Sheet conveying device and image forming system

Abstract

To provide a configuration that is able to stably convey a sheet.SOLUTION: A pair of restriction guides 14A, 14B are capable of guiding both edges, in a sheet width direction Y, of a sheet S conveyed while being sandwiched between a conveyance belt and a spherical body. Further, the pair of restriction guides 14A, 14B are movable between a guide position for guiding both edges of the sheet and a retraction position further retracted from both the edges of the sheet than the guide position. When moving the pair of restriction guides 14A, 14B from the retraction position to the guide position, a guide moving unit causes the restriction guide 14B to reach the guide position after the restriction guide 14A reaches the guide position.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a sheet conveying device for conveying a sheet. and an image forming system including a sheet conveying device

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 has occurred, 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 (inclination 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 conveyance belt provided obliquely, the edge in the width direction of the sheet is abutted against a reference guide. For this reason, it is necessary to convey the sheet until it abuts against the reference guide, and there is a risk that the device will become larger in order to secure the length for conveying the sheet. Therefore, in order to correct the displacement in the width direction of the sheet while suppressing the increase in the size of the device, a configuration in which a pair of restricting guides are provided on both sides in the width direction of the sheet can be considered. In the case of this configuration, the pair of restricting guides are moved from the retracted position to the guide position, and the displacement in the width direction of the sheet is corrected by guiding both end edges in the width direction of the sheet at the guide position.

[0006] In the case of the configuration in which the restricting guide is moved in this way to guide the edge in the width direction of the sheet, the restricting guide vibrates when it moves to the guide position and stops. For this reason, if the pair of restricting guides are simultaneously stopped at the guide position, the pair of restricting guides vibrate simultaneously, increasing the amplitude, and there is a risk that the edge in the width direction of the sheet will be pushed in by the pair of restricting guides. In this case, a load is applied to the sheet, which may affect the conveyance of the sheet.

[0007] An object of the present invention is to provide a configuration capable of stably conveying a sheet.

Means for Solving the Problems

[0008] One aspect of the present invention includes a conveyance belt for conveying a sheet, a plurality of spheres arranged in the conveyance direction of the sheet by the conveyance belt, the spheres being in contact with the sheet conveyed by the conveyance belt and capable of rotating passively, a holding mechanism for holding the spheres so as to allow rotation of the spheres in an arbitrary direction while rubbing against a part of the surface of the spheres, a first standby position provided on one side with respect to the conveyance belt in the width direction intersecting the conveyance direction for receiving the sheet, and closer to the conveyance belt than the first standby position in the width direction First1. A first regulating guide that is movable to a first guide position and regulates skew of a sheet when an edge on one side of the sheet conveyed by the conveyor belt abuts at the first guide position; a second standby position provided opposite to the first regulating guide on the other side in the width direction with respect to the conveyor belt for receiving the sheet; and a second guide position that is movable to a second guide position closer to the conveyor belt than the second standby position in the width direction, and a second regulating guide that regulates skew of the sheet when an edge on the other side of the sheet conveyed by the conveyor belt abuts at the second guide position; and a control unit that controls the first regulating guide and the second regulating guide such that when the leading end of the sheet conveyed by the conveyor belt reaches between the first regulating guide located at the first standby position and the second regulating guide located at the second standby position, the first regulating guide is moved from the first standby position toward the first guide position and the second regulating guide is moved from the second standby position toward the second guide position, and after a predetermined time when the first regulating guide reaches the first guide position in a state where the sheet is conveyed between the first regulating guide and the second regulating guide by the conveyor belt, the second regulating guide is made to reach the second guide position. A sheet conveying apparatus comprising:

Advantages of the Invention

[0009] According to the present invention, the sheet can be stably conveyed.

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

Mode for Carrying Out the Invention

[0011] <First Embodiment> The first embodiment will be described with reference to FIGS. 1 to 9. 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 a 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 apparatus 100, a multi-stage feeding apparatus 200 as a sheet feeding apparatus connected to the image forming apparatus 100, and a feeding deck 500. The multi-stage feeding apparatus 200 has a plurality of storage bins, each of which can store a plurality of sheets, and can feed sheets from each storage bin to the image forming apparatus 100, as will be described in detail later. The feeding deck 500 also has a storage bin that can store a plurality of sheets, and is arranged upstream of the multi-stage feeding apparatus 200 in the sheet conveyance direction. Further, the sheets fed from the feeding deck 500 are conveyed to the image forming apparatus 100 via a relay conveyance apparatus 400 provided in the multi-stage feeding apparatus 200. Examples of the sheet include paper such as plain paper, thin paper, and thick paper, and plastic sheets.

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

[0015] When reading a document, the document reading apparatus 102 irradiates light onto the document placed on the platen glass 103 with a scanning optical system light source, and reads the document image by inputting the reflected light into a CCD. The document reading apparatus 102 also includes an automatic document feeder (ADF) 104, and can automatically convey the document placed on the tray 105 to the reading unit of the document reading apparatus 102 by the ADF 104 to read the document image. Then, the read document image is converted into an electrical signal and transmitted to a laser scanner 113 of an image forming unit 110 described later. Note that the laser scanner 113 may receive 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, etc. Each part of 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 part while reading out a program corresponding to the control procedure stored in the ROM. Also, work data and input data are stored in the RAM, and the CPU performs control by referring to the data stored in the RAM based on the above-mentioned program and the like.

[0017] The plurality of sheet feeding devices 120 each include a cassette 121 that stores a sheet S, a pickup roller 122, and a separation conveyance roller pair 125 composed of 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 conveying device 130 includes a conveyance roller pair 131 and a registration roller pair 133. The sheet S fed from the sheet feeding device 120 is passed through a sheet conveyance path 134 by the conveyance roller pair 131 and then guided to the registration roller pair 133. After that, the sheet S is fed into the image forming unit 110 at a predetermined timing by the registration roller pair 133.

[0019] Note that sheets conveyed from the multi-stage feeding device 200 and the feeding deck 500, which will be described later, via the conveyance roller pair 201 are conveyed into the image forming apparatus 100 via a connection path 202 with the image forming apparatus 100. Then, the sheets conveyed from the multi-stage feeding device 200 and the feeding deck 500 into the image forming apparatus 100 are fed into the image forming unit 110 at a predetermined timing via the registration roller pair 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 unit 114, a transfer device 115, a cleaner 117, etc. During 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, the laser light from the laser scanner 113 that emits light according to the image signal is irradiated onto the charged photosensitive drum 111, thereby forming an electrostatic latent image on the photosensitive drum 111. Further, the electrostatic latent image formed on the photosensitive drum 111 in this way is then visualized as a toner image by the developing unit 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 is discharged to the external discharge tray 152 by the discharge roller 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 onto which the toner image has been transferred to the 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 residual transfer toner remaining on the photosensitive drum 111 after transfer is removed by the cleaner 117.

[0023] [Multi-stage feeding device] Subsequently, 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, etc. In this embodiment, three storage bins 210a to 210c are arranged in three tiers 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 merging point 216, are conveyed through the conveyance path 217 to the conveyance roller pair 201, 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-feed of the sheet are respectively arranged. And the sheet for which double-feed 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-feed is detected is arranged. The sheet for which double-feed is detected and is conveyed to the conveyance path 217 has its conveyance path switched by a switching member 219 provided in the conveyance path 217, and is conveyed to the double-feed sheet storage unit.

[0026] Also, each part of the multi-stage feeding device 200 is controlled by the 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 the conveyance path 510 that merges with the conveyance path 512, and is conveyed to the relay conveyance device 400 via the conveyance path 512 by the conveyance roller pair 511.

[0028] As will be described in detail below, the relay conveyance device 400 includes a position deviation correction unit 410 including a conveyance belt 12 or the like, a pair of conveyance rollers 401 on the upstream side in the sheet conveyance direction of the position deviation correction unit 410, a pair of conveyance rollers 402 on the downstream side in the sheet conveyance direction of the position deviation correction unit 410, and the like. The sheet conveyed through the conveyance path 512 is sent to the position deviation correction unit 410 by the pair of conveyance rollers 401. After the side registration (position deviation of the edge in the sheet width direction) and side skew (tilt of the edge in the sheet width direction with respect to the sheet conveyance direction) of the sheet are corrected by the position deviation 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 pairs of conveyance rollers 402 and 403. In this way, the relay conveyance device 400 corrects the position deviation 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 has an upstream pair of conveyance rollers 401, a downstream pair of conveyance rollers 402, the above-described position deviation correction unit 410, and the like, and conveys the sheet in the conveyance direction X. The position deviation correction unit 410 includes a conveyance belt 12, a plurality of spheres 20, a pair of restricting guides 14A and 14B, a guide moving unit 420, and the like.

[0030] The conveyance belt 12 is disposed downstream in the conveyance direction X of the pair of conveyance rollers 401 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 respectively rotatably held in an arbitrary direction by a holding plate (Holding mechanism) 18 provided above the conveying belt 12. 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. 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 will be 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 conveying belt 12 with respect to the sheet width direction Y (the direction orthogonal to the conveying direction in the present 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 conveying belt 12 and the spheres 20 in the sheet width direction Y. That is, with respect to the sheet width direction Y, on one side ( On one side with respect to the conveying belt 12The regulation guide 14A as the first regulation guide disposed on the front side of the apparatus can guide the edge on one side in the sheet width direction of the sheet conveyed while being sandwiched between the conveyor belt 12 and the sphere 20. Also, on the other side with respect to the sheet width direction Y ( On the other side, which is the side opposite to the regulating guide 14A with respect to the conveying belt 12 the rear side of the apparatus), the regulation guide 14B as the second regulation guide can guide the edge on the other side in the sheet width direction of the sheet conveyed while being sandwiched between the conveyor belt 12 and the sphere 20. Note that one side (front side) in the sheet width direction Y is the side where the image forming system 1000 is operated.

[0034] As shown in FIG. 5, the pair of regulation guides 14A and 14B each have a side plate portion 15, a lower plate portion 16, and an upper plate portion 17, and the end 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 regulation guides 14A and 14B are at a guide position (First guide position, second guide position) and a retracted position (First standby position, second standby position) and are movably supported by support shafts 421A and 421B (see FIG. 3). The support shafts 421A and 421B are each arranged substantially parallel to the sheet width direction Y and support the end side in the conveyance direction X of the pair of regulation guides 14A and 14B. The pair of regulation 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 the edge 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 conveyance direction X. Also, the guide surface 15A is a surface orthogonal to the conveyance 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 to be orthogonal to the side plate portion 15, and at the guide position, it 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 conveyor belt 12 and the spherical body 20. 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 vertically below the conveying surface 12A of the conveyor belt 12.

[0037] Here, hypothetically, consider the case where the support surface 16A and the conveying surface 12A are at the same height, or the support surface 16A is located vertically above the conveying surface 12A. In this case, when a sheet S with high stiffness such as cardboard is conveyed between the conveyor belt 12 and the spherical body 20 in a downwardly 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 of the sheet S in the width direction Y 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 conveyor belt 12 and the spherical body 20 are in a separated state, and the conveying force of the conveyor belt 12 is not 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 to be vertically below the conveying surface 12A of the conveyor belt 12.

[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 conveyor 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 a guide moving means, the guide moving portion 420, as shown in FIGS. 2 and 3, has a first moving portion (First guide moving mechanism) 420A that moves one of the pair of restricting guides 14A, 14B, and a second moving portion (Second guide moving mechanism) 420B that moves the other restricting guide 14B. Further, the guide moving portion 420 has a motor M2 that generates a driving force for moving the restricting guide 14A, and a motor M3 that generates a driving force for moving the other restricting 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 connecting 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 connecting 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 for driving the above-described conveyor belt 12, the motors M2 and M3 for moving the regulation guides 14A and 14B, and the motors M5, M7, and M8 described later are arranged on the other regulation guide 14B side. In particular, regarding the conveyance direction X, for the motors within the conveyance range of the sheet of the position deviation correction unit 410, it is preferable to arrange them on the back side (the other regulation guide 14B side) of the conveyor belt 12. This is because, in the case of this embodiment, the jammed sheet is removed from the front side (one regulation guide 14A side).

[0045] Also, 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, as shown in FIG. 4, the relay conveyance device 400 of the present embodiment has a plurality of sheet detection sensors 433, 435, and 436 for detecting a sheet jam. Note that a sheet jam means that the sheet gets stuck and stays in the conveyance path. The sheet detection sensor 433 detects the sheet conveyed by the conveyance roller pair 401 upstream of the conveyance belt 12. The sheet detection sensor 435 is disposed between the conveyance roller pair 402 and the conveyance roller pair 403 and detects the sheet conveyed by the conveyance roller pair 402. The sheet detection sensor 436 is disposed downstream of the conveyance roller pair 403 and detects the sheet conveyed by the conveyance roller pair 403.

[0047] The control unit 203 (FIG. 1) of the multi-sheet feeder 200 determines whether a sheet is jammed in the conveyance path based on the detection signals of various sheet detection sensors such as the sheet detection sensors 433, 435, and 436. When the control unit 203 determines that the sheet is jammed, it stops the conveyance of the sheet and displays that the sheet is jammed and the location of the jam on a display unit such as a liquid crystal panel provided in the image forming system 1000. At this time, an operator such as a user or a service technician is prompted to open the door at the corresponding location.

[0048] Also, in the case of the present embodiment, as shown in FIG. 3, 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. The opposing members 450 and 460 support the end of the sheet if the end of the sheet is conveyed without being supported by either of the regulating guides 14A and 14B.

[0049] The relay transport device 400 configured as described above clamps the sheet delivered from the transport roller pair 401 upstream in the transport direction X to the transport belt 12 between the transport belt 12 and the sphere 20. Then, the sheet is transported by the rotation of the transport belt 12. At this time, as will be described in detail later, both ends in the width direction Y of the sheet transported to the transport belt 12 are abutted against the guide surfaces 15A of a pair of regulation guides 14A and 14B. When the sheet abuts against the guide surface 15A, while making both side ends follow the guide surface 15A and slipping between the sheet and the transport belt 12, the sheet is transported in a direction parallel to the guide surface 15A. At this time, the sheet is clamped between the transport belt 12 and 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 transport belt 12. Thereby, the side registration and side skew of the sheet are corrected.

[0050] [Restriction Guide] Next, the detailed configuration of the regulation guides 14A and 14B as the first regulation guide and the second regulation guide will be described with reference to FIGS. 6(a) to 6(d). In FIGS. 6(a) to 6(d), only one side regulation guide 14A is shown, but the other side regulation guide 14B has the same configuration. As shown in FIG. 5, the regulation guide 14A has 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.

[0051] 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 transport direction X as shown in FIG. 2 and the like, 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 transport 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 transport direction X. The predetermined region A is substantially the entire region where the sheet is transported by the position deviation correction unit 410.

[0052] On one 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 this embodiment, the upstream end (the upstream end in the conveying direction) B1 of the side plate portion 15 in the conveying direction X is located on the downstream side of the upstream end A1 of the predetermined region A in the conveying direction X. That is, the upstream end B1 of the guide surface 15A of the side plate portion 15 in the conveying direction X is located on the downstream side of the upstream end A1 of the predetermined region A. Further, the guide surface 15A is continuously provided up to the downstream end A2 of the predetermined region A with respect to the conveying direction X. Therefore, the position of the downstream end B2 of the side plate portion 15 in the conveying direction X and the position of the downstream end A2 of the predetermined region A in the conveying direction X are substantially the same position with respect to the conveying direction X.

[0053] In this 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 disposed in a part of this notch 19C. The outside in the sheet width direction Y means the side farther from the conveying 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. Further, with respect to the conveying 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.

[0054] By being configured as described above, the pair of regulating guides 14A and 14B makes the interval in the width direction Y between the inner surfaces 19A of the outer side plate portions 19 on the upstream side in the conveying direction X wider than the interval in the width direction Y between the guide surfaces 15A of the side plate portion 15. For this reason, 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 located between the inner surfaces 19A on the upstream side in the conveying direction X, and are located between the guide surfaces 15A by being conveyed to the downstream side.

[0055] 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 located within the notch 19C, when the sheet is further conveyed, the end portion of the sheet may be caught by the upstream end B1 of the side plate portion 15. 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 the position thereof, and further, the inclined plate portion 19B guides the end portion of the sheet to the guide surface 15A of the side plate portion 15.

[0056] [Contact and separation configuration of conveying roller pair] Next, with reference to FIGS. 1 and 2, the contact and separation configuration of the conveying roller pairs 401 to 403 will be described using FIGS. 7, 8(a), and 8(b). As described above, the 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 rotation 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 rotationally driven independently by a motor M4, the driving roller 32 of the conveying roller pair 402 can be rotationally driven independently by a motor M5, and the driving roller 32 of the conveying roller pair 403 can be rotationally driven independently by a motor M6.

[0057] In the present embodiment, the conveying roller pairs 402 and 403 arranged on the downstream side (downstream in the conveying direction) in the conveying direction X of the conveying belt 12 have 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 can bring the driving roller 32 and the driven roller 33 into contact with and separate from each other independently by a motor M7, and the conveying roller pair 403 can bring the driving roller 32 and the driven roller 33 into contact with and separate from each other independently by a motor M8. Since the configurations of the conveying roller pairs 402 and 403 are the same, hereinafter, the contact and separation configuration will be described taking the conveying roller pair 402 as an example with reference to FIGS. 7, 8(a), and 8(b).

[0058] The contact-separation mechanism 31 that brings the drive roller 32 and the driven roller 33 into contact with and separates them from each other includes 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 roller moving means that can move at least one of a pair of conveying rollers, that is, the driven roller 33, between a nip position where the sheet can be nipped and conveyed and a nip release position where the pair of conveying rollers are separated from the nip position.

[0059] The compression spring 34 is a spring that biases the driven roller 33 toward the drive 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 in a direction in which the driven roller 33 is pressed toward the drive roller 32 about the swing shaft 37a by the compression spring 34. 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 drive roller 32 and a direction away from the drive roller 32.

[0060] The motor M7 rotationally drives the separation cam 36 via pulleys 38a, 38b and a 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, 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.

[0061] 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 in synchronization with the support member 35 via the swing shaft 37a. The link member 37 is arranged so as to come into contact with the separation cam 36 when the support member 35 is biased by the compression spring 34.

[0062] 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 biasing force of the compression spring 34. The state shown 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 axis 37a. Then, the support member 35 connected via the link member 37 and the swing axis 37a swings in the same direction about the swing axis 37a. Since the driven roller 33 is supported by the support member 35 via the rotation axis 33a, it 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.

[0063] 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 shown in Fig. 8(b). Note that the contact and separation mechanism for bringing the driving roller 32 and the driven roller 33 into contact and separating them 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 the pair of conveying rollers may be performed by another driving source such as a solenoid.

[0064] Also, in the above example, the pair of conveying rollers 402 and 403 on the downstream side in the conveying direction X of the conveying belt 12 can be brought into contact and separated, but only the pair of conveying rollers 402 may be made capable of being brought into contact and separated. Further, the pair of conveying rollers 401 on the upstream side in the conveying direction X of the conveying belt 12 may be made capable of being brought into contact and separated. In this case, only the pair of conveying rollers 401 on the upstream side may be made capable of being brought into contact and separated, or the pair of conveying rollers 402 on the downstream side and further the pair of conveying rollers 403 may also be made capable of being brought into contact and separated.

[0065] [Sheet Conveying Operation] Next, the sheet conveyance operation of the relay conveyance device 400 according to the present embodiment will be described with reference to FIG. 9 while referring to FIGS. 2, 3, etc. In the present embodiment, the control unit 203 (FIG. 1) controls the motors M2 and M3 (FIG. 2) according to the conveyance state of the sheet so as to change the positions of the pair of regulation 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 regulation guides 14A and 14B to the guide position and the retracted position. In FIG. 9, the pair of regulation guides 14A and 14B in the retracted position are shown by solid lines, and the pair of regulation guides 14A and 14B in the guide position are shown by broken lines.

[0066] Here, as shown by the broken line in FIG. 9, the guide position is a position where the guide surfaces 15A of the pair of regulation guides 14A and 14B can guide the edges in the sheet width direction Y of the sheet being conveyed while being sandwiched between the conveyance 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 regulation guides 14A and 14B (between the guide surfaces) is longer than the length in the sheet width direction Y of the sheet being conveyed while being sandwiched between the conveyance belt 12 and the sphere 20.

[0067] 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 d is the guide position. This predetermined interval d 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 regulation guides 14A and 14B are each 0.5 mm away from the edge 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.

[0068] In this way, at the guide position, since the pair of regulating guides 14A and 14B are positioned at a position 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, when the distance between the guide surfaces is the same as the length of the sheet in the width direction Y, the end of the sheet will be conveyed while rubbing against the guide surface, and the conveyance resistance will increase. In particular, in this embodiment, since the sheet is conveyed while being sandwiched between the conveyance belt 12 and the spherical body 20, the nip pressure for sandwiching the sheet between the conveyance belt 12 and the spherical body 20 is small. Therefore, if the conveyance resistance of the sheet is large, there is a risk that conveyance failures such as delays in the conveyance of the sheet or stoppage of the conveyance of the sheet will easily occur. Therefore, in this embodiment, by positioning the pair of regulating guides 14A and 14B as described above at the guide position, the conveyance resistance of the sheet is suppressed.

[0069] In addition, as described above, it is preferable to convey the sheet based on the center 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 spherical body 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 (center reference), damage to the sheet during the alignment operation can be reduced.

[0070] On the other hand, as shown by the solid line in FIG. 9, 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 of the sheet in the width direction Y compared 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.

[0071] In this embodiment, as shown in FIG. 9, the retracted position of the regulating guide 14A on the front side (F side (front)) (First standby position) from the guide position(First guide position) The distance D1 up to is shorter than the distance D2 from the retracted position of the rear-side (R-side (rear)) regulating guide 14B to the guide position. (Second standby position) to the guide position (Second guide position) In the illustrated example, for the front-side regulating guide 14A, the retracted position is set at a position where the distance D1´ between the edge in the width direction Y of the sheet conveyed based on the above-described central reference and the guide surface 15A is 4.5 mm. On the other hand, for the rear-side regulating guide 14B, the retracted position is set at a position where the distance D2´ between the edge in the width direction Y of the sheet conveyed based on the above-described central reference and the guide surface 15A is 5.0 mm.

[0072] As described above, the distance d between the pair of regulating guides 14A and 14B at the guide position and the edge in the width direction Y of the sheet is 0.5 mm each. Therefore, the front-side distance D1 is 4.0 mm and the rear-side distance D2 is 4.5 mm. In other words, the amount of movement from the retracted position of the front-side regulating guide 14A to the guide position is 4.0 mm, and the amount of movement from the retracted position of the rear-side regulating guide 14B to the guide position is 4.5 mm, so that the amount of movement of the front-side regulating guide 14A is less than that of the rear-side regulating guide 14B.

[0073] In the present embodiment, when the sheet is transferred from the pair of conveying rollers 401 as a conveying means to the conveying belt 12, the guide moving unit 420 causes the pair of regulating guides 14A and 14B to reach the guide position after at least the leading end of the sheet is transferred to the conveying belt 12 and the sheet no longer contacts the pair of conveying rollers 401. Specifically, the sheet S is transferred from the pair of conveying rollers 401 to the conveying belt 12 in a state where the regulating guides 14A and 14B are in the retracted position. That is, in a state where the sheet S is being conveyed by the pair of conveying rollers 401, the leading end of the sheet S reaches the conveying belt 12. In this state, the vertical movement of the sheet S is regulated by the support surface 16A and the opposing surface 17A. Thereby, even if the sheet S is curled, 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 when the regulating guides 14A and 14B move from the retracted position to the guide position.

[0074] Thus, in this embodiment, when the sheet S is conveyed from the upstream conveying roller pair 401 to the conveying belt 12, the pair of regulating guides 14A and 14B are moved to the retracted position. This is because when the pair of regulating guides 14A and 14B are in the guiding position when the sheet S is transferred to the conveying belt 12, if the sheet S is skewed or displaced in the width direction Y, the end of the sheet S may interfere with one of the regulating guides 14A and 14B, resulting in a risk of poor conveyance of the sheet S.

[0075] Next, after the rear end (upstream end) of the sheet S transferred from the conveying roller pair 401 to the conveying belt 12 has passed through the conveying roller pair 401, the control unit 203 moves the pair of regulating guides 14A and 14B from the retracted position to the guiding position. That is, after the sheet S no longer contacts the conveying roller pair 401, the pair of regulating guides 14A and 14B reach the guiding position. In the case where the upstream conveying roller pair 401 can be brought into contact with and separated from, after the leading end of the sheet S is transferred to the conveying belt 12, the conveying roller pair 401 may be separated before the rear end of the sheet S passes through the conveying roller pair 401. That is, the contact / separation mechanism (conveying roller pair moving means) 31 as described in FIGS. 7 and 8 above can also be applied to the conveying roller pair 401. The contact / separation mechanism 31 can not only bring the conveying roller pair into contact with and separate it, but also move the conveying roller pair to a nip position where a conveying force is applied to the sheet and a nip release position where the nip pressure is weaker than the nip position. Therefore, after the leading end of the sheet S is transferred to the conveying belt 12, the conveying roller pair 401 may be moved to the nip release position where the nip pressure is weak before the rear end of the sheet S passes through the conveying roller pair 401.

[0076] In this case, after the conveying roller pair 401 is separated by the contact / separation mechanism 31 (after moving from the nip position to the nip release position), a pair of regulating guides 14A and 14B reach the guide position. Note that the nip release position is not only the state where complete separation is achieved as described above, but also, for example, a state where the nip pressure is weak to the extent that it does not affect the regulation by the regulating guides 14A and 14B. All states where the conveying roller pair is more separated than this state correspond to the nip release position. That is, the state where the conveying roller pair is separated and the state where the conveying roller pair is in contact with each other but the nip pressure is lower than when conveying the sheet correspond to the nip release position. In any case, in this embodiment, the pair of regulating guides 14A and 14B are moved from the retracted position to the guide position while the sheet S delivered to the conveying belt 12 is in a state within a predetermined area A (in FIG. 6(b), within the predetermined area). Thereby, side registration and side skew correction (alignment operation) of the sheet S are performed.

[0077] That is, when the sheet S 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 S are separated from the guide surface 15A. Then, as the sheet S is conveyed further downstream and the trailing edge of the sheet S passes through the conveying roller pair 401, the regulating guides 14A and 14B move to the guide position. Then, the guide surface 15A is brought into contact with both end edges of the sheet S in the width direction Y. When the sheet S is pressed against the guide surface 15A, while sliding between the guide surface 15A and the conveying belt 12 while keeping the end edges along the guide surface 15A, the sheet S is conveyed in a direction parallel to the guide surface 15A. Thereby, side registration and side skew of the sheet S are corrected.

[0078] In this embodiment, while the sheet is being conveyed while being sandwiched between the conveying belt 12 and the sphere 20, the control unit 203 moves the pair of regulating guides 14A and 14B from the retracted position to the guiding position. As a result, corrections such as side registration and side skew of the sheet can be performed without stopping the conveyance of the sheet, and productivity can be improved. However, it is also possible to perform an alignment operation of moving the pair of regulating guides 14A and 14B from the retracted position to the guiding position after once stopping the conveyance of the sheet. In this case, although productivity decreases, misalignment correction and the like can be performed more reliably.

[0079] Thus, in the case of this embodiment, after the rear end of the sheet delivered to the conveying belt 12 has passed through the upstream conveying roller pair 401 (that is, after the sheet S has stopped contacting the conveying roller pair 401), the pair of regulating guides 14A and 14B are moved from the retracted position to the guiding position. For this reason, when the sheet is delivered to the conveying belt 12, it is possible to make it difficult for the pair of regulating guides 14A and 14B to interfere with the sheet. Further, while the sheet is being conveyed by the upstream conveying roller pair 401, the pair of regulating guides 14A and 14B are not positioned at the guiding position, so that it is possible to prevent the sheet being conveyed by the conveying roller pair 401 from being bent by contacting any of the regulating guides.

[0080] Furthermore, since the pair of regulating guides 14A and 14B are moved to the guiding position after the rear end of the sheet has passed through the conveying roller pair 401, for example, even if the sheet is conveyed obliquely and does not hit the regulating guide, misalignment of the sheet can be corrected. For this reason, correction of misalignment of the sheet and the like can be performed without increasing the length for conveying the sheet, and an increase in the size of the apparatus can be suppressed. That is, while suppressing an increase in the size of the apparatus, misalignment in the width direction Y of the sheet can be corrected.

[0081] Here, when a pair of regulation guides 14A and 14B reach the guide position simultaneously, there is a risk that the vibration of the pair of regulation guides 14A and 14B will affect the conveyance of the sheet S. That is, the regulation guides 14A and 14B vibrate when they move from the retracted position and stop at the guide position. For example, there is a risk of deflecting up to 1 mm due to the vibration at the time of stopping the movement respectively. Therefore, when the regulation guides 14A and 14B reach the guide position simultaneously, there is a risk of deflecting 1 mm each toward the sheet side (inside) at the same time. As described above, at the guide position, the intervals between the regulation guides 14A and 14B and the edges of the sheet in the width direction Y are 0.5 mm each. For this reason, at the guide position, there is a margin of 0.5 mm on both sides in the width direction of the sheet, and a total of 1 mm between the sheet and the regulation guides.

[0082] However, if the pair of regulation guides 14A and 14B deflect 1 mm each toward the inside at the same time, the total deflection will be 2 mm, and the interval between the regulation guides 14 and 14B will be shortened by 1 mm with respect to the margin of 1 mm at the above-described guide position. For this reason, when the regulation guides 14A and 14B reach the guide position simultaneously, there is a possibility that the regulation guides 14A and 14B will push the sheet in. Therefore, in the present embodiment, the timing at which the pair of regulation guides 14A and 14B reach the guide position is shifted.

[0083] That is, when the guide moving unit 420 moves the pair of regulation guides 14A and 14B from the retracted position to the guide position, after the front regulation guide (first regulation guide) 14A reaches the guide position, the rear regulation guide (second regulation guide) 14B is made to reach the guide position. For this purpose, in the present embodiment, as described above, the distance D1 from the retracted position to the guide position of the front regulation guide 14A is made shorter than the distance D2 from the retracted position to the guide position of the rear regulation guide 14B.

[0084] Also, in the case of this embodiment, the moving speeds of the regulation guides 14A and 14B are the same as each other. For example, the moving speeds are each set to 700 mm / s. Also, the moving start timings when the regulation guides 14A and 14B move from the retracted position to the guide position are the same. By configuring in this way, the regulation guide 14A reaches the guide position earlier than the regulation guide 14B. That is, the timings at which the pair of regulation guides 14A and 14B reach the guide position can be shifted. Thus, in this embodiment, since the timings at which the pair of regulation guides 14A and 14B reach the guide position are shifted, it is possible to suppress the vibrations caused by the movement stop from occurring simultaneously, and to suppress the regulation guides 14A and 14B from pushing into the edges in the width direction Y of the sheet. As a result, the conveyance of the sheet can be stably performed.

[0085] Note that the moving speeds of the regulation guides 14A and 14B do not have to be the same as long as the regulation guide 14A reaches the guide position earlier than the regulation guide 14B. For example, the moving speed of the regulation guide 14A may be increased. Also, by appropriately setting the difference in moving distance and the moving start timing, the moving speed of the regulation guide 14A may be decreased.

[0086] Also, the moving start timings of the regulation guides 14A and 14B from the retracted position to the guide position do not have to be the same. For example, the moving start timing of the regulation guide 14A may be increased. Also, by appropriately setting the difference in moving distance and the moving speed, the moving start timing of the regulation guide 14A may be decreased. The main point is that by appropriately setting the moving distances, moving speeds, and moving start timings of each other, the regulation guide 14A may reach the guide position earlier.

[0087] <Second Embodiment> The second embodiment will be described with reference to FIGS. 2, 3, etc. and FIG. 10. In the above-described first embodiment, the configuration in which the distance D1 from the retracted position to the guide position of the front-side regulating guide 14A is shorter than the distance D2 from the retracted position to the guide position of the rear-side regulating guide 14B was described. In contrast, in the present embodiment, these distances D1 and D2 are the same. Since the other configurations and operations are the same as those of the above-described first embodiment, the same reference numerals are given to the same configurations, and the description and illustration are omitted or simplified. Hereinafter, the differences from the first embodiment will be mainly described.

[0088] In the present embodiment, as shown in FIG. 10, the distance D1 from the retracted position to the guide position of the front-side regulating guide (first regulating guide) 14A is the same as the distance from the retracted position to the guide position of the rear-side regulating guide (second regulating guide) 14B. Also in FIG. 10, the pair of regulating guides 14A and 14B in the retracted position are shown by solid lines, and the pair of regulating guides 14A and 14B in the guide position are shown by broken lines.

[0089] For example, the distances D1 and D2 are both 4.5 mm or 4.0 mm. The intervals d between the pair of regulating guides 14A and 14B at the guide position and the edges in the width direction Y of the sheet are each 0.5 mm. Therefore, the interval D1´ between the front-side regulating guide 14A and the edge in the width direction Y of the sheet S is the same as the interval D2´ between the rear-side regulating guide 14B and the edge in the width direction Y of the sheet S.

[0090] In the case of such a present embodiment, the moving speed V1 of the regulating guide 14A from the retracted position to the guide position is made faster than the moving speed V2 of the regulating guide 14B from the retracted position to the guide position so that the regulating guide 14A reaches the guide position earlier than the regulating guide 14B. That is, a difference is provided in the moving speeds of the regulating guides 14A and 14B. For example, the moving speed V1 of the regulating guide 14A is 1000 mm / s, and the moving speed V2 of the regulating guide 14B is 700 mm / s.

[0091] Note that the moving speeds V1 and V2 may be the same, and the moving start timing may be shifted. That is, when moving a pair of regulation guides 14A and 14B from the retracted position to the guide position, the moving start timing of the regulation guide (first regulation guide) 14A is made earlier than the moving start timing of the regulation guide (second regulation guide) 14B. For example, after the regulation guide 14A starts moving from the retracted position to the guide position, 300 ms later, the regulation guide 14B starts moving from the retracted position toward the guide position. At this time, the respective moving speeds V1 and V2 are, for example, 700 mm / s.

[0092] Also in such a case of this embodiment, the regulation guide 14A can reach the guide position earlier than the regulation guide 14B. For this reason, it is possible to suppress vibrations caused by the movement stop from occurring simultaneously and suppress the regulation guides 14A and 14B from pushing into the edges in the width direction Y of the sheet. As a result, the sheet can be stably conveyed.

[0093] <Other Embodiments> In each of the above-described embodiments, 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 shift the position of the sheet, regardless of the above-described relay conveyance device.

[0094] Also, in each of the above-described embodiments, the front regulation guide 14A reaches the guide position earlier than the rear regulation guide 14B, but the rear regulation guide 14B may reach the guide position earlier. In short, it is only necessary to shift the timing at which the pair of regulation guides 14A and 14B reach the guide position.

Explanation of Reference Numerals

[0095] 12... Conveyor Belt / 12A... Conveyor Surface / 14A... Restraining Guide (First Restraining Guide) / 14B... Restraining Guide (Second Restraining Guide) / 20... Sphere / 31... Contact and Separation Mechanism (Conveyor Roller Pair Movement Means) / 200... Multi-Stage Feeding Device / 203... Control Unit / 400... Relay Conveyor Device (Sheet Conveyor Device) / 401... Conveyor Roller Pair (Conveyor Means) / 420... Guide Movement Unit (Guide Movement Means)

Claims

1. A conveying belt for conveying a sheet, a plurality of spheres arranged in the conveying direction of the sheet by the conveying belt, and rotatable in a driven manner in contact with the sheet conveyed by the conveying belt, a holding mechanism for holding the sphere so as to allow rotation of the sphere in any direction while rubbing against a part of the surface of the sphere, a first regulating guide provided on one side with respect to the conveying belt in the width direction intersecting the conveying direction, movable to a first standby position for receiving a sheet and a first guide position closer to the conveying belt than the first standby position in the width direction, and regulating skewing of the sheet when the edge on one side of the sheet conveyed by the conveying belt abuts at the first guide position, a second regulating guide provided opposite to the first regulating guide on the other side with respect to the conveying belt in the width direction, movable to a second standby position for receiving a sheet and a second guide position closer to the conveying belt than the second standby position in the width direction, and regulating skewing of the sheet when the edge on the other side of the sheet conveyed by the conveying belt abuts at the second guide position, a control unit for controlling the first regulating guide and the second regulating guide such that when the leading end of the sheet conveyed by the conveying belt reaches between the first regulating guide located at the first standby position and the second regulating guide located at the second standby position, the first regulating guide is moved from the first standby position toward the first guide position and the second regulating guide is moved from the second standby position toward the second guide position, and after a predetermined time when the first regulating guide reaches the first guide position in a state where the sheet is conveyed between the first regulating guide and the second regulating guide by the conveying belt, the second regulating guide is made to reach the second guide position, A sheet conveying device comprising the above.

2. Further comprising conveying means provided upstream of the conveying belt in the conveying direction for conveying the sheet toward the conveying belt, The control unit causes the first regulating guide to reach the first guide position and the second regulating guide to reach the second guide position after at least the leading end of the sheet is delivered from the conveying means to the conveying belt and the sheet no longer contacts the conveying means. The sheet conveying device according to claim 1, characterized in that...

3. A pair of conveying rollers provided upstream of the conveying belt in the conveying direction for conveying the sheet toward the conveying belt, and conveying roller pair moving means for moving the pair of conveying rollers to a nip position for applying a conveying force to the sheet and a nip release position where the nip pressure is weaker than the nip position, after at least the leading end of the sheet is delivered from the pair of conveying rollers to the conveying belt and the pair of conveying rollers has moved from the nip position to the nip release position, the control unit causes the first regulating guide to reach the first guide position and the second regulating guide to reach the second guide position. The sheet conveying device according to claim 1, characterized in that...

4. The distance from the first standby position to the first guide position of the first regulating guide is shorter than the distance from the second standby position to the second guide position of the second regulating guide. The sheet conveying device according to any one of claims 1 to 3, characterized in that...

5. The moving speed of the first regulating guide from the first standby position to the first guide position is faster than the moving speed of the second regulating guide from the second standby position to the second guide position. The sheet conveying device according to any one of claims 1 to 4, characterized in that...

6. The moving start timing of the first regulating guide from the first standby position to the first guide position is earlier than the moving start timing of the second regulating guide from the second standby position to the second guide position. The sheet conveying device according to any one of claims 1 to 5, characterized in that...

7. The sheet conveying device according to any one of claims 1 to 6, and an image forming unit for forming an image on the sheet conveyed by the sheet conveying device. An image forming system comprising...

8. A first accommodating unit provided upstream of the sheet conveying device in the conveying direction for accommodating the sheet, and an upstream conveying unit for conveying the sheet accommodated in the first accommodating unit to the sheet conveying device. The image forming system according to claim 7, wherein the sheet conveying device further comprises a second accommodating unit for accommodating the sheet vertically below the conveying belt.

Images