is retracted from the edge of the sheet S3. Therefore, it is possible to suppress an increase in the conveyance resistance of the sheet S3. Note that the order of abutting the regulation guides 14A and 14B is not limited to the above, and after abutting the regulation guide 14B, the regulation guide 14A may be abutted.

[0086] In addition, when the basis weight of the sheet delivered from the conveyance roller pair 401 to the conveyance belt 12 is less than a predetermined value (for example, plain paper), as described in FIGS. 9(a) to 9(d) above, after the rear end of the sheet passes through the conveyance roller pair 401, a pair of regulation guides 14A and 14B are moved from the retracted position to the guide position.

[0087] [Conveying Operation of Long Sheet] Next, the conveying operation of a sheet S4 (such as a long sheet) having a size equal to or larger than a predetermined size will be described with reference to FIGS. 4, 7, and 8 and FIGS. 12(a) and 12(b). In the case of a sheet S4 having a length in the conveying direction X equal to or longer than a predetermined length, such as a long sheet, while the side registration and side skew are being corrected by a pair of regulation guides 14A and 14B, there is a possibility that the downstream or upstream side in the conveying direction of the sheet is nipped by the conveyance roller pair. In a state where the sheet is nipped by the conveyance roller pair, even if a pair of regulation guides 14A and 14B are abutted against the edge of the sheet, correction (alignment operation) such as side registration may not be sufficiently performed, or the sheet may be bent.

[0088] On the other hand, even in the case of a long sheet, in order to perform the alignment operation without being nipped by the conveyance roller pair, it is conceivable to increase the distance in the conveying direction X guided by a pair of regulation guides 14A and 14B. However, in this case, the apparatus becomes large-sized. Therefore, in this embodiment, when performing the alignment operation of the sheet S4 having a size equal to or larger than a predetermined size, the nip of the downstream conveyance roller pair 402 is released.

[0089] As described above, the conveying roller pair 402, 403 on the downstream side of the conveying belt 12 can bring the driving roller 32 and the driven roller 33 into contact with or separate them from each other (see, for example, FIG. 4). Further, the contact / separation mechanism 31 for bringing the driving roller 32 and the driven roller 33 into contact with or separating them from each other has motors M7, M8 controlled by the control unit 203. Therefore, the control unit 203 can control the contact / separation mechanism 31 to bring the driving roller 32 and the driven roller 33 into contact with or separate them from each other.

[0090] In the present embodiment, when the control unit 203 moves the pair of regulating guides 14A, 14B from the retracted position to the guiding position by the guide moving unit 420, the control unit 203 can execute a nip release operation in which the conveying roller pair 402, 403 is set to the nip release position. Hereinafter, a specific description will be given with reference to FIGS. 12(a) and (b).

[0091] As shown in FIG. 12(a), when the sheet S4 is transferred from the upstream conveying roller pair 401 to the conveying belt 12, the pair of regulating guides 14A, 14B are located at the retracted position. Then, as shown in FIG. 12(b), after the sheet S4 is further conveyed downstream and the rear end of the sheet S4 passes through the upstream conveying roller pair 401, the control unit 203 sets the downstream conveying roller pair 402, 403 to the nip release position. At the same time, the pair of regulating guides 14A, 14B are moved from the retracted position to the guiding position. That is, in the present embodiment, the nip release operation is executed simultaneously with the movement of the pair of regulating guides 14A, 14B from the retracted position to the guiding position by the guide moving unit 420.

[0092] Note that the timing of the alignment operation for moving the pair of regulation guides 14A and 14B from the retracted position to the guide position and the nip release operation does not have to be simultaneous. For example, after the trailing edge of the sheet has passed through the upstream conveying roller pair 401, if the leading edge (downstream edge) of the sheet has not reached the downstream conveying roller pair 402, the alignment operation may be started first, and the nip release operation may be performed before the leading edge of the sheet reaches the downstream conveying roller pair 402. Also, in the case of a long sheet where the leading edge of the sheet reaches the conveying roller pair 402 before the trailing edge of the sheet passes through the conveying roller pair 401, the nip release operation of the conveying roller pair 402 is performed before the leading edge of the sheet reaches the conveying roller pair 402.

[0093] After the alignment operation of the sheet S4 is completed, the downstream conveying roller pairs 402 and 403 are returned from the nip release position to the nip position, and the sheet S4 is further conveyed downstream by the conveying roller pairs 402 and 403. Note that the timing for returning the downstream conveying roller pairs 402 and 403 to the nip position is, at the latest, before the trailing edge of the sheet S4 passes through the downstream end of the conveying belt 12.

[0094] Also, after the conveying roller pairs 402 and 403 are set from the nip release position to the nip position by the contact / separation mechanism 31, the control unit 203 moves the pair of regulation guides 14A and 14B from the guide position to the retracted position. Here, if the sheet is nipped by the conveying roller pair 402 after the pair of regulation guides 14A and 14B are moved to the retracted position, there is a risk that the position of the sheet will shift due to the operation of nipping the sheet. On the other hand, since the sheet is nipped by the conveying roller pair 402 or the like first and then the pair of regulation guides 14A and 14B are moved to the retracted position, the sheet is guided by the regulation guides 14A and 14B when the sheet is nipped, and it is possible to suppress the inadvertent occurrence of sheet position shift.

[0095] Also, after the sheet is nipped by the conveyance roller pair 402, by moving the pair of regulating guides 14A and 14B to the retracted position, when the next sheet is conveyed, it is possible to suppress the next sheet from interfering with the pair of regulating guides 14A and 14B, and productivity can be increased. The timing of starting the movement of the pair of regulating guides 14A and 14B to the retracted position may be the same as the start of the movement of the conveyance roller pairs 402 and 403 from the nip release position to the nip position. By moving the pair of regulating guides 14A and 14B to the retracted position earlier, the next sheet can be delivered to the conveyance belt 12 as soon as possible, and productivity can be further increased.

[0096] In this embodiment, by performing the nip release operation in this way, even if the downstream side of the sheet S4 has reached the conveyance roller pair 402 and further the conveyance roller pair 403, the alignment operation by the pair of regulating guides 14A and 14B becomes possible. Therefore, without increasing the size of the apparatus, it is possible to execute the alignment operation for a sheet having a length equal to or longer than a predetermined length.

[0097] Also, when the length of the sheet is less than the predetermined length, since the nip release operation of the conveyance roller pair is not performed during the alignment operation, the number of contact and separation operations of the conveyance roller pair can be reduced. When the contact and separation operation is performed, each component of the contact and separation mechanism 31 is consumed and noise is generated. Therefore, by minimizing the contact and separation operation, it is possible to suppress the consumption of components and the generation of noise.

[0098] Note that, not limited to the case where the length of the sheet is equal to or longer than the predetermined length, the nip release operation of the conveyance roller pair may be performed during the alignment operation as described above. Thereby, the length of the position deviation correction unit 410 in the conveyance direction X for performing the alignment operation of the sheet can be further shortened, and the size of the apparatus can be reduced.

[0099] Here, in the case of a sheet with a basis weight of a predetermined value or more, as described with reference to FIGS. 11(a) to 11(c), an alignment operation is performed by abutting a pair of restricting guides 14A and 14B against the sheet, one on each side. In such a sheet with a basis weight of a predetermined value or more, when the sheet is further long, when performing this alignment operation, the conveying roller pairs 402 and 403 are set to the nip release position. That is, when the rear end of the sheet passes through the upstream conveying roller pair 401 and an alignment operation is to be started, simultaneously with one of the pair of restricting guides 14A and 14B moving to the guide position, the conveying roller pairs 402 and 403 are set to the nip release position. Then, after completion of the alignment operation, the conveying roller pairs 402 and 403 are returned to the nip position. The point that the timings of the start of the alignment operation and the nip release operation may be different is the same as in the above-described case.

[0100] In the above description, the nip release operation is performed by the conveying roller pairs 402 and 403, but the nip release operation may be performed only by the conveying roller pair 402. Also, in the case of a configuration in which the driving roller 32 and the driven roller 33 of the upstream conveying roller pair 401 of the conveying belt 12 are brought into contact with or separated from each other, a nip release operation of the conveying roller pair 401 may be performed. That is, when the guide moving unit 420 moves the pair of restricting guides 14A and 14B from the retracted position to the guide position, the control unit 203 may be enabled to execute a nip release operation of setting the upstream conveying roller pair 401 to the nip release position. For example, in the state of FIG. 12(a), the conveying roller pair 401 may be set to the nip release position and the pair of restricting guides 14A and 14B may be moved to the guide position.

[0101] Also, all of the upstream and downstream conveying roller pairs 401, 402, and 403 may be configured to be separable. In this case, the nip release operation of all the conveying roller pairs 401 to 403 may be performed simultaneously with the start of the alignment operation. Alternatively, depending on the length of the sheet and the conveying situation, the timing of the nip release operation of the conveying roller pairs may be made different. For example, when the sheet straddles a plurality of conveying roller pairs during the alignment operation, all of the plurality of conveying roller pairs are set to the nip release position during the alignment operation. Or, in accordance with the conveyance of the sheet, the nip release operation may be performed in order from the upstream conveying roller pair so that the sheet is not nipped by any of the conveying roller pairs during the alignment operation.

[0102] Also, depending on the sheet size, the number of conveying roller pairs that perform the nip release operation may be changed. For example, the conveying roller pair 402 is a pair of first conveying rollers, and the conveying roller pair 403 is a pair of second conveying rollers. The conveying roller pair 403 is disposed at a position farther from the conveying belt 12 than the conveying roller pair 402. Also, the separation mechanism 31 that can move the conveying roller pair 403 between the nip position and the nip release position is used as the second roller moving means.

[0103] In this case, the control unit 203 controls the roller moving means and the separation mechanism 31 as the second roller moving means so that the conveying roller pairs 402 and 403 can operate as follows. First, when the length of the sheet in the conveying direction is equal to or longer than a second predetermined length that is longer than the predetermined length, when moving the pair of restricting guides 14A and 14B from the retracted position to the guide position, the conveying roller pairs 402 and 403 are set to the nip release position. On the other hand, when the length of the sheet is less than the second predetermined length and equal to or longer than the predetermined length, when moving the pair of restricting guides 14A and 14B from the retracted position to the guide position, only the conveying roller pair 402 is set to the nip release position, and the conveying roller pair 403 remains in the nip position.

[0104] The operations of the above-described conveying roller pairs 402 and 403 may be performed by the upstream conveying roller pair 401 and the downstream conveying roller pair 402. Further, in the case where all the conveying roller pairs 401 to 403 are configured to be separable, when the length of the sheet is a third predetermined length longer than the second predetermined length, all the conveying roller pairs 401 to 403 may be set at the nip release position during the alignment operation.

[0105] Note that the basis weight and size of the above-described sheet are based on information input by an input unit (for example, an operation panel) 1001 (FIG. 1) provided in the image forming system 1000. For example, a user inputs information such as the basis weight and size of the sheet stored in the feed deck 500 via the input unit 1001. The control unit 203 determines the basis weight and size of the sheet conveyed to the relay conveyance device 400 from this input information. The input unit 1001 may be an operation panel provided in any one of the image forming apparatus 100, the multi-stage feeding device 200, and the feed deck 500, or may be an external terminal such as a personal computer connected to the image forming system 1000.

[0106] Alternatively, the basis weight and size of the above-described sheet may be detected by providing sensors for detecting the basis weight and size of the sheet in the conveyance path from the feed deck 500 to the relay conveyance device 400 and in the feed deck 500.

[0107] [Operation at the time of sheet jam] Next, the operation of the relay conveyance device 400 when a jam occurs where the sheet stops on the conveyance belt 12 will be described with reference to FIGS. 13 to 15 while referring to FIGS. 2 and 3. As shown in FIGS. 3 and 13, with respect to the sheet width direction Y, opposing members 450 and 460 that face the lower surface of the sheet conveyed by the conveyance belt 12 are disposed between the conveyance belt 12 and the pair of regulating guides 14A and 14B. Among the opposing members 450 and 460, the opposing member 450 on the side of the regulating guide 14A is movable between an opposing position and a take-out position retracted downward from the opposing position, as will be described later. The opposing position is a position that faces the lower surface of the sheet conveyed by the conveyance belt 12. On the other hand, the opposing member 460 on the side of the regulating guide 14B is fixed in the opposing position.

[0108] The opposing members 450 and 460 each have opposing surfaces 450A and 460A that face the lower surface of the sheet in the opposing position. The opposing surfaces 450A and 460A support the end of the sheet in the case where the end of the sheet is conveyed by the conveyance belt 12 without being supported by either of the regulating guides 14A and 14B.

[0109] Further, as shown in FIG. 13, the relay conveyance device 400 has a housing 470 that houses the above-described misalignment correction unit 410. The housing 470 has a take-out port 471 for taking out the sheet in the housing 470 formed in front of the device, that is, on one side with respect to the sheet width direction Y. The take-out port 471 is provided on the side of the regulating guide 14A (the first regulating guide side) with respect to the sheet width direction Y and is mainly an opening for taking out the sheet stopped on the conveyance belt 12.

[0110] Also, as shown in FIG. 13, the take-out port 471 is located below the conveyance belt 12. On the other hand, as shown in FIG. 2, the first moving part 420A and the second moving part 420B that constitute the guide moving part 420 are disposed above the conveyance belt 12. The first moving part 420A and the second moving part 420B have pulleys 422A, 423A, 422B, 423B, belts 424A, 424B, and connecting parts 425A, 425B as described above.

[0111] Here, if the extraction port 471 were on the same side of the conveyor belt 12 as the first moving part 420A and the second moving part 420B, the first moving part 420A and the second moving part 420B might get in the way when taking out the sheet. For this reason, in the present embodiment, the extraction port 471 is provided on the side opposite to the first moving part 420A and the second moving part 420B with respect to the conveyor belt 12. That is, the first moving part 420A and the second moving part 420B are arranged above the conveyor belt 12, and the extraction port 471 is arranged below the conveyor belt 12, respectively.

[0112] When the sheet is being conveyed while being sandwiched between the conveyor belt 12 and the spherical body 20, a jam may occur where the sheet stops on the conveyor belt 12. In the present embodiment, the jammed sheet can be taken out from the extraction port 471. For this purpose, the opposing member 450 on the extraction port 471 side is made movable between the opposing position shown in FIG. 13 and the extraction position shown in FIG. 14. The extraction position is a position where the opposing member 450 retracts downward from the opposing position and can access the sheet that has stopped on the conveyor belt 12 from the extraction port 471.

[0113] As described above, the opposing member 450 is supported by a link mechanism 454 so as to be movable between the opposing position and the extraction position. The link mechanism 454 is a parallel link mechanism having two link members 451, 452 and pins 451A, 451B, 452A, 452B that support both ends of each link member 451, 452. The pins 451A, 451B are supported by the housing 470, and the pins 451B, 452B are supported by the opposing member 450. Both ends of the link member 451 are rotatably supported by the pins 451A, 451B, and both ends of the link member 452 are rotatably supported by the pins 452A, 452B. The lengths of the link members 451, 452 are the same. Thereby, the opposing member 450 can move between the opposing position and the extraction position while maintaining the opposing surface 450A substantially parallel to the conveying direction X (substantially parallel to the horizontal direction in the present embodiment).

[0114] In this way, by making the opposing member 450 movable to the take-out position while maintaining the opposing surface 450A substantially horizontally, when the opposing member 450 is in the take-out position, it becomes easier for the user to take out the sheet. For example, when the opposing member 450 is in the take-out position with the opposing surface 450A inclined with respect to the horizontal direction, there is a risk that the space (the space to access) for inserting a hand or the like from the take-out port 471 beyond the opposing member 450 into the interior becomes narrow due to the inclination of the opposing surface 450A. On the other hand, in the case of this embodiment, for example, when the user inserts a hand or the like from the take-out port 471 beyond the opposing member 450 into the interior, the space for this insertion can be widened, and the sheet can be taken out more easily.

[0115] In addition, at the front end (the left side in FIG. 13) of the opposing member 450, a gripping portion 453 is provided for a user or the like to grip by hand and move the opposing member 450 between the opposing position and the take-out position. When the sheet stops on the conveying belt 12, the user opens the door of at least the portion where the relay conveying device 400 of the multi-stage feeding device 200 is arranged, grips the gripping portion 453, and moves the opposing member 450 from the opposing position to the take-out position as shown in FIGS. 13 to 14. Thereby, the user can access the sheet stopped on the conveying belt 12 through the space above the opposing surface 450A of the opposing member 450 at the take-out port 471 and the take-out position.

[0116] At this time, when the user touches the sheet, the sheet may be pushed to the back side, that is, the regulation guide 14B side (the second regulation guide side). In this case, if the regulation guide 14B on the back side is movable further to the back side, there is a risk that the regulation guide 14B on the back side is also pushed by the sheet being pushed, and the sheet moves further back. When the sheet moves further back, it becomes difficult to take out the sheet.

[0117] Therefore, in the case of this embodiment, the control unit 203 that controls the guide moving unit 420 holds the rear regulating guide 14B at the position where the conveyance of the sheet has stopped when the sheet stops on the conveyance belt. Specifically, a holding current is applied to the motor M3 that generates a driving force for moving the rear regulating guide 14B. In the case of this embodiment, the motors M2 and M3 are pulse motors, and the stopped state is maintained when energized.

[0118] For this reason, when the control unit 203 determines that a jam has occurred in the sheet on the conveyance belt 12, it energizes the motor M3 to hold the position of the regulating guide 14B. As a result, even if the user presses the sheet when accessing the sheet, since the rear regulating guide 14B is held at that position, it is possible to prevent the sheet from going further back. As a result, it is easier to take out the sheet stopped on the conveyance belt 12.

[0119] Note that the control for holding the position of the regulating guide 14B may start when the control unit 203 determines that the sheet has stopped on the conveyance belt 12, or may start at a point in time after a predetermined time has elapsed since the determination. For example, the control unit 203 determines that the conveyance of the sheet has stopped on the conveyance belt 12 when a sensor that detects the sheet on the downstream side of the conveyance belt 12 does not detect the sheet for a predetermined time. Note that a sensor for detecting a jam in the sheet may be provided in the conveyance path of the sheet in the position deviation correction unit 410, and the control unit 203 may determine the stop of the sheet conveyance based on the detection result of this sensor.

[0120] Further, the start of holding the position of the regulating guide 14B may be when the opposing member 450 moves to the take-out position, or even after the movement. In this case, a sensor for detecting that the opposing member 450 has moved to the take-out position may be provided, and the position of the regulating guide 14B may be held when this sensor detects that the opposing member 450 has moved to the take-out position, or after a predetermined time has elapsed from this point in time.

[0121] Also, in the case of this embodiment, when the sheet stops on the conveyance belt 12, the front regulating guide 14A (other regulating guides) is moved in a direction away from the conveyance belt 12 from the position immediately before the conveyance of the sheet stops. Specifically, the regulating guide 14A on the take-out port 471 side is further moved forward as indicated by the arrow α in FIG. 14. For example, when the regulating guide 14A is movable to a home position that is further away from the conveyance belt 12 than the retracted position in addition to the guide position and the retracted position, the control unit 203 moves the regulating guide 14A to the home position when a jam of the sheet is detected on the conveyance belt 12.

[0122] By moving the front regulating guide 14A in a direction away from the conveyance belt 12 when the conveyance of the sheet stops in this way, it becomes easier for the user to access the sheet stopped on the conveyance belt 12. For example, the interval between the conveyance belt 12 and the front regulating guide 14A widens, making it easier for the user to put their hand in between. Also, when the end of the stopped sheet is caught by the regulating guide 14A, by moving the regulating guide 14A in a direction away from the conveyance belt 12, it becomes easier to release the catch of the sheet and easier for the user to take out the sheet.

[0123] Note that when the conveyance of the sheet stops, the energization to the motor M2 that drives the front regulating guide 14A may be stopped to make the front regulating guide 14A manually movable. In this case, when the user manually moves the regulating guide 14A, the space for taking out the sheet can be widened, and the sheet can still be easily taken out.

[0124] Also, in the case of this embodiment, when the sheet stops on the conveyance belt 12, as shown in FIG. 15, the control unit 203 moves the rear regulation guide 14B toward the discharge port 471 side (discharge port side) in the sheet width direction Y. That is, the control unit 203 drives the motor M3 to move the regulation guide 14B forward as indicated by the arrow β in FIG. 15. As a result, since the sheet is pushed by the regulation guide 14B and moves toward the discharge port 14 side, it becomes easier for the user to take out the sheet. Although the sheet is nipped between the conveyance belt 12 and the sphere 20, since this nip pressure is small, the sheet moves forward by being pushed by the regulation guide 14B.

[0125] Here, the timing for moving the regulation guide 14B forward may be when the control unit 203 determines that the sheet has stopped on the conveyance belt 12, or may be when a predetermined time has elapsed since the determination. When the control unit 203 moves the regulation guide 14B by determining the stop of the sheet in this way, as described above, the control for holding the position of the regulation guide 14B is not performed.

[0126] Also, the timing for moving the regulation guide 14B forward may be when the opposing member 450 moves to the discharge position, or even after the movement. In this case, a sensor for detecting that the opposing member 450 has moved to the discharge position is provided, and the regulation guide 14B may be moved forward when this sensor detects that the opposing member 450 has moved to the discharge position, or after a predetermined time has elapsed from this time. In this case, the control for holding the position of the regulation guide 14B at the position when the conveyance of the sheet stops may or may not be performed.

[0127] Alternatively, a button or the like that can be operated by the user may be provided on any part of the apparatus, and the regulation guide 14B may be moved forward by operating this button or the like, or by operating from the input unit 1001. The control for holding the position of the regulation guide 14B at the position when the conveyance of the sheet stops may be performed, and the movement of the regulation guide 14B may be performed by the user's operation.

[0128] Note that, as described above, the operation of moving the regulation guide 14B forward when the conveyance of the sheet stops is not performed when the stopped sheet straddles the conveyance belt 12 and the upstream conveyance roller pair 401 (one pair of upstream conveyance rollers) or the downstream conveyance roller pair 402 (one pair of downstream conveyance rollers). That is, when the sheet stops in a state of straddling the conveyance belt 12 and the conveyance roller pair 401 or the conveyance roller pair 402, the control unit 203 does not move the regulation guide 14B. This is because if the regulation guide 14B is moved when the sheet is nipped by the conveyance roller pair 401 or the conveyance roller pair 402, the sheet may be damaged or torn.

[0129] However, when the sheet stops on the conveyance belt 12, an operation of moving the conveyance roller pairs 401 and 402 to the nip release position may be performed so as to move the regulation guide 14B forward. Whether the sheet straddles the conveyance belt 12 and the conveyance roller pair 401 or the conveyance roller pair 402 can be detected, for example, by providing sensors for detecting the sheet between the conveyance belt 12 and the conveyance roller pair 401 and between the conveyance belt 12 and the conveyance roller pair 402, respectively. That is, when the control unit 203 determines that the sheet has stopped on the conveyance belt 12, if any of the sensors detects the sheet, it can be determined that the sheet has stopped in a state of straddling the conveyance belt 12 and the conveyance roller pair 401 or the conveyance roller pair 402.

[0130] <Other Embodiments> In the above-described embodiment, the control unit 203 that controls the relay conveyance device 400 is provided in the multi-stage feeding device 200, but these controls may be performed by the control unit 140 of the image forming apparatus 100. Further, a control unit for controlling each part of the relay conveyance device 400 may be provided in the relay conveyance device 400. Furthermore, the sheet conveyance device may have another configuration as long as it is a sheet conveyance device that can perform sheet misregistration, regardless of the above-described relay conveyance device.

Description of Reference Numerals

[0131] 12... Conveyor Belt / 12A... Conveyor Surface / 14A... Regulation Guide (First Regulation Guide, Other Regulation Guides) / 14B... Regulation Guide (Second Regulation Guide) / 15A... Guide Surface / 16A... Support Surface / 17A... Opposing Surface / 20... Sphere / 31... Contact and Separation Mechanism (Roller Movement Means) / 100... Image Forming Apparatus / 200... Multi-Stage Feeding Device / 203... Control Unit / 400... Relay Conveyor Device (Sheet Conveyor Device) / 401... Conveyor Roller Pair (Conveyor Member, Pair of Conveyor Rollers, Pair of Upstream Conveyor Rollers) / 402... Conveyor Roller Pair (Pair of Conveyor Rollers, Pair of Downstream Conveyor Rollers) / 403... Conveyor Roller Pair (Pair of Conveyor Rollers, Pair of Second Conveyor Rollers) / 420... Guide Movement Unit (Guide Movement Means) / 420A... First Movement Unit / 420B... Second Movement Unit / 450... Opposing Member / 471... Outlet / M2, M3... Motors (Drive Sources)

Claims

【Claim 1】 A sheet conveying device for conveying a sheet in a conveying direction, comprising: an endless conveying belt having a conveying surface extending along the conveying direction and conveying the sheet received on the conveying surface in the conveying direction; a plurality of spheres arranged along the conveying direction at a position facing the conveying surface, the spheres being rotatable in any direction while sandwiching the sheet between the spheres and the conveying surface; a pair of restricting guides arranged on both sides of the conveying belt in the sheet width direction intersecting the conveying direction, the pair of restricting guides being capable of guiding both end edges of the sheet in the sheet width direction while the sheet is sandwiched between the conveying belt and the spheres; guide moving means for moving the pair of restricting guides to a guide position for guiding both end edges of the sheet in the sheet width direction and a retracted position retracted from both end edges of the sheet in the sheet width direction with respect to the guide position; a pair of conveying rollers arranged on the downstream side of the conveying belt in the conveying direction, the pair of conveying rollers sandwiching the sheet and conveying the sheet in the conveying direction; roller moving means for moving at least one of the pair of conveying rollers to a nip position where the sheet can be sandwiched and conveyed and a nip release position where the pair of conveying rollers are separated from the nip position; the roller moving means is capable of performing a nip release operation of setting the pair of conveying rollers to the nip release position when the guide moving means moves the pair of restricting guides from the retracted position to the guide position; A sheet conveying device characterized by the above.

Images